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Sample records for germcode gcr event-based

  1. Overview of the Graphical User Interface for the GERMcode (GCR Event-Based Risk Model)

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.

    2010-01-01

    The descriptions of biophysical events from heavy ions are of interest in radiobiology, cancer therapy, and space exploration. The biophysical description of the passage of heavy ions in tissue and shielding materials is best described by a stochastic approach that includes both ion track structure and nuclear interactions. A new computer model called the GCR Event-based Risk Model (GERM) code was developed for the description of biophysical events from heavy ion beams at the NASA Space Radiation Laboratory (NSRL). The GERMcode calculates basic physical and biophysical quantities of high-energy protons and heavy ions that have been studied at NSRL for the purpose of simulating space radiobiological effects. For mono-energetic beams, the code evaluates the linear-energy transfer (LET), range (R), and absorption in tissue equivalent material for a given Charge (Z), Mass Number (A) and kinetic energy (E) of an ion. In addition, a set of biophysical properties are evaluated such as the Poisson distribution of ion or delta-ray hits for a specified cellular area, cell survival curves, and mutation and tumor probabilities. The GERMcode also calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle. The contributions from primary ion and nuclear secondaries are evaluated. The GERMcode accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections, and has been used by the GERMcode for application to thick target experiments. The GERMcode provides scientists participating in NSRL experiments with the data needed for the interpretation of their

  2. Development of a GCR Event-based Risk Model

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Ponomarev, Artem L.; Plante, Ianik; Carra, Claudio; Kim, Myung-Hee

    2009-01-01

    A goal at NASA is to develop event-based systems biology models of space radiation risks that will replace the current dose-based empirical models. Complex and varied biochemical signaling processes transmit the initial DNA and oxidative damage from space radiation into cellular and tissue responses. Mis-repaired damage or aberrant signals can lead to genomic instability, persistent oxidative stress or inflammation, which are causative of cancer and CNS risks. Protective signaling through adaptive responses or cell repopulation is also possible. We are developing a computational simulation approach to galactic cosmic ray (GCR) effects that is based on biological events rather than average quantities such as dose, fluence, or dose equivalent. The goal of the GCR Event-based Risk Model (GERMcode) is to provide a simulation tool to describe and integrate physical and biological events into stochastic models of space radiation risks. We used the quantum multiple scattering model of heavy ion fragmentation (QMSFRG) and well known energy loss processes to develop a stochastic Monte-Carlo based model of GCR transport in spacecraft shielding and tissue. We validated the accuracy of the model by comparing to physical data from the NASA Space Radiation Laboratory (NSRL). Our simulation approach allows us to time-tag each GCR proton or heavy ion interaction in tissue including correlated secondary ions often of high multiplicity. Conventional space radiation risk assessment employs average quantities, and assumes linearity and additivity of responses over the complete range of GCR charge and energies. To investigate possible deviations from these assumptions, we studied several biological response pathway models of varying induction and relaxation times including the ATM, TGF -Smad, and WNT signaling pathways. We then considered small volumes of interacting cells and the time-dependent biophysical events that the GCR would produce within these tissue volumes to estimate how

  3. GERMcode: A Stochastic Model for Space Radiation Risk Assessment

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Ponomarev, Artem L.; Cucinotta, Francis A.

    2012-01-01

    A new computer model, the GCR Event-based Risk Model code (GERMcode), was developed to describe biophysical events from high-energy protons and high charge and energy (HZE) particles that have been studied at the NASA Space Radiation Laboratory (NSRL) for the purpose of simulating space radiation biological effects. In the GERMcode, the biophysical description of the passage of HZE particles in tissue and shielding materials is made with a stochastic approach that includes both particle track structure and nuclear interactions. The GERMcode accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections. For NSRL applications, the GERMcode evaluates a set of biophysical properties, such as the Poisson distribution of particles or delta-ray hits for a given cellular area and particle dose, the radial dose on tissue, and the frequency distribution of energy deposition in a DNA volume. By utilizing the ProE/Fishbowl ray-tracing analysis, the GERMcode will be used as a bi-directional radiation transport model for future spacecraft shielding analysis in support of Mars mission risk assessments. Recent radiobiological experiments suggest the need for new approaches to risk assessment that include time-dependent biological events due to the signaling times for activation and relaxation of biological processes in cells and tissue. Thus, the tracking of the temporal and spatial distribution of events in tissue is a major goal of the GERMcode in support of the simulation of biological processes important in GCR risk assessments. In order to validate our approach, basic radiobiological responses such as cell survival curves, mutation, chromosomal

  4. Overview of the Graphical User Interface for the GERM Code (GCR Event-Based Risk Model

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee; Cucinotta, Francis A.

    2010-01-01

    The descriptions of biophysical events from heavy ions are of interest in radiobiology, cancer therapy, and space exploration. The biophysical description of the passage of heavy ions in tissue and shielding materials is best described by a stochastic approach that includes both ion track structure and nuclear interactions. A new computer model called the GCR Event-based Risk Model (GERM) code was developed for the description of biophysical events from heavy ion beams at the NASA Space Radiation Laboratory (NSRL). The GERM code calculates basic physical and biophysical quantities of high-energy protons and heavy ions that have been studied at NSRL for the purpose of simulating space radiobiological effects. For mono-energetic beams, the code evaluates the linear-energy transfer (LET), range (R), and absorption in tissue equivalent material for a given Charge (Z), Mass Number (A) and kinetic energy (E) of an ion. In addition, a set of biophysical properties are evaluated such as the Poisson distribution of ion or delta-ray hits for a specified cellular area, cell survival curves, and mutation and tumor probabilities. The GERM code also calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle. The contributions from primary ion and nuclear secondaries are evaluated. The GERM code accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections, and has been used by the GERM code for application to thick target experiments. The GERM code provides scientists participating in NSRL experiments with the data needed for the interpretation of their

  5. Mixed-field GCR Simulations for Radiobiological Research using Ground Based Accelerators

    NASA Astrophysics Data System (ADS)

    Kim, Myung-Hee Y.; Rusek, Adam; Cucinotta, Francis

    Space radiation is comprised of a large number of particle types and energies, which have differential ionization power from high energy protons to high charge and energy (HZE) particles and secondary neutrons produced by galactic cosmic rays (GCR). Ground based accelerators such as the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL) are used to simulate space radiation for radiobiology research and dosimetry, electronics parts, and shielding testing using mono-energetic beams for single ion species. As a tool to support research on new risk assessment models, we have developed a stochastic model of heavy ion beams and space radiation effects, the GCR Event-based Risk Model computer code (GERMcode). For radiobiological research on mixed-field space radiation, a new GCR simulator at NSRL is proposed. The NSRL-GCR simulator, which implements the rapid switching mode and the higher energy beam extraction to 1.5 GeV/u, can integrate multiple ions into a single simulation to create GCR Z-spectrum in major energy bins. After considering the GCR environment and energy limitations of NSRL, a GCR reference field is proposed after extensive simulation studies using the GERMcode. The GCR reference field is shown to reproduce the Z and LET spectra of GCR behind shielding within 20 percents accuracy compared to simulated full GCR environments behind shielding. A major challenge for space radiobiology research is to consider chronic GCR exposure of up to 3-years in relation to simulations with cell and animal models of human risks. We discuss possible approaches to map important biological time scales in experimental models using ground-based simulation with extended exposure of up to a few weeks and fractionation approaches at a GCR simulator.

  6. Mixed-field GCR Simulations for Radiobiological Research Using Ground Based Accelerators

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Rusek, Adam; Cucinotta, Francis A.

    2014-01-01

    Space radiation is comprised of a large number of particle types and energies, which have differential ionization power from high energy protons to high charge and energy (HZE) particles and secondary neutrons produced by galactic cosmic rays (GCR). Ground based accelerators such as the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL) are used to simulate space radiation for radiobiology research and dosimetry, electronics parts, and shielding testing using mono-energetic beams for single ion species. As a tool to support research on new risk assessment models, we have developed a stochastic model of heavy ion beams and space radiation effects, the GCR Event-based Risk Model computer code (GERMcode). For radiobiological research on mixed-field space radiation, a new GCR simulator at NSRL is proposed. The NSRL-GCR simulator, which implements the rapid switching mode and the higher energy beam extraction to 1.5 GeV/u, can integrate multiple ions into a single simulation to create GCR Z-spectrum in major energy bins. After considering the GCR environment and energy limitations of NSRL, a GCR reference field is proposed after extensive simulation studies using the GERMcode. The GCR reference field is shown to reproduce the Z and LET spectra of GCR behind shielding within 20% accuracy compared to simulated full GCR environments behind shielding. A major challenge for space radiobiology research is to consider chronic GCR exposure of up to 3-years in relation to simulations with cell and animal models of human risks. We discuss possible approaches to map important biological time scales in experimental models using ground-based simulation with extended exposure of up to a few weeks and fractionation approaches at a GCR simulator.

  7. GCR environmental models I: Sensitivity analysis for GCR environments

    NASA Astrophysics Data System (ADS)

    Slaba, Tony C.; Blattnig, Steve R.

    2014-04-01

    Accurate galactic cosmic ray (GCR) models are required to assess crew exposure during long-duration missions to the Moon or Mars. Many of these models have been developed and compared to available measurements, with uncertainty estimates usually stated to be less than 15%. However, when the models are evaluated over a common epoch and propagated through to effective dose, relative differences exceeding 50% are observed. This indicates that the metrics used to communicate GCR model uncertainty can be better tied to exposure quantities of interest for shielding applications. This is the first of three papers focused on addressing this need. In this work, the focus is on quantifying the extent to which each GCR ion and energy group, prior to entering any shielding material or body tissue, contributes to effective dose behind shielding. Results can be used to more accurately calibrate model-free parameters and provide a mechanism for refocusing validation efforts on measurements taken over important energy regions. Results can also be used as references to guide future nuclear cross-section measurements and radiobiology experiments. It is found that GCR with Z > 2 and boundary energies below 500 MeV/n induce less than 5% of the total effective dose behind shielding. This finding is important given that most of the GCR models are developed and validated against Advanced Composition Explorer/Cosmic Ray Isotope Spectrometer (ACE/CRIS) measurements taken below 500 MeV/n. It is therefore possible for two models to very accurately reproduce the ACE/CRIS data while inducing very different effective dose values behind shielding.

  8. GCR Environmental Models I: Sensitivity Analysis for GCR Environments

    NASA Technical Reports Server (NTRS)

    Slaba, Tony C.; Blattnig, Steve R.

    2014-01-01

    Accurate galactic cosmic ray (GCR) models are required to assess crew exposure during long-duration missions to the Moon or Mars. Many of these models have been developed and compared to available measurements, with uncertainty estimates usually stated to be less than 15%. However, when the models are evaluated over a common epoch and propagated through to effective dose, relative differences exceeding 50% are observed. This indicates that the metrics used to communicate GCR model uncertainty can be better tied to exposure quantities of interest for shielding applications. This is the first of three papers focused on addressing this need. In this work, the focus is on quantifying the extent to which each GCR ion and energy group, prior to entering any shielding material or body tissue, contributes to effective dose behind shielding. Results can be used to more accurately calibrate model-free parameters and provide a mechanism for refocusing validation efforts on measurements taken over important energy regions. Results can also be used as references to guide future nuclear cross-section measurements and radiobiology experiments. It is found that GCR with Z>2 and boundary energies below 500 MeV/n induce less than 5% of the total effective dose behind shielding. This finding is important given that most of the GCR models are developed and validated against Advanced Composition Explorer/Cosmic Ray Isotope Spectrometer (ACE/CRIS) measurements taken below 500 MeV/n. It is therefore possible for two models to very accurately reproduce the ACE/CRIS data while inducing very different effective dose values behind shielding.

  9. Mutations in Gcr1, a Transcriptional Activator of Saccharomyces Cerevisiae Glycolytic Genes, Function as Suppressors of Gcr2 Mutations

    PubMed Central

    Uemura, H.; Jigami, Y.

    1995-01-01

    The Saccharomyces cerevisiae GCR1 and GCR2 genes affect expression of most of the glycolytic genes. Evidence for Gcr1p/Gcr2p interaction has been presented earlier and is now supported by the isolation of mutations in Gcr1p suppressing gcr2, as assessed by growth and enzyme assay. Four specific mutation sites were identified. Together with use of the two-hybrid system of FIELDS and SONG, they show that Gcr1p in its N-terminal half has a potential transcriptional activating function as well as elements for interaction with Gcr2p, which perhaps acts normally to expose an otherwise cryptic activation domain on Gcr1p. Complementation of various gcr1 mutant alleles and results with the two-hybrid system also indicate that Gcr1p itself normally functions as an oligomer. PMID:7713414

  10. Event-Based Science.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    1992-01-01

    Suggests that an event-based science curriculum can provide the framework for deciding what to retain in an overloaded science curriculum. Provides examples of current events and the science concepts explored related to the event. (MDH)

  11. Nuclear interactions in heavy ion transport and event-based risk models.

    PubMed

    Cucinotta, Francis A; Plante, Ianik; Ponomarev, Artem L; Kim, Myung-Hee Y

    2011-02-01

    The physical description of the passage of heavy ions in tissue and shielding materials is of interest in radiobiology, cancer therapy and space exploration, including a human mission to Mars. Galactic cosmic rays (GCRs) consist of a large number of ion types and energies. Energy loss processes occur continuously along the path of heavy ions and are well described by the linear energy transfer (LET), straggling and multiple scattering algorithms. Nuclear interactions lead to much larger energy deposition than atomic-molecular collisions and alter the composition of heavy ion beams while producing secondary nuclei often in high multiplicity events. The major nuclear interaction processes of importance for describing heavy ion beams was reviewed, including nuclear fragmentation, elastic scattering and knockout-cascade processes. The quantum multiple scattering fragmentation model is shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections and is studied for application to thick target experiments. A new computer model, which was developed for the description of biophysical events from heavy ion beams at the NASA Space Radiation Laboratory (NSRL), called the GCR Event Risk-Based Model (GERMcode) is described. PMID:21242169

  12. Isotopic Dependence of GCR Fluence behind Shielding

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wilson, John W.; Saganti, Premkumar; Kim, Myung-Hee Y.; Cleghorn, Timothy; Zeitlin, Cary; Tripathi, Ram K.

    2006-01-01

    In this paper we consider the effects of the isotopic composition of the primary galactic cosmic rays (GCR), nuclear fragmentation cross-sections, and isotopic-grid on the solution to transport models used for shielding studies. Satellite measurements are used to describe the isotopic composition of the GCR. For the nuclear interaction data-base and transport solution, we use the quantum multiple-scattering theory of nuclear fragmentation (QMSFRG) and high-charge and energy (HZETRN) transport code, respectively. The QMSFRG model is shown to accurately describe existing fragmentation data including proper description of the odd-even effects as function of the iso-spin dependence on the projectile nucleus. The principle finding of this study is that large errors (+/-100%) will occur in the mass-fluence spectra when comparing transport models that use a complete isotopic-grid (approx.170 ions) to ones that use a reduced isotopic-grid, for example the 59 ion-grid used in the HZETRN code in the past, however less significant errors (<+/-20%) occur in the elemental-fluence spectra. Because a complete isotopic-grid is readily handled on small computer workstations and is needed for several applications studying GCR propagation and scattering, it is recommended that they be used for future GCR studies.

  13. GCR Environmental Models III: GCR Model Validation and Propagated Uncertainties in Effective Dose

    NASA Technical Reports Server (NTRS)

    Slaba, Tony C.; Xu, Xiaojing; Blattnig, Steve R.; Norman, Ryan B.

    2014-01-01

    This is the last of three papers focused on quantifying the uncertainty associated with galactic cosmic rays (GCR) models used for space radiation shielding applications. In the first paper, it was found that GCR ions with Z>2 and boundary energy below 500 MeV/nucleon induce less than 5% of the total effective dose behind shielding. This is an important finding since GCR model development and validation have been heavily biased toward Advanced Composition Explorer/Cosmic Ray Isotope Spectrometer measurements below 500 MeV/nucleon. Weights were also developed that quantify the relative contribution of defined GCR energy and charge groups to effective dose behind shielding. In the second paper, it was shown that these weights could be used to efficiently propagate GCR model uncertainties into effective dose behind shielding. In this work, uncertainties are quantified for a few commonly used GCR models. A validation metric is developed that accounts for measurements uncertainty, and the metric is coupled to the fast uncertainty propagation method. For this work, the Badhwar-O'Neill (BON) 2010 and 2011 and the Matthia GCR models are compared to an extensive measurement database. It is shown that BON2011 systematically overestimates heavy ion fluxes in the range 0.5-4 GeV/nucleon. The BON2010 and BON2011 also show moderate and large errors in reproducing past solar activity near the 2000 solar maximum and 2010 solar minimum. It is found that all three models induce relative errors in effective dose in the interval [-20%, 20%] at a 68% confidence level. The BON2010 and Matthia models are found to have similar overall uncertainty estimates and are preferred for space radiation shielding applications.

  14. Isotopic Effects in Nuclear Fragmentation and GCR Transport Problems

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.

    2002-01-01

    Improving the accuracy of the galactic cosmic ray (GCR) environment and transport models is an important goal in preparing for studies of the projected risks and the efficiency of potential mitigations methods for space exploration. In this paper we consider the effects of the isotopic composition of the primary cosmic rays and the isotopic dependence of nuclear fragmentation cross sections on GCR transport models. Measurements are used to describe the isotopic composition of the GCR including their modulation throughout the solar cycle. The quantum multiple-scattering approach to nuclear fragmentation (QMSFRG) is used as the data base generator in order to accurately describe the odd-even effect in fragment production. Using the Badhwar and O'Neill GCR model, the QMSFRG model and the HZETRN transport code, the effects of the isotopic dependence of the primary GCR composition and on fragment production for transport problems is described for a complete GCR isotopic-grid. The principle finding of this study is that large errors ( 100%) will occur in the mass-flux spectra when comparing the complete isotopic-grid (141 ions) to a reduced isotopic-grid (59 ions), however less significant errors 30%) occur in the elemental-flux spectra. Because the full isotopic-grid is readily handled on small computer work-stations, it is recommended that they be used for future GCR studies.

  15. Impact of AMS-02 Measurements on Reducing GCR Model Uncertainties

    NASA Technical Reports Server (NTRS)

    Slaba, T. C.; O'Neill, P. M.; Golge, S.; Norbury, J. W.

    2015-01-01

    For vehicle design, shield optimization, mission planning, and astronaut risk assessment, the exposure from galactic cosmic rays (GCR) poses a significant and complex problem both in low Earth orbit and in deep space. To address this problem, various computational tools have been developed to quantify the exposure and risk in a wide range of scenarios. Generally, the tool used to describe the ambient GCR environment provides the input into subsequent computational tools and is therefore a critical component of end-to-end procedures. Over the past few years, several researchers have independently and very carefully compared some of the widely used GCR models to more rigorously characterize model differences and quantify uncertainties. All of the GCR models studied rely heavily on calibrating to available near-Earth measurements of GCR particle energy spectra, typically over restricted energy regions and short time periods. In this work, we first review recent sensitivity studies quantifying the ions and energies in the ambient GCR environment of greatest importance to exposure quantities behind shielding. Currently available measurements used to calibrate and validate GCR models are also summarized within this context. It is shown that the AMS-II measurements will fill a critically important gap in the measurement database. The emergence of AMS-II measurements also provides a unique opportunity to validate existing models against measurements that were not used to calibrate free parameters in the empirical descriptions. Discussion is given regarding rigorous approaches to implement the independent validation efforts, followed by recalibration of empirical parameters.

  16. A Stochastic Model of Space Radiation Transport as a Tool in the Development of Time-Dependent Risk Assessment

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Nounu, Hatem N.; Ponomarev, Artem L.; Cucinotta, Francis A.

    2011-01-01

    A new computer model, the GCR Event-based Risk Model code (GERMcode), was developed to describe biophysical events from high-energy protons and heavy ions that have been studied at the NASA Space Radiation Laboratory (NSRL) [1] for the purpose of simulating space radiation biological effects. In the GERMcode, the biophysical description of the passage of heavy ions in tissue and shielding materials is made with a stochastic approach that includes both ion track structure and nuclear interactions. The GERMcode accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model [2]. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections

  17. GCR Simulator Development Status at the NASA Space Radiation Laboratory

    NASA Technical Reports Server (NTRS)

    Slaba, T. C.; Norbury, J. W.; Blattnig, S. R.

    2015-01-01

    There are large uncertainties connected to the biological response for exposure to galactic cosmic rays (GCR) on long duration deep space missions. In order to reduce the uncertainties and gain understanding about the basic mechanisms through which space radiation initiates cancer and other endpoints, radiobiology experiments are performed with mono-energetic ions beams. Some of the accelerator facilities supporting such experiments have matured to a point where simulating the broad range of particles and energies characteristic of the GCR environment in a single experiment is feasible from a technology, usage, and cost perspective. In this work, several aspects of simulating the GCR environment at the NASA Space Radiation Laboratory (NSRL) are discussed. First, comparisons are made between direct simulation of the external, free space GCR field, and simulation of the induced tissue field behind shielding. It is found that upper energy constraints at NSRL limit the ability to simulate the external, free space field directly (i.e. shielding placed in the beam line in front of a biological target and exposed to a free space spectrum). Second, a reference environment for the GCR simulator and suitable for deep space missions is identified and described in terms of fluence and integrated dosimetric quantities. Analysis results are given to justify the use of a single reference field over a range of shielding conditions and solar activities. Third, an approach for simulating the reference field at NSRL is presented. The approach directly considers the hydrogen and helium energy spectra, and the heavier ions are collectively represented by considering the linear energy transfer (LET) spectrum. While many more aspects of the experimental setup need to be considered before final implementation of the GCR simulator, this preliminary study provides useful information that should aid the final design. Possible drawbacks of the proposed methodology are discussed and weighed

  18. Host Event Based Network Monitoring

    SciTech Connect

    Jonathan Chugg

    2013-01-01

    The purpose of INL’s research on this project is to demonstrate the feasibility of a host event based network monitoring tool and the effects on host performance. Current host based network monitoring tools work on polling which can miss activity if it occurs between polls. Instead of polling, a tool could be developed that makes use of event APIs in the operating system to receive asynchronous notifications of network activity. Analysis and logging of these events will allow the tool to construct the complete real-time and historical network configuration of the host while the tool is running. This research focused on three major operating systems commonly used by SCADA systems: Linux, WindowsXP, and Windows7. Windows 7 offers two paths that have minimal impact on the system and should be seriously considered. First is the new Windows Event Logging API, and, second, Windows 7 offers the ALE API within WFP. Any future work should focus on these methods.

  19. GCR as a source for Inner radiation belt of Saturn.

    NASA Astrophysics Data System (ADS)

    Kotova, A.; Roussos, E.; Krupp, N.; Dandouras, I. S.

    2014-12-01

    During the insertion orbit of Cassini in 2004 the Ion and Neutron Camera measured significant fluxes of the energetic neutral atoms (ENA) coming from the area between the D-ring and the Saturn's atmosphere, what brought up the idea of the possible existence of the innermost radiation belt in this narrow gap (1). There are two main sources of energetic charged particles for such inner radiation belt: the interaction of the Galactic Cosmic Rays (GCR) with the Saturn's atmosphere and rings, which due to CRAND process can produce the keV-MeV ions or electrons in the region, and the double charge exchange of the ENAs, coming from the middle magnetosphere, what can bring the keV ions to the region of our interest. Using the particles tracer, which was developed in our group, and GEANT4 software, we study in details those two processes. With a particle tracer we evaluate the GCR access to the Saturn atmosphere and rings. Simulation of the GCR trajectories allows to calculate the energy spectra of the arriving energetic particles, which is much more accurate, compare to the analytically predicted spectra using the Stoermer theory, since simulation includes effects of the ring shadow and non-dipolar processes in the magnetosphere. Using the GEANT4 software the penetration of the GCR through the matter of rings was simulated, and the production of secondaries particles was estimated. Finally, the motion of secondaries was simulated using the particles tracer, and evaluation of the energy spectrum of neutrons the decay of which leads to the production of final CRAND elements in the inner Saturnian radiation belts was done. We show that for inner radiation belt most energetic ions comes from GCR interaction with rings, it's penetration and from interaction of secondaries with Saturn's atmosphere. This simulation allows us to predict the fluxes of energetic ions and electrons, which particle detector MIMI/LEMMS onboard the Cassini can measure during the so-called "proximal

  20. Nuclear fragmentation database for GCR transport code development

    NASA Astrophysics Data System (ADS)

    Zeitlin, C.; Guetersloh, S.; Heilbronn, L.; Miller, J.; Fukumura, A.; Iwata, Y.; Murakami, T.; Sihver, L.

    2010-09-01

    A critical need for NASA is the ability to accurately model the transport of heavy ions in the Galactic Cosmic Rays (GCR) through matter, including spacecraft walls, equipment racks, etc. Nuclear interactions are of great importance in the GCR transport problem, as they can cause fragmentation of the incoming ion into lighter ions. Since the radiation dose delivered by a particle is proportional to the square of (charge/velocity), fragmentation reduces the dose delivered by incident ions. The other mechanism by which dose can be reduced is ionization energy loss, which can lead to some particles stopping in the shielding. This is the conventional notion of shielding, but it is not applicable to human spaceflight since the particles in the GCR tend to be too energetic to be stopped in the relatively thin shielding that is possible within payload mass constraints. Our group has measured a large number of fragmentation cross sections, intended to be used as input to, or for validation of, NASA's radiation transport models. A database containing over 200 charge-changing cross sections and over 2000 fragment production cross sections has been compiled. In this report, we examine in detail the contrast between fragment measurements at large acceptance and small acceptance. We use output from the PHITS Monte Carlo code to test our assumptions using as an example 40Ar data (and simulated data) at a beam energy of 650 MeV/nucleon. We also present preliminary analysis in which isotopic resolution was attained for beryllium fragments produced by beams of 10B and 11B. Future work on the experimental data set will focus on extracting and interpreting production cross sections for light fragments.

  1. The Dynamic Outer Heliosphere and Preliminary Analysis of GCR Trajectories

    NASA Astrophysics Data System (ADS)

    Washimi, Haruichi; Zank, Gary P.; Hu, Qiang; Tanaka, Takashi; Munakata, Kazuoki; Shinagawa, Hiroyuki

    2010-12-01

    We show realistic and time-varying 3D MHD models of the outer heliosphere which satisfy both Voyager 1 (V1) and Voyager 2 (V2) observed crossing times of the termination shock (TS) simultaneously. The short-term variations found are a) the TS position increases whenever a solar-wind high-ram pressure pulse collides with the TS, b) a large amplitude magneto-sonic pulse is generated downstream of the TS when a solar-wind high ram pressure pulse collides with the TS, c) the generated pulse propagates outward in the heliosheath and is reflected at the plasma sheet, and d) when the reflected pulse collides with the TS, the TS position decreases. We also present preliminary results of galactic cosmic rays (GCRs) trajectories as they respond to three-dimensional global electric and magnetic fields in the outer heliosphere. This allows us to investigate (1) how GCRs cross the heliosphere and enter the inner heliosphere, and (2) their long-term variation. Preliminary GCR distributions in the outer heliosphere are shown. GCR diffusion due to magnetic-field fluctuations is not taken into account in this analysis.

  2. Asynchronous event-based hebbian epipolar geometry.

    PubMed

    Benosman, Ryad; Ieng, Sio-Hoï; Rogister, Paul; Posch, Christoph

    2011-11-01

    Epipolar geometry, the cornerstone of perspective stereo vision, has been studied extensively since the advent of computer vision. Establishing such a geometric constraint is of primary importance, as it allows the recovery of the 3-D structure of scenes. Estimating the epipolar constraints of nonperspective stereo is difficult, they can no longer be defined because of the complexity of the sensor geometry. This paper will show that these limitations are, to some extent, a consequence of the static image frames commonly used in vision. The conventional frame-based approach suffers from a lack of the dynamics present in natural scenes. We introduce the use of neuromorphic event-based--rather than frame-based--vision sensors for perspective stereo vision. This type of sensor uses the dimension of time as the main conveyor of information. In this paper, we present a model for asynchronous event-based vision, which is then used to derive a general new concept of epipolar geometry linked to the temporal activation of pixels. Practical experiments demonstrate the validity of the approach, solving the problem of estimating the fundamental matrix applied, in a first stage, to classic perspective vision and then to more general cameras. Furthermore, this paper shows that the properties of event-based vision sensors allow the exploration of not-yet-defined geometric relationships, finally, we provide a definition of general epipolar geometry deployable to almost any visual sensor. PMID:21954205

  3. Landscape of international event-based biosurveillance

    PubMed Central

    Hartley, DM; Nelson, NP; Walters, R; Arthur, R; Yangarber, R; Madoff, L; Linge, JP; Mawudeku, A; Collier, N; Brownstein, JS; Thinus, G; Lightfoot, N

    2010-01-01

    Event-based biosurveillance is a scientific discipline in which diverse sources of data, many of which are available from the Internet, are characterized prospectively to provide information on infectious disease events. Biosurveillance complements traditional public health surveillance to provide both early warning of infectious disease events and situational awareness. The Global Health Security Action Group of the Global Health Security Initiative is developing a biosurveillance capability that integrates and leverages component systems from member nations. This work discusses these biosurveillance systems and identifies needed future studies. PMID:22460393

  4. Asynchronous event-based binocular stereo matching.

    PubMed

    Rogister, Paul; Benosman, Ryad; Ieng, Sio-Hoi; Lichtsteiner, Patrick; Delbruck, Tobi

    2012-02-01

    We present a novel event-based stereo matching algorithm that exploits the asynchronous visual events from a pair of silicon retinas. Unlike conventional frame-based cameras, recent artificial retinas transmit their outputs as a continuous stream of asynchronous temporal events, in a manner similar to the output cells of the biological retina. Our algorithm uses the timing information carried by this representation in addressing the stereo-matching problem on moving objects. Using the high temporal resolution of the acquired data stream for the dynamic vision sensor, we show that matching on the timing of the visual events provides a new solution to the real-time computation of 3-D objects when combined with geometric constraints using the distance to the epipolar lines. The proposed algorithm is able to filter out incorrect matches and to accurately reconstruct the depth of moving objects despite the low spatial resolution of the sensor. This brief sets up the principles for further event-based vision processing and demonstrates the importance of dynamic information and spike timing in processing asynchronous streams of visual events. PMID:24808513

  5. On event-based optical flow detection

    PubMed Central

    Brosch, Tobias; Tschechne, Stephan; Neumann, Heiko

    2015-01-01

    Event-based sensing, i.e., the asynchronous detection of luminance changes, promises low-energy, high dynamic range, and sparse sensing. This stands in contrast to whole image frame-wise acquisition by standard cameras. Here, we systematically investigate the implications of event-based sensing in the context of visual motion, or flow, estimation. Starting from a common theoretical foundation, we discuss different principal approaches for optical flow detection ranging from gradient-based methods over plane-fitting to filter based methods and identify strengths and weaknesses of each class. Gradient-based methods for local motion integration are shown to suffer from the sparse encoding in address-event representations (AER). Approaches exploiting the local plane like structure of the event cloud, on the other hand, are shown to be well suited. Within this class, filter based approaches are shown to define a proper detection scheme which can also deal with the problem of representing multiple motions at a single location (motion transparency). A novel biologically inspired efficient motion detector is proposed, analyzed and experimentally validated. Furthermore, a stage of surround normalization is incorporated. Together with the filtering this defines a canonical circuit for motion feature detection. The theoretical analysis shows that such an integrated circuit reduces motion ambiguity in addition to decorrelating the representation of motion related activations. PMID:25941470

  6. Down-regulated Lotus japonicus GCR1 plants exhibit nodulation signalling pathways alteration.

    PubMed

    Rogato, Alessandra; Valkov, Vladimir Totev; Alves, Ludovico Martins; Apone, Fabio; Colucci, Gabriella; Chiurazzi, Maurizio

    2016-06-01

    G Protein Coupled Receptor (GPCRs) are integral membrane proteins involved in various signalling pathways by perceiving many extracellular signals and transducing them to heterotrimeric G proteins, which further transduce these signals to intracellular downstream effectors. GCR1 is the only reliable plant candidate as a member of the GPCRs superfamily. In the legume/rhizobia symbiotic interaction, G proteins are involved in signalling pathways controlling different steps of the nodulation program. In order to investigate the putative hierarchic role played by GCR1 in these symbiotic pathways we identified and characterized the Lotus japonicus gene encoding the seven transmembrane GCR1 protein. The detailed molecular and topological analyses of LjGCR1 expression patterns that are presented suggest a possible involvement in the early steps of nodule organogenesis. Furthermore, phenotypic analyses of independent transgenic RNAi lines, showing a significant LjGCR1 expression down regulation, suggest an epistatic action in the control of molecular markers of nodulation pathways, although no macroscopic symbiotic phenotypes could be revealed. PMID:27095401

  7. Effect of Implantation Sequence on Tribological Behavior of GCr15 Steel by PBII

    NASA Astrophysics Data System (ADS)

    Gu, Le; Zhou, Hui; Cao, Guojian; Tang, Guangze; Ma, Xinxin; Wang, Liqin

    2016-05-01

    In the present work, the effect of implantation sequence on tribological behavior of GCr15 steel treated by plasma-based ion implantation of carbon and nitrogen has been investigated. The treated GCr15 steels were characterized for microstructure and abrasive wear performance through combination of Raman spectroscopy, nano-indentation, and wear tests. Raman spectroscopy indicated that diamond-like carbon (DLC) films were formed after implantation of carbon with or without implantation of nitrogen, and the implantation of nitrogen after the implantation of carbon destroyed the graphite structure of the DLC films. The nano-indentation and wear tests showed that nanohardness as well as wear resistance of the GCr15 steel treated with the implantation sequence of nitrogen-carbon was better than those with the implantation sequence of carbon-nitrogen. Meanwhile, the properties were improved with increasing of carbon ion fluence.

