Science.gov

Sample records for active fire suppression

  1. Fire Suppression and Response

    NASA Technical Reports Server (NTRS)

    Ruff, Gary A.

    2004-01-01

    This report is concerned with the following topics regarding fire suppression:What is the relative effectiveness of candidate suppressants to extinguish a representative fire in reduced gravity, including high-O2 mole fraction, low -pressure environments? What are the relative advantages and disadvantages of physically acting and chemically-acting agents in spacecraft fire suppression? What are the O2 mole fraction and absolute pressure below which a fire cannot exist? What effect does gas-phase radiation play in the overall fire and post-fire environments? Are the candidate suppressants effective to extinguish fires on practical solid fuels? What is required to suppress non-flaming fires (smoldering and deep seated fires) in reduced gravity? How can idealized space experiment results be applied to a practical fire scenario? What is the optimal agent deployment strategy for space fire suppression?

  2. Next generation fire suppressants

    SciTech Connect

    Brown, J.A.

    1995-03-01

    Spectrex, Inc., located in Cedar Grove, NJ is a manufacturer of fire detection and suppression equipment. Spectrex is one of the original pioneers in high speed fire detection and suppression systems for combat vehicles. Spectrex has installed fire suppressions systems in thousands of combat vehicles and ships throughout the world. Additionally, they manufacture flame explosion detectors, ship damage control systems, and optical gas and vapor detectors. The culmination of several years of research and development has recently produced an innovative electro-optical continuous monitoring systems called SharpEye 20/20I IR(sup 3) and SAFEYE that provide fast and reliable gas, vapor, aerosol, flame, and explosion detection. SharpEye 20/20I IR(sup 3) is a self-contained triple spectrum flame detector which scans for oscillating IR radiation (1 to 10 Hz) in the spectral bands ranging from 4.0 to 5.0 microns and uses programmed algorithms to check the ratio and correlation of data received by the three sensors to make the system highly immune to false alarms. It is extremely sensitive as it can detect a 1 x 1 square foot gasoline pan fire at 200 feet in less than 3 seconds. The sensitivity is user programmable, offering 4 ranges of detection. SAFEYE is comprised of a selected number of multispectral band microprocessor controlled detectors which are in communication with one or more radiation sources that is projected along a 600 feet optical path. The signals from the selected narrow bands are processed and analyzed by highly sophisticated algorithms. It is ideal for high risk, remote, large areas such as petroleum and chemical manufacturing sites, waste dumps, aircraft cargo bays, and ship compartments. The SAFEYE will perform direct readings of the presence or rate of rise of concentrations of gases, vapors, or aerosols at the range of parts per million and provide alarms at various set points at different levels of concentrations.

  3. Next generation fire suppressants

    NASA Technical Reports Server (NTRS)

    Brown, Jerry A.

    1995-01-01

    Spectrex, Inc., located in Cedar Grove, NJ is a manufacturer of fire detection and suppression equipment. Spectrex is one of the original pioneers in high speed fire detection and suppression systems for combat vehicles. Spectrex has installed fire suppressions systems in thousands of combat vehicles and ships throughout the world. Additionally, they manufacture flame explosion detectors, ship damage control systems, and optical gas and vapor detectors. The culmination of several years of research and development has recently produced an innovative electro-optical continuous monitoring systems called SharpEye 20/20I IR(sup 3) and SAFEYE that provide fast and reliable gas, vapor, aerosol, flame, and explosion detection. SharpEye 20/20I IR(sup 3) is a self-contained triple spectrum flame detector which scans for oscillating IR radiation (1 to 10 Hz) in the spectral bands ranging from 4.0 to 5.0 microns and uses programmed algorithms to check the ratio and correlation of data received by the three sensors to make the system highly immune to false alarms. It is extremely sensitive as it can detect a 1 x 1 square foot gasoline pan fire at 200 feet in less than 3 seconds. The sensitivity is user programmable, offering 4 ranges of detection. SAFEYE is comprised of a selected number of multispectral ban microprocessors controlled detectors which are in communication with one or more radiation sources that is projected along a 600 feet optical path. The signals from the selected narrow bands are processed and analyzed by highly sophisticated algorithms. It is ideal for high risk, remote, large areas such as petroleum and chemical manufacturing sites, waste dumps, aircraft cargo bays, and ship compartments. The SAFEYE will perform direct readings of the presence or rate of rise of concentrations of gases, vapors, or aerosols at the range of parts per million and provide alarms at various set points at different levels of concentrations.

  4. Fire suppressing apparatus. [sodium fires

    DOEpatents

    Buttrey, K.E.

    1980-12-19

    Apparatus for smothering a liquid sodium fire comprises a pan, a perforated cover on the pan, and tubed depending from the cover and providing communication between the interior of the pan and the ambient atmosphere through the perforations in the cover. Liquid caught in the pan rises above the lower ends of the tubes and thus serves as a barrier which limits the amount of air entering the pan.

  5. Contrasting Spatial Patterns in Active-Fire and Fire-Suppressed Mediterranean Climate Old-Growth Mixed Conifer Forests

    PubMed Central

    Fry, Danny L.; Stephens, Scott L.; Collins, Brandon M.; North, Malcolm P.; Franco-Vizcaíno, Ernesto; Gill, Samantha J.

    2014-01-01

    In Mediterranean environments in western North America, historic fire regimes in frequent-fire conifer forests are highly variable both temporally and spatially. This complexity influenced forest structure and spatial patterns, but some of this diversity has been lost due to anthropogenic disruption of ecosystem processes, including fire. Information from reference forest sites can help management efforts to restore forests conditions that may be more resilient to future changes in disturbance regimes and climate. In this study, we characterize tree spatial patterns using four-ha stem maps from four old-growth, Jeffrey pine-mixed conifer forests, two with active-fire regimes in northwestern Mexico and two that experienced fire exclusion in the southern Sierra Nevada. Most of the trees were in patches, averaging six to 11 trees per patch at 0.007 to 0.014 ha−1, and occupied 27–46% of the study areas. Average canopy gap sizes (0.04 ha) covering 11–20% of the area were not significantly different among sites. The putative main effects of fire exclusion were higher densities of single trees in smaller size classes, larger proportion of trees (≥56%) in large patches (≥10 trees), and decreases in spatial complexity. While a homogenization of forest structure has been a typical result from fire exclusion, some similarities in patch, single tree, and gap attributes were maintained at these sites. These within-stand descriptions provide spatially relevant benchmarks from which to manage for structural heterogeneity in frequent-fire forest types. PMID:24586472

  6. Contrasting spatial patterns in active-fire and fire-suppressed Mediterranean climate old-growth mixed conifer forests.

    PubMed

    Fry, Danny L; Stephens, Scott L; Collins, Brandon M; North, Malcolm P; Franco-Vizcaíno, Ernesto; Gill, Samantha J

    2014-01-01

    In Mediterranean environments in western North America, historic fire regimes in frequent-fire conifer forests are highly variable both temporally and spatially. This complexity influenced forest structure and spatial patterns, but some of this diversity has been lost due to anthropogenic disruption of ecosystem processes, including fire. Information from reference forest sites can help management efforts to restore forests conditions that may be more resilient to future changes in disturbance regimes and climate. In this study, we characterize tree spatial patterns using four-ha stem maps from four old-growth, Jeffrey pine-mixed conifer forests, two with active-fire regimes in northwestern Mexico and two that experienced fire exclusion in the southern Sierra Nevada. Most of the trees were in patches, averaging six to 11 trees per patch at 0.007 to 0.014 ha(-1), and occupied 27-46% of the study areas. Average canopy gap sizes (0.04 ha) covering 11-20% of the area were not significantly different among sites. The putative main effects of fire exclusion were higher densities of single trees in smaller size classes, larger proportion of trees (≥ 56%) in large patches (≥ 10 trees), and decreases in spatial complexity. While a homogenization of forest structure has been a typical result from fire exclusion, some similarities in patch, single tree, and gap attributes were maintained at these sites. These within-stand descriptions provide spatially relevant benchmarks from which to manage for structural heterogeneity in frequent-fire forest types.

  7. Fire suppressing apparatus

    DOEpatents

    Buttrey, Kenneth E.

    1982-11-02

    Apparatus for smothering a liquid sodium fire comprises a pan, a perforated cover on the pan, and tubes depending from the cover and providing communication between the interior of the pan and the ambient atmosphere through the perforations in the cover. Liquid caught in the pan rises above the lower ends of the tubes and thus serves as a barrier which limits the amount of air entering the pan.

  8. How Fire History, Fire Suppression Practices and Climate Change Affect Wildfire Regimes in Mediterranean Landscapes

    PubMed Central

    Brotons, Lluís; Aquilué, Núria; de Cáceres, Miquel; Fortin, Marie-Josée; Fall, Andrew

    2013-01-01

    Available data show that future changes in global change drivers may lead to an increasing impact of fires on terrestrial ecosystems worldwide. Yet, fire regime changes in highly humanised fire-prone regions are difficult to predict because fire effects may be heavily mediated by human activities We investigated the role of fire suppression strategies in synergy with climate change on the resulting fire regimes in Catalonia (north-eastern Spain). We used a spatially-explicit fire-succession model at the landscape level to test whether the use of different firefighting opportunities related to observed reductions in fire spread rates and effective fire sizes, and hence changes in the fire regime. We calibrated this model with data from a period with weak firefighting and later assess the potential for suppression strategies to modify fire regimes expected under different levels of climate change. When comparing simulations with observed fire statistics from an eleven-year period with firefighting strategies in place, our results showed that, at least in two of the three sub-regions analysed, the observed fire regime could not be reproduced unless taking into account the effects of fire suppression. Fire regime descriptors were highly dependent on climate change scenarios, with a general trend, under baseline scenarios without fire suppression, to large-scale increases in area burnt. Fire suppression strategies had a strong capacity to compensate for climate change effects. However, strong active fire suppression was necessary to accomplish such compensation, while more opportunistic fire suppression strategies derived from recent fire history only had a variable, but generally weak, potential for compensation of enhanced fire impacts under climate change. The concept of fire regime in the Mediterranean is probably better interpreted as a highly dynamic process in which the main determinants of fire are rapidly modified by changes in landscape, climate and

  9. Fire suppression and detection equipment

    SciTech Connect

    E.E. Bates

    2006-01-15

    Inspection and testing guidelines go beyond the 'Code of Federal Regulation'. Title 30 of the US Code of Federal Regulations (30 CFR) contains requirements and references to national standards for inspection, testing and maintenance of fire suppression and detection equipment for mine operators. However, federal requirements have not kept pace with national standards and best practices. The article lists National Fire Protection (NFPA) standards that are referenced by the US Mine Safety and Health Administration (MSHA) in 30 CFR. It then discusses other NFPA Standards excluded from 30 CFR and explains the NFPA standard development process. 2 refs., 3 tabs., 5 photos.

  10. Sodium fire testing: structural evaluation of sodium fire suppression system

    SciTech Connect

    1984-08-01

    This report describes the development and the lessons learned from the Clinch River Breeder Reactor Sodium Fire Testing Program (DRS 26.03). The purpose of this program was to evaluate the behavior of the Sodium Fire Suppression System and validate the analytical techniques used in the calculation of the effects of sodium fires in air-filled cells. This report focuses on the fire suppression capability and the structural integrity of the Fire Suppression System. System features are discussed; the test facility is described and the key results are provided. Modifications to the fire suppression system and the plant made as a result of test experience are also discussed.

  11. Reexamining fire suppression impacts on brushland fire regimes

    USGS Publications Warehouse

    Keeley, Jon E.; Fotheringham, C.J.; Morais, Marco

    1999-01-01

    California shrubland wildfires are increasingly destructive, and it is widely held that the problem has been intensified by fire suppression, leading to larger, more intense wildfires. However, analysis of the California Statewide Fire History Database shows that, since 1910, fire frequency and area burned have not declined, and fire size has not increased. Fire rotation intervals have declined, and fire season has not changed, implying that fire intensity has not increased. Fire frequency and population density were correlated, and it is suggested that fire suppression plays a critical role in offsetting potential impacts of increased ignitions. Large fires were not dependent on old age classes of fuels, and it is thus unlikely that age class manipulation of fuels can prevent large fires. Expansion of the urban-wildland interface is a key factor in wildland fire destruction.

  12. Water Mist fire suppression experiment

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Water Mist commercial research program is scheduled to fly an investigation on STS-107 in 2002. This investigation will be flown as an Experimental Mounting Structure (EMS) insert into the updated Combustion Module (CM-2), a sophisticated combustion chamber plus diagnostic equipment. (The investigation hardware is shown here mounted in a non-flight frame similar to the EMS.) Water Mist is a commercial research program by the Center for Commercial Applications of Combustion in Space (CCACS), a NASA Commercial Space Center located at the Colorado School of Mines, in Golden, CO and Industry Partner Environmental Engineering Concepts. The program is focused on developing water mist as a replacement for bromine-based chemical fire suppression agents (halons). By conducting the experiments in microgravity, interference from convection currents is minimized and fundamental knowledge can be gained. This knowledge is incorporated into models, which can be used to simulate a variety of physical environments. The immediate objective of the project is to study the effect of a fine water mist on a laminar propagating flame generated in a propane-air mixture at various equivalence ratios. The effects of droplet size and concentration on the speed of the flame front is used as a measure of the effectiveness of fire suppression in this highly controlled experimental environment.

  13. Issues in Numerical Simulation of Fire Suppression

    SciTech Connect

    Tieszen, S.R.; Lopez, A.R.

    1999-04-12

    This paper outlines general physical and computational issues associated with performing numerical simulation of fire suppression. Fire suppression encompasses a broad range of chemistry and physics over a large range of time and length scales. The authors discuss the dominant physical/chemical processes important to fire suppression that must be captured by a fire suppression model to be of engineering usefulness. First-principles solutions are not possible due to computational limitations, even with the new generation of tera-flop computers. A basic strategy combining computational fluid dynamics (CFD) simulation techniques with sub-grid model approximations for processes that have length scales unresolvable by gridding is presented.

  14. Active Fire Mapping Program

    MedlinePlus

    ... Incidents (Home) New Large Incidents Fire Detection Maps MODIS Satellite Imagery VIIRS Satellite Imagery Fire Detection GIS ... Data Web Services Latest Detected Fire Activity Other MODIS Products Frequently Asked Questions About Active Fire Maps ...

  15. Fire suppression in human-crew spacecraft

    NASA Technical Reports Server (NTRS)

    Friedman, Robert; Dietrich, Daniel L.

    1991-01-01

    Fire extinguishment agents range from water and foam in early-design spacecraft (Halon 1301 in the present Shuttle) to carbon dioxide proposed for the Space Station Freedom. The major challenge to spacecraft fire extinguishment design and operations is from the micro-gravity environment, which minimizes natural convection and profoundly influences combustion and extinguishing agent effectiveness, dispersal, and post-fire cleanup. Discussed here are extinguishment in microgravity, fire-suppression problems anticipated in future spacecraft, and research needs and opportunities.

  16. Base camp personnel exposure to particulate matter during wildland fire suppression activities.

    PubMed

    McNamara, Marcy L; Semmens, Erin O; Gaskill, Steven; Palmer, Charles; Noonan, Curtis W; Ward, Tony J

    2012-01-01

    Wildland fire base camps commonly house thousands of support personnel for weeks at a time. The selection of the location of these base camps is largely a strategic decision that incorporates many factors, one of which is the potential impact of biomass smoke from the nearby fire event. Biomass smoke has many documented adverse health effects due, primarily, to high levels of fine particulate matter (PM(2.5)). Minimizing particulate matter exposure to potentially susceptible individuals working as support personnel in the base camp is vital. In addition to smoke from nearby wildland fires, base camp operations have the potential to generate particulate matter via vehicle emissions, dust, and generator use. We monitored particulate matter at three base camps during the fire season of 2009 in Washington, Oregon, and California. During the sampling events, 1-min time-weighted averages of PM(2.5) and particle counts from three size fractions (0.3-0.5 microns, 0.5-1.0 microns, and 1.0-2.5 microns) were measured. Results showed that all PM size fractions (as well as overall PM(2.5) concentrations) were higher during the overnight hours, a trend that was consistent at all camps. Our results provide evidence of camp-based, site-specific sources of PM(2.5) that could potentially exceed the contributions from the nearby wildfire. These exposures could adversely impact wildland firefighters who sleep in the camp, as well as the camp support personnel, who could include susceptible individuals. A better understanding of the sources and patterns of poor air quality within base camps would help to inform prevention strategies to reduce personnel exposures.

  17. Fire retardant foams developed to suppress fuel fires

    NASA Technical Reports Server (NTRS)

    Fish, R.; Gilwee, W. J.; Parker, J. A.; Riccitiello, S. R.

    1968-01-01

    Heat insulating polyurethane foam retards and suppresses fuel fires. Uniformly dispersed in the foam is a halogenated polymer capable of splitting off hydrogen halide upon heating and charring of the polyurethane.

  18. Spacecraft Fire Suppression: Testing and Evaluation

    NASA Technical Reports Server (NTRS)

    Abbud-Madrid, Angel; McKinnon, J. Thomas; Delplanque, Jean-Pierre; Kailasanath, Kazhikathra; Gokoglu, Suleyman; Wu, Ming-Shin

    2004-01-01

    The objective of this project is the testing and evaluation of the effectiveness of a variety of fire suppressants and fire-response techniques that will be used in the next generation of spacecraft (Crew Exploration Vehicle, CEV) and planetary habitats. From the many lessons learned in the last 40 years of space travel, there is common agreement in the spacecraft fire safety community that a new fire suppression system will be needed for the various types of fire threats anticipated in new space vehicles and habitats. To date, there is no single fire extinguishing system that can address all possible fire situations in a spacecraft in an effective, reliable, clean, and safe way. The testing conducted under this investigation will not only validate the various numerical models that are currently being developed, but it will provide new design standards on fire suppression that can then be applied to the next generation of spacecraft extinguishment systems. The test program will provide validation of scaling methods by conducting small, medium, and large scale fires. A variety of suppression methods will be tested, such as water mist, carbon dioxide, and nitrogen with single and multiple injection points and direct or distributed agent deployment. These injection methods cover the current ISS fire suppression method of a portable hand-held fire extinguisher spraying through a port in a rack and also next generation spacecraft units that may have a multi-point suppression delivery system built into the design. Consideration will be given to the need of a crew to clean-up the agent and recharge the extinguishers in flight in a long-duration mission. The fire suppression methods mentioned above will be used to extinguish several fire scenarios that have been identified as the most relevant to spaceflight, such as overheated wires, cable bundles, and circuit boards, as well as burning cloth and paper. Further testing will be conducted in which obstructions and

  19. Fuel age and fire spread: Natural conditions versus opportunities for fire suppression

    USGS Publications Warehouse

    Halsey, Richard W.; Keeley, Jon E.; Wilson, Kit

    2009-01-01

    Wildfires are driven and restrained by an interplay of variables that can lead to many potential outcomes. As every wildland firefighter learns in basic training, the ability of a fire to spread is determined by three basic variables: fuel type and condition, weather, and topography. Fire suppression obviously plays a significant role in determining fire spread as well, so firefighter activity becomes an additional variable.

  20. Ultrafine and respirable particle exposure during vehicle fire suppression.

    PubMed

    Evans, Douglas E; Fent, Kenneth W

    2015-10-01

    Vehicle fires are a common occurrence, yet few studies have reported exposures associated with burning vehicles. This article presents an assessment of firefighters' potential for ultrafine and respirable particle exposure during vehicle fire suppression training. Fires were initiated within the engine compartment and passenger cabins of three salvaged vehicles, with subsequent water suppression by fire crews. Firefighter exposures were monitored with an array of direct reading particle and air quality instruments. A flexible metallic duct and blower drew contaminants to the instrument array, positioned at a safe distance from the burning vehicles, with the duct inlet positioned at the nozzle operator's shoulder. The instruments measured the particle number, active surface area, respirable particle mass, photoelectric response, aerodynamic particle size distributions, and air quality parameters. Although vehicle fires were suppressed quickly (<10 minutes), firefighters may be exposed to short duration, high particle concentration episodes during fire suppression, which are orders of magnitude greater than the ambient background concentration. A maximum transient particle concentration of 1.21 × 10(7) particles per cm(3), 170 mg m(-3) respirable particle mass, 4700 μm(2) cm(-3) active surface area and 1400 (arbitrary units) in photoelectric response were attained throughout the series of six fires. Expressed as fifteen minute time-weighted averages, engine compartment fires averaged 5.4 × 10(4) particles per cm(3), 0.36 mg m(-3) respirable particle mass, 92 μm(2) cm(-3) active particle surface area and 29 (arbitrary units) in photoelectric response. Similarly, passenger cabin fires averaged 2.04 × 10(5) particles per cm(3), 2.7 mg m(-3) respirable particle mass, 320 μm(2) cm(-3) active particle surface area, and 34 (arbitrary units) in photoelectric response. Passenger cabin fires were a greater potential source of exposure than engine compartment fires. The

  1. Ultrafine and respirable particle exposure during vehicle fire suppression.

    PubMed

    Evans, Douglas E; Fent, Kenneth W

    2015-10-01

    Vehicle fires are a common occurrence, yet few studies have reported exposures associated with burning vehicles. This article presents an assessment of firefighters' potential for ultrafine and respirable particle exposure during vehicle fire suppression training. Fires were initiated within the engine compartment and passenger cabins of three salvaged vehicles, with subsequent water suppression by fire crews. Firefighter exposures were monitored with an array of direct reading particle and air quality instruments. A flexible metallic duct and blower drew contaminants to the instrument array, positioned at a safe distance from the burning vehicles, with the duct inlet positioned at the nozzle operator's shoulder. The instruments measured the particle number, active surface area, respirable particle mass, photoelectric response, aerodynamic particle size distributions, and air quality parameters. Although vehicle fires were suppressed quickly (<10 minutes), firefighters may be exposed to short duration, high particle concentration episodes during fire suppression, which are orders of magnitude greater than the ambient background concentration. A maximum transient particle concentration of 1.21 × 10(7) particles per cm(3), 170 mg m(-3) respirable particle mass, 4700 μm(2) cm(-3) active surface area and 1400 (arbitrary units) in photoelectric response were attained throughout the series of six fires. Expressed as fifteen minute time-weighted averages, engine compartment fires averaged 5.4 × 10(4) particles per cm(3), 0.36 mg m(-3) respirable particle mass, 92 μm(2) cm(-3) active particle surface area and 29 (arbitrary units) in photoelectric response. Similarly, passenger cabin fires averaged 2.04 × 10(5) particles per cm(3), 2.7 mg m(-3) respirable particle mass, 320 μm(2) cm(-3) active particle surface area, and 34 (arbitrary units) in photoelectric response. Passenger cabin fires were a greater potential source of exposure than engine compartment fires. The

  2. Ultrafine and respirable particle exposure during vehicle fire suppression

    PubMed Central

    Fent, Kenneth W.

    2015-01-01

    Vehicle fires are a common occurrence, yet few studies have reported exposures associated with burning vehicles. This article presents an assessment of firefighters’ potential for ultrafine and respirable particle exposure during vehicle fire suppression training. Fires were initiated within the engine compartment and passenger cabins of three salvaged vehicles, with subsequent water suppression by fire crews. Firefighter exposures were monitored with an array of direct reading particle and air quality instruments. A flexible metallic duct and blower drew contaminants to the instrument array, positioned at a safe distance from the burning vehicles, with the duct inlet positioned at the nozzle operator’s shoulder. The instruments measured the particle number, active surface area, respirable particle mass, photoelectric response, aerodynamic particle size distributions, and air quality parameters. Although vehicle fires were suppressed quickly (<10 minutes), firefighters may be exposed to short duration, high particle concentration episodes during fire suppression, which are orders of magnitude greater than the ambient background concentration. A maximum transient particle concentration of 1.21 × 107 particles per cm3, 170 mg m−3 respirable particle mass, 4700 μm2 cm−3 active surface area and 1400 (arbitrary units) in photoelectric response were attained throughout the series of six fires. Expressed as fifteen minute time-weighted averages, engine compartment fires averaged 5.4 × 104 particles per cm3, 0.36 mg m−3 respirable particle mass, 92 μm2 cm−3 active particle surface area and 29 (arbitrary units) in photoelectric response. Similarly, passenger cabin fires averaged 2.04 × 105 particles per cm3, 2.7 mg m−3 respirable particle mass, 320 μm2 cm−3 active particle surface area, and 34 (arbitrary units) in photoelectric response. Passenger cabin fires were a greater potential source of exposure than engine compartment fires. The wind direction

  3. Definition of experiments to investigate fire suppressants in microgravity

    NASA Technical Reports Server (NTRS)

    Reuther, James J.

    1990-01-01

    Defined and justified here are the conceptual design and operation of a critical set of experiments expected to yield information on suppressants and on suppressant delivery systems under realistic spacecraft-fire conditions (smoldering). Specific experiment parameters are provided on the solid fuel (carbon), oxidants (habitable spacecraft atmospheres), fuel/oxidant supply, mixing mode, and rate (quiescent and finite; ventilated and replenishable), ignition mode, event, and reignition tendency, fire-zone size, fire conditions, lifetime, and consequences (toxicity), suppressants (CO2, H2O, N2) and suppressant delivery systems, and diagnostics. Candidate suppressants were identified after an analysis of how reduced gravity alters combustion, and how these alterations may influence the modes, mechanisms, and capacities of terrestrial agents to suppress unwanted combustion, or fire. Preferred spacecraft suppression concepts included the local, near-quiescent application of a gas, vapor, or mist that has thermophysical fire-suppression activity and is chemically inert under terrestrial (normal gravity) combustion conditions. The scale, number, and duration (about 1 hour) of the proposed low-gravity experiments were estimated using data not only on the limitations imposed by spacecraft-carrier (Shuttle or Space Station Freedom) accommodations, but also data on the details and experience of standardized smolder-suppression experiments at normal gravity. Deliberately incorporated into the conceptual design was sufficient interchangeability for the prototype experimental package to fly either on Shuttle now or Freedom later. This flexibility is provided by the design concept of up to 25 modular fuel canisters within a containment vessel, which permits both integration into existing low-gravity in-space combustion experiments and simultaneous testing of separate experiments to conserve utilities and time.

  4. Verification study of an emerging fire suppression system

    DOE PAGES

    Cournoyer, Michael E.; Waked, R. Ryan; Granzow, Howard N.; Gubernatis, David C.

    2016-01-01

    Self-contained fire extinguishers are a robust, reliable and minimally invasive means of fire suppression for gloveboxes. Moreover, plutonium gloveboxes present harsh environmental conditions for polymer materials; these include radiation damage and chemical exposure, both of which tend to degrade the lifetime of engineered polymer components. Several studies have been conducted to determine the robustness of selfcontained fire extinguishers in plutonium gloveboxes in a nuclear facility, verification tests must be performed. These tests include activation and mass loss calorimeter tests. In addition, compatibility issues with chemical components of the self-contained fire extinguishers need to be addressed. Our study presents activation andmore » mass loss calorimeter test results. After extensive studies, no critical areas of concern have been identified for the plutonium glovebox application of Fire Foe™, except for glovebox operations that use large quantities of bulk plutonium or uranium metal such as metal casting and pyro-chemistry operations.« less

  5. Verification study of an emerging fire suppression system

    SciTech Connect

    Cournoyer, Michael E.; Waked, R. Ryan; Granzow, Howard N.; Gubernatis, David C.

    2016-01-01

    Self-contained fire extinguishers are a robust, reliable and minimally invasive means of fire suppression for gloveboxes. Moreover, plutonium gloveboxes present harsh environmental conditions for polymer materials; these include radiation damage and chemical exposure, both of which tend to degrade the lifetime of engineered polymer components. Several studies have been conducted to determine the robustness of selfcontained fire extinguishers in plutonium gloveboxes in a nuclear facility, verification tests must be performed. These tests include activation and mass loss calorimeter tests. In addition, compatibility issues with chemical components of the self-contained fire extinguishers need to be addressed. Our study presents activation and mass loss calorimeter test results. After extensive studies, no critical areas of concern have been identified for the plutonium glovebox application of Fire Foe™, except for glovebox operations that use large quantities of bulk plutonium or uranium metal such as metal casting and pyro-chemistry operations.

  6. 48 CFR 452.236-78 - Fire Suppression and Liability.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Fire Suppression and... Fire Suppression and Liability. As prescribed in § 436.578, the following clause may be inserted in... Suppression and Liability (MAY 2014) (a) Contractor's Responsibility for Fire Fighting. The Contractor,...

  7. Optimization of sodium fire suppression system

    SciTech Connect

    1985-02-01

    This report describes the major areas of revision and optimization of the design of the CRBRP Sodium Fire Suppression System (SFSS) following the confirmatory testing program. The design temperatures for the SFSS were substantially increased after the Large Scale Sodium Fire Test (LSSFT) making the original design inadequate. A redesign of the main features was performed in which the experience in the construction of the LSSFT test article was also utilized for optimization. The design criteria, loads and load combinations and revised design are discussed.

  8. Manual fire suppression methods on typical machinery space spray fires

    NASA Astrophysics Data System (ADS)

    Carhart, H. W.; Leonard, J. T.; Budnick, E. K.; Ouellette, R. J.; Shanley, J. H., Jr.

    1990-07-01

    A series of tests was conducted to evaluate the effectiveness of Aqueous Film Forming Foam (AFFF), potassium bicarbonate powder (PKP) and Halon 1211, alone and in various combinations, in extinguishing spray fires. The sprays were generated by JP-5 jet fuel issuing from an open sounding tube, and open petcock, a leaking flange or a slit pipe, and contacting an ignition source. The results indicate that typical fuel spray fires, such as those simulated in this series, are very severe. Flame heights ranged from 6.1 m (20 ft) for the split pipe to 15.2 m (50 ft) for the sounding tube scenario. These large flame geometries were accompanied by heat release rates of 6 MW to greater than 50 MW, and hazardous thermal radiation levels in the near field environment, up to 9.1 m (30 ft) away. Successful suppression of these fires requires both a significant reduction in flame radiation and delivery of a suppression agent to shielded areas. Of the nine suppression methods tested, the 95 gpm AFFF hand line and the hand line in conjunction with PKP were particularly effective in reducing the radiant flux.

  9. Automatic swimming pool identification for fire suppression

    NASA Astrophysics Data System (ADS)

    Fitzsimmons, Bo; Buck, Heidi

    2012-09-01

    Southern California experienced some of the largest wildfires ever seen in 2003 and 2007. The Cedar fire in 2003 resulted in 2,820 lost structures and 15 deaths, and the Witch fire in 2007 resulted in 1,650 lost structures and 2 deaths according to the California Department of Forestry and Fire Protection (CAL FIRE). Fighting fires of this magnitude requires every available resource, and an adequate water supply is vital in the firefighting arsenal. Utilizing the fact that many homes in Southern California have swimming pools, firefighters could have access to strategically placed water supplies. The problem is accurately and quickly identifying which residences have actively filled swimming pools at the time of the emergency. The proposed method approaches the problem by employing satellite imagery and remote sensing techniques. Specifically, swimming pool identification is attempted with Spectral Angle Mapper (SAM) on multispectral imagery from the Worldview-2 satellite.

  10. Predicting fire suppression in a simulated engine nacelle.

    SciTech Connect

    Keyser, David R.; Hewson, John C.

    2004-06-01

    The Vulcan fire-field model is employed to simulate the evolution of pool fires and the distribution of fire suppressants in a engine nacelle simulator. The objective is to identify conditions for which suppression will and will not be successful in order to (1) provide input on experimental design and (2) to test the model's predictive capabilities through comparison with future test results. Pool fires, where the fuel pool is on the bottom of the nacelle, have been selected for these tests because they have been identified as among the most challenging to suppress. Modeling of the production HFC-125 fire suppression system predicts that all pool fires are extinguished. Removing nozzles and reducing the rate of suppressant injection eventually lead to a predicted failure to suppress the fires. The stability of the fires, and therefore the difficulty in extinguishing them, depends on a variety of additional factors as discussed in the text.

  11. 30 CFR 75.1107 - Fire suppression devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Fire suppression devices. 75.1107 Section 75.1107 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices...

  12. 30 CFR 75.1107 - Fire suppression devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fire suppression devices. 75.1107 Section 75.1107 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices...

  13. 30 CFR 75.1107 - Fire suppression devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Fire suppression devices. 75.1107 Section 75.1107 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices...

  14. 30 CFR 75.1107 - Fire suppression devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Fire suppression devices. 75.1107 Section 75.1107 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices...

  15. Benchmark enclosure fire suppression experiments - phase 1 test report.

    SciTech Connect

    Figueroa, Victor G.; Nichols, Robert Thomas; Blanchat, Thomas K.

    2007-06-01

    A series of fire benchmark water suppression tests were performed that may provide guidance for dispersal systems for the protection of high value assets. The test results provide boundary and temporal data necessary for water spray suppression model development and validation. A review of fire suppression in presented for both gaseous suppression and water mist fire suppression. The experimental setup and procedure for gathering water suppression performance data are shown. Characteristics of the nozzles used in the testing are presented. Results of the experiments are discussed.

  16. 30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water...

  17. 30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water...

  18. 30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water...

  19. 30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water...

  20. 30 CFR 75.1103-6 - Automatic fire sensors; actuation of fire suppression systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic fire sensors; actuation of fire... Protection § 75.1103-6 Automatic fire sensors; actuation of fire suppression systems. Point-type heat sensors or automatic fire sensor and warning device systems may be used to actuate deluge-type water...

  1. Materials Science Research Rack-1 Fire Suppressant Distribution Test Report

    NASA Technical Reports Server (NTRS)

    Wieland, P. O.

    2002-01-01

    Fire suppressant distribution testing was performed on the Materials Science Research Rack-1 (MSRR-1), a furnace facility payload that will be installed in the U.S. Lab module of the International Space Station. Unlike racks that were tested previously, the MSRR-1 uses the Active Rack Isolation System (ARIS) to reduce vibration on experiments, so the effects of ARIS on fire suppressant distribution were unknown. Two tests were performed to map the distribution of CO2 fire suppressant throughout a mockup of the MSRR-1 designed to have the same component volumes and flowpath restrictions as the flight rack. For the first test, the average maximum CO2 concentration for the rack was 60 percent, achieved within 45 s of discharge initiation, meeting the requirement to reach 50 percent throughout the rack within 1 min. For the second test, one of the experiment mockups was removed to provide a worst-case configuration, and the average maximum CO2 concentration for the rack was 58 percent. Comparing the results of this testing with results from previous testing leads to several general conclusions that can be used to evaluate future racks. The MSRR-1 will meet the requirements for fire suppressant distribution. Primary factors that affect the ability to meet the CO2 distribution requirements are the free air volume in the rack and the total area and distribution of openings in the rack shell. The length of the suppressant flowpath and degree of tortuousness has little correlation with CO2 concentration. The total area of holes in the rack shell could be significantly increased. The free air volume could be significantly increased. To ensure the highest maximum CO2 concentration, the PFE nozzle should be inserted to the stop on the nozzle.

  2. Using unplanned fires to help suppressing future large fires in Mediterranean forests.

    PubMed

    Regos, Adrián; Aquilué, Núria; Retana, Javier; De Cáceres, Miquel; Brotons, Lluís

    2014-01-01

    Despite the huge resources invested in fire suppression, the impact of wildfires has considerably increased across the Mediterranean region since the second half of the 20th century. Modulating fire suppression efforts in mild weather conditions is an appealing but hotly-debated strategy to use unplanned fires and associated fuel reduction to create opportunities for suppression of large fires in future adverse weather conditions. Using a spatially-explicit fire-succession model developed for Catalonia (Spain), we assessed this opportunistic policy by using two fire suppression strategies that reproduce how firefighters in extreme weather conditions exploit previous fire scars as firefighting opportunities. We designed scenarios by combining different levels of fire suppression efficiency and climatic severity for a 50-year period (2000-2050). An opportunistic fire suppression policy induced large-scale changes in fire regimes and decreased the area burnt under extreme climate conditions, but only accounted for up to 18-22% of the area to be burnt in reference scenarios. The area suppressed in adverse years tended to increase in scenarios with increasing amounts of area burnt during years dominated by mild weather. Climate change had counterintuitive effects on opportunistic fire suppression strategies. Climate warming increased the incidence of large fires under uncontrolled conditions but also indirectly increased opportunities for enhanced fire suppression. Therefore, to shift fire suppression opportunities from adverse to mild years, we would require a disproportionately large amount of area burnt in mild years. We conclude that the strategic planning of fire suppression resources has the potential to become an important cost-effective fuel-reduction strategy at large spatial scale. We do however suggest that this strategy should probably be accompanied by other fuel-reduction treatments applied at broad scales if large-scale changes in fire regimes are to be

  3. Using unplanned fires to help suppressing future large fires in Mediterranean forests.

    PubMed

    Regos, Adrián; Aquilué, Núria; Retana, Javier; De Cáceres, Miquel; Brotons, Lluís

    2014-01-01

    Despite the huge resources invested in fire suppression, the impact of wildfires has considerably increased across the Mediterranean region since the second half of the 20th century. Modulating fire suppression efforts in mild weather conditions is an appealing but hotly-debated strategy to use unplanned fires and associated fuel reduction to create opportunities for suppression of large fires in future adverse weather conditions. Using a spatially-explicit fire-succession model developed for Catalonia (Spain), we assessed this opportunistic policy by using two fire suppression strategies that reproduce how firefighters in extreme weather conditions exploit previous fire scars as firefighting opportunities. We designed scenarios by combining different levels of fire suppression efficiency and climatic severity for a 50-year period (2000-2050). An opportunistic fire suppression policy induced large-scale changes in fire regimes and decreased the area burnt under extreme climate conditions, but only accounted for up to 18-22% of the area to be burnt in reference scenarios. The area suppressed in adverse years tended to increase in scenarios with increasing amounts of area burnt during years dominated by mild weather. Climate change had counterintuitive effects on opportunistic fire suppression strategies. Climate warming increased the incidence of large fires under uncontrolled conditions but also indirectly increased opportunities for enhanced fire suppression. Therefore, to shift fire suppression opportunities from adverse to mild years, we would require a disproportionately large amount of area burnt in mild years. We conclude that the strategic planning of fire suppression resources has the potential to become an important cost-effective fuel-reduction strategy at large spatial scale. We do however suggest that this strategy should probably be accompanied by other fuel-reduction treatments applied at broad scales if large-scale changes in fire regimes are to be

  4. 30 CFR 75.1107-1 - Fire-resistant hydraulic fluids and fire suppression devices on underground equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fire-resistant hydraulic fluids and fire...-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment § 75.1107-1 Fire-resistant hydraulic fluids and fire suppression devices on...

  5. Calculation of Fire Severity Factors and Fire Non-Suppression Probabilities For A DOE Facility Fire PRA

    SciTech Connect

    Tom Elicson; Bentley Harwood; Jim Bouchard; Heather Lucek

    2011-03-01

    Over a 12 month period, a fire PRA was developed for a DOE facility using the NUREG/CR-6850 EPRI/NRC fire PRA methodology. The fire PRA modeling included calculation of fire severity factors (SFs) and fire non-suppression probabilities (PNS) for each safe shutdown (SSD) component considered in the fire PRA model. The SFs were developed by performing detailed fire modeling through a combination of CFAST fire zone model calculations and Latin Hypercube Sampling (LHS). Component damage times and automatic fire suppression system actuation times calculated in the CFAST LHS analyses were then input to a time-dependent model of fire non-suppression probability. The fire non-suppression probability model is based on the modeling approach outlined in NUREG/CR-6850 and is supplemented with plant specific data. This paper presents the methodology used in the DOE facility fire PRA for modeling fire-induced SSD component failures and includes discussions of modeling techniques for: • Development of time-dependent fire heat release rate profiles (required as input to CFAST), • Calculation of fire severity factors based on CFAST detailed fire modeling, and • Calculation of fire non-suppression probabilities.

  6. Aging assessment for active fire protection systems

    SciTech Connect

    Ross, S.B.; Nowlen, S.P.; Tanaka, T.

    1995-06-01

    This study assessed the impact of aging on the performance and reliability of active fire protection systems including both fixed fire suppression and fixed fire detection systems. The experience base shows that most nuclear power plants have an aggressive maintenance and testing program and are finding degraded fire protection system components before a failure occurs. Also, from the data reviewed it is clear that the risk impact of fire protection system aging is low. However, it is assumed that a more aggressive maintenance and testing program involving preventive diagnostics may reduce the risk impact even further.

  7. Using Unplanned Fires to Help Suppressing Future Large Fires in Mediterranean Forests

    PubMed Central

    Regos, Adrián; Aquilué, Núria; Retana, Javier; De Cáceres, Miquel; Brotons, Lluís

    2014-01-01

    Despite the huge resources invested in fire suppression, the impact of wildfires has considerably increased across the Mediterranean region since the second half of the 20th century. Modulating fire suppression efforts in mild weather conditions is an appealing but hotly-debated strategy to use unplanned fires and associated fuel reduction to create opportunities for suppression of large fires in future adverse weather conditions. Using a spatially-explicit fire–succession model developed for Catalonia (Spain), we assessed this opportunistic policy by using two fire suppression strategies that reproduce how firefighters in extreme weather conditions exploit previous fire scars as firefighting opportunities. We designed scenarios by combining different levels of fire suppression efficiency and climatic severity for a 50-year period (2000–2050). An opportunistic fire suppression policy induced large-scale changes in fire regimes and decreased the area burnt under extreme climate conditions, but only accounted for up to 18–22% of the area to be burnt in reference scenarios. The area suppressed in adverse years tended to increase in scenarios with increasing amounts of area burnt during years dominated by mild weather. Climate change had counterintuitive effects on opportunistic fire suppression strategies. Climate warming increased the incidence of large fires under uncontrolled conditions but also indirectly increased opportunities for enhanced fire suppression. Therefore, to shift fire suppression opportunities from adverse to mild years, we would require a disproportionately large amount of area burnt in mild years. We conclude that the strategic planning of fire suppression resources has the potential to become an important cost-effective fuel-reduction strategy at large spatial scale. We do however suggest that this strategy should probably be accompanied by other fuel-reduction treatments applied at broad scales if large-scale changes in fire regimes are

  8. 36 CFR 211.5 - Emergency fire suppression assistance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Emergency fire suppression assistance. 211.5 Section 211.5 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE ADMINISTRATION Cooperation § 211.5 Emergency fire suppression assistance. (a) Definitions. For the purpose...

  9. 14 CFR 460.13 - Smoke detection and fire suppression.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Smoke detection and fire suppression. 460.13 Section 460.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... Crew § 460.13 Smoke detection and fire suppression. An operator or crew must have the ability to...

  10. 14 CFR 460.13 - Smoke detection and fire suppression.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Smoke detection and fire suppression. 460.13 Section 460.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... Crew § 460.13 Smoke detection and fire suppression. An operator or crew must have the ability to...

  11. 36 CFR 211.5 - Emergency fire suppression assistance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Emergency fire suppression assistance. 211.5 Section 211.5 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE ADMINISTRATION Cooperation § 211.5 Emergency fire suppression assistance. (a) Definitions. For the purpose...

  12. 36 CFR 211.5 - Emergency fire suppression assistance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Emergency fire suppression assistance. 211.5 Section 211.5 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE ADMINISTRATION Cooperation § 211.5 Emergency fire suppression assistance. (a) Definitions. For the purpose...

  13. 14 CFR 460.13 - Smoke detection and fire suppression.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Smoke detection and fire suppression. 460.13 Section 460.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... Crew § 460.13 Smoke detection and fire suppression. An operator or crew must have the ability to...

  14. 36 CFR 211.5 - Emergency fire suppression assistance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Emergency fire suppression assistance. 211.5 Section 211.5 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE ADMINISTRATION Cooperation § 211.5 Emergency fire suppression assistance. (a) Definitions. For the purpose...

  15. 14 CFR 460.13 - Smoke detection and fire suppression.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Smoke detection and fire suppression. 460.13 Section 460.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... Crew § 460.13 Smoke detection and fire suppression. An operator or crew must have the ability to...

  16. 14 CFR 460.13 - Smoke detection and fire suppression.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Smoke detection and fire suppression. 460.13 Section 460.13 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION... Crew § 460.13 Smoke detection and fire suppression. An operator or crew must have the ability to...

  17. 36 CFR 211.5 - Emergency fire suppression assistance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Emergency fire suppression assistance. 211.5 Section 211.5 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE ADMINISTRATION Cooperation § 211.5 Emergency fire suppression assistance. (a) Definitions. For the purpose...

  18. 30 CFR 75.1107 - Fire suppression devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Fire-Resistant Hydraulic Fluids on Underground Equipment § 75.1107 Fire suppression devices. On and... be installed on unattended underground equipment and suitable fire-resistant hydraulic fluids approved by the Secretary shall be used in the hydraulic systems of such equipment. Such fluids shall...

  19. Fear Expression Suppresses Medial Prefrontal Cortical Firing in Rats

    PubMed Central

    Giustino, Thomas F.; Fitzgerald, Paul J.; Maren, Stephen

    2016-01-01

    The medial prefrontal cortex (mPFC) plays a crucial role in emotional learning and memory in rodents and humans. While many studies suggest a differential role for the prelimbic (PL) and infralimbic (IL) subdivisions of mPFC, few have considered the relationship between neural activity in these two brain regions recorded simultaneously in behaving animals. Importantly, how concurrent PL and IL activity relate to conditioned freezing behavior is largely unknown. Here we used single-unit recordings targeting PL and IL in awake, behaving rats during the acquisition and expression of conditioned fear. On Day 1, rats received either signaled or unsignaled footshocks in the recording chamber; an auditory conditioned stimulus (CS) preceded signaled footshocks. Twenty-four hours later, animals were returned to the recording chamber (modified to create a novel context) where they received 5 CS-alone trials. After fear conditioning, both signaled and unsignaled rats exhibited high levels of post-shock freezing that was associated with an enduring suppression of mPFC spontaneous firing, particularly in the IL of signaled rats. Twenty-four hours later, CS presentation produced differential conditioned freezing in signaled and unsignaled rats: freezing increased in rats that had received signaled shocks, but decreased in animals in the unsignaled condition (i.e., external inhibition). This group difference in CS-evoked freezing was mirrored in the spontaneous firing rate of neurons in both PL and IL. Interestingly, differences in PL and IL firing rate highly correlated with freezing levels. In other words, in the signaled group IL spontaneous rates were suppressed relative to PL, perhaps limiting IL-mediated suppression of fear and allowing PL activity to dominate performance, resulting in high levels of freezing. This was not observed in the unsignaled group, which exhibited low freezing. These data reveal that the activity of mPFC neurons is modulated by both associative and

  20. Suppression of rainfall by fires in African drylands

    NASA Astrophysics Data System (ADS)

    Saha, Michael V.; Scanlon, Todd M.; D'Odorico, Paolo

    2016-08-01

    Fire is a widespread agent of disturbance in African drylands, but the impact of fire on local precipitation remains poorly understood and large-scale observational evidence has been lacking. Here we link fire to a reduction in precipitation across African drylands. Using 15 years of satellite observations over continental sub-Saharan Africa, we find that more extensive and later dry season fires lead to wet season rainfall deficits of up to 30 mm (~10%). The effect is stronger in the Southern Hemisphere, a signal we attribute to the later timing of fires in the dry season. Given the coupling between rainfall, fuel loads, and fire in African drylands, a negative interannual feedback may arise between fire and precipitation, whereby fires suppress precipitation, thereby reducing fuel load and fire in the subsequent season. The reduced fuel load would, in turn, increase precipitation, completing the feedback loop. This feedback may contribute to a pervasive negative autocorrelation observed in Southern Hemisphere annual rainfall.

  1. Wildfire and drought dynamics destabilize carbon stores of fire-suppressed forests.

    PubMed

    Earles, J Mason; North, Malcolm P; Hurteau, Matthew D

    2014-06-01

    Widespread fire suppression and thinning have altered the structure and composition of many forests in the western United States, making them more susceptible to the synergy of large-scale drought and fire events. We examine how these changes affect carbon storage and stability compared to historic fire-adapted conditions. We modeled carbon dynamics under possible drought and fire conditions over a 300-year simulation period in two mixed-conifer conditions common in the western United States: (1) pine-dominated with an active fire regime and (2) fir-dominated, fire suppressed forests. Fir-dominated stands, with higher live- and dead-wood density, had much lower carbon stability as drought and fire frequency increased compared to pine-dominated forest. Carbon instability resulted from species (i.e., fir's greater susceptibility to drought and fire) and stand (i.e., high density of smaller trees) conditions that develop in the absence of active management. Our modeling suggests restoring historic species composition and active fire regimes can significantly increase carbon stability in fire-suppressed, mixed-conifer forests. Long-term management of forest carbon should consider the relative resilience of stand structure and composition to possible increases in disturbance frequency and intensity under changing climate.

  2. 23. FIRE SUPPRESSION SYSTEM PIPE, 'GRINNELL VALVE', 'VICTROLIC COUPLING,' AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. FIRE SUPPRESSION SYSTEM PIPE, 'GRINNELL VALVE', 'VICTROLIC COUPLING,' AND ALARM AT THE REAR OF BAY NO. 5. - Barstow-Daggett Airport, Hangar Shed No. 4, 39500 National Trails Highway, Daggett, San Bernardino County, CA

  3. 123. FIRE SUPPRESSION DELUGE PANEL ON SOUTH WALL OF TRANSFORMER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    123. FIRE SUPPRESSION DELUGE PANEL ON SOUTH WALL OF TRANSFORMER ROOM (112), LSB (BLDG. 770) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  4. Alternative approach for fire suppression of class A, B and C fires in gloveboxes

    SciTech Connect

    Rosenberger, Mark S; Tsiagkouris, James A

    2011-02-10

    Department of Energy (DOE) Orders and National Fire Protection Association (NFPA) Codes and Standards require fire suppression in gloveboxes. Several potential solutions have been and are currently being considered at Los Alamos National Laboratory (LANL). The objective is to provide reliable, minimally invasive, and seismically robust fire suppression capable of extinguishing Class A, B, and C fires; achieve compliance with DOE and NFPA requirements; and provide value-added improvements to fire safety in gloveboxes. This report provides a brief summary of current approaches and also documents the successful fire tests conducted to prove that one approach, specifically Fire Foe{trademark} tubes, is capable of achieving the requirement to provide reliable fire protection in gloveboxes in a cost-effective manner.

  5. 30 CFR 75.1503 - Use of fire suppression equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... fire suppression equipment. In addition to the approved program of instruction required by 30 CFR 75... suppression equipment. (b) Attended equipment. Each operator of attended equipment specified in 30 CFR 75.1107... of attended equipment as described in 30 CFR 75.1107-1(c)(2), shall be proficient in the use of...

  6. 30 CFR 75.1503 - Use of fire suppression equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... fire suppression equipment. In addition to the approved program of instruction required by 30 CFR 75... suppression equipment. (b) Attended equipment. Each operator of attended equipment specified in 30 CFR 75.1107... of attended equipment as described in 30 CFR 75.1107-1(c)(2), shall be proficient in the use of...

  7. 30 CFR 75.1503 - Use of fire suppression equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... fire suppression equipment. In addition to the approved program of instruction required by 30 CFR 75... suppression equipment. (b) Attended equipment. Each operator of attended equipment specified in 30 CFR 75.1107... of attended equipment as described in 30 CFR 75.1107-1(c)(2), shall be proficient in the use of...

  8. 30 CFR 75.1503 - Use of fire suppression equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... fire suppression equipment. In addition to the approved program of instruction required by 30 CFR 75... suppression equipment. (b) Attended equipment. Each operator of attended equipment specified in 30 CFR 75.1107... of attended equipment as described in 30 CFR 75.1107-1(c)(2), shall be proficient in the use of...

  9. 30 CFR 75.1503 - Use of fire suppression equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... fire suppression equipment. In addition to the approved program of instruction required by 30 CFR 75... suppression equipment. (b) Attended equipment. Each operator of attended equipment specified in 30 CFR 75.1107... of attended equipment as described in 30 CFR 75.1107-1(c)(2), shall be proficient in the use of...

  10. MPLM fire detection and suppression: architecture and analysis

    SciTech Connect

    Balocco, P.; Potenza, F.; Cafero, E. |

    1993-12-31

    The Mini Pressurized Logistics Module (MPLM) is a servicer of the Space Station Freedom (SSF), whose purpose is to provide location for both subsystems and payload racks (active racks i.e. namely a freezer and a freezer/refrigerator, is to be serviced, and passive racks). The MPLM will be used to supply and return a pressurized cargo to and from the SSF via the National Space Transportation System (NSTS), optimizing the NSTS cargo capabilities. Being a pressurized module, the MPLM is characterized by an Environmental Control System that consists of two sections: The Enviromental Control and Life Support System (ECLSS) and the Internal Thermal Control System (ITCS). The ECLSS is constituted by other subsections, among which is the Fire Detection and Suppression (FDS) Subsystem. The fire suppression method, selected at SSF level, is the CO2 discharge and diffusion in the affected enclosed areas. As far as the mathematical simulation of the FDS aspects is concerned, a big effort has been made and is still on-going. The related mathematical modelization is quite complex, involving two-phase phenomena, chocked flow and gas diffusion: this means the implementation and running of dedicated Computational Fluid Dynamics (CFD) models. The diffusion analysis is particularly time-consuming, due to the complexity of the geometry with respect to modelization capability.

  11. Physical and Chemical Aspects of Fire Suppression in Extraterrestrial Environments

    NASA Technical Reports Server (NTRS)

    Takahashi, F.; Linteris, G. T.; Katta, V. R.

    2001-01-01

    A fire, whether in a spacecraft or in occupied spaces on extraterrestrial bases, can lead to mission termination or loss of life. While the fire-safety record of US space missions has been excellent, the advent of longer duration missions to Mars, the moon, or aboard the International Space Station (ISS) increases the likelihood of fire events, with more limited mission termination options. The fire safety program of NASA's manned space flight program is based largely upon the principles of controlling the flammability of on-board materials and greatly eliminating sources of ignition. As a result, very little research has been conducted on fire suppression in the microgravity or reduced-gravity environment. The objectives of this study are: to obtain fundamental knowledge of physical and chemical processes of fire suppression, using gravity and oxygen concentration as independent variables to simulate various extraterrestrial environments, including spacecraft and surface bases in Mars and moon missions; to provide rigorous testing of analytical models, which include comprehensive descriptions of combustion and suppression chemistry; and to provide basic research results useful for technological advances in fire safety, including the development of new fire-extinguishing agents and approaches, in the microgravity environment associated with ISS and in the partial-gravity Martian and lunar environments.

  12. Wildland Fire, Fire Suppression, and the US Carbon Budget: a Colorado Case Study

    NASA Astrophysics Data System (ADS)

    Neff, J.; Schimel, D.; Ojima, D.; McKeown, R.; Aulenbach, S.; Hilinski, T.

    2002-12-01

    The carbon budget of the US is poorly understood. Even conservative estimates suggest that US ecosystems take up a significant amount of carbon, largely as a result of historical land use practices. In the western US, fire suppression promotes carbon sequestration but also sets the stage for major losses of carbon, as occurred during the 2002 fire season. Increases in fire due to fire suppression, increased prescribed burning and thinning, and (or) climate change could significantly affect the national carbon budget. The western US accounts for roughly half of US carbon uptake, much of it in fire-prone western coniferous forests. We used a high-resolution ecosystem model coupled to a disturbance model, forced by observed weather and fire occurrence, to simulate the direct release of carbon from western coniferous ecosystems during wildland fire. As a case study, we simulated the 2002 fire season for Colorado, and modeled regrowth for 30 years using a Climate System model scenario (including the effects of elevated atmospheric carbon dioxide) under two scenarios of management, full fire suppression and aggressive thinning. Model results suggest that fire emissions during a severe fire season, coupled with drought-induced reductions in plant productivity, can have a significant impact on the regional carbon balance, and can, under certain conditions, change the region from a net sink of carbon to a net source of atmospheric carbon. Future management for fire risk is likely to have large effects on carbon uptake. In general, continued aggressive fire suppression leads to a slowing of carbon uptake as stands mature. Aggressive thinning leads to initial losses of carbon but may sustain net primary productivity depending on the details of the management scheme, and the degree of ecosystem nutrient loss associated with the thinning techniques. Both scenarios also interact closely with future climate to determine the overall impacts of wildland fire on regional carbon

  13. Supporting FIRE-suppression strategies combining fire spread MODelling and SATellite data in an operational context in Portugal: the FIRE-MODSAT project

    NASA Astrophysics Data System (ADS)

    Sá, Ana C. L.; Benali, Akli; Pinto, Renata M. S.; Pereira, José M. C.; Trigo, Ricardo M.; DaCamara, Carlos C.

    2014-05-01

    Large wildfires are infrequent but account for the most severe environmental, ecological and socio-economic impacts. In recent years Portugal has suffered the impact of major heat waves that fuelled records of burnt area exceeding 400.000ha and 300.000ha in 2003 and 2005, respectively. According to the latest IPCC reports, the frequency and amplitude of summer heat waves over Iberia will very likely increase in the future. Therefore, most climate change studies point to an increase in the number and extent of wildfires. Thus, an increase in both wildfire impacts and fire suppression difficulties is expected. The spread of large wildfires results from a complex interaction between topography, meteorology and fuel properties. Wildfire spread models (e.g. FARSITE) are commonly used to simulate fire growth and behaviour and are an essential tool to understand their main drivers. Additionally, satellite active-fire data have been used to monitor the occurrence, extent, and spread of wildfires. Both satellite data and fire spread models provide different types of information about the spatial and temporal distribution of large wildfires and can potentially be used to support strategic decisions regarding fire suppression resource allocation. However, they have not been combined in a manner that fully exploits their potential and minimizes their limitations. A knowledge gap still exists in understanding how to minimize the impacts of large wildfires, leading to the following research question: What can we learn from past large wildfires in order to mitigate future fire impacts? FIRE-MODSAT is a one-year funded project by the Portuguese Foundation for the Science and Technology (FCT) that is founded on this research question, with the main goal of improving our understanding on the interactions between fire spread and its environmental drivers, to support fire management decisions in an operational context and generate valuable information to improve the efficiency of the

  14. Fire alarm system/fire suppression system for mobile tactical shelters

    NASA Astrophysics Data System (ADS)

    Walker, F. K.; Lecours, C. A.; Radcliff, O.

    1985-08-01

    The objective of this project was to develop a fire detection/suppression capability for DoD standard family mobile tactical shelters. The systems developed and tested provide complete protection during all employment conditions; in garrison use, storage, transportation, and deployed field conditions. The reports outlines the requirement and the test and evaluation program. Two manufacturers of detection systems and two manufacturers of suppression systems were identified and qualified to meet the fire protection requirements for mobile tactical shelters.

  15. 30 CFR 75.1107-8 - Fire suppression devices; extinguishant supply systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... systems. 75.1107-8 Section 75.1107-8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT... Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment § 75.1107-8 Fire suppression devices; extinguishant supply systems. (a) Fire suppression systems using water...

  16. 30 CFR 75.1107-8 - Fire suppression devices; extinguishant supply systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... systems. 75.1107-8 Section 75.1107-8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT... Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment § 75.1107-8 Fire suppression devices; extinguishant supply systems. (a) Fire suppression systems using water...

  17. 61. VIEW SOUTH SHOWING MST RAIL, FIRE SUPPRESSION EQUIPMENT (LEFT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    61. VIEW SOUTH SHOWING MST RAIL, FIRE SUPPRESSION EQUIPMENT (LEFT OF RAIL), MST ANCHORING GROMETS (IN LIGHT SQUARE NEAR CENTER OF PHOTO AND IN BACKGROUND NEAR TERMINUS OF RAIL). NORTHWEST CORNER OF LAUNCHER IN LEFT BACKGROUND. BACK OF MAST CONTROL PANEL ON RIGHT. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  18. 65. FIRE SUPPRESSION PIPES BEHIND FLAME BUCKET. PIPES TO UMBILICAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    65. FIRE SUPPRESSION PIPES BEHIND FLAME BUCKET. PIPES TO UMBILICAL MAST IN LOWER LEFT CORNER; PIPES TO LAUNCHER IN UPPER LEFT CORNER; PIPES TO FLAME BUCKET IN LOWER RIGHT CORNER OF PHOTOGRAPH. POTABLE WATER PIPING IN UPPER RIGHT CORNER OF PHOTO. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  19. Reliability study of an emerging fire suppression system

    DOE PAGES

    Miller, David A.; Rossati, Lyric M.; Fritz, Nathan K.; Cournoyer, Michael E.; Granzow, Howard N.

    2015-02-07

    Self-contained fire extinguishers are a robust, reliable and minimally invasive means of fire suppression for gloveboxes. Plutonium gloveboxes are known to present harsh environmental conditions for polymer materials, these include radiation damage and chemical exposure, both of which tend to degrade the lifetime of engineered polymer components. The primary component of interest in self-contained fire extinguishers is the nylon 6-6 machined tube that comprises the main body of the system.Thermo-mechanical modeling and characterization of nylon 6-6 for use in plutonium glovebox applications has been carried out. Data has been generated regarding property degradation leading to poor, or reduced, engineering performancemore » of nylon 6-6 components. In this study, nylon 6-6 tensile specimens conforming to the casing of self-contained fire extinguisher systems have been exposed to hydrochloric, nitric, and sulfuric acids. This information was used to predict the performance of a load bearing engineering component comprised of nylon 6-6 and designed to operate in a consistent manner over a specified time period. The study provides a fundamental understanding of the engineering performance of the fire suppression system and the effects of environmental degradation due to acid exposure on engineering performance. Data generated help identify the limitations of self-contained fire extinguishers. No critical areas of concern for plutonium glovebox applications of nylon 6-6 have been identified when considering exposure to mineral acid.« less

  20. Reliability study of an emerging fire suppression system

    SciTech Connect

    Miller, David A.; Rossati, Lyric M.; Fritz, Nathan K.; Cournoyer, Michael E.; Granzow, Howard N.

    2015-02-07

    Self-contained fire extinguishers are a robust, reliable and minimally invasive means of fire suppression for gloveboxes. Plutonium gloveboxes are known to present harsh environmental conditions for polymer materials, these include radiation damage and chemical exposure, both of which tend to degrade the lifetime of engineered polymer components. The primary component of interest in self-contained fire extinguishers is the nylon 6-6 machined tube that comprises the main body of the system.Thermo-mechanical modeling and characterization of nylon 6-6 for use in plutonium glovebox applications has been carried out. Data has been generated regarding property degradation leading to poor, or reduced, engineering performance of nylon 6-6 components. In this study, nylon 6-6 tensile specimens conforming to the casing of self-contained fire extinguisher systems have been exposed to hydrochloric, nitric, and sulfuric acids. This information was used to predict the performance of a load bearing engineering component comprised of nylon 6-6 and designed to operate in a consistent manner over a specified time period. The study provides a fundamental understanding of the engineering performance of the fire suppression system and the effects of environmental degradation due to acid exposure on engineering performance. Data generated help identify the limitations of self-contained fire extinguishers. No critical areas of concern for plutonium glovebox applications of nylon 6-6 have been identified when considering exposure to mineral acid.

  1. 30 CFR 75.1107-1 - Fire-resistant hydraulic fluids and fire suppression devices on underground equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... suppression devices on underground equipment. 75.1107-1 Section 75.1107-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids...

  2. 30 CFR 75.1107-1 - Fire-resistant hydraulic fluids and fire suppression devices on underground equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... suppression devices on underground equipment. 75.1107-1 Section 75.1107-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids...

  3. 30 CFR 75.1107-1 - Fire-resistant hydraulic fluids and fire suppression devices on underground equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... suppression devices on underground equipment. 75.1107-1 Section 75.1107-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids...

  4. 30 CFR 75.1107-1 - Fire-resistant hydraulic fluids and fire suppression devices on underground equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... suppression devices on underground equipment. 75.1107-1 Section 75.1107-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids...

  5. 30 CFR 75.1107-6 - Capacity of fire suppression devices; location and direction of nozzles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment... electrical cables on the equipment which are subject to flexing or to external damage; and (2) All...

  6. 30 CFR 75.1912 - Fire suppression systems for permanent underground diesel fuel storage facilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Diesel-Powered Equipment § 75.1912 Fire suppression systems for permanent underground diesel fuel storage... permanent underground diesel fuel storage facility. (1) Alternate types of fire suppression systems shall be... § 75.1502. (d) The fire suppression system shall deenergize all power to the diesel fuel...

  7. 30 CFR 75.1912 - Fire suppression systems for permanent underground diesel fuel storage facilities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Diesel-Powered Equipment § 75.1912 Fire suppression systems for permanent underground diesel fuel storage... permanent underground diesel fuel storage facility. (1) Alternate types of fire suppression systems shall be... § 75.1502. (d) The fire suppression system shall deenergize all power to the diesel fuel...

  8. 30 CFR 75.1912 - Fire suppression systems for permanent underground diesel fuel storage facilities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Diesel-Powered Equipment § 75.1912 Fire suppression systems for permanent underground diesel fuel storage... permanent underground diesel fuel storage facility. (1) Alternate types of fire suppression systems shall be... § 75.1502. (d) The fire suppression system shall deenergize all power to the diesel fuel...

  9. 30 CFR 75.1912 - Fire suppression systems for permanent underground diesel fuel storage facilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Diesel-Powered Equipment § 75.1912 Fire suppression systems for permanent underground diesel fuel storage... permanent underground diesel fuel storage facility. (1) Alternate types of fire suppression systems shall be... § 75.1502. (d) The fire suppression system shall deenergize all power to the diesel fuel...

  10. 30 CFR 75.1912 - Fire suppression systems for permanent underground diesel fuel storage facilities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Diesel-Powered Equipment § 75.1912 Fire suppression systems for permanent underground diesel fuel storage... permanent underground diesel fuel storage facility. (1) Alternate types of fire suppression systems shall be... § 75.1502. (d) The fire suppression system shall deenergize all power to the diesel fuel...

  11. Fire Suppression in Low Gravity Using a Cup Burner

    NASA Technical Reports Server (NTRS)

    Takahashi, Fumiaki; Linteris, Gregory T.; Katta, Viswanath R.

    2004-01-01

    Longer duration missions to the moon, to Mars, and on the International Space Station increase the likelihood of accidental fires. The goal of the present investigation is to: (1) understand the physical and chemical processes of fire suppression in various gravity and O2 levels simulating spacecraft, Mars, and moon missions; (2) provide rigorous testing of numerical models, which include detailed combustion suppression chemistry and radiation sub-models; and (3) provide basic research results useful for advances in space fire safety technology, including new fire-extinguishing agents and approaches. The structure and extinguishment of enclosed, laminar, methane-air co-flow diffusion flames formed on a cup burner have been studied experimentally and numerically using various fire-extinguishing agents (CO2, N2, He, Ar, CF3H, and Fe(CO)5). The experiments involve both 1g laboratory testing and low-g testing (in drop towers and the KC-135 aircraft). The computation uses a direct numerical simulation with detailed chemistry and radiative heat-loss models. An agent was introduced into a low-speed coflowing oxidizing stream until extinguishment occurred under a fixed minimal fuel velocity, and thus, the extinguishing agent concentrations were determined. The extinguishment of cup-burner flames, which resemble real fires, occurred via a blowoff process (in which the flame base drifted downstream) rather than the global extinction phenomenon typical of counterflow diffusion flames. The computation revealed that the peak reactivity spot (the reaction kernel) formed in the flame base was responsible for attachment and blowoff of the trailing diffusion flame. Furthermore, the buoyancy-induced flame flickering in 1g and thermal and transport properties of the agents affected the flame extinguishment limits.

