WorldWideScience

Sample records for extremely cold environments

  1. Constructing and screening a metagenomic library of a cold and alkaline extreme environment

    DEFF Research Database (Denmark)

    Glaring, Mikkel Andreas; Vester, Jan Kjølhede; Stougaard, Peter

    2017-01-01

    Natural cold or alkaline environments are common on Earth. A rare combination of these two extremes is found in the permanently cold (less than 6 °C) and alkaline (pH above 10) ikaite columns in the Ikka Fjord in Southern Greenland. Bioprospecting efforts have established the ikaite columns...

  2. Investigation of Loop Heat Pipe Survival and Restart After Extreme Cold Environment Exposure

    Science.gov (United States)

    Golliher, Eric; Ku, Jentung; Licari, Anthony; Sanzi, James

    2010-01-01

    NASA plans human exploration near the South Pole of the Moon, and other locations where the environment is extremely cold. This paper reports on the heat transfer performance of a loop heat pipe (LHP) exposed to extreme cold under the simulated reduced gravitational environment of the Moon. A common method of spacecraft thermal control is to use a LHP with ammonia working fluid. Typically, a small amount of heat is provided either by electrical heaters or by environmental design, such that the LHP condenser temperature never drops below the freezing point of ammonia. The concern is that a liquid-filled, frozen condenser would not restart, or that a thawing condenser would damage the tubing due to the expansion of ammonia upon thawing. This paper reports the results of an experimental investigation of a novel approach to avoid these problems. The LHP compensation chamber (CC) is conditioned such that all the ammonia liquid is removed from the condenser and the LHP is nonoperating. The condenser temperature is then reduced to below that of the ammonia freezing point. The LHP is then successfully restarted.

  3. Moving in extreme environments: open water swimming in cold and warm water.

    Science.gov (United States)

    Tipton, Michael; Bradford, Carl

    2014-01-01

    Open water swimming (OWS), either 'wild' such as river swimming or competitive, is a fast growing pastime as well as a part of events such as triathlons. Little evidence is available on which to base high and low water temperature limits. Also, due to factors such as acclimatisation, which disassociates thermal sensation and comfort from thermal state, individuals cannot be left to monitor their own physical condition during swims. Deaths have occurred during OWS; these have been due to not only thermal responses but also cardiac problems. This paper, which is part of a series on 'Moving in Extreme Environments', briefly reviews current understanding in pertinent topics associated with OWS. Guidelines are presented for the organisation of open water events to minimise risk, and it is concluded that more information on the responses to immersion in cold and warm water, the causes of the individual variation in these responses and the precursors to the cardiac events that appear to be the primary cause of death in OWS events will help make this enjoyable sport even safer.

  4. Extreme environment electronics

    CERN Document Server

    Cressler, John D

    2012-01-01

    Unfriendly to conventional electronic devices, circuits, and systems, extreme environments represent a serious challenge to designers and mission architects. The first truly comprehensive guide to this specialized field, Extreme Environment Electronics explains the essential aspects of designing and using devices, circuits, and electronic systems intended to operate in extreme environments, including across wide temperature ranges and in radiation-intense scenarios such as space. The Definitive Guide to Extreme Environment Electronics Featuring contributions by some of the world's foremost exp

  5. Extreme environments and exobiology.

    Science.gov (United States)

    Friedmann, E I

    1993-01-01

    Ecological research on extreme environments can be applied to exobiological problems such as the question of life on Mars. If life forms (fossil or extant) are found on Mars, their study will help to solve fundamental questions about the nature of life on Earth. Extreme environments that are beyond the range of adaptability of their inhabitants are defined as "absolute extreme". Such environments can serve as terrestrial models for the last stages of life in the history of Mars, when the surface cooled down and atmosphere and water disappeared. The cryptoendolithic microbial community in porous rocks of the Ross Desert in Antarctica and the microbial mats at the bottom of frozen Antarctic lakes are such examples. The microbial communities of Siberian permafrost show that, in frozen but stable communities, long-term survival is possible. In the context of terraforming Mars, selected microorganisms isolated from absolute extreme environments are considered for use in creation of a biological carbon cycle.

  6. Metagenomics of extreme environments.

    Science.gov (United States)

    Cowan, D A; Ramond, J-B; Makhalanyane, T P; De Maayer, P

    2015-06-01

    Whether they are exposed to extremes of heat or cold, or buried deep beneath the Earth's surface, microorganisms have an uncanny ability to survive under these conditions. This ability to survive has fascinated scientists for nearly a century, but the recent development of metagenomics and 'omics' tools has allowed us to make huge leaps in understanding the remarkable complexity and versatility of extremophile communities. Here, in the context of the recently developed metagenomic tools, we discuss recent research on the community composition, adaptive strategies and biological functions of extremophiles.

  7. Winter Storms and Extreme Cold

    Science.gov (United States)

    ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ...

  8. Moving in extreme environments

    DEFF Research Database (Denmark)

    Lucas, Samuel J E; Helge, Jørn W; Schütz, Uwe H W;

    2016-01-01

    This review addresses human capacity for movement in the context of extreme loading and with it the combined effects of metabolic, biomechanical and gravitational stress on the human body. This topic encompasses extreme duration, as occurs in ultra-endurance competitions (e.g. adventure racing...... and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may...

  9. Moving in extreme environments

    DEFF Research Database (Denmark)

    Lucas, Samuel J E; Helge, Jørn W; Schütz, Uwe H W

    2016-01-01

    and transcontinental races) and expeditions (e.g. polar crossings), to the more gravitationally limited load carriage (e.g. in the military context). Juxtaposed to these circumstances is the extreme metabolic and mechanical unloading associated with space travel, prolonged bedrest and sedentary lifestyle, which may...

  10. Life in Extreme Environments

    Science.gov (United States)

    Rothschild, Lynn; Bray, James A. (Technical Monitor)

    2002-01-01

    Each recent report of liquid water existing elsewhere in the solar system has reverberated through the international press and excited the imagination of humankind. Why? Because in the last few decades we have come to realize that where there is liquid water on Earth, virtually no matter what the physical conditions, there is life. What we previously thought of as insurmountable physical and chemical barriers to life, we now see as yet another niche harboring 'extremophiles'. This realization, coupled with new data on the survival of microbes in the space environment and modeling of the potential for transfer of life between celestial bodies, suggests that life could be more common than previously thought. Here we critically examine what it means to be an extremophile, the implications of this for evolution, biotechnology, and especially the search for life in the cosmos.

  11. Automation Rover for Extreme Environments

    Science.gov (United States)

    Sauder, Jonathan; Hilgemann, Evan; Johnson, Michael; Parness, Aaron; Hall, Jeffrey; Kawata, Jessie; Stack, Kathryn

    2017-01-01

    Almost 2,300 years ago the ancient Greeks built the Antikythera automaton. This purely mechanical computer accurately predicted past and future astronomical events long before electronics existed1. Automata have been credibly used for hundreds of years as computers, art pieces, and clocks. However, in the past several decades automata have become less popular as the capabilities of electronics increased, leaving them an unexplored solution for robotic spacecraft. The Automaton Rover for Extreme Environments (AREE) proposes an exciting paradigm shift from electronics to a fully mechanical system, enabling longitudinal exploration of the most extreme environments within the solar system.

  12. New analogies between extreme QCD and cold atoms

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Yusuke [Los Alamos National Laboratory

    2012-08-15

    We discuss two new analogies between extreme QCD and cold atoms. One is the analogue of 'hard probes' in cold atoms. The other is the analogue of 'quark-hadron continuity' in cold atoms.

  13. Monitoring of Sedimentary Fluxes in Cold Environments: The SEDIBUD (Sediment Budgets in Cold Environments) Programme

    Science.gov (United States)

    Beylich, Achim A.

    2014-05-01

    Projected climate change in cold regions is expected to alter melt season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. These effects will undoubtedly change surface environments in cold regions and alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated geomorphic process monitoring and analysis to understand the sensitivity of the Earth surface environment is acute in cold climate environments. The International Association of Geomorphologists` (I.A.G. / A.I.G.) SEDIBUD (Sediment Budgets in Cold Environments) Program (2005 - 2017) is addressing this existing key knowledge gap. The central research question of this global group of scientists is to: Assess and model the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Research carried out at each of the ca. 50 defined SEDIBUD key test sites varies by program, logistics and available resources, but typically represent interdisciplinary collaborations of geomorphologists, hydrologists, ecologists, permafrost scientists and glaciologists. SEDIBUD has developed manuals and protocols (SEDIFLUX Manual) with a key set of primary surface process monitoring and research data requirements to incorporate results from these diverse projects and allow coordinated quantitative analysis across the program. Defined SEDIBUD key tasks for the coming years include (i) The continued generation and compilation of comparable longer-term datasets on contemporary sedimentary fluxes and sediment yields from SEDIBUD key test sites worldwide, (ii) The continued extension of the SEDIBUD metadata database with these datasets, (iii) The testing of defined SEDIBUD hypotheses (available

  14. Functional metagenomics of extreme environments.

    Science.gov (United States)

    Mirete, Salvador; Morgante, Verónica; González-Pastor, José Eduardo

    2016-04-01

    The bioprospecting of enzymes that operate under extreme conditions is of particular interest for many biotechnological and industrial processes. Nevertheless, there is a considerable limitation to retrieve novel enzymes as only a small fraction of microorganisms derived from extreme environments can be cultured under standard laboratory conditions. Functional metagenomics has the advantage of not requiring the cultivation of microorganisms or previous sequence information to known genes, thus representing a valuable approach for mining enzymes with new features. In this review, we summarize studies showing how functional metagenomics was employed to retrieve genes encoding for proteins involved not only in molecular adaptation and resistance to extreme environmental conditions but also in other enzymatic activities of biotechnological interest.

  15. Photosynthetic microorganisms in cold environments

    Science.gov (United States)

    Kviderova, Jana; Hajek, Josef; Elster, Josef; Bartak, Milos; Vaczi, Peter; Nedbalova, Linda

    and their physiological processes are inactive. If hydrated, they are physiologically active even at subzero temperatures (Kappen et al., 1996). Although living in cold environments, the growth optimum temperature of typical phycobiont Trebouxia (Chlorophyta) sp. is above 15 ° C, so these algae are considered to be rather psychrotolerant. Acknowledgement The work was supported from projects GA AS CR Nos. KJB 601630808 and KJ KJB600050708, CAREX and long-term institutional research plan of the Institute of Botany AS CR AV0Z600050516 and the Masaryk University. Prof. Martin Backor (Safarik University in Kosice) is kindly ac-knowledged for providing the strains Trebouxia erici and T. glomerata (Backor). References Elster, J. , Benson, E.E. Life in the polar terrestrial environment with a focus on algae and cyanobacteria, in Fuller, B.J., Lane, N. , Benson, E.E. (Eds), Life in the Frozen State. CRC Press, pp. 111-150, 2004. Kappen, L., Schroeter, B., Scheidegger, C., Sommerkorn, M. , Hestmark, G. Cold resistance and metabolic activity of lichens below 0 ° C. Adv. Space Res. 18, 119-128, 1996. Kviderova, J. Characterization of the community of snow algae and their photochemical performance in situ in the Giant Mountains, Czech Republic. Arct. Antarct. Alp. Res. accepted, 2010. Nedbalova, L., Kocianova, M. , Lukavsky, J. Ecology of snow algae in the Giant Mountains and their relation to cryoseston in Europe. Opera Corcontica 45, 59-68, 2008.

  16. Cold Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir Workers who ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

  17. Communication path for extreme environments

    Science.gov (United States)

    Jorgensen, Charles C. (Inventor); Betts, Bradley J. (Inventor)

    2010-01-01

    Methods and systems for using one or more radio frequency identification devices (RFIDs), or other suitable signal transmitters and/or receivers, to provide a sensor information communication path, to provide location and/or spatial orientation information for an emergency service worker (ESW), to provide an ESW escape route, to indicate a direction from an ESW to an ES appliance, to provide updated information on a region or structure that presents an extreme environment (fire, hazardous fluid leak, underwater, nuclear, etc.) in which an ESW works, and to provide accumulated thermal load or thermal breakdown information on one or more locations in the region.

  18. QCD matter in extreme environments

    CERN Document Server

    Fukushima, Kenji

    2011-01-01

    We review various theoretical approaches to the states of QCD matter out of quarks and gluons in extreme environments such as the high-temperature states at zero and finite baryon density and the dimensionally reduced state under an intense magnetic field. The topics at high temperature include the Polyakov loop and the 't Hooft loop in the perturbative regime, the Polyakov loop behaviour and the phase transition in some of non-perturbative methods; the strong-coupling expansion, the large-Nc limit and the holographic QCD models. These analyses are extended to hot and dense matter with a finite baryon chemical potential. We point out that the difficulty in the finite-density problem has similarity to that under a strong magnetic field. We make a brief summary of results related to the topological contents probed by the magnetic field and the Chiral Magnetic Effect. We also address the close connection to the (1+1) dimensional system.

  19. Improving diversity in cultures of bacteria from an extreme environment

    DEFF Research Database (Denmark)

    Vester, Jan Kjølhede; Glaring, Mikkel Andreas; Stougaard, Peter

    2013-01-01

    The ikaite columns in the Ikka Fjord in Greenland represent one of the few permanently cold and alkaline environments on Earth, and the interior of the columns is home to a bacterial community adapted to these extreme conditions. The community is characterized by low cell numbers imbedded...

  20. Magnetotactic Bacteria from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Christopher T. Lefèvre

    2013-03-01

    Full Text Available Magnetotactic bacteria (MTB represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4 or greigite (Fe3S4 and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  1. Extremely Cold Winter Months in Europe (1951-2010

    Directory of Open Access Journals (Sweden)

    Twardosz Robert

    2016-12-01

    Full Text Available Investigation of extreme thermal conditions is important from the perspective of global warming. Therefore, this study has been undertaken in order to determine the frequency, timing and spatial extent of extremely cold months in winter time at 60 weather stations across Europe over a sixty-year period from 1951 to 2010. Extremely cold months (ECMs are defined as months in which the average air temperature is lower than the corresponding multi-annual average by at least 2 standard deviations. Half of all the ECMs occurred in the years 1951-1970 (33 out of 67. The lowest number of ECMs was recorded in the decade 1991-2000, but since the beginning of the 21st century, their density and territorial extent has started to increase again. The extremely cold months with ECMs of the greatest spatial extent, covering at least one third of the stations (over 20 stations, included: February 1954 (22, February 1956 (36, January 1963 (25, and January 1987 (23 stations.

  2. Astrobiology: Life in Extreme Environments

    Science.gov (United States)

    Kaur, Preeti

    2011-01-01

    Astrobiology is the study of the origin, evolution and distribution of life in the universe. It seeks to answer two important scientific questions: how did we get here and are we alone in the universe? Scientists begin by studying life on Earth and its limits. The discovery of extremophiles on Earth capable of surviving extremes encourages the…

  3. Astrobiology: Life in Extreme Environments

    Science.gov (United States)

    Kaur, Preeti

    2011-01-01

    Astrobiology is the study of the origin, evolution and distribution of life in the universe. It seeks to answer two important scientific questions: how did we get here and are we alone in the universe? Scientists begin by studying life on Earth and its limits. The discovery of extremophiles on Earth capable of surviving extremes encourages the…

  4. Extreme Programming in a Research Environment

    Science.gov (United States)

    Wood, William A.; Kleb, William L.

    2002-01-01

    This article explores the applicability of Extreme Programming in a scientific research context. The cultural environment at a government research center differs from the customer-centric business view. The chief theoretical difficulty lies in defining the customer to developer relationship. Specifically, can Extreme Programming be utilized when the developer and customer are the same person? Eight of Extreme Programming's 12 practices are perceived to be incompatible with the existing research culture. Further, six of the nine 'environments that I know don't do well with XP' apply. A pilot project explores the use of Extreme Programming in scientific research. The applicability issues are addressed and it is concluded that Extreme Programming can function successfully in situations for which it appears to be ill-suited. A strong discipline for mentally separating the customer and developer roles is found to be key for applying Extreme Programming in a field that lacks a clear distinction between the customer and the developer.

  5. SOI MESFETs for Extreme Environment Electronics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We are proposing a new extreme environment electronics (EEE) technology based on silicon-on-insulator (SOI) metal-semiconductor field-effect transistors (MESFETs)....

  6. Technology of planetary extreme environment simulation

    Science.gov (United States)

    Wakefield, M. E.; Apodaca, L. E.; Hall, C. A.

    1972-01-01

    Four test chamber systems were devleoped to simulate the extreme atmospheric environs of Venus and Jupiter, in order to assure satisfactory performance of scientific entry probes and their experiments.

  7. Sample Handling in Extreme Environments

    Science.gov (United States)

    Avellar, Louisa; Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph

    2013-01-01

    Harsh environments, such as that on Venus, preclude the use of existing equipment for functions that involve interaction with the environment. The operating limitations of current high temperature electronics are well below the actual temperature and pressure found on Venus (460 deg C and 92 atm), so proposed lander configurations typically include a pressure vessel where the science instruments are kept at Earth-like temperature and pressure (25 deg C and 1 atm). The purpose of this project was to develop and demonstrate a method for sample transfer from an external drill to internal science instruments for a lander on Venus. The initial concepts were string and pneumatically driven systems; and the latter system was selected for its ability to deliver samples at very high speed. The pneumatic system was conceived to be driven by the pressure difference between the Venusian atmosphere and the inside of the lander. The pneumatic transfer of a small capsule was demonstrated, and velocity data was collected from the lab experiment. The sample transfer system was modeled using CAD software and prototyped using 3D printing. General structural and thermal analyses were performed to approximate the proposed system's mass and effects on the temperature and pressure inside of the lander. Additionally, a sampler breadboard for use on Titan was tested and functionality problems were resolved.

  8. Sample Handling in Extreme Environments

    Science.gov (United States)

    Avellar, Louisa; Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph

    2013-01-01

    Harsh environments, such as that on Venus, preclude the use of existing equipment for functions that involve interaction with the environment. The operating limitations of current high temperature electronics are well below the actual temperature and pressure found on Venus (460 deg C and 92 atm), so proposed lander configurations typically include a pressure vessel where the science instruments are kept at Earth-like temperature and pressure (25 deg C and 1 atm). The purpose of this project was to develop and demonstrate a method for sample transfer from an external drill to internal science instruments for a lander on Venus. The initial concepts were string and pneumatically driven systems; and the latter system was selected for its ability to deliver samples at very high speed. The pneumatic system was conceived to be driven by the pressure difference between the Venusian atmosphere and the inside of the lander. The pneumatic transfer of a small capsule was demonstrated, and velocity data was collected from the lab experiment. The sample transfer system was modeled using CAD software and prototyped using 3D printing. General structural and thermal analyses were performed to approximate the proposed system's mass and effects on the temperature and pressure inside of the lander. Additionally, a sampler breadboard for use on Titan was tested and functionality problems were resolved.

  9. Psychophysiological Studies in Extreme Environments

    Science.gov (United States)

    Toscano, William B.

    2011-01-01

    This paper reviews the results from two studies that employed the methodology of multiple converging indicators (physiological measures, subjective self-reports and performance metrics) to examine individual differences in the ability of humans to adapt and function in high stress environments. The first study was a joint collaboration between researchers at the US Army Research Laboratory (ARL) and NASA Ames Research Center. Twenty-four men and women active duty soldiers volunteered as participants. Field tests were conducted in the Command and Control Vehicle (C2V), an enclosed armored vehicle, designed to support both stationary and on-the-move operations. This vehicle contains four computer workstations where crew members are expected to perform command decisions in the field under combat conditions. The study objectives were: 1) to determine the incidence of motion sickness in the C2V relative to interior seat orientation/position, and parked, moving and short-haul test conditions; and 2) to determine the impact of the above conditions on cognitive performance, mood, and physiology. Data collected during field tests included heart rate, respiration rate, skin temperature, and skin conductance, self-reports of mood and symptoms, and cognitive performance metrics that included seven subtests in the DELTA performance test battery. Results showed that during 4-hour operational tests over varied terrain motion sickness symptoms increased; performance degraded by at least 5 percent; and physiological response profiles of individuals were categorized based on good and poor cognitive performance. No differences were observed relative to seating orientation or position.

  10. Quantum Thermal Transport through Extremely Cold Dielectric Chains

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-Ping; YI Lin

    2006-01-01

    In the framework of Green's function theory out of equilibrium, a Landauer-Buttiker (LB) formula for thermal conductance is derived. A simplified model for describing extremely cold dielectric chains is proposed for the first time. Fhrther we apply the present LB formula for studying thermal conductance at low-lying modes, emerging in dielectric atom chains. We find that quantum thermal conductance undergoes an anomalous transition due to new quasiparticle excitations, resulting from nonlinear atom-atom interactions. This theoretical prediction is in excellent agreement with a high-accuracy measurement to thermal conductance quantum.

  11. Behavior of microorganisms in the cold environment

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, S.M.; Martin, K.L.

    Two specific research studies are proposed: Mutagenicity of Intermediate Compounds Formed in Microbial Petroleum Degradation and A Study of Obligate Psychrophiles and Environmental Pollutants. In the first study, the mutagenic potential of petroleum components on environmental bacteria, especially in cold climate conditions, is to be investigated. Also, it is to be determined if microbial action on crude petroleum produces these mutagens which may have carcinogenic functions in the aquatic food chain. The second study is to be a thorough investigation of obligate psychrophilic bacteria in the cold fresh water and soil environment. The role of oil spills on this population and the possible decontamination effects of the metabolic action of the organism are to be studied.

  12. Distributed Motor Controller (DMC) for Operation in Extreme Environments

    Science.gov (United States)

    McKinney, Colin M.; Yager, Jeremy A.; Mojarradi, Mohammad M.; Some, Rafi; Sirota, Allen; Kopf, Ted; Stern, Ryan; Hunter, Don

    2012-01-01

    This paper presents an extreme environment capable Distributed Motor Controller (DMC) module suitable for operation with a distributed architecture of future spacecraft systems. This motor controller is designed to be a bus-based electronics module capable of operating a single Brushless DC motor in extreme space environments: temperature (-120 C to +85 C required, -180 C to +100 C stretch goal); radiation (>;20K required, >;100KRad stretch goal); >;360 cycles of operation. Achieving this objective will result in a scalable modular configuration for motor control with enhanced reliability that will greatly lower cost during the design, fabrication and ATLO phases of future missions. Within the heart of the DMC lies a pair of cold-capable Application Specific Integrated Circuits (ASICs) and a Field Programmable Gate Array (FPGA) that enable its miniaturization and operation in extreme environments. The ASICs are fabricated in the IBM 0.5 micron Silicon Germanium (SiGe) BiCMOS process and are comprised of Analog circuitry to provide telemetry information, sensor interface, and health and status of DMC. The FPGA contains logic to provide motor control, status monitoring and spacecraft interface. The testing and characterization of these ASICs have yielded excellent functionality in cold temperatures (-135 C). The DMC module has demonstrated successful operation of a motor at temperature.

  13. Geomicrobiological processes in extreme environments: A review

    Institute of Scientific and Technical Information of China (English)

    Hailiang Dong; Bingsong Yu

    2007-01-01

    @@ The last decade has seen an extraordinary growth of Geomicrobiology. Microorganisms have been studied in numerous extreme environments on Earth, ranging from crystalline rocks from the deep subsurface, ancient sedimentary rocks and hypersaline lakes, to dry deserts and deep-ocean hydrothermal vent systems. In light of this recent progress, we review several currently active research frontiers: deep continental subsurface microbiology, microbial ecology in saline lakes, microbial formation of dolomite, geomicrobiology in dry deserts,fossil DNA and its use in recovery of paleoenvironmental conditions, and geomicrobiology of oceans.Throughout this article we emphasize geomicrobiological processes in these extreme environments.

  14. Propulsion IVHM Extreme Environment Instrumentation Power IVHM

    Science.gov (United States)

    Zakrajsek, June

    2000-01-01

    This paper presents propulsion and instrumentation power for integrated vehicle health management technologies. The topics include: 1) Propulsion IVHM Capabilities Research; 2) Projects: X-33 Post-Test Diagnostic System; 3) X-34 NITEX; 4) Advanced Health Monitoring Systems; 5) Active Vibration Monitoring System; 6) Smart Self Healing Propulsion Systems; 7) Extreme Environment Sensors; and 8) Systems Engineering and Integration.

  15. Wireless Sensor Applications in Extreme Aeronautical Environments

    Science.gov (United States)

    Wilson, William C.; Atkinson, Gary M.

    2013-01-01

    NASA aeronautical programs require rigorous ground and flight testing. Many of the testing environments can be extremely harsh. These environments include cryogenic temperatures and high temperatures (greater than 1500 C). Temperature, pressure, vibration, ionizing radiation, and chemical exposure may all be part of the harsh environment found in testing. This paper presents a survey of research opportunities for universities and industry to develop new wireless sensors that address anticipated structural health monitoring (SHM) and testing needs for aeronautical vehicles. Potential applications of passive wireless sensors for ground testing and high altitude aircraft operations are presented. Some of the challenges and issues of the technology are also presented.

  16. Robust, Thin Optical Films for Extreme Environments

    Science.gov (United States)

    2006-01-01

    The environment of space presents scientists and engineers with the challenges of a harsh, unforgiving laboratory in which to conduct their scientific research. Solar astronomy and X-ray astronomy are two of the more challenging areas into which NASA scientists delve, as the optics for this high-tech work must be extremely sensitive and accurate, yet also be able to withstand the battering dished out by radiation, extreme temperature swings, and flying debris. Recent NASA work on this rugged equipment has led to the development of a strong, thin film for both space and laboratory use.

  17. Embedded I&C for Extreme Environments

    Energy Technology Data Exchange (ETDEWEB)

    Kisner, Roger A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    This project uses embedded instrumentation and control (I&C) technologies to demonstrate potential performance gains of nuclear power plant components in extreme environments. Extreme environments include high temperature, radiation, high pressure, high vibration, and high EMI conditions. For extreme environments, performance gains arise from moment-to-moment sensing of local variables and immediate application of local feedback control. Planning for embedding I&C during early system design phases contrasts with the traditional, serial design approach that incorporates minimal I&C after mechanical and electrical design is complete. The demonstration application involves the development and control of a novel, proof-of-concept motor/pump design. The motor and pump combination operate within the fluid environment, eliminating the need for rotating seals. Actively controlled magnetic bearings also replace failure-prone mechanical contact bearings that typically suspend rotating components. Such as design has the potential to significantly enhance the reliability and life of the pumping system and would not be possible without embedded I&C.

  18. Glenn Extreme Environments Rig (GEER) Independent Review

    Science.gov (United States)

    Jankovsky, Robert S.; Smiles, Michael D.; George, Mark A.; Ton, Mimi C.; Le, Son K.

    2015-01-01

    The Chief of the Space Science Project Office at Glenn Research Center (GRC) requested support from the NASA Engineering and Safety Center (NESC) to satisfy a request from the Science Mission Directorate (SMD) Associate Administrator and the Planetary Science Division Chief to obtain an independent review of the Glenn Extreme Environments Rig (GEER) and the operational controls in place for mitigating any hazard associated with its operation. This document contains the outcome of the NESC assessment.

  19. Endurance cycling results in extreme environments

    Science.gov (United States)

    Guertin, S. M.; Nguyen, D. N.; Scheick, L. Z.

    2003-01-01

    A new test bed for life testing flash memories in extreme environments is introducted. the test bed is based on a state-of-the-art development board. Since space applications often desire state-of-the-art devices, such a basis seems appropriate. Comparison of this tester to other such systems, including those with data presented here in the past is made. Limitations of different testers for varying applications are discussed. Recently developed data, using this test bed is also presented.

  20. Biodegradation and bioremediation of hydrocarbons in extreme environments.

    Science.gov (United States)

    Margesin, R; Schinner, F

    2001-09-01

    Many hydrocarbon-contaminated environments are characterized by low or elevated temperatures, acidic or alkaline pH, high salt concentrations, or high pressure, Hydrocarbon-degrading microorganisms, adapted to grow and thrive in these environments, play an important role in the biological treatment of polluted extreme habitats. The biodegradation (transformation or mineralization) of a wide range of hydrocarbons, including aliphatic, aromatic, halogenated and nitrated compounds, has been shown to occur in various extreme habitats. The biodegradation of many components of petroleum hydrocarbons has been reported in a variety of terrestrial and marine cold ecosystems. Cold-adapted hydrocarbon degraders are also useful for wastewater treatment. The use of thermophiles for biodegradation of hydrocarbons with low water solubility is of interest, as solubility and thus bioavailability, are enhanced at elevated temperatures. Thermophiles, predominantly bacilli, possess a substantial potential for the degradation of environmental pollutants, including all major classes. Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil-polluted desert soil. Some studies have investigated composting as a bioremediation process. Hydrocarbon biodegradation in the presence of high salt concentrations is of interest for the bioremediation of oil-polluted salt marshes and industrial wastewaters, contaminated with aromatic hydrocarbons or with chlorinated hydrocarbons. Our knowledge of the biodegradation potential of acidophilic, alkaliphilic, or barophilic microorganisms is limited.

  1. Biodegradation and bioremediation of hydrocarbons in extreme environments

    Energy Technology Data Exchange (ETDEWEB)

    Margesin, R.; Schinner, F. [Innsbruck Univ. (Austria). Inst. fuer Mikrobiologie

    2001-07-01

    Many hydrocarbon-contaminated environments are characterized by low or elevated temperatures, acidic or alkaline pH, high salt concentrations, or high pressure. Hydrocarbon-degrading microorganisms, adapted to grow and thrive in these environments, play an important role in the biological treatment of polluted extreme habitats. The biodegradation (transformation or mineralization) of a wide range of hydrocarbons, including aliphatic, aromatic, halogenated and nitrated compounds, has been shown to occur in various extreme habitats. The biodegradation of many components of petroleum hydrocarbons has been reported in a variety of terrestrial and marine cold ecosystems. Cold-adapted hydrocarbon degraders are also useful for wastewater treatment. The use of thermophiles for biodegradation of hydrocarbons with low water solubility is of interest, as solubility and thus bioavailability, are enhanced at elevated temperatures. Thermophiles, predominantly bacilli, possess a substantial potential for the degradation of environmental pollutants, including all major classes. Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil-polluted desert soil. Some studies have investigated composting as a bioremediation process. Hydrocarbon biodegradation in the presence of high salt concentrations is of interest for the bioremediation of oil-polluted salt marshes and industrial wastewaters, contaminated with aromatic hydrocarbons or with chlorinated hydrocarbons. Our knowledge of the biodegradation potential of acidophilic, alkaliphilic, or barophilic microorganisms is limited. (orig.)

  2. Are thermophilic microorganisms active in cold environments?

    Science.gov (United States)

    Cockell, Charles S.; Cousins, Claire; Wilkinson, Paul T.; Olsson-Francis, Karen; Rozitis, Ben

    2015-07-01

    The mean air temperature of the Icelandic interior is below 10 °C. However, we have previously observed 16S rDNA sequences associated with thermophilic lineages in Icelandic basalts. Measurements of the temperatures of igneous rocks in Iceland showed that solar insolation of these low albedo substrates achieved a peak surface temperature of 44.5 °C. We isolated seven thermophilic Geobacillus species from basalt with optimal growth temperatures of ~65 °C. The minimum growth temperature of these organisms was ~36 °C, suggesting that they could be active in the rock environment. Basalt dissolution rates at 40 °C were increased in the presence of one of the isolates compared to abiotic controls, showing its potential to be involved in active biogeochemistry at environmental temperatures. These data raise the possibility of transient active thermophilic growth in macroclimatically cold rocky environments, implying that the biogeographical distribution of active thermophiles might be greater than previously understood. These data show that temperatures measured or predicted over large scales on a planet are not in themselves adequate to assess niches available to extremophiles at micron scales.

  3. Mechanism of sand slide - cold lahar induced by extreme rainfall

    Science.gov (United States)

    Fukuoka, Hiroshi; Yamada, Masumi; Dok, Atitkagna

    2014-05-01

    Along with the increasing frequencies of extreme rainfall events in almost every where on the earth, shallow slide - debris flow, i.e. cold lahars running long distance often occurs and claims downslope residents lives. In the midnight of 15 October 2013, Typhoon Wilpha attacked the Izu-Oshima, a active volcanic Island and the extreme rainfall of more than 800 mm / 24 hours was recorded. This downpour of more than 80 mm/hr lasted 4 hours at its peak and caused a number of cold lahars. The initial stage of those lahars was shallow slides of surface black volcanic ash deposits, containing mostly fine sands. The thickness was only 50 cm - 1 m. In the reconnaissance investigation, author found that the sliding surface was the boundary of two separate volcanic ash layers between the black and yellow colored and apparently showing contrast of permeability and hardness. Permeability contrast may have contributed to generation of excess pore pressure on the border and trigger the slide. Then, the unconsolidated, unpacked mass was easily fluidized and transformed into mud flows, that which volcanologists call cold lahars. Seismometers installed for monitoring the active volcano's activities, succeeded to detect many tremors events. Many are spikes but 5 larger and longer events were extracted. They lasted 2 -3 minutes and if we assume that this tremors reflects the runout movement, then we can calculate the mean velocity of the lahars. Estimated velocity was 45 - 60 km/h, which is much higher than the average speed 30 - 40 km/h of debris flows observed in Japan. Flume tests of volcanic ash flows by the Forestry and Forest Products Research Institute showed the wet volcanic ash can run at higher speed than other materials. The two tremor records were compare d with the local residents witnessed and confirmed by newspaper reported that the reach of the lahar was observed at the exact time when tremor ends. We took the black volcanic ash and conducted ring shear tests to

  4. Cold Pool and Surface Flux Interactions in Different Environments

    Science.gov (United States)

    Grant, L. D.; van den Heever, S. C.

    2015-12-01

    Cold pools play important roles in tropical and midlatitude deep convective initiation and organization through their influence on near-surface kinematic and thermodynamic fields. Because temperature, moisture, and winds are perturbed within cold pools, cold pools can also impact surface sensible and latent heat fluxes. In turn, surface fluxes both within the cold pool and in the environment can modify the characteristics of cold pools and their evolution, with subsequent implications for convective initiation and organization. The two-way interaction between cold pools and surface energy fluxes has not been well studied and is likely to vary according to the environment and surface type. The goal of this study is therefore to investigate the mechanisms by which surface fluxes and cold pools interact in environmental conditions ranging from tropical oceanic to dry continental. This goal will be accomplished using high-resolution (grid spacings as fine as 10 m), idealized, 2D simulations of isolated cold pools; such modeling experiments have proven useful for investigating cold pools and their dynamics in many previous studies. In the proposed experiments, the surface flux formulation, surface type, and environmental conditions will be systematically varied. The impact of surface fluxes on various cold pool characteristics and their evolution, including the buoyancy, maximum vertical velocity, and moisture distribution, will be analyzed and presented. Results suggest that the mechanisms by which surface fluxes and cold pools interact vary substantially with the environment. Additionally, the indirect effects of surface fluxes on turbulent entrainment rates into the cold pool are found to play an important role in cold pool evolution. These results suggest that surface fluxes can impact the timing and manner in which cold pools initiate convection, and that their effects may be important to incorporate into cold pool parameterizations for climate simulations.

  5. Radiation Hardened Electronics for Extreme Environments

    Science.gov (United States)

    Keys, Andrew S.; Watson, Michael D.

    2007-01-01

    The Radiation Hardened Electronics for Space Environments (RHESE) project consists of a series of tasks designed to develop and mature a broad spectrum of radiation hardened and low temperature electronics technologies. Three approaches are being taken to address radiation hardening: improved material hardness, design techniques to improve radiation tolerance, and software methods to improve radiation tolerance. Within these approaches various technology products are being addressed including Field Programmable Gate Arrays (FPGA), Field Programmable Analog Arrays (FPAA), MEMS Serial Processors, Reconfigurable Processors, and Parallel Processors. In addition to radiation hardening, low temperature extremes are addressed with a focus on material and design approaches.

  6. Reconfiguration of Analog Electronics for Extreme Environments

    Science.gov (United States)

    Stoica, Adrian; Zebulum, Ricardo; Keymeulen, Didier; Guo, Xin

    2005-01-01

    This paper argues in favor of adaptive reconfiguration as a technique to expand the operational envelope of analog electronics for extreme environments (EE). On a reconfigurable device, although component parameters change in EE, as long as devices still operate, albeit degraded, a new circuit design, suitable for new parameter values, may be mapped into the reconfigurable structure to recover the initial circuit function. Laboratory demonstrations of this technique were performed by JPL in several independent experiments in which bulk CMOS reconfgurable devices were exposed to, and degraded by, high temperatures (approx.300 C) or radiation (300kRad TID), and then recovered by adaptive reconfiguration using evolutionary search algorithms.

  7. Multiple aspects of northern hemispheric wintertime cold extremes as revealed by Markov chain analysis

    Science.gov (United States)

    Kim, Hye-Sil; Choi, Yong-Sang; Kim, Joo-Hong; Kim, WonMoo

    2017-02-01

    High-impact cold extremes have continued to bring devastating socioeconomic losses in recent years. In order to explain the exposure to cold extremes more comprehensively, this study investigates multiple aspects of boreal winter cold extremes, i.e., frequency, persistence, and entropy (Markovian descriptors). Cold extremes are defined by the bottom 10th percentile of daily minimum temperatures during 1950-2014 over the northern hemisphere. The spatial and temporal distributions of Markovian descriptors during 65 years are examined. Climatological mean fields show the spatial coincidence of higher frequency, shorter persistence, and higher entropy of cold extremes, and vice versa. In regard to the temporal variations over six representative regions of North America, Europe, and Asia, all regions share a decreasing tendency of frequency with the increases in regional winter mean temperature. By contrast, persistence and entropy show their intrinsic decadal variability depending on regions irrespective of the regional temperature variability, which give different information from frequency. Therefore, the exposure to cold extremes would not simply decrease with regional warming. Rather these results indicate that the descriptors with multiple aspects of the extremes would be needed to embrace the topical features as well as the holistic nature of cold extremes.

  8. EXTREMELY METAL-POOR GALAXIES: THE ENVIRONMENT

    Energy Technology Data Exchange (ETDEWEB)

    Filho, M. E. [Universidad de Las Palmas de Gran Canaria–Universidad de La Laguna, CIE Canarias: Tri-Continental Atlantic Campus, Canary Islands (Spain); Almeida, J. Sánchez; Muñoz-Tuñón, C. [Instituto Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Nuza, S. E.; Kitaura, F.; Heß, S., E-mail: mfilho@astro.up.pt [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)

    2015-04-01

    We have analyzed bibliographical observational data and theoretical predictions, in order to probe the environment in which extremely metal-poor dwarf galaxies (XMPs) reside. We have assessed the H i component and its relation to the optical galaxy, the cosmic web type (voids, sheets, filaments and knots), the overdensity parameter and analyzed the nearest galaxy neighbors. The aim is to understand the role of interactions and cosmological accretion flows in the XMP observational properties, particularly the triggering and feeding of the star formation. We find that XMPs behave similarly to Blue Compact Dwarfs; they preferably populate low-density environments in the local universe: ∼60% occupy underdense regions, and ∼75% reside in voids and sheets. This is more extreme than the distribution of irregular galaxies, and in contrast to those regions preferred by elliptical galaxies (knots and filaments). We further find results consistent with previous observations; while the environment does determine the fraction of a certain galaxy type, it does not determine the overall observational properties. With the exception of five documented cases (four sources with companions and one recent merger), XMPs do not generally show signatures of major mergers and interactions; we find only one XMP with a companion galaxy within a distance of 100 kpc, and the H i gas in XMPs is typically well-behaved, demonstrating asymmetries mostly in the outskirts. We conclude that metal-poor accretion flows may be driving the XMP evolution. Such cosmological accretion could explain all the major XMP observational properties: isolation, lack of interaction/merger signatures, asymmetric optical morphology, large amounts of unsettled, metal-poor H i gas, metallicity inhomogeneities, and large specific star formation.

  9. Extreme Environments Technologies for Probes to Venus and Jupiter

    Science.gov (United States)

    Balint, Tibor S.; Kolawa, Elizabeth A.; Peterson, Craig E.; Cutts, James A.; Belz, Andrea P.

    2007-01-01

    This viewgraph presentation reviews the technologies that are used to mitigate extreme environments for probes at Venus and Jupiter. The contents include: 1) Extreme environments at Venus and Jupiter; 2) In-situ missions to Venus and Jupiter (past/present/future); and 3) Approaches to mitigate conditions of extreme environments for probes with systems architectures and technologies.

  10. Large reptiles and cold temperatures: Do extreme cold spells set distributional limits for tropical reptiles in Florida?

    Science.gov (United States)

    Mazzotti, Frank J.; Cherkiss, Michael S.; Parry, Mark; Beauchamp, Jeff; Rochford, Mike; Smith, Brian J.; Hart, Kristen M.; Brandt, Laura A.

    2016-01-01

    Distributional limits of many tropical species in Florida are ultimately determined by tolerance to low temperature. An unprecedented cold spell during 2–11 January 2010, in South Florida provided an opportunity to compare the responses of tropical American crocodiles with warm-temperate American alligators and to compare the responses of nonnative Burmese pythons with native warm-temperate snakes exposed to prolonged cold temperatures. After the January 2010 cold spell, a record number of American crocodiles (n = 151) and Burmese pythons (n = 36) were found dead. In contrast, no American alligators and no native snakes were found dead. American alligators and American crocodiles behaved differently during the cold spell. American alligators stopped basking and retreated to warmer water. American crocodiles apparently continued to bask during extreme cold temperatures resulting in lethal body temperatures. The mortality of Burmese pythons compared to the absence of mortality for native snakes suggests that the current population of Burmese pythons in the Everglades is less tolerant of cold temperatures than native snakes. Burmese pythons introduced from other parts of their native range may be more tolerant of cold temperatures. We documented the direct effects of cold temperatures on crocodiles and pythons; however, evidence of long-term effects of cold temperature on their populations within their established ranges remains lacking. Mortality of crocodiles and pythons outside of their current established range may be more important in setting distributional limits.

  11. Using mobile, internet connected deep sea crawlers for spatial and temporal analysis of cold seep ecosystems and the collection of real-time classroom data for extreme environment education.

    Science.gov (United States)

    Purser, Autun; Kwasnitschka, Tom; Duda, Alexander; Schwendner, Jakob; Bamberg, Marlene; Sohl, Frank; Doya, Carol; Aguzzi, Jacopo; Best, Mairi; Llovet, Neus Campanya I.; Scherwath, Martin; Thomsen, Laurenz

    2015-04-01

    Cabled internet and power connectivity with the deep sea allow instruments to operate in the deep sea at higher temporal resolutions than was possible historically, with the reliance on battery life and data storage capacities. In addition to the increase in sensor temporal frequency, cabled infrastructures now allow remote access to and control of mobile platforms on the seafloor. Jacobs University Bremen, in combination with collaborators from the Robotic Exploration of Extreme Environments (ROBEX) project, CSIC Barcelona and Ocean Networks Canada have been operating tracked deep sea crawler vehicles at ~890 m depth at the dynamic Barkley Canyon methane seep site, Pacific Canada during the last ~4 years. The vehicle has been able to explore an area of ~50 m radius, allowing repeated visits to numerous microhabitats. Mounting a range of sensors, including temperature, pressure, conductivity, fluorescence, turbidity, flow and methane concentration sensors, as well as various camera systems a large dataset has been compiled. Several methane pockmarks are present in the survey area, and geological, biological and oceanographic changes have been monitored over a range of timescales. Several publications have been produced, and in this presentation we introduce further data currently under analysis. Cabled internet connectivity further allows mobile platforms to be used directly in education. As part of the ROBEX project, researchers and students from both terrestrial and planetary sciences are using the crawler in an ongoing study project. Students are introduced to statistical methods from both fields during the course and in later stages they can plan their own research using the in-situ crawler, and follow the progress of their investigations live, then analyse the collected data using the techniques introduced during the course. Cabled infrastructures offer a unique facility for spatial investigation of extreme ecosystems over time, and for the 'hands on

  12. Cell physiology of plants growing in cold environments.

    Science.gov (United States)

    Lütz, Cornelius

    2010-08-01

    The life of plants growing in cold extreme environments has been well investigated in terms of morphological, anatomical, and ecophysiological adaptations. In contrast, long-term cellular or metabolic studies have been performed by only a few groups. Moreover, a number of single reports exist, which often represent just a glimpse of plant behavior. The review draws together the literature which has focused on tissue and cellular adaptations mainly to low temperatures and high light. Most studies have been done with European alpine plants; comparably well studied are only two phanerogams found in the coastal Antarctic. Plant adaptation in northern polar regions has always been of interest in terms of ecophysiology and plant propagation, but nowadays, this interest extends to the effects of global warming. More recently, metabolic and cellular investigations have included cold and UV resistance mechanisms. Low-temperature stress resistance in plants from cold environments reflects the climate conditions at the growth sites. It is now a matter of molecular analyses to find the induced genes and their products such as chaperones or dehydrins responsible for this resistance. Development of plants under snow or pollen tube growth at 0 degrees C shows that cell biology is needed to explain the stability and function of the cytoskeleton. Many results in this field are based on laboratory studies, but several publications show that it is not difficult to study cellular mechanisms with the plants adapted to a natural stress. Studies on high light and UV loads may be split in two parts. Many reports describe natural UV as harmful for the plants, but these studies were mainly conducted by shielding off natural UV (as controls). Other experiments apply additional UV in the field and have had practically no negative impact on metabolism. The latter group is supported by the observations that green overwintering plants increase their flavonoids under snow even in the absence of

  13. Magnetic Reconnection in Extreme Astrophysical Environments

    CERN Document Server

    Uzdensky, Dmitri A

    2011-01-01

    Magnetic reconnection is a basic plasma process of dramatic rearrangement of magnetic topology, often leading to a violent release of magnetic energy. It is important in magnetic fusion and in space and solar physics --- areas that have so far provided the context for most of reconnection research. Importantly, these environments consist just of electrons and ions and the dissipated energy always stays with the plasma. In contrast, in this paper I introduce a new direction of research, motivated by several important problems in high-energy astrophysics --- reconnection in high energy density (HED) radiative plasmas, where radiation pressure and radiative cooling become dominant factors in the pressure and energy balance. I identify the key processes distinguishing HED reconnection: special-relativistic effects; radiative effects (radiative cooling, radiation pressure, and Compton resistivity); and, at the most extreme end, QED effects, including pair creation. I then discuss the main astrophysical application...

  14. Plasma physics of extreme astrophysical environments.

    Science.gov (United States)

    Uzdensky, Dmitri A; Rightley, Shane

    2014-03-01

    Among the incredibly diverse variety of astrophysical objects, there are some that are characterized by very extreme physical conditions not encountered anywhere else in the Universe. Of special interest are ultra-magnetized systems that possess magnetic fields exceeding the critical quantum field of about 44 TG. There are basically only two classes of such objects: magnetars, whose magnetic activity is manifested, e.g., via their very short but intense gamma-ray flares, and central engines of supernovae (SNe) and gamma-ray bursts (GRBs)--the most powerful explosions in the modern Universe. Figuring out how these complex systems work necessarily requires understanding various plasma processes, both small-scale kinetic and large-scale magnetohydrodynamic (MHD), that govern their behavior. However, the presence of an ultra-strong magnetic field modifies the underlying basic physics to such a great extent that relying on conventional, classical plasma physics is often not justified. Instead, plasma-physical problems relevant to these extreme astrophysical environments call for constructing relativistic quantum plasma (RQP) physics based on quantum electrodynamics (QED). In this review, after briefly describing the astrophysical systems of interest and identifying some of the key plasma-physical problems important to them, we survey the recent progress in the development of such a theory. We first discuss the ways in which the presence of a super-critical field modifies the properties of vacuum and matter and then outline the basic theoretical framework for describing both non-relativistic and RQPs. We then turn to some specific astrophysical applications of relativistic QED plasma physics relevant to magnetar magnetospheres and to central engines of core-collapse SNe and long GRBs. Specifically, we discuss the propagation of light through a magnetar magnetosphere; large-scale MHD processes driving magnetar activity and responsible for jet launching and propagation in

  15. Plasma physics of extreme astrophysical environments

    Science.gov (United States)

    Uzdensky, Dmitri A.; Rightley, Shane

    2014-03-01

    Among the incredibly diverse variety of astrophysical objects, there are some that are characterized by very extreme physical conditions not encountered anywhere else in the Universe. Of special interest are ultra-magnetized systems that possess magnetic fields exceeding the critical quantum field of about 44 TG. There are basically only two classes of such objects: magnetars, whose magnetic activity is manifested, e.g., via their very short but intense gamma-ray flares, and central engines of supernovae (SNe) and gamma-ray bursts (GRBs)—the most powerful explosions in the modern Universe. Figuring out how these complex systems work necessarily requires understanding various plasma processes, both small-scale kinetic and large-scale magnetohydrodynamic (MHD), that govern their behavior. However, the presence of an ultra-strong magnetic field modifies the underlying basic physics to such a great extent that relying on conventional, classical plasma physics is often not justified. Instead, plasma-physical problems relevant to these extreme astrophysical environments call for constructing relativistic quantum plasma (RQP) physics based on quantum electrodynamics (QED). In this review, after briefly describing the astrophysical systems of interest and identifying some of the key plasma-physical problems important to them, we survey the recent progress in the development of such a theory. We first discuss the ways in which the presence of a super-critical field modifies the properties of vacuum and matter and then outline the basic theoretical framework for describing both non-relativistic and RQPs. We then turn to some specific astrophysical applications of relativistic QED plasma physics relevant to magnetar magnetospheres and to central engines of core-collapse SNe and long GRBs. Specifically, we discuss the propagation of light through a magnetar magnetosphere; large-scale MHD processes driving magnetar activity and responsible for jet launching and propagation in

  16. Coaxial Cables for Martian Extreme Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni; Harvey, Wayne L.; Valas, Sam; Tsai, Michael C.

    2011-01-01

    Work was conducted to validate the use of the rover external flexible coaxial cabling for space under the extreme environments to be encountered during the Mars Science Laboratory (MSL) mission. The antennas must survive all ground operations plus the nominal 670-Martian-day mission that includes summer and winter seasons of the Mars environment. Successful development of processes established coaxial cable hardware fatigue limits, which were well beyond the expected in-flight exposures. In keeping with traditional qualification philosophy, this was accomplished by subjecting flight-representative coaxial cables to temperature cycling of the same depth as expected in-flight, but for three times the expected number of in-flight thermal cycles. Insertion loss and return loss tests were performed on the coaxial cables during the thermal chamber breaks. A vector network analyzer was calibrated and operated over the operational frequency range 7.145 to 8.450 GHz. Even though some of the exposed cables function only at UHF frequencies (approximately 400 MHz), the testing was more sensitive, and extending the test range down to 400 MHz would have cost frequency resolution. The Gore flexible coaxial cables, which were the subject of these tests, proved to be robust and displayed no sign of degradation due to the 3X exposure to the punishing Mars surface operations cycles.

  17. Advanced Flip Chips in Extreme Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni

    2010-01-01

    material and the silicon die or chip, and also the underfill materials. Advanced packaging interconnects technology such as flip-chip interconnect test boards have been subjected to various extreme temperature ranges that cover military specifications and extreme Mars and asteroid environments. The eventual goal of each process step and the entire process is to produce components with 100 percent interconnect and satisfy the reliability requirements. Underfill materials, in general, may possibly meet demanding end use requirements such as low warpage, low stress, fine pitch, high reliability, and high adhesion.

  18. Colors of extreme exo-Earth environments.

    Science.gov (United States)

    Hegde, Siddharth; Kaltenegger, Lisa

    2013-01-01

    The search for extrasolar planets has already detected rocky planets and several planetary candidates with minimum masses that are consistent with rocky planets in the habitable zone of their host stars. A low-resolution spectrum in the form of a color-color diagram of an exoplanet is likely to be one of the first post-detection quantities to be measured for the case of direct detection. In this paper, we explore potentially detectable surface features on rocky exoplanets and their connection to, and importance as, a habitat for extremophiles, as known on Earth. Extremophiles provide us with the minimum known envelope of environmental limits for life on our planet. The color of a planet reveals information on its properties, especially for surface features of rocky planets with clear atmospheres. We use filter photometry in the visible as a first step in the characterization of rocky exoplanets to prioritize targets for follow-up spectroscopy. Many surface environments on Earth have characteristic albedos and occupy a different color space in the visible waveband (0.4-0.9 μm) that can be distinguished remotely. These detectable surface features can be linked to the extreme niches that support extremophiles on Earth and provide a link between geomicrobiology and observational astronomy. This paper explores how filter photometry can serve as a first step in characterizing Earth-like exoplanets for an aerobic as well as an anaerobic atmosphere, thereby prioritizing targets to search for atmospheric biosignatures.

  19. Frequent extreme cold exposure and brown fat and cold-induced thermogenesis: a study in a monozygotic twin.

    Directory of Open Access Journals (Sweden)

    Maarten J Vosselman

    Full Text Available INTRODUCTION: Mild cold acclimation is known to increase brown adipose tissue (BAT activity and cold-induced thermogenesis (CIT in humans. We here tested the effect of a lifestyle with frequent exposure to extreme cold on BAT and CIT in a Dutch man known as 'the Iceman', who has multiple world records in withstanding extreme cold challenges. Furthermore, his monozygotic twin brother who has a 'normal' sedentary lifestyle without extreme cold exposures was measured. METHODS: The Iceman (subject A and his brother (subject B were studied during mild cold (13°C and thermoneutral conditions (31°C. Measurements included BAT activity and respiratory muscle activity by [18F]FDG-PET/CT imaging and energy expenditure through indirect calorimetry. In addition, body temperatures, cardiovascular parameters, skin perfusion, and thermal sensation and comfort were measured. Finally, we determined polymorphisms for uncoupling protein-1 and β3-adrenergic receptor. RESULTS: Subjects had comparable BAT activity (A: 1144 SUVtotal and B: 1325 SUVtotal, within the range previously observed in young adult men. They were genotyped with the polymorphism for uncoupling protein-1 (G/G. CIT was relatively high (A: 40.1% and B: 41.9%, but unlike during our previous cold exposure tests in young adult men, here both subjects practiced a g-Tummo like breathing technique, which involves vigorous respiratory muscle activity. This was confirmed by high [18F]FDG-uptake in respiratory muscle. CONCLUSION: No significant differences were found between the two subjects, indicating that a lifestyle with frequent exposures to extreme cold does not seem to affect BAT activity and CIT. In both subjects, BAT was not higher compared to earlier observations, whereas CIT was very high, suggesting that g-Tummo like breathing during cold exposure may cause additional heat production by vigorous isometric respiratory muscle contraction. The results must be interpreted with caution given the

  20. Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic

    Science.gov (United States)

    Mienis, F.; Duineveld, G. C. A.; Davies, A. J.; Lavaleye, M. M. S.; Ross, S. W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M. J. N.; de Haas, H.; Brooke, S.; van Weering, T. C. E.

    2014-05-01

    The Cape Lookout cold-water coral area off the coast of North Carolina forms the shallowest and northernmost cold-water coral mound area on the Blake Plateau in the NW Atlantic. Cold-water coral habitats near Cape Lookout are occasionally bathed in the Gulf Stream, which is characterised by oligotrophic warm water and strong surface currents. Here, we present the first insights into the mound distribution and morphology, sedimentary environment and coral cover and near-bed environmental conditions as recorded by bottom landers from this coral area. The mounds occur between 320 and 550 m water depth and are characterised by high acoustic backscatter indicating the presence of hard structure. Three distinct mound morphologies were observed: (1) a mound with a flattened top at 320 m, (2) multi-summited mounds with a teardrop shape in the middle part of the area and (3) a single mound at 540 m water depth. Echosounder profiles show the presence of a strong reflector underneath all mound structures that forms the base of the mounds. This reflector cropped out at the downstream side of the single mound and consists of carbonate slabs. Video analysis revealed that all mounds are covered by Lophelia pertusa and that living colonies only occur close to the summits of the SSW side of the mounds, which is the side that faces the strongest currents. Off-mound areas were characterised by low backscatter and sediment ripples, indicating the presence of relatively strong bottom currents. Two bottom landers were deployed amidst the coral mounds between December 2009 and May 2010. Both landers recorded prominent events, characterised by large fluctuations in environmental conditions near the seabed as well as in the overlying water column. The period between December and April was characterised by several events of increasing temperature and salinity, coinciding with increased flow and near-bed acoustic backscatter. During these events temperature fluctuated by up to 9 °C within a

  1. Fungi living in diverse extreme habitats of the marine environment

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, S.; Raghukumar, C.; Manohar, C.S.

    . Fungi are capable of withstanding high salinity conditions, such as those in intertidal mangrove environments and salt pans. Cold water, psychrotolerant fungi have been identified from polar waters. Numerous studies have shown that fungi grow actively...

  2. Improving diversity in cultures of bacteria from an extreme environment.

    Science.gov (United States)

    Vester, Jan Kjølhede; Glaring, Mikkel Andreas; Stougaard, Peter

    2013-08-01

    The ikaite columns in the Ikka Fjord in Greenland represent one of the few permanently cold and alkaline environments on Earth, and the interior of the columns is home to a bacterial community adapted to these extreme conditions. The community is characterized by low cell numbers imbedded in a calcium carbonate matrix, making extraction of bacterial cells and DNA a challenge and limiting molecular and genomic studies of this environment. To utilize this genetic resource, cultivation at high pH and low temperature was studied as a method for obtaining biomass and DNA from the fraction of this community that would not otherwise be amenable to genetic analyses. The diversity and community dynamics in mixed cultures of bacteria from ikaite columns was investigated using denaturing gradient gel electrophoresis and pyrosequencing of 16S rDNA. Both medium composition and incubation time influenced the diversity of the culture and many hitherto uncharacterized genera could be brought into culture by extended incubation time. Extended incubation time also gave rise to a more diverse community with a significant number of rare species not detected in the initial community.

  3. Bioremediation of Oil Spills in Cold Environments: A Review

    Institute of Scientific and Technical Information of China (English)

    YANG Si-Zhong; JIN Hui-Jun; WEI Zhi; HE Rui-Xia; JI Yan-Jun; LI Xiu-Mei; YU Shao-Peng

    2009-01-01

    Oil spills have become a serious problem in cold environments with the ever-increasing resource exploitation,transportation,storage,and accidental leakage of oil.Several techniques,including physical,chemical,and biological methods,are used to recover spilled oil from the environment.Bioremediation is a promising option for remediation since it is effective and economic in removing oil with less undue environmental damages.However,it is a relatively slow process in cold regions and the degree of success depends on a number of factors,including the properties and fate of oil spilled in cold environments,and the major microbial and environmental limitations of bioremediation.The microbial factors include bioavailability of hydrocarbons,mass transfer through the cell membrane,and metabolic limitations.As for the environmental limitations in the cold regions,the emphasis is on soil temperatures,freeze-thaw processes,oxygen and nutrients availability,toxicity,and electron acceptors.There have been several cases of success in the polar regions,particularly in the Arctic and sub-Arctic regions.However,the challenges and constraints for bioremediation in cold environments remain large.

  4. Extreme Environment High Temperature Communication Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop and demonstrate a communications system capable of operation at extreme temperatures and pressures in hostile and corrosive...

  5. Magnetic Logic Circuits for Extreme Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The program aims to demonstrate a new genre of all-magnetic logic circuits which are radiation-tolerant and capable of reliable operation in extreme environmental...

  6. A neuroscience approach to optimizing brain resources for human performance in extreme environments.

    Science.gov (United States)

    Paulus, Martin P; Potterat, Eric G; Taylor, Marcus K; Van Orden, Karl F; Bauman, James; Momen, Nausheen; Padilla, Genieleah A; Swain, Judith L

    2009-07-01

    Extreme environments requiring optimal cognitive and behavioral performance occur in a wide variety of situations ranging from complex combat operations to elite athletic competitions. Although a large literature characterizes psychological and other aspects of individual differences in performances in extreme environments, virtually nothing is known about the underlying neural basis for these differences. This review summarizes the cognitive, emotional, and behavioral consequences of exposure to extreme environments, discusses predictors of performance, and builds a case for the use of neuroscience approaches to quantify and understand optimal cognitive and behavioral performance. Extreme environments are defined as an external context that exposes individuals to demanding psychological and/or physical conditions, and which may have profound effects on cognitive and behavioral performance. Examples of these types of environments include combat situations, Olympic-level competition, and expeditions in extreme cold, at high altitudes, or in space. Optimal performance is defined as the degree to which individuals achieve a desired outcome when completing goal-oriented tasks. It is hypothesized that individual variability with respect to optimal performance in extreme environments depends on a well "contextualized" internal body state that is associated with an appropriate potential to act. This hypothesis can be translated into an experimental approach that may be useful for quantifying the degree to which individuals are particularly suited to performing optimally in demanding environments.

  7. Extreme Environments: The Ghetto and the South Pole.

    Science.gov (United States)

    Pierce, Chester M.

    Extreme environments, such as polar regions or space crafts, provide an analogue for speculations concerning the needs of, educational provisions for, and environmental impacts on ghetto youth in kindergarten through the third grade. This discussion first centers on the common qualities of an extreme environment (whether exotic or mundane): forced…

  8. Plasma Physics of Extreme Astrophysical Environments

    CERN Document Server

    Uzdensky, Dmitri A

    2014-01-01

    Certain classes of astrophysical objects, namely magnetars and central engines of supernovae and gamma-ray bursts (GRBs), are characterized by extreme physical conditions not encountered elsewhere in the Universe. In particular, they possess magnetic fields that exceed the critical quantum field of 44 teragauss. Figuring out how these complex ultra-magnetized systems work requires understanding various plasma processes, both small-scale kinetic and large-scale magnetohydrodynamic (MHD). However, an ultra-strong magnetic field modifies the underlying physics to such an extent that many relevant plasma-physical problems call for building QED-based relativistic quantum plasma physics. In this review, after describing the extreme astrophysical systems of interest and identifying the key relevant plasma-physical problems, we survey the recent progress in the development of such a theory. We discuss how a super-critical field modifies the properties of vacuum and matter and outline the basic theoretical framework f...

  9. Potential contributions of extremophiles to hydrocarbon resources in marine extreme environments:A review

    Institute of Scientific and Technical Information of China (English)

    WANG Jiasheng; WANG Yongbiao; LI Qing

    2007-01-01

    To understand the potential mechanism of marine extremophiles participating in the formation and the evolution of hydrocarbon resources in marine extreme environments,some typical kinds of extremophiles and their distributions in marine hydrothermal and cold vents are discussed and evaluated respectively.The potential relationship between extremophile activities and hydrocarbon resources in marine extreme environments are then discussed in details.It could be now preliminary concluded that archaea and bacteria are the two main kinds of extremophiles in marine extreme environments.The dominating microbe communities in hydrothermal vents are heterotrophic zymogens,sulfate reducers and methanogens,while the ANME-2 group(Methanosarcinales) surrounded by sulfate-reducing bacteria and ANME-1 group dominate in cold vents.Marine extremophiles would be able to use CH,and H2S to synthesize energy for metabolism and to support food chains for other unique macrobiota nearby,which together present a high abundance but a low diversity with distinct characteristics of horizontal and vertical distributions.Marine extremophiles might play an important role either directly or indirectly in the processes of hydrocarbon formation and subsequent alteration,and could indicate the evolution of hydrocarbon resources in marine extreme environments.Our research thus has a great significance both in theoretical approach of potential hydrocarbon resources formed by marine extremophile activities and in practical exploration of the potential hydrocarbonsource sedimentary layers formed in the Earth history or the potential strata in southern China.

  10. The Definition and Classification of Extensive and Persistent Extreme Cold Events in China

    Institute of Scientific and Technical Information of China (English)

    PENG Jing-Bei; BUEH Cholaw

    2011-01-01

    Using the observed daily temperatures from 756 stations in China during the period from 1951 to 2009, extensive and persistent extreme cold events (EPECEs) were defined according to the following three steps: 1) a station was defined as an extreme cold station (ECS) if the observed temperature was lower than its 10th percentile threshold; 2) an extensive extreme cold event was determined to be present if the approximated area occupied by the ECSs was more than 10% of the total area of China (83rd percentile) on its starting day and the maximum area occupied by the ECSs was at least 20% of the total area of China (96th percentile); and 3) an EPECE was determined to be present if the extensive extreme cold event lasted for at least for eight days. 52 EPECEs were identified in this manner, and these identification results were also verified using other reliable data. On the basis of cluster analysis, five types of EPECEs were classified according to the spatial distribution of ECSs at their most extensive time over the course of the EPECE.

  11. Plant volatiles in extreme terrestrial and marine environments.

    Science.gov (United States)

    Rinnan, Riikka; Steinke, Michael; McGenity, Terry; Loreto, Francesco

    2014-08-01

    This review summarizes the current understanding on plant and algal volatile organic compound (VOC) production and emission in extreme environments, where temperature, water availability, salinity or other environmental factors pose stress on vegetation. Here, the extreme environments include terrestrial systems, such as arctic tundra, deserts, CO₂ springs and wetlands, and marine systems such as sea ice, tidal rock pools and hypersaline environments, with mangroves and salt marshes at the land-sea interface. The emission potentials at fixed temperature and light level or actual emission rates for phototrophs in extreme environments are frequently higher than for organisms from less stressful environments. For example, plants from the arctic tundra appear to have higher emission potentials for isoprenoids than temperate species, and hypersaline marine habitats contribute to global dimethyl sulphide (DMS) emissions in significant amounts. DMS emissions are more widespread than previously considered, for example, in salt marshes and some desert plants. The reason for widespread VOC, especially isoprenoid, emissions from different extreme environments deserves further attention, as these compounds may have important roles in stress resistance and adaptation to extremes. Climate warming is likely to significantly increase VOC emissions from extreme environments both by direct effects on VOC production and volatility, and indirectly by altering the composition of the vegetation.

  12. Heatshield for Extreme Entry Environment Technology (HEEET)

    Science.gov (United States)

    Venkatapathy, E.; Ellerby, D.; Stackpoole, M..; Peterson, K.; Gage, P.; Beerman, A.; Blosser, M.; Chinnapongse, R.; Dillman, R.; Feldman, J.; Gasch, M.; Munk, M.; Prabhu, D.; Poteet, C.

    2013-01-01

    Heat-shield for Extreme Entry Technology (HEEET) project is based on the 3-D Woven TPS, an emerging innovative and game changing technology funded by SMD and STMD to fill the ablative TPS gap that exists currently for reaching the depths of Saturn and Venus. Woven TPS technology will address the challenges currently faced by the Venus, Saturn, and higher speed sample return mission Science community due to lack of availability of the only TPS, namely Carbon Phenolic and enable the Science community to move forward with proposals in this decade with Woven TPS. This presentation describes the approach in maturing the technology in the next three years enabling NF-4 mission proposers to address the challenges of Venus, Saturn or higher speed sample return missions.

  13. Extreme Environment Ceramic-to-Metal Seal Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Phase 1 program will demonstrate the feasibility of large ceramic to metal joints/seals that can tolerate extreme environments. The immediate...

  14. The SEDIBUD (Sediment Budgets in Cold Environments) Programme: Ongoing activities and selected key tasks for the coming years

    Science.gov (United States)

    Beylich, Achim A.; Lamoureux, Scott F.; Decaulne, Armelle

    2012-09-01

    Projected climate change in cold environments is expected to alter melt-season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. In addition, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. The combined effects of these changes will alter surface environments in cold climate regions and change the fluxes of sediments, nutrients and solutes, but the absence of data, coordinated process monitoring and coordinated quantitative analysis to understand the sensitivity of the Earth surface environment are acute in cold climate environments. The International Association of Geomorphologists (I.A.G./A.I.G.) SEDIBUD (Sediment Budgets in Cold Environments) Programme has been formed to address this key knowledge gap and builds on the earlier European Science Foundation (ESF) SEDIFLUX (Sedimentary Source-to-Sink-Fluxes in Cold Environments) Network. Coordinated efforts are carried out to monitor, quantify, compare and model sedimentary fluxes and possible effects of predicted climate change in currently 44 selected SEDIBUD Key Test Sites (cold climate environment catchments) worldwide.

  15. Diving In Extreme Environments:: The Scientific Diving Experience

    OpenAIRE

    Lang, Michael A.

    2012-01-01

    The scope of extreme-environment diving defined within this work encompasses diving modes outside of the generally accepted no-decompression, open-circuit, compressed-air diving limits on selfcontained underwater breathing apparatus (scuba) in temperate or warmer waters. Extreme-environment diving is scientifically and politically interesting. The scientific diving operational safety and medical framework is the cornerstone from which diving takes place in the scientific community. From this ...

  16. HEALTH AND PERFORMANCE OF MILITARY PERSONNEL IN COLD CLIMATIC ENVIRONMENT OF THE WESTERN HIMALAYAS.

    Science.gov (United States)

    Jayaswal, R; Sivadas, P; Mishra, S S

    2001-10-01

    Indian Armed Forces are constrained to deploy a large number of troops in the western Himalayas in the interest of national security and territorial integrity. The region represents extremely rugged, arid and cold climatic conditions. The altitude ranges from 8000 to 23000 feet with winter temperatures ranging from -35°C to - 55°C in some regions. Low environmental humidity, hypo-baric hypoxia and high solar ultra-violet radiation with its attendant problems further compound the hardships faced by the troops in these climatic conditions. The role of the Armed Forces medical personnel is extremely challenging, as they have to ensure maintenance of health and physical fitness of the troops to ensure optimal performance during peace and during operations. These considerations include nutrition, physical fitness programmes suitable for the terrain and climatic conditions, protection against cold and hypoxia induced health problems, clothing and shelter taking into consideration the ergonomic factors, human waste disposal and prompt medical attention and evacuation in case of illness. An overview of the effects of cold hypoxic environment on health and performance of Indian troops, measures employed by the Armed Forces to maintain health of troops including psychological factors and the incidence of various cold induced health problems during peace time compared to operational period over the last 10 years is presented in this paper.

  17. Cold & Black Environment Design in Large Space Simulator

    Science.gov (United States)

    Min, Liu; Botao, Liu; Zijuan, Wang; Weiwei, Shan; Wenjing, Ding

    A space simulator provides a spacecraft with a specified environment during a thermal test of which a cold & black background is one of the important technical specifications. A shroud and nitrogen system used to simulate a cold & black environment with the effective space of 8500 mm × 9000 mm are studied in this article. In terms of the design of the shroud of the large space simulator, we should not only consider heat exchange and temperature uniformity, but also the feasibility of manufacture, transportation and installation. The cooling system adopts single-phase closed loop cycle. Based on the result of the test, it can be concluded that test data accord with the computational simulation result. The average temperature is 90 K and the temperature uniformity of the shroud meets the technical requirement.