  8. Flexible gray component replacement (GCR) based on CIE L*a*b*

    NASA Astrophysics Data System (ADS)

    Ogatsu, Hitoshi; Murai, Kazumasa; Kita, Shinji

    1995-04-01

    To improve the color fidelity of 4 color reproduction and to increase the flexibility of Gray Component Replacement (GCR) for the text and continuous images, a novel GCR algorithm based on CIE L*a*b* signals is proposed. The algorithm consist of (1) maximum (achromatic) black determination part, (2) black adjustment part based on chroma, and (3) 3 color determination part. On this configuration, black signal is determined ahead of MCY signals, and the freedom of 3 input i.e L*a*b* 4 output i.e. CMYBk conversion is concentrated in (2). By using xerographic color printer, by neural network technique for resolving this, the algorithm is examined. As a result, it is shown that the algorithm can conserve the color fidelity in any GCR rate, and which is applicable on both of text and continuous images.

  9. GCR Simulator Reference Field and a Spectral Approach for Laboratory Simulation

    NASA Technical Reports Server (NTRS)

    Slaba, Tony C.; Blattnig, Steve R.; Norbury, John W.; Rusek, Adam; La Tessa, Chiara; Walker, Steven A.

    2015-01-01

    The galactic cosmic ray (GCR) simulator at the NASA Space Radiation Laboratory (NSRL) is intended to deliver the broad spectrum of particles and energies encountered in deep space to biological targets in a controlled laboratory setting. In this work, certain aspects of simulating the GCR environment in the laboratory are discussed. Reference field specification and beam selection strategies at NSRL are the main focus, but the analysis presented herein may be modified for other facilities. First, comparisons are made between direct simulation of the external, free space GCR field and simulation of the induced tissue field behind shielding. It is found that upper energy constraints at NSRL limit the ability to simulate the external, free space field directly (i.e. shielding placed in the beam line in front of a biological target and exposed to a free space spectrum). Second, variation in the induced tissue field associated with shielding configuration and solar activity is addressed. It is found that the observed variation is likely within the uncertainty associated with representing any GCR reference field with discrete ion beams in the laboratory, given current facility constraints. A single reference field for deep space missions is subsequently identified. Third, an approach for selecting beams at NSRL to simulate the designated reference field is presented. Drawbacks of the proposed methodology are discussed and weighed against alternative simulation strategies. The neutron component and track structure characteristics of the simulated field are discussed in this context.

  10. Reference field specification and preliminary beam selection strategy for accelerator-based GCR simulation.

    PubMed

    Slaba, Tony C; Blattnig, Steve R; Norbury, John W; Rusek, Adam; La Tessa, Chiara

    2016-02-01

    The galactic cosmic ray (GCR) simulator at the NASA Space Radiation Laboratory (NSRL) is intended to deliver the broad spectrum of particles and energies encountered in deep space to biological targets in a controlled laboratory setting. In this work, certain aspects of simulating the GCR environment in the laboratory are discussed. Reference field specification and beam selection strategies at NSRL are the main focus, but the analysis presented herein may be modified for other facilities and possible biological considerations. First, comparisons are made between direct simulation of the external, free space GCR field and simulation of the induced tissue field behind shielding. It is found that upper energy constraints at NSRL limit the ability to simulate the external, free space field directly (i.e. shielding placed in the beam line in front of a biological target and exposed to a free space spectrum). Second, variation in the induced tissue field associated with shielding configuration and solar activity is addressed. It is found that the observed variation is likely within the uncertainty associated with representing any GCR reference field with discrete ion beams in the laboratory, given current facility constraints. A single reference field for deep space missions is subsequently identified. Third, a preliminary approach for selecting beams at NSRL to simulate the designated reference field is presented. This approach is not a final design for the GCR simulator, but rather a single step within a broader design strategy. It is shown that the beam selection methodology is tied directly to the reference environment, allows facility constraints to be incorporated, and may be adjusted to account for additional constraints imposed by biological or animal care considerations. The major biology questions are not addressed herein but are discussed in a companion paper published in the present issue of this journal. Drawbacks of the proposed methodology are discussed

  11. Reference field specification and preliminary beam selection strategy for accelerator-based GCR simulation

    NASA Astrophysics Data System (ADS)

    Slaba, Tony C.; Blattnig, Steve R.; Norbury, John W.; Rusek, Adam; La Tessa, Chiara

    2016-02-01

    The galactic cosmic ray (GCR) simulator at the NASA Space Radiation Laboratory (NSRL) is intended to deliver the broad spectrum of particles and energies encountered in deep space to biological targets in a controlled laboratory setting. In this work, certain aspects of simulating the GCR environment in the laboratory are discussed. Reference field specification and beam selection strategies at NSRL are the main focus, but the analysis presented herein may be modified for other facilities and possible biological considerations. First, comparisons are made between direct simulation of the external, free space GCR field and simulation of the induced tissue field behind shielding. It is found that upper energy constraints at NSRL limit the ability to simulate the external, free space field directly (i.e. shielding placed in the beam line in front of a biological target and exposed to a free space spectrum). Second, variation in the induced tissue field associated with shielding configuration and solar activity is addressed. It is found that the observed variation is likely within the uncertainty associated with representing any GCR reference field with discrete ion beams in the laboratory, given current facility constraints. A single reference field for deep space missions is subsequently identified. Third, a preliminary approach for selecting beams at NSRL to simulate the designated reference field is presented. This approach is not a final design for the GCR simulator, but rather a single step within a broader design strategy. It is shown that the beam selection methodology is tied directly to the reference environment, allows facility constraints to be incorporated, and may be adjusted to account for additional constraints imposed by biological or animal care considerations. The major biology questions are not addressed herein but are discussed in a companion paper published in the present issue of this journal. Drawbacks of the proposed methodology are discussed

  12. Multi-field coupled numerical simulation of hot reversible rolling process of GCr15 steel rod

    NASA Astrophysics Data System (ADS)

    Gu, Sendong; Zhang, Liwen; Ruan, Jinhua; Mei, Hongyu; Zhen, Yu; Shi, Xinhua

    2013-05-01

    In this paper, based on rolling technology of hot reversible rolling mill, a multi-filed coupled finite element (FE) model of hot reversible rolling process of large dimension cross-section GCr15 steel rod is established. Thermal, mechanical and microstructural phenomena during the rolling process are coupled in the model. By employing grain growth experiment, double and single hit hot compression experiments, the austenite grain size growth mathematical model and recrystallization behavior mathematical models are determined. And a designed subprogram is coupled in the FE model. Actual hot reversible rolling process of GCr15 steel is simulated using the model and the distribution and evolution of different filed-variables, such as temperature, effective strain and austenite grain size are obtained. To verify the model predictions, hot rolling experiments are carried out and the temperature and microstructure of the rolling metal are compared with the predicted results. The comparison between the two sets of data shows a good agreement.

  13. A Reference Field for GCR Simulation and an LET-Based Implementation at NSRL

    NASA Technical Reports Server (NTRS)

    Slaba, Tony C.; Blattnig, Steve R.; Walker, Steven A.; Norbury, John W.

    2015-01-01

    Exposure to galactic cosmic rays (GCR) on long duration deep space missions presents a serious health risk to astronauts, with large uncertainties connected to the biological response. In order to reduce the uncertainties and gain understanding about the basic mechanisms through which space radiation initiates cancer and other endpoints, radiobiology experiments are performed. Some of the accelerator facilities supporting such experiments have matured to a point where simulating the broad range of particles and energies characteristic of the GCR environment in a single experiment is feasible from a technology, usage, and cost perspective. In this work, several aspects of simulating the GCR environment in the laboratory are discussed. First, comparisons are made between direct simulation of the external, free space GCR field and simulation of the induced tissue field behind shielding. It is found that upper energy constraints at the NASA Space Radiation Laboratory (NSRL) limit the ability to simulate the external, free space field directly (i.e. shielding placed in the beam line in front of a biological target and exposed to a free space spectrum). Second, variation in the induced tissue field associated with shielding configuration and solar activity is addressed. It is found that the observed variation is within physical uncertainties, allowing a single reference field for deep space missions to be defined. Third, an approach for simulating the reference field at NSRL is presented. The approach allows for the linear energy transfer (LET) spectrum of the reference field to be approximately represented with discrete ion and energy beams and implicitly maintains a reasonably accurate charge spectrum (or, average quality factor). Drawbacks of the proposed methodology are discussed and weighed against alternative simulation strategies. The neutron component and track structure characteristics of the proposed strategy are discussed in this context.

  14. Effect of Ultrasonic Treatment on the Solidification Microstructure of GCr15 Bearing Steel

    NASA Astrophysics Data System (ADS)

    Wang, Jianjun; Shi, Xiaofang; Chang, Lizhong; Wang, Haijun; Meng, Lipeng

    2016-02-01

    Ultrasonic treatment with various powers is introduced to liquid steel from the side wall of a mold during GCr15 steel solidification, and the effect of ultrasonic on the microstructure and properties of GCr15 steel is investigated. Results show that the columnar grains in the GCr15 steel are coarse and that the microstructure is inhomogeneous when ultrasonic is not applied on the liquid steel. A suitable power ultrasonic leads to the appearance of a large number of equiaxed grains and increases the uniformity of the microstructure. The segregation of alloy elements gradually decreases as the power increases from 0 W to 500 W. The maximum segregations of carbon and silicon decrease from 2.541 to 1.129 and 2.861 to 1.196, respectively. Given a power of 500 W, the statistical segregations of carbon and silicon decrease from 0.0964 to 0.0693 and 0.1152 to 0.1075, respectively. A further increase in ultrasonic power is not conducive for improving the element segregation. Ultrasonic treatment can remarkably refine the size of carbide and increase the uniformity of its distribution. When the powers are 0 W, 300 W, 500 W, 700 W, and 1,000 W, the average sizes of carbide are 14.63 μm, 2.96 μm, 3.05 μm, 3.72 μm, and 7.83 μm, respectively. The tensile strength, yield strength, and ductility and reduction of the area of the GCr15 bearing steel are correspondingly improved to varying degrees.

  15. Geo-effectiveness and GCR-effectiveness of Interplanetary Coronal Mass Ejections Observed during the Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Aslam, O. P. M.; Badruddin, B.

    2016-07-01

    We study the geomagnetic and Galactic Cosmic Ray (GCR) response of Interplanetary Coronal Mass ejections (ICMEs) observed for the period of 2010 - 2015. We identify the distinct features of ICMEs during their passage. We analyze the hourly resolution data of geomagnetic indices and ground based neutron monitors, with the simultaneous and same time resolution data of interplanetary plasma and field parameters to identify the features of ICMEs and solar wind parameters during their passage when GCR intensity is affected to its maximum level. Similarly, we identify features of ICMEs and solar wind parameters during their passage when geo-effectiveness is at its maximum level. We discuss the similarities and distinctions in the Geo-effectiveness and GCR-effectiveness of the same ICME structure in the light of plasma and field variations, and physical mechanism(s) playing important role in influencing the GCR intensity and geomagnetic activity.

  16. Badhwar-O'Neil 2007 Galactic Cosmic Ray (GCR) Model Using Advanced Composition Explorer (ACE) Measurements for Solar Cycle 23

    NASA Technical Reports Server (NTRS)

    ONeill, P. M.

    2007-01-01

    Advanced Composition Explorer (ACE) satellite measurements of the galactic cosmic ray flux and correlation with the Climax Neutron Monitor count over Solar Cycle 23 are used to update the Badhwar O'Neill Galactic Cosmic Ray (GCR) model.

  17. HZETRN: neutron and proton production in quasi-elastic scattering of GCR heavy-ions

    NASA Technical Reports Server (NTRS)

    Shavers, M. R.; Cucinotta, F. A.; Wilson, J. W.

    2001-01-01

    The development of transport models for radiation shielding design and evaluation has provided a series of deterministic computer codes that describe galactic cosmic radiation (GCR), solar particle events, and experimental beams at particle accelerators. These codes continue to be modified to accommodate new theory and improvements to the particle interaction database (Cucinotta et al., 1994, NASA Technical Paper 3472, US Government Printing Office, Washington DC). The solution employed by the heavy-ion transport code HZETRN was derived with the assumption that nuclear fragments are emitted with the same velocity as the incident ion through velocity conserving nuclear interactions. This paper presents a version of the HZETRN transport code that provides a more realistic distribution of the energy of protons and neutrons emitted from GCR interactions in shields. This study shows that the expected GCR dose equivalent is lower than previously calculated for water shields that are less than 110 g cm-2 thick. Calculations of neutron energy spectra in low Earth orbit indicate substantial contributions from relativistic neutrons. c2001 Elsevier Science Ltd. All rights reseved.

  18. Characterization of the DNA-binding activity of GCR1: in vivo evidence for two GCR1-binding sites in the upstream activating sequence of TPI of Saccharomyces cerevisiae.

    PubMed Central

    Huie, M A; Scott, E W; Drazinic, C M; Lopez, M C; Hornstra, I K; Yang, T P; Baker, H V

    1992-01-01

    GCR1 gene function is required for high-level glycolytic gene expression in Saccharomyces cerevisiae. Recently, we suggested that the CTTCC sequence motif found in front of many genes encoding glycolytic enzymes lay at the core of the GCR1-binding site. Here we mapped the DNA-binding domain of GCR1 to the carboxy-terminal 154 amino acids of the polypeptide. DNase I protection studies showed that a hybrid MBP-GCR1 fusion protein protected a region of the upstream activating sequence of TPI (UASTPI), which harbored the CTTCC sequence motif, and suggested that the fusion protein might also interact with a region of the UAS that contained the related sequence CATCC. A series of in vivo G methylation protection experiments of the native TPI promoter were carried out with wild-type and gcr1 deletion mutant strains. The G doublets that correspond to the C doublets in each site were protected in the wild-type strain but not in the gcr1 mutant strain. These data demonstrate that the UAS of TPI contains two GCR1-binding sites which are occupied in vivo. Furthermore, adjacent RAP1/GRF1/TUF- and REB1/GRF2/QBP/Y-binding sites in UASTPI were occupied in the backgrounds of both strains. In addition, DNA band-shift assays were used to show that the MBP-GCR1 fusion protein was able to form nucleoprotein complexes with oligonucleotides that contained CTTCC sequence elements found in front of other glycolytic genes, namely, PGK, ENO1, PYK, and ADH1, all of which are dependent on GCR1 gene function for full expression. However, we were unable to detect specific interactions with CTTCC sequence elements found in front of the translational component genes TEF1, TEF2, and CRY1. Taken together, these experiments have allowed us to propose a consensus GCR1-binding site which is 5'-(T/A)N(T/C)N(G/A)NC(T/A)TCC(T/A)N(T/A)(T/A)(T/G)-3'. Images PMID:1588965

  19. Asynchronous visual event-based time-to-contact.

    PubMed

    Clady, Xavier; Clercq, Charles; Ieng, Sio-Hoi; Houseini, Fouzhan; Randazzo, Marco; Natale, Lorenzo; Bartolozzi, Chiara; Benosman, Ryad

    2014-01-01

    Reliable and fast sensing of the environment is a fundamental requirement for autonomous mobile robotic platforms. Unfortunately, the frame-based acquisition paradigm at the basis of main stream artificial perceptive systems is limited by low temporal dynamics and redundant data flow, leading to high computational costs. Hence, conventional sensing and relative computation are obviously incompatible with the design of high speed sensor-based reactive control for mobile applications, that pose strict limits on energy consumption and computational load. This paper introduces a fast obstacle avoidance method based on the output of an asynchronous event-based time encoded imaging sensor. The proposed method relies on an event-based Time To Contact (TTC) computation based on visual event-based motion flows. The approach is event-based in the sense that every incoming event adds to the computation process thus allowing fast avoidance responses. The method is validated indoor on a mobile robot, comparing the event-based TTC with a laser range finder TTC, showing that event-based sensing offers new perspectives for mobile robotics sensing. PMID:24570652

  20. Asynchronous visual event-based time-to-contact

    PubMed Central

    Clady, Xavier; Clercq, Charles; Ieng, Sio-Hoi; Houseini, Fouzhan; Randazzo, Marco; Natale, Lorenzo; Bartolozzi, Chiara; Benosman, Ryad

    2014-01-01

    Reliable and fast sensing of the environment is a fundamental requirement for autonomous mobile robotic platforms. Unfortunately, the frame-based acquisition paradigm at the basis of main stream artificial perceptive systems is limited by low temporal dynamics and redundant data flow, leading to high computational costs. Hence, conventional sensing and relative computation are obviously incompatible with the design of high speed sensor-based reactive control for mobile applications, that pose strict limits on energy consumption and computational load. This paper introduces a fast obstacle avoidance method based on the output of an asynchronous event-based time encoded imaging sensor. The proposed method relies on an event-based Time To Contact (TTC) computation based on visual event-based motion flows. The approach is event-based in the sense that every incoming event adds to the computation process thus allowing fast avoidance responses. The method is validated indoor on a mobile robot, comparing the event-based TTC with a laser range finder TTC, showing that event-based sensing offers new perspectives for mobile robotics sensing. PMID:24570652

  1. 27-day variation of the GCR intensity based on corrected and uncorrected for geomagnetic disturbances data of neutron monitors

    NASA Astrophysics Data System (ADS)

    Alania, M. V.; Modzelewska, R.; Wawrzynczak, A.; Sdobnov, V. E.; Kravtsova, M. V.

    2015-08-01

    We study 27-day variations of the galactic cosmic ray (GCR) intensity for 2005-2008 period of the solar cycle #23. We use neutron monitors (NMs) data corrected and uncorrected for geomagnetic disturbances. Besides the limited time intervals when the 27-day variations are clearly established, always exist some feeble 27-day variations in the GCR intensity related to the constantly present weak heliolongitudinal asymmetry in the heliosphere. We calculate the amplitudes of the 27-day variation of the GCR intensity based on the NMs data corrected and uncorrected for geomagnetic disturbances. We show that these amplitudes do not differ for NMs with cut-off rigidities smaller than 4-5 GV comparing with NMs of higher cut-off rigidities. Rigidity spectrum of the 27-day variation of the GCR intensity found in the uncorrected data is soft while it is hard in the case of the corrected data. For both cases exists definite tendency of softening the temporal changes of the 27-day variation's rigidity spectrum in period of 2005 to 2008 approaching the minimum of solar activity. We believe that a study of the 27-day variation of the GCR intensity based on the data uncorrected for geomagnetic disturbances should be carried out by NMs with cut-off rigidities smaller than 4-5 GV.

  2. Asynchronous event-based corner detection and matching.

    PubMed

    Clady, Xavier; Ieng, Sio-Hoi; Benosman, Ryad

    2015-06-01

    This paper introduces an event-based luminance-free method to detect and match corner events from the output of asynchronous event-based neuromorphic retinas. The method relies on the use of space-time properties of moving edges. Asynchronous event-based neuromorphic retinas are composed of autonomous pixels, each of them asynchronously generating "spiking" events that encode relative changes in pixels' illumination at high temporal resolutions. Corner events are defined as the spatiotemporal locations where the aperture problem can be solved using the intersection of several geometric constraints in events' spatiotemporal spaces. A regularization process provides the required constraints, i.e. the motion attributes of the edges with respect to their spatiotemporal locations using local geometric properties of visual events. Experimental results are presented on several real scenes showing the stability and robustness of the detection and matching. PMID:25828960

  3. Abstracting event-based control models for high autonomy systems

    NASA Technical Reports Server (NTRS)

    Luh, Cheng-Jye; Zeigler, Bernard P.

    1993-01-01

    A high autonomy system needs many models on which to base control, management, design, and other interventions. These models differ in level of abstraction and in formalism. Concepts and tools are needed to organize the models into a coherent whole. The paper deals with the abstraction processes for systematic derivation of related models for use in event-based control. The multifaceted modeling methodology is briefly reviewed. The morphism concepts needed for application to model abstraction are described. A theory for supporting the construction of DEVS models needed for event-based control is then presented. An implemented morphism on the basis of this theory is also described.

  4. GCR-induced Photon Luminescence of the Moon: The Moon as a CR Detector

    NASA Technical Reports Server (NTRS)

    Wilson, Thomas L.; Lee, Kerry; Andersen, Vic

    2007-01-01

    We report on the results of a preliminary study of the GCR-induced photon luminescence of the Moon using the Monte Carlo program FLUKA. The model of the lunar surface is taken to be the chemical composition of soils found at various landing sites during the Apollo and Luna programs, averaged over all such sites to define a generic regolith for the present analysis. This then becomes the target that is bombarded by Galactic Cosmic Rays (GCRs) in FLUKA to determine the photon fluence when there is no sunshine or Earthshine. From the photon fluence we derive the energy spectrum which can be utilized to design an orbiting optical instrument for measuring the GCR-induced luminescence. This is to be distinguished from the gamma-ray spectrum produced by the radioactive decay of its radiogenic constituents lying in the surface and interior. Also, we investigate transient optical flashes from high-energy CRs impacting the lunar surface (boulders and regolith). The goal is to determine to what extent the Moon could be used as a rudimentary CR detector. Meteor impacts on the Moon have been observed for centuries to generate such flashes, so why not CRs?

  5. Elemental GCR Observations during the 2009-2010 Solar Minimum Period

    NASA Technical Reports Server (NTRS)

    Lave, K. A.; Israel, M. H.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; deNolfo, G. A.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; vonRosenvinge, T. T.; Wiedenbeck, M. E.

    2013-01-01

    Using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer (ACE), we present new measurements of the galactic cosmic ray (GCR) elemental composition and energy spectra for the species B through Ni in the energy range approx. 50-550 MeV/nucleon during the record setting 2009-2010 solar minimum period. These data are compared with our observations from the 1997-1998 solar minimum period, when solar modulation in the heliosphere was somewhat higher. For these species, we find that the intensities during the 2009-2010 solar minimum were approx. 20% higher than those in the previous solar minimum, and in fact were the highest GCR intensities recorded during the space age. Relative abundances for these species during the two solar minimum periods differed by small but statistically significant amounts, which are attributed to the combination of spectral shape differences between primary and secondary GCRs in the interstellar medium and differences between the levels of solar modulation in the two solar minima. We also present the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe for both solar minimum periods, and demonstrate that these ratios are reasonably well fit by a simple "leaky-box" galactic transport model that is combined with a spherically symmetric solar modulation model.

  6. Comparison of Transport Codes, HZETRN, HETC and FLUKA, Using 1977 GCR Solar Minimum Spectra

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.; Slaba, Tony C.; Tripathi, Ram K.; Blattnig, Steve R.; Norbury, John W.; Badavi, Francis F.; Townsend, Lawrence W.; Handler, Thomas; Gabriel, Tony A.; Pinsky, Lawrence S.; Reddell, Brandon; Aumann, Aric R.

    2009-01-01

    The HZETRN deterministic radiation transport code is one of several tools developed to analyze the effects of harmful galactic cosmic rays (GCR) and solar particle events (SPE) on mission planning, astronaut shielding and instrumentation. This paper is a comparison study involving the two Monte Carlo transport codes, HETC-HEDS and FLUKA, and the deterministic transport code, HZETRN. Each code is used to transport ions from the 1977 solar minimum GCR spectrum impinging upon a 20 g/cm2 Aluminum slab followed by a 30 g/cm2 water slab. This research is part of a systematic effort of verification and validation to quantify the accuracy of HZETRN and determine areas where it can be improved. Comparisons of dose and dose equivalent values at various depths in the water slab are presented in this report. This is followed by a comparison of the proton fluxes, and the forward, backward and total neutron fluxes at various depths in the water slab. Comparisons of the secondary light ion 2H, 3H, 3He and 4He fluxes are also examined.

  7. Miniaturized Hollow-Waveguide Gas Correlation Radiometer (GCR) for Trace Gas Detection in the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    Wilson, Emily L.; Georgieva, E. M.; Melroy, H. R.

    2012-01-01

    Gas correlation radiometry (GCR) has been shown to be a sensitive and versatile method for detecting trace gases in Earth's atmosphere. Here, we present a miniaturized and simplified version of this instrument capable of mapping multiple trace gases and identifying active regions on the Mars surface. Reduction of the size and mass of the GCR instrument has been achieved by implementing a lightweight, 1 mm inner diameter hollow-core optical fiber (hollow waveguide) for the gas correlation cell. Based on a comparison with an Earth orbiting CO2 gas correlation instrument, replacement of the 10 meter mUltipass cell with hollow waveguide of equivalent pathlength reduces the cell mass from approx 150 kg to approx 0.5 kg, and reduces the volume from 1.9 m x 1.3 m x 0.86 m to a small bundle of fiber coils approximately I meter in diameter by 0.05 m in height (mass and volume reductions of >99%). This modular instrument technique can be expanded to include measurements of additional species of interest including nitrous oxide (N2O), hydrogen sulfide (H2S), methanol (CH3OH), and sulfur dioxide (SO2), as well as carbon dioxide (CO2) for a simultaneous measure of mass balance.

  8. Spatiotemporal features for asynchronous event-based data

    PubMed Central

    Lagorce, Xavier; Ieng, Sio-Hoi; Clady, Xavier; Pfeiffer, Michael; Benosman, Ryad B.

    2015-01-01

    Bio-inspired asynchronous event-based vision sensors are currently introducing a paradigm shift in visual information processing. These new sensors rely on a stimulus-driven principle of light acquisition similar to biological retinas. They are event-driven and fully asynchronous, thereby reducing redundancy and encoding exact times of input signal changes, leading to a very precise temporal resolution. Approaches for higher-level computer vision often rely on the reliable detection of features in visual frames, but similar definitions of features for the novel dynamic and event-based visual input representation of silicon retinas have so far been lacking. This article addresses the problem of learning and recognizing features for event-based vision sensors, which capture properties of truly spatiotemporal volumes of sparse visual event information. A novel computational architecture for learning and encoding spatiotemporal features is introduced based on a set of predictive recurrent reservoir networks, competing via winner-take-all selection. Features are learned in an unsupervised manner from real-world input recorded with event-based vision sensors. It is shown that the networks in the architecture learn distinct and task-specific dynamic visual features, and can predict their trajectories over time. PMID:25759637

  9. A Multinomial Model of Event-Based Prospective Memory

    ERIC Educational Resources Information Center

    Smith, Rebekah E.; Bayen, Ute J.