  12. Fire Suppression in Low Gravity Using a Cup Burner

    NASA Technical Reports Server (NTRS)

    Takahashi, Fumiaki; Linteris, Gregory T.; Katta, Viswanath R.

    2004-01-01

    Longer duration missions to the moon, to Mars, and on the International Space Station increase the likelihood of accidental fires. The goal of the present investigation is to: (1) understand the physical and chemical processes of fire suppression in various gravity and O2 levels simulating spacecraft, Mars, and moon missions; (2) provide rigorous testing of numerical models, which include detailed combustion-suppression chemistry and radiation sub-models; and (3) provide basic research results useful for advances in space fire safety technology, including new fire-extinguishing agents and approaches.The structure and extinguishment of enclosed, laminar, methane-air co-flow diffusion flames formed on a cup burner have been studied experimentally and numerically using various fire-extinguishing agents (CO2, N2, He, Ar, CF3H, and Fe(CO)5). The experiments involve both 1g laboratory testing and low-g testing (in drop towers and the KC-135 aircraft). The computation uses a direct numerical simulation with detailed chemistry and radiative heat-loss models. An agent was introduced into a low-speed coflowing oxidizing stream until extinguishment occurred under a fixed minimal fuel velocity, and thus, the extinguishing agent concentrations were determined. The extinguishment of cup-burner flames, which resemble real fires, occurred via a blowoff process (in which the flame base drifted downstream) rather than the global extinction phenomenon typical of counterflow diffusion flames. The computation revealed that the peak reactivity spot (the reaction kernel) formed in the flame base was responsible for attachment and blowoff of the trailing diffusion flame. Furthermore, the buoyancy-induced flame flickering in 1g and thermal and transport properties of the agents affected the flame extinguishment limits.

  13. Decreases in Soil Moisture and Organic Matter Quality Suppress Microbial Decomposition Following a Boreal Forest Fire

    SciTech Connect

    Holden, Sandra R.; Berhe, Asmeret A.; Treseder, Kathleen K.

    2015-08-01

    Climate warming is projected to increase the frequency and severity of wildfires in boreal forests, and increased wildfire activity may alter the large soil carbon (C) stocks in boreal forests. Changes in boreal soil C stocks that result from increased wildfire activity will be regulated in part by the response of microbial decomposition to fire, but post-fire changes in microbial decomposition are poorly understood. Here, we investigate the response of microbial decomposition to a boreal forest fire in interior Alaska and test the mechanisms that control post-fire changes in microbial decomposition. We used a reciprocal transplant between a recently burned boreal forest stand and a late successional boreal forest stand to test how post-fire changes in abiotic conditions, soil organic matter (SOM) composition, and soil microbial communities influence microbial decomposition. We found that SOM decomposing at the burned site lost 30.9% less mass over two years than SOM decomposing at the unburned site, indicating that post-fire changes in abiotic conditions suppress microbial decomposition. Our results suggest that moisture availability is one abiotic factor that constrains microbial decomposition in recently burned forests. In addition, we observed that burned SOM decomposed more slowly than unburned SOM, but the exact nature of SOM changes in the recently burned stand are unclear. Finally, we found no evidence that post-fire changes in soil microbial community composition significantly affect decomposition. Taken together, our study has demonstrated that boreal forest fires can suppress microbial decomposition due to post-fire changes in abiotic factors and the composition of SOM. Models that predict the consequences of increased wildfires for C storage in boreal forests may increase their predictive power by incorporating the observed negative response of microbial decomposition to boreal wildfires.

  14. 30 CFR 75.1107-14 - Guards and handrails; requirements where fire suppression devices are employed.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... suppression devices are employed. 75.1107-14 Section 75.1107-14 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  15. 30 CFR 75.1107-14 - Guards and handrails; requirements where fire suppression devices are employed.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... suppression devices are employed. 75.1107-14 Section 75.1107-14 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  16. 30 CFR 75.1107-14 - Guards and handrails; requirements where fire suppression devices are employed.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... suppression devices are employed. 75.1107-14 Section 75.1107-14 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  17. 30 CFR 75.1107-14 - Guards and handrails; requirements where fire suppression devices are employed.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... suppression devices are employed. 75.1107-14 Section 75.1107-14 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  18. 30 CFR 75.1107-14 - Guards and handrails; requirements where fire suppression devices are employed.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... suppression devices are employed. 75.1107-14 Section 75.1107-14 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  19. Examining the relative effects of fire weather, suppression and fuel treatment on fire behaviour--a simulation study.

    PubMed

    Penman, T D; Collins, L; Price, O F; Bradstock, R A; Metcalf, S; Chong, D M O

    2013-12-15

    Large budgets are spent on both suppression and fuel treatments in order to reduce the risk of wildfires. There is little evidence regarding the relative contribution of fire weather, suppression and fuel treatments in determining the risk posed from wildfires. Here we undertake a simulation study in the Sydney Basin, Australia, to examine this question using a fire behaviour model (Phoenix Rapidfire). Results of the study indicate that fire behaviour is most strongly influenced by fire weather. Suppression has a greater influence on whether a fire reaches 5 ha in size compared to fuel treatments. In contrast, fuel treatments have a stronger effect on the fire size and maximum distance the fire travels. The study suggests that fire management agencies will receive additional benefits from fuel treatment if they are located in areas which suppression resources can respond rapidly and attempt to contain the fires. No combination of treatments contained all fires, and the proportion of uncontained fires increased under more severe fire weather when the greatest number of properties are lost. Our study highlights the importance of alternative management strategies to reduce the risk of property loss.

  20. A feasibility study: California Department of Forestry and Fire Protection utilization of infrared technologies for wildland fire suppression and management

    NASA Technical Reports Server (NTRS)

    Nichols, J. D.; Britten, R. A.; Parks, G. S.; Voss, J. M.

    1990-01-01

    NASA's JPL has completed a feasibility study using infrared technologies for wildland fire suppression and management. The study surveyed user needs, examined available technologies, matched the user needs with technologies, and defined an integrated infrared wildland fire mapping concept system configuration. System component trade-offs were presented for evaluation in the concept system configuration. The economic benefits of using infrared technologies in fire suppression and management were examined. Follow-on concept system configuration development and implementation were proposed.

  1. Active fire detection using a peat fire radiance model

    NASA Astrophysics Data System (ADS)

    Kushida, K.; Honma, T.; Kaku, K.; Fukuda, M.

    2011-12-01

    The fire fractional area and radiances at 4 and 11 μm of active fires in Indonesia were estimated using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images. Based on these fire information, a stochastic fire model was used for evaluating two fire detection algorithms of Moderate Resolution Imaging Spectroradiometer (MODIS). One is single-image stochastic fire detection, and the other is multitemporal stochastic fire detection (Kushida, 2010 - IEEE Geosci. Remote Sens. Lett.). The average fire fractional area per one 1 km2 ×1 km2 pixel was 1.7%; this value corresponds to 32% of that of Siberian and Mongolian boreal forest fires. The average radiances at 4 and 11 μm of active fires were 7.2 W/(m2.sr.μm) and 11.1 W/(m2.sr.μm); these values correspond to 47% and 91% of those of Siberian and Mongolian boreal forest fires, respectively. In order to get false alarms less than 20 points per 106 km2 area, for the Siberian and Mongolian boreal forest fires, omission errors (OE) of 50-60% and about 40% were expected for the detections by using the single and multitemporal images, respectively. For Indonesian peat fires, OE of 80-90% was expected for the detections by using the single images. For the peat-fire detections by using the multitemporal images, OE of about 40% was expected, provided that the background radiances were estimated from past multitemporal images with less than the standard deviation of 1K. The analyses indicated that it was difficult to obtain sufficient active-fire information of Indonesian peat fires from single MODIS images for the fire fighting, and that the use of the multitemporal images was important.

  2. Suppression of pool fires with HRC-125 in a simulated engine nacelle.

    SciTech Connect

    Keyser, David R.; Hewson, John C.

    2007-06-01

    CFD simulations are conducted to predict the distribution of fire suppressant in an engine nacelle and to predict the suppression of pool fires by the application of this suppressant. In the baseline configuration, which is based on an installed system, suppressant is injected through four nozzles at a rate fast enough to suppress all simulated pool fires. Variations that reduce the mass of the suppression system (reducing the impact of the suppression system on meeting mission needs) are considered, including a reduction in the rate of suppressant injection, a reduction in the mass of suppressant and a reduction in the number of nozzles. In general, these variations should work to reduce the effectiveness of the suppression system, but the CFD results point out certain changes that have negligible impact, at least for the range of phenomena considered here. The results are compared with measurements where available. Comparisons with suppressant measurements are reasonable. A series of twenty-three fire suppression tests were conducted to check the predictions. The pre-test predictions were generally successful in identifying the range of successful suppression tests. In two separate cases, each where one nozzle of the suppression system was capped, the simulation results did indicate a failure to suppress for a condition where the tests indicated successful suppression. When the test-suppressant discharge rate was reduced by roughly 25%, the tests were in agreement with the predictions. That is, the simulations predict a failure to suppress slightly before observed in these cases.

  3. Production and efficiency of large wildland fire suppression effort: A stochastic frontier analysis.

    PubMed

    Katuwal, Hari; Calkin, David E; Hand, Michael S

    2016-01-15

    This study examines the production and efficiency of wildland fire suppression effort. We estimate the effectiveness of suppression resource inputs to produce controlled fire lines that contain large wildland fires using stochastic frontier analysis. Determinants of inefficiency are identified and the effects of these determinants on the daily production of controlled fire line are examined. Results indicate that the use of bulldozers and fire engines increase the production of controlled fire line, while firefighter crews do not tend to contribute to controlled fire line production. Production of controlled fire line is more efficient if it occurs along natural or built breaks, such as rivers and roads, and within areas previously burned by wildfires. However, results also indicate that productivity and efficiency of the controlled fire line are sensitive to weather, landscape and fire characteristics.

  4. Avian response to fire in pine–oak forests of Great Smoky Mountains National Park following decades of fire suppression

    USGS Publications Warehouse

    Rose, Eli T.; Simons, Theodore R.

    2016-01-01

    Fire suppression in southern Appalachian pine–oak forests during the past century dramatically altered the bird community. Fire return intervals decreased, resulting in local extirpation or population declines of many bird species adapted to post-fire plant communities. Within Great Smoky Mountains National Park, declines have been strongest for birds inhabiting xeric pine–oak forests that depend on frequent fire. The buildup of fuels after decades of fire suppression led to changes in the 1996 Great Smoky Mountains Fire Management Plan. Although fire return intervals remain well below historic levels, management changes have helped increase the amount of fire within the park over the past 20 years, providing an opportunity to study patterns of fire severity, time since burn, and bird occurrence. We combined avian point counts in burned and unburned areas with remote sensing indices of fire severity to infer temporal changes in bird occurrence for up to 28 years following fire. Using hierarchical linear models that account for the possibility of a species presence at a site when no individuals are detected, we developed occurrence models for 24 species: 13 occurred more frequently in burned areas, 2 occurred less frequently, and 9 showed no significant difference between burned and unburned areas. Within burned areas, the top models for each species included fire severity, time since burn, or both, suggesting that fire influenced patterns of species occurrence for all 24 species. Our findings suggest that no single fire management strategy will suit all species. To capture peak occupancy for the entire bird community within xeric pine–oak forests, at least 3 fire regimes may be necessary; one applying frequent low severity fire, another using infrequent low severity fire, and a third using infrequently applied high severity fire.

  5. Has fire suppression increased the amount of carbon stored in western U.S. forests?

    NASA Astrophysics Data System (ADS)

    Fellows, Aaron W.; Goulden, Michael L.

    2008-06-01

    Active 20th century fire suppression in western US forests, and a resulting increase in stem density, is thought to account for a significant fraction of the North American carbon sink. We compared California forest inventories from the 1930s with inventories from the 1990s to quantify changes in aboveground biomass. Stem density in mid-montane conifer forests increased by 34%, while live aboveground carbon stocks decreased by 26%. Increased stem density reflected an increase in the number of small trees and a net loss of large trees. Large trees contain a disproportionate amount of carbon, and the loss of large trees accounts for the decline in biomass between surveys. 20th century fire suppression and increasing stand density may have decreased, rather than increased, the amount of aboveground carbon in western US forests.

  6. Effects of fire retardant chemical and fire suppressant foam on shrub steppe vegetation in northern Nevada

    USGS Publications Warehouse

    Larson, Diane L.; Newton, Wesley E.; Anderson, Patrick J.; Stein, Steven J.

    1999-01-01

    The objectives of this study were to determine the effects of fire retardantchemical (Phos-Chek G75-F*) and fire suppressant foam (Silv-Ex) application,alone and in combination with fire, on Great Basin shrub steppe vegetation. Wemeasured growth, resprouting, flowering, and incidence of galling insects onChrysothamnus viscidiflorusandArtemisia tridentata. These characteristics were notaffected by any chemical treatment. We measured community characteristics,including species richness, evenness, and diversity, and number of stems ofwoody and herbaceous plants in riparian and upland plots. Of these characteristics, only species richness and number ofstems/m2 clearly responded to the chemicaltreatments, and the response was modified by fire. In general, speciesrichness declined, especially after Phos-Chek application. However, by the endof the growing season, species richness did not differ between treated andcontrol plots. Acanonical variate analysis suggested that burning had agreater influence on community composition than did the chemical treatments.In general, riparian areas showed more significant responses to the treatmentsthan did upland areas, and June applications produced greater changes inspecies richness and stem density than did July applications.

  7. Study of toxicological evaluation of fire suppressants and extinguishers

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The application of fluorocarbons as possible candidates for fire extinguishers and/or suppressants in confined spaces (such as spacecraft, aircraft, or submarines) was investigated, with special emphasis on their safety to man since they would be inhaled on an almost continuous basis. Short-term exposure experiments, using various animal species, were devised to look at specific parameters in order to determine which of the candidate compounds were sufficiently non-toxic to warrant long-term investigations. The following physiologic criteria were examined; tissue distribution, fluoride concentration, effect on mitochondria, microsomes, liposomes, and liver cell nuclei, erythrocyte fragility, clinical chemistry values, hematology, pathology, cardiac sensitization, behavioral effects. Various rodent species were used for initial investigations, with non-human primate exposures for Freon 116 which was warranted for negative results on rodents. Various types of exposure chambers were used, including closed dynamic chambers allowing for a recirculating atmosphere.

  8. 30 CFR 75.1107-13 - Approval of other fire suppression devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... suppression devices, if used on the protected equipment, shall meet the flame-resistant requirements of Part... rate of application of the fire suppression agent shall minimize the time for quenching and the total quantity applied shall be sufficient to quench a fire in its incipient stage. (k) The effectiveness of...

  9. 30 CFR 75.1107-13 - Approval of other fire suppression devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... suppression devices, if used on the protected equipment, shall meet the flame-resistant requirements of Part... rate of application of the fire suppression agent shall minimize the time for quenching and the total quantity applied shall be sufficient to quench a fire in its incipient stage. (k) The effectiveness of...

  10. 30 CFR 75.1107-13 - Approval of other fire suppression devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... suppression devices, if used on the protected equipment, shall meet the flame-resistant requirements of Part... rate of application of the fire suppression agent shall minimize the time for quenching and the total quantity applied shall be sufficient to quench a fire in its incipient stage. (k) The effectiveness of...

  11. 30 CFR 75.1107-13 - Approval of other fire suppression devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... suppression devices, if used on the protected equipment, shall meet the flame-resistant requirements of Part... rate of application of the fire suppression agent shall minimize the time for quenching and the total quantity applied shall be sufficient to quench a fire in its incipient stage. (k) The effectiveness of...

  12. 30 CFR 75.1107-13 - Approval of other fire suppression devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... suppression devices, if used on the protected equipment, shall meet the flame-resistant requirements of Part... rate of application of the fire suppression agent shall minimize the time for quenching and the total quantity applied shall be sufficient to quench a fire in its incipient stage. (k) The effectiveness of...

  13. 33 CFR 149.416 - What are the requirements for a dry chemical fire suppression system?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false What are the requirements for a dry chemical fire suppression system? 149.416 Section 149.416 Navigation and Navigable Waters COAST... the requirements for a dry chemical fire suppression system? Each natural gas deepwater port must...

  14. 33 CFR 149.416 - What are the requirements for a dry chemical fire suppression system?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false What are the requirements for a dry chemical fire suppression system? 149.416 Section 149.416 Navigation and Navigable Waters COAST... the requirements for a dry chemical fire suppression system? Each natural gas deepwater port must...

  15. 33 CFR 149.416 - What are the requirements for a dry chemical fire suppression system?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false What are the requirements for a dry chemical fire suppression system? 149.416 Section 149.416 Navigation and Navigable Waters COAST... the requirements for a dry chemical fire suppression system? Each natural gas deepwater port must...

  16. 33 CFR 149.416 - What are the requirements for a dry chemical fire suppression system?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false What are the requirements for a dry chemical fire suppression system? 149.416 Section 149.416 Navigation and Navigable Waters COAST... the requirements for a dry chemical fire suppression system? Each natural gas deepwater port must...

  17. 33 CFR 149.416 - What are the requirements for a dry chemical fire suppression system?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What are the requirements for a dry chemical fire suppression system? 149.416 Section 149.416 Navigation and Navigable Waters COAST... the requirements for a dry chemical fire suppression system? Each natural gas deepwater port must...

  18. 30 CFR 75.1107-5 - Electrical components of fire suppression devices; permissibility requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... devices; permissibility requirements. 75.1107-5 Section 75.1107-5 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  19. 30 CFR 75.1107-5 - Electrical components of fire suppression devices; permissibility requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... devices; permissibility requirements. 75.1107-5 Section 75.1107-5 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  20. 30 CFR 75.1107-15 - Fire suppression devices; hazards; training of miners.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... miners. 75.1107-15 Section 75.1107-15 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  1. 30 CFR 75.1107-15 - Fire suppression devices; hazards; training of miners.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... miners. 75.1107-15 Section 75.1107-15 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  2. 30 CFR 75.1107-6 - Capacity of fire suppression devices; location and direction of nozzles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and direction of nozzles. 75.1107-6 Section 75.1107-6 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  3. 30 CFR 75.1107-15 - Fire suppression devices; hazards; training of miners.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... miners. 75.1107-15 Section 75.1107-15 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  4. 30 CFR 75.1107-5 - Electrical components of fire suppression devices; permissibility requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... devices; permissibility requirements. 75.1107-5 Section 75.1107-5 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  5. 30 CFR 75.1107-3 - Fire suppression devices; approved components; installation requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...; installation requirements. 75.1107-3 Section 75.1107-3 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  6. 30 CFR 75.1107-3 - Fire suppression devices; approved components; installation requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...; installation requirements. 75.1107-3 Section 75.1107-3 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  7. 30 CFR 75.1107-6 - Capacity of fire suppression devices; location and direction of nozzles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... and direction of nozzles. 75.1107-6 Section 75.1107-6 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  8. 30 CFR 75.1107-8 - Fire suppression devices; extinguishant supply systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... systems. 75.1107-8 Section 75.1107-8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  9. 30 CFR 75.1107-15 - Fire suppression devices; hazards; training of miners.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... miners. 75.1107-15 Section 75.1107-15 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  10. 30 CFR 75.1107-5 - Electrical components of fire suppression devices; permissibility requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... devices; permissibility requirements. 75.1107-5 Section 75.1107-5 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  11. 30 CFR 75.1107-5 - Electrical components of fire suppression devices; permissibility requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... devices; permissibility requirements. 75.1107-5 Section 75.1107-5 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  12. 30 CFR 75.1107-6 - Capacity of fire suppression devices; location and direction of nozzles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and direction of nozzles. 75.1107-6 Section 75.1107-6 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  13. 30 CFR 75.1107-3 - Fire suppression devices; approved components; installation requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...; installation requirements. 75.1107-3 Section 75.1107-3 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  14. 30 CFR 75.1107-3 - Fire suppression devices; approved components; installation requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...; installation requirements. 75.1107-3 Section 75.1107-3 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  15. 30 CFR 75.1107-15 - Fire suppression devices; hazards; training of miners.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... miners. 75.1107-15 Section 75.1107-15 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  16. 30 CFR 75.1107-3 - Fire suppression devices; approved components; installation requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...; installation requirements. 75.1107-3 Section 75.1107-3 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  17. 30 CFR 75.1107-6 - Capacity of fire suppression devices; location and direction of nozzles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and direction of nozzles. 75.1107-6 Section 75.1107-6 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground...

  18. 30 CFR 75.1107-8 - Fire suppression devices; extinguishant supply systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... systems. 75.1107-8 Section 75.1107-8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  19. 30 CFR 75.1107-8 - Fire suppression devices; extinguishant supply systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... systems. 75.1107-8 Section 75.1107-8 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire Suppression Devices and Fire-Resistant Hydraulic Fluids on Underground Equipment §...

  20. 29 CFR 553.210 - Fire protection activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... worker, ambulance personnel, or hazardous materials worker, who—(1) is trained in fire suppression, has the legal authority and responsibility to engage in fire suppression, and is employed by a...

  1. 29 CFR 553.210 - Fire protection activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... worker, ambulance personnel, or hazardous materials worker, who—(1) is trained in fire suppression, has the legal authority and responsibility to engage in fire suppression, and is employed by a...

  2. 29 CFR 553.210 - Fire protection activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... worker, ambulance personnel, or hazardous materials worker, who—(1) is trained in fire suppression, has the legal authority and responsibility to engage in fire suppression, and is employed by a...

  3. 29 CFR 553.210 - Fire protection activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... worker, ambulance personnel, or hazardous materials worker, who—(1) is trained in fire suppression, has the legal authority and responsibility to engage in fire suppression, and is employed by a...

  4. Progress in Fire Detection and Suppression Technology for Future Space Missions

    NASA Technical Reports Server (NTRS)

    Friedman, Robert; Urban, David L.

    2000-01-01

    Fire intervention technology (detection and suppression) is a critical part of the strategy of spacecraft fire safety. This paper reviews the status, trends, and issues in fire intervention, particularly the technology applied to the protection of the International Space Station and future missions beyond Earth orbit. An important contribution to improvements in spacecraft fire safety is the understanding of the behavior of fires in the non-convective (microgravity) environment of Earth-orbiting and planetary-transit spacecraft. A key finding is the strong influence of ventilation flow on flame characteristics, flammability limits and flame suppression in microgravity. Knowledge of these flow effects will aid the development of effective processes for fire response and technology for fire suppression.

  5. Overview of ISS U.S. Fire Detection and Suppression System

    NASA Technical Reports Server (NTRS)

    Whitaker, Alana

    2003-01-01

    This paper presents a general overview of the International Space Station's Fire Detection and Suppression System. The topics include: 1) Introduction to Fire Detection and Suppression (FDS); 2) Description of (FDS) Subsystems; 3) FDS System Component Location and Status; 4) FDS System Capabilities; 5) FDS Automatic and Manual Response; 6) Post Fire Atmosphere Restoration and Air Quality Assessment; and 7) FDS Research Needs. This paper is in viewgraph form.

  6. 30 CFR 75.1911 - Fire suppression systems for diesel-powered equipment and fuel transportation units.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Fire suppression systems for diesel-powered... Diesel-Powered Equipment § 75.1911 Fire suppression systems for diesel-powered equipment and fuel transportation units. (a) The fire suppression system required by §§ 75.1907 and 75.1909 shall be a...

  7. 30 CFR 75.1911 - Fire suppression systems for diesel-powered equipment and fuel transportation units.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Fire suppression systems for diesel-powered... Diesel-Powered Equipment § 75.1911 Fire suppression systems for diesel-powered equipment and fuel transportation units. (a) The fire suppression system required by §§ 75.1907 and 75.1909 shall be a...

  8. 30 CFR 75.1911 - Fire suppression systems for diesel-powered equipment and fuel transportation units.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Fire suppression systems for diesel-powered... Diesel-Powered Equipment § 75.1911 Fire suppression systems for diesel-powered equipment and fuel transportation units. (a) The fire suppression system required by §§ 75.1907 and 75.1909 shall be a...

  9. 30 CFR 75.1103-10 - Fire suppression systems; additional requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements. 75.1103-10 Section 75.1103-10 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-10 Fire suppression systems; additional requirements. For each conveyor belt...

  10. 30 CFR 75.1103-10 - Fire suppression systems; additional requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements. 75.1103-10 Section 75.1103-10 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-10 Fire suppression systems; additional requirements. For each conveyor belt...

  11. 30 CFR 75.1103-10 - Fire suppression systems; additional requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements. 75.1103-10 Section 75.1103-10 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-10 Fire suppression systems; additional requirements. For each conveyor belt...

  12. 30 CFR 75.1103-10 - Fire suppression systems; additional requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements. 75.1103-10 Section 75.1103-10 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-10 Fire suppression systems; additional requirements. For each conveyor belt...

  13. 30 CFR 75.1103-10 - Fire suppression systems; additional requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... requirements. 75.1103-10 Section 75.1103-10 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-10 Fire suppression systems; additional requirements. For each conveyor belt...

  14. Effects of Three Fire-Suppressant Foams on the Germination and Physiological Responses of Plants

    NASA Astrophysics Data System (ADS)

    Song, Uhram; Mun, Saeromi; Waldman, Bruce; Lee, Eun Ju

    2014-10-01

    Suppressant foams used to fight forest fires may leave residual effects on surviving biota that managers need to consider prior to using them. We examined how three fire-suppressant foams (FSFs) (Forexpan S, Phos-Chek-WD881, and Silv-ex) affected seed germination and physiological responses of three plant species. Exposure to FSFs, whether in diluted concentrations or those typical in the field, reduced final germination percentages of seeds grown in petri dishes and within growth chambers. However, the FSFs did not cause total germination failure in any treatment. Inhibition of germination increased with longer exposure times, but only to diluted FSF solutions. Unlike in the laboratory experiments, none of the three FSFs affected seedling emergence when tested in field conditions. Further, we found no evidence of long-term phytotoxic effects on antioxidant enzyme activity nor chlorophyll content of the plant saplings. Therefore, although the three FSFs showed evidence of phytotoxicity to plants in laboratory tests, their actual impact on terrestrial ecosystems may be minimal. We suggest that the benefits of using these FSFs to protect plants in threatened forest ecosystems outweigh their minor risks.

  15. Assessing the risk to firefighters from chemical vapors and gases during vehicle fire suppression.

    PubMed

    Fent, Kenneth W; Evans, Douglas E

    2011-03-01

    Despite the frequent occurrence of vehicle fires, very few studies investigating firefighters' potential inhalation exposures during vehicle fire suppression have been conducted. In this paper, we present an assessment of firefighters' health risk from vehicle fire suppression that accounts for the mixture of gases and vapors likely to be found in these fires. Summa canisters were used to collect emissions from the engine and cabin fires of a single vehicle and were analyzed for 75 volatile organic compounds (VOCs). Firefighters' breathing zone concentrations (BZCs) of aromatic hydrocarbons, aldehydes, isocyanates, and carbon monoxide were measured during the suppression of three vehicle fires. The Summa canister and BZC data were used to develop a simple model for predicting BZCs for the compounds that were not measured in the firefighters' breathing zones. Hazard quotients (HQs) were calculated by dividing the predicted and measured BZCs by the most conservative short-term exposure limits (STELs) or ceiling limits. Hazard indices (HIs) were determined by adding HQs for compounds grouped by the target organ for acute health effects. Any HIs above unity represented unacceptable risks. According to this mixture analysis, the estimated 95(th) percentile of the exposure distribution for the study population represents ≥ 9.2 times the acceptable level of risk to the respiratory tract and eyes. Furthermore, chemicals known or reasonably anticipated to be human carcinogens contributed to > 45% of these HIs. While STELs are not usually based on carcinogenicity, maintaining exposures below STELs may protect individuals from the biological stress that could result from short-term exposures to carcinogens over time. Although vehicle fires are suppressed quickly (<10 min), this assessment suggests that firefighters have the potential to be overexposed to acute toxins during vehicle fire suppression and should therefore wear self-contained breathing apparatus at all times

  16. Evaluation of CO2, N2 and He as Fire Suppression Agents in Microgravity

    NASA Technical Reports Server (NTRS)

    Ruff, Gary A.; Hicks, Michael; Pettegrew, Richard

    2004-01-01

    The U.S. modules of the International Space Station use gaseous CO2 as the fire extinguishing agent. This was selected as a result of extensive experience with CO2 as a fire suppressant in terrestrial applications, trade studies on various suppressants, and experiments. The selection of fire suppressants and suppression strategies for NASA s Lunar and Martian exploration missions will be based on the same studies and normal-gravity data unless reduced gravity fire suppression data is obtained. In this study, the suppressant agent concentrations required to extinguish a flame in low velocity convective flows within the 20-sec of low gravity on the KC-135 aircraft were investigated. Suppressant gas mixtures of CO2, N2, and He with the balance being oxygen/nitrogen mixtures with either 21% or 25% O2 were used to suppress flames on a 19-mm diameter PMMA cylinder in reduced gravity. For each of the suppressant mixtures, limiting concentrations were established that would extinguish the flame at any velocity. Similarly, concentrations were established that would not extinguish the flame. The limiting concentrations were generally consistent with previous studies but did suggest that geometry had an effect on the limiting conditions. Between the extinction and non-extinction limits, the suppression characteristics depended on the extinguishing agent, flow velocity, and O2 concentration. The limiting velocity data from the CO2, He, and N2 suppressants were well correlated using an effective mixture enthalpy per mole of O2, indicating that all act via O2 displacement and cooling mechanisms. In reduced gravity, the agent concentration required to suppress the flames increased as the velocity increased, up to approximately 10 cm/s (the maximum velocity evaluated in this experiment). The effective enthalpy required to extinguish flames at velocities of 10 cm/s is approximately the same as the concentrations in normal gravity. A computational study is underway to further

  17. 36 CFR Appendix B to Part 1234 - Alternative Certified Fire-Safety Detection and Suppression System(s)

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-Safety Detection and Suppression System(s) B Appendix B to Part 1234 Parks, Forests, and Public Property... Suppression System(s) 1. General. This Appendix B contains information on the Fire-safety Detection and Suppression System(s) tested by NARA through independent live fire testing that are certified to meet...

  18. 36 CFR Appendix B to Part 1234 - Alternative Certified Fire-Safety Detection and Suppression System(s)

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-Safety Detection and Suppression System(s) B Appendix B to Part 1234 Parks, Forests, and Public Property... Suppression System(s) 1. General. This Appendix B contains information on the Fire-safety Detection and Suppression System(s) tested by NARA through independent live fire testing that are certified to meet...

  19. 36 CFR Appendix B to Part 1234 - Alternative Certified Fire-Safety Detection and Suppression System(s)

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-Safety Detection and Suppression System(s) B Appendix B to Part 1234 Parks, Forests, and Public Property... Suppression System(s) 1. General. This Appendix B contains information on the Fire-safety Detection and Suppression System(s) tested by NARA through independent live fire testing that are certified to meet...

  20. Thalamocortical neurons display suppressed burst-firing due to an enhanced Ih current in a genetic model of absence epilepsy.

    PubMed

    Cain, Stuart M; Tyson, John R; Jones, Karen L; Snutch, Terrance P

    2015-06-01

    Burst-firing in distinct subsets of thalamic relay (TR) neurons is thought to be a key requirement for the propagation of absence seizures. However, in the well-regarded Genetic Absence Epilepsy Rats from Strasbourg (GAERS) model as yet there has been no link described between burst-firing in TR neurons and spike-and-wave discharges (SWDs). GAERS ventrobasal (VB) neurons are a specific subset of TR neurons that do not normally display burst-firing during absence seizures in the GAERS model, and here, we assessed the underlying relationship of VB burst-firing with Ih and T-type calcium currents between GAERS and non-epileptic control (NEC) animals. In response to 200-ms hyperpolarizing current injections, adult epileptic but not pre-epileptic GAERS VB neurons displayed suppressed burst-firing compared to NEC. In response to longer duration 1,000-ms hyperpolarizing current injections, both pre-epileptic and epileptic GAERS VB neurons required significantly more hyperpolarizing current injection to burst-fire than those of NEC animals. The current density of the Hyperpolarization and Cyclic Nucleotide-activated (HCN) current (Ih) was found to be increased in GAERS VB neurons, and the blockade of Ih relieved the suppressed burst-firing in both pre-epileptic P15-P20 and adult animals. In support, levels of HCN-1 and HCN-3 isoform channel proteins were increased in GAERS VB thalamic tissue. T-type calcium channel whole-cell currents were found to be decreased in P7-P9 GAERS VB neurons, and also noted was a decrease in CaV3.1 mRNA and protein levels in adults. Z944, a potent T-type calcium channel blocker with anti-epileptic properties, completely abolished hyperpolarization-induced VB burst-firing in both NEC and GAERS VB neurons.

  1. Suomi NPP VIIRS active fire product status

    NASA Astrophysics Data System (ADS)

    Ellicott, E. A.; Csiszar, I. A.; Schroeder, W.; Giglio, L.; Wind, B.; Justice, C. O.

    2012-12-01

    We provide an overview of the evaluation and development of the Active Fires product derived from the Visible Infrared Imager Radiometer Suite (VIIRS) sensor on the Suomi National Polar-orbiting Partnership (SNPP) satellite during the first year of on-orbit data. Results from the initial evaluation of the standard SNPP Active Fires product, generated by the SNPP Interface Data Processing System (IDPS), supported the stabilization of the VIIRS Sensor Data Record (SDR) product. This activity focused in particular on the processing of the dual-gain 4 micron VIIRS M13 radiometric measurements into 750m aggregated data, which are fundamental for active fire detection. Following the VIIRS SDR product's Beta maturity status in April 2012, correlative analysis between VIIRS and near-simultaneous fire detections from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA Earth Observing System Aqua satellite confirmed the expected relative detection rates driven primarily by sensor differences. The VIIRS Active Fires Product Development and Validation Team also developed a science code that is based on the latest MODIS Collection 6 algorithm and provides a full spatially explicit fire mask to replace the sparse array output of fire locations from a MODIS Collection 4 equivalent algorithm in the current IDPS product. The Algorithm Development Library (ADL) was used to support the planning for the transition of the science code into IDPS operations in the future. Product evaluation and user outreach was facilitated by a product website that provided end user access to fire data in user-friendly format over North America as well as examples of VIIRS-MODIS comparisons. The VIIRS fire team also developed an experimental product based on 375m VIIRS Imagery band measurements and provided high quality imagery of major fire events in US. By August 2012 the IDPS product achieved Beta maturity, with some known and documented shortfalls related to the processing of

  2. [Combustion under microgravity and technique of fire prevention and suppression in space cabin].

    PubMed

    Jiang, X; Shen, L; Zheng, C; Zeng, Q; Fan, W

    1996-08-01

    This is a brief review on microgravity combustion, along with the discussion of the fundamental characteristics of combustion and fire processes under microgravity. Recent research activities in microgravity combustion and space fire prevention were emphasized. In addition, the potential use of flame-inhibiting atmospheres in the space cabin was introduced. The technique of fire detection and extinguishment in spacecraft environments was also discussed.

  3. Final Report: Fire Prevention, Detection, and Suppression Project, Exploration Technology Development Program

    NASA Technical Reports Server (NTRS)

    Ruff, Gary A.

    2011-01-01

    The Fire Prevention, Detection, and Suppression (FPDS) project is a technology development effort within the Exploration Technology Development Program of the Exploration System Missions Directorate (ESMD) that addresses all aspects of fire safety aboard manned exploration systems. The overarching goal for work in the FPDS area is to develop technologies that will ensure crew health and safety on exploration missions by reducing the likelihood of a fire, or, if one does occur, minimizing the risk to the crew, mission, or system. This is accomplished by addressing the areas of (1) fire prevention and material flammability, (2) fire signatures and detection, and (3) fire suppression and response. This report describes the outcomes of this project from the formation of the Exploration Technology Development Program (ETDP) in October 2005 to September 31, 2010 when the Exploration Technology Development Program was replaced by the Enabling Technology Development and Demonstration Program. NASA s fire safety work will continue under this new program and will build upon the accomplishments described herein.

  4. Nonexocytotic serotonin release tonically suppresses serotonergic neuron activity

    PubMed Central

    Montalbano, Alberto; Baccini, Gilda; Tatini, Francesca; Palmini, Rolando Berlinguer; Corradetti, Renato

    2015-01-01

    The firing activity of serotonergic neurons in raphe nuclei is regulated by negative feedback exerted by extracellular serotonin (5-HT)o acting through somatodendritic 5-HT1A autoreceptors. The steady-state [5-HT]o, sensed by 5-HT1A autoreceptors, is determined by the balance between the rates of 5-HT release and reuptake. Although it is well established that reuptake of 5-HTo is mediated by 5-HT transporters (SERT), the release mechanism has remained unclear. It is also unclear how selective 5-HT reuptake inhibitor (SSRI) antidepressants increase the [5-HT]o in raphe nuclei and suppress serotonergic neuron activity, thereby potentially diminishing their own therapeutic effect. Using an electrophysiological approach in a slice preparation, we show that, in the dorsal raphe nucleus (DRN), continuous nonexocytotic 5-HT release is responsible for suppression of phenylephrine-facilitated serotonergic neuron firing under basal conditions as well as for autoinhibition induced by SSRI application. By using 5-HT1A autoreceptor-activated G protein–gated inwardly rectifying potassium channels of patched serotonergic neurons as 5-HTo sensors, we show substantial nonexocytotic 5-HT release under conditions of abolished firing activity, Ca2+ influx, vesicular monoamine transporter 2–mediated vesicular accumulation of 5-HT, and SERT-mediated 5-HT transport. Our results reveal a cytosolic origin of 5-HTo in the DRN and suggest that 5-HTo may be supplied by simple diffusion across the plasma membrane, primarily from the dense network of neurites of serotonergic neurons surrounding the cell bodies. These findings indicate that the serotonergic system does not function as a sum of independently acting neurons but as a highly interdependent neuronal network, characterized by a shared neurotransmitter pool and the regulation of firing activity by an interneuronal, yet activity-independent, nonexocytotic mechanism. PMID:25712017

  5. Suppressing Irrelevant Information: Knowledge Activation or Inhibition?

    ERIC Educational Resources Information Center

    McNamara, Danielle S.; McDaniel, Mark A.

    2004-01-01

    In 3 experiments, the authors examined the role of knowledge activation in the suppression of contextually irrelevant meanings for ambiguous homographs. In Experiments 1 and 2, participants with greater baseball knowledge, regardless of reading skill, more quickly suppressed the irrelevant meaning of ambiguous words in baseball-related, but not…

  6. Modelling threats to water quality from fire suppression chemicals and post-fire erosion

    NASA Astrophysics Data System (ADS)

    Hyde, Kevin; Ziemniak, Chris; Elliot, William; Samuels, William

    2014-05-01

    Misapplication of fire retardant chemicals into streams and rivers may threaten aquatic life. The possible threat depends on the contaminant concentration that, in part, is controlled by dispersion within flowing water. In the event of a misapplication, methods are needed to rapidly estimate the chemical mass entering the waterway and the dispersion and transport within the system. Here we demonstrate a new tool that calculates the chemical mass based on aircraft delivery system, fire chemical type, and stream and intersect geometry. The estimated mass is intended to be transferred into a GIS module that uses real-time stream data to map and simulate the dispersion and transport downstream. This system currently accounts only for aqueous transport. We envision that the GIS module can be modified to incorporate sediment transport, specifically to model movement of sediments from post-fire erosion. This modification could support assessment of threats of post-fire erosion to water quality and water supply systems.

  7. Acute toxicity of fire-retardant and foam-suppressant chemicals to yalella azteca (Saussure)

    USGS Publications Warehouse

    McDonald, Susan F.; Hamilton, Steven J.; Buhl, Kevin J.; Heisinger, James F.

    1997-01-01

    Acute toxicity tests were conducted with Hyalella azteca Saussure (an amphipod) exposed in soft and hard waters to three fire retardants (Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F) and two foam suppressants (Phos-Chek WD-881 and Silv-Ex). The chemicals were slightly to moderately toxic to amphipods. The most toxic chemical to amphipods in soft and hard water was Phos-Chek WD-881 (96-h mean lethal concentration [LC50] equal to 10 mg/L and 22 mg/L, respectively), and the least toxic chemical to amphipods in soft water was Fire-Trol GTS-R (96-h LC50 equal to 127 mg/L) and in hard water was Fire-Trol LCG-R (96-h LC50 equal to 535 mg/L). Concentrations of ammonia in tests with the three fire retardants and both water types were greater than reported LC50 values and probably were the major toxic component. Estimated un-ionized ammonia concentrations near the LC50 were frequently less than the reported LC50 ammonia concentrations for amphipods. The three fire retardants were more toxic in soft water than in hard water even though ammonia and un-ionized ammonia concentrations were higher in hard water tests than in soft water tests. The accidental entry of fire-fighting chemicals into aquatic environments could adversely affect aquatic invertebrates, thereby disrupting ecosystem function.

  8. Suppressing irrelevant information: knowledge activation or inhibition?

    PubMed

    McNamara, Danielle S; McDaniel, Mark A

    2004-03-01

    In 3 experiments, the authors examined the role of knowledge activation in the suppression of contextually irrelevant meanings for ambiguous homographs. In Experiments 1 and 2, participants with greater baseball knowledge, regardless of reading skill, more quickly suppressed the irrelevant meaning of ambiguous words in baseball-related, but not general-topic, sentences. Experiment 3 demonstrated that participants with greater general knowledge, regardless of reading skill, more quickly suppressed the irrelevant meaning of the ambiguous words in general-topic sentences. As predicted by D. S. McNamara's (1997) knowledge-based account of suppression, ambiguity effects are influenced by greater activation of knowledge related to the intended meaning of the homograph. These results challenge inhibition (e.g. M. A. Gernsbacher, K. R. Varner. & M. Faust, 1990) as the sole mechanism responsible for the suppression of irrelevant information.

  9. Lessons Learned from the Node 1 Fire Detection and Suppression Subsystem Design

    NASA Technical Reports Server (NTRS)

    Williams, David E.

    2008-01-01

    This paper will provide an overview of the International Space Station (ISS) Environmental Control and Life Support (ECLS) design of the Node 1 Fire Detection and Suppression (FDS) subsystem and it will document some of the lessons that have been learned to date for this subsystem.

  10. METHOD OF SUPPRESSING GASTROINTESTINAL UREASE ACTIVITY

    DOEpatents

    Visek, W.J.

    1963-04-23

    This patent shows a method of increasing the growth rate of chicks. Certain diacyl substituted ureas such as alloxan, murexide, and barbituric acid are added to their feed, thereby suppressing gastrointestinal urease activity and thus promoting growth. (AEC)

  11. Measurement of myeloid cell immune suppressive activity.

    PubMed

    Dolcetti, Luigi; Peranzoni, Elisa; Bronte, Vincenzo

    2010-11-01

    This unit presents simple methods to assess the immunosuppressive properties of immunoregulatory cells of myeloid origin, such as myeloid-derived suppressor cells (MDSCs), both in vitro and in vivo. These methods are general and could be adapted to test the impact of different suppressive populations on T cell activation, proliferation, and cytotoxic activity; moreover they could be useful to assess the influence exerted on immune suppressive pathways by genetic modifications, chemical inhibitors, and drugs.

  12. Using Topography to Meet Wildlife and Fuels Treatment Objectives in Fire-Suppressed Landscapes

    NASA Astrophysics Data System (ADS)

    Underwood, Emma C.; Viers, Joshua H.; Quinn, James F.; North, Malcolm

    2010-11-01

    Past forest management practices, fire suppression, and climate change are increasing the need to actively manage California Sierra Nevada forests for multiple environmental amenities. Here we present a relatively low-cost, repeatable method for spatially parsing the landscape to help the U.S. Forest Service manage for different forest and fuel conditions to meet multiple goals relating to sensitive species, fuels reduction, forest products, water, carbon storage, and ecosystem restoration. Using the Kings River area of the Sierra Nevada as a case study, we create areas of topographically-based units, Landscape Management Units (LMUs) using a three by three matrix (canyon, mid-slope, ridge-top and northerly, southerly, and neutral aspects). We describe their size, elevation, slope, aspect, and their difference in inherent wetness and solar radiation. We assess the predictive value and field applicability of LMUs by using existing data on stand conditions and two sensitive wildlife species. Stand conditions varied significantly between LMUs, with canyons consistently having the greatest stem and snag densities. Pacific fisher ( Martes pennanti) activity points (from radio telemetry) and California spotted owl ( Strix occidentalis occidentalis) nests, roosts, and sightings were both significantly different from uniform, with a disproportionate number of observations in canyons, and fewer than expected on ridge-tops. Given the distinct characteristics of the LMUs, these units provide a relatively simple but ecologically meaningful template for managers to spatially allocate forest treatments, thereby meeting multiple National Forest objectives. These LMUs provide a framework that can potentially be applied to other fire-dependent western forests with steep topographic relief.

  13. Using topography to meet wildlife and fuels treatment objectives in fire-suppressed landscapes.

    PubMed

    Underwood, Emma C; Viers, Joshua H; Quinn, James F; North, Malcolm

    2010-11-01

    Past forest management practices, fire suppression, and climate change are increasing the need to actively manage California Sierra Nevada forests for multiple environmental amenities. Here we present a relatively low-cost, repeatable method for spatially parsing the landscape to help the U.S. Forest Service manage for different forest and fuel conditions to meet multiple goals relating to sensitive species, fuels reduction, forest products, water, carbon storage, and ecosystem restoration. Using the Kings River area of the Sierra Nevada as a case study, we create areas of topographically-based units, Landscape Management Units (LMUs) using a three by three matrix (canyon, mid-slope, ridge-top and northerly, southerly, and neutral aspects). We describe their size, elevation, slope, aspect, and their difference in inherent wetness and solar radiation. We assess the predictive value and field applicability of LMUs by using existing data on stand conditions and two sensitive wildlife species. Stand conditions varied significantly between LMUs, with canyons consistently having the greatest stem and snag densities. Pacific fisher (Martes pennanti) activity points (from radio telemetry) and California spotted owl (Strix occidentalis occidentalis) nests, roosts, and sightings were both significantly different from uniform, with a disproportionate number of observations in canyons, and fewer than expected on ridge-tops. Given the distinct characteristics of the LMUs, these units provide a relatively simple but ecologically meaningful template for managers to spatially allocate forest treatments, thereby meeting multiple National Forest objectives. These LMUs provide a framework that can potentially be applied to other fire-dependent western forests with steep topographic relief. PMID:20872142

  14. Fighting fire and fatigue: sleep quantity and quality during multi-day wildfire suppression.

    PubMed

    Vincent, Grace E; Aisbett, Brad; Hall, Sarah J; Ferguson, Sally A

    2016-07-01

    This study examined firefighters' sleep quantity and quality throughout multi-day wildfire suppression, and assessed the impact of sleep location, shift length, shift start time and incident severity on these variables. For 4 weeks, 40 volunteer firefighters' sleep was assessed using wrist actigraphy. Analyses revealed that the quantity of sleep obtained on fire days was restricted, and pre- and post-sleep fatigue ratings were higher, compared to non-fire days. On fire days, total sleep time was less when: (i) sleep location was in a tent or vehicle, (ii) shifts were greater than 14 h and (iii) shifts started between 05:00 and 06:00 h. This is the first empirical investigation providing objective evidence that firefighters' sleep is restricted during wildfire suppression. Furthermore, sleep location, shift length and shift start time should be targeted when designing appropriate controls to manage fatigue-related risk and preserve firefighters' health and safety during wildfire events. Practitioner Summary: During multi-day wildfire suppression, firefighters' sleep quantity was restricted, and pre- and post-sleep fatigue ratings were higher, compared to non-fire days. Furthermore, total sleep time was less when: (i) sleep occurred in a tent/vehicle, (ii) shifts were >14 h and (iii) shifts started between 05:00 and 06:00 h.

  15. Variability in the Geographic Distribution of Fires in Interior Alaska Considering Cause, Human Proximity, and Level of Suppression

    NASA Astrophysics Data System (ADS)

    Calef, M. P.; Varvak, A.; McGuire, A. D.; Chapin, T.

    2015-12-01

    The boreal forest of Interior Alaska is characterized by frequent extensive wildfires that have been mapped for the past 70 years. Simple predictions based on this record indicate that area burned will increase as a response to climate warming in Alaska. However, two additional factors have affected the area burned in this time record: the Pacific Decadal Oscillation (PDO) switched from cool and moist to warm and dry in the late 1970s and the Alaska Fire Service instituted a fire suppression policy in the late 1980s. Using Geographic Information Systems (GIS) and statistics, this presentation evaluates the variability in area burned and fire ignitions in Interior Alaska in space and time with particular emphasis on the human influence via ignition and suppression. Our analysis shows that while area burned has been increasing by 2.4% per year, the number of lightning ignitions has decreased by 1.9 ignitions per year. Human ignitions account for 50% of all fire ignitions in Interior Alaska and are clearly influenced by human proximity: human fires mostly occur close to settlements, highways and in intense fire suppression zones (which are in turn close to human settlements and roads); fires close to settlements, highways and in intense fire suppression zones burn much shorter than fires further away from this sphere of human influence; and 60% of all human fire ignitions in Interior Alaska are concentrated in the Fairbanks area and thereby strongly influence regional analyses. Fire suppression has effectively reduced area burned since it was implemented but the PDO change has also had some influence. Finally, we found that human fires start earlier in the year and burn for a shorter duration than lightning fires. This study provides insights into the importance of human behavior as well as regional climate patterns as large-scale controls on fires over time and across the Alaskan boreal forest.

  16. 36 CFR 1234.32 - What does an agency have to do to certify a fire-safety detection and suppression system?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... do to certify a fire-safety detection and suppression system? 1234.32 Section 1234.32 Parks, Forests... agency have to do to certify a fire-safety detection and suppression system? (a) Content of documentation... the fire-safety detection and suppression system used. The documentation must demonstrate how...

  17. 36 CFR 1234.32 - What does an agency have to do to certify a fire-safety detection and suppression system?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... do to certify a fire-safety detection and suppression system? 1234.32 Section 1234.32 Parks, Forests... agency have to do to certify a fire-safety detection and suppression system? (a) Content of documentation... the fire-safety detection and suppression system used. The documentation must demonstrate how...

  18. 36 CFR 1234.32 - What does an agency have to do to certify a fire-safety detection and suppression system?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... do to certify a fire-safety detection and suppression system? 1234.32 Section 1234.32 Parks, Forests... agency have to do to certify a fire-safety detection and suppression system? (a) Content of documentation... the fire-safety detection and suppression system used. The documentation must demonstrate how...

  19. 36 CFR 1234.32 - What does an agency have to do to certify a fire-safety detection and suppression system?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... to certify a fire-safety detection and suppression system? 1234.32 Section 1234.32 Parks, Forests... agency have to do to certify a fire-safety detection and suppression system? (a) Content of documentation... the fire-safety detection and suppression system used. The documentation must demonstrate how...

  20. Forest construction infrastructures for the prevision, suppression, and protection before and after forest fires

    NASA Astrophysics Data System (ADS)

    Drosos, Vasileios C.; Giannoulas, Vasileios J.; Daoutis, Christodoulos

    2014-08-01

    Climatic changes cause temperature rise and thus increase the risk of forest fires. In Greece the forests with the greatest risk to fire are usually those located near residential and tourist areas where there are major pressures on land use changes, while there are no currently guaranteed cadastral maps and defined title deeds because of the lack of National and Forest Cadastre. In these areas the deliberate causes of forest fires are at a percentage more than 50%. This study focuses on the forest opening up model concerning both the prevention and suppression of forest fires. The most urgent interventions that can be done after the fire destructions is also studied in relation to soil protection constructions, in order to minimize the erosion and the torrential conditions. Digital orthophotos were used in order to produce and analyze spatial data using Geographical Information Systems (GIS). Initially, Digital Elevation Models were generated, based on photogrammetry and forest areas as well as the forest road network were mapped. Road density, road distance, skidding distance and the opening up percentage were accurately measured for a forest complex. Finally, conclusions and suggestions have been drawn about the environmental compatibility of forest protection and wood harvesting works. In particular the contribution of modern technologies such as digital photogrammetry, remote sensing and Geographical Information Systems is very important, allowing reliable, effective and fast process of spatial analysis contributing to a successful planning of opening up works and fire protection.

  1. Syn-pandemic Fire Suppression in the Tropical Americas During European Conquest

    NASA Astrophysics Data System (ADS)

    Nevle, R. J.; Bird, D. K.

    2006-12-01

    A new reconstruction of the biomass burning history of the tropical Americas during the past 5 millennia documents the expansion of fire use by Mesoamerican and Amazonian agriculturalists and a subsequent period of fire suppression beginning ~500 years BP. Fire suppression is synchronous with the collapse of the American indigenous population during European conquest. The present work synthesizes microscopic charcoal accumulation records preserved in lake, bog, and basin sediments from 14 sites in Central America and equatorial South America to reconstruct regional variation in charcoal accumulation rates, averaged over 200-year increments, relative to the mean rate of regional charcoal accumulation during the past 5 millennia. This study builds upon prior fire history reconstructions by synthesizing a substantially greater number of stratigraphic charcoal accumulation sequences to resolve features of the Late Holocene biomass burning record in the tropical Americas. We find that between ~5000 and ~4000 years BP, charcoal accumulation generally persisted at rates >1 standard deviation (s.d.) below the 5-millennium mean. Subsequently charcoal accumulation rates fluctuated until ~3000 years BP and then increased, maintaining an average level >0.5 s.d. above the 5-millenium mean until ~500 years BP. After ~500 years BP, charcoal accumulation rates dropped to values below the 5000-year mean and remained suppressed for the next several centuries. The variation in charcoal accumulation rates over the past 5000 years reflects both climatic and anthropogenic factors affecting the regional fire history of the tropical Americas. The transition to above-average charcoal accumulation rates after 3000 years BP is synchronous with a trend toward a drier climate in the circum-Caribbean region and expanding forest clearance and cultivation by Mesoamerican and Amazonian societies. The subsequent, prolonged period of enhanced biomass burning between ~3000 and ~500 years BP is

  2. Transient and selective suppression of neural activity with infrared light

    PubMed Central

    Duke, Austin R.; Jenkins, Michael W.; Lu, Hui; McManus, Jeffrey M.; Chiel, Hillel J.; Jansen, E. Duco

    2013-01-01

    Analysis and control of neural circuitry requires the ability to selectively activate or inhibit neurons. Previous work showed that infrared laser light selectively excited neural activity in endogenous unmyelinated and myelinated axons. However, inhibition of neuronal firing with infrared light was only observed in limited cases, is not well understood and was not precisely controlled. Using an experimentally tractable unmyelinated preparation for detailed investigation and a myelinated preparation for validation, we report that it is possible to selectively and transiently inhibit electrically-initiated axonal activation, as well as to both block or enhance the propagation of action potentials of specific motor neurons. Thus, in addition to previously shown excitation, we demonstrate an optical method of suppressing components of the nervous system with functional spatiotemporal precision. We believe this technique is well-suited for non-invasive investigations of diverse excitable tissues and may ultimately be applied for treating neurological disorders. PMID:24009039

  3. Acute toxicity of three fire-retardant and two fire-suppressant foam formulations to the early life stages of rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Gaikowski, Mark P.; Hamilton, Steven J.; Buhl, Kevin J.; McDonald, Susan F.; Summers, Cliff H.; Linder, G.; Krest, S.; Sparling, D.; Little, E.

    1996-01-01

    Laboratory studies were conducted with five early life stages of rainbow trout, Oncorhynchus mykiss, to determine the acute toxicities of five fire-fighting chemical formulations in standardized soft and hard water. Eyed egg, embryo–larvae, swim-up fry, and 60- and 90-d posthatch juveniles were exposed to three fire retardants (Fire-Trol LCG-R, Fire-Trol GTS-R, and Phos-Chek D75-F) and two fire-suppressant foams (Phos-Chek WD-881 and Silv-Ex). Swim-up fry were generally the most sensitive life stage, whereas the eyed-egg was the least sensitive. Toxicity of fire-fighting formulations was greater in hard water than in soft water for all life stages tested with Fire-Trol GTS-R and Silv-Ex and for 90-d-old juveniles tested with Fire-Trol LCG-R. The fire-suppressant foams were more toxic than the fire retardants. The 96-h median lethal concentrations (LC50s) were ranked from the most toxic to the least toxic formulation as follows (ranges are the lowest and highest 96-h LC50 calculated for each formulation): Phos-Chek WD-881 (11–44 mg/L), Silv-Ex (11–78 mg/L), Phos-Chek D75-F (218–>3,600 mg/L), Fire-Trol GTS-R (207–>6,000 mg/L), and Fire-Trol LCG-R (872–>10,000 mg/L). Toxicity values suggest that accidental entry of fire-fighting chemicals into aquatic environments could adversely affect fish populations.

  4. Active Suppression Of Vibrations On Aircraft Structures

    NASA Technical Reports Server (NTRS)

    Maestrello, Lucio

    1995-01-01

    Method of active suppression of nonlinear and nonstationary vibrations developed to reduce sonic fatigue and interior noise in high-speed aircraft. Structure of aircraft exhibits periodic, chaotic, and random vibrations when forced by high-intensity sound from jet engines, shock waves, turbulence, and separated flows. Method of suppressing vibrations involves feedback control: Strain gauges or other sensors mounted in paths of propagation of vibrations on structure sense vibrations; outputs of sensors processed into control signal applied to actuator mounted on structure, inducing compensatory forces.

  5. 30 CFR 75.1103-9 - Minimum requirements; fire suppression materials and location; maintenance of entries and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-expansion foam devices. 75.1103-9 Section 75.1103-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-9 Minimum requirements; fire suppression materials and location; maintenance of...

  6. 30 CFR 75.1103-9 - Minimum requirements; fire suppression materials and location; maintenance of entries and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-expansion foam devices. 75.1103-9 Section 75.1103-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-9 Minimum requirements; fire suppression materials and location; maintenance of...

  7. 30 CFR 75.1103-9 - Minimum requirements; fire suppression materials and location; maintenance of entries and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-expansion foam devices. 75.1103-9 Section 75.1103-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-9 Minimum requirements; fire suppression materials and location; maintenance of...

  8. 30 CFR 75.1103-9 - Minimum requirements; fire suppression materials and location; maintenance of entries and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-expansion foam devices. 75.1103-9 Section 75.1103-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-9 Minimum requirements; fire suppression materials and location; maintenance of...

  9. 30 CFR 75.1103-9 - Minimum requirements; fire suppression materials and location; maintenance of entries and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-expansion foam devices. 75.1103-9 Section 75.1103-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1103-9 Minimum requirements; fire suppression materials and location; maintenance of...

  10. Immune Suppression and Immune Activation in Depression

    PubMed Central

    Blume, Joshua; Douglas, Steven D.; Evans, Dwight L.

    2010-01-01

    Depression has been characterized as a disorder of both immune suppression and immune activation. Markers of impaired cellular immunity (decreased natural killer cell cytotoxicity) and inflammation (elevated IL-6, TNFα, CRP) have been associated with depression. These immunological markers have been associated with other medical illnesses, suggesting that immune dysregulation may be a central feature common to both depression and to its frequent medical comorbidities. Yet the significant associations of findings of both immune suppression and immune activation with depression raise questions concerning the relationship between these two classes of immunological observations. Depressed populations are heterogeneous groups, and there may be differences in the immune profiles of populations that are more narrowly defined in terms of symptom profile and/or demographic features. There have been few reports concurrently investigating markers of immune suppression and immune activation in the same depressed individuals. An emerging preclinical literature suggests that chronic inflammation may directly contribute to the pathophysiology of immune suppression in the context of illnesses such as cancer and rheumatoid arthritis. This literature provides us with specific immunoregulatory mechanisms mediating these relationships that could also explain differences in immune disturbances between subsets of depressed individuals We propose a research agenda emphasizing the assessment of these immunoregulatory mechanisms in large samples of depressed subjects as a means to define the relationships among immune findings (suppression and/or activation) within the same depressed individuals and to characterize subsets of depressed subjects based on shared immune profiles. Such a program of research, building on and integrating our knowledge of the psychoneuroimmunology of depression, could lead to innovation in the assessment and treatment of depression and its medical comorbidities

  11. Improving global fire carbon emissions estimates by combining moderate resolution burned area and active fire observations

    NASA Astrophysics Data System (ADS)

    Randerson, J. T.; Chen, Y.; Giglio, L.; Rogers, B. M.; van der Werf, G.

    2011-12-01

    In several important biomes, including croplands and tropical forests, many small fires exist that have sizes that are well below the detection limit for the current generation of burned area products derived from moderate resolution spectroradiometers. These fires likely have important effects on greenhouse gas and aerosol emissions and regional air quality. Here we developed an approach for combining 1km thermal anomalies (active fires; MOD14A2) and 500m burned area observations (MCD64A1) to estimate the prevalence of these fires and their likely contribution to burned area and carbon emissions. We first estimated active fires within and outside of 500m burn scars in 0.5 degree grid cells during 2001-2010 for which MCD64A1 burned area observations were available. For these two sets of active fires we then examined mean fire radiative power (FRP) and changes in enhanced vegetation index (EVI) derived from 16-day intervals immediately before and after each active fire observation. To estimate the burned area associated with sub-500m fires, we first applied burned area to active fire ratios derived solely from within burned area perimeters to active fires outside of burn perimeters. In a second step, we further modified our sub-500m burned area estimates using EVI changes from active fires outside and within of burned areas (after subtracting EVI changes derived from control regions). We found that in northern and southern Africa savanna regions and in Central and South America dry forest regions, the number of active fires outside of MCD64A1 burned areas increased considerably towards the end of the fire season. EVI changes for active fires outside of burn perimeters were, on average, considerably smaller than EVI changes associated with active fires inside burn scars, providing evidence for burn scars that were substantially smaller than the 25 ha area of a single 500m pixel. FRP estimates also were lower for active fires outside of burn perimeters. In our

  12. Active flutter suppression using dipole filters

    NASA Technical Reports Server (NTRS)

    Srinathkumar, S.; Waszak, Martin R.

    1992-01-01

    By using traditional control concepts of gain root locus, the active suppression of a flutter mode of a flexible wing is examined. It is shown that the attraction of the unstable mode towards a critical system zero determines the degree to which the flutter mode can be stabilized. For control situations where the critical zero is adversely placed in the complex plane, a novel compensation scheme called a 'Dipole' filter is proposed. This filter ensures that the flutter mode is stabilized with acceptable control energy. The control strategy is illustrated by designing flutter suppression laws for an active flexible wing (AFW) wind-tunnel model, where minimal control effort solutions are mandated by control rate saturation problems caused by wind-tunnel turbulence.

  13. The Water-Mist Fire Suppression Experiment (Mist): Preliminary Results From The STS-107 Mission

    NASA Technical Reports Server (NTRS)

    Abbud-Madrid, Angel; McKinnon, J. Thomas; Amon, Francine; Gokoglu, Suleyman

    2003-01-01

    An investigation of the effect of water mists on premixed flame propagation has been conducted onboard the Space Shuttle to take advantage of the prolonged microgravity environment to study the effect of uniformly distributed clouds of polydisperse water mists on the speed and shape of propagating propane-air premixed flames. The suspension of a quiescent and uniform water mist cloud was confirmed during the microgravity tests. Preliminary results show good agreement with trends obtained by the numerical predictions of a computational model that uses a hybrid Eulerian-Lagrangian formulation to simulate the two-phase, flame/mist interaction. Effective flame suppression is observed at progressively higher water loadings and smaller water droplet sizes. Other unusual flame behavior, such as flame front breakup and pulsating flames, is still under investigation. The promising results from the microgravity tests will be used to assess the feasibility of using water mists as fire suppressants on Earth and on spacecraft.

  14. 29 CFR 553.210 - Fire protection activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... charged with forest fire fighting responsibilities, and who direct or engage in (1) fire spotting or... 29 Labor 3 2010-07-01 2010-07-01 false Fire protection activities. 553.210 Section 553.210 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR REGULATIONS...

  15. Mapping the Daily Progression of Large Wildland Fires Using MODIS Active Fire Data

    NASA Technical Reports Server (NTRS)

    Veraverbeke, Sander; Sedano, Fernando; Hook, Simon J.; Randerson, James T.; Jin, Yufang; Rogers, Brendan

    2013-01-01

    High temporal resolution information on burned area is a prerequisite for incorporating bottom-up estimates of wildland fire emissions in regional air transport models and for improving models of fire behavior. We used the Moderate Resolution Imaging Spectroradiometer (MODIS) active fire product (MO(Y)D14) as input to a kriging interpolation to derive continuous maps of the evolution of nine large wildland fires. For each fire, local input parameters for the kriging model were defined using variogram analysis. The accuracy of the kriging model was assessed using high resolution daily fire perimeter data available from the U.S. Forest Service. We also assessed the temporal reporting accuracy of the MODIS burned area products (MCD45A1 and MCD64A1). Averaged over the nine fires, the kriging method correctly mapped 73% of the pixels within the accuracy of a single day, compared to 33% for MCD45A1 and 53% for MCD64A1.

  16. Increasing late winter-early spring fire activity in Northern Spain: climate change or human footprint?

    NASA Astrophysics Data System (ADS)

    Carracedo Martín, Virginia; García Codron, Juan Carlos; Rasilla Álvarez, Domingo

    2016-04-01

    Most of the fire activity across Spain concentrates during the summer months, but a secondary peak appears also during late winter and early spring (February and March). This peak represents a tiny fraction of the burned surface but in northern Spain becomes the main fire season, representing up to 60 % of the total burned surface. Moreover, the impact of this "unseasonal" fire regime is becoming more relevant; an analysis of the temporal evolution of the burned surface since 2005 shows that the suppression efforts of summer forest fires have apparently succeeded, while the opposite has occurred with late winter-early spring forest fires. For example, during March 2012 more than 22,000 ha were burned in the Spanish provinces of Asturias and Cantabria, while about 14,000 suffers the effects of fires in Northern Portugal. Anthropogenic factor (mostly linked to an extensive cattle farming in the mountains) are the main cause of such fire activity, but atmospheric factors also play a relevant role in the spread of this fires. Consequently, the main aim of this poster is to explore if the recent evolution of forest fires in the study area are consequence of an aggravation of the atmospheric conditions driving to more fire risk conditions, or other factor could also explain the increase in fire activity. Burned surface data obtained from official statistics since 1971 were compared with atmospheric data at two temporal scales: daily fire risk values calculated from synoptic records and long term drought indices (SPI and SPEI). The results show a long term increase in both daily fire risk and drought conditions, but this trend can be related to the background warming of the area, rather to an increase in the frequency and magnitude of the extreme fire weather events. Thus, we consider that the regional atmospheric evolution cannot explain by itself the recent increase in late winter-early spring fire activity. Additional anthropogenic factors, such as recent changes in

  17. Eigenspace techniques for active flutter suppression

    NASA Technical Reports Server (NTRS)

    Garrard, William L.; Liebst, Bradley S.; Farm, Jerome A.

    1987-01-01

    The use of eigenspace techniques for the design of an active flutter suppression system for a hypothetical research drone is discussed. One leading edge and two trailing edge aerodynamic control surfaces and four sensors (accelerometers) are available for each wing. Full state control laws are designed by selecting feedback gains which place closed loop eigenvalues and shape closed loop eigenvectors so as to stabilize wing flutter and reduce gust loads at the wing root while yielding accepatable robustness and satisfying constrains on rms control surface activity. These controllers are realized by state estimators designed using an eigenvalue placement/eigenvector shaping technique which results in recovery of the full state loop transfer characteristics. The resulting feedback compensators are shown to perform almost as well as the full state designs. They also exhibit acceptable performance in situations in which the failure of an actuator is simulated.