  18. Hetero-Interfaces for Extreme Electronic Environments

    Science.gov (United States)

    2014-07-23

    describing the intrinsic behavior. In the original intrinsic hypothesis, it was described as the electrostatic field reaching the band gap energy...ELECTRONIC ENVIRONMENTS Quasi-two-dimensional electron gas (Q-2D-EG) forms at the interface between two perovskite band insulators; LaAlO3 (LAO) and...SrO)0 or ( TiO2 )0 – intersecting with negatively charged (AlO2)1- or positively charged (LaO)1+ layers, respectively. (this latter "LaO" layer

  19. Hypohydration Effects on Physical and Cognitive Performance in Cold Environments

    Science.gov (United States)

    2009-01-01

    sensitive to a wide variety of environmental conditions, nutritional factors, and sleep loss (28). The test required participants to Hypohydration...Scand J Work Environ Health 16: 44-50, 1990. 14. Freund BJ and Sawka MN. Influence of cold stress on human fluid balance. In: Nutritional Needs... Marathon : biometeorological factors. Int J Biometeorol 36: 63-68, 1989. 58. Van Orden KF, Ahlers ST, Thomas JR, House JF and Schrot J. Moderate

  20. Physiological changes in women during exercise in cold environments

    Science.gov (United States)

    Murray, S. J.; Shephard, R. J.; Radomski, M. W. M.

    1986-12-01

    Both the stress of exercise and the stress of a cold environment have been shown to increase the mobilization and utilization of body fat, thereby reducing body fat stores. Much of the research has been done on either rats or male human subjects. The purpose of this research was to show the physiological changes which occur to young, relatively obese, women who exercised during five consecutive days, for 200 min per day, in each of three environmental, chamber conditions: (1) warm-warm (WW), +15‡C; (2) cold-cold (CC), -20‡C; and (3) cold-warm (CW), -20‡C ambient temperature, with +18‡C air pumped to face masks for warmed air breathing. Oxygen cost of exercise, respiratory quotients, energy intake and utilization, and body composition changes were measured before, during, and after each environmental condition. While the respiratory quotients and the skinfold measurements decreased in the colder conditions, the underwater weighing determined percentage body fat did not show the same decrement as the skinfold measures, indicating a possible translocation of body fat from the subcutaneous depots to the deep body fat depots. Body mass loss was significant (Pmuscle and liver during the CW condition; however, with facial and upper airway cooling in the CC condition; brown adipose tissue (BAT) hypertrophy may be postulated at this more intense level of cold stress. Due to a greater stability of depot fat in the female, a longer cold exposure would be required to observe the fully developed BAT thermogenesis which would follow after the consequences of fat translocation which we have documented.

  1. The epidemiology of extreme hiking injuries in volcanic environments.

    Science.gov (United States)

    Heggie, Travis W; Heggie, Tracey M

    2012-01-01

    The objective of this review was to summarize the epidemiological literature for extreme hikers in volcanic environments and describe the incidence, nature and severity of injuries, the factors contributing to the injuries, and strategies for preventing injuries. Due to the relative newness of extreme hiking in volcanic environments, there are only a small handful of studies addressing the topic. Moreover, these studies are primarily focused on extreme hikers in Hawaii Volcanoes National Park. These studies found that the majority of extreme hikers in volcanic environments are inexperienced and unfamiliar with the potential hazards present in volcanic environments. The studies found that upper respiratory irritation resulting from exposure to volcanic gases and dehydration and scrapes, abrasions, lacerations, and thermal burns to the extremities were common injuries. The severity of the injuries ranged from simple on-site treat-and-release incidents to more severe incidents and even death. This review reveals a need for well-designed epidemiologic research from volcanic destinations outside of Hawaii that identify the nature and severity of injuries along with the factors contributing to injury incidents. There is also a demonstrated need for studies identifying preventive measures that reduce both the occurrence and severity of extreme hiking incidents in volcanic environments.

  2. Colors of extreme exoEarth environments

    CERN Document Server

    Hegde, Siddharth

    2012-01-01

    Context. The search for extrasolar planets has already detected rocky planets and several planetary candidates with minimum masses that are consistent with rocky planets in the Habitable Zone of their host stars. A low-resolution spectrum in the form of a color-color diagram of an exoplanet is likely to be one of the first post-detection quantities to be measured for the case of direct detection. Aims. In this paper, we explore potentially detectable surface features on rocky exoplanets and their connection to and importance as a habitat for extremophiles, as known on Earth. Extremophiles provide us with the minimum known envelope of environmental limits for life on our planet. Methods. The color of a planet reveals information on its properties, especially for surface features of rocky planets with clear atmospheres. We use filter photometry in the visible as a first step in the characterization of rocky exoplanets to prioritize targets for follow up spectroscopy. Results. Many surface environments on Earth ...

  3. Autonomous Mission Design in Extreme Orbit Environments

    Science.gov (United States)

    Surovik, David Allen

    An algorithm for autonomous online mission design at asteroids, comets, and small moons is developed to meet the novel challenges of their complex non-Keplerian orbit environments, which render traditional methods inapplicable. The core concept of abstract reachability analysis, in which a set of impulsive maneuvering options is mapped onto a space of high-level mission outcomes, is applied to enable goal-oriented decision-making with robustness to uncertainty. These nuanced analyses are efficiently computed by utilizing a heuristic-based adaptive sampling scheme that either maximizes an objective function for autonomous planning or resolves details of interest for preliminary analysis and general study. Illustrative examples reveal the chaotic nature of small body systems through the structure of various families of reachable orbits, such as those that facilitate close-range observation of targeted surface locations or achieve soft impact upon them. In order to fulfill extensive sets of observation tasks, the single-maneuver design method is implemented in a receding-horizon framework such that a complete mission is constructed on-the-fly one piece at a time. Long-term performance and convergence are assured by augmenting the objective function with a prospect heuristic, which approximates the likelihood that a reachable end-state will benefit the subsequent planning horizon. When state and model uncertainty produce larger trajectory deviations than were anticipated, the next control horizon is advanced to allow for corrective action -- a low-frequency form of feedback control. Through Monte Carlo analysis, the planning algorithm is ultimately demonstrated to produce mission profiles that vary drastically in their physical paths but nonetheless consistently complete all goals, suggesting a high degree of flexibility. It is further shown that the objective function can be tuned to preferentially minimize fuel cost or mission duration, as well as to optimize

  4. [Sports and extreme conditions. Cardiovascular incidence in long term exertion and extreme temperatures (heat, cold)].

    Science.gov (United States)

    Melin, B; Savourey, G

    2001-06-30

    During ultra-endurance exercise, both increase in body temperature and dehydration due to sweat losses, lead to a decrease in central blood volume. The heart rate drift allows maintaining appropriate cardiac output, in order to satisfy both muscle perfusion and heat transfer requirements by increasing skin blood flow. The resulting dehydration can impair thermal regulation and increase the risks of serious accidents as heat stroke. Endurance events, lasting more than 8 hours, result in large sweat sodium chloride losses. Thus, ingestion of large amounts of water with poor salt intake can induce symptomatic hyponatremia (plasma sodium extreme condition.

  5. From symmetric cold fission fragment mass distributions to extremely asymmetric alpha decay

    Science.gov (United States)

    Poenaru, D. N.; Ivascu, M.; Maruhn*, J. A.; Greiner*, W.

    1987-12-01

    The analytical superasymmetric fission model, successful in the study of extremely asymmetric decay modes like α-decay and heavy ion radioactivities, is applied to cold fission phenomena. The three groups of processes are described in a unifield manner, showing that cold fission could be considered heavy cluster emission. For 234U all groups have been detected. The highest symmetry of the gragment mass distributions should be observed for the neutron rich nucleus 264Fm, leading to doubly magic products 132Sn. The most probable light fragments from cold fission of 234,236U, 239Np and 240Pu are 100Zr, 104,106,108Mo respectively, in good agreement with experimental data.

  6. From symmetric cold fission fragment mass distributions to extremely asymmetric alpha decay

    Energy Technology Data Exchange (ETDEWEB)

    Poenaru, D.N.; Ivascu, M.; Maruhn, J.A.; Greiner, W.

    1987-12-10

    The analytical superasymmetric fission model, successful in the study of extremely asymmetric decay modes like ..cap alpha..-decay and heavy ion radioactivities, is applied to cold fission phenomena. The three groups of processes are described in a unifield manner, showing that cold fission could be considered heavy cluster emission. For /sup 234/U all groups have been detected. The highest symmetry of the gragment mass distributions should be observed for the neutron rich nucleus /sup 264/Fm, leading to doubly magic products /sup 132/Sn. The most probable light fragments from cold fission of /sup 234,236/U, /sup 239/Np and /sup 240/Pu are /sup 100/Zr, /sup 104,106,108/Mo respectively, in good agreement with experimental data.

  7. Coordinated analysis and quantification of sedimentary fluxes and budgets in cold environments: The SEDIBUD Programme

    Science.gov (United States)

    Beylich, Achim A.; Lamoureux, Scott F.

    2010-05-01

    Amplified climate change and ecological sensitivity of polar and high-altitude cold environments has been highlighted as a key global environmental issue. Projected climate change in cold climate environments is expected to alter melt season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depth. These effects will undoubtedly change surface environments in cold environments and alter fluxes of sediments, nutrients and solutes, but the absense of data and coordinated analysis to understand the sensitivity of the surface environment are acute in cold climate environments. The SEDIBUD (Sediment Budgets in Cold Environments) Programme of the International Association of Geomorphologists (I.A.G./A.I.G.) was formed in 2005 to address this key knowledge gap. SEDIBUD has currently about 400 members worldwide and the Steering Committee of this international programme is composed of ten scientists from nine different countries. The central research question of this global group of scientists is to Assess the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Research carried out at currently 38 defined SEDIBUD Key Test Sites varies by programme, logistics and available ressources, but typically represent interdisciplinary collaborations of geomorphologists, hydrologists, ecologists, and permafrost scientists and glaciologists with different levels of detail. SEDIBUD key test sites provide data on annual climate conditions, total runoff and particulate and dissolved fluxes as well as information on other relevant surface processes. A number of selected key test sites are providing high-resolution data on climatic conditions, runoff and fluvial fluxes, which in addition to the

  8. Genomics and Metagenomics of Extreme Acidophiles in Biomining Environments

    Science.gov (United States)

    Holmes, D. S.

    2015-12-01

    Over 160 draft or complete genomes of extreme acidophiles (pH models of the ecophysiology of biomining environments and provide insight into the gene and genome evolution of extreme acidophiles. Additionally, since most of these acidophiles are also chemoautolithotrophs that use minerals as energy sources or electron sinks, their genomes can be plundered for clues about the evolution of cellular metabolism and bioenergetic pathways during the Archaean abiotic/biotic transition on early Earth. Acknowledgements: Fondecyt 1130683.

  9. Effects of cold water immersion on lower extremity joint biomechanics during running.

    Science.gov (United States)

    Fukuchi, Claudiane Arakaki; da Rocha, Emmanuel Souza; Stefanyshyn, Darren John

    2015-01-01

    The purpose of this study was to identify the influence of cryotherapy on lower extremity running biomechanics. Twenty-six healthy male volunteers were randomised into two intervention groups: cold water (cold water at ~11°C) or tepid water (tepid water at ~26°C). They were required to run at 4.0 ± 0.2 m · s(-1) before and after they underwent water immersion for 20 min. Differences between pre- and post-intervention were used to compare the influence of water intervention during running. Peak joint angles, peak joint moments, peak ground reaction forces (GRF) and contact time (CT) were calculated using three-dimensional gait analysis. Independent t-tests were applied with a significant alpha level set at 0.05. Decreased peak propulsive and vertical GRF, decreased plantarflexion moments, increased hip flexion angle and longer CT were observed following cold water immersion. Although cold water immersion (cryotherapy) affected the running movement, none of the alterations have been related to running biomechanical patterns associated with injuries. Therefore, our results indicated that cold water immersion appears safe prior to running activities.

  10. [Hormonal changes in response to extreme environment factors].

    Science.gov (United States)

    Koubassov, R V

    2014-01-01

    In this paper presented current state about hormonal changes in sympathetic-adrenal, hypophysis-adrenal, hypophysis-gonads and thyroid levels from extreme environment factors. It's shown that hypophysis gonads and thyroid endocrine links along with sympathetic adrenal, hypophysis adrenal axes are very important relevance in response to extreme environment factors and organism adaptation. In this time a hormonal secretion changes corresponds as interrelated reactions cascade in mechanisms of homeostasis maintenance. A studying of this mechanisms and revealing of its role in stress pathogenesis is fundamental biomedical investigation task. A problem solving allow to perfect prophylactic and treatment methods against stress diseases.

  11. Time of death of victims found in cold water environment.

    Science.gov (United States)

    Karhunen, Pekka J; Goebeler, Sirkka; Winberg, Olli; Tuominen, Markku

    2008-04-01

    Limited data is available on the application of post-mortem temperature methods to non-standard conditions, especially in problematic real life cases in which the body of the victim is found in cold water environment. Here we present our experience on two cases with known post-mortem times. A 14-year-old girl (rectal temperature 15.5 degrees C) was found assaulted and drowned after a rainy cold night (+5 degrees C) in wet clothing (four layers) at the bottom of a shallow ditch, lying in non-flowing water. The post-mortem time turned out to be 15-16 h. Four days later, at the same time in the morning, after a cold (+/- 0 degrees C) night, a young man (rectal temperature 10.8 degrees C) was found drowned in a shallow cold drain (+4 degrees C) wearing similar clothing (four layers) and being exposed to almost similar environmental and weather conditions, except of flow (7.7 l/s or 0.3 m/s) in the drain. The post-mortem time was deduced to be 10-12 h. We tested the applicability of five practical methods to estimate time of death. Henssge's temperature-time of death nomogram method with correction factors was the most versatile and gave also most accurate results, although there is limited data on choosing of correction factors. In the first case, the right correction factor was close to 1.0 (recommended 1.1-1.2), suggesting that wet clothing acted like dry clothing in slowing down body cooling. In the second case, the right correction factor was between 0.3 and 0.5, similar to the recommended 0.35 for naked bodies in flowing water.

  12. Risk of hospitalization for fire-related burns during extreme cold weather.

    Science.gov (United States)

    Ayoub, Aimina; Kosatsky, Tom; Smargiassi, Audrey; Bilodeau-Bertrand, Marianne; Auger, Nathalie

    2017-10-01

    Environmental factors are important predictors of fires, but no study has examined the association between outdoor temperature and fire-related burn injuries. We sought to investigate the relationship between extremely cold outdoor temperatures and the risk of hospitalization for fire-related burns. We carried out a time-stratified case-crossover study of 2470 patients hospitalized for fire-related burn injuries during cold months between 1989 and 2014 in Quebec, Canada. The main exposure was the minimum outdoor temperature on the day of and the day before the burn. We computed odds ratios (OR) and 95% confidence intervals (CI) to evaluate the relationship between minimum temperature and fire-related burns, and assessed how associations varied across sex and age. Exposure to extreme cold temperature was associated with a significantly higher risk of hospitalization for fire-related burns. Compared with 0°C, exposure to a minimum temperature of -30°C was associated with an OR of 1.51 (95% CI 1.22-1.87) for hospitalization for fire-related burns. The associations were somewhat stronger for women, youth, and the elderly. Compared with 0°C, a minimum temperature of -30°C was associated with an OR for fire-related burn hospitalization of 1.65 for women (95% CI 1.13-2.40), 1.60 for age fire-related burns. Measures to prevent fires should be implemented prior to the winter season, and enhanced during extreme cold. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Mitochondrial Plasticity With Exercise Training and Extreme Environments

    DEFF Research Database (Denmark)

    Boushel, Robert; Lundby, Carsten; Qvortrup, Klaus

    2014-01-01

    Mitochondria form a reticulum in skeletal muscle. Exercise training stimulates mitochondrial biogenesis, yet an emerging hypothesis is that training also induces qualitative regulatory changes. Substrate oxidation, oxygen affinity and biochemical coupling efficiency may be differentially regulated...... with training and exposure to extreme environments. Threshold training doses inducing mitochondrial up-regulation remain to be elucidated considering fitness level. SUMMARY: Muscle mitochondrial are responsive to training and environment, yet thresholds for volume vs. regulatory changes and their physiological...

  14. JD3 - Neutron Stars: Timing in Extreme Environments

    NARCIS (Netherlands)

    Belloni, Tomaso M.; Méndez, Mariano; Zhang, Chengmin

    2009-01-01

    The space-time around Neutron Stars is indeed an extreme environment. Whether they are in accreting binary systems, isolated or in non-accreting binaries (perhaps with another Neutron Star), Neutron Stars provide a window onto physical processes not accessible by other means. In particular, the stud

  15. JD3 - Neutron Stars: Timing in Extreme Environments

    NARCIS (Netherlands)

    Belloni, Tomaso M.; Méndez, Mariano; Zhang, Chengmin

    2010-01-01

    The space-time around Neutron Stars is indeed an extreme environment. Whether they are in accreting binary systems, isolated or in non-accreting binaries (perhaps with another Neutron Star), Neutron Stars provide a window onto physical processes not accessible by other means. In particular, the stud

  16. Flexible Electronics-Based Transformers for Extreme Environments

    Science.gov (United States)

    Quadrelli, Marco B.; Stoica, Adrian; Ingham, Michel; Thakur, Anubhav

    2015-01-01

    This paper provides a survey of the use of modular multifunctional systems, called Flexible Transformers, to facilitate the exploration of extreme and previously inaccessible environments. A novel dynamics and control model of a modular algorithm for assembly, folding, and unfolding of these innovative structural systems is also described, together with the control model and the simulation results.

  17. Mitochondrial plasticity with exercise training and extreme environments.

    Science.gov (United States)

    Boushel, Robert; Lundby, Carsten; Qvortrup, Klaus; Sahlin, Kent

    2014-10-01

    Mitochondria form a reticulum in skeletal muscle. Exercise training stimulates mitochondrial biogenesis, yet an emerging hypothesis is that training also induces qualitative regulatory changes. Substrate oxidation, oxygen affinity, and biochemical coupling efficiency may be regulated differentially with training and exposure to extreme environments. Threshold training doses inducing mitochondrial upregulation remain to be elucidated considering fitness level.

  18. Imaging polarimetry of circumstellar environments with the Extreme Polarimeter

    NARCIS (Netherlands)

    Rodenhuis, M.|info:eu-repo/dai/nl/325801843; Canovas, H.; Jeffers, S.V.|info:eu-repo/dai/nl/326052658; Min, M.|info:eu-repo/dai/nl/277318416; Keller, C.U.|info:eu-repo/dai/nl/304824550

    2010-01-01

    Three successful observation campaigns have been conducted with the Extreme Polarimeter, an imaging polarimeter for the study of circumstellar environments in scattered light at visible wavelengths. A contrast ratio between the central star and the circumstellar source of 10-5 can be achieved with p

  19. Cold fronts in the Colombian Caribbean Sea and their relationship to extreme wave events

    Science.gov (United States)

    Ortiz-Royero, J. C.; Otero, L. J.; Restrepo, J. C.; Ruiz, J.; Cadena, M.

    2013-11-01

    Extreme ocean waves in the Caribbean Sea are commonly related to the effects of storms and hurricanes during the months of June through November. The collapse of 200 m of the Puerto Colombia pier in March 2009 revealed the effects of meteorological phenomena other than storms and hurricanes that may be influencing the extreme wave regime in the Colombian Caribbean. The marked seasonality of these atmospheric fronts was established by analyzing the meteorological-marine reports of the Instituto de Hidrología, Meteorología y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and the Centro de Investigación en Oceanografía y Meteorología of Colombia (CIOH, based on its initials in Spanish) during the last 16 yr. The highest number of cold fronts was observed during the months of January, February, and March, with 6 fronts occurring per year. An annual trend was observed and the highest number of fronts occurred in 2010 (20 in total); moreover, an annual strong relationship between the maximum average wave values and the cold fronts in the central zone of the Colombian Caribbean during the first three months of the year was established. In addition, the maximum values of the significant height produced by the passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the

  20. Terrestrial Applications of Extreme Environment Stirling Space Power Systems

    Science.gov (United States)

    Dyson, Rodger. W.

    2012-01-01

    NASA has been developing power systems capable of long-term operation in extreme environments such as the surface of Venus. This technology can use any external heat source to efficiently provide electrical power and cooling; and it is designed to be extremely efficient and reliable for extended space missions. Terrestrial applications include: use in electric hybrid vehicles; distributed home co-generation/cooling; and quiet recreational vehicle power generation. This technology can reduce environmental emissions, petroleum consumption, and noise while eliminating maintenance and environmental damage from automotive fluids such as oil lubricants and air conditioning coolant. This report will provide an overview of this new technology and its applications.

  1. TransFormers for Ensuring Long-Term Operations in Lunar Extreme Environments

    Science.gov (United States)

    Mantovani, J. G.; Stoica, A.; Alkalai, L.; Wilcox, B.; Quadrelli, M.

    2016-01-01

    "Surviving Extreme Space Environments" (EE) is one of NASA's Space Technology Grand Challenges. Power generation and thermal control are the key survival ingredients that allow a robotic explorer to cope with the EE using resources available to it, for example, by harvesting the local solar energy or by utilizing an onboard radioisotope thermoelectric generator (RTG). TransFormers (TFs) are a new technology concept designed to transform a localized area within a harsh extreme environment into a survivable micro-environment by projecting energy to the precise location where robots or humans operate. For example, TFs placed at a location on the rim of Shackleton Crater, which is illuminated by solar radiation for most of the year, would be able to reflect solar energy onto robots operating in the dark cold crater. TFs utilize a shape transformation mechanism to un-fold from a compact volume to a large reflective surface, and to control how much-and where-the energy is projected, and by adjusting for the changing position of the sun. TFs would enable in-situ resource utilization (ISRU) activities within locations of high interest that would normally be unreachable because of their extreme environment

  2. Applying positive psychology in the study of extreme environments.

    Science.gov (United States)

    Suedfeld, P

    2001-12-01

    Positive psychology orientation for the selection of personnel for isolated, confined environments and extreme and unusual environments is presented. It is suggested that personnel for isolated environments be selected for their ability to live and work in such an environment. The traditional negative psychology orientation focuses on characteristics such as demanding work, long stretches of empty time, unusual circadian rhythms, problems with group and interpersonal relationships, narrowed cognitive focus, cross-cultural differences, flattened leadership hierarchy, excessive interpersonal intimacy, and interaction with off site management. A positive psychology orientation focuses on the natural grandeur of the environment, mystery, efficiency, coziness, comfort, novelty and familiarity, improvisation, free time, time out from daily hassles, and social group characteristics such as camaraderie, intimacy, inderdependence, superordinate goals, and belonging to an elite group.

  3. Evaluation of occupational cold environments: field measurements and subjective analysis.

    Science.gov (United States)

    Oliveira, A Virgílio M; Gaspar, Adélio R; Raimundo, António M; Quintela, Divo A

    2014-01-01

    The present work is dedicated to the study of occupational cold environments in food distribution industrial units. Field measurements and a subjective assessment based on an individual questionnaire were considered. The survey was carried out in 5 Portuguese companies. The field measurements include 26 workplaces, while a sample of 160 responses was considered for the subjective assessment. In order to characterize the level of cold exposure, the Required Clothing Insulation Index (IREQ) was adopted. The IREQ index highlights that in the majority of the workplaces the clothing ensembles worn are inadequate, namely in the freezing chambers where the protection provided by clothing is always insufficient. The questionnaires results show that the food distribution sector is characterized by a female population (70.6%), by a young work force (60.7% are less than 35 yr old) and by a population with a medium-length professional career (80.1% in this occupation for less than 10 yr). The incidence of health effects which is higher among women, the distribution of protective clothing (50.0% of the workers indicate one garment) and the significant percentage of workers (>75%) that has more difficulties in performing the activity during the winter represent other important results of the present study.

  4. Plasmids of psychrophilic and psychrotolerant bacteria and their role in adaptation to cold environments.

    Science.gov (United States)

    Dziewit, Lukasz; Bartosik, Dariusz

    2014-01-01

    Extremely cold environments are a challenge for all organisms. They are mostly inhabited by psychrophilic and psychrotolerant bacteria, which employ various strategies to cope with the cold. Such harsh environments are often highly vulnerable to the influence of external factors and may undergo frequent dynamic changes. The rapid adjustment of bacteria to changing environmental conditions is crucial for their survival. Such "short-term" evolution is often enabled by plasmids-extrachromosomal replicons that represent major players in horizontal gene transfer. The genomic sequences of thousands of microorganisms, including those of many cold-active bacteria have been obtained over the last decade, but the collected data have yet to be thoroughly analyzed. This report describes the results of a meta-analysis of the NCBI sequence databases to identify and characterize plasmids of psychrophilic and psychrotolerant bacteria. We have performed in-depth analyses of 66 plasmids, almost half of which are cryptic replicons not exceeding 10 kb in size. Our analyses of the larger plasmids revealed the presence of numerous genes, which may increase the phenotypic flexibility of their host strains. These genes encode enzymes possibly involved in (i) protection against cold and ultraviolet radiation, (ii) scavenging of reactive oxygen species, (iii) metabolism of amino acids, carbohydrates, nucleotides and lipids, (iv) energy production and conversion, (v) utilization of toxic organic compounds (e.g., naphthalene), and (vi) resistance to heavy metals, metalloids and antibiotics. Some of the plasmids also contain type II restriction-modification systems, which are involved in both plasmid stabilization and protection against foreign DNA. Moreover, approx. 50% of the analyzed plasmids carry genetic modules responsible for conjugal transfer or mobilization for transfer, which may facilitate the spread of these replicons among various bacteria, including across species boundaries.

  5. IMPROVED, FAVORABLE FOR ENVIRONMENT POLYURETHANE COLD-BOX-PROCESS (COLD BOX «HUTTENES-ALBERTUS» .

    Directory of Open Access Journals (Sweden)

    A. Sergini

    2005-01-01

    Full Text Available The results of the laboratory and industrial investigations, the purpose of which is improvement of the classical Cold-box-process, i.e. the process of the slugs hardening in cold boxes, are presented.

  6. Extreme Environment Technologies for Space and Terrestrial Applications

    Science.gov (United States)

    Balint, Tibor S.; Cutts, James A.; Kolawa, Elizabeth A.; Peterson, Craig E.

    2008-01-01

    Over the next decades, NASA's planned solar system exploration missions are targeting planets, moons and small bodies, where spacecraft would be expected to encounter diverse extreme environmental (EE) conditions throughout their mission phases. These EE conditions are often coupled. For instance, near the surface of Venus and in the deep atmospheres of giant planets, probes would experience high temperatures and pressures. In the Jovian system low temperatures are coupled with high radiation. Other environments include thermal cycling, and corrosion. Mission operations could also introduce extreme conditions, due to atmospheric entry heat flux and deceleration. Some of these EE conditions are not unique to space missions; they can be encountered by terrestrial assets from the fields of defense,oil and gas, aerospace, and automotive industries. In this paper we outline the findings of NASA's Extreme Environments Study Team, including discussions on state of the art and emerging capabilities related to environmental protection, tolerance and operations in EEs. We will also highlight cross cutting EE mitigation technologies, for example, between high g-load tolerant impactors for Europa and instrumented projectiles on Earth; high temperature electronics sensors on Jupiter deep probes and sensors inside jet engines; and pressure vessel technologies for Venus probes and sea bottom monitors. We will argue that synergistic development programs between these fields could be highly beneficial and cost effective for the various agencies and industries. Some of these environments, however, are specific to space and thus the related technology developments should be spear headed by NASA with collaboration from industry and academia.

  7. How predictable is the winter extremely cold days over temperate East Asia?

    Science.gov (United States)

    Luo, Xiao; Wang, Bin

    2016-07-01

    Skillful seasonal prediction of the number of extremely cold day (NECD) has considerable benefits for climate risk management and economic planning. Yet, predictability of NECD associated with East Asia winter monsoon remains largely unexplored. The present work estimates the NECD predictability in temperate East Asia (TEA, 30°-50°N, 110°-140°E) where the current dynamical models exhibit limited prediction skill. We show that about 50 % of the total variance of the NECD in TEA region is likely predictable, which is estimated by using a physics-based empirical (P-E) model with three consequential autumn predictors, i.e., developing El Niño/La Niña, Eurasian Arctic Ocean temperature anomalies, and geopotential height anomalies over northern and eastern Asia. We find that the barotropic geopotential height anomaly over Asia can persist from autumn to winter, thereby serving as a predictor for winter NECD. Further analysis reveals that the sources of the NECD predictability and the physical basis for prediction of NECD are essentially the same as those for prediction of winter mean temperature over the same region. This finding implies that forecasting seasonal mean temperature can provide useful information for prediction of extreme cold events. Interpretation of the lead-lag linkages between the three predictors and the predictand is provided for stimulating further studies.

  8. Exascale Co-design for Modeling Materials in Extreme Environments

    Energy Technology Data Exchange (ETDEWEB)

    Germann, Timothy C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-07-08

    Computational materials science has provided great insight into the response of materials under extreme conditions that are difficult to probe experimentally. For example, shock-induced plasticity and phase transformation processes in single-crystal and nanocrystalline metals have been widely studied via large-scale molecular dynamics simulations, and many of these predictions are beginning to be tested at advanced 4th generation light sources such as the Advanced Photon Source (APS) and Linac Coherent Light Source (LCLS). I will describe our simulation predictions and their recent verification at LCLS, outstanding challenges in modeling the response of materials to extreme mechanical and radiation environments, and our efforts to tackle these as part of the multi-institutional, multi-disciplinary Exascale Co-design Center for Materials in Extreme Environments (ExMatEx). ExMatEx has initiated an early and deep collaboration between domain (computational materials) scientists, applied mathematicians, computer scientists, and hardware architects, in order to establish the relationships between algorithms, software stacks, and architectures needed to enable exascale-ready materials science application codes within the next decade. We anticipate that we will be able to exploit hierarchical, heterogeneous architectures to achieve more realistic large-scale simulations with adaptive physics refinement, and are using tractable application scale-bridging proxy application testbeds to assess new approaches and requirements. Such current scale-bridging strategies accumulate (or recompute) a distributed response database from fine-scale calculations, in a top-down rather than bottom-up multiscale approach.

  9. Fabrication of Diamond Based Sensors for Use in Extreme Environments

    Directory of Open Access Journals (Sweden)

    Gopi K. Samudrala

    2015-04-01

    Full Text Available Electrical and magnetic sensors can be lithographically fabricated on top of diamond substrates and encapsulated in a protective layer of chemical vapor deposited single crystalline diamond. This process when carried out on single crystal diamond anvils employed in high pressure research is termed as designer diamond anvil fabrication. These designer diamond anvils allow researchers to study electrical and magnetic properties of materials under extreme conditions without any possibility of damaging the sensing elements. We describe a novel method for the fabrication of designer diamond anvils with the use of maskless lithography and chemical vapor deposition in this paper. This method can be utilized to produce diamond based sensors which can function in extreme environments of high pressures, high and low temperatures, corrosive and high radiation conditions. We demonstrate applicability of these diamonds under extreme environments by performing electrical resistance measurements during superconducting transition in rare earth doped iron-based compounds under high pressures to 12 GPa and low temperatures to 10 K.

  10. Technology perspectives in the future exploration of extreme environments

    Science.gov (United States)

    Cutts, J.; Balint, T.; Kolawa, El.; Peterson, C.

    2007-08-01

    Solar System exploration is driven by high priority science goals and objectives at diverse destinations, as described in the NRC Decadal Survey and in NASA's 2006 Solar System Exploration (SSE) Roadmap. Proposed missions to these targets encounter extreme environments, including high or low temperatures, high pressure, corrosion, high heat flux, radiation and thermal cycling. These conditions are often coupled, such as low temperature and high radiation at Europa; and high temperature and high pressure near the surface of Venus. Mitigation of these environmental conditions frequently reaches beyond technologies developed for terrestrial applications, for example, by the automotive and oil industries. Therefore, space agencies require dedicated technology developments to enable these future missions. Within NASA, proposed missions are divided into three categories. Competed small (Discovery class) and medium (New Frontiers class) missions are cost capped, thus limiting significant technology developments. Therefore, large (Flagship class) missions are required not only to tackle key science questions which can't be addressed by smaller missions, but also to develop mission enabling technologies that can feed forward to smaller missions as well. In a newly completed extreme environment technology assessment at NASA, we evaluated technologies from the current State of Practice (SoP) to advanced concepts for proposed missions over the next decades. Highlights of this report are discussed here, including systems architectures, such as hybrid systems; protection systems; high temperature electronics; power generation and storage; mobility technologies; sample acquisition and mechanisms; and the need to test these technologies in relevant environments. It is expected that the findings - documented in detail in NASA's Extreme Environments Technologies report - would help identifying future technology investment areas, and in turn enable or enhance planned SSE missions

  11. Directional Dependence for Dark Matter Annihilation in Extreme Astrophysical Environments

    Science.gov (United States)

    Valadie, O. Grahm; Tinsley, Todd

    2017-01-01

    This research explores the directional dependence that extreme magnetic fields have on the annihilation of dark matter into electron-positron pairs. We take the neutralino of the Minimally Supersymmetric Standard Model (MSSM) as our dark matter candidate and assume magnetic field strengths on the order of the critical field (Bc 1013 G). This is characteristic of extreme astrophysical environments in which dark matter may accumulate. We will present the results for the annihilation cross section at varying incoming particle direction. In addition, we will present how these results differ with neutralino mass and energy, as well as with the magnetic field strength. Our goal is to demonstrate the ways that the direction of the magnetic field affects the states of the final electron and positron. This work is supported by NASA/Arkansas Space Grant Consortium and the Hendrix Odyssey Program.

  12. Storms or cold fronts? What is really responsible for the extreme waves regime in the Colombian Caribbean coast

    Science.gov (United States)

    Otero, L. J.; Ortiz-Royero, J. C.; Ruiz-Merchan, J. K.; Higgins, A. E.; Henriquez, S. A.

    2015-05-01

    On Friday, 7 March 2009, a 200 m-long section of the tourist pier in Puerto Colombia collapsed under the impact of the waves generated by a cold front in the area. The aim of this study is to determine the contribution and importance of cold fronts and storms on extreme waves in different areas of the Colombian Caribbean to determine the degree of the threat posed by the flood processes to which these coastal populations are exposed and the actions to which coastal engineering constructions should be subject. In the calculation of maritime constructions, the most important parameter is the wave's height; therefore, it is necessary to definitively know the design wave height to which a coastal engineering structure should be resistant. This wave height varies according to the return period considered. Using Gumbel's extreme value methodology, the significant height values for the study area were calculated. The methodology was evaluated using data from the re-analysis of the spectral NOAA Wavewatch III (WW3) model for 15 points along the 1600 km of the Colombia Caribbean coast (continental and insular) of the last 15 years. The results demonstrated that the extreme waves caused by tropical cyclones and cold fronts have different effects along the Colombian Caribbean coast. Storms and hurricanes are of greater importance in the Guajira Peninsula (Alta Guajira). In the central area formed by Baja Guajira, Santa Marta, Barranquilla, and Cartagena, the strong influence of cold fronts on extreme waves is evident. On the other hand, in the southern region of the Colombian Caribbean coast, from the Gulf of Morrosquillo to the Gulf of Urabá, even though extreme waves are lower than in the previous regions, extreme waves are dominated mainly by the passage of cold fronts. Extreme waves in the San Andrés and Providencia insular region present a different dynamic from that in the continental area due to its geographic location. The wave heights in the extreme regime are

  13. Storms or cold fronts? What is really responsible for the extreme waves regime in the Colombian Caribbean coast

    Directory of Open Access Journals (Sweden)

    L. J. Otero

    2015-05-01

    Full Text Available On Friday, 7 March 2009, a 200 m-long section of the tourist pier in Puerto Colombia collapsed under the impact of the waves generated by a cold front in the area. The aim of this study is to determine the contribution and importance of cold fronts and storms on extreme waves in different areas of the Colombian Caribbean to determine the degree of the threat posed by the flood processes to which these coastal populations are exposed and the actions to which coastal engineering constructions should be subject. In the calculation of maritime constructions, the most important parameter is the wave's height; therefore, it is necessary to definitively know the design wave height to which a coastal engineering structure should be resistant. This wave height varies according to the return period considered. Using Gumbel's extreme value methodology, the significant height values for the study area were calculated. The methodology was evaluated using data from the re-analysis of the spectral NOAA Wavewatch III (WW3 model for 15 points along the 1600 km of the Colombia Caribbean coast (continental and insular of the last 15 years. The results demonstrated that the extreme waves caused by tropical cyclones and cold fronts have different effects along the Colombian Caribbean coast. Storms and hurricanes are of greater importance in the Guajira Peninsula (Alta Guajira. In the central area formed by Baja Guajira, Santa Marta, Barranquilla, and Cartagena, the strong influence of cold fronts on extreme waves is evident. On the other hand, in the southern region of the Colombian Caribbean coast, from the Gulf of Morrosquillo to the Gulf of Urabá, even though extreme waves are lower than in the previous regions, extreme waves are dominated mainly by the passage of cold fronts. Extreme waves in the San Andrés and Providencia insular region present a different dynamic from that in the continental area due to its geographic location. The wave heights in the

  14. Remotely Powered Reconfigurable Receiver for Extreme Environment Sensing Platforms

    Science.gov (United States)

    Sheldon, Douglas J.

    2012-01-01

    Wireless sensors connected in a local network offer revolutionary exploration capabilities, but the current solutions do not work in extreme environments of low temperatures (200K) and low to moderate radiation levels (<50 krad). These sensors (temperature, radiation, infrared, etc.) would need to operate outside the spacecraft/ lander and be totally independent of power from the spacecraft/lander. Flash memory field-programmable gate arrays (FPGAs) are being used as the main signal processing and protocol generation platform in a new receiver. Flash-based FPGAs have been shown to have at least 100 reduced standby power and 10 reduction operating power when compared to normal SRAM-based FPGA technology.

  15. Human and team performance in extreme environments: Antarctica

    Science.gov (United States)

    Stuster, J.

    1998-01-01

    Analogous experience is often instructive when attempting to understand human behavior in extreme environments. The current paper refers to the experiences of polar explorers and remote duty personnel to help identify the factors that influence individual and team performance when small groups are isolated and confined for long durations. The principal factors discussed include organizational structure, intracrew communications, interpersonal relations, leadership style, personnel selection, and training. Behavioral implications also are addressed for the design of procedures and equipment to facilitate sustained individual and group performance under conditions of isolation and confinement. To be consistent with the theme of the symposium, this paper emphasizes the crew requirements for an international expedition to Mars.

  16. Study on the Outdoor Wind Environment Simulation and Design Strategies of Rural Settlements in Cold Areas

    Institute of Scientific and Technical Information of China (English)

    Ming Li; Hong Jin; Xin-Yu Zhang

    2014-01-01

    To improve the outdoor environment of rural settlement and reduce the energy consumption of rural houses in winterin cold areas,the seriously bad wind environment should been controlled and considered. This paper applies the method of numerical simulation to simulate the wind environment of some typical arrangement of building and courtyard in winter, and concludes the optimal building and courtyard arrangement types and strategies. It aims to provide some technical supports for improving the wind environment of rural settlements in cold regions.

  17. Psychological factors in exceptional, extreme and torturous environments.

    Science.gov (United States)

    Leach, John

    2016-01-01

    Our cognitive system has adapted to support goal-directed behaviour within a normal environment. An abnormal environment is one to which we are not optimally adapted but can accommodate through the development of coping strategies. These abnormal environments can be 'exceptional', e.g., polar base, space station, submarine, prison, intensive care unit, isolation ward etc.; 'extreme', marked by more intense environmental stimuli and a real or perceived lack of control over the situation, e.g., surviving at sea in a life-raft, harsh prison camp etc.; or 'tortuous', when specific environmental stimuli are used deliberately against a person in an attempt to undermine his will or resistance. The main factors in an abnormal environment are: psychological (isolation, sensory deprivation, sensory overload, sleep deprivation, temporal disorientation); psychophysiological (thermal, stress positions), and psychosocial (cultural humiliation, sexual degradation). Each single factor may not be considered tortuous, however, if deliberately structured into a systemic cluster may constitute torture under legal definition. The individual experience of extremis can be pathogenic or salutogenic and attempts are being made to capitalise on these positive experiences whilst ameliorating the more negative aspects of living in an abnormal environment.

  18. Whole lot of parts: stress in extreme environments.

    Science.gov (United States)

    Steel, G Daniel

    2005-06-01

    Stress has been a central interest for researchers of human behavior in extreme and unusual environments and also for those who are responsible for planning and carrying out expeditions involving such environments. This paper compares the actuarial and case study methods for predicting reactions to stress. Actuarial studies are useful, but do not tap enough variables to allow us to predict how a specific individual will cope with the rigors of an individual mission. Case histories provide a wealth of detail, but few investigators understand the challenges of properly applying this method. This study reviews some of the strengths and weaknesses of the actuarial and case history methods, and presents a four celled taxonomy of stress based on method (actuarial and case history) and effects (distress and eustress). For both research and operational purposes, the person, the setting, and time should not be considered independently; rather, it is an amalgam of these variables that provides the proper basis of analysis.

  19. Microbes Thriving in Extreme Environments: How Do They Do It?

    Directory of Open Access Journals (Sweden)

    Prameela Jha

    2014-12-01

    Full Text Available Our knowledge about habitat of microorganisms appears diminutive when we witness amazing flexibility in choice of survival under various conditions. Extremophiles refers to the organisms living and carrying out vital life processes at extreme conditions of temperature, pressure, pH, salt concentration among others and this is why they have attracted attention of researchers worldwide. There is a continuous quest to unreveal the probable mechanism or structural and functional adaptations that make extremophiles survive under other holistic conditions. There occur modifications primarily in cell membrane, DNA, RNA, protein and enzymes in order to render fit microbial cell to its external environment. Thus, extremophiles are robust source of high temperature and alkali stable enzymes. Various enzymes as lipase and protease have found several applications in food and cosmetic industry while Taq polymerase from bacteria Thermus aquaticus has revolutionized entire scene of molecular biology. Present review focuses on extremophiles, their structural and molecular adaptations to overcome unfavorable conditions of environment.

  20. WISDOM GPR performance assessment in a cold artificial environment

    Science.gov (United States)

    Dechambre, M.; Ciarletti, V.; Biancheri-Astier, M.; Saintenoy, A.; Costard, F.; Hassen-Khodja, R.

    2012-04-01

    The WISDOM (Water Ice Subsurface Deposit Observation on Mars) GPR is one of the instruments that have been selected as part of the Pasteur payload of ESA's 2018 ExoMars Rover mission. WISDOM has been designed to obtain information about the nature of the subsurface along the rover path with the objective to explore the first ~ 3 m of the soil with a vertical resolution of a few centimetres. The sub-surface properties that can be addressed with WISDOM are variations in composition, texture, stratification (e.g., number, thickness and orientation of layers), the presence of unconformities and other structural characteristics (such as fractures and the deformation of strata). It is then essential to quantify the performances of WISDOM in controlled conditions, and several full polarimetric measurements have been carried out with the prototype in a cold artificial environment. The main objectives are the detection of different interface between homogeneous materials with WISDOM. The characterization of the material (porosity, % of water, dielectric properties, thickness and depth, temperature ...) is well-controlled. The cold room facility of IDES at Orsay (France) has been used, the ambient temperature ranged from -7° C to -10° C. A tank laying on the metallic floor (height: 0.5m, width: 0.80 m, length: 1.20m) in macrolon can contain liquid or frozen water or layers (dielectric contrasts) of home-maid permafrost (frozen saturated sand) with and without embedded objects or fractures. The temperature inside the medium (ice or permafrost) is controlled, the radar antennas are put on a sheet of polystyrene over the tank. Frequent measurements were performed (every 2cm) along a track from one side to the other side of the tank. The experimental conditions were: (1)dry cold sand (Fontainebleau sand) : porosity 35% density 2,67 (2) saturated wet sand : 35% of water (3) permafrost (frozen saturated sand) : 35% of ice content 1 layer: 3 consecutive experiments : 10cm dry

  1. Extreme environments in the forests of Ushuaia, Argentina

    Science.gov (United States)

    D'Antoni, Hector; Rothschild, Lynn; Schultz, Cynthia; Burgess, Seth; Skiles, J. W.

    2007-11-01

    A survey over two mountain slopes (Glaciar Martial and Cerro Guanaco) in the vicinity of Ushuaia (Tierra del Fuego, Argentina) showed normal results for the region in terms of chlorophyll concentration in the leaves of the dominant tree species Nothofagus antarctica, N. pumilio and N. betuloides, and soil variables such as temperature, moisture, pH, and concentration of nitrogen, sodium and potassium. Solar radiation, on the other hand, showed high values of ultraviolet over the 200-400 nm range, suggesting that the environment is extreme in terms of incoming solar radiation. The forest canopy absorbs and/or reflects a significant amount of that radiation. In separate analyses we showed that these tree species contain UV-absorbing pigments (cyanidin, delphidin, and flavonol glycosides). We submit that the rippled and glossy surface of leaves serves as a reflection/backscattering mechanism that protects their inner structure and function. The presence of krummholz (= twisted, dwarf trees) in the upper end of the forest shows the effects of an extreme environment.

  2. Re-Configurable Electronics Characterization under Extreme Thermal Environment

    Science.gov (United States)

    Stoica, Adrian; Lacayo, Veronica; Ramesham, Rajeshuni; Keymeulen, Didier; Zebulum, Ricardo; Neff, Joe; Burke, Gary; Daud, Taher

    2005-01-01

    The need for reconfigurable electronics is driven by requirements to survive longer missions and harsher environments. It is possible to compensate for degradations in Extreme Environments (EE). EE has effect on electronics: circuits are designed to exploit device characteristics and when a certain temperature or radiation range is exceeded the circuit function gradually degrades. It is possible to employ Hardening by reconfiguration (HBR) to mitigate drifts, degradation, or damage on electronic devices in EE by using reconfigurable devices and an adaptive self-reconfiguration of circuit topology. In this manner degraded components can be salvaged, and completely damaged components can be bypassed. The challenge of conventional design is replaced with that of designing a recover process that automatically performs the (re) design in place of the designer. The objective of testing a Digital Signal Processor (DSP) under the extreme temperatures was to determine the lowest temperature at which the DAP can operate. The objective of testing a Xilinx VirtexII Pro FPGA board was to initially find our whether the evaluation board and the FPGA would survive and continue at temperature ranges from -180 C, and 120 C. The Virtex II functioned correctly at the temperatures tested. The next test was done on the GM-C filter building block using the same temperature range as the Virtex II. The current lower and upper limits were shown to be reduced as the temperature gets lower. The device function can be recovered by increasing the Vb from .08V to .85V. The negative and positive saturation voltages increases as the temperature gets higher. The function of the device can be recovered by decreasing the Vb from .8V to around .75V. The next test was performed to test the recovery of the GmC low pass filter through Vb in a filter circuit. The test indicate that bias voltage control adjustment is an efficient mechanism for circuit recovery at extreme temperatures.

  3. Heatshield for Extreme Entry Environment Technology (HEEET) Development Status

    Science.gov (United States)

    Ellerby, Don; Gage, Peter; Kazemba, Cole; Mahzari, Milad; Nishioka, Owen; Peterson, Keith; Stackpoole, Mairead; Venkatapathy, Ethiraj; Young, Zion; Poteet, Carl; Splinter, Scott; Fowler, Mike; Kellerman, Charles

    2016-01-01

    The Heat shield for Extreme Entry Environment Technology (HEEET) Project is a NASA STMD and SMD co-funded effort. The goal is to develop and mission infuse a new ablative Thermal Protection System that can withstand extreme entry. It is targeted to support NASAs high priority missions, as defined in the latest decadal survey, to destinations such as Venus and Saturn in-situ robotic science missions. Entry into these planetary atmospheres results in extreme heating. The entry peak heat-flux and associated pressure are estimated to be between one and two orders of magnitude higher than those experienced by Mars Science Laboratory or Lunar return missions. In the recent New Frontiers community announcement NASA has indicated that it is considering providing an increase to the PI managed mission cost (PIMMC) for investigations utilizing the Heat Shield for Extreme Entry Environment Technology (HEEET) and in addition, NASA is considering limiting the risk assessment to only their accommodation on the spacecraft and the mission environment. The HEEET ablative TPS utilizes 3D weaving technology to manufacture a dual layer material architecture. The 3-D weaving allows for flat panels to be woven. The dual layer consists of a top layer designed to withstand the extreme external environment while the inner or insulating layer by design, is designed to achieve low thermal conductivity, and it keeps the heat from conducting towards the structure underneath. Both arc jet testing combined with material properties have been used to develop thermal response models that allows for comparison of performance with heritage carbon phenolic. A 50 mass efficiency is achieved by the dual layer construct compared to carbon phenolic for a broad range of missions both to Saturn and Venus. The 3-D woven flat preforms are molded to achieve the shape as they are compliant and then resin infusion with curing forms a rigid panels. These panels are then bonded on to the aeroshell structure. Gaps

  4. Electronic Components and Circuits for Extreme Temperature Environments

    Science.gov (United States)

    Patterson, Richard L.; Hammoud, Ahmad; Dickman, John E.; Gerber, Scott

    2003-01-01

    Planetary exploration missions and deep space probes require electrical power management and control systems that are capable of efficient and reliable operation in very low temperature environments. Presently, spacecraft operating in the cold environment of deep space carry a large number of radioisotope heating units in order to maintain the surrounding temperature of the on-board electronics at approximately 20 C. Electronics capable of operation at cryogenic temperatures will not only tolerate the hostile environment of deep space but also reduce system size and weight by eliminating or reducing the radioisotope heating units and their associate structures; thereby reducing system development as well as launch costs. In addition, power electronic circuits designed for operation at low temperatures are expected to result in more efficient systems than those at room temperature. This improvement results from better behavior and tolerance in the electrical and thermal properties of semiconductor and dielectric materials at low temperatures. The Low Temperature Electronics Program at the NASA Glenn Research Center focuses on research and development of electrical components, circuits, and systems suitable for applications in the aerospace environment and deep space exploration missions. Research is being conducted on devices and systems for reliable use down to cryogenic temperatures. Some of the commercial-off-the-shelf as well as developed components that are being characterized include switching devices, resistors, magnetics, and capacitors. Semiconductor devices and integrated circuits including digital-to-analog and analog-to-digital converters, DC/DC converters, operational amplifiers, and oscillators are also being investigated for potential use in low temperature applications. An overview of the NASA Glenn Research Center Low Temperature Electronic Program will be presented in this paper. A description of the low temperature test facilities along with

  5. In-Situ Micromechanical Testing in Extreme Environments

    Science.gov (United States)

    Lupinacci, Amanda Sofia

    In order to design engineering applications that can withstand extreme environments, we must first understand the underlying deformation mechanisms that can hinder material performance. It is not enough to characterize the mechanical properties alone, we must also characterize the microstructural changes as well so that we can understand the origin of material degradation. This dissertation focuses on two different extreme environments. The first environment is the cryogenic environment, where we focus on the deformation behavior of solder below the ductile to brittle transition temperature (DBTT). The second environment is the irradiated environment, where we focus on the effects that ion beam irradiation has on both the mechanical properties and microstructure of 304 stainless steel. Both classes of materials and testing environments utilize novel in situ micromechanical testing techniques inside a scanning electron microscope which enhances our ability to link the observed deformation behavior with its associated mechanical response. Characterizing plasticity mechanisms below the DBTT is traditionally difficult to accomplish in a systematic fashion. Here, we use a new experimental setup to perform in situ cryogenic mechanical testing of pure Sn micropillars at room temperature and at -142 °C. Subsequent electron microscopy characterization of the micropillars shows a clear difference in the deformation mechanisms at room temperature and at cryogenic temperatures. At room temperature, the Sn micropillars deformed through dislocation plasticity while at -142 °C they exhibited both higher strength and deformation twinning. Two different orientations were tested, a symmetric (100) orientation and a non-symmetric (45¯1) orientation. The deformation mechanisms were found to be the same for both orientations. This approach was also extended to a more complex solder alloy that is commonly used in industry, Sn96. In the case of the solder alloy more complex geometries

  6. Electro-Mechanical Systems for Extreme Space Environments

    Science.gov (United States)

    Mojarradi, Mohammad M.; Tyler, Tony R.; Abel, Phillip B.; Levanas, Greg

    2011-01-01

    Exploration beyond low earth orbit presents challenges for hardware that must operate in extreme environments. The current state of the art is to isolate and provide heating for sensitive hardware in order to survive. However, this protection results in penalties of weight and power for the spacecraft. This is particularly true for electro-mechanical based technology such as electronics, actuators and sensors. Especially when considering distributed electronics, many electro-mechanical systems need to be located in appendage type locations, making it much harder to protect from the extreme environments. The purpose of this paper to describe the advances made in the area of developing electro-mechanical technology to survive these environments with minimal protection. The Jet Propulsion Lab (JPL), the Glenn Research Center (GRC), the Langley Research Center (LaRC), and Aeroflex, Inc. over the last few years have worked to develop and test electro-mechanical hardware that will meet the stringent environmental demands of the moon, and which can also be leveraged for other challenging space exploration missions. Prototype actuators and electronics have been built and tested. Brushless DC actuators designed by Aeroflex, Inc have been tested with interface temperatures as low as 14 degrees Kelvin. Testing of the Aeroflex design has shown that a brushless DC motor with a single stage planetary gearbox can operate in low temperature environments for at least 120 million cycles (measured at motor) if long life is considered as part of the design. A motor control distributed electronics concept developed by JPL was built and operated at temperatures as low as -160 C, with many components still operational down to -245 C. Testing identified the components not capable of meeting the low temperature goal of -230 C. This distributed controller is universal in design with the ability to control different types of motors and read many different types of sensors. The controller

  7. Improved cultivation and metagenomics as new tools for bioprospecting in cold environments.

    Science.gov (United States)

    Vester, Jan Kjølhede; Glaring, Mikkel Andreas; Stougaard, Peter

    2015-01-01

    Only a small minority of microorganisms from an environmental sample can be cultured in the laboratory leaving the enormous bioprospecting potential of the uncultured diversity unexplored. This resource can be accessed by improved cultivation methods in which the natural environment is brought into the laboratory or through metagenomic approaches where culture-independent DNA sequence information can be combined with functional screening. The coupling of these two approaches circumvents the need for pure, cultured isolates and can be used to generate targeted information on communities enriched for specific activities or properties. Bioprospecting in extreme environments is often associated with additional challenges such as low biomass, slow cell growth, complex sample matrices, restricted access, and problematic in situ analyses. In addition, the choice of vector system and expression host may be limited as few hosts are available for expression of genes with extremophilic properties. This review summarizes the methods developed for improved cultivation as well as the metagenomic approaches for bioprospecting with focus on the challenges faced by bioprospecting in cold environments.

  8. Characterization and effects of cold fronts in the Colombian Caribbean Coast and their relationship to extreme wave events

    Directory of Open Access Journals (Sweden)

    J. C. Ortiz-Royero

    2013-07-01

    passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that, there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the purpose of informing the design of structures in this region of the Caribbean.

  9. Characterization of Polarizing Splitter Optics in Extreme Environments

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, Ryand; Olson, Matthew; Morelli, Gregg

    2013-01-04

    Development of laser systems capable of surviving extreme conditions experienced in military applications requires mounts and components that are able to survive these conditions. The characterization of mounted and/or bonded optical assemblies in harsh environments is critical for the development of laser and optical systems for functionality in these extreme conditions. Customized mounts, bonding assemblies and packaging strategies are utilized to develop and field reliable and robust optical subassemblies. Thin film polarizers operating at 45o and polarizing beam splitter cubes were chosen for initial testing based on past experiences, advancements in optical coating and construction technologies and material properties. Shock, vibration, shear strength, tensile strength and temperature testing are performed on mounted polarizing beam splitter cubes and thin film polarizers from two manufacturers. Previous testing showed that polarizing beam splitter cubes constructed using epoxy would become damaged in the laser resonator. The cubes being tested in this report are constructed using epoxy- free direct optical contact bonding. Thin film polarizers operating at 45o are chosen opposed to Brewster’s angle thin film polarizers to reduce the size and simplify design and construction since an optical wedge is not required. The components and mounts are each environmentally tested beyond the manufacturers’ specifications for shock, vibration, and temperature. Component functionality is monitored during and after the environmental testing. Experimental results from the testing will be discussed as will the impact on future laser resonator designs.

  10. Qualification of Fiber Optic Cables for Martian Extreme Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni; Lindensmith, Christian A.; Roberts, William T.; Rainen, Richard A.

    2011-01-01

    Means have been developed for enabling fiber optic cables of the Laser Induced Breakdown Spectrometer instrument to survive ground operations plus the nominal 670 Martian conditions that include Martian summer and winter seasons. The purpose of this development was to validate the use of the rover external fiber optic cabling of ChemCam for space applications under the extreme thermal environments to be encountered during the Mars Science Laboratory (MSL) mission. Flight-representative fiber optic cables were subjected to extreme temperature thermal cycling of the same diurnal depth (or delta T) as expected in flight, but for three times the expected number of in-flight thermal cycles. The survivability of fiber optic cables was tested for 600 cumulative thermal cycles from -130 to +15 C to cover the winter season, and another 1,410 cumulative cycles from -105 to +40 C to cover the summer season. This test satisfies the required 3 times the design margin that is a total of 2,010 thermal cycles (670 x 3). This development test included functional optical transmission tests during the course of the test. Transmission of the fiber optic cables was performed prior to and after 1,288 thermal cycles and 2,010 thermal cycles. No significant changes in transmission were observed on either of the two representative fiber cables subject through the 3X MSL mission life that is 2,010 thermal cycles.

  11. Integrating Simulation and Data for Materials in Extreme Environments

    Science.gov (United States)

    Germann, Timothy

    2014-03-01

    We are using large-scale molecular dynamics (MD) simulations to study the response of nanocrystalline metals such as tantalum to uniaxial (e.g., shock) compression. With modern petascale-class platforms, we are able to model sample sizes with edge lengths over one micrometer, which match the length and time scales experimentally accessible at Argonne's Advanced Photon Source (APS) and SLAC's Linac Coherent Light Source (LCLS). I will describe our simulation predictions and their recent verification at LCLS, as well as outstanding challenges in modeling the response of materials to extreme mechanical and radiation environments, and our efforts to tackle these as part of the multi-institutional, multi-disciplinary Exascale Co-design Center for Materials in Extreme Environments (ExMatEx). ExMatEx has initiated an early and deep collaboration between domain (computational materials) scientists, applied mathematicians, computer scientists, and hardware architects, in order to establish the relationships between algorithms, software stacks, and architectures needed to enable exascale-ready materials science application codes within the next decade. We anticipate that we will be able to exploit hierarchical, heterogeneous architectures to achieve more realistic large-scale simulations with adaptive physics refinement, and are using tractable application scale-bridging proxy application testbeds to assess new approaches and requirements. The current scale-bridging strategies accumulate (or recompute) a distributed response database from fine-scale calculations, in a top-down rather than bottom-up multiscale approach. I will demonstrate this approach and our initial assessments, using the newly emerging capabilities at new 4th generation synchrotron light sources as an experimental driver.

  12. Effect of cold indoor environment on physical performance of older women living in the community

    DEFF Research Database (Denmark)

    Lindemann, Ulrich; Oksa, Juha; Skelton, Dawn A

    2014-01-01

    BACKGROUND: the effects of cold on older persons' body and mind are not well documented, but with an increased number of older people with decreasing physical performance, these possible effects need to be understood. OBJECTIVE: to investigate the effect of cold indoor environment on physical per...... strength (P = 0.015), but not for hand grip strength. CONCLUSION: in healthy older women a moderately cold indoor environment decreased important physical performance measures necessary for independent living.......BACKGROUND: the effects of cold on older persons' body and mind are not well documented, but with an increased number of older people with decreasing physical performance, these possible effects need to be understood. OBJECTIVE: to investigate the effect of cold indoor environment on physical...

  13. Adaptation of psychrophilic and psychrotrophic sulfate-reducing bacteria to permanently cold marine environments

    DEFF Research Database (Denmark)

    Isaksen, MF; Jørgensen, BB

    1996-01-01

    The potential for sulfate reduction at low temperatures was examined in two different cold marine sediments, Mariager Fjord (Denmark), which is permanently cold (3 to 6 degrees C) but surrounded by seasonally warmer environments, and the Weddell Sea (Antarctica), which is permanently below 0 degr...

  14. Bounding Extreme Spacecraft Charging in the Lunar Environment

    Science.gov (United States)

    Minow, Joseph I.; Parker, Linda N.

    2008-01-01

    Robotic and manned spacecraft from the Apollo era demonstrated that the lunar surface in daylight will charge to positive potentials of a few tens of volts because the photoelectron current dominates the charging process. In contrast, potentials of the lunar surface in darkness which were predicted to be on the order of a hundred volts negative in the Apollo era have been shown more recently to reach values of a few hundred volts negative with extremes on the order of a few kilovolts. The recent measurements of night time lunar surface potentials are based on electron beams in the Lunar Prospector Electron Reflectometer data sets interpreted as evidence for secondary electrons generated on the lunar surface accelerated through a plasma sheath from a negatively charged lunar surface. The spacecraft potential was not evaluated in these observations and therefore represents a lower limit to the magnitude of the lunar negative surface potential. This paper will describe a method for obtaining bounds on the magnitude of lunar surface potentials from spacecraft measurements in low lunar orbit based on estimates of the spacecraft potential. We first use Nascap-2k surface charging analyses to evaluate potentials of spacecraft in low lunar orbit and then include the potential drops between the ambient space environment and the spacecraft to the potential drop between the lunar surface and the ambient space environment to estimate the lunar surface potential from the satellite measurements.

  15. Biofilms and planktonic cells of Deinococcus geothermalis in extreme environments

    Science.gov (United States)

    Panitz, Corinna; Reitz, Guenther; Rabbow, Elke; Rettberg, Petra; Flemming, Hans-Curt; Wingender, Jost; Froesler, Jan

    In addition to the several extreme environments on Earth, Space can be considered as just another exceptional environment with a unique mixture of stress factors comprising UV radiation, vacuum, desiccation, temperature, ionizing radiation and microgravity. Life that processes in these environments can depend on the life forms and their state of living. The question is whether there are different strategies for individual microorganisms compared to communities of the same organisms to cope with the different factors of their surroundings. Comparative studies of the survi-val of these communities called biofilms and planktonic cell samples of Deinococcus geothermalis stand at the focal point of the presented investigations. A biofilm is a structured community of microorganisms that live encapsulated in a matrix of extracellular polymeric substances on a surface. Microorganisms living in a biofilm usually have significantly different properties to cooperate than individually living microorganisms of the same species. An advantage of the biofilm is increased resistance to various chemical and physical effects, while the dense extracellular matrix and the outer layer of the cells protect the interior of the microbial consortium. The space experiment BOSS (Biofilm organisms surfing Space) as part the ESA experimental unit EXPOSE R-2 with a planned launch date in July 2014 will be subsequently mounted on the Russian Svesda module outside the ISS. An international team of scientists coordinated by Dr. P. Rettberg will investigate the hypothesis whether microorganisms organized as biofilm outmatch the same microorganisms exposed individually in the long-term survival of the harsh environmental conditions as they occur in space and on Mars. Another protective function in the samples could be dust par-ticles for instance Mars regolith simulant contained inside the biofilms or mixed with the planktonic cells, as additional shelter especially against the extraterrestrial UV

  16. The SEDIBUD (Sediment Budgets in Cold Environments) Programme: Current activities and future key tasks

    Science.gov (United States)

    Beylich, A. A.; Lamoureux, S. F.; Decaulne, A.

    2012-04-01

    Projected climate change in cold regions is expected to alter melt season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. These effects will undoubtedly change surface environments in cold regions and alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated process monitoring and analysis to understand the sensitivity of the Earth surface environment is acute in cold climate environments. The International Association of Geomorphologists (I.A.G./A.I.G.)SEDIBUD (Sediment Budgets in Cold Environments) Programme was formed in 2005 to address this existing key knowledge gap. SEDIBUD currently has about 400 members worldwide and the Steering Committee of this international programme is composed of ten scientists from eight different countries: Achim A. Beylich (Chair) (Norway), Armelle Decaulne (Secretary) (France), John C. Dixon (USA), Scott F. Lamoureux (Vice-Chair) (Canada), John F. Orwin (Canada), Jan-Christoph Otto (Austria), Irina Overeem (USA), Thorsteinn Saemundsson (Iceland), Jeff Warburton (UK), Zbigniew Zwolinski (Poland). The central research question of this global group of scientists is to: Assess and model the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Initially formed as European Science Foundation (ESF) Network SEDIFLUX (2004-2006), SEDIBUD has further expanded to a global group of researchers with field research sites located in polar and alpine regions in the northern and southern hemisphere. Research carried out at each of the close to 50 defined SEDIBUD key test sites varies by programme, logistics and available resources, but typically represent interdisciplinary collaborations of

  17. Damage Characteristics of Altered and Unaltered Diabases Subjected to Extremely Cold Freeze-Thaw Cycles

    Science.gov (United States)

    Luo, Xuedong; Jiang, Nan; Zuo, Changqun; Dai, Zhenwei; Yan, Suntao

    2014-11-01

    Altered and unaltered diabases are commonly deposited on hydrothermally mineralized slopes. To study their damage characteristics during freeze-thaw cycles, they were sampled from Cihai iron ore mine located in an extremely cold region, Xinjiang, China and examined using acoustic and X-ray diffraction experiments to analyze the differences in their main mineral components and explore their damage characteristics under freeze-thaw conditions. Based on the results of these experiments, their damage and degradation patterns were obtained and the evolution of their physical characteristics including the rock mass loss rate ( L F), rock strength loss rate ( R σ ), P-wave velocity loss rate ( V l), and freeze-thaw coefficient ( K f) was analyzed. In addition, two groups of equations were established to characterize the relationships of these physical and mechanical properties of the rock specimens with the number and temperature of freeze-thaw cycles. The results show that the mineral composition of diabase changes during its alteration, showing increased clay and calcite, and the degradation and evolution patterns of the physical and mechanical parameters ( L F, R σ , V l, and K f) of the altered rocks during freeze-thaw cycles are different from those of diabase, with the altered diabase exhibiting greater damage than the diabase.

  18. Policy Jolts in U.S. Arms Transfers: The Post Cold War Security Environment

    OpenAIRE

    Misheloff, Jane

    1999-01-01

    Policy Jolts in U.S. Arms Transfers: The Post-Cold War Security Environment Jane Misheloff (ABSTRACT) This research addresses the subject of conventional arms transfers in the Post Cold War Era. ("Conventional arms" herein are defined as high cost, state-of-the-art weapons systems in aerospace, land vehicles, missiles and naval vessels. ") The rapid and startling changes in the international political environment that took place in the late 1980's forced the U.S. and her Wes...

  19. Storms or cold fronts: what is really responsible for the extreme waves regime in the Colombian Caribbean coastal region?

    Science.gov (United States)

    Otero, L. J.; Ortiz-Royero, J. C.; Ruiz-Merchan, J. K.; Higgins, A. E.; Henriquez, S. A.

    2016-02-01

    The aim of this study is to determine the contribution and importance of cold fronts and storms to extreme waves in different areas of the Colombian Caribbean in an attempt to determine the extent of the threat posed by the flood processes to which these coastal populations are exposed. Furthermore, the study wishes to establish the actions to which coastal engineering constructions should be subject. In the calculation of maritime constructions, the most important parameter is the height of the wave. For this reason, it is necessary to establish the design wave height to which a coastal engineering structure should be resistant. This wave height varies according to the return period considered. The significant height values for the areas focused on in the study were calculated in accordance with Gumbel's extreme value methodology. The methodology was evaluated using data from the reanalysis of the spectral National Oceanic and Atmospheric Administration (NOAA) WAVEWATCH III® (WW3) model for 15 points along the 1600 km of the Colombian Caribbean coastline (continental and insular) between the years 1979 and 2009. The results demonstrated that the extreme waves caused by tropical cyclones and those caused by cold fronts have different effects along the Colombian Caribbean coast. Storms and hurricanes are of greater importance in the Guajira Peninsula (Alta Guajira). In the central area (consisting of Baja Guajira, and the cities of Santa Marta, Barranquilla, and Cartagena), the strong impact of cold fronts on extreme waves is evident. However, in the southern region of the Colombian Caribbean coast (ranging from the Gulf of Morrosquillo to the Gulf of Urabá), the extreme values of wave heights are lower than in the previously mentioned regions, despite being dominated mainly by the passage of cold fronts. Extreme waves in the San Andrés and Providencia insular region present a different dynamic from that in the continental area due to their geographic location

  20. Characterizing the Effects of Extreme Cold Using Real-time Syndromic Surveillance, Ontario, Canada, 2010-2016.

    Science.gov (United States)

    VanStone, Nancy; van Dijk, Adam; Chisamore, Timothy; Mosley, Brian; Hall, Geoffrey; Belanger, Paul; Michael Moore, Kieran

    Morbidity and mortality from exposure to extreme cold highlight the need for meaningful temperature thresholds to activate public health alerts. We analyzed emergency department (ED) records for cold temperature-related visits collected by the Acute Care Enhanced Surveillance system-a syndromic surveillance system that captures data on ED visits from hospitals in Ontario-for geographic trends related to ambient winter temperature. We used 3 Early Aberration Reporting System algorithms of increasing sensitivity-C1, C2, and C3-to determine the temperature at which anomalous counts of cold temperature-related ED visits occurred in northern and southern Ontario from 2010 to 2016. The C2 algorithm was the most sensitive detection method. Results showed lower threshold temperatures for Acute Care Enhanced Surveillance alerts in northern Ontario than in southern Ontario. Public health alerts for cold temperature warnings that are based on cold temperature-related ED visit counts and ambient temperature may improve the accuracy of public warnings about cold temperature risks.