    2004-01-01

    Prospective memory is remembering to perform an action in the future. The authors introduce the 1st formal model of event-based prospective memory, namely, a multinomial model that includes 2 separate parameters related to prospective memory processes. The 1st measures preparatory attentional processes, and the 2nd measures retrospective memory…

  10. Nuclear fragmentation of GCR-like ions: comparisons between data and PHITS

    NASA Astrophysics Data System (ADS)

    Zeitlin, Cary; Guetersloh, Stephen; Heilbronn, Lawrence; Miller, Jack; Sihver, Lembit; Mancusi, Davide; Fukumura, Aki; Iwata, Yoshi; Murakami, Takeshi

    We present a summary of results from recent work in which we have compared nuclear fragmentation cross section data to predictions of the PHITS Monte Carlo simulation. The studies used beams of 12 C, 35 Cl, 40 Ar, 48 Ti, and 56 Fe at energies ranging from 290 MeV/nucleon to 1000 MeV/nucleon. Some of the data were obtained at the Brookhaven National Laboratory, others at the National Institute of Radiological Sciences in Japan. These energies and ion species are representative of the heavy ion component of the Galactic Cosmic Rays (GCR), which contribute significantly to the dose and dose equivalent that will be received by astronauts on deep-space missions. A critical need for NASA is the ability to accurately model the transport of GCR heavy ions through matter, including spacecraft walls, equipment racks, and other shielding materials, as well as through tissue. Nuclear interaction cross sections are of primary importance in the GCR transport problem. These interactions generally cause the incoming ion to break up (fragment) into one or more lighter ions, which continue approximately along the initial trajectory and with approximately the same velocity the incoming ion had prior to the interaction. Since the radiation dose delivered by a particle is proportional to the square of the quantity (charge/velocity), i.e., to (Z/β)2 , fragmentation reduces the dose (and, typically, dose equivalent) delivered by incident ions. The other mechanism by which dose can be reduced is ionization energy loss, which can lead to some particles stopping in the shielding. This is the conventional notion of shielding, but it is not applicable to human spaceflight, since the particles in the GCR tend to be highly energetic and because shielding must be relatively thin in order to keep overall mass as low as possible, keeping launch costs within reason. To support these goals, our group has systematically measured a large number of nuclear cross sections, intended to be used as either

  11. Secondary Cosmic Ray Particles Due to GCR Interactions in the Earth's Atmosphere

    SciTech Connect

    Battistoni, G.; Cerutti, F.; Fasso, A.; Ferrari, A.; Garzelli, M.V.; Lantz, M.; Muraro, S. Pinsky, L.S.; Ranft, J.; Roesler, S.; Sala, P.R.; /Milan U. /INFN, Milan

    2009-06-16

    Primary GCR interact with the Earth's atmosphere originating atmospheric showers, thus giving rise to fluxes of secondary particles in the atmosphere. Electromagnetic and hadronic interactions interplay in the production of these particles, whose detection is performed by means of complementary techniques in different energy ranges and at different depths in the atmosphere, down to the Earth's surface. Monte Carlo codes are essential calculation tools which can describe the complexity of the physics of these phenomena, thus allowing the analysis of experimental data. However, these codes are affected by important uncertainties, concerning, in particular, hadronic physics at high energy. In this paper we shall report some results concerning inclusive particle fluxes and atmospheric shower properties as obtained using the FLUKA transport and interaction code. Some emphasis will also be given to the validation of the physics models of FLUKA involved in these calculations.

  12. Solar Activity and GCR Particle Flux Variations: Assessment and Modeling with Ulysses and ACE/CRIS

    NASA Astrophysics Data System (ADS)

    Saganti, Premkumar

    Galactic Cosmic Ray (GCR) environment during the current and historically known lower solar minimum condition indicate some of the very high anticipated measurements of particle spectral data. Data from the Ulysses spacecraft in the polar orbit about the sun during the years 2004 and 2008 (about 5 AU) provided proton and alpha particle flux data and showed such anticipated high particle flux variations. Also, ACE/CRIS spacecraft data during the years 2007 and 2009 showed some of the high particle flux measurements of several heavy ions such as oxygen and iron. We present Ulysses and ACE/CRIS measured particle flux data and discuss their high density and variations in the context of the current low solar activity for depicting current space radiation environment.

  13. Microstructure of warm rolling and pearlitic transformation of ultrafine-grained GCr15 steel

    SciTech Connect

    Sun, Jun-Jie; Lian, Fu-Liang; Liu, Hong-Ji; Jiang, Tao; Guo, Sheng-Wu; Du, Lin-Xiu; Liu, Yong-Ning

    2014-09-15

    Pearlitic transformation mechanisms have been investigated in ultra-fine grained GCr15 steel. The ultrafine-grained steel, whose grain size was less than 1 μm, was prepared by thermo-mechanical treatment at 873 K and then annealing at 923 K for 2 h. Pearlitic transformation was conducted by reheating the ultra-fine grained samples at 1073 K and 1123 K for different periods of time and then cooling in air. Scanning electron microscope observation shows that normal lamellar pearlite, instead of granular cementite and ferrite, cannot be formed when the grain size is approximately less than 4(± 0.6) μm, which yields a critical grain size for normal lamellar pearlitic transformations in this chromium alloyed steel. The result confirms that grain size has a great influence on pearlitic transformation by increasing the diffusion rate of carbon atoms in the ultra-fine grained steel, and the addition of chromium element doesn't change this pearlitic phase transformation rule. Meanwhile, the grain growth rate is reduced by chromium alloying, which is beneficial to form fine grains during austenitizing, thus it facilitating pearlitic transformation by divorced eutectoid transformation. Moreover, chromium element can form a relatively high gradient in the frontier of the undissolved carbide, which promotes carbide formation in the frontier of the undissolved carbide, i.e., chromium promotes divorced eutectoid transformation. - Highlights: • Ultrafine-grained GCr15 steel was obtained by warm rolling and annealing technology. • Reduction of grain size makes pearlite morphology from lamellar to granular. • Adding Cr does not change normal pearlitic phase transformation rule in UFG steel. • Cr carbide resists grain growth and facilitates pearlitic transformation by DET.

  14. Mars Science Laboratory; A Model for Event-Based EPO

    NASA Astrophysics Data System (ADS)

    Mayo, Louis; Lewis, E.; Cline, T.; Stephenson, B.; Erickson, K.; Ng, C.

    2012-10-01

    The NASA Mars Science Laboratory (MSL) and its Curiosity Rover, a part of NASA's Mars Exploration Program, represent the most ambitious undertaking to date to explore the red planet. MSL/Curiosity was designed primarily to determine whether Mars ever had an environment capable of supporting microbial life. NASA's MSL education program was designed to take advantage of existing, highly successful event based education programs to communicate Mars science and education themes to worldwide audiences through live webcasts, video interviews with scientists, TV broadcasts, professional development for teachers, and the latest social media frameworks. We report here on the success of the MSL education program and discuss how this methodological framework can be used to enhance other event based education programs.

  15. Mutations in GCR3, a gene involved in the expression of glycolytic genes in Saccharomyces cerevisiae, suppress the temperature-sensitive growth of hpr1 mutants

    SciTech Connect

    Uemura, Hiroshi; Jigami, Yoshifumi; Pandit, Sunil; Sternglanz, R.

    1996-04-01

    To study the functions of DNA topoisomerase I and Hpr1 protein, a suppressor mutant of the temperature-sensitive growth of an hpr1 top1-5{sup ts} double mutant was isolated. The isolated triple mutant showed cold-sensitive growth. By complementation of this phenotype, the suppressor gene was cloned. DNA sequencing showed it to be GCR3, a gene involved in the expression of glycol genes. Further analysis showed that gcr3 mutations also suppressed the temperature-sensitive growth of hpr1 single mutants. Experiments with gcr3 truncation mutants also suggested a genetic interaction between GCR3 and HPR1. The fact that top1 suppressed the growth defect of gcr3 suggested an interaction between those two genes also. Plasmid DNA isolated from gcr3 mutants was significantly more negatively supercoiled than normal, suggesting that Gcr3 protein, like topoisomerase I and Hpr1p, affects chromatin structure, perhaps during transcription. 43 refs., 2 figs., 6 tabs.

  16. GCR Transport in the Brain: Assessment of Self-Shielding, Columnar Damage, and Nuclear Reactions on Cell Inactivation Rates

    NASA Technical Reports Server (NTRS)

    Shavers, M. R.; Atwell, W.; Cucinotta, F. A.; Badhwar, G. D. (Technical Monitor)

    1999-01-01

    Radiation shield design is driven by the need to limit radiation risks while optimizing risk reduction with launch mass/expense penalties. Both limitation and optimization objectives require the development of accurate and complete means for evaluating the effectiveness of various shield materials and body-self shielding. For galactic cosmic rays (GCR), biophysical response models indicate that track structure effects lead to substantially different assessments of shielding effectiveness relative to assessments based on LET-dependent quality factors. Methods for assessing risk to the central nervous system (CNS) from heavy ions are poorly understood at this time. High-energy and charge (HZE) ion can produce tissue events resulting in damage to clusters of cells in a columnar fashion, especially for stopping heavy ions. Grahn (1973) and Todd (1986) have discussed a microlesion concept or model of stochastic tissue events in analyzing damage from HZE's. Some tissues, including the CNS, maybe sensitive to microlesion's or stochastic tissue events in a manner not illuminated by either conventional dosimetry or fluence-based risk factors. HZE ions may also produce important lateral damage to adjacent cells. Fluences of high-energy proton and alpha particles in the GCR are many times higher than HZE ions. Behind spacecraft and body self-shielding the ratio of protons, alpha particles, and neutrons to HZE ions increases several-fold from free-space values. Models of GCR damage behind shielding have placed large concern on the role of target fragments produced from tissue atoms. The self-shielding of the brain reduces the number of heavy ions reaching the interior regions by a large amount and the remaining light particle environment (protons, neutrons, deuterons. and alpha particles) may be the greatest concern. Tracks of high-energy proton produce nuclear reactions in tissue, which can deposit doses of more than 1 Gv within 5 - 10 cell layers. Information on rates of

  17. Event-based Simulation Model for Quantum Optics Experiments

    SciTech Connect

    De Raedt, H.; Michielsen, K.

    2011-03-28

    We present a corpuscular simulation model of optical phenomena that does not require the knowledge of the solution of a wave equation of the whole system and reproduces the results of Maxwell's theory by generating detection events one-by-one. The event-based corpuscular model gives a unified description of multiple-beam fringes of a plane parallel plate and single-photon Mach-Zehnder interferometer, Wheeler's delayed choice, photon tunneling, quantum eraser, two-beam interference, double-slit, Einstein-Podolsky-Rosen-Bohm and Hanbury Brown-Twiss experiments. We also discuss the possibility to refute our corpuscular model.

  18. Event-Based Processing of Neutron Scattering Data

    SciTech Connect

    Peterson, Peter F.; Campbell, Stuart I.; Reuter, Michael A.; Taylor, Russell J.; Zikovsky, Janik L.

    2015-09-16

    Many of the world's time-of-flight spallation neutrons sources are migrating to the recording of individual neutron events. This provides for new opportunities in data processing, the least of which is to filter the events based on correlating them with logs of sample environment and other ancillary equipment. This paper will describe techniques for processing neutron scattering data acquired in event mode that preserve event information all the way to a final spectrum, including any necessary corrections or normalizations. This results in smaller final errors, while significantly reducing processing time and memory requirements in typical experiments. Results with traditional histogramming techniques will be shown for comparison.

  19. MHD compressor---expander conversion system integrated with GCR inside a deployable reflector

    SciTech Connect

    Tuninetti, G. . Research Div.); Botta, E.; Criscuolo, C.; Riscossa, P. . Nuclear Div.); Giammanco, F. . Dipt. di Fisica); Rosa-Clot, M. . Dipt. di Fisica)

    1989-04-20

    This work originates from the proposal MHD Compressor-Expander Conversion System Integrated with a GCR Inside a Deployable Reflector''. The proposal concerned an innovative concept of nuclear, closed-cycle MHD converter for power generation on space-based systems in the multi-megawatt range. The basic element of this converter is the Power Conversion Unit (PCU) consisting of a gas core reactor directly coupled to an MHD expansion channel. Integrated with the PCU, a deployable reflector provides reactivity control. The working fluid could be either uranium hexafluoride or a mixture of uranium hexafluoride and helium, added to enhance the heat transfer properties. The original Statement of Work, which concerned the whole conversion system, was subsequently redirected and focused on the basic mechanisms of neutronics, reactivity control, ionization and electrical conductivity in the PCU. Furthermore, the study was required to be inherently generic such that the study was required to be inherently generic such that the analysis an results can be applied to various nuclear reactor and/or MHD channel designs''.

  20. Assessment and Requirements of Nuclear Reaction Databases for GCR Transport in the Atmosphere and Structures

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Wilson, J. W.; Shinn, J. L.; Tripathi, R. K.

    1998-01-01

    The transport properties of galactic cosmic rays (GCR) in the atmosphere, material structures, and human body (self-shielding) am of interest in risk assessment for supersonic and subsonic aircraft and for space travel in low-Earth orbit and on interplanetary missions. Nuclear reactions, such as knockout and fragmentation, present large modifications of particle type and energies of the galactic cosmic rays in penetrating materials. We make an assessment of the current nuclear reaction models and improvements in these model for developing required transport code data bases. A new fragmentation data base (QMSFRG) based on microscopic models is compared to the NUCFRG2 model and implications for shield assessment made using the HZETRN radiation transport code. For deep penetration problems, the build-up of light particles, such as nucleons, light clusters and mesons from nuclear reactions in conjunction with the absorption of the heavy ions, leads to the dominance of the charge Z = 0, 1, and 2 hadrons in the exposures at large penetration depths. Light particles are produced through nuclear or cluster knockout and in evaporation events with characteristically distinct spectra which play unique roles in the build-up of secondary radiation's in shielding. We describe models of light particle production in nucleon and heavy ion induced reactions and make an assessment of the importance of light particle multiplicity and spectral parameters in these exposures.

  1. Event-Based Processing of Neutron Scattering Data

    DOE PAGESBeta

    Peterson, Peter F.; Campbell, Stuart I.; Reuter, Michael A.; Taylor, Russell J.; Zikovsky, Janik L.

    2015-09-16

    Many of the world's time-of-flight spallation neutrons sources are migrating to the recording of individual neutron events. This provides for new opportunities in data processing, the least of which is to filter the events based on correlating them with logs of sample environment and other ancillary equipment. This paper will describe techniques for processing neutron scattering data acquired in event mode that preserve event information all the way to a final spectrum, including any necessary corrections or normalizations. This results in smaller final errors, while significantly reducing processing time and memory requirements in typical experiments. Results with traditional histogramming techniquesmore » will be shown for comparison.« less

  2. The yeast protein Gcr1p binds to the PGK UAS and contributes to the activation of transcription of the PGK gene.

    PubMed

    Henry, Y A; López, M C; Gibbs, J M; Chambers, A; Kingsman, S M; Baker, H V; Stanway, C A

    1994-11-15

    Analysis of the upstream activation sequence (UAS) of the yeast phosphoglycerate kinase gene (PGK) has demonstrated that a number of sequence elements are involved in its activity and two of these sequences are bound by the multifunctional factors Rap1p and Abf1p. In this report we show by in vivo footprinting that the regulatory factor encoded by GCR1 binds to two elements in the 3' half of the PGK UAS. These elements contain the sequence CTTCC, which was previously suggested to be important for the activity of the PGK UAS and has been shown to be able to bind Gcr1p in vitro. Furthermore, we find that Gcr1p positively influences PGK transcription, although it is not responsible for the carbon source dependent regulation of PGK mRNA synthesis. In order to mediate its transcriptional influence we find that Gcr1p requires the Rap1p binding site, in addition to its own, but not the Abf1p site. As neither a Rap1p nor a Gcr1p binding site alone is able to activate transcription, we propose that Gcr1p and Rap1p interact in an interdependent fashion to activate PGK transcription. PMID:7808400

  3. G-protein Signaling Components GCR1 and GPA1 Mediate Responses to Multiple Abiotic Stresses in Arabidopsis

    PubMed Central

    Chakraborty, Navjyoti; Singh, Navneet; Kaur, Kanwaljeet; Raghuram, Nandula

    2015-01-01

    G-protein signaling components have been implicated in some individual stress responses in Arabidopsis, but have not been comprehensively evaluated at the genetic and biochemical level. Stress emerged as the largest functional category in our whole transcriptome analyses of knock-out mutants of GCR1 and/or GPA1 in Arabidopsis (Chakraborty et al., 2015a,b). This led us to ask whether G-protein signaling components offer converging points in the plant's response to multiple abiotic stresses. In order to test this hypothesis, we carried out detailed analysis of the abiotic stress category in the present study, which revealed 144 differentially expressed genes (DEGs), spanning a wide range of abiotic stresses, including heat, cold, salt, light stress etc. Only 10 of these DEGs are shared by all the three mutants, while the single mutants (GCR1/GPA1) shared more DEGs between themselves than with the double mutant (GCR1-GPA1). RT-qPCR validation of 28 of these genes spanning different stresses revealed identical regulation of the DEGs shared between the mutants. We also validated the effects of cold, heat and salt stresses in all the 3 mutants and WT on % germination, root and shoot length, relative water content, proline content, lipid peroxidation and activities of catalase, ascorbate peroxidase and superoxide dismutase. All the 3 mutants showed evidence of stress tolerance, especially to cold, followed by heat and salt, in terms of all the above parameters. This clearly shows the role of GCR1 and GPA1 in mediating the plant's response to multiple abiotic stresses for the first time, especially cold, heat and salt stresses. This also implies a role for classical G-protein signaling pathways in stress sensitivity in the normal plants of Arabidopsis. This is also the first genetic and biochemical evidence of abiotic stress tolerance rendered by knock-out mutation of GCR1 and/or GPA1. This suggests that G-protein signaling pathway could offer novel common targets for the

  4. Determining the Magnitude of Neutron and Galactic Cosmic Ray (GCR) Fluxes at the Moon using the Lunar Exploration Neutron Detector during the Historic Space-Age Era of High GCR Flux

    NASA Astrophysics Data System (ADS)

    Chin, G.; Sagdeev, R.; Boynton, W. V.; Mitrofanov, I. G.; Milikh, G. M.; Su, J. J.; Livengood, T. A.; McClanahan, T. P.; Evans, L.; Starr, R. D.; litvak, M. L.; Sanin, A.

    2013-12-01

    The Lunar Reconnaissance Orbiter (LRO) was launched June 18, 2009 during an historic space-age era of minimum solar activity [1]. The lack of solar sunspot activity signaled a complex set of heliospheric phenomena [2,3,4] that also gave rise to a period of unprecedentedly high Galactic Cosmic Ray (GCR) flux [5]. These events coincided with the primary mission of the Lunar Exploration Neutron Detector (LEND, [6]), onboard LRO in a nominal 50-km circular orbit of the Moon [7]. Methods to calculate the emergent neutron albedo population using Monte Carlo techniques [8] rely on an estimate of the GCR flux and spectra calibrated at differing periods of solar activity [9,10,11]. Estimating the actual GCR flux at the Moon during the LEND's initial period of operation requires a correction using a model-dependent heliospheric transport modulation parameter [12] to adjust the GCR flux appropriate to this unique solar cycle. These corrections have inherent uncertainties depending on model details [13]. Precisely determining the absolute neutron and GCR fluxes is especially important in understanding the emergent lunar neutrons measured by LEND and subsequently in estimating the hydrogen/water content in the lunar regolith [6]. LEND is constructed with a set of neutron detectors to meet differing purposes [6]. Specifically there are two sets of detector systems that measure the flux of epithermal neutrons: a) the uncollimated Sensor for Epi-Thermal Neutrons (SETN) and b) the Collimated Sensor for Epi-Thermal Neutrons (CSETN). LEND SETN and CSETN observations form a complementary set of simultaneous measurements that determine the absolute scale of emergent lunar neutron flux in an unambiguous fashion and without the need for correcting to differing solar-cycle conditions. LEND measurements are combined with a detailed understanding of the sources of instrumental back-ground, and the performance of CSETN and SETN. This comparison allows us to calculate a constant scale factor

  5. Event-Based User Classification in Weibo Media

    PubMed Central

    Wang, Wendong; Cheng, Shiduan; Que, Xirong

    2014-01-01

    Weibo media, known as the real-time microblogging services, has attracted massive attention and support from social network users. Weibo platform offers an opportunity for people to access information and changes the way people acquire and disseminate information significantly. Meanwhile, it enables people to respond to the social events in a more convenient way. Much of the information in Weibo media is related to some events. Users who post different contents, and exert different behavior or attitude may lead to different contribution to the specific event. Therefore, classifying the large amount of uncategorized social circles generated in Weibo media automatically from the perspective of events has been a promising task. Under this circumstance, in order to effectively organize and manage the huge amounts of users, thereby further managing their contents, we address the task of user classification in a more granular, event-based approach in this paper. By analyzing real data collected from Sina Weibo, we investigate the Weibo properties and utilize both content information and social network information to classify the numerous users into four primary groups: celebrities, organizations/media accounts, grassroots stars, and ordinary individuals. The experiments results show that our method identifies the user categories accurately. PMID:25133235

  6. Neuromorphic Event-Based 3D Pose Estimation

    PubMed Central

    Reverter Valeiras, David; Orchard, Garrick; Ieng, Sio-Hoi; Benosman, Ryad B.

    2016-01-01

    Pose estimation is a fundamental step in many artificial vision tasks. It consists of estimating the 3D pose of an object with respect to a camera from the object's 2D projection. Current state of the art implementations operate on images. These implementations are computationally expensive, especially for real-time applications. Scenes with fast dynamics exceeding 30–60 Hz can rarely be processed in real-time using conventional hardware. This paper presents a new method for event-based 3D object pose estimation, making full use of the high temporal resolution (1 μs) of asynchronous visual events output from a single neuromorphic camera. Given an initial estimate of the pose, each incoming event is used to update the pose by combining both 3D and 2D criteria. We show that the asynchronous high temporal resolution of the neuromorphic camera allows us to solve the problem in an incremental manner, achieving real-time performance at an update rate of several hundreds kHz on a conventional laptop. We show that the high temporal resolution of neuromorphic cameras is a key feature for performing accurate pose estimation. Experiments are provided showing the performance of the algorithm on real data, including fast moving objects, occlusions, and cases where the neuromorphic camera and the object are both in motion. PMID:26834547

  7. A storm event-based approach to TMDL development.

    PubMed

    Hsu, Tsung-Hung; Lin, Jen-Yang; Lee, Tsu-Chuan; Zhang, Harry X; Yu, Shaw L

    2010-04-01

    It is vitally important to define the critical condition for a receiving water body in the total maximum daily load (TMDL) development process. One of the major disadvantages of using a continuous simulation approach is that there is no guarantee that the most critical condition will be covered within the subjectively selected representative hydrologic period, which is usually several years depending on the availability of data. Another limitation of the continuous simulation approach, compared to a design storm approach, is the lack of an estimate of the risk involved. Because of the above limitations, a storm event-based critical flow-storm (CFS) approach was previously developed to explicitly address the critical condition as a combination of a prescribed stream flow and a storm event of certain magnitude, both having a certain frequency of occurrence and when combined, would create a critical condition. The CFS approach was tested successfully in a TMDL study for Muddy Creek in Virginia. The present paper reports results of a comparative study on the applicability of the CFS approach in Taiwan. The Dy-yu creek watershed in northern Taiwan differs significantly from Muddy Creek in terms of climate, hydrology, terrain, and other characteristics. Results show that the critical condition for different watersheds might be also different, and that the CFS approach could clearly define that critical condition and should be considered as an alternative method for TMDL development to a continuous simulation approach. PMID:19266300

  8. Event-based user classification in Weibo media.

    PubMed

    Guo, Liang; Wang, Wendong; Cheng, Shiduan; Que, Xirong

    2014-01-01

    Weibo media, known as the real-time microblogging services, has attracted massive attention and support from social network users. Weibo platform offers an opportunity for people to access information and changes the way people acquire and disseminate information significantly. Meanwhile, it enables people to respond to the social events in a more convenient way. Much of the information in Weibo media is related to some events. Users who post different contents, and exert different behavior or attitude may lead to different contribution to the specific event. Therefore, classifying the large amount of uncategorized social circles generated in Weibo media automatically from the perspective of events has been a promising task. Under this circumstance, in order to effectively organize and manage the huge amounts of users, thereby further managing their contents, we address the task of user classification in a more granular, event-based approach in this paper. By analyzing real data collected from Sina Weibo, we investigate the Weibo properties and utilize both content information and social network information to classify the numerous users into four primary groups: celebrities, organizations/media accounts, grassroots stars, and ordinary individuals. The experiments results show that our method identifies the user categories accurately. PMID:25133235

  9. Self-Driven Decay Heat Removal in a GCR Closed Brayton Cycle Power System

    SciTech Connect

    Wright, Steven A.; Lipinski, Ronald J.

    2006-07-01

    Closed Brayton Cycle (CBC) systems that are driven by Gas Cooled Reactors (GCR) are being evaluated for high-efficiency electricity generation. These systems were also selected by the Naval Reactor Prime Contractor team for use as space power systems. This paper describes the decay heat removal performance of these systems. A key question for such space or terrestrial based CBC systems is how to shut down the reactor while still removing the decay heat without using substantial amounts of auxiliary power. Tests in the Sandia Brayton Loop (SBL) show that the Brayton cycle is capable of operating on sensible heat for very long times ({approx} hour) after the reactor is shut down. This paper describes the measured and predicted results of generated electrical power produced as a function of time after the heat source had been turned off in the Sandia Brayton Loop. The measured results were obtained from an electrically heated closed Brayton cycle test loop (SBL) that Sandia fabricated and has operating within the laboratories. The predicted behavior is based on integrated dynamic system models that are capable of predicting both the transient and steady state behavior of nuclear heated or electrically heated Brayton cycle systems. The measured data was obtained by running the SBL and shutting off the electrical heater while adjusting the flow through the loop to keep the system operating at (or just above) its self-sustaining operating power level. During the test we were able to produce {approx}500 W of power for over 73 minutes after the heater power was turned off. Thus the Brayton loop was able to operate at self-sustaining conditions (or better) for over one hour. During this time the turbo-compressor was transporting the sensible heat in the heater, ducting, and recuperator to the waste heat rejection system for over an hour. For a reactor-driven system in space, this would give the shutdown decay power sufficient time to decay to levels where it could be

  10. Event-based internet biosurveillance: relation to epidemiological observation

    PubMed Central

    2012-01-01

    Background The World Health Organization (WHO) collects and publishes surveillance data and statistics for select diseases, but traditional methods of gathering such data are time and labor intensive. Event-based biosurveillance, which utilizes a variety of Internet sources, complements traditional surveillance. In this study we assess the reliability of Internet biosurveillance and evaluate disease-specific alert criteria against epidemiological data. Methods We reviewed and compared WHO epidemiological data and Argus biosurveillance system data for pandemic (H1N1) 2009 (April 2009 – January 2010) from 8 regions and 122 countries to: identify reliable alert criteria among 15 Argus-defined categories; determine the degree of data correlation for disease progression; and assess timeliness of Internet information. Results Argus generated a total of 1,580 unique alerts; 5 alert categories generated statistically significant (p < 0.05) correlations with WHO case count data; the sum of these 5 categories was highly correlated with WHO case data (r = 0.81, p < 0.0001), with expected differences observed among the 8 regions. Argus reported first confirmed cases on the same day as WHO for 21 of the first 64 countries reporting cases, and 1 to 16 days (average 1.5 days) ahead of WHO for 42 of those countries. Conclusion Confirmed pandemic (H1N1) 2009 cases collected by Argus and WHO methods returned consistent results and confirmed the reliability and timeliness of Internet information. Disease-specific alert criteria provide situational awareness and may serve as proxy indicators to event progression and escalation in lieu of traditional surveillance data; alerts may identify early-warning indicators to another pandemic, preparing the public health community for disease events. PMID:22709988

  11. The bacterial cell cycle regulator GcrA is a σ70 cofactor that drives gene expression from a subset of methylated promoters.

    PubMed

    Haakonsen, Diane L; Yuan, Andy H; Laub, Michael T

    2015-11-01

    Cell cycle progression in most organisms requires tightly regulated programs of gene expression. The transcription factors involved typically stimulate gene expression by binding specific DNA sequences in promoters and recruiting RNA polymerase. Here, we found that the essential cell cycle regulator GcrA in Caulobacter crescentus activates the transcription of target genes in a fundamentally different manner. GcrA forms a stable complex with RNA polymerase and localizes to almost all active σ(70)-dependent promoters in vivo but activates transcription primarily at promoters harboring certain DNA methylation sites. Whereas most transcription factors that contact σ(70) interact with domain 4, GcrA interfaces with domain 2, the region that binds the -10 element during strand separation. Using kinetic analyses and a reconstituted in vitro transcription assay, we demonstrated that GcrA can stabilize RNA polymerase binding and directly stimulate open complex formation to activate transcription. Guided by these studies, we identified a regulon of ∼ 200 genes, providing new insight into the essential functions of GcrA. Collectively, our work reveals a new mechanism for transcriptional regulation, and we discuss the potential benefits of activating transcription by promoting RNA polymerase isomerization rather than recruitment exclusively. PMID:26545812

  12. The bacterial cell cycle regulator GcrA is a σ70 cofactor that drives gene expression from a subset of methylated promoters

    PubMed Central

    Haakonsen, Diane L.; Yuan, Andy H.; Laub, Michael T.