  18. Projecting climate-driven increases in North American fire activity

    NASA Astrophysics Data System (ADS)

    Wang, D.; Morton, D. C.; Collatz, G. J.

    2013-12-01

    Climate regulates fire activity through controls on vegetation productivity (fuels), lightning ignitions, and conditions governing fire spread. In many regions of the world, human management also influences the timing, duration, and extent of fire activity. These coupled interactions between human and natural systems make fire a complex component of the Earth system. Satellite data provide valuable information on the spatial and temporal dynamics of recent fire activity, as active fires, burned area, and land cover information can be combined to separate wildfires from intentional burning for agriculture and forestry. Here, we combined satellite-derived burned area data with land cover and climate data to assess fire-climate relationships in North America between 2000-2012. We used the latest versions of the Global Fire Emissions Database (GFED) burned area product and Modern-Era Retrospective Analysis for Research and Applications (MERRA) climate data to develop regional relationships between burned area and potential evaporation (PE), an integrated dryness metric. Logistic regression models were developed to link burned area with PE and individual climate variables during and preceding the fire season, and optimal models were selected based on Akaike Information Criterion (AIC). Overall, our model explained 85% of the variance in burned area since 2000 across North America. Fire-climate relationships from the era of satellite observations provide a blueprint for potential changes in fire activity under scenarios of climate change. We used that blueprint to evaluate potential changes in fire activity over the next 50 years based on twenty models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). All models suggest an increase of PE under low and high emissions scenarios (Representative Concentration Pathways (RCP) 4.5 and 8.5, respectively), with largest increases in projected burned area across the western US and central Canada. Overall, near

  19. PETRO-SAFE '91 conference papers: Volume 6 (Treatment, disposal and remedial action) and Volume 7 (Fire prevention and suppression)

    SciTech Connect

    Not Available

    1991-01-01

    This proceedings contains two volumes of a ten volume set of papers pertaining to the oil, gas, and petrochemical industries. The first volume deals with waste treatment, disposal, and site remediation, and the second volume deals with fire prevention and suppression. Papers include subjects on cost and techniques of treatment and disposal; bioremediation technology; treatment and disposal technology; and technologies for water and soil clean-up. The volume on fire prevention and suppression includes papers on risk management; process safety, detection, and alarm systems; hazard mitigation and minimizing environmental damage; and advanced technologies, including foams, halon, etc.

  20. Recent Extreme Forest Fire Activity in Western Russia: Fire Danger Conditions, Fire Behavior and Smoke Transport

    NASA Astrophysics Data System (ADS)

    Stocks, B. J.; Fromm, M.; Goldammer, J.; Carr, R.; Sukhinin, A. I.

    2010-12-01

    During the summer of 2010, widespread forest and peatland fires in western Russia burned over hundreds of thousands of hectares, burning over croplands, destroying hundreds of homes, and directly causing the death of more than 50 people. Unprecedented drought conditions, combined with an extended heat wave, resulted in extreme fire danger conditions and explosive fire behavior in a region of Russia not noted for large fires. Several fires exhibited pyroconvection, injecting smoke directly into the upper troposphere and lower stratosphere, while deep-burning fires created major regional smoke problems. This smoke persisted in the heavily-populated areas around Moscow, exposing millions to high levels of ozone and particulate matter, and creating both immediate and longer-term health risks. This presentation will explore the drought conditions leading to the catastrophic fire behavior experienced in western Russia, and analyze fire behavior in terms of fuel consumption, smoke production, fire intensity levels, and pyroconvection. Impacts of regional and long-range smoke transport will also be discussed.

  1. Acute toxicity of fire-retardant and foam-suppressant chemicals to early life stages of chinook salmon (Oncorhynchus tshawytscha)

    USGS Publications Warehouse

    Buhl, Kevin J.; Hamilton, Steven J.

    1998-01-01

    Laboratorys studies were conducted to determine the acute toxicity of three fire retardants (Fire-Trol GTS-R, Fire-Trol LCG-R, and Phos-Chek D75-F), and two fire-suppressant foams (Phos-Chek WD-881 and Ansul Silv-Ex) to early life stages of chinook salmon, Oncorhynchus tshawytscha, in hard and soft water. Regardless of water type, swim-up fry and juveniles (60 and 90 d posthatch) exhibited similar sensitivities to each chemical and these life stages were more sensitive than eyed eggs. Foam suppressants were more toxic to each life stage than the fire retardants in both water types. The descending rank order of toxicity for these chemicals tested with swim-up fry and juveniles (range of 96-h median lethal concentrations [LC50s]) was Phos-Chek WD-881 (7–13 mg/L) > Ansul Silv-Ex (11–22 mg/L) > Phos-Chek D75-F (218–305 mg/L) > Fire-Trol GTS-R (218–412 mg/L) > Fire-Trol LCG-R (685–1,195 mg/L). Water type had a minor effect on the toxicity of these chemicals. Comparison of acute toxicity values with recommended application concentrations indicates that accidental inputs of these chemicals into stream environments would require substantial dilution (237- to 1,429-fold) to reach concentrations equivalent to their 96-h LC50s.

  2. Reptile assemblage response to restoration of fire-suppressed longleaf pine sandhills.

    PubMed

    Steen, David A; Smith, Lora L; Conner, L M; Litt, Andrea R; Provencher, Louis; Hiers, J Kevin; Pokswinski, Scott; Guyer, Craig

    2013-01-01

    Measuring the effects of ecological restoration on wildlife assemblages requires study on broad temporal and spatial scales. Longleaf pine (Pinus palustris) forests are imperiled due to fire suppression and subsequent invasion by hardwood trees. We employed a landscape-scale, randomized-block design to identify how reptile assemblages initially responded to restoration treatments including removal of hardwood trees via mechanical methods (felling and girdling), application of herbicides, or prescribed burning alone. Then, we examined reptile assemblages after all sites experienced more than a decade of prescribed burning at two- to thee-year return intervals. Data were collected concurrently at reference sites chosen to represent target conditions for restoration. Reptile assemblages changed most rapidly in response to prescribed burning, but reptile assemblages at all sites, including reference sites, were generally indistinguishable by the end of the study. Thus, we suggest that prescribed burning in longleaf pine forests over long time periods is an effective strategy for restoring reptile assemblages to the reference condition. Application of herbicides or mechanical removal of hardwood trees provided no apparent benefit to reptiles beyond what was achieved by prescribed fire alone.

  3. Analyses of fire growth and behavior using new VIIRS 375 m active fire data and a coupled weather-fire model (CAWFE)

    NASA Astrophysics Data System (ADS)

    Schroeder, W.; Coen, J. L.; Oliva, P.

    2014-12-01

    Recent advances in satellite fire detection and mapping and coupled weather-wildland fire modeling present a new opportunity to routinely map fire extent and progression, examine active fire areas in greater detail, and predict fire growth, intensification, and extreme behaviors of wildfires lasting several days. The new Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the NASA/NOAA Suomi-NPP satellite provides 12h global coverage at spatial resolutions of 375 m and 750 m. Compared to coarser resolution products, the new VIIRS 375 m active fire detection product enables early detection of small fires and improved mapping of large wildfires. NCAR's Coupled Atmosphere-Wildland Fire Environment (CAWFE) combines a numerical weather prediction model with wildland fire behavior algorithms to simulate fire behavior. These not only predict a fire's shape and extent, but extreme behaviors such as fire whirls, blow-ups, splitting of the head, flank runs, and pyrocumulus, all resulting from a fire's interaction with its environment, i.e. how the fire creates its own weather. We use the new VIIRS 375 m fire data to initialize and evaluate the CAWFE model, enabling accurate simulation of complex fire behavior during long-lasting wildfires. Compared to traditional models, this approach can now be applied to monitor and predict the growth of a fire or a group of simultaneous wildfires in a management unit from first detection until containment - a previously unattainable goal due to accumulation of model error.

  4. Forest fires and lightning activity during the outstanding 2003 and 2005 fire seasons

    NASA Astrophysics Data System (ADS)

    Russo, Ana; Ramos, Alexandre; Trigo, Ricardo

    2013-04-01

    Wildfires in southern Europe cause frequent extensive economical and ecological losses and, even human casualties. Comparatively to other Mediterranean countries, Portugal is the country with more burnt area and fires per unit area in the last decade, mainly during the summer season (Pereira et al., 2011). According to the fire records available, between 1980 and 2009, wildfires have affected over 3 million hectares in Portugal (JRC, 2011), which corresponds to approximately a third of the Portuguese Continental territory. The main factors that influence fire ignition and propagation are: (1) the presence of fuel (i.e. vegetation); (2) climate and weather; (3) socioeconomic conditions that affect land use/land cover patterns, fire-prevention and fire-fighting capacity and (4) topography. Specifically, weather (e.g. wind, temperature, precipitation, humidity, and lightning occurrence) plays an important role in fire behavior, affecting both ignition and spread of wildfires. Some countries have a relatively large fraction of fires caused by lightning, e.g. northwestern USA, Canada, Russia (). In contrast, Portugal has only a small percentage of fire records caused by lightning. Although significant doubts remain for the majority of fires in the catalog since they were cataloged without a likely cause. The recent years of 2003 and 2005 were particularly outstanding for fire activity in Portugal, registering, respectively, total burned areas of 425 726 ha and 338 262 ha. However, while the 2003 was triggered by an exceptional heatwave that struck the entire western Europe, the 2005 fire season registered was coincident with one of the most severe droughts of the 20th century. In this work we have used mainly two different databases: 1) the Portuguese Rural Fire Database (PRFD) which is representative of rural fires that have occurred in Continental Portugal, 2001-2011, with the original data provided by the Autoridade Florestal Nacional (AFN, 2011); 2) lightning

  5. Experimental study of radiant-heat blocking function of fine water mist suppressing small-scale pool fire

    NASA Astrophysics Data System (ADS)

    Xu, Qiang

    2004-04-01

    Fine water mist with droplet diameter less than 20 microns is less studied in water mist family used as firefighting agent. Experiments were conducted to study the radiant heat blocking function of fine water mist in suppressing pool fire. The fine water mist was generated by a jet atomizer. The jet flow of mist was with low momentum when it exerted on the pool fire. The interaction of this kind of fine water mist with pool fire is quite different from those mists with large droplet size and momentum. A group of ethyl-alcohol and gasoline pool fires with different power is used in the research. Fine water mist was exerted on the pool fire from different distances. Radiant heat flux was measured before and after the mist application. The experiment results show that because of its small droplet size and low momentum, the fine water mist could not even penetrate the buoyant plum zone of relatively larger scale pool fire. No water mist could reach the surface of the flame and result in no radiant heat blocking function would realize in the flame zone. This function is valid in low power pool fire and this limitation is obtained from the research for the studied pool fire.

  6. 30 CFR 75.1911 - Fire suppression systems for diesel-powered equipment and fuel transportation units.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... equipment and fuel transportation units. 75.1911 Section 75.1911 Mineral Resources MINE SAFETY AND HEALTH... transportation units. (a) The fire suppression system required by §§ 75.1907 and 75.1909 shall be a multipurpose... transportation units. (1) The system shall be installed in accordance with the manufacturer's specifications...

  7. 30 CFR 75.1911 - Fire suppression systems for diesel-powered equipment and fuel transportation units.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... equipment and fuel transportation units. 75.1911 Section 75.1911 Mineral Resources MINE SAFETY AND HEALTH... transportation units. (a) The fire suppression system required by §§ 75.1907 and 75.1909 shall be a multipurpose... transportation units. (1) The system shall be installed in accordance with the manufacturer's specifications...

  8. Experimental Evaluation of Pool Fire Suppression Performance of Sodium Leak Collection Tray in Open Air

    SciTech Connect

    Parida, F.C.; Rao, P.M.; Ramesh, S.S.; Malarvizhi, B.; Gopalakrishnan, V.; Rao, E.H.V.M.; Kasinathan, N.; Kannan, S.E.

    2006-07-01

    In the event of sodium leakage from heat transfer circuits of fast breeder reactors (FBR), liquid sodium catches fire in ambient air leading to production of flame, smoke and heat. One of the passive fire protection methods involves immediate collection of the leaking sodium to a sodium hold-up vessel (SHV) covered with a sloping cover tray (SCT) having a few drain pipes and one vent pipe (as in Fig. 1). As soon as the liquid sodium falls on the sloping cover tray, gravity guides the sodium through drain pipes into the bottom tray in which self-extinction occurs due to oxygen starvation. This sodium fire protection equipment called leak collection tray (LCT) works without the intervention of an operator and external power source. A large number of LCTs are strategically arranged under the sodium circulating pipe lines in the FBR plants to serve as passive suppression devices. In order to test the efficacy of the LCT, four tests were conducted. Two tests were with LCT having three drain pipes and rest with one. In each experiment, nearly 40 kg of hot liquid sodium at 550 deg. C was discharged on the LCT in the open air. Continuous on-line monitoring of temperature at strategic locations ({approx} 28 points) were carried out. Colour video-graphy was employed for taking motion pictures of various time-dependent events like sodium dumping, appearance of flame and release of smoke through vent pipes. After self-extinction of sodium fire, the LCT was allowed to cool overnight in an argon atmosphere. Solid samples of sodium debris in the SCT and SHV were collected by manual core drilling machine. The samples were subjected to chemical analysis for determination of unburnt and burnt sodium. The results of the four tests revealed an interesting feature: LCT with three drain pipes showed far lower sodium collection efficiency and much higher sodium combustion than that with just one drain pipe. Thermal fluctuations in temperature sensor located near the tip of the drain pipe

  9. 30 CFR 75.1107-16 - Inspection of fire suppression devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-16 Section 75.1107-16 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire... No. 13A—1971). National Fire Code No. 15 “Water Spray Fixed Systems for Fire Protection” (NFPA No....

  10. 30 CFR 75.1107-16 - Inspection of fire suppression devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-16 Section 75.1107-16 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire... No. 13A—1971). National Fire Code No. 15 “Water Spray Fixed Systems for Fire Protection” (NFPA No....

  11. 30 CFR 75.1107-16 - Inspection of fire suppression devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-16 Section 75.1107-16 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire... No. 13A—1971). National Fire Code No. 15 “Water Spray Fixed Systems for Fire Protection” (NFPA No....

  12. 30 CFR 75.1107-16 - Inspection of fire suppression devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-16 Section 75.1107-16 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire... No. 13A—1971). National Fire Code No. 15 “Water Spray Fixed Systems for Fire Protection” (NFPA No....

  13. 30 CFR 75.1107-16 - Inspection of fire suppression devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-16 Section 75.1107-16 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection Fire... No. 13A—1971). National Fire Code No. 15 “Water Spray Fixed Systems for Fire Protection” (NFPA No....

  14. Burned area, active fires and biomass burning - approaches to account for emissions from fires in Tanzania

    NASA Astrophysics Data System (ADS)

    Ruecker, Gernot; Hoffmann, Anja; Leimbach, David; Tiemann, Joachim; Ng'atigwa, Charles

    2013-04-01

    Eleven years of data from the globally available MODIS burned area and the MODS Active Fire Product have been analysed for Tanzania in conjunction with GIS data on land use and cover to provide a baseline for fire activity in this East African country. The total radiated energy (FRE) emitted by fires that were picked up by the burned area and active fire product is estimated based on a spatio-temporal clustering algorithm over the burned areas, and integration of the fire radiative power from the MODIS Active Fires product over the time of burning and the area of each burned area cluster. Resulting biomass combusted by unit area based on Woosteŕs scaling factor for FRE to biomass combusted is compared to values found in the literature, and to values found in the Global Fire Emissions Database (GFED). Pyrogenic emissions are then estimated using emission factors. According to our analysis, an average of 11 million ha burn annually (ranging between 8.5 and 12.9 million ha) in Tanzania corresponding to between 10 and 14 % of Tanzaniás land area. Most burned area is recorded in the months from May to October. The land cover types most affected are woodland and shrubland cover types: they comprise almost 70 % of Tanzania's average annual burned area or 6.8 million ha. Most burning occurs in gazetted land, with an annual average of 3.7 million ha in forest reserves, 3.3 million ha in game reserves and 1.46 million ha in national parks, totalling close to 8.5 million ha or 77 % of the annual average burned area of Tanzania. Annual variability of burned area is moderate for most of the analysed classes, and in most cases there is no clear trend to be detected in burned area, except for the Lindi region were annual burned area appears to be increasing. Preliminary results regarding emissions from fires show that for larger fires that burn over a longer time, biomass burned derived through the FRP method compares well to literature values, while the integration over

  15. Early warning of active fire hotspots through NASA FIRMS fire information system

    NASA Astrophysics Data System (ADS)

    Ilavajhala, S.; Davies, D.; Schmaltz, J. E.; Murphy, K. J.

    2014-12-01

    Forest fires and wildfires can threaten ecosystems, wildlife, property, and often, large swaths of populations. Early warning of active fire hotspots plays a crucial role in planning, managing, and mitigating the damaging effects of wildfires. The NASA Fire Information for Resource Management System (FIRMS) has been providing active fire location information to users in easy-to-use formats for the better part of last decade, with a view to improving the alerting mechanisms and response times to fight forest and wildfires. FIRMS utilizes fires flagged as hotspots by the MODIS instrument flying aboard the Aqua and Terra satellites and sends early warning of detected hotspots via email in near real-time or as daily and weekly summaries. The email alerts can also be customized to send alerts for a particular region of interest, a country, or a specific protected area or park. In addition, a web mapping component, named "Web Fire Mapper" helps query and visualize hotspots. A newer version of Web Fire Mapper is being developed to enhance the existing visualization and alerting capabilities. Plans include supporting near real-time imagery from Aqua and Terra satellites to provide a more helpful context while viewing fires. Plans are also underway to upgrade the email alerts system to provide mobile-formatted messages and short text messages (SMS). The newer version of FIRMS will also allow users to obtain geo-located image snapshots, which can be imported into local GIS software by stakeholders to help further analyses. This talk will discuss the FIRMS system, its enhancements and its role in helping map, alert, and monitor fire hotspots by providing quick data visualization, querying, and download capabilities.

  16. Suppression of Antigen-Specific Lymphocyte Activation in Simulated Microgravity

    NASA Technical Reports Server (NTRS)

    Cooper, David; Pride, Michael W.; Brown, Eric L.; Risin, Diana; Pellis, Neal R.

    1999-01-01

    Various parameters of immune suppression are observed in astronauts during and after spaceflight, and in isolated immune cells in true and simulated microgravity. Specifically, polyclonal activation of T cells is severely suppressed in true and simulated microgravity. These recent findings with various polyclonal activators suggests a suppression of oligoclonal lymphocyte activation in microgravity. We utilized rotating wall vessel (RWV) bioreactors that simulate aspects of microgravity for cell cultures to analyze three models of antigen-specific activation. A mixed-lymphocyte reaction (MLR), as a model for a primary immune response; a tetanus toxoid (TT) response and a B. burgdorferi (Bb) response, as models of a secondary immune response, were all suppressed in the RWV bioreactor. Our findings confirm that the suppression of activation observed with polyclonal models also encompasses oligoclonal antigen-specific activation.

  17. New Model Predicts Fire Activity in South America

    NASA Video Gallery

    UC Irvine scientist Jim Randerson discusses a new model that is able to predict fire activity in South America using sea surface temperature observations of the Pacific and Atlantic Ocean. The find...

  18. Low-cost active optical system for fire surveillance

    NASA Astrophysics Data System (ADS)

    Utkin, A. B.; Lavrov, A. V.; Vilar, R. M.

    2009-06-01

    Detection of smoke plumes using active optical sensors provides many advantages with respect to passive methods of fire surveillance. However, the price of these sensors is often too high as compared to passive fire detection instruments, such as infrared and video cameras. This article describes robust and cost effective diode-laser optical sensor for automatic fire surveillance in industrial environment. Physical aspects of the sensing process allowing to simplify the hardware and software design, eventually leading to significant reduction of manufacturing and maintenance costs, are discussed.

  19. Fires

    MedlinePlus

    Whether a fire happens in your home or in the wild, it can be very dangerous. Fire spreads quickly. There is no time to gather ... a phone call. In just two minutes, a fire can become life-threatening. In five minutes, a ...

  20. Trunk postures and upper-body muscle activations during physically demanding wildfire suppression tasks.

    PubMed

    Neesham-Smith, Daniel; Aisbett, Brad; Netto, Kevin

    2014-01-01

    This study examined the trunk postures and upper-body muscle activations during four physically demanding wildfire suppression tasks. Bilateral, wireless surface electromyography was recorded from the trapezius and erector spinae muscles of nine experienced, wildfire fighters. Synchronised video captured two retroreflective markers to allow for quantification of two-dimensional sagittal trunk flexion. In all tasks, significantly longer time was spent in the mild and severe trunk flexion (p ≤ 0.002) compared to the time spent in a neutral posture. Mean and peak muscle activation in all tasks exceeded previously established safe limits. These activation levels also significantly increased through the performance of each task (p < 0.001). The results suggest that the wildfire suppression tasks analysed impose significant musculoskeletal demand on firefighters. Fire agencies should consider developing interventions to reduce the exposure of their personnel to these potentially injurious musculoskeletal demands.

  1. Trunk postures and upper-body muscle activations during physically demanding wildfire suppression tasks.

    PubMed

    Neesham-Smith, Daniel; Aisbett, Brad; Netto, Kevin

    2014-01-01

    This study examined the trunk postures and upper-body muscle activations during four physically demanding wildfire suppression tasks. Bilateral, wireless surface electromyography was recorded from the trapezius and erector spinae muscles of nine experienced, wildfire fighters. Synchronised video captured two retroreflective markers to allow for quantification of two-dimensional sagittal trunk flexion. In all tasks, significantly longer time was spent in the mild and severe trunk flexion (p ≤ 0.002) compared to the time spent in a neutral posture. Mean and peak muscle activation in all tasks exceeded previously established safe limits. These activation levels also significantly increased through the performance of each task (p < 0.001). The results suggest that the wildfire suppression tasks analysed impose significant musculoskeletal demand on firefighters. Fire agencies should consider developing interventions to reduce the exposure of their personnel to these potentially injurious musculoskeletal demands. PMID:24365452

  2. Active flutter suppression - Control system design and experimental validation

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.; Srinathkumar, S.

    1991-01-01

    The synthesis and experimental validation of an active flutter suppression controller for the Active Flexible Wing wind-tunnel model is presented. The design is accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and with extensive use of simulation-based analysis. The design approach uses a fundamental understanding of the flutter mechanism to formulate a simple controller structure to meet stringent design specifications. Experimentally, the flutter suppression controller succeeded in simultaneous suppression of two flutter modes, significantly increasing the flutter dynamic pressure despite errors in flutter dynamic pressure and flutter frequency in the mathematical model. The flutter suppression controller was also successfully operated in combination with a roll maneuver controller to perform flutter suppression during rapid rolling maneuvers.

  3. 36 CFR 1234.32 - What does an agency have to do to certify a fire-safety detection and suppression system?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... storage equipment used, or how the space is designed, controlled, and operated) and the characteristics of... report under seal of a licensed fire protection engineer that: (i) Describes the design intent of the... the design intent of the fire suppression system. The report may make reasonable engineering and...

  4. Robust control design techniques for active flutter suppression

    NASA Technical Reports Server (NTRS)

    Ozbay, Hitay; Bachmann, Glen R.

    1994-01-01

    In this paper, an active flutter suppression problem is studied for a thin airfoil in unsteady aerodynamics. The mathematical model of this system is infinite dimensional because of Theodorsen's function which is irrational. Several second order approximations of Theodorsen's function are compared. A finite dimensional model is obtained from such an approximation. We use H infinity control techniques to find a robustly stabilizing controller for active flutter suppression.

  5. Functional connectivity in raphé-pontomedullary circuits supports active suppression of breathing during hypocapnic apnea.

    PubMed

    Nuding, Sarah C; Segers, Lauren S; Iceman, Kimberly E; O'Connor, Russell; Dean, Jay B; Bolser, Donald C; Baekey, David M; Dick, Thomas E; Shannon, Roger; Morris, Kendall F; Lindsey, Bruce G

    2015-10-01

    Hyperventilation is a common feature of disordered breathing. Apnea ensues if CO2 drive is sufficiently reduced. We tested the hypothesis that medullary raphé, ventral respiratory column (VRC), and pontine neurons have functional connectivity and persistent or evoked activities appropriate for roles in the suppression of drive and rhythm during hyperventilation and apnea. Phrenic nerve activity, arterial blood pressure, end-tidal CO2, and other parameters were monitored in 10 decerebrate, vagotomized, neuromuscularly-blocked, and artificially ventilated cats. Multielectrode arrays recorded spiking activity of 649 neurons. Loss and return of rhythmic activity during passive hyperventilation to apnea were identified with the S-transform. Diverse fluctuating activity patterns were recorded in the raphé-pontomedullary respiratory network during the transition to hypocapnic apnea. The firing rates of 160 neurons increased during apnea; the rates of 241 others decreased or stopped. VRC inspiratory neurons were usually the last to cease firing or lose rhythmic activity during the transition to apnea. Mayer wave-related oscillations (0.04-0.1 Hz) in firing rate were also disrupted during apnea. Four-hundred neurons (62%) were elements of pairs with at least one hyperventilation-responsive neuron and a correlational signature of interaction identified by cross-correlation or gravitational clustering. Our results support a model with distinct groups of chemoresponsive raphé neurons contributing to hypocapnic apnea through parallel processes that incorporate disfacilitation and active inhibition of inspiratory motor drive by expiratory neurons. During apnea, carotid chemoreceptors can evoke rhythm reemergence and an inspiratory shift in the balance of reciprocal inhibition via suppression of ongoing tonic expiratory neuron activity. PMID:26203111

  6. Functional connectivity in raphé-pontomedullary circuits supports active suppression of breathing during hypocapnic apnea

    PubMed Central

    Nuding, Sarah C.; Segers, Lauren S.; Iceman, Kimberly E.; O'Connor, Russell; Dean, Jay B.; Bolser, Donald C.; Baekey, David M.; Dick, Thomas E.; Shannon, Roger; Morris, Kendall F.

    2015-01-01

    Hyperventilation is a common feature of disordered breathing. Apnea ensues if CO2 drive is sufficiently reduced. We tested the hypothesis that medullary raphé, ventral respiratory column (VRC), and pontine neurons have functional connectivity and persistent or evoked activities appropriate for roles in the suppression of drive and rhythm during hyperventilation and apnea. Phrenic nerve activity, arterial blood pressure, end-tidal CO2, and other parameters were monitored in 10 decerebrate, vagotomized, neuromuscularly-blocked, and artificially ventilated cats. Multielectrode arrays recorded spiking activity of 649 neurons. Loss and return of rhythmic activity during passive hyperventilation to apnea were identified with the S-transform. Diverse fluctuating activity patterns were recorded in the raphé-pontomedullary respiratory network during the transition to hypocapnic apnea. The firing rates of 160 neurons increased during apnea; the rates of 241 others decreased or stopped. VRC inspiratory neurons were usually the last to cease firing or lose rhythmic activity during the transition to apnea. Mayer wave-related oscillations (0.04–0.1 Hz) in firing rate were also disrupted during apnea. Four-hundred neurons (62%) were elements of pairs with at least one hyperventilation-responsive neuron and a correlational signature of interaction identified by cross-correlation or gravitational clustering. Our results support a model with distinct groups of chemoresponsive raphé neurons contributing to hypocapnic apnea through parallel processes that incorporate disfacilitation and active inhibition of inspiratory motor drive by expiratory neurons. During apnea, carotid chemoreceptors can evoke rhythm reemergence and an inspiratory shift in the balance of reciprocal inhibition via suppression of ongoing tonic expiratory neuron activity. PMID:26203111

  7. Functional connectivity in raphé-pontomedullary circuits supports active suppression of breathing during hypocapnic apnea.

    PubMed

    Nuding, Sarah C; Segers, Lauren S; Iceman, Kimberly E; O'Connor, Russell; Dean, Jay B; Bolser, Donald C; Baekey, David M; Dick, Thomas E; Shannon, Roger; Morris, Kendall F; Lindsey, Bruce G

    2015-10-01

    Hyperventilation is a common feature of disordered breathing. Apnea ensues if CO2 drive is sufficiently reduced. We tested the hypothesis that medullary raphé, ventral respiratory column (VRC), and pontine neurons have functional connectivity and persistent or evoked activities appropriate for roles in the suppression of drive and rhythm during hyperventilation and apnea. Phrenic nerve activity, arterial blood pressure, end-tidal CO2, and other parameters were monitored in 10 decerebrate, vagotomized, neuromuscularly-blocked, and artificially ventilated cats. Multielectrode arrays recorded spiking activity of 649 neurons. Loss and return of rhythmic activity during passive hyperventilation to apnea were identified with the S-transform. Diverse fluctuating activity patterns were recorded in the raphé-pontomedullary respiratory network during the transition to hypocapnic apnea. The firing rates of 160 neurons increased during apnea; the rates of 241 others decreased or stopped. VRC inspiratory neurons were usually the last to cease firing or lose rhythmic activity during the transition to apnea. Mayer wave-related oscillations (0.04-0.1 Hz) in firing rate were also disrupted during apnea. Four-hundred neurons (62%) were elements of pairs with at least one hyperventilation-responsive neuron and a correlational signature of interaction identified by cross-correlation or gravitational clustering. Our results support a model with distinct groups of chemoresponsive raphé neurons contributing to hypocapnic apnea through parallel processes that incorporate disfacilitation and active inhibition of inspiratory motor drive by expiratory neurons. During apnea, carotid chemoreceptors can evoke rhythm reemergence and an inspiratory shift in the balance of reciprocal inhibition via suppression of ongoing tonic expiratory neuron activity.

  8. Modulation of the firing activity of noradrenergic neurones in the rat locus coeruleus by the 5-hydroxtryptamine system

    PubMed Central

    Haddjeri, Nasser; de Montigny, Claude; Blier, Pierre

    1997-01-01

    The aim of the present study was to investigate the putative modulation of locus coeruleus (LC) noradrenergic (NA) neurones by the 5-hydroxytryptaminergic (5-HT) system by use of in vivo extracellular unitary recordings and microiontophoresis in anaesthetized rats. To this end, the potent and selective 5-HT1A receptor antagonist WAY 100635 (N-{2-[4(2-methoxyphenyl)-1-piperazinyl]ethyl}-N-(2-pyridinyl)cyclohexanecarboxamide trihydroxychloride) was used.In the dorsal hippocampus, both local (by microiontophoresis, 20 nA) and systemic (100 μg kg−1, i.v.) administration of WAY 100635 antagonized the suppressant effect of microiontophorectically-applied 5-HT on the firing activity of CA3 pyramidal neurones, indicating its antagonistic effect on postsynaptic 5-HT1A receptors.WAY 100635 and 5-HT failed to modify the spontaneous firing activity of LC NA neurones when applied by microiontophoresis. However, the intravenous injection of WAY 100635 (100 μg kg−1) readily suppressed the spontaneous firing activity of LC NA neurones.The lesion of 5-HT neurones with the neurotoxin 5,7-dihydroxytryptamine increased the spontaneous firing activity of LC NA neurones and abolished the suppressant effect of WAY 100635 on the firing activity of LC NA neurones.In order to determine the nature of the 5-HT receptor subtypes mediating the suppressant effect of WAY 100635 on NA neurone firing activity, several 5-HT receptor antagonists were used. The selective 5-HT3 receptor antagonist BRL 46470A (10 and 100 μg kg−1, i.v.), the 5-HT1D receptor antagonist GR 127935 (100 μg kg−1, i.v.) and the 5-HT1A/1B receptor antagonist (−)-pindolol (15 mg kg−1, i.p.) did not prevent the suppressant effect of WAY 100635 on the firing activity of LC NA neurones. However, the suppressant effect of WAY 100635 was prevented by the non-selective 5-HT receptor antagonists spiperone (1 mg kg−1, i.v.) and metergoline (1 mg kg−1, i.v.), by the 5-HT2 receptor

  9. Plans for the Sentinel-3 SLSTR Active Fire Product

    NASA Astrophysics Data System (ADS)

    Wooster, Martin; Xu, Weidong

    2010-05-01

    The Sea and Land Surface Temperature Radiometer (SLSTR) will fly on the ESA Sentinel-3 satellites as a follow-on to the highly successful ERS/ENVISAR (A)ATSR series of imaging radiometers. SLSTR has been designed to offer a series of new capabilities over and above those of the forunner instruments (including an increased number of spectral channels, a much wider swath width, and an increased revisit frequency) whist still maintaining the key characteristics of dual-view, high accuracy and high precision radiometry. Included in the SLSTR-design are two dedicated "fire channels" that will allow unsaturated thermal spectral radiance observations over even high intensity and/or large open vegetation fires. Data from these and the other spectral channels will be used to generate an operational near real-time SLSTR active fire detection and fire radiative power product, to be used for both scientific studies on wildfire causes, behaviour and effects, and also operational applications involved with forecasting the short-term atmospheric impact of wildfire smoke. This work will present the plans for the SLSTR fire product, including details of the algorithm design and performance analysis, and an evaluation of the ver1 algorithm using MODIS data of global fire events.

  10. Suppression of antigen-specific lymphocyte activation in modeled microgravity

    NASA Technical Reports Server (NTRS)

    Cooper, D.; Pride, M. W.; Brown, E. L.; Risin, D.; Pellis, N. R.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    Various parameters of immune suppression are observed in lymphocytes from astronauts during and after a space flight. It is difficult to ascribe this suppression to microgravity effects on immune cells in crew specimens, due to the complex physiological response to space flight and the resultant effect on in vitro immune performance. Use of isolated immune cells in true and modeled microgravity in immune performance tests, suggests a direct effect of microgravity on in vitro cellular function. Specifically, polyclonal activation of T-cells is severely suppressed in true and modeled microgravity. These recent findings suggest a potential suppression of oligoclonal antigen-specific lymphocyte activation in microgravity. We utilized rotating wall vessel (RWV) bioreactors as an analog of microgravity for cell cultures to analyze three models of antigen-specific activation. A mixed-lymphocyte reaction, as a model for a primary immune response, a tetanus toxoid response and a Borrelia burgdorferi response, as models of a secondary immune response, were all suppressed in the RWV bioreactor. Our findings confirm that the suppression of activation observed with polyclonal models also encompasses oligoclonal antigen-specific activation.

  11. Vegetation stress and summer fire activity in Portugal

    NASA Astrophysics Data System (ADS)

    Carlos, DaCamara; Sílvia, Nunes

    2013-04-01

    Fire activity in Mediterranean Europe is closely related to the climatological background where the occurrence of rainy and mild winters, followed by warm and dry summers, may induce high levels of vegetation stress over the different regions making them prone to the occurrence of fire events. The aim of the present study is to investigate whether years of very high or very low levels of fire activity over forests in Portugal are linked to contrasting vegetation cycles associated to high and low degrees of vegetation stress during the summer season. The present study relies on time series of yearly amounts of burned areas provided by Instituto de Conservação da Natureza e das Florestas (ICNF), the national authority for forests as well as on monthly values of NDVI and of brightness temperature as obtained from the Mediterranean Extended Daily One Km AVHRR Data Set (MEDOKADS) product provided by the Free University of Berlin. Both datasets cover the 16-year period from 1990 to 2005. The area of forest is first identified by means of a k-means cluster analysis that is performed on climatological yearly means of NDVI and brightness temperature. Monthly means of NDVI and of brightness temperature are then evaluated over the area of forest and composites are made for severe and mild years of fire activity defined as those with yearly burned areas respectively above the third quartile and below the first quartile. The composite of severe years presents a brightness temperature cycle with values above average during spring and summer together with values of NDVI below average during summer, the behavior of both parameters providing an indication of vegetation stress. In contrast, the composite of mild years of fire activity presents an NDVI cycle with values well below average during spring, an indication of lack of biomass, and a brightness temperature cycle with values below average during spring and summer, an indication that vegetation is not under stress. Results

  12. Highly Effective, Low Toxicity, Low Environmental Impact Total Flooding Fire Suppressants

    NASA Technical Reports Server (NTRS)

    Glass, S. M.; Dhooge, P. M.; Nimitz, J. S.

    2001-01-01

    Halon 1301 (CF3Br) has been used for decades as the primary fire suppression agent for areas where powder agents cannot be used because of concerns for sensitive equipment. Halon 1301 is an excellent extinguishing agent, effective at about 3% in air and quite non-toxic. It has an effective exposure limit much greater than its extinguishing concentration, so it can be used in normally occupied areas. The ability of a chemical to destroy stratospheric ozone is its ozone-depletion potential (ODP). ODP is the amount of ozone destroyed per pound of a chemical, relative to the standard CFC-11 with an ODP = 1.0. Because halons have been implicated in stratospheric ozone depletion, their production was stopped at the end of 1995 under the provisions of the Montreal Protocol plus later amendments. In the US, the Clean Air Act Amendments of 1990, Presidential directives, and DoD Directive 6050.9 implemented this phaseout. These regulations and penalties have provided strong incentives for US businesses to decrease CFC use. The Omnibus Budget Reconciliation Act of 1989 mandates high Federal taxes on CFCs and halons, designed to price them out of the market. The taxes also capture for the government the windfall profits that would otherwise go to producers as scarcity drives up prices. Several replacements have been developed for Halon 1301. One is carbon dioxide, which has been used as a firefighting agent for many years. However, a high concentration of carbon dioxide is necessary to inert fuels. The effective concentration for inerting with carbon dioxide is approximately 29%, which is above the concentration lethal to humans. HFC-227ea is being used extensively to replace Halon 1301 systems in nominally occupied areas and some normally unoccupied areas. However, since the effective concentration of HFC-227ea is about three to four times that of Halon 1301 the extinguishing systems have to be larger and new extinguishing systems have to be installed. HFC-125 is also being

  13. Detection rates of the MODIS active fire product in the United States

    USGS Publications Warehouse

    Hawbaker, T.J.; Radeloff, V.C.; Syphard, A.D.; Zhu, Z.; Stewart, S.I.

    2008-01-01

    MODIS active fire data offer new information about global fire patterns. However, uncertainties in detection rates can render satellite-derived fire statistics difficult to interpret. We evaluated the MODIS 1??km daily active fire product to quantify detection rates for both Terra and Aqua MODIS sensors, examined how cloud cover and fire size affected detection rates, and estimated how detection rates varied across the United States. MODIS active fire detections were compared to 361 reference fires (??? 18??ha) that had been delineated using pre- and post-fire Landsat imagery. Reference fires were considered detected if at least one MODIS active fire pixel occurred within 1??km of the edge of the fire. When active fire data from both Aqua and Terra were combined, 82% of all reference fires were found, but detection rates were less for Aqua and Terra individually (73% and 66% respectively). Fires not detected generally had more cloudy days, but not when the Aqua data were considered exclusively. MODIS detection rates decreased with fire size, and the size at which 50% of all fires were detected was 105??ha when combining Aqua and Terra (195??ha for Aqua and 334??ha for Terra alone). Across the United States, detection rates were greatest in the West, lower in the Great Plains, and lowest in the East. The MODIS active fire product captures large fires in the U.S. well, but may under-represent fires in areas with frequent cloud cover or rapidly burning, small, and low-intensity fires. We recommend that users of the MODIS active fire data perform individual validations to ensure that all relevant fires are included. ?? 2008 Elsevier Inc. All rights reserved.

  14. Flutter suppression by active control and its benefits

    NASA Technical Reports Server (NTRS)

    Doggett, R. V., Jr.; Townsend, J. C.

    1976-01-01

    A general discussion of the airplane applications of active flutter suppression systems is presented with focus on supersonic cruise aircraft configurations. Topics addressed include a brief historical review; benefits, risks, and concerns; methods of application; and applicable configurations. Results are presented where the direct operating costs and performance benefits of an arrow wing supersonic cruise vehicle equipped with an active flutter suppression system are compared with corresponding costs and performance of the same baseline airplane where the flutter deficiency was corrected by passive methods (increases in structural stiffness). The design, synthesis, and conceptual mechanization of the active flutter suppression system are discussed. The results show that a substantial weight savings can be accomplished by using the active system. For the same payload and range, airplane direct operating costs are reduced by using the active system. The results also indicate that the weight savings translates into increased range or payload.

  15. Diversity and Activity of Lysobacter Species from Disease Suppressive Soils

    PubMed Central

    Gómez Expósito, Ruth; Postma, Joeke; Raaijmakers, Jos M.; De Bruijn, Irene

    2015-01-01

    The genus Lysobacter includes several species that produce a range of extracellular enzymes and other metabolites with activity against bacteria, fungi, oomycetes, and nematodes. Lysobacter species were found to be more abundant in soil suppressive against the fungal root pathogen Rhizoctonia solani, but their actual role in disease suppression is still unclear. Here, the antifungal and plant growth-promoting activities of 18 Lysobacter strains, including 11 strains from Rhizoctonia-suppressive soils, were studied both in vitro and in vivo. Based on 16S rRNA sequencing, the Lysobacter strains from the Rhizoctonia-suppressive soil belonged to the four species Lysobacter antibioticus, Lysobacter capsici, Lysobacter enzymogenes, and Lysobacter gummosus. Most strains showed strong in vitro activity against R. solani and several other pathogens, including Pythium ultimum, Aspergillus niger, Fusarium oxysporum, and Xanthomonas campestris. When the Lysobacter strains were introduced into soil, however, no significant and consistent suppression of R. solani damping-off disease of sugar beet and cauliflower was observed. Subsequent bioassays further revealed that none of the Lysobacter strains was able to promote growth of sugar beet, cauliflower, onion, and Arabidopsis thaliana, either directly or via volatile compounds. The lack of in vivo activity is most likely attributed to poor colonization of the rhizosphere by the introduced Lysobacter strains. In conclusion, our results demonstrated that Lysobacter species have strong antagonistic activities against a range of pathogens, making them an important source for putative new enzymes and antimicrobial compounds. However, their potential role in R. solani disease suppressive soil could not be confirmed. In-depth omics'–based analyses will be needed to shed more light on the potential contribution of Lysobacter species to the collective activities of microbial consortia in disease suppressive soils. PMID:26635735

  16. Diversity and Activity of Lysobacter Species from Disease Suppressive Soils.

    PubMed

    Gómez Expósito, Ruth; Postma, Joeke; Raaijmakers, Jos M; De Bruijn, Irene

    2015-01-01

    The genus Lysobacter includes several species that produce a range of extracellular enzymes and other metabolites with activity against bacteria, fungi, oomycetes, and nematodes. Lysobacter species were found to be more abundant in soil suppressive against the fungal root pathogen Rhizoctonia solani, but their actual role in disease suppression is still unclear. Here, the antifungal and plant growth-promoting activities of 18 Lysobacter strains, including 11 strains from Rhizoctonia-suppressive soils, were studied both in vitro and in vivo. Based on 16S rRNA sequencing, the Lysobacter strains from the Rhizoctonia-suppressive soil belonged to the four species Lysobacter antibioticus, Lysobacter capsici, Lysobacter enzymogenes, and Lysobacter gummosus. Most strains showed strong in vitro activity against R. solani and several other pathogens, including Pythium ultimum, Aspergillus niger, Fusarium oxysporum, and Xanthomonas campestris. When the Lysobacter strains were introduced into soil, however, no significant and consistent suppression of R. solani damping-off disease of sugar beet and cauliflower was observed. Subsequent bioassays further revealed that none of the Lysobacter strains was able to promote growth of sugar beet, cauliflower, onion, and Arabidopsis thaliana, either directly or via volatile compounds. The lack of in vivo activity is most likely attributed to poor colonization of the rhizosphere by the introduced Lysobacter strains. In conclusion, our results demonstrated that Lysobacter species have strong antagonistic activities against a range of pathogens, making them an important source for putative new enzymes and antimicrobial compounds. However, their potential role in R. solani disease suppressive soil could not be confirmed. In-depth omics'-based analyses will be needed to shed more light on the potential contribution of Lysobacter species to the collective activities of microbial consortia in disease suppressive soils. PMID:26635735

  17. Diversity and Activity of Lysobacter Species from Disease Suppressive Soils.

    PubMed

    Gómez Expósito, Ruth; Postma, Joeke; Raaijmakers, Jos M; De Bruijn, Irene

    2015-01-01

    The genus Lysobacter includes several species that produce a range of extracellular enzymes and other metabolites with activity against bacteria, fungi, oomycetes, and nematodes. Lysobacter species were found to be more abundant in soil suppressive against the fungal root pathogen Rhizoctonia solani, but their actual role in disease suppression is still unclear. Here, the antifungal and plant growth-promoting activities of 18 Lysobacter strains, including 11 strains from Rhizoctonia-suppressive soils, were studied both in vitro and in vivo. Based on 16S rRNA sequencing, the Lysobacter strains from the Rhizoctonia-suppressive soil belonged to the four species Lysobacter antibioticus, Lysobacter capsici, Lysobacter enzymogenes, and Lysobacter gummosus. Most strains showed strong in vitro activity against R. solani and several other pathogens, including Pythium ultimum, Aspergillus niger, Fusarium oxysporum, and Xanthomonas campestris. When the Lysobacter strains were introduced into soil, however, no significant and consistent suppression of R. solani damping-off disease of sugar beet and cauliflower was observed. Subsequent bioassays further revealed that none of the Lysobacter strains was able to promote growth of sugar beet, cauliflower, onion, and Arabidopsis thaliana, either directly or via volatile compounds. The lack of in vivo activity is most likely attributed to poor colonization of the rhizosphere by the introduced Lysobacter strains. In conclusion, our results demonstrated that Lysobacter species have strong antagonistic activities against a range of pathogens, making them an important source for putative new enzymes and antimicrobial compounds. However, their potential role in R. solani disease suppressive soil could not be confirmed. In-depth omics'-based analyses will be needed to shed more light on the potential contribution of Lysobacter species to the collective activities of microbial consortia in disease suppressive soils.

  18. Experimental results of water film formation on various fuel forms from a fire suppression system

    SciTech Connect

    Ross, R.H.; Davis, J.R.

    1993-12-31

    The purpose of the study was to determine the thickness and coverage of water film formations on various materials during fire sprinkler deluge. An exhaustive literature search revealed that no applicable research data exists that governs water film formations from fire protection systems. Therefore, a controlled, infield, mockup was created to predict the thickness and coverage of water film on fissile material forms. This paper discusses the background, experimental procedure and the characterization of these water films.

  19. Active Suppression of Instabilities in Engine Combustors

    NASA Technical Reports Server (NTRS)

    Kopasakis, George

    2004-01-01

    A method of feedback control has been proposed as a means of suppressing thermo-acoustic instabilities in a liquid- fueled combustor of a type used in an aircraft engine. The basic principle of the method is one of (1) sensing combustor pressure oscillations associated with instabilities and (2) modulating the rate of flow of fuel to the combustor with a control phase that is chosen adaptively so that the pressure oscillations caused by the modulation oppose the sensed pressure oscillations. The need for this method arises because of the planned introduction of advanced, lean-burning aircraft gas turbine engines, which promise to operate with higher efficiencies and to emit smaller quantities of nitrogen oxides, relative to those of present aircraft engines. Unfortunately, the advanced engines are more susceptible to thermoacoustic instabilities. These instabilities are hard to control because they include large dead-time phase shifts, wide-band noise characterized by amplitudes that are large relative to those of the instabilities, exponential growth of the instabilities, random net phase walks, and amplitude fluctuations. In this method (see figure), the output of a combustion-pressure sensor would be wide-band-pass filtered and then further processed to generate a control signal that would be applied to a fast-actuation valve to modulate the flow of fuel. Initially, the controller would rapidly take large phase steps in order to home in, within a fraction of a second, to a favorable phase region within which the instability would be reduced. Then the controller would restrict itself to operate within this phase region and would further restrict itself to operate within a region of stability, as long as the power in the instability signal was decreasing. In the phase-shifting scheme of this method, the phase of the control vector would be made to continuously bounce back and forth from one boundary of an effective stability region to the other. Computationally

  20. Management and climate contributions to satellite-derived active fire trends in the contiguous United States

    PubMed Central

    Lin, Hsiao-Wen; McCarty, Jessica L; Wang, Dongdong; Rogers, Brendan M; Morton, Douglas C; Collatz, G James; Jin, Yufang; Randerson, James T

    2014-01-01

    Fires in croplands, plantations, and rangelands contribute significantly to fire emissions in the United States, yet are often overshadowed by wildland fires in efforts to develop inventories or estimate responses to climate change. Here we quantified decadal trends, interannual variability, and seasonality of Terra Moderate Resolution Imaging Spectroradiometer (MODIS) observations of active fires (thermal anomalies) as a function of management type in the contiguous U.S. during 2001–2010. We used the Monitoring Trends in Burn Severity database to identify active fires within the perimeter of large wildland fires and land cover maps to identify active fires in croplands. A third class of fires defined as prescribed/other included all residual satellite active fire detections. Large wildland fires were the most variable of all three fire types and had no significant annual trend in the contiguous U.S. during 2001–2010. Active fires in croplands, in contrast, increased at a rate of 3.4% per year. Cropland and prescribed/other fire types combined were responsible for 77% of the total active fire detections within the U.S and were most abundant in the south and southeast. In the west, cropland active fires decreased at a rate of 5.9% per year, likely in response to intensive air quality policies. Potential evaporation was a dominant regulator of the interannual variability of large wildland fires, but had a weaker influence on the other two fire types. Our analysis suggests it may be possible to modify landscape fire emissions within the U.S. by influencing the way fires are used in managed ecosystems. Key Points Wildland, cropland, and prescribed fires had different trends and patterns Sensitivity to climate varied with fire type Intensity of air quality regulation influenced cropland burning trends PMID:26213662

  1. Pairing broadband noise with cortical stimulation induces extensive suppression of ascending sensory activity

    PubMed Central

    Markovitz, Craig D.; Hogan, Patrick S.; Wesen, Kyle A.; Lim, Hubert H.

    2015-01-01

    Objective The corticofugal system can alter coding along the ascending sensory pathway. Within the auditory system, electrical stimulation of the auditory cortex (AC) paired with a pure tone can cause egocentric shifts in the tuning of auditory neurons, making them more sensitive to the pure tone frequency. Since tinnitus has been linked with hyperactivity across auditory neurons, we sought to develop a new neuromodulation approach that could suppress a wide range of neurons rather than enhance specific frequency-tuned neurons. Approach We performed experiments in the guinea pig to assess the effects of cortical stimulation paired with broadband noise (PN-Stim) on ascending auditory activity within the central nucleus of the inferior colliculus (CNIC), a widely studied region for AC stimulation paradigms. Main results All eight stimulated AC regions induced extensive suppression of activity across the CNIC that was not possible with noise stimulation alone. This suppression built up over time and remained after the PN-Stim paradigm. Significance We propose that the corticofugal system is designed to decrease the brain’s input gain to irrelevant stimuli and PN-Stim is able to artificially amplify this effect to suppress neural firing across the auditory system. The PN-Stim concept may have potential for treating tinnitus and other neurological disorders. PMID:25686163

  2. Pairing broadband noise with cortical stimulation induces extensive suppression of ascending sensory activity

    NASA Astrophysics Data System (ADS)

    Markovitz, Craig D.; Hogan, Patrick S.; Wesen, Kyle A.; Lim, Hubert H.

    2015-04-01

    Objective. The corticofugal system can alter coding along the ascending sensory pathway. Within the auditory system, electrical stimulation of the auditory cortex (AC) paired with a pure tone can cause egocentric shifts in the tuning of auditory neurons, making them more sensitive to the pure tone frequency. Since tinnitus has been linked with hyperactivity across auditory neurons, we sought to develop a new neuromodulation approach that could suppress a wide range of neurons rather than enhance specific frequency-tuned neurons. Approach. We performed experiments in the guinea pig to assess the effects of cortical stimulation paired with broadband noise (PN-Stim) on ascending auditory activity within the central nucleus of the inferior colliculus (CNIC), a widely studied region for AC stimulation paradigms. Main results. All eight stimulated AC subregions induced extensive suppression of activity across the CNIC that was not possible with noise stimulation alone. This suppression built up over time and remained after the PN-Stim paradigm. Significance. We propose that the corticofugal system is designed to decrease the brain’s input gain to irrelevant stimuli and PN-Stim is able to artificially amplify this effect to suppress neural firing across the auditory system. The PN-Stim concept may have potential for treating tinnitus and other neurological disorders.

  3. The serotonin reuptake inhibitor citalopram suppresses activity in the neonatal rat barrel cortex in vivo.

    PubMed

    Akhmetshina, Dinara; Zakharov, Andrei; Vinokurova, Daria; Nasretdinov, Azat; Valeeva, Guzel; Khazipov, Roustem

    2016-06-01

    Inhibition of serotonin uptake, which causes an increase in extracellular serotonin levels, disrupts the development of thalamocortical barrel maps in neonatal rodents. Previous in vitro studies have suggested that the disruptive effect of excessive serotonin on barrel map formation involves a depression at thalamocortical synapses. However, the effects of serotonin uptake inhibitors on the early thalamocortical activity patterns in the developing barrel cortex in vivo remain largely unknown. Here, using extracellular recordings of the local field potentials and multiple unit activity (MUA) we explored the effects of the selective serotonin reuptake inhibitor (SSRI) citalopram (10-20mg/kg, intraperitoneally) on sensory evoked activity in the barrel cortex of neonatal (postnatal days P2-5) rats in vivo. We show that administration of citalopram suppresses the amplitude and prolongs the delay of the sensory evoked potentials, reduces the power and frequency of the early gamma oscillations, and suppresses sensory evoked and spontaneous neuronal firing. In the adolescent P21-29 animals, citalopram affected neither sensory evoked nor spontaneous activity in barrel cortex. We suggest that suppression of the early thalamocortical activity patterns contributes to the disruption of the barrel map development caused by SSRIs and other conditions elevating extracellular serotonin levels. PMID:27016034

  4. Fire suppression impacts on postfire recovery of Sierra Nevada chaparral shrublands

    USGS Publications Warehouse

    Keeley, J.E.; Pfaff, A.H.; Safford, H.D.

    2005-01-01

    A substantial portion of chaparral shrublands in the southern part of California's Sierra Nevada Mountain Range has never had a recorded fire since record keeping began in 1910. We hypothesised that such long periods without fire are outside the historical range of variability and that when such areas burn, postfire recovery is weaker than in younger stands. We predicted that long fire-free periods will result in loss of shrub species and deterioration of soil seed banks, which, coupled with higher fire intensities from the greater accumulation of dead biomass, will lead to poorer postfire regeneration. The 2002 McNally Fire burned ancient stands that were as much as 150 years old, as well as much younger (mature) stands. Based on shrub skeletons in the burned area as a surrogate for prefire density, we found that ancient stands change in structure, owing primarily to the loss of obligate seeding Ceanothus cuneatus; other species appear to have great longevity. Despite the reduction in C. cuneatus, postfire shrub-seedling recruitment remained strong in these ancient stands, although some seed bank deterioration is suggested by the three-quarters lower seedling recruitment than recorded from mature stands. Total diversity and the abundance of postfire endemic annuals are two other response variables that suggest that these ancient stands are recovering as well as mature stands. The one area of some concern is that non-native species richness and abundance increased in the ancient stands, suggesting that these are more open to alien colonisers. It is concluded that chaparral more than a century old is resilient to such long fire-free periods and fire severity impacts are indistinguishable from those in younger chaparral stands.

  5. Neuronal firing sensitivity to morphologic and active membrane parameters.

    PubMed

    Weaver, Christina M; Wearne, Susan L

    2008-01-01

    Both the excitability of a neuron's membrane, driven by active ion channels, and dendritic morphology contribute to neuronal firing dynamics, but the relative importance and interactions between these features remain poorly understood. Recent modeling studies have shown that different combinations of active conductances can evoke similar firing patterns, but have neglected how morphology might contribute to homeostasis. Parameterizing the morphology of a cylindrical dendrite, we introduce a novel application of mathematical sensitivity analysis that quantifies how dendritic length, diameter, and surface area influence neuronal firing, and compares these effects directly against those of active parameters. The method was applied to a model of neurons from goldfish Area II. These neurons exhibit, and likely contribute to, persistent activity in eye velocity storage, a simple model of working memory. We introduce sensitivity landscapes, defined by local sensitivity analyses of firing rate and gain to each parameter, performed globally across the parameter space. Principal directions over which sensitivity to all parameters varied most revealed intrinsic currents that most controlled model output. We found domains where different groups of parameters had the highest sensitivities, suggesting that interactions within each group shaped firing behaviors within each specific domain. Application of our method, and its characterization of which models were sensitive to general morphologic features, will lead to advances in understanding how realistic morphology participates in functional homeostasis. Significantly, we can predict which active conductances, and how many of them, will compensate for a given age- or development-related structural change, or will offset a morphologic perturbation resulting from trauma or neurodegenerative disorder, to restore normal function. Our method can be adapted to analyze any computational model. Thus, sensitivity landscapes, and the

  6. Next Generation Active Buffet Suppression System

    NASA Technical Reports Server (NTRS)

    Galea, Stephen C.; Ryall, Thomas G.; Henderson, Douglas A.; Moses, Robert W.; White, Edward V.; Zimcik, David G.

    2003-01-01

    Buffeting is an aeroelastic phenomenon that is common to high performance aircraft, especially those with twin vertical tails like the F/A-18, at high angles of attack. These loads result in significant random stresses, which may cause fatigue damage leading to restricted capabilities and availability of the aircraft. This paper describes an international collaborative research activity among Australia, Canada and the United States involving the use of active structural control to alleviate the damaging structural response to these loads. The research program is being co-ordinated by the Air Force Research Laboratory (AFRL) and is being conducted under the auspices of The Technical Cooperative Program (TTCP). This truly unique collaborative program has been developed to enable each participating country to contribute resources toward a program that coalesces a broad range of technical knowledge and expertise into a single investigation. This collaborative program is directed toward a full-scale test of an F/A-18 empennage, which is an extension of an earlier initial test. The current program aims at applying advanced directional piezoactuators, the aircraft rudder, switch mode amplifiers and advanced control strategies on a full-scale structure to demonstrate the enhanced performance and capability of the advanced active BLA control system in preparation for a flight test demonstration.

  7. Experiences with active cosmic background suppression

    SciTech Connect

    Lindstrom, R.M.; Lamaze, G.P.

    1994-12-31

    The dominant source of background in a bare germanium gamma-ray detector is natural radiation originating from potassium, uranium, and thorium decay in the laboratory environment and from cosmic rays. Most of the background is removed by surrounding the detector with lead shielding, which is commonly 20 cm thick. In a well-shielded detector, the largest contributor to the integral counting rate is cosmic rays, and to a lesser extent beta particles from {sup 210}Pb. Most of the counting rate in the continuum is due to highly penetrating muons. Many of the characteristic peaks in the background also originate from fast tertiary neutrons of cosmic-ray origin, which generate neutron activation products or create gamma rays from inelastic scattering in materials of the detector and shield. Very massive shielding is required to remove this penetrating component of background; we have found a fivefold reduction in the cosmic components by moving the detector into a laboratory 20 m underground. However, lacking an underground lab, we have attempted to use active shielding to reduce the background of a Ge detector located above ground. The guard detector is a proportional counter forming a roof 23 cm above the detector. The counter is placed inside the lead shielding to reduce it`s background counting rate.

  8. Management and climate contributions to satellite-derived active fire trends in the contiguous United States

    NASA Astrophysics Data System (ADS)

    Lin, Hsiao-Wen; McCarty, Jessica L.; Wang, Dongdong; Rogers, Brendan M.; Morton, Douglas C.; Collatz, G. James; Jin, Yufang; Randerson, James T.

    2014-04-01

    Fires in croplands, plantations, and rangelands contribute significantly to fire emissions in the United States, yet are often overshadowed by wildland fires in efforts to develop inventories or estimate responses to climate change. Here we quantified decadal trends, interannual variability, and seasonality of Terra Moderate Resolution Imaging Spectroradiometer (MODIS) observations of active fires (thermal anomalies) as a function of management type in the contiguous U.S. during 2001-2010. We used the Monitoring Trends in Burn Severity database to identify active fires within the perimeter of large wildland fires and land cover maps to identify active fires in croplands. A third class of fires defined as prescribed/other included all residual satellite active fire detections. Large wildland fires were the most variable of all three fire types and had no significant annual trend in the contiguous U.S. during 2001-2010. Active fires in croplands, in contrast, increased at a rate of 3.4% per year. Cropland and prescribed/other fire types combined were responsible for 77% of the total active fire detections within the U.S and were most abundant in the south and southeast. In the west, cropland active fires decreased at a rate of 5.9% per year, likely in response to intensive air quality policies. Potential evaporation was a dominant regulator of the interannual variability of large wildland fires, but had a weaker influence on the other two fire types. Our analysis suggests it may be possible to modify landscape fire emissions within the U.S. by influencing the way fires are used in managed ecosystems.

  9. Phermone biosynthesis activation in fire ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 20 years ago, a neurohormone, pheromone biosynthesis activating neuropeptide (PBAN), was identified to stimulate sex pheromone biosynthesis in a moth. Since then, the physiological role, target site and signal transduction of PBAN has become well understood for sex pheromone biosynthesis in mot...

  10. 77 FR 33859 - Carbon Dioxide Fire Suppression Systems on Commercial Vessels

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-07

    .... Environmental Protection Agency FR Federal Register FSS IMO's International Code for Fire Systems Safety IMO... Commercial Vessels'' in the Federal Register (75 FR 8432). We received 18 comments on the proposed rule. No... systems. IV. Background This discussion is adapted from Parts III and IV of our NPRM. See 75 FR 8432,...

  11. Natural fire-defense of raw white and brown cotton fibers evidenced by suppressed unzipping depolymerization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pre-cleaned (scoured or scoured/bleached), cotton-based materials, whose utilization has greatly been enhanced in support of environmental sustainability, burn rapidly, causing a difficulty in controlling the spread of fire. This high burning rate is primarily associated with the unzipping depolymer...

  12. Improved estimates of boreal Fire Radiative Energy using high temporal resolution data and a modified active fire detection algorithm

    NASA Astrophysics Data System (ADS)

    Barrett, Kirsten

    2016-04-01

    Reliable estimates of biomass combusted during wildfires can be obtained from satellite observations of fire radiative power (FRP). Total fire radiative energy (FRE) is typically estimated by integrating instantaneous measurements of fire radiative power (FRP) at the time of orbital satellite overpass or geostationary observation. Remotely-sensed FRP products from orbital satellites are usually global in extent, requiring several thresholding and filtering operations to reduce the number of false fire detections. Some filters required for a global product may not be appropriate to fire detection in the boreal forest resulting in errors of omission and increased data processing times. We evaluate the effect of a boreal-specific active fire detection algorithm and estimates of FRP/FRE. Boreal fires are more likely to escape detection due to lower intensity smouldering combustion and sub canopy fires, therefore improvements in boreal fire detection could substantially reduce the uncertainty of emissions from biomass combustion in the region. High temporal resolution data from geostationary satellites have led to improvements in FRE estimation in tropical and temperate forests, but such a perspective is not possible for high latitude ecosystems given the equatorial orbit of geostationary observation. The increased density of overpasses in high latitudes from polar-orbiting satellites, however, may provide adequate temporal sampling for estimating FRE.

  13. Nitric oxide mediates caerulein-induced suppression of locomotor activity.

    PubMed

    Volke, V; Soosaar, A; Kõks, S; Bourin, M; Männistö, P T; Vasar, E

    1996-08-01

    Caerulein, a non-selective agonist of cholecystokinin (CCK) receptors, is shown to suppress locomotor activity in rodents via stimulation of CCK(A) receptors. In the present study we examined the possible involvement of nitric oxide (NO) in caerulein-induced hypolocomotion in rats. Caerulein (10 microg/kg) markedly decreased the horizontal and vertical components of locomotor activity in rats measured in dark motility boxes. Pretreatment with a nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME), at 5 mg/kg i.p., abolished the inhibiting action of caerulein on the horizontal activity, but did not affect the reduced frequency of rearing. The other doses of L-NAME (1, 10 and 20 mg/kg) were ineffective against caerulein. As L-NAME at this dose range does not stimulate locomotor activity, it is likely that NO is involved in the motor suppressant effect of systemically administered caerulein.

  14. Fire and climate in Mongolia (1532-2010 Common Era)

    NASA Astrophysics Data System (ADS)

    Hessl, Amy E.; Brown, Peter; Byambasuren, Oyunsanaa; Cockrell, Shawn; Leland, Caroline; Cook, Ed; Nachin, Baatarbileg; Pederson, Neil; Saladyga, Thomas; Suran, Byambagerel

    2016-06-01

    Recent increases in wildland fire, warming temperatures, and land use change have coincided in many forested regions, making it difficult to parse causes of elevated fire activity. Here we use 20 multicentury fire scar chronologies (464 fire scar samples) from Mongolia to evaluate the role of climate forcing of fire in the context of livestock grazing and minimal fire suppression. We observe no change in fire return intervals post-1900; however, since the 1500s, periods of drought are coincident with more fire and shorter fire return intervals. We observe same year and some antecedent year effects of drought on fire, a pattern typical of semiarid forests elsewhere. During the instrumental period, drought remains an important driver of fire; however, limited fire activity in recent decades may be due to the coincidence of drought and intensive grazing that have synergized to reduce fuel continuity and fire spread.

  15. Possibility of increasing the fire-suppression efficiency of the foam in automatic extinguishing installations

    NASA Astrophysics Data System (ADS)

    Kachanov, I. V.; Veremenyuk, V. V.; Karpenchuk, I. V.; Pavlyukov, S. Yu.

    2013-05-01

    The mechanics of movement of a liquid in the diffuser of the injector of an automatic extinguishing installation with preaeration of the fire-fighting substance was theoretically investigated. An integral solution of the equation for movement of the preaerated fire-fighting gas-liquid mixture in the indicated diffuser has been obtained. A mathematical model of two-phase liquid flow in this diffuser, which allows one to calculate the distribution of the average pressure in the diffuser along its length and to determine the loss in this pressure, has been developed. This model can be used for designing the output region of a hydraulic system with a hydrodynamic drag providing the operation of its injector in a definite regime.

  16. Potent cough suppression by physiologically active substance in human plasma.

    PubMed

    Akaike, Norio; Ito, Yushi; Ogawa, Sachie K; Maeda, Megumi; Wakita, Masahito; Takahama, Kazuo; Noguchi, Tetsuro; Kamei, Shintaro; Hamamoto, Takayoshi; Umehashi, Misako; Maeda, Hiroaki

    2014-01-01

    Human plasma contains wide variety of bioactive proteins that have proved essential in therapeutic discovery. However many human plasma proteins remain orphans with unknown biological functions. Evidences suggest that some plasma components target the respiratory system. In the present study we adapted heparin affinity chromatography to fractionate human plasma for functional bioassay. Fractions from pooled human plasma yielded particular plasma fractions with strong cough suppressing effects. Purification yielded a fraction that was finally identified as an activated blood coagulation factor fXIa using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI/TOF-MS). The fraction almost completely suppressed coughs induced by either chemical or mechanical stimulation applied to larynx or bifurcation of guinea-pig trachea. Cough suppressing effect of the fraction and commercially available fXIa were one million times stronger than codeine and codeine only partially suppressed the mechanically triggered coughing in animal model. Recent reviews highlighted prominent shortcomings of current available antitussives, including narcotic opioids such as codeine and their unpleasant or intolerable side effects. Therefore, safer and more effective cough suppressants would be welcome, and present findings indicate that fXIa in human plasma as a very promising, new therapeutic candidate for effective antitussive action.