  1. Biodegradation of Aromatic Hydrocarbons in an Extremely Acidic Environment

    Science.gov (United States)

    Stapleton, Raymond D.; Savage, Dwayne C.; Sayler, Gary S.; Stacey, Gary

    1998-01-01

    The potential for biodegradation of aromatic hydrocarbons was evaluated in soil samples recovered along gradients of both contaminant levels and pH values existing downstream of a long-term coal pile storage basin. pH values for areas greatly impacted by runoff from the storage basin were 2.0. Even at such a reduced pH, the indigenous microbial community was metabolically active, showing the ability to oxidize more than 40% of the parent hydrocarbons, naphthalene and toluene, to carbon dioxide and water. Treatment of the soil samples with cycloheximide inhibited mineralization of the aromatic substrates. DNA hybridization analysis indicated that whole-community nucleic acids recovered from these samples did not hybridize with genes, such as nahA, nahG, nahH, todC1C2, and tomA, that encode common enzymes from neutrophilic bacteria. Since these data suggested that the degradation of aromatic compounds may involve a microbial consortium instead of individual acidophilic bacteria, experiments using microorganisms isolated from these samples were initiated. While no defined mixed cultures were able to evolve 14CO2 from labeled substrates in these mineralization experiments, an undefined mixed culture including a fungus, a yeast, and several bacteria successfully metabolized approximately 27% of supplied naphthalene after 1 week. This study shows that biodegradation of aromatic hydrocarbons can occur in environments with extremely low pH values. PMID:9797263

  2. IR DirectFET Extreme Environments Evaluation Final Report

    Science.gov (United States)

    Burmeister, Martin; Mottiwala, Amin

    2008-01-01

    In 2007, International Rectifier (IR) introduced a new version of its DirectFET metal oxide semiconductor field effect transistor (MOSFET) packaging. The new version (referred to as 'Version 2') enhances device moisture resistance, makes surface mount (SMT) assembly of these devices to printed wiring boards (PWBs) more repeatable, and subsequent assembly inspection simpler. In the present study, the National Aeronautics Space Administration (NASA) Jet Propulsion Laboratory (JPL), in collaboration with Stellar Microelectronics (Stellar), continued an evaluation of the DirectFET that they started together in 2006. The present study focused on comparing the two versions of the DirectFET and examining the suitability of the DirectFET devices for space applications. This study evaluated both versions of two DirectFET packaged devices that had both been shown in the 2006 study to have the best electrical and thermal properties: the IRF6635 and IRF6644. The present study evaluated (1) the relative electrical and thermal performance of both versions of each device, (2) the performance through high reliability testing, and (3) the performance of these devices in combination with a range of alternate solder alloys in the extreme thermal environments of deep space....

  3. Annual fish: developmental adaptations for an extreme environment.

    Science.gov (United States)

    Berois, Nibia; Arezo, María J; Papa, Nicolás G; Clivio, Graciela A

    2012-01-01

    Annual fish are freshwater teleosts found in South America and Africa that are exposed to an extremely variable environment. They develop and reproduce in seasonal ponds that dry during the summer eliminating the entire adult population. Remarkably, desiccation-resistant embryos survive in these dry ponds that hatch during the next rainy season when the ponds are recreated. Among vertebrates, they represent one of the most remarkable extremophiles. They share several features with other fish models; however, they exhibit unique traits related to their peculiar life cycle. Epiboly is temporally and spatially uncoupled from organogenesis, and the embryos can undergo reversible developmental arrests (diapauses). These attributes make them a useful model to study diverse topics in developmental biology using a comparative and evolutionary approach. In this article, different aspects related to annual fish biology, taxonomy and phylogenetic considerations, reproductive strategy, and developmental characteristics with special focus on arrests, are summarized. The current challenge is to document and determine the factors that generate such high diversity and unique adaptations of annual fish. To understand this complexity, interdisciplinary approaches are being employed taking into consideration evolutionary biology, ethology, reproductive strategies, regulation of developmental mechanisms, and senescence.

  4. Reconfiguration of Analog Electronics for Extreme Environments: Problem or Solution?

    Science.gov (United States)

    Stoica, Adrian; Zebulum, Ricardo; Keymeulen, Didier; Guo, Xin

    2005-01-01

    This paper argues in favor of adaptive reconfiguration as a technique to expand the operational envelope of analog electronics for extreme environments (EE). In addition to hardening-by-process and hardening-by-design, "hardening-by-reconfiguration", when applicable, could be used to mitigate drifts, degradation, or damage on electronic devices (chips) in EE, by using re-configurable devices and an adaptive self-reconfiguration of their circuit topology. Conventional circuit design exploits device characteristics within a certain temperature/radiation range; when that is exceeded, the circuit function degrades. On a reconfigurable device, although component parameters change in EE, as long as devices still operate, albeit degraded, a new circuit design, suitable for new parameter values, may be mapped into the reconfigurable structure to recover the initial circuit function. Partly degraded resources are still used, while completely damaged resources are bypassed. Designs suitable for various environmental conditions can be determined prior to operation or can be determined in-situ, by adaptive reconfiguration algorithms running on built-in digital controllers. Laboratory demonstrations of this technique were performed by JPL in several independent experiments in which bulk CMOS reconfigurable devices were exposed to, and degraded by, low temperatures (approx. 196 C), high temperatures (approx.300 C) or radiation (300kRad TID), and then recovered by adaptive reconfiguration using evolutionary search algorithms. Taking this technology from Technology Readiness Level (TRL) 3 to TRL 5 is the target of a current NASA project.

  5. Extreme Environment Silicon Carbide Hybrid Temperature & Pressure Optical Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Nabeel Riza

    2010-09-01

    This final report contains the main results from a 3-year program to further investigate the merits of SiC-based hybrid sensor designs for extreme environment measurements in gas turbines. The study is divided in three parts. Part 1 studies the material properties of SiC such as temporal response, refractive index change with temperature, and material thermal response reversibility. Sensor data from a combustion rig-test using this SiC sensor technology is analyzed and a robust distributed sensor network design is proposed. Part 2 of the study focuses on introducing redundancy in the sensor signal processing to provide improved temperature measurement robustness. In this regard, two distinct measurement methods emerge. A first method uses laser wavelength sensitivity of the SiC refractive index behavior and a second method that engages the Black-Body (BB) radiation of the SiC package. Part 3 of the program investigates a new way to measure pressure via a distance measurement technique that applies to hot objects including corrosive fluids.

  6. Phospholipid and Respiratory Quinone Analyses From Extreme Environments

    Science.gov (United States)

    Pfiffner, S. M.

    2008-12-01

    Extreme environments on Earth have been chosen as surrogate sites to test methods and strategies for the deployment of space craft in the search for extraterrestrial life. Surrogate sites for many of the NASA astrobiology institutes include the South African gold mines, Canadian subpermafrost, Atacama Desert, and acid rock drainage. Soils, sediments, rock cores, fracture waters, biofilms, and service and drill waters represent the types of samples collected from these sites. These samples were analyzed by gas chromatography mass spectrometry for phospholipid fatty acid methyl esters and by high performance liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry for respiratory quinones. Phospholipid analyses provided estimates of biomass, community composition, and compositional changes related to nutritional limitations or exposure to toxic conditions. Similar to phospholipid analyses, respiratory quinone analyses afforded identification of certain types of microorganisms in the community based on respiration and offered clues to in situ redox conditions. Depending on the number of samples analyzed, selected multivariate statistical methods were applied to relate membrane lipid results with site biogeochemical parameters. Successful detection of life signatures and refinement of methodologies at surrogate sites on Earth will be critical for the recognition of extraterrestrial life. At this time, membrane lipid analyses provide useful information not easily obtained by other molecular techniques.

  7. Qualification of UHF Antenna for Extreme Martian Thermal Environments

    Science.gov (United States)

    Ramesham, Rajeshuni; Amaro, Luis R.; Brown, Paula R.; Usiskin, Robert

    2013-01-01

    The purpose of this development was to validate the use of the external Rover Ultra High Frequency (RUHF) antenna for space under extreme thermal environments to be encountered during the surface operations of the Mars Science Laboratory (MSL) mission. The antenna must survive all ground operations plus the nominal 670 Martian sol mission that includes summer and winter seasons of the Mars thermal environment.The qualification effort was to verify that the RUHF antenna design and its bonding and packaging processes are adequate to survive the harsh environmental conditions. The RUHF is a quadrifilar helix antenna mounted on the MSL Curiosity rover deck. The main components of the RUHF antenna are the helix structure, feed cables, and hybrid coupler, and the high-power termination load. In the case of MSL rover externally mounted hardware, not only are the expected thermal cycle depths severe, but there are temperature offsets between the Mars summer and winter seasons. The total number of temperature cycles needed to be split into two regimes of summer cycles and winter cycles. The qualification test was designed to demonstrate a survival life of three times more than all expected ground testing, plus a nominal 670 Martian sol missions. Baseline RF tests and a visual inspection were performed prior to the start of the qualification test. Functional RF tests were performed intermittently during chamber breaks over the course of the qualification test. For the RF return loss measurements, the antenna was tested in a controlled environment outside the thermal chamber with a vector network analyzer that was calibrated over the antenna s operational frequency range. A total of 2,010 thermal cycles were performed. Visual inspection showed a dulling of the solder material. This change will not affect the performance of the antenna. No other changes were observed. RF tests were performed on the RUHF helix antenna, hybrid, and load after the 2,010 qualification cycles test

  8. The effect of extreme cold temperatures on the risk of death in the two major Portuguese cities

    Science.gov (United States)

    Antunes, Liliana; Silva, Susana Pereira; Marques, Jorge; Nunes, Baltazar; Antunes, Sílvia

    2016-06-01

    It is well known that meteorological conditions influence the comfort and human health. Southern European countries, including Portugal, show the highest mortality rates during winter, but the effects of extreme cold temperatures in Portugal have never been estimated. The objective of this study was the estimation of the effect of extreme cold temperatures on the risk of death in Lisbon and Oporto, aiming the production of scientific evidence for the development of a real-time health warning system. Poisson regression models combined with distributed lag non-linear models were applied to assess the exposure-response relation and lag patterns of the association between minimum temperature and all-causes mortality and between minimum temperature and circulatory and respiratory system diseases mortality from 1992 to 2012, stratified by age, for the period from November to March. The analysis was adjusted for over dispersion and population size, for the confounding effect of influenza epidemics and controlled for long-term trend, seasonality and day of the week. Results showed that the effect of cold temperatures in mortality was not immediate, presenting a 1-2-day delay, reaching maximum increased risk of death after 6-7 days and lasting up to 20-28 days. The overall effect was generally higher and more persistent in Lisbon than in Oporto, particularly for circulatory and respiratory mortality and for the elderly. Exposure to cold temperatures is an important public health problem for a relevant part of the Portuguese population, in particular in Lisbon.

  9. The effect of extreme cold temperatures on the risk of death in the two major Portuguese cities

    Science.gov (United States)

    Antunes, Liliana; Silva, Susana Pereira; Marques, Jorge; Nunes, Baltazar; Antunes, Sílvia

    2017-01-01

    It is well known that meteorological conditions influence the comfort and human health. Southern European countries, including Portugal, show the highest mortality rates during winter, but the effects of extreme cold temperatures in Portugal have never been estimated. The objective of this study was the estimation of the effect of extreme cold temperatures on the risk of death in Lisbon and Oporto, aiming the production of scientific evidence for the development of a real-time health warning system. Poisson regression models combined with distributed lag non-linear models were applied to assess the exposure-response relation and lag patterns of the association between minimum temperature and all-causes mortality and between minimum temperature and circulatory and respiratory system diseases mortality from 1992 to 2012, stratified by age, for the period from November to March. The analysis was adjusted for over dispersion and population size, for the confounding effect of influenza epidemics and controlled for long-term trend, seasonality and day of the week. Results showed that the effect of cold temperatures in mortality was not immediate, presenting a 1-2-day delay, reaching maximum increased risk of death after 6-7 days and lasting up to 20-28 days. The overall effect was generally higher and more persistent in Lisbon than in Oporto, particularly for circulatory and respiratory mortality and for the elderly. Exposure to cold temperatures is an important public health problem for a relevant part of the Portuguese population, in particular in Lisbon.

  10. Cold work effects on sulfide stress cracking of pipeline steel exposed to sour environments

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.; Shaw, W.J.D. (Calgary Univ., AB (Canada). Dept. of Mechanical Engineering)

    1993-01-01

    Cold work effects on sulfide stress cracking of a pipeline steel were examined for exposure to a sour gas environment. Cold worked steel was found to be sensitive to hydrogen embrittlement. The fracture toughness decreases with increasing cold work. Sufficiently low values of fracture toughness may be achieved to promote plane strain fracture even in relatively thin laboratory specimens after a steady state level of hydrogen has occurred in the material. Sulfide stress cracking failure of steel with low amounts of cold work (<30%) is by transgranular cleavage fracture, while heavily cold worked steel shows secondary cracks and microvoid coalescence. The results indicate that sulfide stress cracking of the steel is a mixture of anodic stress corrosion cracking (SCC) and hydrogen embrittlement. The anodic SCC mechanism is mainly promoted by carbon dioxide and a high level of chloride. (author).

  11. NEEMO - NASA's Extreme Environment Mission Operations: On to a NEO

    Science.gov (United States)

    Bell, M. S.; Baskin, P. J.; Todd, W. L.

    2011-01-01

    During NEEMO missions, a crew of six Aquanauts lives aboard the National Oceanic and Atmospheric Administration (NOAA) Aquarius Underwater Laboratory the world's only undersea laboratory located 5.6 km off shore from Key Largo, Florida. The Aquarius habitat is anchored 62 feet deep on Conch Reef which is a research only zone for coral reef monitoring in the Florida Keys National Marine Sanctuary. The crew lives in saturation for a week to ten days and conducts a variety of undersea EVAs (Extra Vehicular Activities) to test a suite of long-duration spaceflight Engineering, Biomedical, and Geoscience objectives. The crew also tests concepts for future lunar exploration using advanced navigation and communication equipment in support of the Constellation Program planetary exploration analog studies. The Astromaterials Research and Exploration Science (ARES) Directorate and Behavioral Health and Performance (BHP) at NASA/Johnson Space Center (JSC), Houston, Texas support this effort to produce a high-fidelity test-bed for studies of human planetary exploration in extreme environments as well as to develop and test the synergy between human and robotic curation protocols including sample collection, documentation, and sample handling. The geoscience objectives for NEEMO missions reflect the requirements for Lunar Surface Science outlined by the LEAG (Lunar Exploration Analysis Group) and CAPTEM (Curation and Analysis Planning Team for Extraterrestrial Materials) white paper [1]. The BHP objectives are to investigate best meas-ures and tools for assessing decrements in cogni-tive function due to fatigue, test the feasibility study examined how teams perform and interact across two levels, use NEEMO as a testbed for the development, deployment, and evaluation of a scheduling and planning tool. A suite of Space Life Sciences studies are accomplished as well, ranging from behavioral health and performance to immunology, nutrition, and EVA suit design results of which will

  12. Study on the Improvement Strategies of Physical Environment for Square in Severe Cold Regions’ Rural Areas

    Institute of Scientific and Technical Information of China (English)

    XinYu Zhang; Hong Jin

    2014-01-01

    To improve the comfortable physical environment for square in severe cold regions’ rural areas. This paper applies the methods of questionnaires, field testing and statistical analysis to compare and analyze two different square cases of Qingyunpu in Liaoning Province, and conclude the main factors which affect the physical environmental comfort. The improvement strategies for physical environment of rural square are put forward from the aspects of site selection, road position, orientation, landscape design, and ground pavement material selection, aiming to provide the design basis for the physical environment of square in severe cold regions’ rural areas.

  13. Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic

    NARCIS (Netherlands)

    Mienis, F.; Duineveld, G.C.A.; Davis, A.J.; Lavaleye, M.M.S.; Rosso, S.W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M.J.N.; de Haas, H.; Brooke, S.; van Weering, T.C.E.

    2014-01-01

    The Cape Lookout cold-water coral area off thecoast of North Carolina forms the shallowest and northernmostcold-water coral mound area on the Blake Plateau inthe NW Atlantic. Cold-water coral habitats near Cape Lookoutare occasionally bathed in the Gulf Stream, which is characterisedby oligotrophic

  14. Survival strategies of freshwater insects in cold environments

    Directory of Open Access Journals (Sweden)

    Valeria LENCIONI

    2004-09-01

    Full Text Available At high latitudes and altitudes, ice formation is a major variable affecting survival of freshwater fauna and hence the abundance and composition of invertebrate communities. Freezing, but also desiccation and anoxia, are lethal threats to all life stages of aquatic insects, from the eggs to the adults. During cold periods, the aquatic stages commonly remain in or move to a portion of the water body that will not freeze or dry (e.g., deep waters of lakes, springs and hyporheic zone where they can remain active. Less frequently they migrate to habitats that will freeze at the onset of winter. Insects have developed a complex of strategies to survive at their physiological temperature minimum, comprising (a morphological (melanism, reduction in size, hairiness/pubescence, brachyptery and aptery, (b behavioural (basking in the sun, changes in feeding and mating habit, parthenogenesis, polyploidy, ovoviviparity, habitat selection and cocoon building, (c ecological (extension of development to several years by quiescence or diapause and reduction of the number of generations per year, (d physiological and biochemical (freezing tolerance and freezing avoidance adaptations. Most species develop a combination of these survival strategies that can be different in the aquatic and terrestrial phase. Freezing avoidance and freezing tolerance may be accompanied by diapause. Both cold hardiness and diapause manifest during the unfavourable season and: (i involve storage of food resources (commonly glycogen and lipids; (ii are under hormonal control (ecdysone and juvenile hormone; (iii involve a depression or suppression of the oxidative metabolism with mitochondrial degradation. However, where the growing season is reduced to a few weeks, insects may develop cold hardiness without entering diapause, maintaining in the haemolymph a high concentration of Thermal Hysteris Proteins (THPs for the entire year and a slow but continuous growth. A synthesis of

  15. Cold-region environments along the China-Russia Crude Oil Pipeline and their management

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The cold-region eco-environments along the China-Russia Crude Oil Pipeline (CRCOP) in northern Northeast China are in disequilibrium due to the combined influences of pronounced climate warming and intensive anthropogenic activities.This is evidenced by the sharp areal reduction and northward shifting of the boreal forests,shrinking of wetlands,enhancing of soil erosion,accelerating degradation of permafrost and deteriorating of cold-region eco-environments.The degradation of permafrost plays an important role as an internal drive in the eco-environmental changes.Many components of the cold-region eco-environments,including frozen ground,forests,wetlands and peatlands,forest fires and "heating island effect" of rapid urbanization,are interdependent,interactive,and integrated in the boreal ecosystems.The construction and long-term operation of the CRCOP system will inevitably disturb the cold-region environments along the pipeline.Therefore,a mandatory and carefully-elaborated environ-mental impact statement is indispensable for the proper mitigation of the ensued adverse impacts.Proper management,effective protection and practical rehabilitation of the damaged cold-region environments are a daunting,costly and long-term commitment.The recommended measures for protection and restoration of permafrost eco-environments along the pipeline route include adequate investigation,assessment and monitoring of permafrost and cold-region environments,compliance of pipeline construction and operation codes for environmental management,proper and timely re-vegetation,returning the cultivated lands to forests and grasslands,and effective mitigation of forest fire hazards.

  16. White fingers, cold environment, and vibration--exposure among Swedish construction workers.

    Science.gov (United States)

    Burström, Lage; Järvholm, Bengt; Nilsson, Tohr; Wahlström, Jens

    2010-11-01

    The aim of this study was to examine the association between white fingers, cold environment, and exposure to hand-arm vibration (HAV). The hypothesis was that working in cold climate increases the risk of white fingers. The occurrence of white fingers was investigated as a cross-sectional study in a cohort of Swedish male construction workers (N=134 757). Exposure to HAV was based on a job-exposure matrix. Living in the north or south of Sweden was, in a subgroup of the cohort, used as an indicator of the exposure to cold environment (ie, living in the north meant a higher exposure to cold climate). The analyses were adjusted for age and use of nicotine products (smoking and snuff). HAV-exposed workers living in a colder climate had a higher risk for white fingers than those living in a warmer climate [odds ratio (OR) 1.71, 95% confidence interval (95% CI) 1.42-2.06]. As expected, we found that HAV-exposed workers had an increased risk compared to controls (OR 2.02, 95% CI 1.75-2.34). The risk for white fingers increased with increased level of exposure to HAV and also age. Cold environment increases the risk for white fingers in workers occupationally exposed to HAV. The results underscore the need to keep exposure to HAV at workplaces as low as possible especially in cold climate.

  17. Who is more vulnerable to death from extremely cold temperatures? A case-only approach in Hong Kong with a temperate climate

    Science.gov (United States)

    Qiu, Hong; Tian, Linwei; Ho, Kin-fai; Yu, Ignatius T. S.; Thach, Thuan-Quoc; Wong, Chit-Ming

    2016-05-01

    The short-term effects of ambient cold temperature on mortality have been well documented in the literature worldwide. However, less is known about which subpopulations are more vulnerable to death related to extreme cold. We aimed to examine the personal characteristics and underlying causes of death that modified the association between extreme cold and mortality in a case-only approach. Individual information of 197,680 deaths of natural causes, daily temperature, and air pollution concentrations in cool season (November-April) during 2002-2011 in Hong Kong were collected. Extreme cold was defined as those days with preceding week with a daily maximum temperature at or less than the 1st percentile of its distribution. Logistic regression models were used to estimate the effects of modification, further controlling for age, seasonal pattern, and air pollution. Sensitivity analyses were conducted by using the 5th percentile as cutoff point to define the extreme cold. Subjects with age of 85 and older were more vulnerable to extreme cold, with an odds ratio (OR) of 1.33 (95 % confidence interval (CI), 1.22-1.45). The greater risk of extreme cold-related mortality was observed for total cardiorespiratory diseases and several specific causes including hypertensive diseases, stroke, congestive heart failure, chronic obstructive pulmonary disease (COPD), and pneumonia. Hypertensive diseases exhibited the greatest vulnerability to extreme cold exposure, with an OR of 1.37 (95 % CI, 1.13-1.65). Sensitivity analyses showed the robustness of these effect modifications. This evidence on which subpopulations are vulnerable to the adverse effects of extreme cold is important to inform public health measures to minimize those effects.

  18. Significance of Environmental Variables on Flight Electronics and Design Concerns for Extreme Environments

    Science.gov (United States)

    Hazeli, K.; Kingstedt, O. T.

    2017-05-01

    It is critical to investigate the performance of electronic systems and their components under the environments experienced during proposed missions to improve spacecraft and robotic vehicle functionality and performance in extreme environments.

  19. A Fault-Oblivious Extreme-Scale Execution Environment (FOX)

    Energy Technology Data Exchange (ETDEWEB)

    Van Hensbergen, Eric; Speight, William; Xenidis, Jimi

    2013-03-15

    IBM Research’s contribution to the Fault Oblivious Extreme-scale Execution Environment (FOX) revolved around three core research deliverables: • collaboration with Boston University around the Kittyhawk cloud infrastructure which both enabled a development and deployment platform for the project team and provided a fault-injection testbed to evaluate prototypes • operating systems research focused on exploring role-based operating system technologies through collaboration with Sandia National Labs on the NIX research operating system and collaboration with the broader IBM Research community around a hybrid operating system model which became known as FusedOS • IBM Research also participated in an advisory capacity with the Boston University SESA project, the core of which was derived from the K42 operating system research project funded in part by DARPA’s HPCS program. Both of these contributions were built on a foundation of previous operating systems research funding by the Department of Energy’s FastOS Program. Through the course of the X-stack funding we were able to develop prototypes, deploy them on production clusters at scale, and make them available to other researchers. As newer hardware, in the form of BlueGene/Q, came online, we were able to port the prototypes to the new hardware and release the source code for the resulting prototypes as open source to the community. In addition to the open source coded for the Kittyhawk and NIX prototypes, we were able to bring the BlueGene/Q Linux patches up to a more recent kernel and contribute them for inclusion by the broader Linux community. The lasting impact of the IBM Research work on FOX can be seen in its effect on the shift of IBM’s approach to HPC operating systems from Linux and Compute Node Kernels to role-based approaches as prototyped by the NIX and FusedOS work. This impact can be seen beyond IBM in follow-on ideas being incorporated into the proposals for the Exasacale Operating

  20. Evidence of Molecular Adaptation to Extreme Environments and Applicability to Space Environments

    Directory of Open Access Journals (Sweden)

    Filipović, M. D.

    2008-06-01

    Full Text Available This is initial investigation of gene signatures responsible for adapting microscopic life to the extreme Earth environments. We present preliminary results on identification of the clusters of orthologous groups (COGs common to several hyperthermophiles and exclusion of those common to a mesophile (non-hyperthermophile: {it Escherichia coli (E. coli K12}, will yield a group of proteins possibly involved in adaptation to life under extreme temperatures. Comparative genome analyses represent a powerful tool in discovery of novel genes responsible for adaptation to specific extreme environments. Methanogens stand out as the only group of organisms that have species capable of growth at 0D C ({it Metarhizium frigidum (M.~frigidum} and {it Methanococcoides burtonii (M.~burtonii} and 110D C ({it Methanopyrus kandleri (M.~kandleri}. Although not all the components of heat adaptation can be attributed to novel genes, the {it chaperones} known as heat shock proteins stabilize the enzymes under elevated temperature. However, highly conserved {it chaperons} found in bacteria and eukaryots are not present in hyperthermophilic Archea, rather, they have a unique {it chaperone TF55}. Our aim was to use software which we specifically developed for extremophile genome comparative analyses in order to search for additional novel genes involved in hyperthermophile adaptation. The followinghyperthermophile genomes incorporated in this software were used forthese studies: {it Methanocaldococcus jannaschii (M.~jannaschii, M.~kandleri, Archaeoglobus fulgidus (A.~fulgidus} and threespecies of {it Pyrococcus}. Common genes were annotated and groupedaccording to their roles in cellular processes where such informationwas available and proteins not previously implicated in theheat-adaptation of hyperthermophiles were identified. Additionalexperimental data are needed in order to learn more about theseproteins. To address non-gene based components of thermaladaptation

  1. Evidence of molecular adaptation to extreme environments and applicability to space environments

    Directory of Open Access Journals (Sweden)

    Filipović M.

    2008-01-01

    Full Text Available This is initial investigation of gene signatures responsible for adapting microscopic life to the extreme Earth environments. We present preliminary results on identification of the clusters of orthologous groups (COGs common to several hyperthermophiles and exclusion of those common to a mesophile (non-hyperthermophile: Escherichia coli (E. coli K12, will yield a group of proteins possibly involved in adaptation to life under extreme temperatures. Comparative genome analyses represent a powerful tool in discovery of novel genes responsible for adaptation to specific extreme environments. Methanogens stand out as the only group of organisms that have species capable of growth at 0ºC (Metarhizium frigidum (M. frigidum and Methanococcoides burtonii (M. burtonii and 110ºC (Methanopyrus kandleri (M. kandleri. Although not all the components of heat adaptation can be attributed to novel genes, the chaperones known as heat shock proteins stabilize the enzymes under elevated temperature. However, highly conserved chaperons found in bacteria and eukaryots are not present in hyperthermophilic Archea, rather, they have a unique chaperone TF55. Our aim was to use software which we specifically developed for extremophile genome comparative analyses in order to search for additional novel genes involved in hyperthermophile adaptation. The following hyperthermophile genomes incorporated in this software were used for these studies: Methanocaldococcus jannaschii (M. jannaschii, M. kandleri, Archaeoglobus fulgidus (A. fulgidus and three species of Pyrococcus. Common genes were annotated and grouped according to their roles in cellular processes where such information was available and proteins not previously implicated in the heat-adaptation of hyperthermophiles were identified. Additional experimental data are needed in order to learn more about these proteins. To address non-gene based components of thermal adaptation, all sequenced extremophiles were

  2. Microbial ecology of extreme environments: Antarctic yeasts and growth in substrate-limited habitats

    Science.gov (United States)

    Vishniac, H. S.

    1985-01-01

    The high, dry valleys of the Ross Desert of Antarctic, characterized by extremely low temperatures, aridity and a depauperate biota, are used as an analog of the postulated extreme climates of other planetary bodies of the Solar System to test the hypothesis that if life could be supported by Ross, it might be possible where similar conditions prevail. The previously considered sterility of the Ross Desert soil ecosystem has yielded up an indigenous yeast, Cryptoccus vishniacci, which is able to resist the extremes of cold, wet and dry freezing, and long arid periods, while making minimal nutritional demands on the soil.

  3. Molecular environments of 51 Planck cold clumps in Orion complex

    CERN Document Server

    Liu, Tie; Zhang, Huawei

    2012-01-01

    A mapping survey towards 51 Planck cold clumps projected on Orion complex was performed with J=1-0 lines of $^{12}$CO and $^{13}$CO at the 13.7 m telescope of Purple Mountain Observatory. The mean column densities of the Planck gas clumps range from 0.5 to 9.5$\\times10^{21}$ cm$^{-2}$, with an average value of (2.9$\\pm$1.9)$\\times10^{21}$ cm$^{-2}$. While the mean excitation temperatures of these clumps range from 7.4 to 21.1 K, with an average value of 12.1$\\pm$3.0 K. The averaged three-dimensional velocity dispersion $\\sigma_{3D}$ in these molecular clumps is 0.66$\\pm$0.24 km s$^{-1}$. Most of the clumps have $\\sigma_{NT}$ larger than or comparable with $\\sigma_{Therm}$. The H$_{2}$ column density of the molecular clumps calculated from molecular lines correlates with the aperture flux at 857 GHz of the dust emission. Through analyzing the distributions of the physical parameters, we suggest turbulent flows can shape the clump structure and dominate their density distribution in large scale, but not affect ...

  4. Mechanisms of interfacial reactivity in near surface and extreme environments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying [Univ. of California, San Diego, CA (United States); Balaska, Eric [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weare, John [Univ. of California, San Diego, CA (United States); Fulton, John [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bogatko, Stuart [Univ. of California, San Diego, CA (United States); Balasubramanian, Mahalingam [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cauet, Emilie [Univ. of California, San Diego, CA (United States); Kerisit, Sebastien [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Felmy, Andrew [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schenter, Gregory [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weare, Jonathan [U of Chicago

    2017-01-09

    +, Co2+, Mn2+, Fe3+, Cr3+. Calculations on these systems are demanding because of their open electronic shells, and high ionic charge. Principal Investigator: Professor John Weare (University of California, San Diego) The prediction of the interactions of geochemical fluids with minerals, nanoparticles, and colloids under extreme near surface conditions of temperature (T) and pressure (P) is a grand challenge research need in geosciences (U.S. DOE 2007, Basic Research Needs for Geosciences: Facilitating the 21st Energy Systems.). To evaluate the impact of these processes on energy production and management strategies it is necessary to have a high level of understanding of the interaction between complex natural fluids and mineral formations. This program emphasizes 1st principle parameter free simulations of complex chemical processes in solutions, in the mineral phase, and in the interfaces between these phases The development of new computational tools (with emphasis on oxide materials and reaction dynamics) tailored to treat wide range of conditions and time scales experienced in such geochemical applications is has been developed. Because of the sensitivity of the interaction in these systems to electronic structure and local bonding environments, and of the need to describe bond breaking/formation, our simulations are based on interactions calculated at the electronic structure level (ab-initio molecular dynamics, AIMD). The progress in the computational aspects of program may be summarized in terms of the following themes (objectives); Development of efficient parameter free dynamical simulation technology based on 1st principles force and energy calculations especially adapted for geochemical applications (e.g., mineral, interfaces and aqueous solutions) (continuing program); Calculation of the dynamics of water structure of in the surface-water interface of transition metal oxides and oxihydroxides; and

  5. Tyrosine Supplementation Attenuates Cognitive and Psychomotor Deficits in Cold Environments

    Science.gov (United States)

    2009-01-01

    caused by low body temperature. J Appl Physiol 55: 27-31, 1983. 11. Fine BJ, Kobrick JL and Lieberman HR. Effects of caffeine or diphenhydramine on...Hale B and Lieberman HR. Caffeine effects on marksmanship during high- stress military training with 72 hour sleep deprivation. Aviat Space Environ Med...D, Hyde, DE, Schrot, J, and Thomas, JR. Thermal protection and diver performance in special operations forces combat swimmers (resting diver phase

  6. Thermal discomfort with cold extremities in relation to age, gender, and body mass index in a random sample of a Swiss urban population

    Directory of Open Access Journals (Sweden)

    Orgül Selim

    2010-06-01

    Full Text Available Abstract Background The aim of this epidemiological study was to investigate the relationship of thermal discomfort with cold extremities (TDCE to age, gender, and body mass index (BMI in a Swiss urban population. Methods In a random population sample of Basel city, 2,800 subjects aged 20-40 years were asked to complete a questionnaire evaluating the extent of cold extremities. Values of cold extremities were based on questionnaire-derived scores. The correlation of age, gender, and BMI to TDCE was analyzed using multiple regression analysis. Results A total of 1,001 women (72.3% response rate and 809 men (60% response rate returned a completed questionnaire. Statistical analyses revealed the following findings: Younger subjects suffered more intensely from cold extremities than the elderly, and women suffered more than men (particularly younger women. Slimmer subjects suffered significantly more often from cold extremities than subjects with higher BMIs. Conclusions Thermal discomfort with cold extremities (a relevant symptom of primary vascular dysregulation occurs at highest intensity in younger, slimmer women and at lowest intensity in elderly, stouter men.

  7. Effect of cold water and inverse lighting on growth performance of broiler chickens under extreme heat stress.

    Science.gov (United States)

    Park, Sang-oh; Park, Byung-sung; Hwangbo, Jong

    2015-07-01

    The present study was carried out to investigate the effect of provision of extreme heat stress diet (EHD), inverse lighting, cold water on growth performance of broiler chickens exposed to extreme heat stress. The chickens were divided into four treatment groups, (T1, T2, T3, T4) as given below: Ti (EHD 1, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T2 (EHD 2, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T3 (EHD 1, 09:00-18:00 dark, 18:00-09:00 light, cool water 141C); T4 (EHD 2, 09:00-18:00 dark, 18:00-09:00 light, cool water 14 degrees C. EHD 1 contained soybean oil, molasses, methionine and lysine; EHD 2 contained the same ingredients as EHD 1 with addition of vitamin C. Groups T1 and T2 were given cooler water than the othertwo groups, and displayed higher body weight increase and diet intake as compared to T3 and T4 (pstress diet, inverse lighting (10:00-19:00 dark, 19:00-10:00 light) with cold water at 9 degrees C under extreme heat stress could enhance growth performance of broiler chickens.

  8. Evidence of molecular adaptation to extreme environments and applicability to space environments

    CERN Document Server

    Filipovic, M D; Ognjanovic, M

    2008-01-01

    This is initial study of a gene signatures responsible for adapting microscopic life to the life in extreme Earth environments. We present a results on ID of the clusters of COGs common to several hyperthermophiles and exclusion of those common to a mesophile: E.coli.K12, will yield a group of proteins possibly involved in adaptation to life under extreme T. Methanogens stand out as the only group of organisms that have species capable of growth at 0C (M.frigidum and M.burtonii) and 110C (M.kandleri). Not all the components of heat adaptation can be attributed to novel genes, the chaperones known as heat shock proteins stabilize the enzymes under elevated temperature. Highly conserved chaperons found in bacteria and eukaryots are not present in hyperthermophilic Archea, rather, they have a unique chaperone TF55. Our aim is to use software which we specifically developed for extremophile genome comparative analyses in order to search for additional novel genes involved in hyperthermophile adaptation. The follo...

  9. The dependence on environment of Cold Dark Matter Halo properties

    CERN Document Server

    Avila-Reese, V; Gottlöber, S; Firmani, C; Maulbetsch, C

    2005-01-01

    High-resolution LCDM cosmological N-body simulations are used to study the properties of galaxy-size dark halos in different environments (cluster, void, and "field"). Halos in clusters and their surroundings have a median spin parameter ~1.3 times lower, and tend to be more spherical and to have less aligned internal angular momentum than halos in voids and the field. For halos in clusters the concentration parameters decrease on average with mass with a slope of ~0.1; for halos in voids these concentrations do not change with mass. For masses <5 10^11 M_sh^-1, halos in clusters are on average ~30-40% more concentrated and have ~2 times higher central densities than halos in voids. When comparing only parent halos, the differences are less pronounced but they are still significant. The Vmax-and Vrms-mass relations are shallower and more scattered for halos in clusters than in voids, and for a given Vmax or Vrms, the mass is smaller at z=1 than at z=0 in all the environments. At z=1, the differences in the...

  10. Characterization and effects of cold fronts in the Colombian Caribbean Coast and their relationship to extreme wave events

    Science.gov (United States)

    Ortiz-Royero, J. C.; Otero, L. J.; Restrepo, J. C.; Ruiz, J.; Cadena, M.

    2013-07-01

    Extreme ocean waves in the Caribbean Sea are commonly related to the effects of storms and hurricanes during the months of June through November. The collapse of 200 m of the Puerto Colombia pier in March 2009 revealed the effects of meteorological phenomena other than storms and hurricanes that may be influencing the extreme wave regime in the Colombian Caribbean. The marked seasonality of these atmospheric fronts was established by analyzing the meteorological-marine reports of Instituto de Hidrología, Meteorología y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and Centro de Investigación en Oceanografía y Meteorología of Colombia (CIOH, based on its initials in Spanish). The highest occurrences were observed during the months of January, February, and March, with 6 fronts occurring per year. An annual trend was not observed, although the highest number of fronts occurred in 2010 (20 in total). An annual strong relationship between the maximum average wave values and the cold fronts, in the central zone of the Colombian Caribbean during the first three months of the year was established. In addition, the maximum values of the significant height produced by the passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that, there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the purpose of informing the design of

  11. New insights into microbial adaptation to extreme saline environments

    Directory of Open Access Journals (Sweden)

    Vauclare P.

    2014-02-01

    Full Text Available Extreme halophiles are microorganisms adapted to low water activity living at the upper salt concentration that life can tolerate. We review here recent data that specify the main factors, which determine their peculiar salt-dependent biochemistry. The data suggested that evolution proceeds by stage to modify the molecular dynamics properties of the entire proteome. Extreme halophiles therefore represent tractable models to understand how fast and to what extent microorganisms adapt to environmental changes. Halophiles are also robust organisms, capable to resist multiple stressors. Preliminary studies indicated that they have developed a cellular response specifically aimed to survive when the salt condition fluctuates. Because of these properties halophilic organisms deserve special attention in the search for traces of life on other planets.

  12. VALIDATION OF HANFORD PERSONNEL AND EXTREMITY DOSIMETERS IN PLUTONIUM ENVIRONMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Scherpelz, Robert I.; Fix, John J.; Rathbone, Bruce A.

    2000-02-10

    A study was performed in the Plutonium Finishing Plant to assess the performance of Hanford personnel neutron dosimetry. The study was assessed whole body dosimetry and extremity dosimetry performance. For both parts of the study, the TEPC was used as the principle instrument for characterizing workplace neutron fields. In the whole body study, 12.7-cm-diameter TEPCs were used in ten different locations in the facility. TLD and TED personnel dosimeters were exposed on a water-filled phantom to enable a comparison of TEPC and dosimeter response. In the extremity study, 1.27-cm-diameter TEPCs were exposed inside the fingers of a gloveboxe glove. Extremity dosimeters were wrapped around the TEPCs. The glove was then exposed to six different cans of plutonium, simulating the exposure that a worker's fingers would receive in a glovebox. The comparison of TEPC-measured neutron dose equivalent to TLD-measured gamma dose equivalent provided neutron-to-gamma ratios that can be used to estimate the neutron dose equivalent received by a worker's finger based on the gamma readings of an extremity dosimeter. The study also utilized a Snoopy and detectors based on bubble technology for assessing neutron exposures, providing a comparison of the effectiveness of these instruments for workplace monitoring. The study concludes that the TLD component of the HCND performs adequately overall, with a positive bias of 30%, but exhibits excessive variability in individual results due to instabilities in the algorithm. The TED response was less variable but only 20% of the TEPC reference dose on average because of the low neutron energies involved. The neutron response of the HSD was more variable than the TLD component of the HCND and biased high by a factor of 8 overall due to its calibration to unmoderated 252Cf. The study recommends further work to correct instabilities in the HCND algorithm and to explore the potential shown by the bubble-based dosimeters.

  13. Dynamical Influence and Operational Impacts of an Extreme Mediterranean Cold Surge

    Science.gov (United States)

    2013-06-01

    in significant flooding over regions surrounding the Mediterranean Sea ( Trigo , Bigg, & Davies 2002). The cold air mass and associated cyclogenesis...119, 17–55. Trigo , I., G. Bigg, and T. Davies, 2002: Climatology of cyclogenesis mechanisms in the Mediterranean. Mon. Wea. Rev., 130, 549–569

  14. The Role of Rossby-Wave Propagation in a North American Extreme Cold Event

    Directory of Open Access Journals (Sweden)

    Chunhua Shi

    2017-01-01

    Full Text Available The Eliassen–Palm flux and Plumb wave activity flux are calculated using the European Centre for Medium-Range Weather Forecasts interim reanalysis daily dataset to determine the propagation of Rossby waves before a North American cold wave in January 2014. The results show that the upward wave activity fluxes mainly come from planetary waves 1 and 2, which provide a stable circulation background for the influence of the subplanetary-scale waves 3 and 4. The Rossby-wave propagation anomalies between the troposphere and the stratosphere are due to the modulating effects of waves 3 and 4 on waves 1 and 2. During 9–14 January 2014, the modulating effects helped strengthen upward and eastward wave activity fluxes over the Atlantic region and enhance the Pacific high in the stratosphere in its early stage. Later in 19–24 January, the downward wave activity fluxes over the east Pacific due to the modulating effects were beneficial to downward development of the stratospheric high over the Pacific and the formation of a blocking high over the west coast of North America in the troposphere accompanied by a strong adjacent cold low on the east side. These circulations benefit the southward invasion of polar cold air reaching the lower latitudes of east North America, leading to the cold wave outbreak.

  15. Rapid self-organized criticality: Fractal evolution in extreme environments

    Science.gov (United States)

    Halley, Julianne D.; Warden, Andrew C.; Sadedin, Suzanne; Li, Wentian

    2004-09-01

    We introduce the phenomenon of rapid self-organized criticality (RSOC) and show that, like some models of self-organized criticality (SOC), RSOC generates scale-invariant event distributions and 1/f noise. Unlike SOC, however, RSOC persists despite more than an order of magnitude variation in driving rate and displays extremely thick and dynamic branching geometry. Starting with an initial set of parameter values, we perform two numerical experiments in which nonequilibrium RSOC systems are tuned towards their critical points. The approach to the critical state is tracked using average branching rates, which must equal 1 if systems are genuinely critical.

  16. Star formation in extreme environments : The effects of cosmic rays and mechanical heating

    NARCIS (Netherlands)

    Meijerink, R.; Spaans, M.; Loenen, A. F.; van der Werf, Paul P.

    Context. The molecular interstellar medium in extreme environments, such as Arp 220, but also NGC 253 appears to have extremely high cosmic ray (CR) rates (10(3)-10(4) x Milky Way) and substantial mechanical heating from supernova driven turbulence. Aims. We explore the consequences of high CR rates

  17. Thermal Protection System Materials (TPSM): Heat Shield for Extreme Entry Environment Technology (HEEET) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Heatshield for Extreme Entry Environ­ment Technology (HEEET) project seeks to mature a game changing Woven Ther­mal Protection System (TPS) technology to...

  18. Motor Controller for Extreme Environments Based on SiGe Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a motor-control subsystem capable of operation in extreme environments, including those to be encountered on the Moon and Mars....

  19. Evolution of Fish in Extreme Environments : Insights from the Magadi tilapia (Alcolapia grahami)

    OpenAIRE

    Kavembe, Geraldine Dorcas

    2015-01-01

    Extreme environments such as soda lakes are largely unexplored habitats where a surprising number of often endemic species thrive regardless of multiple co-occurring abiotic stresses, depleted food resources and restricted dispersal abilities. Their distinct geochemistry, ecological boundaries, simplified biota and high levels of endemism strikingly resemble the features found on islands that have long been used for evolutionary studies. Extreme environments thus represent prime natural labor...

  20. Eukaryotic Organisms in Extreme Acidic Environments, the Río Tinto Case

    OpenAIRE

    Angeles Aguilera

    2013-01-01

    A major issue in microbial ecology is to identify the limits of life for growth and survival, and to understand the molecular mechanisms that define these limits. Thus, interest in the biodiversity and ecology of extreme environments has grown in recent years for several reasons. Some are basic and revolve around the idea that extreme environments are believed to reflect early Earth conditions. Others are related to the biotechnological potential of extremophiles. In this regard, the study of...

  1. Moving in extreme environments: inert gas narcosis and underwater activities

    OpenAIRE

    Clark, James E

    2015-01-01

    Exposure to the underwater environment for pleasure or work poses many challenges on the human body including thermal stress, barotraumas, decompression sickness as well as the acute effects of breathing gases under pressure. With the popularity of recreational self-contained underwater breathing apparatus (SCUBA) diving on the increase and deep inland dive sites becoming more accessible, it is important that we understand the effects of breathing pressurised gas at depth can have on the body...

  2. Thermal Testing of Woven TPS Materials in Extreme Entry Environments

    Science.gov (United States)

    Gonzales, G.; Stackpoole, M.

    2014-01-01

    NASAs future robotic missions to Venus and outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of current mid density ablators (PICA or Avcoat). Therefore mission planners assume the use of a fully dense carbon phenolic heatshield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic (CP) is a robust TPS however its high density and thermal conductivity constrain mission planners to steep entries, high heat fluxes, high pressures and short entry durations, in order for CP to be feasible from a mass perspective. In 2012 the Game Changing Development Program in NASAs Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System to meet the needs of NASAs most challenging entry missions. The high entry conditions pose certification challenges in existing ground based test facilities. Recent updates to NASAs IHF and AEDCs H3 high temperature arcjet test facilities enable higher heatflux (2000 Wcm2) and high pressure (5 atm) testing of TPS. Some recent thermal tests of woven TPS will be discussed in this paper. These upgrades have provided a way to test higher entry conditions of potential outer planet and Venus missions and provided a baseline against carbon phenolic material. The results of these tests have given preliminary insight to sample configuration and physical recession profile characteristics.

  3. Cold air plasma to decontaminate inanimate surfaces of the hospital environment.

    Science.gov (United States)

    Cahill, Orla J; Claro, Tânia; O'Connor, Niall; Cafolla, Anthony A; Stevens, Niall T; Daniels, Stephen; Humphreys, Hilary

    2014-03-01

    The hospital environment harbors bacteria that may cause health care-associated infections. Microorganisms, such as multiresistant bacteria, can spread around the patient's inanimate environment. Some recently introduced biodecontamination approaches in hospitals have significant limitations due to the toxic nature of the gases and the length of time required for aeration. This study evaluated the in vitro use of cold air plasma as an efficient alternative to traditional methods of biodecontamination of hospital surfaces. Cultures of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli, and Acinetobacter baumannii were applied to different materials similar to those found in the hospital environment. Artificially contaminated sections of marmoleum, mattress, polypropylene, powder-coated mild steel, and stainless steel were then exposed to a cold air pressure plasma single jet for 30 s, 60 s, and 90 s, operating at approximately 25 W and 12 liters/min flow rate. Direct plasma exposure successfully reduced the bacterial load by log 3 for MRSA, log 2.7 for VRE, log 2 for ESBL-producing E. coli, and log 1.7 for A. baumannii. The present report confirms the efficient antibacterial activity of a cold air plasma single-jet plume on nosocomial bacterially contaminated surfaces over a short period of time and highlights its potential for routine biodecontamination in the clinical environment.

  4. Differentiating Hydrothermal, Pedogenic, and Glacial Weathering in a Cold Volcanic Mars-Analog Environment

    Science.gov (United States)

    Scudder, N. A.; Horgan, B.; Havig, J.; Rutledge, A.; Rampe, E. B.; Hamilton, T.

    2016-01-01

    Although the current cold, dry environment of Mars extends back through much of its history, its earliest periods experienced significant water- related surface activity. Both geomorphic features (e.g., paleolakes, deltas, and river valleys) and hydrous mineral detections (e.g., clays and salts) have historically been interpreted to imply a "warm and wet" early Mars climate. More recently, atmospheric modeling studies have struggled to produce early climate conditions with temperatures above 0degC, leading some studies to propose a "cold and icy" early Mars dominated by widespread glaciation with transient melting. However, the alteration mineralogy produced in subglacial environments is not well understood, so the extent to which cold climate glacial weathering can produce the diverse alteration mineralogy observed on Mars is unknown. This summer, we will be conducting a field campaign in a glacial weathering environment in the Cascade Range, OR in order to determine the types of minerals that these environments produce. However, we must first disentangle the effects of glacial weathering from other significant alteration processes. Here we attempt a first understanding of glacial weathering by differentiating rocks and sediments weathered by hydrothermal, pedogenic, and glacial weathering processes in the Cascades volcanic range.

  5. The I.A.G. / A.I.G. SEDIBUD (Sediment Budgets in Cold Environments) Programme: Current and future activities

    Science.gov (United States)

    Beylich, Achim A.; Lamoureux, Scott; Decaulne, Armelle

    2013-04-01

    Projected climate change in cold regions is expected to alter melt season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active layer depths. These effects will undoubtedly change surface environments in cold regions and alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated geomorphic process monitoring and analysis to understand the sensitivity of the Earth surface environment is acute in cold climate environments. The International Association of Geomorphologists (I.A.G. / A.I.G. ) SEDIBUD (Sediment Budgets in Cold Environments) Programme was formed in 2005 to address this existing key knowledge gap. SEDIBUD currently has about 400 members worldwide and the Steering Committee of this international programme is composed of ten scientists from eight different countries: Achim A. Beylich (Chair) (Norway), Armelle Decaulne (Secretary) (France), John C. Dixon (USA), Scott F. Lamoureux (Vice-Chair) (Canada), John F. Orwin (Canada), Jan-Christoph Otto (Austria), Irina Overeem (USA), Thorsteinn Sæmundsson (Iceland), Jeff Warburton (UK) and Zbigniew Zwolinski (Poland). The central research question of this global group of scientists is to: Assess and model the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Initially formed as European Science Foundation (ESF) Network SEDIFLUX (Sedimentary Source-to-Sink Fluxes in Cold Environments) (2004 - ), SEDIBUD has further expanded to a global group of researchers with field research sites located in polar and alpine regions in the northern and southern hemisphere. Research carried out at each of the close to 50 defined SEDIBUD key test sites varies by programme, logistics and available

  6. The Lusi drone: a mutidisciplinary tool to access extreme environments.

    Science.gov (United States)

    Romeo, Giovanni; Mazzini, Adriano; Alessandro, Iarocci; Di Stefano, Giuseppe; Benedetti, Paolo

    2014-05-01

    Active eruptions are notoriously inaccessible for monitoring and sampling. The "Lusi drone" is a hexacopter developed and assembled in order to complete multidisciplinary studies in such inaccessible environments. The Lusi drone is equipped with three gimbaled cameras that can complete video, photogrammetry, and thermal surveys during the missions. Two different prototypes of remote controlled gas containers can vacuum multiple samples when required. A remote controlled winch is able to deploy 1) a logger to monitor high temperature (up to 250° C) variations of erupted fluids (water-gas) and 2) a specifically designed sampler to collect solid and fluid specimens at preselected coordinates. A GPS-connected software allows to pre-plan the full mission of the drone and to constantly communicate and monitor its position. The device is solid, stable even with significant wind, affordable, and easy to transport. The Lusi drone has been successfully used at the active Lusi eruption site in Indonesia and proved to be an excellent tool to study harsh environments, where operations with more conventional methods are too expensive, dangerous or simply impossible.

  7. A Fault-oblivious Extreme-scale Execution Environment

    Energy Technology Data Exchange (ETDEWEB)

    Sadayappan, Ponnuswamy [The Ohio State Univ., Columbus, OH (United States)

    2016-08-31

    Exascale computing systems will provide a thousand-fold increase in parallelism and a proportional increase in failure rate relative to today's machines. Systems software for exascale machines must provide the infrastructure to support existing applications while simultaneously enabling efficient execution of new programming models that naturally express dynamic, adaptive, irregular computation; coupled simulations; and massive data analysis in a highly unreliable hardware environment with billions of threads of execution. We propose a new approach to the data and work distribution model provided by system software based on the unifying formalism of an abstract file system. The proposed hierarchical data model provides simple, familiar visibility and access to data structures through the file system hierarchy, while providing fault tolerance through selective redundancy. The hierarchical task model features work queues whose form and organization are represented as file system objects. Data and work are both first class entities. By exposing the relationships between data and work to the runtime system, information is available to optimize execution time and provide fault tolerance. The data distribution scheme provides replication (where desirable and possible) for fault tolerance and efficiency, and it is hierarchical to make it possible to take advantage of locality. The user, tools, and applications, including legacy applications, can interface with the data, work queues, and one another through the abstract file model. This runtime environment will provide multiple interfaces to support traditional Message Passing Interface applications, languages developed under DARPA's High Productivity Computing Systems program, as well as other, experimental programming models. We will validate our runtime system with pilot codes on existing platforms and will use simulation to validate for exascale-class platforms. In this final report, we summarize research

  8. Studies on Actinomycetal Resources under Extreme Environments in the West of China

    Science.gov (United States)

    Li, W.

    2005-12-01

    s: Actinomycetes play a quite important role in natural ecological system and they are also profile producers of antibiotics, antitumor agents, enzymes, enzyme inhibitors and immunomodifiers. which have been widely applied in industry, agriculture, forestry and pharmaceutical industry. In the past, the research work on actinomycetes was mainly concentrated on that of common habitats. Actinomycetes resources under extreme environments (including extreme high and low temperature, extreme high or low pH, high salt concentration etc.) have received comparatively little attention from microbiologists. Actinomycetes are regarded as one kind of sideline microorganisms and those under extreme environments are better materials for biological evolution and phylogenetic development in research. There are much more unknown species and much more worth researching for actinomycetes under extreme environments. There are many extreme environmental resources in the west of China. For example, wide range snow-mountains, basified soil and lakes, widely distributed acid and alkaline hot-springs in Yunnan provinces; more than 73.3 million hektares basified soil and salt lakes in Xinjiang Province and many unusual environments in Qinghai Province and other western Provinces. They were mostly precious natural resources and were destroyed, relatively fewer can provided us with unique conditions for study on actinomycetal resources under extreme environments. In recent years, our main work was focusing on study of extremophilic actinomycetal resources in the west of China by using conventional cultivation-methods and culture-independent methods (PCR-clone and DGGE/TGGE, etc), Results showed that large amount of unknown microbial resources (including actinomycetal resources) existed in natural extreme environments. Additionally, lots of new taxa were isolated and characterized using a polyphasic approach. Further, we got some new compounds with different bioactivities from these

  9. Cold Environment Assessment Tool (CEAT) User’s Guide for Apple Mobile Devices

    Science.gov (United States)

    2015-06-01

    Tool (CEAT) User’s Guide for Apple Mobile Devices by David Sauter Computational and Information Sciences Directorate, ARL...2015 4. TITLE AND SUBTITLE Cold Environment Assessment Tool (CEAT) User’s Guide for Apple Mobile Devices 5a. CONTRACT NUMBER 5b. GRANT NUMBER...CEAT) application (from here on also referred to as the “app”) for iOS (Apple mobile operating system) mobile devices (smart phones and tablets

  10. Assessment of SOI AND Gate, Type CHT-7408, for Operation in Extreme Temperature Environments

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad; Dones, Keishla Rivera

    2009-01-01

    Electronic parts based on silicon-on-insulator (SOI) technology are finding widespread applications due to their ability to operate in harsh environments and the benefits they offer as compared to their silicon counterparts. Due to their construction, they are tailored for high temperature operation and show good tolerance to radiation events. In addition, their inherent design lessens the formation of parasitic junctions, thereby reducing leakage currents, decreasing power consumption, and enhancing speed. These devices are typically rated in temperature capability from -55 C to about +225 C, and their characteristics over this temperature range are documented in data sheets. Since electronics in some of NASA space exploration missions are required to operate under extreme temperature conditions, both cold and hot, their characteristic behavior within the full temperature spectrum must be determined to establish suitability for use in space applications. The effects of extreme temperature exposure on the performance of a new commercial-off-the-shelf (COTS) SOI AND gate device were evaluated in this work. The high temperature, quad 2-inputs AND gate device, which was recently introduced by CISSOID, is fabricated using a CMOS SOI process. Some of the specifications of the CHT-7408 chip are listed in a table. By supplying a constant DC voltage to one gate input and a 10 kHz square wave into the other associated gate input, the chip was evaluated in terms of output response, output rise (t(sub r)) and fall times (tf), and propagation delays (using a 50% level between input and output during low to high (tPLH) and high to low (tPHL) transitions). The supply current of the gate circuit was also obtained. These parameters were recorded at various test temperatures between -195 C and +250 C using a Sun Systems environmental chamber programmed at a temperature rate of change of 10 C/min. In addition, the effects of thermal cycling on this chip were determined by exposing

  11. The Extreme Chemical Environments Associated with Dying Stars

    Science.gov (United States)

    Ziurys, Lucy

    Mass loss from dying stars is the main avenue by which material enters the interstellar medium, and eventually forms solar systems and planets. When stars consume all the hydrogen burning in their core, they start to burn helium, first in their centers, and then in a surrounding shell. During these phases, the so-called ``giant branches,'' large instabilities are created, and stars begin to shed their outer atmospheres, producing so-called circumstellar envelopes. Molecules form readily in these envelopes, in part by LTE chemistry at the base of the stellar photosphere, and also by radical reactions in the outer regions. Eventually most stars shed almost all their mass, creating ``planetary nebulae,'' which consist of a hot, ultraviolet-emitting white dwarf surrounded by the remnant stellar material. The environs in such nebulae are not conducive to chemical synthesis; yet molecular gas exits. The ejecta from these nebulae then flows into the interstellar medium, becoming the starting material for diffuse clouds, which subsequently collapse into dense clouds and then stars. This molecular ``life cycle'' is repeated many times in the course of the evolution of our Galaxy. We have been investigating the interstellar molecular life cycle, in particular the chemical environments of circumstellar shells and planetary nebulae, through both observational and laboratory studies. Using the facilities of the Arizona Radio Observatory (ARO), we have conducted broad-band spectral-line surveys to characterize the contrasting chemical and physical properties of carbon (IRC +10216) vs. oxygen-rich envelopes (VY CMa and NML Cyg). The carbon-rich types are clearly more complex in terms of numbers of chemical compounds, but the O-rich variety appear to have more energetic, shocked material. We have also been conducting surveys of polyatomic molecules towards planetary nebulae. Species such as HCN, HCO+, HNC, CCH, and H2CO appear to be common constituents of these objects, and their

  12. Public perspectives of nuclear weapons in the post-cold war environment

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins-Smith, H.C.; Herron, K.G. [Univ. of New Mexico, Albuquerque, NM (United States). Institute for Public Policy; Barke, R.P. [Georgia Institute of Technology, Atlanta, GA (United States). School of Public Policy

    1994-04-01

    This report summarizes the findings of a nationwide survey of public perceptions of nuclear weapons in the post-cold war environment. Participants included 1,301 members of the general public, 1,155 randomly selected members of the Union of Concerned Scientists, and 1,226 employees randomly selected from the technical staffs of four DOE national laboratories. A majority of respondents from all three samples perceived the post-cold war security environment to pose increased likelihood of nuclear war, nuclear proliferation, and nuclear terrorism. Public perceptions of nuclear weapons threats, risks, utilities, and benefits were found to systematically affect nuclear weapons policy preferences in predictable ways. Highly significant relationships were also found between public trust and nuclear weapons policy preferences. As public trust and official government information about nuclear weapons increased, perceptions of nuclear weapons management risks decreased and perceptions of nuclear weapons utilities and benefits increased. A majority of respondents favored decreasing funding for: (1) developing and testing new nuclear weapons; (2) maintaining existing nuclear weapons, and (3) maintaining the ability to develop and improve nuclear weapons. Substantial support was found among all three groups for increasing funding for: (1) enhancing nuclear weapons safety; (2) training nuclear weapons personnel; (3) preventing nuclear proliferation; and (4) preventing nuclear terrorism. Most respondents considered nuclear weapons to be a persistent feature of the post-cold war security environment.

  13. Extreme Environments Facilitate Hybrid Superiority – The Story of a Successful Daphnia galeata × longispina Hybrid Clone

    Science.gov (United States)

    Griebel, Johanna; Gießler, Sabine; Poxleitner, Monika; Navas Faria, Amanda; Yin, Mingbo; Wolinska, Justyna

    2015-01-01

    Hybridization within the animal kingdom has long been underestimated. Hybrids have often been considered less fit than their parental species. In the present study, we observed that the Daphnia community of a small lake was dominated by a single D. galeata × D. longispina hybrid clone, during two consecutive years. Notably, in artificial community set-ups consisting of several clones representing parental species and other hybrids, this hybrid clone took over within about ten generations. Neither the fitness assay conducted under different temperatures, or under crowded and non-crowded environments, nor the carrying capacity test revealed any outstanding life history parameters of this hybrid clone. However, under simulated winter conditions (i.e. low temperature, food and light), the hybrid clone eventually showed a higher survival probability and higher fecundity compared to parental species. Hybrid superiority in cold-adapted traits leading to an advantage of overwintering as parthenogenetic lineages might consequently explain the establishment of successful hybrids in natural communities of the D. longispina complex. In extreme cases, like the one reported here, a superior hybrid genotype might be the only clone alive after cold winters. Overall, superiority traits, such as enhanced overwintering here, might explain hybrid dominance in nature, especially in extreme and rapidly changing environments. Although any favoured gene complex in cyclic parthenogens could be frozen in successful clones independent of hybridization, we did not find similarly successful clones among parental species. We conclude that the emergence of the observed trait is linked to the production of novel recombined hybrid genotypes. PMID:26448651

  14. Risk analysis for autonomous underwater vehicle operations in extreme environments.

    Science.gov (United States)

    Brito, Mario Paulo; Griffiths, Gwyn; Challenor, Peter

    2010-12-01

    Autonomous underwater vehicles (AUVs) are used increasingly to explore hazardous marine environments. Risk assessment for such complex systems is based on subjective judgment and expert knowledge as much as on hard statistics. Here, we describe the use of a risk management process tailored to AUV operations, the implementation of which requires the elicitation of expert judgment. We conducted a formal judgment elicitation process where eight world experts in AUV design and operation were asked to assign a probability of AUV loss given the emergence of each fault or incident from the vehicle's life history of 63 faults and incidents. After discussing methods of aggregation and analysis, we show how the aggregated risk estimates obtained from the expert judgments were used to create a risk model. To estimate AUV survival with mission distance, we adopted a statistical survival function based on the nonparametric Kaplan-Meier estimator. We present theoretical formulations for the estimator, its variance, and confidence limits. We also present a numerical example where the approach is applied to estimate the probability that the Autosub3 AUV would survive a set of missions under Pine Island Glacier, Antarctica in January-March 2009.

  15. Moving in extreme environments: inert gas narcosis and underwater activities.

    Science.gov (United States)

    Clark, James E

    2015-01-01

    Exposure to the underwater environment for pleasure or work poses many challenges on the human body including thermal stress, barotraumas, decompression sickness as well as the acute effects of breathing gases under pressure. With the popularity of recreational self-contained underwater breathing apparatus (SCUBA) diving on the increase and deep inland dive sites becoming more accessible, it is important that we understand the effects of breathing pressurised gas at depth can have on the body. One of the common consequences of hyperbaric gas is the narcotic effect of inert gas. Nitrogen (a major component of air) under pressure can impede mental function and physical performance at depths of as little as 10 m underwater. With increased depth, symptoms can worsen to include confusion, disturbed coordination, lack of concentration, hallucinations and unconsciousness. Narcosis has been shown to contribute directly to up to 6% of deaths in divers and is likely to be indirectly associated with other diving incidents at depth. This article explores inert gas narcosis, the effect on divers' movement and function underwater and the proposed physiological mechanisms. Also discussed are some of the factors that affect the susceptibility of divers to the condition. In conclusion, understanding the cause of this potentially debilitating problem is important to ensure that safe diving practices continue.

  16. Small RNA transcriptomes of mangroves evolve adaptively in extreme environments.

    Science.gov (United States)

    Wen, Ming; Lin, Xingqin; Xie, Munan; Wang, Yushuai; Shen, Xu; Liufu, Zhongqi; Wu, Chung-I; Shi, Suhua; Tang, Tian

    2016-01-01

    MicroRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs) are key players in plant stress responses. Here, we present the sRNA transcriptomes of mangroves Bruguiera gymnorrhiza and Kandelia candel. Comparative computational analyses and target predictions revealed that mangroves exhibit distinct sRNA regulatory networks that differ from those of glycophytes. A total of 32 known and three novel miRNA families were identified. Conserved and mangrove-specific miRNA targets were predicted; the latter were widely involved in stress responses. The known miRNAs showed differential expression between the mangroves and glycophytes, reminiscent of the adaptive stress-responsive changes in Arabidopsis. B. gymnorrhiza possessed highly abundant but less conserved TAS3 trans-acting siRNAs (tasiRNAs) in addition to tasiR-ARFs, with expanded potential targets. Our results indicate that the evolutionary alteration of sRNA expression levels and the rewiring of sRNA-regulatory networks are important mechanisms underlying stress adaptation. We also identified sRNAs that are involved in salt and/or drought tolerance and nutrient homeostasis as possible contributors to mangrove success in stressful environments.

  17. Nonlinear optical field sensors in extreme electromagnetic and acoustic environments

    Science.gov (United States)

    Garzarella, Anthony; Wu, Dong Ho

    2014-03-01

    Sensors based on electro-optic (EO) and magneto-optic (MO) crystals measure external electric and magnetic fields through changes in birefringence which the fields induce on the nonlinear crystals. Due to their small size and all-dielectric structure, EO and MO sensors are ideal in environments involving very large electromagnetic powers. Conventional antennas and metallic probes not only present safety hazards, due to their metallic structure and the presence of large currents, but they can also perturb the very fields they intend to measure. In the case of railguns, the large electromagnetic signals are also accompanied by tremendous acoustic noise, which presents a noise background that the sensors must overcome. In this presentation, we describe extensive data obtained from fiber optic EO and MO sensors used in the railgun of the Naval Research Laboratory. Along with the field measurements obtained, we will describe the interactions between the acoustic noise and the nonlinear crystals (most notably, photoelastic effects), the noise equivalent fields they produce, and methods they could be suppressed through the optical and geometrical configurations of the sensor so that the signal to noise ratio can be maximized.

  18. Self-Recovery Experiments in Extreme Environments Using a Field Programmable Transistor Array

    Science.gov (United States)

    Stoica, Adrian; Keymeulen, Didier; Arslan, Tughrul; Duong, Vu; Zebulum, Ricardo; Ferguson, Ian; Guo, Xin

    2004-01-01

    Temperature and radiation tolerant electronics, as well as long life survivability are key capabilities required for future NASA missions. Current approaches to electronics for extreme environments focus on component level robustness and hardening. However, current technology can only ensure very limited lifetime in extreme environments. This paper describes novel experiments that allow adaptive in-situ circuit redesign/reconfiguration during operation in extreme temperature and radiation environments. This technology would complement material/device advancements and increase the mission capability to survive harsh environments. The approach is demonstrated on a mixed-signal programmable chip (FPTA-2), which recovers functionality for temperatures until 28 C and with total radiation dose up to 250kRad.

  19. A Fault Oblivious Extreme-Scale Execution Environment

    Energy Technology Data Exchange (ETDEWEB)

    McKie, Jim

    2014-11-20

    The FOX project, funded under the ASCR X-stack I program, developed systems software and runtime libraries for a new approach to the data and work distribution for massively parallel, fault oblivious application execution. Our work was motivated by the premise that exascale computing systems will provide a thousand-fold increase in parallelism and a proportional increase in failure rate relative to today’s machines. To deliver the capability of exascale hardware, the systems software must provide the infrastructure to support existing applications while simultaneously enabling efficient execution of new programming models that naturally express dynamic, adaptive, irregular computation; coupled simulations; and massive data analysis in a highly unreliable hardware environment with billions of threads of execution. Our OS research has prototyped new methods to provide efficient resource sharing, synchronization, and protection in a many-core compute node. We have experimented with alternative task/dataflow programming models and shown scalability in some cases to hundreds of thousands of cores. Much of our software is in active development through open source projects. Concepts from FOX are being pursued in next generation exascale operating systems. Our OS work focused on adaptive, application tailored OS services optimized for multi → many core processors. We developed a new operating system NIX that supports role-based allocation of cores to processes which was released to open source. We contributed to the IBM FusedOS project, which promoted the concept of latency-optimized and throughput-optimized cores. We built a task queue library based on distributed, fault tolerant key-value store and identified scaling issues. A second fault tolerant task parallel library was developed, based on the Linda tuple space model, that used low level interconnect primitives for optimized communication. We designed fault tolerance mechanisms for task parallel computations

  20. In-Situ Acoustic Measurements of Temperature Profile in Extreme Environments

    Energy Technology Data Exchange (ETDEWEB)

    Skliar, Mikhail [Univ. of Utah, Salt Lake City, UT (United States)

    2015-03-31

    A gasifier’s temperature is the primary characteristic that must be monitored to ensure its performance and the longevity of its refractory. One of the key technological challenges impacting the reliability and economics of coal and biomass gasification is the lack of temperature sensors that are capable of providing accurate, reliable, and long-life performance in an extreme gasification environment. This research has proposed, demonstrated, and validated a novel approach that uses a noninvasive ultrasound method that provides real-time temperature distribution monitoring across the refractory, especially the hot face temperature of the refractory. The essential idea of the ultrasound measurements of segmental temperature distribution is to use an ultrasound propagation waveguide across a refractory that has been engineered to contain multiple internal partial reflectors at known locations. When an ultrasound excitation pulse is introduced on the cold side of the refractory, it will be partially reflected from each scatterer in the US propagation path in the refractory wall and returned to the receiver as a train of partial echoes. The temperature in the corresponding segment can be determined based on recorded ultrasonic waveform and experimentally defined relationship between the speed of sound and temperature. The ultrasound measurement method offers a powerful solution to provide continuous real time temperature monitoring for the occasions that conventional thermal, optical and other sensors are infeasible, such as the impossibility of insertion of temperature sensor, harsh environment, unavailable optical path, and more. Our developed ultrasound system consists of an ultrasound engineered waveguide, ultrasound transducer/receiver, and data acquisition, logging, interpretation, and online display system, which is simple to install on the existing units with minimal modification on the gasifier or use with new units. This system has been successfully tested

  1. The Dependence of the Mass Assembly History of Cold Dark Matter Halos on Environment

    CERN Document Server

    Maulbetsch, C; Colin, Pierre; Gottlöber, S; Khalatyan, A; Steinmetz, M

    2006-01-01

    We show by means of a high-resolution N-body simulation how the mass assembly histories of galaxy-size cold dark matter (CDM) halos depend on environment. Halos in high density environments form earlier and a higher fraction of their mass is assembled in major mergers,compared to low density environments. The distribution of the present--day specific mass aggregation rate is bimodal and strongly dependent on environment. While in low density environments only ~20% of the halos are not accreting mass at the present epoch, this fraction rises to ~80% at high densities. At z=1 the median of the specific aggregation rate is ~4 times larger than at z=0 and almost independent on environment. All the dependences on environment found here are critically enhanced by local processes associated to subhalos because the fraction of subhalos increases as the environment gets denser. The distribution of the halo specific mass aggregation rate as well as its dependence on environment resemble the relations for the specific s...