    2015-01-01

    Cell cycle progression in most organisms requires tightly regulated programs of gene expression. The transcription factors involved typically stimulate gene expression by binding specific DNA sequences in promoters and recruiting RNA polymerase. Here, we found that the essential cell cycle regulator GcrA in Caulobacter crescentus activates the transcription of target genes in a fundamentally different manner. GcrA forms a stable complex with RNA polymerase and localizes to almost all active σ70-dependent promoters in vivo but activates transcription primarily at promoters harboring certain DNA methylation sites. Whereas most transcription factors that contact σ70 interact with domain 4, GcrA interfaces with domain 2, the region that binds the −10 element during strand separation. Using kinetic analyses and a reconstituted in vitro transcription assay, we demonstrated that GcrA can stabilize RNA polymerase binding and directly stimulate open complex formation to activate transcription. Guided by these studies, we identified a regulon of ∼200 genes, providing new insight into the essential functions of GcrA. Collectively, our work reveals a new mechanism for transcriptional regulation, and we discuss the potential benefits of activating transcription by promoting RNA polymerase isomerization rather than recruitment exclusively. PMID:26545812

  13. Event based climatology of extreme precipitation in Europe

    NASA Astrophysics Data System (ADS)

    Nissen, Katrin M.; Becker, Nico; Ulbrich, Uwe

    2015-04-01

    An event based detection algorithm to identify extreme precipitation events in gridded data sets is introduced and applied to the observational E-OBS data set. The algorithm identifies all grid boxes in which the rainfall exceeds a threshold, which depends on the location and the aggregation period. The aggregation periods taken into account in this study range from a single time step up to 72 hours. The local 50-year return level is calculated for all aggregation periods and used as a threshold. All identified grid boxes which are located within the same continuous rain area (i.e. which are not separated by rain free grid boxes) are considered as belonging to the same event and form a cluster. The centre of mass is calculated for each cluster. The clusters are then tracked in time using a nearest neighbor approach. Thus, each detected event can consist of several grid boxes and can last for several time steps. A precipitation severity index (PSI) is assigned to the events. The severity index takes the affected area and the amount of precipitation accumulated over the duration of the event into account. It is normalized by the long-term mean annual precipitation sum expected for the grid box. The severity index can be used to compare the strength of the identified events. The detection algorithm also stores additional information for each event, such as the date, location, affected area, duration, severity and maximum precipitation. Comparing all events detected in the E-OBS data set, which exceeded the local 50-year return levels, the highest severity index was calculated for an event affecting Spain, which took place in November 1997. It had a severity index of 49.9 and was also described in the literature. In comparison, the average PSI for the extreme precipitation events over Europe is 2.4. Overall, the most active season for extreme precipitation in Europe is summer. The longest duration of an event in the data set was 11 days. It occurred over Estonia in

  14. Fraud! An Event-Based Science Module. Teacher's Guide. Chemistry Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school life science or physical science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  15. Gold Medal! An Event-Based Science Module. Student Edition. Physiology Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  16. Gold Medal!: An Event-Based Science Module. Teacher's Guide. Physiology Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school life science or physical science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  17. Toxic Leak!: An Event-Based Science Module. Student Edition. Groundwater Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for the middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  18. Blight! An Event-Based Science Module. Teacher's Guide. Plants and Plant Diseases Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school life science or physical science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  19. Blight! An Event-Based Science Module. Student Edition. Plants and Plant Diseases Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  20. Asteroid! An Event-Based Science Module. Teacher's Guide. Astronomy Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school earth science or general science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  1. Asteroid! An Event-Based Science Module. Student Edition. Astronomy Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  2. Volcano!: An Event-Based Science Module. Teacher's Guide. Geology Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school earth science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research,…

  3. Volcano!: An Event-Based Science Module. Student Edition. Geology Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  4. Fire!: An Event-Based Science Module. Teacher's Guide. Chemistry and Fire Ecology Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school earth science or physical science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  5. Fire!: An Event-Based Science Module. Student Edition. Chemistry and Fire Ecology Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  6. Tornado! An Event-Based Science Module. Student Edition. Meteorology Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  7. Tornado! An Event-Based Science Module. Teacher's Guide. Meteorology Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school earth science teachers to help their students learn about problems with tornadoes and scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning,…

  8. Earthquake!: An Event-Based Science Module. Teacher's Guide. Earth Science Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school earth science teachers to help their students learn about earthquakes and scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  9. Earthquake!: An Event-Based Science Module. Student Edition. Earth Science Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  10. Gold Rush!: An Event-Based Science Module. Teacher's Guide. Geology Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school earth science or general science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  11. Gold Rush!: An Event-Based Science Module. Student Edition. Rocks and Minerals Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  12. Survive? An Event-Based Science Module. Teacher's Guide. Animals and Adaptation Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school earth science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research,…

  13. Blackout!: An Event-Based Science Module. Teacher's Guide. Electricity and Solar Activity Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school earth science or physical science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  14. First Flight!: An Event-Based Science Module. Student Edition. Physics Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  15. First Flight!: An Event-Based Science Module Teacher's Guide. Physics Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school life science or physical science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  16. The Source of Adult Age Differences in Event-Based Prospective Memory: A Multinomial Modeling Approach

    ERIC Educational Resources Information Center

    Smith, Rebekah E.; Bayen, Ute J.

    2006-01-01

    Event-based prospective memory involves remembering to perform an action in response to a particular future event. Normal younger and older adults performed event-based prospective memory tasks in 2 experiments. The authors applied a formal multinomial processing tree model of prospective memory (Smith & Bayen, 2004) to disentangle age differences…

  17. Oil Spill! An Event-Based Science Module. Student Edition. Oceanography Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  18. Oil Spill!: An Event-Based Science Module. Teacher's Guide. Oceanography Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school earth science or general science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  19. Fraud! An Event-Based Science Module. Student Edition. Chemistry Module.

    ERIC Educational Resources Information Center

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  20. Draft Title 40 CFR 191 compliance certification application for the Waste Isolation Pilot Plant. Volume 6: Appendix GCR Volume 1

    SciTech Connect

    1995-03-31

    The Geological Characterization Report (GCR) for the WIPP site presents, in one document, a compilation of geologic information available to August, 1978, which is judged to be relevant to studies for the WIPP. The Geological Characterization Report for the WIPP site is neither a preliminary safety analysis report nor an environmental impact statement; these documents, when prepared, should be consulted for appropriate discussion of safety analysis and environmental impact. The Geological Characterization Report of the WIPP site is a unique document and at this time is not required by regulatory process. An overview is presented of the purpose of the WIPP, the purpose of the Geological Characterization Report, the site selection criteria, the events leading to studies in New Mexico, status of studies, and the techniques employed during geological characterization.

  1. The regular measurements of the GCR intensity in the stratosphere in comparison with the measurements by the neutron monitors and aboard the IMP8 spacecraft

    NASA Astrophysics Data System (ADS)

    Krainev, M.B.; Belov, A.V.; Gushchina, R.T.; Yanke, V.G.

    We estimate to what extent the neutron monitor and stratospheric GCR data can be used for getting information on the intensity of the GCRs in a so called medium energy range (100-500 MeV/n), very important for studying the heliosphere and the GCR modulation there. The hourly data of the neutron monitors Apatity (since 1969) and Moscow (since 1958) are used as well as the standard set of the quiet time daily medium energy GCR intensities (p, 121-229.5 MeV; He, 168.8-455.5 MeV/n) and the integral count rate for GCR nuclei with ? > 80 MeV/n, kindly put at our disposal by Drs. F. McDonald and B. Heikkila (GSFC, USA). As stratospheric data we use the daily and monthly count rates in the Pfoetzer maxima at the high (Murmansk; the geomagnetic cut-off rigidity Rc = 0.6 GV) and the middle (Moscow; Rc = 2.3 GV) latitudes and the difference between these two count rates. Special emphasis is placed upon the long-term trends in all time series studied.

  2. Assessing the continuum of event-based biosurveillance through an operational lens.

    PubMed

    Corley, Courtney D; Lancaster, Mary J; Brigantic, Robert T; Chung, James S; Walters, Ronald A; Arthur, Ray R; Bruckner-Lea, Cynthia J; Calapristi, Augustin; Dowling, Glenn; Hartley, David M; Kennedy, Shaun; Kircher, Amy; Klucking, Sara; Lee, Eva K; McKenzie, Taylor; Nelson, Noele P; Olsen, Jennifer; Pancerella, Carmen; Quitugua, Teresa N; Reed, Jeremy Todd; Thomas, Carla S

    2012-03-01

    This research follows the Updated Guidelines for Evaluating Public Health Surveillance Systems, Recommendations from the Guidelines Working Group, published by the Centers for Disease Control and Prevention nearly a decade ago. Since then, models have been developed and complex systems have evolved with a breadth of disparate data to detect or forecast chemical, biological, and radiological events that have a significant impact on the One Health landscape. How the attributes identified in 2001 relate to the new range of event-based biosurveillance technologies is unclear. This article frames the continuum of event-based biosurveillance systems (that fuse media reports from the internet), models (ie, computational that forecast disease occurrence), and constructs (ie, descriptive analytical reports) through an operational lens (ie, aspects and attributes associated with operational considerations in the development, testing, and validation of the event-based biosurveillance methods and models and their use in an operational environment). A workshop was held in 2010 to scientifically identify, develop, and vet a set of attributes for event-based biosurveillance. Subject matter experts were invited from 7 federal government agencies and 6 different academic institutions pursuing research in biosurveillance event detection. We describe 8 attribute families for the characterization of event-based biosurveillance: event, readiness, operational aspects, geographic coverage, population coverage, input data, output, and cost. Ultimately, the analyses provide a framework from which the broad scope, complexity, and relevant issues germane to event-based biosurveillance useful in an operational environment can be characterized. PMID:22320664

  3. Spatial gradients of GCR protons in the inner heliosphere derived from Ulysses COSPIN/KET and PAMELA measurements

    NASA Astrophysics Data System (ADS)

    Gieseler, J.; Heber, B.

    2016-05-01

    Context. During the transition from solar cycle 23 to 24 from 2006 to 2009, the Sun was in an unusual solar minimum with very low activity over a long period. These exceptional conditions included a very low interplanetary magnetic field (IMF) strength and a high tilt angle, which both play an important role in the modulation of galactic cosmic rays (GCR) in the heliosphere. Thus, the radial and latitudinal gradients of GCRs are very much expected to depend not only on the solar magnetic epoch, but also on the overall modulation level. Aims: We determine the non-local radial and the latitudinal gradients of protons in the rigidity range from ~0.45 to 2 GV. Methods: This was accomplished by using data from the satellite-borne experiment Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) at Earth and the Kiel Electron Telescope (KET) onboard Ulysses on its highly inclined Keplerian orbit around the Sun with the aphelion at Jupiter's orbit. Results: In comparison to the previous A> 0 solar magnetic epoch, we find that the absolute value of the latitudinal gradient is lower at higher and higher at lower rigidities. This energy dependence is therefore a crucial test for models that describe the cosmic ray transport in the inner heliosphere.

  4. In vitro Manganese-Dependent Cross-Talk between Streptococcus mutans VicK and GcrR: Implications for Overlapping Stress Response Pathways

    PubMed Central

    Downey, Jennifer S.; Mashburn-Warren, Lauren; Ayala, Eduardo A.; Senadheera, Dilani B.; Hendrickson, Whitney K.; McCall, Lathan W.; Sweet, Julie G.; Cvitkovitch, Dennis G.; Spatafora, Grace A.; Goodman, Steven D.

    2014-01-01

    Streptococcus mutans, a major acidogenic component of the dental plaque biofilm, has a key role in caries etiology. Previously, we demonstrated that the VicRK two-component signal transduction system modulates biofilm formation, oxidative stress and acid tolerance responses in S. mutans. Using in vitro phosphorylation assays, here we demonstrate for the first time, that in addition to activating its cognate response regulator protein, the sensor kinase, VicK can transphosphorylate a non-cognate stress regulatory response regulator, GcrR, in the presence of manganese. Manganese is an important micronutrient that has been previously correlated with caries incidence, and which serves as an effector of SloR-mediated metalloregulation in S. mutans. Our findings supporting regulatory effects of manganese on the VicRK, GcrR and SloR, and the cross-regulatory networks formed by these components are more complex than previously appreciated. Using DNaseI footprinting we observed overlapping DNA binding specificities for VicR and GcrR in native promoters, consistent with these proteins being part of the same transcriptional regulon. Our results also support a role for SloR as a positive regulator of the vicRK two component signaling system, since its transcription was drastically reduced in a SloR-deficient mutant. These findings demonstrate the regulatory complexities observed with the S. mutans manganese-dependent response, which involves cross-talk between non-cognate signal transduction systems (VicRK and GcrR) to modulate stress response pathways. PMID:25536343

  5. Use of glucose consumption rate (GCR) as a tool to monitor and control animal cell production processes in packed-bed bioreactors.

    PubMed

    Meuwly, F; Papp, F; Ruffieux, P-A; Bernard, A R; Kadouri, A; von Stockar, U

    2006-03-01

    For animal cell cultures growing in packed-bed bioreactors where cell number cannot be determined directly, there is a clear need to use indirect methods that are not based on cell counts in order to monitor and control the process. One option is to use the glucose consumption rate (GCR) of the culture as an indirect measure to monitor the process in bioreactors. This study was done on a packed-bed bioreactor process using recombinant CHO cells cultured on Fibra-Cel disk carriers in perfusion mode at high cell densities. A key step in the process is the switch of the process from the cell growth phase to the production phase triggered by a reduction of the temperature. In this system, we have used a GCR value of 300 g of glucose per kilogram of disks per day as a criterion for the switch. This paper will present results obtained in routine operations for the monitoring and control of an industrial process at pilot-scale. The process operated with this GCR-based strategy yielded consistent, reproducible process performance across numerous bioreactor runs performed on multiple production sites. PMID:16153735

  6. KlGcr1 controls glucose-6-phosphate dehydrogenase activity and responses to H2O2, cadmium and arsenate in Kluyveromyces lactis.

    PubMed

    Lamas-Maceiras, Mónica; Rodríguez-Belmonte, Esther; Becerra, Manuel; González-Siso, Ma Isabel; Cerdán, Ma Esperanza

    2015-09-01

    It has been previously reported that Gcr1 differentially controls growth and sugar utilization in Saccharomyces cerevisiae and Kluyveromyces lactis, although the regulatory mechanisms causing activation of glycolytic genes are conserved (Neil et al., 2004). We have found that KlGCR1 deletion diminishes glucose consumption and ethanol production, but increases resistance to oxidative stress caused by H2O2, cadmium and arsenate, glucose 6P dehydrogenase activity, and the NADPH/NADP(+) and GSH/GSSG ratios in K. lactis. The gene KlZWF1 that encodes for glucose 6P dehydrogenase, the first enzyme in the pentose phosphate pathway, is transcriptionally regulated by KlGcr1. The high resistance to oxidative stress observed in the ΔKlgcr1 mutant strain, could be explained as a consequence of an increased flux of glucose through the pentose phosphate pathway. Since mitochondrial respiration decreases in the ΔKlgcr1 mutant (García-Leiro et al., 2010), the reoxidation of the NADPH, produced through the pentose phosphate pathway, has to be achieved by the reduction of other molecules implied in the defense against oxidative stress, like GSSG. The higher GSH/GSSG ratio in the mutant would explain its phenotype of increased resistance to oxidative stress. PMID:26164373

  7. An Event-Based Approach to Distributed Diagnosis of Continuous Systems

    NASA Technical Reports Server (NTRS)

    Daigle, Matthew; Roychoudhurry, Indranil; Biswas, Gautam; Koutsoukos, Xenofon

    2010-01-01

    Distributed fault diagnosis solutions are becoming necessary due to the complexity of modern engineering systems, and the advent of smart sensors and computing elements. This paper presents a novel event-based approach for distributed diagnosis of abrupt parametric faults in continuous systems, based on a qualitative abstraction of measurement deviations from the nominal behavior. We systematically derive dynamic fault signatures expressed as event-based fault models. We develop a distributed diagnoser design algorithm that uses these models for designing local event-based diagnosers based on global diagnosability analysis. The local diagnosers each generate globally correct diagnosis results locally, without a centralized coordinator, and by communicating a minimal number of measurements between themselves. The proposed approach is applied to a multi-tank system, and results demonstrate a marked improvement in scalability compared to a centralized approach.

  8. Disentangling the effect of event-based cues on children's time-based prospective memory performance.

    PubMed

    Redshaw, Jonathan; Henry, Julie D; Suddendorf, Thomas

    2016-10-01

    Previous time-based prospective memory research, both with children and with other groups, has measured the ability to perform an action with the arrival of a time-dependent yet still event-based cue (e.g., the occurrence of a specific clock pattern) while also engaged in an ongoing activity. Here we introduce a novel means of operationalizing time-based prospective memory and assess children's growing capacities when the availability of an event-based cue is varied. Preschoolers aged 3, 4, and 5years (N=72) were required to ring a bell when a familiar 1-min sand timer had completed a cycle under four conditions. In a 2×2 within-participants design, the timer was either visible or hidden and was either presented in the context of a single task or embedded within a dual picture-naming task. Children were more likely to ring the bell before 2min had elapsed in the visible-timer and single-task conditions, with performance improving with age across all conditions. These results suggest a divergence in the development of time-based prospective memory in the presence versus absence of event-based cues, and they also suggest that performance on typical time-based tasks may be partly driven by event-based prospective memory. PMID:27295204

  9. An Observation on the Spontaneous Noticing of Prospective Memory Event-Based Cues

    ERIC Educational Resources Information Center

    Knight, Justin B.; Meeks, J. Thadeus; Marsh, Richard L.; Cook, Gabriel I.; Brewer, Gene A.; Hicks, Jason L.

    2011-01-01

    In event-based prospective memory, current theories make differing predictions as to whether intention-related material can be spontaneously noticed (i.e., noticed without relying on preparatory attentional processes). In 2 experiments, participants formed an intention that was contextually associated to the final phase of the experiment, and…

  10. The Cost of Event-Based Prospective Memory: Salient Target Events

    ERIC Educational Resources Information Center

    Smith, Rebekah E.; Hunt, R. Reed; McVay, Jennifer C.; McConnell, Melissa D.

    2007-01-01

    Evidence has begun to accumulate showing that successful performance of event-based prospective memory (PM) comes at a cost to other ongoing activities. The current study builds on previous work by examining the cost associated with PM when the target event is salient. Target salience is among the criteria for automatic retrieval of intentions…

  11. The role of musical training in emergent and event-based timing

    PubMed Central

    Baer, L. H.; Thibodeau, J. L. N.; Gralnick, T. M.; Li, K. Z. H.; Penhune, V. B.

    2013-01-01

    Introduction: Musical performance is thought to rely predominantly on event-based timing involving a clock-like neural process and an explicit internal representation of the time interval. Some aspects of musical performance may rely on emergent timing, which is established through the optimization of movement kinematics, and can be maintained without reference to any explicit representation of the time interval. We predicted that musical training would have its largest effect on event-based timing, supporting the dissociability of these timing processes and the dominance of event-based timing in musical performance. Materials and Methods: We compared 22 musicians and 17 non-musicians on the prototypical event-based timing task of finger tapping and on the typically emergently timed task of circle drawing. For each task, participants first responded in synchrony with a metronome (Paced) and then responded at the same rate without the metronome (Unpaced). Results: Analyses of the Unpaced phase revealed that non-musicians were more variable in their inter-response intervals for finger tapping compared to circle drawing. Musicians did not differ between the two tasks. Between groups, non-musicians were more variable than musicians for tapping but not for drawing. We were able to show that the differences were due to less timer variability in musicians on the tapping task. Correlational analyses of movement jerk and inter-response interval variability revealed a negative association for tapping and a positive association for drawing in non-musicians only. Discussion: These results suggest that musical training affects temporal variability in tapping but not drawing. Additionally, musicians and non-musicians may be employing different movement strategies to maintain accurate timing in the two tasks. These findings add to our understanding of how musical training affects timing and support the dissociability of event-based and emergent timing modes. PMID:23717275

  12. Event-Based Control Strategy for Mobile Robots in Wireless Environments

    PubMed Central

    Socas, Rafael; Dormido, Sebastián; Dormido, Raquel; Fabregas, Ernesto

    2015-01-01

    In this paper, a new event-based control strategy for mobile robots is presented. It has been designed to work in wireless environments where a centralized controller has to interchange information with the robots over an RF (radio frequency) interface. The event-based architectures have been developed for differential wheeled robots, although they can be applied to other kinds of robots in a simple way. The solution has been checked over classical navigation algorithms, like wall following and obstacle avoidance, using scenarios with a unique or multiple robots. A comparison between the proposed architectures and the classical discrete-time strategy is also carried out. The experimental results shows that the proposed solution has a higher efficiency in communication resource usage than the classical discrete-time strategy with the same accuracy. PMID:26633412

  13. Event-Based Control Strategy for Mobile Robots in Wireless Environments.

    PubMed

    Socas, Rafael; Dormido, Sebastián; Dormido, Raquel; Fabregas, Ernesto

    2015-01-01

    In this paper, a new event-based control strategy for mobile robots is presented. It has been designed to work in wireless environments where a centralized controller has to interchange information with the robots over an RF (radio frequency) interface. The event-based architectures have been developed for differential wheeled robots, although they can be applied to other kinds of robots in a simple way. The solution has been checked over classical navigation algorithms, like wall following and obstacle avoidance, using scenarios with a unique or multiple robots. A comparison between the proposed architectures and the classical discrete-time strategy is also carried out. The experimental results shows that the proposed solution has a higher efficiency in communication resource usage than the classical discrete-time strategy with the same accuracy. PMID:26633412

  14. Event-based prospective memory and executive control of working memory.

    PubMed

    Marsh, R L; Hicks, J L

    1998-03-01

    In 5 experiments, the character of concurrent cognitive processing was manipulated during an event-based prospective memory task. High- and low-load conditions that differed only in the difficulty of the concurrent task were tested in each experiment. In Experiments 1 and 2, attention-demanding tasks from the literature on executive control produced decrements in prospective memory. In Experiment 3, attention was divided by different loads of articulatory suppression that did not ultimately lead to decrements in prospective memory. A high-load manipulation of a visuospatial task requiring performance monitoring resulted in worse prospective memory in Experiment 4, whereas in Experiment 5 a visuospatial task with little monitoring did not. Results are discussed in terms of executive functions, such as planning and monitoring, that appear to be critical to successful event-based prospective memory. PMID:9530843

  15. Use of Unstructured Event-Based Reports for Global Infectious Disease Surveillance

    PubMed Central

    Blench, Michael; Tolentino, Herman; Freifeld, Clark C.; Mandl, Kenneth D.; Mawudeku, Abla; Eysenbach, Gunther; Brownstein, John S.

    2009-01-01

    Free or low-cost sources of unstructured information, such as Internet news and online discussion sites, provide detailed local and near real-time data on disease outbreaks, even in countries that lack traditional public health surveillance. To improve public health surveillance and, ultimately, interventions, we examined 3 primary systems that process event-based outbreak information: Global Public Health Intelligence Network, HealthMap, and EpiSPIDER. Despite similarities among them, these systems are highly complementary because they monitor different data types, rely on varying levels of automation and human analysis, and distribute distinct information. Future development should focus on linking these systems more closely to public health practitioners in the field and establishing collaborative networks for alert verification and dissemination. Such development would further establish event-based monitoring as an invaluable public health resource that provides critical context and an alternative to traditional indicator-based outbreak reporting. PMID:19402953

  16. NASA Space Radiation Program Integrative Risk Model Toolkit

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Hu, Shaowen; Plante, Ianik; Ponomarev, Artem L.; Sandridge, Chris

    2015-01-01

    NASA Space Radiation Program Element scientists have been actively involved in development of an integrative risk models toolkit that includes models for acute radiation risk and organ dose projection (ARRBOD), NASA space radiation cancer risk projection (NSCR), hemocyte dose estimation (HemoDose), GCR event-based risk model code (GERMcode), and relativistic ion tracks (RITRACKS), NASA radiation track image (NASARTI), and the On-Line Tool for the Assessment of Radiation in Space (OLTARIS). This session will introduce the components of the risk toolkit with opportunity for hands on demonstrations. The brief descriptions of each tools are: ARRBOD for Organ dose projection and acute radiation risk calculation from exposure to solar particle event; NSCR for Projection of cancer risk from exposure to space radiation; HemoDose for retrospective dose estimation by using multi-type blood cell counts; GERMcode for basic physical and biophysical properties for an ion beam, and biophysical and radiobiological properties for a beam transport to the target in the NASA Space Radiation Laboratory beam line; RITRACKS for simulation of heavy ion and delta-ray track structure, radiation chemistry, DNA structure and DNA damage at the molecular scale; NASARTI for modeling of the effects of space radiation on human cells and tissue by incorporating a physical model of tracks, cell nucleus, and DNA damage foci with image segmentation for the automated count; and OLTARIS, an integrated tool set utilizing HZETRN (High Charge and Energy Transport) intended to help scientists and engineers study the effects of space radiation on shielding materials, electronics, and biological systems.

  17. An Event-Based Solution to the Perspective-n-Point Problem

    PubMed Central

    Reverter Valeiras, David; Kime, Sihem; Ieng, Sio-Hoi; Benosman, Ryad Benjamin

    2016-01-01

    The goal of the Perspective-n-Point problem (PnP) is to find the relative pose between an object and a camera from a set of n pairings between 3D points and their corresponding 2D projections on the focal plane. Current state of the art solutions, designed to operate on images, rely on computationally expensive minimization techniques. For the first time, this work introduces an event-based PnP algorithm designed to work on the output of a neuromorphic event-based vision sensor. The problem is formulated here as a least-squares minimization problem, where the error function is updated with every incoming event. The optimal translation is then computed in closed form, while the desired rotation is given by the evolution of a virtual mechanical system whose energy is proven to be equal to the error function. This allows for a simple yet robust solution of the problem, showing how event-based vision can simplify computer vision tasks. The approach takes full advantage of the high temporal resolution of the sensor, as the estimated pose is incrementally updated with every incoming event. Two approaches are proposed: the Full and the Efficient methods. These two methods are compared against a state of the art PnP algorithm both on synthetic and on real data, producing similar accuracy in addition of being faster. PMID:27242412

  18. Music, clicks, and their imaginations favor differently the event-based timing component for rhythmic movements.

    PubMed

    Bravi, Riccardo; Quarta, Eros; Del Tongo, Claudia; Carbonaro, Nicola; Tognetti, Alessandro; Minciacchi, Diego

    2015-06-01

    The involvement or noninvolvement of a clock-like neural process, an effector-independent representation of the time intervals to produce, is described as the essential difference between event-based and emergent timing. In a previous work (Bravi et al. in Exp Brain Res 232:1663-1675, 2014a. doi: 10.1007/s00221-014-3845-9 ), we studied repetitive isochronous wrist's flexion-extensions (IWFEs), performed while minimizing visual and tactile information, to clarify whether non-temporal and temporal characteristics of paced auditory stimuli affect the precision and accuracy of the rhythmic motor performance. Here, with the inclusion of new recordings, we expand the examination of the dataset described in our previous study to investigate whether simple and complex paced auditory stimuli (clicks and music) and their imaginations influence in a different way the timing mechanisms for repetitive IWFEs. Sets of IWFEs were analyzed by the windowed (lag one) autocorrelation-wγ(1), a statistical method recently introduced for the distinction between event-based and emergent timing. Our findings provide evidence that paced auditory information and its imagination favor the engagement of a clock-like neural process, and specifically that music, unlike clicks, lacks the power to elicit event-based timing, not counteracting the natural shift of wγ(1) toward positive values as frequency of movements increase. PMID:25837726

  19. The Effects of Age and Cue-Action Reminders on Event-Based Prospective Memory Performance in Preschoolers

    ERIC Educational Resources Information Center

    Kliegel, Matthias; Jager, Theodor

    2007-01-01

    The present study investigated event-based prospective memory in five age groups of preschoolers (i.e., 2-, 3-, 4-, 5-, and 6-year-olds). Applying a laboratory-controlled prospective memory procedure, the data showed that event-based prospective memory performance improves across the preschool years, at least between 3 and 6 years of age. However,…

  20. Improvement of glucose uptake rate and production of target chemicals by overexpressing hexose transporters and transcriptional activator Gcr1 in Saccharomyces cerevisiae.

    PubMed

    Kim, Daehee; Song, Ji-Yoon; Hahn, Ji-Sook

    2015-12-01

    Metabolic engineering to increase the glucose uptake rate might be beneficial to improve microbial production of various fuels and chemicals. In this study, we enhanced the glucose uptake rate in Saccharomyces cerevisiae by overexpressing hexose transporters (HXTs). Among the 5 tested HXTs (Hxt1, Hxt2, Hxt3, Hxt4, and Hxt7), overexpression of high-affinity transporter Hxt7 was the most effective in increasing the glucose uptake rate, followed by moderate-affinity transporters Hxt2 and Hxt4. Deletion of STD1 and MTH1, encoding corepressors of HXT genes, exerted differential effects on the glucose uptake rate, depending on the culture conditions. In addition, improved cell growth and glucose uptake rates could be achieved by overexpression of GCR1, which led to increased transcription levels of HXT1 and ribosomal protein genes. All genetic modifications enhancing the glucose uptake rate also increased the ethanol production rate in wild-type S. cerevisiae. Furthermore, the growth-promoting effect of GCR1 overexpression was successfully applied to lactic acid production in an engineered lactic acid-producing strain, resulting in a significant improvement of productivity and titers of lactic acid production under acidic fermentation conditions. PMID:26431967

  1. Measuring pesticides in surface waters - continuous versus event-based sampling design

    NASA Astrophysics Data System (ADS)

    Eyring, J.; Bach, M.; Frede, H.-G.

    2009-04-01

    Monitoring pesticides in surface waters is still a work- and cost-intensive procedure. Therefore, studies are normally carried out with a low monitoring frequency or with only a small selection of substances to be analyzed. In this case, it is not possible to picture the high temporal variability of pesticide concentrations, depending on application dates, weather conditions, cropping seasons and other factors. In 2007 the Institute of Landscape Ecology and Resource Management at Giessen University implemented a monitoring program during two pesticide application periods aiming to produce a detailed dataset of pesticide concentration for a wide range of substances, and which would also be suitable for the evaluation of catchment-scale pesticide exposure models. The Weida catchment in Thuringia (Eastern Germany) was selected as study area due to the availability of detailed pesticide application data for this region. The samples were taken from the river Weida at the gauge Zeulenroda, where it flows into a drinking water reservoir. The catchment area is 102 km². 67% of the area are in agricultural use, the main crops being winter wheat, maize, winter barley and winter rape. Dominant soil texture classes are loamy sand and loamy silt. About one third of the agricultural area is drained. The sampling was carried out in cooperation with the water supply agency of Thuringia (Fernwasserversorgung Thueringen). The sample analysis was done by the Institute of Environmental Research at Dortmund University. Two sampling schemes were carried out using two automatic samplers: continuous sampling with composite samples bottled two times per week and event-based sampling triggered by a discharge threshold. 53 samples from continuous sampling were collected. 19 discharge events were sampled with 45 individual samples (one to six per event). 34 pesticides and two metabolites were analyzed. 21 compounds were detected, nine of which having concentrations above the drinking water

  2. Event-based prospective memory deficits in individuals with high depressive symptomatology: problems controlling attentional resources?

    PubMed

    Li, Yanqi Ryan; Loft, Shayne; Weinborn, Michael; Maybery, Murray T

    2014-01-01

    Depression has been found to be related to neurocognitive deficits in areas important to successful prospective memory (PM) performance, including executive function, attention, and retrospective memory. However, research specific to depression and PM has produced a mixed pattern of results. The current study further examined the task conditions in which event-based PM deficits may emerge in individuals with high depressive symptomatology (HDS) relative to individuals with low depressive symptomatology (LDS) and the capacity of HDS individuals to allocate attentional resources to event-based PM tasks. Sixty-four participants (32 HDS, 32 LDS) were required to make a PM response when target words were presented during an ongoing lexical decision task. When the importance of the ongoing task was emphasized, response time costs to the ongoing task, and PM accuracy, did not differ between the HDS and LDS groups. This finding is consistent with previous research demonstrating that event-based PM task accuracy is not always impaired by depression, even when the PM task is resource demanding. When the importance of the PM task was emphasized, costs to the ongoing task further increased for both groups, indicating an increased allocation of attentional resources to the PM task. Crucially, while a corresponding improvement in PM accuracy was observed in the LDS group when the importance of the PM task was emphasized, this was not true for the HDS group. The lack of improved PM accuracy in the HDS group compared with the LDS group despite evidence of increased cognitive resources allocated to PM tasks may have been due to inefficiency in the application of the allocated attention, a dimension likely related to executive function difficulties in depression. Qualitatively different resource allocation patterns may underlie PM monitoring in HDS versus LDS individuals. PMID:24848441

  3. Lessons Learned from Real-Time, Event-Based Internet Science Communications

    NASA Technical Reports Server (NTRS)

    Phillips, T.; Myszka, E.; Gallagher, D. L.; Adams, M. L.; Koczor, R. J.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    For the last several years the Science Directorate at Marshall Space Flight Center has carried out a diverse program of Internet-based science communication. The Directorate's Science Roundtable includes active researchers, NASA public relations, educators, and administrators. The Science@NASA award-winning family of Web sites features science, mathematics, and space news. The program includes extended stories about NASA science, a curriculum resource for teachers tied to national education standards, on-line activities for students, and webcasts of real-time events. The focus of sharing science activities in real-time has been to involve and excite students and the public about science. Events have involved meteor showers, solar eclipses, natural very low frequency radio emissions, and amateur balloon flights. In some cases, broadcasts accommodate active feedback and questions from Internet participants. Through these projects a pattern has emerged in the level of interest or popularity with the public. The pattern differentiates projects that include science from those that do not, All real-time, event-based Internet activities have captured public interest at a level not achieved through science stories or educator resource material exclusively. The worst event-based activity attracted more interest than the best written science story. One truly rewarding lesson learned through these projects is that the public recognizes the importance and excitement of being part of scientific discovery. Flying a camera to 100,000 feet altitude isn't as interesting to the public as searching for viable life-forms at these oxygen-poor altitudes. The details of these real-time, event-based projects and lessons learned will be discussed.