  17. Molecular hydrogen suppresses activated Wnt/β-catenin signaling.

    PubMed

    Lin, Yingni; Ohkawara, Bisei; Ito, Mikako; Misawa, Nobuaki; Miyamoto, Kentaro; Takegami, Yasuhiko; Masuda, Akio; Toyokuni, Shinya; Ohno, Kinji

    2016-01-01

    Molecular hydrogen (H2) is effective for many diseases. However, molecular bases of H2 have not been fully elucidated. Cumulative evidence indicates that H2 acts as a gaseous signal modulator. We found that H2 suppresses activated Wnt/β-catenin signaling by promoting phosphorylation and degradation οf β-catenin. Either complete inhibition of GSK3 or mutations at CK1- and GSK3-phosphorylation sites of β-catenin abolished the suppressive effect of H2. H2 did not increase GSK3-mediated phosphorylation of glycogen synthase, indicating that H2 has no direct effect on GSK3 itself. Knock-down of adenomatous polyposis coli (APC) or Axin1, which form the β-catenin degradation complex, minimized the suppressive effect of H2 on β-catenin accumulation. Accordingly, the effect of H2 requires CK1/GSK3-phosphorylation sites of β-catenin, as well as the β-catenin degradation complex comprised of CK1, GSK3, APC, and Axin1. We additionally found that H2 reduces the activation of Wnt/β-catenin signaling in human osteoarthritis chondrocytes. Oral intake of H2 water tended to ameliorate cartilage degradation in a surgery-induced rat osteoarthritis model through attenuating β-catenin accumulation. We first demonstrate that H2 suppresses abnormally activated Wnt/β-catenin signaling, which accounts for the protective roles of H2 in a fraction of diseases. PMID:27558955

  18. Molecular hydrogen suppresses activated Wnt/β-catenin signaling

    PubMed Central

    Lin, Yingni; Ohkawara, Bisei; Ito, Mikako; Misawa, Nobuaki; Miyamoto, Kentaro; Takegami, Yasuhiko; Masuda, Akio; Toyokuni, Shinya; Ohno, Kinji

    2016-01-01

    Molecular hydrogen (H2) is effective for many diseases. However, molecular bases of H2 have not been fully elucidated. Cumulative evidence indicates that H2 acts as a gaseous signal modulator. We found that H2 suppresses activated Wnt/β-catenin signaling by promoting phosphorylation and degradation οf β-catenin. Either complete inhibition of GSK3 or mutations at CK1- and GSK3-phosphorylation sites of β-catenin abolished the suppressive effect of H2. H2 did not increase GSK3-mediated phosphorylation of glycogen synthase, indicating that H2 has no direct effect on GSK3 itself. Knock-down of adenomatous polyposis coli (APC) or Axin1, which form the β-catenin degradation complex, minimized the suppressive effect of H2 on β-catenin accumulation. Accordingly, the effect of H2 requires CK1/GSK3-phosphorylation sites of β-catenin, as well as the β-catenin degradation complex comprised of CK1, GSK3, APC, and Axin1. We additionally found that H2 reduces the activation of Wnt/β-catenin signaling in human osteoarthritis chondrocytes. Oral intake of H2 water tended to ameliorate cartilage degradation in a surgery-induced rat osteoarthritis model through attenuating β-catenin accumulation. We first demonstrate that H2 suppresses abnormally activated Wnt/β-catenin signaling, which accounts for the protective roles of H2 in a fraction of diseases. PMID:27558955

  19. Incorporating anthropogenic influences into fire probability models: Effects of development and climate change on fire activity in California

    NASA Astrophysics Data System (ADS)

    Mann, M.; Moritz, M.; Batllori, E.; Waller, E.; Krawchuk, M.; Berck, P.

    2014-12-01

    The costly interactions between humans and natural fire regimes throughout California demonstrate the need to understand the uncertainties surrounding wildfire, especially in the face of a changing climate and expanding human communities. Although a number of statistical and process-based wildfire models exist for California, there is enormous uncertainty about the location and number of future fires. Models estimate an increase in fire occurrence between nine and fifty-three percent by the end of the century. Our goal is to assess the role of uncertainty in climate and anthropogenic influences on the state's fire regime from 2000-2050. We develop an empirical model that integrates novel information about the distribution and characteristics of future plant communities without assuming a particular distribution, and improve on previous efforts by integrating dynamic estimates of population density at each forecast time step. Historically, we find that anthropogenic influences account for up to fifty percent of the total fire count, and that further housing development will incite or suppress additional fires according to their intensity. We also find that the total area burned is likely to increase but at a slower than historical rate. Previous findings of substantially increased numbers of fires may be tied to the assumption of static fuel loadings, and the use of proxy variables not relevant to plant community distributions. We also find considerable agreement between GFDL and PCM model A2 runs, with decreasing fire counts expected only in areas of coastal influence below San Francisco and above Los Angeles. Due to potential shifts in rainfall patterns, substantial uncertainty remains for the semiarid deserts of the inland south. The broad shifts of wildfire between California's climatic regions forecast in this study point to dramatic shifts in the pressures plant and human communities will face by midcentury. The information provided by this study reduces the

  20. Application of MODIS-Derived Active Fire Radiative Energy to Fire Disaster and Smoke Pollution Monitoring

    NASA Technical Reports Server (NTRS)

    Ichoku, Charles; Kaufman, Yoram J.; Hao, Wei Min; Habib, Shahid

    2004-01-01

    The radiative energy emitted by large fires and the corresponding smoke aerosol loading are simultaneously measured from the MODIS sensor from both the Terra and Aqua satellites. Quantitative relationships between the rates of emission of fire radiative energy and smoke are being developed for different fire-prone regions of the globe. Preliminary results are presented. When fully developed, the system will enable the use of MODIS direct broadcast fire data for near real-time monitoring of fire strength and smoke emission as well as forecasting of fire progression and smoke dispersion, several hours to a few days in advance.

  1. Idaho National Engineering and Environmental Laboratory Wildland Fire Management Environmental Assessment

    SciTech Connect

    Irving, John S

    2003-04-01

    DOE prepared an environmental assessment (EA)for wildland fire management activities on the Idaho National Engineering and Environmental Laboratory (INEEL) (DOE/EA-1372). The EA was developed to evaluate wildland fire management options for pre-fire, fire suppression, and post fire activities. Those activities have an important role in minimizing the conversion of the native sagebrush steppe ecosystem found on the INEEL to non-native weeds. Four alternative management approaches were analyzed: Alternative 1 - maximum fire protection; Alternative 2 - balanced fire protection; Alternative 2 - balanced fire protection; Alternative 3 - protect infrastructure and personnel; and Alternative 4 - no action/traditional fire protection.

  2. Idaho National Engineering and Environmental Laboratory Wildland Fire Management Environmental Assessment - April 2003

    SciTech Connect

    Irving, J.S.

    2003-04-30

    DOE prepared an environmental assessment (EA)for wildland fire management activities on the Idaho National Engineering and Environmental Laboratory (INEEL) (DOE/EA-1372). The EA was developed to evaluate wildland fire management options for pre-fire, fire suppression, and post fire activities. Those activities have an important role in minimizing the conversion of the native sagebrush steppe ecosystem found on the INEEL to non-native weeds. Four alternative management approaches were analyzed: Alternative 1 - maximum fire protection; Alternative 2 - balanced fire protection; Alternative 2 - balanced fire protection; Alternative 3 - protect infrastructure and personnel; and Alternative 4 - no action/traditional fire protection.

  3. Detection, evaluation, and analysis of global fire activity using MODIS data

    NASA Astrophysics Data System (ADS)

    Giglio, Louis

    Global biomass burning plays a significant role in regional and global climate change, and spaceborne sensors offer the only practical way to monitor fire activity at these scales. This dissertation primarily concerns the development, evaluation, and use of the NASA Terra and Aqua MODIS instruments for fire monitoring. MODIS is the first satellite sensor designed specifically for global monitoring of fires. An improved operational fire detection algorithm was developed for the MODIS instrument. This algorithm offers a sensitivity to small, cool fires and minimizes false alarm rates. To support the accuracy assessment of the MODIS global fire product, an operational fire detection algorithm was developed and evaluated for the ASTER instrument, which provides higher resolution observations coincident with the Terra MODIS. The unique data set of multi-year MODIS day and night fire observations was used to analyze the global distribution of biomass burning using five different temporal metrics which included, for the first time, mean fire radiative power, a measure of fire intensity. The metrics show the planetary extent, seasonality, and interannual variability of fire. Recognizing differences in fire activity between morning and afternoon overpasses, the impact of the diurnal cycle of fire activity was addressed using seven years of fire data from the VIRS sensor on-board the TRMM satellite. A strong diurnal cycle was found in all regions, with the time of peak burning varying between approximately 13:00 and 18:30 local time. Given interest in area burned among atmospheric chemical transport and carbon cycle modelers, a data set was developed utilizing the MODIS global fire and vegetation cover products to estimate monthly burned area at 1-degree spatial resolution. The methods, products and results presented in this thesis provide the global change research and fire management communities with products for global fire monitoring and are currently being used in the

  4. Solar activity as a possible cause of large forest fires--a case study: analysis of the Portuguese forest fires.

    PubMed

    Gomes, J F P; Radovanovic, M

    2008-05-01

    Fires of large dimension destroy forests, harvests and housing objects. Apart from that combustion products and burned surfaces become large ecological problems. Very often fires emerge simultaneously on different locations of a region so a question could be asked if they always have been a consequence of negligence, pyromania, high temperatures or maybe there has been some other cause. This paper is an attempt of establishing the possible connection between forest fires that numerous satellites registered and activities happening on the Sun immediately before fires ignite. Fires emerged on relatively large areas from Portugal and Spain on August 2005, as well as on other regions of Europe. The cases that have been analyzed show that, in every concrete situation, an emission of strong electromagnetic and thermal corpuscular energy from highly energetic regions that were in geo-effective position had preceded the fires. Such emissions have, usually, very high energy and high speeds of particles and come from coronary holes that also have been either in the very structure or in the immediate closeness of the geo-effective position. It should also be noted that the solar wind directed towards the Earth becomes weaker with deeper penetration towards the topographic surface. However, the results presented in this paper suggest that, there is a strong causality relationship between solar activity and the ignition of these forest fires taking place in South-western Europe.

  5. Synchronous fire activity in the tropical high Andes: an indication of regional climate forcing.

    PubMed

    Román-Cuesta, R M; Carmona-Moreno, C; Lizcano, G; New, M; Silman, M; Knoke, T; Malhi, Y; Oliveras, I; Asbjornsen, H; Vuille, M

    2014-06-01

    Global climate models suggest enhanced warming of the tropical mid and upper troposphere, with larger temperature rise rates at higher elevations. Changes in fire activity are amongst the most significant ecological consequences of rising temperatures and changing hydrological properties in mountainous ecosystems, and there is a global evidence of increased fire activity with elevation. Whilst fire research has become popular in the tropical lowlands, much less is known of the tropical high Andean region (>2000 masl, from Colombia to Bolivia). This study examines fire trends in the high Andes for three ecosystems, the Puna, the Paramo and the Yungas, for the period 1982-2006. We pose three questions: (i) is there an increased fire response with elevation? (ii) does the El Niño- Southern Oscillation control fire activity in this region? (iii) are the observed fire trends human driven (e.g., human practices and their effects on fuel build-up) or climate driven? We did not find evidence of increased fire activity with elevation but, instead, a quasicyclic and synchronous fire response in Ecuador, Peru and Bolivia, suggesting the influence of high-frequency climate forcing on fire responses on a subcontinental scale, in the high Andes. ENSO variability did not show a significant relation to fire activity for these three countries, partly because ENSO variability did not significantly relate to precipitation extremes, although it strongly did to temperature extremes. Whilst ENSO did not individually lead the observed regional fire trends, our results suggest a climate influence on fire activity, mainly through a sawtooth pattern of precipitation (increased rainfall before fire-peak seasons (t-1) followed by drought spells and unusual low temperatures (t0), which is particularly common where fire is carried by low fuel loads (e.g., grasslands and fine fuel). This climatic sawtooth appeared as the main driver of fire trends, above local human influences and fuel build

  6. Synchronous fire activity in the tropical high Andes: an indication of regional climate forcing.

    PubMed

    Román-Cuesta, R M; Carmona-Moreno, C; Lizcano, G; New, M; Silman, M; Knoke, T; Malhi, Y; Oliveras, I; Asbjornsen, H; Vuille, M

    2014-06-01

    Global climate models suggest enhanced warming of the tropical mid and upper troposphere, with larger temperature rise rates at higher elevations. Changes in fire activity are amongst the most significant ecological consequences of rising temperatures and changing hydrological properties in mountainous ecosystems, and there is a global evidence of increased fire activity with elevation. Whilst fire research has become popular in the tropical lowlands, much less is known of the tropical high Andean region (>2000 masl, from Colombia to Bolivia). This study examines fire trends in the high Andes for three ecosystems, the Puna, the Paramo and the Yungas, for the period 1982-2006. We pose three questions: (i) is there an increased fire response with elevation? (ii) does the El Niño- Southern Oscillation control fire activity in this region? (iii) are the observed fire trends human driven (e.g., human practices and their effects on fuel build-up) or climate driven? We did not find evidence of increased fire activity with elevation but, instead, a quasicyclic and synchronous fire response in Ecuador, Peru and Bolivia, suggesting the influence of high-frequency climate forcing on fire responses on a subcontinental scale, in the high Andes. ENSO variability did not show a significant relation to fire activity for these three countries, partly because ENSO variability did not significantly relate to precipitation extremes, although it strongly did to temperature extremes. Whilst ENSO did not individually lead the observed regional fire trends, our results suggest a climate influence on fire activity, mainly through a sawtooth pattern of precipitation (increased rainfall before fire-peak seasons (t-1) followed by drought spells and unusual low temperatures (t0), which is particularly common where fire is carried by low fuel loads (e.g., grasslands and fine fuel). This climatic sawtooth appeared as the main driver of fire trends, above local human influences and fuel build

  7. Genipin Suppresses NLRP3 Inflammasome Activation Through Uncoupling Protein-2

    PubMed Central

    Rajanbabu, Venugopal; Galam, Lakshmi; Fukumoto, Jutaro; Enciso, Juan; Tadikonda, Pratima; Lane, Troy N.; Bandyopadhyay, Sayantani; Parthasarathy, Prasanna Tamarapu; Cho, Young; Cho, Seong Ho; Lee, Yong Chul; Lockey, Richard F.; Kolliputi, Narasaiah

    2015-01-01

    Incomplete clearance of apoptotic cells and reactive oxygen species (ROS) release are known to trigger inflammasome activation causing severe inflammation in acute lung injury and various metabolic and autoimmune diseases. Moreover, it has been reported that apoptotic cell clearance and ROS-mediated apoptosis critically depend on mitochondrial uncoupling protein-2 (UCP2). However, the relationship between UCP2 and inflammasome activation has not been studied. This report investigates the role of UCP2 in the expression and activation of NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome in human macrophages. We found that UCP2 overexpression significantly enhanced the expression levels of NLRP3. The NLRP3 expression levels were significantly suppressed in THP1 cells treated with genipin, a UCP2 inhibitor, compared to controls. In addition, genipin altered adenosine triphosphate (ATP)- and hydrogen peroxide (H2O2)-mediated interleukin-1 beta (IL-1β) secretion and significantly suppressed caspase-1 activity in inflammasome-activated human macrophages. Taken together, our results suggest that genipin modulates NLRP3 inflammasome activation and ATP- or H2O2-mediated IL-1β release. PMID:26123077

  8. Directory of workers in the fire field

    NASA Technical Reports Server (NTRS)

    Kuvshinoff, B. W.; Mcleod, S. B.; Katz, R. G.

    1973-01-01

    A directory was compiled to provide a list of workers engaged in fire research, their addresses and affiliations, and their principal fields of activity. The initial criteria for the selection of names for the directory are recent contributions to fire literature, teaching of subjects relevant to fire science, or participation in or support of fire research programs. With some exceptions, fire service personnel and fire protection engineers were excluded because directories already exist for these professionals. Also excluded are investigators engaged principally in studies of propulsion, combustion, and explosion phenomena, because these areas of study are somewhat aside from the main focus of fire research. For purposes of the directory, fire science is taken to be the body of knowledge, art, and skill related to the investigation, analysis, and interpretation of the phenomena of unwanted fires and the evaluation of materials methods, systems, and equipment related to fire safety, prevention, detection, and suppression.

  9. Bootstrap testing for cross-correlation under low firing activity.

    PubMed

    González-Montoro, Aldana M; Cao, Ricardo; Espinosa, Nelson; Cudeiro, Javier; Mariño, Jorge

    2015-06-01

    A new cross-correlation synchrony index for neural activity is proposed. The index is based on the integration of the kernel estimation of the cross-correlation function. It is used to test for the dynamic synchronization levels of spontaneous neural activity under two induced brain states: sleep-like and awake-like. Two bootstrap resampling plans are proposed to approximate the distribution of the test statistics. The results of the first bootstrap method indicate that it is useful to discern significant differences in the synchronization dynamics of brain states characterized by a neural activity with low firing rate. The second bootstrap method is useful to unveil subtle differences in the synchronization levels of the awake-like state, depending on the activation pathway.

  10. Incorporating Anthropogenic Influences into Fire Probability Models: Effects of Human Activity and Climate Change on Fire Activity in California.

    PubMed

    Mann, Michael L; Batllori, Enric; Moritz, Max A; Waller, Eric K; Berck, Peter; Flint, Alan L; Flint, Lorraine E; Dolfi, Emmalee

    2016-01-01

    The costly interactions between humans and wildfires throughout California demonstrate the need to understand the relationships between them, especially in the face of a changing climate and expanding human communities. Although a number of statistical and process-based wildfire models exist for California, there is enormous uncertainty about the location and number of future fires, with previously published estimates of increases ranging from nine to fifty-three percent by the end of the century. Our goal is to assess the role of climate and anthropogenic influences on the state's fire regimes from 1975 to 2050. We develop an empirical model that integrates estimates of biophysical indicators relevant to plant communities and anthropogenic influences at each forecast time step. Historically, we find that anthropogenic influences account for up to fifty percent of explanatory power in the model. We also find that the total area burned is likely to increase, with burned area expected to increase by 2.2 and 5.0 percent by 2050 under climatic bookends (PCM and GFDL climate models, respectively). Our two climate models show considerable agreement, but due to potential shifts in rainfall patterns, substantial uncertainty remains for the semiarid inland deserts and coastal areas of the south. Given the strength of human-related variables in some regions, however, it is clear that comprehensive projections of future fire activity should include both anthropogenic and biophysical influences. Previous findings of substantially increased numbers of fires and burned area for California may be tied to omitted variable bias from the exclusion of human influences. The omission of anthropogenic variables in our model would overstate the importance of climatic ones by at least 24%. As such, the failure to include anthropogenic effects in many models likely overstates the response of wildfire to climatic change.

  11. Incorporating Anthropogenic Influences into Fire Probability Models: Effects of Human Activity and Climate Change on Fire Activity in California

    PubMed Central

    Batllori, Enric; Moritz, Max A.; Waller, Eric K.; Berck, Peter; Flint, Alan L.; Flint, Lorraine E.; Dolfi, Emmalee

    2016-01-01

    The costly interactions between humans and wildfires throughout California demonstrate the need to understand the relationships between them, especially in the face of a changing climate and expanding human communities. Although a number of statistical and process-based wildfire models exist for California, there is enormous uncertainty about the location and number of future fires, with previously published estimates of increases ranging from nine to fifty-three percent by the end of the century. Our goal is to assess the role of climate and anthropogenic influences on the state’s fire regimes from 1975 to 2050. We develop an empirical model that integrates estimates of biophysical indicators relevant to plant communities and anthropogenic influences at each forecast time step. Historically, we find that anthropogenic influences account for up to fifty percent of explanatory power in the model. We also find that the total area burned is likely to increase, with burned area expected to increase by 2.2 and 5.0 percent by 2050 under climatic bookends (PCM and GFDL climate models, respectively). Our two climate models show considerable agreement, but due to potential shifts in rainfall patterns, substantial uncertainty remains for the semiarid inland deserts and coastal areas of the south. Given the strength of human-related variables in some regions, however, it is clear that comprehensive projections of future fire activity should include both anthropogenic and biophysical influences. Previous findings of substantially increased numbers of fires and burned area for California may be tied to omitted variable bias from the exclusion of human influences. The omission of anthropogenic variables in our model would overstate the importance of climatic ones by at least 24%. As such, the failure to include anthropogenic effects in many models likely overstates the response of wildfire to climatic change. PMID:27124597

  12. Incorporating Anthropogenic Influences into Fire Probability Models: Effects of Human Activity and Climate Change on Fire Activity in California.

    PubMed

    Mann, Michael L; Batllori, Enric; Moritz, Max A; Waller, Eric K; Berck, Peter; Flint, Alan L; Flint, Lorraine E; Dolfi, Emmalee

    2016-01-01

    The costly interactions between humans and wildfires throughout California demonstrate the need to understand the relationships between them, especially in the face of a changing climate and expanding human communities. Although a number of statistical and process-based wildfire models exist for California, there is enormous uncertainty about the location and number of future fires, with previously published estimates of increases ranging from nine to fifty-three percent by the end of the century. Our goal is to assess the role of climate and anthropogenic influences on the state's fire regimes from 1975 to 2050. We develop an empirical model that integrates estimates of biophysical indicators relevant to plant communities and anthropogenic influences at each forecast time step. Historically, we find that anthropogenic influences account for up to fifty percent of explanatory power in the model. We also find that the total area burned is likely to increase, with burned area expected to increase by 2.2 and 5.0 percent by 2050 under climatic bookends (PCM and GFDL climate models, respectively). Our two climate models show considerable agreement, but due to potential shifts in rainfall patterns, substantial uncertainty remains for the semiarid inland deserts and coastal areas of the south. Given the strength of human-related variables in some regions, however, it is clear that comprehensive projections of future fire activity should include both anthropogenic and biophysical influences. Previous findings of substantially increased numbers of fires and burned area for California may be tied to omitted variable bias from the exclusion of human influences. The omission of anthropogenic variables in our model would overstate the importance of climatic ones by at least 24%. As such, the failure to include anthropogenic effects in many models likely overstates the response of wildfire to climatic change. PMID:27124597

  13. Fires in Southern Georgia

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Several large fires were burning in southern Georgia on April 29, 2007, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite passed overhead and captured this image. Places where MODIS detected actively burning fires are outlined in red. The Roundabout Fire sprang up on April 27, according to the U.S. Southern Area Coordination Center, and was about 3,500 acres as of April 30. That fire was threatening homes in the community of Kirkland. Meanwhile, south of Waycross, two large blazes were burning next to each other in the northern part of Okefenokee Swamp. The Sweat Farm Road Fire threatened the town of Waycross in previous weeks, but at the end of April, activity had moved to the southeastern perimeter. The fire had affected more than 50,000 acres of timber (including pine tree plantations) and swamps. Scores of residences scattered throughout the rural area are threatened. The Big Turnaround Complex is burning to the east. The 26,000-acre fire was extremely active over the weekend, with flame lengths more than 60 feet (just over 18 meters) in places. The two blazes appeared to overlap in fire perimeter maps available from the U.S. Geospatial Multi-Agency Coordination Team. According to the Southern Area Coordination Center morning report on April 30, the Sweat Farm Road Fire 'will be a long term fire. Containment and control will depend on significant rainfall, due to the inaccessible swamp terrain.' No expected containment date was available for the Big Turnaround Complex Fire, either. Describing that fire, the report stated, 'Heavy fuel loading, high fire danger, and difficulty of access continue to hamper suppression efforts.' The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides twice-daily images of the region in additional resolutions. They also provide a version of the image that shows smoke plumes stretching out across the Atlantic Ocean.

  14. Genetic Suppression of Transgenic APP Rescues Hypersynchronous Network Activity in a Mouse Model of Alzeimer's Disease

    PubMed Central

    Born, Heather A.; Kim, Ji-Yoen; Savjani, Ricky R.; Das, Pritam; Dabaghian, Yuri A.; Guo, Qinxi; Yoo, Jong W.; Schuler, Dorothy R.; Cirrito, John R.; Zheng, Hui; Golde, Todd E.; Noebels, Jeffrey L.

    2014-01-01

    Alzheimer's disease (AD) is associated with an elevated risk for seizures that may be fundamentally connected to cognitive dysfunction. Supporting this link, many mouse models for AD exhibit abnormal electroencephalogram (EEG) activity in addition to the expected neuropathology and cognitive deficits. Here, we used a controllable transgenic system to investigate how network changes develop and are maintained in a model characterized by amyloid β (Aβ) overproduction and progressive amyloid pathology. EEG recordings in tet-off mice overexpressing amyloid precursor protein (APP) from birth display frequent sharp wave discharges (SWDs). Unexpectedly, we found that withholding APP overexpression until adulthood substantially delayed the appearance of epileptiform activity. Together, these findings suggest that juvenile APP overexpression altered cortical development to favor synchronized firing. Regardless of the age at which EEG abnormalities appeared, the phenotype was dependent on continued APP overexpression and abated over several weeks once transgene expression was suppressed. Abnormal EEG discharges were independent of plaque load and could be extinguished without altering deposited amyloid. Selective reduction of Aβ with a γ-secretase inhibitor has no effect on the frequency of SWDs, indicating that another APP fragment or the full-length protein was likely responsible for maintaining EEG abnormalities. Moreover, transgene suppression normalized the ratio of excitatory to inhibitory innervation in the cortex, whereas secretase inhibition did not. Our results suggest that APP overexpression, and not Aβ overproduction, is responsible for EEG abnormalities in our transgenic mice and can be rescued independently of pathology. PMID:24623762

  15. Berberine Suppresses Adipocyte Differentiation via Decreasing CREB Transcriptional Activity

    PubMed Central

    Deng, Ruyuan; Wang, Ning; Zhang, Yuqing; Wang, Yao; Liu, Yun; Li, Fengying; Wang, Xiao; Zhou, Libin

    2015-01-01

    Berberine, one of the major constituents of Chinese herb Rhizoma coptidis, has been demonstrated to lower blood glucose, blood lipid, and body weight in patients with type 2 diabetes mellitus. The anti-obesity effect of berberine has been attributed to its anti-adipogenic activity. However, the underlying molecular mechanism remains largely unknown. In the present study, we found that berberine significantly suppressed the expressions of CCAAT/enhancer-binding protein (C/EBP)α, peroxisome proliferators-activated receptor γ2 (PPARγ2), and other adipogenic genes in the process of adipogenesis. Berberine decreased cAMP-response element-binding protein (CREB) phosphorylation and C/EBPβ expression at the early stage of 3T3-L1 preadipocyte differentiation. In addition, CREB phosphorylation and C/EBPβ expression induced by 3-isobutyl-1-methylxanthine (IBMX) and forskolin were also attenuated by berberine. The binding activities of cAMP responsive element (CRE) stimulated by IBMX and forskolin were inhibited by berberine. The binding of phosphorylated CREB to the promoter of C/EBPβ was abrogated by berberine after the induction of preadipocyte differentiation. These results suggest that berberine blocks adipogenesis mainly via suppressing CREB activity, which leads to a decrease in C/EBPβ-triggered transcriptional cascades. PMID:25928058

  16. Triacylglycerol kinetics in endotoxic rats with suppressed lipoprotein lipase activity

    SciTech Connect

    Bagby, G.J.; Corll, C.B.; Martinez, R.R.

    1987-07-01

    Hypertriglyceridemia observed in animals after bacterial endotoxin administration and some forms of sepsis can result from increased hepatic triacylglycerol (TG) output or decreased TG clearance by extrahepatic tissues. To differentiate between these two possibilities, TG and free fatty acid (FFA) kinetics were determined in control and endotoxin-injected rats 18 h after treatment. Plasma TG and FFA kinetics were assessed by a constant intravenous infusion with (9,10-/sup 3/H)palmitate-labeled very low-density lipoprotein and (1-/sup 14/C)palmitate bound to albumin, respectively. In addition, lipoprotein lipase (LPL) activity was determined in heart, skeletal muscle, and adipose tissue as well as in postheparin plasma of functionally hepatectomized, adrenalectomized, and gonadectomized rats. Plasma FFA acid concentrations were slightly increased in endotoxin-treated rats but their turnover did not differ from control. Endotoxin-treated rats had a threefold increase in plasma TG concentrations and decreased heart, skeletal muscle, and post-heparin plasma LPL activity. Plasma TG turnover was decreased, indicating that hypertriglyceridemia was not due to an increased TG output by the liver. Instead, the endotoxin-induced increase in plasma TG concentration was consequence of the 80% reduction in TG metabolic clearance rate. Thus, suppression of LPL activity in endotoxic animals impairs TG clearance resulting in hypertriglyceridemia. Furthermore, endotoxin administration reduced the delivery of TG-FFA to extrahepatic tissues because hepatic synthesis and secretion of TG from plasma FFA was decreased and LPL activity was suppressed.

  17. Design, test, and evaluation of three active flutter suppression controllers

    NASA Technical Reports Server (NTRS)

    Adams, William M., Jr.; Christhilf, David M.; Waszak, Martin R.; Mukhopadhyay, Vivek; Srinathkumar, S.

    1992-01-01

    Three control law design techniques for flutter suppression are presented. Each technique uses multiple control surfaces and/or sensors. The first method uses traditional tools (such as pole/zero loci and Nyquist diagrams) for producing a controller that has minimal complexity and which is sufficiently robust to handle plant uncertainty. The second procedure uses linear combinations of several accelerometer signals and dynamic compensation to synthesize the model rate of the critical mode for feedback to the distributed control surfaces. The third technique starts with a minimum-energy linear quadratic Gaussian controller, iteratively modifies intensity matrices corresponding to input and output noise, and applies controller order reduction to achieve a low-order, robust controller. The resulting designs were implemented digitally and tested subsonically on the active flexible wing wind-tunnel model in the Langley Transonic Dynamics Tunnel. Only the traditional pole/zero loci design was sufficiently robust to errors in the nominal plant to successfully suppress flutter during the test. The traditional pole/zero loci design provided simultaneous suppression of symmetric and antisymmetric flutter with a 24-percent increase in attainable dynamic pressure. Posttest analyses are shown which illustrate the problems encountered with the other laws.

  18. Effect of fire residues (ash and char) on microbial activity, respiration and methanogenesis in three subtropical wetland soils

    NASA Astrophysics Data System (ADS)

    Medvedeff, C.; Hogue, B.; Inglett, P.

    2011-12-01

    Prescribed fire is a common restoration and maintenance technique in the southern United States. Prescribed burns coupled with frequent natural fires in South Florida can have devastating effects on ecosystem function. To determine the effect fire residues have on carbon biogeochemical cycling litter material was obtained from two restored and one native marl wetland in Everglades National Park and manipulated in a laboratory setting to produce ash and vegetation derived char. Based on vegetation biomass removal pre and post fire (insitu) appropriate aliquots of each fire residue was added to experimental microcosms as a soil amendment. Soil enzymes (β-glucosidase, cellobiohydrolase, phosphatase, bis-phosphate and leucine amino peptidase), aerobic and anaerobic respiration (CO2) potentials, extractable C and methanogenesis were measured over a 25 day period. Regardless of site C enzymes responded to both amendments within 5 days of addition. Similarly amended soil contained more extractable carbon in the reference and one of the restored sites. In the restored sites ash and char inhibited methanogenesis, had no effect on anaerobic CO2 potentials, but stimulated aerobic respiration after ten days. In contrast, within the first ten days phosphatase enzyme activity was lower in the ash treatment when compared to the control treatment and stimulation of aerobic respiration was observed in both treatment soils. After ten days ash stimulated methanogenic processing while suppressing anaerobic CO2 production suggesting methanogens in this ecosystem may be dependant on usable carbon substrates derived from aerobic microbial processing. This study illustrates the variable response of C parameters to complete and incomplete combusted materials produced from both prescribed and natural fires with particular importance to fire adapted ecosystems.

  19. Comparative study between two different active flutter suppression systems

    NASA Technical Reports Server (NTRS)

    Nissim, E.

    1978-01-01

    An activated leading-edge (LE)-tailing-edge (TE) control system is applied to a drone aircraft with the objective of enabling the drone to fly subsonically at dynamic pressures which are 44% above the open-loop flutter dynamic pressure. The control synthesis approach is based on the aerodynamic energy concept and it incorporates recent developments in this area. A comparison is made between the performance of the activated LE-TE control system and the performance of a TE control system, analyzed in a previous work. The results obtained indicate that although all the control systems achieve the flutter suppression objectives, the TE control system appears to be somewhat superior to the LE-TE control system, in this specific application. This superiority is manifested through reduced values of control surface activity over a wide range of flight conditions.

  20. Assessment of the Fire Radiative Power retrieved by BIRD and the MODIS Active Fire Products from near coincident data acquisitions

    NASA Astrophysics Data System (ADS)

    Ruecker, Gernot; Tiemann, Joachim; Leimbach, David; Lorenz, Eckehard

    2013-04-01

    Due to its spatial resolution and sensor characteristics, the experimental small satellite BIRD (Bispectral InfraRed Detection, active from 2001 through 2003) was superior to any past or current spaceborne instrument in its capacity to detect and characterize fires. Based on a comparison of historical BIRD data with observations from MODIS, we present the first systematic comparison of MODIS FRP retrievals to higher resolution data and provide a first estimate of FRP underestimation due to coarse resolution and variable pixel sizes of the MODIS product. We also highlight differences in FRP retrievals that are due to the usage of different FRP retrieval algorithms, namely the MODIS algorithm adapted to BIRD, the BIRD algorithm and the MIR-radiance algorithm adapted to BIRD. We conclude that the algorithm independent FRP underestimation of MODIS when compared to BIRD may be in the order of 20 %. Since many of the low intensity fires are not detected are smouldering fires - such as peat fires - which release a greater share of methane and carbon monoxide per mass unit burned when compared to flaming fires the FRP underestimation may lead to a larger underestimation of global warming potential by algorithms that derive emissions from fire radiative energy. Prospects for cross validation efforts using the BIRD type sensor on the TET-1 satellite launched in 2012 and on the BIROS satellite to be launched in 2014 with the VIIRS sensor on Suomi NPP as well as geostationary sensors are briefly discussed.

  1. [Suppression of cycling activity in sheep using parenteral progestagen treatment].

    PubMed

    Janett, F; Camponovo, L; Lanker, U; Hässig, M; Thun, R

    2004-03-01

    The objective of this study was to evaluate the effect of two synthetic progestagen preparations Chlormadinone acetate (CAP, Chronosyn, Veterinaria AG Zürich) and Medroxyprogesterone acetate (MPA, Nadigest, G Streuli & Co. Uznach) on cycling activity and fertility in sheep. A flock of 28 non pregnant white alpine sheep was randomly divided into three groups, A (n = 10), B (n = 9) and C (n = 9). During a period of 4 weeks the cycling activity was confirmed by blood progesterone analysis. Thereafter, the animals of group A were treated with 50 mg CAP, those of group B with 140 mg MPA and those of group C with physiological saline solution. All injections were given intramuscularly. Suppression of endogenous progesterone secretion lasted from 28 to 49 days (mean = 39 days) in group A and from 42 to 70 days (mean = 50 days) in group B. The synchronization effect of both preparations was unsatisfactory as the occurrence of first estrus was distributed over a period of 3 weeks in group A and 4 weeks in group B. These findings could also be confirmed by the lambing period which lasted 52 days in group A and 36 days in group B. Control animals lambed within 9 days due to the synchronizing effect of the ram. The first fertile estrus was observed 36 days (group A) and 45 days (group B) after the treatment. In group A all 10 animals and in groups B and C 8 of 9 ewes each became pregnant. Parenteral progestagen application with CAP and MPA is a simple, safe and reversible method of estrus suppression in the sheep. The minimal suppressive duration of 4 (CAP) and 5 weeks (MPA) is not sufficient when a period of 3 months (alpine pasture period) is desired.

  2. Design and test of three active flutter suppression controllers

    NASA Technical Reports Server (NTRS)

    Christhilf, David M.; Waszak, Martin R.; Adams, William M.; Srinathkumar, S.; Mukhopadhyay, Vivek

    1991-01-01

    Three flutter suppression control law design techniques are presented. Each uses multiple control surfaces and/or sensors. The first uses linear combinations of several accelerometer signals together with dynamic compensation to synthesize the modal rate of the critical mode for feedback to distributed control surfaces. The second uses traditional tools (pole/zero loci and Nyquist diagrams) to develop a good understanding of the flutter mechanism and produce a controller with minimal complexity and good robustness to plant uncertainty. The third starts with a minimum energy Linear Quadratic Gaussian controller, applies controller order reduction, and then modifies weight and noise covariance matrices to improve multi-variable robustness. The resulting designs were implemented digitally and tested subsonically on the Active Flexible Wing (AFW) wind tunnel model. Test results presented here include plant characteristics, maximum attained closed-loop dynamic pressure, and Root Mean Square control surface activity. A key result is that simultaneous symmetric and antisymmetric flutter suppression was achieved by the second control law, with a 24 percent increase in attainable dynamic pressure.

  3. Activated chemical defenses suppress herbivory on freshwater red algae.

    PubMed

    Goodman, Keri M; Hay, Mark E

    2013-04-01

    The rapid life cycles of freshwater algae are hypothesized to suppress selection for chemical defenses against herbivores, but this notion remains untested. Investigations of chemical defenses are rare for freshwater macrophytes and absent for freshwater red algae. We used crayfish to assess the palatability of five freshwater red algae relative to a palatable green alga and a chemically defended aquatic moss. We then assessed the roles of structural, nutritional, and chemical traits in reducing palatability. Both native and non-native crayfish preferred the green alga Cladophora glomerata to four of the five red algae. Batrachospermum helminthosum, Kumanoa holtonii, and Tuomeya americana employed activated chemical defenses that suppressed feeding by 30-60 % following damage to algal tissues. Paralemanea annulata was defended by its cartilaginous structure, while Boldia erythrosiphon was palatable. Activated defenses are thought to reduce ecological costs by expressing potent defenses only when actually needed; thus, activation might be favored in freshwater red algae whose short-lived gametophytes must grow and reproduce rapidly over a brief growing season. The frequency of activated chemical defenses found here (three of five species) is 3-20× higher than for surveys of marine algae or aquatic vascular plants. If typical for freshwater red algae, this suggests that (1) their chemical defenses may go undetected if chemical activation is not considered and (2) herbivory has been an important selective force in the evolution of freshwater Rhodophyta. Investigations of defenses in freshwater rhodophytes contribute to among-system comparisons and provide insights into the generality of plant-herbivore interactions and their evolution.

  4. Systemic Exposure to PAHs and Benzene in Firefighters Suppressing Controlled Structure Fires

    PubMed Central

    Fent, Kenneth W.; Eisenberg, Judith; Snawder, John; Sammons, Deborah; Pleil, Joachim D.; Stiegel, Matthew A.; Mueller, Charles; Horn, Gavin P.; Dalton, James

    2014-01-01

    Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination. To ensure that any increase in systemic PAH levels after the burn was the result of dermal rather than inhalation exposure, the firefighters did not remove their self-contained breathing apparatus until overhaul was completed and they were >30 m upwind from the burn structure. Specimens were collected before and at intervals after the burn for biomarker analysis. Urine was analyzed for phenanthrene equivalents using enzyme-linked immunosorbent assay and a benzene metabolite (s-phenylmercapturic acid) using liquid chromatography/tandem mass spectrometry; both were adjusted by creatinine. Exhaled breath collected on thermal desorption tubes was analyzed for PAHs and other aromatic hydrocarbons using gas chromatography/mass spectrometry. We collected personal air samples during the burn and skin wipe samples (corn oil medium) on several body sites before and after the burn. The air and wipe samples were analyzed for PAHs using a liquid chromatography with photodiode array detection. We explored possible changes in external exposures or biomarkers over time and the relationships between these variables using non-parametric sign tests and Spearman tests, respectively. We found significantly elevated (P < 0.05) post-exposure breath concentrations of benzene compared with pre-exposure concentrations for both rounds. We also found significantly elevated post-exposure levels of PAHs on the neck compared with pre

  5. Systemic exposure to PAHs and benzene in firefighters suppressing controlled structure fires.

    PubMed

    Fent, Kenneth W; Eisenberg, Judith; Snawder, John; Sammons, Deborah; Pleil, Joachim D; Stiegel, Matthew A; Mueller, Charles; Horn, Gavin P; Dalton, James

    2014-08-01

    Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination. To ensure that any increase in systemic PAH levels after the burn was the result of dermal rather than inhalation exposure, the firefighters did not remove their self-contained breathing apparatus until overhaul was completed and they were >30 m upwind from the burn structure. Specimens were collected before and at intervals after the burn for biomarker analysis. Urine was analyzed for phenanthrene equivalents using enzyme-linked immunosorbent assay and a benzene metabolite (s-phenylmercapturic acid) using liquid chromatography/tandem mass spectrometry; both were adjusted by creatinine. Exhaled breath collected on thermal desorption tubes was analyzed for PAHs and other aromatic hydrocarbons using gas chromatography/mass spectrometry. We collected personal air samples during the burn and skin wipe samples (corn oil medium) on several body sites before and after the burn. The air and wipe samples were analyzed for PAHs using a liquid chromatography with photodiode array detection. We explored possible changes in external exposures or biomarkers over time and the relationships between these variables using non-parametric sign tests and Spearman tests, respectively. We found significantly elevated (P < 0.05) post-exposure breath concentrations of benzene compared with pre-exposure concentrations for both rounds. We also found significantly elevated post-exposure levels of PAHs on the neck compared with pre

  6. Flame-powered trigger device for activating explosion suppression barrier

    SciTech Connect

    Cortese, R.A.; Sapko, M.J.

    1991-01-01

    This paper reports that the U.S. Bureau of Mines has developed a flame-radiation-powered trigger device to explosively activate suppression barriers to quench gas and coal dust explosions. The major component of the device is a silicon solar panel, which concerts radiation from the developing explosion into electrical energy to initiate an electric detonator, which releases an extinguishing agent into the advancing flame front. Solar panels that are rated to produce 20 W of electrical power when exposed to the sunlight are producing about 200 W when exposed to a full-scale dust explosion. The solar panel is electrically isolated from the detonator by a pressure-sensitive switch until the arrival of the precursor pressure pulse, which always precedes a deflagration. This combination of pressure arming and flame-powered photogenerator prevents false barrier activation and requires no external power supply.

  7. Active flutter suppression using optical output feedback digital controllers

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A method for synthesizing digital active flutter suppression controllers using the concept of optimal output feedback is presented. A convergent algorithm is employed to determine constrained control law parameters that minimize an infinite time discrete quadratic performance index. Low order compensator dynamics are included in the control law and the compensator parameters are computed along with the output feedback gain as part of the optimization process. An input noise adjustment procedure is used to improve the stability margins of the digital active flutter controller. Sample rate variation, prefilter pole variation, control structure variation and gain scheduling are discussed. A digital control law which accommodates computation delay can stabilize the wing with reasonable rms performance and adequate stability margins.

  8. Flutter suppression and gust alleviation using active controls

    NASA Technical Reports Server (NTRS)

    Nissim, E.

    1974-01-01

    The effects of active controls on the suppression of flutter and gust alleviation of two different types of subsonic aircraft (the Arava, twin turboprop STOL transport, and the Westwind twin-jet business transport) are investigated. The active controls are introduced in pairs which include, in any chosen wing strip, a leading-edge (LE) control and a trailing-edge (TE) control. Each control surface is allowed to be driven by a combined linear-rotational sensor system, located on the activated strip. The control law, which translates the sensor signals into control surface rotations, is based on the concept of aerodynamic energy. The results indicate the extreme effectiveness of the active systems in controlling flutter. A single system spanning 10% of the wing semispan made the Arava flutter-free, and a similar active system, for the Westwind aircraft, yielded a reduction of 75% in the maximum bending moment of the wing and a reduction of 90% in the acceleration of the cg of the aircraft. Results for simultaneous activation of several LE - TE systems are presented. Further work needed to bring the investigation to completion is also discussed.

  9. Fire activity as a function of fire-weather seasonal severity and antecedent climate across spatial scales in southern Europe and Pacific western USA

    NASA Astrophysics Data System (ADS)

    Urbieta, Itziar R.; Zavala, Gonzalo; Bedia, Joaquín; Gutiérrez, José M.; San Miguel-Ayanz, Jesús; Camia, Andrea; Keeley, Jon E.; Moreno, José M.

    2015-11-01

    Climate has a strong influence on fire activity, varying across time and space. We analyzed the relationships between fire-weather conditions during the main fire season and antecedent water-balance conditions and fires in two Mediterranean-type regions with contrasted management histories: five southern countries of the European Union (EUMED)(all fires); the Pacific western coast of the USA (California and Oregon, PWUSA)(national forest fires). Total number of fires (≥1 ha), number of large fires (≥100 ha) and area burned were related to mean seasonal fire weather index (FWI), number of days over the 90th percentile of the FWI, and to the standardized precipitation-evapotranspiration index (SPEI) from the preceding 3 (spring) or 8 (autumn through spring) months. Calculations were made at three spatial aggregations in each area, and models related first-difference (year-to-year change) of fires and FWI/climate variables to minimize autocorrelation. An increase in mean seasonal FWI resulted in increases in the three fire variables across spatial scales in both regions. SPEI contributed little to explain fires, with few exceptions. Negative water-balance (dry) conditions from autumn through spring (SPEI8) were generally more important than positive conditions (moist) in spring (SPEI3), both of which contributed positively to fires. The R2 of the models generally improved with increasing area of aggregation. For total number of fires and area burned, the R2 of the models tended to decrease with increasing mean seasonal FWI. Thus, fires were more susceptible to change with climate variability in areas with less amenable conditions for fires (lower FWI) than in areas with higher mean FWI values. The relationships were similar in both regions, albeit weaker in PWUSA, probably due to the wider latitudinal gradient covered in PWUSA than in EUMED. The large variance explained by some of the models indicates that large-scale seasonal forecast could help anticipating fire

  10. The largest forest fires in Portugal: the constraints of burned area size on the comprehension of fire severity.

    PubMed

    Tedim, Fantina; Remelgado, Ruben; Martins, João; Carvalho, Salete

    2015-01-01

    Portugal is a European country with highest forest fires density and burned area. Since beginning of official forest fires database in 1980, an increase in number of fires and burned area as well as appearance of large and catastrophic fires have characterized fire activity in Portugal. In 1980s, the largest fires were just a little bit over 10,000 ha. However, in the beginning of 21st century several fires occurred with a burned area over 20,000 ha. Some of these events can be classified as mega-fires due to their ecological and socioeconomic severity. The present study aimed to discuss the characterization of large forest fires trend, in order to understand if the largest fires that occurred in Portugal were exceptional events or evidences of a new trend, and the constraints of fire size to characterize fire effects because, usually, it is assumed that larger the fire higher the damages. Using Portuguese forest fire database and satellite imagery, the present study showed that the largest fires could be seen at the same time as exceptional events and as evidence of a new fire regime. It highlighted the importance of size and patterns of unburned patches within fire perimeter as well as heterogeneity of fire ecological severity, usually not included in fire regime description, which are critical to fire management and research. The findings of this research can be used in forest risk reduction and suppression planning.

  11. Fire Protection for Buildings

    ERIC Educational Resources Information Center

    Edmunds, Jane

    1972-01-01

    Reviews attack on fire safety in high rise buildings made by a group of experts representing the iron and steel industry at a recent conference. According to one expert, fire problems are people oriented, which calls for emphasis on fire prevention rather than reliance on fire suppression and for fire pretection to be built into a structure.…

  12. Immune-suppressive activity of punicalagin via inhibition of NFAT activation

    SciTech Connect

    Lee, Sang-Ik; Kim, Byoung-Soo; Kim, Kyoung-Shin; Lee, Samkeun; Shin, Kwang-Soo; Lim, Jong-Soon

    2008-07-11

    Since T cell activation is central to the development of autoimmune diseases, we screened a natural product library comprising 1400 samples of medicinal herbal extracts, to identify compounds that suppress T cell activity. Punicalagin (PCG) isolated from the fruit of Punica granatum was identified as a potent immune suppressant, based on its inhibitory action on the activation of the nuclear factor of activated T cells (NFAT). PCG downregulated the mRNA and soluble protein expression of interleukin-2 from anti-CD3/anti-CD28-stimulated murine splenic CD4+ T cells and suppressed mixed leukocytes reaction (MLR) without exhibiting cytotoxicity to the cells. In vivo, the PCG treatment inhibited phorbol 12-myristate 13-acetate (PMA)-induced chronic ear edema in mice and decreased CD3+ T cell infiltration of the inflamed tissue. These results suggest that PCG could be a potential candidate for the therapeutics of various immune pathologies.

  13. Notum deacylates Wnt proteins to suppress signalling activity.

    PubMed

    Kakugawa, Satoshi; Langton, Paul F; Zebisch, Matthias; Howell, Steven A; Chang, Tao-Hsin; Liu, Yan; Feizi, Ten; Bineva, Ganka; O'Reilly, Nicola; Snijders, Ambrosius P; Jones, E Yvonne; Vincent, Jean-Paul

    2015-03-12

    Signalling by Wnt proteins is finely balanced to ensure normal development and tissue homeostasis while avoiding diseases such as cancer. This is achieved in part by Notum, a highly conserved secreted feedback antagonist. Notum has been thought to act as a phospholipase, shedding glypicans and associated Wnt proteins from the cell surface. However, this view fails to explain specificity, as glypicans bind many extracellular ligands. Here we provide genetic evidence in Drosophila that Notum requires glypicans to suppress Wnt signalling, but does not cleave their glycophosphatidylinositol anchor. Structural analyses reveal glycosaminoglycan binding sites on Notum, which probably help Notum to co-localize with Wnt proteins. They also identify, at the active site of human and Drosophila Notum, a large hydrophobic pocket that accommodates palmitoleate. Kinetic and mass spectrometric analyses of human proteins show that Notum is a carboxylesterase that removes an essential palmitoleate moiety from Wnt proteins and thus constitutes the first known extracellular protein deacylase. PMID:25731175

  14. Semantic activation and letter search: blocking or suppression?

    PubMed

    Cinel, Caterina; Avons, Steve E; Russo, Riccardo

    2010-03-01

    Two experiments investigated associative priming with a letter-search prime task where either the prime and letter probe were presented simultaneously, or the letter probe appeared 200 ms (Experiment 1) or 300 ms (Experiment 2) after the prime. Weak associative priming was observed in both experiments, but unlike Stolz and Besner (1996) we found no evidence that priming was increased when the probe was delayed. However, strong associative priming was observed when a semantic decision had to be made on the prime (Experiment 3). Our results are consistent with an account where semantic activation of the prime occurs but its action on the target is suppressed by the prime task. The persistence of weak priming effects with the letter search task is explained in terms of the low-frequency items used.

  15. Hybrid Active/Passive Jet Engine Noise Suppression System

    NASA Technical Reports Server (NTRS)

    Parente, C. A.; Arcas, N.; Walker, B. E.; Hersh, A. S.; Rice, E. J.

    1999-01-01

    A novel adaptive segmented liner concept has been developed that employs active control elements to modify the in-duct sound field to enhance the tone-suppressing performance of passive liner elements. This could potentially allow engine designs that inherently produce more tone noise but less broadband noise, or could allow passive liner designs to more optimally address high frequency broadband noise. A proof-of-concept validation program was undertaken, consisting of the development of an adaptive segmented liner that would maximize attenuation of two radial modes in a circular or annular duct. The liner consisted of a leading active segment with dual annuli of axially spaced active Helmholtz resonators, followed by an optimized passive liner and then an array of sensing microphones. Three successively complex versions of the adaptive liner were constructed and their performances tested relative to the performance of optimized uniform passive and segmented passive liners. The salient results of the tests were: The adaptive segmented liner performed well in a high flow speed model fan inlet environment, was successfully scaled to a high sound frequency and successfully attenuated three radial modes using sensor and active resonator arrays that were designed for a two mode, lower frequency environment.

  16. Exogenous melatonin inhibits neutrophil migration through suppression of ERK activation.

    PubMed

    Ren, Da-Long; Sun, Ai-Ai; Li, Ya-Juan; Chen, Min; Ge, Shu-Chao; Hu, Bing

    2015-10-01

    Neutrophil migration to inflammatory sites is the fundamental process of innate immunity among organisms against pathogen invasion. As a major sleep adjusting hormone, melatonin has also been proved to be involved in various inflammatory events. This study aimed to evaluate the impact of exogenous melatonin on neutrophil migration to the injury site in live zebrafish and further investigate whether ERK signaling is involved in this process. Using the tail fin transection model, the fluorescently labeled neutrophil was in vivo visualized in transgenic Tg(lyz:EGFP), Tg(lyz:DsRed) zebrafish. We found that exogenous melatonin administration dramatically inhibited the injury-induced neutrophil migration in a dose-dependent and time-dependent manner. The inhibited effect of melatonin on neutrophil migration could be attenuated by melatonin receptor 1, 2, and 3 antagonists. The ERK phosphorylation level was significantly decreased post injury when treated with melatonin. The blocking of ERK activation with inhibitor PD0325901 suppressed the number of migrated neutrophils in response to injury. However, the activation of ERK with the epidermal growth factor could impair the inhibited effect of melatonin on neutrophil migration. We also detected that PD0325901 significantly suppressed the in vivo neutrophils transmigrating over the vessel endothelial cell using the transgenic Tg(flk:EGFP);(lyz:DsRed) line labeled as both vessel and neutrophil. Taking all of these data together, the results indicated that exogenous melatonin had an anti-migratory effect on neutrophils by blocking the ERK phosphorylation signal, and it led to the subsequent adhesion molecule expression. Thus, the crossing of the vessel endothelial cells of neutrophils became difficult.

  17. Atlantic SSTs control regime shifts in forest fire activity of Northern Scandinavia

    NASA Astrophysics Data System (ADS)

    Drobyshev, Igor; Bergeron, Yves; Vernal, Anne De; Moberg, Anders; Ali, Adam A.; Niklasson, Mats

    2016-03-01

    Understanding the drivers of the boreal forest fire activity is challenging due to the complexity of the interactions driving fire regimes. We analyzed drivers of forest fire activity in Northern Scandinavia (above 60 N) by combining modern and proxy data over the Holocene. The results suggest that the cold climate in northern Scandinavia was generally characterized by dry conditions favourable to periods of regionally increased fire activity. We propose that the cold conditions over the northern North Atlantic, associated with low SSTs, expansion of sea ice cover, and the southward shift in the position of the subpolar gyre, redirect southward the precipitation over Scandinavia, associated with the westerlies. This dynamics strengthens high pressure systems over Scandinavia and results in increased regional fire activity. Our study reveals a previously undocumented teleconnection between large scale climate and ocean dynamics over the North Atlantic and regional boreal forest fire activity in Northern Scandinavia. Consistency of the pattern observed annually through millennium scales suggests that a strong link between Atlantic SST and fire activity on multiple temporal scales over the entire Holocene is relevant for understanding future fire activity across the European boreal zone.

  18. Atlantic SSTs control regime shifts in forest fire activity of Northern Scandinavia.

    PubMed

    Drobyshev, Igor; Bergeron, Yves; Vernal, Anne de; Moberg, Anders; Ali, Adam A; Niklasson, Mats

    2016-01-01

    Understanding the drivers of the boreal forest fire activity is challenging due to the complexity of the interactions driving fire regimes. We analyzed drivers of forest fire activity in Northern Scandinavia (above 60 N) by combining modern and proxy data over the Holocene. The results suggest that the cold climate in northern Scandinavia was generally characterized by dry conditions favourable to periods of regionally increased fire activity. We propose that the cold conditions over the northern North Atlantic, associated with low SSTs, expansion of sea ice cover, and the southward shift in the position of the subpolar gyre, redirect southward the precipitation over Scandinavia, associated with the westerlies. This dynamics strengthens high pressure systems over Scandinavia and results in increased regional fire activity. Our study reveals a previously undocumented teleconnection between large scale climate and ocean dynamics over the North Atlantic and regional boreal forest fire activity in Northern Scandinavia. Consistency of the pattern observed annually through millennium scales suggests that a strong link between Atlantic SST and fire activity on multiple temporal scales over the entire Holocene is relevant for understanding future fire activity across the European boreal zone. PMID:26940995

  19. Atlantic SSTs control regime shifts in forest fire activity of Northern Scandinavia

    PubMed Central

    Drobyshev, Igor; Bergeron, Yves; Vernal, Anne de; Moberg, Anders; Ali, Adam A.; Niklasson, Mats

    2016-01-01

    Understanding the drivers of the boreal forest fire activity is challenging due to the complexity of the interactions driving fire regimes. We analyzed drivers of forest fire activity in Northern Scandinavia (above 60 N) by combining modern and proxy data over the Holocene. The results suggest that the cold climate in northern Scandinavia was generally characterized by dry conditions favourable to periods of regionally increased fire activity. We propose that the cold conditions over the northern North Atlantic, associated with low SSTs, expansion of sea ice cover, and the southward shift in the position of the subpolar gyre, redirect southward the precipitation over Scandinavia, associated with the westerlies. This dynamics strengthens high pressure systems over Scandinavia and results in increased regional fire activity. Our study reveals a previously undocumented teleconnection between large scale climate and ocean dynamics over the North Atlantic and regional boreal forest fire activity in Northern Scandinavia. Consistency of the pattern observed annually through millennium scales suggests that a strong link between Atlantic SST and fire activity on multiple temporal scales over the entire Holocene is relevant for understanding future fire activity across the European boreal zone. PMID:26940995

  20. Inhibiting Delta-6 Desaturase Activity Suppresses Tumor Growth in Mice

    PubMed Central

    He, Chengwei; Qu, Xiying; Wan, Jianbo; Rong, Rong; Huang, Lili; Cai, Chun; Zhou, Keyuan; Gu, Yan; Qian, Steven Y.; Kang, Jing X.

    2012-01-01

    Recent studies have shown that a tumor-supportive microenvironment is characterized by high levels of pro-inflammatory and pro-angiogenic eicosanoids derived from omega-6 (n−6) arachidonic acid (AA). Although the metabolic pathways (COX, LOX, and P450) that generate these n−6 AA eicosanoids have been targeted, the role of endogenous AA production in tumorigenesis remains unexplored. Delta-6 desaturase (D6D) is the rate-limiting enzyme responsible for the synthesis of n−6 AA and increased D6D activity can lead to enhanced n−6 AA production. Here, we show that D6D activity is upregulated during melanoma and lung tumor growth and that suppressing D6D activity, either by RNAi knockdown or a specific D6D inhibitor, dramatically reduces tumor growth. Accordingly, the content of AA and AA-derived tumor-promoting metabolites is significantly decreased. Angiogenesis and inflammatory status are also reduced. These results identify D6D as a key factor for tumor growth and as a potential target for cancer therapy and prevention. PMID:23112819

  1. MDMX exerts its oncogenic activity via suppression of retinoblastoma protein.

    PubMed

    Zhang, H; Hu, L; Qiu, W; Deng, T; Zhang, Y; Bergholz, J; Xiao, Z-X

    2015-10-29

    Inactivation of the retinoblastoma protein (RB) has a major role in the development of human malignancies. We have previously shown that MDM2, an ubiquitin E3 ligase and major negative regulator of p53, binds to and promotes proteasome-mediated degradation of RB. MDMX, a homolog of MDM2, also binds to and inhibits p53 transactivation activity, yet it does not possess intrinsic ubiquitin ligase activity. Here, we show that MDMX binds to and promotes RB degradation in an MDM2-dependent manner. Specifically, the MDMX C-terminal ring domain binds to the RB C-pocket and enhances MDM2-RB interaction. Silencing MDMX induces RB accumulation, cell cycle arrest and senescence-like phenotypes, which are reverted by simultaneous RB knockdown. Furthermore, MDMX ablation leads to significant retardation of xenograft tumor growth, concomitant with RB accumulation. These results demonstrate that MDMX exerts oncogenic activity via suppression of RB, and suggest that both MDM2 and MDMX could be chemotherapeutic targets. PMID:25703327

  2. Characterization of indoor and outdoor pool fires with active calorimetry

    SciTech Connect

    Koski, J.A.; Gill, W.; Gritzo, L.A.; Kent, L.A.; Wix, S.D.

    1994-12-31

    A water cooled, 1 m {times} 1 m, vertical calorimeter panel has been used in conjunction with other fire diagnostics to characterize a 6 m {times} 6 m outdoor and three 3 m {times} 3 m indoor JP-4 pool fires. Measurements reported include calorimeter surface heat flux and surface temperatures, flame temperatures, and gas flow velocities in the fire. From the data, effective radiative absorption coefficients for various zones in the fires have been estimated. The outdoor test was conducted at Sandia`s Coyote Canyon test facility, while indoor tests were conducted at the indoor SMokE Reduction Facility (SMERF) at the same location. The measurements provide data useful in calibrating simple analytic fire models intended for the analysis of packages containing hazardous materials.

  3. Effects of biotic feedback and harvest management on boreal forest fire activity under climate change.

    PubMed

    Krawchuk, Meg A; Cumming, Steve G

    2011-01-01

    Predictions of future fire activity over Canada's boreal forests have primarily been generated from climate data following assumptions that direct effects of weather will stand alone in contributing to changes in burning. However, this assumption needs explicit testing. First, areas recently burned can be less likely to burn again in the near term, and this endogenous regulation suggests the potential for self-limiting, negative biotic feedback to regional climate-driven increases in fire. Second, forest harvest is ongoing, and resulting changes in vegetation structure have been shown to affect fire activity. Consequently, we tested the assumption that fire activity will be driven by changes in fire weather without regulation by biotic feedback or regional harvest-driven changes in vegetation structure in the mixedwood boreal forest of Alberta, Canada, using a simulation experiment that includes the interaction of fire, stand dynamics, climate change, and clear cut harvest management. We found that climate change projected with fire weather indices calculated from the Canadian Regional Climate Model increased fire activity, as expected, and our simulations established evidence that the magnitude of regional increase in fire was sufficient to generate negative feedback to subsequent fire activity. We illustrate a 39% (1.39-fold) increase in fire initiation and 47% (1.47-fold) increase in area burned when climate and stand dynamics were included in simulations, yet 48% (1.48-fold) and 61% (1.61-fold) increases, respectively, when climate was considered alone. Thus, although biotic feedbacks reduced burned area estimates in important ways, they were secondary to the direct effect of climate on fire. We then show that ongoing harvest management in this region changed landscape composition in a way that led to reduced fire activity, even in the context of climate change. Although forest harvesting resulted in decreased regional fire activity when compared to unharvested

  4. Fire activity inside and outside protected areas in Sub-Saharan Africa: a continental analysis of fire and its implications for biodiversity and land management

    NASA Astrophysics Data System (ADS)

    Palumbo, Ilaria; Gregoire, Jean-Marie; Simonetti, Dario; Punga, Mihkel; Dubois, Gregoire

    2010-05-01

    Fire is an important ecological factor in many natural ecosystems. Without doubt one of the biomes with the highest fire activity in the world is the African savannah. Savannahs have evolved with fires since climate in these regions is characterized by definite dry and wet seasons that create the conditions for burning. During the wet months the herbaceous vegetation shows a quick growth, followed by a long dry period during which the abundant build-up of fine materials becomes highly flammable and most of fires occur. Animals and plants are adapted to these conditions and their lives depend on recurrent fires. In this context fire becomes an essential element to promote biodiversity and nature conservation. Park managers are using programmed fires as a tool to maintain the habitats and favorable conditions to the animal communities. Satellite products like burned areas and active fire maps are a valuable mean to analyze the fire activity and provide support to experts working for conservation and natural resource management. In the framework of the Digital Observatory for Protected Areas (DOPA), the MONDE group (Monitoring Natural Resources for Development) of the Joint Research Centre of the European Commission is using satellite products to analyze the fire occurrence and its effects on protected areas located in sub-Saharan Africa. Information on the fire activity was derived from the MODIS fire products (active fires and burned areas) and allows the DOPA to provide support to park managers as well as to experts working for conservation and natural resource management. We assessed 741 protected areas classified by the IUCN (International Union for Conservation of Nature) with a level of protection between class I and IV. The MODIS datasets are available since the year 2000 and were used to characterize the spatio-temporal distribution of fires over a period of 10 years. Information on fire activity was extracted for the protected areas and a 25km buffer zone

  5. Fire activity inside and outside protected areas in Sub-Saharan Africa: a continental analysis of fire and its implications for biodiversity and management

    NASA Astrophysics Data System (ADS)

    Palumbo, Ilaria; Gregoire, Jean-Marie; Simonetti, Dario; Punga, Mihkel; Dubois, Gregoire

    2010-05-01

    Fire is an important ecological factor in many natural ecosystems. Without doubt one of the biomes with the highest fire activity in the world is the African savannah. Savannahs have evolved with fires since climate in these regions is characterized by definite dry and wet seasons that create the conditions for burning. During the wet months the herbaceous vegetation shows a quick growth, followed by a long dry period during which the abundant build-up of fine materials becomes highly flammable and most of fires occur. Animals and plants are adapted to these conditions and their lives depend on recurrent fires. In this context fire becomes an essential element to promote biodiversity and nature conservation. Park managers are using programmed fires as a tool to maintain the habitats and favorable conditions to the animal communities. Satellite products like burned areas and active fire maps are a valuable mean to analyze the fire activity and provide support to experts working for conservation and natural resource management. In the framework of the Digital Observatory for Protected Areas (DOPA), the MONDE group (Monitoring Natural Resources for Development) of the Joint Research Centre of the European Commission is using satellite products to analyze the fire occurrence and its effects on protected areas located in sub-Saharan Africa. Information on the fire activity was derived from the MODIS fire products (active fires and burned areas) and allows the DOPA to provide support to park managers as well as to experts working for conservation and natural resource management. We assessed 741 protected areas classified by the IUCN (International Union for Conservation of Nature) with a level of protection between class I and IV. The MODIS datasets are available since the year 2000 and were used to characterize the spatio-temporal distribution of fires over a period of 10 years. Information on fire activity was extracted for the protected areas and a 25km buffer zone

  6. Monetary reward suppresses anterior insula activity during social pain.

    PubMed

    Cristofori, Irene; Harquel, Sylvain; Isnard, Jean; Mauguière, François; Sirigu, Angela

    2015-12-01

    Social pain after exclusion by others activates brain regions also involved in physical pain. Here we evaluated whether monetary reward could compensate for the negative feeling of social pain in the brain. To address this question we used the unique technique of intracranial electroencephalography in subjects with drug resistant epilepsy. Specifically, we recorded theta activity from intracranial electrodes implanted in the insular cortex while subjects experienced conditions of social inclusion and exclusion associated with monetary gain and loss. Our study confirmed that theta rhythm in the insular cortex is the neural signature of social exclusion. We found that while monetary gain suppresses the effect of social pain in the anterior insula, there is no such effect in the posterior insula. These results imply that the anterior insula can use secondary reward signals to compensate for the negative feeling of social pain. Hence, here we propose that the anterior insula plays a pivotal role in integrating contingencies to update social pain feelings. Finally, the possibility to modulate the theta rhythm through the reward system might open new avenues of research for treating pathologies related to social exclusion. PMID:25964499

  7. Monetary reward suppresses anterior insula activity during social pain.

    PubMed

    Cristofori, Irene; Harquel, Sylvain; Isnard, Jean; Mauguière, François; Sirigu, Angela

    2015-12-01

    Social pain after exclusion by others activates brain regions also involved in physical pain. Here we evaluated whether monetary reward could compensate for the negative feeling of social pain in the brain. To address this question we used the unique technique of intracranial electroencephalography in subjects with drug resistant epilepsy. Specifically, we recorded theta activity from intracranial electrodes implanted in the insular cortex while subjects experienced conditions of social inclusion and exclusion associated with monetary gain and loss. Our study confirmed that theta rhythm in the insular cortex is the neural signature of social exclusion. We found that while monetary gain suppresses the effect of social pain in the anterior insula, there is no such effect in the posterior insula. These results imply that the anterior insula can use secondary reward signals to compensate for the negative feeling of social pain. Hence, here we propose that the anterior insula plays a pivotal role in integrating contingencies to update social pain feelings. Finally, the possibility to modulate the theta rhythm through the reward system might open new avenues of research for treating pathologies related to social exclusion.