  2. Heatshield for Extreme Entry Environment Technology: Results from Acreage and Integrated Seams Arcjet Testing

    Science.gov (United States)

    Venkatapathy, Ethiraj

    2016-01-01

    This invited talk will give a brief overview of the integrated heat-shield system design that requires seams and the extreme environment conditions that HEEET should be demonstrated to be capable of thermal performance without fail. We have tested HEEET across many different facilities and at conditions that are extreme. The presentation will highlight the performance of both the acreage as well as integrated seam at these conditions. The Invite talks are 10 min and hence this presentation will be short.

  3. Eukaryotic Organisms in Extreme Acidic Environments, the Río Tinto Case

    Science.gov (United States)

    Angeles Aguilera, Angeles

    2013-07-01

    A major issue in microbial ecology is to identify the limits of life for growth and survival, and to understand the molecular mechanisms that define these limits. Thus, interest in the biodiversity and ecology of extreme environments has grown in recent years for several reasons. Some are basic and revolve around the idea that extreme environments are believed to reflect early Earth conditions. Others are related to the biotechnological potential of extremophiles. In this regard, the study of extremely acidic environments has become increasingly important since environmental acidity is often caused by microbial activity. Highly acidic environments are relatively scarce worldwide and are generally associated with volcanic activity or mining operations. For most acidic environments, low pH facilitates metal solubility, and therefore acidic waters tend to have high concentrations of heavy metals. However, highly acidic environments are usually inhabited by acidophilic and acidotolerant eukaryotic microorganisms such as algae, amoebas, ciliates, heliozoan and rotifers, not to mention filamentous fungi and yeasts. Here, we review the general trends concerning the diversity and ecophysiology of eukaryotic acidophilic microorganims, as well as summarize our latest results on this topic in one of the largest extreme acidic rivers, Río Tinto (SW, Spain).

  4. Eukaryotic Organisms in Extreme Acidic Environments, the Río Tinto Case

    Directory of Open Access Journals (Sweden)

    Angeles Aguilera

    2013-07-01

    Full Text Available A major issue in microbial ecology is to identify the limits of life for growth and survival, and to understand the molecular mechanisms that define these limits. Thus, interest in the biodiversity and ecology of extreme environments has grown in recent years for several reasons. Some are basic and revolve around the idea that extreme environments are believed to reflect early Earth conditions. Others are related to the biotechnological potential of extremophiles. In this regard, the study of extremely acidic environments has become increasingly important since environmental acidity is often caused by microbial activity. Highly acidic environments are relatively scarce worldwide and are generally associated with volcanic activity or mining operations. For most acidic environments, low pH facilitates metal solubility, and therefore acidic waters tend to have high concentrations of heavy metals. However, highly acidic environments are usually inhabited by acidophilic and acidotolerant eukaryotic microorganisms such as algae, amoebas, ciliates, heliozoan and rotifers, not to mention filamentous fungi and yeasts. Here, we review the general trends concerning the diversity and ecophysiology of eukaryotic acidophilic microorganims, as well as summarize our latest results on this topic in one of the largest extreme acidic rivers, Río Tinto (SW, Spain.

  5. Whole-Genome Sequencing of Native Sheep Provides Insights into Rapid Adaptations to Extreme Environments.

    Science.gov (United States)

    Yang, Ji; Li, Wen-Rong; Lv, Feng-Hua; He, San-Gang; Tian, Shi-Lin; Peng, Wei-Feng; Sun, Ya-Wei; Zhao, Yong-Xin; Tu, Xiao-Long; Zhang, Min; Xie, Xing-Long; Wang, Yu-Tao; Li, Jin-Quan; Liu, Yong-Gang; Shen, Zhi-Qiang; Wang, Feng; Liu, Guang-Jian; Lu, Hong-Feng; Kantanen, Juha; Han, Jian-Lin; Li, Meng-Hua; Liu, Ming-Jun

    2016-10-01

    Global climate change has a significant effect on extreme environments and a profound influence on species survival. However, little is known of the genome-wide pattern of livestock adaptations to extreme environments over a short time frame following domestication. Sheep (Ovis aries) have become well adapted to a diverse range of agroecological zones, including certain extreme environments (e.g., plateaus and deserts), during their post-domestication (approximately 8-9 kya) migration and differentiation. Here, we generated whole-genome sequences from 77 native sheep, with an average effective sequencing depth of ∼5× for 75 samples and ∼42× for 2 samples. Comparative genomic analyses among sheep in contrasting environments, that is, plateau (>4,000 m above sea level) versus lowland (1500 m) versus low-altitude region (600 mm), and arid zone (400 mm), detected a novel set of candidate genes as well as pathways and GO categories that are putatively associated with hypoxia responses at high altitudes and water reabsorption in arid environments. In addition, candidate genes and GO terms functionally related to energy metabolism and body size variations were identified. This study offers novel insights into rapid genomic adaptations to extreme environments in sheep and other animals, and provides a valuable resource for future research on livestock breeding in response to climate change.

  6. Joint probability analysis of extreme precipitation and storm tide in a coastal city under changing environment.

    Directory of Open Access Journals (Sweden)

    Kui Xu

    Full Text Available Catastrophic flooding resulting from extreme meteorological events has occurred more frequently and drawn great attention in recent years in China. In coastal areas, extreme precipitation and storm tide are both inducing factors of flooding and therefore their joint probability would be critical to determine the flooding risk. The impact of storm tide or changing environment on flooding is ignored or underestimated in the design of drainage systems of today in coastal areas in China. This paper investigates the joint probability of extreme precipitation and storm tide and its change using copula-based models in Fuzhou City. The change point at the year of 1984 detected by Mann-Kendall and Pettitt's tests divides the extreme precipitation series into two subsequences. For each subsequence the probability of the joint behavior of extreme precipitation and storm tide is estimated by the optimal copula. Results show that the joint probability has increased by more than 300% on average after 1984 (α = 0.05. The design joint return period (RP of extreme precipitation and storm tide is estimated to propose a design standard for future flooding preparedness. For a combination of extreme precipitation and storm tide, the design joint RP has become smaller than before. It implies that flooding would happen more often after 1984, which corresponds with the observation. The study would facilitate understanding the change of flood risk and proposing the adaption measures for coastal areas under a changing environment.

  7. Joint probability analysis of extreme precipitation and storm tide in a coastal city under changing environment.

    Science.gov (United States)

    Xu, Kui; Ma, Chao; Lian, Jijian; Bin, Lingling

    2014-01-01

    Catastrophic flooding resulting from extreme meteorological events has occurred more frequently and drawn great attention in recent years in China. In coastal areas, extreme precipitation and storm tide are both inducing factors of flooding and therefore their joint probability would be critical to determine the flooding risk. The impact of storm tide or changing environment on flooding is ignored or underestimated in the design of drainage systems of today in coastal areas in China. This paper investigates the joint probability of extreme precipitation and storm tide and its change using copula-based models in Fuzhou City. The change point at the year of 1984 detected by Mann-Kendall and Pettitt's tests divides the extreme precipitation series into two subsequences. For each subsequence the probability of the joint behavior of extreme precipitation and storm tide is estimated by the optimal copula. Results show that the joint probability has increased by more than 300% on average after 1984 (α = 0.05). The design joint return period (RP) of extreme precipitation and storm tide is estimated to propose a design standard for future flooding preparedness. For a combination of extreme precipitation and storm tide, the design joint RP has become smaller than before. It implies that flooding would happen more often after 1984, which corresponds with the observation. The study would facilitate understanding the change of flood risk and proposing the adaption measures for coastal areas under a changing environment.

  8. Modeling deuterium fractionation in cold and warm molecular environments with large chemical networks

    CERN Document Server

    Albertsson, T; Henning, Th

    2013-01-01

    Observations of deuterated species have long proven essential to probe properties and thermal history of various astrophysical environments. We present an elaborated chemical model that includes tens of thousands of reactions with multi-deuterated species, both gas-phase and surface, in which the most recent information on deuterium chemistry is implemented. A detailed study of the chemical evolution under wide range of temperatures and densities typical of cold molecular cores, warm protostellar envelopes, and hot cores/corinos is performed. We consider two cases of initial abundances, with 1) mainly atomic composition and all deuterium locked in HD, and 2) molecular abundances accumulated at 1 Myr of the evolution of a cold prestellar core. We indicate deuterated species that are particularly sensitive to temperature gradients and initial chemical composition. Many multiply-deuterated species produced at 10 K by exothermic ion-molecule chemistry retain large abundances even when temperature rises above 100 ...

  9. Extreme Space Weather Events and Charging Hazard Assessments in Lunar Environments

    Science.gov (United States)

    Minow, Joseph I.; Parker, Linda N.; Blackwell, William C., Jr.

    2008-01-01

    The sunlit lunar surface charges to positive potentials with mean values of a few tens of volts where photoelectron currents dominate the charging process. In contrast, surfaces in darkness may charge to negative potentials on the order of a few hundred volts when the charging process is dominated by hot electron populations in the absence of solar photons. Recently, observations of electron beams measured by instruments on spacecraft in low lunar orbit have been interpreted as evidence for extreme lunar surface potentials exceeding a few kilovolts suggesting that lunar orbital and surface plasma environments may contain charging risks similar to geostationary orbit during extreme space weather conditions. Space system design for successful operation in a wide range of lunar environments will therefore require evaluation of charging hazards during extreme space weather conditions. We present results from a study of space weather environments conducted to obtained credible extreme charging environments for use in charging hazard assessments for lunar missions including extreme conditions encountered when the Moon is in the solar wind, the magnetosheath, and the Earth's magnetotail.

  10. Fault Tolerant Magnetic Bearing Testing and Conical Magnetic Bearing Development for Extreme Temperature Environments

    Science.gov (United States)

    Keith, Theo G., Jr.; Clark, Daniel

    2004-01-01

    During the six month tenure of the grant, activities included continued research of hydrostatic bearings as a viable backup-bearing solution for a magnetically levitated shaft system in extreme temperature environments (1000 F), developmental upgrades of the fault-tolerant magnetic bearing rig at the NASA Glenn Research Center, and assisting in the development of a conical magnetic bearing for extreme temperature environments, particularly turbomachinery. It leveraged work from the ongoing Smart Efficient Components (SEC) and the Turbine-Based Combined Cycle (TBCC) program at NASA Glenn Research Center. The effort was useful in providing technology for more efficient and powerful gas turbine engines.

  11. Extreme Environments Development of Decision Processes and Training Programs for Medical Policy Formulation

    Science.gov (United States)

    Stough, Roger

    2004-01-01

    The purpose of this workshop was to survey existing health and safety policies as well as processes and practices for various extreme environments; to identify strengths and shortcomings of these processes; and to recommend parameters for inclusion in a generic approach to policy formulation, applicable to the broadest categories of extreme environments. It was anticipated that two additional workshops would follow. The November 7, 2003 workshop would be devoted to the evaluation of different model(s) and a concluding expert evaluation of the usefulness of the model using a policy formulation example. The final workshop was planned for March 2004.

  12. Numerical Simulation Analysis and Ecological Evaluation on Wind Environment of Dwelling Groups in Severe Cold Regions

    Institute of Scientific and Technical Information of China (English)

    Hong Jin; Teng Shao

    2014-01-01

    The wind environment around residential building groups is increasingly concerned, while the dwelling groups as the elementary unit of planning design, its quality of surrounding wind environment will directly affect people’ s life. This study based on the climatic conditions of severe cold regions, selects four dwellings groups with different openings scale and position as the research objects, and then simulates and analyzes the wind speed distribution characteristics of each pattern. Meanwhile, it extracts the wind speed values of one hundred points of each pattern and applies the coefficient of uniformity method to the ecological evaluation. It has been found that grouping pattern of buildings has a dramatic effect on the resulting airflow behavior. Configurations that contain a T⁃shaped central space with small opened side can effectively prevent and contain airflow in the site offer. The interactive influence between layout of dwelling groups and wind environment are explored, so as to provide basis for the planning design of dwelling groups.

  13. Sample environment for in situ synchrotron corrosion studies of materials in extreme environments

    Science.gov (United States)

    Elbakhshwan, Mohamed S.; Gill, Simerjeet K.; Motta, Arthur T.; Weidner, Randy; Anderson, Thomas; Ecker, Lynne E.

    2016-10-01

    A new in situ sample environment has been designed and developed to study the interfacial interactions of nuclear cladding alloys with high temperature steam. The sample environment is particularly optimized for synchrotron X-ray diffraction studies for in situ structural analysis. The sample environment is highly corrosion resistant and can be readily adapted for steam environments. The in situ sample environment design complies with G2 ASTM standards for studying corrosion in zirconium and its alloys and offers remote temperature and pressure monitoring during the in situ data collection. The use of the in situ sample environment is exemplified by monitoring the oxidation of metallic zirconium during exposure to steam at 350 °C. The in situ sample environment provides a powerful tool for fundamental understanding of corrosion mechanisms by elucidating the substoichiometric oxide phases formed during the early stages of corrosion, which can provide a better understanding of the oxidation process.

  14. Examining personal values in extreme environment contexts: Revisiting the question of generalizability

    Science.gov (United States)

    Smith, N.; Sandal, G. M.; Leon, G. R.; Kjærgaard, A.

    2017-08-01

    Land-based extreme environments (e.g. polar expeditions, Antarctic research stations, confinement chambers) have often been used as analog settings for spaceflight. These settings share similarities with the conditions experienced during space missions, including confinement, isolation and limited possibilities for evacuation. To determine the utility of analog settings for understanding human spaceflight, researchers have examined the extent to which the individual characteristics (e.g., personality) of people operating in extreme environments can be generalized across contexts (Sandal, 2000) [1]. Building on previous work, and utilising new and pre-existing data, the present study examined the extent to which personal value motives could be generalized across extreme environments. Four populations were assessed; mountaineers (N =59), military personnel (N = 25), Antarctic over-winterers (N = 21) and Mars simulation participants (N = 12). All participants completed the Portrait Values Questionnaire (PVQ; Schwartz; 2) capturing information on 10 personal values. Rank scores suggest that all groups identified Self-direction, Stimulation, Universalism and Benevolence as important values and acknowledged Power and Tradition as being low priorities. Results from difference testing suggest the extreme environment groups were most comparable on Self-direction, Stimulation, Benevolence, Tradition and Security. There were significant between-group differences on five of the ten values. Overall, findings pinpointed specific values that may be important for functioning in challenging environments. However, the differences that emerged on certain values highlight the importance of considering the specific population when comparing results across extreme settings. We recommend that further research examine the impact of personal value motives on indicators of adjustment, group working, and performance. Information from such studies could then be used to aid selection and

  15. Rapid assimilation of yolk enhances growth and development of lizard embryos from a cold environment.

    Science.gov (United States)

    Storm, Melissa A; Angilletta, Michael J

    2007-10-01

    Selection for rapid growth and development in cold environments results in a geographic pattern known as countergradient variation. The eastern fence lizard, Sceloporus undulatus, exhibits countergradient variation in embryonic growth and development along latitudinal clines. To identify the proximate causes of countergradient variation, we compared the energy budgets of embryos from a cold environment (Virginia) and a warm environment (South Carolina) during development at a realistic thermal cycle. The difference in mean egg size between populations was controlled by removing yolk from large eggs and performing a sham manipulation on other eggs. Respiration was measured every 4 days throughout 48 days of incubation. After this period, eggs were dissected and the energy contents of embryos and yolk were determined by calorimetry. As expected from previous experiments, embryos from Virginia reached a more advanced stage of development and deposited more energy within tissues than embryos from South Carolina. The greater absorption of yolk by embryos from Virginia was associated with a higher rate of respiration. Assimilation of yolk by rapidly growing embryos could reduce growth or survival after hatching. Such costs might explain the maintenance of countergradient variation in S. undulatus.

  16. Improved cultivation and metagenomics as new tools for bioprospecting in cold environments

    DEFF Research Database (Denmark)

    Vester, Jan Kjølhede; Glaring, Mikkel Andreas; Stougaard, Peter

    2015-01-01

    into the laboratory or through metagenomic approaches where culture-independent DNA sequence information can be combined with functional screening. The coupling of these two approaches circumvents the need for pure, cultured isolates and can be used to generate targeted information on communities enriched...... be limited as few hosts are available for expression of genes with extremophilic properties. This review summarizes the methods developed for improved cultivation as well as the metagenomic approaches for bioprospecting with focus on the challenges faced by bioprospecting in cold environments....

  17. Occurrence, activity and contribution of anammox in some freshwater extreme environments.

    Science.gov (United States)

    Zhu, Guibing; Xia, Chao; Shanyun, Wang; Zhou, Leiliu; Liu, Lu; Zhao, Siyan

    2015-12-01

    Anaerobic ammonium oxidation (anammox) widely occurs in marine ecosystems, and it plays an important role in the global nitrogen cycle. But in freshwater ecosystems its occurrence, distribution and contribution, especially in extreme environments, are still not well known. In this study, anammox process was investigated in some extreme environments of freshwater ecosystems, such as those with high (above 75°C) and low (below -35°C) temperature, high (pH > 8) and low (pH  300 mg kg(-1) ). The polymerase chain reaction (PCR) screening results showed that anammox bacteria were widespread in the examined sediments from freshwater extreme environments. Quantitative PCR showed that the abundance of anammox bacteria ranged from 6.94 × 10(4) to 8.05 × 10(6) hydrazine synthase (hzsB) gene copies g(-1) dry soil. (15) N-labelled incubation experiments indicated the occurrence of anammox in all examined sediments and the potential anammox rates ranged from 0.02 to 6.24 nmol N g(-1)  h(-1) , with a contribution of 3.45-58.74% of the total N2 production. In summary, these results demonstrate the occurrence of anammox in these extreme environments, inferring that anammox may harbour a wide ecological niche in the freshwater ecosystems.

  18. Rhizobacterial Community Structures Associated with Native Plants Grown in Chilean Extreme Environments.

    Science.gov (United States)

    Jorquera, Milko A; Maruyama, Fumito; Ogram, Andrew V; Navarrete, Oscar U; Lagos, Lorena M; Inostroza, Nitza G; Acuña, Jacquelinne J; Rilling, Joaquín I; de La Luz Mora, María

    2016-10-01

    Chile is topographically and climatically diverse, with a wide array of diverse undisturbed ecosystems that include native plants that are highly adapted to local conditions. However, our understanding of the diversity, activity, and role of rhizobacteria associated with natural vegetation in undisturbed Chilean extreme ecosystems is very poor. In the present study, the combination of denaturing gradient gel electrophoresis and 454-pyrosequencing approaches was used to describe the rhizobacterial community structures of native plants grown in three representative Chilean extreme environments: Atacama Desert (ATA), Andes Mountains (AND), and Antarctic (ANT). Both molecular approaches revealed the presence of Proteobacteria, Bacteroidetes, and Actinobacteria as the dominant phyla in the rhizospheres of native plants. Lower numbers of operational taxonomic units (OTUs) were observed in rhizosphere soils from ATA compared with AND and ANT. Both approaches also showed differences in rhizobacterial community structures between extreme environments and between plant species. The differences among plant species grown in the same environment were attributed to the higher relative abundance of classes Gammaproteobacteria and Alphaproteobacteria. However, further studies are needed to determine which environmental factors regulate the structures of rhizobacterial communities, and how (or if) specific bacterial groups may contribute to the growth and survival of native plants in each Chilean extreme environments.

  19. W(310) cold-field emission characteristics reflecting the vacuum states of an extreme high vacuum electron gun

    Science.gov (United States)

    Cho, Boklae; Shigeru, Kokubo; Oshima, Chuhei

    2013-01-01

    An extremely high vacuum cold-field electron emission (CFE) gun operating at pressures ranging from ˜10-8 Pa to ˜10-10 Pa was constructed. Only the CFE current emitting from W(310) surfaces revealed the existence of a "stable region" with high current angular density just after tip flash heating. In the "stable region," the CFE current was damped very slowly. The presence of non-hydrogen gas eliminated this region from the plot. Improvement of the vacuum prolonged the 90% damping time of the CFE current from ˜10 min to 800 min. The current angular density I' of CFE current was 60 and 250 μA/sr in the "stable region" for total CFE currents of 10 and 50 μA, respectively. These results were about three times larger than I' when measured after the complete damping of the CFE current. The CFE gun generated bright scanning transmission electron microscopy images of a carbon nanotube at 30 kV.

  20. Nonthermal sensory input and altered human thermoregulation: effects of visual information depicting hot or cold environments

    Science.gov (United States)

    Takakura, Jun'ya; Nishimura, Takayuki; Choi, Damee; Egashira, Yuka; Watanuki, Shigeki

    2015-10-01

    A recent study showed that thermoregulatory-like cardiovascular responses can be invoked simply by exposure to visual information, even though the thermal environments are neutral and unchanged. However, it was not clear how such responses affect actual human body temperature regulation. We investigated whether such visually invoked physiological responses can substantively affect human core body temperature in a thermally challenging cold environment. Participants comprised 13 graduate or undergraduate students viewing different video images containing hot, cold, or no scenery, while room temperature was gradually lowered from 28 to 16 °C over 80 min. Rectal temperature, mean skin temperature, core to skin temperature gradient, and oxygen consumption were measured during the experiment. Rectal temperature was significantly lower when hot video images were presented compared to when control video images were presented. Oxygen consumption was comparable among all video images, but core to skin temperature gradient was significantly lower when hot video images were presented. This result suggests that visual information, even in the absence of thermal energy, can affect human thermodynamics and core body temperature.

  1. Nonthermal sensory input and altered human thermoregulation: effects of visual information depicting hot or cold environments.

    Science.gov (United States)

    Takakura, Jun'ya; Nishimura, Takayuki; Choi, Damee; Egashira, Yuka; Watanuki, Shigeki

    2015-10-01

    A recent study showed that thermoregulatory-like cardiovascular responses can be invoked simply by exposure to visual information, even though the thermal environments are neutral and unchanged. However, it was not clear how such responses affect actual human body temperature regulation. We investigated whether such visually invoked physiological responses can substantively affect human core body temperature in a thermally challenging cold environment. Participants comprised 13 graduate or undergraduate students viewing different video images containing hot, cold, or no scenery, while room temperature was gradually lowered from 28 to 16 °C over 80 min. Rectal temperature, mean skin temperature, core to skin temperature gradient, and oxygen consumption were measured during the experiment. Rectal temperature was significantly lower when hot video images were presented compared to when control video images were presented. Oxygen consumption was comparable among all video images, but core to skin temperature gradient was significantly lower when hot video images were presented. This result suggests that visual information, even in the absence of thermal energy, can affect human thermodynamics and core body temperature.

  2. Photosynthesis in extreme environments: responses to different light regimes in the Antarctic alga Koliella antarctica.

    Science.gov (United States)

    La Rocca, Nicoletta; Sciuto, Katia; Meneghesso, Andrea; Moro, Isabella; Rascio, Nicoletta; Morosinotto, Tomas

    2015-04-01

    Antarctic algae play a fundamental role in polar ecosystem thanks to their ability to grow in an extreme environment characterized by low temperatures and variable illumination. Here, for prolonged periods, irradiation is extremely low and algae must be able to harvest light as efficiently as possible. On the other side, at low temperatures even dim irradiances can saturate photosynthesis and drive to the formation of reactive oxygen species. Colonization of this extreme environment necessarily required the optimization of photosynthesis regulation mechanisms by algal organisms. In order to investigate these adaptations we analyzed the time course of physiological and morphological responses to different irradiances in Koliella antarctica, a green microalga isolated from Ross Sea (Antarctica). Koliella antarctica not only modulates cell morphology and composition of its photosynthetic apparatus on a long-term acclimation, but also shows the ability of a very fast response to light fluctuations. Koliella antarctica controls the activity of two xanthophyll cycles. The first, involving lutein epoxide and lutein, may be important for the growth under very low irradiances. The second, involving conversion of violaxanthin to antheraxanthin and zeaxanthin, is relevant to induce a fast and particularly strong non-photochemical quenching, when the alga is exposed to higher light intensities. Globally K. antarctica thus shows the ability to activate a palette of responses of the photosynthetic apparatus optimized for survival in its natural extreme environment.

  3. Impacts of extreme climatic events on the energetics of long-lived vertebrates: the case of the greater flamingo facing cold spells in the Camargue.

    Science.gov (United States)

    Deville, Anne-Sophie; Labaude, Sophie; Robin, Jean-Patrice; Béchet, Arnaud; Gauthier-Clerc, Michel; Porter, Warren; Fitzpatrick, Megan; Mathewson, Paul; Grémillet, David

    2014-10-15

    Most studies analyzing the effects of global warming on wild populations focus on gradual temperature changes, yet it is also important to understand the impact of extreme climatic events. Here we studied the effect of two cold spells (January 1985 and February 2012) on the energetics of greater flamingos (Phoenicopterus roseus) in the Camargue (southern France). To understand the cause of observed flamingo mass mortalities, we first assessed the energy stores of flamingos found dead in February 2012, and compared them with those found in other bird species exposed to cold spells and/or fasting. Second, we evaluated the monthly energy requirements of flamingos across 1980-2012 using the mechanistic model Niche Mapper. Our results show that the body lipids of flamingos found dead in 2012 corresponded to 2.6±0.3% of total body mass, which is close to results found in woodcocks (Scolopax rusticola) that died from starvation during a cold spell (1.7±0.1%), and much lower than in woodcocks which were fed throughout this same cold spell (13.0±2%). Further, Niche Mapper predicted that flamingo energy requirements were highest (+6-7%) during the 1985 and 2012 cold spells compared with 'normal' winters. This increase was primarily driven by cold air temperatures. Overall, our findings strongly suggest that flamingos starved to death during both cold spells. This study demonstrates the relevance of using mechanistic energetics modelling and body condition analyses to understand and predict the impact of extreme climatic events on animal energy balance and winter survival probabilities. © 2014. Published by The Company of Biologists Ltd.

  4. Whole-body cryotherapy (extreme cold air exposure) for preventing and treating muscle soreness after exercise in adults.

    Science.gov (United States)

    Costello, Joseph T; Baker, Philip R A; Minett, Geoffrey M; Bieuzen, Francois; Stewart, Ian B; Bleakley, Chris

    2015-09-18

    Recovery strategies are often used with the intention of preventing or minimising muscle soreness after exercise. Whole-body cryotherapy, which involves a single or repeated exposure(s) to extremely cold dry air (below -100 °C) in a specialised chamber or cabin for two to four minutes per exposure, is currently being advocated as an effective intervention to reduce muscle soreness after exercise. To assess the effects (benefits and harms) of whole-body cryotherapy (extreme cold air exposure) for preventing and treating muscle soreness after exercise in adults. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, the British Nursing Index and the Physiotherapy Evidence Database. We also searched the reference lists of articles, trial registers and conference proceedings, handsearched journals and contacted experts.The searches were run in August 2015. We aimed to include randomised and quasi-randomised trials that compared the use of whole-body cryotherapy (WBC) versus a passive or control intervention (rest, no treatment or placebo treatment) or active interventions including cold or contrast water immersion, active recovery and infrared therapy for preventing or treating muscle soreness after exercise in adults. We also aimed to include randomised trials that compared different durations or dosages of WBC. Our prespecified primary outcomes were muscle soreness, subjective recovery (e.g. tiredness, well-being) and adverse effects. Two review authors independently screened search results, selected studies, assessed risk of bias and extracted and cross-checked data. Where appropriate, we pooled results of comparable trials. The random-effects model was used for pooling where there was substantial heterogeneity. We assessed the quality of the evidence using GRADE. Four laboratory-based randomised controlled trials were included. These reported results for 64

  5. Tardigrades living in extreme environments have naturally selected prerequisites useful to space conquer

    Science.gov (United States)

    Guidetti, Roberto; Tiziana, Altiero; Cesari, Michele; Rizzo, Angela Maria; Bertolani, Roberto; Galletta, Giuseppe; Dalessandro, Maurizio; Rebecchi, Lorena

    Extreme habitats are highly selective and can host only living organisms possessing specific adaptations to stressors. Among extreme habitats, space environment has particular charac-teristics of radiations, vacuum, microgravity and temperature, which induce rapid changes in living systems. Consequently, the response of multicellular complex organisms, able to colo-nize extreme environments, to space stresses can give very useful information on the ability to withstand a single stress or stress combinations. This knowledge on changes in living systems in space, with their similarity to the ageing processes, offers the opportunity to improve human life both on Earth and in space. Even though experimentation in space has often been carried out using unicellular organisms, multicellular organisms are very relevant in order to develop the appropriate countermeasures to avoid the risks imposed by environmental space in humans. The little attention received by multicellular organisms is probably due, other than to difficul-ties in the manipulation of biological materials in space, to the presence of only few organisms with the potential to tolerate environmental space stresses. Among them, tardigrades are small invertebrates representing an attractive animal model to study adaptive strategies for surviving extreme environments, including space environment. Tardigrades are little known microscopic aquatic animals (250-800 m in body length) distributed in different environments (from the deep sea to high mountains and deserts all over the world), and frequently inhabiting very unstable and unpredictable habitats (e.g. interstices of mosses, lichens, leaf litter, freshwater ponds, cryoconite holes). Their ability to live in the extreme environments is related to a wide variety of their life histories and adaptive strategies. A widespread and crucial strategy is cryptobiosis, a form of quiescence. It includes strategies such as anhydrobiosis and cryobiosis, characterized by

  6. Rapid adaptation of microalgae to bodies of water with extreme pollution from uranium mining: an explanation of how mesophilic organisms can rapidly colonise extremely toxic environments.

    Science.gov (United States)

    García-Balboa, C; Baselga-Cervera, B; García-Sanchez, A; Igual, J M; Lopez-Rodas, V; Costas, E

    2013-11-15

    Extreme environments may support communities of microalgae living at the limits of their tolerance. It is usually assumed that these extreme environments are inhabited by extremophile species. However, global anthropogenic environmental changes are generating new extreme environments, such as mining-effluent pools of residual waters from uranium mining with high U levels, acidity and radioactivity in Salamanca (Spain). Certain microalgal species have rapidly adapted to these extreme waters (uranium mining in this area began in 1960). Experiments have demonstrated that physiological acclimatisation would be unable to achieve adaptation. In contrast, rapid genetic adaptation was observed in waters ostensibly lethal to microalgae by means of rare spontaneous mutations that occurred prior to the exposure to effluent waters from uranium mining. However, adaptation to the most extreme conditions was only possible after recombination through sexual mating because adaptation requires more than one mutation. Microalgae living in extreme environments could be the descendants of pre-selective mutants that confer significant adaptive value to extreme contamination. These "lucky mutants" could allow for the evolutionary rescue of populations faced with rapid environmental change.

  7. Facial convective heat exchange coefficients in cold and windy environments estimated from human experiments.

    Science.gov (United States)

    Ben Shabat, Yael; Shitzer, Avraham

    2012-07-01

    Facial heat exchange convection coefficients were estimated from experimental data in cold and windy ambient conditions applicable to wind chill calculations. Measured facial temperature datasets, that were made available to this study, originated from 3 separate studies involving 18 male and 6 female subjects. Most of these data were for a -10°C ambient environment and wind speeds in the range of 0.2 to 6 m s(-1). Additional single experiments were for -5°C, 0°C and 10°C environments and wind speeds in the same range. Convection coefficients were estimated for all these conditions by means of a numerical facial heat exchange model, applying properties of biological tissues and a typical facial diameter of 0.18 m. Estimation was performed by adjusting the guessed convection coefficients in the computed facial temperatures, while comparing them to measured data, to obtain a satisfactory fit (r(2) > 0.98, in most cases). In one of the studies, heat flux meters were additionally used. Convection coefficients derived from these meters closely approached the estimated values for only the male subjects. They differed significantly, by about 50%, when compared to the estimated female subjects' data. Regression analysis was performed for just the -10°C ambient temperature, and the range of experimental wind speeds, due to the limited availability of data for other ambient temperatures. The regressed equation was assumed in the form of the equation underlying the "new" wind chill chart. Regressed convection coefficients, which closely duplicated the measured data, were consistently higher than those calculated by this equation, except for one single case. The estimated and currently used convection coefficients are shown to diverge exponentially from each other, as wind speed increases. This finding casts considerable doubts on the validity of the convection coefficients that are used in the computation of the "new" wind chill chart and their applicability to humans in

  8. Fate and Effects of Oil Pollutants in Extremely Cold Marine Environment.

    Science.gov (United States)

    nitrogen and phosphorus. Enhancement of biodegradation was greater for an oleophilic fertilizer than a water-soluble fertilizer , even with repeated...addition of the soluble fertilizer . In addition to Prudhoe crude, Arctic Diesel and JP5, as well as fractions of Prudhoe crude and individual hydrocarbons

  9. Structural Adaptation of Microorganisms For Survival In Extreme Terrestrial Cold Environments

    Science.gov (United States)

    Soina, V.

    Study of viability and diversity of microorganisms in subterranean permafrost sediments showed a high colonization of various groups of microorganisms in such biotopes. Results obtained by TEM and SEM methods demonstrate a successful preservation of cell structures both in situ and under freezing and thawing of isolated strains in model experiments. Study of microstructure of permafrost samples defined that bacterial strains, isolated from permafrost, are protected against mechanical damage by ice crystals by a gel-like sheath in which they are lying. The results obtained in model experiments revealed cell differentiation into various cell types under temperature fluctuations. Such cell types preserve high viability and were similar to the forms of microorganisms viewed by TEM methods in situ. Cytological aspects of structural stability of different types of microbial cells solated from permafrost sediments in respect to exobiology is discussed.

  10. Rapid adaptation of microalgae to bodies of water with extreme pollution from uranium mining: An explanation of how mesophilic organisms can rapidly colonise extremely toxic environments

    Energy Technology Data Exchange (ETDEWEB)

    García-Balboa, C.; Baselga-Cervera, B. [Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid (Spain); García-Sanchez, A.; Igual, J.M. [Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA-CSIC), PO Box 257, 37071 Salamanca (Spain); Lopez-Rodas, V. [Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid (Spain); Costas, E., E-mail: ecostas@vet.ucm.es [Genetica, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid (Spain)

    2013-11-15

    Highlights: •Some microalgae species survive to extreme environments in ponds of residual waters from uranium mining. •Adaptation of microalgae to U arose very fast. •Spontaneous mutations that confer large adaptive value were able to produce the adaptation to residual waters of U mining. •Adaptation to more extreme waters of U mining is only possible after the recombination subsequent to sexual mating. •Resistant microalgae bio-adsorbs uranium to the cell wall and internalises uranium inside the cytoplasm. -- Abstract: Extreme environments may support communities of microalgae living at the limits of their tolerance. It is usually assumed that these extreme environments are inhabited by extremophile species. However, global anthropogenic environmental changes are generating new extreme environments, such as mining-effluent pools of residual waters from uranium mining with high U levels, acidity and radioactivity in Salamanca (Spain). Certain microalgal species have rapidly adapted to these extreme waters (uranium mining in this area began in 1960). Experiments have demonstrated that physiological acclimatisation would be unable to achieve adaptation. In contrast, rapid genetic adaptation was observed in waters ostensibly lethal to microalgae by means of rare spontaneous mutations that occurred prior to the exposure to effluent waters from uranium mining. However, adaptation to the most extreme conditions was only possible after recombination through sexual mating because adaptation requires more than one mutation. Microalgae living in extreme environments could be the descendants of pre-selective mutants that confer significant adaptive value to extreme contamination. These “lucky mutants” could allow for the evolutionary rescue of populations faced with rapid environmental change.

  11. Extreme Environment Simulation - Current and New Capabilities to Simulate Venus and Other Planetary Bodies

    Science.gov (United States)

    Kremic, Tibor; Vento, Dan; Lalli, Nick; Palinski, Timothy

    2014-01-01

    Science, technology, and planetary mission communities have a growing interest in components and systems that are capable of working in extreme (high) temperature and pressure conditions. Terrestrial applications range from scientific research, aerospace, defense, automotive systems, energy storage and power distribution, deep mining and others. As the target environments get increasingly extreme, capabilities to develop and test the sensors and systems designed to operate in such environments will be required. An application of particular importance to the planetary science community is the ability for a robotic lander to survive on the Venus surface where pressures are nearly 100 times that of Earth and temperatures approach 500C. The scientific importance and relevance of Venus missions are stated in the current Planetary Decadal Survey. Further, several missions to Venus were proposed in the most recent Discovery call. Despite this interest, the ability to accurately simulate Venus conditions at a scale that can test and validate instruments and spacecraft systems and accurately simulate the Venus atmosphere has been lacking. This paper discusses and compares the capabilities that are known to exist within and outside the United States to simulate the extreme environmental conditions found in terrestrial or planetary surfaces including the Venus atmosphere and surface. The paper then focuses on discussing the recent additional capability found in the NASA Glenn Extreme Environment Rig (GEER). The GEER, located at the NASA Glenn Research Center in Cleveland, Ohio, is designed to simulate not only the temperature and pressure extremes described, but can also accurately reproduce the atmospheric compositions of bodies in the solar system including those with acidic and hazardous elements. GEER capabilities and characteristics are described along with operational considerations relevant to potential users. The paper presents initial operating results and concludes

  12. Development and Testing of Mechanism Technology for Space Exploration in Extreme Environments

    Science.gov (United States)

    Tyler, Tony R.; Levanas, Greg; Mojarradi, Mohammad M.; Abel, Phillip B.

    2011-01-01

    The NASA Jet Propulsion Lab (JPL), Glenn Research Center (GRC), Langley Research Center (LaRC), and Aeroflex, Inc. have partnered to develop and test actuator hardware that will survive the stringent environment of the moon, and which can also be leveraged for other challenging space exploration missions. Prototype actuators have been built and tested in a unique low temperature test bed with motor interface temperatures as low as 14 degrees Kelvin. Several years of work have resulted in specialized electro-mechanical hardware to survive extreme space exploration environments, a test program that verifies and finds limitations of the designs at extreme temperatures, and a growing knowledge base that can be leveraged by future space exploration missions.

  13. Extreme Environment Capable, Modular and Scalable Power Processing Unit for Solar Electric Propulsion

    Science.gov (United States)

    Carr, Gregory A.; Iannello, Christopher J.; Chen, Yuan; Hunter, Don J.; Del Castillo, Linda; Bradley, Arthur T.; Stell, Christopher; Mojarradi, Mohammad M.

    2013-01-01

    This paper is to present a concept of a modular and scalable High Temperature Boost (HTB) Power Processing Unit (PPU) capable of operating at temperatures beyond the standard military temperature range. The various extreme environments technologies are also described as the fundamental technology path to this concept. The proposed HTB PPU is intended for power processing in the area of space solar electric propulsion, where the reduction of in-space mass and volume are desired, and sometimes even critical, to achieve the goals of future space flight missions. The concept of the HTB PPU can also be applied to other extreme environment applications, such as geothermal and petroleum deep-well drilling, where higher temperature operation is required.

  14. Exploring knowledge about microbes living in the extreme environments – the resources review

    Directory of Open Access Journals (Sweden)

    Urszula K. Czyżewska

    2011-06-01

    Full Text Available Extremophiles are organisms that tolerate or require to live the extreme ranges of variation ofthe environmental factors such as temperature, pH, salinity, concentrations of heavy metals, highhydrostatic pressure, ionizing radiation, ultraviolet, availability of water, light, oxygen, and nutritionallylimited environments, etc. Exposure to such diverse factors caused, in the light of evolutionary changes,the appearence of many biochemical adaptations. In most cases, extremophiles are unicellular organismsbelonging to the Archaea domain, but there are also representatives of other domains (Bacteria,Eucaryota and multicellular organisms. The diversity of the Internet resources and printed materials(scientific publications reflect areas of this interest. Special characteristics of extremophiles are ofinterest to researchers in various fields of biological sciences (astrobiology, ecology, biotechnology,biospeleology. The purpose of this article is to review the most representative resources aboutmicroorganisms living in extreme environments and indicate the directions of the future research.

  15. The I.A.G./A.I.G. SEDIBUD (Sediment Budgets in Cold Environments) Program (2005 - 2017): Key activities and outcomes

    Science.gov (United States)

    Beylich, Achim A.

    2017-04-01

    Amplified climate change and ecological sensitivity of high-latitude and high-altitude cold climate environments has been highlighted as a key global environmental issue. Projected climate change in largely undisturbed cold regions is expected to alter melt-season duration and intensity, along with the number of extreme rainfall events, total annual precipitation and the balance between snowfall and rainfall. Similarly, changes to the thermal balance are expected to reduce the extent of permafrost and seasonal ground frost and increase active-layer depths. These combined effects will undoubtedly change Earth surface environments in cold regions and will alter the fluxes of sediments, solutes and nutrients. However, the absence of quantitative data and coordinated analysis to understand the sensitivity of the Earth surface environment are acute in cold regions. Contemporary cold climate environments generally provide the opportunity to identify solute and sedimentary systems where anthropogenic impacts are still less important than the effects of climate change. Accordingly, it is still possible to develop a library of baseline fluvial yields and sedimentary budgets before the natural environment is completely transformed. The SEDIBUD (Sediment Budgets in Cold Environments) Program, building on the European Science Foundation (ESF) Network SEDIFLUX (Sedimentary Source-to-Sink Fluxes in Cold Environments, since 2004) was formed in 2005 as a new Program (Working Group) of the International Association of Geomorphologists (I.A.G./A.I.G.) to address this still existing key knowledge gap. SEDIBUD (2005-2017) has currently about 400 members worldwide and the Steering Committee of this international program is composed of eleven scientists from ten different countries. The central research question of this global program is to: Assess and model the contemporary sedimentary fluxes in cold climates, with emphasis on both particulate and dissolved components. Research carried

  16. EVOLUTION OF THE CIRCADIAN CLOCK IN EXTREME ENVIRONMENT: LESSONS FROM CAVEFISH.

    OpenAIRE

    Cavallari, Nicola

    2010-01-01

    Evolution has been strongly influenced by the daily cycles of temperature and light imposed by the rotation of the Earth. Fascinating demonstrations of this are seen in extreme environments such as caves where some animals have remained completely isolated from the day-night cycle for millions of years. Most of these species show convergent evolution, sharing a range of striking physical properties such as eye loss. One fundamental issue is whether “hypogean” species retain a functional circa...

  17. GNC of the SphereX Robot for Extreme Environment Exploration on Mars

    OpenAIRE

    Kalita, Himangshu; Nallapu, Ravi teja; Warren, Andrew; Thangavelautham, Jekan

    2017-01-01

    Wheeled ground robots are limited from exploring extreme environments such as caves, lava tubes and skylights. Small robots that can utilize unconventional mobility through hopping, flying or rolling can overcome these limitations. Mul-tiple robots operating as a team offer significant benefits over a single large ro-bot, as they are not prone to single-point failure, enable distributed command and control and enable execution of tasks in parallel. These robots can complement large rovers and...

  18. Heatshield for Extreme Entry Environment Technology (HEEET) Development and Maturation Status for NF Missions

    Science.gov (United States)

    Ellerby, D.; Blosser, M.; Boghozian, T.; Chavez-Garcia, J.; Chinnapongse, R.; Fowler, M.; Gage, P.; Gasch, M.; Gonzales, G.; Hamm, K.; Kazemba, C.; Ma, J.; Mahzari, M.; Milos, F.; Nishioka, O.; Peterson, K.; Poteet, C.; Prabhu, D.; Splinter, S.; Stackpoole, M.; Venkatapathy, E.; Young, Z.

    2016-01-01

    This poster provides an overview of the requirements, design, development and testing of the 3D Woven TPS being developed under NASA's Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a Thermal Protection System (TPS) capable of surviving entry into Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2017.

  19. Heatshield for Extreme Entry Environment Technology (HEEET) - Enabling Missions Beyond Heritage Carbon Phenolic

    Science.gov (United States)

    Ellerby, D.; Beerman, A.; Blosser, M.; Boghozian, T.; Chavez-Garcia, J.; Chinnapongse, R.; Fowler, M.; Gage, P.; Gasch, M.; Gonzales, G.; Hamm, K.; Ma, J.; Milos, F.; Nishioka, O.; Poteet, C.; Splinter, S.; Stackpoole, M.; Venkatapathy, E.; Young, Z.

    2015-01-01

    This poster provides an overview of the requirements, design, development and testing of the 3D Woven TPS being developed under NASA's Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a Thermal Protection System (TPS) capable of surviving entry into Venus or Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2017.

  20. Heatshield for Extreme Entry Environment Technology (HEEET) Enabling Missions Beyond Heritage Carbon Phenolic

    Science.gov (United States)

    Ellerby, D.; Beerman, A.; Blosser, M.; Boghozian, T.; Chavez-Garcia, J.; Chinnapongse, R.; Fowler, M.; Gage, P.; Gasch, M.; Gonzaes, G.; Hamm, K.; Kazemba, C.; Ma, J.; Mahzari, M.; Milos, F.; Nishioka, O.; Peterson, K.; Poteet, C.; Prabhu, D.; Splinter, S.; Stackpoole, M.; Venkatapathy, E.; Young, Z.

    2015-01-01

    This poster provides an overview of the requirements, design, development and testing of the 3D Woven TPS being developed under NASAs Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a Thermal Protection System (TPS) capable of surviving entry into Venus or Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2017.

  1. Heatshield for Extreme Entry Environment Technology (HEEET) for Missions to Saturn and Beyond

    Science.gov (United States)

    Ellerby, D.; Blosser, M.; Chinnapongse, R.; Fowler, M.; Gasch, M.; Hamm, K.; Kazemba, C.; Ma, J.; Milos, F.; Nishioka, O.; Poteet, C.; Splinter, S.; Stackpoole, M.; Venkatapathy, E.; Young, Z.; Gasch, Matthew J.

    2015-01-01

    This poster provides an overview of the requirements, design, development and testing of the 3D Woven TPS being developed under NASAs Heatshield for Extreme Entry Environment Technology (HEEET) project. Under this current program, NASA is working to develop a Thermal Protection System (TPS) capable of surviving entry into Saturn. A primary goal of the project is to build and test an Engineering Test Unit (ETU) to establish a Technical Readiness Level (TRL) of 6 for this technology by 2017.

  2. Extreme-Environment Silicon-Carbide (SiC) Wireless Sensor Suite

    Science.gov (United States)

    Yang, Jie

    2015-01-01

    Phase II objectives: Develop an integrated silicon-carbide wireless sensor suite capable of in situ measurements of critical characteristics of NTP engine; Compose silicon-carbide wireless sensor suite of: Extreme-environment sensors center, Dedicated high-temperature (450 deg C) silicon-carbide electronics that provide power and signal conditioning capabilities as well as radio frequency modulation and wireless data transmission capabilities center, An onboard energy harvesting system as a power source.

  3. Empirical probability model of the cold plasma environment in Jovian inner magnetosphere

    CERN Document Server

    Futaana, Yoshifumi; Roussos, Elias; Trouscott, Pete; Heynderickx, Daniel; Cipriani, Fabrice; Rodgers, David

    2016-01-01

    A new empirical, analytical model of cold plasma (< 10 keV) in the Jovian inner magnetosphere is constructed. Plasmas in this energy range impact surface charging. A new feature of this model is predicting each plasma parameter for a specified probability (percentile). The new model was produced as follows. We start from a reference model for each plasma parameter, which was scaled to fit the data of Galileo plasma spectrometer. The scaled model was then represented as a function of radial distance, magnetic local time, and magnetic latitude, presumably describing the mean states. Then, the deviation of the observed values from the model were attribute to the variability in the environment, which was accounted for by the percentile at a given location.The input parameters for this model are the spacecraft position and the percentile. The model is inteded to be used for the JUICE mission analysis.

  4. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-12-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  5. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment.

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L; McCulloch, Malcolm T

    2015-12-02

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  6. Alteration of a human intestinal microbiota under extreme life environment in the Antarctica.

    Science.gov (United States)

    Jin, Jong-Sik; Touyama, Mutsumi; Yamada, Shin; Yamazaki, Takashi; Benno, Yoshimi

    2014-01-01

    The human intestinal microbiota (HIM) settles from birth and continues to change phenotype by some factors (e.g. host's diet) throughout life. However, the effect of extreme life environment on human HIM composition is not well known. To understand HIM fluctuation under extreme life environment in humans, fecal samples were collected from six Japanese men on a long Antarctic expedition. They explored Antarctica for 3 months and collected their fecal samples at once-monthly intervals. Using terminal restriction fragment length polymorphism (T-RFLP) and real time polymerase chain reaction (PCR) analysis, the composition of HIM in six subjects was investigated. Three subjects presented restoration of HIM after the expedition compared versus before and during the expedition. Two thirds samples collected during the expedition belonged to the same cluster in dendrogram. However, all through the expedition, T-RFLP patterns showed interindividual variability. Especially, Bifidobacterium spp. showed a tendency to decrease during and restore after the expedition. A reduction of Bifidobacterium spp. was observed in five subjects the first 1 month of the expedition. Bacteroides thetaiotaomicron, which is thought to proliferate during emotional stress, significantly decreased in one subject, indicating that other factors in addition to emotional stress may affect the composition of HIM in this study. These findings could be helpful to understand the effect of extreme life environment on HIM.

  7. Improved cultivation and metagenomics as new tools for bioprospecting in cold environments

    DEFF Research Database (Denmark)

    Vester, Jan Kjølhede; Glaring, Mikkel Andreas; Stougaard, Peter

    2015-01-01

    into the laboratory or through metagenomic approaches where culture-independent DNA sequence information can be combined with functional screening. The coupling of these two approaches circumvents the need for pure, cultured isolates and can be used to generate targeted information on communities enriched...... for specific activities or properties. Bioprospecting in extreme environments is often associated with additional challenges such as low biomass, slow cell growth, complex sample matrices, restricted access, and problematic in situ analyses. In addition, the choice of vector system and expression host may...

  8. Two-dimensional Electrophoresis Analysis of Proteins in Response to Cold Stress in Extremely Cold-resistant Winter Wheat Dongnongdongmai 1 Tillering Nodes

    Institute of Scientific and Technical Information of China (English)

    Cang Jing; Yu Jing; Liu Li-jie; Yang Yang; Cui Hong; Hao Zai-bin; Li Zhuo-fu

    2012-01-01

    The overwintering survival ratio of the cultivar Dongnongdongmai 1 with strong cold-resistance in paramos of Heilongjiang Province in China are over 85%. The tillering nodes are the most important organs for overwintering survival of winter wheat, because there are more substances associated with cold resistance in tillering nodes than those in leaves and roots. Proteins in the tillering nodes of the cold-resistant cultivar Dongnongdongmai 1 grown under field conditions with or without any lowtemperature stress were analyzed by 2-dimensional electrophoresis and identified by mass spectrometry. In the range of pH 4-7, the expression of 37 proteins showed obvious difference (±more than two fold) in the proteomic maps of cold-stressed and non-stressed tillering nodes, including a new protein spot. All proteins exhibiting the difference in expression were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, followed by a database search for protein identification and function prediction. Five groups of proteins were confirmed, namely stress-related proteins (22%), metabolism-associated proteins (35%), and signaling molecules (24%), cell wall-binding proteins (5%), unclear proteins (14%). This indicated that tillering node cells supported the energy requirements of plant growth and stress resistance by signal transduction adapting to metabolism and structure.

  9. Copahue Geothermal System: A Volcanic Environment with Rich Extreme Prokaryotic Biodiversity

    Directory of Open Access Journals (Sweden)

    María Sofía Urbieta

    2015-07-01

    Full Text Available The Copahue geothermal system is a natural extreme environment located at the northern end of the Cordillera de los Andes in Neuquén province in Argentina. The geochemistry and consequently the biodiversity of the area are dominated by the activity of the Copahue volcano. The main characteristic of Copahue is the extreme acidity of its aquatic environments; ponds and hot springs of moderate and high temperature as well as Río Agrio. In spite of being an apparently hostile location, the prokaryotic biodiversity detected by molecular ecology techniques as well as cultivation shows a rich and diverse environment dominated by acidophilic, sulphur oxidising bacteria or archaea, depending on the conditions of the particular niche studied. In microbial biofilms, found in the borders of the ponds where thermal activity is less intense, the species found are completely different, with a high presence of cyanobacteria and other photosynthetic species. Our results, collected during more than 10 years of work in Copahue, have enabled us to outline geomicrobiological models for the different environments found in the ponds and Río Agrio. Besides, Copahue seems to be the habitat of novel, not yet characterised autochthonous species, especially in the domain Archaea.

  10. Copahue Geothermal System: A Volcanic Environment with Rich Extreme Prokaryotic Biodiversity.

    Science.gov (United States)

    Urbieta, María Sofía; Porati, Graciana Willis; Segretín, Ana Belén; González-Toril, Elena; Giaveno, María Alejandra; Donati, Edgardo Rubén

    2015-07-08

    The Copahue geothermal system is a natural extreme environment located at the northern end of the Cordillera de los Andes in Neuquén province in Argentina. The geochemistry and consequently the biodiversity of the area are dominated by the activity of the Copahue volcano. The main characteristic of Copahue is the extreme acidity of its aquatic environments; ponds and hot springs of moderate and high temperature as well as Río Agrio. In spite of being an apparently hostile location, the prokaryotic biodiversity detected by molecular ecology techniques as well as cultivation shows a rich and diverse environment dominated by acidophilic, sulphur oxidising bacteria or archaea, depending on the conditions of the particular niche studied. In microbial biofilms, found in the borders of the ponds where thermal activity is less intense, the species found are completely different, with a high presence of cyanobacteria and other photosynthetic species. Our results, collected during more than 10 years of work in Copahue, have enabled us to outline geomicrobiological models for the different environments found in the ponds and Río Agrio. Besides, Copahue seems to be the habitat of novel, not yet characterised autochthonous species, especially in the domain Archaea.

  11. An exceptionally cold-adapted alpha-amylase from a metagenomic library of a cold and alkaline environment

    DEFF Research Database (Denmark)

    Vester, Jan Kjølhede; Glaring, Mikkel Andreas; Stougaard, Peter

    2015-01-01

    A cold-active α-amylase, AmyI3C6, identified by a functional metagenomics approach was expressed in Escherichia coli and purified to homogeneity. Sequence analysis showed that the AmyI3C6 amylase was similar to α-amylases from the class Clostridia and revealed classical characteristics of cold......-adapted enzymes, as did comparison of the kinetic parameters Km and kcat to a mesophilic α-amylase. AmyI3C6 was shown to be heat-labile. Temperature optimum was at 10-15 °C, and more than 70 % of the relative activity was retained at 1 °C. The pH optimum of AmyI3C6 was at pH 8-9, and the enzyme displayed activity...... in two commercial detergents tested, suggesting that the AmyI3C6 α-amylase may be useful as a detergent enzyme in environmentally friendly, low-temperature laundry processes....

  12. Consideration of Task Performance for Robots Engaged in Extremely Dangerous Environment in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seung Mo; Han, Kee Soo; Yi, Sung Deok; Kim, Seoung Rae [Nuclear Engineering Service and Solution Co. Ltd., Daejeon (Korea, Republic of); Choi, Young [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    After Fukushima Daiichi Nuclear Accident, it is started to pay more attention to operation and accident of nuclear power plants (NPPs). For domestic nuclear industry, it was recommended to establish corresponding strategies against accidents due to extremely dangerous natural disasters. Each nuclear power plant is also preparing to establish strategies to secure nuclear safety functions by estimating the counterplans for extreme accidents. Robots are particularly being used to access the areas where those are dangerous for human beings to access or to restore the accident. Robot technologies in NPPs are emerging cutting-edge technologies that are just a start except the developed countries like USA, Japan, etc. But they are carefully considered because they have the advantages of performing tasks in extremely dangerous environment in NPPs instead of human beings. In this study, the applicability of robots will be considered in extremely dangerous environment in NPPs. Accurate judgment of the inside situation of the plant and quick actions in the extreme condition like earthquake accompanied by loss of all AC powers should be considered as major function in terms of prevention of accident spread. According to the reported stress test results of domestic NPPs, the difficult things for operators to carry out in extreme conditions can be predictable, therefore the active use of robots as accident mitigation strategies will be helpful to reduce the unnecessary spending for facility improvement. Current trend of domestic and foreign robot technology development focuses on the information search of the inside of the plant and development of preventive maintenance of NPPs. As seen actually in Fukushima Daiichi, main roles of robots place emphasis on measuring the inside radiation level accessing to the area where operator cannot access and delivering information which can support operator's decision-making and actions. Therefore, it is considered that development of

  13. Nanomaterials in Extreme Environments: Fundamentals and Applications Rostislav A. Andrievski and Arsen V. Khatchoyan

    Energy Technology Data Exchange (ETDEWEB)

    Devanathan, Ram

    2016-10-01

    Nanomaterials in Extreme Environments Rostislav A. Andrievski and Arsen V. Khatchoyan Springer, 2016 106 pages, $99.00 (e-book $69.99) ISBN 978–3-319–25331–2 This slim volume is an extensive review of our current understanding of the response of nanostructured materials to extreme operating conditions, such as high temperature, flux of high energy neutrons, high pressure, mechanical stress, and oxidizing environments. The emphasis is on metallic materials, especially Cu alloys. Graphene-based materials, fullerenes, polymeric materials, nano-glasses and glass-ceramics are not covered by this review. The book has six chapters including an introduction and a brief conclusion. The introduction documents the growth of scientific interest in nanostructured materials and stresses the need to study the behavior of nanomaterials under extreme conditions. This chapter also presents Herbert Gleiter’s classification of nanomaterials into twelve groups based on the shapes of the nanoscale features and chemical composition of the components of the nanostructure. The second chapter deals with the high temperature environment and the thermodynamics and kinetics of grain growth. The authors identify the lack of reliable thermodynamic data as a key limitation in this field. The discussion brings out the interplay of structural relaxation, redistribution of excess free volume, diffusion, and recrystallization in multicomponent nanostructures at elevated temperature. Chapter 3 focuses on the effects of ion and neutron irradiation on the structure and properties of nanomaterials. The authors do a good job of highlighting recent studies on the radiation tolerance of nanocrystalline oxides and rapid grain growth under irradiation. The material addresses both fission and fusion reactor applications. Chapter 4 reviews the effects of severe plastic deformation and cyclic loading on nanostructure formation and phase transformation. This chapter also explores the challenge of

  14. Enabling Structured Exploration of Workflow Performance Variability in Extreme-Scale Environments

    Energy Technology Data Exchange (ETDEWEB)

    Kleese van Dam, Kerstin; Stephan, Eric G.; Raju, Bibi; Altintas, Ilkay; Elsethagen, Todd O.; Krishnamoorthy, Sriram

    2015-11-15

    Workflows are taking an Workflows are taking an increasingly important role in orchestrating complex scientific processes in extreme scale and highly heterogeneous environments. However, to date we cannot reliably predict, understand, and optimize workflow performance. Sources of performance variability and in particular the interdependencies of workflow design, execution environment and system architecture are not well understood. While there is a rich portfolio of tools for performance analysis, modeling and prediction for single applications in homogenous computing environments, these are not applicable to workflows, due to the number and heterogeneity of the involved workflow and system components and their strong interdependencies. In this paper, we investigate workflow performance goals and identify factors that could have a relevant impact. Based on our analysis, we propose a new workflow performance provenance ontology, the Open Provenance Model-based WorkFlow Performance Provenance, or OPM-WFPP, that will enable the empirical study of workflow performance characteristics and variability including complex source attribution.

  15. Compact genome of the Antarctic midge is likely an adaptation to an extreme environment

    Science.gov (United States)

    Kelley, Joanna L.; Peyton, Justin T.; Fiston-Lavier, Anna-Sophie; Teets, Nicholas M.; Yee, Muh-Ching; Johnston, J. Spencer; Bustamante, Carlos D.; Lee, Richard E.; Denlinger, David L.

    2014-01-01

    The midge, Belgica antarctica, is the only insect endemic to Antarctica, and thus it offers a powerful model for probing responses to extreme temperatures, freeze tolerance, dehydration, osmotic stress, ultraviolet radiation and other forms of environmental stress. Here we present the first genome assembly of an extremophile, the first dipteran in the family Chironomidae, and the first Antarctic eukaryote to be sequenced. At 99 megabases, B. antarctica has the smallest insect genome sequenced thus far. Although it has a similar number of genes as other Diptera, the midge genome has very low repeat density and a reduction in intron length. Environmental extremes appear to constrain genome architecture, not gene content. The few transposable elements present are mainly ancient, inactive retroelements. An abundance of genes associated with development, regulation of metabolism and responses to external stimuli may reflect adaptations for surviving in this harsh environment. PMID:25118180

  16. Compact genome of the Antarctic midge is likely an adaptation to an extreme environment.

    Science.gov (United States)

    Kelley, Joanna L; Peyton, Justin T; Fiston-Lavier, Anna-Sophie; Teets, Nicholas M; Yee, Muh-Ching; Johnston, J Spencer; Bustamante, Carlos D; Lee, Richard E; Denlinger, David L

    2014-08-12

    The midge, Belgica antarctica, is the only insect endemic to Antarctica, and thus it offers a powerful model for probing responses to extreme temperatures, freeze tolerance, dehydration, osmotic stress, ultraviolet radiation and other forms of environmental stress. Here we present the first genome assembly of an extremophile, the first dipteran in the family Chironomidae, and the first Antarctic eukaryote to be sequenced. At 99 megabases, B. antarctica has the smallest insect genome sequenced thus far. Although it has a similar number of genes as other Diptera, the midge genome has very low repeat density and a reduction in intron length. Environmental extremes appear to constrain genome architecture, not gene content. The few transposable elements present are mainly ancient, inactive retroelements. An abundance of genes associated with development, regulation of metabolism and responses to external stimuli may reflect adaptations for surviving in this harsh environment.

  17. An Overview of 2014 SBIR Phase I and Phase II Materials Structures for Extreme Environments

    Science.gov (United States)

    Nguyen, Hung D.; Steele, Gynelle C.; Morris, Jessica R.

    2015-01-01

    NASA's Small Business Innovation Research (SBIR) program focuses on technological innovation by investing in development of innovative concepts and technologies to help NASA mission directorates address critical research needs for Agency programs. This report highlights nine of the innovative SBIR 2014 Phase I and Phase II projects that emphasize one of NASA Glenn Research Center's six core competencies-Materials and Structures for Extreme Environments. The technologies cover a wide spectrum of applications such as high temperature environmental barrier coating systems, deployable space structures, solid oxide fuel cells, and self-lubricating hard coatings for extreme temperatures. Each featured technology describes an innovation, technical objective, and highlights NASA commercial and industrial applications. This report provides an opportunity for NASA engineers, researchers, and program managers to learn how NASA SBIR technologies could help their programs and projects, and lead to collaborations and partnerships between the small SBIR companies and NASA that would benefit both.

  18. Evaporation from Bare Soil in Extremely Arid Environment in Southern Israel

    Institute of Scientific and Technical Information of China (English)

    WANGXUEFENG; XUFUAN; 等

    1996-01-01

    Microlysimeters of different sizes(5cm 10cm and 15cm in length) were used extensively in the present study of the measurements of soil evaporation in situ in an extremely arid area in southern Israel,All of the data obtained from the microlysimeters were used to evaluate two conventional evaporation models developed by Black et al.and Ritchie,respectively.Our results indicated that the models could overestimate total cumulative evaporation by about 30% in the extremely arid environment.Reducing the power factor of the conventional model by a factor of 0.1 produced good agreement between the measured and simulated cumulative evaporation.Microlysimeter method proved to be a simple and accurate approach for the evaluation of soil evaporation.

  19. Constant, cycling, hot and cold thermal environments: strong effects on mean viability but not on genetic estimates

    DEFF Research Database (Denmark)

    Ketola, Tarmo; Kellermann, Vanessa; Kristensen, Torsten Nygård;

    2012-01-01

    It has frequently been suggested that trait heritabilities are environmentally sensitive, and there are genetic trade-offs between tolerating different environments such as hot and cold or constant and fluctuating temperatures. Future climate predictions suggest an increase in both temperatures a...

  20. Pyrosequencing-Based Assessment of the Microbial Community Structure of Pastoruri Glacier Area (Huascarán National Park, Perú), a Natural Extreme Acidic Environment.

    Science.gov (United States)

    González-Toril, Elena; Santofimia, Esther; Blanco, Yolanda; López-Pamo, Enrique; Gómez, Manuel J; Bobadilla, Miguel; Cruz, Rolando; Palomino, Edwin Julio; Aguilera, Ángeles

    2015-11-01

    The exposure of fresh sulfide-rich lithologies by the retracement of the Nevado Pastoruri glacier (Central Andes, Perú) is increasing the presence of heavy metals in the water as well as decreasing the pH, producing an acid rock drainage (ARD) process in the area. We describe the microbial communities of an extreme ARD site in Huascarán National Park as well as their correlation with the water physicochemistry. Microbial biodiversity was analyzed by FLX 454 sequencing of the 16S rRNA gene. The suggested geomicrobiological model of the area distinguishes three different zones. The proglacial zone is located in the upper part of the valley, where the ARD process is not evident yet. Most of the OTUs detected in this area were related to sequences associated with cold environments (i.e., psychrotolerant species of Cyanobacteria or Bacteroidetes). After the proglacial area, an ARD-influenced zone appeared, characterized by the presence of phylotypes related to acidophiles (Acidiphilium) as well as other species related to acidic and cold environments (i.e., acidophilic species of Chloroflexi, Clostridium and Verrumicrobia). Sulfur- and iron-oxidizing acidophilic bacteria (Acidithiobacillus) were also identified. The post-ARD area was characterized by the presence of OTUs related to microorganisms detected in soils, permafrost, high mountain environments, and deglaciation areas (Sphingomonadales, Caulobacter or Comamonadaceae).

  1. Reliability of High I/O High Density CCGA Interconnect Electronic Packages under Extreme Thermal Environment

    Science.gov (United States)

    Ramesham, Rajeshuni

    2012-01-01

    This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions. Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surface-mount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non

  2. Reliability of High I/O High Density CCGA Interconnect Electronic Packages under Extreme Thermal Environment

    Science.gov (United States)

    Ramesham, Rajeshuni

    2012-01-01

    This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non-destructive inspection tools were used to assess the reliability of high density CCGA packages for deep space extreme temperature missions. Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performances, compatibility with standard surface-mount packaging assembly processes, and so on. CCGA packages are used in space applications such as in logic and microprocessor functions, telecommunications, payload electronics, and flight avionics. As these packages tend to have less solder joint strain relief than leaded packages or more strain relief over lead-less chip carrier packages, the reliability of CCGA packages is very important for short-term and long-term deep space missions. We have employed high density CCGA 1152 and 1272 daisy chained electronic packages in this preliminary reliability study. Each package is divided into several daisy-chained sections. The physical dimensions of CCGA1152 package is 35 mm x 35 mm with a 34 x 34 array of columns with a 1 mm pitch. The dimension of the CCGA1272 package is 37.5 mm x 37.5 mm with a 36 x 36 array with a 1 mm pitch. The columns are made up of 80% Pb/20%Sn material. CCGA interconnect electronic package printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging techniques. The assembled CCGA boards were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space missions. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling. This paper provides the experimental test results of advanced CCGA packages tested in extreme temperature thermal environments. Standard optical inspection and x-ray non

  3. Can we colonize the solar system? Human biology and survival in the extreme space environment.

    Science.gov (United States)

    Launius, Roger D

    2010-09-01

    Throughout the history of the space age the dominant vision for the future has been great spaceships plying the solar system, and perhaps beyond, moving living beings from one planet to another. Spacesuited astronauts would carry out exploration, colonization, and settlement as part of a relentlessly forward looking movement of humanity beyond Earth. As time has progressed this image has not changed appreciably even as the full magnitude of the challenges it represents have become more and more apparent. This essay explores the issues associated with the human movement beyond Earth and raises questions about whether humanity will ever be able to survive in the extreme environment of space and the other bodies of the solar system. This paper deals with important historical episodes as well as wider conceptual issues about life in space. Two models of expansion beyond Earth are discussed: (1) the movement of microbes and other types of life on Earth that can survive the space environment and (2) the modification of humans into cyborgs for greater capability to survive in the extreme environments encountered beyond this planet.

  4. Evaluation of pediatric lower extremity fractures managed with external fixation: outcomes in a deployed environment.

    Science.gov (United States)

    Eichinger, Josef K; McKenzie, Colin S; Devine, John G

    2012-01-01

    External fixation of pediatric lower extremity fractures is usually reserved for severe, open fractures in polytraumatized patients, but it is often the only available treatment option for deployed military surgeons. We analyzed the outcomes and complications of 17 consecutive pediatric long bone fractures treated with external fixation at a Forward Surgical Team facility in an austere environment during Operation Enduring Freedom in Afghanistan during a 12-month period. Treatment consisted of uniplanar external fixation for 12 femoral shaft fractures (11 closed), 4 tibial shaft fractures (all open), and 1 subtrochanteric fracture (closed) in 14 males and 3 females with an average age of 7.4 years. All 17 fractures went on to union with no incidences of refracture. Complications included 1 broken pin and 3 pin site infections treated with wound care and oral antibiotics. In a deployed environment, external fixation is the treatment method of choice for lower extremity fractures by virtue of patient, environment, equipment, and mission factors. This case series validates the usage of a simple, uniplanar external fixator for a variety of open and closed pediatric long bone fractures as evidenced by the successful union rate and low number of complications.

  5. Ion Pair in Extreme Aqueous Environments, Molecular-Based and Electric Conductance Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Chialvo, Ariel A [ORNL; Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Simonson, J Michael {Mike} [ORNL; Palmer, Donald [ORNL; Cole, David R [ORNL

    2009-01-01

    We determine by molecular-based simulation the density profiles of the Na+!Cl! ion-pair association constant in steam environments along three supercritical isotherms to interrogate the behavior of ion speciation in dilute aqueous solutions at extreme conditions. Moreover, we describe a new ultra-sensitive flow-through electric conductance apparatus designed to bridge the gap between the currently lowest steam-density conditions at which we are experimentally able to attain electric conductance measurements and the theoretically-reachable zero-density limit. Finally, we highlight important modeling challenges encountered near the zero-density limit and discuss ways to overcome them.