  4. Event-based Plausibility Immediately Influences On-line Language Comprehension

    PubMed Central

    Matsuki, Kazunaga; Chow, Tracy; Hare, Mary; Elman, Jeffrey L.; Scheepers, Christoph; McRae, Ken

    2011-01-01

    In some theories of sentence comprehension, linguistically-relevant lexical knowledge such as selectional restrictions is privileged in terms of the time-course of its access and influence. We examined whether event knowledge computed by combining multiple concepts can rapidly influence language understanding even in the absence of selectional restriction violations. Specifically, we investigated whether instruments can combine with actions to influence comprehension of ensuing patients. Instrument-verb-patient triplets were created in a norming study designed to tap directly into event knowledge. In self-paced reading (Experiment 1), participants were faster to read patient nouns such as hair when they were typical of the instrument-action pair (Donna used the shampoo to wash vs. the hose to wash). Experiment 2 showed that these results were not due to direct instrument-patient relations. Experiment 3 replicated Experiment 1 using eyetracking, with effects of event typicality observed in first fixation and gaze durations on the patient noun. This research demonstrates that conceptual event-based expectations are computed and used rapidly and dynamically during on-line language comprehension. We discuss relationships among plausibility and predictability, as well as their implications. We conclude that selectional restrictions may be best considered as event-based conceptual knowledge, rather than lexical-grammatical knowledge. PMID:21517222

  5. Event-Based Parareal: A data-flow based implementation of parareal

    SciTech Connect

    Berry, Lee A; Elwasif, Wael R; Reynolds-Barredo, J.; Samaddar, D.; Sanchez, R.; Newman, David E; Chen, J.

    2012-01-01

    Parareal is an iterative algorithm that, in effect, achieves temporal decomposition for a time-dependent system of differential or partial differential equations. A solution is obtained in a shorter wall-clock time, but at the expense of increased compute cycles. The algorithm combines a fine solver that solves the system to acceptable accuracy with an approximate coarse solver. The critical task for the successful implementation of parareal on any system is the development of a coarse solver that leads to convergence in a small number of iterations compared to the number of time slices in the full time interval, and is, at the same time, much faster than the fine solver. Fast coarse solvers may not lead to sufficiently rapid convergence, and slow coarse solvers may not lead to significant gains even if the number of iterations to convergence is satisfactory. We find that the difficulty of meeting these conflicting demands can be substantially eased by using a data-driven, event-based implementation of parareal instead of the conventional algorithm where solver tasks are executed sequentially. For given convergence properties, the event-based approach relaxes the speed requirements on the coarse solver by a factor of , where is the number of iterations required for a converged solution. This may, for many problems, lead to an efficient parareal implementation that would otherwise not be possible or would require substantial coarse solver development.

  6. Event-based plausibility immediately influences on-line language comprehension.

    PubMed

    Matsuki, Kazunaga; Chow, Tracy; Hare, Mary; Elman, Jeffrey L; Scheepers, Christoph; McRae, Ken

    2011-07-01

    In some theories of sentence comprehension, linguistically relevant lexical knowledge, such as selectional restrictions, is privileged in terms of the time-course of its access and influence. We examined whether event knowledge computed by combining multiple concepts can rapidly influence language understanding even in the absence of selectional restriction violations. Specifically, we investigated whether instruments can combine with actions to influence comprehension of ensuing patients of (as in Rayner, Warren, Juhuasz, & Liversedge, 2004; Warren & McConnell, 2007). Instrument-verb-patient triplets were created in a norming study designed to tap directly into event knowledge. In self-paced reading (Experiment 1), participants were faster to read patient nouns, such as hair, when they were typical of the instrument-action pair (Donna used the shampoo to wash vs. the hose to wash). Experiment 2 showed that these results were not due to direct instrument-patient relations. Experiment 3 replicated Experiment 1 using eyetracking, with effects of event typicality observed in first fixation and gaze durations on the patient noun. This research demonstrates that conceptual event-based expectations are computed and used rapidly and dynamically during on-line language comprehension. We discuss relationships among plausibility and predictability, as well as their implications. We conclude that selectional restrictions may be best considered as event-based conceptual knowledge rather than lexical-grammatical knowledge. PMID:21517222

  7. Event-based and Multi Agent Control of an Innovative Wheelchair

    NASA Astrophysics Data System (ADS)

    Diomin, U.; Witczak, P.; Stetter, R.

    2015-11-01

    Due to the aging population more and more people require mobility assistance in form of a wheelchair. Generally it would be desirable that such wheelchairs would be easy to use and would allow their users the possibility to move in any direction at any time. Concepts which allow such movements are existing since many years but have for several reasons not found their way to the market. Additionally for semi-autonomous (assisted) operation and fully autonomous operation (e. g. an empty wheelchair driving to its charging station) the control task is much less challenging for such drive system, because no complex manoeuvres needs to be considered and planned. In an ongoing research a drive system for a wheelchair was developed which offers such possibilities employing a relatively simple mechanical design. This drive system is based on a certain steering principle which is based on torque differences between different wheels. This allows a relatively simple mechanical design but poses challenges on the control of the vehicle. This paper describes two possible approaches to address this challenge - the use of an event based control and the application of multiple software agents. Both approaches can solve the control problem individually but can also complement each other for better system performance. The paper stars with a description of the wheelchair drive system. Then the asynchronous event based control software is described as well the multi agent based approach. The next sections report the results of the experiments and discuss the further improvements.

  8. A Markovian event-based framework for stochastic spiking neural networks.

    PubMed

    Touboul, Jonathan D; Faugeras, Olivier D

    2011-11-01

    In spiking neural networks, the information is conveyed by the spike times, that depend on the intrinsic dynamics of each neuron, the input they receive and on the connections between neurons. In this article we study the Markovian nature of the sequence of spike times in stochastic neural networks, and in particular the ability to deduce from a spike train the next spike time, and therefore produce a description of the network activity only based on the spike times regardless of the membrane potential process. To study this question in a rigorous manner, we introduce and study an event-based description of networks of noisy integrate-and-fire neurons, i.e. that is based on the computation of the spike times. We show that the firing times of the neurons in the networks constitute a Markov chain, whose transition probability is related to the probability distribution of the interspike interval of the neurons in the network. In the cases where the Markovian model can be developed, the transition probability is explicitly derived in such classical cases of neural networks as the linear integrate-and-fire neuron models with excitatory and inhibitory interactions, for different types of synapses, possibly featuring noisy synaptic integration, transmission delays and absolute and relative refractory period. This covers most of the cases that have been investigated in the event-based description of spiking deterministic neural networks. PMID:21499739

  9. Specific components of the SAGA complex are required for Gcn4- and Gcr1-mediated activation of the his4-912delta promoter in Saccharomyces cerevisiae.

    PubMed Central

    Dudley, A M; Gansheroff, L J; Winston, F

    1999-01-01

    Mutations selected as suppressors of Ty or solo delta insertion mutations in Saccharomyces cerevisiae have identified several genes, SPT3, SPT7, SPT8, and SPT20, that encode components of the SAGA complex. However, the mechanism by which SAGA activates transcription of specific RNA polymerase II-dependent genes is unknown. We have conducted a fine-structure mutagenesis of one widely used SAGA-dependent promoter, the delta element of his4-912delta, to identify sequence elements important for its promoter activity. Our analysis has characterized three delta regions necessary for full promoter activity and accurate start site selection: an upstream activating sequence, a TATA region, and an initiator region. In addition, we have shown that factors present at the adjacent UASHIS4 (Gcn4, Bas1, and Pho2) also activate the delta promoter in his4-912delta. Our results suggest a model in which the delta promoter in his4-912delta is primarily activated by two factors: Gcr1 acting at the UASdelta and Gcn4 acting at the UASHIS4. Finally, we tested whether activation by either of these factors is dependent on components of the SAGA complex. Our results demonstrate that Spt3 and Spt20 are required for full delta promoter activity, but that Gcn5, another member of SAGA, is not required. Spt3 appears to be partially required for activation of his4-912delta by both Gcr1 and Gcn4. Thus, our work suggests that SAGA exerts a large effect on delta promoter activity through a combination of smaller effects on multiple factors. PMID:10101163

  10. An efficient hybrid causative event-based approach for deriving the annual flood frequency distribution

    NASA Astrophysics Data System (ADS)

    Thyer, Mark; Li, Jing; Lambert, Martin; Kuczera, George; Metcalfe, Andrew

    2015-04-01

    Flood extremes are driven by highly variable and complex climatic and hydrological processes. Derived flood frequency methods are often used to predict the flood frequency distribution (FFD) because they can provide predictions in ungauged catchments and evaluate the impact of land-use or climate change. This study presents recent work on development of a new derived flood frequency method called the hybrid causative events (HCE) approach. The advantage of the HCE approach is that it combines the accuracy of the continuous simulation approach with the computational efficiency of the event-based approaches. Derived flood frequency methods, can be divided into two classes. Event-based approaches provide fast estimation, but can also lead to prediction bias due to limitations of inherent assumptions required for obtaining input information (rainfall and catchment wetness) for events that cause large floods. Continuous simulation produces more accurate predictions, however, at the cost of massive computational time. The HCE method uses a short continuous simulation to provide inputs for a rainfall-runoff model running in an event-based fashion. A proof-of-concept pilot study that the HCE produces estimates of the flood frequency distribution with similar accuracy as the continuous simulation, but with dramatically reduced computation time. Recent work incorporated seasonality into the HCE approach and evaluated with a more realistic set of eight sites from a wide range of climate zones, typical of Australia, using a virtual catchment approach. The seasonal hybrid-CE provided accurate predictions of the FFD for all sites. Comparison with the existing non-seasonal hybrid-CE showed that for some sites the non-seasonal hybrid-CE significantly over-predicted the FFD. Analysis of the underlying cause of whether a site had a high, low or no need to use seasonality found it was based on a combination of reasons, that were difficult to predict apriori. Hence it is recommended

  11. Event based self-supervised temporal integration for multimodal sensor data.

    PubMed

    Barakova, Emilia I; Lourens, Tino

    2005-06-01

    A method for synergistic integration of multimodal sensor data is proposed in this paper. This method is based on two aspects of the integration process: (1) achieving synergistic integration of two or more sensory modalities, and (2) fusing the various information streams at particular moments during processing. Inspired by psychophysical experiments, we propose a self-supervised learning method for achieving synergy with combined representations. Evidence from temporal registration and binding experiments indicates that different cues are processed individually at specific time intervals. Therefore, an event-based temporal co-occurrence principle is proposed for the integration process. This integration method was applied to a mobile robot exploring unfamiliar environments. Simulations showed that integration enhanced route recognition with many perceptual similarities; moreover, they indicate that a perceptual hierarchy of knowledge about instant movement contributes significantly to short-term navigation, but that visual perceptions have bigger impact over longer intervals. PMID:15988800

  12. Pinning cluster synchronization in an array of coupled neural networks under event-based mechanism.

    PubMed

    Li, Lulu; Ho, Daniel W C; Cao, Jinde; Lu, Jianquan

    2016-04-01

    Cluster synchronization is a typical collective behavior in coupled dynamical systems, where the synchronization occurs within one group, while there is no synchronization among different groups. In this paper, under event-based mechanism, pinning cluster synchronization in an array of coupled neural networks is studied. A new event-triggered sampled-data transmission strategy, where only local and event-triggering states are utilized to update the broadcasting state of each agent, is proposed to realize cluster synchronization of the coupled neural networks. Furthermore, a self-triggered pinning cluster synchronization algorithm is proposed, and a set of iterative procedures is given to compute the event-triggered time instants. Hence, this will reduce the computational load significantly. Finally, an example is given to demonstrate the effectiveness of the theoretical results. PMID:26829603

  13. Event-Based Study of the Effect of Execution Environments on Parallel Program Performance

    NASA Technical Reports Server (NTRS)

    Sarukkai, Sekhar R.; Yan, Jerry C.; Craw, James (Technical Monitor)

    1995-01-01

    In this paper we seek to demonstrate the importance of studying the effect of changes in execution environment parameters, on parallel applications executed on state-of-the-art multiprocessors. A comprehensive methodology for event-based analysis of program behavior is introduced. This methodology is used to study the performance significance of various system parameters such as processor speed, message-buffer size, buffer copy speed, network bandwidth, communication latency, interrupt overheads and other system parameters. With the help cf a few CFD examples, we illustrate the use of our technique in determining suitable parameter values of the execution environment for three applications. We also demonstrate how this approach can be used to predict performance across architectures and illustrate the use of visual and profile-like feedback to expose the effect of system parameters changes on the performance of specific applications module.

  14. Qualitative Event-Based Diagnosis: Case Study on the Second International Diagnostic Competition

    NASA Technical Reports Server (NTRS)

    Daigle, Matthew; Roychoudhury, Indranil

    2010-01-01

    We describe a diagnosis algorithm entered into the Second International Diagnostic Competition. We focus on the first diagnostic problem of the industrial track of the competition in which a diagnosis algorithm must detect, isolate, and identify faults in an electrical power distribution testbed and provide corresponding recovery recommendations. The diagnosis algorithm embodies a model-based approach, centered around qualitative event-based fault isolation. Faults produce deviations in measured values from model-predicted values. The sequence of these deviations is matched to those predicted by the model in order to isolate faults. We augment this approach with model-based fault identification, which determines fault parameters and helps to further isolate faults. We describe the diagnosis approach, provide diagnosis results from running the algorithm on provided example scenarios, and discuss the issues faced, and lessons learned, from implementing the approach

  15. Comparing Event-Based Storage across Tropical Land-Cover Gradients in the Panama Canal Watershed

    NASA Astrophysics Data System (ADS)

    Litt, G.; Gardner, C.; Ogden, F. L.; Lyons, W. B.

    2015-12-01

    Quantifying watershed storage is a difficult undertaking, yet serves as a critical state variable for understanding catchment runoff processes and modeling applications. Hydrograph recession rates have traditionally been used to characterize relative watershed storage characteristics, but may neglect the different flowpaths taken during recession periods. Separating event-based hydrograph recession into 'old' and 'new' water can help distinguish between different catchment storages (Stewart, 2015). By coupling geochemical tracer-based hydrograph separation with post-storm recession rates in humid tropical catchments (<185 ha), we test the hypothesis that both 'old' and 'new' water stores are greater in forested areas relative to disturbed land covers. Stewart, M. K. (2015), Promising new baseflow separation and recession analysis methods applied to streamflow at Glendhu Catchment, New Zealand. Hydrol. Earth Syst. Sci., 19(6), 2587-2603.

  16. Event-based surveillance in north-western Ethiopia: experience and lessons learnt in the field.

    PubMed

    Toyama, Yumi; Ota, Masaki; Beyene, Belay Bezabih

    2015-01-01

    This study piloted an event-based surveillance system at the health centre (HC) level in Ethiopia. The system collects rumours in the community and registers them in rumour logbooks to record events of disease outbreaks and public health emergencies. Descriptive analysis was conducted on the events captured at the 59 study HCs in the Amhara Region in north-western Ethiopia between October 2013 and November 2014. A total of 126 rumours were registered at two thirds of the HCs during the study period. The average event reporting time was 3.8 days; response time of the HCs was 0.6 days, resulting in a total response time of 4.4 days. The most commonly reported rumours were measles-related (n = 90, 71%). These rumours followed a similar pattern of measles cases reported in the routine surveillance system. The largest proportion of rumours were reported by community members (n = 38, 36%) followed by health post workers (n = 36, 29%) who were normally informed by the community members about the rumours. This surveillance system was established along with an existing indicator-based surveillance system and was simple to implement. The implementation cost was minimal, requiring only printing and distribution of rumour logbooks to the HCs and brief orientations to focal persons. In countries where routine surveillance is still weak, an event-based surveillance system similar to this should be considered as a supplementary tool for disease monitoring. PMID:26668763

  17. Improvement of hydrological flood forecasting through an event based output correction method

    NASA Astrophysics Data System (ADS)

    Klotz, Daniel; Nachtnebel, Hans Peter

    2014-05-01

    This contribution presents an output correction method for hydrological models. A conceptualisation of the method is presented and tested in an alpine basin in Salzburg, Austria. The aim is to develop a method which is not prone to the drawbacks of autoregressive models. Output correction methods are an attractive option for improving hydrological predictions. They are complementary to the main modelling process and do not interfere with the modelling process itself. In general, output correction models estimate the future error of a prediction and use the estimation to improve the given prediction. Different estimation techniques are available dependent on the utilized information and the estimation procedure itself. Autoregressive error models are widely used for such corrections. Autoregressive models with exogenous inputs (ARX) allow the use of additional information for the error modelling, e.g. measurements from upper basins or predicted input-signals. Autoregressive models do however exhibit deficiencies, since the errors of hydrological models do generally not behave in an autoregressive manner. The decay of the error is usually different from an autoregressive function and furthermore the residuals exhibit different patterns under different circumstances. As for an example, one might consider different error-propagation behaviours under high- and low-flow situations or snow melt driven conditions. This contribution presents a conceptualisation of an event-based correction model and focuses on flood events only. The correction model uses information about the history of the residuals and exogenous variables to give an error-estimation. The structure and parameters of the correction models can be adapted to given event classes. An event-class is a set of flood events that exhibit a similar pattern for the residuals or the hydrological conditions. In total, four different event-classes have been identified in this study. Each of them represents a different

  18. Assessment of Community Event-Based Surveillance for Ebola Virus Disease, Sierra Leone, 2015.

    PubMed

    Ratnayake, Ruwan; Crowe, Samuel J; Jasperse, Joseph; Privette, Grayson; Stone, Erin; Miller, Laura; Hertz, Darren; Fu, Clementine; Maenner, Matthew J; Jambai, Amara; Morgan, Oliver

    2016-08-01

    In 2015, community event-based surveillance (CEBS) was implemented in Sierra Leone to assist with the detection of Ebola virus disease (EVD) cases. We assessed the sensitivity of CEBS for finding EVD cases during a 7-month period, and in a 6-week subanalysis, we assessed the timeliness of reporting cases with no known epidemiologic links at time of detection. Of the 12,126 CEBS reports, 287 (2%) met the suspected case definition, and 16 were confirmed positive. CEBS detected 30% (16/53) of the EVD cases identified during the study period. During the subanalysis, CEBS staff identified 4 of 6 cases with no epidemiologic links. These CEBS-detected cases were identified more rapidly than those detected by the national surveillance system; however, too few cases were detected to determine system timeliness. Although CEBS detected EVD cases, it largely generated false alerts. Future versions of community-based surveillance could improve case detection through increased staff training and community engagement. PMID:27434608

  19. Selection of intense rainfall events based on intensity thresholds and lightning data in Switzerland

    NASA Astrophysics Data System (ADS)

    Gaal, L.; Molnar, P.; Szolgay, J.

    2014-01-01

    This paper presents a method to identify intense warm season storms of convective character based on intensity thresholds and lightning, and analyzes their statistical properties. Long records of precipitation and lightning data at 4 stations and 10 min resolution in different climatological regions in Switzerland are used. Our premise is that thunderstorms associated with lightning generate bursts of high rainfall intensity. We divided all storms into those accompanied by lightning and those without lightning and found the threshold I* that separates intense events based on peak 10 min intensity Ip ≥ I* for a chosen misclassification rate α. The performance and robustness of the selection method was tested by investigating the inter-annual variability of I* and its relation to the frequency of lightning strikes. The probability distributions of the main storm properties (rainfall depth R, event duration D, average storm intensity Ia and peak 10 min intensity Ip) for the intense storm subsets show that the event average and peak intensities are significantly different between the stations, and highest in Lugano in southern Switzerland. Non-parametric correlations between the main storm properties were estimated for the subsets of intense storms and all storms including stratiform rain. The differences in the correlations between storm subsets are greater than those between stations, which indicates that care must be exercised not to mix events when they are sampled for multivariate analysis, e.g. copula fitting to rainfall data.

  20. Selection of intense rainfall events based on intensity thresholds and lightning data in Switzerland

    NASA Astrophysics Data System (ADS)

    Gaál, L.; Molnar, P.; Szolgay, J.

    2014-05-01

    This paper presents a method to identify intense warm season storms with convective character based on intensity thresholds and the presence of lightning, and analyzes their statistical properties. Long records of precipitation and lightning data at 4 stations and 10 min resolution in different climatological regions in Switzerland are used. Our premise is that thunderstorms associated with lightning generate bursts of high rainfall intensity. We divided all recorded storms into those accompanied by lightning and those without lightning and found the threshold I* that separates intense events based on peak 10 min intensity Ip ≥ I* for a chosen misclassification rate α. The performance and robustness of the selection method was tested by investigating the inter-annual variability of I* and its relation to the frequency of lightning strikes. The probability distributions of the main storm properties (rainfall depth R, event duration D, average storm intensity Ia and peak 10 min intensity Ip) for the intense storm subsets show that the event average and peak intensities are significantly different between the stations. Non-parametric correlations between the main storm properties were estimated for intense storms and all storms including stratiform rain. The differences in the correlations between storm subsets are greater than those between stations, which indicates that care must be exercised not to mix events of different origin when they are sampled for multivariate analysis, for example, copula fitting to rainfall data.

  1. Hydrologic Modeling in the Kenai River Watershed using Event Based Calibration

    NASA Astrophysics Data System (ADS)

    Wells, B.; Toniolo, H. A.; Stuefer, S. L.

    2015-12-01

    Understanding hydrologic changes is key for preparing for possible future scenarios. On the Kenai Peninsula in Alaska the yearly salmon runs provide a valuable stimulus to the economy. It is the focus of a large commercial fishing fleet, but also a prime tourist attraction. Modeling of anadromous waters provides a tool that assists in the prediction of future salmon run size. Beaver Creek, in Kenai, Alaska, is a lowlands stream that has been modeled using the Army Corps of Engineers event based modeling package HEC-HMS. With the use of historic precipitation and discharge data, the model was calibrated to observed discharge values. The hydrologic parameters were measured in the field or calculated, while soil parameters were estimated and adjusted during the calibration. With the calibrated parameter for HEC-HMS, discharge estimates can be used by other researches studying the area and help guide communities and officials to make better-educated decisions regarding the changing hydrology in the area and the tied economic drivers.

  2. Event-Based Surveillance During EXPO Milan 2015: Rationale, Tools, Procedures, and Initial Results

    PubMed Central

    Manso, Martina Del; Caporali, Maria Grazia; Napoli, Christian; Linge, Jens P.; Mantica, Eleonora; Verile, Marco; Piatti, Alessandra; Pompa, Maria Grazia; Vellucci, Loredana; Costanzo, Virgilio; Bastiampillai, Anan Judina; Gabrielli, Eugenia; Gramegna, Maria; Declich, Silvia

    2016-01-01

    More than 21 million participants attended EXPO Milan from May to October 2015, making it one of the largest protracted mass gathering events in Europe. Given the expected national and international population movement and health security issues associated with this event, Italy fully implemented, for the first time, an event-based surveillance (EBS) system focusing on naturally occurring infectious diseases and the monitoring of biological agents with potential for intentional release. The system started its pilot phase in March 2015 and was fully operational between April and November 2015. In order to set the specific objectives of the EBS system, and its complementary role to indicator-based surveillance, we defined a list of priority diseases and conditions. This list was designed on the basis of the probability and possible public health impact of infectious disease transmission, existing statutory surveillance systems in place, and any surveillance enhancements during the mass gathering event. This article reports the methodology used to design the EBS system for EXPO Milan and the results of 8 months of surveillance. PMID:27314656

  3. Simulation of Greenhouse Climate Monitoring and Control with Wireless Sensor Network and Event-Based Control

    PubMed Central

    Pawlowski, Andrzej; Guzman, Jose Luis; Rodríguez, Francisco; Berenguel, Manuel; Sánchez, José; Dormido, Sebastián

    2009-01-01

    Monitoring and control of the greenhouse environment play a decisive role in greenhouse production processes. Assurance of optimal climate conditions has a direct influence on crop growth performance, but it usually increases the required equipment cost. Traditionally, greenhouse installations have required a great effort to connect and distribute all the sensors and data acquisition systems. These installations need many data and power wires to be distributed along the greenhouses, making the system complex and expensive. For this reason, and others such as unavailability of distributed actuators, only individual sensors are usually located in a fixed point that is selected as representative of the overall greenhouse dynamics. On the other hand, the actuation system in greenhouses is usually composed by mechanical devices controlled by relays, being desirable to reduce the number of commutations of the control signals from security and economical point of views. Therefore, and in order to face these drawbacks, this paper describes how the greenhouse climate control can be represented as an event-based system in combination with wireless sensor networks, where low-frequency dynamics variables have to be controlled and control actions are mainly calculated against events produced by external disturbances. The proposed control system allows saving costs related with wear minimization and prolonging the actuator life, but keeping promising performance results. Analysis and conclusions are given by means of simulation results. PMID:22389597

  4. A Review of Evaluations of Electronic Event-Based Biosurveillance Systems

    PubMed Central

    Gajewski, Kimberly N.; Peterson, Amy E.; Chitale, Rohit A.; Pavlin, Julie A.; Russell, Kevin L.; Chretien, Jean-Paul

    2014-01-01

    Electronic event-based biosurveillance systems (EEBS’s) that use near real-time information from the internet are an increasingly important source of epidemiologic intelligence. However, there has not been a systematic assessment of EEBS evaluations, which could identify key uncertainties about current systems and guide EEBS development to most effectively exploit web-based information for biosurveillance. To conduct this assessment, we searched PubMed and Google Scholar to identify peer-reviewed evaluations of EEBS’s. We included EEBS’s that use publicly available internet information sources, cover events that are relevant to human health, and have global scope. To assess the publications using a common framework, we constructed a list of 17 EEBS attributes from published guidelines for evaluating health surveillance systems. We identified 11 EEBS’s and 20 evaluations of these EEBS’s. The number of published evaluations per EEBS ranged from 1 (Gen-Db, GODsN, MiTAP) to 8 (GPHIN, HealthMap). The median number of evaluation variables assessed per EEBS was 8 (range, 3–15). Ten published evaluations contained quantitative assessments of at least one key variable. No evaluations examined usefulness by identifying specific public health decisions, actions, or outcomes resulting from EEBS outputs. Future EEBS assessments should identify and discuss critical indicators of public health utility, especially the impact of EEBS’s on public health response. PMID:25329886

  5. On-Board Event-Based State Estimation for Trajectory Approaching and Tracking of a Vehicle.

    PubMed

    Martínez-Rey, Miguel; Espinosa, Felipe; Gardel, Alfredo; Santos, Carlos

    2015-01-01

    For the problem of pose estimation of an autonomous vehicle using networked external sensors, the processing capacity and battery consumption of these sensors, as well as the communication channel load should be optimized. Here, we report an event-based state estimator (EBSE) consisting of an unscented Kalman filter that uses a triggering mechanism based on the estimation error covariance matrix to request measurements from the external sensors. This EBSE generates the events of the estimator module on-board the vehicle and, thus, allows the sensors to remain in stand-by mode until an event is generated. The proposed algorithm requests a measurement every time the estimation distance root mean squared error (DRMS) value, obtained from the estimator's covariance matrix, exceeds a threshold value. This triggering threshold can be adapted to the vehicle's working conditions rendering the estimator even more efficient. An example of the use of the proposed EBSE is given, where the autonomous vehicle must approach and follow a reference trajectory. By making the threshold a function of the distance to the reference location, the estimator can halve the use of the sensors with a negligible deterioration in the performance of the approaching maneuver. PMID:26102489

  6. Too exhausted to remember: ego depletion undermines subsequent event-based prospective memory.

    PubMed

    Li, Jian-Bin; Nie, Yan-Gang; Zeng, Min-Xia; Huntoon, Meghan; Smith, Jessi L

    2013-01-01

    Past research has consistently found that people are likely to do worse on high-level cognitive tasks after exerting self-control on previous actions. However, little has been unraveled about to what extent ego depletion affects subsequent prospective memory. Drawing upon the self-control strength model and the relationship between self-control resources and executive control, this study proposes that the initial actions of self-control may undermine subsequent event-based prospective memory (EBPM). Ego depletion was manipulated through watching a video requiring visual attention (Experiment 1) or completing an incongruent Stroop task (Experiment 2). Participants were then tested on EBPM embedded in an ongoing task. As predicted, the results showed that after ruling out possible intervening variables (e.g. mood, focal and nonfocal cues, and characteristics of ongoing task and ego depletion task), participants in the high-depletion condition performed significantly worse on EBPM than those in the low-depletion condition. The results suggested that the effect of ego depletion on EBPM was mainly due to an impaired prospective component rather than to a retrospective component. PMID:23432682

  7. Can readers ignore implausibility? Evidence for nonstrategic monitoring of event-based plausibility in language comprehension.