  8. Vegetation burned areas derived from multiple satellite-based active fires

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoyang; Kondragunta, Shobha

    2008-08-01

    Biomass burning releases a significant amount of trace gases and aerosol emissions into the atmosphere. If unaccounted for in the modeling of climate, carbon cycle, and air quality, it leads to large uncertainties. The amount of biomass burning emissions depends significantly on burned areas. This study estimates near-real time burned areas from multiple satellite-based active fires in Hazard Mapping System (HMS) developed in NOAA, which capitalizes automated fire detections from Geostationary Operational Environmental Satellite (GOES) Imager, Advanced Very High Resolution Radiometer (AVHRR), Moderate Resolution Imaging Spectroradiometer (MODIS). The HMS fire counts are compared with a set of Landsat ETM+ burn scars for various ecosystems to investigate the rate of burned area in a fire count. The fire size and fire duration derived from multiple satellites are then used to calculate burned area every half hour. The estimated burned areas are evaluated using national inventory of burned area across the United States for 2005.

  9. Controls on interannual variability in lightning-caused fire activity in the western US

    NASA Astrophysics Data System (ADS)

    Abatzoglou, John T.; Kolden, Crystal A.; Balch, Jennifer K.; Bradley, Bethany A.

    2016-04-01

    Lightning-caused wildfires account for a majority of burned area across the western United States (US), yet lightning remains among the more unpredictable spatiotemporal aspects of the fire environment and a challenge for both modeling and managing fire activity. A data synthesis of cloud-to-ground lightning strikes, climate and fire data across the western US from 1992 to 2013 was conducted to better understand geographic variability in lightning-caused wildfire and the factors that influence interannual variability in lightning-caused wildfire at regional scales. Distinct geographic variability occurred in the proportion of fires and area burned attributed to lightning, with a majority of fires in the interior western US attributed to lightning. Lightning ignition efficiency was highest across the western portion of the region due to the concomitance of peak lightning frequency and annual nadir in fuel moisture in mid-to-late summer. For most regions the number of total and dry lightning strikes exhibited strong interannual correlation with the number of lightning-caused fires, yet were a poor predictor of area burned at regional scales. Commonality in climate-fire relationships for regional annual area burned by lightning- versus human-ignited fires suggests climate conditions, rather than lightning activity, are the predominant control of interannual variability in area burned by lightning-caused fire across much of the western US.

  10. Fire protection for launch facilities using machine vision fire detection

    NASA Astrophysics Data System (ADS)

    Schwartz, Douglas B.

    1993-02-01

    Fire protection of critical space assets, including launch and fueling facilities and manned flight hardware, demands automatic sensors for continuous monitoring, and in certain high-threat areas, fast-reacting automatic suppression systems. Perhaps the most essential characteristic for these fire detection and suppression systems is high reliability; in other words, fire detectors should alarm only on actual fires and not be falsely activated by extraneous sources. Existing types of fire detectors have been greatly improved in the past decade; however, fundamental limitations of their method of operation leaves open a significant possibility of false alarms and restricts their usefulness. At the Civil Engineering Laboratory at Tyndall Air Force Base in Florida, a new type of fire detector is under development which 'sees' a fire visually, like a human being, and makes a reliable decision based on known visual characteristics of flames. Hardware prototypes of the Machine Vision (MV) Fire Detection System have undergone live fire tests and demonstrated extremely high accuracy in discriminating actual fires from false alarm sources. In fact, this technology promises to virtually eliminate false activations. This detector could be used to monitor fueling facilities, launch towers, clean rooms, and other high-value and high-risk areas. Applications can extend to space station and in-flight shuttle operations as well; fiber optics and remote camera heads enable the system to see around obstructed areas and crew compartments. The capability of the technology to distinguish fires means that fire detection can be provided even during maintenance operations, such as welding.

  11. Fire protection for launch facilities using machine vision fire detection

    NASA Technical Reports Server (NTRS)

    Schwartz, Douglas B.

    1993-01-01

    Fire protection of critical space assets, including launch and fueling facilities and manned flight hardware, demands automatic sensors for continuous monitoring, and in certain high-threat areas, fast-reacting automatic suppression systems. Perhaps the most essential characteristic for these fire detection and suppression systems is high reliability; in other words, fire detectors should alarm only on actual fires and not be falsely activated by extraneous sources. Existing types of fire detectors have been greatly improved in the past decade; however, fundamental limitations of their method of operation leaves open a significant possibility of false alarms and restricts their usefulness. At the Civil Engineering Laboratory at Tyndall Air Force Base in Florida, a new type of fire detector is under development which 'sees' a fire visually, like a human being, and makes a reliable decision based on known visual characteristics of flames. Hardware prototypes of the Machine Vision (MV) Fire Detection System have undergone live fire tests and demonstrated extremely high accuracy in discriminating actual fires from false alarm sources. In fact, this technology promises to virtually eliminate false activations. This detector could be used to monitor fueling facilities, launch towers, clean rooms, and other high-value and high-risk areas. Applications can extend to space station and in-flight shuttle operations as well; fiber optics and remote camera heads enable the system to see around obstructed areas and crew compartments. The capability of the technology to distinguish fires means that fire detection can be provided even during maintenance operations, such as welding.

  12. Cytokine treatment of macrophage suppression of T cell activation.

    PubMed

    Silberman, Daniel; Bucknum, Amanda; Kozlowski, Megan; Matlack, Robin; Riggs, James

    2010-01-01

    High Mphi:T cell ratios suppress the immune response to the retroviral superantigen Mls by IFNgamma-triggered production of the arg- and trp-consuming enzymes iNOS and IDO. Attempts to reverse suppression by treatment with pro-inflammatory cytokines revealed that IL-6 improved the T cell response to Mls and the pro-hematopoietic cyokines IL-3 and GM-CSF increased suppression. GM-CSF treatment increased Mphi expression of CD80, a ligand for the immune suppressive B7H1 and CTLA-4 receptors. These results illustrate potential strategies for reversing the suppression of cell-mediated immunity characteristic of the high Mphi:T cell ratios found in many tumors.

  13. Fire activity and severity in the western US vary along proxy gradients representing fuel amount and fuel moisture.

    PubMed

    Parks, Sean A; Parisien, Marc-André; Miller, Carol; Dobrowski, Solomon Z

    2014-01-01

    Numerous theoretical and empirical studies have shown that wildfire activity (e.g., area burned) at regional to global scales may be limited at the extremes of environmental gradients such as productivity or moisture. Fire activity, however, represents only one component of the fire regime, and no studies to date have characterized fire severity along such gradients. Given the importance of fire severity in dictating ecological response to fire, this is a considerable knowledge gap. For the western US, we quantify relationships between climate and the fire regime by empirically describing both fire activity and severity along two climatic water balance gradients, actual evapotranspiration (AET) and water deficit (WD), that can be considered proxies for fuel amount and fuel moisture, respectively. We also concurrently summarize fire activity and severity among ecoregions, providing an empirically based description of the geographic distribution of fire regimes. Our results show that fire activity in the western US increases with fuel amount (represented by AET) but has a unimodal (i.e., humped) relationship with fuel moisture (represented by WD); fire severity increases with fuel amount and fuel moisture. The explicit links between fire regime components and physical environmental gradients suggest that multivariable statistical models can be generated to produce an empirically based fire regime map for the western US. Such models will potentially enable researchers to anticipate climate-mediated changes in fire recurrence and its impacts based on gridded spatial data representing future climate scenarios. PMID:24941290

  14. Fire Activity and Severity in the Western US Vary along Proxy Gradients Representing Fuel Amount and Fuel Moisture

    PubMed Central

    Parks, Sean A.; Parisien, Marc-André; Miller, Carol; Dobrowski, Solomon Z.

    2014-01-01

    Numerous theoretical and empirical studies have shown that wildfire activity (e.g., area burned) at regional to global scales may be limited at the extremes of environmental gradients such as productivity or moisture. Fire activity, however, represents only one component of the fire regime, and no studies to date have characterized fire severity along such gradients. Given the importance of fire severity in dictating ecological response to fire, this is a considerable knowledge gap. For the western US, we quantify relationships between climate and the fire regime by empirically describing both fire activity and severity along two climatic water balance gradients, actual evapotranspiration (AET) and water deficit (WD), that can be considered proxies for fuel amount and fuel moisture, respectively. We also concurrently summarize fire activity and severity among ecoregions, providing an empirically based description of the geographic distribution of fire regimes. Our results show that fire activity in the western US increases with fuel amount (represented by AET) but has a unimodal (i.e., humped) relationship with fuel moisture (represented by WD); fire severity increases with fuel amount and fuel moisture. The explicit links between fire regime components and physical environmental gradients suggest that multivariable statistical models can be generated to produce an empirically based fire regime map for the western US. Such models will potentially enable researchers to anticipate climate-mediated changes in fire recurrence and its impacts based on gridded spatial data representing future climate scenarios. PMID:24941290

  15. IL-27 suppresses antimicrobial activity in human leprosy

    PubMed Central

    Teles, Rosane M. B.; Kelly-Scumpia, Kindra M.; Sarno, Euzenir N.; Rea, Thomas H.; Ochoa, Maria T.; Cheng, Genhong; Modlin, Robert L.

    2015-01-01

    The mechanisms by which intracellular pathogens trigger immunosuppressive pathways are critical for understanding the pathogenesis of microbial infection. One pathway that inhibits host defense responses involves the induction of type I interferons and subsequently IL-10, yet the mechanism by which type I IFN induces IL-10 remains unclear. Our studies of gene expression profiles derived from leprosy skin lesions suggested a link between IL-27 and the IFN-β induced IL-10 pathway. Here, we demonstrate that the IL-27p28 subunit is upregulated following treatment of monocytes with IFN-β and Mycobacterium leprae, the intracellular bacterium that causes leprosy. The ability of IFN-β and M. leprae to induce IL-10 was diminished by IL-27 knockdown. Additionally, treatment of monocytes with recombinant IL-27 was sufficient to induce the production of IL-10. Functionally, IL-27 inhibited the ability of IFN-γ to trigger antimicrobial activity against M. leprae in infected monocytes. At the site of disease, IL-27 was more strongly expressed in skin lesions of patients with progressive lepromatous leprosy, correlating and colocalizing with IFN-β and IL-10 in macrophages. Together, these data provide evidence that in the human cutaneous immune responses to microbial infection, IL-27 contributes to the suppression of host antimicrobial responses. PMID:26030183

  16. The suppression of star formation by powerful active galactic nuclei.

    PubMed

    Page, M J; Symeonidis, M; Vieira, J D; Altieri, B; Amblard, A; Arumugam, V; Aussel, H; Babbedge, T; Blain, A; Bock, J; Boselli, A; Buat, V; Castro-Rodríguez, N; Cava, A; Chanial, P; Clements, D L; Conley, A; Conversi, L; Cooray, A; Dowell, C D; Dubois, E N; Dunlop, J S; Dwek, E; Dye, S; Eales, S; Elbaz, D; Farrah, D; Fox, M; Franceschini, A; Gear, W; Glenn, J; Griffin, M; Halpern, M; Hatziminaoglou, E; Ibar, E; Isaak, K; Ivison, R J; Lagache, G; Levenson, L; Lu, N; Madden, S; Maffei, B; Mainetti, G; Marchetti, L; Nguyen, H T; O'Halloran, B; Oliver, S J; Omont, A; Panuzzo, P; Papageorgiou, A; Pearson, C P; Pérez-Fournon, I; Pohlen, M; Rawlings, J I; Rigopoulou, D; Riguccini, L; Rizzo, D; Rodighiero, G; Roseboom, I G; Rowan-Robinson, M; Sánchez Portal, M; Schulz, B; Scott, D; Seymour, N; Shupe, D L; Smith, A J; Stevens, J A; Trichas, M; Tugwell, K E; Vaccari, M; Valtchanov, I; Viero, M; Vigroux, L; Wang, L; Ward, R; Wright, G; Xu, C K; Zemcov, M

    2012-05-09

    The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight correlation between the mass of the black hole and the mass of the stellar bulge results from the AGN quenching the surrounding star formation as it approaches its peak luminosity. X-rays trace emission from AGN unambiguously, whereas powerful star-forming galaxies are usually dust-obscured and are brightest at infrared and submillimetre wavelengths. Here we report submillimetre and X-ray observations that show that rapid star formation was common in the host galaxies of AGN when the Universe was 2-6 billion years old, but that the most vigorous star formation is not observed around black holes above an X-ray luminosity of 10(44) ergs per second. This suppression of star formation in the host galaxy of a powerful AGN is a key prediction of models in which the AGN drives an outflow, expelling the interstellar medium of its host and transforming the galaxy's properties in a brief period of cosmic time.

  17. The Suppression of Star Formation by Powerful Active Galactic Nuclei

    NASA Technical Reports Server (NTRS)

    Dwek, E.

    2012-01-01

    The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight corre1ation between the mass of the black hole and the mas. of the stellar bulge results from the AGN quenching the surrounding star formation as it approaches its peak luminosity. X-rays trace emission from AGN unambiguously, whereas powerful star-forming ga1axies are usually dust-obscured and are brightest at infrared and submillimeter wavelengths. Here we report submillimetre and X-ray observations that show that rapid star formation was common in the host galaxies of AGN when the Universe was 2-6 billion years old, but that the most vigorous star formation is not observed around black holes above an X-ray luminosity of 10(exp 44) ergs per second. This suppression of star formation in the host galaxy of a powerful AGN is a key prediction of models in which the AGN drives an outflow, expe11ing the interstellar medium of its host and transforming the galaxy's properties in a brief period of cosmic time.

  18. Controls on fire activity simulated for the last 6000 years - fuel availability versus fuel moisture

    NASA Astrophysics Data System (ADS)

    Kloster, Silvia; Bruecher, Tim; Brovkin, Victor

    2013-04-01

    Fire is an important natural disturbance factor, which significantly impacts vegetation dynamics. Fire activity depends on climate and information on fire history can, as such, be interpreted in climatic terms. However, the fire-climate relationship is often highly non-linear, as fire occurrence is controlled via several climate controlled factors, such as fuel availability and fuel moisture. Higher drought stress, for example, will decrease fuel moisture but can also impact fuel availability. In more recent times, fires are in addition strongly influenced by anthropogenic factors, which might mask any given natural fire-climate relationship. Here we present results from a process-based fire model (Arora and Boer, 2004) implemented into the vegetation model JSBACH as part of the Earth System Model of the Max Planck Institute for Meteorology (MPI-ESM). The model is forced with meteorological data from a fully coupled simulation of the MPI-ESM covering the last 6000 years, which show a small decrease of the surface temperature and a decline in precipitation. The resulting land carbon storage undergoes a significant decrease. Due to the changes in the orbital parameters with time, regionally the effect on precipitation and temperature is stronger, which results in a shift of the tropical rain belt combined with changes in vegetation. Striking is for example a reduction in the vegetation cover in central East Asia over the last 6000 years with a subsequent decreasing trend in land carbon storage. Simulated changes in fire activity are compared paleo fire reconstructions. In addition, we used the model for sensitivity experiments in which we keep either fuel availability or fuel moisture constant. This factor separation study allows us to interpret the fire-climate relationship in terms of the dominant driving forces.

  19. 5 CFR 551.215 - Fire protection activities and 7(k) coverage for FLSA pay and exemption determinations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Fire protection activities and 7(k... ACT Exemptions and Exclusions § 551.215 Fire protection activities and 7(k) coverage for FLSA pay and... section 7(k) of the Act apply to certain categories of fire protection employees based on...

  20. 5 CFR 551.215 - Fire protection activities and 7(k) coverage for FLSA pay and exemption determinations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Fire protection activities and 7(k... ACT Exemptions and Exclusions § 551.215 Fire protection activities and 7(k) coverage for FLSA pay and... section 7(k) of the Act apply to certain categories of fire protection employees based on...

  1. Advanced fire-resistant forms of activated carbon and methods of adsorbing and separating gases using same

    DOEpatents

    Xiong, Yongliang; Wang, Yifeng

    2016-04-19

    A method of removing a target gas from a gas stream is disclosed. The method uses advanced, fire-resistant activated carbon compositions having vastly improved fire resistance. Methods for synthesizing the compositions are also provided. The advanced compositions have high gas adsorption capacities and rapid adsorption kinetics (comparable to commercially-available activated carbon), without having any intrinsic fire hazard.

  2. Utilizing GIS Technology to Improve Fire Prevention Activities in an Urban Fire Department.

    PubMed

    Shields, Wendy C; Shields, Timothy M; McDonald, Eileen M; Perry, Elise C; Hanna, Peter; Gielen, Andrea C

    2015-01-01

    The Baltimore City Fire Department (BCFD) has been installing smoke alarms city wide for more than three decades. Though data on each visit are entered into a database, no system existed for using these data for planning or evaluation. The objective of this study is to use Geographic Information System (GIS) technology and existing databases to 1) determine the number of residences in need of a home visit; 2) determine total visits, visits per household, and number of homes entered for eligible households; and 3) demonstrate integration of various data via GIS for use in prevention planning. The tax assessment database was queried to determine the number of eligible (as determined by BCFD policy) residences in need of a visit. Each attempted BCFD home visit was coded to identify, if the BCFD personnel interacted with residents ("pass door") and installed alarms. Home visits were geocoded and compared to the tax assessment database to determine city wide pass door rates. Frequency of visits was run by individual residences to measure efficiency. A total of 206,850 residences met BCFD eligibility for a home visit. In 2007, the BCFD attempted 181,757 home visits and 177,213 were successfully geocoded to 122,118 addresses. A total of 122,118 eligible residences (59%) received a home visit. A total of 35,317 residences (29%) received a repeat visit attempt. The pass door rate was 22% (46,429) of all residences. GIS technology offers a promising means for fire departments to plan and evaluate the fire prevention services they provide. PMID:25185929

  3. Utilizing GIS Technology to Improve Fire Prevention Activities in an Urban Fire Department.

    PubMed

    Shields, Wendy C; Shields, Timothy M; McDonald, Eileen M; Perry, Elise C; Hanna, Peter; Gielen, Andrea C

    2015-01-01

    The Baltimore City Fire Department (BCFD) has been installing smoke alarms city wide for more than three decades. Though data on each visit are entered into a database, no system existed for using these data for planning or evaluation. The objective of this study is to use Geographic Information System (GIS) technology and existing databases to 1) determine the number of residences in need of a home visit; 2) determine total visits, visits per household, and number of homes entered for eligible households; and 3) demonstrate integration of various data via GIS for use in prevention planning. The tax assessment database was queried to determine the number of eligible (as determined by BCFD policy) residences in need of a visit. Each attempted BCFD home visit was coded to identify, if the BCFD personnel interacted with residents ("pass door") and installed alarms. Home visits were geocoded and compared to the tax assessment database to determine city wide pass door rates. Frequency of visits was run by individual residences to measure efficiency. A total of 206,850 residences met BCFD eligibility for a home visit. In 2007, the BCFD attempted 181,757 home visits and 177,213 were successfully geocoded to 122,118 addresses. A total of 122,118 eligible residences (59%) received a home visit. A total of 35,317 residences (29%) received a repeat visit attempt. The pass door rate was 22% (46,429) of all residences. GIS technology offers a promising means for fire departments to plan and evaluate the fire prevention services they provide.

  4. Measurements in large pool fires with an actively cooled calorimeter

    SciTech Connect

    Koski, J.A.; Wix, S.D.

    1995-12-31

    The pool fire thermal test described in Safety Series 6 published by the International Atomic Energy Agency (IAEA) or Title 10, Code of Federal Regulations, Part 71 (10CFR71) in the United States is one of the most difficult tests that a container for larger ``Type B`` quantities of nuclear materials must pass. If retests of a container are required, costly redesign and project delays can result. Accurate measurements and modeling of the pool fire environment will ultimately lower container costs by assuring that containers past the pool fire test on the first attempt. Experiments indicate that the object size or surface temperature of the container can play a role in determining local heat fluxes that are beyond the effects predicted from the simple radiative heat transfer laws. An analytical model described by Nicolette and Larson 1990 can be used to understand many of these effects. In this model a gray gas represents soot particles present in the flame structure. Close to the container surface, these soot particles are convectively and radiatively cooled and interact with incident energy from the surrounding fire. This cooler soot cloud effectively prevents some thermal radiation from reaching the container surface, reducing the surface heat flux below the value predicted by a transparent medium model. With some empirical constants, the model suggested by Nicolette and Larson can be used to more accurately simulate the pool fire environment. Properly formulated, the gray gas approaches also fast enough to be used with standard commercial computer codes to analyze shipping containers. To calibrate this type of model, accurate experimental measurements of radiative absorption coefficients, flame temperatures, and other parameters are necessary. A goal of the calorimeter measurements described here is to obtain such parameters so that a fast, useful design tool for large pool fires can be constructed.

  5. Glucagon-Like Peptide-1 Excites Firing and Increases GABAergic Miniature Postsynaptic Currents (mPSCs) in Gonadotropin-Releasing Hormone (GnRH) Neurons of the Male Mice via Activation of Nitric Oxide (NO) and Suppression of Endocannabinoid Signaling Pathways

    PubMed Central

    Farkas, Imre; Vastagh, Csaba; Farkas, Erzsébet; Bálint, Flóra; Skrapits, Katalin; Hrabovszky, Erik; Fekete, Csaba; Liposits, Zsolt

    2016-01-01

    Glucagon-like peptide-1 (GLP-1), a metabolic signal molecule, regulates reproduction, although, the involved molecular mechanisms have not been elucidated, yet. Therefore, responsiveness of gonadotropin-releasing hormone (GnRH) neurons to the GLP-1 analog Exendin-4 and elucidation of molecular pathways acting downstream to the GLP-1 receptor (GLP-1R) have been challenged. Loose patch-clamp recordings revealed that Exendin-4 (100 nM–5 μM) elevated firing rate in hypothalamic GnRH-GFP neurons of male mice via activation of GLP-1R. Whole-cell patch-clamp measurements demonstrated increased excitatory GABAergic miniature postsynaptic currents (mPSCs) frequency after Exendin-4 administration, which was eliminated by the GLP-1R antagonist Exendin-3(9–39) (1 μM). Intracellular application of the G-protein inhibitor GDP-β-S (2 mM) impeded action of Exendin-4 on mPSCs, suggesting direct excitatory action of GLP-1 on GnRH neurons. Blockade of nitric-oxide (NO) synthesis by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 100 μM) or N5-[Imino(propylamino)methyl]-L-ornithine hydrochloride (NPLA; 1 μM) or intracellular scavenging of NO by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO; 1 mM) partially attenuated the excitatory effect of Exendin-4. Similar partial inhibition was achieved by hindering endocannabinoid pathway using cannabinoid receptor type-1 (CB1) inverse-agonist 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-(1-piperidyl) pyrazole-3-carboxamide (AM251; 1 μM). Simultaneous blockade of NO and endocannabinoid signaling mechanisms eliminated action of Exendin-4 suggesting involvement of both retrograde machineries. Intracellular application of the transient receptor potential vanilloid 1 (TRPV1)-antagonist 2E-N-(2, 3-Dihydro-1,4-benzodioxin-6-yl)-3-[4-(1, 1-dimethylethyl)phenyl]-2-Propenamide (AMG9810; 10 μM) or the fatty acid amide hydrolase (FAAH)-inhibitor PF3845 (5 μM) impeded the GLP-1-triggered endocannabinoid

  6. Glucagon-Like Peptide-1 Excites Firing and Increases GABAergic Miniature Postsynaptic Currents (mPSCs) in Gonadotropin-Releasing Hormone (GnRH) Neurons of the Male Mice via Activation of Nitric Oxide (NO) and Suppression of Endocannabinoid Signaling Pathways.

    PubMed

    Farkas, Imre; Vastagh, Csaba; Farkas, Erzsébet; Bálint, Flóra; Skrapits, Katalin; Hrabovszky, Erik; Fekete, Csaba; Liposits, Zsolt

    2016-01-01

    Glucagon-like peptide-1 (GLP-1), a metabolic signal molecule, regulates reproduction, although, the involved molecular mechanisms have not been elucidated, yet. Therefore, responsiveness of gonadotropin-releasing hormone (GnRH) neurons to the GLP-1 analog Exendin-4 and elucidation of molecular pathways acting downstream to the GLP-1 receptor (GLP-1R) have been challenged. Loose patch-clamp recordings revealed that Exendin-4 (100 nM-5 μM) elevated firing rate in hypothalamic GnRH-GFP neurons of male mice via activation of GLP-1R. Whole-cell patch-clamp measurements demonstrated increased excitatory GABAergic miniature postsynaptic currents (mPSCs) frequency after Exendin-4 administration, which was eliminated by the GLP-1R antagonist Exendin-3(9-39) (1 μM). Intracellular application of the G-protein inhibitor GDP-β-S (2 mM) impeded action of Exendin-4 on mPSCs, suggesting direct excitatory action of GLP-1 on GnRH neurons. Blockade of nitric-oxide (NO) synthesis by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 100 μM) or N(5)-[Imino(propylamino)methyl]-L-ornithine hydrochloride (NPLA; 1 μM) or intracellular scavenging of NO by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO; 1 mM) partially attenuated the excitatory effect of Exendin-4. Similar partial inhibition was achieved by hindering endocannabinoid pathway using cannabinoid receptor type-1 (CB1) inverse-agonist 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-(1-piperidyl) pyrazole-3-carboxamide (AM251; 1 μM). Simultaneous blockade of NO and endocannabinoid signaling mechanisms eliminated action of Exendin-4 suggesting involvement of both retrograde machineries. Intracellular application of the transient receptor potential vanilloid 1 (TRPV1)-antagonist 2E-N-(2, 3-Dihydro-1,4-benzodioxin-6-yl)-3-[4-(1, 1-dimethylethyl)phenyl]-2-Propenamide (AMG9810; 10 μM) or the fatty acid amide hydrolase (FAAH)-inhibitor PF3845 (5 μM) impeded the GLP-1-triggered endocannabinoid

  7. Glucagon-Like Peptide-1 Excites Firing and Increases GABAergic Miniature Postsynaptic Currents (mPSCs) in Gonadotropin-Releasing Hormone (GnRH) Neurons of the Male Mice via Activation of Nitric Oxide (NO) and Suppression of Endocannabinoid Signaling Pathways.

    PubMed

    Farkas, Imre; Vastagh, Csaba; Farkas, Erzsébet; Bálint, Flóra; Skrapits, Katalin; Hrabovszky, Erik; Fekete, Csaba; Liposits, Zsolt

    2016-01-01

    Glucagon-like peptide-1 (GLP-1), a metabolic signal molecule, regulates reproduction, although, the involved molecular mechanisms have not been elucidated, yet. Therefore, responsiveness of gonadotropin-releasing hormone (GnRH) neurons to the GLP-1 analog Exendin-4 and elucidation of molecular pathways acting downstream to the GLP-1 receptor (GLP-1R) have been challenged. Loose patch-clamp recordings revealed that Exendin-4 (100 nM-5 μM) elevated firing rate in hypothalamic GnRH-GFP neurons of male mice via activation of GLP-1R. Whole-cell patch-clamp measurements demonstrated increased excitatory GABAergic miniature postsynaptic currents (mPSCs) frequency after Exendin-4 administration, which was eliminated by the GLP-1R antagonist Exendin-3(9-39) (1 μM). Intracellular application of the G-protein inhibitor GDP-β-S (2 mM) impeded action of Exendin-4 on mPSCs, suggesting direct excitatory action of GLP-1 on GnRH neurons. Blockade of nitric-oxide (NO) synthesis by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 100 μM) or N(5)-[Imino(propylamino)methyl]-L-ornithine hydrochloride (NPLA; 1 μM) or intracellular scavenging of NO by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO; 1 mM) partially attenuated the excitatory effect of Exendin-4. Similar partial inhibition was achieved by hindering endocannabinoid pathway using cannabinoid receptor type-1 (CB1) inverse-agonist 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-(1-piperidyl) pyrazole-3-carboxamide (AM251; 1 μM). Simultaneous blockade of NO and endocannabinoid signaling mechanisms eliminated action of Exendin-4 suggesting involvement of both retrograde machineries. Intracellular application of the transient receptor potential vanilloid 1 (TRPV1)-antagonist 2E-N-(2, 3-Dihydro-1,4-benzodioxin-6-yl)-3-[4-(1, 1-dimethylethyl)phenyl]-2-Propenamide (AMG9810; 10 μM) or the fatty acid amide hydrolase (FAAH)-inhibitor PF3845 (5 μM) impeded the GLP-1-triggered endocannabinoid

  8. Glucagon-Like Peptide-1 Excites Firing and Increases GABAergic Miniature Postsynaptic Currents (mPSCs) in Gonadotropin-Releasing Hormone (GnRH) Neurons of the Male Mice via Activation of Nitric Oxide (NO) and Suppression of Endocannabinoid Signaling Pathways

    PubMed Central

    Farkas, Imre; Vastagh, Csaba; Farkas, Erzsébet; Bálint, Flóra; Skrapits, Katalin; Hrabovszky, Erik; Fekete, Csaba; Liposits, Zsolt

    2016-01-01

    Glucagon-like peptide-1 (GLP-1), a metabolic signal molecule, regulates reproduction, although, the involved molecular mechanisms have not been elucidated, yet. Therefore, responsiveness of gonadotropin-releasing hormone (GnRH) neurons to the GLP-1 analog Exendin-4 and elucidation of molecular pathways acting downstream to the GLP-1 receptor (GLP-1R) have been challenged. Loose patch-clamp recordings revealed that Exendin-4 (100 nM–5 μM) elevated firing rate in hypothalamic GnRH-GFP neurons of male mice via activation of GLP-1R. Whole-cell patch-clamp measurements demonstrated increased excitatory GABAergic miniature postsynaptic currents (mPSCs) frequency after Exendin-4 administration, which was eliminated by the GLP-1R antagonist Exendin-3(9–39) (1 μM). Intracellular application of the G-protein inhibitor GDP-β-S (2 mM) impeded action of Exendin-4 on mPSCs, suggesting direct excitatory action of GLP-1 on GnRH neurons. Blockade of nitric-oxide (NO) synthesis by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME; 100 μM) or N5-[Imino(propylamino)methyl]-L-ornithine hydrochloride (NPLA; 1 μM) or intracellular scavenging of NO by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO; 1 mM) partially attenuated the excitatory effect of Exendin-4. Similar partial inhibition was achieved by hindering endocannabinoid pathway using cannabinoid receptor type-1 (CB1) inverse-agonist 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-(1-piperidyl) pyrazole-3-carboxamide (AM251; 1 μM). Simultaneous blockade of NO and endocannabinoid signaling mechanisms eliminated action of Exendin-4 suggesting involvement of both retrograde machineries. Intracellular application of the transient receptor potential vanilloid 1 (TRPV1)-antagonist 2E-N-(2, 3-Dihydro-1,4-benzodioxin-6-yl)-3-[4-(1, 1-dimethylethyl)phenyl]-2-Propenamide (AMG9810; 10 μM) or the fatty acid amide hydrolase (FAAH)-inhibitor PF3845 (5 μM) impeded the GLP-1-triggered endocannabinoid

  9. Patterns of fire activity over Indonesia and Malaysia from polar and geostationary satellite observations

    NASA Astrophysics Data System (ADS)

    Hyer, Edward J.; Reid, Jeffrey S.; Prins, Elaine M.; Hoffman, Jay P.; Schmidt, Christopher C.; Miettinen, Jukka I.; Giglio, Louis

    2013-03-01

    Biomass burning patterns over the Maritime Continent of Southeast Asia are examined using a new active fire detection product based on application of the Wildfire Automated Biomass Burning Algorithm (WF_ABBA) to data from the imagers on the MTSAT geostationary satellites operated by the Japanese space agency JAXA. Data from MTSAT-1R and MTSAT-2 covering 34 months from September 2008 to July 2011 are examined for a study region consisting of Indonesia, Malaysia, and nearby environs. The spatial and temporal distributions of fires detected in the MTSAT WF_ABBA product are described and compared with active fire observations from MODIS MOD14 data. Land cover distributions for the two instruments are examined using a new 250 m land cover product from the National University of Singapore. The two products show broadly similar patterns of fire activity, land cover distribution of fires, and pixel fire radiative power (FRP). However, the MTSAT WF_ABBA data differ from MOD14 in important ways. Relative to MODIS, the MTSAT WF_ABBA product has lower overall detection efficiency, but more fires detected due to more frequent looks, a greater relative fraction of fires in forest and a lower relative fraction of fires in open areas, and significantly higher single-pixel retrieved FRP. The differences in land cover distribution and FRP between the MTSAT and MODIS products are shown to be qualitatively consistent with expectations based on pixel size and diurnal sampling. The MTSAT WF_ABBA data are used to calculate coverage-corrected diurnal cycles of fire for different regions within the study area. These diurnal cycles are preliminary but demonstrate that the fraction of diurnal fire activity sampled by the two MODIS sensors varies significantly by region and vegetation type. Based on the results from comparison of the two fire products, a series of steps is outlined to account for some of the systematic biases in each of these satellite products in order to produce a

  10. [Suppression of sexual activity and reproduction in male small ruminants].

    PubMed

    Mihsler, Lisa; Wagner, Henrik; Wehrend, Axel

    2016-06-16

    Handling and husbandry of male small ruminants after sexual maturity often become difficult. Castration is currently the most reliable solution to this problem. Medicinal procedures for temporary inhibition of the gonad function could provide an alternative. Following a short overview of surgical castration, the current knowledge on the application of vaccines against gonadotropin-releasing hormone (GnRH) and GnRH agonist in rams and billy goats is presented in a literature overview. In rams, GnRH vaccination has been used successfully for temporary suppression of the reproduction function, regardless of an animal's age at the time of therapy initiation. Fewer investigations are available for the billy goat. A complete suppression of spermatogenesis was not achieved in all cases. Currently, treatment with GnRH agonists does not represent a relible method for the suppression of gonad function. PMID:27189125

  11. Optogenetic activation of septal GABAergic afferents entrains neuronal firing in the medial habenula

    PubMed Central

    Choi, Kyuhyun; Lee, Youngin; Lee, Changwoo; Hong, Seokheon; Lee, Soonje; Kang, Shin Jung; Shin, Ki Soon

    2016-01-01

    The medial habenula (MHb) plays an important role in nicotine-related behaviors such as nicotine aversion and withdrawal. The MHb receives GABAergic input from the medial septum/diagonal band of Broca (MS/DB), yet the synaptic mechanism that regulates MHb activity is unclear. GABA (γ -aminobutyric acid) is a major inhibitory neurotransmitter activating both GABAA receptors and GABAB receptors. Depending on intracellular chloride concentration, however, GABAA receptors also function in an excitatory manner. In the absence of various synaptic inputs, we found that MHb neurons displayed spontaneous tonic firing at a rate of about ~4.4 Hz. Optogenetic stimulation of MS/DB inputs to the MHb evoked GABAA receptor-mediated synaptic currents, which produced stimulus-locked neuronal firing. Subsequent delayed yet lasting activation of GABAB receptors attenuated the intrinsic tonic firing. Consequently, septal GABAergic input alone orchestrates both excitatory GABAA and inhibitory GABAB receptors, thereby entraining the firing of MHb neurons. PMID:27703268

  12. New Technology for the Fire Attire

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Although little can be done to reduce the risks of firefighting, something can be done to curb the injuries and fatalities. This is the goal of Project FIRES, a program jointly sponsored by NASA and the Federal Emergency Management Agency's U.S. Fire Administration with technical management provided by Marshall Space Flight Center. Project FIRES (Firefighter's Integrated Response Equipment System) involves applications of advanced materials and design concepts, derived from Apollo to update existing gear which does not adequately protect against many of the hazards encountered in fire suppression activities. A major focus of the effort involves application to the FIRES ensemble of lightweight, fire-resistant, heat-protective materials originally developed for use in astronauts' space suits or in spacecraft components which require thermal protection. Data from the fourteen municipal fire departments participating in the field evaluation will form a basis for development of new nationwide protective ensemble students.

  13. Application of a work penalty threat in the treatment of a case of juvenile fire setting.

    PubMed

    Carstens, C

    1982-06-01

    The treatment of a juvenile fire setter is described. A work penalty was utilized, in which the child was to do 1 hr of hard labor for each incident of fire setting or fire related activity. Immediate and complete suppression of the behavior occurred, with no recurrence at 6 month follow-up.

  14. The Southern Annular Mode determines interannual and centennial-scale fire activity in temperate southwest Tasmania, Australia

    NASA Astrophysics Data System (ADS)

    Mariani, Michela; Fletcher, Michael-Shawn

    2016-02-01

    Southern Annular Mode (SAM) is the primary mode of atmospheric variability in the Southern Hemisphere. While it is well established that the current anthropogenic-driven trend in SAM is responsible for decreased rainfall in southern Australia, its role in driving fire regimes in this region has not been explored. We examined the connection between fire activity and SAM in southwest Tasmania, which lies in the latitudinal band of strongest correlation between SAM and rainfall in the Southern Hemisphere. We reveal that fire activity during a fire season is significantly correlated with the phase of SAM in the preceding year using superposed epoch analysis. We then synthesized new 14 charcoal records from southwest Tasmania spanning the last 1000 years, revealing a tight coupling between fire activity and SAM at centennial timescales, observing a multicentury increase in fire activity over the last 500 years and a spike in fire activity in the 21st century in response to natural and anthropogenic SAM trends.

  15. Adaptive top-down suppression of hippocampal activity and the purging of intrusive memories from consciousness.

    PubMed

    Benoit, Roland G; Hulbert, Justin C; Huddleston, Ean; Anderson, Michael C

    2015-01-01

    When reminded of unwanted memories, people often attempt to suppress these experiences from awareness. Prior work indicates that control processes mediated by the dorsolateral prefrontal cortex (DLPFC) modulate hippocampal activity during such retrieval suppression. It remains unknown whether this modulation plays a role in purging an intrusive memory from consciousness. Here, we combined fMRI and effective connectivity analyses with phenomenological reports to scrutinize a role for adaptive top-down suppression of hippocampal retrieval processes in terminating mnemonic awareness of intrusive memories. Participants either suppressed or recalled memories of pictures depicting faces or places. After each trial, they reported their success at regulating awareness of the memory. DLPFC activation was greatest when unwanted memories intruded into consciousness and needed to be purged, and this increased engagement predicted superior control of intrusive memories over time. However, hippocampal activity was decreased during the suppression of place memories only. Importantly, the inhibitory influence of the DLPFC on the hippocampus was linked to the ensuing reduction in intrusions of the suppressed memories. Individuals who exhibited negative top-down coupling during early suppression attempts experienced fewer involuntary memory intrusions later on. Over repeated suppressions, the DLPFC-hippocampus connectivity grew less negative with the degree that they no longer had to purge unwanted memories from awareness. These findings support a role of DLPFC in countermanding the unfolding recollection of an unwanted memory via the suppression of hippocampal processing, a mechanism that may contribute to adaptation in the aftermath of traumatic experiences.

  16. A trend analysis of global fire activity. Is it land use or climate the main driver?

    NASA Astrophysics Data System (ADS)

    Bistinas, Ioannis; Oom, Duarte; Silva, Joao M. N.; Lopez-Saldaña, Gerardo; Pereira, Jose M. C.

    2016-04-01

    We perform a global trend analysis of active fire counts at 0.5o spatial resolution, using 156 months (January 2001 - December 2013) of MODIS Climate Modelling Grid data (TERRA). We use the Contextual Mann-Kendall (CMK) test to assess the statistical significance at cell level and found that 13% of the global land area displays statistically significant active fire count trends, with a slight predominance of negative trends (50.63% of the total significant cells). We perform the same trend analysis with the unexplained variability (residuals) between active fires and the Fire Weather Index (FWI) that is used as a proxy for climate. There is agreement between the main patterns from the trend analysis coming from the residuals and the active fire trends, implying that the main contemporary fire trends are not climate driven. Spatially coherent patches with significant trends were found in all continents (with the obvious exception of Antarctica). The majority of significant trends occur in areas of high fire incidence, and both increasing and decreasing trends appear to be associated with land use change processes. The analysis reveals large negative trends at the Sahel and between Russia and Kazakhstan, whereas a massive and coherent positive trend appears in southeastern Asia. Smaller patches of positive trends appear in southeastern United States and in Mexico, as well as in Brazil and between Argentina and Paraguay, and in Asia in India. There are also negative trends in Brazil, Argentina and in Australia. The study highlights the land use activities as the main driver of these trends, but also the need for data driven analyses and longer time series for future studies in order to gain better knowledge on fire occurrence.

  17. Fire safety applications for spacecraft

    NASA Technical Reports Server (NTRS)

    Friedman, Robert; Olson, Sandra L.

    1989-01-01

    Fire safety for spacecraft is reviewed by first describing current practices, many of which are adapted directly from aircraft. Then, current analyses and experimental knowledge in low-gravity combustion, with implications for fire safety are discussed. In orbiting spacecraft, the detection and suppression of flames are strongly affected by the large reduction in buoyant flows under low gravity. Generally, combustion intensity is reduced in low gravity. There are some notable exceptions, however, one example being the strong enhancement of flames by low-velocity ventilation flows in space. Finally, the future requirements in fire safety, particularly the needs of long-duration space stations in fire prevention, detection, extinguishment, and atmospheric control are examined. The goal of spacecraft fire-safety investigations is the establishment of trade-offs that promote maximum safety without hampering the useful human and scientific activities in space.

  18. Fire Effects on Microbial Enzyme Activities in Larch Forests of the Siberian Arctic

    NASA Astrophysics Data System (ADS)

    Ludwig, S.; Alexander, H. D.; Bulygina, E. B.; Mann, P. J.; Natali, S.

    2012-12-01

    Arctic forest ecosystems are warming at an accelerated rate relative to lower latitudes, with global implications for C cycling within these regions. As climate continues to warm and dry, wildfire frequency and severity are predicted to increase, creating a positive feedback to climate warming. Increased fire activity will also influence the microenvironment experienced by soil microbes in disturbed soils. Because soil microbes regulate carbon (C) and nitrogen (N) cycling between terrestrial ecosystems and the atmosphere, it is important to understand microbial response to fires, particularly in the understudied larch forests in the Siberian Arctic. In this project, we created experimental burn plots in a mature larch forest in the Kolyma River watershed of Northeastern Siberia. Plots were burned at several treatments: control (no burn), low, moderate, and severe. After, 1 and 8 d post-fire, we measured soil organic layer depth, soil organic matter (SOM) content, soil moisture, and CO2 flux from the plots. Additionally, we leached soils and measured dissolved organic carbon (DOC), total dissolved nitrogen (TDN), NH4, NO3, soluble reactive phosphorus (SRP), and chromophoric dissolved organic matter (CDOM). Furthermore, we measured extracellular activity of four enzymes involved in soil C and nutrient cycling (leucine aminopeptidase (LAP), β-glucosidase, phosphatase, and phenol oxidase). One day post-fire, LAP activity was similarly low in all treatments, but by 8 d post-fire, LAP activity was lower in burned plots compared to control plots, likely due to increased nitrogen content with increasing burn severity. Phosphatase activity decreased with burn severity 1 d post-fire, but after 8 d, moderate and severe burn plots exhibited increased phosphatase activity. Coupled with trends in LAP activity, this suggests a switch in nutrient limitation from N to phosphorus that is more pronounced with burn severity. β-glucosidase activity similarly decreased with burn

  19. Sentinel-3 Satellite Applications In The Monitoring Of The Active Forest Fires

    NASA Astrophysics Data System (ADS)

    Calle, A.; Gonzalez-Alonso, F.

    2013-12-01

    FRP (Fire Radiative Power) is the magnitude associated to the thermal radiance which explains the ecological effects of active fire; it is the component of the chemical power released from burning vegetation and emitted as radiation during the process of combustion. In this paper, a discussion of the procedures for active fire FRP is presented: The Dozier method, the MODIS (Moderate Resolution Imaging Spectroradiometer) fire detection algorithm and semi-empirical relation-ship based on previous studies of BIRD (Bi-spectral InfraRed Detection) satellite. These procedures, described above, are applied to simulated data by a radiative transfer model, based on Sentinel-3/SLSTR spectral characteristics in order to analyze the impact of atmospheric conditions on FRP estimations.

  20. Repeated landscape-scale treatments following fire suppress a non-native annual grass and promote recovery of native perennial vegetation

    USGS Publications Warehouse

    Munson, Seth M.; Long, A. Lexine; Decker, Cheryl E.; Johnson, Katie A.; Walsh, Kathleen; Miller, Mark E.

    2015-01-01

    Invasive non-native species pose a large threat to restoration efforts following large-scale disturbances. Bromus tectorum (cheatgrass) is a non-native annual grass in the western U.S. that both spreads quickly following fire and accelerates the fire cycle. Herbicide and seeding applications are common restoration practices to break the positive fire-invasion feedback loop and recover native perennial species, but their interactive effects have infrequently been tested at the landscape-scale and repeated in time to encourage long-lasting effects. We determined the efficacy of repeated post-fire application of the herbicide imazapic and seeding treatments to suppressBromus abundance and promote perennial vegetation recovery. We found that the selective herbicide reduced Bromus cover by ~30 % and density by >50 % across our study sites, but had a strong initial negative effect on seeded species. The most effective treatment to promote perennial seeded species cover was seeding them alone followed by herbicide application 3 years later when the seeded species had established. The efficacy of the treatments was strongly influenced by water availability, as precipitation positively affected the density and cover of Bromus; soil texture and aspect secondarily influenced Bromus abundance and seeded species cover by modifying water retention in this semi-arid region. Warmer temperatures positively affected the non-native annual grass in the cool-season, but negatively affected seeded perennial species in the warm-season, suggesting an important role of seasonality in a region projected to experience large increases in warming in the future. Our results highlight the importance of environmental interactions and repeated treatments in influencing restoration outcomes at the landscape-scale.

  1. Evaluating Greenhouse Gas Emissions Reporting Systems for Agricultural Waste Burning Using MODIS Active Fires

    NASA Astrophysics Data System (ADS)

    Lin, H.; Jin, Y.; Giglio, L.; Foley, J. A.; Randerson, J. T.

    2010-12-01

    Fires in agricultural ecosystems emit greenhouse gases and aerosols that influence climate on multiple spatial and temporal scales. Annex 1 countries of the United Nations Framework Convention on Climate Change (UNFCCC), many of which ratified the Kyoto Protocol, are required to report emissions of CO2, CH4 and N2O from these fires annually. We evaluated several aspects of this reporting system, including the optimality of the crops targeted by the UNFCCC globally and within Annex 1 countries and the consistency of emissions reporting among countries. We also evaluated the success of the individual countries in capturing interannual variability and long-term trends in agricultural fire activity. We combined global crop maps with Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) active fire detections. At a global scale, we recommend adding ground nuts, cocoa, cotton and oil palm, and removing potato, oats, pulse other and rye from the UNFCCC list of 14 crops. This leads to an overall increase of 6% of the active fires covered by the reporting system. Optimization led to a different recommended list for Annex 1 countries. Extending emissions reporting to all Annex 1 countries (from the current set of 19 countries) would increase the efficacy of the reporting system from 10% to 20%, and further including several non-Annex 1 countries (Argentina, Brazil, China, India, Indonesia, Thailand, Kazakhstan, Mexico and Nigeria) would capture over 58% of active fires in croplands worldwide. Analyses of interannual trends from the U.S. and Australia showed the importance of both intensity of fire use and crop production in controlling year-to-year variations in agricultural fire emissions. Remote sensing provides an efficient tool for an independent assessment of current UNFCCC emissions reporting system; and, if combined with census data, field experiments and expert opinion, has the potential for improving the robustness of the next generation inventory

  2. Role of activation in alveolar macrophage-mediated suppression of the plaque-forming cell response.

    PubMed Central

    Mbawuike, I N; Herscowitz, H B

    1988-01-01

    Alveolar macrophages (AM) are highly suppressive of the in vitro plaque-forming cell (PFC) response of spleen cells obtained from mice primed with sheep erythrocytes. Comparison of macrophage populations obtained from disparate anatomical sites revealed that although in both cases there was a cell-concentration-dependent suppression of the PFC response, resident AM or AM activated as a result of intravenous injection of Mycobacterium bovis BCG were equally suppressive at the doses examined. Although there was a similar dose-dependent suppression with peritoneal macrophages, BCG-activated cells were more suppressive of the PFC response than were resident cells. In contrast, splenic macrophages at comparable concentrations were not at all suppressive. Resident AM exhibited significantly lower levels of 5'-nucleotidase activity than did resident peritoneal macrophages. Macrophage-mediated suppression of the in vitro PFC response could not be attributed to the release of toxic oxygen metabolites (H2O2, O2- ,and .OH) or prostaglandins, since the addition of catalase, superoxide dismutase, 2-mercaptoethanol, or indomethacin did not completely reverse suppression. These results suggest that the lung microenvironment may maintain AM in an activated state which contributes to their potential immunoregulatory functions. PMID:2830191

  3. Appetite suppression and weight reduction by a centrally active aminosterol.

    PubMed

    Ahima, Rexford S; Patel, Hiralben R; Takahashi, Nobuhiko; Qi, Yong; Hileman, Stanley M; Zasloff, Michael A

    2002-07-01

    The rise in obesity and its complications has generated enormous interest in the regulation of feeding and body weight. We show that a spermine metabolite of cholesterol (MSI-1436) decreases body weight, specifically fat, by suppressing feeding and preventing the reduction in energy expenditure, hormonal changes, and patterns of neuropeptide expression normally associated with weight loss. MSI-1436 enters the brain after peripheral injection and is more potent when injected into the cerebral ventricle (intracerebroventricular [ICV]). Systemic or ICV MSI-1436 administration induced similar patterns of Fos immunoreactivity in the brain, especially the paraventricular hypothalamic nucleus (PVN). This brain region integrates neural signals from hypothalamic and brain stem nuclei and regulates feeding behavior, autonomic function, and neuroendocrine function. Microinjection of MSI-1436 into the PVN potently suppressed feeding and reduced body weight for several days. Unlike caloric restriction, MSI-1436 decreased mRNA levels of agouti-related peptide and neuropeptide Y in the hypothalamus. These findings indicate that MSI-1436 acts in the brain to regulate food intake and energy expenditure, likely through suppression of orexigenic hypothalamic pathways. PMID:12086938

  4. Vitamin K2 stimulates osteoblastogenesis and suppresses osteoclastogenesis by suppressing NF-κB activation.

    PubMed

    Yamaguchi, Masayoshi; Weitzmann, M Neale

    2011-01-01

    Several bone protective factors are reported to exhibit stimulatory activities on bone formation coupled with inhibitory effects on bone resorption; one such factor is vitamin K2. Vitamin K species [K1 (phylloquinone) and K2 (menaquinone)] have long been associated with bone protective activities and are receiving intense interest as nutritional supplements for the prevention or amelioration of bone disease in humans. However, the mechanisms of vitamin K action on the skeleton are poorly defined. Activation of the nuclear factor κB (NF-κB) signal transduction pathway is essential for osteoclast formation and resorption. By contrast, NF-κB signaling potently antagonizes osteoblast differentiation and function, prompting us to speculate that NF-κB antagonists may represent a novel class of dual anti-catabolic and pro-anabolic agents. We now show that vitamin K2 action on osteoblast and osteoclast formation and activity is accomplished by down-regulating basal and cytokine-induced NF-κB activation, by increasing IκB mRNA, in a γ-carboxylation-independent manner. Furthermore, vitamin K2 prevented repression by tumor necrosis factor α (TNFα) of SMAD signaling induced by either transforming growth factor ß (TGFß) or bone morphogenetic protein-2 (BMP-2). Vitamin K2 further antagonized receptor activator of NF-κB (RANK) ligand (RANKL)-induced NF-κB activation in osteoclast precursors. Our data provide a novel mechanism to explain the dual pro-anabolic and anti-catabolic activities of vitamin K2, and may further support the concept that pharmacological modulation of NF-κB signal transduction may constitute an effective mechanism for ameliorating pathological bone loss and for promoting bone health. PMID:21072493

  5. Design and experimental validation of a flutter suppression controller for the active flexible wing

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.; Srinathkumar, S.

    1992-01-01

    The synthesis and experimental validation of an active flutter suppression controller for the Active Flexible Wing wind tunnel model is presented. The design is accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and extensive simulation based analysis. The design approach uses a fundamental understanding of the flutter mechanism to formulate a simple controller structure to meet stringent design specifications. Experimentally, the flutter suppression controller succeeded in simultaneous suppression of two flutter modes, significantly increasing the flutter dynamic pressure despite modeling errors in predicted flutter dynamic pressure and flutter frequency. The flutter suppression controller was also successfully operated in combination with another controller to perform flutter suppression during rapid rolling maneuvers.

  6. Flutter suppression for the Active Flexible Wing - Control system design and experimental validation

    NASA Technical Reports Server (NTRS)

    Waszak, M. R.; Srinathkumar, S.

    1992-01-01

    The synthesis and experimental validation of a control law for an active flutter suppression system for the Active Flexible Wing wind-tunnel model is presented. The design was accomplished with traditional root locus and Nyquist methods using interactive computer graphics tools and with extensive use of simulation-based analysis. The design approach relied on a fundamental understanding of the flutter mechanism to formulate understanding of the flutter mechanism to formulate a simple control law structure. Experimentally, the flutter suppression controller succeeded in simultaneous suppression of two flutter modes, significantly increasing the flutter dynamic pressure despite errors in the design model. The flutter suppression controller was also successfully operated in combination with a rolling maneuver controller to perform flutter suppression during rapid rolling maneuvers.

  7. Interneuron firing precedes sequential activation of neuronal ensembles in hippocampal slices.

    PubMed

    Sasaki, Takuya; Matsuki, Norio; Ikegaya, Yuji

    2014-06-01

    Neuronal firing sequences that occur during behavioral tasks are precisely reactivated in the neocortex and the hippocampus during rest and sleep. These precise firing sequences are likely to reflect latent memory traces, and their reactivation is believed to be essential for memory consolidation and working memory maintenance. However, how the organized repeating patterns emerge through the coordinated interplay of distinct types of neurons remains unclear. In this study, we monitored ongoing spatiotemporal firing patterns using a multi-neuron calcium imaging technique and examined how the activity of individual neurons is associated with repeated ensembles in hippocampal slice cultures. To determine the cell types of the imaged neurons, we applied an optical synapse mapping method that identifies network connectivity among dozens of neurons. We observed that inhibitory interneurons exhibited an increase in their firing rates prior to the onset of repeating sequences, while the overall activity level of excitatory neurons remained unchanged. A specific repeating sequence emerged preferentially after the firing of a specific interneuron that was located close to the neuron first activated in the sequence. The times of repeating sequences could be more precisely predicted based on the activity patterns of inhibitory cells than excitatory cells. In line with these observations, stimulation of a single interneuron could trigger the emergence of repeating sequences. These findings provide a conceptual framework that interneurons serve as a key regulator of initiating sequential spike activity.

  8. What Fraction of Global Fire Activity Can Be Forecast Using Sea Surface Temperatures?

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Randerson, J. T.; Morton, D. C.; Andela, N.; Giglio, L.

    2015-12-01

    Variations in sea surface temperatures (SSTs) can influence climate dynamics in local and remote land areas, and thus influence fire-climate interactions that govern burned area. SST information has been recently used in statistical models to create seasonal outlooks of fire season severity in South America and as the initial condition for dynamical model predictions of fire activity in Indonesia. However, the degree to which large-scale ocean-atmosphere interactions can influence burned area in other continental regions has not been systematically explored. Here we quantified the amount of global burned area that can be predicted using SSTs in 14 different oceans regions as statistical predictors. We first examined lagged correlations between GFED4s burned area and the 14 ocean climate indices (OCIs) individually. The maximum correlations from different OCIs were used to construct a global map of fire predictability. About half of the global burned area can be forecast by this approach 3 months before the peak burning month (with a Pearson's r of 0.5 or higher), with the highest levels of predictability in Central America and Equatorial Asia. Several hotspots of predictability were identified using k-means cluster analysis. Within these regions, we tested the improvements of the forecast by using two OCIs from different oceans. Our forecast models were based on near-real-time SST data and may therefore support the development of new seasonal outlooks for fire activity that can aid the sustainable management of these fire-prone ecosystems.

  9. Analysis Of Wind And Fire Direction During The 2005's Portuguese Fire Season

    NASA Astrophysics Data System (ADS)

    Barros, A. M.; Miranda, P. M.; Pereira, J. M.

    2010-12-01

    and, to some extent, by fuel distribution and suppression activities. Extending the analysis to multiple years may help identify fire-wind interactions capable of providing insightful information to support the location of landscape scale fuel treatments and to identify landscape features that can induce topographic wind channelling.

  10. Suppression of Active-Region CME Production by the Presence of Other Active Regions

    NASA Technical Reports Server (NTRS)

    Falconer, David; Moore, Ron; Barghouty, Abdulnasser; Khazanov, Igor

    2009-01-01

    From the SOHO mission s data base of MDI full-disk magnetograms spanning solar cycle 23, we have obtained a set of 40,000 magnetograms of 1,300 active regions, tracking each active region across the 30 degree central solar disk. Each active region magnetogram is cropped from the full-disk magnetogram by an automated code. The cadence is 96 minutes. From each active-region magnetogram, we have measured two whole-active-region magnetic quantities: (1) the magnetic size of the active region (the active region s total magnetic flux), and (2) a gauge of the active region s free magnetic energy (part of the free energy is released in the production of a flare and/or CME eruption). From NOAA Flare/CME catalogs, we have obtained the event (Flare/CME/SEP event) production history of each active region. Using all these data, we find that for each type of eruptive event, an active region s expected rate of event production increases as a power law of our gauge of active-region free magnetic energy. We have also found that, among active regions having nearly the same free energy, the rate of the CME production is less when there are many other active regions on the disk than when there are few or none, but there is no significant discernible suppression of the rate of flare production. This indicates that the presence of other active regions somehow tends to inhibit an active region s flare-producing magnetic explosions from becoming CMEs, contrary to the expectation from the breakout model for the production of CMEs.

  11. Suppression of Myc oncogenic activity by ribosomal protein haploinsufficiency.

    PubMed

    Barna, Maria; Pusic, Aya; Zollo, Ornella; Costa, Maria; Kondrashov, Nadya; Rego, Eduardo; Rao, Pulivarthi H; Ruggero, Davide

    2008-12-18

    The Myc oncogene regulates the expression of several components of the protein synthetic machinery, including ribosomal proteins, initiation factors of translation, RNA polymerase III and ribosomal DNA. Whether and how increasing the cellular protein synthesis capacity affects the multistep process leading to cancer remains to be addressed. Here we use ribosomal protein heterozygote mice as a genetic tool to restore increased protein synthesis in Emu-Myc/+ transgenic mice to normal levels, and show that the oncogenic potential of Myc in this context is suppressed. Our findings demonstrate that the ability of Myc to increase protein synthesis directly augments cell size and is sufficient to accelerate cell cycle progression independently of known cell cycle targets transcriptionally regulated by Myc. In addition, when protein synthesis is restored to normal levels, Myc-overexpressing precancerous cells are more efficiently eliminated by programmed cell death. Our findings reveal a new mechanism that links increases in general protein synthesis rates downstream of an oncogenic signal to a specific molecular impairment in the modality of translation initiation used to regulate the expression of selective messenger RNAs. We show that an aberrant increase in cap-dependent translation downstream of Myc hyperactivation specifically impairs the translational switch to internal ribosomal entry site (IRES)-dependent translation that is required for accurate mitotic progression. Failure of this translational switch results in reduced mitotic-specific expression of the endogenous IRES-dependent form of Cdk11 (also known as Cdc2l and PITSLRE), which leads to cytokinesis defects and is associated with increased centrosome numbers and genome instability in Emu-Myc/+ mice. When accurate translational control is re-established in Emu-Myc/+ mice, genome instability is suppressed. Our findings demonstrate how perturbations in translational control provide a highly specific outcome

  12. Suppression of ventilatory muscle activity in healthy subjects and COPD patients with negative pressure ventilation.

    PubMed

    Gigliotti, F; Duranti, R; Fabiani, A; Schiavina, M; Scano, G

    1991-05-01

    We evaluated the ability of NPV to suppress EMGd and EMGint in seven patients with severe COPD and five normal subjects. Subjects were studied either without (A) or with mouthpiece and nose clip (B). Electromyographic suppression was assessed comparing EMG activity during NPV with the control activity without a mouthpiece and prior to the initiation of the NPV run. In normal subjects, in A, NPV resulted in a partial suppression of EMGd; in B, prior to NPV, EMGd rose compared with A prior to NPV. In patients, in A, NPV resulted in a suppression of both EMGd and EMGint. In B, prior to NPV, both EMGd and EMGint rose compared with A prior to NPV. Thus, it seems that NPV is able to produce a consistent reduction in inspiratory muscle EMG activity. This variable NPV ability would have to be assessed for better selection criteria for patient candidates in a rehabilitation program.

  13. Characterizing context-dependent differential firing activity in the hippocampus and entorhinal cortex.

    PubMed

    Prerau, Michael J; Lipton, Paul A; Eichenbaum, Howard B; Eden, Uri T

    2014-04-01

    The rat hippocampus and entorhinal cortex have been shown to possess neurons with place fields that modulate their firing properties under different behavioral contexts. Such context-dependent changes in neural activity are commonly studied through electrophysiological experiments in which a rat performs a continuous spatial alternation task on a T-maze. Previous research has analyzed context-based differential firing during this task by describing differences in the mean firing activity between left-turn and right-turn experimental trials. In this article, we develop qualitative and quantitative methods to characterize and compare changes in trial-to-trial firing rate variability for sets of experimental contexts. We apply these methods to cells in the CA1 region of hippocampus and in the dorsocaudal medial entorhinal cortex (dcMEC), characterizing the context-dependent differences in spiking activity during spatial alternation. We identify a subset of cells with context-dependent changes in firing rate variability. Additionally, we show that dcMEC populations encode turn direction uniformly throughout the T-maze stem, whereas CA1 populations encode context at major waypoints in the spatial trajectory. Our results suggest scenarios in which individual cells that sparsely provide information on turn direction might combine in the aggregate to produce a robust population encoding. PMID:24436108

  14. Remotely-Sensed Active Fire Data for Protected Area Management: Eight-Year Patterns in the Manas National Park, India

    NASA Astrophysics Data System (ADS)

    Takahata, Chihiro; Amin, Rajan; Sarma, Pranjit; Banerjee, Gitanjali; Oliver, William; Fa, John E.

    2010-02-01

    The Terai-Duar savanna and grasslands, which once extended along most of the Himalayan foothills, now only remain in a number of protected areas. Within these localities, grassland burning is a major issue, but data on frequency and distribution of fires are limited. Here, we analysed the incidence of active fires, which only occur during the dry season (Nov.-Mar.), within a significant area of Terai grasslands: the Manas National Park (MNP), India. We obtained locations of 781 fires during the 2000-2008 dry seasons, from the Fire Information for Resource Management System (FIRMS) that delivers global MODIS hotspot/fire locations using remote sensing and GIS technologies. Annual number of fires rose significantly from around 20 at the start of the study period to over 90 after 2002, with most (85%) detected between December and January. Over half of the fires occurred in tall grasslands, but fire density was highest in wetland and riverine vegetation, dry at the time. Most burning took place near rivers, roads and the park boundary, suggesting anthropogenic origins. A kernel density map of all recorded fires indicated three heavily burnt areas in the MNP, all within the tall grasslands. Our study demonstrates, despite some technical caveats linked to fire detection technology, which is improving, that remote fire data can be a practical tool in understanding fire concentration and burning temporal patterns in highly vulnerable habitats, useful in guiding management.

  15. Fire mosaics in southern california and northern baja california.

    PubMed

    Minnich, R A

    1983-03-18

    In spite of suppression efforts, severe wildfires burn large areas of southern California grassland, coastal sage scrub, and chaparral. Such large burns may not have been characteristic prior to the initiation of fire suppression more than 70 years ago. To compare controlled with uncontrolled areas, wildfires of southern California and adjacent northern Baja California were evaluated for the period 1972 to 1980 from Landsat imagery. Fire size and location, vegetation, year, and season were recorded. It was found that suppression has divergent effects on different plant communities depending on successional processes, growth rates, fuel accumulation, decomposition rates, and length of flammability cycles. These variables establish feedback between the course of active fires, fire history, spatial configuration of flammable vegetation, and fire size. Suppression has minimal impact in coastal sage scrub and grassland. Fire control in chaparral reduces the number of fires, not burned hectarage; fires consequently increase in size, spread rate, and intensity and become uncontrollable in severe weather conditions. The Baja California chaparral fire regime may serve as a model for prescribed burning in southern California.