  6. Bipolar integrated circuits in SiC for extreme environment operation

    Science.gov (United States)

    Zetterling, Carl-Mikael; Hallén, Anders; Hedayati, Raheleh; Kargarrazi, Saleh; Lanni, Luigia; Malm, B. Gunnar; Mardani, Shabnam; Norström, Hans; Rusu, Ana; Saveda Suvanam, Sethu; Tian, Ye; Östling, Mikael

    2017-03-01

    Silicon carbide (SiC) integrated circuits have been suggested for extreme environment operation. The challenge of a new technology is to develop process flow, circuit models and circuit designs for a wide temperature range. A bipolar technology was chosen to avoid the gate dielectric weakness and low mobility drawback of SiC MOSFETs. Higher operation temperatures and better radiation hardness have been demonstrated for bipolar integrated circuits. Both digital and analog circuits have been demonstrated in the range from room temperature to 500 °C. Future steps are to demonstrate some mixed signal circuits of greater complexity. There are remaining challenges in contacting, metallization, packaging and reliability.

  7. Greenhouses in extreme environments: The Arthur Clarke Mars Greenhouse design and operation overview

    Science.gov (United States)

    Giroux, Richard; Berinstain, Alain; Braham, Stephen; Graham, Thomas; Bamsey, Matthew; Boyd, Keegan; Silver, Matthew; Lussier-Desbiens, Alexis; Lee, Pascal; Boucher, Marc; Cowing, Keith; Dixon, Michael

    2006-01-01

    Since its deployment on Devon Island, Canadian High Arctic, in 2002, the Haughton Mars Project's Arthur Clarke Mars Greenhouse (ACMG) has supported extreme environment related scientific and operation research that is relevant to Mars analogue studies - each at a specific level of fidelity and complexity. The Greenhouse serves as an initial experimental test-bed supporting field research, from which lessons may be learned to support the design and implementation of future field facilities, and enabling higher fidelity demonstrations. This paper provides an overall description of the ACMG, describes the different subsystems, explains its operational modes, details some results over the three years of operation and discusses future development plans.

  8. Responses of the bed bug, Cimex lectularius, to temperature extremes and dehydration: levels of tolerance, rapid cold hardening and expression of heat shock proteins.

    Science.gov (United States)

    Benoit, J B; Lopez-Martinez, G; Teets, N M; Phillips, S A; Denlinger, D L

    2009-12-01

    This study of the bed bug, Cimex lectularius, examines tolerance of adult females to extremes in temperature and loss of body water. Although the supercooling point (SCP) of the bed bugs was approximately -20 degrees C, all were killed by a direct 1 h exposure to -16 degrees C. Thus, this species cannot tolerate freezing and is killed at temperatures well above its SCP. Neither cold acclimation at 4 degrees C for 2 weeks nor dehydration (15% loss of water content) enhanced cold tolerance. However, bed bugs have the capacity for rapid cold hardening, i.e. a 1-h exposure to 0 degrees C improved their subsequent tolerance of -14 and -16 degrees C. In response to heat stress, fewer than 20% of the bugs survived a 1-h exposure to 46 degrees C, and nearly all were killed at 48 degrees C. Dehydration, heat acclimation at 30 degrees C for 2 weeks and rapid heat hardening at 37 degrees C for 1 h all failed to improve heat tolerance. Expression of the mRNAs encoding two heat shock proteins (Hsps), Hsp70 and Hsp90, was elevated in response to heat stress, cold stress and during dehydration and rehydration. The response of Hsp90 was more pronounced than that of Hsp70 during dehydration and rehydration. Our results define the tolerance limits for bed bugs to these commonly encountered stresses of temperature and low humidity and indicate a role for Hsps in responding to these stresses.

  9. Tolerance of anhydrobiotic eggs of the Tardigrade Ramazzottius varieornatus to extreme environments.

    Science.gov (United States)

    Horikawa, Daiki D; Yamaguchi, Ayami; Sakashita, Tetsuya; Tanaka, Daisuke; Hamada, Nobuyuki; Yukuhiro, Fumiko; Kuwahara, Hirokazu; Kunieda, Takekazu; Watanabe, Masahiko; Nakahara, Yuichi; Wada, Seiichi; Funayama, Tomoo; Katagiri, Chihiro; Higashi, Seigo; Yokobori, Shin-Ichi; Kuwabara, Mikinori; Rothschild, Lynn J; Okuda, Takashi; Hashimoto, Hirofumi; Kobayashi, Yasuhiko

    2012-04-01

    Tardigrades are tiny (less than 1 mm in length) invertebrate animals that have the potential to survive travel to other planets because of their tolerance to extreme environmental conditions by means of a dry ametabolic state called anhydrobiosis. While the tolerance of adult tardigrades to extreme environments has been reported, there are few reports on the tolerance of their eggs. We examined the ability of hydrated and anhydrobiotic eggs of the tardigrade Ramazzottius varieornatus to hatch after exposure to ionizing irradiation (helium ions), extremely low and high temperatures, and high vacuum. We previously reported that there was a similar pattern of tolerance against ionizing radiation between hydrated and anhydrobiotic adults. In contrast, anhydrobiotic eggs (50% lethal dose; 1690 Gy) were substantially more radioresistant than hydrated ones (50% lethal dose; 509 Gy). Anhydrobiotic eggs also have a broader temperature resistance compared with hydrated ones. Over 70% of the anhydrobiotic eggs treated at either -196°C or +50°C hatched successfully, but all the hydrated eggs failed to hatch. After exposure to high-vacuum conditions (5.3×10(-4) Pa to 6.2×10(-5) Pa), the hatchability of the anhydrobiotic eggs was comparable to that of untreated control eggs.

  10. Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

    Science.gov (United States)

    Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

    2016-01-01

    Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

  11. A study of meteorological variables in some extreme environments via cross correlations

    Science.gov (United States)

    Cruz-Kuri, L.; McKay, C. P.; Navarro-Gonzalez, R.

    Some of us have been studying soils in the Atacama Desert, Chile and in Pico de Orizaba, Mexico. The Atacama, is an extreme, arid, temperate desert that extends across 1000 km with monthly mean air temperatures between 16 to 14°C and is remarkably uniform throughout the year (±3°C). Pico de Orizaba (19° N) is a mountain that possesses a glacier and has tropical alpine environments. Both of such environments are of interest as models for Mars. Meteorological data for the Yungay area of the Atacama Desert, as well as meteorological data of the Northern and Southern faces of Pico de Orizaba have been collected. Both sets of data were analyzed using the cross correlation technique of multivariate time series. In this report we describe some of the patterns found for these statistics.

  12. The Relationship Between Walkability and Environment Characteristics in Cold Region Cities: Case Study in Harbin

    Science.gov (United States)

    Ye, Yang; Fei, Teng; Mei, Hongyuan

    2017-05-01

    This study attempts to comprehensively and objectively understand whether the physical characteristic of urban space affect the walkability of Harbin city center. Besides, due to Harbin is located in the cold region, the temperature change a lot between winter and summer, this study also tried to find out whether the physical environment characteristics effect on walkability is different in winter and summer. Spatial feature and traffic management have been thought as the main determinate of walkability of urban space, however physical features and urban design details have been rarely mentioned. Yet, does physical quality deterioration of space decrease the walkability of urban center, does specific physical feature influence walkability differently in different season? To answer these question, users’ perception toward the physical features of mix-used streets, have been examined in this study. 14 physical characteristic problems have been identified in the studied area based on the understanding of pervious researches. Through observations and questionnaire surveys, the physical characteristics of each case study were evaluated and the physical problems were discovered. Additionally, users’ perception on the identified problems and their effects on walkability of the studied areas were found and defined, in both winter and summer.

  13. Biota and Biomolecules in Extreme Environments on Earth: Implications for Life Detection on Mars

    Directory of Open Access Journals (Sweden)

    Joost W. Aerts

    2014-10-01

    Full Text Available The three main requirements for life as we know it are the presence of organic compounds, liquid water, and free energy. Several groups of organic compounds (e.g., amino acids, nucleobases, lipids occur in all life forms on Earth and are used as diagnostic molecules, i.e., biomarkers, for the characterization of extant or extinct life. Due to their indispensability for life on Earth, these biomarkers are also prime targets in the search for life on Mars. Biomarkers degrade over time; in situ environmental conditions influence the preservation of those molecules. Nonetheless, upon shielding (e.g., by mineral surfaces, particular biomarkers can persist for billions of years, making them of vital importance in answering questions about the origins and limits of life on early Earth and Mars. The search for organic material and biosignatures on Mars is particularly challenging due to the hostile environment and its effect on organic compounds near the surface. In support of life detection on Mars, it is crucial to investigate analogue environments on Earth that resemble best past and present Mars conditions. Terrestrial extreme environments offer a rich source of information allowing us to determine how extreme conditions affect life and molecules associated with it. Extremophilic organisms have adapted to the most stunning conditions on Earth in environments with often unique geological and chemical features. One challenge in detecting biomarkers is to optimize extraction, since organic molecules can be low in abundance and can strongly adsorb to mineral surfaces. Methods and analytical tools in the field of life science are continuously improving. Amplification methods are very useful for the detection of low concentrations of genomic material but most other organic molecules are not prone to amplification methods. Therefore, a great deal depends on the extraction efficiency. The questions “what to look for”, “where to look”, and “how to

  14. Biota and biomolecules in extreme environments on Earth: implications for life detection on Mars.

    Science.gov (United States)

    Aerts, Joost W; Röling, Wilfred F M; Elsaesser, Andreas; Ehrenfreund, Pascale

    2014-10-13

    The three main requirements for life as we know it are the presence of organic compounds, liquid water, and free energy. Several groups of organic compounds (e.g., amino acids, nucleobases, lipids) occur in all life forms on Earth and are used as diagnostic molecules, i.e., biomarkers, for the characterization of extant or extinct life. Due to their indispensability for life on Earth, these biomarkers are also prime targets in the search for life on Mars. Biomarkers degrade over time; in situ environmental conditions influence the preservation of those molecules. Nonetheless, upon shielding (e.g., by mineral surfaces), particular biomarkers can persist for billions of years, making them of vital importance in answering questions about the origins and limits of life on early Earth and Mars. The search for organic material and biosignatures on Mars is particularly challenging due to the hostile environment and its effect on organic compounds near the surface. In support of life detection on Mars, it is crucial to investigate analogue environments on Earth that resemble best past and present Mars conditions. Terrestrial extreme environments offer a rich source of information allowing us to determine how extreme conditions affect life and molecules associated with it. Extremophilic organisms have adapted to the most stunning conditions on Earth in environments with often unique geological and chemical features. One challenge in detecting biomarkers is to optimize extraction, since organic molecules can be low in abundance and can strongly adsorb to mineral surfaces. Methods and analytical tools in the field of life science are continuously improving. Amplification methods are very useful for the detection of low concentrations of genomic material but most other organic molecules are not prone to amplification methods. Therefore, a great deal depends on the extraction efficiency. The questions "what to look for", "where to look", and "how to look for it" require more of

  15. Predictors of Behavior and Performance in Extreme Environments: The Antarctic Space Analogue Program

    Science.gov (United States)

    Palinkas, Lawrence A.; Gunderson, E K. Eric; Holland, A. W.; Miller, Christopher; Johnson, Jeffrey C.

    2000-01-01

    To determine which, if any, characteristics should be incorporated into a select-in approach to screening personnel for long-duration spaceflight, we examined the influence of crewmember social/ demographic characteristics, personality traits, interpersonal needs, and characteristics of station physical environments on performance measures in 657 American men who spent an austral winter in Antarctica between 1963 and 1974. During screening, subjects completed a Personal History Questionnaire which obtained information on social and demographic characteristics, the Deep Freeze Opinion Survey which assessed 5 different personality traits, and the Fundamental Interpersonal Relations Orientation-Behavior (FIRO-B) Scale which measured 6 dimensions of interpersonal needs. Station environment included measures of crew size and severity of physical environment. Performance was assessed on the basis of combined peer-supervisor evaluations of overall performance, peer nominations of fellow crewmembers who made ideal winter-over candidates, and self-reported depressive symptoms. Social/demographic characteristics, personality traits, interpersonal needs, and characteristics of station environments collectively accounted for 9-17% of the variance in performance measures. The following characteristics were significant independent predictors of more than one performance measure: military service, low levels of neuroticism, extraversion and conscientiousness, and a low desire for affection from others. These results represent an important first step in the development of select-in criteria for personnel on long-duration missions in space and other extreme environments. These criteria must take into consideration the characteristics of the environment and the limitations they place on meeting needs for interpersonal relations and task performance, as well as the characteristics of the individuals and groups who live and work in these environments.

  16. Predictors of Behavior and Performance in Extreme Environments: The Antarctic Space Analogue Program

    Science.gov (United States)

    Palinkas, Lawrence A.; Gunderson, E K. Eric; Holland, A. W.; Miller, Christopher; Johnson, Jeffrey C.

    2000-01-01

    To determine which, if any, characteristics should be incorporated into a select-in approach to screening personnel for long-duration spaceflight, we examined the influence of crewmember social/ demographic characteristics, personality traits, interpersonal needs, and characteristics of station physical environments on performance measures in 657 American men who spent an austral winter in Antarctica between 1963 and 1974. During screening, subjects completed a Personal History Questionnaire which obtained information on social and demographic characteristics, the Deep Freeze Opinion Survey which assessed 5 different personality traits, and the Fundamental Interpersonal Relations Orientation-Behavior (FIRO-B) Scale which measured 6 dimensions of interpersonal needs. Station environment included measures of crew size and severity of physical environment. Performance was assessed on the basis of combined peer-supervisor evaluations of overall performance, peer nominations of fellow crewmembers who made ideal winter-over candidates, and self-reported depressive symptoms. Social/demographic characteristics, personality traits, interpersonal needs, and characteristics of station environments collectively accounted for 9-17% of the variance in performance measures. The following characteristics were significant independent predictors of more than one performance measure: military service, low levels of neuroticism, extraversion and conscientiousness, and a low desire for affection from others. These results represent an important first step in the development of select-in criteria for personnel on long-duration missions in space and other extreme environments. These criteria must take into consideration the characteristics of the environment and the limitations they place on meeting needs for interpersonal relations and task performance, as well as the characteristics of the individuals and groups who live and work in these environments.

  17. A cold-adapted reptile becomes a more effective thermoregulator in a thermally challenging environment.

    Science.gov (United States)

    Besson, Anne Amélie; Cree, Alison

    2010-07-01

    Thermoregulation is of great importance for the survival and fitness of ectotherms as physiological functions are optimized within a narrow range of body temperature (T(b)). The precision with which reptiles thermoregulate has been proposed to be related to the thermal quality of their environments. Although a number of studies have looked at the effect of thermal constraints imposed by diel, seasonal and altitudinal variation on thermoregulatory strategies, few have addressed this question in a laboratory setting. We conducted a laboratory experiment to test whether tuatara, Sphenodon punctatus (order Rhynchocephalia), a cold-adapted reptile endemic to New Zealand, modify their thermoregulatory behaviour in response to different thermal environments. We provided tuatara with three thermal treatments: high-quality habitat [preferred T(b) (T(sel)) could be reached for 8 h/day], medium-quality habitat (T(sel) available for 5 h/day) and low-quality habitat (T(sel) available for 3 h/day). All groups maintained body mass, but tuatara in the low-quality habitat thermoregulated more accurately and tended to maintain higher T (b)s than tuatara in the high-quality habitat. This study thus provides experimental evidence that reptiles are capable of adjusting their thermoregulatory behaviour in response to different thermal constraints. This result also has implications for the conservation of tuatara. A proposed translocation from their current habitat to a higher latitudinal range within New Zealand (similar to the shift from our 8 h/day to our 5 h/day regime) is unlikely to induce thermoconformity; rather, tuatara will probably engage in more effective thermoregulatory behaviour.

  18. Applying systems biology methods to the study of human physiology in extreme environments.

    Science.gov (United States)

    Edwards, Lindsay M; Thiele, Ines

    2013-03-22

    Systems biology is defined in this review as 'an iterative process of computational model building and experimental model revision with the aim of understanding or simulating complex biological systems'. We propose that, in practice, systems biology rests on three pillars: computation, the omics disciplines and repeated experimental perturbation of the system of interest. The number of ethical and physiologically relevant perturbations that can be used in experiments on healthy humans is extremely limited and principally comprises exercise, nutrition, infusions (e.g. Intralipid), some drugs and altered environment. Thus, we argue that systems biology and environmental physiology are natural symbionts for those interested in a system-level understanding of human biology. However, despite excellent progress in high-altitude genetics and several proteomics studies, systems biology research into human adaptation to extreme environments is in its infancy. A brief description and overview of systems biology in its current guise is given, followed by a mini review of computational methods used for modelling biological systems. Special attention is given to high-altitude research, metabolic network reconstruction and constraint-based modelling.

  19. Refuge from predation, the benefit of living in an extreme acidic environment?

    Science.gov (United States)

    Borgonie, Gaëtan; Dierick, Manuel; Houthoofd, Wouter; Willems, Maxime; Jacobs, Patric; Bert, Wim

    2010-12-01

    Organisms living in extreme habitats require costly adaptations to cope with these conditions. Among the suggested potential benefits that trade off these costs is refuge from predation. To study these interactions in extreme environments, samples were taken in the cave Cueva de Villa Luz, Tabasco, Mexico, where more than 32 subterranean springs, some H(2)S rich, rise from the floor. Hydrogen sulfide gas plus oxygen is absorbed by freshwater, and oxidation forms concentrated sulfuric acid. Snottites, whitish hollow mucous tubes, hang from the ceiling of the cave. Fluid drops from these snottites were recorded as having pH values of 0-3. We report the discovery of a new species of nematode that thrives in the highly acidic environment of the snottite. Micro CT scan of snottites reveals a complex interaction between the acidic snottite, nematodes, and abundant nematode-eating mites. The nematode adaptation to low pH probably protects them against mite predation, for which nematodes are most likely the most important source of carbon in this sulfur-driven ecosystem.

  20. A walk on the tundra: Host-parasite interactions in an extreme environment.

    Science.gov (United States)

    Kutz, Susan J; Hoberg, Eric P; Molnár, Péter K; Dobson, Andy; Verocai, Guilherme G

    2014-08-01

    Climate change is occurring very rapidly in the Arctic, and the processes that have taken millions of years to evolve in this very extreme environment are now changing on timescales as short as decades. These changes are dramatic, subtle and non-linear. In this article, we discuss the evolving insights into host-parasite interactions for wild ungulate species, specifically, muskoxen and caribou, in the North American Arctic. These interactions occur in an environment that is characterized by extremes in temperature, high seasonality, and low host species abundance and diversity. We believe that lessons learned in this system can guide wildlife management and conservation throughout the Arctic, and can also be generalized to more broadly understand host-parasite interactions elsewhere. We specifically examine the impacts of climate change on host-parasite interactions and focus on: (I) the direct temperature effects on parasites; (II) the importance of considering the intricacies of host and parasite ecology for anticipating climate change impacts; and (III) the effect of shifting ecological barriers and corridors. Insights gained from studying the history and ecology of host-parasite systems in the Arctic will be central to understanding the role that climate change is playing in these more complex systems.

  1. Tracing molecular gas mass in extreme extragalactic environments: an observational study

    CERN Document Server

    Zhu, Ming; Xilouris, Emmanuel M; Kuno, Nario; Lisenfeld, Ute

    2009-01-01

    We present a new observational study of the CO(1-0) line emission as an H2 gas mass tracer under extreme conditions in extragalactic environments. Our approach is to study the full neutral interstellar medium (H2, HI and dust) of two galaxies whose bulk interstellar medium (ISM) resides in environments that mark (and bracket) the excitation extremes of the ISM conditions found in infrared luminous galaxies, the starburst NGC3310 and the quiescent spiral NGC157. Our study maintains a robust statistical notion of the so-called X factor (i.e. a large ensemble of clouds is involved) while exploring its dependency on the very different average ISM conditions prevailing within these two systems. These are constrained by fully-sampled CO(3-2) and CO(1-0) observations, at a matched beam resolution of Half Power Beam Width 15'', obtained with the JCMT the Nobeyama 45-m telescope, combined with sensitive 850 and 450 micron dust emission and HI interferometric images which allow a complete view of all the neutral ISM co...

  2. PRELIMINARY BIOGEOCHEMICAL DATA ON MICROBIAL CARBONATOGENESIS IN ANCIENT EXTREME ENVIRONMENTS (KESS-KESS MOUNDS, MOROCCO

    Directory of Open Access Journals (Sweden)

    ADRIANO GUIDO

    2013-03-01

    Full Text Available The Devonian Kess-Kess mounds, cropping out in the Hamar Laghdad Ridge (SE Morocco, provide a useful case-study for understanding the relationships between the microbial metabolic activities and micrite precipitation in an extreme environment. Very fine dark and white wrinkled laminae record microbial activity and the geochemistry of the organic matter allows the  characterization of the source organisms. The biogeochemical characterization of extracted organic matter was performed through the functional group analyses by FT-IR Spectroscopy. FT-IR parameters indicate a marine origin and low thermal evolution for the organic material. The organic matter is characterized by the presence of stretching ?C=C vibrations attributable to alkene and/or unsaturated carboxylic acids. Preliminary analysis with GC-MS provides evidence for an autochthonous (extreme environment may have implications in astrobiological research considering the recent discovery of carbonate deposits on Mars. 

  3. Correlating microbial diversity patterns with geochemistry in an extreme and heterogeneous environment of mine tailings.

    Science.gov (United States)

    Liu, Jun; Hua, Zheng-Shuang; Chen, Lin-Xing; Kuang, Jia-Liang; Li, Sheng-Jin; Shu, Wen-Sheng; Huang, Li-Nan

    2014-06-01

    Recent molecular surveys have advanced our understanding of the forces shaping the large-scale ecological distribution of microbes in Earth's extreme habitats, such as hot springs and acid mine drainage. However, few investigations have attempted dense spatial analyses of specific sites to resolve the local diversity of these extraordinary organisms and how communities are shaped by the harsh environmental conditions found there. We have applied a 16S rRNA gene-targeted 454 pyrosequencing approach to explore the phylogenetic differentiation among 90 microbial communities from a massive copper tailing impoundment generating acidic drainage and coupled these variations in community composition with geochemical parameters to reveal ecological interactions in this extreme environment. Our data showed that the overall microbial diversity estimates and relative abundances of most of the dominant lineages were significantly correlated with pH, with the simplest assemblages occurring under extremely acidic conditions and more diverse assemblages associated with neutral pHs. The consistent shifts in community composition along the pH gradient indicated that different taxa were involved in the different acidification stages of the mine tailings. Moreover, the effect of pH in shaping phylogenetic structure within specific lineages was also clearly evident, although the phylogenetic differentiations within the Alphaproteobacteria, Deltaproteobacteria, and Firmicutes were attributed to variations in ferric and ferrous iron concentrations. Application of the microbial assemblage prediction model further supported pH as the major factor driving community structure and demonstrated that several of the major lineages are readily predictable. Together, these results suggest that pH is primarily responsible for structuring whole communities in the extreme and heterogeneous mine tailings, although the diverse microbial taxa may respond differently to various environmental conditions.

  4. Correlating Microbial Diversity Patterns with Geochemistry in an Extreme and Heterogeneous Environment of Mine Tailings

    Science.gov (United States)

    Liu, Jun; Hua, Zheng-Shuang; Chen, Lin-Xing; Kuang, Jia-Liang; Li, Sheng-Jin; Shu, Wen-Sheng

    2014-01-01

    Recent molecular surveys have advanced our understanding of the forces shaping the large-scale ecological distribution of microbes in Earth's extreme habitats, such as hot springs and acid mine drainage. However, few investigations have attempted dense spatial analyses of specific sites to resolve the local diversity of these extraordinary organisms and how communities are shaped by the harsh environmental conditions found there. We have applied a 16S rRNA gene-targeted 454 pyrosequencing approach to explore the phylogenetic differentiation among 90 microbial communities from a massive copper tailing impoundment generating acidic drainage and coupled these variations in community composition with geochemical parameters to reveal ecological interactions in this extreme environment. Our data showed that the overall microbial diversity estimates and relative abundances of most of the dominant lineages were significantly correlated with pH, with the simplest assemblages occurring under extremely acidic conditions and more diverse assemblages associated with neutral pHs. The consistent shifts in community composition along the pH gradient indicated that different taxa were involved in the different acidification stages of the mine tailings. Moreover, the effect of pH in shaping phylogenetic structure within specific lineages was also clearly evident, although the phylogenetic differentiations within the Alphaproteobacteria, Deltaproteobacteria, and Firmicutes were attributed to variations in ferric and ferrous iron concentrations. Application of the microbial assemblage prediction model further supported pH as the major factor driving community structure and demonstrated that several of the major lineages are readily predictable. Together, these results suggest that pH is primarily responsible for structuring whole communities in the extreme and heterogeneous mine tailings, although the diverse microbial taxa may respond differently to various environmental conditions

  5. A Motor Drive Electronics Assembly for Mars Curiosity Rover: An Example of Assembly Qualification for Extreme Environments

    Science.gov (United States)

    Kolawa, Elizabeth; Chen, Yuan; Mojarradi, Mohammad M.; Weber, Carissa Tudryn; Hunter, Don J.

    2013-01-01

    This paper describes the technology development and infusion of a motor drive electronics assembly for Mars Curiosity Rover under space extreme environments. The technology evaluation and qualification as well as space qualification of the assembly are detailed and summarized. Because of the uncertainty of the technologies operating under the extreme space environments and that a high level reliability was required for this assembly application, both component and assembly board level qualifications were performed.

  6. Heat-shield for Extreme Entry Environment Technology (HEEET) Development Status

    Science.gov (United States)

    Venkatapathy, Ethiraj; Ellerby, Don; Gage, Peter

    2016-01-01

    The Heat shield for Extreme Entry Environment Technology (HEEET) Project is a NASA STMD and SMD co-funded effort. The goal is to develop and mission infuse a new ablative Thermal Protection System that can withstand extreme entry. It is targeted to support NASA's high priority missions, as defined in the latest decadal survey, to destinations such as Venus and Saturn in-situ robotic science missions. Entry into these planetary atmospheres results in extreme heating. The entry peak heat-flux and associated pressure are estimated to be between one and two orders of magnitude higher than those experienced by Mars Science Laboratory or Lunar return missions. In the recent New Frontiers community announcement NASA has indicated that it is considering providing an increase to the PI managed mission cost (PIMMC) for investigations utilizing the Heat Shield for Extreme Entry Environment Technology (HEEET) and in addition, NASA is considering limiting the risk assessment to only their accommodation on the spacecraft and the mission environment. The HEEET ablative TPS utilizes 3D weaving technology to manufacture a dual layer material architecture. The 3-D weaving allows for flat panels to be woven. The dual layer consists of a top layer designed to withstand the extreme external environment while the inner or insulating layer by design, is designed to achieve low thermal conductivity, and it keeps the heat from conducting towards the structure underneath. Both arc jet testing combined with material properties have been used to develop thermal response models that allows for comparison of performance with heritage carbon phenolic. A 50% mass efficiency is achieved by the dual layer construct compared to carbon phenolic for a broad range of missions both to Saturn and Venus. The 3-D woven flat preforms are molded to achieve the shape as they are compliant and then resin infusion with curing forms a rigid panels. These panels are then bonded on to the aeroshell structure. Gaps

  7. Metagenomics unveils the attributes of the alginolytic guilds of sediments from four distant cold coastal environments: Alginolytic guilds from cold sediments

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Marina N. [Laboratorio de Microbiología Ambiental, Centro para el Estudio de Sistemas Marinos (CESIMAR, CONICET), Puerto Madryn U9120ACD Argentina; Lozada, Mariana [Laboratorio de Microbiología Ambiental, Centro para el Estudio de Sistemas Marinos (CESIMAR, CONICET), Puerto Madryn U9120ACD Argentina; Anselmino, Luciano E. [Laboratorio de Microbiología Ambiental, Centro para el Estudio de Sistemas Marinos (CESIMAR, CONICET), Puerto Madryn U9120ACD Argentina; Musumeci, Matías A. [Laboratorio de Microbiología Ambiental, Centro para el Estudio de Sistemas Marinos (CESIMAR, CONICET), Puerto Madryn U9120ACD Argentina; Henrissat, Bernard [Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, Marseille 13288 France; INRA, USC 1408 AFMB, Marseille F-13288 France; Department of Biological Sciences, King Abdulaziz University, Jeddah 21589 Saudi Arabia; Jansson, Janet K. [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; Mac Cormack, Walter P. [Instituto Antártico Argentino, Ciudad Autónoma de Buenos Aires, C1064ABR, Argentina; Instituto Nanobiotec, CONICET - Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, C1113AAC, Argentina; Carroll, JoLynn [Akvaplan-niva, Fram - High North Research Centre for Climate and the Environment, Tromsø NO-9296 Norway; CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, UiT The Arctic University of Norway, Tromsø N-9037 Norway; Sjöling, Sara [School of Natural Sciences and Environmental Studies, Södertörn University, Huddinge 141 89 Sweden; Lundgren, Leif [Stockholm University, Stockholm SE-106 91 Sweden; Dionisi, Hebe M. [Laboratorio de Microbiología Ambiental, Centro para el Estudio de Sistemas Marinos (CESIMAR, CONICET), Puerto Madryn U9120ACD Argentina

    2016-07-18

    Alginates are abundant polysaccharides in brown algae that constitute an important energy source for marine heterotrophic bacteria. Despite the key role of alginate assimilation processes in the marine carbon cycle, little information is available on the bacterial populations involved in these processes. The goal of this work was to gain insight into the structure and functional traits of the alginolytic communities from sediments of cold coastal environments. Sediment metagenomes from high-latitude regions of both Hemispheres were interrogated for alginate lyase gene homolog sequences and their genomic context. Sediments contained highly abundant and diverse bacterial assemblages with alginolytic potential, including members of Bacteroidetes and Proteobacteria, as well as several poorly characterized taxa. Temperature and salinity were correlated to the variation in community structure. The microbial communities in Arctic and Antarctic sediments exhibited the most similar alginolytic profiles, whereas brackish sediments had a higher proportion of novel members. Examination of the gene context of the alginate lyase homologs revealed distinct patterns according to the phylogenetic origin of the scaffolds, with evidence of evolutionary relationships among lineages. This information is relevant for understanding carbon fluxes in cold coastal environments and provides valuable information for the development of biotechnological applications from brown algae biomass.

  8. Solid Lubricants and Coatings for Extreme Environments: State-of-the-Art Survey

    Science.gov (United States)

    Miyoshi, Kazuhisa

    2007-01-01

    An investigation was conducted to survey anticipated requirements for solid lubricants in lunar and Martian environments, as well as the effects of these environments on lubricants and their performance and durability. The success of habitats and vehicles on the Moon and Mars, and ultimately, of the human exploration of and permanent human presence on the Moon and Mars, are critically dependent on the correct and reliable operation of many moving mechanical assemblies and tribological components. The coefficient of friction and lifetime of any lubricant generally vary with the environment, and lubricants have very different characteristics under different conditions. It is essential, therefore, to select the right lubrication technique and lubricant for each mechanical and tribological application. Several environmental factors are hazardous to performance integrity on the Moon and Mars. Potential threats common to both the Moon and Mars are low ambient temperatures, wide daily temperature swings (thermal cycling), solar flux, cosmic radiation, and large quantities of dust. The surface of Mars has the additional challenges of dust storms, winds, and a carbon dioxide atmosphere. Solid lubricants and coatings are needed for lunar and Martian applications, where liquid lubricants are ineffective and undesirable, and these lubricants must perform well in the extreme environments of the Moon, Mars, and space, as well as on Earth, where they will be assembled and tested. No solid lubricants and coatings and their systems currently exist or have been validated that meet these requirements, so new solid lubricants must be designed and validated for these applications.

  9. Ingestion of a cold temperature/menthol beverage increases outdoor exercise performance in a hot, humid environment.

    Directory of Open Access Journals (Sweden)

    Than Tran Trong

    Full Text Available A recent laboratory study demonstrated that the ingestion of a cold/menthol beverage improved exercise performance in a hot and humid environment during 20 km of all-out cycling. Therefore, the aim of this study was to determine whether the ingestion of cold water/ice-slurry with menthol would improve performance in hot and humid outdoor conditions.Ten trained males completed three trials of five blocks consisting of 4-km cycling and 1.5-km running. During warm-up, every block and recovery, the athletes drank 190 ml of aromatized (i.e., with 0.05 mL of menthol beverage at three temperatures: Neutral (ambient temperature (28.7°C±0. 5°C, Cold (3.1°C±0.6°C or Ice-slurry (0.17°C±0.07°C. Trial time, core temperature (Tco, heart rate (HR, rate of perceived exertion (RPE, thermal sensation (TS and thermal comfort (TC were assessed.Ice-slurry/menthol increased performance by 6.2% and 3.3% compared with neutral water/menthol and cold water/menthol, respectively. No between-trial differences were noted for Tco, HR, RPE, TC and TS was lower with ice-slurry/menthol and cold water/menthol compared with neutral water/menthol.A low drink temperature combined with menthol lessens the performance decline in hot/humid outdoor conditions (i.e., compared with cold water alone. Performances were better with no difference in psycho-physiological stress (Tco, HR and RPE between trials. The changes in perceptual parameters caused by absorbing a cold/menthol beverage reflect the psychological impact. The mechanism leading to these results seems to involve brain integration of signals from physiological and psychological sources.

  10. Women and Couples in Isolated Extreme Environments: Applications for Long-Duration Missions

    Science.gov (United States)

    Leon, G. R.; Sandal, G. M.

    four women from Greenland, Denmark, UK and Russia who traversed the Greenland ice by ski. The participants did not know each other prior to the expedition. Three were classified as "the right stuff' based on PCI findings. Diary and post-expedition reports indicated that incidents of interpersonal tension were often related to fatigue, homesickness, pain or cold. The participants also indicated that respect and tolerance for differences between them, as weIl as mutual emotional support were crucial factors for the successful completion of the expedition. Group 3 consisted of 3 married couples and the 2 1/2 year old child of the leader and his wife. Five of the crew sailed a small boat from Norway to the Canadian High Arctic; the leader's wife and child joined the team in Greenland. Over a 9 month period, the icelocked boat was ilie center of habitation, scientific, and other activities. Three of the group carried out a 6 week exploratory trek at the end of the winter-over. Participants completed the MPQ prior to the expedition, a WRF over the entire Arctic period, and a semi-structured personality interview at the close of the interval during which the entire group was together. AlI participants scored relatively highest on the Absorption scale, manifested in the salutory experience of enjoying and becoming engrossed in the beauty of the environment. WRF and interview findings indicated that team members consistently reported that the emotional support of and ability to confide in their partner were extremely important in alleviating interpersonal tensions with other team members, and contributed to the overall effective functioning of the group. Reported level of emotional response to stress and coping patterns used while in the stationary habitat were consistent with WRF responses during the later exploratory trek. The woman team member on the trek reported more discomfort regarding personal hygiene issues and fear of injury .In alI groups, the salience of the

  11. The I.A.G. / A.I.G. SEDIBUD Book Project: Source-to-Sink Fluxes in Undisturbed Cold Environments

    Science.gov (United States)

    Beylich, Achim A.; Dixon, John C.; Zwolinski, Zbigniew

    2015-04-01

    The currently prepared SEDIBUD Book on "Source-to-Sink Fluxes in Undisturbed Cold Environments" (edited by Achim A. Beylich, John C. Dixon and Zbigniew Zwolinski and published by Cambridge University Press) is summarizing and synthesizing the achievements of the International Association of Geomorphologists` (I.A.G./A.I.G.) Working Group SEDIBUD (Sediment Budgets in Cold Environments), which has been active since 2005 (http://www.geomorph.org/wg/wgsb.html). Amplified climate change and ecological sensitivity of largely undisturbed polar and high-altitude cold climate environments have been highlighted as key global environmental issues. The effects of projected climate change will change surface environments in cold regions and will alter the fluxes of sediments, nutrients and solutes, but the absence of quantitative data and coordinated geomorphic process monitoring and analysis to understand the sensitivity of the Earth surface environment in these largely undisturbed environments is acute. Our book addresses this existing key knowledge gap. The applied approach of integrating comparable and longer-term field datasets on contemporary solute and sedimentary fluxes from a number of different defined cold climate catchment geosystems for better understanding (i) the environmental drivers and rates of contemporary denudational surface processes and (ii) possible effects of projected climate change in cold regions is unique in the field of geomorphology. Largely undisturbed cold climate environments can provide baseline data for modeling the effects of environmental change. The book synthesizes work carried out by numerous SEDIBUD Members over the last decade in numerous cold climate catchment geosystems worldwide. For reaching a global cover of different cold climate environments the book is - after providing an introduction part and a basic part on climate change in cold environments and general implications for solute and sedimentary fluxes - dealing in different

  12. Gas-solid carbonation as a possible source of carbonates in cold planetary environments

    Science.gov (United States)

    Garenne, A.; Montes-Hernandez, G.; Beck, P.; Schmitt, B.; Brissaud, O.; Pommerol, A.

    2013-02-01

    process. To the best of our knowledge, we report for the first time that calcium carbonate can be formed at a negative temperature (-10 °C) via gas-solid carbonation of Ca hydroxide. We note that the carbonation process at low temperature (<0 °C) described in the present study could also have important implications on the dust-water ice-CO2 interactions in cold terrestrial environments (e.g. Antarctic).

  13. Looking for Life in Extreme Environments on Earth and Beyond: Professional Development Workshop for Educators

    Science.gov (United States)

    Droppo, R.; Pratt, L.; Suchecki, P. C.

    2010-08-01

    The Looking for Life in Extreme Environments workshop held at Indiana University Bloomington in July of 2009 was the first in a series of workshops for high-school teachers that are currently in development. The workshops' modules are based on the research of faculty members in the Departments of Geological Sciences, Biology, and Astronomy, the School of Education, and the School of Public and Environmental Affairs at Indiana University Bloomington; the modules use lessons from Exploring Deep-Subsurface Life. Earth Analogues for Possible Life on Mars: Lessons and Activities, curricular materials that were produced and edited by Lisa Pratt and Ruth Droppo and published by NASA in 2008. Exploring Deep-Subsurface Life is a workbook, a DVD (with closed-captioning), and a CD with the lessons in digital text format for adaptation to classroom needs and printing. Each lesson includes the National Education Standards that apply to the materials. The workbook's lessons are written with three considerations: Life Domains, Cellular Metabolism, and Extreme Environments and Microbes. Students are challenged to build, draw, measure, discuss, and participate in laboratory processes and experiments that help them understand and describe microbes and their environments. In the Capstone, the students write a grant proposal based on the three lessons' analogues. The DVD is collection of videotaped interviews with scientists in laboratories at Michigan State, Princeton, and Indiana University, who are working on water and gas samples they collected from deep gold mines in South Africa and the Canadian Arctic. The interview materials and some animated graphics are compiled into four video pieces that support and compliment the accompanying workbook lessons and activities, and offer students insight into the excitement of scientific discovery.

  14. Individual Traits, Personal Values, and Conflict Resolution in an Isolated, Confined, Extreme Environment.

    Science.gov (United States)

    Corneliussen, Jesper G; Leon, Gloria R; Kjærgaard, Anders; Fink, Birgit A; Venables, Noah C

    2017-06-01

    The study of personality traits, personal values, and the emergence of conflicts within groups performing in an isolated, confined, and extreme environment (ICE) may provide insights helpful for the composition and support of space crews for long duration missions. Studied pre/post and over the 2-yr period of the investigation were 10 Danish military personnel deployed to stations in Greenland on a 26-mo staggered rotation. Subjects completed the NEO PI-R, Triarchic Psychopathy Measure, and Portrait Values Questionnaire, and participated in structured interviews. During deployment, questionnaires were completed biweekly and a cognitive function test once a month. Personality findings indicated a generally well-adjusted group, above average in positive personality traits [Conscientiousness T-score = 59.4 (11.41); Agreeableness T-score = 54.4 (9.36)] and boldness. Personal values of benevolence and self-direction were highly rated. The decision when to "pick sides" and intervene during disagreements between group members was viewed as an important component of conflict resolution. There were no changes in positive/negative affect or cognitive function over the annual light/dark cycle. The personal values of group members appear highly compatible for living in a small group ICE environment for an extended period. Disagreements between group members impact the functioning of the entire group, particularly in regard to decisions whether to support one of the individuals or let the argument run its course. Extended training in strategies for conflict resolution are needed in planning for future long duration missions to avoid fault lines forming within the group.Corneliussen JG, Leon GR, Kjærgaard A, Fink BA, Venables NC. Individual traits, personal values, and conflict resolution in an isolated, confined, extreme environment. Aerosp Med Hum Perform. 2017; 88(6):535-543.

  15. Pathophysiology of Blood-Brain Barrier in Brain Injury in Cold and Hot Environments: Novel Drug Targets for Neuroprotection.

    Science.gov (United States)

    Sharma, Hari Shanker; Muresanu, Dafin F; Lafuente, José V; Nozari, Ala; Patnaik, Ranjana; Skaper, Stephen D; Sharma, Aruna

    2016-01-01

    The blood-brain barrier (BBB) plays a pivotal role in the maintenance of central nervous system function in health and disease. Thus, in almost all neurodegenerative, traumatic or metabolic insults BBB breakdown occurs, allowing entry of serum proteins into the brain fluid microenvironment with subsequent edema formation and cellular injury. Accordingly, pharmacological restoration of BBB function will lead to neurorepair. However, brain injury which occurs following blast, bullet wounds, or knife injury appears to initiate different sets of pathophysiological responses. Moreover, other local factors at the time of injury such as cold or elevated ambient temperatures could also impact the final outcome. Obviously, drug therapy applied to different kinds of brain trauma occurring at either cold or hot environments may respond differently. This is largely due to the fact that internal defense mechanisms of the brain, gene expression, release of neurochemicals and binding of drugs to specific receptors are affected by external ambient temperature changes. These factors may also affect BBB function and development of edema formation after brain injury. In this review, the effects of seasonal exposure to heat and cold on traumatic brain injury using different models i.e., concussive brain injury and cerebral cortical lesion, on BBB dysfunction in relation to drug therapy are discussed. Our observations clearly suggest that closed head injury and open brain injury are two different entities and the external hot or cold environments affect both of them remarkably. Thus, effective pharmacological therapeutic strategies should be designed with these views in mind, as military personnel often experience blunt or penetrating head injuries in either cold or hot environments.

  16. Composite Materials under Extreme Radiation and Temperature Environments of the Next Generation Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Simos, N.

    2011-05-01

    In the nuclear energy renaissance, driven by fission reactor concepts utilizing very high temperatures and fast neutron spectra, materials with enhanced performance that exceeds are expected to play a central role. With the operating temperatures of the Generation III reactors bringing the classical reactor materials close to their performance limits there is an urgent need to develop and qualify new alloys and composites. Efforts have been focused on the intricate relations and the high demands placed on materials at the anticipated extreme states within the next generation fusion and fission reactors which combine high radiation fluxes, elevated temperatures and aggressive environments. While nuclear reactors have been in operation for several decades, the structural materials associated with the next generation options need to endure much higher temperatures (1200 C), higher neutron doses (tens of displacements per atom, dpa), and extremely corrosive environments, which are beyond the experience on materials accumulated to-date. The most important consideration is the performance and reliability of structural materials for both in-core and out-of-core functions. While there exists a great body of nuclear materials research and operating experience/performance from fission reactors where epithermal and thermal neutrons interact with materials and alter their physio-mechanical properties, a process that is well understood by now, there are no operating or even experimental facilities that will facilitate the extreme conditions of flux and temperature anticipated and thus provide insights into the behaviour of these well understood materials. Materials, however, still need to be developed and their interaction and damage potential or lifetime to be quantified for the next generation nuclear energy. Based on material development advances, composites, and in particular ceramic composites, seem to inherently possess properties suitable for key functions within the

  17. Second workshop of I.A.G./A.I.G. SEDIBUD - Sediment Budgets in Cold Environments: Sediment fluxes and sediment budgets in changing high-latitude and high-altitude cold environments

    Energy Technology Data Exchange (ETDEWEB)

    Beylich, Achim A.; Lamoureux, Scott F.; Decaulne, Armelle

    2007-07-01

    This Second Workshop of the I.A.G./A.I.G. Working Group SEDIBUD (Sediment Budgets in Cold Environments) builds on four previous ESF SEDIFLUX Science Meetings held in Saudarkrokur (Iceland) in June 2004, Clermont-Ferrand (France) in January 2005, Durham (UK) in December 2005 and Trondheim (Norway) in the end of October/beginning of November 2006. A first kick-off Meeting of the new I.A.G./A.I.G. SEDIBUD Workshop. The theme of this Second I.A.G./A.I.G. SEDIBUD Workshop is Sediment FLuxes and Sediment Budgets in Changing High-Latitude Cold Environments. The Workshop is split between scientific paper and poster presentations, presentation and discussion of SEDIBUD key test sites, discussions within defined work groups and guided field trip to Kaerkevagge. This workshop will address the key aim of SEDIBUD to discuss Source-to-Sink-Fluxes and Sediment Budgets in Changing Cold Environments. Major emphasis will be given to consequences of climate change, scaling issues and source-to-sink correlations. Central issues will be presentation and discussion of the SEDIFLUX Manual (First Edition), the selection of SEDIBUD key test sites, the discussion and development of further ideas to extend the scientific activities within SEDIBUD in a global framework.(auth)

  18. In situ environment rather than substrate type dictates microbial community structure of biofilms in a cold seep system

    KAUST Repository

    Lee, O.O.

    2014-01-08

    Using microscopic and molecular techniques combined with computational analysis, this study examined the structure and composition of microbial communities in biofilms that formed on different artificial substrates in a brine pool and on a seep vent of a cold seep in the Red Sea to test our hypothesis that initiation of the biofilm formation and spreading mode of microbial structures differs between the cold seep and the other aquatic environments. Biofilms on different substrates at two deployment sites differed morphologically, with the vent biofilms having higher microbial abundance and better structural features than the pool biofilms. Microbes in the pool biofilms were more taxonomically diverse and mainly composed of various sulfate-reducing bacteria whereas the vent biofilms were exclusively dominated by sulfur-oxidizing Thiomicrospira. These results suggest that the redox environments at the deployment sites might have exerted a strong selection on microbes in the biofilms at two sites whereas the types of substrates had limited effects on the biofilm development.

  19. High yield simultaneous hydrogen and ethanol production under extreme-thermophilic (70 C) mixed culture environment

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chenxi [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Department of Environmental Engineering, Technical University of Denmark, DK-2800, Kgs Lyngby (Denmark); O-Thong, Sompong [Department of Biology, Faculty of Science, Thaksin University, Patthalung 93110 (Thailand); Karakashev, Dimitar; Angelidaki, Irini [Department of Environmental Engineering, Technical University of Denmark, DK-2800, Kgs Lyngby (Denmark); Lu, Wenjing; Wang, Hongtao [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2009-07-15

    The effect of pH and medium composition on extreme-thermophilic (70 C) dark fermentative simultaneous hydrogen and ethanol production (process performance and microbial ecology) was investigated. Hydrogen and ethanol yields were optimized with respect to glucose, peptone, FeSO{sub 4}, NaHCO{sub 3}, yeast extract, trace mineral salts, vitamins, and phosphate buffer concentrations as well as initial pH as independent variables. A combination of low levels of both glucose ({<=}2 g/L) and vitamin solutions ({<=}1 mL/L) and high levels of initial pH ({>=}7), mineral salts solution ({>=}5 mL/L) and FeSO{sub 4} ({>=}100 mg/L) stimulated the hydrogen production, while high level of glucose ({>=}5 g/L) and low levels of both initial pH ({<=}5.5) and mineral salts solution ({<=}1 mL/L) enhanced the ethanol production. High yield of simultaneous hydrogen and ethanol production (1.58 mol H{sub 2}/mol glucose combined with an ethanol yield of 0.90 mol ethanol/mol glucose) was achieved under extreme-thermophilic mixed culture environment. Results obtained showed that the shift of the metabolic pathways favouring either hydrogen or ethanol production was affected by the change in cultivation conditions (pH and medium composition). The mixed culture in this study demonstrated flexible ability for simultaneous hydrogen and ethanol production, depending on pH and nutrients formulation. The microorganisms involved could be regarded as simultaneous hydrogen/ethanol producers, as hydrogen and ethanol fermentation under all conditions was carried out by a group of extreme-thermophilic bacterial species related to Thermoanaerobacter, Thermoanaerobacterium and Caldanaerobacter. (author)

  20. Experimental selection for Drosophila survival in extremely low O(2 environment.

    Directory of Open Access Journals (Sweden)

    Dan Zhou

    Full Text Available BACKGROUND: Cellular hypoxia, if severe enough, results usually in injury or cell death. Our research in this area has focused on the molecular mechanisms underlying hypoxic tissue injury to explore strategies to prevent injury or enhance tolerance. The current experiments were designed to determine the genetic basis for adaptation to long term low O(2 environments. METHODOLOGY/PRINCIPAL FINDINGS: With long term experimental selection over many generations, we obtained a Drosophila melanogaster strain that can live perpetually in extremely low, normally lethal, O(2 condition (as low as 4% O(2. This strain shows a dramatic phenotypic divergence from controls, including a decreased recovery time from anoxic stupor, a higher rate of O(2 consumption in hypoxic conditions, and a decreased body size and mass due to decreased cell number and size. Expression arrays showed that about 4% of the Drosophila genome altered in expression and about half of the alteration was down-regulation. The contribution of some altered transcripts to hypoxia tolerance was examined by testing the survival of available corresponding P-element insertions (and their excisions under extremely low O(2 conditions. We found that down-regulation of several candidate genes including Best1, broad, CG7102, dunce, lin19-like and sec6 conferred severe hypoxia tolerance in Drosophila. CONCLUSIONS/SIGNIFICANCE: We have identified a number of genes that play an important role in the survival of a selected Drosophila strain in extremely low O(2 conditions, selected by decreasing O(2 availability over many generations. Because of conservation of pathways, we believe that such genes are critical in hypoxia adaptation in physiological or pathological conditions not only in Drosophila but also in mammals.

  1. 2D DEM analyses for T-M coupling effects of extreme temperatures on surrounding rock-supporting system of a tunnel in cold region

    Institute of Scientific and Technical Information of China (English)

    张玉军; 杨朝帅; 王永刚

    2013-01-01

    Taking the Kunlunshan Tunnel on Qinghai Tibet Railway as an engineering background, the curved wall-inverted arch lining of the tunnel was simplified into the straight wall-umbrella arch one, and the fractured rock mass with developed joints was treated as a discrete medium in the calculation. Using the UDEC code, the numerical simulations for thermo-mechanical coupling processes in the surrounding rock mass-supporting system were carried out aiming at the conditions of mean temperature, extreme highest temperature and extreme lowest temperature in one year. The distributions and changes of stresses, displacements, plastic zones, temperatures in the rock mass of near field, as well as the loading states in the model-building concrete and bolting were investigated and compared for these three computation cases. The results show that compared with the case of mean temperature, the ranges, where the temperatures of surrounding rock mass change obviously, are 6.0 m and 6.5 m, respectively, for the cases of extreme highest temperature and extreme lowest temperature; the displacements of tunnel are raised by 3.2 9.3 and 5.7 12.7 times, and the thicknesses of plastic zones reach 1.5 2.5 m and 2.0 4.5 m for case 2 and 3, respectively; the extreme temperatures of air have strong effects on the stress, deformation and failure states of supporting structure of tunnel in cold region, and the influence degree of extreme lowest temperature is the highest.

  2. Reliability of CCGA 1152 and CCGA 1272 Interconnect Packages for Extreme Thermal Environments

    Science.gov (United States)

    Ramesham, Rajeshuni

    2013-01-01

    Ceramic column grid array (CCGA) packages have been increasing in use based on their advantages of high interconnect density, very good thermal and electrical performance, and compatibility with standard surface-mount packaging assembly processes. CCGA packages are used in space applications such as in logics and microprocessor functions, telecommunications, flight avionics, and payload electronics. As these packages tend to have less solder joint strain relief than leaded packages, the reliability of CCGA packages is very important for short- and long-term space missions. Certain planetary satellites require operations of thermally uncontrolled hardware under extremely cold and hot temperatures with large diurnal temperature change from day to night. The planetary protection requires the hardware to be baked at +125 C for 72 hours to kill microbugs to avoid any biological contamination, especially for sample return missions. Therefore, the present CCGA package reliability research study has encompassed the temperature range of 185 to +125 C to cover various NASA deep space missions. Advanced 1152 and 1272 CCGA packaging interconnects technology test hardware objects have been subjected to ex treme temperature thermal cycles from 185 to +125 C. X-ray inspections of CCGA packages have been made before thermal cycling. No anomalous behavior and process problems were observed in the x-ray images. The change in resistance of the daisy-chained CCGA interconnects was measured as a function of increasing number of thermal cycles. Electrical continuity measurements of daisy chains have shown no anomalies, even until 596 thermal cycles. Optical inspections of hardware have shown a significant fatigue for CCGA 1152 packages over CCGA 1272 packages. No catastrophic failures have been observed yet in the results. Process qualification and assembly are required to optimize the CCGA assembly processes. Optical inspections of CCGA boards have been made after 258 and 596 thermal

  3. Solar Probe Plus MAG Sensor Thermal Design for Low Heater Power and Extreme Thermal Environment

    Science.gov (United States)

    Choi, Michael K.

    2015-01-01

    The heater power available for the Solar Probe Plus FIELDS MAG sensor is less than half of the heritage value for other missions. Nominally the MAG sensors are in the spacecraft's umbra. In the worst hot case, approximately 200 spacecraft communication downlinks, up to 10 hours each, are required at 0.7 AU. These downlinks require the spacecraft to slew 45 deg. about the Y-axis, exposing the MAG sensors and boom to sunlight. This paper presents the thermal design to meet the MAG sensor thermal requirements in the extreme thermal environment and with low heater power. A thermal balance test on the MAG sensor engineering model has verified the thermal design and correlated the thermal model for flight temperature predictions.

  4. Structures and Materials Technologies for Extreme Environments Applied to Reusable Launch Vehicles

    Science.gov (United States)

    Scotti, Stephen J.; Clay, Christopher; Rezin, Marc

    2003-01-01

    This paper provides an overview of the evolution of structures and materials technology approaches to survive the challenging extreme environments encountered by earth-to-orbit space transportation systems, with emphasis on more recent developments in the USA. The evolution of technology requirements and experience in the various approaches to meeting these requirements has significantly influenced the technology approaches. While previous goals were primarily performance driven, more recently dramatic improvements in costs/operations and in safety have been paramount goals. Technologies that focus on the cost/operations and safety goals in the area of hot structures and thermal protection systems for reusable launch vehicles are presented. Assessments of the potential ability of the various technologies to satisfy the technology requirements, and their current technology readiness status are also presented.

  5. Plant adaptation to extreme environments: the example of Cistus salviifolius of an active geothermal alteration field.

    Science.gov (United States)

    Bartoli, Giacomo; Bottega, Stefania; Forino, Laura M C; Ciccarelli, Daniela; Spanò, Carmelina

    2014-02-01

    Cistus salviifolius is able to colonise one of the most extreme active geothermal alteration fields in terms of both soil acidity and hot temperatures. The analyses of morpho-functional and physiological characters, investigated in leaves of plants growing around fumaroles (G leaves) and in leaves developed by the same plants after transfer into growth chamber under controlled conditions (C leaves) evidenced the main adaptive traits developed by this pioneer plant in a stressful environment. These traits involved leaf shape and thickness, mesophyll compactness, stomatal and trichome densities, chloroplast size. Changes of functional and physiological traits concerned dry matter content, peroxide and lipid peroxidation, leaf area, relative water and pigment contents. A higher reducing power and antioxidant enzymatic activity were typical of G leaves. Though the high levels of stress parameters, G leaves showed stress-induced specific morphogenic and physiological responses putatively involved in their surviving in active geothermal habitats.

  6. Mitigating Extreme Environments for In-Situ Jupiter and Venus Missions

    Science.gov (United States)

    Balint, Tibor S.; Kolawa, Elizabeth A.; Cutts, James A.

    2006-01-01

    In response to the recommendations by the National Research Council (NRC), NASA's Solar System Exploration (SSE) Roadmap identified the in situ exploration of Venus and Jupiter as high priority science objectives. For Jupiter, deep entry probes are recommended, which would descend to approx.250 km - measured from the 1 bar pressure depth. At this level the pressure would correspond to approx.100 bar and the temperature would reach approx.500(deg)C. Similarly, at the surface of Venus the temperature and pressure conditions are approx.460(deg)C and approx.90 bar. Lifetime of the Jupiter probes during descent can be measured in hours, while in{situ operations at and near the surface of Venus are envisioned over weeks or months. In this paper we discuss technologies, which share commonalities in mitigating these extreme conditions over proposed mission lifetimes, specially focusing on pressure and temperature environments.

  7. Targeted isolation of proteins from natural microbial communities living in an extreme environment.

    Science.gov (United States)

    Singer, Steven W

    2012-01-01

    Microorganisms from extreme environments are often very difficult to cultivate, precluding detailed study by biochemical and physiological techniques. Recent advances in genomic sequencing and proteomic measurements of samples obtained from natural communities have allowed new access to these uncultivated extremophiles and identified abundant proteins that can be isolated directly from natural samples. Here we report the isolation of two abundant heme proteins from low-diversity biofilm microbial communities that thrive in very acidic (pH ~ 1), metal-rich water in a subsurface mine. Purification and detailed characterization of these proteins has afforded new insight into the possible mechanism of Fe(II) oxidation by Leptospirillum Group II, the dominant population in most of these biofilms, and demonstrated that the abundance and posttranslational modifications of one of these proteins is dependent on the lifecycle of the biofilm.

  8. A SiGe BiCMOS Instrumentation Channel for Extreme Environment Applications

    Directory of Open Access Journals (Sweden)

    Chandradevi Ulaganathan

    2010-01-01

    Full Text Available An instrumentation channel is designed, implemented, and tested in a 0.5-μm SiGe BiCMOS process. The circuit features a reconfigurable Wheatstone bridge network that interfaces an assortment of external sensors to signal processing circuits. Also, analog sampling is implemented in the channel using a flying capacitor configuration. The analog samples are digitized by a low-power multichannel A/D converter. Measurement results show that the instrumentation channel supports input signals up to 200 Hz and operates across a wide temperature range of -180°C to 125°C. This work demonstrates the use of a commercially available first generation SiGe BiCMOS process in designing circuits suitable for extreme environment applications.

  9. Influence of chronic exposure to cold environment on thyroid gland function in rabbits.

    Science.gov (United States)

    Mustafa, S; Elgazzar, A

    2014-07-01

    Chronic exposure to cold can affect the thyroid gland. However, the effect on thyroid gland perfusion images and the ratio between thyroid hormones secretion were not addressed in any previous study. The present study investigates the effects of chronic cold exposure on thyroid gland function using radionuclide tracer and thyroid hormones secretion concentration. New Zealand white rabbits weighing approximately 1.8-2 kg were kept in a cold room (4°C) for 7 weeks. Thyroid scintigraphy was performed for cold exposed rabbits and a control rabbit group. Each rabbit was injected with 115 MBq (3.1 mCi) technetium-99m pertechnetate (99mTc pertechnetate). Studies were performed using Gamma camera equipped with a low energy, high resolution, pinhole collimator interfaced with a computer. Static images were acquired 20 min after administration of the radiotracer. Rabbits chronically exposed to cold had less body weights than control. Thyroid gland uptake is higher in rabbits chronically exposed to cold than controls using radionuclide perfusion study. The increase was proportional to the time period, so the increase after 7 weeks was greater than 5 weeks. There is also an increase in free triiodothyronine (FT3) and a decrease in free thyroxine (FT4) values. Our results indicate that thyroid gland uptake is higher in rabbits chronically exposed to cold than control and the increase was proportional to the duration. The decrease in rabbit body weights may be related to the increase in metabolism due to the increase of thyroid hormones. Chronic cold exposure also increased the conversion of T4 to T3, which is more potent in thermogenic effect.

  10. Biodiversity and geochemistry of an extremely acidic, low-temperature subterranean environment sustained by chemolithotrophy.

    Science.gov (United States)

    Kimura, Sakurako; Bryan, Christopher G; Hallberg, Kevin B; Johnson, D Barrie

    2011-08-01

    The geochemical dynamics and composition of microbial communities within a low-temperature (≈ 8.5°C), long-abandoned (> 90 years) underground pyrite mine (Cae Coch, located in north Wales) were investigated. Surface water percolating through fractures in the residual pyrite ore body that forms the roof of the mine becomes extremely acidic and iron-enriched due to microbially accelerated oxidative dissolution of the sulfide mineral. Water droplets on the mine roof were found to host a very limited diversity of exclusively autotrophic microorganisms, dominated by the recently described psychrotolerant iron/sulfur-oxidizing acidophile Acidithiobacillus ferrivorans, and smaller numbers of iron-oxidizing Leptospirillum ferrooxidans. In contrast, flowing water within the mine chamber was colonized with vast macroscopic microbial growths, in the form of acid streamers and microbial stalactites, where the dominant microorganisms were Betaproteobacteria (autotrophic iron oxidizers such as 'Ferrovum myxofaciens' and a bacterium related to Gallionella ferruginea). An isolated pool within the mine showed some similarity (although greater biodiversity) to the roof droplets, and was the only site where archaea were relatively abundant. Bacteria not previously associated with extremely acidic, metal-rich environments (a Sphingomonas sp. and Ralstonia pickettii) were found within the abandoned mine. Data supported the hypothesis that the Cae Coch ecosystem is underpinned by acidophilic, mostly autotrophic, bacteria that use ferrous iron present in the pyrite ore body as their source of energy, with a limited role for sulfur-based autotrophy. Results of this study highlight the importance of novel bacterial species (At. ferrivorans and acidophilic iron-oxidizing Betaproteobacteria) in mediating mineral oxidation and redox transformations of iron in acidic, low-temperature environments. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  11. Woven Thermal Protection System Based Heat-shield for Extreme Entry Environments Technology (HEEET)

    Science.gov (United States)

    Ellerby, Donald; Venkatapathy, Ethiraj; Stackpoole, Margaret; Chinnapongse, Ronald; Munk, Michelle; Dillman, Robert; Feldman, Jay; Prabhu, Dinesh; Beerman, Adam

    2013-01-01

    NASA's future robotic missions utilizing an entry system into Venus and the outer planets, namely, Saturn, Uranus, Neptune, result in extremely high entry conditions that exceed the capabilities of state of the art low to mid density ablators such as PICA or Avcoat. Therefore mission planners typically assume the use of a fully dense carbon phenolic heat shield similar to what was flown on Pioneer Venus and Galileo. Carbon phenolic is a robust TPS material however its high density and relatively high thermal conductivity constrain mission planners to steep entries, with high heat fluxes and pressures and short entry durations, in order for CP to be feasible from a mass perspective. The high entry conditions pose challenges for certification in existing ground based test facilities and the longer-term sustainability of CP will continue to pose challenges. In 2012 the Game Changing Development Program (GCDP) in NASA's Space Technology Mission Directorate funded NASA ARC to investigate the feasibility of a Woven Thermal Protection System (WTPS) to meet the needs of NASA's most challenging entry missions. This project was highly successful demonstrating that a Woven TPS solution compares favorably to CP in performance in simulated reentry environments and provides the opportunity to manufacture graded materials that should result in overall reduced mass solutions and enable a much broader set of missions than does CP. Building off the success of the WTPS project GCDP has funded a follow on project to further mature and scale up the WTPS concept for insertion into future NASA robotic missions. The matured WTPS will address the CP concerns associated with ground based test limitations and sustainability. This presentation will briefly discuss results from the WTPS Project and the plans for WTPS maturation into a heat-shield for extreme entry environment.

  12. Study on the Morphological Characteristics of Skin and Hair Coat of Yak and the Adaptability to the Cold Living Environment

    Institute of Scientific and Technical Information of China (English)

    杨博辉

    2005-01-01

    Selecting 6 heads of new yak strains(the offspring of reciprocal cross of F1 produced by wild yak male mated with domestic yak female)and 6 domestic yaks at 3 and 12 age in months respectively at Datong Yak Farm of Qinghai Province. This paper was studied for the morphological characteristics of the skin and hair coat of yak and their adaptability to the cold living environment in Qinghai-Tibetan plateau. The results indicated that it should be of vital importance marker for the morphological characteristics of the skin and hair coat with two type of yaks at 3 and 12 age in months and their regulations of growth and development to adapt to the cold living environment in Qinghai-Tibetan plateau,The main morphological indexes of the skin and hair coat of the rearing new yak strain were higher than those of the domestic yaks at the same age in months, or speak precisely, the new yak strain was more powerful adaptable to the alpine cold living environment than that of the domestic yaks. The resvlts above provided scientific basis for the native strain breeding of yak and the new yak strain rearing.

  13. Characterizing the Chemical Stability of High Temperature Materials for Application in Extreme Environments

    Science.gov (United States)

    Opila, Elizabeth

    2005-01-01

    The chemical stability of high temperature materials must be known for use in the extreme environments of combustion applications. The characterization techniques available at NASA Glenn Research Center vary from fundamental thermodynamic property determination to material durability testing in actual engine environments. In this paper some of the unique techniques and facilities available at NASA Glenn will be reviewed. Multiple cell Knudsen effusion mass spectrometry is used to determine thermodynamic data by sampling gas species formed by reaction or equilibration in a Knudsen cell held in a vacuum. The transpiration technique can also be used to determine thermodynamic data of volatile species but at atmospheric pressures. Thermodynamic data in the Si-O-H(g) system were determined with this technique. Free Jet Sampling Mass Spectrometry can be used to study gas-solid interactions at a pressure of one atmosphere. Volatile Si(OH)4(g) was identified by this mass spectrometry technique. A High Pressure Burner Rig is used to expose high temperature materials in hydrocarbon-fueled combustion environments. Silicon carbide (SiC) volatility rates were measured in the burner rig as a function of total pressure, gas velocity and temperature. Finally, the Research Combustion Lab Rocket Test Cell is used to expose high temperature materials in hydrogen/oxygen rocket engine environments to assess material durability. SiC recession due to rocket engine exposures was measured as a function of oxidant/fuel ratio, temperature, and total pressure. The emphasis of the discussion for all techniques will be placed on experimental factors that must be controlled for accurate acquisition of results and reliable prediction of high temperature material chemical stability.

  14. Microorganisms in extreme environments with a view to astrobiology in the outer solar system

    Science.gov (United States)

    Seckbach, Joseph; Chela-Flores, Julian

    2015-09-01

    We review the various manifestations of the evolution of life in extreme environments. We review those aspects of extremophiles that are most relevant for astrobiology. We are aware that geothermal energy triggering sources of heat in oceanic environments are not unique to our planet, a fact that was exposed by the Voyager mission images of volcanic activity on Io, the Jovian moon. Such activity exceeded by far what was known form terrestrial geology. The science of astrobiology has considered the possible presence of several moon oceans in the vicinity of both giant gas and icy planets. These watery environments include, not only Europa (strongly suggested by data from the Galileo mission), but the Voyager flybys exposed, not only the unusual geothermal activity on Io, but also the possible presence of subsurface oceans and some geothermal activity on the Neptune's moon Triton. More recently, calculations of Hussmann and coworkers with available data do not exclude that even Uranus moons may be candidates for bearing subsurface oceans. These possibilities invite a challenge that we gladly welcome, of preliminary discussions of habitability of extremophiles in so far novel environments for the science of astrobiology. Nevertheless, such exploration is currently believed to be feasible with the new generations of missions suggested for the time window of 2030 - 2040, or even earlier. We are envisaging, not only the current exploration of the moons of Saturn, but in the coming years we expect to go beyond to Uranus and Neptune to include dwarf planets and trans-neptunian worlds. Consequently, it is necessary to begin questioning whether the Europa-like conditions for the evolution of microorganisms are repeatable elsewhere. At present three new missions are in the process of being formulated, including the selection of payloads that will be necessary for the exploration of the various so far unexplored moons.

  15. NASA Extreme Environment Mission Operations: Science Operations Development for Human Exploration

    Science.gov (United States)

    Bell, Mary S.

    2014-01-01

    The purpose of NASA Extreme Environment Mission Operations (NEEMO) mission 16 in 2012 was to evaluate and compare the performance of a defined series of representative near-Earth asteroid (NEA) extravehicular activity (EVA) tasks under different conditions and combinations of work systems, constraints, and assumptions considered for future human NEA exploration missions. NEEMO 16 followed NASA's 2011 Desert Research and Technology Studies (D-RATS), the primary focus of which was understanding the implications of communication latency, crew size, and work system combinations with respect to scientific data quality, data management, crew workload, and crew/mission control interactions. The 1-g environment precluded meaningful evaluation of NEA EVA translation, worksite stabilization, sampling, or instrument deployment techniques. Thus, NEEMO missions were designed to provide an opportunity to perform a preliminary evaluation of these important factors for each of the conditions being considered. NEEMO 15 also took place in 2011 and provided a first look at many of the factors, but the mission was cut short due to a hurricane threat before all objectives were completed. ARES Directorate (KX) personnel consulted with JSC engineers to ensure that high-fidelity planetary science protocols were incorporated into NEEMO mission architectures. ARES has been collaborating with NEEMO mission planners since NEEMO 9 in 2006, successively building upon previous developments to refine science operations concepts within engineering constraints; it is expected to continue the collaboration as NASA's human exploration mission plans evolve.

  16. Adrenocortical stress responses influence an invasive vertebrate's fitness in an extreme environment.

    Science.gov (United States)

    Jessop, Tim S; Letnic, Mike; Webb, Jonathan K; Dempster, Tim

    2013-10-07

    Continued range expansion into physiologically challenging environments requires invasive species to maintain adaptive phenotypic performance. The adrenocortical stress response, governed in part by glucocorticoid hormones, influences physiological and behavioural responses of vertebrates to environmental stressors. However, any adaptive role of this response in invasive populations that are expanding into extreme environments is currently unclear. We experimentally manipulated the adrenocortical stress response of invasive cane toads (Rhinella marina) to investigate its effect on phenotypic performance and fitness at the species' range front in the Tanami Desert, Australia. Here, toads are vulnerable to overheating and dehydration during the annual hot-dry season and display elevated plasma corticosterone levels indicative of severe environmental stress. By comparing unmanipulated control toads with toads whose adrenocortical stress response was manipulated to increase acute physiological stress responsiveness, we found that control toads had significantly reduced daily evaporative water loss and higher survival relative to the experimental animals. The adrenocortical stress response hence appears essential in facilitating complex phenotypic performance and setting fitness trajectories of individuals from invasive species during range expansion.