    PubMed

    Isberner, Maj-Britt; Richter, Tobias

    2013-01-01

    We present evidence for a nonstrategic monitoring of event-based plausibility during language comprehension by showing that readers cannot ignore the implausibility of information even if it is detrimental to the task at hand. In two experiments using a Stroop-like paradigm, participants were required to provide positive and negative responses independent of plausibility in an orthographical task (Experiment 1) or a nonlinguistic color judgment task (Experiment 2) to target words that were either plausible or implausible in their context. We expected a nonstrategic assessment of plausibility to interfere with positive responses to implausible words. ANOVAs and linear mixed models analyses of the response latencies revealed a significant interaction of plausibility and required response that supported this prediction in both experiments, despite the use of two very different tasks. Moreover, it could be shown that the effect was not driven by the differential predictability of plausible and implausible words. These results suggest that plausibility monitoring is an inherent component of information processing. PMID:23165201

  8. An event-based approach for examining the effects of wildland fire decisions on communities.

    PubMed

    McCool, Stephen F; Burchfield, James A; Williams, Daniel R; Carroll, Matthew S

    2006-04-01

    Public concern over the consequences of forest fire to wildland interface communities has led to increased resources devoted to fire suppression, fuel treatment, and management of fire events. The social consequences of the decisions involved in these and other fire-related actions are largely unknown, except in an anecdotal sense, but do occur at a variety of temporal and social organizational scales. These consequences are not limited to the fire event itself. Preparation for the possibility of a fire, actions that suppression agencies take during a fire, and postfire decisions all have consequences, if unknown currently. This article presents an "event-based" approach that can be useful for constructing and systematic discussion about the consequences of wildland fire to human communities. For each of the three major periods within this approach, agencies, communities, and individuals make decisions and take actions that have consequences. The article presents an integrated, temporally based process for examining these consequences, which is similar to others developed in the natural hazards and disaster management literature. PMID:16465562

  9. Assessing the Continuum of Event-Based Biosurveillance Through an Operational Lens

    SciTech Connect

    Corley, Courtney D.; Lancaster, Mary J.; Brigantic, Robert T.; Chung, James S.; Walters, Ronald A.; Arthur, Ray; Bruckner-Lea, Cindy J.; Calapristi, Augustin J.; Dowling, Glenn; Hartley, David M.; Kennedy, Shaun; Kircher, Amy; Klucking, Sara; Lee, Eva K.; McKenzie, Taylor K.; Nelson, Noele P.; Olsen, Jennifer; Pancerella, Carmen M.; Quitugua, Teresa N.; Reed, Jeremy T.; Thomas, Carla S.

    2012-03-28

    This research follows the Updated Guidelines for Evaluating Public Health Surveillance Systems, Recommendations from the Guidelines Working Group, published by the Centers for Disease Control and Prevention nearly a decade ago. Since then, models have been developed and complex systems have evolved with a breadth of disparate data to detect or forecast chemical, biological, and radiological events that have significant impact in the One Health landscape. How the attributes identified in 2001 relate to the new range of event-based biosurveillance (EBB) technologies is unclear. This manuscript frames the continuum of EBB methods, models, and constructs through an operational lens (i.e., aspects and attributes associated with operational considerations in the development, testing, and validation of the EBB methods and models and their use in an operational environment). A 2-day subject matter expert workshop was held to scientifically identify, develop, and vet a set of attributes for the broad range of such operational considerations. Workshop participants identified and described comprehensive attributes for the characterization of EBB. The identified attributes are: (1) event, (2) readiness, (3) operational aspects, (4) geographic coverage, (5) population coverage, (6) input data, (7) output, and (8) cost. Ultimately, the analyses herein discuss the broad scope, complexity, and relevant issues germane to EBB useful in an operational environment.

  10. On-Board Event-Based State Estimation for Trajectory Approaching and Tracking of a Vehicle

    PubMed Central

    Martínez-Rey, Miguel; Espinosa, Felipe; Gardel, Alfredo; Santos, Carlos

    2015-01-01

    For the problem of pose estimation of an autonomous vehicle using networked external sensors, the processing capacity and battery consumption of these sensors, as well as the communication channel load should be optimized. Here, we report an event-based state estimator (EBSE) consisting of an unscented Kalman filter that uses a triggering mechanism based on the estimation error covariance matrix to request measurements from the external sensors. This EBSE generates the events of the estimator module on-board the vehicle and, thus, allows the sensors to remain in stand-by mode until an event is generated. The proposed algorithm requests a measurement every time the estimation distance root mean squared error (DRMS) value, obtained from the estimator's covariance matrix, exceeds a threshold value. This triggering threshold can be adapted to the vehicle's working conditions rendering the estimator even more efficient. An example of the use of the proposed EBSE is given, where the autonomous vehicle must approach and follow a reference trajectory. By making the threshold a function of the distance to the reference location, the estimator can halve the use of the sensors with a negligible deterioration in the performance of the approaching maneuver. PMID:26102489

  11. Fluence-based and microdosimetric event-based methods for radiation protection in space

    NASA Technical Reports Server (NTRS)

    Curtis, Stanley B.; Meinhold, C. B. (Principal Investigator)

    2002-01-01

    The National Council on Radiation Protection and Measurements (NCRP) has recently published a report (Report #137) that discusses various aspects of the concepts used in radiation protection and the difficulties in measuring the radiation environment in spacecraft for the estimation of radiation risk to space travelers. Two novel dosimetric methodologies, fluence-based and microdosimetric event-based methods, are discussed and evaluated, along with the more conventional quality factor/LET method. It was concluded that for the present, any reason to switch to a new methodology is not compelling. It is suggested that because of certain drawbacks in the presently-used conventional method, these alternative methodologies should be kept in mind. As new data become available and dosimetric techniques become more refined, the question should be revisited and that in the future, significant improvement might be realized. In addition, such concepts as equivalent dose and organ dose equivalent are discussed and various problems regarding the measurement/estimation of these quantities are presented.

  12. Event-Based Surveillance During EXPO Milan 2015: Rationale, Tools, Procedures, and Initial Results.

    PubMed

    Riccardo, Flavia; Manso, Martina Del; Caporali, Maria Grazia; Napoli, Christian; Linge, Jens P; Mantica, Eleonora; Verile, Marco; Piatti, Alessandra; Pompa, Maria Grazia; Vellucci, Loredana; Costanzo, Virgilio; Bastiampillai, Anan Judina; Gabrielli, Eugenia; Gramegna, Maria; Declich, Silvia

    2016-01-01

    More than 21 million participants attended EXPO Milan from May to October 2015, making it one of the largest protracted mass gathering events in Europe. Given the expected national and international population movement and health security issues associated with this event, Italy fully implemented, for the first time, an event-based surveillance (EBS) system focusing on naturally occurring infectious diseases and the monitoring of biological agents with potential for intentional release. The system started its pilot phase in March 2015 and was fully operational between April and November 2015. In order to set the specific objectives of the EBS system, and its complementary role to indicator-based surveillance, we defined a list of priority diseases and conditions. This list was designed on the basis of the probability and possible public health impact of infectious disease transmission, existing statutory surveillance systems in place, and any surveillance enhancements during the mass gathering event. This article reports the methodology used to design the EBS system for EXPO Milan and the results of 8 months of surveillance. PMID:27314656

  13. A coupled model of TiN inclusion growth in GCr15SiMn during solidification in the electroslag remelting process

    NASA Astrophysics Data System (ADS)

    Yang, Liang; Cheng, Guo-guang; Li, Shi-jian; Zhao, Min; Feng, Gui-ping; Li, Tao

    2015-12-01

    TiN inclusions observed in an ingot produced by electroslag remelting (ESR) are extremely harmful to GCr15SiMn steel. Therefore, accurate predictions of the growth size of these inclusions during steel solidification are significant for clean ESR ingot production. On the basis of our previous work, a coupled model of solute microsegregation and TiN inclusion growth during solidification has been established. The results demonstrate that compared to a non-coupled model, the coupled model predictions of the size of TiN inclusions are in good agreement with experimental results using scanning electron microscopy with energy disperse spectroscopy (SEM-EDS). Because of high cooling rate, the sizes of TiN inclusions in the edge area of the ingots are relatively small compared to the sizes in the center area. During the ESR process, controlling the content of Ti in the steel is a feasible and effective method of decreasing the sizes of TiN inclusions.

  14. Advanced Science/Event-based Data Service Framework at GES DISC

    NASA Astrophysics Data System (ADS)

    Shie, C. L.; Shen, S.; Kempler, S. J.

    2014-12-01

    The NASA Goddard Earth Sciences Data and Information Service Center (GES DISC) has provided numerous Earth science data, information, and services to various research communities and general publics for decades. To maintain an overall fine service including improving serving our users with advanced data services has been our primary goal. We are developing an advanced science/event-based data service framework. The framework aims to effectively provide users with a sophisticatedly integrated data package via user-friendly discovering and selecting a system-preset science/event topic (e.g., hurricane, volcano, etc.) from an in-developing knowledge database of the framework. A data recipe page related to the Hurricane topic has been developed to demo the concept. More showcases of various subjects such as Volcano, Dust Storm, and Forest Fire are also under development. This framework is in developing on top of existing data services at GES DISC, such as Mirador (data search engine), Giovanni (visualization), OPeNDAP, and data recipes. It also involves other data tools, such as Panoply, GrADS, IDL, etc. The Hurricane Sandy (Oct 22-31 2012) event is used here for a sample description. As Hurricane Sandy being selected as a user case, a table containing nine system-preset data variables (i.e., precipitation, winds, sea surface temperature, sea level pressure, air temperature, relative humidity, aerosols, soil moisture and surface runoff, and trace gases) linked to the respective data products with fine temporal and spatial resolutions from various in-house sources is provided. The "bundled" variable data can thus be readily downloaded through Mirador. The in-house Giovanni is accessible for users to acquire quick views of Level 3 (gridded) variables. For Level 2 (swath) or the Giovanni-unavailable Level 3 data, the system provides a link to data recipes that give a how-to guide to read and visualize the data using offline tools, such as Panoply, GrADS, or IDL.

  15. A Neuromorphic Event-Based Neural Recording System for Smart Brain-Machine-Interfaces.

    PubMed

    Corradi, Federico; Indiveri, Giacomo

    2015-10-01

    Neural recording systems are a central component of Brain-Machince Interfaces (BMIs). In most of these systems the emphasis is on faithful reproduction and transmission of the recorded signal to remote systems for further processing or data analysis. Here we follow an alternative approach: we propose a neural recording system that can be directly interfaced locally to neuromorphic spiking neural processing circuits for compressing the large amounts of data recorded, carrying out signal processing and neural computation to extract relevant information, and transmitting only the low-bandwidth outcome of the processing to remote computing or actuating modules. The fabricated system includes a low-noise amplifier, a delta-modulator analog-to-digital converter, and a low-power band-pass filter. The bio-amplifier has a programmable gain of 45-54 dB, with a Root Mean Squared (RMS) input-referred noise level of 2.1 μV, and consumes 90 μW . The band-pass filter and delta-modulator circuits include asynchronous handshaking interface logic compatible with event-based communication protocols. We describe the properties of the neural recording circuits, validating them with experimental measurements, and present system-level application examples, by interfacing these circuits to a reconfigurable neuromorphic processor comprising an array of spiking neurons with plastic and dynamic synapses. The pool of neurons within the neuromorphic processor was configured to implement a recurrent neural network, and to process the events generated by the neural recording system in order to carry out pattern recognition. PMID:26513801

  16. Coupling urban event-based and catchment continuous modelling for combined sewer overflow river impact assessment

    NASA Astrophysics Data System (ADS)

    Andrés-Doménech, I.; Múnera, J. C.; Francés, F.; Marco, J. B.

    2010-05-01

    Since the Water Framework Directive (WFD) was passed in year 2000, the protection of water bodies in the EU must be understood in a completely different way. Regarding to combined sewer overflows (CSOs) from urban drainage networks, the WFD implies that CSOs cannot be accepted because of their intrinsic features, but must be assessed for their impact on the receiving water bodies in agreement with specific environmental aims. Consequently, both, the urban system and the receiving one must be jointly analysed to evaluate their impact. In this context, a coupled scheme is presented in this paper to assess the CSOs impact in a river system in Torrelavega (Spain). First, an urban model is developed to characterise statistically the CSOs frequency, volume and duration. The main feature of this first model is the fact of being event-based: the system is modelled with some built synthetic storms which cover adequately the probability range of the main rainfall descriptors, i.e., rainfall event volume and peak intensity. Thus, CSOs are characterised in terms of their occurrence probability. Secondly, a continuous and distributed basin model is built to assess the river response at different points in the river network. This model was calibrated initially on a daily scale and downscaled later to the hourly scale. The main objective of this second element of the scheme is to provide the most likely state of the receiving river when a CSO occurs. By combining results of both models, CSO and river flows are homogeneously characterised from a statistical point of view. Finally, results from both models were coupled to estimate the final concentration of some analysed pollutants (the biochemical oxygen demand, BOD, and the total ammonium, NH4+), in the river just after the spills.

  17. Coupling urban event-based and catchment continuous modelling for combined sewer overflow river impact assessment

    NASA Astrophysics Data System (ADS)

    Andrés-Doménech, I.; Múnera, J. C.; Francés, F.; Marco, J. B.

    2010-10-01

    Since Water Framework Directive (WFD) was passed in year 2000, the conservation of water bodies in the EU must be understood in a completely different way. Regarding to combined sewer overflows (CSOs) from urban drainage networks, the WFD implies that we cannot accept CSOs because of their intrinsic features, but they must be assessed for their impact on the receiving water bodies in agreement with specific environmental aims. Consequently, both, urban system and the receiving water body must be jointly analysed to evaluate the environmental impact generated on the latter. In this context, a coupled scheme is presented in this paper to assess the CSOs impact on a river system in Torrelavega (Spain). First, a urban model is developed to statistically characterise the CSOs frequency, volume and duration. The main feature of this first model is the fact of being event-based: the system is modelled with some built synthetic storms which cover adequately the probability range of the main rainfall descriptors, i.e., rainfall event volume and peak intensity. Thus, CSOs are characterised in terms of their occurrence probability. Secondly, a continuous and distributed basin model is built to assess river response at different points in the river network. This model was calibrated initially on a daily scale and downscaled later to hourly scale. The main objective of this second element of the scheme is to provide the most likely state of the receiving river when a CSO occurs. By combining results of both models, CSO and river flows are homogeneously characterised from a statistical point of view. Finally, results from both models were coupled to estimate the final concentration of some analysed pollutants (biochemical oxygen demand, BOD, and total ammonium, NH4+), within the river just after the spills.

  18. Modulation of a Fronto-Parietal Network in Event-Based Prospective Memory: An rTMS Study

    ERIC Educational Resources Information Center

    Bisiacchi, P. S.; Cona, G.; Schiff, S.; Basso, D.

    2011-01-01

    Event-based prospective memory (PM) is a multi-component process that requires remembering the delayed execution of an intended action in response to a pre-specified PM cue, while being actively engaged in an ongoing task. Some neuroimaging studies have suggested that both prefrontal and parietal areas are involved in the maintenance and…

  19. On the Relationship Between Effort Toward an Ongoing Task and Cue Detection in Event-Based Prospective Memory

    ERIC Educational Resources Information Center

    Marsh, Richard L.; Hicks, Jason L.; Cook, Gabriel I.

    2005-01-01

    In recent theories of event-based prospective memory, researchers have debated what degree of resources are necessary to identify a cue as related to a previously established intention. In order to simulate natural variations in attention, the authors manipulated effort toward an ongoing cognitive task in which intention-related cues were embedded…

  20. Event-based approach of downstream Rhône River flood regimes variability since 1982

    NASA Astrophysics Data System (ADS)

    Hénaff, Quentin; Arnaud-Fassetta, Gilles; Beltrando, Gérard

    2015-04-01

    Numerous downstream Rhône River floods have been recorded as catastrophic by French inter-ministerial order since the creation of natural disaster state recognition in 1982. Downstream Rhône River flood regimes, influenced by Mediterranean climate, are fundamentally affected by the spatio-temporal variability of rainfall events, especially in case of widespread flooding. Event-based analysis of cumulative rainfall data should allow us to characterise downstream Rhône River flood regimes variability by applying data mining methods to a spatio-temporal hydro-meteorological database. The first objective of this study is to determine if extreme rainfall events could be considered as geographical events, in other words if rainfall distribution is related to spatial processes. The proposed method is based on the measure of rainfall distribution spatial auto-correlation through the calculation of (i) Global Moran's index and (ii) the significance evaluation of that index with a z-score statistical test and its associated p-value. Secondly, cumulative rainfall data are integrated into a geo-event two-dimensional matrix: (i) cumulative rainfall per sub-catchment in row (spatial base unit) and (ii) cumulative rainfall per catastrophic event in column (temporal base unit). This matrix was co-clustered which allows simultaneous clustering of the rows (sub-catchment) and columns (events) by hierarchical clustering on principal components (HCPC) using Ward's method applying Euclidean Distance as similarity measure. Computing the Global Moran's index demonstrated a spatial aggregation tendency of rainfall distribution and the associated statistical test (z-core and p-value) noted the improbability of statistical evidence of random spatial pattern. Spatial variability of rainfall distribution is the result of two factors: rainfall event structure and rainfall event scale. The co-clustering geo-event matrix provided two co-clustering maps on two different cumulative rainfall

  1. Comparison of event-based landslide inventory maps obtained interpreting satellite images and aerial photographs

    NASA Astrophysics Data System (ADS)

    Fiorucci, Federica; Cardinali, Mauro; Carlà Roberto; Mondini, Alessandro; Santurri, Leonardo; Guzzetti, Fausto

    2010-05-01

    Landslide inventory maps are a common type of map used for geomorphological investigations, land planning, and hazard and risk assessment. Landslide inventory maps covering medium to large areas are obtained primarily exploiting traditional geomorphological techniques. These techniques combine the visual and heuristic interpretation of stereoscopic aerial photographs with more or less extensive field investigations. Aerial photographs most commonly used to prepare landslide inventory maps range in scale from about 1:10,000 to about 1:40,000. Interpretation of satellite images is a relatively recent, powerful tool to obtain information of the Earth surface potentially useful for the production of landslide inventory maps. The usefulness of satellite information - and the associated technology - for the identification of landslides and the production of landslide inventory maps, remains largely unexplored. In this context, it is of interest to investigate the type, quantity, and quality of the information that can be retrieved analyzing images taken by the last generation of high and very-high resolution satellite sensors, and to compare this information with the information obtained from the analysis of traditional stereoscopic aerial photographs, or in the field. In the framework of the MORFEO project for the exploitation of Earth Observation data and technology for landslide identification and risk assessment, of the Italian Space Agency, we have compared two event-based landslide inventory maps prepared exploiting two different techniques. The two maps portray the geographical distribution and types of landslides triggered by rainfall in the period from November 2004 to May 2005 in the Collazzone area, Umbria, central Italy. The first map was prepared through reconnaissance field surveys carried out mostly along roads. The second map was obtained through the combined visual interpretation of 1:10,000 scale, colour ortho-photo maps, and images taken by the IKONOS

  2. Scalable Parallel Execution of an Event-based Radio Signal Propagation Model for Cluttered 3D Terrains

    SciTech Connect

    Seal, Sudip K; Perumalla, Kalyan S

    2009-01-01

    Radio signal strength estimation is essential in many applications, including the design of military radio communications and industrial wireless installations. While classical approaches such as finite difference methods are well-known, new event-based models of radio signal propagation have been recently shown to deliver such estimates faster (via serial execution) than other methods. For scenarios with large or richly-featured geographical volumes, however, parallel processing is required to meet the memory and computation time demands. Here, we present a scalable and efficient parallel execution of a recently-developed event-based radio signal propagation model. We demonstrate its scalability to thousands of processors, with parallel speedups over 1000x. The speed and scale achieved by our parallel execution enable larger scenarios and faster execution than has ever been reported before.

  3. Incorporating seasonality into event-based joint probability methods for predicting flood frequency: A hybrid causative event approach

    NASA Astrophysics Data System (ADS)

    Li, Jing; Thyer, Mark; Lambert, Martin; Kuzera, George; Metcalfe, Andrew

    2016-02-01

    Flood extremes are driven by highly variable and complex climatic and hydrological processes. Observational evidence has identified that seasonality of climate variables has a major impact on flood peaks. However, event-based joint probability approaches for predicting the flood frequency distribution (FFD), which are commonly used in practice, do not commonly incorporate climate seasonality. This study presents an advance in event-based joint probability approaches by incorporating seasonality using the hybrid causative events (HCE) approach. The HCE was chosen because it uses the true causative events of the floods of interest and is able to combine the accuracy of continuous simulation with the computational efficiency of event-based approaches. The incorporation of seasonality is evaluated using a virtual catchment approach at eight sites over a wide range of Australian climate zones, including tropical, temperature, Mediterranean and desert climates (virtual catchment data for the eight sites is freely available via digital repository). The seasonal HCE provided accurate predictions of the FFD at all sites. In contrast, the non-seasonal HCE significantly over-predicted the FFD at some sites. The need to include seasonality was influenced by the magnitude of the seasonal variation in soil moisture and its coherence with the seasonal variation in extreme rainfall. For sites with a low seasonal variation in soil moisture the non-seasonal HCE provided reliable estimates of the FFD. For the remaining sites, it was found difficult to predict a priori whether ignoring seasonality provided a reliable estimate of the FFD, hence it is recommended that the seasonal HCE always be used. The practical implications of this study are that the HCE approach with seasonality is an accurate and efficient event-based joint probability approach to derive the flood frequency distribution across a wide range of climatologies.

  4. Effective utilization of flue gases in raceway reactor with event-based pH control for microalgae culture.

    PubMed

    Pawlowski, A; Mendoza, J L; Guzmán, J L; Berenguel, M; Acién, F G; Dormido, S

    2014-10-01

    This work addresses effective utilization of flue gases through the proper pH control in raceway reactors. The pH control problem has been addressed with an event-based control approach using a Generalized Predictive Controller (GPC) with actuator deadband. Applying this control strategy it is possible to reduce the control effort, and at the same time saving control resources. In the pH process case, the event-based controller with actuator deadband can be tuned to supply only necessary amount of CO2 to keep the pH close to its optimal value. On the other hand, the evaluated control algorithm significantly improves the pH control accuracy, what has a direct influence on biomass production. In order to test the performance of the event-based GPC controller, several experiments have been performed on a real raceway reactor. Additionally, several control performance indexes have been used to compare the analyzed technique with commonly used on/off controller. PMID:25113401

  5. Breaking the millisecond barrier on SpiNNaker: implementing asynchronous event-based plastic models with microsecond resolution.

    PubMed

    Lagorce, Xavier; Stromatias, Evangelos; Galluppi, Francesco; Plana, Luis A; Liu, Shih-Chii; Furber, Steve B; Benosman, Ryad B

    2015-01-01

    Spike-based neuromorphic sensors such as retinas and cochleas, change the way in which the world is sampled. Instead of producing data sampled at a constant rate, these sensors output spikes that are asynchronous and event driven. The event-based nature of neuromorphic sensors implies a complete paradigm shift in current perception algorithms toward those that emphasize the importance of precise timing. The spikes produced by these sensors usually have a time resolution in the order of microseconds. This high temporal resolution is a crucial factor in learning tasks. It is also widely used in the field of biological neural networks. Sound localization for instance relies on detecting time lags between the two ears which, in the barn owl, reaches a temporal resolution of 5 μs. Current available neuromorphic computation platforms such as SpiNNaker often limit their users to a time resolution in the order of milliseconds that is not compatible with the asynchronous outputs of neuromorphic sensors. To overcome these limitations and allow for the exploration of new types of neuromorphic computing architectures, we introduce a novel software framework on the SpiNNaker platform. This framework allows for simulations of spiking networks and plasticity mechanisms using a completely asynchronous and event-based scheme running with a microsecond time resolution. Results on two example networks using this new implementation are presented. PMID:26106288

  6. Breaking the millisecond barrier on SpiNNaker: implementing asynchronous event-based plastic models with microsecond resolution

    PubMed Central

    Lagorce, Xavier; Stromatias, Evangelos; Galluppi, Francesco; Plana, Luis A.; Liu, Shih-Chii; Furber, Steve B.; Benosman, Ryad B.

    2015-01-01

    Spike-based neuromorphic sensors such as retinas and cochleas, change the way in which the world is sampled. Instead of producing data sampled at a constant rate, these sensors output spikes that are asynchronous and event driven. The event-based nature of neuromorphic sensors implies a complete paradigm shift in current perception algorithms toward those that emphasize the importance of precise timing. The spikes produced by these sensors usually have a time resolution in the order of microseconds. This high temporal resolution is a crucial factor in learning tasks. It is also widely used in the field of biological neural networks. Sound localization for instance relies on detecting time lags between the two ears which, in the barn owl, reaches a temporal resolution of 5 μs. Current available neuromorphic computation platforms such as SpiNNaker often limit their users to a time resolution in the order of milliseconds that is not compatible with the asynchronous outputs of neuromorphic sensors. To overcome these limitations and allow for the exploration of new types of neuromorphic computing architectures, we introduce a novel software framework on the SpiNNaker platform. This framework allows for simulations of spiking networks and plasticity mechanisms using a completely asynchronous and event-based scheme running with a microsecond time resolution. Results on two example networks using this new implementation are presented. PMID:26106288

  7. Event-based knowledge elicitation of operating room management decision-making using scenarios adapted from information systems data

    PubMed Central

    2011-01-01

    Background No systematic process has previously been described for a needs assessment that identifies the operating room (OR) management decisions made by the anesthesiologists and nurse managers at a facility that do not maximize the efficiency of use of OR time. We evaluated whether event-based knowledge elicitation can be used practically for rapid assessment of OR management decision-making at facilities, whether scenarios can be adapted automatically from information systems data, and the usefulness of the approach. Methods A process of event-based knowledge elicitation was developed to assess OR management decision-making that may reduce the efficiency of use of OR time. Hypothetical scenarios addressing every OR management decision influencing OR efficiency were created from published examples. Scenarios are adapted, so that cues about conditions are accurate and appropriate for each facility (e.g., if OR 1 is used as an example in a scenario, the listed procedure is a type of procedure performed at the facility in OR 1). Adaptation is performed automatically using the facility's OR information system or anesthesia information management system (AIMS) data for most scenarios (43 of 45). Performing the needs assessment takes approximately 1 hour of local managers' time while they decide if their decisions are consistent with the described scenarios. A table of contents of the indexed scenarios is created automatically, providing a simple version of problem solving using case-based reasoning. For example, a new OR manager wanting to know the best way to decide whether to move a case can look in the chapter on "Moving Cases on the Day of Surgery" to find a scenario that describes the situation being encountered. Results Scenarios have been adapted and used at 22 hospitals. Few changes in decisions were needed to increase the efficiency of use of OR time. The few changes were heterogeneous among hospitals, showing the usefulness of individualized assessments

  8. Substance Use and Other Risk Factors for Unprotected Sex: Results From An Event-Based Study of Homeless Youth

    PubMed Central

    Tucker, Joan S.; Ryan, Gery W.; Golinelli, Daniela; Munjas, Brett; Wenzel, Suzanne L.; Kennedy, David P.; Green, Harold D.; Zhou, Annie

    2011-01-01

    This study used an event-based approach to understand condom use in a probability sample of 309 homeless youth recruited from service and street sites in Los Angeles County. Condom use was significantly less likely when hard drug use preceded sex, the relationship was serious, the partners talked about “pulling out”, or sex occurred in a non-private place (and marginally less likely when heavier drinking preceded sex, or the partnership was monogamous or abusive). Condom use was significantly more likely when the youth held positive condom attitudes or were concerned about pregnancy, the partners talked about condom use, and the partners met up by chance. This study extends previous work by simultaneously examining a broad range of individual, relationship, and contexual factors that may play a role in condom use. Results identify a number of actionable targets for programs aimed at reducing HIV/STI transmission and pregnancy risk among homeless youth. PMID:21932093

  9. Flexible readout and integration sensor (FRIS): a bio-inspired, system-on-chip, event-based readout architecture

    NASA Astrophysics Data System (ADS)

    Lin, Joseph H.; Pouliquen, Philippe O.; Andreou, Andreas G.; Goldberg, Arnold C.; Rizk, Charbel G.

    2012-06-01

    We present a bio-inspired system-on-chip focal plane readout architecture which at the system level, relies on an event based sampling scheme where only pixels within a programmable range of photon flux rates are output. At the pixel level, a one bit oversampled analog-to-digital converter together with a decimator allows for the quantization of signals up to 26 bits. Furthermore, digital non-uniformity correction of both gain and offset errors is applied at the pixel level prior to readout. We report test results for a prototype array fabricated in a standard 90nm CMOS process. Tests performed at room and cryogenic temperatures demonstrate the capability to operate at a temporal noise ratio as low as 1.5, an electron well capacity over 100Ge-, and an ADC LSB down to 1e-.

  10. Substance use and other risk factors for unprotected sex: results from an event-based study of homeless youth.

    PubMed

    Tucker, Joan S; Ryan, Gery W; Golinelli, Daniela; Ewing, Brett; Wenzel, Suzanne L; Kennedy, David P; Green, Harold D; Zhou, Annie

    2012-08-01

    This study used an event-based approach to understand condom use in a probability sample of 309 homeless youth recruited from service and street sites in Los Angeles County. Condom use was significantly less likely when hard drug use preceded sex, the relationship was serious, the partners talked about "pulling out", or sex occurred in a non-private place (and marginally less likely when heavier drinking preceded sex, or the partnership was monogamous or abusive). Condom use was significantly more likely when the youth held positive condom attitudes or were concerned about pregnancy, the partners talked about condom use, and the partners met up by chance. This study extends previous work by simultaneously examining a broad range of individual, relationship, and contexual factors that may play a role in condom use. Results identify a number of actionable targets for programs aimed at reducing HIV/STI transmission and pregnancy risk among homeless youth. PMID:21932093

  11. Allowing Brief Delays in Responding Improves Event-Based Prospective Memory for Young Adults Living with HIV Disease

    PubMed Central

    Loft, Shayne; Doyle, Katie L.; Naar-King, Sylvie; Outlaw, Angulique Y.; Nichols, Sharon L.; Weber, Erica; Blackstone, Kaitlin; Woods, Steven Paul

    2014-01-01

    Event-based prospective memory (PM) tasks require individuals to remember to perform an action when they encounter a specific cue in the environment, and have clear relevance for daily functioning for individuals with HIV. In many everyday tasks, the individual must not only maintain the intent to perform the PM task, but the PM task response also competes with the alternative and more habitual task response. The current study examined whether event-based PM can be improved by slowing down the pace of the task environment. Fifty-seven young adults living with HIV performed an ongoing lexical decision task while simultaneously performing a PM task of monitoring for a specific word (which was focal to the ongoing task of making lexical decisions) or syllable contained in a word (which was nonfocal). Participants were instructed to refrain from making task responses until after a tone was presented, which occurred at varying onsets (0–1600ms) after each stimulus appeared. Improvements in focal and non-focal PM accuracy were observed with response delays of 600ms. Furthermore, the difference in PM accuracy between the low demand focal PM task and the resource demanding non-focal PM task was reduced by half across increasingly longer delays, falling from 31% at 0ms delay to only 14% at 1600ms delay. The degree of ongoing task response slowing for the PM conditions, relative to a control condition that did not have a PM task and made lexical decisions only, also decreased with increased delay. Overall, the evidence indicates that delaying the task responses of younger HIV-infected adults increased the probability that the PM relevant features of task stimuli were adequately assessed prior to the ongoing task response, and by implication that younger HIV infected adults can more adequately achieve PM goals when the pace of the task environment is slowed down. PMID:25116075

  12. Deficits in cue detection underlie event-based prospective memory impairment in major depression: an eye tracking study.