  16. Fire mosaics in southern california and northern baja california.

    PubMed

    Minnich, R A

    1983-03-18

    In spite of suppression efforts, severe wildfires burn large areas of southern California grassland, coastal sage scrub, and chaparral. Such large burns may not have been characteristic prior to the initiation of fire suppression more than 70 years ago. To compare controlled with uncontrolled areas, wildfires of southern California and adjacent northern Baja California were evaluated for the period 1972 to 1980 from Landsat imagery. Fire size and location, vegetation, year, and season were recorded. It was found that suppression has divergent effects on different plant communities depending on successional processes, growth rates, fuel accumulation, decomposition rates, and length of flammability cycles. These variables establish feedback between the course of active fires, fire history, spatial configuration of flammable vegetation, and fire size. Suppression has minimal impact in coastal sage scrub and grassland. Fire control in chaparral reduces the number of fires, not burned hectarage; fires consequently increase in size, spread rate, and intensity and become uncontrollable in severe weather conditions. The Baja California chaparral fire regime may serve as a model for prescribed burning in southern California. PMID:17735593

  17. Validation of MODIS and SEVIRI Active Fire Monitoring products over Western Romania. Case study: Arad County

    NASA Astrophysics Data System (ADS)

    Oanea, Lavinia; Alina Ristea, Mihaela

    2014-05-01

    At the national level, the issue of wildfire monitoring represents a long debated topic. However, in the present situation, fire management requires various improvements in terms of detection, monitoring and post-fire analysis. The objectives of this study are to validate the data provided by MODIS (Terra and Aqua) Active Fire Monitoring and SEVIRI (MSG) FIR (Active Fire Monitoring) satellite products, with wildfires field data from The Romanian General Inspectorate for Emergency Situations (IGSU) (1), to chart the efficiency of satellite products in locating fires and study their strengths and weaknesses using a SWOT analysis (2). This is the initial step of a larger project that aims to implement an online Geographic Information System for fire management that will ease wildfire data manipulation and facilitate the decision making process. In order to do so, the current study objectives must be achieved. Our general strategy is to determine the consistency of direct (field measurements) and indirect (satellite data) observations. Depending on the amount of field information, the fire characteristics (location, frequency, extension area, moment of occurrence, type of fire, and others) will be studied through a statistical analysis. The products show some peculiar restrictiveness like spatial and temporal resolution. Specifically, we will process and interpret satellite products to identify wildfires according to the data from IGSU using specialized software. The case study for the application of these procedures is a set of fire events from Arad county - Romania, that occurred between 2007 and 2013. In order to do so, it is important to compare results from different sensors with field information through various methods and to use only consistent results. The results will play an important role in achieving the above mentioned informational system, which will integrate field information, satellite data and values of parameters that influence the evolution of

  18. SIRT1 Suppresses Activator Protein-1 Transcriptional Activity and Cyclooxygenase-2 Expression in Macrophages*

    PubMed Central

    Zhang, Ran; Chen, Hou-Zao; Liu, Jin-Jing; Jia, Yu-Yan; Zhang, Zhu-Qin; Yang, Rui-Feng; Zhang, Yuan; Xu, Jing; Wei, Yu-Sheng; Liu, De-Pei; Liang, Chih-Chuan

    2010-01-01

    SIRT1 (Sirtuin type 1), a mammalian orthologue of yeast SIR2 (silent information regulator 2), has been shown to mediate a variety of calorie restriction (CR)-induced physiological events, such as cell fate regulation via deacetylation of the substrate proteins. However, whether SIRT1 deacetylates activator protein-1 (AP-1) to influence its transcriptional activity and target gene expression is still unknown. Here we demonstrate that SIRT1 directly interacts with the basic leucine zipper domains of c-Fos and c-Jun, the major components of AP-1, by which SIRT1 suppressed the transcriptional activity of AP-1. This process requires the deacetylase activity of SIRT1. Notably, SIRT1 reduced the expression of COX-2, a typical AP-1 target gene, and decreased prostaglandin E2 (PGE2) production of peritoneal macrophages (pMΦs). pMΦs with SIRT1 overexpression displayed improved phagocytosis and tumoricidal functions, which are associated with depressed PGE2. Furthermore, SIRT1 protein level was up-regulated in CR mouse pMΦs, whereas elevated SIRT1 decreased COX-2 expression and improved PGE2-related macrophage functions that were reversed following inhibition of SIRT1 deacetylase activity. Thus, our results indicate that SIRT1 may be a mediator of CR-induced macrophage regulation, and its deacetylase activity contributes to the inhibition of AP-1 transcriptional activity and COX-2 expression leading to amelioration of macrophage function. PMID:20042607

  19. Suppression of newborn natural killer cell activity by prostaglandin E2

    SciTech Connect

    Milch, P.O.; Salvatore, W.; Luft, B.; Baker, D.A.

    1988-10-01

    The effect of prostaglandin E2 on natural killer cell activity of cord blood was examined. Natural killer cell activity, determined by chromium 51 release, was significantly reduced after prostaglandin E2 (1 microgram/ml) treatment. Prostaglandin E2 has been found to enhance the cellular spread of herpesvirus. Thus prostaglandins may enhance viral infections indirectly by suppressing natural killer cell activity.

  20. Platelet activating factor receptor binding plays a critical role in jet fuel-induced immune suppression.

    PubMed

    Ramos, Gerardo; Kazimi, Nasser; Nghiem, Dat X; Walterscheid, Jeffrey P; Ullrich, Stephen E

    2004-03-15

    Applying military jet fuel (JP-8) or commercial jet fuel (Jet-A) to the skin of mice suppresses the immune response in a dose-dependent manner. The release of biological response modifiers, particularly prostaglandin E2 (PGE2), is a critical step in activating immune suppression. Previous studies have shown that injecting selective cyclooxygenase-2 inhibitors into jet fuel-treated mice blocks immune suppression. Because the inflammatory phospholipid mediator, platelet-activating factor (PAF), up-regulates cyclooxygenase-2 production and PGE2 synthesis by keratinocytes, we tested the hypothesis that PAF-receptor binding plays a role in jet fuel-induced immune suppression. Treating keratinocyte cultures with PAF and/or jet fuel (JP-8 and Jet-A) stimulates PGE2 secretion. Jet fuel-induced PGE2 production was suppressed by treating the keratinocytes with specific PAF-receptor antagonists. Injecting mice with PAF, or treating the skin of the mice with JP-8, or Jet-A, induced immune suppression. Jet fuel-induced immune suppression was blocked when the jet fuel-treated mice were injected with PAF-receptor antagonists before treatment. Jet fuel treatment has been reported to activate oxidative stress and treating the mice with anti-oxidants (Vitamins C, or E or beta-hydroxy toluene), before jet fuel application, interfered with immune suppression. These findings confirm previous studies showing that PAF-receptor binding can modulate immune function. Furthermore, they suggest that PAF-receptor binding may be an early event in the induction of immune suppression by immunotoxic environmental agents that target the skin. PMID:15020195

  1. Measurement of inter- and intra-annual variability of landscape fire activity at a continental scale: the Australian case

    NASA Astrophysics Data System (ADS)

    Williamson, Grant J.; Prior, Lynda D.; Jolly, W. Matt; Cochrane, Mark A.; Murphy, Brett P.; Bowman, David M. J. S.

    2016-03-01

    Climate dynamics at diurnal, seasonal and inter-annual scales shape global fire activity, although difficulties of assembling reliable fire and meteorological data with sufficient spatio-temporal resolution have frustrated quantification of this variability. Using Australia as a case study, we combine data from 4760 meteorological stations with 12 years of satellite-derived active fire detections to determine day and night time fire activity, fire season start and end dates, and inter-annual variability, across 61 objectively defined climate regions in three climate zones (monsoon tropics, arid and temperate). We show that geographic patterns of landscape burning (onset and duration) are related to fire weather, resulting in a latitudinal gradient from the monsoon tropics in winter, through the arid zone in all seasons except winter, and then to the temperate zone in summer and autumn. Peak fire activity precedes maximum lightning activity by several months in all regions, signalling the importance of human ignitions in shaping fire seasons. We determined median daily McArthur forest fire danger index (FFDI50) for days and nights when fires were detected: FFDI50 varied substantially between climate zones, reflecting effects of fire management in the temperate zone, fuel limitation in the arid zone and abundance of flammable grasses in the monsoon tropical zone. We found correlations between the proportion of days when FFDI exceeds FFDI50 and the Southern Oscillation index across the arid zone during spring and summer, and Indian Ocean dipole mode index across south-eastern Australia during summer. Our study demonstrates that Australia has a long fire weather season with high inter-annual variability relative to all other continents, making it difficult to detect long term trends. It also provides a way of establishing robust baselines to track changes to fire seasons, and supports a previous conceptual model highlighting multi-temporal scale effects of climate in

  2. Human and climate impacts on Holocene fire activity recorded in polar and mountain ice cores

    NASA Astrophysics Data System (ADS)

    Kehrwald, Natalie; Zennaro, Piero; Kirchgeorg, Torben; Li, Quanlian; Wang, Ninglian; Power, Mitchell; Zangrando, Roberta; Gabrielli, Paolo; Thompson, Lonnie; Gambaro, Andrea; Barbante, Carlo

    2014-05-01

    Fire is one of the major influences of biogeochemical change on local to hemispheric scales through emitting greenhouse gases, altering atmospheric chemistry, and changing primary productivity. Levoglucosan (1,6-anhydro-β-D-glucopyranose) is a specific molecular that can only be produced by cellulose burning at temperatures > 300°C, comprises a major component of smoke plumes, and can be transported across > 1000 km distances. Levoglucosan is deposited on and archived in glaciers over glacial interglacial cycles resulting in pyrochemical evidence for exploring interactions between fire, climate and human activity. Ice core records provide records of past biomass burning from regions of the world with limited paleofire data including polar and low-latitude, high-altitude regions. Here, we present Holocene fire activity records from the NEEM, Greenland (77° 27'N; 51° 3'W; 2454 masl), EPICA Dome C, Antarctica (75° 06'S; 123° 21'E; 3233 masl), Kilimanjaro, Tanzania (3° 05'S, 21.2° E, 5893 masl) and the Muztagh, China (87.17° E; 36.35° N; 5780 masl ice cores. The NEEM ice core reflects boreal fire activity from both North American and Eurasian sources. Temperature is the dominant control of NEEM levoglucosan flux over decadal to millennial time scales, while droughts influence fire activity over sub-decadal timescales. Our results demonstrate the prominence of Siberian fire sources during intense multiannual droughts. Unlike the NEEM core, which incorporates the largest land masses in the world as potential fire sources, EPICA Dome C is located far from any possible fire source. However, EPICA Dome C levoglucosan concentrations are consistently above detection limits and demonstrate a substantial 1000-fold increase in fire activity beginning approximately 800 years ago. This significant and sustained increase coincides with Maori arrival and dispersal in New Zealand augmented by later European arrival in Australia. The EPICA Dome C levoglucosan profile is

  3. Active vertical tail buffeting suppression based on macro fiber composites

    NASA Astrophysics Data System (ADS)

    Zou, Chengzhe; Li, Bin; Liang, Li; Wang, Wei

    2016-04-01

    Aerodynamic buffet is unsteady airflow exerting forces onto a surface, which can lead to premature fatigue damage of aircraft vertical tail structures, especially for aircrafts with twin vertical tails at high angles of attack. In this work, Macro Fiber Composite (MFC), which can provide strain actuation, was used as the actuator for the buffet-induced vibration control, and the positioning of the MFC patches was led by the strain energy distribution on the vertical tail. Positive Position Feedback (PPF) control algorithm has been widely used for its robustness and simplicity in practice, and consequently it was developed to suppress the buffet responses of first bending and torsional mode of vertical tail. However, its performance is usually attenuated by the phase contributions from non-collocated sensor/actuator configuration and plants. The phase lag between the input and output signals of the control system was identified experimentally, and the phase compensation was considered in the PPF control algorithm. The simulation results of the amplitude frequency of the closed-loop system showed that the buffet response was alleviated notably around the concerned bandwidth. Then the wind tunnel experiment was conducted to verify the effectiveness of MFC actuators and compensated PPF, and the Root Mean Square (RMS) of the acceleration response was reduced 43.4%, 28.4% and 39.5%, respectively, under three different buffeting conditions.

  4. Active Suppression of Drilling System Vibrations For Deep Drilling

    SciTech Connect

    Raymond, David W.; Blankenship, Douglas A.; Buerger, Stephen; Mesh, Mikhail; Radigan, William Thomas; Su, Jiann-Cherng

    2015-10-01

    The dynamic stability of deep drillstrings is challenged by an inability to impart controllability with ever-changing conditions introduced by geology, depth, structural dynamic properties and operating conditions. A multi-organizational LDRD project team at Sandia National Laboratories successfully demonstrated advanced technologies for mitigating drillstring vibrations to improve the reliability of drilling systems used for construction of deep, high-value wells. Using computational modeling and dynamic substructuring techniques, the benefit of controllable actuators at discrete locations in the drillstring is determined. Prototype downhole tools were developed and evaluated in laboratory test fixtures simulating the structural dynamic response of a deep drillstring. A laboratory-based drilling applicability demonstration was conducted to demonstrate the benefit available from deployment of an autonomous, downhole tool with self-actuation capabilities in response to the dynamic response of the host drillstring. A concept is presented for a prototype drilling tool based upon the technical advances. The technology described herein is the subject of U.S. Patent Application No. 62219481, entitled "DRILLING SYSTEM VIBRATION SUPPRESSION SYSTEMS AND METHODS", filed September 16, 2015.

  5. Robust Multivariable Flutter Suppression for the Benchmark Active Control Technology (BACT) Wind-Tunnel Model

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.

    1997-01-01

    The Benchmark Active Controls Technology (BACT) project is part of NASA Langley Research Center s Benchmark Models Program for studying transonic aeroelastic phenomena. In January of 1996 the BACT wind-tunnel model was used to successfully demonstrate the application of robust multivariable control design methods (H and -synthesis) to flutter suppression. This paper addresses the design and experimental evaluation of robust multivariable flutter suppression control laws with particular attention paid to the degree to which stability and performance robustness was achieved.

  6. Degradation of Nylon 6,6 Fire-Suppression Casing from Plutonium Glove Boxes Under Alpha and Neutron Irradiation

    SciTech Connect

    Millsap, Donald W.; Cournoyer, Michael E.; Landsberger, Sheldon; Tesmer, Joseph R.; Wang, Matthew Y.

    2015-04-23

    Nylon 6,6 tensile specimens, conforming to the casing for self-contained fire extinguisher systems, have been irradiated using both an accelerator He++ ion beam and a 5-Ci PuBe neutron source to model the radiation damage these systems would likely incur over a lifetime of operation within glove boxes. Following irradiation, these samples were mechanically tested using standard practices as described in ASTM D638. The results of the He++ study indicate that the tensile strength of the nylon specimens undergoes some slight (<10%) degradation while other properties of the samples, such as elongation and tangent modulus, appear to fluctuate with increasing dose levels. The He++-irradiated specimens also have a noticeable level of discoloration corresponding to increasing levels of dose. The neutron-irradiated samples show a higher degree of mechanical degradation than the He++-irradiated samples.

  7. Degradation of Nylon 6,6 Fire-Suppression Casing from Plutonium Glove Boxes Under Alpha and Neutron Irradiation

    DOE PAGES

    Millsap, Donald W.; Cournoyer, Michael E.; Landsberger, Sheldon; Tesmer, Joseph R.; Wang, Matthew Y.

    2015-04-23

    Nylon 6,6 tensile specimens, conforming to the casing for self-contained fire extinguisher systems, have been irradiated using both an accelerator He++ ion beam and a 5-Ci PuBe neutron source to model the radiation damage these systems would likely incur over a lifetime of operation within glove boxes. Following irradiation, these samples were mechanically tested using standard practices as described in ASTM D638. The results of the He++ study indicate that the tensile strength of the nylon specimens undergoes some slight (<10%) degradation while other properties of the samples, such as elongation and tangent modulus, appear to fluctuate with increasing dosemore » levels. The He++-irradiated specimens also have a noticeable level of discoloration corresponding to increasing levels of dose. The neutron-irradiated samples show a higher degree of mechanical degradation than the He++-irradiated samples.« less

  8. Using satellite fire detection to calibrate components of the fire weather index system in Malaysia and Indonesia.

    PubMed

    Dymond, Caren C; Field, Robert D; Roswintiarti, Orbita; Guswanto

    2005-04-01

    Indonesia have two new sources of information to initiate fire prevention and suppression activities. PMID:15902449

  9. Neuromodulation impact on nonlinear firing behavior of a reduced model motoneuron with the active dendrite

    PubMed Central

    Kim, Hojeong; Heckman, C. J.

    2014-01-01

    Neuromodulatory inputs from brainstem systems modulate the normal function of spinal motoneurons by altering the activation properties of persistent inward currents (PICs) in their dendrites. However, the effect of the PIC on firing outputs also depends on its location in the dendritic tree. To investigate the interaction between PIC neuromodulation and PIC location dependence, we used a two-compartment model that was biologically realistic in that it retains directional and frequency-dependent electrical coupling between the soma and the dendrites, as seen in multi-compartment models based on full anatomical reconstructions of motoneurons. Our two-compartment approach allowed us to systematically vary the coupling parameters between the soma and the dendrite to accurately reproduce the effect of location of the dendritic PIC on the generation of nonlinear (hysteretic) motoneuron firing patterns. Our results show that as a single parameter value for PIC activation was either increased or decreased by 20% from its default value, the solution space of the coupling parameter values for nonlinear firing outputs was drastically reduced by approximately 80%. As a result, the model tended to fire only in a linear mode at the majority of dendritic PIC sites. The same results were obtained when all parameters for the PIC activation simultaneously changed only by approximately ±10%. Our results suggest the democratization effect of neuromodulation: the neuromodulation by the brainstem systems may play a role in switching the motoneurons with PICs at different dendritic locations to a similar mode of firing by reducing the effect of the dendritic location of PICs on the firing behavior. PMID:25309410

  10. Evaluating greenhouse gas emissions inventories for agricultural burning using satellite observations of active fires.

    PubMed

    Lin, Hsiao-Wen; Jin, Yufang; Giglio, Louis; Foley, Jonathan A; Randerson, James T

    2012-06-01

    Fires in agricultural ecosystems emit greenhouse gases and aerosols that influence climate on multiple spatial and temporal scales. Annex 1 countries of the United Nations Framework Convention on Climate Change (UNFCCC), many of which ratified the Kyoto Protocol, are required to report emissions of CH4 and N2O from these fires annually. In this study, we evaluated several aspects of this reporting system, including the optimality of the crops targeted by the UNFCCC globally and within Annex 1 countries, and the consistency of emissions inventories among different countries. We also evaluated the success of individual countries in capturing interannual variability and long-term trends in agricultural fire activity. In our approach, we combined global high-resolution maps of crop harvest area and production, derived from satellite maps and ground-based census data, with Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) measurements of active fires. At a global scale, we found that adding ground nuts (e.g., peanuts), cocoa, cotton and oil palm, and removing potato, oats, rye, and pulse other from the list of 14 crops targeted by the UNFCCC increased the percentage of active fires covered by the reporting system by 9%. Optimization led to a different recommended list for Annex 1 countries, requiring the addition of sunflower, cotton, rapeseed, and alfalfa and the removal of beans, sugarcane, pulse others, and tuber-root others. Extending emissions reporting to all Annex 1 countries (from the current set of 19 countries) would increase the efficacy of the reporting system from 6% to 15%, and further including several non-Annex 1 countries (Argentina, Brazil, China, India, Indonesia, Thailand, Kazakhstan, Mexico, and Nigeria) would capture over 55% of active fires in croplands worldwide. Analyses of interannual trends from the United States and Australia showed the importance of both intensity of fire use and crop production in controlling year

  11. Evaluating greenhouse gas emissions inventories for agricultural burning using satellite observations of active fires.

    PubMed

    Lin, Hsiao-Wen; Jin, Yufang; Giglio, Louis; Foley, Jonathan A; Randerson, James T

    2012-06-01

    Fires in agricultural ecosystems emit greenhouse gases and aerosols that influence climate on multiple spatial and temporal scales. Annex 1 countries of the United Nations Framework Convention on Climate Change (UNFCCC), many of which ratified the Kyoto Protocol, are required to report emissions of CH4 and N2O from these fires annually. In this study, we evaluated several aspects of this reporting system, including the optimality of the crops targeted by the UNFCCC globally and within Annex 1 countries, and the consistency of emissions inventories among different countries. We also evaluated the success of individual countries in capturing interannual variability and long-term trends in agricultural fire activity. In our approach, we combined global high-resolution maps of crop harvest area and production, derived from satellite maps and ground-based census data, with Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) measurements of active fires. At a global scale, we found that adding ground nuts (e.g., peanuts), cocoa, cotton and oil palm, and removing potato, oats, rye, and pulse other from the list of 14 crops targeted by the UNFCCC increased the percentage of active fires covered by the reporting system by 9%. Optimization led to a different recommended list for Annex 1 countries, requiring the addition of sunflower, cotton, rapeseed, and alfalfa and the removal of beans, sugarcane, pulse others, and tuber-root others. Extending emissions reporting to all Annex 1 countries (from the current set of 19 countries) would increase the efficacy of the reporting system from 6% to 15%, and further including several non-Annex 1 countries (Argentina, Brazil, China, India, Indonesia, Thailand, Kazakhstan, Mexico, and Nigeria) would capture over 55% of active fires in croplands worldwide. Analyses of interannual trends from the United States and Australia showed the importance of both intensity of fire use and crop production in controlling year

  12. Predicting fire activity in the US over the next 50 years using new IPCC climate projections

    NASA Astrophysics Data System (ADS)

    Wang, D.; Morton, D. C.; Collatz, G. J.

    2012-12-01

    Fire is an integral part of the Earth system with both direct and indirect effects on terrestrial ecosystems, the atmosphere, and human societies (Bowman et al. 2009). Climate conditions regulate fire activities through a variety of ways, e.g., influencing the conditions for ignition and fire spread, changing vegetation growth and decay and thus the accumulation of fuels for combustion (Arora and Boer 2005). Our recent study disclosed the burned area (BA) in US is strongly correlated with potential evaporation (PE), a measurement of climatic dryness derived from National Centers for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR) climate data (Morton et al. 2012). The correlation varies spatially and temporally. With regard to fire of peak fire seasons, Northwestern US, Great Plains and Alaska have the strongest BA/PE relationship. Using the recently released the Global Fire Emissions Database (GFED) Version 3 (van der Werf et al. 2010), we showed increasing BA in the last decade in most of NCA regions. Longer time series of Monitoring Trends in Burn Severity (MTBS) (Eidenshink et al. 2007) data showed the increasing trends occurred in all NCA regions from 1984 to 2010. This relationship between BA and PE provides us the basis to predict the future fire activities in the projected climate conditions. In this study, we build spatially explicit predictors using the historic PE/BA relationship. PE from 2011 to 2060 is calculated from the Coupled Model Intercomparison Project Phase 5 (CMIP5) data and the historic PE/BA relationship is then used to estimate BA. This study examines the spatial pattern and temporal dynamics of the future US fires driven by new climate predictions for the next 50 years. Reference: Arora, V.K., & Boer, G.J. (2005). Fire as an interactive component of dynamic vegetation models. Journal of Geophysical Research-Biogeosciences, 110 Bowman, D.M.J.S., Balch, J.K., Artaxo, P., Bond, W.J., Carlson, J.M., Cochrane, M.A., D

  13. Activated T cells sustain myeloid-derived suppressor cell-mediated immune suppression

    PubMed Central

    Damuzzo, Vera; Francescato, Samuela; Pozzuoli, Assunta; Berizzi, Antonio; Mocellin, Simone; Rossi, Carlo Riccardo; Bronte, Vincenzo; Mandruzzato, Susanna

    2016-01-01

    The expansion of myeloid derived suppressor cells (MDSCs), a suppressive population able to hamper the immune response against cancer, correlates with tumor progression and overall survival in several cancer types. We have previously shown that MDSCs can be induced in vitro from precursors present in the bone marrow and observed that these cells are able to actively proliferate in the presence of activated T cells, whose activation level is critical to drive the suppressive activity of MDSCs. Here we investigated at molecular level the mechanisms involved in the interplay between MDSCs and activated T cells. We found that activated T cells secrete IL-10 following interaction with MDSCs which, in turn, activates STAT3 phosphorylation on MDSCs then leading to B7-H1 expression. We also demonstrated that B7-H1+ MDSCs are responsible for immune suppression through a mechanism involving ARG-1 and IDO expression. Finally, we show that the expression of ligands B7-H1 and MHC class II both on in vitro-induced MDSCs and on MDSCs in the tumor microenvironment of cancer patients is paralleled by an increased expression of their respective receptors PD-1 and LAG-3 on T cells, two inhibitory molecules associated with T cell dysfunction. These findings highlight key molecules and interactions responsible for the extensive cross-talk between MDSCs and activated T cells that are at the basis of immune suppression. PMID:26700461

  14. Activated T cells sustain myeloid-derived suppressor cell-mediated immune suppression.

    PubMed

    Pinton, Laura; Solito, Samantha; Damuzzo, Vera; Francescato, Samuela; Pozzuoli, Assunta; Berizzi, Antonio; Mocellin, Simone; Rossi, Carlo Riccardo; Bronte, Vincenzo; Mandruzzato, Susanna

    2016-01-12

    The expansion of myeloid derived suppressor cells (MDSCs), a suppressive population able to hamper the immune response against cancer, correlates with tumor progression and overall survival in several cancer types. We have previously shown that MDSCs can be induced in vitro from precursors present in the bone marrow and observed that these cells are able to actively proliferate in the presence of activated T cells, whose activation level is critical to drive the suppressive activity of MDSCs. Here we investigated at molecular level the mechanisms involved in the interplay between MDSCs and activated T cells. We found that activated T cells secrete IL-10 following interaction with MDSCs which, in turn, activates STAT3 phosphorylation on MDSCs then leading to B7-H1 expression. We also demonstrated that B7-H1+ MDSCs are responsible for immune suppression through a mechanism involving ARG-1 and IDO expression. Finally, we show that the expression of ligands B7-H1 and MHC class II both on in vitro-induced MDSCs and on MDSCs in the tumor microenvironment of cancer patients is paralleled by an increased expression of their respective receptors PD-1 and LAG-3 on T cells, two inhibitory molecules associated with T cell dysfunction. These findings highlight key molecules and interactions responsible for the extensive cross-talk between MDSCs and activated T cells that are at the basis of immune suppression.

  15. Somatosensory Anticipatory Alpha Activity Increases to Suppress Distracting Input

    ERIC Educational Resources Information Center

    Haegens, Saskia; Luther, Lisa; Jensen, Ole

    2012-01-01

    Effective processing of sensory input in daily life requires attentional selection and amplification of relevant input and, just as importantly, attenuation of irrelevant information. It has been proposed that top-down modulation of oscillatory alpha band activity (8-14 Hz) serves to allocate resources to various regions, depending on task…

  16. Hysteresis Control for Current Harmonics Suppression Using Shunt Active Filter

    NASA Astrophysics Data System (ADS)

    Ahuja, Rajesh Kr; Chauhan, Aasha; Sharma, Sachin

    2012-11-01

    Recently wide spread of power electronic equipment has caused an increase of the harmonic disturbances in the power systems. The nonlinear loads draw harmonic and reactive power components of current from ac mains. Current harmonics generated by nonlinear loads such as adjustable speed drives,static powersupplies and UPS. Thus a perfect compensator is required to avoid the consequences due to harmonics. To overcome problems due to harmonics, Shunt Active Power Filter (SAPF) has been considered extensively. SAPF has better harmonic compensation than the other approaches used for solving the harmonic related problems. The performance of the SAPF depends upon different control strategies. This paper presents the performance analysis of SAPF under most important control strategy namely instantaneous real active and reactive power method (p-q) for extracting reference currents of shunt active filters under unbalanced load condition. Detailed simulations have been carried out considering this control strategy and adequate results were presented. In this paper, harmonic control strategy is applied to compensate the current harmonics in the system. A detailed study about the harmonic control method has been used using shunt active filter technique.

  17. Properties of human motor units after prolonged activity at a constant firing rate.

    PubMed

    Johnson, K V B; Edwards, S C; Van Tongeren, C; Bawa, P

    2004-02-01

    The primary purpose of this study was to examine if there are changes in the intrinsic properties of spinal motoneurons after prolonged submaximal contractions. To do this, we assessed whether or not the synaptic drive to motoneurons needs to increase in order to maintain a constant firing rate of a motor unit. Recruitment of new units and an increase in total electromyographic (EMG) activity of the muscle of interest were taken as estimates of an increase in synaptic drive. Subjects were asked to maintain a constant firing rate of a clearly identifiable (targeted) motor unit from the first dorsal interosseous muscle for approximately 10 min, while surface EMG and force were recorded simultaneously. For the 60 units studied, the duration of the constant-firing-rate period ranged from 73 to 1,140 s (448 +/- 227 s; mean +/- SD). There was a significant increase ( t-test, p<0.001) in the magnitude of mean surface EMG, and DC force while the targeted motoneuron maintained a constant rate suggesting an increase in the net excitatory input to the motoneuron pool. Changes occurring simultaneously in other parameters, namely, variability in interspike interval, magnitude of force fluctuations, the duration of motor unit action potentials, and the median power frequency of surface EMG were also computed. The firing rates of 16 concurrently firing motoneurons, not controlled by the subject, remained constant. The key finding of this study is that after prolonged activity, a motoneuron requires a stronger excitatory input to maintain its firing rate. Additional results are indicative of significant changes in the characteristics of the synaptic inputs, changes at the neuromuscular junction (both pre- and postsynaptic regions) and the sarcolemma.

  18. Miltefosine Suppresses Hepatic Steatosis by Activating AMPK Signal Pathway

    PubMed Central

    Zhu, Yaqin; Tong, Xing; Li, Kexue; Bai, Hui; Li, Xiaoyu; Ben, Jingjing; Zhang, Hanwen; Yang, Qing; Chen, Qi

    2016-01-01

    Background and Purpose It has been accepted that AMPK (Adenosine monophosphate–activated protein kinase) activation exhibits many beneficial effects on glucolipid metabolism. Lysophosphatidylcholine (LPC) is an important lysophospholipid which can improve blood glucose levels in diabetic mice and attenuate inflammation by activating AMPK signal pathway in macrophages. Synthetic alkylphospholipids (ALPs), such as miltefosine, is used as an alternate of LPC for the clinical application. Here, we investigated whether miltefosine could have an impact on hepatic steatosis and related metabolic disorders. Experimental Approach Mice were fed with high fat diet (HFD) for 16 weeks to generate an obese model. Next, the obese mice were randomly divided into three groups: saline-treated and miltefosine-treated (2.5 or 5 mg/kg/d) groups. Miltefosine was intraperitoneally administrated into mice for additional 4 weeks plus HFD treatment. Key Results It was shown that miltefosine treatment could substantially improve glucose metabolism, prevented hepatic lipid accumulation, and inhibited liver inflammation in HFD-fed mice by activating AMPK signal pathway. In vitro, miltefosine stimulated AMPKα phosphorylation both in time and dose dependent manner and decreased lipid accumulation in liver cells. When a specific AMPK inhibitor compound C was used to treat mice, the antagonistic effects of miltefosine on HFD-induced mouse hyperlipidaemia and liver steatosis were abolished. Treatment with miltefosine also dramatically inhibited the HFD-induced liver inflammation in mice. Conclusions and Implications Here we demonstrated that miltefosine might be a new activator of AMPK signal pathway in vivo and in vitro and be useful for treatment of hepatic steatosis and related metabolic disorders. PMID:27681040

  19. Cortical Network Models of Firing Rates in the Resting and Active States Predict BOLD Responses.

    PubMed

    Bennett, Maxwell R; Farnell, Les; Gibson, William G; Lagopoulos, Jim

    2015-01-01

    Measurements of blood oxygenation level dependent (BOLD) signals have produced some surprising observations. One is that their amplitude is proportional to the entire activity in a region of interest and not just the fluctuations in this activity. Another is that during sleep and anesthesia the average BOLD correlations between regions of interest decline as the activity declines. Mechanistic explanations of these phenomena are described here using a cortical network model consisting of modules with excitatory and inhibitory neurons, taken as regions of cortical interest, each receiving excitatory inputs from outside the network, taken as subcortical driving inputs in addition to extrinsic (intermodular) connections, such as provided by associational fibers. The model shows that the standard deviation of the firing rate is proportional to the mean frequency of the firing when the extrinsic connections are decreased, so that the mean BOLD signal is proportional to both as is observed experimentally. The model also shows that if these extrinsic connections are decreased or the frequency of firing reaching the network from the subcortical driving inputs is decreased, or both decline, there is a decrease in the mean firing rate in the modules accompanied by decreases in the mean BOLD correlations between the modules, consistent with the observed changes during NREM sleep and under anesthesia. Finally, the model explains why a transient increase in the BOLD signal in a cortical area, due to a transient subcortical input, gives rises to responses throughout the cortex as observed, with these responses mediated by the extrinsic (intermodular) connections.

  20. High pre-industrial and modern Tibetan Plateau fire activity

    NASA Astrophysics Data System (ADS)

    Kehrwald, N. M.; Li, Q.; Wang, N.; Zennaro, P.; Zangrando, R.; Barbante, C.

    2013-12-01

    The South Asian brown cloud created from a mix of biomass burning and fossil fuel aerosols is warming the atmosphere between 5000 to 7000 meters above sea level (m asl) along the southern slope of the Himalaya. The extent to which this atmospheric brown cloud is transported up and over the 7000 to 8000 m asl ridge of the Himalaya and northward across the Tibetan Plateau is unknown. Intense Eastern Asian industry and associated coal burning may also export fossil fuel burning products to the Tibetan Plateau. In addition, local cooking, agricultural and natural fires emit combustion products that alter atmospheric chemistry and are deposited on glacier surfaces. It is essential to differentiate between the effects of fossil fuel and biomass burning across the Tibetan Plateau to determine if combustion products affect glacier surfaces and, by extension, glacier volume. The specific biomarker levoglucosan can only be produced by biomass burning at temperatures of 300°C or higher and is trapped and preserved in glaciers across the globe. This specificity may allow the possibility of differentiating between fossil fuel and biomass burning contributions when comparing levoglucosan concentrations with more general ice core combustion proxies such as black carbon. Here, we present a biomass burning record from the entire 164 m Muztag ice core (36.35°N; 87.17°E; 5780 m asl) and from a southwest to northeast transect of snow pits across the Tibetan Plateau. Multiple total organic carbon and dissolved organic carbon surface samples demonstrate organic carbon concentrations at or near detection limits. However, these samples have high levoglucosan concentrations suggesting that the biomass burning recorded in these sites may be from a regional rather than local source. The Tibetan Plateau levoglucosan concentrations are surprisingly substantially greater than Kilimanjaro levoglucosan concentrations, where Kilimanjaro is located in a relatively similar low-latitude high

  1. Emergence of spatially heterogeneous burst suppression in a neural field model of electrocortical activity

    PubMed Central

    Bojak, Ingo; Stoyanov, Zhivko V.; Liley, David T. J.

    2015-01-01

    Burst suppression in the electroencephalogram (EEG) is a well-described phenomenon that occurs during deep anesthesia, as well as in a variety of congenital and acquired brain insults. Classically it is thought of as spatially synchronous, quasi-periodic bursts of high amplitude EEG separated by low amplitude activity. However, its characterization as a “global brain state” has been challenged by recent results obtained with intracranial electrocortigraphy. Not only does it appear that burst suppression activity is highly asynchronous across cortex, but also that it may occur in isolated regions of circumscribed spatial extent. Here we outline a realistic neural field model for burst suppression by adding a slow process of synaptic resource depletion and recovery, which is able to reproduce qualitatively the empirically observed features during general anesthesia at the whole cortex level. Simulations reveal heterogeneous bursting over the model cortex and complex spatiotemporal dynamics during simulated anesthetic action, and provide forward predictions of neuroimaging signals for subsequent empirical comparisons and more detailed characterization. Because burst suppression corresponds to a dynamical end-point of brain activity, theoretically accounting for its spatiotemporal emergence will vitally contribute to efforts aimed at clarifying whether a common physiological trajectory is induced by the actions of general anesthetic agents. We have taken a first step in this direction by showing that a neural field model can qualitatively match recent experimental data that indicate spatial differentiation of burst suppression activity across cortex. PMID:25767438

  2. Optimal area of retinal photocoagulation necessary for suppressing active iris neovascularisation associated with diabetic retinopathy.

    PubMed

    Shiraya, Tomoyasu; Kato, Satoshi; Shigeeda, Takashi

    2014-10-01

    To determine the optimal area of retinal photocoagulation required for suppressing active neovascularisation (NVI) associated with diabetic retinopathy. We studied 1 eye each of 4 patients in whom active NVI was ophthalmoscopically shown to have been suppressed by additional photocoagulation. These patients initially underwent pan-retinal photocoagulation for diabetic retinopathy at another hospital, but NVI developed subsequently. We compared the areas of photocoagulation before and after additional photocoagulation and compared the area of retinal photocoagulation. The photocoagulated areas before and after additional photocoagulation in the four eyes were 20.7 and 45.2, 36.6 and 56.3, 30.4 and 67.4, and 11.7 and 53.4 %, respectively. The area of retinal photocoagulation required to suppress active NVI is calculated to be ~50 %.

  3. Fire Protection in Educational Occupancies.

    ERIC Educational Resources Information Center

    Gervais, Romeo P.

    2000-01-01

    Discusses the origins of school fires and the components of the fire protection code called the Life Safety Code (LSC). Three of the following LSC requirements are described: means of egress; protection from hazards; and fire suppression and alarm systems. Information on who starts fires is highlighted along with preventive measures. (GR)

  4. Effect of cardiopulmonary C fibre activation on the firing activity of ventral respiratory group neurones in the rat.

    PubMed Central

    Wilson, C G; Bonham, A C

    1997-01-01

    1. Cardiopulmonary C fibre receptor stimulation elicits apnoea and rapid shallow breathing, but the effects on the firing activity of central respiratory neurones are not well understood. This study examined the responses of ventral respiratory group neurones: decrementing expiratory (Edec), augmenting expiratory (Eaug), and inspiratory (I) neurones during cardiopulmonary C fibre receptor-evoked apnoea and rapid shallow breathing. 2. Extracellular neuronal activity, phrenic nerve activity and arterial pressure were recorded in urethane-anaesthetized rats. Cardiopulmonary C fibre receptors were stimulated by right atrial injections of phenylbiguanide. Neurones were tested for antidromic activation from the contra- and ipsilateral ventral respiratory group (VRG), spinal cord and cervical vagus nerve. 3. Edec neurones discharged tonically during cardiopulmonary C fibre-evoked apnoea and rapid shallow breathing, displaying increased burst durations, number of impulses per burst, and mean impulse frequencies. Edec neurones recovered either with the phrenic nerve activity (25 s) or much later (3 min). 4. By contrast, the firing activity of Eaug and most I neurones was decreased, featuring decreased burst durations and number of impulses per burst and increased interburst intervals. Eaug activity recovered in approximately 3 min and inspiratory activity in approximately 1 min. 5. The results indicate that cardiopulmonary C fibre receptor stimulation causes tonic firing of Edec neurones and decreases in Eaug and I neuronal activity coincident with apnoea or rapid shallow breathing. PMID:9365917

  5. Full p53 transcriptional activation potential is dispensable for tumor suppression in diverse lineages.

    PubMed

    Jiang, Dadi; Brady, Colleen A; Johnson, Thomas M; Lee, Eunice Y; Park, Eunice J; Scott, Matthew P; Attardi, Laura D

    2011-10-11

    Over half of all human cancers, of a wide variety of types, sustain mutations in the p53 tumor suppressor gene. Although p53 limits tumorigenesis through the induction of apoptosis or cell cycle arrest, its molecular mechanism of action in tumor suppression has been elusive. The best-characterized p53 activity in vitro is as a transcriptional activator, but the identification of numerous additional p53 biochemical activities in vitro has made it unclear which mechanism accounts for tumor suppression. Here, we assess the importance of transcriptional activation for p53 tumor suppression function in vivo in several tissues, using a knock-in mouse strain expressing a p53 mutant compromised for transcriptional activation, p53(25,26). p53(25,26) is severely impaired for the transactivation of numerous classical p53 target genes, including p21, Noxa, and Puma, but it retains the ability to activate a small subset of p53 target genes, including Bax. Surprisingly, p53(25,26) can nonetheless suppress tumor growth in cancers derived from the epithelial, mesenchymal, central nervous system, and lymphoid lineages. Therefore, full transactivation of most p53 target genes is dispensable for p53 tumor suppressor function in a range of tissue types. In contrast, a transcriptional activation mutant that is completely defective for transactivation, p53(25,26,53,54), fails to suppress tumor development. These findings demonstrate that transcriptional activation is indeed broadly critical for p53 tumor suppressor function, although this requirement reflects the limited transcriptional activity observed with p53(25,26) rather than robust transactivation of a full complement of p53 target genes.

  6. Citral, a component of lemongrass oil, activates PPARα and γ and suppresses COX-2 expression.

    PubMed

    Katsukawa, Michiko; Nakata, Rieko; Takizawa, Yoshie; Hori, Kazuyuki; Takahashi, Saori; Inoue, Hiroyasu

    2010-11-01

    Lemongrass is a widely used herb as a food flavoring, as a perfume, and for its analgesic and anti-inflammatory purposes; however, the molecular mechanisms of these effects have not been elucidated. Previously, we identified carvacrol from the essential oil of thyme as a suppressor of cyclooxygenase (COX)-2, a key enzyme for prostaglandin synthesis, and also an activator of peroxisome proliferator-activated receptor (PPAR), a molecular target for "lifestyle-related" diseases. In this study, we evaluated the essential oil of lemongrass using our established assays for COX-2 and PPARs. We found that COX-2 promoter activity was suppressed by lemongrass oil in cell-based transfection assays, and we identified citral as a major component in the suppression of COX-2 expression and as an activator of PPARα and γ. PPARγ-dependent suppression of COX-2 promoter activity was observed in response to citral treatment. In human macrophage-like U937 cells, citral suppressed both LPS-induced COX-2 mRNA and protein expression, dose-dependently. Moreover, citral induced the mRNA expression of the PPARα-responsive carnitine palmitoyltransferase 1 gene and the PPARγ-responsive fatty acid binding protein 4 gene, suggesting that citral activates PPARα and γ, and regulates COX-2 expression. These results are important for understanding the anti-inflammatory and anti-lifestyle-related disease properties of lemongrass.

  7. Blue light irradiation suppresses dendritic cells activation in vitro.

    PubMed

    Fischer, Michael R; Abel, Manuela; Lopez Kostka, Susanna; Rudolph, Berenice; Becker, Detlef; von Stebut, Esther

    2013-08-01

    Blue light is a UV-free irradiation suitable for treating chronic skin inflammation, for example, atopic dermatitis, psoriasis, and hand- and foot eczema. However, a better understanding of the mode of action is still missing. For this reason, we investigated whether dendritic cells (DC) are directly affected by blue light irradiation in vitro. Here, we report that irradiation neither induced apoptosis nor maturation of monocyte-derived and myeloid DC. However, subsequent DC maturation upon LPS/IFNγ stimulation was impaired in a dose-dependent manner as assessed by maturation markers and cytokine release. Moreover, the potential of this DC to induce cytokine secretion from allogeneic CD4 T cells was reduced. In conclusion, unlike UV irradiation, blue light irradiation at high and low doses only resulted in impaired DC maturation upon activation and a reduced subsequent stimulatory capacity in allogeneic MLRs with strongest effects at higher doses. PMID:23879817

  8. A basin-wide assessment of the GOES and MODIS active fire products for the Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Schroeder, W.; Csiszar, I.; Prins, E.; Schmidt, C.; Setzer, A.; Longo, K.; Freitas, S.; Morisette, J.; Brunner, J.

    2007-05-01

    This LBE-ECO Phase III study is designed to assess the performance of active fire products which have been used to delineate the fire dynamics in the Brazilian Amazon basin and which are routinely used to feed biomass burning emissions models for the region. The initial analyses are focused primarily on the creation of a validated long term (1995-present) record for the WF-ABBA active fire product using GOES East geostationary satellite data. Active fire masks were produced for 285 ASTER and ETM+ scenes distributed across the Brazilian Amazon representing our ground truth for the validation of the WF-ABBA. For comparison purposes we also included the MODIS/Terra "Thermal Anomalies" (MOD14) data in our analyses. Approximately 14,500 fire pixels were analyzed for the GOES data and 7,300 fire pixels were analyzed for the MODIS data. We found that at the 50% detection probability mark (p<0.001), the GOES fire product requires four times more active fire area than it is necessary for MODIS to achieve the same probability of detection. However, the higher observation frequency of GOES resulted in less than 40% omission error compared to 80% with MODIS. Basin-wide commission errors for MODIS and GOES were approximately 15 and 17%, respectively. Commission errors were higher over areas of active deforestation due to the high thermal contrast between the deforested sites and the adjacent green forests which can cause multiple false detections. Burnt area estimates were also produced based on ETM+ data to assess the average burnt area size associated with the coarse resolution active fire data above. For this application over 2,700 burn scar polygons were digitized representing all major biomass burning regions across the Brazilian Amazon. Burn scar polygons were then intersected with the MODIS/Terra and Aqua active fire data. 50% of all polygons containing active fires in the MODIS imagery showed a burnt area size larger than 300ha. Burnt areas of less than 100ha in size

  9. An algorithm to detect fire activity using Meteosat: fine tuning and quality assesment

    NASA Astrophysics Data System (ADS)

    Amraoui, M.; DaCamara, C. C.; Ermida, S. L.

    2012-04-01

    Hot spot detection by means of sensors on-board geostationary satellites allows studying wildfire activity at hourly and even sub-hourly intervals, an advantage that cannot be met by polar orbiters. Since 1997, the Satellite Application Facility for Land Surface Analysis has been running an operational procedure that allows detecting active fires based on information from Meteosat-8/SEVIRI. This is the so-called Fire Detection and Monitoring (FD&M) product and the procedure takes advantage of the temporal resolution of SEVIRI (one image every 15 min), and relies on information from SEVIRI channels (namely 0.6, 0.8, 3.9, 10.8 and 12.0 μm) together with information on illumination angles. The method is based on heritage from contextual algorithms designed for polar, sun-synchronous instruments, namely NOAA/AVHRR and MODIS/TERRAAQUA. A potential fire pixel is compared with the neighboring ones and the decision is made based on relative thresholds as derived from the pixels in the neighborhood. Generally speaking, the observed fire incidence compares well against hot spots extracted from the global daily active fire product developed by the MODIS Fire Team. However, values of probability of detection (POD) tend to be quite low, a result that may be partially expected by the finer resolution of MODIS. The aim of the present study is to make a systematic assessment of the impacts on POD and False Alarm Ratio (FAR) of the several parameters that are set in the algorithms. Such parameters range from the threshold values of brightness temperature in the IR3.9 and 10.8 channels that are used to select potential fire pixels up to the extent of the background grid and thresholds used to statistically characterize the radiometric departures of a potential pixel from the respective background. The impact of different criteria to identify pixels contaminated by clouds, smoke and sun glint is also evaluated. Finally, the advantages that may be brought to the algorithm by adding

  10. The Activating Transcription Factor 3 Protein Suppresses the Oncogenic Function of Mutant p53 Proteins*

    PubMed Central

    Wei, Saisai; Wang, Hongbo; Lu, Chunwan; Malmut, Sarah; Zhang, Jianqiao; Ren, Shumei; Yu, Guohua; Wang, Wei; Tang, Dale D.; Yan, Chunhong

    2014-01-01

    Mutant p53 proteins (mutp53) often acquire oncogenic activities, conferring drug resistance and/or promoting cancer cell migration and invasion. Although it has been well established that such a gain of function is mainly achieved through interaction with transcriptional regulators, thereby modulating cancer-associated gene expression, how the mutp53 function is regulated remains elusive. Here we report that activating transcription factor 3 (ATF3) bound common mutp53 (e.g. R175H and R273H) and, subsequently, suppressed their oncogenic activities. ATF3 repressed mutp53-induced NFKB2 expression and sensitized R175H-expressing cancer cells to cisplatin and etoposide treatments. Moreover, ATF3 appeared to suppress R175H- and R273H-mediated cancer cell migration and invasion as a consequence of preventing the transcription factor p63 from inactivation by mutp53. Accordingly, ATF3 promoted the expression of the metastasis suppressor SHARP1 in mutp53-expressing cells. An ATF3 mutant devoid of the mutp53-binding domain failed to disrupt the mutp53-p63 binding and, thus, lost the activity to suppress mutp53-mediated migration, suggesting that ATF3 binds to mutp53 to suppress its oncogenic function. In line with these results, we found that down-regulation of ATF3 expression correlated with lymph node metastasis in TP53-mutated human lung cancer. We conclude that ATF3 can suppress mutp53 oncogenic function, thereby contributing to tumor suppression in TP53-mutated cancer. PMID:24554706

  11. Studies on Synthesis of Electrochemically Exfoliated Functionalized Graphene and Polylactic Acid/Ferric Phytate Functionalized Graphene Nanocomposites as New Fire Hazard Suppression Materials.

    PubMed

    Feng, Xiaming; Wang, Xin; Cai, Wei; Qiu, Shuilai; Hu, Yuan; Liew, Kim Meow

    2016-09-28

    Practical application of functionalized graphene in polymeric nanocomposites is hampered by the lack of cost-effective and eco-friendly methods for its production. Here, we reported a facile and green electrochemical approach for preparing ferric phytate functionalized graphene (f-GNS) by simultaneously utilizing biobased phytic acid as electrolyte and modifier for the first time. Due to the presence of phytic acid, electrochemical exfoliation leads to low oxidized graphene sheets (a C/O ratio of 14.8) that are tens of micrometers large. Successful functionalization of graphene was confirmed by the appearance of phosphorus and iron peaks in the X-ray photoelectron spectrum. Further, high-performance polylactic acid/f-GNS nanocomposites are readily fabricated by a convenient masterbatch strategy. Notably, inclusion of well-dispersed f-GNS resulted in dramatic suppression on fire hazards of polylactic acid in terms of reduced peak heat-release rate (decreased by 40%), low CO yield, and formation of a high graphitized protective char layer. Moreover, obviously improvements in crystallization rate and thermal conductivities of polylactic acid nanocomposites were observed, highlighting its promising potential in practical application. This novel strategy toward the simultaneous exfoliation and functionalization for graphene demonstrates a simple yet very effective approach for fabricating graphene-based flame retardants.

  12. Studies on Synthesis of Electrochemically Exfoliated Functionalized Graphene and Polylactic Acid/Ferric Phytate Functionalized Graphene Nanocomposites as New Fire Hazard Suppression Materials.

    PubMed

    Feng, Xiaming; Wang, Xin; Cai, Wei; Qiu, Shuilai; Hu, Yuan; Liew, Kim Meow

    2016-09-28

    Practical application of functionalized graphene in polymeric nanocomposites is hampered by the lack of cost-effective and eco-friendly methods for its production. Here, we reported a facile and green electrochemical approach for preparing ferric phytate functionalized graphene (f-GNS) by simultaneously utilizing biobased phytic acid as electrolyte and modifier for the first time. Due to the presence of phytic acid, electrochemical exfoliation leads to low oxidized graphene sheets (a C/O ratio of 14.8) that are tens of micrometers large. Successful functionalization of graphene was confirmed by the appearance of phosphorus and iron peaks in the X-ray photoelectron spectrum. Further, high-performance polylactic acid/f-GNS nanocomposites are readily fabricated by a convenient masterbatch strategy. Notably, inclusion of well-dispersed f-GNS resulted in dramatic suppression on fire hazards of polylactic acid in terms of reduced peak heat-release rate (decreased by 40%), low CO yield, and formation of a high graphitized protective char layer. Moreover, obviously improvements in crystallization rate and thermal conductivities of polylactic acid nanocomposites were observed, highlighting its promising potential in practical application. This novel strategy toward the simultaneous exfoliation and functionalization for graphene demonstrates a simple yet very effective approach for fabricating graphene-based flame retardants. PMID:27588582

  13. Inhibitory effects of propofol on neuron firing activities in the rostral ventrolateral medulla.

    PubMed

    Yang, Ching-Yue; Tan, P C; Wu, Wun-Chin; Hsu, Jee-Ching; See, Lai-Chu; Chai, Chok-Yung

    2007-10-31

    The effect of propofol on neuronal activity in the rostral ventrolateral medulla (RVLM) is not well established. Therefore, we performed extracellular recording on neurons of the RVLM to investigate neuronal activity before and after administration of intravenous propofol. The mean systemic arterial pressure (MSAP), heart rate and integrated neuronal firing rate (INFR) in the RVLM were continuously recorded in anesthetized cats before and after intravenous injection of 2 mg/kg propofol or supplemental injections of 1, 2 and 4 mg/kg propofol that were given respectively. Additionally, we compared the MSAP, heart rate (HR), and INFR in the RVLM following intravenous injection of 2 mg/kg propofol or 12.5 microg/kg nitroprusside. Neuronal firing was dose-dependently and reversibly inhibited after the supplemental doses of 1, 2 and 4 mg/kg propofol. The control INFR was 14.2 +/- 9.9 Hz, and this decreased to 12.1 +/- 9.4 Hz after the first dose of propofol (P = 0.085 vs. control), and further decreased to 9.3 +/- 7.7 Hz (P = 0.001 vs. control) and 7.5 +/- 7.7 Hz (P < 0.001 vs. control) after the second and third doses of propofol, respectively. Besides, SAP and HR were dose-dependently decreased by propofol as well. However, the effects of propofol and nitroprusside on neuronal activity in the RVLM differed. Propofol inhibited neuronal firing, whereas nitroprusside activated neuronal firing. In conclusion, propofol may dose-dependently inhibit spontaneous neuronal activity and the baroreflex in the RVLM. PMID:18274161

  14. Salidroside Suppresses HUVECs Cell Injury Induced by Oxidative Stress through Activating the Nrf2 Signaling Pathway.

    PubMed

    Zhu, Yao; Zhang, Ya-Jie; Liu, Wei-Wei; Shi, Ai-Wu; Gu, Ning

    2016-01-01

    Oxidative stress plays an important role in the pathogenesis of cardiovascular diseases. Salidroside (SAL), one of the main effective constituents of Rhodiola rosea, has been reported to suppress oxidative stress-induced cardiomyocyte injury and necrosis by promoting transcription of nuclear factor E2-related factor 2 (Nrf2)-regulated genes such as heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase (quinone1) (NQO1). However, it has not been indicated whether SAL might ameliorate endothelial injury induced by oxidative stress. Here, our study demonstrated that SAL might suppress HUVEC cell injury induced by oxidative stress through activating the Nrf2 signaling pathway. The results of our study indicated that SAL decreased the levels of intercellular reactive oxygen species (ROS) and malondialdehyde (MDA), and improved the activities of superoxide dismutase (SOD) and catalase (CAT), resulting in protective effects against oxidative stress-induced cell damage in HUVECs. It suppressed oxidative stress damage by inducing Nrf2 nuclear translocation and activating the expression of Nrf2-regulated antioxidant enzyme genes such as HO-1 and NQO1 in HUVECs. Knockdown of Nrf2 with siRNA abolished the cytoprotective effects against oxidative stress, decreased the expression of Nrf2, HO-1, and NQO1, and inhibited the nucleus translocation of Nrf2 in HUVECs. This study is the first to demonstrate that SAL suppresses HUVECs cell injury induced by oxidative stress through activating the Nrf2 signaling pathway. PMID:27517893

  15. Salidroside Suppresses HUVECs Cell Injury Induced by Oxidative Stress through Activating the Nrf2 Signaling Pathway.

    PubMed

    Zhu, Yao; Zhang, Ya-Jie; Liu, Wei-Wei; Shi, Ai-Wu; Gu, Ning

    2016-01-01

    Oxidative stress plays an important role in the pathogenesis of cardiovascular diseases. Salidroside (SAL), one of the main effective constituents of Rhodiola rosea, has been reported to suppress oxidative stress-induced cardiomyocyte injury and necrosis by promoting transcription of nuclear factor E2-related factor 2 (Nrf2)-regulated genes such as heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase (quinone1) (NQO1). However, it has not been indicated whether SAL might ameliorate endothelial injury induced by oxidative stress. Here, our study demonstrated that SAL might suppress HUVEC cell injury induced by oxidative stress through activating the Nrf2 signaling pathway. The results of our study indicated that SAL decreased the levels of intercellular reactive oxygen species (ROS) and malondialdehyde (MDA), and improved the activities of superoxide dismutase (SOD) and catalase (CAT), resulting in protective effects against oxidative stress-induced cell damage in HUVECs. It suppressed oxidative stress damage by inducing Nrf2 nuclear translocation and activating the expression of Nrf2-regulated antioxidant enzyme genes such as HO-1 and NQO1 in HUVECs. Knockdown of Nrf2 with siRNA abolished the cytoprotective effects against oxidative stress, decreased the expression of Nrf2, HO-1, and NQO1, and inhibited the nucleus translocation of Nrf2 in HUVECs. This study is the first to demonstrate that SAL suppresses HUVECs cell injury induced by oxidative stress through activating the Nrf2 signaling pathway.

  16. Contribution of wood stoves and fire places to mutagenic activity of airborne particulate matter inside homes.

    PubMed

    van Houdt, J J; Daenen, C M; Boleij, J S; Alink, G M

    1986-01-01

    Wood combustion produces compounds that are mutagenic in the Salmonella/microsome assay. As combustion products can be emitted in the home and the use of wood as a residential energy source is growing, an impact on human health might be of concern. In this study experiments were carried out to determine the contribution of wood combustion in stoves and fire places to indoor mutagenic activity under normal living conditions. Airborne particles from living rooms which were heated by stoves, or by fire places, and from outdoors were collected simultaneously. In each room two samples were collected during two consecutive weeks: one week the room was heated by central heating, the other week by wood combustion. Sampling took place in a total of 24 homes. Methanol extracts of the samples were tested in the Salmonella/mammalian microsome assay. Results show that mutagenic activity of outdoor air exceeds indoor mutagenicity. At the same time a correlation is found between in- and out-door mutagenicity, both with and without S9. However, a large difference is found between the ratio -S9/+S9 of in- and out-door mutagenic activity. Systematic differences in the ratio -S9/+S9 between control and experimental conditions are not observed. The use of wood stoves caused an increase of indoor mutagenicity in 8 out of 12 homes. It could be concluded that the use of an open fire consistently leads to an increase of mutagenic activity. This increase was caused by wood combustion products.

  17. Azithromycin suppresses CD4+ T-cell activation by direct modulation of mTOR activity

    PubMed Central

    Ratzinger, F.; Haslacher, H.; Poeppl, W.; Hoermann, G.; Kovarik, J. J.; Jutz, S.; Steinberger, P.; Burgmann, H.; Pickl, W. F.; Schmetterer, K. G.

    2014-01-01

    Advanced macrolides, such as azithromycin (AZM) or clarithromycin (CLM), are antibiotics with immunomodulatory properties. Here we have sought to evaluate their in vitro influence on the activation of CD4+ T-cells. Isolated CD4+ T-cells were stimulated with agonistic anti-CD3/anti-CD28 monoclonal antibodies in the presence of 0.6 mg/L, 2.5 mg/L, 10 mg/L or 40 mg/L AZM or CLM. Cell proliferation, cytokine level in supernatants and cell viability was assessed. Intracellular signaling pathways were evaluated using reporter cell lines, FACS analysis, immunoblotting and in vitro kinase assays. AZM inhibited cell proliferation rate and cytokine secretion of CD4+ T-cells in a dose-dependent manner. Similarly, high concentrations of CLM (40 mg/L) also suppressed these T-cell functions. Analysis of molecular signaling pathways revealed that exposure to AZM reduced the phosphorylation of the S6 ribosomal protein, a downstream target of mTOR. This effect was also observed at 40 mg/L CLM. In vitro kinase studies using recombinant mTOR showed that AZM inhibited mTOR activity. In contrast to rapamycin, this inhibition was independent of FKBP12. We show for the first time that AZM and to a lesser extent CLM act as immunosuppressive agents on CD4+ T-cells by inhibiting mTOR activity. Our results might have implications for the clinical use of macrolides. PMID:25500904

  18. Evaluation of a wearable physiological status monitor during simulated fire fighting activities.

    PubMed

    Smith, Denise L; Haller, Jeannie M; Dolezal, Brett A; Cooper, Christopher B; Fehling, Patricia C

    2014-01-01

    A physiological status monitor (PSM) has been embedded in a fire-resistant shirt. The purpose of this research study was to examine the ability of the PSM-shirt to accurately detect heart rate (HR) and respiratory rate (RR) when worn under structural fire fighting personal protective equipment (PPE) during the performance of various activities relevant to fire fighting. Eleven healthy, college-aged men completed three activities (walking, searching/crawling, and ascending/descending stairs) that are routinely performed during fire fighting operations while wearing the PSM-shirt under structural fire fighting PPE. Heart rate and RR recorded by the PSM-shirt were compared to criterion values measured concurrently with an ECG and portable metabolic measurement system, respectively. For all activities combined (overall) and for each activity, small differences were found between the PSM-shirt and ECG (mean difference [95% CI]: overall: -0.4 beats/min [-0.8, -0.1]; treadmill: -0.4 beats/min [-0.7, -0.1]; search: -1.7 beats/min [-3.1, -.04]; stairs: 0.4 beats/min [0.04, 0.7]). Standard error of the estimate was 3.5 beats/min for all tasks combined and 1.9, 5.9, and 1.9 beats/min for the treadmill walk, search, and stair ascent/descent, respectively. Correlations between the PSM-shirt and criterion heart rates were high (r = 0.95 to r = 0.99). The mean difference between RR recorded by the PSM-shirt and criterion overall was 1.1 breaths/min (95% CI: -1.9 to -0.4). The standard error of the estimate for RR ranged from 4.2 breaths/min (treadmill) to 8.2 breaths/min (search), with an overall value of 6.2 breaths/min. These findings suggest that the PSM-shirt provides valid measures of HR and useful approximations of RR when worn during fire fighting duties. PMID:24433269

  19. EGFR activation suppresses respiratory virus-induced IRF1-dependent CXCL10 production.

    PubMed

    Kalinowski, April; Ueki, Iris; Min-Oo, Gundula; Ballon-Landa, Eric; Knoff, David; Galen, Benjamin; Lanier, Lewis L; Nadel, Jay A; Koff, Jonathan L

    2014-07-15

    Airway epithelial cells are the primary cell type involved in respiratory viral infection. Upon infection, airway epithelium plays a critical role in host defense against viral infection by contributing to innate and adaptive immune responses. Influenza A virus, rhinovirus, and respiratory syncytial virus (RSV) represent a broad range of human viral pathogens that cause viral pneumonia and induce exacerbations of asthma and chronic obstructive pulmonary disease. These respiratory viruses induce airway epithelial production of IL-8, which involves epidermal growth factor receptor (EGFR) activation. EGFR activation involves an integrated signaling pathway that includes NADPH oxidase activation of metalloproteinase, and EGFR proligand release that activates EGFR. Because respiratory viruses have been shown to activate EGFR via this signaling pathway in airway epithelium, we investigated the effect of virus-induced EGFR activation on airway epithelial antiviral responses. CXCL10, a chemokine produced by airway epithelial cells in response to respiratory viral infection, contributes to the recruitment of lymphocytes to target and kill virus-infected cells. While respiratory viruses activate EGFR, the interaction between CXCL10 and EGFR signaling pathways is unclear, and the potential for EGFR signaling to suppress CXCL10 has not been explored. Here, we report that respiratory virus-induced EGFR activation suppresses CXCL10 production. We found that influenza virus-, rhinovirus-, and RSV-induced EGFR activation suppressed IFN regulatory factor (IRF) 1-dependent CXCL10 production. In addition, inhibition of EGFR during viral infection augmented IRF1 and CXCL10. These findings describe a novel mechanism that viruses use to suppress endogenous antiviral defenses, and provide potential targets for future therapies.

  20. Regular theta-firing neurons in the nucleus incertus during sustained hippocampal activation.

    PubMed

    Martínez-Bellver, Sergio; Cervera-Ferri, Ana; Martínez-Ricós, Joana; Ruiz-Torner, Amparo; Luque-Garcia, Aina; Luque-Martinez, Aina; Blasco-Serra, Arantxa; Guerrero-Martínez, Juan; Bataller-Mompeán, Manuel; Teruel-Martí, Vicent

    2015-04-01

    This paper describes the existence of theta-coupled neuronal activity in the nucleus incertus (NI). Theta rhythm is relevant for cognitive processes such as spatial navigation and memory processing, and can be recorded in a number of structures related to the hippocampal activation including the NI. Strong evidence supports the role of this tegmental nucleus in neural circuits integrating behavioural activation with the hippocampal theta rhythm. Theta oscillations have been recorded in the local field potential of the NI, highly coupled to the hippocampal waves, although no rhythmical activity has been reported in neurons of this nucleus. The present work analyses the neuronal activity in the NI in conditions leading to sustained hippocampal theta in the urethane-anaesthetised rat, in order to test whether such activation elicits a differential firing pattern. Wavelet analysis has been used to better define the neuronal activity already described in the nucleus, i.e., non-rhythmical neurons firing at theta frequency (type I neurons) and fast-firing rhythmical neurons (type II). However, the most remarkable finding was that sustained stimulation activated regular-theta neurons (type III), which were almost silent in baseline conditions and have not previously been reported. Thus, we describe the electrophysiological properties of type III neurons, focusing on their coupling to the hippocampal theta. Their spike rate, regularity and phase locking to the oscillations increased at the beginning of the stimulation, suggesting a role in the activation or reset of the oscillation. Further research is needed to address the specific contribution of these neurons to the entire circuit.

  1. Improving the vibration suppression capabilities of a magneto-rheological damper using hybrid active and semi-active control

    NASA Astrophysics Data System (ADS)

    Ullah Khan, Irfan; Wagg, David; Sims, Neil D.

    2016-08-01

    This paper presents a new hybrid active and semi-active control method for vibration suppression in flexible structures. The method uses a combination of a semi-active device and an active control actuator situated elsewhere in the structure to suppress vibrations. The key novelty is to use the hybrid controller to enable the magneto-rheological damper to achieve a performance as close to a fully active device as possible. This is achieved by ensuring that the active actuator can assist the magneto-rheological damper in the regions where energy is required. In addition, the hybrid active and semi-active controller is designed to minimize the switching of the semi-active controller. The control framework used is the immersion and invariance control technique in combination with sliding mode control. A two degree-of-freedom system with lightly damped resonances is used as an example system. Both numerical and experimental results are generated for this system, and then compared as part of a validation study. The experimental system uses hardware-in-the-loop to simulate the effect of both the degrees-of-freedom. The results show that the concept is viable both numerically and experimentally, and improved vibration suppression results can be obtained for the magneto-rheological damper that approach the performance of an active device.

  2. Comparison of analysis and flight test data for a drone aircraft with active flutter suppression

    NASA Technical Reports Server (NTRS)

    Newsom, J. R.; Pototzky, A. S.

    1981-01-01

    This paper presents a comparison of analysis and flight test data for a drone aircraft equipped with an active flutter suppression system. Emphasis is placed on the comparison of modal dampings and frequencies as a function of Mach number. Results are presented for both symmetric and antisymmetric motion with flutter suppression off. Only symmetric results are presented for flutter suppression on. Frequency response functions of the vehicle are presented from both flight test data and analysis. The analysis correlation is improved by using an empirical aerodynamic correction factor which is proportional to the ratio of experimental to analytical steady-state lift curve slope. In addition to presenting the mathematical models and a brief description of existing analytical techniques, an alternative analytical technique for obtaining closed-loop results is presented.

  3. Comparison of analysis and flight test data for a drone aircraft with active flutter suppression

    NASA Technical Reports Server (NTRS)

    Newsom, J. R.; Pototzky, A. S.

    1981-01-01

    A drone aircraft equipped with an active flutter suppression system is considered with emphasis on the comparison of modal dampings and frequencies as a function of Mach number. Results are presented for both symmetric and antisymmetric motion with flutter suppression off. Only symmetric results are given for flutter suppression on. Frequency response functions of the vehicle are presented from both flight test data and analysis. The analysis correlation is improved by using an empirical aerodynamic correction factor which is proportional to the ratio of experimental to analytical steady-state lift curve slope. The mathematical models are included and existing analytical techniques are described as well as an alternative analytical technique for obtaining closed-loop results.

  4. Phosphorous transient enhanced diffusion suppression and activation enhancement with cluster carbon co-implantation

    NASA Astrophysics Data System (ADS)

    Nakashima, Yoshiki; Hamamoto, Nariaki; Nagayama, Tsutomu; Koga, Yuji; Umisedo, Sei; Kawamura, Yasunori; Hashimoto, Masahiro; Onoda, Hiroshi

    2012-11-01

    Carbon co-implantation is well known as an effective method for suppressing boron/phosphorous transient enhanced diffusion (TED). Germanium pre-amorphization implantation (PAI) is usually applied prior to carbon co-implantation for suppressing channeling tail of dopants. In this study, cluster carbon was applied instead of the combination of germanium PAI and monomer carbon co-implantation prior to phosphorous implantation. Dependence of phosphorous activation and TED on amorphous layer thickness, carbon dose, carbon distribution and substrate temperature have been investigated. Cluster carbon implantation enables thick amorphous layer formation and TED suppression at the same time and low temperature implantation enhances the ability of amorphous layer formation so that shallow junction and low Rs can be achieved without Ge implantation.