  17. A Multi-Wavelength View of the Environments of Extreme Clustered Star Formation

    Science.gov (United States)

    De Buizer, James M.

    2017-01-01

    It is believed that the vast majority of, if not all, stars form within OB clusters. Most theories of star formation assume a star forms in isolation and ignore the fact that the cluster environment and, especially, the presence of extremely energetic and high mass young stellar objects nearby, may have a profound impact on the formation process of a typical cluster member. Giant HII (GHII) regions are Galactic analogs to starburst regions seen in external galaxies, hosting the most active areas of clustered star formation. As such, GHII regions represent a population of objects that can reveal a wealth of information on the environment of the earliest stages of clustered star formation and how it is affected by feedback from the most massive cluster members. This study employs new mid-infrared imaging data obtained from the airborne observatory, SOFIA, as well as archival imaging data from the near-infrared to cm radio wavelengths to create a rich multi-wavelength dataset of a dozen galactic GHII regions. These data allow quantification of the detailed physical conditions within GHII regions individually and as a population on both global and small scales.

  18. Extreme operative temperatures are better descriptors of the thermal environment than mean temperatures.

    Science.gov (United States)

    Camacho, Agustín; Trefaut Rodrigues, Miguel; Navas, Carlos

    2015-01-01

    In ecological studies of thermal biology the thermal environment is most frequently described using the mean or other measures of central tendency in environmental temperatures. However, this procedure may hide biologically relevant thermal variation for ectotherms, potentially misleading interpretations. Extremes of operative temperatures (EOT) can help with this problem by bracketing the thermal environment of focal animals. Within this paper, we quantify how mean operative temperatures relate to the range of simultaneously available operative temperatures (a measure of error). We also show how EOT: 1) detect more thermal differences among microsites than measures of central tendency, like the mean OT, 2) allow inferring on microsite use by ectothermic animals, and 3) clarify the relationships between field operative temperatures and temperatures measured at weather stations (WS). To do that, we explored operative temperatures measured at four sites of the Brazilian Caatingas and their correspondent nearest weather stations. We found that the daily mean OT can hide temperature ranges of 41 °C simultaneously available at our study sites. In addition, EOT detected more thermal differences among microsites than central quantiles. We also show how EOT allow inferring about microsite use of ectothermic animals in a given site. Finally, the daily maximum temperature and the daily temperature range measured at WSs predicted well the minimum available field OT at localities many kilometers away. Based on our results, we recommend the use of EOT, instead of mean OT, in thermal ecology studies.

  19. A milestone toward understanding PDR properties in the extreme environment of LMC-30Dor

    CERN Document Server

    Chevance, M; Lebouteiller, V; Godard, B; Cormier, D; Galliano, F; Hony, S; Indebetouw, R; Bourlot, J Le; Lee, M Y; Petit, F Le; Pellegrini, E; Roueff, E; Wu, R

    2016-01-01

    More complete knowledge of galaxy evolution requires understanding the process of star formation and interaction between the interstellar radiation field and the interstellar medium in galactic environments traversing a wide range of physical parameter space. Here we focus on the impact of massive star formation on the surrounding low metallicity ISM in 30 Doradus in the Large Magellanic Cloud. A low metal abundance, as is the case of some galaxies of the early universe, results in less ultra-violet shielding for the formation of the molecular gas necessary for star formation to proceed. The half-solar metallicity gas in this region is strongly irradiated by the super star cluster R136, making it an ideal laboratory to study the structure of the ISM in an extreme environment. Our spatially resolved study investigates the gas heating and cooling mechanisms, particularly in the photo-dissociation regions where the chemistry and thermal balance are regulated by far-ultraviolet photons (6 eV< h\

  20. Rapid toluene mineralization by aquifer microorganisms at Adak, Alaska: Implications for intrinsic bioremediation in cold environments

    Science.gov (United States)

    Bradley, P.M.; Chapelle, F.H.

    1995-01-01

    Sediments from a relatively cold (5??C), petroleum hydrocarbon-contaminated aquifer in Adak, AK, mineralized [14C]toluene at an aerobic rate (16.3% day-1 at 5??C) comparable to that (5.1% day-1 at 20??C) of sediments from a more temperate aquifer at Hanahan, SC. In addition, rates of overall microbial metabolism in sediments from the two aquifers, as estimated by [1 -14C]acetate mineralization, were similar (???10.6% h-1) at their respective in situ temperatures. These results are not consistent with the common assumption that biodegradation rates in cold ground-water systems are depressed relative to more temperate systems. Furthermore, these results suggest that intrinsic bioremediation of petroleum hydrocarbon contaminants in cold groundwater systems may be technically feasible, in some cases.

  1. Extremely environment-hard and low work function transfer-mold field emitter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Nakamoto, Masayuki, E-mail: m-nakamoto@rie.shizuoka.ac.jp [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka 432-8011 (Japan); Moon, Jonghyun [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka 432-8011 (Japan)

    2013-06-15

    Extremely environment-hard and low work function field-emitter arrays (FEAs) were fabricated by a transfer-mold emitter fabrication method to produce highly reliable vacuum nanoelectronic devices able to operate stably at low voltage in highly oxidizing atmospheres. Amorphous carbon (a-C) having a work function of 3.6 eV and sp{sup 3} fraction of 85.6% prepared by plasma-enhanced chemical vapor deposition was used as the emitter material. The field-emission characteristics of the obtained transfer-mold FEAs strongly depended on their work function and morphology. The environment-hard characteristics of the transfer-mold a-C FEAs were compared with those of the transfer-mold titanium nitride FEAs and nickel FEAs. X-ray photoelectron spectroscopy was used to confirm the stable chemical states of the FEAs after oxygen radical treatment. The small amount of material oxidized (6.3%) at the surface of the a-C FEAs compared with 11.8% for the TiN-FEAs and 39.0% for Ni FEAs after oxygen radical treatment explained their almost constant work function in oxidizing atmospheres. The emission fluctuation rates of transfer-mold a-C FEAs without resistive layers under in situ radical treatment were as low as ±5.0%, compared with 5–100% for conventional FEAs with resistive layers not under highly oxidizing atmospheres. Therefore, the present environment-hard and low work function transfer-mold a-C FEAs are expected to be useful for reliable vacuum nanoelectronic devices.

  2. Cold-climate, fluvial to paralic coal-forming environments in the Permian Collinsville Coal Measures, Bowen Basin, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Martini, I.P.; Johnson, D.P.

    1987-05-01

    The Middle Permian Collinsville Coal Measures of the northern Bowen Basin illustrate a range of cold to cold-temperate, coal-forming environments. Cold climate is indicated by Glossopteris flora in the Coal Measures and by restricted marine fauna dominated by brachiopods and bryozoa in correlative marine sequences of the Back Creek Group which contains also abundant lonestones (dropstones). Sedimentation was characterised by an overall transgression, interrupted by local fluvial and coastal progradation in a shallow, epicontinental sea during a relatively quiescent tectonic period. Six sedimentary environments are represented: fluvial, fluvio-paralic, barrier-strandplain, back-barrier, tidal flat and open marine. The basal coal formed from peat of swamps of abandoned areas of gravelly braided streams, and is massive, dull, and with high ash (20%), low sulphur (1%) contents. Overlying coals developed from peats formed in fluvio-paralic and paralic environments, and thicker seams are generally brighter, with low to moderate ash (8-17%) and moderate to high total sulphur (1-6%) contents. Seams associated with fluvial influence show splits and high ash yield, while seams associated with coastal deposits show high sulphur levels (up to 21%). In contrast to reported models of coal-forming environments, no clearly defined deltaic or interdistributary bay-fill sequences were identified in the area studied. Rather, vast freshwater wetlands backed low-gradient, progradational coasts locally having bars and barriers. The barriers were not prerequisites for substantial peat accumulation, although may have locally assisted peatland development by raising the profile of coastal equilibrium. 37 refs.

  3. Comparison of Environment Impact between Conventional and Cold Chain Management System in Paprika Distribution Process

    Directory of Open Access Journals (Sweden)

    Eidelweijs A Putri

    2012-09-01

    Full Text Available Pasir Langu village in Cisarua, West Java, is the largest central production area of paprika in Indonesia. On average, for every 200 kilograms of paprika produced, there is rejection amounting to 3 kilograms. This resulted in money loss for wholesalers and wastes. In one year, this amount can be approximately 11.7 million Indonesian rupiahs. Recently, paprika wholesalers in Pasir Langu village recently are developing cold chain management system to maintain quality of paprika so that number of rejection can be reduced. The objective of this study is to compare environmental impacts between conventional and cold chain management system in paprika distribution process using Life Cycle Assessment (LCA methodology and propose Photovoltaic (PV system in paprika distribution process. The result implies that the cold chain system produces more CO2 emission compared to conventional system. However, due to the promotion of PV system, the emission would be reduced. For future research, it is necessary to reduce CO2 emission from transportation process since this process is biggest contributor of CO2 emission at whole distribution process. Keywords: LCA, environmentally friendly distribution, paprika,cold chain, PV system

  4. In Situ Raman Spectral Characteristics of Carbon Dioxide in a Deep-Sea Simulator of Extreme Environments Reaching 300 ℃ and 30 MPa.

    Science.gov (United States)

    Li, Lianfu; Du, Zengfeng; Zhang, Xin; Xi, Shichuan; Wang, Bing; Luan, Zhendong; Lian, Chao; Yan, Jun

    2017-01-01

    Deep-sea carbon dioxide (CO2) plays a significant role in the global carbon cycle and directly affects the living environment of marine organisms. In situ Raman detection technology is an effective approach to study the behavior of deep-sea CO2. However, the Raman spectral characteristics of CO2 can be affected by the environment, thus restricting the phase identification and quantitative analysis of CO2. In order to study the Raman spectral characteristics of CO2 in extreme environments (up to 300 ℃ and 30 MPa), which cover most regions of hydrothermal vents and cold seeps around the world, a deep-sea extreme environment simulator was developed. The Raman spectra of CO2 in different phases were obtained with Raman insertion probe (RiP) system, which was also used in in situ Raman detection in the deep sea carried by remotely operated vehicle (ROV) "Faxian". The Raman frequency shifts and bandwidths of gaseous, liquid, solid, and supercritical CO2 and the CO2-H2O system were determined with the simulator. In our experiments (0-300 ℃ and 0-30 MPa), the peak positions of the symmetric stretching modes of gaseous CO2, liquid CO2, and supercritical CO2 shift approximately 0.6 cm(-1) (1387.8-1388.4 cm(-1)), 0.7 cm(-1) (1385.5-1386.2 cm(-1)), and 2.5 cm(-1) (1385.7-1388.2 cm(-1)), and those of the bending modes shift about 1.0 cm(-1) (1284.7-1285.7 cm(-1)), 1.9 cm(-1) (1280.1-1282.0 cm(-1)), and 4.4 cm(-1) (1281.0-1285.4 cm(-1)), respectively. The Raman spectral characteristics of the CO2-H2O system were also studied under the same conditions. The peak positions of dissolved CO2 varied approximately 4.5 cm(-1) (1282.5-1287.0 cm(-1)) and 2.4 cm(-1) (1274.4-1276.8 cm(-1)) for each peak. In comparison with our experiment results, the phases of CO2 in extreme conditions (0-3000 m and 0-300 ℃) can be identified with the Raman spectra collected in situ. This qualitative research on CO2 can also support the further quantitative

  5. Characterizing the effect of creep on stress corrosion cracking of cold worked Alloy 690 in supercritical water environment

    Science.gov (United States)

    Zhang, Lefu; Chen, Kai; Du, Donghai; Gao, Wenhua; Andresen, Peter L.; Guo, Xianglong

    2017-08-01

    The effect of creep on stress corrosion cracking (SCC) was studied by measuring crack growth rates (CGRs) of 30% cold worked (CW) Alloy 690 in supercritical water (SCW) and inert gas environments at temperatures ranging from 450 °C to 550 °C. The SCC crack growth rate under SCW environments can be regarded as the cracking induced by the combined effect of corrosion and creep, while the CGR in inert gas environment can be taken as the portion of creep induced cracking. Results showed that the CW Alloy 690 sustained high susceptibility to intergranular (IG) cracking, and creep played a dominant role in the SCC crack growth behavior, contributing more than 80% of the total crack growth rate at each testing temperature. The temperature dependence of creep induced CGRs follows an Arrhenius dependency, with an apparent activation energy (QE) of about 225 kJ/mol.

  6. An Overview of Materials Structures for Extreme Environments Efforts for 2015 SBIR Phases I and II

    Science.gov (United States)

    Nguyen, Hung D.; Steele, Gynelle C.

    2017-01-01

    Technological innovation is the overall focus of NASA's Small Business Innovation Research (SBIR) program. The program invests in the development of innovative concepts and technologies to help NASA's mission directorates address critical research and development needs for Agency projects. This report highlights innovative SBIR 2015 Phase I and II projects that specifically address areas in Materials and Structures for Extreme Environments, one of six core competencies at NASA Glenn Research Center. Each article describes an innovation, defines its technical objective, and highlights NASA applications as well as commercial and industrial applications. Ten technologies are featured: metamaterials-inspired aerospace structures, metallic joining to advanced ceramic composites, multifunctional polyolefin matrix composite structures, integrated reacting fluid dynamics and predictive materials degradation models for propulsion system conditions, lightweight inflatable structural airlock (LISA), copolymer materials for fused deposition modeling 3-D printing of nonstandard plastics, Type II strained layer superlattice materials development for space-based focal plane array applications, hydrogenous polymer-regolith composites for radiation-shielding materials, a ceramic matrix composite environmental barrier coating durability model, and advanced composite truss printing for large solar array structures. This report serves as an opportunity for NASA engineers, researchers, program managers, and other personnel to learn about innovations in this technology area as well as possibilities for collaboration with innovative small businesses that could benefit NASA programs and projects.

  7. Digital Learning Network Education Events of NASA's Extreme Environments Mission Operations

    Science.gov (United States)

    Paul, Heather; Guillory, Erika

    2007-01-01

    NASA's Digital Learning Network (DLN) reaches out to thousands of students each year through video conferencing and web casting. The DLN has created a series of live education videoconferences connecting NASA s Extreme Environment Missions Operations (NEEMO) team to students across the United States. The programs are also extended to students around the world live web casting. The primary focus of the events is the vision for space exploration. During the programs, NEEMO Crewmembers including NASA astronauts, engineers and scientists inform and inspire students about the importance of exploration and share the impact of the project as it correlates with plans to return to the moon and explore the planet Mars. These events highlight interactivity. Students talk live with the aquanauts in Aquarius, the National Oceanic and Atmospheric Administration s underwater laboratory. With this program, NASA continues the Agency s tradition of investing in the nation's education programs. It is directly tied to the Agency's major education goal of attracting and retaining students in science, technology, and engineering disciplines. Before connecting with the aquanauts, the students conduct experiments of their own designed to coincide with mission objectives. This paper describes the events that took place in September 2006.

  8. An Overview of SBIR Phase 2 Materials Structures for Extreme Environments

    Science.gov (United States)

    Nguyen, Hung D.; Steele, Gynelle C.

    2015-01-01

    Technological innovation is the overall focus of NASA's Small Business Innovation Research (SBIR) program. The program invests in the development of innovative concepts and technologies to help NASA's mission directorates address critical research and development needs for agency projects. This report highlights innovative SBIR Phase II projects from 2007-2012 specifically addressing Areas in Materials and Structures for Extreme Environments which is one of six core competencies at NASA Glenn Research Center. There are twenty three technologies featured with emphasis on a wide spectrum of applications such as fine-filament superconductor wire, composite oxide cathode materials, nano-composites, high radiation solar cell, wrapped multilayer insulation, thin aerogel, and much more. Each article in this booklet describes an innovation, technical objective, and highlights NASA commercial and industrial applications. This report serves as an opportunity for NASA personnel including engineers, researchers, and program managers to learn of NASA SBIR's capabilities that might be crosscutting into this technology area. As the result, it would cause collaborations and partnerships between the small companies and NASA Programs and Projects resulting in benefit to both SBIR companies and NASA.

  9. Disease transmission in an extreme environment: nematode parasites infect reindeer during the Arctic winter.

    Science.gov (United States)

    Carlsson, Anja M; Justin Irvine, R; Wilson, Kenneth; Piertney, Stuart B; Halvorsen, Odd; Coulson, Stephen J; Stien, Audun; Albon, Steve D

    2012-07-01

    Parasitic nematodes are found in almost all wild vertebrate populations but few studies have investigated these host-parasite relationships in the wild. For parasites with free-living stages, the external environment has a major influence on life-history traits, and development and survival is generally low at sub-zero temperatures. For reindeer that inhabit the high Arctic archipelago of Svalbard, parasite transmission is expected to occur in the summer, due to the extreme environmental conditions and the reduced food intake by the host in winter. Here we show experimentally that, contrary to most parasitic nematodes, Marshallagia marshalli of Svalbard reindeer is transmitted during the Arctic winter. Winter transmission was demonstrated by removing parasites in the autumn, using a novel delayed-release anthelmintic bolus, and estimating re-infection rates in reindeer sampled in October, February and April. Larval stages of nematodes were identified using molecular tools, whereas adult stages were identified using microscopy. The abundance of M. marshalli adult worms and L4s increased significantly from October to April, indicating that reindeer were being infected with L3s from the pasture throughout the winter. To our knowledge, this study is the first to experimentally demonstrate over-winter transmission of a gastro-intestinal nematode parasite in a wild animal. Potential mechanisms associated with this unusual transmission strategy are discussed in light of our knowledge of the life-history traits of this parasite.

  10. Adaptation to extreme environments: structure-function relationships in Emperor penguin haemoglobin.

    Science.gov (United States)

    Tamburrini, M; Condò, S G; di Prisco, G; Giardina, B

    1994-04-15

    The functional properties of the single haemoglobin (Hb) of Emperor penguin (Aptenodytes forsteri) have been investigated at different temperatures as a function of proton and organic phosphate concentration. The complete amino acid sequence has been established. Comparison with that of human HbA shows 12 substitutions in the contact regions of alpha beta dimers. In addition to overall similarities shared with most of the avian Hbs previously described, this Hb shows significant differences, which could be related to the peculiar behaviour of this penguin. In particular we may consider that: (1) the shape of the Bohr effect curve seems well adapted for gas exchange during very prolonged dives, preserving penguin Hb from a sudden and not controlled stripping of oxygen; (2) the very minor enthalpy change observed at lower pH could be an example of molecular adaptation, through which oxygen delivery becomes essentially insensitive to exposure to the extremely low temperatures of the environment. Moreover, the small alkaline Bohr effect has been found to be only chloride-linked, since the pH dependence of the oxygen affinity is totally abolished in the absence of this ion. These functional characteristics are discussed on the basis of the primary structure of alpha and beta-chains.

  11. Present knowledge of the bacterial microflora in the extreme environment of sugar thick juice.

    Science.gov (United States)

    Justé, Annelies; Lievens, Bart; Frans, Ingeborg; Klingeberg, Michael; Michiels, Chris W; Willems, Kris A

    2008-09-01

    The diversity of the bacterial population in sugar thick juice, an intermediate product in the production of beet sugar, which exhibits an extreme, osmophilic environment with a water activity value (a(w)) less than 0.86, was assessed with both culture-dependent and -independent 16S ribosomal RNA (rRNA) gene-based analyses. In comparison with previous studies, the number of different thick juice bacterial species increased from 29 to 72. Remarkably, a limited, gram-positive, culturable flora, encompassing species of Bacillus, Staphylococcus and mainly Tetragenococcus dominated thick juice during storage, while a more heterogeneous and unculturable fraction of Acinetobacter, Sporolactobacillus and Thermus species could be detected in freshly produced thick juice. Notably, almost all bacteria detected in the thick juice were also detected in the air, emphasising the importance of further investigation and assessment of strategies to reduce (air) contamination during processing and storage. The discovery of the contamination source may be used for the development of management strategies for thick juice degradation resulting from microbial activity.

  12. Time-of-flight Extreme Environment Diffractometer at the Helmholtz-Zentrum Berlin.

    Science.gov (United States)

    Prokhnenko, Oleksandr; Stein, Wolf-Dieter; Bleif, Hans-Jürgen; Fromme, Michael; Bartkowiak, Maciej; Wilpert, Thomas

    2015-03-01

    The Extreme Environment Diffractometer (EXED) is a new neutron time-of-flight instrument at the BER II research reactor at the Helmholtz-Zentrum Berlin, Germany. Although EXED is a special-purpose instrument, its early construction made it available for users as a general-purpose diffractometer. In this respect, EXED became one of the rare examples, where the performance of a time-of-flight diffractometer at a continuous source can be characterized. In this paper, we report on the design and performance of EXED with an emphasis on the unique instrument capabilities. The latter comprise variable wavelength resolution and wavelength band, control of the incoming beam divergence, the possibility to change the angular positions of detectors and their distance to the sample, and use of event recording and offline histogramming. These features combined make EXED easily tunable to the requirements of a particular problem, from conventional diffraction to small angle neutron scattering. The instrument performance is demonstrated by several reference measurements and user experiments.

  13. Reaction Product Identification in Extreme Chemical Environments by Broadband Rotational Spectroscopy

    Science.gov (United States)

    Pate, Brooks

    Molecular rotational spectroscopy has several advantages for detection of reaction intermediates and products under extreme laboratory conditions. Rotational spectroscopy has high sensitivity to the molecular structure and provides high spectral resolution in low pressure environments. Furthermore, quantum chemistry provides accurate estimates of the spectroscopic parameters. As a result, rotational spectroscopy can identify molecular species in complex reaction mixtures without the need for chromatographic separation and without the need for a previously recorded ``library spectrum'' of the molecule. The application of chirped pulse Fourier transform rotational spectroscopy methods for the identification of molecules of astrochemical interest formed in pulsed discharge sources will be described including recent advances for high-throughput mm-wave spectroscopy. The set of reaction products created in the experiment can provide insight into the reaction mechanism. Reactions involving the CN radical will be discussed. These reactions can be barrierless making them candidates for interstellar gas reactions. The possibility that interstellar cyanomethanimine is produced by gas phase radical-neutral reactions instead of surface chemistry on grain-supported ices will be discussed using recent spatially resolved chemical images in Sagittarius B2 observed with the Jansky Very Large Array. This work supported by NSF CHE 1213200.

  14. Planetary protection in the extreme environments of low-mass stars

    CERN Document Server

    Vidotto, A A; Morin, J; Donati, J -F; Lang, P; Russell, A J B

    2013-01-01

    Recent results showed that the magnetic field of M-dwarf (dM) stars, currently the main targets in searches for terrestrial planets, is very different from the solar one, both in topology as well as in intensity. In particular, the magnetised environment surrounding a planet orbiting in the habitable zone (HZ) of dM stars can differ substantially to the one encountered around the Earth. These extreme magnetic fields can compress planetary magnetospheres to such an extent that a significant fraction of the planet's atmosphere may be exposed to erosion by the stellar wind. Using observed surface magnetic maps for a sample of 15 dM stars, we investigate the minimum degree of planetary magnetospheric compression caused by the intense stellar magnetic fields. We show that hypothetical Earth-like planets with similar terrestrial magnetisation (~1G) orbiting at the inner (outer) edge of the HZ of these stars would present magnetospheres that extend at most up to 6.1 (11.7) planetary radii. To be able to sustain an E...

  15. Study on the extremely cold winter of 1670 over the middle and lower reaches of the Yangtze River

    Institute of Scientific and Technical Information of China (English)

    JunHui Yan; MingQi Li; HaoLong Liu; JingYun Zheng; Hui Fu

    2014-01-01

    The snow-cover days over the middle and lower reaches of the Yangtze River (MLRYR) in the winter of 1670 were extracted from Chinese historical documents. By these records, the winter temperature anomalies (compared to the mean of 1961-1990) recorded at seven meteorological stations and the regional mean winter temperature were estimated. The results show that:(1) There was an average of about 30 snow-cover days over the MLRYR region in 1670, ranging from 11-20 days in Shanghai and eastern Zhejiang to 51-60 days in eastern Hunan Province. The snow-cover days averaged about 40 days in Anqing and Nan-cheng, and ranged from 30 to 40 days in Quzhou, Jingdezhen, and Nanchang;and (2) the regional mean winter temperature in 1670 was estimated to be approximately 4.0 °C lower than that of 1961-1990. The maximum negative anomaly of 5.6 °C oc-curred in Nanchang and the minimum anomaly of-2.8 °C was detected in Quzhou. Both of these were lower than that of the coldest winter during the instrumental observation period of 1951-2010. This research could not only provide a method to es-timate historical climate extremes, but also provide a background to understand the recent instrumentally climate extremes.

  16. Effect of environment on extremely severe road traffic crashes:retrospective epidemic analysis during 2000-2001

    Institute of Scientific and Technical Information of China (English)

    覃华丽; 赵新才; 周继红; 邱俊; 杨在亮; 蒋志泉; 朱秉忠

    2004-01-01

    Objective: To make an epidemiological analysis of the effect of environment on extremely severe road traffic crashes (RTCs). Methods: Epidemiologic data of extremely severe RTCs associated with environmental factors, including weather, topography, road conditions and other traffic conditions in Mainland China during 2000-2001, were collected and analyzed. Results: (1) During 2000-2001, there were 3 365 extremely severe RTCs with 13 666 deaths, 12 204 injuries and a direct economical loss of 136 million RMB. (2) Most extremely severe RTCs occurred in fine weather days and in the daytime. The high occurrence sites were plain areas, horizontal and straight roads, Grade B and C roads, ordinary road segment, and asphalt, smooth and mixed roads. (3) Compared with other RTCs, extremely severe RTCs were more likely to happen under following conditions: on cloudy, snowing, misty and blustering days; in hill and mountainous areas; on crooked and sloping roads; on freeway, Grade A, B, and C roads; mixed roads; ordinary, bridge, narrow and transitional roads; sand and dirt-roads; without traffic control measures; night without lighting. (4) Extremely severe RTCs of mountainous area or crooked and sloping roads were most severe in terms of deaths and injures per crash. Conclusions: Extremely severe RTCs are closely related with environmental factors. Rational road programming, enhancing road establishment and improving road conditions are probably effective measures to reduce the road traffic injuries.

  17. Four newly isolated fuselloviruses from extreme geothermal environments reveal unusual morphologies and a possible interviral recombination mechanism

    DEFF Research Database (Denmark)

    Greve, Bo Bjørn

    2009-01-01

    Spindle-shaped virus-like particles are abundant in extreme geothermal environments, from which five spindle-shaped viral species have been isolated to date. They infect members of the hyperthermophilic archaeal genus Sulfolobus, and constitute the Fuselloviridae, a family of double-stranded DNA...

  18. Effects of hydrogen water chemistry on corrosion fatigue behavior of cold-worked 304L stainless steel in simulated BWR coolant environments

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, M.F., E-mail: mfchiang@iner.gov.tw [Institute of Nuclear Energy Research, Division of Nuclear Fuels and Materials, Lungtan, Taoyuan 325, Taiwan (China); Young, M.C.; Huang, J.Y. [Institute of Nuclear Energy Research, Division of Nuclear Fuels and Materials, Lungtan, Taoyuan 325, Taiwan (China)

    2011-04-15

    Corrosion fatigue behavior of stainless steel 304L (SS304L) in a simulated BWR coolant with hydrogen injection was investigated. Hydrogen water chemistry slightly mitigated the corrosion fatigue degradation of the as-received SS304L specimens, but, on the contrary, it slightly increased the corrosion fatigue crack growth rates (CFCGRs) of the cold-worked specimens. All the CFCGR-tested specimens showed similar fracture features, except for the amounts of deposited corrosion debris. The results indicated that decreasing the oxygen concentration of water environment is not an effective measure to suppress the fatigue crack growth rate of cold-worked SS304L. The CFCGRs of the SS304L were determined by an interaction between corrosion, oxide-induced crack closure and cold work in corrosive environments. At a specific level of reduction, cold work could enhance the corrosion fatigue resistance of SS304 both in the air-saturated and HWC coolant environments.

  19. Effects of hydrogen water chemistry on corrosion fatigue behavior of cold-worked 304L stainless steel in simulated BWR coolant environments

    Science.gov (United States)

    Chiang, M. F.; Young, M. C.; Huang, J. Y.

    2011-04-01

    Corrosion fatigue behavior of stainless steel 304L (SS304L) in a simulated BWR coolant with hydrogen injection was investigated. Hydrogen water chemistry slightly mitigated the corrosion fatigue degradation of the as-received SS304L specimens, but, on the contrary, it slightly increased the corrosion fatigue crack growth rates (CFCGRs) of the cold-worked specimens. All the CFCGR-tested specimens showed similar fracture features, except for the amounts of deposited corrosion debris. The results indicated that decreasing the oxygen concentration of water environment is not an effective measure to suppress the fatigue crack growth rate of cold-worked SS304L. The CFCGRs of the SS304L were determined by an interaction between corrosion, oxide-induced crack closure and cold work in corrosive environments. At a specific level of reduction, cold work could enhance the corrosion fatigue resistance of SS304 both in the air-saturated and HWC coolant environments.

  20. Sports in extreme conditions: the impact of exercise in cold temperatures on asthma and bronchial hyper-responsiveness in athletes.

    Science.gov (United States)

    Carlsen, Kai-Håkon

    2012-09-01

    Exercise-induced asthma (EIA) and bronchial hyper-responsiveness (BHR) are frequently reported among elite athletes of outdoor endurance winter sports, particularly in cross-country and biathlon skiers. The pathogenesis of EIA is related to water loss and heat-loss through the increased respiration during exercise, leading to mediator release, airways inflammation and increased parasympathetic nervous activity in the airways, causing bronchial constriction and BHR. In the competing elite athlete this is presently considered to be due to the frequently repeated increased ventilation during training and competitions in combination with the repeated environmental exposure to cold air in outdoor winter sports. It is important that athletes at risk of asthma and BHR are monitored through regular medical control with assessment of lung function and BHR, and when BHR or asthma is diagnosed, optimal controlling treatment through anti-inflammatory treatment by inhaled steroids should be started and relieving treatment (inhaled ipratropium bromide and inhaled β2-agonists) should be used to relieve bronchial constriction if present.

  1. Microbial iron management mechanisms in extremely acidic environments: comparative genomics evidence for diversity and versatility

    Directory of Open Access Journals (Sweden)

    Nieto Pamela A

    2008-11-01

    uptake systems could reflect their obligatory occupation of extremely low pH environments where high concentrations of soluble iron may always be available and were oxidized sulfur species might not compromise iron speciation dynamics. Presence of bacterioferritin in the Acidithiobacilli, polyphosphate accumulation functions and variants of FieF-like diffusion facilitators in both Acidithiobacilli and Leptospirilla, indicate that they may remove or store iron under conditions of variable availability. In addition, the Fe(II-oxidizing capacity of both A. ferrooxidans and Leptospirilla could itself be a way to evade iron stress imposed by readily available Fe(II ions at low pH. Fur regulatory sites have been predicted for a number of gene clusters including iron related and non-iron related functions in both the Acidithiobacilli and Leptospirilla, laying the foundation for the future discovery of iron regulated and iron-phosphate coordinated regulatory control circuits. Conclusion In silico analyses of the genomes of acidophilic bacteria are beginning to tease apart the mechanisms that mediate iron uptake and homeostasis in low pH environments. Initial models pinpoint significant differences in abundance and diversity of iron management mechanisms between Leptospirilla and Acidithiobacilli, and begin to reveal how these two groups respond to iron cycling and iron fluctuations in naturally acidic environments and in industrial operations. Niche partitions and ecological successions between acidophilic microorganisms may be partially explained by these observed differences. Models derived from these analyses pave the way for improved hypothesis testing and well directed experimental investigation. In addition, aspects of these models should challenge investigators to evaluate alternative iron management strategies in non-acidophilic model organisms.

  2. Modular SiGe 130 nm Cell Library for Extreme Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA space missions utilizing application-specific integrated circuits (ASICs) under extreme conditions have a critical need for high performance analog cell...

  3. Conduccion de lombricultivos en condiciones de temperie extremas (zonas frias - Vermiculture management in extreme weather conditions (cold areas

    Directory of Open Access Journals (Sweden)

    Miguel SCHULDT

    2006-07-01

    Full Text Available Para optimizar la conducción de vermicultivos en climas fríos y condiciones de temperie se recomienda implementar durante la primavera – verano, alimentación periódica (semanal que se inicia con una siembra de 10.000 lombrices / Lecho (2 m2. Tras una subdivisión del cultivo en el verano y el despoblamiento de los sectores en el otoño, las lombrices obtenidas se utilizan para poblar sectores de materia orgánica (MO de 1,5 m de altura a razón de 4.000 lombrices / Lecho, donde permanecerán hasta la primavera siguiente. Esta modalidad de manejo, al cabo de un año, permite potencialmente multiplicar elc área de cultivo en aproximadamente 150 veces el inicial y paralelamente aumentar el tamaño de la población de lombrices 1.470 veces. Esta producción de lombrices corresponde al 31% de la potencialmente alcanzable en climas moderados (4.800X. In order to optimize vermiculture management in cold climates, it is recommended to implement periodic (weekly feeding during spring - summer, beginning with the inoculation of 10,000 worms/Bed (2 m2. After subdivision of the culture in summer and extraction of earthworms from the sectors in autumn, the obtained worms are used to populate new sectors with 1.5 m high organic matter (OM piles at a rate of 4,000 worms/Bed, where they are kept until the following spring. After one year, this management method allows a potential 150-fold increase of the original culture area and a simultaneous growth of the earthworm population to 1,470 times its initial size. This earthworm production represents 31% of the potential production for moderate climates (4.800X

  4. Nutritional Assessment During a 14-d Saturation Dive: the NASA Extreme Environment Mission Operation V Project

    Science.gov (United States)

    Smith, S. M.; Davis-Street, J. E.; Fesperman, J. V.; Smith, M. D.; Rice, B. L.; Zwart, S. R.

    2006-01-01

    Ground-based analogs of spaceflight are an important means of studying physiological and nutritional changes associated with space travel, particularly since exploration missions are anticipated, and flight research opportunities are limited. A clinical nutritional assessment of the NASA Extreme Environment Mission Operation V (NEEMO) crew (4 M, 2 F) was conducted before, during, and after the 14-d saturation dive. Blood and urine samples were collected before (D-12 and D-1), during (MD 7 and MD 12), and after (R + 0 and R + 7) the dive. The foods were typical of the spaceflight food system. A number of physiological changes were reported both during the dive and post dive that are also commonly observed during spaceflight. Serum hemoglobin and hematocrit were decreased (P less than 0.05) post dive. Serum ferritin and ceruloplasmin significantly increased during the dive, while transferring receptors tended to go down during the dive and were significantly decreased by the last day (R + 0). Along with significant hematological changes, there was also evidence for increased oxidative damage and stress during the dive. 8-hydroxydeoxyguanosine was elevated (P less than 0.05) during the dive, while glutathione peroxidase and superoxide disrnutase activities were decreased (P less than 0.05) during the dive. Serum C-reactive protein (CRP) concentration also tended to increase during the dive, suggesting the presence of a stress-induced inflammatory response, Decreased leptin during the dive (P less than 0.05) may also be related to the increased stress. Similar to what is observed during spaceflight, subjects had decreased energy intake and weight loss during the dive. Together, these similarities to spaceflight provide a model to further define the physiological effects of spaceflight and investigate potential countermeasures.

  5. Comparative community genomics in the Dead Sea: an increasingly extreme environment.

    Science.gov (United States)

    Bodaker, Idan; Sharon, Itai; Suzuki, Marcelino T; Feingersch, Roi; Shmoish, Michael; Andreishcheva, Ekaterina; Sogin, Mitchell L; Rosenberg, Mira; Maguire, Michael E; Belkin, Shimshon; Oren, Aharon; Béjà, Oded

    2010-03-01

    Owing to the extreme salinity ( approximately 10 times saltier than the oceans), near toxic magnesium levels (approximately 2.0 M Mg(2+)), the dominance of divalent cations, acidic pH (6.0) and high-absorbed radiation flux rates, the Dead Sea represents a unique and harsh ecosystem. Measures of microbial presence (microscopy, pigments and lipids) indicate that during rare bloom events after exceptionally rainy seasons, the microbial communities can reach high densities. However, most of the time, when the Dead Sea level is declining and halite is precipitating from the water column, it is difficult to reliably measure the presence of microorganisms and their activities. Although a number of halophilic Archaea have been previously isolated from the Dead Sea, polar lipid analyses of biomass collected during Dead Sea blooms suggested that these isolates were not the major components of the microbial community of these blooms. In this study, in an effort to characterize the perennial microbial community of the Dead Sea and compare it with bloom assemblages, we performed metagenomic analyses of concentrated biomass from hundreds of liters of brine and of microbial material from the last massive Dead Sea bloom. The difference between the two conditions was reflected in community composition and diversity, in which the bloom was different and less diverse from the residual brine population. The distributional patterns of microbial genes suggested Dead Sea community trends in mono- and divalent cation metabolisms as well as in transposable elements. This may indicate possible mechanisms and pathways enabling these microbes to survive in such a harsh environment.

  6. A 200 C Universal Gate Driver Integrated Circuit for Extreme Environment Applications

    Energy Technology Data Exchange (ETDEWEB)

    Tolbert, Leon M [ORNL; Huque, Mohammad A [ORNL; Islam, Syed K [ORNL; Blalock, Benjamin J [ORNL

    2012-01-01

    High-temperature power converters (dc-dc, dc-ac, etc.) have enormous potential in extreme environment applications, including automotive, aerospace, geothermal, nuclear, and well logging. For successful realization of such high-temperature power conversion modules, the associated control electronics also need to perform at high temperature. This paper presents a silicon-on-insulator (SOI) based high-temperature gate driver integrated circuit (IC) incorporating an on-chip low-power temperature sensor and demonstrating an improved peak output current drive over our previously reported work. This driver IC has been primarily designed for automotive applications, where the underhood temperature can reach 200 C. This new gate driver prototype has been designed and implemented in a 0.8 {micro}m, 2-poly, and 3-metal bipolar CMOS-DMOS (Double-Diffused Metal-Oxide Semiconductor) on SOI process and has been successfully tested for up to 200 C ambient temperature driving a SiC MOSFET and a SiC normally-ON JFET. The salient feature of the proposed universal gate driver is its ability to drive power switches over a wide range of gate turn-ON voltages such as MOSFET (0 to 20 V), normally-OFF JFET (-7 to 3 V), and normally-ON JFET (-20 to 0 V). The measured peak output current capability of the driver is around 5 A and is thus capable of driving several power switches connected in parallel. An ultralow-power on-chip temperature supervisory circuit has also been integrated into the die to safeguard the driver circuit against excessive die temperature ({ge}220 C). This approach utilizes increased diode leakage current at higher temperature to monitor the die temperature. The power consumption of the proposed temperature sensor circuit is below 10 {micro}W for operating temperature up to 200 C.

  7. A milestone toward understanding PDR properties in the extreme environment of LMC-30 Doradus

    Science.gov (United States)

    Chevance, M.; Madden, S. C.; Lebouteiller, V.; Godard, B.; Cormier, D.; Galliano, F.; Hony, S.; Indebetouw, R.; Le Bourlot, J.; Lee, M.-Y.; Le Petit, F.; Pellegrini, E.; Roueff, E.; Wu, R.

    2016-05-01

    Context. More complete knowledge of galaxy evolution requires understanding the process of star formation and the interaction between the interstellar radiation field and interstellar medium (ISM) in galactic environments traversing a wide range of physical parameter space. We focus on the impact of massive star formation on the surrounding low metallicity ISM in 30 Doradus in the Large Magellanic Cloud (LMC). A low metal abundance, which can characterizes some galaxies of the early Universe, results in less ultraviolet (UV) shielding for the formation of the molecular gas necessary for star formation to proceed. The half-solar metallicity gas in this region is strongly irradiated by the super star cluster R136, making it an ideal laboratory to study the structure of the ISM in an extreme environment. Aims: Our goal is to construct a comprehensive, self-consistent picture of the density, radiation field, and ISM structure in the most active star-forming region in the LMC, 30 Doradus. Our spatially resolved study investigates the gas heating and cooling mechanisms, particularly in the photodissociation regions (PDR) where the chemistry and thermal balance are regulated by far-UV photons (6 eV parallel geometry and a uniform medium, we find a total extinction AVmax of 1-3 mag, which corresponds to a PDR cloud size of 0.2 to 3pc with small CO depth scale of 0.06 to 0.5 pc. At least 90% of the [C ii] originates in PDRs in this region, while a significant fraction of the LFIR (up to 70% in some places) can be associated with an ionized gas component. The high [O iii]/[C ii] ratio (2 to 60) throughout the observed map, correlated with the filling factor, reveals the porosity of the ISM in this region, which is traversed by hard UV photons surrounding small PDR clumps. We also determine the three-dimensional structure of the gas, showing that the clouds are distributed 20 to 80 pc away from the main ionizing cluster, R136. The reduced images are only available at the CDS

  8. Development of in-vessel neutron flux monitor equipped with microfission chambers to withstand the extreme ITER environment

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Masao, E-mail: ishikawa.masao@jaea.go.jp; Takeda, Keigo; Itami, Kiyoshi

    2016-11-01

    Highlights: • The in-vessel components of MFC system must withstand the extreme ITER environment. • To verify this, the thermal cycle test and the vibration tests were conducted. • Both tests were conducted under much severer conditions than ITER environment. • Soundness verification tests after the tests indicated that no problemswere found. • It is shown that the in-vessel component is sufficiently robust ITER environment. - Abstract: Via thermal cycling and vibration tests, this study aims to demonstrate that the in-vessel components of the microfission chamber (MFC) system can withstand the extreme International Thermonuclear Experimental Reactor (ITER) environment. In thermal cycle tests, the signal cable of the device was bent into a smaller radius and it was given more bends than those in its actual configuration within ITER. A faster rate of temperature change than that under the typical ITER baking scenario was then imposed on in-vessel components. For the vibration tests, strong 10 G vibrational accelerations with frequencies ranging from 30 Hz to 2000 Hz were imposed to the detector and the connector of the in-vessel components to simulate various types of electromagnetic events. Soundness verification tests of the in-vessel components conducted after thermal cycling and vibration testing indicated that problems related to the signal transmission cable functioning were not found. Thus, it was demonstrated that the in-vessel components of the MFC can withstand the extreme environment within ITER.

  9. Triggering optical AGN: the need for cold gas, and the indirect roles of galaxy environment and interactions

    CERN Document Server

    Sabater, J; Heckman, T M

    2014-01-01

    We present a study of the prevalence and luminosity of Active Galactic Nuclei (AGN; traced by optical spectra) as a function of both environment and galaxy interactions. For this study we used a sample of more than 250000 galaxies drawn from the Sloan Digital Sky Survey and, crucially, we controlled for the effect of both stellar mass and central star formation activity. Once these two factors are taken into account, the effect of the local density of galaxies and of one-on-one interactions is minimal in both the prevalence of AGN activity and AGN luminosity. This suggests that the level of nuclear activity depends primarily on the availability of cold gas in the nuclear regions of galaxies and that secular processes can drive the AGN activity in the majority of cases. Large scale environment and galaxy interactions only affect AGN activity in an indirect manner, by influencing the central gas supply.

  10. Mechanical behaviour of membrane electrode assembly (MEA during cold start of PEM fuel cell from subzero environment temperature

    Directory of Open Access Journals (Sweden)

    Maher A.R. Sadiq Al-Baghdadi

    2015-01-01

    Full Text Available Durability is one of the most critical remaining issues impeding successful commercialization of broad PEM fuel cell transportation energy applications. Automotive fuel cells are likely to operate with neat hydrogen under load-following or load-levelled modes and be expected to withstand variations in environmental conditions, particularly in the context of temperature and atmospheric composition. In addition, they are also required to survive over the course of their expected operational lifetimes i.e., around 5,500 hrs, while undergoing as many as 30,000 startup/shutdown cycles. Cold start capability and survivability of proton exchange membrane fuel cells (PEM in a subzero environment temperature remain a challenge for automotive applications. A key component of increasing the durability of PEM fuel cells is studying the behaviour of the membrane electrode assembly (MEA at the heart of the fuel cell. The present work investigates how the mechanical behaviour of MEA are influenced during cold start of the PEM fuel cell from subzero environment temperatures. Full three-dimensional, non-isothermal computational fluid dynamics model of a PEM fuel cell has been developed to simulate the stresses inside the PEM fuel cell, which are occurring during fuel cell assembly (bolt assembling, and the stresses arise during fuel cell running due to the changes of temperature and relative humidity. The model is shown to be able to understand the many interacting, complex electrochemical, transport phenomena, and stresses distribution that have limited experimental data.

  11. In situ environment rather than substrate type dictates microbial community structure of biofilms in a cold seep system

    Science.gov (United States)

    Lee, On On; Wang, Yong; Tian, Renmao; Zhang, Weipeng; Shek, Chun Shum; Bougouffa, Salim; Al-Suwailem, Abdulaziz; Batang, Zenon B.; Xu, Wei; Wang, Guang Chao; Zhang, Xixiang; Lafi, Feras F.; Bajic, Vladmir B.; Qian, Pei-Yuan

    2014-01-01

    Using microscopic and molecular techniques combined with computational analysis, this study examined the structure and composition of microbial communities in biofilms that formed on different artificial substrates in a brine pool and on a seep vent of a cold seep in the Red Sea to test our hypothesis that initiation of the biofilm formation and spreading mode of microbial structures differs between the cold seep and the other aquatic environments. Biofilms on different substrates at two deployment sites differed morphologically, with the vent biofilms having higher microbial abundance and better structural features than the pool biofilms. Microbes in the pool biofilms were more taxonomically diverse and mainly composed of various sulfate-reducing bacteria whereas the vent biofilms were exclusively dominated by sulfur-oxidizing Thiomicrospira. These results suggest that the redox environments at the deployment sites might have exerted a strong selection on microbes in the biofilms at two sites whereas the types of substrates had limited effects on the biofilm development. PMID:24399144

  12. Life in extreme environments: single molecule force spectroscopy as a tool to explore proteins from extremophilic organisms.

    Science.gov (United States)

    Tych, Katarzyna M; Hoffmann, Toni; Batchelor, Matthew; Hughes, Megan L; Kendrick, Katherine E; Walsh, Danielle L; Wilson, Michael; Brockwell, David J; Dougan, Lorna

    2015-04-01

    Extremophiles are organisms which survive and thrive in extreme environments. The proteins from extremophilic single-celled organisms have received considerable attention as they are structurally stable and functionally active under extreme physical and chemical conditions. In this short article, we provide an introduction to extremophiles, the structural adaptations of proteins from extremophilic organisms and the exploitation of these proteins in industrial applications. We provide a review of recent developments which have utilized single molecule force spectroscopy to mechanically manipulate proteins from extremophilic organisms and the information which has been gained about their stability, flexibility and underlying energy landscapes.

  13. The DYNAFLUX / DYNACOLD Network: Dynamics, Fluxes, Stability, Succession and Landscape Formation in Cold Climate Environments

    Science.gov (United States)

    Beylich, Achim A.

    2016-04-01

    There is a wide range of high-latitude and high-altitude cold climate landscapes in Europe, covering a significant proportion of the total land surface area. This spectrum of defined cold climate landscapes represents a variety of stages of deglaciation history and landscape formation. We can find landscapes at different levels of postglacial stabilization which is providing the opportunity to study the interactions between geo-, bio-, social and socio-economic systems at the land surface. The DYNAFLUX / DYNACOLD Network (2004-) bridges across the geo-, bio-, social and socio-economic sciences in order to analyze the complex dynamics of stabilization, succession and landscape formation during and after ice retreat and under ongoing human influences. The network provides a multidisciplinary forum where researchers come together. In addition, it is linking a number of networks, working groups and programs and creates an umbrella network and a forum for sharing knowledge. The scientific focus of this network is also relevant for different end users, including risk and vulnerability assessment, sustainable land use, land management and conservation. In addition, key questions related to Global Change like, e.g., hazards, permafrost degradation and loss of biodiversity are discussed.

  14. Sustaining the shelf life of fresh food in cold chain – A burden on the environment

    Directory of Open Access Journals (Sweden)

    Oludaisi Adekomaya

    2016-06-01

    Full Text Available Energy consumption in cold chains has been predicted to rise significantly in view of the increasing world population. Of critical attention is the increasing number of road transport refrigeration which is highly gaining enormous ground globally. In view of the fact that 40% of all foods require refrigeration, 15% of world fossil fuel energy is used in food transport refrigeration. This concern necessitates this study to examine cold chain system with the emphasis on the impact of energy consumption in sustaining the shelf life of fresh food. As the world continues to battle with the global warming occasioned by emission of carbon dioxide from fossil fuel, this study identifies alternative means of saving energy in food transportation system through minimizing energy consumption in diesel engine driven vapour compression system. Preserving perishable fresh food (mainly vegetable under sub-zero weather is another debacle the authors envisaged in the quest to reduce fossil fuel consumption. This process requires heating the mechanical refrigeration unit in a reverse-cycle to raise the temperature at 0 °C which may further result in more energy demand. The conclusion drawn from this study could be useful in re-designing food transport system for optimal energy saving.

  15. The limits of drought-induced rapid cold-hardening: extremely brief, mild desiccation triggers enhanced freeze-tolerance in Eurosta solidaginis larvae.

    Science.gov (United States)

    Gantz, J D; Lee, Richard E

    2015-02-01

    Rapid cold-hardening (RCH) is a highly conserved response in insects that induces physiological changes within minutes to hours of exposure to low temperature and provides protection from chilling injury. Recently, a similar response, termed drought-induced RCH, was described following as little as 6h of desiccation, producing a loss of less than 10% of fresh mass. In this study, we investigated the limits and mechanisms of this response in larvae of the goldenrod gall fly Eurosta solidaginis (Diptera, Tephritidae). The cold-hardiness of larvae increased markedly after as few as 2h of desiccation and a loss of less than 1% fresh mass, as organismal survival increased from 8% to 41% following exposure to -18 °C. Tissue-level effects of desiccation were observed within 1h, as 87% of midgut cells from desiccated larvae remained viable following freezing compared to 57% of controls. We also demonstrated that drought-induced RCH occurs independently of neuroendocrine input, as midgut tissue desiccated ex vivo displayed improved freeze-tolerance relative to control tissue (78-11% survival, respectively). Finally, though there was an increase in hemolymph osmolality beyond the expected effects of the osmo-concentration of solutes during dehydration, we determined that this increase was not due to the synthesis of glycerol, glucose, sorbitol, or trehalose. Our results indicate that E. solidaginis larvae are extremely sensitive to desiccation, which is a triggering mechanism for one or more physiological pathways that confer enhanced freeze-tolerance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Extreme Environment Circuit Blocks for Spacecraft Power & Propulsion System & Other High Reliability Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Chronos Technology (DIv of FMI, Inc.) proposes to design, fabricate, and deliver a performance proven, and commercially available set of extreme high operating...

  17. A Miniature Extreme Environment Powder Delivery System (M-PoDS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This innovation is a low mass, low volume, gas based system that will acquire size selective powdered samples from the extreme ambient (such as Mars or Venus...

  18. A lesson from science in polar extreme environments: ethics and social values for primary school

    Science.gov (United States)

    La Longa, Federica; Crescimbene, Massimo; Alfonsi, Lucilla; Romano, Vincenzo; Cesaroni, Claudio

    2015-04-01

    experiences (doing); to develop civics path linked to "sense of belonging and citizenship", that will make the children aware that Antarctica does not belong to anyone but it belongs to everybody: it is a common and unique good (being). The proposed work is an example of how it is possible, by means of educational paths, promote and support integration values between human beings and nature also in extreme environments as the Antarctic continent.

  19. Altered Responses to Cold Environment in Urocortin 1 and Corticotropin-Releasing Factor Deficient Mice

    Directory of Open Access Journals (Sweden)

    Bayan Chaker

    2013-01-01

    Full Text Available We examined core body temperature (CBT of urocortin 1 (UCN1 and corticotropin releasing factor (CRF knockout (KO mice exposed to 4°C for 2 h. UCN1KO mice showed higher average CBT during cold exposure as compared to WT. The CBT of male and female WT mice dropped significantly to 34.1 ± 2.4 and 34.9 ± 3.1 C at 4°C, respectively. In contrast, the CBT of male and female UCN1KO mice dropped only slightly after 2 h at 4°C to 36.8 ± 0.7 and 38.1 ± 0.5 C, respectively. WT female and male UCN1KO mice showed significant acclimatization to cold; however, female UCN1KO mice did not show such a significant acclimatization. CRFKO mice showed a dramatic decline in CBT from 38.2 ±  0.4 at 22°C to 26.1 ± 9.8 at 4°C for 2 h. The CRF/UCN1 double KO (dKO mice dropped their CBT to 32.5 ± 4.0 after 2 h exposure to 4°C. Dexamethasone treatment prevented the decline in CBT of the CRFKO and the dKO mice. Taken together, the data suggest a novel role for UCN1 in thermoregulation. The role of CRF is likely secondary to adrenal glucocorticoids, which have an important regulatory role on carbohydrate, fat, and protein metabolism.

  20. Nutritional Guidance for Military Field Operations in Temperate and Extreme Environments

    Science.gov (United States)

    1993-06-01

    suffering from AMS include Cream of Wheat or oatmeal,I instant mashed potatoes, instant rice, Ramen noodles , crackers, bread, and vanilla pudding. A...canned fruit, granola bars, crackers Fig Newtons, hot chocolate, juices, hot and cold breakfast cereals, instant mashed potatoes, rice, Cup of Noodles ...or fresh), instant mashed potatoes, rice, couscous, noodles , MRE and T ration cakes (except pound cake), crackers, Fig Newtons, and pouch bread. High

  1. Application of Natural Cold to Maintain the Environment in Cold Area%应用"天然冷"维护寒区环境

    Institute of Scientific and Technical Information of China (English)

    崔广心

    2004-01-01

    The changes of frozen ground caused by the rising temperature will destroy the heat balance of frozen ground and then damage the roadbeds and foundations in cold area. It is a new idea to collect and store the "natural cold" as a resource and apply it to keep the frozen ground frozen permanently and regulate the summer temperature in cities. This paper introduces the principles and systems used in collecting, storing and transmitting the natural cold , analyses the techniques which keep the frozen ground unchanged and protect the roadbed. The paper also studies the systems and techniques by which the natural cold is used for temperature regulation in cities. And the theories involved in this subject and the prospect of industrializing those techniques are presented as well by the author.

  2. How Do Modern Extreme Hydrothermal Environments Inform the Identification of Martian Habitability? The Case of the El Tatio Geyser Field

    Directory of Open Access Journals (Sweden)

    Roberto Barbieri

    2014-11-01

    Full Text Available Despite the success in knowledge gained by the Mars missions in the last two decades, the search for traces of life on Mars is still in progress. The reconstruction of (paleo- environments on Mars have seen a dramatic increase, in particular with regard to the potentially habitable conditions, and it is now possible to recognize a significant role to subaerial hydrothermal processes. For this reason, and because the conditions of the primordial Earth—when these extreme environments had to be common—probably resembled Mars during its most suitable time to host life, research on terrestrial extreme hydrothermal habitats may assist in understanding how to recognize life on Mars. A number of geological and environmental reasons, and logistics opportunities, make the geothermal field of El Tatio, in the Chilean Andes an ideal location to study.

  3. Fieldwork Test Research of the Impact on Building Physical Environment on Six Types of Atrium Space in Cold Climates

    Institute of Scientific and Technical Information of China (English)

    YeHao Song; JunJie Li; Ning Zhu; JiaLiang Wang; ZhengHao Lin

    2014-01-01

    Since the research on verification to passive design strategies in sustainable building is at the initial stage, and its test method and verification conclusion are not scientific enough to validate, this paper proposes the necessity of building physical environmental monitoring to quantitative optimization of passive strategies efficiency from the perspective of architecture design and building environment. Adopting comparative research method, this research chooses six types of atrium space in cold climate in China as a prototype, focusing on building physical environmental performance difference in and between atrium and building main space. Spatial parameters of the atrium space will be divided into four factors:spatial geometry, interfacial properties, internal and external related categories. With subdividing these four factors into sub-factors, this paper makes cross-comparison among the sub-factors to clarify passive strategies effectiveness in atrium. Data comparison analysis shows that Winter atrium passive strategy in cold regions from traditional view is not obvious in practical application, and test data need to be stratified refined in atrium design in case of optimizing passive strategy from building prototype perspective.

  4. Four newly isolated fuselloviruses from extreme geothermal environments reveal unusual morphologies and a possible interviral recombination mechanism

    DEFF Research Database (Denmark)

    Redder, Peter; Peng, Xu; Brügger, Kim;

    2009-01-01

    Spindle-shaped virus-like particles are abundant in extreme geothermal environments, from which five spindle-shaped viral species have been isolated to date. They infect members of the hyperthermophilic archaeal genus Sulfolobus, and constitute the Fuselloviridae, a family of double-stranded DNA ...... that the spacers of the Sulfolobus CRISPR antiviral system are not biased to the highly similar regions of the fusellovirus genomes....

  5. The genomic sequence of Exiguobacterium chiriqhucha str. N139 reveals a species that thrives in cold waters and extreme environmental conditions

    Directory of Open Access Journals (Sweden)

    Ana Gutiérrez-Preciado

    2017-04-01

    Full Text Available We report the genome sequence of Exiguobacterium chiriqhucha str. N139, isolated from a high-altitude Andean lake. Comparative genomic analyses of the Exiguobacterium genomes available suggest that our strain belongs to the same species as the previously reported E. pavilionensis str. RW-2 and Exiguobacterium str. GIC 31. We describe this species and propose the chiriqhucha name to group them. ‘Chiri qhucha’ in Quechua means ‘cold lake’, which is a common origin of these three cosmopolitan Exiguobacteria. The 2,952,588-bp E. chiriqhucha str. N139 genome contains one chromosome and three megaplasmids. The genome analysis of the Andean strain suggests the presence of enzymes that confer E. chiriqhucha str. N139 the ability to grow under multiple environmental extreme conditions, including high concentrations of different metals, high ultraviolet B radiation, scavenging for phosphorous and coping with high salinity. Moreover, the regulation of its tryptophan biosynthesis suggests that novel pathways remain to be discovered, and that these pathways might be fundamental in the amino acid metabolism of the microbial community from Laguna Negra, Argentina.

  6. Cryptococcus vaughanmartiniae sp. nov. and Cryptococcus onofrii sp. nov.: two new species isolated from worldwide cold environments.

    Science.gov (United States)

    Turchetti, Benedetta; Selbmann, Laura; Blanchette, Robert A; Di Mauro, Simone; Marchegiani, Elisabetta; Zucconi, Laura; Arenz, Brett E; Buzzini, Pietro

    2015-01-01

    Twenty yeast strains, representing a selection from a wider group of more than 60 isolates were isolated from cold environments worldwide (Antarctica, Iceland, Russia, USA, Italian and French Alps, Apennines). The strains were grouped based on their common morphological and physiological characteristics. A phylogeny based on D1/D2 ribosomal DNA sequences placed them in an intermediate position between Cryptococcus saitoi and Cryptococcus friedmannii; the ITS1 and ITS2 rDNA phylogeny demonstrated that these strains belong to two related but hitherto unknown species within the order Filobasidiales, albidus clade. These two novel species are described with the names Cryptococcus vaughanmartiniae (type strain DBVPG 4736(T)) and Cryptococcus onofrii (type strain DBVPG 5303(T)).

  7. Cold War and the environment: the role of Finland in international environmental politics in the Baltic Sea region.

    Science.gov (United States)

    Räsänen, Tuomas; Laakkonen, Simo

    2007-04-01

    The Convention on the Protection of the Marine Environment of the Baltic Sea Area signed in 1974 in Helsinki is probably the most important environmental agreement consummated in the Baltic Sea region. This article is the first study that explores the history of this agreement, also known as the Helsinki Convention, by using primary archival sources. The principal sources are the archives of the Ministry for Foreign Affairs of Finland. We examine the role of Finland in the process that led to the signing of the Helsinki Convention from the perspective of international politics. The study focuses primarily on Finnish, Swedish, and Soviet state-level parties from the end of the 1960s to 1974. We show that Cold War politics affected in several ways negotiations and contents of the Helsinki Convention. We also argue that the Soviet Union used the emerging international environmental issues as a new tool of power politics.

  8. Glycol cold thermal energy storage systems : performance and the effect of varying environment temperature

    Energy Technology Data Exchange (ETDEWEB)

    Bakan, K.; Dincer, I.; Rosen, M.A. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Engineering and Applied Science

    2006-07-01

    This paper examined the effect of varying ambient temperatures on glycol cold thermal energy storage (CTES) systems. When glycol thermal storage is incorporated into a new or existing building, a low temperature chilled-water supply allows the use of low-temperature air distribution and smaller fans and ducts. A reduction and shift in peak electric power demand can be realized through the use of glycol CTES as it permits the storage of night-time electric power. This study investigated the thermodynamic system parameters of: storage temperature; storage heat load; exergy destructions; and energy and exergy efficiencies. A storage tank with a capacity of 150,000 kg was used in the investigation. The air-conditioning cycle was simulated using the commercial software package Engineering Equation Solver (EES). Exergy analyses considered quantities of exergy, energy and mass. It was concluded that the exergy efficiency of the system was approximately 46 per cent less than energy efficiency due to irreversibilities. Results indicated that maximum energy efficiency was 75 per cent, and the corresponding exergy efficiency was 40 per cent for a 50 degrees C ambient air temperature. 13 refs., 5 figs.

  9. Effectiveness of the Space Shuttle anti-exposure system in a cold water environment

    Science.gov (United States)

    Bagian, James P.; Kaufman, Jonathan W.

    1990-01-01

    The purpose of this study was to evaluate the NASA Space Shuttle launch entry suit (LES) and raft for 24 h of protection against cold water immersion. Two configurations, the LES and the LES with raft (LES/r) were evaluated for antiexposure protection. Conditions were selected to simulate worst-case water and air temperatures along projected Space Shuttle ground tracks; i.e., water temperatures = 4.4 C, air temperature = 5.6 C, 1-foot waves (chop), and constant spray. Four males 31-44 years of age and one 32-year-old female were studied once in each configuration. Trials with and without a raft were scheduled for up to 24 and 6 h, respectively. Mean LES trial durations were 150 + or - 9 min and final rectal temperature (FRT) = 36.5 + or - 0.3 C. Mean LES/r trial durations were 398 + or - 126 min and FRT = 35.6 + or - 0.4 C. LES and LES/r trials were terminated for reaching FRT = 35.0 C or subject-requested termination due to discomfort. The longest LES and LES/r trials were terminated due to subject discomfort. Although not achieving the desired durations, the LES and LES/r did prove capable of protecting individuals, respectively, for up to 3 and 13.5 h. Since the longest runs were terminated due to subjective tolerance, actual survival times greater than 3 and 13.5 h could be expected.

  10. Geomembrane applications for controlling diffusive migration of petroleum hydrocarbons in cold region environments.

    Science.gov (United States)

    McWatters, Rebecca S; Rutter, Allison; Rowe, R Kerry

    2016-10-01

    Laboratory permeation tests examine the migration of aromatic hydrocarbons (benzene, toluene, ethylbenzene and xylenes (BTEX)) at 2, 7 and 14 °C through three different types of geomembrane (high density polyethylene (HDPE), linear low density polyethylene (LLDPE) and polyvinyl chloride (PVC)). Tests on both virgin and exhumed field samples provide permeation parameters (partitioning (Sgf), diffusion (Dg), and permeation (Pg) coefficients) for the three geomembranes. These results are combined with published values for the same geomembranes at 23 °C to establish an Arrhenius relationship that can be used to estimate diffusion parameters at temperatures other than those for which tests were conducted. Tests on an HDPE geomembrane sample exhumed after 3 years from a landfill site in the Canadian Arctic showed no significant difference in diffusion characteristics compared to an otherwise similar unaged and unexposed HDPE geomembrane. Contaminant transport modeling for benzene through HDPE, LLPDE and PVC in a simulated landfill cover show that for the conditions examined the presence of any of the three geomembranes below the 2 m thick soil cover substantially reduced the contaminant flux compared to the soils alone for realistic degrees of saturation in the cover soil. For these same realistic cold climate cases, of the three geomembranes examined, the HDPE geomembrane was the most effective at controlling the contaminant flux out of the landfill. An increase in soil cover and liner temperature by 2 °C (from potential climate change effects) above those currently measured at an Arctic landfill showed an increase in contaminant transport through the cover system for all geomembranes due to the increase surface temperature (especially in the summer months). Modeling of the addition of an extra 0.5 m of soil cover, as a mitigation measure for the effects of climate change, indicates that the main benefit of adding this unsaturated soil was to reduce the

  11. Sialyte(TM)-Based Composite Pressure Vessels for Extreme Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — While traveling to Venus, electronics and instruments go through enormous pressure, temperature, and atmospheric environment changes. In the past, this has caused...

  12. Microbial diversity in a permanently cold and alkaline environment in Greenland

    DEFF Research Database (Denmark)

    Glaring, Mikkel Andreas; Vester, Jan Kjølhede; Lylloff, Jeanette Eva

    2015-01-01

    representatives of the Firmicutes and Bacteroidetes. The results suggest a stratification of the ikaite columns similar to that of classical soda lakes, with a light-exposed surface inhabited by primary producers and an anoxic subsurface. This was further supported by identification of major taxonomic groups...... with close relatives in soda lake environments, including members of the genera Rhodobaca, Dethiobacter, Thioalkalivibrio and Tindallia, as well as very abundant groups related to uncharacterised environmental sequences originally isolated from Mono Lake in California....

  13. Summary of presentation for research on social structure, agreement, and conflict in groups in extreme and isolated environments

    Science.gov (United States)

    1990-01-01

    Despite a vast amount of research, little is known concerning the effect of group structure, and individuals' understanding of that structure, on conflict in Antarctic groups. The overall objective of the research discussed is to determine the interrelationships of group structure, social cognition, and group function and conflict in isolated and extreme environments. In the two decades following WWII, a large body of research focused on the physiological, psychological, and social psychological factors affecting the functioning of individuals and groups in a variety of extreme and isolated environments in both the Arctic and Antarctic. There are two primary reasons for further research of this type. First, Antarctic polar stations are considered to be natural laboratories for the social and behavioral sciences and provide an opportunity to address certain theoretical and empirical questions concerned with agreement and conflict in social groups in general and group behavior in extreme, isolated environments in particular. Recent advances in the analysis of social networks and intracultural variation have improved the methods and have shifted the theoretical questions. The research is motivated by three classes of questions: (1) What are the characteristics of the social relations among individuals working and living together in extreme and isolated environments?; (2) What do individuals understand about their group, how does that understanding develop, and how is it socially distributed?; and (3) What is the relationship between that understanding and the functioning of the social group? Answers to these questions are important if we are to advance our knowledge of how individuals and groups adapt to extreme environments. Second, although Antarctic winter-over candidates may be evaluated as qualified on the basis of individual characteristics, they may fail to adapt because of certain characteristics of the social group. Consequently, the ability of winter

  14. Life on the Edge-the Biology of Organisms Inhabiting Extreme Environments: An Introduction to the Symposium.

    Science.gov (United States)

    Lindgren, Annie R; Buckley, Bradley A; Eppley, Sarah M; Reysenbach, Anna-Louise; Stedman, Kenneth M; Wagner, Josiah T

    2016-10-01

    Life persists, even under extremely harsh conditions. While the existence of extremophiles is well known, the mechanisms by which these organisms evolve, perform basic metabolic functions, reproduce, and survive under extreme physical stress are often entirely unknown. Recent technological advances in terms of both sampling and studying extremophiles have yielded new insight into their evolution, physiology and behavior, from microbes and viruses to plants to eukaryotes. The goal of the "Life on the Edge-the Biology of Organisms Inhabiting Extreme Environments" symposium was to unite researchers from taxonomically and methodologically diverse backgrounds to highlight new advances in extremophile biology. Common themes and new insight that emerged from the symposium included the important role of symbiotic associations, the continued challenges associated with sampling and studying extremophiles and the important role these organisms play in terms of studying climate change. As we continue to explore our planet, especially in difficult to reach areas from the poles to the deep sea, we expect to continue to discover new and extreme circumstances under which life can persist.

  15. MOLECULAR ENVIRONMENTS OF 51 PLANCK COLD CLUMPS IN THE ORION COMPLEX

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tie; Wu Yuefang; Zhang Huawei, E-mail: liutiepku@gmail.com, E-mail: ywu@pku.edu.cn [Department of Astronomy, Peking University, 100871 Beijing (China)

    2012-09-15

    A mapping survey of 51 Planck cold clumps projected on the Orion complex was performed with J = 1-0 lines of {sup 12}CO and {sup 13}CO with the 13.7 m telescope at the Purple Mountain Observatory. The mean column densities of the Planck gas clumps range from 0.5 to 9.5 Multiplication-Sign 10{sup 21} cm{sup -2}, with an average value of (2.9 {+-} 1.9) Multiplication-Sign 10{sup 21} cm{sup -2}. The mean excitation temperatures of these clumps range from 7.4 to 21.1 K, with an average value of 12.1 {+-} 3.0 K and the average three-dimensional velocity dispersion {sigma}{sub 3D} in these molecular clumps is 0.66 {+-} 0.24 km s{sup -1}. Most of the clumps have {sigma}{sub NT} larger than or comparable to {sigma}{sub Therm}. The H{sub 2} column density of the molecular clumps calculated from molecular lines correlates with the aperture flux at 857 GHz of the dust emission. By analyzing the distributions of the physical parameters, we suggest that turbulent flows can shape the clump structure and dominate their density distribution on large scales, but not function on small scales due to local fluctuations. Eighty-two dense cores are identified in the molecular clumps. The dense cores have an average radius and local thermal equilibrium (LTE) mass of 0.34 {+-} 0.14 pc and 38{sup +5}{sub -30} M{sub Sun }, respectively. The structures of low column density cores are more affected by turbulence, while the structures of high column density cores are more affected by other factors, especially by gravity. The correlation of velocity dispersion versus core size is very weak for the dense cores. The dense cores are found to be most likely gravitationally bounded rather than pressure confined. The relationship between M{sub vir} and M{sub LTE} can be well fitted with a power law. The core mass function here is much flatter than the stellar initial mass function. The lognormal behavior of the core mass distribution is most likely determined by internal turbulence.