    PubMed

    Chen, Siyi; Zhou, Renlai; Cui, Hong; Chen, Xinyin

    2013-10-30

    This study examined the cue detection in the non-focal event-based prospective memory (PM) of individuals with and without a major depressive disorder using behavioural and eye tracking assessments. The participants were instructed to search on each trial for a different target stimulus that could be present or absent and to make prospective responses to the cue object. PM tasks included cue only and target plus cue, whereas ongoing tasks included target only and distracter only. The results showed that a) participants with depression performed more poorly than those without depression in PM; b) participants with depression showed more fixations and longer total and average fixation durations in both ongoing and PM conditions; c) participants with depression had lower scores on accuracy in target-plus-cue trials than in cue-only trials and had a higher gaze rate of targets on hits and misses in target-plus-cue trials than did those without depression. The results indicate that the state of depression may impair top-down cognitive control function, which in turn results in particular deficits in the engagement of monitoring for PM cues. PMID:23477903

  13. Infectious diseases prioritisation for event-based surveillance at the European Union level for the 2012 Olympic and Paralympic Games.

    PubMed

    Economopoulou, A; Kinross, P; Domanovic, D; Coulombier, D

    2014-01-01

    In 2012, London hosted the Olympic and Paralympic Games (the Games), with events occurring throughout the United Kingdom (UK) between 27 July and 9 September 2012. Public health surveillance was performed by the Health Protection Agency (HPA). Collaboration between the HPA and the European Centre for Disease Prevention and Control (ECDC) was established for the detection and assessment of significant infectious disease events (SIDEs) occurring outside the UK during the time of the Games. Additionally, ECDC undertook an internal prioritisation exercise to facilitate ECDC’s decisions on which SIDEs should have preferentially enhanced monitoring through epidemic intelligence activities for detection and reporting in daily surveillance in the European Union (EU). A team of ECDC experts evaluated potential public health risks to the Games, selecting and prioritising SIDEs for event-based surveillance with regard to their potential for importation to the Games, occurrence during the Games or export to the EU/European Economic Area from the Games. The team opted for a multilevel approach including comprehensive disease selection, development and use of a qualitative matrix scoring system and a Delphi method for disease prioritisation. The experts selected 71 infectious diseases to enter the prioritisation exercise of which 27 were considered as priority for epidemic intelligence activities by ECDC for the EU for the Games. PMID:24762663

  14. Event-based minimum-time control of oscillatory neuron models: phase randomization, maximal spike rate increase, and desynchronization.

    PubMed

    Danzl, Per; Hespanha, João; Moehlis, Jeff

    2009-12-01

    We present an event-based feedback control method for randomizing the asymptotic phase of oscillatory neurons. Phase randomization is achieved by driving the neuron's state to its phaseless set, a point at which its phase is undefined and is extremely sensitive to background noise. We consider the biologically relevant case of a fixed magnitude constraint on the stimulus signal, and show how the control objective can be accomplished in minimum time. The control synthesis problem is addressed using the minimum-time-optimal Hamilton-Jacobi-Bellman framework, which is quite general and can be applied to any spiking neuron model in the conductance-based Hodgkin-Huxley formalism. We also use this methodology to compute a feedback control protocol for optimal spike rate increase. This framework provides a straightforward means of visualizing isochrons, without actually calculating them in the traditional way. Finally, we present an extension of the phase randomizing control scheme that is applied at the population level, to a network of globally coupled neurons that are firing in synchrony. The applied control signal desynchronizes the population in a demand-controlled way. PMID:19911192

  15. Evaluation of the Health Protection Event-Based Surveillance for the London 2012 Olympic and Paralympic Games.

    PubMed

    Severi, E; Kitching, A; Crook, P

    2014-01-01

    The Health Protection Agency (HPA) (currently Public Health England) implemented the Health Protection Event-Based Surveillance (EBS) to provide additional national epidemic intelligence for the 2012 London Olympic and Paralympic Games (the Games). We describe EBS and evaluate the system attributes. EBS aimed at identifying, assessing and reporting to the HPA Olympic Coordination Centre (OCC) possible national infectious disease threats that may significantly impact the Games. EBS reported events in England from 2 July to 12 September 2012. EBS sourced events from reports from local health protection units and from screening an electronic application 'HPZone Dashboard' (DB). During this period, 147 new events were reported to EBS, mostly food-borne and vaccine-preventable diseases: 79 from regional units, 144 from DB (76 from both). EBS reported 61 events to the OCC: 21 of these were reported onwards. EBS sensitivity was 95.2%; positive predictive value was 32.8%; reports were timely (median one day; 10th percentile: 0 days - same day; 90th percentile: 3.6 days); completeness was 99.7%; stability was 100%; EBS simplicity was assessed as good; the daily time per regional or national unit dedicated to EBS was approximately 4 hours (weekdays) and 3 hours (weekends). OCC directors judged EBS as efficient, fast and responsive. EBS provided reliable, reassuring, timely, simple and stable national epidemic intelligence for the Games. PMID:24970374

  16. Event-based washload transport and sedimentation in and around flood bypasses: Case study from the Sacramento Valley, California

    NASA Astrophysics Data System (ADS)

    Singer, M. B.; Aalto, R. A.

    2005-05-01

    In large river systems, suspended sediment transport and deposition patterns are often affected by channel constraints engineered for flood conveyance or navigation. Such managed channels typically have a limited number of overflow loci through which suspended sediment enters the river's floodplain. Engineered flood bypasses are narrow relic floodplains that are supplied by overflow diversion weirs along managed river channels, and support agriculture and complex aquatic and riparian habitats that are sensitive to the delivery of floods, fine sediment, and adsorbed contaminants. They function as wide, shallow conveyance channels parallel to the main river, and therefore present an opportunity to assess the applicability of existing theory for delivery to and settling of suspended sediment within floodplains. This study is an investigation of hydrograph characteristics, sediment delivery, and sedimentation within the upstream reaches of flood bypasses closest to the weir. We present analysis of hydrologic and sediment records and modeling in the Sacramento River basin. The effects of a single large flood in 1964-1965 were analyzed by documenting hydrograph characteristics, computing event-based sediment discharges and reach erosion/deposition through the bypass system, modeling bypass deposition, and comparing modeled results near the weirs with dated sediment cores. The rapidly rising, slowly declining 1964 flood was generated by storm runoff in the Sierra Nevada. The modeling results indicate: washload discharge through the lower valley 0.5 to 1.7 times long-term annual averages; mainstem reach erosion/deposition 0.5 to 1.25 times annual averages; and centimeter scale deposition in flood bypasses. The results are corroborated by a set of sediment cores extracted from Sacramento Valley bypasses, which were dated with 210Pb geochronology and analyzed for grain size. The modeling and data suggest net sediment accumulation between the channel and flood weirs and in

  17. Continuous and event-based time series analysis of observed floodplain groundwater flow under contrasting land-use types.

    PubMed

    Kellner, Elliott; Hubbart, Jason A

    2016-10-01

    There is an ongoing need to improve quantitative understanding of land-use impacts on floodplain groundwater flow regimes. A study was implemented in Hinkson Creek Watershed, Missouri, USA, including equidistant grids of nine piezometers, equipped with pressure transducers, which were installed at two floodplain study sites: a remnant bottomland hardwood forest (BHF) and a historical agricultural field (Ag). Data were logged at thirty minute intervals for the duration of the 2011, 2012, 2013, and 2014 water years (October 1, 2010-September 30, 2014). Results show significant (p<0.001) differences between Darcy-estimated groundwater flow at the two study sites. Although median flow values at the two sites were similar (0.009 and 0.010mday(-1) for the Ag and BHF sites, respectively), the BHF displayed a more dynamic flow regime compared to the Ag site. Maximum flow values were 0.020 and 0.049mday(-1) for the Ag and BHF sites, respectively. Minimum flow values were -0.018 and -0.029mday(-1) for the Ag and BHF sites, respectively. The BHF showed greater magnitude, longer duration, and more frequent negative flows, relative to the Ag site. Event-based analyses indicated a more seasonally responsive flow regime at the BHF, with higher flows than the Ag site during the wet season and lower flows than the Ag site during the dry season. Notably, the seasonal pattern of relative site flow differences was consistent across a wide range of precipitation event magnitudes (i.e. 8-45mm). Results are by majority attributable to greater rates of plant water use by woody vegetation and preferential subsurface flow at the BHF site. Collectively, results suggest greater flood attenuation capacity and streamwater buffering potential by the BHF floodplain, relative to the Ag, and highlight the value of floodplain forests as a land and water resource management tool. PMID:27232970

  18. Assessing the impact of utilizing event based water erosion versus static average water erosion (RUSLE) in carbon turnover modeling

    NASA Astrophysics Data System (ADS)

    Wilken, Florian; Fiener, Peter

    2015-04-01

    The discrepancy between the time scales at which soil redistribution processes and SOC turnover occur is an unresolved issue in erosion related carbon turnover modeling. The use of a static average erosion rate (e.g. revised universal soil loss equation; RUSLE) ignores event dynamic processes of (i) SOC enrichment during erosion, transport and deposition, (ii) event specific C release to the atmosphere during erosion processes, and (iii) event specific depth of SOC burial,. We hypothesize that event driven SOC enrichment and SOC burial is of fundamental importance for inter-annual carbon turnover. The study was carried out in an arable watershed (3.7 ha) with no-till management located in the loess dominated Tertiary hills 40 km north of Munich, Germany. To assess the importance of event dynamic SOC redistribution processes, we implemented two different water erosion modelling approaches in the coupled erosion and turnover model SPEROS-C. The first, RUSLE-based approach as already implemented in SPEROS-C, represents long-term mean erosion, while the second is based on the high-resolution, event-based and especially sediment size class selective Multi-Class Sediment Transport model (MCST). In both cases bulk sediment delivery and in case of MCST sediment size specific sediment delivery are tested and partly calibrated against an eight year monitoring data set. First results indicate that especially SOC enrichment during erosion, transport and deposition should be included in estimates of soil redistribution processes upon watershed C balances. The modelling with MCST also indicates that interpreting SOC patterns in eroding landscapes might be also biased if the selective nature of SOC erosion and deposition is ignored.

  19. Investigating the variation and non-stationarity in precipitation extremes based on the concept of event-based extreme precipitation

    NASA Astrophysics Data System (ADS)

    She, Dunxian; Shao, Quanxi; Xia, Jun; Taylor, John A.; Zhang, Yongyong; Zhang, Liping; Zhang, Xiang; Zou, Lei

    2015-11-01

    Extreme precipitations (EP) could induce a series of social, environmental and ecological problems. Traditional EP analysis usually investigated the characteristics based on a fixed time scale and therefore ignored the continuity of EP occurrence. As a result, a comprehensive assessment on the influence and consequence of the EP occurring during consecutive time periods were largely eliminated. On the other hand, the characteristics of EP, including variables such as frequency, intensity and extreme volume, were commonly defined without sufficient consideration of the local tolerance capacity (which can be represented by a threshold level of EP) and therefore would sometimes be inappropriate. In this study, we proposed a concept of event-based extreme precipitation (EEP) by considering the continuity of EP and defined the statistical variables for the characteristics of an EEP event by taking account of local tolerance capacity. An EEP was identified as a collection of precipitation data over the consecutive time period in which all the precipitation amounts are above the pre-defined threshold, and EEP events are separated by at least one time step (e.g., day or hour) with precipitation amount below the threshold. As a case study which in fact motivated our proposal, we investigated the changes and variations of EEP with the consideration of potential non-stationarity in the Hanjiang River Basin of China (HJRB) during the time period of 1960-2013. Results showed that the concept of EEP, which could reflect the impact of continuity of EP occurrence and mirror the differences of local tolerance capacity, was more appropriate than the traditional method in the EP analysis.

  20. Time-Based and Event-Based Prospective Memory in Autism Spectrum Disorder: The Roles of Executive Function and Theory of Mind, and Time-Estimation

    ERIC Educational Resources Information Center

    Williams, David; Boucher, Jill; Lind, Sophie; Jarrold, Christopher

    2013-01-01

    Prospective memory (remembering to carry out an action in the future) has been studied relatively little in ASD. We explored time-based (carry out an action at a pre-specified time) and event-based (carry out an action upon the occurrence of a pre-specified event) prospective memory, as well as possible cognitive correlates, among 21…

  1. The Cognitive Processes Underlying Event-Based Prospective Memory in School-Age Children and Young Adults: A Formal Model-Based Study

    ERIC Educational Resources Information Center

    Smith, Rebekah E.; Bayen, Ute J.; Martin, Claudia

    2010-01-01

    Fifty children 7 years of age (29 girls, 21 boys), 53 children 10 years of age (29 girls, 24 boys), and 36 young adults (19 women, 17 men) performed a computerized event-based prospective memory task. All 3 groups differed significantly in prospective memory performance, with adults showing the best performance and with 7-year-olds showing the…

  2. An event-based approach to understanding the hydrological impacts of different land uses in semi-arid catchments

    NASA Astrophysics Data System (ADS)

    Wang, Shengping; Zhang, Zhiqiang; McVicar, Tim R.; Zhang, Jianjun; Zhu, Jinzhao; Guo, Junting

    2012-01-01

    SummaryIn semi-arid catchments around the world re-vegetation is often implemented to reduce quick surface runoff, combat severe soil erosion, restore degraded ecosystem functionality, and, ultimately, improve ecosystem productivity. However, to date, in these water stressed regions, the event-based hydrological impact of different land uses induced by re-vegetation activities is not fully understood at the watershed scale. Traditional hillslope plot experiments and paired watershed experiments have proved difficult to up-scale to a watershed level. In 2006 and 2007, we used broad-crested weirs to measure event streamflow from six catchments within the Caijiachuan watershed (area = 40.1 km 2), located in the Loess Plateau, a semi-arid region in China. The six catchments have different land use compositions with functional combinations of crop, grassland, shrubland, secondary forest, and plantations. Over the same period, event rainfall was measured by a network of rainfall gauges deployed over the study site. We examined the difference in hydrological properties between the catchments using the non-parametric Firedman test, and differentiated the role of each land use in governing watershed hydrology using a numerical analysis technique. Our results showed important differences between the six catchments with respect to event runoff coefficients, normalized peak flow, and event duration. Each land use played a different role in catchment hydrology, as shown by the different mean runoff coefficients ( rc) and mean representative surface flow velocities ( V). Compared to secondary forest ( rc = 0.017 and V = 0.07 m s -1), plantations ( rc = 0.001 and V = 0.18 m s -1) provide a greater potential for increasing shearing force and had a larger impact on runoff reduction. Although shrubland ( rc = 0.096 and V = 0.20 m s -1) and grassland ( rc = 0.127 and V = 0.02 m s -1) have similar magnitude of mean runoff coefficients, grassland seems more capable of trapping sediment

  3. Time-based and event-based prospective memory in autism spectrum disorder: the roles of executive function and theory of mind, and time-estimation.

    PubMed

    Williams, David; Boucher, Jill; Lind, Sophie; Jarrold, Christopher

    2013-07-01

    Prospective memory (remembering to carry out an action in the future) has been studied relatively little in ASD. We explored time-based (carry out an action at a pre-specified time) and event-based (carry out an action upon the occurrence of a pre-specified event) prospective memory, as well as possible cognitive correlates, among 21 intellectually high-functioning children with ASD, and 21 age- and IQ-matched neurotypical comparison children. We found impaired time-based, but undiminished event-based, prospective memory among children with ASD. In the ASD group, time-based prospective memory performance was associated significantly with diminished theory of mind, but not with diminished cognitive flexibility. There was no evidence that time-estimation ability contributed to time-based prospective memory impairment in ASD. PMID:23179340

  4. Influence of intra-event-based flood regime on sediment flow behavior from a typical agro-catchment of the Chinese Loess Plateau

    NASA Astrophysics Data System (ADS)

    Zhang, Le-Tao; Li, Zhan-Bin; Wang, He; Xiao, Jun-Bo

    2016-07-01

    The pluvial erosion process is significantly affected by tempo-spatial patterns of flood flows. However, despite their importance, only a few studies have investigated the sediment flow behavior that is driven by different flood regimes. The study aims to investigate the effect of intra-event-based flood regimes on the dynamics of sediment exports at Tuanshangou catchment, a typical agricultural catchment (unmanaged) in the hilly loess region on the Chinese Loess Plateau. Measurements of 193 flood events and 158 sediment-producing events were collected from Tuanshangou station between 1961 and 1969. The combined methods of hierarchical clustering approach, discriminant analysis and One-Way ANOVA were used to classify the flood events in terms of their event-based flood characteristics, including flood duration, peak discharge, and event flood runoff depth. The 193 flood events were classified into five regimes, and the mean statistical features of each regime significantly differed. Regime A includes flood events with the shortest duration (76 min), minimum flood crest (0.045 m s-1), least runoff depth (0.2 mm), and highest frequency. Regime B includes flood events with a medium duration (274 min), medium flood crest (0.206 m s-1), and minor runoff depth (0.7 mm). Regime C includes flood events with the longest duration (822 min), medium flood crest (0.236 m s-1), and medium runoff depth (1.7 mm). Regime D includes flood events with a medium duration (239 min), large flood crest (4.21 m s-1), and large runoff depth (10 mm). Regime E includes flood events with a medium duration (304 min), maximum flood crest (8.62 m s-1), and largest runoff depth (25.9 mm). The sediment yield by different flood regimes is ranked as follows: Regime E > Regime D > Regime B > Regime C > Regime A. In terms of event-based average and maximum suspended sediment concentration, these regimes are ordered as follows: Regime E > Regime D > Regime C > Regime B > Regime A. Regimes D and E

  5. Issues for Simulation of Galactic Cosmic Ray Exposures for Radiobiological Research at Ground-Based Accelerators.

    PubMed

    Kim, Myung-Hee Y; Rusek, Adam; Cucinotta, Francis A

    2015-01-01

    For radiobiology research on the health risks of galactic cosmic rays (GCR) ground-based accelerators have been used with mono-energetic beams of single high charge, Z and energy, E (HZE) particles. In this paper, we consider the pros and cons of a GCR reference field at a particle accelerator. At the NASA Space Radiation Laboratory (NSRL), we have proposed a GCR simulator, which implements a new rapid switching mode and higher energy beam extraction to 1.5 GeV/u, in order to integrate multiple ions into a single simulation within hours or longer for chronic exposures. After considering the GCR environment and energy limitations of NSRL, we performed extensive simulation studies using the stochastic transport code, GERMcode (GCR Event Risk Model) to define a GCR reference field using 9 HZE particle beam-energy combinations each with a unique absorber thickness to provide fragmentation and 10 or more energies of proton and (4)He beams. The reference field is shown to well represent the charge dependence of GCR dose in several energy bins behind shielding compared to a simulated GCR environment. However, a more significant challenge for space radiobiology research is to consider chronic GCR exposure of up to 3 years in relation to simulations with animal models of human risks. We discuss issues in approaches to map important biological time scales in experimental models using ground-based simulation, with extended exposure of up to a few weeks using chronic or fractionation exposures. A kinetics model of HZE particle hit probabilities suggests that experimental simulations of several weeks will be needed to avoid high fluence rate artifacts, which places limitations on the experiments to be performed. Ultimately risk estimates are limited by theoretical understanding, and focus on improving knowledge of mechanisms and development of experimental models to improve this understanding should remain the highest priority for space radiobiology research. PMID:26090339

  6. Issues for Simulation of Galactic Cosmic Ray Exposures for Radiobiological Research at Ground-Based Accelerators

    PubMed Central

    Kim, Myung-Hee Y.; Rusek, Adam; Cucinotta, Francis A.

    2015-01-01

    For radiobiology research on the health risks of galactic cosmic rays (GCR) ground-based accelerators have been used with mono-energetic beams of single high charge, Z and energy, E (HZE) particles. In this paper, we consider the pros and cons of a GCR reference field at a particle accelerator. At the NASA Space Radiation Laboratory (NSRL), we have proposed a GCR simulator, which implements a new rapid switching mode and higher energy beam extraction to 1.5 GeV/u, in order to integrate multiple ions into a single simulation within hours or longer for chronic exposures. After considering the GCR environment and energy limitations of NSRL, we performed extensive simulation studies using the stochastic transport code, GERMcode (GCR Event Risk Model) to define a GCR reference field using 9 HZE particle beam–energy combinations each with a unique absorber thickness to provide fragmentation and 10 or more energies of proton and 4He beams. The reference field is shown to well represent the charge dependence of GCR dose in several energy bins behind shielding compared to a simulated GCR environment. However, a more significant challenge for space radiobiology research is to consider chronic GCR exposure of up to 3 years in relation to simulations with animal models of human risks. We discuss issues in approaches to map important biological time scales in experimental models using ground-based simulation, with extended exposure of up to a few weeks using chronic or fractionation exposures. A kinetics model of HZE particle hit probabilities suggests that experimental simulations of several weeks will be needed to avoid high fluence rate artifacts, which places limitations on the experiments to be performed. Ultimately risk estimates are limited by theoretical understanding, and focus on improving knowledge of mechanisms and development of experimental models to improve this understanding should remain the highest priority for space radiobiology research. PMID:26090339

  7. Event-Based Runoff Across Changing Land Covers in the Panama Canal Watershed: A Synthesis of Hydrophysical Measurements and Hydrochemical Tracers Using Hydrograph Separation

    NASA Astrophysics Data System (ADS)

    Litt, G.; Gardner, C.; Ogden, F. L.; Lyons, W. B.

    2014-12-01

    Tropical hydrology is understudied relative to its temperate counterparts and thus presents challenges for understanding catchment runoff behavior undergoing land use change. Combining hydrometric and hydrochemical observations can shed light on potential differences in runoff processes under changing land covers. We compare event-based dual member hydrograph separations across humid tropical lowland forest (142 ha), mixed land use (176 ha) and pasture (36 ha) catchments following two years of monitoring during the seasonal dry to wet season transition. Stable water isotope and electrical conductivity tracer event water fraction estimations agree well during small runoff events, but exhibit different results during a large runoff event with a greater runoff coefficient. Geochemical tracers exhibit event water fraction maximums during hydrograph recessions and a seasonal transition in runoff behavior among all land uses. From these results we identify potential runoff mechanisms in these steep humid tropical catchments under varying land uses.

  8. Preserved Intention Maintenance and Impaired Execution of Prospective Memory Responses in Schizophrenia: Evidence from an Event-based Prospective Memory Study

    PubMed Central

    Demeter, Gyula; Szendi, István; Domján, Nóra; Juhász, Marianna; Greminger, Nóra; Szőllősi, Ágnes; Racsmány, Mihály

    2016-01-01

    Executive system dysfunction and impaired prospective memory (PM) are widely documented in schizophrenia. However, it is not yet clarified which components of PM function are impaired in this disorder. Two plausible target components are the maintenance of delayed intentions and the execution of PM responses. Furthermore, it is debated whether the impaired performance on frequently used executive tasks is associated with deficit in PM functions. The aim of our study was twofold. First, we aimed to investigate the specific processes involved in event-based PM function, mainly focusing on difference between maintenance of intention and execution of PM responses. Second, we aimed to unfold the possible connections between executive functions, clinical symptoms, and PM performance. An event-based PM paradigm was applied with three main conditions: baseline (with no expectation of PM stimuli, and without PM stimuli), expectation condition (participants were told that PM stimuli might occur, though none actually did), and execution condition (participants were told that PM stimuli might occur, and PM stimuli did occur). This procedure allowed us to separately investigate performances associated with intention maintenance and execution of PM responses. We assessed working memory and set-shifting executive functions by memory span tasks and by the Wisconsin Card Sorting Test (WCST), respectively. Twenty patients diagnosed with schizophrenia and 20 healthy control subjects (matched according to age and education) took part in the study. It was hypothesized that patients would manifest different levels of performance in the expectation and execution conditions of the PM task. Our results confirmed that the difference between baseline performance and performance in the execution condition (execution cost) was significantly larger for participants diagnosed with schizophrenia in comparison with matched healthy control group. However, this difference was not observed in the

  9. Task Importance Affects Event-based Prospective Memory Performance in Adults with HIV-Associated Neurocognitive Disorders and HIV-infected Young Adults with Problematic Substance Use

    PubMed Central

    Woods, Steven Paul; Doyle, Katie L.; Morgan, Erin E.; Naar-King, Sylvie; Outlaw, Angulique Y.; Nichols, Sharon L.; Loft, Shayne

    2014-01-01

    Objective Two experiments were conducted to examine the effects of task importance on event-based prospective memory (PM) in separate samples of adults with HIV-associated Neurocognitive Disorders (HAND) and HIV-infected young adults with Substance Use Disorders (SUD). Method All participants completed three conditions of an ongoing lexical decision task: 1) without PM task requirements; 2) with PM task requirements that emphasized the importance of the ongoing task; and 3) with PM task requirements that emphasized the importance of the PM task. Results In both experiments, all HIV+ groups showed the expected increase in response costs to the ongoing task when the PM task’s importance was emphasized. In Experiment 1, individuals with HAND showed significantly lower PM accuracy as compared to HIV+ subjects without HAND when the importance of the ongoing task was emphasized, but improved significantly and no longer differed from HIV+ subjects without HAND when the PM task was emphasized. A similar pattern of findings emerged in Experiment 2, whereby HIV+ young adults with SUD (especially cannabis) showed significant improvements in PM accuracy when the PM task was emphasized. Conclusions Findings suggest that both HAND and SUD may increase the amount of cognitive attentional resources that need to be allocated to support PM performance in persons living with HIV infection. PMID:24834469

  10. Comment of "Event-based soil loss models for construction sites" by Trenouth and Gharabaghi, J. Hydrol. doi: 10.1016/jhydrol.2015.03.010

    NASA Astrophysics Data System (ADS)

    Kinnell, P. I. A.

    2015-09-01

    Trenouth and Gharabaghi (2015) present two models which replace the EI30 index used as the event erosivity index in the USLE/RUSLE with ones that include runoff and values of EI30 to powers that differ for 1.0 as the event erosivity factor in modelling soil loss for construction sites. Their analysis on the application of these models focused on data from 5 locations as a whole but did not show how the models worked at each location. Practically, the ability to predict sediment yields at a specific location is more relevant than the capacity of a model to predict sediment yields globally. Also, the mathematical structure of their proposed models shows little regard to the physical processes involved in causing erosion and sediment yield. There is still the need to develop event-based empirical models for construction sites that are robust because they give proper consideration to the erosion process involved, and take account of the fact that sediment yield is usually determined from measurements of suspended load whereas soil loss at the scale for which the USLE/RUSLE model was developed includes both suspended load and bed load.

  11. Flood-event based metal distribution patterns in water as approach for source apportionment of pollution on catchment scale: Examples from the River Elbe

    NASA Astrophysics Data System (ADS)

    Baborowski, Martina; Einax, Jürgen W.

    2016-04-01

    With the implementation of European Water Frame Work Directive (EU-WFD), the pollution sources in the River Elbe were assessed by the River Basin Community Elbe (RBC Elbe). Contaminated old sediments played the most significant role for inorganic and organic pollution. In terms of further improvement of the water quality in the river system, a prioritization of the known pollution sources is necessary, with respect to the expected effect in the case of their remediation. This requires information on mobility of contaminated sediments. To create a tool that allows the assessment of pollution trends in the catchment area, event based flood investigations were carried out at a sampling site in the Middle Elbe. The investigations were based on a comparable, discharge related sampling strategy. Four campaigns were performed between 1995 and 2006. The majority of the investigated 16 elements (>80%) studied more intensively in 2006 reached its maximum concentration during the first five days of the event. Only the concentrations of B, Cl-, and U declined with increasing discharge during the flood. The aim of the study was to verify that each flood event is characterized by an internal structure of the water quality. This structure is formed by the appearance of maximum values of water quality parameters at different times during the event. It could be detected by descriptive and multivariate statistical methods. As a result, internal structure of the water quality during the flood was influenced primarily by the source of the metals in the catchment area and its distance from the sampling point. The transport of metals in dissolved, colloidal or particulate form and changes of their ratios during the flood were however, not decisive for the formation of the structure. Our results show that the comparison of the structures obtained from events in different years is indicative of the pollution trend in the catchment area. Exemplarily the trend of the metal pollution in the

  12. Developing a Framework for Testing Distributed Hydrologic Models at the Catchment Scale - Examples of Test Model Runs for Event Based and Long Term Simulations

    NASA Astrophysics Data System (ADS)

    Cristea, N. C.; Kampf, S. K.; Mirus, B. B.; Loague, K.; Burges, S. J.

    2008-12-01

    We develop a testing framework for distributed hydrologic models at the catchment scale using the hypothetical reality concept. The hypothetical reality, considered an error-free hydrologic response modeled after the 10.5-ha Tarrawarra catchment in Australia, is generated using the sophisticated Integrated Hydrology Model (InHM) representing fully coupled 3D variably saturated subsurface and 2D surface flow with finite-element discretization. The hypothetical realty consists in a data set composed of two subsets designed to test long-term and event-based behavior of the test model. The first subset, a long term data set, comprises an 11-year variable time step time series of hydrograph output and head and saturation levels at 55 observation nodes as well as daily snapshots of head and saturation levels at all nodes in the domain. The second subset, short term data set, has the same type of output, but the domain snapshots are at a much finer time scale, every half hour for the selected rain events. Both data sets were obtained with the same InHM configuration but different output time steps. We use MODHMS (HydroGeoLogic, Inc.), a MODFLOW-based code that solves Richards equation for the 3-D variably saturated subsurface flow and the diffuse wave approximation 2D overland flow with finite differences in a coupled approach as the test model. We present examples of model testing scenarios with variations in spatial discretization, initial conditions, and representation of hydrologic processes. Future work includes testing of model parameters and soil characteristics, with the test model running first without any calibration and then with calibration against the hypothetical reality.

  13. Modeller subjectivity and calibration impacts on hydrological model applications: an event-based comparison for a road-adjacent catchment in south-east Norway.