  5. Phosphorous transient enhanced diffusion suppression and activation enhancement with cluster carbon co-implantation

    SciTech Connect

    Nakashima, Yoshiki; Hamamoto, Nariaki; Nagayama, Tsutomu; Koga, Yuji; Umisedo, Sei; Kawamura, Yasunori; Hashimoto, Masahiro; Onoda, Hiroshi

    2012-11-06

    Carbon co-implantation is well known as an effective method for suppressing boron/phosphorous transient enhanced diffusion (TED). Germanium pre-amorphization implantation (PAI) is usually applied prior to carbon co-implantation for suppressing channeling tail of dopants. In this study, cluster carbon was applied instead of the combination of germanium PAI and monomer carbon co-implantation prior to phosphorous implantation. Dependence of phosphorous activation and TED on amorphous layer thickness, carbon dose, carbon distribution and substrate temperature have been investigated. Cluster carbon implantation enables thick amorphous layer formation and TED suppression at the same time and low temperature implantation enhances the ability of amorphous layer formation so that shallow junction and low Rs can be achieved without Ge implantation.

  6. Suppression of SOS-inducing activity of chemical mutagens by metabolites from microbial transformation of (+)-longicyclene.

    PubMed

    Sakata, Kazuki; Miyazawa, Mitsuo

    2010-08-25

    In this study, biotransformation of (+)-longicyclene (1) by Aspergillus niger (NBRC 4414) and the suppressive effect on umuC gene expression by chemical mutagens 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide) and aflatoxin B1 (AFB1) of the SOS response in Salmonella typhimurium TA1535/pSK1002 were investigated. Initially, compound 1 was converted to three new terpenoids, (-)-(10R)-10-hydroxy-longicyclic acid (2), (+)-(10S)-10-hydroxy-longicyclic acid (3), and (+)-10-oxo-longicyclic acid (4) by A. niger , and their conversion rates were 27, 23, and 30%, respectively. The metabolites suppressed the SOS-inducing activity of furylfuramide and AFB1 in the umu test. Compounds 1-4 were hardly showing a suppressive effect on umu gene expression of the SOS responses in S. typhimurium TA1535/pSK1002 against furylfuramid. However, metabolites showed a suppressive effect against AFB1. Compound 4 had gene expression by chemical mutagen AFB1, was suppressed 53% at <1.0 mM, and was the most effective compound in this experiment. PMID:20662538

  7. ESCRT-0 is not required for ectopic Notch activation and tumor suppression in Drosophila.

    PubMed

    Tognon, Emiliana; Wollscheid, Nadine; Cortese, Katia; Tacchetti, Carlo; Vaccari, Thomas

    2014-01-01

    Multivesicular endosome (MVE) sorting depends on proteins of the Endosomal Sorting Complex Required for Transport (ESCRT) family. These are organized in four complexes (ESCRT-0, -I, -II, -III) that act in a sequential fashion to deliver ubiquitylated cargoes into the internal luminal vesicles (ILVs) of the MVE. Drosophila genes encoding ESCRT-I, -II, -III components function in sorting signaling receptors, including Notch and the JAK/STAT signaling receptor Domeless. Loss of ESCRT-I, -II, -III in Drosophila epithelia causes altered signaling and cell polarity, suggesting that ESCRTs genes are tumor suppressors. However, the nature of the tumor suppressive function of ESCRTs, and whether tumor suppression is linked to receptor sorting is unclear. Unexpectedly, a null mutant in Hrs, encoding one of the components of the ESCRT-0 complex, which acts upstream of ESCRT-I, -II, -III in MVE sorting is dispensable for tumor suppression. Here, we report that two Drosophila epithelia lacking activity of Stam, the other known components of the ESCRT-0 complex, or of both Hrs and Stam, accumulate the signaling receptors Notch and Dome in endosomes. However, mutant tissue surprisingly maintains normal apico-basal polarity and proliferation control and does not display ectopic Notch signaling activation, unlike cells that lack ESCRT-I, -II, -III activity. Overall, our in vivo data confirm previous evidence indicating that the ESCRT-0 complex plays no crucial role in regulation of tumor suppression, and suggest re-evaluation of the relationship of signaling modulation in endosomes and tumorigenesis. PMID:24718108

  8. A novel function for Wnt signaling modulating neuronal firing activity and the temporal structure of spontaneous oscillation in the entorhinal-hippocampal circuit.

    PubMed

    Oliva, Carolina A; Inestrosa, Nibaldo C

    2015-07-01

    During early and late postnatal developments, the establishment of functional neuronal connectivity depends on molecules like Wnt that help the recently formed synapses to establish and consolidate their new cellular interactions. However, unlike other molecules, whether Wnt can modulate the firing properties of cells is unknown. Here, for the first time we explore the physiological effect of the canonical and non-canonical Wnt pathways on a circuit that is currently generating oscillatory activity, the entorhinal cortex-hippocampal circuit. Our results indicate that Wnt pathways have strong influence in the circuital and cellular properties depending on the Wnt protein isoforms, concentration, and type of neuronal circuit. Antibodies against canonical and non-canonical ligands, as well as WASP-1 and sFRP-2, demonstrate that constitutive release of Wnts contributes to the maintenance of the network and intrinsic properties of the circuit. Furthermore, we found that the excess of Wnt3a or the permanent intracellular activation of the pathway with BIO-6 accelerates the period of the oscillation by disrupting the oscillatory units (Up states) in short units, presumably by affecting the synaptic mechanisms that couples neurons into the oscillatory cycle, but without affecting the spike generation. Instead, low doses of Wnt5a increase the period of the oscillation in EC by incorporating new cells into the network activity, probably modifying firing activity in other places of the circuit. Moreover, we found that Wnt signaling operates under different principles in the hippocampus. Using pyrvinium pamoate, a Wnt/β-catenin dependent pathway inhibitor, we demonstrated that this pathway is essential to keep the firing activity in the circuit CA3, and in less degree of CA1 circuit. However, CA1 circuit possesses homeostatic mechanisms to up-regulate the firing activity when it has been suppressed in CA3, and to down-modulate the cellular excitability when exacerbated

  9. A novel function for Wnt signaling modulating neuronal firing activity and the temporal structure of spontaneous oscillation in the entorhinal-hippocampal circuit.

    PubMed

    Oliva, Carolina A; Inestrosa, Nibaldo C

    2015-07-01

    During early and late postnatal developments, the establishment of functional neuronal connectivity depends on molecules like Wnt that help the recently formed synapses to establish and consolidate their new cellular interactions. However, unlike other molecules, whether Wnt can modulate the firing properties of cells is unknown. Here, for the first time we explore the physiological effect of the canonical and non-canonical Wnt pathways on a circuit that is currently generating oscillatory activity, the entorhinal cortex-hippocampal circuit. Our results indicate that Wnt pathways have strong influence in the circuital and cellular properties depending on the Wnt protein isoforms, concentration, and type of neuronal circuit. Antibodies against canonical and non-canonical ligands, as well as WASP-1 and sFRP-2, demonstrate that constitutive release of Wnts contributes to the maintenance of the network and intrinsic properties of the circuit. Furthermore, we found that the excess of Wnt3a or the permanent intracellular activation of the pathway with BIO-6 accelerates the period of the oscillation by disrupting the oscillatory units (Up states) in short units, presumably by affecting the synaptic mechanisms that couples neurons into the oscillatory cycle, but without affecting the spike generation. Instead, low doses of Wnt5a increase the period of the oscillation in EC by incorporating new cells into the network activity, probably modifying firing activity in other places of the circuit. Moreover, we found that Wnt signaling operates under different principles in the hippocampus. Using pyrvinium pamoate, a Wnt/β-catenin dependent pathway inhibitor, we demonstrated that this pathway is essential to keep the firing activity in the circuit CA3, and in less degree of CA1 circuit. However, CA1 circuit possesses homeostatic mechanisms to up-regulate the firing activity when it has been suppressed in CA3, and to down-modulate the cellular excitability when exacerbated

  10. Multiplatform inversion of the 2013 Rim Fire smoke emissions using regional-scale modeling: important nocturnal fire activity, air quality, and climate impacts

    NASA Astrophysics Data System (ADS)

    Saide, P. E.; Peterson, D. A.; da Silva, A. M., Jr.; Ziemba, L. D.; Anderson, B.; Diskin, G. S.; Sachse, G. W.; Hair, J. W.; Butler, C. F.; Fenn, M. A.; Jimenez, J. L.; Campuzano Jost, P.; Dibb, J. E.; Yokelson, R. J.; Toon, B.; Carmichael, G. R.

    2014-12-01

    Large wildfire events are increasingly recognized for their adverse effects on air quality and visibility, thus providing motivation for improving smoke emission estimates. The Rim Fire, one of the largest events in California's history, produced a large smoke plume that was sampled by the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) DC-8 aircraft with a full suite of in-situ and remote sensing measurements on 26-27 August 2013. We developed an inversion methodology which uses the WRF-Chem modeling system to constrain hourly fire emissions, using as initial estimates the NASA Quick Fire Emissions Dataset (QFED). This method differs from the commonly performed top-down estimates that constrain daily (or longer time scale) emissions. The inversion method is able to simultaneously improve the model fit to various SEAC4RS airborne measurements (e.g., organic aerosol, carbon monoxide (CO), aerosol extinction), ground based measurements (e.g., AERONET aerosol optical depth (AOD), CO), and satellite data (MODIS AOD) by modifying fire emissions and utilizing the information content of all these measurements. Preliminary results show that constrained emissions for a 6 day period following the largest fire growth are a factor 2-4 higher than the initial top-down estimates. Moreover, there is a tendency to increase nocturnal emissions by factors sometimes larger than 20, indicating that vigorous fire activity continued during the night. This deviation from a typical diurnal cycle is confirmed using geostationary satellite data. The constrained emissions also have a larger day-to-day variability than the initial emissions and correlate better to daily area burned estimates as observed by airborne infrared measurements (NIROPS). Experiments with the assimilation system show that performing the inversion using only satellite AOD data produces much smaller correction factors than when using all available data

  11. Active suppression of vortex-driven combustion instability using controlled liquid-fuel injection

    NASA Astrophysics Data System (ADS)

    Pang, Bin

    Combustion instabilities remain one of the most challenging problems encountered in developing propulsion and power systems. Large amplitude pressure oscillations, driven by unsteady heat release, can produce numerous detrimental effects. Most previous active control studies utilized gaseous fuels to suppress combustion instabilities. However, using liquid fuel to suppress combustion instabilities is more realistic for propulsion applications. Active instability suppression in vortex-driven combustors using a direct liquid fuel injection strategy was theoretically established and experimentally demonstrated in this dissertation work. Droplet size measurements revealed that with pulsed fuel injection management, fuel droplet size could be modulated periodically. Consequently, desired heat release fluctuation could be created. If this oscillatory heat release is coupled with the natural pressure oscillation in an out of phase manner, combustion instabilities can be suppressed. To identify proper locations of supplying additional liquid fuel for the purpose of achieving control, the natural heat release pattern in a vortex-driven combustor was characterized in this study. It was found that at high Damkohler number oscillatory heat release pattern closely followed the evolving vortex front. However, when Damkohler number became close to unity, heat release fluctuation wave no longer coincided with the coherent structures. A heat release deficit area was found near the dump plane when combustor was operated in lean premixed conditions. Active combustion instability suppression experiments were performed in a dump combustor using a controlled liquid fuel injection strategy. High-speed Schlieren results illustrated that vortex shedding plays an important role in maintaining self-sustained combustion instabilities. Complete combustion instability control requires total suppression of these large-scale coherent structures. The sound pressure level at the excited dominant

  12. Estimates of fire emissions from an active deforestation region in the southern Amazon based on satellite data and biogeochemical modelling

    NASA Astrophysics Data System (ADS)

    van der Werf, G. R.; Morton, D. C.; Defries, R. S.; Giglio, L.; Randerson, J. T.; Collatz, G. J.; Kasibhatla, P. S.

    2009-02-01

    Tropical deforestation contributes to the build-up of atmospheric carbon dioxide in the atmosphere. Within the deforestation process, fire is frequently used to eliminate biomass in preparation for agricultural use. Quantifying these deforestation-induced fire emissions represents a challenge, and current estimates are only available at coarse spatial resolution with large uncertainty. Here we developed a biogeochemical model using remote sensing observations of plant productivity, fire activity, and deforestation rates to estimate emissions for the Brazilian state of Mato Grosso during 2001-2005. Our model of DEforestation CArbon Fluxes (DECAF) runs at 250-m spatial resolution with a monthly time step to capture spatial and temporal heterogeneity in fire dynamics in our study area within the ''arc of deforestation'', the southern and eastern fringe of the Amazon tropical forest where agricultural expansion is most concentrated. Fire emissions estimates from our modelling framework were on average 90 Tg C year-1, mostly stemming from fires associated with deforestation (74%) with smaller contributions from fires from conversions of Cerrado or pastures to cropland (19%) and pasture fires (7%). In terms of carbon dynamics, about 80% of the aboveground living biomass and litter was combusted when forests were converted to pasture, and 89% when converted to cropland because of the highly mechanized nature of the deforestation process in Mato Grosso. The trajectory of land use change from forest to other land uses often takes more than one year, and part of the biomass that was not burned in the dry season following deforestation burned in consecutive years. This led to a partial decoupling of annual deforestation rates and fire emissions, and lowered interannual variability in fire emissions. Interannual variability in the region was somewhat dampened as well because annual emissions from fires following deforestation and from maintenance fires did not covary, although

  13. Estimates of fire emissions from an active deforestation region in the southern Amazon based on satellite data and biogeochemical modelling

    NASA Astrophysics Data System (ADS)

    van der Werf, G. R.; Morton, D. C.; Defries, R. S.; Giglio, L.; Randerson, J. T.; Collatz, G. J.; Kasibhatla, P. S.

    2008-09-01

    Tropical deforestation contributes to the build-up of atmospheric carbon dioxide in the atmosphere. Within the deforestation process, fire is frequently used to eliminate biomass in preparation for agricultural use. Quantifying these deforestation-induced fire emissions represents a challenge, and current estimates are only available at coarse spatial resolution with large uncertainty. Here we developed a biogeochemical model using remote sensing observations of plant productivity, fire activity, and deforestation rates to estimate emissions for the Brazilian state of Mato Grosso during 2001 2005. Our model of DEforestation CArbon Fluxes (DECAF) runs at 250-m spatial resolution with a monthly time step to capture spatial and temporal heterogeneity in fire dynamics in our study area within the "arc of deforestation", the southern and eastern fringe of the Amazon tropical forest where agricultural expansion is most concentrated. Fire emissions estimates from our modelling framework were on average 90 Tg C year-1, mostly stemming from fires associated with deforestation (74%) with smaller contributions from fires from conversions of Cerrado or pastures to cropland (19%) and pasture fires (7%). In terms of carbon dynamics, about 80% of the aboveground living biomass and litter was combusted when forests were converted to pasture, and 89% when converted to cropland because of the highly mechanized nature of the deforestation process in Mato Grosso. The trajectory of land use change from forest to other land uses often takes more than one year, and part of the biomass that was not burned in the dry season following deforestation burned in consecutive years. This led to a partial decoupling of annual deforestation rates and fire emissions, and lowered interannual variability in fire emissions. Interannual variability in the region was somewhat dampened as well because annual emissions from fires following deforestation and from maintenance fires did not covary, although

  14. Isoniazid suppresses antioxidant response element activities and impairs adipogenesis in mouse and human preadipocytes

    SciTech Connect

    Chen, Yanyan; Xue, Peng; Hou, Yongyong; Zhang, Hao; Zheng, Hongzhi; Zhou, Tong; Qu, Weidong; Teng, Weiping; Zhang, Qiang; Andersen, Melvin E.; Pi, Jingbo

    2013-12-15

    Transcriptional signaling through the antioxidant response element (ARE), orchestrated by the Nuclear factor E2-related factor 2 (Nrf2), is a major cellular defense mechanism against oxidative or electrophilic stress. Here, we reported that isoniazid (INH), a widely used antitubercular drug, displays a substantial inhibitory property against ARE activities in diverse mouse and human cells. In 3T3-L1 preadipocytes, INH concentration-dependently suppressed the ARE-luciferase reporter activity and mRNA expression of various ARE-dependent antioxidant genes under basal and oxidative stressed conditions. In keeping with our previous findings that Nrf2-ARE plays a critical role in adipogenesis by regulating expression of CCAAT/enhancer-binding protein β (C/EBPβ) and peroxisome proliferator-activated receptor γ (PPARγ), suppression of ARE signaling by INH hampered adipogenic differentiation of 3T3-L1 cells and human adipose-derived stem cells (ADSCs). Following adipogenesis induced by hormonal cocktails, INH-treated 3T3-L1 cells and ADSCs displayed significantly reduced levels of lipid accumulation and attenuated expression of C/EBPα and PPARγ. Time-course studies in 3T3-L1 cells revealed that inhibition of adipogenesis by INH occurred in the early stage of terminal adipogenic differentiation, where reduced expression of C/EBPβ and C/EBPδ was observed. To our knowledge, the present study is the first to demonstrate that INH suppresses ARE signaling and interrupts with the transcriptional network of adipogenesis, leading to impaired adipogenic differentiation. The inhibition of ARE signaling may be a potential underlying mechanism by which INH attenuates cellular antioxidant response contributing to various complications. - Highlights: • Isoniazid suppresses ARE-mediated transcriptional activity. • Isoniazid inhibits adipogenesis in preadipocytes. • Isoniazid suppresses adipogenic gene expression during adipogenesis.

  15. The human dimension of fire regimes on Earth

    USGS Publications Warehouse

    Bowman, David M.J.S.; Balch, Jennifer; Artaxo, Paulo; Bond, William J.; Cochrane, Mark A.; D'Antonio, Carla M.; DeFries, Ruth; Johnston, Fay H.; Keeley, Jon E.; Krawchuk, Meg A.; Kull, Christian A.; Michelle, Mack; Moritz, Max A.; Pyne, Stephen; Roos, Christopher I.; Scott, Andrew C.; Sodhi, Navjot S.; Swetnam, Thomas W.

    2011-01-01

    Humans and their ancestors are unique in being a fire-making species, but 'natural' (i.e. independent of humans) fires have an ancient, geological history on Earth. Natural fires have influenced biological evolution and global biogeochemical cycles, making fire integral to the functioning of some biomes. Globally, debate rages about the impact on ecosystems of prehistoric human-set fires, with views ranging from catastrophic to negligible. Understanding of the diversity of human fire regimes on Earth in the past, present and future remains rudimentary. It remains uncertain how humans have caused a departure from 'natural' background levels that vary with climate change. Available evidence shows that modern humans can increase or decrease background levels of natural fire activity by clearing forests, promoting grazing, dispersing plants, altering ignition patterns and actively suppressing fires, thereby causing substantial ecosystem changes and loss of biodiversity. Some of these contemporary fire regimes cause substantial economic disruptions owing to the destruction of infrastructure, degradation of ecosystem services, loss of life, and smoke-related health effects. These episodic disasters help frame negative public attitudes towards landscape fires, despite the need for burning to sustain some ecosystems. Greenhouse gas-induced warming and changes in the hydrological cycle may increase the occurrence of large, severe fires, with potentially significant feedbacks to the Earth system. Improved understanding of human fire regimes demands: (1) better data on past and current human influences on fire regimes to enable global comparative analyses, (2) a greater understanding of different cultural traditions of landscape burning and their positive and negative social, economic and ecological effects, and (3) more realistic representations of anthropogenic fire in global vegetation and climate change models. We provide an historical framework to promote understanding

  16. The human dimension of fire regimes on Earth.

    PubMed

    Bowman, David M J S; Balch, Jennifer; Artaxo, Paulo; Bond, William J; Cochrane, Mark A; D'Antonio, Carla M; Defries, Ruth; Johnston, Fay H; Keeley, Jon E; Krawchuk, Meg A; Kull, Christian A; Mack, Michelle; Moritz, Max A; Pyne, Stephen; Roos, Christopher I; Scott, Andrew C; Sodhi, Navjot S; Swetnam, Thomas W; Whittaker, Robert

    2011-12-01

    Humans and their ancestors are unique in being a fire-making species, but 'natural' (i.e. independent of humans) fires have an ancient, geological history on Earth. Natural fires have influenced biological evolution and global biogeochemical cycles, making fire integral to the functioning of some biomes. Globally, debate rages about the impact on ecosystems of prehistoric human-set fires, with views ranging from catastrophic to negligible. Understanding of the diversity of human fire regimes on Earth in the past, present and future remains rudimentary. It remains uncertain how humans have caused a departure from 'natural' background levels that vary with climate change. Available evidence shows that modern humans can increase or decrease background levels of natural fire activity by clearing forests, promoting grazing, dispersing plants, altering ignition patterns and actively suppressing fires, thereby causing substantial ecosystem changes and loss of biodiversity. Some of these contemporary fire regimes cause substantial economic disruptions owing to the destruction of infrastructure, degradation of ecosystem services, loss of life, and smoke-related health effects. These episodic disasters help frame negative public attitudes towards landscape fires, despite the need for burning to sustain some ecosystems. Greenhouse gas-induced warming and changes in the hydrological cycle may increase the occurrence of large, severe fires, with potentially significant feedbacks to the Earth system. Improved understanding of human fire regimes demands: (1) better data on past and current human influences on fire regimes to enable global comparative analyses, (2) a greater understanding of different cultural traditions of landscape burning and their positive and negative social, economic and ecological effects, and (3) more realistic representations of anthropogenic fire in global vegetation and climate change models. We provide an historical framework to promote understanding

  17. The human dimension of fire regimes on Earth.

    PubMed

    Bowman, David M J S; Balch, Jennifer; Artaxo, Paulo; Bond, William J; Cochrane, Mark A; D'Antonio, Carla M; Defries, Ruth; Johnston, Fay H; Keeley, Jon E; Krawchuk, Meg A; Kull, Christian A; Mack, Michelle; Moritz, Max A; Pyne, Stephen; Roos, Christopher I; Scott, Andrew C; Sodhi, Navjot S; Swetnam, Thomas W; Whittaker, Robert

    2011-12-01

    Humans and their ancestors are unique in being a fire-making species, but 'natural' (i.e. independent of humans) fires have an ancient, geological history on Earth. Natural fires have influenced biological evolution and global biogeochemical cycles, making fire integral to the functioning of some biomes. Globally, debate rages about the impact on ecosystems of prehistoric human-set fires, with views ranging from catastrophic to negligible. Understanding of the diversity of human fire regimes on Earth in the past, present and future remains rudimentary. It remains uncertain how humans have caused a departure from 'natural' background levels that vary with climate change. Available evidence shows that modern humans can increase or decrease background levels of natural fire activity by clearing forests, promoting grazing, dispersing plants, altering ignition patterns and actively suppressing fires, thereby causing substantial ecosystem changes and loss of biodiversity. Some of these contemporary fire regimes cause substantial economic disruptions owing to the destruction of infrastructure, degradation of ecosystem services, loss of life, and smoke-related health effects. These episodic disasters help frame negative public attitudes towards landscape fires, despite the need for burning to sustain some ecosystems. Greenhouse gas-induced warming and changes in the hydrological cycle may increase the occurrence of large, severe fires, with potentially significant feedbacks to the Earth system. Improved understanding of human fire regimes demands: (1) better data on past and current human influences on fire regimes to enable global comparative analyses, (2) a greater understanding of different cultural traditions of landscape burning and their positive and negative social, economic and ecological effects, and (3) more realistic representations of anthropogenic fire in global vegetation and climate change models. We provide an historical framework to promote understanding

  18. Exploratory breath analyses for assessing toxic dermal exposure of firefighters during suppression of structural burns

    EPA Science Inventory

    Firefighters wear fireproof clothing and self-contained breathing apparatus (SCBA) during rescue and fire suppression activities to protect against acute effects from heat and toxic chemicals. Fire services are also concerned about long-term health outcomes from chemical exposure...

  19. Global suppression of mitogen-activated ovine peripheral blood mononuclear cells by surface protein activity from Mycoplasma ovipneumoniae.

    PubMed

    Shahzad, W; Ajuwape, Adebowale Titilayo Phillip; Rosenbusch, Ricardo Francisco

    2010-07-01

    Mycoplasma ovipneumoniae is associated with chronic non-progressive pneumonia of sheep and goats. As with many other mycoplasmas involved in animal diseases, protective immune responses have not been achieved with vaccines, even though antibody responses can be obtained. This study focuses on characterizing the interaction of M. ovipneumoniae with ovine PBMC using carboxy-fluorescein-succinimidyl-ester (CFSE) loading and flow cytometry to measure lymphoid cell division. M. ovipneumoniae induced a strong in vitro polyclonal suppression of CD4(+), CD8(+), and B blood lymphocyte subsets. The suppressive activity could be destroyed by heating to 60 degrees C, and partially impaired by formalin and binary ethyleneimine treatment that abolished its viability. The activity resided on the surface-exposed membrane protein fraction of the mycoplasma, since mild trypsin treatment not affecting viability was shown to reduce suppressive activity. Trypsin-treated mycoplasma regained suppressive activity once the mycoplasma was allowed to re-synthesize its surface proteins. Implications for the design of vaccines against M. ovipneumoniae are discussed.

  20. Design for active and passive flutter suppression and gust alleviation. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Karpel, M.

    1981-01-01

    Analytical design techniques for active and passive control of aeroelastic systems are based on a rational approximation of the unsteady aerodynamic loads in the entire Laplace domain, which yields matrix equations of motion with constant coefficients. Some existing schemes are reviewed, the matrix Pade approximant is modified, and a technique which yields a minimal number of augmented states for a desired accuracy is presented. The state-space aeroelastic model is used to design an active control system for simultaneous flutter suppression and gust alleviation. The design target is for a continuous controller which transfers some measurements taken on the vehicle to a control command applied to a control surface. Structural modifications are formulated in a way which enables the treatment of passive flutter suppression system with the same procedures by which active control systems are designed.

  1. Phencyclidine affects firing activity of ventral tegmental area neurons that are related to reward and social behaviors in rats.

    PubMed

    Katayama, T; Okamoto, M; Suzuki, Y; Hoshino, K-Y; Jodo, E

    2013-06-14

    Patients with schizophrenia exhibit deficits in motivation and affect, which suggests an impairment in the reward system. The psychotomimetic drug, phencyclidine (PCP), also induces schizophrenia-like negative symptoms, such as reduced motivation, blunted affect, and social withdrawal in both humans and animals. Previous studies have indicated that the dopaminergic neurons in the ventral tegmental area (VTA) play a pivotal role in the development of reward-associated learning and motivation. However, how PCP affects the activity of VTA neurons during performance of a reward-related task and social interaction with others in unanesthetized animals remains unclear. Here, we recorded the unit activity of VTA neurons in freely moving rats before and after systemic administration of PCP in a classical conditioning paradigm, and during social interaction with an unfamiliar partner. In the classical conditioning task, two different tones were sequentially presented, one of which accompanied electrical stimulation of the medial forebrain bundle as an unconditioned stimulus. After identifying the response properties of recorded neurons in the classical conditioning task and social interaction, animals received an intraperitoneal injection of PCP. Our study demonstrated that most VTA neurons responsive to reward-associated stimuli were also activated during social interaction. Such activation of neurons was considerably suppressed by systemic administration of PCP, thus, PCP may affect the firing activity of VTA neurons that are involved in motivation, learning, and social interaction. Disruption of the response of VTA neurons to reward stimuli and socially interactive situations may be involved in PCP-induced impairments similar to the negative symptoms of schizophrenia.

  2. Fire Safety in Extraterrestrial Environments

    NASA Technical Reports Server (NTRS)

    Friedman, Robert

    1998-01-01

    Despite rigorous fire-safety policies and practices, fire incidents are possible during lunar and Martian missions. Fire behavior and hence preventive and responsive safety actions in the missions are strongly influenced by the low-gravity environments in flight and on the planetary surfaces. This paper reviews the understanding and key issues of fire safety in the missions, stressing flame spread, fire detection, suppression, and combustion performance of propellants produced from Martian resources.

  3. Vibration suppression of satellites using multifunctional platforms

    NASA Astrophysics Data System (ADS)

    Antin, Nicolas; Russ, Richard; Ma, Kougen; Ghasemi-Nejhad, Mehrdad N.

    2009-03-01

    This research focuses on a finite element analysis of active vibration suppression capabilities of a smart composite platform, which is a structural interface between a satellite main thruster and its structure and possesses simultaneous precision positioning and vibration suppression capabilities for thrust vector control of a satellite. First, the combined system of the smart composite platform and the satellite structure are briefly described followed by the finite element modeling and simulations. The smart platform piezoelectric patches and stacks material properties modeling, for the finite element analysis, are developed consistent with the manufacturer data. Next, a vibration suppression scheme, based on the modal analysis, is presented and used in vibration suppression analysis of satellite structures of the thrust vector under the thruster-firing excitation. The approach introduced here is an effective technique for the design of smart structures with complex geometry to study their MIMO active vibration suppression capabilities.

  4. Cationic chlorophyl derivatives with SOD mimicking activity suppress the proliferation of human ovarian cancer cells.

    PubMed

    Kobayashi, Y; Maniki, M; Nakamura, K

    1996-06-01

    Derivatives of chlorophyl, e.g. Fe-chlorin e6-Na, alpha, beta, gamma, delta-Tetraphenylporphine-tetrasulfonic acid disulfonic acid salt tetrahydrate (Fe-TPPTS) and alpha, beta, gamma, delta-Tetrakis (4-N-trimethylaminophenyl) porphine, tetra (p-toluensulfonate (Fe-TTMAPP), express SOD mimicking activity. Examination was made of suppressive effects of human cancer cell lines by derivatives of chlorophyl. Fe-TPPTS and Fe-TTMAPP suppressed proliferation of the human ovarian cancer cell lines but Fe-chlorin e6-Na failed to suppress the proliferation. Lipid peroxide was increased by application of Fe-TPPTS and Fe-TTMAPP, but decreased by application of Fe-chlorin e6-Na. SOD activity of the cancer cells did not change by application of these drugs. TPPTS and TTMAPP have a cationic charge but Fe-chlorin e6-Na has an anionic charge. It is suggested that charge of these drugs relates to the suppressive effects of the cancer cell proliferation. PMID:10851538

  5. Broad-spectrum therapeutic suppression of metastatic melanoma through nuclear hormone receptor activation.

    PubMed

    Pencheva, Nora; Buss, Colin G; Posada, Jessica; Merghoub, Taha; Tavazoie, Sohail F

    2014-02-27

    Melanoma metastasis is a devastating outcome lacking an effective preventative therapeutic. We provide pharmacologic, molecular, and genetic evidence establishing the liver-X nuclear hormone receptor (LXR) as a therapeutic target in melanoma. Oral administration of multiple LXR agonists suppressed melanoma invasion, angiogenesis, tumor progression, and metastasis. Molecular and genetic experiments revealed these effects to be mediated by LXRβ, which elicits these outcomes through transcriptional induction of tumoral and stromal apolipoprotein-E (ApoE). LXRβ agonism robustly suppressed tumor growth and metastasis across a diverse mutational spectrum of melanoma lines. LXRβ targeting significantly prolonged animal survival, suppressed the progression of established metastases, and inhibited brain metastatic colonization. Importantly, LXRβ activation displayed melanoma-suppressive cooperativity with the frontline regimens dacarbazine, B-Raf inhibition, and the anti-CTLA-4 antibody and robustly inhibited melanomas that had acquired resistance to B-Raf inhibition or dacarbazine. We present a promising therapeutic approach that uniquely acts by transcriptionally activating a metastasis suppressor gene.

  6. G protein β interacts with the glucocorticoid receptor and suppresses its transcriptional activity in the nucleus

    PubMed Central

    Kino, Tomoshige; Tiulpakov, Anatoly; Ichijo, Takamasa; Chheng, Ly; Kozasa, Tohru; Chrousos, George P.

    2005-01-01

    Extracellular stimuli that activate cell surface receptors modulate glucocorticoid actions via as yet unclear mechanisms. Here, we report that the guanine nucleotide-binding protein (G protein)–coupled receptor-activated WD-repeat Gβ interacts with the glucocorticoid receptor (GR), comigrates with it into the nucleus and suppresses GR-induced transactivation of the glucocorticoid-responsive genes. Association of Gγ with Gβ is necessary for this action of Gβ. Both endogenous and enhanced green fluorescent protein (EGFP)–fused Gβ2 and Gγ2 proteins were detected in the nucleus at baseline, whereas a fraction of EGFP-Gβ2 and DsRed2-GR comigrated to the nucleus or the plasma membrane, depending on the exposure of cells to dexamethasone or somatostatin, respectively. Gβ2 was associated with GR/glucocorticoid response elements (GREs) in vivo and suppressed activation function-2–directed transcriptional activity of the GR. We conclude that the Gβγ complex interacts with the GR and suppresses its transcriptional activity by associating with the transcriptional complex formed on GR-responsive promoters. PMID:15955845

  7. Oral progestin induces rapid, reversible suppression of ovarian activity in the cat.

    PubMed

    Stewart, R A; Pelican, K M; Brown, J L; Wildt, D E; Ottinger, M A; Howard, J G

    2010-04-01

    The influence of oral progestin (altrenogest; ALT) on cat ovarian activity was studied using non-invasive fecal steroid monitoring. Queens were assigned to various ALT dosages: (1) 0mg/kg (control; n=5 cats); (2) 0.044 mg/kg (LOW; n=5); (3) 0.088 mg/kg (MID; n=6); or (4) 0.352 mg/kg (HIGH; n=6). Fecal estrogen and progestagen concentrations were quantified using enzyme immunoassays for 60 days before, 38 days during and 60 days after ALT treatment. Initiation of follicular activity was suppressed in all cats during progestin treatment, whereas controls continued to cycle normally. Females (n=6) with elevated fecal estrogens at treatment onset completed a normal follicular phase before returning to baseline and remained suppressed until treatment withdrawal. All cats receiving oral progestin re-initiated follicular activity after treatment, although MID cats experienced the most synchronized return (within 10-16 days). Mean baseline fecal estrogens and progestagens were higher (P<0.05) after treatment in HIGH, but not in LOW or MID cats compared to pre-treatment values. The results demonstrate that: (1) oral progestin rapidly suppresses initiation of follicular activity in the cat, but does not influence a follicular phase that exists before treatment initiation; and (2) queens return to normal follicular activity after progestin withdrawal. This study provides foundational information for research aimed at using progestin priming to improve ovarian response in felids scheduled for ovulation induction and assisted breeding. PMID:20051246

  8. Suppression of cellular proliferation and invasion by the concerted lipid and protein phosphatase activities of PTEN

    PubMed Central

    Davidson, Lindsay; Maccario, Helene; Perera, Nevin M.; Yang, Xuesong; Spinelli, Laura; Tibarewal, Priyanka; Glancy, Ben; Gray, Alex; Weijer, Cornelis J.; Downes, C. Peter; Leslie, Nick R.

    2009-01-01

    PTEN is a tumour suppressor with phosphatase activity in vitro against both lipids and proteins and other potential non-enzymatic mechanisms of action. Although the importance of PTEN’s lipid phosphatase activity in regulating the PI3K signalling pathway is recognised, the significance of PTEN’s other mechanisms of action is currently unclear. Here, we describe the systematic identification of a PTEN mutant, PTEN Y138L, with activity against lipid, but not soluble substrates. Using this mutant we provide evidence for the interfacial activation of PTEN against lipid substrates. We also show that when re-expressed at physiological levels in PTEN null U87MG glioblastoma cells the protein phosphatase activity of PTEN is not required to regulate cellular PtdInsP3 levels or the downstream protein kinase Akt/PKB. Finally, in 3D Matrigel cultures of U87MG cells similarly re-expressing PTEN mutants, both the protein and lipid phosphatase activities were required to inhibit invasion, but either activity alone significantly inhibited proliferation, albeit only weakly for the protein phosphatase activity. Our data provides a novel tool to address the significance of PTEN’s separable lipid and protein phosphatase activities and suggest that both activities act to suppress proliferation and act together to suppress invasion. PMID:19915616

  9. Vegetation Response to Holocene Variations in Climate and Fire Activity in Southwestern Oregon

    NASA Astrophysics Data System (ADS)

    White, A.; Briles, C.; Whitlock, C. L.

    2014-12-01

    Past ecosystem responses to fire and climate change have been well studied in many parts of the Pacific Northwest, but forest history of the southern Cascades is poorly understood. Pollen and charcoal records from Hobart Lake (42.099°N, 122.482°W, 1458m) in southwestern Oregon were analyzed to reconstruct past changes in vegetation and fire activity. The watershed today supports mixed conifer forest of Abies, Pseudotsuga, Cupressaceae, and Pinus. From 8000 to 3500 cal yr BP, the forest had more xerophytic species, such as Pinus and Cupressaceae, and higher frequency of fires than at present, suggesting a climate that was warmer and drier than current conditions. The last 3500 cal years was characterized by increasing mesophytic taxa, such as Abies and Pseudotsuga, and decreasing fire activity; these trends are consistent with the establishment of cooler wetter conditions in the late Holocene. Changes in the abundance of Abies and Pseudotsuga pollen were compared at multiple sites to better understand their history in relation to long-term variations in climate and local disturbance. The pollen record suggests that Abies (i.e., Abies concolor, A. magnifica, A. amabilis or A. grandis) was abundant during the late-glacial period in a widespread subalpine forest that was present at all elevations. The genus declined in abundance during the early Holocene when it was best represented at higher elevations. Abies species gradually became more widespread and abundant during the mid- and late Holocene consistent with cooler conditions and expansion of closed mesic forest. Pseudotsuga was most abundant at low-elevation sites in the Coast and Cascade ranges during the early Holocene and then most abundant in more southern, mid-elevation sites in the Klamath and southern Cascade ranges in the late Holocene. Thus, the regional conifer history was strongly governed by variations in the summer insolation as they relate to changes in summer effective moisture.

  10. Integrated Active Fire Retrievals and Biomass Burning Emissions Using Complementary Near-Coincident Ground, Airborne and Spaceborne Sensor Data

    NASA Technical Reports Server (NTRS)

    Schroeder, Wilfrid; Ellicott, Evan; Ichoku, Charles; Ellison, Luke; Dickinson, Matthew B.; Ottmar, Roger D.; Clements, Craig; Hall, Dianne; Ambrosia, Vincent; Kremens, Robert

    2013-01-01

    Ground, airborne and spaceborne data were collected for a 450 ha prescribed fire implemented on 18 October 2011 at the Henry W. Coe State Park in California. The integration of various data elements allowed near coincident active fire retrievals to be estimated. The Autonomous Modular Sensor-Wildfire (AMS) airborne multispectral imaging system was used as a bridge between ground and spaceborne data sets providing high quality reference information to support satellite fire retrieval error analyses and fire emissions estimates. We found excellent agreement between peak fire radiant heat flux data (less than 1% error) derived from near-coincident ground radiometers and AMS. Both MODIS and GOES imager active fire products were negatively influenced by the presence of thick smoke, which was misclassified as cloud by their algorithms, leading to the omission of fire pixels beneath the smoke, and resulting in the underestimation of their retrieved fire radiative power (FRP) values for the burn plot, compared to the reference airborne data. Agreement between airborne and spaceborne FRP data improved significantly after correction for omission errors and atmospheric attenuation, resulting in as low as 5 difference between AquaMODIS and AMS. Use of in situ fuel and fire energy estimates in combination with a collection of AMS, MODIS, and GOES FRP retrievals provided a fuel consumption factor of 0.261 kg per MJ, total energy release of 14.5 x 10(exp 6) MJ, and total fuel consumption of 3.8 x 10(exp 6) kg. Fire emissions were calculated using two separate techniques, resulting in as low as 15 difference for various species

  11. Role of high-voltage activated potassium currents in high-frequency neuronal firing: evidence from a basal metazoan.

    PubMed

    Buckingham, Steven D; Spencer, Andrew N

    2002-08-01

    Certain neurons of vertebrates are specialized for high-frequency firing. Interestingly, high-frequency firing is also seen in central neurons in basal bilateral metazoans. Recently, the role of potassium currents with rightward-shifted activation curves in producing high-frequency firing has come under scrutiny. We apply intracellular recording, patch-clamp techniques, and compartmental modeling to examine the roles of rightward-shifted potassium currents in repetitive firing and shaping of action potentials in central neurons of the flatworm, Notoplana atomata (Phylum Platyhelminthes). The kinetic properties of potassium and sodium currents were determined from patch-clamp experiments on dissociated brain cells. To predict the effects of changing the steady-state and kinetic properties of these potassium currents, these data were incorporated into a computer model of a 30-microm spherical cell with the levels of current adjusted to approximate the values recorded in voltage-clamp experiments. The model was able to support regenerative spikes at high frequencies in response to injected current. Current-clamp recordings of cultured cells and of neurons in situ also showed evidence of very-high-frequency firing. Adjusting the ratio of inactivating to non-inactivating potassium currents had little effect upon the firing pattern of the cell or its ability to fire at high frequencies, whereas the presence of the non-inactivating current was necessary for repetitive firing. Computer simulations suggested that the rightward shift in voltage sensitivity confers a raised firing threshold, while rapid channel kinetics underlie high frequency firing, and the large activation range enhances the coding range of the cell.

  12. Comparative study of two structures of shunt active filter suppressing particular harmonics

    NASA Astrophysics Data System (ADS)

    Benchaita, L.; Salem Nia, A.; Saadate, S.

    1998-07-01

    This paper deals with the study of shunt active filters used for suppressing particular harmonics generated by nonlinear loads in utility distribution power systems. Both structures of shunt active filter, voltage source active filter (VSAF) and current source active filter (CSAF), are considered. The analytical study of specific harmonics identification in a given spectrum is first presented. For simulation as well as experimentation the nonlinear load is a conventional three phase thyristor rectifier and harmonics 5 and 7 are selected to be eliminated by active filter. The whole system consisting of the ac power supply network, the SCR rectifier and the shunt active filter (VSAF/CSAF) is then simulated. The simulation results are discussed and the efficiency of the two kinds of active filter are compared. Finally, for the first structure, VSAF, the simulation results are confirmed by experimental test realized by means of a fully digital control active power filter developed in our laboratory.

  13. Phenotypic plasticity of post-fire activity and thermal biology of a free-ranging small mammal.

    PubMed

    Stawski, Clare; Körtner, Gerhard; Nowack, Julia; Geiser, Fritz

    2016-05-15

    Ecosystems can change rapidly and sometimes irreversibly due to a number of anthropogenic and natural factors, such as deforestation and fire. How individual animals exposed to such changes respond behaviourally and physiologically is poorly understood. We quantified the phenotypic plasticity of activity patterns and torpor use - a highly efficient energy conservation mechanism - in brown antechinus (Antechinus stuartii), a small Australian marsupial mammal. We compared groups in densely vegetated forest areas (pre-fire and control) with a group in a burned, open habitat (post-fire). Activity and torpor patterns differed among groups and sexes. Females in the post-fire group spent significantly less time active than the other groups, both during the day and night. However, in males only daytime activity declined in the post-fire group, although overall activity was also reduced on cold days in males for all groups. The reduction in total or diurnal activity in the post-fire group was made energetically possible by a ~3.4-fold and ~2.2-fold increase in the proportion of time females and males, respectively, used torpor in comparison to that in the pre-fire and control groups. Overall, likely due to reproductive needs, torpor was more pronounced in females than in males, but low ambient temperatures increased torpor bout duration in both sexes. Importantly, for both male and female antechinus and likely other small mammals, predator avoidance and energy conservation - achieved by reduced activity and increased torpor use - appear to be vital for post-fire survival where ground cover and refuges have been obliterated. PMID:27001165

  14. Omega-3 Free Fatty Acids Suppress Macrophage Inflammasome Activation by Inhibiting NF-κB Activation and Enhancing Autophagy

    PubMed Central

    Williams-Bey, Yolanda; Boularan, Cedric; Vural, Ali; Huang, Ning-Na; Hwang, Il-Young; Shan-Shi, Chong; Kehrl, John H.

    2014-01-01

    The omega-3 (ω3) fatty acid docosahexaenoic acid (DHA) can suppress inflammation, specifically IL-1β production through poorly understood molecular mechanisms. Here, we show that DHA reduces macrophage IL-1β production by limiting inflammasome activation. Exposure to DHA reduced IL-1β production by ligands that stimulate the NLRP3, AIM2, and NAIP5/NLRC4 inflammasomes. The inhibition required Free Fatty Acid Receptor (FFAR) 4 (also known as GPR120), a G-protein coupled receptor (GPR) known to bind DHA. The exposure of cells to DHA recruited the adapter protein β-arrestin1/2 to FFAR4, but not to a related lipid receptor. DHA treatment reduced the initial inflammasome priming step by suppressing the nuclear translocation of NF-κB. DHA also reduced IL-1β levels by enhancing autophagy in the cells. As a consequence macrophages derived from mice lacking the essential autophagy protein ATG7 were partially resistant to suppressive effects of DHA. Thus, DHA suppresses inflammasome activation by two distinct mechanisms, inhibiting the initial priming step and by augmenting autophagy, which limits inflammasome activity. PMID:24911523

  15. Carvacrol, a component of thyme oil, activates PPARalpha and gamma and suppresses COX-2 expression.

    PubMed

    Hotta, Mariko; Nakata, Rieko; Katsukawa, Michiko; Hori, Kazuyuki; Takahashi, Saori; Inoue, Hiroyasu

    2010-01-01

    Cyclooxygenase-2 (COX-2), the rate-limiting enzyme in prostaglandin biosynthesis, plays a key role in inflammation and circulatory homeostasis. Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent transcription factors belonging to the nuclear receptor superfamily and are involved in the control of COX-2 expression, and vice versa. Here, we show that COX-2 promoter activity was suppressed by essential oils derived from thyme, clove, rose, eucalyptus, fennel, and bergamot in cell-based transfection assays using bovine arterial endothelial cells. Moreover, from thyme oil, we identified carvacrol as a major component of the suppressor of COX-2 expression and an activator of PPARalpha and gamma. PPARgamma-dependent suppression of COX-2 promoter activity was observed in response to carvacrol treatment. In human macrophage-like U937 cells, carvacrol suppressed lipopolysaccharide-induced COX-2 mRNA and protein expression, suggesting that carvacrol regulates COX-2 expression through its agonistic effect on PPARgamma. These results may be important in understanding the antiinflammatory and antilifestyle-related disease properties of carvacrol. PMID:19578162

  16. Deep brain stimulation suppresses pallidal low frequency activity in patients with phasic dystonic movements.

    PubMed

    Barow, Ewgenia; Neumann, Wolf-Julian; Brücke, Christof; Huebl, Julius; Horn, Andreas; Brown, Peter; Krauss, Joachim K; Schneider, Gerd-Helge; Kühn, Andrea A

    2014-11-01

    Deep brain stimulation of the globus pallidus internus alleviates involuntary movements in patients with dystonia. However, the mechanism is still not entirely understood. One hypothesis is that deep brain stimulation suppresses abnormally enhanced synchronized oscillatory activity within the motor cortico-basal ganglia network. Here, we explore deep brain stimulation-induced modulation of pathological low frequency (4-12 Hz) pallidal activity that has been described in local field potential recordings in patients with dystonia. Therefore, local field potentials were recorded from 16 hemispheres in 12 patients undergoing deep brain stimulation for severe dystonia using a specially designed amplifier allowing simultaneous high frequency stimulation at therapeutic parameter settings and local field potential recordings. For coherence analysis electroencephalographic activity (EEG) over motor areas and electromyographic activity (EMG) from affected neck muscles were recorded before and immediately after cessation of high frequency stimulation. High frequency stimulation led to a significant reduction of mean power in the 4-12 Hz band by 24.8 ± 7.0% in patients with predominantly phasic dystonia. A significant decrease of coherence between cortical EEG and pallidal local field potential activity in the 4-12 Hz range was revealed for the time period of 30 s after switching off high frequency stimulation. Coherence between EMG activity and pallidal activity was mainly found in patients with phasic dystonic movements where it was suppressed after high frequency stimulation. Our findings suggest that high frequency stimulation may suppress pathologically enhanced low frequency activity in patients with phasic dystonia. These dystonic features are the quickest to respond to high frequency stimulation and may thus directly relate to modulation of pathological basal ganglia activity, whereas improvement in tonic features may depend on long-term plastic changes within the

  17. Multirate flutter suppression system design for the Benchmark Active Controls Technology Wing

    NASA Technical Reports Server (NTRS)

    Berg, Martin C.; Mason, Gregory S.

    1994-01-01

    To study the effectiveness of various control system design methodologies, the NASA Langley Research Center initiated the Benchmark Active Controls Project. In this project, the various methodologies will be applied to design a flutter suppression system for the Benchmark Active Controls Technology (BACT) Wing (also called the PAPA wing). Eventually, the designs will be implemented in hardware and tested on the BACT wing in a wind tunnel. This report describes a project at the University of Washington to design a multirate flutter suppression system for the BACT wing. The objective of the project was two fold. First, to develop a methodology for designing robust multirate compensators, and second, to demonstrate the methodology by applying it to the design of a multirate flutter suppression system for the BACT wing. The contributions of this project are (1) development of an algorithm for synthesizing robust low order multirate control laws (the algorithm is capable of synthesizing a single compensator which stabilizes both the nominal plant and multiple plant perturbations; (2) development of a multirate design methodology, and supporting software, for modeling, analyzing and synthesizing multirate compensators; and (3) design of a multirate flutter suppression system for NASA's BACT wing which satisfies the specified design criteria. This report describes each of these contributions in detail. Section 2.0 discusses our design methodology. Section 3.0 details the results of our multirate flutter suppression system design for the BACT wing. Finally, Section 4.0 presents our conclusions and suggestions for future research. The body of the report focuses primarily on the results. The associated theoretical background appears in the three technical papers that are included as Attachments 1-3. Attachment 4 is a user's manual for the software that is key to our design methodology.

  18. Using tree recruitment patterns and fire history to guide restoration of an unlogged ponderosa pine/Douglas-fir landscape in the southern Rocky Mountains after a century of fire suppression

    USGS Publications Warehouse

    Kaufmann, M.R.; Huckaby, L.S.; Fornwalt, P.J.; Stoker, J.M.; Romme, W.H.

    2003-01-01

    Tree age and fire history were studied in an unlogged ponderosa pine/Douglas-fir (Pinus ponderosa/Pseudotsuga menziesii) landscape in the Colorado Front Range mountains. These data were analysed to understand tree survival during fire and post-fire recruitment patterns after fire, as a basis for understanding the characteristics of, and restoration needs for, an ecologically sustainable landscape. Comparisons of two independent tree age data sets indicated that sampling what subjectively appear to be the five oldest trees in a forest polygon could identify the oldest tree. Comparisons of the ages of the oldest trees in each data set with maps of fire history suggested that delays in establishment of trees, after stand-replacing fire, ranged from a few years to more than a century. These data indicate that variable fire severity, including patches of stand replacement, and variable temporal patterns of tree recruitment into openings after fire were major causes of spatial heterogeneity of patch structure in the landscape. These effects suggest that restoring current dense and homogeneous ponderosa pine forests to an ecologically sustainable and dynamic condition should reflect the roles of fires and variable patterns of tree recruitment in regulating landscape structure.

  19. Marijuana effects on immunity: suppression of human natural killer cell activity of delta-9-tetrahydrocannabinol.

    PubMed

    Specter, S C; Klein, T W; Newton, C; Mondragon, M; Widen, R; Friedman, H

    1986-01-01

    Delta-9-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, was tested for its ability to modulate human natural killer (NK) cell function. THC was toxic for peripheral blood lymphocytes at 20 micrograms/ml but not at 10 micrograms/ml or less. This component of marijuana also was inhibitory for NK activity against K562, a human tumor cell line at concentrations down to 5 micrograms/ml when pre-incubated with the effector cells. Suppression of NK function was dependent upon the concentration of THC and the length of time of pre-incubation but was independent of the ratio of effector to target cells. Prostaglandins were not involved in suppression of NK activity.

  20. Does adrenergic activity suppress insulin secretion during surgery? A clinical experiment with halothane anesthesia.

    PubMed Central

    Aärimaa, M; Syvälahti, E; Ovaska, J

    1978-01-01

    Peroperative inhibition of insulin release is widely attributed to increased alpha-adrenergic activity. To test this hypothesis serum insulin and glucose concentrations were measured at short intervals in 11 patients who underwent major surgery. Five patients were anesthetized with halothane and six with general anesthesia without halothane. The results were similar in both patient groups; halothane had no effect on insulin. This suggests that suppression of insulin under operations is probably not due to activation of the alpha-adrenergic receptors of the pancreatic beta-cells. The authors propose that suppression of insulin secretion during surgery may be caused by adrenaline, which, in competing for the glucose receptors, insensitizes the pancreatic beta-cells. PMID:202205

  1. Synthesis of active controls for flutter suppression on a flight research wing

    NASA Technical Reports Server (NTRS)

    Abel, I.; Perry, B., III; Murrow, H. N.

    1977-01-01

    This paper describes some activities associated with the preliminary design of an active control system for flutter suppression capable of demonstrating a 20% increase in flutter velocity. Results from two control system synthesis techniques are given. One technique uses classical control theory, and the other uses an 'aerodynamic energy method' where control surface rates or displacements are minimized. Analytical methods used to synthesize the control systems and evaluate their performance are described. Some aspects of a program for flight testing the active control system are also given. This program, called DAST (Drones for Aerodynamics and Structural Testing), employs modified drone-type vehicles for flight assessments and validation testing.

  2. 77 FR 1945 - Agency Information Collection Activities: Proposed Collection; Comment Request, National Fire...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-12

    ...; Comment Request, National Fire Department Census AGENCY: Federal Emergency Management Agency, DHS. ACTION... collect data for the development and continuation of the National Fire Department Census. DATES: Comments..., Statistician, United States Fire Administration, National Fire Data Center, (301) 447-1154 for...

  3. Troglitazone inhibits endothelial cell proliferation through suppression of casein kinase 2 activity

    SciTech Connect

    Lee, Kuy-Sook; Park, Jin-Hee; Lee, Seahyoung; Lim, Hyun-Joung; Jang, Yangsoo; Park, Hyun-Young . E-mail: hypark65@nih.go.kr

    2006-07-21

    Troglitazone, an agonist of peroxisome proliferator activated receptor{gamma} (PPAR{gamma}), has been reported to inhibit endothelial cell proliferation by suppressing Akt activation. Recently, it has been also proposed that phosphatase and tensin homolog deleted from chromosome 10 (PTEN) plays an important role in such effect of troglitazone. However, the mechanism of how troglitazone regulates PTEN remains to be elucidated. We therefore investigated the effects of troglitazone on casein kinase 2 (CK2), which is known to negatively regulate PTEN activity. Troglitazone significantly inhibited serum-induced proliferation of HUVEC in a concentration dependent manner. Serum-induced Akt and its downstream signaling pathway activation was attenuated by troglitazone (10 {mu}M) pretreatment. The phosphorylation of PTEN, which was directly related to Akt activation, was decreased with troglitazone pretreatment and was inversely proportional to CK2 activity. DRB, a CK2 inhibitor, also showed effects similar to that of troglitazone on Akt and its downstream signaling molecules. In conclusion, our results suggest that troglitazone inhibits proliferation of HUVECs through suppression of CK2 activity rendering PTEN to remain activated, and this effect of troglitazone in HUVECs seems to be PPAR{gamma} independent.

  4. Influence of mineral amendment on disease suppressive activity of Pseudomonas fluorescens to Fusarium wilt of chickpea.

    PubMed

    Saikia, Ratul; Varghese, Saju; Singh, Bhim Pratap; Arora, Dilip K

    2009-01-01

    Fusarium wilt caused by Fusarium oxysporum f. sp. ciceri causes considerable yield loss of chickpea. Pseudomonas fluorescens4-92 (Pf4-92) strain can suppress the disease. Amendment of zinc EDTA and copper EDTA could not suppress the disease significantly when used alone; however, they significantly suppressed the disease in presence of Pf4-92. In vitro observation showed that at 40, 30 and 20microgml(-1) concentrations of these minerals, i.e. Zn, Cu and Zn plus Cu, respectively, completely repressed the production of the phytotoxin, fusaric acid (FA). FA concentration (0.5microgml(-1)) has been shown to suppress the production of 2,4-diacetylphloroglucinol (DAPG) by Pf4-92, and DAPG, salicylic acid, pyochelin and pyoluteorin production was enhanced by these mineral amendments. In rockwool bioassays, Zn, Cu and Zn plus Cu amendments reduced FA production and enhanced DAPG production. This study demonstrates that Zn and Cu enhance biocontrol activity by reducing FA produced by the pathogen, F. oxysporum f. sp. ciceri. PMID:17604612

  5. PDF neuron firing phase-shifts key circadian activity neurons in Drosophila.

    PubMed

    Guo, Fang; Cerullo, Isadora; Chen, Xiao; Rosbash, Michael

    2014-06-17

    Our experiments address two long-standing models for the function of the Drosophila brain circadian network: a dual oscillator model, which emphasizes the primacy of PDF-containing neurons, and a cell-autonomous model for circadian phase adjustment. We identify five different circadian (E) neurons that are a major source of rhythmicity and locomotor activity. Brief firing of PDF cells at different times of day generates a phase response curve (PRC), which mimics a light-mediated PRC and requires PDF receptor expression in the five E neurons. Firing also resembles light by causing TIM degradation in downstream neurons. Unlike light however, firing-mediated phase-shifting is CRY-independent and exploits the E3 ligase component CUL-3 in the early night to degrade TIM. Our results suggest that PDF neurons integrate light information and then modulate the phase of E cell oscillations and behavioral rhythms. The results also explain how fly brain rhythms persist in constant darkness and without CRY.

  6. Research Plan for Fire Signatures and Detection

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Viewgraphs on the prevention, suppression, and detection of fires aboard a spacecraft is presented. The topics include: 1) Fire Prevention, Detection, and Suppression Sub-Element Products; 2) FPDS Organizing Questions; 3) FPDS Organizing Questions; 4) Signatures, Sensors, and Simulations; 5) Quantification of Fire and Pre-Fire Signatures; 6) Smoke; 7) DAFT Hardware; 8) Additional Benefits of DAFT; 9) Development and Characterization of Sensors 10) Simulation of the Transport of Smoke and Fire Precursors; and 11) FPDS Organizing Questions.

  7. Transdermal neuromodulation of noradrenergic activity suppresses psychophysiological and biochemical stress responses in humans

    PubMed Central

    Tyler, William J.; Boasso, Alyssa M.; Mortimore, Hailey M.; Silva, Rhonda S.; Charlesworth, Jonathan D.; Marlin, Michelle A.; Aebersold, Kirsten; Aven, Linh; Wetmore, Daniel Z.; Pal, Sumon K.

    2015-01-01

    We engineered a transdermal neuromodulation approach that targets peripheral (cranial and spinal) nerves and utilizes their afferent pathways as signaling conduits to influence brain function. We investigated the effects of this transdermal electrical neurosignaling (TEN) method on sympathetic physiology under different experimental conditions. The TEN method involved delivering high-frequency pulsed electrical currents to ophthalmic and maxillary divisions of the right trigeminal nerve and cervical spinal nerve afferents. Under resting conditions, TEN significantly suppressed basal sympathetic tone compared to sham as indicated by functional infrared thermography of facial temperatures. In a different experiment, subjects treated with TEN reported significantly lower levels of tension and anxiety on the Profile of Mood States scale compared to sham. In a third experiment when subjects were experimentally stressed TEN produced a significant suppression of heart rate variability, galvanic skin conductance, and salivary α-amylase levels compared to sham. Collectively these observations demonstrate TEN can dampen basal sympathetic tone and attenuate sympathetic activity in response to acute stress induction. Our physiological and biochemical observations are consistent with the hypothesis that TEN modulates noradrenergic signaling to suppress sympathetic activity. We conclude that dampening sympathetic activity in such a manner represents a promising approach to managing daily stress. PMID:26353920

  8. Transdermal neuromodulation of noradrenergic activity suppresses psychophysiological and biochemical stress responses in humans.

    PubMed

    Tyler, William J; Boasso, Alyssa M; Mortimore, Hailey M; Silva, Rhonda S; Charlesworth, Jonathan D; Marlin, Michelle A; Aebersold, Kirsten; Aven, Linh; Wetmore, Daniel Z; Pal, Sumon K

    2015-01-01

    We engineered a transdermal neuromodulation approach that targets peripheral (cranial and spinal) nerves and utilizes their afferent pathways as signaling conduits to influence brain function. We investigated the effects of this transdermal electrical neurosignaling (TEN) method on sympathetic physiology under different experimental conditions. The TEN method involved delivering high-frequency pulsed electrical currents to ophthalmic and maxillary divisions of the right trigeminal nerve and cervical spinal nerve afferents. Under resting conditions, TEN significantly suppressed basal sympathetic tone compared to sham as indicated by functional infrared thermography of facial temperatures. In a different experiment, subjects treated with TEN reported significantly lower levels of tension and anxiety on the Profile of Mood States scale compared to sham. In a third experiment when subjects were experimentally stressed TEN produced a significant suppression of heart rate variability, galvanic skin conductance, and salivary α-amylase levels compared to sham. Collectively these observations demonstrate TEN can dampen basal sympathetic tone and attenuate sympathetic activity in response to acute stress induction. Our physiological and biochemical observations are consistent with the hypothesis that TEN modulates noradrenergic signaling to suppress sympathetic activity. We conclude that dampening sympathetic activity in such a manner represents a promising approach to managing daily stress. PMID:26353920

  9. Transdermal neuromodulation of noradrenergic activity suppresses psychophysiological and biochemical stress responses in humans.

    PubMed

    Tyler, William J; Boasso, Alyssa M; Mortimore, Hailey M; Silva, Rhonda S; Charlesworth, Jonathan D; Marlin, Michelle A; Aebersold, Kirsten; Aven, Linh; Wetmore, Daniel Z; Pal, Sumon K

    2015-01-01

    We engineered a transdermal neuromodulation approach that targets peripheral (cranial and spinal) nerves and utilizes their afferent pathways as signaling conduits to influence brain function. We investigated the effects of this transdermal electrical neurosignaling (TEN) method on sympathetic physiology under different experimental conditions. The TEN method involved delivering high-frequency pulsed electrical currents to ophthalmic and maxillary divisions of the right trigeminal nerve and cervical spinal nerve afferents. Under resting conditions, TEN significantly suppressed basal sympathetic tone compared to sham as indicated by functional infrared thermography of facial temperatures. In a different experiment, subjects treated with TEN reported significantly lower levels of tension and anxiety on the Profile of Mood States scale compared to sham. In a third experiment when subjects were experimentally stressed TEN produced a significant suppression of heart rate variability, galvanic skin conductance, and salivary α-amylase levels compared to sham. Collectively these observations demonstrate TEN can dampen basal sympathetic tone and attenuate sympathetic activity in response to acute stress induction. Our physiological and biochemical observations are consistent with the hypothesis that TEN modulates noradrenergic signaling to suppress sympathetic activity. We conclude that dampening sympathetic activity in such a manner represents a promising approach to managing daily stress.

  10. Cold Vacuum Drying facility fire protection system design description (SYS 24)

    SciTech Connect

    PITKOFF, C.C.

    1999-07-06

    This document describes the Cold Vacuum Drying Facility (CVDF) fire protection system (FPS). The FPS provides fire detection, suppression, and loss limitation for the CVDF structure, personnel, and in-process spent nuclear fuel. The system provides, along with supporting interfacing systems, detection, alarm, and activation instrumentation and controls, distributive piping system, isolation valves, and materials and controls to limit combustibles and the associated fire loadings.

  11. Chronic activation of pattern recognition receptors suppresses brown adipogenesis of multipotent mesodermal stem cells and brown pre-adipocytes.

    PubMed

    Bae, Jiyoung; Chen, Jiangang; Zhao, Ling

    2015-06-01

    Brown adipose tissue (BAT) holds promise to combat obesity through energy-spending, non-shivering thermogenesis. Understanding of regulation of BAT development can lead to novel strategies to increase BAT mass and function for obesity treatment and prevention. Here, we report the effects of chronic activation of PRR on brown adipogenesis of multipotent mesodermal stem C3H10T1/2 cells and immortalized brown pre-adipocytes from the classical interscapular BAT of mice. Activation of NOD1, TLR4, or TLR2 by their respective synthetic ligand suppressed brown marker gene expression and lipid accumulation during differentiation of brown-like adipocytes of C3H10T1/2. Activation of the PRR only during the commitment was sufficient to suppress the differentiation. PRR activation suppressed PGC-1α mRNA, but induced PRDM16 mRNA at the commitment. Consistently, PRR activation suppressed the differentiation of immortalized brown pre-adipocytes. Activation of PRR induced NF-κB activation in both cells, which correlated with their abilities to suppress PPARγ transactivation, a critical event for brown adipogenesis. Taken together, our results demonstrate that chronic PRR activation suppressed brown adipogenesis of multipotent mesodermal stem cells and brown pre-adipocytes, possibly through suppression of PPARγ transactivation. The results suggest that anti- inflammatory therapies targeting PRRs may be beneficial for the BAT development.

  12. Fire Prevention, Detection and Suppression

    NASA Technical Reports Server (NTRS)

    Ruff, Gary A.

    2004-01-01

    In mid-1999, the Space and Life Sciences Directorate at Johnson Space Center was challenged to develop a new paradigm for NASA human life sciences: space medicine, space biomedical research and countermeasures, advanced human support technology. A new thrust - Bioastronautics - was formulated with a budget augmentation request. The objective are: expanded extramural community participation through the National Space Biomedical Research Institute, initiated the detailed planning and implementation of Bioastronautics, an integrated approach to ensure healthy and safe human space travel, assist in the solution of earth-based problems.