  16. HotSense: a high temperature piezoelectric platform for sensing and monitoring in extreme environments (Conference Presentation)

    Science.gov (United States)

    Stevenson, Tim; Wines, Thomas; Martin, David; Vickers, William; Laws, Michael

    2016-04-01

    Effective monitoring of asset integrity subject to corrosion and erosion while minimizing the exposure of personnel to difficult and hazardous working environments has always been a major problem in many industries. One solution of this problem is permanently installed ultrasonic monitoring equipment which can continuously provide information on the rate of corrosion or cracking, even in the most severe environments and at extreme temperatures to prevent the need for shutdown. Here, a permanently installed 5 MHz ultrasonic monitoring system based on our HotSense® technology is designed and investigated. The system applicability for wall thickness, crack monitoring and weld inspection in high temperature environments is demonstrated through experimental studies on a range of Schedule 40 pipes at temperatures up to 350 °C continuously. The applicability for this technology to be distributed to Aerospace and Nuclear sectors are also explored and preliminary results discussed.

  17. Geochemistry meets Biochemistry: Minimal Metabolic Systems in Extremely Thermophilic Bacteria from Geothermal Environments.

    Science.gov (United States)

    Robb, F. T.; DiRuggiero, J.; Davila, J.; Schwartz, M.

    2002-05-01

    A growing body of research confirms that extreme thermophiles can grow at temperatures of at least 113.5oC, at elevated pressures. Other archaeal isolates can thrive in hostile chemical conditions, for example pH 0.8. We, and others have shown that hyperthermophiles have novel heat shock proteins and other chaperonins that permit them to maintain native protein structures in unfavorable conditions. They are also able to survive using individual gases and gas mixtures We have determined the complete genome sequence of a bacterial isolate from thermal mats on the Kamchatka Peninsula that grows on a salts medium with carbon monoxide as its sole energy and carbon source. It forms hydrogen in proportion with CO consumption. The minimal size of its genome, 2.1 megabase pairs, and its ability to form spores have led us to propose that this autotrophic bacterium can serve as a model for ancestral microbial cells. We have isolated a new class of thermophilic, extremely radiation resistant bacteria from Yellowstone National Park that can withstand space vacuum for extended periods. In collaboration with NASA Goddard, we have exposed filters coated with one of these isolates to space vacuum and to extreme UV during a sounding rocket flight at White Sands. Deinococcus radiodurans, the most desiccation and radiation resistant organism characterized so far, was exposed as a control. The new isolate was slightly more desiccation resistant than D. radiodurans, and significantly more resistant than D. radiodurans to extreme UV at 34 nm. These studies may provide insights into the potential for viable bacterial cells to survive transmission through space, a phenomenon usually referred to as panspermia.

  18. Survival in extreme environments – on the current knowledge of adaptations in tardigrades

    DEFF Research Database (Denmark)

    Møbjerg, Nadja; Halberg, Kenneth Agerlin; Jørgensen, Aslak

    2011-01-01

    of the tardigrades and highlight species that are currently used as models for physiological and molecular investigations. Tardigrades are uniquely adapted to a range of environmental extremes. Cryptobiosis, currently referred to as a reversible ametabolic state induced by e.g. desiccation, is common especially...... to below )20 C, presumably relying on efficient DNA repair mechanisms and osmoregulation. This review summarizes the current knowledge on adaptations found among tardigrades, and presents new data on tardigrade cell numbers and osmoregulation....

  19. Survival in extreme environments - on the current knowledge of adaptations in tardigrades.

    Science.gov (United States)

    Møbjerg, N; Halberg, K A; Jørgensen, A; Persson, D; Bjørn, M; Ramløv, H; Kristensen, R M

    2011-07-01

    Tardigrades are microscopic animals found worldwide in aquatic as well as terrestrial ecosystems. They belong to the invertebrate superclade Ecdysozoa, as do the two major invertebrate model organisms: Caenorhabditis elegans and Drosophila melanogaster. We present a brief description of the tardigrades and highlight species that are currently used as models for physiological and molecular investigations. Tardigrades are uniquely adapted to a range of environmental extremes. Cryptobiosis, currently referred to as a reversible ametabolic state induced by e.g. desiccation, is common especially among limno-terrestrial species. It has been shown that the entry and exit of cryptobiosis may involve synthesis of bioprotectants in the form of selective carbohydrates and proteins as well as high levels of antioxidant enzymes and other free radical scavengers. However, at present a general scheme of mechanisms explaining this phenomenon is lacking. Importantly, recent research has shown that tardigrades even in their active states may be extremely tolerant to environmental stress, handling extreme levels of ionizing radiation, large fluctuation in external salinity and avoiding freezing by supercooling to below -20 °C, presumably relying on efficient DNA repair mechanisms and osmoregulation. This review summarizes the current knowledge on adaptations found among tardigrades, and presents new data on tardigrade cell numbers and osmoregulation.

  20. ALMA observation of high-z extreme star-forming environments discovered by Planck/Herschel

    Science.gov (United States)

    Kneissl, R.

    2016-05-01

    The Comic Microwave Background satellite Planck with its High Frequency Instrument has surveyed the mm/sub-mm sky in six frequency channels from 100 to 900 GHz. A sample of 228 cold sources of the Cosmic Infrared Background was observed in follow-up with Herschel SPIRE. The majority of sources appear to be over-densities of star-forming galaxies matching the size of high-z proto-cluster regions, while a 3% fraction are individual bright, lensed galaxies. A large observing program is underway with the aim of resolving the regions into the constituent members of the Planck sources. First ALMA data have been received on one Planck/Herschel proto-cluster candidate, showing the expected large over-abundance of bright mm/sub-mm sources within the cluster region. ALMA long baseline data of the brightest lensed galaxy in the sample with > 1 Jy at 350 μm are also forthcoming.

  1. Condition and biochemical profile of blue mussels (Mytilus edulis L.) cultured at different depths in a cold water coastal environment

    Science.gov (United States)

    Gallardi, Daria; Mills, Terry; Donnet, Sebastien; Parrish, Christopher C.; Murray, Harry M.

    2017-08-01

    The growth and health of cultured blue mussels (Mytilus edulis) are affected by environmental conditions. Typically, culture sites are situated in sheltered areas near shore (i.e., impact in coastal areas are concerns and interest in developing deep water (> 20 m depth) mussel culture has been growing. This study evaluated the effect of culture depth on blue mussels in a cold water coastal environment (Newfoundland, Canada). Culture depth was examined over two years from September 2012 to September 2014; mussels from three shallow water (5 m) and three deep water (15 m) sites were compared for growth and biochemical composition; culture depths were compared for temperature and chlorophyll a. Differences between the two years examined were noted, possibly due to harsh winter conditions in the second year of the experiment. In both years shallow and deep water mussels presented similar condition; in year 2 deep water mussels had a significantly better biochemical profile. Lipid and glycogen analyses showed seasonal variations, but no significant differences between shallow and deep water were noted. Fatty acid profiles showed a significantly higher content of omega-3 s (20:5ω3; EPA) and lower content of bacterial fatty acids in deep water sites in year 2. Everything considered, deep water appeared to provide a more favorable environment for mussel growth than shallow water under harsher weather conditions.

  2. THE RELATIONSHIP AMONG METABOLIC RATE OF TREE SHREWS (TUPAIA BELANGERI) UNDER COLD ACCLIMATION

    OpenAIRE

    Lin Zhang; Wenrong Gao; Wenxiu Jiang; Zhengkun Wang

    2012-01-01

    Many small mammals inhabiting cold environments display enhanced capacity for seasonal changes in nonshivering thermogenesis (NST) and thermoregulatory maximum metabolic rate (MMR). However, it is not known how this plasticity remains in a mammal that rarely experiences extreme cold fluctuations. In order to answer this question, we determined body mass ( Mb), basal metabolic rate (BMR), NST, and MMR on a tree shrews (Tupaia belangeri), acclimated to cold (5 ºC) conditions. NST was measured a...

  3. Urine temperature as an index for the core temperature of industrial workers in hot or cold environments

    Science.gov (United States)

    Kawanami, Shoko; Horie, Seichi; Inoue, Jinro; Yamashita, Makiko

    2012-11-01

    Workers working in hot or cold environments are at risk for heat stroke and hypothermia. In Japan, 1718 people including 47 workers died of heat stroke in 2010 (Ministry of Health Labour and Welfare, Japan 2011). While the American Conference of Governmental Industrial Hygienists (ACGIH) recommendation lists the abnormal core temperature of workers as a criterion for halting work, no method has been established for reliably measuring core temperatures at workplaces. ISO 9886 (Ergonomics-evaluation of thermal strain by physiological measurements. ISO copyright office, Geneva, pp 3-14; 2004) recognizes urine temperature as an index of core temperature only at normal temperature. In this study we ascertained whether or not urine temperature could serve as an index for core temperature at temperatures above and below the ISO range. We measured urine temperature of 31 subjects (29.8 ± 11.9 years) using a thermocouple sensor placed in the toilet bowl at ambient temperature settings of 40, 20, and 5˚C, and compared them with rectal temperature. At all ambient temperature settings, urine temperature correlated closely with rectal temperature exhibiting small mean bias. Urine temperature changed in a synchronized manner with rectal temperature at 40˚C. A Bland and Altman analysis showed that the limits of agreement (mean bias ± 2SD) between rectal and urine temperatures were -0.39 to +0.15˚C at 40˚C (95%CI -0.44 to +0.20˚C) and -0.79 to +0.29˚C at 5˚C (-0.89 to +0.39˚C). Hence, urine temperature as measured by the present method is a practical surrogate index for rectal temperature and represents a highly reliable biological monitoring index for assessing hot and cold stresses of workers at actual workplaces.

  4. Spatial and temporal change characteristics of extremely cold weather in Hulun Buir%呼伦贝尔市极寒天气时空分布特征

    Institute of Scientific and Technical Information of China (English)

    阴秀霞

    2016-01-01

    With extremely cold days data from 16 stations in Hulun Buir during 1960—2014,the results showed that the geographical distribution of arctic days were unevenness and decreased from north to south;the forest area was more than pastoral area and rural area was the least. Interdecadal characteristics showed that arctic days in the 1960 s and 1970 s were the most,up to the 1960 s and the number of days significantly reduced in the 1980 s,at least in the 1990 s. At the beginning of 21 century,another arctic day slightly increased.The arctic days more appered in late December to late January, up to mid-January,followed by late January and gradual decreased after the beginning of spring in February.%文章对呼伦贝尔市16个台站1960—2014年极寒日进行了统计分析,结果表明:极寒日的地域分布不均匀,由北向南逐渐减少,林区多于牧区,牧区又多于农区;年代际特征是20世纪60年代与70年代日数较多,60年代最多;到了80年代日数大幅减少,90年代最少。进入21世纪初,极寒日又有小幅增多。隆冬12月下旬至1月下旬是极寒日数多的月份,其中1月中旬最多,1月下旬次之,立春后2月份逐渐减少。

  5. Radiation Hardened High Speed Fiber Optic Transceivers for Extreme Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This program develops fiber optic transceivers that offer wide bandwidth (1 Mbps to 10 Gbps) and operate in space environments targeted by NASA for robotic...

  6. Perspectives of extreme sample environment in neutron scattering and consequences for instrumentation

    Indian Academy of Sciences (India)

    Michael Steiner

    2008-11-01

    Because neutrons can penetrate bulky pieces of matter, increasingly complex sample environment is requested by the users of neutron beams. This corresponds to the ever-growing complexity of the scientific problems addressed by neutron scatterers. Until now such requirements could be satisfied by sample environment, which could be added to the instruments without major modifications. Now it becomes evident, that for certain applications further progress is possible only by bringing the neutrons to the sample environment instead of bringing the sample environment to the neutrons. As one of the first examples of this concept we will discuss the high field magnet (HFM), which Hahn-Meitner-Institute Berlin (HMI) and the National High Magnetic Field Laboratory Tallahassy (NHFML) are constructing jointly for BENSC at HMI. At BENSC the HMI has built in the meantime a dedicated instrument based on the TOF principle to be equipped with the HFM to enable experiments at fields up to 25 T.

  7. Radiation Hardened High Speed Fiber Optic Transceivers for Extreme Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the development of transceiver offering wide bandwidth (1 Mbps to 10 Gbps) that operates in space environments targeted by NASA for robotic exploration....

  8. Effect of dissolved oxygen content on stress corrosion cracking of a cold worked 316L stainless steel in simulated pressurized water reactor primary water environment

    Science.gov (United States)

    Zhang, Litao; Wang, Jianqiu

    2014-03-01

    Stress corrosion crack growth tests of a cold worked nuclear grade 316L stainless steel were conducted in simulated pressurized water reactor (PWR) primary water environment containing various dissolved oxygen (DO) contents but no dissolved hydrogen. The crack growth rate (CGR) increased with increasing DO content in the simulated PWR primary water. The fracture surface exhibited typical intergranular stress corrosion cracking (IGSCC) characteristics.

  9. Instrument developments for chemical and physical characterization, mapping and sampling of extreme environments (Antarctic sub ice environment)

    Science.gov (United States)

    Vogel, S. W.; Powell, R. D.; Griffith, I.; Lawson, T.; Schiraga, S.; Ludlam, G.; Oen, J.

    2009-12-01

    A number of instrumentation is currently under development designed to enable the study of subglacial environments in Antarctica through narrow kilometer long boreholes. Instrumentation includes: - slim line Sub-Ice ROV (SIR), - Geochemical Instrumentation Package for Sub Ice Environments (GIPSIE) to study geochemical fluxes in water and across the sediment water interface (CO2, CH4, dO, NH4, NO3, Si, PO4, pH, redox, T, H2, HS, O2, N2O, CTD, particle size, turbidity, color camera, current meter and automated water sampler) with real-time telemetry for targeted sampling, - long term energy-balance mooring system, - active source slide hammer sediment corer, and - integration of a current sensor into the ITP profiler. The instrumentation design is modular and suitable for remote operated as well as autonomous long-term deployment. Of interest to the broader science community is the development of the GIPSIE and efforts to document the effect of sample recovery from depth on the sample chemistry. The GIPSIE is a geochemical instrumentation package with life stream telemetry, allowing for user controlled targeted sampling of water column and the water sediment interphase for chemical and biological work based on actual measurements and not a preprogrammed automated system. The porewater profiler (pH, redox, T, H2, HS, O2, N2O) can penetrate the upper 50 cm of sediment and penetration is documented with real time video. Associated with GIPSIE is an on-site lab set-up, utilizing a set of identical sensors. Comparison between the insitu measurements and measurements taken onsite directly after samples are recovered from depth permits assessing the effect of sample recovery on water and sediment core chemistry. Sample recovery related changes are mainly caused by changes in the pressure temperature field and exposure of samples to atmospheric conditions. Exposure of anaerobic samples to oxygen is here a specific concern. Recovery from depth effects in generally p

  10. STRUCTURAL SCALE LIFE PREDICTION OF AERO STRUCTURES EXPERIENCING COMBINED EXTREME ENVIRONMENTS

    Science.gov (United States)

    2017-07-01

    superiority of tomorrow’s USAF. These platforms experience long-duration, combined and intense, thermo-mechanical-acoustic loads over significant...analysts’ past experience , a heavy reliance on testing, and limited choices to tailor material attributes. 15. SUBJECT TERMS lifing, combined environment...6 Figure 3. Correlation Between Mean Life and Deviation of Mean life with the Addition of New Metallic Systems of

  11. Characteristics of vesicomyid clams and their environment at the Blake Ridge cold seep, South Carolina, USA

    Science.gov (United States)

    Heyl, Taylor P.; Gilhooly, William P.; Chambers, Randolph M.; Gilchrist, George W.; Macko, Stephen A.; Ruppel, Carolyn D.; Van Dover, Cindy L.

    2007-01-01

    Spatial distributions and patchiness of dominant megafaunal invertebrates in deep-sea seep environments may indicate heterogeneities in the flux of reduced chemical compounds. At the Blake Ridge seep off South Carolina, USA, the invertebrate assemblage includes dense populations of live vesicomyid clams (an undescribed species) as well as extensive clam shell beds (i.e. dead clams). In the present study, we characterized clam parameters (density, size-frequency distribution, reproductive condition) in relation to sulfur chemistry (sulfide and sulfate concentrations and isotopic compositions, pyrite and elemental sulfur concentrations) and other sedimentary metrics (grain size, organic content). For clams >5 mm, clam density was highest where the total dissolved sulfide concentration at 10 cm depth (ΣH2S10cm) was 0.4 to 1.1 mmol l–1; juvenile clams (2S10cm was lowest. Clams were reproductively capable across a broad range of ΣH2S10cm (0.1 to 6.4 mmol l–1), and females in the sampled populations displayed asynchronous gametogenesis. Sulfide concentrations in porewaters at the shell–sediment interface of cores from shell beds were high, 3.3 to 12.1 mmol l–1, compared to –1 sulfide concentrations at the clam–sediment interface in live clam beds. Concentration profiles for sulfide and sulfate in shell beds were typical of those expected where there is active microbial sulfate reduction. In clam beds, profiles of sulfide and sulfate concentrations were also consistent with rapid uptake of sulfide by the clams. Sulfate in shell beds was systematically enriched in 34S relative to that in clam beds due to microbial fractionation during sulfate reduction, but in clam beds, sulfate δ34S matched that of seawater (~20‰). Residual sulfide values in clam and shell beds were correspondingly depleted in 34S. Based on porewater sulfide concentrations in shell beds at the time of sampling, we suggest that clam mortality may have been due to an abrupt increase in

  12. Defining Population Health Vulnerability Following an Extreme Weather Event in an Urban Pacific Island Environment: Honiara, Solomon Islands.

    Science.gov (United States)

    Natuzzi, Eileen S; Joshua, Cynthia; Shortus, Matthew; Reubin, Reginald; Dalipanda, Tenneth; Ferran, Karen; Aumua, Audrey; Brodine, Stephanie

    2016-08-03

    Extreme weather events are common and increasing in intensity in the southwestern Pacific region. Health impacts from cyclones and tropical storms cause acute injuries and infectious disease outbreaks. Defining population vulnerability to extreme weather events by examining a recent flood in Honiara, Solomon Islands, can help stakeholders and policymakers adapt development to reduce future threats. The acute and subacute health impacts following the April 2014 floods were defined using data obtained from hospitals and clinics, the Ministry of Health and in-country World Health Organization office in Honiara. Geographical information system (GIS) was used to assess morbidity and mortality, and vulnerability of the health system infrastructure and households in Honiara. The April flash floods were responsible for 21 acute deaths, 33 injuries, and a diarrhea outbreak that affected 8,584 people with 10 pediatric deaths. A GIS vulnerability assessment of the location of the health system infrastructure and households relative to rivers and the coastline identified 75% of the health infrastructure and over 29% of Honiara's population as vulnerable to future hydrological events. Honiara, Solomon Islands, is a rapidly growing, highly vulnerable urban Pacific Island environment. Evaluation of the mortality and morbidity from the April 2014 floods as well as the infectious disease outbreaks that followed allows public health specialists and policy makers to understand the health system and populations vulnerability to future shocks. Understanding the negative impacts natural disaster have on people living in urban Pacific environments will help the government as well as development partners in crafting resilient adaptation development.

  13. Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert

    Directory of Open Access Journals (Sweden)

    Jacek eWierzchos

    2015-09-01

    Full Text Available The Atacama Desert, northern Chile, is one of the driest deserts on Earth and, as such, a natural laboratory to explore the limits of life and the strategies evolved by microorganisms to adapt to extreme environments. Here we report the exceptional adaptation strategies of chlorophototrophic and eukaryotic algae, and chlorophototrophic and prokaryotic cyanobacteria to the hyperarid and extremely high solar radiation conditions occurring in this desert. Our approach combined several microscopy techniques, spectroscopic analytical methods, and molecular analyses. We found that the major adaptation strategy was to avoid the extreme environmental conditions by colonizing cryptoendolithic, as well as, hypoendolithic habitats within gypsum deposits. The cryptoendolithic colonization occurred a few millimeters beneath the gypsum surface and showed a succession of organized horizons of algae and cyanobacteria, which has never been reported for endolithic microbial communities. The presence of cyanobacteria beneath the algal layer, in close contact with sepiolite inclusions, and their hypoendolithic colonization suggest that occasional liquid water might persist within these sub-microhabitats. We also identified the presence of abundant carotenoids in the upper cryptoendolithic algal habitat and scytonemin in the cyanobacteria hypoendolithic habitat. This study illustrates that successful lithobiontic microbial colonization at the limit for microbial life is the result of a combination of adaptive strategies to avoid excess solar irradiance and extreme evapotranspiration rates, taking advantage of the complex structural and mineralogical characteristics of gypsum deposits – conceptually called rock’s habitable architecture. Additionally self-protection by synthesis and accumulation of secondary metabolites likely produces a shielding effect that prevents photoinhibition and lethal photooxidative damage to the chlorophototrophs, representing another

  14. Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert

    Science.gov (United States)

    Wierzchos, Jacek; DiRuggiero, Jocelyne; Vítek, Petr; Artieda, Octavio; Souza-Egipsy, Virginia; Škaloud, Pavel; Tisza, Michel; Davila, Alfonso F.; Vílchez, Carlos; Garbayo, Inés; Ascaso, Carmen

    2015-01-01

    The Atacama Desert, northern Chile, is one of the driest deserts on Earth and, as such, a natural laboratory to explore the limits of life and the strategies evolved by microorganisms to adapt to extreme environments. Here we report the exceptional adaptation strategies of chlorophototrophic and eukaryotic algae, and chlorophototrophic and prokaryotic cyanobacteria to the hyperarid and extremely high solar radiation conditions occurring in this desert. Our approach combined several microscopy techniques, spectroscopic analytical methods, and molecular analyses. We found that the major adaptation strategy was to avoid the extreme environmental conditions by colonizing cryptoendolithic, as well as, hypoendolithic habitats within gypsum deposits. The cryptoendolithic colonization occurred a few millimeters beneath the gypsum surface and showed a succession of organized horizons of algae and cyanobacteria, which has never been reported for endolithic microbial communities. The presence of cyanobacteria beneath the algal layer, in close contact with sepiolite inclusions, and their hypoendolithic colonization suggest that occasional liquid water might persist within these sub-microhabitats. We also identified the presence of abundant carotenoids in the upper cryptoendolithic algal habitat and scytonemin in the cyanobacteria hypoendolithic habitat. This study illustrates that successful lithobiontic microbial colonization at the limit for microbial life is the result of a combination of adaptive strategies to avoid excess solar irradiance and extreme evapotranspiration rates, taking advantage of the complex structural and mineralogical characteristics of gypsum deposits—conceptually called “rock's habitable architecture.” Additionally, self-protection by synthesis and accumulation of secondary metabolites likely produces a shielding effect that prevents photoinhibition and lethal photooxidative damage to the chlorophototrophs, representing another level of

  15. Adaptation strategies of endolithic chlorophototrophs to survive the hyperarid and extreme solar radiation environment of the Atacama Desert.

    Science.gov (United States)

    Wierzchos, Jacek; DiRuggiero, Jocelyne; Vítek, Petr; Artieda, Octavio; Souza-Egipsy, Virginia; Škaloud, Pavel; Tisza, Michel; Davila, Alfonso F; Vílchez, Carlos; Garbayo, Inés; Ascaso, Carmen

    2015-01-01

    The Atacama Desert, northern Chile, is one of the driest deserts on Earth and, as such, a natural laboratory to explore the limits of life and the strategies evolved by microorganisms to adapt to extreme environments. Here we report the exceptional adaptation strategies of chlorophototrophic and eukaryotic algae, and chlorophototrophic and prokaryotic cyanobacteria to the hyperarid and extremely high solar radiation conditions occurring in this desert. Our approach combined several microscopy techniques, spectroscopic analytical methods, and molecular analyses. We found that the major adaptation strategy was to avoid the extreme environmental conditions by colonizing cryptoendolithic, as well as, hypoendolithic habitats within gypsum deposits. The cryptoendolithic colonization occurred a few millimeters beneath the gypsum surface and showed a succession of organized horizons of algae and cyanobacteria, which has never been reported for endolithic microbial communities. The presence of cyanobacteria beneath the algal layer, in close contact with sepiolite inclusions, and their hypoendolithic colonization suggest that occasional liquid water might persist within these sub-microhabitats. We also identified the presence of abundant carotenoids in the upper cryptoendolithic algal habitat and scytonemin in the cyanobacteria hypoendolithic habitat. This study illustrates that successful lithobiontic microbial colonization at the limit for microbial life is the result of a combination of adaptive strategies to avoid excess solar irradiance and extreme evapotranspiration rates, taking advantage of the complex structural and mineralogical characteristics of gypsum deposits-conceptually called "rock's habitable architecture." Additionally, self-protection by synthesis and accumulation of secondary metabolites likely produces a shielding effect that prevents photoinhibition and lethal photooxidative damage to the chlorophototrophs, representing another level of adaptation.

  16. A new extreme environment for aerobic anoxygenic phototrophs: biological soil crusts.

    Science.gov (United States)

    Csotonyi, Julius T; Swiderski, Jolantha; Stackebrandt, Erko; Yurkov, Vladimir

    2010-01-01

    Biological soil crusts improve the health of arid or semiarid soils by enhancing water content, nutrient relations and mechanical stability, facilitated largely by phototrophic microorganisms. Until recently, only oxygenic phototrophs were known from soil crusts. A recent study has demonstrated the presence of aerobic representatives of Earth's second major photosynthetic clade, the evolutionarily basal anoxygenic phototrophs. Three Canadian soil crust communities yielded pink and orange aerobic anoxygenic phototrophic strains possessing the light-harvesting pigment bacteriochlorophyll a. At relative abundances of 0.1-5.9% of the cultivable bacterial community, they were comparable in density to aerobic phototrophs in other documented habitats. 16S rDNA sequence analysis revealed the isolates to be related to Methylobacterium, Belnapia, Muricoccus and Sphingomonas. This result adds a new type of harsh habitat, dry soil environments, to the environments known to support aerobic anoxygenic phototrophs.

  17. Toward Advanced Human Reliability Programs. Structural Development Considerations and Options for Extreme Risk Environments

    Science.gov (United States)

    1992-05-01

    performance inefficiency psychopathy errors/accidents self-destructive behavior target (non)detection sleeping disturbanco-s reduced productivity suicide...levels sufficiently high to warrant treatment (Rahe, 1988; Steinglass and Gerrity, 1990; GTA 21-3-6, 1986). D. DECISION MAKING IN EXTREMF RISK ENVIRONMENTS...warning mechanism for the individual and the organization that help was or would be needed (with a clear focus on treatment vice separation). 4. It could

  18. Processing of N2O ice by fast ions: implications on nitrogen chemistry in cold astrophysical environments

    Science.gov (United States)

    Almeida, G. C.; Pilling, S.; de Barros, A. L. F.; da Costa, C. A. P.; Pereira, R. C.; da Silveira, E. F.

    2017-10-01

    Nitrous oxide, N2O, is found in the interstellar medium associated with dense molecular clouds and its abundance is explained by active chemistry occurring on N2 rich ice surfaces of dust grains. Such regions are being constantly exposed to ionizing radiation that triggers chemical processes which change molecular abundances with time. Due to its non-zero dipole moment, N2O can be used as an important tracer for the abundance of N2 in such regions as well as for characterization of nitrogen content of ices in outer bodies of Solar system. In this work, we experimentally investigate the resistance of frozen N2O molecules against radiation in attempt to estimate their half-life in astrophysical environments. All the radiolysis products, such as NO2 and NO, were identified by Fourier transform infrared spectroscopy. The infrared absorbance as a function of fluence is modified by ice compaction and by radiolysis, the compaction being dominant at the beginning of the ice processing. The N2O destruction cross-section as well the formation cross-sections of the products NxOy (x = 1-2 and y = 1-5) oxides and ozone (O3) by 1.5 MeV 14N+ ion beam are determined. The characterization of radiation resistance of N2O in cold astrophysical environments is relevant since it yields limits for the nitrogen abundance where the N2O molecule is used to indirectly derive its concentration. The half-life of solid N2O molecules dissociated by medium-mass cosmic rays at Pluto's orbit and at the interstellar medium is estimated.

  19. Characterization and antimicrobial potential of extremely halophilic archaea isolated from hypersaline environments of the Algerian Sahara.

    Science.gov (United States)

    Quadri, Inès; Hassani, Imene Ikrame; l'Haridon, Stéphane; Chalopin, Morgane; Hacène, Hocine; Jebbar, Mohamed

    2016-01-01

    Halophilic archaea were isolated from different chotts and sebkha, dry salt lakes and salt flat respectively, of the Algerian Sahara and characterized using phenotypic and phylogenetic approaches. From 102 extremely halophilic strains isolated, forty three were selected and studied. These strains were also screened for their antagonistic potential and the production of hydrolytic enzymes. Sequencing of the 16S rRNA genes and phylogenetic analysis allowed the identification of 10 archaeal genera within the class Halobacteria: Natrinema (13 strains), Natrialba (12 strains), Haloarcula (4 strains), Halopiger (4 strains), Haloterrigena (3 strains), Halorubrum (2 strains), Halostagnicola (2 strains), Natronococcus, Halogeometricum and Haloferax (1 strain each). The most common producers of antimicrobial compounds belong to the genus Natrinema while the most hydrolytic isolates, with combined production of several enzymes, belong to the genus Natrialba. The strain affiliated to Halopiger djelfamassilliensis was found to produce some substances of interest (halocins, anti-Candida, enzymes). After partial purification and characterization of one of the strains Natrinema gari QI1, we found similarities between the antimicrobial compound and the halocin C8. Therefore, the gene encoding halocin C8 was amplified and sequenced.

  20. Numerical implementation of time-dependent density functional theory for extended systems in extreme environments

    Energy Technology Data Exchange (ETDEWEB)

    Baczewski, Andrew David; Shulenburger, Luke; Desjarlais, Michael Paul; Magyar, Rudolph J.

    2014-02-01

    In recent years, DFT-MD has been shown to be a useful computational tool for exploring the properties of WDM. These calculations achieve excellent agreement with shock compression experiments, which probe the thermodynamic parameters of the Hugoniot state. New X-ray Thomson Scattering diagnostics promise to deliver independent measurements of electronic density and temperature, as well as structural information in shocked systems. However, they require the development of new levels of theory for computing the associated observables within a DFT framework. The experimentally observable x-ray scattering cross section is related to the electronic density-density response function, which is obtainable using TDDFT - a formally exact extension of conventional DFT that describes electron dynamics and excited states. In order to develop a capability for modeling XRTS data and, more generally, to establish a predictive capability for rst principles simulations of matter in extreme conditions, real-time TDDFT with Ehrenfest dynamics has been implemented in an existing PAW code for DFT-MD calculations. The purpose of this report is to record implementation details and benchmarks as the project advances from software development to delivering novel scienti c results. Results range from tests that establish the accuracy, e ciency, and scalability of our implementation, to calculations that are veri ed against accepted results in the literature. Aside from the primary XRTS goal, we identify other more general areas where this new capability will be useful, including stopping power calculations and electron-ion equilibration.

  1. PRTs and Their Bonding for Long-Duration, Extreme-Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni; Cucullu, Gordon C., III; Mikhaylov, Rebecca L.

    2012-01-01

    Research was conducted on the qualification of Honeywell platinum resistance thermometer (PRT) bonding for use in the Mars Science Laboratory (MSL). This is the first time these sensors will be used for Mars-related projects. Different types of PRTs were employed for the Mars Exploration Rover (MER) project, and several reliability issues were experienced, even for a shortduration mission like MER compared to MSL. Therefore, the development of a qualification process for the Honeywell PRT bonding was needed for the MSL project. Reliability of the PRT sensors, and their bonding processes, is a key element to understand the health of the hardware during all stages of the project, and particularly during surface operations on Mars. Three extreme temperature summer season cycles and three winter season cycles (total: 1983 thermal cycles) were completed, and no Honeywell PRT failures associated with the bonding process were found. Seventy-eight PRTs were bonded onto six different substrate materials using four different adhesives during the thermal cycling, which included a planetary protection cycle to +125 C for two hours, three protoflight/qualification cycles (-135 to 70 C), 1,384 summer cycles (-105 to 40 C), and 599 winter cycles (-130 to 15 C). There were no observed changes in PRT resistances, bonding characteristics, or damage identified from the package evaluation as a result of the qualification tests.

  2. Polar Microalgae: New Approaches towards Understanding Adaptations to an Extreme and Changing Environment.

    Science.gov (United States)

    Lyon, Barbara R; Mock, Thomas

    2014-01-28

    Polar Regions are unique and highly prolific ecosystems characterized by extreme environmental gradients. Photosynthetic autotrophs, the base of the food web, have had to adapt physiological mechanisms to maintain growth, reproduction and metabolic activity despite environmental conditions that would shut-down cellular processes in most organisms. High latitudes are characterized by temperatures below the freezing point, complete darkness in winter and continuous light and high UV in the summer. Additionally, sea-ice, an ecological niche exploited by microbes during the long winter seasons when the ocean and land freezes over, is characterized by large salinity fluctuations, limited gas exchange, and highly oxic conditions. The last decade has been an exciting period of insights into the molecular mechanisms behind adaptation of microalgae to the cryosphere facilitated by the advancement of new scientific tools, particularly "omics" techniques. We review recent insights derived from genomics, transcriptomics, and proteomics studies. Genes, proteins and pathways identified from these highly adaptable polar microbes have far-reaching biotechnological applications. Furthermore, they may provide insights into life outside this planet, as well as glimpses into the past. High latitude regions also have disproportionately large inputs into global biogeochemical cycles and are the region most sensitive to climate change.

  3. Raman spectroscopy of the Dukhan sabkha: identification of geological and biogeological molecules in an extreme environment.

    Science.gov (United States)

    Edwards, Howell G M; Sadooni, Fadhil; Vítek, Petr; Jehlicka, Jan

    2010-07-13

    The characterization of minerals and biogeological deposits in a terrestrial Arabian sabkha has a direct relevance for the exploration of Mars since the discovery by the NASA rovers Spirit and Opportunity of evaporate minerals on Mars that could have arisen from aquifers and subsurface water movement. The recognition of carbonates and sulphates in Gusev Crater has afforded an additional impetus to these studies, as relict or extant microbial extremophilic organisms could have colonized these geological matrices, as has been recorded on Earth. Here, we describe the Raman spectroscopic analysis of specimens of evaporitic materials sampled from the Dukhan sabkha, the largest inland sabkha in the Persian Gulf. With daily temperatures reaching in excess of 60 degrees C and extreme salinity, we have identified the characteristic Raman signatures of key biomolecular compounds in association with evaporitic minerals and geological carbonate and sulphate matrices, which indicate that extremophilic cyanobacterial colonies are existent there. This evidence, the first to be acquired spectroscopically from such a region, establishes a platform for further studies using remote, portable Raman instrumentation that will inform the potential of detection of similar systems on the Martian surface or subsurface in future space missions. A comparison is made between the results from this study and the previous analysis of a gypsum/halite sabkha where the extremophilic molecular signatures were better preserved.

  4. Mechanical Development of a Very Non-Standard Patch Array Antenna for Extreme Environments

    Science.gov (United States)

    Hughes, Richard; Chamberlain, Neil; Jakoboski, Julie; Petkov, Mihail

    2012-01-01

    This paper describes the mechanical development of patch antenna arrays for the Juno mission. The patch arrays are part of a six-frequency microwave radiometer instrument that will be used to measure thermal emissions from Jupiter. The very harsh environmental conditions in Jupiter orbit, as well as a demanding launch environment, resulted in a design that departs radically from conventional printed circuit patch antennas. The paper discusses the development and qualification of the Juno patch array antennas, with emphasis on the materials approach that was devised to mitigate the effects of electron charging in Jupiter orbit.

  5. Thermal-Acoustic Fatigue of a Multilayer Thermal Protection System in Combined Extreme Environments

    Directory of Open Access Journals (Sweden)

    Liu Liu

    2014-06-01

    Full Text Available In order to ensure integrity of thermal protection system (TPS structure for hypersonic vehicles exposed to severe operating environments, a study is undertaken to investigate the response and thermal-acoustic fatigue damage of a representative multilayer TPS structure under combined thermal and acoustic loads. An unsteady-state flight of a hypersonic vehicle is composed of a series of steady-state snapshots, and for each snapshot an acoustic load is imposed to a static steady-state TPS structure. A multistep thermal-acoustic fatigue damage intensity analysis procedure is given and consists of a heat transfer analysis, a nonlinear thermoelastic analysis, and a random response analysis under a combined loading environment and the fatigue damage intensity has been evaluated with two fatigue analysis techniques. The effects of thermally induced deterministic stress and nondeterministic dynamic stress due to the acoustic loading have been considered in the damage intensity estimation with a maximum stress fatigue model. The results show that the given thermal-acoustic fatigue intensity estimation procedure is a viable approach for life prediction of TPS structures under a typical mission cycle with combined loadings characterized by largely different time-scales. A discussion of the effects of the thermal load, the acoustic load, and fatigue analysis methodology on the fatigue damage intensity has been provided.

  6. Extreme Environment Effects on Cognitive Functions: A Longitudinal Study in High Altitude in Antarctica.

    Science.gov (United States)

    Barkaszi, Irén; Takács, Endre; Czigler, István; Balázs, László

    2016-01-01

    This paper focuses on the impact of long-term Antarctic conditions on cognitive processes. Behavioral responses and event-related potentials were recorded during an auditory distraction task and an attention network paradigm. Participants were members of the over-wintering crew at Concordia Antarctic Research Station. Due to the reduced partial pressure of oxygen this environment caused moderate hypoxia. Beyond the hypoxia, the fluctuation of sunshine duration, isolation and confinement were the main stress factors of this environment. We compared 6 measurement periods completed during the campaign. Behavioral responses and N1/MMN (mismatch negativity), N1, N2, P3, RON (reorientation negativity) event-related potential components have been analyzed. Reaction time decreased in both tasks in response to repeated testing during the course of mission. The alerting effect increased, the inhibition effect decreased and the orienting effect did not change in the ANT task. Contrary to our expectations the N2, P3, RON components related to the attentional functions did not show any significant changes. Changes attributable to early stages of information processing were observed in the ANT task (N1 component) but not in the distraction task (N1/MMN). The reaction time decrements and the N1 amplitude reduction in ANT task could be attributed to sustained effect of practice. We conclude that the Antarctic conditions had no negative impacts on cognitive activity despite the presence of numerous stressors.

  7. Psychological Adaptation to Extreme Environments: Effects of Team Composition on Individual Adaptation

    Science.gov (United States)

    Wood, J.; Hysong, S. J.; Lugg, D. J.; Harm, D. L.

    1999-01-01

    This study is part of an ongoing program of research examining the psychological effects of isolation and confinement on individual adaptation, productivity and group relations in Antarctic winter personnel. This environment is used as an analogue for long-duration space mission scenarios, such as a space station sojourn, or a mission to Mars. Earlier results from this and other environments have demonstrated that: (1) most changes in psychological well-being are event-related and of relatively short duration; and (2) the greatest problem facing most individuals is interpersonal conflict. Content analysis of responses to open-ended questions has identified the numerous enjoyable aspects of Antarctic living, and confirmed that many of the problems reported were interpersonal in nature, and that problems varied significantly by station. Current work is exploring the effects of team assignment on the self-reported psychological changes and self-evaluations of members of isolated teams. This work includes identifying the dimensions by which subjects determine how well they are functioning. These dimensions (e.g., work, social life, internal emotional state) appear to play an important role in how subjects evaluate many aspects of life in isolation.

  8. Galactic Dark Matter Halos and Globular Cluster Populations. III. Extension to Extreme Environments

    Science.gov (United States)

    Harris, William E.; Blakeslee, John P.; Harris, Gretchen L. H.

    2017-02-01

    The total mass {M}{GCS} in the globular cluster (GC) system of a galaxy is empirically a near-constant fraction of the total mass {M}h\\equiv {M}{bary}+{M}{dark} of the galaxy across a range of 105 in galaxy mass. This trend is radically unlike the strongly nonlinear behavior of total stellar mass M ⋆ versus M h . We discuss extensions of this trend to two more extreme situations: (a) entire clusters of galaxies and (b) the ultra-diffuse galaxies (UDGs) recently discovered in Coma and elsewhere. Our calibration of the ratio {η }M={M}{GCS}/{M}h from normal galaxies, accounting for new revisions in the adopted mass-to-light ratio for GCs, now gives {η }M=2.9× {10}-5 as the mean absolute mass fraction. We find that the same ratio appears valid for galaxy clusters and UDGs. Estimates of {η }M in the four clusters we examine tend to be slightly higher than for individual galaxies, but more data and better constraints on the mean GC mass in such systems are needed to determine if this difference is significant. We use the constancy of {η }M to estimate total masses for several individual cases; for example, the total mass of the Milky Way is calculated to be {M}h=1.1× {10}12 {M}ȯ . Physical explanations for the uniformity of {η }M are still descriptive, but point to a picture in which massive dense star clusters in their formation stages were relatively immune to the feedback that more strongly influenced lower-density regions where most stars form.

  9. Performance differences of Rhode Island Red, Bashang Long-tail Chicken, and their reciprocal crossbreds under natural cold stress

    Directory of Open Access Journals (Sweden)

    Shanshan Xie

    2017-10-01

    Full Text Available Objective The Bashang Long-tail chicken (BS, an indigenous Chinese breed, is considered cold tolerant. We selected BS, the Rhode Island Red (RIR, and their reciprocal crossbreds for the present study. The objectives were: i to validate whether BS is cold tolerant and whether egg production and cold tolerance of crossbreds could be improved; and ii to determine the physiological characteristics that underlie cold tolerance and favorable egg production performance in cold environments. Methods A total of 916 chickens were reared in warm and natural cold environments (daily mean ambient temperature varied from 7.4°C to 26.5°C in the warm environment and from −17.5°C to 27.0°C in the cold environment. To investigate their adaptability to the cold environment, the egg production performance and body weight were monitored and compared between breeds and environments. The cloacal temperature and serum biochemical parameters were monitored to reveal the physiological characteristics underlie cold tolerance and favorable egg production performance in the cold environment. Results The warm environment experiment showed that RIR had the highest egg production performance, and that the reciprocal crossbreds had a higher egg production performance than BS. While in the cold environment RIR had the lowest egg production performance, and the reciprocal crossbreds had a higher egg production performance than BS. In the cold environment BS and reciprocal crossbreds had higher triiodothyronine, tetraiodothyronine levels than RIR. At 35 and 39 wk of age, when the ambient temperature was extremely low (varied from −20°C to 0°C, serum glucose, follicle-stimulating hormone, luteinizing hormone, estradiol of BS and crossbreds were higher than RIR. Conclusion Bashang Long-tail chicken has a favorable cold tolerance ability. Crossbreeding with RIR and BS is an effective way to develop cold tolerant chickens with improved egg production performance.

  10. Influence of Hot and Cold Environments on the Regulation of Energy Balance Following a Single Exercise Session: A Mini-Review

    Directory of Open Access Journals (Sweden)

    Keyne Charlot

    2017-06-01

    Full Text Available Understanding the regulation of human food intake in response to an acute exercise session is of importance for interventions with athletes and soldiers, as well as overweight individuals. However, the influence of hot and cold environments on this crucial function for the regulation of body mass and motor performance has not been summarized. The purpose of this review was to exhaustively search the literature on the effect of ambient temperature during an exercise session on the subsequent subjective feeling of appetite, energy intake (EI and its regulation. In the absence of stress due to environmental temperature, exercise-induced energy expenditure is not compensated by EI during an ad libitum meal following the session, probably due to decreased acylated ghrelin and increased peptide tyrosine tyrosine (PYY, glucagon-like peptide 1 (GLP-1, and pancreatic polypeptide (PP levels. No systematic analysis has been yet made for major alterations of relative EI in cold and hot environments. However, observed eating behaviors are altered (proportion of solid/liquid food, carbohydrate/fat and physiological regulation appears also to be altered. Anorexigenic signals, particularly PYY, appear to further increase in hot environments than in those that are thermoneutral. Ghrelin and leptin may be involved in the observed increase in EI after exercise in the cold, in parallel with increased energy expenditure. The potential influence of ambient thermal environment on eating behaviors after an exercise session should not be neglected.

  11. Influence of Hot and Cold Environments on the Regulation of Energy Balance Following a Single Exercise Session: A Mini-Review.

    Science.gov (United States)

    Charlot, Keyne; Faure, Cécile; Antoine-Jonville, Sophie

    2017-06-10

    Understanding the regulation of human food intake in response to an acute exercise session is of importance for interventions with athletes and soldiers, as well as overweight individuals. However, the influence of hot and cold environments on this crucial function for the regulation of body mass and motor performance has not been summarized. The purpose of this review was to exhaustively search the literature on the effect of ambient temperature during an exercise session on the subsequent subjective feeling of appetite, energy intake (EI) and its regulation. In the absence of stress due to environmental temperature, exercise-induced energy expenditure is not compensated by EI during an ad libitum meal following the session, probably due to decreased acylated ghrelin and increased peptide tyrosine tyrosine (PYY), glucagon-like peptide 1 (GLP-1), and pancreatic polypeptide (PP) levels. No systematic analysis has been yet made for major alterations of relative EI in cold and hot environments. However, observed eating behaviors are altered (proportion of solid/liquid food, carbohydrate/fat) and physiological regulation appears also to be altered. Anorexigenic signals, particularly PYY, appear to further increase in hot environments than in those that are thermoneutral. Ghrelin and leptin may be involved in the observed increase in EI after exercise in the cold, in parallel with increased energy expenditure. The potential influence of ambient thermal environment on eating behaviors after an exercise session should not be neglected.

  12. Evaluation of unmanned airborne vehicles and mobile robotic telesurgery in an extreme environment.

    Science.gov (United States)

    Harnett, Brett M; Doarn, Charles R; Rosen, Jacob; Hannaford, Blake; Broderick, Timothy J

    2008-08-01

    As unmanned extraction vehicles become a reality in the military theater, opportunities to augment medical operations with telesurgical robotics become more plausible. This project demonstrated an experimental surgical robot using an unmanned airborne vehicle (UAV) as a network topology. Because battlefield operations are dynamic and geographically challenging, the installation of wireless networks is not a feasible option at this point. However, to utilize telesurgical robotics to assist in the urgent medical care of wounded soldiers, a robust, high bandwidth, low latency network is requisite. For the first time, a mobile surgical robotic system was deployed to an austere environment and surgeons were able to remotely operate the systems wirelessly using a UAV. Two University of Cincinnati surgeons were able to remotely drive the University of Washington's RAVEN robot's end effectors. The network topology demonstrated a highly portable, quickly deployable, bandwidth-sufficient and low latency wireless network required for battlefield use.

  13. 'Extreme mass spectrometry': the role of mass spectrometry in the study of the Antarctic environment.

    Science.gov (United States)

    Magi, Emanuele; Tanwar, Shivani

    2014-11-01

    A focus on the studies of the Antarctic environment that have been performed by mass spectrometry is presented herein; our aim is to give evidence of the essential role of this instrumental technique in the framework of the scientific research in Antarctica, with a comprehensive review on the main literature of the last two decades. Due to the wideness of the topic, the present review is limited to the determination of organic pollutants, natural molecules and biomarkers in Antarctica, thus excluding elemental analysis and studies on inorganic species. The work has been divided into five sections, on the basis of the considered environmental compartment: air; ice and snow; seawater, pack ice and lakes; soil and sediments; and organisms and biomarkers.

  14. Converging Indicators for Assessing Individual Differences in Adaptation to Extreme Environments: Preliminary Report

    Science.gov (United States)

    Cowings, Patricia S.; Toscano, William B.; DeRoshia, Charles W.; Taylor, Bruce; Hines, Seleimah; Bright, Andrew; Dodds, Anika

    2006-01-01

    This paper describes the development and validation of a new methodology for assessing the deleterious effects of spaceflight on crew health and performance. It is well known that microgravity results in various physiological alterations, e.g., headward fluid shifts which can impede physiological adaptation. Other factors that may affect crew operational efficiency include disruption of sleep-wake cycles, high workload, isolation, confinement, stress and fatigue. From an operational perspective, it is difficult to predict which individuals will be most or least affected in this unique environment given that most astronauts are first-time flyers. During future lunar and Mars missions space crews will include both men and women of multi-national origins, different professional backgrounds, and various states of physical condition. Therefore, new methods or technologies are needed to monitor and predict astronaut performance and health, and to evaluate the effects of various countermeasures on crew during long duration missions. This paper reviews several studies conducted in both laboratory and operational environments with men and women ranging in age between 18 to 50 years. The studies included the following: soldiers performing command and control functions during mobile operations in enclosed armored vehicles; subjects participating in laboratory tests of an anti-motion sickness medication; subjects exposed to chronic hypergravity aboard a centrifuge, and subject responses to 36-hours of sleep deprivation. Physiological measurements, performance metrics, and subjective self-reports were collected in each study. The results demonstrate that multivariate converging indicators provide a significantly more reliable method for assessing environmental effects on performance and health than any single indicator.

  15. Massive stars dying alone: The extremely remote environment of SN 2009ip

    CERN Document Server

    Smith, Nathan; Mauerhan, Jon C

    2016-01-01

    We present late-time HST images of the site of supernova (SN) 2009ip taken almost 3 yr after its bright 2012 luminosity peak. SN 2009ip is now slightly fainter in broad filters than the progenitor candidate detected by HST in 1999. The current source continues to be dominated by ongoing late-time CSM interaction that produces strong H-alpha emission and a weak pseudo-continuum, as found previously for 1-2 yr after explosion. The intent of these observations was to search for evidence of recent star formation in the local (1kpc; 10 arcsec) environment around SN 2009ip, in the remote outskirts of its host spiral galaxy NGC 7259. We can rule out the presence of any massive star-forming complexes like 30 Dor or the Carina Nebula at the SN site or within a few kpc. If the progenitor of SN 2009ip was really a 50-80 Msun star as archival HST images suggested, then it is strange that there is no sign of this type of massive star formation anywhere in the vicinity. A possible explanation is that the progenitor was the...

  16. Genetic differentiation and selection against migrants in evolutionarily replicated extreme environments.

    Science.gov (United States)

    Plath, Martin; Pfenninger, Markus; Lerp, Hannes; Riesch, Rüdiger; Eschenbrenner, Christoph; Slattery, Patrick A; Bierbach, David; Herrmann, Nina; Schulte, Matthias; Arias-Rodriguez, Lenin; Rimber Indy, Jeane; Passow, Courtney; Tobler, Michael

    2013-09-01

    We investigated mechanisms of reproductive isolation in livebearing fishes (genus Poecilia) inhabiting sulfidic and nonsulfidic habitats in three replicate river drainages. Although sulfide spring fish convergently evolved divergent phenotypes, it was unclear if mechanisms of reproductive isolation also evolved convergently. Using microsatellites, we found strongly reduced gene flow between adjacent populations from different habitat types, suggesting that local adaptation to sulfidic habitats repeatedly caused the emergence of reproductive isolation. Reciprocal translocation experiments indicate strong selection against immigrants into sulfidic waters, but also variation among drainages in the strength of selection against immigrants into nonsulfidic waters. Mate choice experiments revealed the evolution of assortative mating preferences in females from nonsulfidic but not from sulfidic habitats. The inferred strength of sexual selection against immigrants (RI(s)) was negatively correlated with the strength of natural selection (RI(m)), a pattern that could be attributed to reinforcement, whereby natural selection strengthens behavioral isolation due to reduced hybrid fitness. Overall, reproductive isolation and genetic differentiation appear to be replicated and direct consequences of local adaptation to sulfide spring environments, but the relative contributions of different mechanisms of reproductive isolation vary across these evolutionarily independent replicates, highlighting both convergent and nonconvergent evolutionary trajectories of populations in each drainage. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  17. Textile technology for the vital signs monitoring in telemedicine and extreme environments.

    Science.gov (United States)

    Di Rienzo, Marco; Meriggi, Paolo; Rizzo, Francesco; Castiglioni, Paolo; Lombardi, Carolina; Ferratini, Maurizio; Parati, Gianfranco

    2010-05-01

    This paper illustrates two extensive applications of a smart garment we previously developed for the monitoring of ECG, respiration, and movement. In the first application, the device, named Maglietta Interattiva Computerizzata (MagIC), was used for the home monitoring of cardiac patients. The used platform included MagIC for signals collection, a touchscreen computer with a dedicated software for data handling, and a universal mobile telecommunications system (UMTS) dongle for data transmission, via email, to three cardiologists. Three patients daily-performed 3-min telemonitoring sessions for 30 days by using the platform. The whole system behaved correctly in 85 out of 90 sessions. In five instances, a second session was required due to UMTS traffic congestion. Only in three sessions, cardiologists asked the patient to repeat the acquisition because of poor signal quality. In the second application, MagIC was used to evaluate the effects of high-altitude hypoxia on sleep and 24 h daily life in 30 healthy subjects at 3500 and 5400 m above sea level on Mount Everest slopes. The use of MagIC garment was reported to be simple and requiring short instrumentation time even in the demanding expedition environment. The signal quality was adequate in 111 out of 115 recordings and 90% of the subjects found the vest comfortable.

  18. Molecular adaptation to an extreme environment: origin of the thermal stability of the pompeii worm collagen.

    Science.gov (United States)

    Sicot, F X; Mesnage, M; Masselot, M; Exposito, J Y; Garrone, R; Deutsch, J; Gaill, F

    2000-09-29

    The annelid Alvinella pompejana is probably the most heat-tolerant metazoan organism known. Previous results have shown that the level of thermal stability of its interstitial collagen is significantly greater than that of coastal annelids and of vent organisms, such as the vestimentiferan Riftia pachyptila, living in colder parts of the deep-sea hydrothermal environment. In order to investigate the molecular basis of this thermal behavior, we cloned and sequenced a large cDNA molecule coding the fibrillar collagen of Alvinella, including one half of the helical domain and the entire C-propeptide domain. For comparison, we also cloned the 3' part of the homologous cDNA from Riftia. Comparison of the corresponding helical domains of these two species, together with that of the previously sequenced domain of the coastal lugworm Arenicola marina, showed that the increase in proline content and in the number of stabilizing triplets correlate with the outstanding thermostability of the interstitial collagen of A. pompejana. Phylogenetic analysis showed that triple helical and the C-propeptide parts of the same collagen molecule evolve at different rates, in favor of an adaptive mechanism at the molecular level. Copyright 2000 Academic Press.

  19. Millimeter waves or extremely high frequency electromagnetic fields in the environment: what are their effects on bacteria?

    Science.gov (United States)

    Soghomonyan, Diana; Trchounian, Karen; Trchounian, Armen

    2016-06-01

    Millimeter waves (MMW) or electromagnetic fields of extremely high frequencies at low intensity is a new environmental factor, the level of which is increased as technology advance. It is of interest that bacteria and other cells might communicate with each other by electromagnetic field of sub-extremely high frequency range. These MMW affected Escherichia coli and many other bacteria, mainly depressing their growth and changing properties and activity. These effects were non-thermal and depended on different factors. The significant cellular targets for MMW effects could be water, cell plasma membrane, and genome. The model for the MMW interaction with bacteria is suggested; a role of the membrane-associated proton FOF1-ATPase, key enzyme of bioenergetic relevance, is proposed. The consequences of MMW interaction with bacteria are the changes in their sensitivity to different biologically active chemicals, including antibiotics. Novel data on MMW effects on bacteria and their sensitivity to different antibiotics are presented and discussed; the combined action of MMW and antibiotics resulted with more strong effects. These effects are of significance for understanding changed metabolic pathways and distinguish role of bacteria in environment; they might be leading to antibiotic resistance in bacteria. The effects might have applications in the development of technique, therapeutic practices, and food protection technology.

  20. Strain response of thermal barrier coatings captured under extreme engine environments through synchrotron X-ray diffraction

    Science.gov (United States)

    Knipe, Kevin; Manero, Albert; Siddiqui, Sanna F.; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M.; Bartsch, Marion; Raghavan, Seetha

    2014-07-01

    The mechanical behaviour of thermal barrier coatings in operation holds the key to understanding durability of jet engine turbine blades. Here we report the results from experiments that monitor strains in the layers of a coating subjected to thermal gradients and mechanical loads representing extreme engine environments. Hollow cylindrical specimens, with electron beam physical vapour deposited coatings, were tested with internal cooling and external heating under various controlled conditions. High-energy synchrotron X-ray measurements captured the in situ strain response through the depth of each layer, revealing the link between these conditions and the evolution of local strains. Results of this study demonstrate that variations in these conditions create corresponding trends in depth-resolved strains with the largest effects displayed at or near the interface with the bond coat. With larger temperature drops across the coating, significant strain gradients are seen, which can contribute to failure modes occurring within the layer adjacent to the interface.

  1. Two-dimensional resonant magnetic soft X-ray scattering set-up for extreme sample environment.

    Science.gov (United States)

    Stanescu, Stefan; Mocuta, Cristian; Merlet, Frederic; Barbier, Antoine

    2013-01-01

    The newly built MagSAXS (magnetic small-angle X-ray scattering) set-up dedicated to the direct two-dimensional measurement of magnetic scattering using polarized synchrotron radiation in extreme sample environments is presented. Pure optical transport of the image is used to record the magnetic scattering with a two-dimensional CCD visible-light camera. The set-up is able to probe magnetic correlation lengths from the micrometer down to the nanometer scale. A detailed layout is presented along with preliminary results obtained at several beamlines at Synchrotron SOLEIL. The presented examples underline the wide range of possible applications spanning from correlation lengths determination to Fourier transform holography.

  2. Strain response of thermal barrier coatings captured under extreme engine environments through synchrotron X-ray diffraction.

    Science.gov (United States)

    Knipe, Kevin; Manero, Albert; Siddiqui, Sanna F; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M; Bartsch, Marion; Raghavan, Seetha

    2014-07-31

    The mechanical behaviour of thermal barrier coatings in operation holds the key to understanding durability of jet engine turbine blades. Here we report the results from experiments that monitor strains in the layers of a coating subjected to thermal gradients and mechanical loads representing extreme engine environments. Hollow cylindrical specimens, with electron beam physical vapour deposited coatings, were tested with internal cooling and external heating under various controlled conditions. High-energy synchrotron X-ray measurements captured the in situ strain response through the depth of each layer, revealing the link between these conditions and the evolution of local strains. Results of this study demonstrate that variations in these conditions create corresponding trends in depth-resolved strains with the largest effects displayed at or near the interface with the bond coat. With larger temperature drops across the coating, significant strain gradients are seen, which can contribute to failure modes occurring within the layer adjacent to the interface.

  3. The design of the inelastic neutron scattering mode for the Extreme Environment Diffractometer with the 26 T High Field Magnet

    Energy Technology Data Exchange (ETDEWEB)

    Bartkowiak, Maciej, E-mail: maciej.bartkowiak@helmholtz-berlin.de; Stüßer, Norbert; Prokhnenko, Oleksandr

    2015-10-11

    The Extreme Environment Diffractometer is a neutron time-of-flight instrument, designed to work with a constant-field hybrid magnet capable of reaching fields over 26 T, unprecedented in neutron science; however, the presence of the magnet imposes both spatial and technical limitations on the surrounding instrument components. In addition to the existing diffraction and small-angle neutron scattering modes, the instrument will operate also in an inelastic scattering mode, as a direct time-of-flight spectrometer. In this paper we present the Monte Carlo ray-tracing simulations, the results of which illustrate the performance of the instrument in the inelastic-scattering mode. We describe the focussing neutron guide and the chopper system of the existing instrument and the planned design for the instrument upgrade. The neutron flux, neutron spatial distribution, divergence distribution and energy resolution are calculated for standard instrument configurations.

  4. Trainability of cold induced vasodilation

    NARCIS (Netherlands)

    Daanen, H.A.M.; Raymann, R.J.E.M.; Stoop, M.

    2007-01-01

    Peripheral cold injuries are often reported in mountaineers. Not only low ambient temperatures, but also the hypobaric circumstances are known to be major environmental risk factors. When the fingers are exposed to extreme cold for several minutes, cold induced vasodilation (CIVD) occurs, that is

  5. Trainability of cold induced vasodilation

    NARCIS (Netherlands)

    Daanen, H.A.M.; Raymann, R.J.E.M.; Stoop, M.

    2007-01-01

    Peripheral cold injuries are often reported in mountaineers. Not only low ambient temperatures, but also the hypobaric circumstances are known to be major environmental risk factors. When the fingers are exposed to extreme cold for several minutes, cold induced vasodilation (CIVD) occurs, that is re

  6. Seasonal variations in microbial populations and environmental conditions in an extreme acid mine drainage environment.

    Science.gov (United States)

    Edwards, K J; Gihring, T M; Banfield, J F

    1999-08-01

    Microbial populations, their distributions, and their aquatic environments were studied over a year (1997) at an acid mine drainage (AMD) site at Iron Mountain, Calif. Populations were quantified by fluorescence in situ hybridizations with group-specific probes. Probes were used for the domains Eucarya, Bacteria, and Archaea and the two species most widely studied and implicated for their role in AMD production, Thiobacillus ferrooxidans and Leptospirillum ferrooxidans. Results show that microbial populations, in relative proportions and absolute numbers, vary spatially and seasonally and correlate with geochemical and physical conditions (pH, temperature, conductivity, and rainfall). Bacterial populations were in the highest proportion (>95%) in January. Conversely, archaeal populations were in the highest proportion in July and September ( approximately 50%) and were virtually absent in the winter. Bacterial and archaeal populations correlated with conductivity and rainfall. High concentrations of dissolved solids, as reflected by high conductivity values (up to 125 mS/cm), occurred in the summer and correlated with high archaeal populations and proportionally lower bacterial populations. Eukaryotes were not detected in January, when total microbial cell numbers were lowest (numbers of prokaryotes (10(8) to 10(9) cells/ml). T. ferrooxidans was in highest abundance (>30%) at moderate pHs and temperatures ( approximately 2.5 and 20 degrees C) in sites that were peripheral to primary acid-generating sites and lowest (0 to 5%) at low-pH sites (pH approximately 0.5) that were in contact with the ore body. L. ferrooxidans was more widely distributed with respect to geochemical conditions (pH = 0 to 3; 20 to 50 degrees C) but was more abundant at higher temperatures and lower pHs ( approximately 40 degrees C; pH approximately 0.5) than T. ferrooxidans.

  7. Massive stars dying alone: the extremely remote environment of SN 2009ip

    Science.gov (United States)

    Smith, Nathan; Andrews, Jennifer E.; Mauerhan, Jon C.

    2016-12-01

    We present late-time Hubble Space Telescope (HST) images of the site of supernova (SN) 2009ip taken almost 3 yr after its bright 2012 luminosity peak. SN 2009ip is now slightly fainter in broad filters than the progenitor candidate detected by HST in 1999. The current source continues to be dominated by ongoing late-time circumstellar material interaction that produces strong Hα emission and a weak pseudo-continuum, as found previously for 1-2 yr after explosion. The intent of these observations was to search for evidence of recent star formation in the local (˜1 kpc; 10 arcsec) environment around SN 2009ip, in the remote outskirts of its host spiral galaxy NGC 7259. We can rule out the presence of any massive star-forming complexes like 30 Dor or the Carina nebula at the SN site or within a few kpc. If the progenitor of SN 2009ip was really a 50-80 M⊙ star as archival HST images suggested, then it is strange that there is no sign of this type of massive star formation anywhere in the vicinity. A possible explanation is that the progenitor was the product of a merger or binary mass transfer, rejuvenated after a lifetime that was much longer than 4-5 Myr, allowing its natal H II region to have faded. A smaller region like the Orion nebula would be an unresolved but easily detected point source. This is ruled out within ˜1.5 kpc around SN 2009ip, but a small H II region could be hiding in the glare of SN 2009ip itself. Later images after a few more years have passed are needed to confirm that the progenitor candidate is truly gone and to test for the possibility of a small H II region or cluster at the SN position.

  8. Yeast diversity in the extreme acidic environments of the Iberian Pyrite Belt.

    Science.gov (United States)

    Gadanho, Mário; Libkind, Diego; Sampaio, José Paulo

    2006-10-01

    In the Iberian Pyrite Belt (IPB), acid rock drainage gives rise to aquatic habitats with low pH and high concentrations of heavy metals, a situation that causes important environmental problems. We investigated the occurrence and diversity of yeasts in two localities of the IPB: São Domingos (Portugal) and Rio Tinto (Spain). Yeast isolation was performed on conventional culture media (MYP), acidified (pH 3) media (MYP3), and on media prepared with water from the study sites (MYPw). The main goal of the study was to determine the structure of the yeast community; a combination of molecular methods was used for accurate species identifications. Our results showed that the largest fraction of the yeast community was recovered on MYPw rather than on MYP and MYP3. Twenty-seven yeast species were detected, 48% of which might represent undescribed taxa. Among these, an undescribed species of the genus Cryptococcus required low pH for growth, a property that has not been observed before in yeasts. The communities of S. Domingos and R. Tinto showed a considerable resemblance, and eight yeast species were simultaneously found in both localities. Taking into consideration the physicochemical parameters studied, we propose a hierarchic organization of the yeast community in terms of high-, intermediate-, or low-stress conditions of the environment. According to this ranking, the acidophile yeast Cryptococcus sp. 5 is considered the most tolerant species, followed by Cryptococcus sp. 3 and Lecytophora sp. Species occurring in situations of intermediate environmental stress were Candida fluviatilis, Rhodosporidium toruloides, Williopsis californica, and three unidentified yeasts belonging to Rhodotorula and Cryptococcus.

  9. Current developments of research on permafrost engineering and cold region environment:a report of the 8th International Symposium on Permafrost Engineering

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The Eighth International Symposium on Permafrost Engineering was held in Xi’an,China,October 2009.The major topics discussed in the symposium included:permafrost engineering (involving design,construction and evaluation);mitigation of frost hazards in the regions affected by seasonally frozen ground;properties of frozen soils,model development and their applications;frost hazards and periglacial environments in mountain and plateau regions;climatic,environmental and cryospheric changes;and permafrost hydrology,cold regions water resources and land uses.The papers submitted to the symposium and lectures during the meeting represented some new developments of research on cold region engineering and environment.Here we summarized the works of the symposium in topics including:Permafrost engineering;General geocryology;Properties of frozen soils:model development and their applications;And climatic,environmental and cryospheric changes.During the symposium,the attendees pointed out that future studies should pay more attention to theoretical study and engineering mechanism study,and also on interaction between climate change and cold region environments and their engineering affects.

  10. Testing of different soil combinations as substrates in slalom slopes and golf courses in the cold climate environment

    Science.gov (United States)

    Pihlaja, Jouni

    2010-05-01

    Testing of different soil combinations as substrates in slalom slopes and golf courses in the cold climate environment Jouni Pihlaja, Geological Survey of Finland, Northern Finland Office, P.O. Box 77, FIN-96101 Rovaniemi, Finland. jouni.pihlaja@gtk.fi, www.gtk.fi The Geological Survey of Finland (GTK) is, with some partners, carrying out a cooperative project, POMARA, in the Levi tourist center in northern Finland. The purpose of this applied geology project is to determine which soil combinations work best over the long term as substrates on slalom slopes and golf course areas. Since the tourist center is located in a cold climate area, it gives extra challenges to those landscaping activities. The average temperature in January is about -15°C and in July +14°C. In the Levi area, the slalom slopes have normally been covered by local carex peat during the shaping phase of slopes. The problem has been that on the top part of the fell, the peat has "disappeared" after some years and stones have come up under the peat layer, since these areas are naturally covered by block fields. The main assumption at the beginning of the project was that frost weathering is causing the problems. In this project, test areas have been prepared on the slopes. The most important task is to compare test areas covered by carex peat to areas covered by a combination of sandy till and carex peat. The reason why sandy till was chosen to be the additional material was that it is supposed to stand up better against frost weathering than peat itself. Also, when considering future landscaping, the sandy till is the most economically viable mineral material to be used because of its nearby location . In the golf course areas, a combination of fine sand and sphagnum peat has been used in landscaping. The peat was brought from the Simo area, 300 km south of Levi. In this project, the goal is to determine if the local carex peat is working properly in the green areas of the golf club. The

  11. Insights from the metagenome of an acid salt lake: the role of biology in an extreme depositional environment.

    Science.gov (United States)

    Johnson, Sarah Stewart; Chevrette, Marc Gerard; Ehlmann, Bethany L; Benison, Kathleen Counter

    2015-01-01

    The extremely acidic brine lakes of the Yilgarn Craton of Western Australia are home to some of the most biologically challenging waters on Earth. In this study, we employed metagenomic shotgun sequencing to generate a microbial profile of the depositional environment associated with the sulfur-rich sediments of one such lake. Of the 1.5 M high-quality reads generated, 0.25 M were mapped to protein features, which in turn provide new insights into the metabolic function of this community. In particular, 45 diverse genes associated with sulfur metabolism were identified, the majority of which were linked to either the conversion of sulfate to adenylylsulfate and the subsequent production of sulfide from sulfite or the oxidation of sulfide, elemental sulfur, and thiosulfate via the sulfur oxidation (Sox) system. This is the first metagenomic study of an acidic, hypersaline depositional environment, and we present evidence for a surprisingly high level of microbial diversity. Our findings also illuminate the possibility that we may be meaningfully underestimating the effects of biology on the chemistry of these sulfur-rich sediments, thereby influencing our understanding of past geobiological conditions that may have been present on Earth as well as early Mars.