  13. Firing of antagonist small-diameter muscle afferents reduces voluntary activation and torque of elbow flexors.

    PubMed

    Kennedy, David S; McNeil, Chris J; Gandevia, Simon C; Taylor, Janet L

    2013-07-15

    During muscle fatigue, firing of small-diameter muscle afferents can decrease voluntary activation of the fatigued muscle. However, these afferents may have a more widespread effect on other muscles in the exercising limb. We examined if the firing of fatigue-sensitive afferents from elbow extensor muscles in the same arm reduces torque production and voluntary activation of elbow flexors. In nine subjects we examined voluntary activation of elbow flexors by measuring changes in superimposed twitches evoked by transcranial magnetic stimulation of the motor cortex during brief (2-3 s) maximal voluntary contractions (MVC). Inflation of a blood pressure cuff following a 2-min sustained MVC blocked blood flow to the fatigued muscle and maintained firing of small-diameter afferents. After a fatiguing elbow flexion contraction, maximal flexion torque was lower (26.0 ± 4.4% versus 67.9 ± 5.2% of initial maximal torque; means ± s.d.; P < 0.001) and superimposed twitches were larger (4.1 ± 1.1% versus 1.8 ± 0.2% ongoing MVC, P = 0.01) with than without ischaemia. After a fatiguing elbow extensor contraction, maximal flexion torque was also reduced (82.2 ± 4.9% versus 91.4 ± 2.3% of initial maximal torque; P = 0.007), superimposed twitches were larger (2.7 ± 0.7% versus 1.3 ± 0.2% ongoing MVC; P = 0.02) and voluntary activation lower (81.6 ± 8.2% versus 95.5 ± 6.9%; P = 0.04) with than without ischaemia. After a fatiguing contraction, voluntary drive to the fatigued muscles is reduced with continued input from small-diameter muscle afferents. Furthermore, fatigue of the elbow extensor muscles decreases voluntary drive to unfatigued elbow flexors of the same arm. Therefore, firing of small-diameter muscle afferents from one muscle can affect voluntary activation and hence torque generation of another muscle in the same limb. PMID:23652589

  14. PML suppresses oncogenic transformation of NIH/3T3 cells by activated neu

    PubMed Central

    1995-01-01

    The chromosomal translocation t(15;17)(q22;q12) is a consistent feature of acute promyelocytic leukemia (APL) that results in the disruption of genes for the zinc finger transcription factor PML and the retinoic acid receptor alpha (RAR alpha). We have previously shown that PML is a growth suppressor and is able to suppress transformation of NIH/3T3 by activated neu oncogene. In the study presented here, the full-length PML cDNA was transfected into B104-1-1 cells (NIH/3T3 cells transformed by the activated neu oncogene) by retrovirally mediated gene transfer. We found that expression of PML could reverse phenotypes of B104-1-1 including morphology, contact-limiting properties, and growth rate in both transient-expression and stable transfectants. We also demonstrated that PML is able to suppress clonogenicity of B104-1-1 in soft agar assay and tumorigenicity in nude mice. These results strongly support our previous finding that PML is a transformation or growth suppressor. Our results further demonstrate that expression of PML in B104-1-1 cells has little effect on cell cycle distribution. Western blot analysis demonstrated that suppression of neu expression in B104-1- 1 by PML was insignificant in the transient transfection experiment but significant in the PML stable transfectants. This study suggests that PML may suppress neu expression and block signaling events associated with activated neu. This study supports our hypothesis that disruption of the normal function of PML, a growth or transformation suppressor, is a critical event in APL leukomogenesis. PMID:7759992

  15. GBF-dependent family genes morphologically suppress the partially active Dictyostelium STATa strain.

    PubMed

    Shimada, Nao; Kanno-Tanabe, Naoko; Minemura, Kakeru; Kawata, Takefumi

    2008-02-01

    Transcription factor Dd-STATa, a functional Dictyostelium homologue of metazoan signal transducers and activators of transcription proteins, is necessary for culmination during development. We have isolated more than 18 putative multicopy suppressors of Dd-STATa using genetic screening. One was hssA gene, whose expression is known to be G-box-binding-factor-dependent and which was specific to prestalk A (pstA) cells, where Dd-STATa is activated. Also, hssA mRNA was expressed in pstA cells in the Dd-STATa-null mutant. At least 40 hssA-related genes are present in the genome and constitute a multigene family. The tagged HssA protein was translated; hssA encodes an unusually high-glycine-serine-rich small protein (8.37 kDa), which has strong homology to previously reported cyclic-adenosine-monophosphate-inducible 2C and 7E proteins. Overexpression of hssA mRNA as well as frame-shifted versions of hssA RNA suppressed the phenotype of the partially active Dd-STATa strain, suggesting that translation is not necessary for suppression. Although overexpression of prespore-specific genes among the family did not suppress the parental phenotype, prestalk-specific family members did. Although overexpression of the hssA did not revert the expression of Dd-STATa target genes, and although its suppression mechanism remains unknown, morphological reversion implies functional relationships between Dd-STATa and hssA.

  16. Technology Development for Fire Safety in Exploration Spacecraft and Habitats

    NASA Technical Reports Server (NTRS)

    Ruff, Gary A.; Urban, David L.

    2007-01-01

    Fire during an exploration mission far from Earth is a particularly critical risk for exploration vehicles and habitats. The Fire Prevention, Detection, and Suppression (FPDS) project is part of the Exploration Technology Development Program (ETDP) and has the goal to enhance crew health and safety on exploration missions by reducing the likelihood of a fire, or, if one does occur, minimizing the risk to the mission, crew, or system. Within the past year, the FPDS project has been formalized within the ETDP structure and has seen significant progress on its tasks in fire prevention, detection, and suppression. As requirements for Constellation vehicles and, specifically, the CEV have developed, the need for the FPDS technologies has become more apparent and we continue to make strides to infuse them into the Constellation architecture. This paper describes the current structure of the project within the ETDP and summarizes the significant programmatic activities. Major technical accomplishments are identified as are activities planned for FY07.

  17. Technology Development for Fire Safety in Exploration Spacecraft and Habitats

    NASA Technical Reports Server (NTRS)

    Ruff, Gary A.; Urban, David L.

    2006-01-01

    Fire during an exploration mission far from Earth is a particularly critical risk for exploration vehicles and habitats. The Fire Prevention, Detection, and Suppression (FPDS) project is part of the Exploration Technology Development Program (ETDP) and has the goal to enhance crew health and safety on exploration missions by reducing the likelihood of a fire, or, if one does occur, minimizing the risk to the mission, crew, or system. Within the past year, the FPDS project has been formalized within the ETDP structure and has seen significant progress on its tasks in fire prevention, detection, and suppression. As requirements for Constellation vehicles and, specifically, the CEV have developed, the need for the FPDS technologies has become more apparent and we continue to make strides to infuse them into the Constellation architecture. This paper describes the current structure of the project within the ETDP and summarizes the significant programmatic activities. Major technical accomplishments are identified as are activities planned for FY07.

  18. Fire Protection Research Program at Sandia National Laboratories

    SciTech Connect

    Klamerus, L. J.

    1980-01-01

    Sandia National Laboratories is executing a program for the Nuclear Regulatory Commission to provide data needed for confirmation of the suitability of current design standards and regulatory guides for fire protection and control in water reactor power plants. This paper summarizes the activities of this ongoing program through October 1980. Characterization of electrically initiated fires revealed a margin of safety in the separation criteria of Regulatory Guide 1.75 for such fires in IEEE-383 qualified cable. However, tests confirmed that these guidelines and standards are not sufficient, in themselves, to protect against exposure fires. This paper describes both small and full scale tests to assess the adequacy of fire retardant coatings and full scale tests on fire shields to determine their effectiveness. It also describes full scale tests to determine the effects of walls and ceilings on fire propagation between cable trays. Some small-scale scoping tests have been conducted to investigate the effects of varying the furnace pressure on cable penetration performance in the ASTM-E-119 Fire Test. The Sandia Fire Research Facility has been completed and a series of tests have been run to assess the effectiveness of Halon-1301 as a suppression system in extinguishing deep-seated cable-tray fires. It was found that given sufficient soak times Halon systems are effective in extinguishing such fires.

  19. Physicochemically and pharmacokinetically stable nonapeptide KISS1 receptor agonists with highly potent testosterone-suppressive activity.

    PubMed

    Asami, Taiji; Nishizawa, Naoki; Matsui, Hisanori; Takatsu, Yoshihiro; Suzuki, Atsuko; Kiba, Atsushi; Terada, Michiko; Nishibori, Kimiko; Nakayama, Masaharu; Ban, Junko; Matsumoto, Shin-ichi; Tarui, Naoki; Ikeda, Yukihiro; Yamaguchi, Masashi; Kusaka, Masami; Ohtaki, Tetsuya; Kitada, Chieko

    2014-07-24

    Modifications of metastin(45-54) produced peptide analogues with higher metabolic stability than metastin(45-54). N-terminally truncated nonapeptide 4 ([D-Tyr46,D-Pya(4)47,azaGly51,Arg(Me)53]metastin(46-54)) is a representative compound with both potent agonistic activity and metabolic stability. Although 4 had more potent testosterone-suppressant activity than metastin, it possessed physicochemical instability at pH 7 and insufficient in vivo activity. Instability at pH 7 was dependent upon Asn48 and Ser49; substitution of Ser49 with Thr49 reduced this instability and maintained KISS1 receptor agonistic activity. Furthermore, [D-Tyr46,D-Trp47,Thr49,azaGly51,Arg(Me)53,Trp54]metastin(46-54) (14) showed 2-fold greater [Ca2+]i-mobilizing activity than metastin(45-54) and an apparent increase in physicochemical stability. N-terminal acetylation of 14 resulted in the most potent analogue, 22 (Ac-[D-Tyr46,D-Trp47,Thr49,azaGly51,Arg(Me)53,Trp54]metastin(46-54)). With continuous administration, 22 possessed 10-50-fold more potent testosterone-suppressive activity in rats than 4. These results suggested that a controlled release of short-length KISS1 receptor agonists can suppress the hypothalamic-pituitary-gonadal axis and reduce testosterone levels. Compound 22 was selected for further preclinical evaluation for hormone-dependent diseases.

  20. Tumor Suppressive Function of p21-activated Kinase 6 in Hepatocellular Carcinoma.

    PubMed

    Liu, Weisi; Liu, Yidong; Liu, Haiou; Zhang, Weijuan; Fu, Qiang; Xu, Jiejie; Gu, Jianxin

    2015-11-20

    Our previous studies identified the oncogenic role of p21-activated kinase 1 (PAK1) in hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC). Contrarily, PAK6 was found to predict a favorable prognosis in RCC patients. Nevertheless, the ambiguous tumor suppressive function of PAK6 in hepatocarcinogenesis remains obscure. Herein, decreased PAK6 expression was found to be associated with tumor node metastasis stage progression and unfavorable overall survival in HCC patients. Additionally, overexpression and silence of PAK6 experiments showed that PAK6 inhibited xenografted tumor growth in vivo, and restricted cell proliferation, colony formation, migration, and invasion and promoted cell apoptosis and anoikis in vitro. Moreover, overexpression of kinase dead and nuclear localization signal deletion mutants of PAK6 experiments indicated the tumor suppressive function of PAK6 was partially dependent on its kinase activity and nuclear translocation. Furthermore, gain or loss of function in polycomb repressive complex 2 (PRC2) components, including EZH2, SUZ12, and EED, elucidated epigenetic control of H3K27me3-arbitrated PAK6 down-regulation in hepatoma cells. More importantly, negative correlation between PAK6 and EZH2 expression was observed in hepatoma tissues from HCC patients. These data identified the tumor suppressive role and potential underlying mechanism of PAK6 in hepatocarcinogenesis.

  1. Cilnidipine but not amlodipine suppresses sympathetic activation elicited by isometric exercise in hypertensive patients.

    PubMed

    Koike, Yumi; Kawabe, Tetsuya; Nishihara, Kanami; Iwane, Naomi; Hano, Takuzo

    2015-01-01

    Pupillometry was used to evaluate the effects of the calcium channel blockers cilnidipine (CL) and amlodipine (AM) on changes in autonomic nervous activity induced by isometric exercise in patients with hypertension. After handgrip exercise, the velocity of miosis increased in both the CL and AM groups. However, the velocity of mydriasis increased in only the AM group. Velocity slopes of miosis and mydriasis were smaller in the CL group than in the AM group. The low-to-high frequency ratio obtained from pulse wave analysis increased in only the AM group. Sympathetic activation elicited by isometric exercise was suppressed more effectively by CL than by AM. PMID:25977982

  2. Flutter suppression control law synthesis for the active flexible wing model

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek; Perry, Boyd, III; Noll, Thomas E.

    1989-01-01

    The Active Flexible Wing Project is a collaborative effort between the NASA Langley Research Center and Rockwell International. The objectives are the validation of methodologies associated with mathematical modeling, flutter suppression control law development and digital implementation of the control system for application to flexible aircraft. A flutter suppression control law synthesis for this project is described. The state-space mathematical model used for the synthesis included ten flexible modes, four control surface modes and rational function approximation of the doublet-lattice unsteady aerodynamics. The design steps involved developing the full-order optimal control laws, reducing the order of the control law, and optimizing the reduced-order control law in both the continuous and the discrete domains to minimize stochastic response. System robustness was improved using singular value constraints. An 8th order robust control law was designed to increase the symmetric flutter dynamic pressure by 100 percent. Preliminary results are provided and experiences gained are discussed.

  3. Flutter suppression control law synthesis for the Active Flexible Wing model

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek; Perry, Boyd, III; Noll, Thomas E.

    1989-01-01

    The Active Flexible Wing Project is a collaborative effort between the NASA Langley Research Center and Rockwell International. The objectives are the validation of methodologies associated with mathematical modeling, flutter suppression control law development and digital implementation of the control system for application to flexible aircraft. A flutter suppression control law synthesis for this project is described. The state-space mathematical model used for the synthesis included ten flexible modes, four control surface modes and rational function approximation of the doublet-lattice unsteady aerodynamics. The design steps involved developing the full-order optimal control laws, reducing the order of the control law, and optimizing the reduced-order control law in both the continuous and the discrete domains to minimize stochastic response. System robustness was improved using singular value constraints. An 8th order robust control law was designed to increase the symmetric flutter dynamic pressure by 100 percent. Preliminary results are provided and experiences gained are discussed.

  4. USP10 antagonizes c-Myc transcriptional activation through SIRT6 stabilization to suppress tumor formation.

    PubMed

    Lin, Zhenghong; Yang, Heeyoung; Tan, Can; Li, Jinping; Liu, Zhaojian; Quan, Qiu; Kong, Sinyi; Ye, Junsheng; Gao, Beixue; Fang, Deyu

    2013-12-26

    The reduced protein expression of SIRT6 tumor suppressor is involved in tumorigenesis. The molecular mechanisms underlying SIRT6 protein downregulation in human cancers remain unknown. Using a proteomic approach, we have identified the ubiquitin-specific peptidase USP10, another tumor suppressor, as one of the SIRT6-interacting proteins. USP10 suppresses SIRT6 ubiquitination to protect SIRT6 from proteasomal degradation. USP10 antagonizes the transcriptional activity of the c-Myc oncogene through SIRT6, as well as p53, to inhibit cell-cycle progression, cancer cell growth, and tumor formation. To support this conclusion, we detected significant reductions in both USP10 and SIRT6 protein expression in human colon cancers. Our study discovered crosstalk between two tumor-suppressive genes in regulating cell-cycle progression and proliferation and showed that dysregulated USP10 function promotes tumorigenesis through SIRT6 degradation.

  5. Climate change, fire management, and ecological services in the southwestern US

    USGS Publications Warehouse

    Hurteau, Matthew D.; Bradford, John B.; Fulé, Peter Z.; Taylor, Alan H.; Martin, Katherine L.

    2013-01-01

    The diverse forest types of the southwestern US are inseparable from fire. Across climate zones in California, Nevada, Arizona, and New Mexico, fire suppression has left many forest types out of sync with their historic fire regimes. As a result, high fuel loads place them at risk of severe fire, particularly as fire activity increases due to climate change. A legacy of fire exclusion coupled with a warming climate has led to increasingly large and severe wildfires in many southwest forest types. Climate change projections include an extended fire season length due to earlier snowmelt and a general drying trend due to rising temperatures. This suggests the future will be warmer and drier regardless of changes in precipitation. Hotter, drier conditions are likely to increase forest flammability, at least initially. Changes in climate alone have the potential to alter the distribution of vegetation types within the region, and climate-driven shifts in vegetation distribution are likely to be accelerated when coupled with stand-replacing fire. Regardless of the rate of change, the interaction of climate and fire and their effects on Southwest ecosystems will alter the provisioning of ecosystem services, including carbon storage and biodiversity. Interactions between climate, fire, and vegetation growth provide a source of great uncertainty in projecting future fire activity in the region, as post-fire forest recovery is strongly influenced by climate and subsequent fire frequency. Severe fire can be mitigated with fuels management including prescribed fire, thinning, and wildfire management, but new strategies are needed to ensure the effectiveness of treatments across landscapes. We review the current understanding of the relationship between fire and climate in the Southwest, both historical and projected. We then discuss the potential implications of climate change for fire management and examine the potential effects of climate change and fire on ecosystem

  6. Holocene fire dynamics in Fennoscandia

    NASA Astrophysics Data System (ADS)

    Clear, Jennifer; Seppa, Heikki; Kuosmanen, Niina; Molinari, Chiara; Lehsten, Veiko; Allen, Katherine; Bradshaw, Richard

    2015-04-01

    Prescribed burning is advocated in Fennoscandia to promote regeneration and to encourage biodiversity. This method of forest management is based on the perception that fire was much more frequent in the recent past and over a century of active fire suppression has created a boreal forest ecosystem almost free of natural fire. The absence of fire is thought to have contributed to the widespread dominance of Picea abies (Norway spruce) with the successive spruce dominated forest further reducing fire ignition potential. However, humans have altered the natural fire dynamics of Fennoscandia since the early- to mid-Holocene and disentangling the anthropogenic driven fire dynamics from the natural fire dynamics is challenging. Through palaeoecology and sedimentary charcoal deposits we are able to explore the Holocene spatial and temporal variability and changing drivers of fire and vegetation dynamics in Fennoscandia. At the local-scale, two forest hollow environments (<20km apart) were analysed for high resolution macroscopic charcoal and pollen analysis and their fire and vegetation history are compared to identify unique and mutual changes in disturbance history. Pollen derived quantitative reconstruction of vegetation at both the local- and regional-scale identifies local-scale disturbance dynamics and large-scale ecosystem response. Spatio-temporal heterogeneity and variability in biomass burning is explored throughout Fennoscandia and Denmark to identify the changing drives of fire dynamics throughout the Holocene. Palaeo-vegetation reconstructions are compared to process-based, climate driven dynamic vegetation model output to test the significance of fire frequency as a driver of vegetation composition and dynamics. Early-Holocene fire regimes in Fennoscandia are driven by natural climate variations and fuel availability. The establishment and spread of Norway spruce is driven by an increase in continentality of climate, but local natural and anthropogenic

  7. Functional clonal deletion versus active suppression in transplantation tolerance induced by total-lymphoid irradiation

    SciTech Connect

    Morecki, S.; Leshem, B.; Weigensberg, M.; Bar, S.; Slavin, S.

    1985-08-01

    Transplantation tolerance and stable chimerism were established in adult mice conditioned with a short course of total-lymphoid irradiation (TLI) followed by infusion of 30 X 10(6) allogeneic bone marrow cells. Spleen cells of tolerant mice could not exert a proliferative or cytotoxic response against host-type cells in vitro and were unable to induce graft-versus-host reaction in secondary host-type recipients. The degree of suppression assessed by coculturing tolerant splenocytes in vitro in the one-way mixed lymphocyte reaction was quite variable--and, in some cases, was not at all demonstrable, although tolerance was clearly maintained. Suppression, when apparent, could not be ascribed to T lymphocytes. Suppressor cells were found to bind soybean agglutinin and could be separated from the nonsuppressive cells by means of this lectin. Dissociation of the suppressive population (SBA+ cells) from that which is normally alloreactive (SBA- cells) resulted in a suppressor cell-depleted fraction that was still unable to respond to host-type cells but regained reactivity to unrelated cells. Limiting dilution analysis of chimeric splenocytes revealed markedly reduced frequencies of cytotoxic T lymphocyte precursors (CTL-P) directed against host-type cells, as compared with normal splenocytes reacting against the same target cells. This difference was accentuated when these cells were sensitized to host-type target cells prior to plating in limiting dilution cultures. In 1:1 mixing experiments of normal and chimeric splenocytes, there was no evidence of any in vitro suppressive activity to account for hyporeactivity of chimeric cells against host-type cells. Thus, maintenance of TLI-induced tolerance seemed not to be mediated primarily through an active suppressor cell mechanism.

  8. Flutter suppression and gust alleviation using active controls - Review of developments and applications based on the aerodynamic energy concept

    NASA Technical Reports Server (NTRS)

    Nissim, E.

    1978-01-01

    The state of the art of the aerodynamic energy concept, involving the use of active controls for flutter suppression, is reviewed. Applications of the concept include the suppression of external-store flutter of three different configurations of the YF-17 flutter model using a single trailing edge control surface activated by a single fixed-gain control law. Consideration is also given to some initial results concerning the flutter suppression of the 1/20 scale low speed wind-tunnel model of the Boeing 2707-300 supersonic transport using an activated trailing edge control surface.

  9. Myxoma virus suppresses proliferation of activated T lymphocytes yet permits oncolytic virus transfer to cancer cells

    PubMed Central

    Villa, Nancy Y.; Wasserfall, Clive H.; Meacham, Amy M.; Wise, Elizabeth; Chan, Winnie; Wingard, John R.; McFadden, Grant

    2015-01-01

    Allogeneic hematopoietic cell transplant (allo-HCT) can be curative for certain hematologic malignancies, but the risk of graft-versus-host disease (GVHD) is a major limitation for wider application. Ideally, strategies to improve allo-HCT would involve suppression of T lymphocytes that drive GVHD while sparing those that mediate graft-versus-malignancy (GVM). Recently, using a xenograft model, we serendipitously discovered that myxoma virus (MYXV) prevented GVHD while permitting GVM. In this study, we show that MYXV binds to resting, primary human T lymphocytes but will only proceed into active virus infection after the T cells receive activation signals. MYXV-infected T lymphocytes exhibited impaired proliferation after activation with reduced expression of interferon-γ, interleukin-2 (IL-2), and soluble IL-2Rα, but did not affect expression of IL-4 and IL-10. MYXV suppressed T-cell proliferation in 2 patterns (full vs partial) depending on the donor. In terms of GVM, we show that MYXV-infected activated human T lymphocytes effectively deliver live oncolytic virus to human multiple myeloma cells, thus augmenting GVM by transfer of active oncolytic virus to residual cancer cells. Given this dual capacity of reducing GVHD plus increasing the antineoplastic effectiveness of GVM, ex vivo virotherapy with MYXV may be a promising clinical adjunct to allo-HCT regimens. PMID:25904246

  10. Antiosteoclastic activity of milk thistle extract after ovariectomy to suppress estrogen deficiency-induced osteoporosis.

    PubMed

    Kim, Jung-Lye; Kim, Yun-Ho; Kang, Min-Kyung; Gong, Ju-Hyun; Han, Seoung-Jun; Kang, Young-Hee

    2013-01-01

    Bone integrity abnormality and imbalance between bone formation by osteoblasts and bone resorption by osteoclasts are known to result in metabolic bone diseases such as osteoporosis. Silymarin-rich milk thistle extract (MTE) and its component silibinin enhanced alkaline phosphatase activity of osteoblasts but reduced tartrate-resistant acid phosphatase (TRAP) activity of osteoclasts. The osteoprotective effects of MTE were comparable to those of estrogenic isoflavone. Low-dose combination of MTE and isoflavone had a pharmacological synergy that may be useful for osteogenic activity. This study attempted to reveal the suppressive effects of MTE on bone loss. C57BL/6 female mice were ovariectomized (OVX) as a model for postmenopausal osteopenia and orally administered 10 mg/kg MTE or silibinin for 8 weeks. The sham-operated mice served as estrogen controls. The treatment of ovariectomized mice with nontoxic MTE and silibinin improved femoral bone mineral density and serum receptor activator of nuclear factor- κB ligand/osteoprotegerin ratio, an index of osteoclastogenic stimulus. In addition, the administration of MTE or silibinin inhibited femoral bone loss induced by ovariectomy and suppressed femoral TRAP activity and cathepsin K induction responsible for osteoclastogenesis and bone resorption. Collectively, oral dosage of MTE containing silibinin in the preclinical setting is effective in preventing estrogen deficiency-induced bone loss.

  11. Ion channel TRPV1-dependent activation of PTP1B suppresses EGFR-associated intestinal tumorigenesis

    PubMed Central

    de Jong, Petrus R.; Takahashi, Naoki; Harris, Alexandra R.; Lee, Jihyung; Bertin, Samuel; Jeffries, James; Jung, Michael; Duong, Jen; Triano, Amy I.; Lee, Jongdae; Niv, Yaron; Herdman, David S.; Taniguchi, Koji; Kim, Chang-Whan; Dong, Hui; Eckmann, Lars; Stanford, Stephanie M.; Bottini, Nunzio; Corr, Maripat; Raz, Eyal

    2014-01-01

    The intestinal epithelium has a high rate of turnover, and dysregulation of pathways that regulate regeneration can lead to tumor development; however, the negative regulators of oncogenic events in the intestinal epithelium are not fully understood. Here we identified a feedback loop between the epidermal growth factor receptor (EGFR), a known mediator of proliferation, and the transient receptor potential cation channel, subfamily V, member 1 (TRPV1), in intestinal epithelial cells (IECs). We found that TRPV1 was expressed by IECs and was intrinsically activated upon EGFR stimulation. Subsequently, TRPV1 activation inhibited EGFR-induced epithelial cell proliferation via activation of Ca2+/calpain and resulting activation of protein tyrosine phosphatase 1B (PTP1B). In a murine model of multiple intestinal neoplasia (ApcMin/+ mice), TRPV1 deficiency increased adenoma formation, and treatment of these animals with an EGFR kinase inhibitor reversed protumorigenic phenotypes, supporting a functional association between TRPV1 and EGFR signaling in IECs. Administration of a TRPV1 agonist suppressed intestinal tumorigenesis in ApcMin/+ mice, similar to — as well as in conjunction with — a cyclooxygenase-2 (COX-2) inhibitor, which suggests that targeting both TRPV1 and COX-2 has potential as a therapeutic approach for tumor prevention. Our findings implicate TRPV1 as a regulator of growth factor signaling in the intestinal epithelium through activation of PTP1B and subsequent suppression of intestinal tumorigenesis. PMID:25083990

  12. Fine organic particle, formaldehyde, acetaldehyde concentrations under and after the influence of fire activity in the atmosphere of Riverside, California.

    PubMed

    Na, Kwangsam; Cocker, David R

    2008-09-01

    Concentrations of gas-phase organic carbons (formaldehyde (HCHO) and acetaldehyde (CH(3)CHO)) and fine particle-phase carbons (organic carbon (OC) and elemental carbon (EC)) were measured under and after the influence of fire activity in southern California. The measurement was conducted after the start of the wildfire activities from October 27 through November 6, 2003 at a site in Riverside, southern California. Under the influence of the fire activities, HCHO, CH(3)CHO and EC concentrations were found to be over two times as high as those after the fire activities ended. The total lifetime cancer risk estimated by HCHO and CH(3)CHO concentrations measured was significantly higher under the influence of the wildfire activities than that after the activities ended. OC showed a larger difference in concentrations between the two event periods as compared with gas-phase organic carbons and EC. OC/EC ratios ranged from 3.7 to 12.5 during the study period with the highest OC/EC ratio observed when the study area was under the influence of the fire activities. Correlation analysis and multiple linear regressions between OC/EC concentrations and visibility were performed. It was found that the visibility was even worse under the influence of fire activity as compared to the period after fire activity ended. EC was a stronger contributor to the visibility reduction compared to OC. The influence of air mass pathways on HCHO, CH(3)CHO, OC, and EC concentrations during the wildfire activities was addressed using a backward trajectory model developed by NOAA.

  13. Burst firing in gonadotrophin-releasing hormone neurones does not require ionotrophic GABA or glutamate receptor activation.

    PubMed

    Lee, K; Liu, X; Herbison, A E

    2012-12-01

    Burst firing is a feature of many neuroendocrine cell types, including the hypothalamic gonadotrophin-releasing hormone (GnRH) neurones that control fertility. The role of intrinsic and extrinsic influences in generating GnRH neurone burst firing is presently unclear. In the present study, we investigated the role of fast amino acid transmission in burst firing by examining the effects of receptor antagonists on bursting displayed by green fluorescent protein GnRH neurones in sagittal brain slices prepared from adult male mice. Blockade of AMPA and NMDA glutamate receptors with a cocktail of CNQX and AP5 was found to have no effects on burst firing in GnRH neurones. The frequency of bursts, dynamics of individual bursts, or percentage of firing clustered in bursts was not altered. Similarly, GABA(A) receptor antagonists bicuculline and picrotoxin had no effects upon burst firing in GnRH neurones. To examine the importance of both glutamate and GABA ionotrophic signalling, a cocktail including picrotoxin, CNQX and AP5 was used but, again, this was found to have no effects on GnRH neurone burst firing. To further question the impact of endogenous amino acid release on burst firing, electrical activation of anteroventral periventricular nuclei GABA/glutamate inputs to GnRH neurones was undertaken and found to have no impact on burst firing. Taken together, these observations indicate that bursting in GnRH neurones is not dependent upon acute ionotrophic GABA and glutamate signalling and suggest that extrinsic inputs to GnRH neurones acting through AMPA, NMDA and GABA(A) receptors are unlikely to be required for burst initiation in these cells.

  14. MODELING VENTILATION SYSTEM RESPONSE TO FIRE

    SciTech Connect

    Coutts, D

    2007-04-17

    Fires in facilities containing nuclear material have the potential to transport radioactive contamination throughout buildings and may lead to widespread downwind dispersal threatening both worker and public safety. Development and implementation of control strategies capable of providing adequate protection from fire requires realistic characterization of ventilation system response which, in turn, depends on an understanding of fire development timing and suppression system response. This paper discusses work in which published HEPA filter data was combined with CFAST fire modeling predictions to evaluate protective control strategies for a hypothetical DOE non-reactor nuclear facility. The purpose of this effort was to evaluate when safety significant active ventilation coupled with safety class passive ventilation might be a viable control strategy.

  15. Assessment of the Utility of the Advanced Himawari Imager to Detect Active Fire Over Australia

    NASA Astrophysics Data System (ADS)

    Hally, B.; Wallace, L.; Reinke, K.; Jones, S.

    2016-06-01

    Wildfire detection and attribution is an issue of importance due to the socio-economic impact of fires in Australia. Early detection of fires allows emergency response agencies to make informed decisions in order to minimise loss of life and protect strategic resources in threatened areas. Until recently, the ability of land management authorities to accurately assess fire through satellite observations of Australia was limited to those made by polar orbiting satellites. The launch of the Japan Meteorological Agency (JMA) Himawari-8 satellite, with the 16-band Advanced Himawari Imager (AHI-8) onboard, in October 2014 presents a significant opportunity to improve the timeliness of satellite fire detection across Australia. The near real-time availability of images, at a ten minute frequency, may also provide contextual information (background temperature) leading to improvements in the assessment of fire characteristics. This paper investigates the application of the high frequency observation data supplied by this sensor for fire detection and attribution. As AHI-8 is a new sensor we have performed an analysis of the noise characteristics of the two spectral bands used for fire attribution across various land use types which occur in Australia. Using this information we have adapted existing algorithms, based upon least squares error minimisation and Kalman filtering, which utilise high frequency observations of surface temperature to detect and attribute fire. The fire detection and attribution information provided by these algorithms is then compared to existing satellite based fire products as well as in-situ information provided by land management agencies. These comparisons were made Australia-wide for an entire fire season - including many significant fire events (wildfires and prescribed burns). Preliminary detection results suggest that these methods for fire detection perform comparably to existing fire products and fire incident reporting from relevant

  16. Withaferin A inhibits matrix metalloproteinase-9 activity by suppressing the Akt signaling pathway.

    PubMed

    Lee, Dae Hyung; Lim, In-Hye; Sung, Eon-Gi; Kim, Joo-Young; Song, In-Hwan; Park, Yoon Ki; Lee, Tae-Jin

    2013-08-01

    Withaferin A (Wit A), a steroidal lactone isolated from Withania somnifera, exhibits anti-inflammatory, immuno-modulatory and anti-angiogenic properties and antitumor activities. In the present study, we investigated the effects of Wit A on protease-mediated invasiveness of the human metastatic cancer cell lines Caski and SK-Hep1. We found that treatment with Wit A resulted in marked inhibition of the TGF‑β‑induced increase in expression and activity of matrix metalloproteinase (MMP)‑9 in Caski cell line. These effects of Wit A were dose-dependent and showed a correlation with suppression of MMP‑9 mRNA expression levels. Treatment with Wit A resulted in an ~1.6-fold induction of MMP-9 promoter activity, which was also suppressed by treatment with Wit A in Caski cells. We found that treatment with Wit A resulted in inhibition of TGF‑β‑induced phosphorylation of Akt, which was involved in the downregulation of expression of MMP-9 at the protein level. Introduction with constitutively active (CA)‑Akt resulted in a partial increase in the secretion of TGF-β-induced MMP-9 blocked by treatment with Wit A in Caski cells. According to these results, Wit A may inhibit the invasive and migratory abilities of Caski cells through a reduction in MMP-9 expression through suppression of the pAkt signaling pathway. These findings indicate that use of Wit A may be an effective strategy for control of metastasis and invasiveness of tumors.

  17. Ketamine suppresses intestinal NF-kappa B activation and proinflammatory cytokine in endotoxic rats

    PubMed Central

    Sun, Jie; Wang, Xiao-Dong; Liu, Hong; Xu, Jian-Guo

    2004-01-01

    AIM: To investigate the protective effect of ketamine on the endotoxin-induced proinflammatory cytokines and NF-kappa B activation in the intestine. METHODS: Adult male Wistar rats were randomly divided into 6 groups: (a) normal saline control, (b) challenged with endotoxin (5 mg/kg) and treated by saline, (c) challenged with endotoxin (5 mg/kg) and treated by ketamine (0.5 mg/kg), (d) challenged with endotoxin (5 mg/kg) and treated by ketamine (5 mg/kg ), (e) challenged with endotoxin (5 mg/kg) and treated by ketamine (50 mg/kg), and (f) saline injected and treated by ketamine (50 mg/kg). After 1, 4 or 6 h, TNF-α and IL-6 mRNA were investigated in the tissues of the intestine (jejunum) by RT-PCR. TNF-α and IL-6 were measured by ELISA. We used electrophoretic mobility shift assay (EMSA) to investigate NF-kappa B activity in the intestine. RESULTS: NF-kappa B activity, the expression of TNF-α and IL-6 were enhanced in the intestine by endotoxin. Ketamine at a dose of 0.5 mg/kg could suppress endotoxin-induced TNF-α mRNA and protein elevation and inhibit NF-kappa B activation in the intestine. However the least dosage of ketamine to inhibit IL-6 was 5 mg/kg in our experiment. CONCLUSION: Ketamine can suppress endotoxin-induced production of proinflammatory cytokines such as TNF-α and IL-6 production in the intestine. This suppressive effect may act through inhibiting NF-kappa B. PMID:15052687

  18. Fatty Amines from Little Black Ants, Monomorium minimum, and Their Biological Activities Against Red Imported Fire Ants, Solenopsis invicta.

    PubMed

    Wang, Lei; Chen, Jian

    2015-08-01

    Red imported fire ants, Solenopsis invicta, are significant invasive pests. Certain native ant species can compete with S. invicta, such as the little black ant, Monomorium minimum. Defensive secretions may contribute to the competition capacity of native ants. The chemistry of ant defensive secretions in the genus Monomorium has been subjected to extensive research. The insecticidal alkaloids, 2,5-dialkyl-pyrrolidines and 2,5-dialkyl-pyrrolines have been reported to dominate the venom of M. minimum. In this study, analysis of defensive secretions of workers and queens of M. minimum revealed two primary amines, decylamine and dodecylamine. Neither amine has been reported previously from natural sources. Toxicity and digging suppression by these two amines against S. invicta were examined. Decylamine had higher toxicity to S. invicta workers than dodecylamine, a quicker knockdown effect, and suppressed the digging behavior of S. invicta workers at lower concentration. However, the amount of fatty amines in an individual ant was not enough to knockdown a fire ant or suppress its digging behavior. These amines most likely work in concert with other components in the chemical defense of M. minimum.

  19. The relationship between particulate pollution levels in Australian cities, meteorology, and landscape fire activity detected from MODIS hotspots.

    PubMed

    Price, Owen F; Williamson, Grant J; Henderson, Sarah B; Johnston, Fay; Bowman, David M J S

    2012-01-01

    Smoke from bushfires is an emerging issue for fire managers because of increasing evidence for its public health effects. Development of forecasting models to predict future pollution levels based on the relationship between bushfire activity and current pollution levels would be a useful management tool. As a first step, we use daily thermal anomalies detected by the MODIS Active Fire Product (referred to as "hotspots"), pollution concentrations, and meteorological data for the years 2002 to 2008, to examine the statistical relationship between fire activity in the landscapes and pollution levels around Perth and Sydney, two large Australian cities. Resultant models were statistically significant, but differed in their goodness of fit and the distance at which the strength of the relationship was strongest. For Sydney, a univariate model for hotspot activity within 100 km explained 24% of variation in pollution levels, and the best model including atmospheric variables explained 56% of variation. For Perth, the best radius was 400 km, explaining only 7% of variation, while the model including atmospheric variables explained 31% of the variation. Pollution was higher when the atmosphere was more stable and in the presence of on-shore winds, whereas there was no effect of wind blowing from the fires toward the pollution monitors. Our analysis shows there is a good prospect for developing region-specific forecasting tools combining hotspot fire activity with meteorological data.

  20. The Relationship between Particulate Pollution Levels in Australian Cities, Meteorology, and Landscape Fire Activity Detected from MODIS Hotspots

    PubMed Central

    Price, Owen F.; Williamson, Grant J.; Henderson, Sarah B.; Johnston, Fay; Bowman, David M. J. S.

    2012-01-01

    Smoke from bushfires is an emerging issue for fire managers because of increasing evidence for its public health effects. Development of forecasting models to predict future pollution levels based on the relationship between bushfire activity and current pollution levels would be a useful management tool. As a first step, we use daily thermal anomalies detected by the MODIS Active Fire Product (referred to as “hotspots”), pollution concentrations, and meteorological data for the years 2002 to 2008, to examine the statistical relationship between fire activity in the landscapes and pollution levels around Perth and Sydney, two large Australian cities. Resultant models were statistically significant, but differed in their goodness of fit and the distance at which the strength of the relationship was strongest. For Sydney, a univariate model for hotspot activity within 100 km explained 24% of variation in pollution levels, and the best model including atmospheric variables explained 56% of variation. For Perth, the best radius was 400 km, explaining only 7% of variation, while the model including atmospheric variables explained 31% of the variation. Pollution was higher when the atmosphere was more stable and in the presence of on-shore winds, whereas there was no effect of wind blowing from the fires toward the pollution monitors. Our analysis shows there is a good prospect for developing region-specific forecasting tools combining hotspot fire activity with meteorological data. PMID:23071788

  1. Melatonin suppresses hypoxia-induced migration of HUVECs via inhibition of ERK/Rac1 activation.

    PubMed

    Yang, Ling; Zheng, Jianchao; Xu, Rui; Zhang, Yujie; Gu, Luo; Dong, Jing; Zhu, Yichao; Zhou, Ruijue; Zheng, Lu; Zhang, Xiaoying; Du, Jun

    2014-01-01

    Melatonin, a naturally-occurring hormone, possesses antioxidant properties and ameliorates vascular endothelial dysfunction. In this study, we evaluate the impact of melatonin on the migratory capability of human umbilical vein endothelial cells (HUVECs) to hypoxia and further investigate whether ERK/Rac1 signaling is involved in this process. Here, we found that melatonin inhibited hypoxia-stimulated hypoxia-inducible factor-1α (HIF-1α) expression and cell migration in a dose-dependent manner. Mechanistically, melatonin inhibited Rac1 activation and suppressed the co-localized Rac1 and F-actin on the membrane of HUVECs under hypoxic condition. In addition, the blockade of Rac1 activation with ectopic expression of an inactive mutant form of Rac1-T17N suppressed HIF-1α expression and cell migration in response to hypoxia, as well, but constitutive activation of Rac1 mutant Rac1-V12 restored HIF-1α expression, preventing the inhibition of melatonin on cell migration. Furthermore, the anti-Rac1 effect of melatonin in HUVECs appeared to be associated with its inhibition of ERK phosphorylation, but not that of the PI3k/Akt signaling pathway. Taken together, our work indicates that melatonin exerts an anti-migratory effect on hypoxic HUVECs by blocking ERK/Rac1 activation and subsequent HIF-1α upregulation. PMID:25123138

  2. Nobiletin suppresses MMP-9 expression through modulation of p38 MAPK activity in human dermal fibrobalsts.

    PubMed

    Kim, Jin-Ju; Korm, Sovannarith; Kim, Won-Seok; Kim, Ok-Seon; Lee, Ji-Seon; Min, Hyung-Geun; Chin, Young-Won; Cha, Hyuk-Jin

    2014-01-01

    We aimed to identify a novel flavonoid from the in-house natural products to suppress matrix metalloproteases (MMPs), which is responsible for degradation of collagen and other extracellular matrix proteins. Total eight natural products were screened for identification of a novel MMP-9 suppressor using MMP-9 reporter system, where the prompt initial screening with multiple samples is readily examined. Among the extracts used in the present study, one extract (Citrus unshiu) was found active in this assay system. Furthermore, three representative flavonoids in this active extract of Citrus unshiu peel were tested in MMP-9 reporter system. Nobiletin (NB) of the tested flavonoids suppressed MMP-9 expression without cytotoxicity, which was validated by both real-time polymerase chain reaction (PCR) and zymography analyses. Sustained p38 mitogen activated protein kinase (MAPK) activity, closely associated with induction of MMP-9 under stress condition, was markedly reduced by NB treatment, which implies that modulation of p38MAPK by nobiletin is responsible for reduction of MMP9 expression. Hence, nobiletin, identified from MMP-9 reporter system based screening, may be further applied for the purpose of delaying collagen degradation in skin fibroblasts.

  3. Fear conditioning suppresses large-conductance calcium-activated potassium channels in lateral amygdala neurons.

    PubMed

    Sun, P; Zhang, Q; Zhang, Y; Wang, F; Wang, L; Yamamoto, R; Sugai, T; Kato, N

    2015-01-01

    It was previously shown that depression-like behavior is accompanied with suppression of the large-conductance calcium activated potassium (BK) channel in cingulate cortex pyramidal cells. To test whether BK channels are also involved in fear conditioning, we studied neuronal properties of amygdala principal cells in fear conditioned mice. After behavior, we made brain slices containing the amygdala, the structure critically relevant to fear memory. The resting membrane potential in lateral amygdala (LA) neurons obtained from fear conditioned mice (FC group) was more depolarized than in neurons from naïve controls. The frequencies of spikes evoked by current injections were higher in neurons from FC mice, demonstrating that excitability of LA neurons was elevated by fear conditioning. The depolarization in neurons from FC mice was shown to depend on BK channels by using the BK channel blocker charybdotoxin. Suppression of BK channels in LA neurons from the FC group was further confirmed on the basis of the spike width, since BK channels affect the descending phase of spikes. Spikes were broader in the FC group than those in the naïve control in a manner dependent on BK channels. Consistently, quantitative real-time PCR revealed a decreased expression of BK channel mRNA. The present findings suggest that emotional disorder manifested in the forms of fear conditioning is accompanied with BK channel suppression in the amygdala, the brain structure critical to this emotional disorder.

  4. Activation of the alphavirus spike protein is suppressed by bound E3.

    PubMed

    Sjöberg, Mathilda; Lindqvist, Birgitta; Garoff, Henrik

    2011-06-01

    Alphaviruses are taken up into the endosome of the cell, where acidic conditions activate the spikes for membrane fusion. This involves dissociation of the three E2-E1 heterodimers of the spike and E1 interaction with the target membrane as a homotrimer. The biosynthesis of the heterodimer as a pH-resistant p62-E1 precursor appeared to solve the problem of premature activation in the late and acidic parts of the biosynthetic transport pathway in the cell. However, p62 cleavage into E2 and E3 by furin occurs before the spike has left the acidic compartments, accentuating the problem. In this work, we used a furin-resistant Semliki Forest virus (SFV) mutant, SFV(SQL), to study the role of E3 in spike activation. The cleavage was reconstituted with proteinase K in vitro using free virus or spikes on SFV(SQL)-infected cells. We found that E3 association with the spikes was pH dependent, requiring acidic conditions, and that the bound E3 suppressed spike activation. This was shown in an in vitro spike activation assay monitoring E1 trimer formation with liposomes and a fusion-from-within assay with infected cells. Furthermore, the wild type, SFV(wt), was found to bind significant amounts of E3, especially if produced in dense cultures, which lowered the pH of the culture medium. This E3 also suppressed spike activation. The results suggest that furin-cleaved E3 continues to protect the spike from premature activation in acidic compartments of the cell and that its release in the neutral extracellular space primes the spike for low-pH activation.

  5. Mechanism of PTC124 activity in cell-based luciferase assays of nonsense codon suppression.

    PubMed

    Auld, Douglas S; Thorne, Natasha; Maguire, William F; Inglese, James

    2009-03-01

    High-throughput screening (HTS) assays used in drug discovery frequently use reporter enzymes such as firefly luciferase (FLuc) as indicators of target activity. An important caveat to consider, however, is that compounds can directly affect the reporter, leading to nonspecific but highly reproducible assay signal modulation. In rare cases, this activity appears counterintuitive; for example, some FLuc inhibitors, acting through posttranslational Fluc reporter stabilization, appear to activate gene expression. Previous efforts to characterize molecules that influence luciferase activity identified a subset of 3,5-diaryl-oxadiazole-containing compounds as FLuc inhibitors. Here, we evaluate a number of compounds with this structural motif for activity against FLuc. One such compound is PTC124 {3-[5-(2-fluorophenyl)-1,2,4-oxadiazol-3-yl]benzoic acid}, a molecule originally identified in a cell-based FLuc assay as having nonsense codon suppression activity [Welch EM, et al., Nature (2007) 447:87-91]. We find that the potency of FLuc inhibition for the tested compounds strictly correlates with their activity in a FLuc reporter cell-based nonsense codon assay, with PTC124 emerging as the most potent FLuc inhibitor (IC(50) = 7 +/- 1 nM). However, these compounds, including PTC124, fail to show nonsense codon suppression activity when Renilla reniformis luciferase (RLuc) is used as a reporter and are inactive against the RLuc enzyme. This suggests that the initial discovery of PTC124 may have been biased by its direct effect on the FLuc reporter, implicating firefly luciferase as a molecular target of PTC124. Our results demonstrate the value of understanding potential interactions between reporter enzymes and chemical compounds and emphasize the importance of implementing the appropriate control assays before interpreting HTS results.

  6. Defining global syndromes of fire and the relationship of these to biomes, climate and human activity

    NASA Astrophysics Data System (ADS)

    Lehmann, C.; Archibald, S.; Gomez-Dans, J.; Bradstock, R.

    2012-12-01

    Fire is a ubiquitous component of the Earth system that remains poorly understood. To date, global scale understanding of fire is limited largely to the annual extent of burning as detected by satellites. This is problematic because fire is multi-dimensional, and focus on individual metrics belies both the complexity and importance of fire within the Earth system. In an applied sense, the lack of a unified understanding of fire impedes estimation of GHG emissions or prediction of future fire regimes as a consequence of changing patterns of climate and land use. To address this we identified five key characteristics of fire regimes: size, frequency, intensity, season and extent. We combined new global datasets with existing datasets to examine cross-correlations among characteristics. We demonstrate that only certain combinations of fire characteristics are possible and this likely reflects fundamental energetic constraints derived from interactions between under-lying fuel types, climate and rates of re-growth post-fire. For example, very intense fires can only occur infrequently because a system requires a lengthy period to develop sufficient fuel to burn. Further, very cool fires only occur infrequently because fuels are not available to burn. Following, we applied a clustering algorithm to these data to determine whether we could identify syndromes of fire regimes. Pyromes, as global syndromes of fire are conceptually analogous to biomes (global syndromes of vegetation) where the extent of each pyrome is determined solely as a product of the fire characteristics themselves. A point of difference to biomes being that no one has previously attempted to quantify the global range of fire syndromes. We identified five pyromes, four of which we believe represent distinctions between crown, litter and grass-fuelled fires. The relationship of pyromes to biomes and climate are not deterministic as different biomes and climates may be represented within a single pyrome

  7. Dihydro-CDDO-trifluoroethyl amide suppresses inflammatory responses in macrophages via activation of Nrf2

    SciTech Connect

    Li, Bin; Abdalrahman, Akram; Lai, Yimu; Janicki, Joseph S.; Ward, Keith W.; Meyer, Colin J.; Wang, Xing Li; Tang, Dongqi; Cui, Taixing

    2014-02-21

    Highlights: • Dh404 suppresses the expression of a selected set of pro-inflammatory cytokines in inflamed macrophages via activating Nrf2. • Dh404 activates Nrf2 while keeping Keap1 function intact in macrophages. • Dh404 minimally regulates NF-κB pathway in macrophages. - Abstract: Nuclear factor erythroid 2-related factor (Nrf2) is the major regulator of cellular defenses against various pathological stresses in a variety of organ systems, thus Nrf2 has evolved to be an attractive drug target for the treatment and/or prevention of human disease. Several synthetic oleanolic triterpenoids including dihydro-CDDO-trifluoroethyl amide (dh404) appear to be potent activators of Nrf2 and exhibit chemopreventive promises in multiple disease models. While the pharmacological efficacy of Nrf2 activators may be dependent on the nature of Nrf2 activation in specific cell types of target organs, the precise role of Nrf2 in mediating biological effects of Nrf2 activating compounds in various cell types remains to be further explored. Herein we report a unique and Nrf2-dependent anti-inflammatory profile of dh404 in inflamed macrophages. In lipopolysaccharide (LPS)-inflamed RAW264.7 macrophages, dh404 dramatically suppressed the expression of pro-inflammatory cytokines including inducible nitric oxide synthase (iNOS), monocyte chemotactic protein-1 (MCP-1), and macrophage inflammatory protein-1 beta (MIP-1β), while minimally regulating the expression of interleulin-6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNFα). Dh404 potently activated Nrf2 signaling; however, it did not affect LPS-induced NF-κB activity. Dh404 did not interrupt the interaction of Nrf2 with its endogenous inhibitor Kelch-like ECH associating protein 1 (Keap1) in macrophages. Moreover, knockout of Nrf2 blocked the dh404-induced anti-inflammatory responses in LPS-inflamed macrophages. These results demonstrated that dh404 suppresses pro-inflammatory responses in macrophages via an activation

  8. Fire activity as a function of fire–weather seasonal severity and antecedent climate across spatial scales in southern Europe and Pacific western USA

    USGS Publications Warehouse

    Urbieta, Itziar R.; Zavala, Gonzalo; Bedia, Joaquin; Gutierrez, Jose M.; San Miguel-Ayanz, Jesus; Camia, Andrea; Keeley, Jon E.; Moreno, Jose M.

    2015-01-01

    Climate has a strong influence on fire activity, varying across time and space. We analyzed the relationships between fire–weather conditions during the main fire season and antecedent water-balance conditions and fires in two Mediterranean-type regions with contrasted management histories: five southern countries of the European Union (EUMED)(all fires); the Pacific western coast of the USA (California and Oregon, PWUSA)(national forest fires). Total number of fires (≥1 ha), number of large fires (≥100 ha) and area burned were related to mean seasonal fire weather index (FWI), number of days over the 90th percentile of the FWI, and to the standardized precipitation-evapotranspiration index (SPEI) from the preceding 3 (spring) or 8 (autumn through spring) months. Calculations were made at three spatial aggregations in each area, and models related first-difference (year-to-year change) of fires and FWI/climate variables to minimize autocorrelation. An increase in mean seasonal FWI resulted in increases in the three fire variables across spatial scales in both regions. SPEI contributed little to explain fires, with few exceptions. Negative water-balance (dry) conditions from autumn through spring (SPEI8) were generally more important than positive conditions (moist) in spring (SPEI3), both of which contributed positively to fires. The R2 of the models generally improved with increasing area of aggregation. For total number of fires and area burned, the R2 of the models tended to decrease with increasing mean seasonal FWI. Thus, fires were more susceptible to change with climate variability in areas with less amenable conditions for fires (lower FWI) than in areas with higher mean FWI values. The relationships were similar in both regions, albeit weaker in PWUSA, probably due to the wider latitudinal gradient covered in PWUSA than in EUMED. The large variance explained by some of the models indicates that large-scale seasonal forecast could help anticipating

  9. Fire history, related to climate and land use in three southern Appalachian landscapes in the eastern United States.

    PubMed

    Flatley, William T; Lafon, Charles W; Grissino-Mayer, Henri D; LaForest, Lisa B

    2013-09-01

    Fire-maintained ecosystems and associated species are becoming increasingly rare in the southern Appalachian Mountains because of fire suppression policies implemented in the early 20th century. Restoration of these communities through prescribed fire has been hindered by a lack of information on historical fire regimes. To characterize past fire regimes, we collected and absolutely dated the tree rings on cross sections from 242 fire-scarred trees at three different sites in the southern Appalachian Mountains of Tennessee and North Carolina. Our objectives were to (1) characterize the historical frequency of fire in southern Appalachian mixed pine-oak forests, (2) assess the impact of interannual climatic variability on the historical occurrence of fire, and (3) determine whether changes in human culture and land use altered the frequency of fire. Results demonstrate that fires burned frequently at all three sites for at least two centuries prior to the implementation of fire suppression and prevention in the early to mid 20th century. Composite mean fire return intervals were 2-4 yr, and point mean fire return intervals were 9-13 yr. Area-wide fires that burned across multiple stands occurred at 6-13-yr intervals. The majority of fires were recorded during the dormant season. Fire occurrence exhibited little relationship with reconstructed annual drought conditions. Also, fire activity did not change markedly during the transition from Native American to Euro-American settlement or during the period of industrial logging at the start of the 20th century. Fire activity declined significantly, however, during the fire suppression period, with a nearly complete absence of fire during recent decades. The characterization of past fire regimes should provide managers with specific targets for restoration of fire-associated communities in the southern Appalachian Mountains. The fire chronologies reported here are among the longest tree-ring reconstructions of fire

  10. Fire history, related to climate and land use in three southern Appalachian landscapes in the eastern United States.

    PubMed

    Flatley, William T; Lafon, Charles W; Grissino-Mayer, Henri D; LaForest, Lisa B

    2013-09-01

    Fire-maintained ecosystems and associated species are becoming increasingly rare in the southern Appalachian Mountains because of fire suppression policies implemented in the early 20th century. Restoration of these communities through prescribed fire has been hindered by a lack of information on historical fire regimes. To characterize past fire regimes, we collected and absolutely dated the tree rings on cross sections from 242 fire-scarred trees at three different sites in the southern Appalachian Mountains of Tennessee and North Carolina. Our objectives were to (1) characterize the historical frequency of fire in southern Appalachian mixed pine-oak forests, (2) assess the impact of interannual climatic variability on the historical occurrence of fire, and (3) determine whether changes in human culture and land use altered the frequency of fire. Results demonstrate that fires burned frequently at all three sites for at least two centuries prior to the implementation of fire suppression and prevention in the early to mid 20th century. Composite mean fire return intervals were 2-4 yr, and point mean fire return intervals were 9-13 yr. Area-wide fires that burned across multiple stands occurred at 6-13-yr intervals. The majority of fires were recorded during the dormant season. Fire occurrence exhibited little relationship with reconstructed annual drought conditions. Also, fire activity did not change markedly during the transition from Native American to Euro-American settlement or during the period of industrial logging at the start of the 20th century. Fire activity declined significantly, however, during the fire suppression period, with a nearly complete absence of fire during recent decades. The characterization of past fire regimes should provide managers with specific targets for restoration of fire-associated communities in the southern Appalachian Mountains. The fire chronologies reported here are among the longest tree-ring reconstructions of fire

  11. Active Suppression Induced by Repetitive Self-Epitopes Protects against EAE Development

    PubMed Central

    Puentes, Fabiola; Dickhaut, Katharina; Hofstätter, Maria; Falk, Kirsten; Rötzschke, Olaf

    2013-01-01

    Background Autoimmune diseases result from a breakdown in self-tolerance to autoantigens. Self-tolerance is induced and sustained by central and peripheral mechanisms intended to deviate harmful immune responses and to maintain homeostasis, where regulatory T cells play a crucial role. The use of self-antigens in the study and treatment of a range of autoimmune diseases has been widely described; however, the mechanisms underlying the induced protection by these means are unclear. This study shows that protection of experimental autoimmune disease induced by T cell self-epitopes in a multimerized form (oligomers) is mediated by the induction of active suppression. Principal Findings The experimental autoimmune encephalomyelitis (EAE) animal model for multiple sclerosis was used to study the mechanisms of protection induced by the treatment of oligomerized T cell epitope of myelin proteolipid protein (PLP139–151). Disease protection attained by the administration of oligomers was shown to be antigen specific and effective in both prevention and treatment of ongoing EAE. Oligomer mediated tolerance was actively transferred by cells from treated mice into adoptive hosts. The induction of active suppression was correlated with the recruitment of cells in the periphery associated with increased production of IL-10 and reduction of the pro-inflammatory cytokine TNF-α. The role of suppressive cytokines was demonstrated by the reversion of oligomer-induced protection after in vivo blocking of either IL-10 or TGF-β cytokines. Conclusions This study strongly supports an immunosuppressive role of repeat auto-antigens to control the development of EAE with potential applications in vaccination and antigen specific treatment of autoimmune diseases. PMID:23738007

  12. Conical Euler simulation and active suppression of delta wing rocking motion

    NASA Technical Reports Server (NTRS)

    Lee, Elizabeth M.; Batina, John T.

    1990-01-01

    A conical Euler code was developed to study unsteady vortex-dominated flows about rolling highly-swept delta wings, undergoing either forced or free-to-roll motions including active roll suppression. The flow solver of the code involves a multistage Runge-Kutta time-stepping scheme which uses a finite volume spatial discretization of the Euler equations on an unstructured grid of triangles. The code allows for the additional analysis of the free-to-roll case, by including the rigid-body equation of motion for its simultaneous time integration with the governing flow equations. Results are presented for a 75 deg swept sharp leading edge delta wing at a freestream Mach number of 1.2 and at alpha equal to 10 and 30 deg angle of attack. A forced harmonic analysis indicates that the rolling moment coefficient provides: (1) a positive damping at the lower angle of attack equal to 10 deg, which is verified in a free-to-roll calculation; (2) a negative damping at the higher angle of attack equal to 30 deg at the small roll amplitudes. A free-to-roll calculation for the latter case produces an initially divergent response, but as the amplitude of motion grows with time, the response transitions to a wing-rock type of limit cycle oscillation. The wing rocking motion may be actively suppressed, however, through the use of a rate-feedback control law and antisymmetrically deflected leading edge flaps. The descriptions of the conical Euler flow solver and the free-to-roll analysis are presented. Results are also presented which give insight into the flow physics associated with unsteady vortical flows about forced and free-to-roll delta wings, including the active roll suppression of this wing-rock phenomenon.

  13. 77 FR 7171 - Agency Information Collection Activities: Proposed Collection; Comment Request, National Fire...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-10

    ...; Comment Request, National Fire Incident Reporting System (NFIRS) v5.0 AGENCY: Federal Emergency Management... National Fire Incident Reporting System (NFIRS) v5.0. The program provides a well established mechanism, using standardized reporting methods, to collect and analyze fire incident data at the Federal,...

  14. Multirate Flutter Suppression System Design for the Benchmark Active Controls Technology Wing. Part 1; Theory and Design Procedure

    NASA Technical Reports Server (NTRS)

    Mason, Gregory S.; Berg, Martin C.; Mukhopadhyay, Vivek

    2002-01-01

    To study the effectiveness of various control system design methodologies, the NASA Langley Research Center initiated the Benchmark Active Controls Project. In this project, the various methodologies were applied to design a flutter suppression system for the Benchmark Active Controls Technology (BACT) Wing. This report describes a project at the University of Washington to design a multirate suppression system for the BACT wing. The objective of the project was two fold. First, to develop a methodology for designing robust multirate compensators, and second, to demonstrate the methodology by applying it to the design of a multirate flutter suppression system for the BACT wing.

  15. A monoclonal antibody to alpha 4 integrin suppresses and reverses active experimental allergic encephalomyelitis.

    PubMed

    Kent, S J; Karlik, S J; Cannon, C; Hines, D K; Yednock, T A; Fritz, L C; Horner, H C

    1995-04-01

    In experimental allergic encephalomyelitis (EAE), circulating leukocytes enter the central nervous system (CNS) producing inflammation, myelin damage and paralysis. Prevention of leukocyte infiltration by an antibody against alpha 4 integrin suppressed clinical and pathological features of EAE in the guinea pig. Rapid clearance of leukocytes from the CNS and reversal of clinical findings were observed when anti-alpha 4 treatment was administered during active disease. Clinical improvement was accompanied by a marked decrease in abnormal pathological findings, including demyelination. Therefore anti-alpha 4 is an effective treatment of EAE and may be similarly useful in the treatment of autoimmune diseases such as multiple sclerosis.

  16. Cholesterol synthesis inhibitor RO 48-8071 suppresses transcriptional activity of human estrogen and androgen receptor.

    PubMed

    Mafuvadze, Benford; Liang, Yayun; Hyder, Salman M

    2014-10-01

    Breast cancer cells express enzymes that convert cholesterol, the synthetic precursor of steroid hormones, into estrogens and androgens, which then drive breast cancer cell proliferation. In the present study, we sought to determine whether oxidosqualene cyclase (OSC), an enzyme in the cholesterol biosynthetic pathway, may be targeted to suppress progression of breast cancer cells. In previous studies, we showed that the OSC inhibitor RO 48-8071 (RO) may be a ligand which could potentially be used to control the progression of estrogen receptor-α (ERα)-positive breast cancer cells. Herein, we showed, by real-time PCR analysis of mRNA from human breast cancer biopsies, no significant differences in OSC expression at various stages of disease, or between tumor and normal mammary cells. Since the growth of hormone-responsive tumors is ERα-dependent, we conducted experiments to determine whether RO affects ERα. Using mammalian cells engineered to express human ERα or ERβ protein, together with an ER-responsive luciferase promoter, we found that RO dose-dependently inhibited 17β-estradiol (E2)-induced ERα responsive luciferase activity (IC50 value, ~10 µM), under conditions that were non-toxic to the cells. RO was less effective against ERβ-induced luciferase activity. Androgen receptor (AR) mediated transcriptional activity was also reduced by RO. Notably, while ERα activity was reduced by atorvastatin, the HMG-CoA reductase inhibitor did not influence AR activity, showing that RO possesses broader antitumor properties. Treatment of human BT-474 breast cancer cells with RO reduced levels of estrogen-induced PR protein, confirming that RO blocks ERα activity in tumor cells. Our findings demonstrate that an important means by which RO suppresses hormone-dependent growth of breast cancer cells is through its ability to arrest the biological activity of ERα. This warrants further investigation of RO as a potential therapeutic agent for use against hormone

  17. Multirate Flutter Suppression System Design for the Benchmark Active Controls Technology Wing. Part 2; Methodology Application Software Toolbox

    NASA Technical Reports Server (NTRS)

    Mason, Gregory S.; Berg, Martin C.; Mukhopadhyay, Vivek

    2002-01-01

    To study the effectiveness of various control system design methodologies, the NASA Langley Research Center initiated the Benchmark Active Controls Project. In this project, the various methodologies were applied to design a flutter suppression system for the Benchmark Active Controls Technology (BACT) Wing. This report describes the user's manual and software toolbox developed at the University of Washington to design a multirate flutter suppression control law for the BACT wing.

  18. MHC-derived allopeptide activates TCR-biased CD8+ Tregs and suppresses organ rejection

    PubMed Central

    Picarda, Elodie; Bézie, Séverine; Venturi, Vanessa; Echasserieau, Klara; Mérieau, Emmanuel; Delhumeau, Aurélie; Renaudin, Karine; Brouard, Sophie; Bernardeau, Karine; Anegon, Ignacio; Guillonneau, Carole

    2014-01-01

    In a rat heart allograft model, preventing T cell costimulation with CD40Ig leads to indefinite allograft survival, which is mediated by the induction of CD8+CD45RClo regulatory T cells (CD8+CD40Ig Tregs) interacting with plasmacytoid dendritic cells (pDCs). The role of TCR-MHC-peptide interaction in regulating Treg activity remains a topic of debate. Here, we identified a donor MHC class II–derived peptide (Du51) that is recognized by TCR-biased CD8+CD40Ig Tregs and activating CD8+CD40Ig Tregs in both its phenotype and suppression of antidonor alloreactive T cell responses. We generated a labeled tetramer (MHC-I RT1.Aa/Du51) to localize and quantify Du51-specific T cells within rat cardiac allografts and spleen. RT1.Aa/Du51-specific CD8+CD40Ig Tregs were the most suppressive subset of the total Treg population, were essential for in vivo tolerance induction, and expressed a biased, restricted Vβ11-TCR repertoire in the spleen and the graft. Finally, we demonstrated that treatment of transplant recipients with the Du51 peptide resulted in indefinite prolongation of allograft survival. These results show that CD8+CD40Ig Tregs recognize a dominant donor antigen, resulting in TCR repertoire alterations in the graft and periphery. Furthermore, this allopeptide has strong therapeutic activity and highlights the importance of TCR-peptide-MHC interaction for Treg generation and function. PMID:24789907

  19. Identification of Small Molecules That Suppress Ricin-Induced Stress-Activated Signaling Pathways

    PubMed Central

    Wahome, Paul G.; Ahlawat, Sarita; Mantis, Nicholas J.

    2012-01-01

    Ricin is a member of the ribosome-inactivating protein (RIP) family of plant and bacterial toxins. In this study we used a high-throughput, cell-based assay to screen more than 118,000 compounds from diverse chemical libraries for molecules that reduced ricin-induced cell death. We describe three compounds, PW66, PW69, and PW72 that at micromolar concentrations significantly delayed ricin-induced cell death. None of the compounds had any demonstrable effect on ricin's ability to arrest protein synthesis in cells or on ricin's enzymatic activity as assessed in vitro. Instead, all three compounds appear to function by blocking downstream stress-induced signaling pathways associated with the toxin-mediated apoptosis. PW66 virtually eliminated ricin-induced TNF-α secretion by J774A.1 macrophages and concomitantly blocked activation of the p38 MAPK and JNK signaling pathways. PW72 suppressed ricin-induced TNF-α secretion, but not p38 MAPK and JNK signaling. PW69 suppressed activity of the executioner caspases 3/7 in ricin toxin- and Shiga toxin 2-treated cells. While the actual molecular targets of the three compounds have yet to be identified, these data nevertheless underscore the potential of small molecules to down-regulate inflammatory signaling pathways associated with exposure to the RIP family of toxins. PMID:23133670

  20. Pyruvate kinase M2 activators promote tetramer formation and suppress tumorigenesis

    SciTech Connect

    Anastasiou, Dimitrios; Yu, Yimin; Israelsen, William J.; Jiang, Jian-Kang; Boxer, Matthew B.; Hong, Bum Soo; Tempel, Wolfram; Dimov, Svetoslav; Shen, Min; Jha, Abhishek; Yang, Hua; Mattaini, Katherine R.; Metallo, Christian M.; Fiske, Brian P.; Courtney, Kevin D.; Malstrom, Scott; Khan, Tahsin M.; Kung, Charles; Skoumbourdis, Amanda P.; Veith, Henrike; Southall, Noel; Walsh, Martin J.; Brimacombe, Kyle R.; Leister, William; Lunt, Sophia Y.; Johnson, Zachary R.; Yen, Katharine E.; Kunii, Kaiko; Davidson, Shawn M.; Christofk, Heather R.; Austin, Christopher P.; Inglese, James; Harris, Marian H.; Asara, John M.; Stephanopoulos, Gregory; Salituro, Francesco G.; Jin, Shengfang; Dang, Lenny; Auld, Douglas S.; Park, Hee-Won; Cantley, Lewis C.; Thomas, Craig J.; Vander Heiden, Matthew G.

    2012-08-26

    Cancer cells engage in a metabolic program to enhance biosynthesis and support cell proliferation. The regulatory properties of pyruvate kinase M2 (PKM2) influence altered glucose metabolism in cancer. The interaction of PKM2 with phosphotyrosine-containing proteins inhibits enzyme activity and increases the availability of glycolytic metabolites to support cell proliferation. This suggests that high pyruvate kinase activity may suppress tumor growth. We show that expression of PKM1, the pyruvate kinase isoform with high constitutive activity, or exposure to published small-molecule PKM2 activators inhibits the growth of xenograft tumors. Structural studies reveal that small-molecule activators bind PKM2 at the subunit interaction interface, a site that is distinct from that of the endogenous activator fructose-1,6-bisphosphate (FBP). However, unlike FBP, binding of activators to PKM2 promotes a constitutively active enzyme state that is resistant to inhibition by tyrosine-phosphorylated proteins. This data supports the notion that small-molecule activation of PKM2 can interfere with anabolic metabolism.