  12. Psychological and psychophysiological factors in prevention and treatment of cold injuries.

    Science.gov (United States)

    Kappes, B; Mills, W; O'Malley, J

    1993-01-01

    Cold injured patients in Alaska come from many sources. Although sport and work continues to provide large numbers of cold injured, most severe repeat injuries tend to reflect other biopsychosocial consequences. Certain behaviors can increase the probability of injury, however all persons living in cold climates are potential candidates. One can decrease risk by education, knowledge and intelligent behavior. Proper respect for adequate protection and hydration seem to be critical factors. Understanding the psychological, physiological and psychophysiological aspects of the cold environment performer helps refine the prevention and treatment strategies for cold injury. Skill training with bio-behavioral methods, such as thermal biofeedback, and the value of medical psychotherapy appear to offer continued promise by facilitating physiologic recovery from injury, as well as assisting in long term rehabilitation. Both approaches increase the likelihood of a favorable healing response by soliciting active patient participation. Medical Psychotherapy for traumatic injuries can also help identify and manage cognitive emotional issues for families and patients faced with the permanent consequences of severe thermal injuries. Thermal biofeedback therapy has the potential benefit of encouraging greater self-reliance and responsibility for self-regulating overall health by integrating self-management skills regarding physiology, diet and lifestyle. Inpatient and outpatient biofeedback training offers specific influence over vascular responses for healing, as well as providing an effective tool for pain management. Interest in cold region habitation has continued to expand our study of human tolerance to harsh, extreme environments. Biological, psychological, sociological, and anthropological views on adaptation, habituation, acclimatization, and injury in cold environments acknowledges the role of development, learning and educated responses to cold environments. The study of

  13. Computer game-based upper extremity training in the home environment in stroke persons: a single subject design

    Science.gov (United States)

    2014-01-01

    Background The objective of the present study was to assess whether computer game-based training in the home setting in the late phase after stroke could improve upper extremity motor function. Methods Twelve subjects with prior stroke were recruited; 11 completed the study. Design The study had a single subject design; there was a baseline test (A1), a during intervention test (B) once a week, a post-test (A2) measured directly after the treatment phase, plus a follow-up (C) 16–18 weeks after the treatment phase. Information on motor function (Fugl-Meyer), grip force (GrippitR) and arm function in activity (ARAT, ABILHAND) was gathered at A1, A2 and C. During B, only Fugl-Meyer and ARAT were measured. The intervention comprised five weeks of game-based computer training in the home environment. All games were designed to be controlled by either the affected arm alone or by both arms. Conventional formulae were used to calculate the mean, median and standard deviations. Wilcoxon’s signed rank test was used for tests of dependent samples. Continuous data were analyzed by methods for repeated measures and ordinal data were analyzed by methods for ordered multinomial data using cumulative logistic models. A p-value of game time and changes in the outcomes investigated in this study. Conclusion The results indicate that computer game-based training could be a promising approach to improve upper extremity function in the late phase after stroke, since in this study, changes were achieved in motor function and activity capacity. PMID:24625289

  14. Two spatial scales in a bleaching event: Corals from the mildest and the most extreme thermal environments escape mortality

    KAUST Repository

    Pineda, Jesús

    2013-07-28

    In summer 2010, a bleaching event decimated the abundant reef flat coral Stylophora pistillata in some areas of the central Red Sea, where a series of coral reefs 100–300 m wide by several kilometers long extends from the coastline to about 20 km offshore. Mortality of corals along the exposed and protected sides of inner (inshore) and mid and outer (offshore) reefs and in situ and satellite sea surface temperatures (SSTs) revealed that the variability in the mortality event corresponded to two spatial scales of temperature variability: 300 m across the reef flat and 20 km across a series of reefs. However, the relationship between coral mortality and habitat thermal severity was opposite at the two scales. SSTs in summer 2010 were similar or increased modestly (0.5°C) in the outer and mid reefs relative to 2009. In the inner reef, 2010 temperatures were 1.4°C above the 2009 seasonal maximum for several weeks. We detected little or no coral mortality in mid and outer reefs. In the inner reef, mortality depended on exposure. Within the inner reef, mortality was modest on the protected (shoreward) side, the most severe thermal environment, with highest overall mean and maximum temperatures. In contrast, acute mortality was observed in the exposed (seaward) side, where temperature fluctuations and upper water temperature values were relatively less extreme. Refuges to thermally induced coral bleaching may include sites where extreme, high-frequency thermal variability may select for coral holobionts preadapted to, and physiologically condition corals to withstand, regional increases in water temperature.

  15. Two cold-sensitive neurons within one sensillum code for different parameters of the thermal environment in the ant Camponotus rufipes.

    Science.gov (United States)

    Nagel, Manuel; Kleineidam, Christoph J

    2015-01-01

    Ants show high sensitivity when responding to minute temperature changes and are able to track preferred temperatures with amazing precision. As social insects, they have to detect and cope with thermal fluctuations not only for their individual benefit but also for the developmental benefit of the colony and its brood. In this study we investigate the sensory basis for the fine-tuned, temperature guided behaviors found in ants, specifically what information about their thermal environment they can assess. We describe the dose-response curves of two cold-sensitive neurons, associated with the sensillum coelocapitulum on the antenna of the carpenter ant Camponotus rufipes.One cold-sensitive neuron codes for temperature changes, thus functioning as a thermal flux-detector. Neurons of such type continuously provide the ant with information about temperature transients (TT-neuron). The TT-neurons are able to resolve a relative change of 37% in stimulus intensity (ΔT) and antennal scanning of the thermal environment may aid the ant's ability to use temperature differences for orientation.The second cold-sensitive neuron in the S. coelocapitulum responds to temperature only within a narrow temperature range. A temperature difference of 1.6°C can be resolved by this neuron type. Since the working range matches the preferred temperature range for brood care of Camponotus rufipes, we hypothesize that this temperature sensor can function as a thermal switch to trigger brood care behavior, based on absolute (steady state) temperature.

  16. Extremophiles and extreme environments

    National Research Council Canada - National Science Library

    Rampelotto, Pabulo Henrique

    2013-01-01

    Over the last decades, the study of extremophiles has providing ground breaking discoveries that challenge the paradigms of modern biology and make us rethink intriguing questions such as "what is life...

  17. Dormant stages of crustaceans as a mechanism of propagation in the extreme and unpredictable environment in the Crimean hypersaline lakes

    Science.gov (United States)

    Shadrin, Nickolai V.; Anufriieva, Elena V.; Amat, Francisco; Eremin, Oleg Yu.

    2015-11-01

    A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities; we need to take it into account to understand plankton dynamics. Hypersaline water bodies in Crimea, the largest peninsula in the Black Sea, constitute a very characteristic and peculiar habitat type in the region. We examined the presence of crustacean resting stages in sediments of dried up sites of the Crimean hypersaline lakes. Sediment samples were taken in 9 different lakes. Experiments performed on the hatching of these resting stages showed the presence of Moina salina (Cladocera), parthenogenetic Artemia and Artemia urmiana (Anostraca), Eucypris mareotica ( inflata) (Ostracoda), and Cletocamptus retrogressus (Harpacticoida). Comparing the experimental results obtained with clean dried brine shrimp cysts and those kept in sediment samples, it was noted that clean cysts hatched much faster than those from sediments did. Some components in bottom sediments slow down and desynchronize hatching from resting eggs in different groups of crustaceans. The sediments of different lakes inhibited the nauplii output from Artemia and ostracod resting eggs to different degrees. More data are needed before we can discuss the reasons of this inhibition. The nonsynchronous output of active stages from the bottom resting ones may be an adaptation that allows crustacean species to exist in extreme and unpredictably changing environments, avoiding the risk that all may emerge at once under unsuitable conditions.

  18. Understanding the Adaptation of Halobacterium Species NRC-1 to Its Extreme Environment through Computational Analysis of Its Genome Sequence

    Science.gov (United States)

    Kennedy, Sean P.; Ng, Wailap Victor; Salzberg, Steven L.; Hood, Leroy; DasSarma, Shiladitya

    2001-01-01

    The genome of the halophilic archaeon Halobacterium sp. NRC-1 and predicted proteome have been analyzed by computational methods and reveal characteristics relevant to life in an extreme environment distinguished by hypersalinity and high solar radiation: (1) The proteome is highly acidic, with a median pI of 4.9 and mostly lacking basic proteins. This characteristic correlates with high surface negative charge, determined through homology modeling, as the major adaptive mechanism of halophilic proteins to function in nearly saturating salinity. (2) Codon usage displays the expected GC bias in the wobble position and is consistent with a highly acidic proteome. (3) Distinct genomic domains of NRC-1 with bacterial character are apparent by whole proteome BLAST analysis, including two gene clusters coding for a bacterial-type aerobic respiratory chain. This result indicates that the capacity of halophiles for aerobic respiration may have been acquired through lateral gene transfer. (4) Two regions of the large chromosome were found with relatively lower GC composition and overrepresentation of IS elements, similar to the minichromosomes. These IS-element-rich regions of the genome may serve to exchange DNA between the three replicons and promote genome evolution. (5) GC-skew analysis showed evidence for the existence of two replication origins in the large chromosome. This finding and the occurrence of multiple chromosomes indicate a dynamic genome organization with eukaryotic character. PMID:11591641

  19. Comparing the Consumption of CPU Hours with Scientific Output for the Extreme Science and Engineering Discovery Environment (XSEDE).

    Science.gov (United States)

    Knepper, Richard; Börner, Katy

    2016-01-01

    This paper presents the results of a study that compares resource usage with publication output using data about the consumption of CPU cycles from the Extreme Science and Engineering Discovery Environment (XSEDE) and resulting scientific publications for 2,691 institutions/teams. Specifically, the datasets comprise a total of 5,374,032,696 central processing unit (CPU) hours run in XSEDE during July 1, 2011 to August 18, 2015 and 2,882 publications that cite the XSEDE resource. Three types of studies were conducted: a geospatial analysis of XSEDE providers and consumers, co-authorship network analysis of XSEDE publications, and bi-modal network analysis of how XSEDE resources are used by different research fields. Resulting visualizations show that a diverse set of consumers make use of XSEDE resources, that users of XSEDE publish together frequently, and that the users of XSEDE with the highest resource usage tend to be "traditional" high-performance computing (HPC) community members from astronomy, atmospheric science, physics, chemistry, and biology.

  20. Nutritional status changes in humans during a 14-day saturation dive: the NASA Extreme Environment Mission Operations V project

    Science.gov (United States)

    Smith, Scott M.; Davis-Street, Janis E.; Fesperman, J. Vernell; Smith, Myra D.; Rice, Barbara L.; Zwart, Sara R.

    2004-01-01

    Ground-based analogs of spaceflight are an important means of studying physiologic and nutritional changes associated with space travel, and the NASA Extreme Environment Mission Operations V (NEEMO) is such an analog. To determine whether saturation diving has nutrition-related effects similar to those of spaceflight, we conducted a clinical nutritional assessment of the NEEMO crew (4 men, 2 women) before, during, and after their 14-d saturation dive. Blood and urine samples were collected before, during, and after the dive. The foods consumed by the crew were typical of the spaceflight food system. A number of physiologic changes were observed, during and after the dive, that are also commonly observed during spaceflight. Hemoglobin and hematocrit were lower (P < 0.05) after the dive. Transferrin receptors were significantly lower immediately after the dive. Serum ferritin increased significantly during the dive. There was also evidence indicating that oxidative damage and stress increased during the dive. Glutathione peroxidase and superoxide dismutase decreased during and after the dive (P < 0.05). Decreased leptin during the dive (P < 0.05) may have been related to the increased stress. Subjects had decreased energy intake and weight loss during the dive, similar to what is observed during spaceflight. Together, these similarities to spaceflight provide a model to use in further defining the physiologic effects of spaceflight and investigating potential countermeasures.

  1. Silicified virus-like nanoparticles in an extreme thermal environment: implications for the preservation of viruses in the geological record.

    Science.gov (United States)

    Peng, X; Xu, H; Jones, B; Chen, S; Zhou, H

    2013-11-01

    Biofilms that grow around Gumingquan hot spring (T = 71 °C, pH = 9.2) in the Rehai geothermal area, Tengchong, China, are formed of various cyanobacteria, Firmicutes, Aquificae, Thermodesulfobacteria, Desulfurococcales, and Thermoproteales. Silicified virus-like nanoparticles, 40-200 nm in diameter, are common inside the microbial cells and the extracellular polymeric substances around the cells. These nanoparticles, which are formed of a core encased by a silica cortex, are morphologically akin to known viruses and directly comparable to silicified virus-like particles that were produced in biofilms cultured in the laboratory. The information obtained from examination of the natural and laboratory-produced samples suggests that viruses can be preserved by silicification, especially while they are still encased in their host cells. These results expand our views of virus-host mineral interaction in extreme thermal environments and imply that viruses can be potentially preserved and identified in the geological record.

  2. Plant functional traits and phylogenetic relatedness explain variation in associations with root fungal endophytes in an extreme arid environment.

    Science.gov (United States)

    Lugo, Mónica A; Reinhart, Kurt O; Menoyo, Eugenia; Crespo, Esteban M; Urcelay, Carlos

    2015-02-01

    Since root endophytes may ameliorate drought stress, understanding which plants associate with endophytes is important, especially in arid ecosystems. Here, the root endophytes were characterized of 42 plants from an arid region of Argentina. Colonization by arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSEs) was related to plant functional type (PFT), family, and phylogenetic relatedness. Overall, three main findings were observed. Firstly, only moderate levels of endophyte associations were found across all taxa (e.g., most Poaceae were not colonized by endophytes despite numerous accounts of colonization by AMF and DSEs). We determined 69% of plant taxa associated with some form of root endophyte but levels were lower than other regional studies. Secondly, comparisons by PFT and phylogeny were often qualitatively similar (e.g., succulents and Portulacineae consistently lacked AMF; variation occurred among terrestrial vs. epiphytic bromeliads) and often differed from comparisons based on plant family. Thirdly, comparisons by plant family often failed to account for important variation either within families (e.g., Bromeliaceae and Poaceae) or trait conservatism among related families (i.e., Rosidae consistently lacked DSEs and Portulacineae lacked AMF). This study indicates the value of comparing numerous taxa based on PFTs and phylogenetic similarity. Overall, the results suggest an uncertain benefit of endophytes in extremely arid environments where plant traits like succulence may obviate the need to establish associations.

  3. Comparing the Consumption of CPU Hours with Scientific Output for the Extreme Science and Engineering Discovery Environment (XSEDE.

    Directory of Open Access Journals (Sweden)

    Richard Knepper

    Full Text Available This paper presents the results of a study that compares resource usage with publication output using data about the consumption of CPU cycles from the Extreme Science and Engineering Discovery Environment (XSEDE and resulting scientific publications for 2,691 institutions/teams. Specifically, the datasets comprise a total of 5,374,032,696 central processing unit (CPU hours run in XSEDE during July 1, 2011 to August 18, 2015 and 2,882 publications that cite the XSEDE resource. Three types of studies were conducted: a geospatial analysis of XSEDE providers and consumers, co-authorship network analysis of XSEDE publications, and bi-modal network analysis of how XSEDE resources are used by different research fields. Resulting visualizations show that a diverse set of consumers make use of XSEDE resources, that users of XSEDE publish together frequently, and that the users of XSEDE with the highest resource usage tend to be "traditional" high-performance computing (HPC community members from astronomy, atmospheric science, physics, chemistry, and biology.

  4. Reinforced Feedback in Virtual Environment for Rehabilitation of Upper Extremity Dysfunction after Stroke: Preliminary Data from a Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Paweł Kiper

    2014-01-01

    Full Text Available Objectives. To study whether the reinforced feedback in virtual environment (RFVE is more effective than traditional rehabilitation (TR for the treatment of upper limb motor function after stroke, regardless of stroke etiology (i.e., ischemic, hemorrhagic. Design. Randomized controlled trial. Participants. Forty-four patients affected by stroke. Intervention. The patients were randomized into two groups: RFVE (N=23 and TR (N=21, and stratified according to stroke etiology. The RFVE treatment consisted of multidirectional exercises providing augmented feedback provided by virtual reality, while in the TR treatment the same exercises were provided without augmented feedbacks. Outcome Measures. Fugl-Meyer upper extremity scale (F-M UE, Functional Independence Measure scale (FIM, and kinematics parameters (speed, time, and peak. Results. The F-M UE (P=0.030, FIM (P=0.021, time (P=0.008, and peak (P=0.018, were significantly higher in the RFVE group after treatment, but not speed (P=0.140. The patients affected by hemorrhagic stroke significantly improved FIM (P=0.031, time (P=0.011, and peak (P=0.020 after treatment, whereas the patients affected by ischemic stroke improved significantly only speed (P=0.005 when treated by RFVE. Conclusion. These results indicated that some poststroke patients may benefit from RFVE program for the recovery of upper limb motor function. This trial is registered with NCT01955291.

  5. Measurement with verification of stationary signals and noise in extremely quiet environments: measuring below the noise floor.

    Science.gov (United States)

    Ellingson, Roger M; Gallun, Frederick J; Bock, Guillaume

    2015-03-01

    It can be problematic to measure stationary acoustic sound pressure level in any environment when the target level approaches or lies below the minimum measureable sound pressure level of the measurement system itself. This minimum measureable level, referred to as the inherent measurement system noise floor, is generally established by noise emission characteristics of measurement system components such as microphones, preamplifiers, and other system circuitry. In this paper, methods are presented and shown accurate measuring stationary levels within 20 dB above and below this system noise floor. Methodology includes (1) measuring inherent measurement system noise, (2) subtractive energy based, inherent noise adjustment of levels affected by system noise floor, and (3) verifying accuracy of inherent noise adjustment technique. While generalizable to other purposes, the techniques presented here were specifically developed to quantify ambient noise levels in very quiet rooms used to evaluate free-field human hearing thresholds. Results obtained applying the methods to objectively measure and verify the ambient noise level in an extremely quiet room, using various measurement system noise floors and analysis bandwidths, are presented and discussed. The verified results demonstrate the adjustment method can accurately extend measurement range to 20 dB below the measurement system noise floor, and how measurement system frequency bandwidth can affect accuracy of reported noise levels.

  6. Reaction of Basaltic Materials under High-Fidelity Venus Surface Conditions using the Glenn Extreme Environment Rig: First Results

    Science.gov (United States)

    Radoman-Shaw, Brandon; Harvey, Ralph; Costa, Gustavo; Nakley, Leah Michelle; Jacobson, Nathan S.

    2016-01-01

    Both historical and current investigations of Venus suggest that atmosphererock interactions play a critical role in the evolution of its atmosphere and crust. We have begun a series of systematic experiments designed to further our understanding of atmosphere-driven weathering and secondary mineralization of basaltic materials that may be occurring on Venus today. Our experiments expose representative igneous phases (mineral, glasses and rocks) to a high-fidelity simulation of Venus surface conditions using the NASA Glenn Extreme Environment Rig (GEER) located at the NASA Glenn Research Center in Cleveland, Ohio. GEER is a very large (800L) vessel capable of producing a long-term, high fidelity simulation of both the physical conditions (750 K and 92 bar) and atmospheric chemistry (down to the ppb-level) asso-ciated with the Venusian surface. As of this writing we have just finished the first of several planned experiments: a 42-day exposure of selected mineral, rocks and volcanic glasses. Our goal is to identify and prioritize the reactions taking place and better our understanding of their importance in Venus' climate history.

  7. Exascale Co-Design Center for Materials in Extreme Environments (ExMatEx) Annual Report - Year 2

    Energy Technology Data Exchange (ETDEWEB)

    Germann, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Richards, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McPherson, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Belak, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-11-25

    All activities of the Exascale Co-design Center for Materials in Extreme Environments (Ex- MatEx) are focused on the two ultimate goals of the project: (1) demonstrating and delivering a prototype scale-bridging materials science application based upon adaptive physics refinement, and (2) identifying the requirements for the exascale ecosystem that are necessary to perform computational materials science simulations (both single- and multi-scale). During the first year of ExMatEx, our focus was on establishing how we do computational materials science, by developing an initial suite of flexible proxy applications. These “proxy apps” are the primary vehicle for the co-design process, involving assessments and tradeoff evaluations both within the ExMatEx team, and with the entire exascale ecosystem. These interactions have formed the basis of our second year activities. The set of artifacts from these co-design interactions are the lessons learned, that are used to re-express the applications and algorithms within the context of emerging architectures, programming models, and runtime systems.

  8. Cold Urticaria

    Science.gov (United States)

    Diseases and Conditions Cold urticaria By Mayo Clinic Staff Cold urticaria (ur-tih-KAR-e-uh) is a skin reaction to cold. Skin that has ... in contact with cold develops reddish, itchy welts (hives). The severity of cold urticaria symptoms varies widely. ...

  9. The role of crown architecture for light harvesting and carbon gain in extreme light environments assessed with a structurally realistic 3-D model

    OpenAIRE

    2000-01-01

    Main results from different studies of crown architecture adaptation to extreme light environments are presented. Light capture and carbon gain by plants from low (forest understory) and high (open Mediterranean-type ecosystems) light environments were simulated with a 3-D model (YPLANT), which was developed specifically to analyse the structural features that determine light interception and photosynthesis at the whole plant level. Distantly related taxa with contrasting architectures exhibi...

  10. Metagenomic Analysis of Hot Springs in Central India Reveals Hydrocarbon Degrading Thermophiles and Pathways Essential for Survival in Extreme Environments

    Science.gov (United States)

    Saxena, Rituja; Dhakan, Darshan B.; Mittal, Parul; Waiker, Prashant; Chowdhury, Anirban; Ghatak, Arundhuti; Sharma, Vineet K.

    2017-01-01

    Extreme ecosystems such as hot springs are of great interest as a source of novel extremophilic species, enzymes, metabolic functions for survival and biotechnological products. India harbors hundreds of hot springs, the majority of which are not yet explored and require comprehensive studies to unravel their unknown and untapped phylogenetic and functional diversity. The aim of this study was to perform a large-scale metagenomic analysis of three major hot springs located in central India namely, Badi Anhoni, Chhoti Anhoni, and Tattapani at two geographically distinct regions (Anhoni and Tattapani), to uncover the resident microbial community and their metabolic traits. Samples were collected from seven distinct sites of the three hot spring locations with temperature ranging from 43.5 to 98°C. The 16S rRNA gene amplicon sequencing of V3 hypervariable region and shotgun metagenome sequencing uncovered a unique taxonomic and metabolic diversity of the resident thermophilic microbial community in these hot springs. Genes associated with hydrocarbon degradation pathways, such as benzoate, xylene, toluene, and benzene were observed to be abundant in the Anhoni hot springs (43.5–55°C), dominated by Pseudomonas stutzeri and Acidovorax sp., suggesting the presence of chemoorganotrophic thermophilic community with the ability to utilize complex hydrocarbons as a source of energy. A high abundance of genes belonging to methane metabolism pathway was observed at Chhoti Anhoni hot spring, where methane is reported to constitute >80% of all the emitted gases, which was marked by the high abundance of Methylococcus capsulatus. The Tattapani hot spring, with a high-temperature range (61.5–98°C), displayed a lower microbial diversity and was primarily dominated by a nitrate-reducing archaeal species Pyrobaculum aerophilum. A higher abundance of cell metabolism pathways essential for the microbial survival in extreme conditions was observed at Tattapani. Taken together

  11. Diamond-Dispersed Fiber-Reinforced Composite for Superior Friction and Wear Properties in Extreme Environments and Method for Fabricating the Same

    Science.gov (United States)

    Street, Kenneth (Inventor); Voronov, Oleg A (Inventor); Kear, Bernard H (Inventor)

    2017-01-01

    Systems, methods, and articles of manufacture related to composite materials are discussed herein. These materials can be based on a mixture of diamond particles with a matrix and fibers or fabrics. The matrix can be formed into the composite material through optional pressurization and via heat treatment. These materials display exceptionally low friction coefficient and superior wear resistance in extreme environments.

  12. Attacking the Mobile Ballistic Missile Threat in the Post-Cold War Environment. New Rules to an Old Game

    Science.gov (United States)

    2006-05-01

    and other moving target indicator (MTI) platforms, such as the Army’s OV-1D Mohawk , tracked the movement of Iraqi logistics/supply units through... society of the nation that initiated the attack. A balance and understanding had been reached that would govern the Cold War period. The anxiety of...Donald R. Baucom, The Origins of SDI: 1944–1983 (Lawrence, Kans.: University Press of Kansas, 1992); William J. Broad, Star Warriors : A Penetrating Look

  13. Archaeal Haloarcula californiae Icosahedral Virus 1 Highlights Conserved Elements in Icosahedral Membrane-Containing DNA Viruses from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Tatiana A. Demina

    2016-07-01

    Full Text Available Despite their high genomic diversity, all known viruses are structurally constrained to a limited number of virion morphotypes. One morphotype of viruses infecting bacteria, archaea, and eukaryotes is the tailless icosahedral morphotype with an internal membrane. Although it is considered an abundant morphotype in extreme environments, only seven such archaeal viruses are known. Here, we introduce Haloarcula californiae icosahedral virus 1 (HCIV-1, a halophilic euryarchaeal virus originating from salt crystals. HCIV-1 also retains its infectivity under low-salinity conditions, showing that it is able to adapt to environmental changes. The release of progeny virions resulting from cell lysis was evidenced by reduced cellular oxygen consumption, leakage of intracellular ATP, and binding of an indicator ion to ruptured cell membranes. The virion contains at least 12 different protein species, lipids selectively acquired from the host cell membrane, and a 31,314-bp-long linear double-stranded DNA (dsDNA. The overall genome organization and sequence show high similarity to the genomes of archaeal viruses in the Sphaerolipoviridae family. Phylogenetic analysis based on the major conserved components needed for virion assembly—the major capsid proteins and the packaging ATPase—placed HCIV-1 along with the alphasphaerolipoviruses in a distinct, well-supported clade. On the basis of its virion morphology and sequence similarities, most notably, those of its core virion components, we propose that HCIV-1 is a member of the PRD1-adenovirus structure-based lineage together with other sphaerolipoviruses. This addition to the lineage reinforces the notion of the ancient evolutionary links observed between the viruses and further highlights the limits of the choices found in nature for formation of a virion.

  14. Extreme environments in the critical zone: Linking acidification hazard of acid sulfate soils in mound spring discharge zones to groundwater evolution and mantle degassing.

    Science.gov (United States)

    Shand, Paul; Gotch, Travis; Love, Andrew; Raven, Mark; Priestley, Stacey; Grocke, Sonia

    2016-10-15

    A decrease in flow from the iconic travertine mound springs of the Great Artesian Basin in South Australia has led to the oxidation of hypersulfidic soils and extreme soil acidification, impacting their unique groundwater dependent ecosystems. The build-up of pyrite in these systems occurred over millennia by the discharge of deep artesian sulfate-containing groundwaters through organic-rich subaqueous soils. Rare iron and aluminium hydroxysulfate minerals form thick efflorescences due to high evaporation rates in this arid zone environment, and the oxidised soils pose a significant risk to local aquatic and terrestrial ecosystems. The distribution of extreme acidification hazard is controlled by regional variations in the hydrochemistry of groundwater. Geochemical processes fractionate acidity and alkalinity into separate parts of the discharge zone allowing potentially extreme environments to form locally. Differences in groundwater chemistry in the aquifer along flow pathways towards the spring discharge zone are related to a range of processes including mineral dissolution and redox reactions, which in turn are strongly influenced by degassing of the mantle along deep crustal fractures. There is thus a connection between shallow critical zone ecosystems and deep crustal/mantle processes which ultimately control the formation of hypersulfidic soils and the potential for extreme geochemical environments.

  15. Two cold-sensitive neurons within one sensillum code for different parameters of the thermal environment in the ant Camponotus rufipes

    Directory of Open Access Journals (Sweden)

    Manuel eNagel

    2015-09-01

    Full Text Available Ants show high sensitivity when responding to minute temperature changes and are able to track preferred temperatures with amazing precision. As social insects, they have to detect and cope with thermal fluctuations not only for their individual benefit but also for the developmental benefit of the colony and its brood. In this study we investigate the sensory basis for the fine-tuned, temperature guided behaviors found in ants, specifically what information about their thermal environment they can assess. We describe the dose-response curves of two cold-sensitive neurons, associated with the sensillum coelocapitulum on the antenna of the carpenter ant Camponotus rufipes.One cold-sensitive neuron codes for temperature changes, thus functioning as a thermal flux-detector. Neurons of such type continuously provide the ant with information about temperature transients (TT-neuron. The TT-neurons are able to resolve a relative change of 37% in stimulus intensity (ΔT and antennal scanning of the thermal environment may aid the ant’s ability to use temperature differences for orientation.The second cold-sensitive neuron in the S. coelocapitulum responds to temperature only within a narrow temperature range. A temperature difference of 1.6°C can be resolved by this neuron type. Since the working range matches the preferred temperature range for brood care of Camponotus rufipes, we hypothesize that this temperature sensor can function as a thermal switch to trigger brood care behavior, based on absolute (steady state temperature.

  16. Multidimensional extremal dependence coefficients

    OpenAIRE

    2017-01-01

    Extreme values modeling has attracting the attention of researchers in diverse areas such as the environment, engineering, or finance. Multivariate extreme value distributions are particularly suitable to model the tails of multidimensional phenomena. The analysis of the dependence among multivariate maxima is useful to evaluate risk. Here we present new multivariate extreme value models, as well as, coefficients to assess multivariate extremal dependence.

  17. Analysis of Source-to-Sink-Fluxes and Sediment Budgets in Changing High-Latitude and High-Altitude Cold Environments: SEDIFLUX Manual

    Energy Technology Data Exchange (ETDEWEB)

    Beylich, Achim A.; Warburton, Jeff

    2007-07-01

    This First Edition of the SEDIFLUX Manual is an outcome of the European Science Foundation (ESF) Network SEDIFLUX - Sedimentary Source-to-Sink-Fluxes in Cold Environments (2004 - 2006) (http://www.ngu.no/sediflux, http://www.esf.org/sediflux). The development of this publication has been based on four ESF SEDIFLUX Science Meetings, which were held in Saudarkrokur (Iceland), June 18. - 21., 2004, Clermont-Ferrand (France), January 20. - 22., 2005, Durham (UK), December 16. - 19., 2005 and Trondheim (Norway), October 29. - November 2., 2006. The aim of this Manual is to provide guidance on developing quantitative frameworks for characterising catchment (field-based) sediment budget studies, so that: (1) baseline measurements at SEDIFLUX/SEDIBUD key test catchments are standardised thus enabling intersite comparisons, and (2) long-term changes in catchment geosystems as related to climate change are well documented. The main focus is on non-glacial processes, although within the context of glacierised catchments glacial sediment transfer processes are assumed as inputs/outputs of the periglacial / paraglacial system. This First Edition of the SEDIFLUX Manual will be further developed within the I.A.G./A.I.G. Working Group SEDIBUD - Sediment Budgets in Cold Environments (http://www.geomorph.org/wg/wgsb.html).(auth)

  18. Response of the Gulf of Mexico to an Extreme Cold Front: A Numerical Study of the October 23-November 1, 2007 Event

    Science.gov (United States)

    Zavala-Hidalgo, J.

    2016-12-01

    The dynamic response of the Gulf of Mexico to an intense cold front that occurred in October 23, 2007 is studied by a numerical simulation. The ocean model was forced by hourly fields and obtained from a simulation using the Weather, Research and Forecasting Model (WRF). The model simulation was performed with the Navy Coastal Ocean Model (NCOM). Results show processes in different time and space scales on the shelves and deep waters. Initially strong surface currents are generated near the surface with a westward and southwestward transport, these currents piles water on the shelves and deepens the thermocline over the slope generating coastal trapped waves (CTW) that travel at different speeds on the shelves as barotropic CTW and over the slope as baroclinc CTW. A subsurface northward current along the Campeche escarpment is developed which turn eastward in the northern tip of the escarpment. In addition strong inertial oscillations develop mainly on the Bay of Campeche.

  19. Research Progress of Adaptation Mechanism and Application of Extreme Microbes Toward Extreme Environment%极端微生物对极端环境的适应机理及应用研究进展

    Institute of Scientific and Technical Information of China (English)

    孟素香; 曹健

    2014-01-01

    Extreme microbes grow in the extreme environments,so they must own special cell structure,physiological mechanism and gene etc.In this paper,the latest studies on the survival mechanism,classification and application of six kinds of extreme microbes were reviewed,which can provide some theoretical basis for utilization and metabolites exploitation of extreme microbes strains resource.%极端微生物在极端环境中生长繁殖,其必然有适应恶劣环境下的特殊细胞结构、生理机制、遗传基因等。对近几年的六大类极端微生物在分类、生存机制和应用方面的最新研究进展进行综述,为极端微生物菌种资源利用及代谢产物开发提供了一些理论依据。

  20. The DYNAFLUX / DYNACOLD (Dynamics, Fluxes, Stability, Succession and Landscape Formation in Cold Environments) Network (2004-2017)

    Science.gov (United States)

    Beylich, Achim A.

    2017-04-01

    There is a wide range of high-latitude and high-altitude cold climate landscapes within Europe, covering a significant proportion of the total land surface area. This spectrum of defined cold-climate landscapes represents a variety of stages of deglaciation history and landscape formation. We can find landscapes at different levels of postglacial stabilization which is providing the unique opportunity to study the interactions between geo-, bio-, social and socio-economic systems at the land surface. The DYNAFLUX / DYNACOLD Network (2004-2017) bridges across the geo-, bio-, social and socio-economic sciences in order to analyze the complex dynamics of adjustment, stabilization, succession and landscape formation during and after ice retreat and under ongoing anthropogenic influences. The network provides a multidisciplinary forum where researchers come together and discuss. In addition, this network is linking a number of other scientific networks, working groups and programs and creates an umbrella network and a forum for sharing knowledge and experience. The scientific focus of DYNAFLUX / DYNACOLD is also relevant for a number of end users, including risk and vulnerability assessment, sustainable land use, land management and conservation. In addition, present key questions related to environmental change like, e.g., hazards, permafrost degradation and loss of biodiversity are addressed and discussed. Further information is found under http://www.ngu.no/sediflux.

  1. The early diagenetic and PETROphysical behaviour of recent cold-water CARbonate mounds in Deep Environments (PETROCARDE)

    Science.gov (United States)

    Foubert, Anneleen; Pirlet, Hans; Thierens, Mieke; de Mol, Ben; Henriet, Jean-Pierre; Swennen, Rudy

    2010-05-01

    Sub-recent cold-water carbonate mounds localized in deeper slope settings on the Atlantic continental margins cannot be any longer neglected in the study of carbonate systems. They clearly play a major role in the dynamics of mixed siliciclastic-carbonate and/or carbonate-dominated continental slopes. Carbonate accumulation rates of cold-water carbonate mounds are about 4 to 12 % of the carbonate accumulation rates of tropical shallow-water reefs but exceed the carbonate accumulation rates of their slope settings by a factor of 4 to 12 (Titschack et al., 2009). These findings emphasize the importance of these carbonate factories as carbonate niches on the continental margins. The primary environmental architecture of such carbonate bodies is well-characterized. However, despite proven evidences of early diagenesis overprinting the primary environmental record (e.g. aragonite dissolution) (Foubert & Henriet, 2009), the extent of early diagenetic and biogeochemical processes shaping the petrophysical nature of mounds is until now not yet fully understood. Understanding (1) the functioning of a carbonate mound as biogeochemical reactor triggering early diagenetic processes and (2) the impact of early diagenesis on the petrophysical behaviour of a carbonate mound in space and through time are necessary (vital) for the reliable prediction of potential late diagenetic processes. Approaching the fossil carbonate mound record, through a profound study of recent carbonate bodies is innovative and will help to better understand processes observed in the fossil mound world (such as cementation, brecciation, fracturing, etc…). In this study, the 155-m high Challenger mound (Porcupine Seabight, SW of Ireland), drilled during IODP Expedition 307 aboard the R/V Joides Resolution (Foubert & Henriet, 2009), and mounds from the Gulf of Cadiz (Moroccan margin) will be discussed in terms of early diagenetic processes and petrophysical behaviour. Early differential diagenesis

  2. A Motor Drive Electronics Assembly for Mars Curiosity Rover: An Example of Assembly Qualification for Extreme Environments

    Science.gov (United States)

    Kolawa, Elizabeth; Chen, Yuan; Mojarradi, Mohammad M.; Tudryn Weber, Carissa

    2013-01-01

    In this paper, the technology development and infusion of the motor drive electronics assembly, along with the technology qualification and space qualification, is described and detailed. The process is an example of the qualification methodology for extreme environmen

  3. Structural and Mechanical Characterization of Nanocrystalline Tungsten and Tungsten-Based Alloy Thin Films for Extreme Environment Applications

    Science.gov (United States)

    Martinez, Gustavo

    Extreme environments associated with nuclear applications often results in degradation of the physical, mechanical and thermo-mechanical properties of the materials. Tungsten (W) exhibits unique physical and mechanical properties, which makes tungsten a good candidate for nuclear applications; however, intrinsic W exhibits low fracture toughness at all temperatures in addition to a high ductile to brittle transition. In the present work, nanocrystalline W, W-Y and W-Mo alloys were nanoengineered for nuclear applications. Nanocrystalline tungsten coatings with a thickness of 1 microm were deposited onto Silicon (100) and Sapphire (C-plane) using RF and DC sputtering techniques under various growth conditions. Yttrium content in W-Y alloys has been varied to enhance the irradiation tolerance under optimum concentration. The W, W-Y coatings were characterized to understand the structure and morphology and to establish a mapping of conditions to obtain phase and size controlled materials. The samples were then subjected to depth-controlled irradiation by neutrons and Au3+ ions. Solid solution strengthening was achieved by doping molybdenum (Mo) solute atoms to W matrix under varied sputtering pressures and temperatures with the intention of creating interstitial point defects in the crystals that impede dislocation motion, increasing the hardness and young modulus of the material. The effect of PAr (3-19 mTorr) was also investigated and associated microstructure are significant on the mechanical characteristics; the hardness (H) and modulus of elasticity (Er) of the nc W-Mo thin films were higher at lower pressures but decreases continuously with increasing PAr. Using nano-indentation and nano-scratch technique, mechanical characterization testing was performed before and after irradiation. The structure, mechanics and irradiation stability of the W and W-Y coatings will be presented and discussed to demonstrate that Y-addition coupled with nano-scale features

  4. Remote, Real-time Investigations of Extreme Environments Using High Power and Bandwidth Cabled Observatories: The OOI Regional Scale Nodes

    Science.gov (United States)

    Kelley, D. S.; Delaney, J. R.

    2012-12-01

    Methane hydrate deposits and hydrothermal vents are two of the most extreme environments on Earth. Seismic events and flow of gases from the seafloor support and modulate novel microbial communities within these systems. Although studied intensely for several decades, significant questions remain about the flux of heat, volatiles and microbial material from the subsurface to the hydrosphere in these dynamic environments. Quantification of microbial communities, their structure and abundances, and metabolic activities is in an infant state. To better understand these systems, the National Science Foundation's Ocean Observatory Initiative has installed high power (8 kW), high bandwidth (10 Gb/s) nodes on the seafloor that provide access to active methane seeps at Southern Hydrate Ridge, and at the most magmatically robust volcano on the Juan de Fuca Ridge - Axial Seamount. The real-time interactive capabilities of the cabled observatory are critical to studying gas-hydrate systems because many of the key processes occur over short time scales. Events such as bubble plume formation, the creation of collapse zones, and increased seepage in response to earthquakes require adaptive response and sampling capabilities. To meet these challenges a suite of instruments will be connected to the cable in 2013. These sensors include full resolution sampling by upward-looking sonars, fluid and gas chemical characterization by mass spectrometers and osmo samplers, long-term duration collection of seep imagery from cameras, and in situ manipulation of chemical sensors coupled with flow meters. In concert, this instrument suite will provide quantification of transient and more stable chemical fluxes. Similarly, at Axial Seamount the high bandwidth and high power fiber optic cables will be used to communicate with and power a diverse array of sensors at the summit of the volcano. Real-time high definition video will provide unprecedented views of macrofaunal and microbial communities

  5. BET surface area distributions in polar stream sediments: Implications for silicate weathering in a cold-arid environment

    Science.gov (United States)

    Marra, Kristen R.; Elwood Madden, Megan E; Soreghan, Gerilyn S.; Hall, Brenda L

    2014-01-01

    BET surface area values are critical for quantifying the amount of potentially reactive sediments available for chemical weathering and ultimately, prediction of silicate weathering fluxes. BET surface area values of fine-grained (glacier surfaces, where dust is trapped and subsequently liberated during summer melting. Additionally, variations in stream discharge rate, which mobilizes sediment in pulses and influences water:rock ratios, the origin and nature of the underlying drift material, and the contribution of organic acids may play significant roles in the production and mobilization of high-surface area sediment. This study highlights the presence of sediments with high surface area in cold-based glacier systems, which influences models of chemical denudation rates and the impact of glacial systems on the global carbon cycle.

  6. Investigations on the Behavior of HVOF and Cold Sprayed Ni-20Cr Coating on T22 Boiler Steel in Actual Boiler Environment

    Science.gov (United States)

    Bala, Niraj; Singh, Harpreet; Prakash, Satya; Karthikeyan, J.

    2012-01-01

    High temperature corrosion accompanied by erosion is a severe problem, which may result in premature failure of the boiler tubes. One countermeasure to overcome this problem is the use of thermal spray protective coatings. In the current investigation high velocity oxy-fuel (HVOF) and cold spray processes have been used to deposit commercial Ni-20Cr powder on T22 boiler steel. To evaluate the performance of the coatings in actual conditions the bare as well as the coated steels were subjected to cyclic exposures, in the superheater zone of a coal fired boiler for 15 cycles. The weight change and thickness loss data were used to establish kinetics of the erosion-corrosion. X-ray diffraction, surface and cross-sectional field emission scanning electron microscope/energy dispersive spectroscopy (FE-SEM/EDS) and x-ray mapping techniques were used to analyse the as-sprayed and corroded specimens. The HVOF sprayed coating performed better than its cold sprayed counterpart in actual boiler environment.

  7. The state of the warm and cold gas in the extreme starburst at the core of the Phoenix galaxy cluster (SPT-CLJ2344-4243)

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Michael; Bautz, Marshall W. [Kavli Institute for Astrophysics and Space Research, MIT, Cambridge, MA 02139 (United States); Swinbank, Mark; Edge, Alastair C.; Hogan, Michael T. [Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Wilner, David J.; Bayliss, Matthew B. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Veilleux, Sylvain [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Benson, Bradford A. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Marrone, Daniel P. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); McNamara, Brian R. [Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Wei, Lisa H., E-mail: mcdonald@space.mit.edu [Atmospheric and Environmental Research, 131 Hartwell Avenue, Lexington, MA 02421 (United States)

    2014-03-20

    We present new optical integral field spectroscopy (Gemini South) and submillimeter spectroscopy (Submillimeter Array) of the central galaxy in the Phoenix cluster (SPT-CLJ2344-4243). This cluster was previously reported to have a massive starburst (∼800 M {sub ☉} yr{sup –1}) in the central, brightest cluster galaxy, most likely fueled by the rapidly cooling intracluster medium. These new data reveal a complex emission-line nebula, extending for >30 kpc from the central galaxy, detected at [O II]λλ3726, 3729, [O III]λλ4959, 5007, Hβ, Hγ, Hδ, [Ne III]λ3869, and He II λ4686. The total Hα luminosity, assuming Hα/Hβ = 2.85, is L {sub Hα} = 7.6 ± 0.4 ×10{sup 43} erg s{sup –1}, making this the most luminous emission-line nebula detected in the center of a cool core cluster. Overall, the relative fluxes of the low-ionization lines (e.g., [O II], Hβ) to the UV continuum are consistent with photoionization by young stars. In both the center of the galaxy and in a newly discovered highly ionized plume to the north of the galaxy, the ionization ratios are consistent with both shocks and active galactic nucleus (AGN) photoionization. We speculate that this extended plume may be a galactic wind, driven and partially photoionized by both the starburst and central AGN. Throughout the cluster we measure elevated high-ionization line ratios (e.g., He II/Hβ, [O III]/Hβ), coupled with an overall high-velocity width (FWHM ≳ 500 km s{sup –1}), suggesting that shocks are likely important throughout the interstellar medium of the central galaxy. These shocks are most likely driven by a combination of stellar winds from massive young stars, core-collapse supernovae, and the central AGN. In addition to the warm, ionized gas, we detect a substantial amount of cold, molecular gas via the CO(3-2) transition, coincident in position with the galaxy center. We infer a molecular gas mass of M{sub H{sub 2}} = 2.2 ± 0.6 × 10{sup 10} M {sub ☉}, which implies that

  8. Spatiotemporal variability of extreme temperature frequency and amplitude in China

    Science.gov (United States)

    Zhang, Yuanjie; Gao, Zhiqiu; Pan, Zaitao; Li, Dan; Huang, Xinhui

    2017-03-01

    Temperature extremes in China are examined based on daily maximum and minimum temperatures from station observations and multiple global climate models. The magnitude and frequency of extremes are expressed in terms of return values and periods, respectively, estimated by the fitted Generalized Extreme Value (GEV) distribution of annual extreme temperatures. The observations suggest that changes in temperature extremes considerably exceed changes in the respective climatological means during the past five decades, with greater amplitude of increases in cold extremes than in warm extremes. The frequency of warm (cold) extremes increases (decreases) over most areas, with an increasingly faster rate as the extremity level rises. Changes in warm extremes are more dependent on the varying shape of GEV distribution than the location shift, whereas changes in cold extremes are more closely associated with the location shift. The models simulate the overall pattern of temperature extremes during 1961-1981 reasonably well in China, but they show a smaller asymmetry between changes in warm and cold extremes primarily due to their underestimation of increases in cold extremes especially over southern China. Projections from a high emission scenario show the multi-model median change in warm and cold extremes by 2040 relative to 1971 will be 2.6 °C and 2.8 °C, respectively, with the strongest changes in cold extremes shifting southward. By 2040, warm extremes at the 1971 20-year return values would occur about every three years, while the 1971 cold extremes would occur once in > 500 years.

  9. Understanding Adaptive Capacity in Real Estate and the Built Environment: Climate Change and Extreme Weather in New York City

    NARCIS (Netherlands)

    Keenan, J.M.

    2016-01-01

    With climate change well underway, cities worldwide are struggling to develop and apply knowledge that will help advance social, environmental and economic adaptation to extreme weather and changing ecologies. Nowhere is this need more pressing than in the design, development and management of the b

  10. Cryptic species of deep-sea clams (Mollusca: Bivalvia: Vesicomyidae) from hydrothermal vent and cold-water seep environments

    Science.gov (United States)

    Vrijenhoek, Robert C.; Schutz, Steven J.; Gustafson, Richard G.; Lutz, Richard A.

    1994-08-01

    A protein-electrophoretic analysis of six putative morphospecies in the bivalve family Vesicomyidae from eight deep-sea hydrothermal vent sites in the eastern Pacific, three cold-water seep sites in the eastern Pacific and the Gulf of Mexico, and one whale-carcass site off Southern California revealed electromorph patterns diagnostic of 10 vesicomyid species. Electrophoretic patterns for 14 enzymes encoded by 17 presumptive gene loci were scored in all 10 species. The pairwise genetic distances (Nei's D) for these 10 species ranged from 0.857 to 2.792, values within the range expected for distinct species and genera. However, the degree of genetic divergence among these taxa could not be used for phylogenetic inferences because allozyme differences had in many cases reached evolutionary saturation. Notwithstanding, the present results revealed a significant problem with current morphospecies identifications of these clams and with applications of the current generic names Calyptogena and Vesicomya. Given the cryptic nature of these taxa, we suggest that subsequent studies simply refer to these clams as "vesicomyids" until careful morphological analyses and molecular studies are completed and systematic relationships are clarified.

  11. Pectinolytic yeasts from cold environments: novel findings of Guehomyces pullulans, Cystofilobasidium infirmominiatum and Cryptococcus adeliensis producing pectinases.

    Science.gov (United States)

    Cavello, Ivana; Albanesi, Agustín; Fratebianchi, Dante; Garmedia, Gabriela; Vero, Silvana; Cavalitto, Sebastián

    2017-03-01

    One hundred and three yeasts isolated from soil samples from King George Island and Tierra del Fuego province were screened in relation with their capability to produce pectinolytic enzymes. Although all the yeasts showed well-developed colonies at 20 °C, only eight showed a clear halo around the colony, indicative of pectin degradation. A secondary screening demonstrated that only four yeasts were capable to produce pectinases at low temperatures (8 °C). It could be seen that the selected yeasts were able to grow and produce high levels of polygalacturonase activity when submerged fermentations were performed using pectin-containing fruit wastes as substrates. None of the strains produced neither lyase nor rhamnogalacturonan hydrolase activities. Regarding pectin esterase activity, it was only produced in lower amounts by G. pullulans 8E (0.022 U ml(-1)). A TLC analysis of the substrate cleavage pattern of the pectinolytic systems was consistent with an endo-type activity. The clarification of apple juice was only accomplished by G. pullulans pectinolytic system, with a clarification of 80% (%T650) using 4 U/ml of enzyme at 20 °C. As far as we concern this work describes for the first time the production of pectinases by the cold-adapted yeasts species Cystofilobasidium infirmominiatum, Cryptococcus adeliensis and G. pullulans.

  12. PdBI Cold Dust Imaging of Two Extremely Red H-[4.5]>4 Galaxies Discovered with SEDS and CANDELS

    CERN Document Server

    Caputi, Karina I; Krips, Melanie; Geach, James E; Ashby, Matthew L N; Huang, Jiasheng; Fazio, Giovanni G; Koekemoer, Anton M; Popping, Gergo; Spaans, Marco; Castellano, Marco; Dunlop, James S; Fontana, Adriano; Santini, Paola

    2014-01-01

    We report Plateau de Bure Interferometer (PdBI) 1.1 mm continuum imaging towards two extremely red H-[4.5]>4 (AB) galaxies at z>3, which we have previously discovered making use of Spitzer SEDS and Hubble Space Telescope (HST) CANDELS ultra-deep images of the UDS field. One of our objects is detected on the PdBI map with a 4.3 sigma significance, corresponding to Snu(1.1mm)=(0.78 +/- 0.18) mJy. By combining this detection with the Spitzer 8 and 24 micron photometry for this source, and SCUBA2 flux density upper limits, we infer that this galaxy is a composite active galactic nucleus (AGN)/star-forming system. The infrared (IR)-derived star formation rate is SFR~(200 +/- 100) Msun/yr, which implies that this galaxy is a higher-redshift analogue of the ordinary ultra-luminous infrared galaxies (ULIRGs) more commonly found at z~2-3. In the field of the other target, we find a tentative 3.1 sigma detection on the PdBI 1.1 mm map, but 3.7 arcsec away of our target position, so it likely corresponds to a different ...

  13. The genome and transcriptome of Trichormus sp. NMC-1: insights into adaptation to extreme environments on the Qinghai-Tibet Plateau

    Science.gov (United States)

    Qiao, Qin; Huang, Yanyan; Qi, Ji; Qu, Mingzhi; Jiang, Chen; Lin, Pengcheng; Li, Renhui; Song, Lirong; Yonezawa, Takahiro; Hasegawa, Masami; Crabbe, M. James C.; Chen, Fan; Zhang, Ticao; Zhong, Yang

    2016-01-01

    The Qinghai-Tibet Plateau (QTP) has the highest biodiversity for an extreme environment worldwide, and provides an ideal natural laboratory to study adaptive evolution. In this study, we generated a draft genome sequence of cyanobacteria Trichormus sp. NMC-1 in the QTP and performed whole transcriptome sequencing under low temperature to investigate the genetic mechanism by which T. sp. NMC-1 adapted to the specific environment. Its genome sequence was 5.9 Mb with a G+C content of 39.2% and encompassed a total of 5362 CDS. A phylogenomic tree indicated that this strain belongs to the Trichormus and Anabaena cluster. Genome comparison between T. sp. NMC-1 and six relatives showed that functionally unknown genes occupied a much higher proportion (28.12%) of the T. sp. NMC-1 genome. In addition, functions of specific, significant positively selected, expanded orthogroups, and differentially expressed genes involved in signal transduction, cell wall/membrane biogenesis, secondary metabolite biosynthesis, and energy production and conversion were analyzed to elucidate specific adaptation traits. Further analyses showed that the CheY-like genes, extracellular polysaccharide and mycosporine-like amino acids might play major roles in adaptation to harsh environments. Our findings indicate that sophisticated genetic mechanisms are involved in cyanobacterial adaptation to the extreme environment of the QTP. PMID:27381465

  14. Twenty-five years of change in scleractinian coral communities of Daya Bay (northern South China Sea)and its response to the 2008 AD extreme cold climate event

    Institute of Scientific and Technical Information of China (English)

    CHEN TianRan; YU KeFu; SHI Qi; LI Shu; Gilbert J. Price; WANG Rong; ZHAO MeiXia; CHEN TeGu; ZHAO JianXin

    2009-01-01

    taking into account additional factors,we hypothesize that direct anthropogenic impacts, rather than climatic events, have both restricted the development, and drove the decline, of Daya Bay coral communities in the last 15 years. The Daya Bay has also been subjected to occasional extreme cold events during the past 50 years, with the most recent occurring in early 2008 (13 January-13 February). During the 2008 cold event, the lowest air temperature reaches only 6.6℃, and the mean sea surface temperature for February fall to<14℃, in-cluding six continuous days at 12.3℃. Significantly, the sea surface temperatures fall below the hypothesized critical lower temperature threshold (~13℃) that commonly leads to mass mortality in scleractinian coral communities. Surprisingly, our coral community surveys, conducted both before(August 2007) and after (late February 2008) the extreme 2008 cold event, demonstrate that the Daya Bay coral ecosystems are barely impacted upon during the cold period. Those observations suggest that the Daya Bay scleractinian coral communities have developed adaptations to low sea surface temperatures. Overall, our data support the hypothesis that high-latitude coral communities, such as Daya Bay, have the potential to act as areas of refugia for scieractinian corals in the advent of potential future global warming.

  15. Common Cold

    Science.gov (United States)

    ... nose, coughing - everyone knows the symptoms of the common cold. It is probably the most common illness. In the course of a year, people ... avoid colds. There is no cure for the common cold. For relief, try Getting plenty of rest ...

  16. PdBI cold dust imaging of two extremely red H – [4.5] > 4 galaxies discovered with SEDS and CANDELS

    Energy Technology Data Exchange (ETDEWEB)

    Caputi, K. I.; Popping, G.; Spaans, M. [Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700 AV Groningen (Netherlands); Michałowski, M. J.; Dunlop, J. S. [SUPA, Institute for Astronomy, The University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ (United Kingdom); Krips, M. [Institut de Radio Astronomie Millimétrique (IRAM), 300 rue de la Piscine, Domaine Universitaire, F-38406 Saint Martin d' Hères (France); Geach, J. E. [Centre for Astrophysics Research, Science and Technology Research Institute, University of Hertfordshire, Hatfield, AL10 9AB (United Kingdom); Ashby, M. L. N.; Huang, J.-S.; Fazio, G. G. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Koekemoer, A. M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Castellano, M.; Fontana, A.; Santini, P., E-mail: karina@astro.rug.nl [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monteporzio (Italy)

    2014-06-20

    We report Plateau de Bure Interferometer (PdBI) 1.1 mm continuum imaging toward two extremely red H – [4.5] > 4 (AB) galaxies at z > 3, which we have previously discovered making use of Spitzer SEDS and Hubble Space Telescope CANDELS ultra-deep images of the Ultra Deep Survey field. One of our objects is detected on the PdBI map with a 4.3σ significance, corresponding to S{sub ν}(1.1 mm)=0.78±0.18 mJy. By combining this detection with the Spitzer 8 and 24 μm photometry for this source, and SCUBA2 flux density upper limits, we infer that this galaxy is a composite active galactic nucleus/star-forming system. The infrared (IR)-derived star formation rate is SFR ≈ 200 ± 100 M {sub ☉} yr{sup –1}, which implies that this galaxy is a higher-redshift analogue of the ordinary ultra-luminous infrared galaxies more commonly found at z ∼ 2-3. In the field of the other target, we find a tentative 3.1σ detection on the PdBI 1.1 mm map, but 3.7 arcsec away of our target position, so it likely corresponds to a different object. In spite of the lower significance, the PdBI detection is supported by a close SCUBA2 3.3σ detection. No counterpart is found on either the deep SEDS or CANDELS maps, so, if real, the PdBI source could be similar in nature to the submillimeter source GN10. We conclude that the analysis of ultra-deep near- and mid-IR images offers an efficient, alternative route to discover new sites of powerful star formation activity at high redshifts.

  17. In hot and cold water: differential life-history traits are key to success in contrasting thermal deep-sea environments.

    Science.gov (United States)

    Marsh, Leigh; Copley, Jonathan T; Tyler, Paul A; Thatje, Sven

    2015-07-01

    Few species of reptant decapod crustaceans thrive in the cold-stenothermal waters of the Southern Ocean. However, abundant populations of a new species of anomuran crab, Kiwa tyleri, occur at hydrothermal vent fields on the East Scotia Ridge. As a result of local thermal conditions at the vents, these crabs are not restricted by the physiological limits that otherwise exclude reptant decapods south of the polar front. We reveal the adult life history of this species by piecing together variation in microdistribution, body size frequency, sex ratio, and ovarian and embryonic development, which indicates a pattern in the distribution of female Kiwaidae in relation to their reproductive development. High-density 'Kiwa' assemblages observed in close proximity to sources of vent fluids are constrained by the thermal limit of elevated temperatures and the availability of resources for chemosynthetic nutrition. Although adult Kiwaidae depend on epibiotic chemosynthetic bacteria for nutrition, females move offsite after extrusion of their eggs to protect brooding embryos from the chemically harsh, thermally fluctuating vent environment. Consequently, brooding females in the periphery of the vent field are in turn restricted by low-temperature physiological boundaries of the deep-water Southern Ocean environment. Females have a high reproductive investment in few, large, yolky eggs, facilitating full lecithotrophy, with the release of larvae prolonged, and asynchronous. After embryos are released, larvae are reliant on locating isolated active areas of hydrothermal flow in order to settle and survive as chemosynthetic adults. Where the cold water restricts the ability of all adult stages to migrate over long distances, these low temperatures may facilitate the larvae in the location of vent sites by extending the larval development period through hypometabolism. These differential life-history adaptations to contrasting thermal environments lead to a disjunct life history

  18. Influence of recrystallization and environment on tensile behavior of cold-rolled Ni3Al(Zr) alloys

    Institute of Scientific and Technical Information of China (English)

    LI Yu-fang; GUO Jian-ting; SHEN Yi-fu

    2006-01-01

    The effects of recrystallization and environment (vacuum versus air) on tensile properties of B-free Ni3Al (Zr) alloys were investigated. The results indicate that the incompletely recrystallized and stress-relieved specimens show the most desirable ductility and ultimate tensile strength, and that the recrystallization treatment promotes susceptibility to the test environment of the alloys. It is found that the amount of ductile fracture is reduced by air for completely recrystallized specimens. The Auger analyses show that Zr atoms do not segregate to the grain boundaries(GBs) for specimens heat-treated at 1 100 ℃, however Zr atoms segregate to the GBs for specimens heat-treated at 900 ℃. These results imply that Zr-doping cannot suppress environmental embrittlement.

  19. Rain Characteristics and Large-Scale Environments of Precipitation Objects with Extreme Rain Volumes from TRMM Observations

    Science.gov (United States)

    Zhou, Yaping; Lau, William K M.; Liu, Chuntao

    2013-01-01

    This study adopts a "precipitation object" approach by using 14 years of Tropical Rainfall Measuring Mission (TRMM) Precipitation Feature (PF) and National Centers for Environmental Prediction (NCEP) reanalysis data to study rainfall structure and environmental factors associated with extreme heavy rain events. Characteristics of instantaneous extreme volumetric PFs are examined and compared to those of intermediate and small systems. It is found that instantaneous PFs exhibit a much wider scale range compared to the daily gridded precipitation accumulation range. The top 1% of the rainiest PFs contribute over 55% of total rainfall and have 2 orders of rain volume magnitude greater than those of the median PFs. We find a threshold near the top 10% beyond which the PFs grow exponentially into larger, deeper, and colder rain systems. NCEP reanalyses show that midlevel relative humidity and total precipitable water increase steadily with increasingly larger PFs, along with a rapid increase of 500 hPa upward vertical velocity beyond the top 10%. This provides the necessary moisture convergence to amplify and sustain the extreme events. The rapid increase in vertical motion is associated with the release of convective available potential energy (CAPE) in mature systems, as is evident in the increase in CAPE of PFs up to 10% and the subsequent dropoff. The study illustrates distinct stages in the development of an extreme rainfall event including: (1) a systematic buildup in large-scale temperature and moisture, (2) a rapid change in rain structure, (3) explosive growth of the PF size, and (4) a release of CAPE before the demise of the event.

  20. Extinction risk and eco-evolutionary dynamics in a variable environment with increasing frequency of extreme events.

    Science.gov (United States)

    Vincenzi, Simone

    2014-08-06

    One of the most dramatic consequences of climate change will be the intensification and increased frequency of extreme events. I used numerical simulations to understand and predict the consequences of directional trend (i.e. mean state) and increased variability of a climate variable (e.g. temperature), increased probability of occurrence of point extreme events (e.g. floods), selection pressure and effect size of mutations on a quantitative trait determining individual fitness, as well as the their effects on the population and genetic dynamics of a population of moderate size. The interaction among climate trend, variability and probability of point extremes had a minor effect on risk of extinction, time to extinction and distribution of the trait after accounting for their independent effects. The survival chances of a population strongly and linearly decreased with increasing strength of selection, as well as with increasing climate trend and variability. Mutation amplitude had no effects on extinction risk, time to extinction or genetic adaptation to the new climate. Climate trend and strength of selection largely determined the shift of the mean phenotype in the population. The extinction or persistence of the populations in an 'extinction window' of 10 years was well predicted by a simple model including mean population size and mean genetic variance over a 10-year time frame preceding the 'extinction window', although genetic variance had a smaller role than population size in predicting contemporary risk of extinction.

  1. Assessment of the Effects of Cold Work on Crack Initiation in a Light Water Environment Using the Small-Punch Test

    Science.gov (United States)

    Isselin, Jerome; Kai, Akira; Sakaguchi, Kazuhiko; Shoji, Tetsuo

    2008-05-01

    Work hardening induced by manufacturing processes has important consequences for the resistance to the stress corrosion cracking (SCC) of low-carbon stainless steel in high-temperature water conditions. It is of great importance to understand the mechanisms and the factors promoting environmentally assisted cracking in such environments. In this study, the effect of work hardening on 316L austenitic stainless steel was studied using a small-punch SCC test facility applied to miniaturized specimens. Tests were performed in a boiling water reactor (BWR) environment with trapezoidal loading. After the tests, the fracture faces and the surfaces of the samples were examined with a scanning electron microscope (SEM). Focused ion beam (FIB) etching was used to prepare samples for the SEM observations. Identification of the oxide was done using a Raman spectroscope and comparison of the data to reference spectra. The results showed the unfavorable effect of cold rolling against crack initiation. The oxide composition is affected by work hardening. Hence, the ferrous oxide formation is promoted by Fe diffusion caused by the dislocation density increase associated with an active strain during the test.

  2. Extreme rainfall events in karst environments: the case study of September 2014 in the Gargano area (southern Italy)

    Science.gov (United States)

    Martinotti, Maria Elena; Pisano, Luca; Trabace, Maria; Marchesini, Ivan; Peruccacci, Silvia; Rossi, Mauro; Amoruso, Giuseppe; Loiacono, Pierluigi; Vennari, Carmela; Vessia, Giovanna; Parise, Mario; Brunetti, Maria Teresa

    2015-04-01

    In the first week of September 2014, the Gargano Promontory (Apulia, SE Italy) was hit by an extreme rainfall event that caused several landslides, floods and sinkholes. As a consequence of the floods, two people lost their lives and severe socio-economic damages were reported. The highest peaks of rainfall were recorded between September 3rd and 6th at the Cagnano Varano and San Marco in Lamis rain gauges with a maximum daily rainfall (over 230 mm) that is about 30% the mean annual rainfall. The Gargano Promontory is characterized by complex orographic conditions, with the highest elevation of about 1000 m a.s.l. The geological setting consists of different types of carbonate deposits affected by intensive development of karst processes. The morphological and climatic settings of the area, associated with frequent extreme rainfall events can cause various types of geohazards (e.g., landslides, floods, sinkholes). A further element enhancing the natural predisposition of the area to the occurrence of landslides, floods and sinkholes is an intense human activity, characterized by an inappropriate land use and management. In order to obtain consistent and reliable data on the effects produced by the storm, a systematic collection of information through field observations, a critical analysis of newspaper articles and web-news, and a co-operation with the Regional Civil Protection and local geologists started immediately after the event. The information collected has been organized in a database including the location, the occurrence time and the type of geohazard documented with photographs. The September 2014 extreme rainfall event in the Gargano Promontory was also analyzed to validate the forecasts issued by the Italian national early-warning system for rainfall-induced landslides (SANF), developed by the Research Institute for Geo-Hydrological Protection (IRPI) for the Italian national Department for Civil Protection (DPC). SANF compares rainfall measurements and

  3. Short-term, daily exposure to cold temperature may be an efficient way to prevent muscle atrophy and bone loss in a microgravity environment

    Science.gov (United States)

    Deng, Claudia; Wang, Ping; Zhang, Xiangming; Wang, Ya

    2015-04-01

    Microgravity induces less pressure on muscle/bone, which is a major reason for muscle atrophy as well as bone loss. Currently, physical exercise is the only countermeasure used consistently in the U.S. human space program to counteract the microgravity-induced skeletal muscle atrophy and bone loss. However, the routinely almost daily time commitment is significant and represents a potential risk to the accomplishment of other mission operational tasks. Therefore, development of more efficient exercise programs (with less time) to prevent astronauts from muscle atrophy and bone loss are needed. Consider the two types of muscle contraction: exercising forces muscle contraction and prevents microgravity-induced muscle atrophy/bone loss, which is a voluntary response through the motor nervous system; and cold temperature exposure-induced muscle contraction is an involuntary response through the vegetative nervous system, we formed a new hypothesis. The main purpose of this pilot study was to test our hypothesis that exercise at 4 °C is more efficient than at room temperature to prevent microgravity-induced muscle atrophy/bone loss and, consequently reduces physical exercise time. Twenty mice were divided into two groups with or without daily short-term (10 min × 2, at 12 h interval) cold temperature (4 °C) exposure for 30 days. The whole bodyweight, muscle strength and bone density were measured after terminating the experiments. The results from the one-month pilot study support our hypothesis and suggest that it would be reasonable to use more mice, in a microgravity environment and observe for a longer period to obtain a conclusion. We believe that the results from such a study will help to develop efficient exercise, which will finally benefit astronauts' heath and NASA's missions.

  4. Variations of the Stellar Initial Mass Function in the Progenitors of Massive Early-type Galaxies and in Extreme Starburst Environments

    Science.gov (United States)

    Chabrier, Gilles; Hennebelle, Patrick; Charlot, Stéphane

    2014-12-01

    We examine variations of the stellar initial mass function (IMF) in extreme environments within the formalism derived by Hennebelle & Chabrier. We focus on conditions encountered in progenitors of massive early-type galaxies and starburst regions. We show that, when applying the concept of turbulent Jeans mass as the characteristic mass for fragmentation in a turbulent medium, the peak of the IMF in such environments is shifted toward smaller masses, leading to a bottom-heavy IMF, as suggested by various observations. In very dense and turbulent environments, we predict that the high-mass tail of the IMF can become even steeper than the standard Salpeter IMF, with a limit for the power-law exponent α ~= -2.7, in agreement with recent observational determinations. This steepening is a direct consequence of the high densities and Mach values in such regions but also of the time dependence of the fragmentation process, as incorporated in the Hennebelle-Chabrier theory. We provide analytical parameterizations of these IMFs in such environments to be used in galaxy evolution calculations. We also calculate the star-formation rates and the mass-to-light ratios expected under such extreme conditions and show that they agree well with the values inferred in starburst environments and massive high-redshift galaxies. This reinforces the paradigm of star formation as being a universal process, i.e., the direct outcome of gravitationally unstable fluctuations in a density field initially generated by large-scale, shock-dominated turbulence. This globally enables us to infer the variations of the stellar IMF and related properties for atypical galactic conditions.

  5. Variations of the stellar initial mass function in the progenitors of massive early-type galaxies and in extreme starburst environments

    Energy Technology Data Exchange (ETDEWEB)

    Chabrier, Gilles [Ecole Normale Supérieure de Lyon, CRAL, UMR CNRS 5574, F-69364 Lyon Cedex 07 (France); Hennebelle, Patrick [Laboratoire AIM, CEA/IRFU, F-91191 Gif-sur-Yvette Cedex (France); Charlot, Stéphane [UPMC-CNRS, UMR7095, Institut d' Astrophysique de Paris, F-75014 Paris (France)

    2014-12-01

    We examine variations of the stellar initial mass function (IMF) in extreme environments within the formalism derived by Hennebelle and Chabrier. We focus on conditions encountered in progenitors of massive early-type galaxies and starburst regions. We show that, when applying the concept of turbulent Jeans mass as the characteristic mass for fragmentation in a turbulent medium, the peak of the IMF in such environments is shifted toward smaller masses, leading to a bottom-heavy IMF, as suggested by various observations. In very dense and turbulent environments, we predict that the high-mass tail of the IMF can become even steeper than the standard Salpeter IMF, with a limit for the power-law exponent α ≅ –2.7, in agreement with recent observational determinations. This steepening is a direct consequence of the high densities and Mach values in such regions but also of the time dependence of the fragmentation process, as incorporated in the Hennebelle-Chabrier theory. We provide analytical parameterizations of these IMFs in such environments to be used in galaxy evolution calculations. We also calculate the star-formation rates and the mass-to-light ratios expected under such extreme conditions and show that they agree well with the values inferred in starburst environments and massive high-redshift galaxies. This reinforces the paradigm of star formation as being a universal process, i.e., the direct outcome of gravitationally unstable fluctuations in a density field initially generated by large-scale, shock-dominated turbulence. This globally enables us to infer the variations of the stellar IMF and related properties for atypical galactic conditions.

  6. Planck cold clumps in the $\\lambda$ Orionis complex: I. Discovery of an extremely young Class 0 protostellar object and a proto-brown dwarf candidate in a bright rimmed clump PGCC G192.32-11.88

    CERN Document Server

    Liu, Tie; Kim, Kee-Tae; Wu, Yuefang; Lee, Chang Won; Lee, Jeong-Eun; Tatematsu, Kenichi; Choi, Minho; Juvela, Mika; Thompson, Mark; Goldsmith, Paul F; Liu, Sheng-yuan; Naomi, Hirano; Koch, Patrick; Henkel, Christian; Sanhueza, Patricio; He, JinHua; Rivera-Ingraham, Alana; Wang, Ke; Cunningham, Maria R; Tang, Ya-Wen; Lai, Shih-Ping; Yuan, Jinghua; Li, Di; Fuller, Gary; Kang, Miju; Luong, Quang Nguyen; Liu, Hauyu Baobab; Ristorcelli, Isabelle; Yang, Ji; Xu, Ye; Hirota, Tomoya; Mardones, Diego; Qin, Sheng-Li; Chen, Huei-Ru; Kwon, Woojin; Meng, FanYi; Zhang, Huawei; Kim, Mi-Ryang; Yi, Hee-Weon

    2015-01-01

    We are performing a series of observations with ground-based telescopes toward Planck Galactic cold clumps (PGCCs) in the $\\lambda$ Orionis complex in order to systematically investigate the effects of stellar feedback. In the