    PubMed

    Kalantari, Zahra; Lyon, Steve W; Jansson, Per-Erik; Stolte, Jannes; French, Helen K; Folkeson, Lennart; Sassner, Mona

    2015-01-01

    Identifying a 'best' performing hydrologic model in a practical sense is difficult due to the potential influences of modeller subjectivity on, for example, calibration procedure and parameter selection. This is especially true for model applications at the event scale where the prevailing catchment conditions can have a strong impact on apparent model performance and suitability. In this study, two lumped models (CoupModel and HBV) and two physically-based distributed models (LISEM and MIKE SHE) were applied to a small catchment upstream of a road in south-eastern Norway. All models were calibrated to a single event representing typical winter conditions in the region and then applied to various other winter events to investigate the potential impact of calibration period and methodology on model performance. Peak flow and event-based hydrographs were simulated differently by all models leading to differences in apparent model performance under this application. In this case-study, the lumped models appeared to be better suited for hydrological events that differed from the calibration event (i.e., events when runoff was generated from rain on non-frozen soils rather than from rain and snowmelt on frozen soil) while the more physical-based approaches appeared better suited during snowmelt and frozen soil conditions more consistent with the event-specific calibration. This was due to the combination of variations in subsurface conditions over the eight events considered, the subsequent ability of the models to represent the impact of the conditions (particularly when subsurface conditions varied greatly from the calibration event), and the different approaches adopted to calibrate the models. These results indicate that hydrologic models may not only need to be selected on a case-by-case basis but also have their performance evaluated on an application-by-application basis since how a model is applied can be equally important as inherent model structure. PMID

  14. Comparison of event-based analysis of glaucoma progression assessed subjectively on visual fields and retinal nerve fibre layer attenuation measured by optical coherence tomography.

    PubMed

    Kaushik, Sushmita; Mulkutkar, Samyak; Pandav, Surinder Singh; Verma, Neelam; Gupta, Amod

    2015-02-01

    The purpose is to study the ability of an event-based analysis of retinal nerve fibre layer (RNFL) attenuation measured by Stratus(®) optical coherence tomography (OCT) and to detect progression across the spectrum of glaucoma. Adult glaucoma suspects, ocular hypertensives and glaucoma patients who had undergone baseline RNFL thickness measurement on Stratus OCT and reliable automated visual field examination by Humphrey's visual field analyser prior to March 2007 and had 5-year follow-up data were recruited. Progression on OCT was defined by two criteria: decrease in average RNFL thickness from baseline by at least 10 and 20 µ. Visual field progression was defined by the modified Hodapp-Parrish-Anderson criteria. Absolute and percentage change in RNFL thickness from baseline was compared in progressors and non-progressors on visual fields. Concordance between structural and functional progression was analysed. 318 eyes of 162 patients were analysed. 35 eyes (11 %) progressed by visual fields, 8 (2.5 %) progressed using the 20 µ loss criterion, while 30 eyes (9.4 %) progressed using the 10 µ loss criterion. In glaucoma suspects, mean absolute RNFL attenuation was 8.6 µ (12.1 % of baseline) in those who progressed to glaucoma by visual fields. OCT was more useful to detect progression in early glaucoma, but performed poorly in advanced glaucoma. The 10 µ criterion appears to be closer to visual field progression. However, the ability to detect progression varies considerably between functional and structural tools depending upon the severity of the disease. PMID:25502985

  15. Event-based Recession Analysis across Scales

    NASA Astrophysics Data System (ADS)

    Chen, B.; Krajewski, W. F.

    2012-12-01

    Hydrograph recessions have long been a window to investigate hydrological processes and their interactions. The authors conducted an exploratory analysis of about 1000 individual hydrograph recessions in a period of around 15 years (1995-2010) from time series of hourly discharge (USGS IDA stream flow data set) at 27 USGS gauges located in Iowa and Cedar River basins with drainage area ranging from 6.7 to around 17000 km2. They calculated recession exponents with the same recession length but different time lags from the hydrograph peak ranging from ~0 to 96 hours, and then plotted them against time lags to construct the evolution of recession exponent. The result shows that, as recession continues, the recession exponent in first increases quickly, then decreases quickly, and finally stays constant. Occasionally and for different reasons, the decreasing portion is missing due to negligible contribution from soil water storage. The increasing part of the evolution of can be related to fast response to rainfall including overland flow and quick subsurface flow through macropores (or tiles), and the decreasing portion can be connected to the delayed soil water response. Lastly, the constant segment can be attributed to the groundwater storage with the slowest response. The points where recession exponent reaches its maximum and begins to plateau are the times that fast response and soil water response end, respectively. The authors conducted further theoretical analysis by combining mathematical derivation and literature results to explain the observed evolution path of the recession exponent . Their results have a direct application in hydrograph separation and important implications for dynamic basin storage-discharge relation analysis and hydrological process understanding across scales.

  16. GCR-Induced Photon Luminescence of the Moon

    NASA Technical Reports Server (NTRS)

    Lee, K. T.; Wilson, T. L.

    2008-01-01

    It is shown that the Moon has a ubiquitous photon luminescence induced by Galactic cosmic-rays (GCRs), using the Monte Carlo particle-physics program FLUKA. Both the fluence and the flux of the radiation can be determined by this method, but only the fluence will be presented here. This is in addition to thermal radiation emitted due to the Moon s internal temperature and radioactivity. This study is a follow-up to an earlier discussion [1] that addressed several misconceptions regarding Moonshine in the Earth-Moon system (Figure 1) and predicted this effect. There also exists a related x-ray fluorescence induced by solar energetic particles (SEPs, <350 MeV) and solar photons at lower x-ray energies, although this latter fluorescence was studied on Apollo 15 and 16 [2- 5], Lunar Prospector [6], and even EGRET [7].

  17. Production of neutrons from interactions of GCR-like particles

    NASA Technical Reports Server (NTRS)

    Heilbronn, L.; Frankel, K.; Holabird, K.; Zeitlin, C.; McMahan, M. A.; Rathbun, W.; Cronqvist, M.; Gong, W.; Madey, R.; Htun, M.; Elaasar, M.; Anderson, B. D.; Baldwin, A. R.; Jiang, J.; Keane, D.; Scott, A.; Shao, Y.; Watson, J. W.; Zhang, W. M.; Galonsky, A.; Ronningen, R.; Zecher, P.; Kruse, J.; Wang, J.; Miller, J. (Principal Investigator)

    1998-01-01

    In order to help assess the risk to astronauts due to the long-term exposure to the natural radiation environment in space, an understanding of how the primary radiation field is changed when passing through shielding and tissue materials must be obtained. One important aspect of the change in the primary radiation field after passing through shielding materials is the production of secondary particles from the breakup of the primary. Neutrons are an important component of the secondary particle field due to their relatively high biological weighting factors, and due to their relative abundance, especially behind thick shielding scenarios. Because of the complexity of the problem, the estimation of the risk from exposure to the secondary neutron field must be handled using calculational techniques. However, those calculations will need an extensive set of neutron cross section and thicktarget neutron yield data in order to make an accurate assessment of the risk. In this paper we briefly survey the existing neutron-production data sets that are applicable to the space radiation transport problem, and we point out how neutron production from protons is different than neutron production from heavy ions. We also make comparisons of one the heavy-ion data sets with Boltzmann-Uehling-Uhlenbeck (BUU) calculations.

  18. Characterizing intra and inter annual variability of storm events based on very high frequency monitoring of hydrological and chemical variables: what can we learn about hot spots and hot moments from continuous hydro-chemical sensors ?

    NASA Astrophysics Data System (ADS)

    Fovet, O.; Thelusma, G.; Humbert, G.; Dupas, R.; Jaffrezic, A.; Grimaldi, C.; Faucheux, M.; Gilliet, N.; Hamon, Y.; Gruau, G.

    2015-12-01

    storm events based on the descriptors.

  19. Event-based text mining for biology and functional genomics.

    PubMed

    Ananiadou, Sophia; Thompson, Paul; Nawaz, Raheel; McNaught, John; Kell, Douglas B

    2015-05-01

    The assessment of genome function requires a mapping between genome-derived entities and biochemical reactions, and the biomedical literature represents a rich source of information about reactions between biological components. However, the increasingly rapid growth in the volume of literature provides both a challenge and an opportunity for researchers to isolate information about reactions of interest in a timely and efficient manner. In response, recent text mining research in the biology domain has been largely focused on the identification and extraction of 'events', i.e. categorised, structured representations of relationships between biochemical entities, from the literature. Functional genomics analyses necessarily encompass events as so defined. Automatic event extraction systems facilitate the development of sophisticated semantic search applications, allowing researchers to formulate structured queries over extracted events, so as to specify the exact types of reactions to be retrieved. This article provides an overview of recent research into event extraction. We cover annotated corpora on which systems are trained, systems that achieve state-of-the-art performance and details of the community shared tasks that have been instrumental in increasing the quality, coverage and scalability of recent systems. Finally, several concrete applications of event extraction are covered, together with emerging directions of research. PMID:24907365

  20. Event-based stormwater management pond runoff temperature model

    NASA Astrophysics Data System (ADS)

    Sabouri, F.; Gharabaghi, B.; Sattar, A. M. A.; Thompson, A. M.

    2016-09-01

    Stormwater management wet ponds are generally very shallow and hence can significantly increase (about 5.4 °C on average in this study) runoff temperatures in summer months, which adversely affects receiving urban stream ecosystems. This study uses gene expression programming (GEP) and artificial neural networks (ANN) modeling techniques to advance our knowledge of the key factors governing thermal enrichment effects of stormwater ponds. The models developed in this study build upon and compliment the ANN model developed by Sabouri et al. (2013) that predicts the catchment event mean runoff temperature entering the pond as a function of event climatic and catchment characteristic parameters. The key factors that control pond outlet runoff temperature, include: (1) Upland Catchment Parameters (catchment drainage area and event mean runoff temperature inflow to the pond); (2) Climatic Parameters (rainfall depth, event mean air temperature, and pond initial water temperature); and (3) Pond Design Parameters (pond length-to-width ratio, pond surface area, pond average depth, and pond outlet depth). We used monitoring data for three summers from 2009 to 2011 in four stormwater management ponds, located in the cities of Guelph and Kitchener, Ontario, Canada to develop the models. The prediction uncertainties of the developed ANN and GEP models for the case study sites are around 0.4% and 1.7% of the median value. Sensitivity analysis of the trained models indicates that the thermal enrichment of the pond outlet runoff is inversely proportional to pond length-to-width ratio, pond outlet depth, and directly proportional to event runoff volume, event mean pond inflow runoff temperature, and pond initial water temperature.

  1. Address-event-based platform for bioinspired spiking systems

    NASA Astrophysics Data System (ADS)

    Jiménez-Fernández, A.; Luján, C. D.; Linares-Barranco, A.; Gómez-Rodríguez, F.; Rivas, M.; Jiménez, G.; Civit, A.

    2007-05-01

    Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows a real-time virtual massive connectivity between huge number neurons, located on different chips. By exploiting high speed digital communication circuits (with nano-seconds timings), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Also, neurons generate "events" according to their activity levels. More active neurons generate more events per unit time, and access the interchip communication channel more frequently, while neurons with low activity consume less communication bandwidth. When building multi-chip muti-layered AER systems, it is absolutely necessary to have a computer interface that allows (a) reading AER interchip traffic into the computer and visualizing it on the screen, and (b) converting conventional frame-based video stream in the computer into AER and injecting it at some point of the AER structure. This is necessary for test and debugging of complex AER systems. In the other hand, the use of a commercial personal computer implies to depend on software tools and operating systems that can make the system slower and un-robust. This paper addresses the problem of communicating several AER based chips to compose a powerful processing system. The problem was discussed in the Neuromorphic Engineering Workshop of 2006. The platform is based basically on an embedded computer, a powerful FPGA and serial links, to make the system faster and be stand alone (independent from a PC). A new platform is presented that allow to connect up to eight AER based chips to a Spartan 3 4000 FPGA. The FPGA is responsible of the network communication based in Address-Event and, at the same time, to map and transform the address space of the traffic to implement a pre-processing. A MMU microprocessor (Intel XScale 400MHz Gumstix Connex computer) is also connected to the FPGA to allow the platform to implement eventbased algorithms to interact to the AER system, like control algorithms, network connectivity, USB support, etc. The LVDS transceiver allows a bandwidth of up to 1.32 Gbps, around ~66 Mega events per second (Mevps).

  2. Event-based total suspended sediment particle size distribution model

    NASA Astrophysics Data System (ADS)

    Thompson, Jennifer; Sattar, Ahmed M. A.; Gharabaghi, Bahram; Warner, Richard C.

    2016-05-01

    One of the most challenging modelling tasks in hydrology is prediction of the total suspended sediment particle size distribution (TSS-PSD) in stormwater runoff generated from exposed soil surfaces at active construction sites and surface mining operations. The main objective of this study is to employ gene expression programming (GEP) and artificial neural networks (ANN) to develop a new model with the ability to more accurately predict the TSS-PSD by taking advantage of both event-specific and site-specific factors in the model. To compile the data for this study, laboratory scale experiments using rainfall simulators were conducted on fourteen different soils to obtain TSS-PSD. This data is supplemented with field data from three construction sites in Ontario over a period of two years to capture the effect of transport and deposition within the site. The combined data sets provide a wide range of key overlooked site-specific and storm event-specific factors. Both parent soil and TSS-PSD in runoff are quantified by fitting each to a lognormal distribution. Compared to existing regression models, the developed model more accurately predicted the TSS-PSD using a more comprehensive list of key model input parameters. Employment of the new model will increase the efficiency of deployment of required best management practices, designed based on TSS-PSD, to minimize potential adverse effects of construction site runoff on aquatic life in the receiving watercourses.

  3. An event-based architecture for solving constraint satisfaction problems

    PubMed Central

    Mostafa, Hesham; Müller, Lorenz K.; Indiveri, Giacomo

    2015-01-01

    Constraint satisfaction problems are ubiquitous in many domains. They are typically solved using conventional digital computing architectures that do not reflect the distributed nature of many of these problems, and are thus ill-suited for solving them. Here we present a parallel analogue/digital hardware architecture specifically designed to solve such problems. We cast constraint satisfaction problems as networks of stereotyped nodes that communicate using digital pulses, or events. Each node contains an oscillator implemented using analogue circuits. The non-repeating phase relations among the oscillators drive the exploration of the solution space. We show that this hardware architecture can yield state-of-the-art performance on random SAT problems under reasonable assumptions on the implementation. We present measurements from a prototype electronic chip to demonstrate that a physical implementation of the proposed architecture is robust to practical non-idealities and to validate the theory proposed. PMID:26642827

  4. Visual tracking using neuromorphic asynchronous event-based cameras.

    PubMed

    Ni, Zhenjiang; Ieng, Sio-Hoi; Posch, Christoph; Régnier, Stéphane; Benosman, Ryad

    2015-04-01

    This letter presents a novel computationally efficient and robust pattern tracking method based on a time-encoded, frame-free visual data. Recent interdisciplinary developments, combining inputs from engineering and biology, have yielded a novel type of camera that encodes visual information into a continuous stream of asynchronous, temporal events. These events encode temporal contrast and intensity locally in space and time. We show that the sparse yet accurately timed information is well suited as a computational input for object tracking. In this letter, visual data processing is performed for each incoming event at the time it arrives. The method provides a continuous and iterative estimation of the geometric transformation between the model and the events representing the tracked object. It can handle isometry, similarities, and affine distortions and allows for unprecedented real-time performance at equivalent frame rates in the kilohertz range on a standard PC. Furthermore, by using the dimension of time that is currently underexploited by most artificial vision systems, the method we present is able to solve ambiguous cases of object occlusions that classical frame-based techniques handle poorly. PMID:25710087

  5. Event-based text mining for biology and functional genomics

    PubMed Central

    Thompson, Paul; Nawaz, Raheel; McNaught, John; Kell, Douglas B.

    2015-01-01

    The assessment of genome function requires a mapping between genome-derived entities and biochemical reactions, and the biomedical literature represents a rich source of information about reactions between biological components. However, the increasingly rapid growth in the volume of literature provides both a challenge and an opportunity for researchers to isolate information about reactions of interest in a timely and efficient manner. In response, recent text mining research in the biology domain has been largely focused on the identification and extraction of ‘events’, i.e. categorised, structured representations of relationships between biochemical entities, from the literature. Functional genomics analyses necessarily encompass events as so defined. Automatic event extraction systems facilitate the development of sophisticated semantic search applications, allowing researchers to formulate structured queries over extracted events, so as to specify the exact types of reactions to be retrieved. This article provides an overview of recent research into event extraction. We cover annotated corpora on which systems are trained, systems that achieve state-of-the-art performance and details of the community shared tasks that have been instrumental in increasing the quality, coverage and scalability of recent systems. Finally, several concrete applications of event extraction are covered, together with emerging directions of research. PMID:24907365

  6. An event-based architecture for solving constraint satisfaction problems

    NASA Astrophysics Data System (ADS)

    Mostafa, Hesham; Müller, Lorenz K.; Indiveri, Giacomo

    2015-12-01

    Constraint satisfaction problems are ubiquitous in many domains. They are typically solved using conventional digital computing architectures that do not reflect the distributed nature of many of these problems, and are thus ill-suited for solving them. Here we present a parallel analogue/digital hardware architecture specifically designed to solve such problems. We cast constraint satisfaction problems as networks of stereotyped nodes that communicate using digital pulses, or events. Each node contains an oscillator implemented using analogue circuits. The non-repeating phase relations among the oscillators drive the exploration of the solution space. We show that this hardware architecture can yield state-of-the-art performance on random SAT problems under reasonable assumptions on the implementation. We present measurements from a prototype electronic chip to demonstrate that a physical implementation of the proposed architecture is robust to practical non-idealities and to validate the theory proposed.

  7. MCD for detection of event-based landslides

    NASA Astrophysics Data System (ADS)

    Mondini, A. C.; Chang, K.; Guzzetti, F.

    2011-12-01

    Landslides play an important role in the landscape evolution of mountainous terrain. They also present a socioeconomic problem in terms of risk for people and properties. Landslide inventory maps are not available for many areas affected by slope instabilities, resulting in a lack of primary information for the comprehension of the phenomenon, evaluation of relative landslide statistics, and civil protection operations on large scales. Traditional methods for the preparation of landslide inventory maps are based on the geomorphological interpretation of stereoscopic aerial photography and field surveys. These methods are expensive and time consuming. The exploitation of new remote sensing data, in particular very high resolution (VHR) satellite images, and new dedicated methods present an alternative to the traditional methods and are at the forefront of modern landslide research. Recent studies have showed the possibility to produce accurate landslide maps, reducing the time and resources required for their compilation and systematic update. This paper presents the Multiple Change Detection (MCD) technique, a new method that has shown promising results in landslide mapping. Through supervised or unsupervised classifiers, MCD combines different algorithms of change detection metrics, such as change in Normalized Differential Vegetation Index, spectral angle, principal component analysis, and independent component analysis, and applies them to a multi-temporal set of VHR satellite images to distinguish new landslides from stable areas. MCD has been applied with success in different geographical areas and with different satellite images, suggesting it is a reliable and robust technique. The technique can distinguish old from new landslides and capture runout features. Results of these case studies will be presented in the conference. Also to be presented are new developments of MCD involving the introduction of a priori information on landslide susceptibility within a Bayesian framework.

  8. Galactic Cosmic Ray Event-Based Risk Model (GERM) Code

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Plante, Ianik; Ponomarev, Artem L.; Kim, Myung-Hee Y.

    2013-01-01

    This software describes the transport and energy deposition of the passage of galactic cosmic rays in astronaut tissues during space travel, or heavy ion beams in patients in cancer therapy. Space radiation risk is a probability distribution, and time-dependent biological events must be accounted for physical description of space radiation transport in tissues and cells. A stochastic model can calculate the probability density directly without unverified assumptions about shape of probability density function. The prior art of transport codes calculates the average flux and dose of particles behind spacecraft and tissue shielding. Because of the signaling times for activation and relaxation in the cell and tissue, transport code must describe temporal and microspatial density of functions to correlate DNA and oxidative damage with non-targeted effects of signals, bystander, etc. These are absolutely ignored or impossible in the prior art. The GERM code provides scientists data interpretation of experiments; modeling of beam line, shielding of target samples, and sample holders; and estimation of basic physical and biological outputs of their experiments. For mono-energetic ion beams, basic physical and biological properties are calculated for a selected ion type, such as kinetic energy, mass, charge number, absorbed dose, or fluence. Evaluated quantities are linear energy transfer (LET), range (R), absorption and fragmentation cross-sections, and the probability of nuclear interactions after 1 or 5 cm of water equivalent material. In addition, a set of biophysical properties is evaluated, such as the Poisson distribution for a specified cellular area, cell survival curves, and DNA damage yields per cell. Also, the GERM code calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle in a selected material. The GERM code makes the numerical estimates of basic physical and biophysical quantities of high-energy protons and heavy ions that have been studied at the NASA Space Radiation Laboratory (NSRL) for the purpose of simulating space radiation biological effects. In the first option, properties of monoenergetic beams are treated. In the second option, the transport of beams in different materials is treated. Similar biophysical properties as in the first option are evaluated for the primary ion and its secondary particles. Additional properties related to the nuclear fragmentation of the beam are evaluated. The GERM code is a computationally efficient Monte-Carlo heavy-ion-beam model. It includes accurate models of LET, range, residual energy, and straggling, and the quantum multiple scattering fragmentation (QMSGRG) nuclear database.

  9. Visualization of Sedentary Behavior Using an Event-Based Approach

    ERIC Educational Resources Information Center

    Loudon, David; Granat, Malcolm H.

    2015-01-01

    Visualization is commonly used in the interpretation of physical behavior (PB) data, either in conjunction with or as precursor to formal analysis. Effective representations of the data can enable the identification of patterns of behavior, and how they relate to the temporal context in a single day, or across multiple days. An understanding of…

  10. Microstructure and corrosion behavior of hot-rolled GCr15 bearing steel

    NASA Astrophysics Data System (ADS)

    Fu, Junwei

    2016-04-01

    Microstructure, corrosion behavior and evolution of hot-rolled high-carbon-chromium bearing steel were investigated using scanning electron microscopy and energy dispersive spectrometer (EDS). The results show that corrosion initiates adjacent to the network carbide, which is the initial austenite grain boundary. With the further increase in corrosion time, corrosion fraction is increased and extended into the grains. Finally, the whole grain near the network carbide is etched off and the grain boundary is detached from the sample, which forms the corroded holes. Based on the EDS analyses, it is confirmed that this corrosion behavior is resulted from the depletion of Cr as solid solute at the grain boundary. The depletion of Cr is the result of the formation of Cr carbide near the grain boundary.

  11. SCR and GCR exposure ages of plagioclase grains from lunar soil

    NASA Technical Reports Server (NTRS)

    Etique, P.; Baur, H.; Signer, P.; Wieler, R.

    1986-01-01

    The concentrations of solar wind implanted Ar-36 in mineral grains extracted from lunar soils show that they were exposed to the solar wind on the lunar surface for an integrated time of 10E4 to 10E5 years. From the bulk soil 61501 plagioclase separates of 8 grain size ranges was prepared. The depletion of the implanted gases was achieved by etching aliquot samples of 4 grain sizes to various degrees. The experimental results pertinent to the present discussion are: The spallogenic Ne is, as in most plagioclases from lunar soils, affected by diffusive losses and of no use. The Ar-36 of solar wind origin amounts to (2030 + or - 100) x 10E-8 ccSTP/g in the 150 to 200 mm size fraction and shows that these grains were exposed to the solar wind for at least 10,000 years. The Ne-21/Ne-22 ratio of the spallogenic Ne is 0.75 + or - 0.01 and in very good agreement with the value of this ratio in a plagioclase separate from rock 76535. This rock has had a simple exposure history and its plagioclases have a chemical composition quite similar to those studied. In addition to the noble gases, the heavy particle tracks in an aliquot of the 150 to 200 mm plagioclase separate were investigated and found 92% of the grains to contain more than 10E8 tracks/sq cm. This corresponds to a mean track density of (5 + or - 1) x 10E8 tracks/sq cm. The exploration of the exposure history of the plagioclase separates from the soil 61501 do not contradict the model for the regolith dynamics but also fail to prove it.

  12. No-migration variance petition: Draft. Volume 4, Appendices DIF, GAS, GCR (Volume 1)

    SciTech Connect

    1995-05-31

    The Department of Energy is responsible for the disposition of transuranic (TRU) waste generated by national defense-related activities. Approximately 2.6 million cubic feet of the se waste have been generated and are stored at various facilities across the country. The Waste Isolation Pilot Plant (WIPP), was sited and constructed to meet stringent disposal requirements. In order to permanently dispose of TRU waste, the DOE has elected to petition the US EPA for a variance from the Land Disposal Restrictions of RCRA. This document fulfills the reporting requirements for the petition. This report is volume 4 of the petition which presents details about the transport characteristics across drum filter vents and polymer bags; gas generation reactions and rates during long-term WIPP operation; and geological characterization of the WIPP site.

  13. Draft Title 40 CFR 191 compliance certification application for the Waste Isolation Pilot Plant. Volume 7: Appendix GCR Volume 2

    SciTech Connect

    1995-03-31

    This report contains the second part of the geological characterization report for the Waste Isolation Pilot Plant. Both hydrology and geochemistry are evaluated. The following aspects of hydrology are discussed: surface hydrology; ground water hydrology; and hydrology drilling and testing. Hydrologic studies at the site and adjacent site areas have concentrated on defining the hydrogeology and associated salt dissolution phenomena. The geochemical aspects include a description of chemical properties of geologic media presently found in the surface and subsurface environments of southeastern New Mexico in general, and of the proposed WIPP withdrawal area in particular. The characterization does not consider any aspect of artificially-introduced material, temperature, pressure, or any other physico-chemical condition not native to the rocks of southeastern New Mexico.

  14. Event based analysis of chlorothalonil concentrations following application to managed turf.

    PubMed

    King, Kevin W; Balogh, James C

    2013-03-01

    Chlorothalonil concentrations exceeding acute toxicity levels for certain organisms have been measured in surface water discharge events from managed turf watersheds. The duration of exceedence and the timing of these events related to precipitation/runoff and time since application, however, have not been explored. Chlorothalonil concentrations were measured from discharge waters draining a managed turf watershed in Duluth, Minnesota, USA, between 2003 and 2009. The median chlorothalonil concentration was 0.58 µg/L. Approximately 2% of all measured concentrations exceeded the 7.6 µg/L median lethal concentration (LC50) acute toxicity level for rainbow trout. One-twentieth the LC50 concentration, equivalent to the level of concern (0.38 µg/L) for endangered species, was exceeded 31% of the time during the present study. The concentrations that exceeded the LC50 threshold were associated with eight rainfall/runoff events. Low dose exposures are a more important biological concern than acute occurrences. Exceedence concentrations associated with acute effects were significantly (p < 0.05) correlated to time since application and were measured only in the fall following extensive application. A conflict exists between the transportability of chlorothalonil as suggested by its chemical properties and the data collected in the present study. With respect to course-wide golf course application, avoiding application until after the major autumn rainfall period but before the first snow coverage is recommended to reduce occurrence of chlorothalonil concentrations that exceed toxic levels associated with acute and chronic levels of concern. PMID:23233324

  15. Event-based prediction of stream turbidity using a combined cluster analysis and classification tree approach

    NASA Astrophysics Data System (ADS)

    Mather, Amanda L.; Johnson, Richard L.

    2015-11-01

    Stream turbidity typically increases during streamflow events; however, similar event hydrographs can produce markedly different event turbidity behaviors because many factors influence turbidity in addition to streamflow, including antecedent moisture conditions, season, and supply of turbidity-causing materials. Modeling of sub-hourly turbidity as a function of streamflow shows that event model parameters vary on an event-by-event basis. Here we examine the extent to which stream turbidity can be predicted through the prediction of event model parameters. Using three mid-sized streams from the Mid-Atlantic region of the U.S., we show the model parameter set for each event can be predicted based on the event characteristics (e.g., hydrologic, meteorologic and antecedent moisture conditions) using a combined cluster analysis and classification tree approach. The results suggest that the ratio of beginning event discharge to peak event discharge (an estimate of the event baseflow index), as well as catchment antecedent moisture, are important factors in the prediction of event turbidity. Indicators of antecedent moisture, particularly those derived from antecedent discharge, account for the majority of the splitting nodes in the classification trees for all three streams. For this study, prediction of turbidity during streamflow events is based upon observed data (e.g., measured streamflow, precipitation and air temperature). However, the results also suggest that the methods presented here can, in future work, be used in conjunction with forecasts of streamflow, precipitation and air temperature to forecast stream turbidity.

  16. Topology and signatures of a model for flux transfer events based on vortex-induced reconnection

    SciTech Connect

    Liu, Z.X.; Zhu, Z.W.; Li, F. ); Pu, Z.Y. )

    1992-12-01

    A model of the disturbed magnetic field and disturbed velocity of flux transfer events (FTEs) is deduced on the basis of the vortex-induced reconnection theory. The topology and signatures of FTEs are calculated and discussed. The authors propose that the observed forms of FTE signatures depend on the motional direction of the FTE tube, the positions of the spacecraft relative to the passing FTE tube, and which part of the FTE tube (the magnetosphere part, the magnetopause part, or the magnetosheath part) the spacecraft is passing through. It is found that when a FTE tube moves from south to north along a straight line in the northern hemisphere, positive FTEs appear for most passages; however, reverse FTEs are also observed occasionally while the signatures of B[sub Z] (B[sub L]) appear as a single peak, and the irregular FTEs always correspond to oblique line motions of the FTE tube. The velocity signatures are similar to those of the magnetic field, but in the northern hemisphere their directions are all just opposite to the magnetic field. The calculated results for the magnetic field are compared with 61 observed FTEs. The observed signatures (B[sub N] and B[sub L]) of 52 FTEs are consistent with the calculations. The results indicate that a majority of observed FTEs correspond to passages of spacecraft through the edges of FTE tubes.

  17. Extraction of spatio-temporal information of earthquake event based on semantic technology

    NASA Astrophysics Data System (ADS)

    Fan, Hong; Guo, Dan; Li, Huaiyuan

    2015-12-01

    In this paper a web information extraction method is presented which identifies a variety of thematic events utilizing the event knowledge framework derived from text training, and then further uses the syntactic analysis to extract the event key information. The method which combines the text semantic information and domain knowledge of the event makes the extraction of information people interested more accurate. In this paper, web based earthquake news extraction is taken as an example. The paper firstly briefs the overall approaches, and then details the key algorithm and experiments of seismic events extraction. Finally, this paper conducts accuracy analysis and evaluation experiments which demonstrate that the proposed method is a promising way of hot events mining.

  18. Classification of cyclogenesis events based on a comprehensive set of potential precursors

    NASA Astrophysics Data System (ADS)

    Graf, M.; Sprenger, M.; Wernli, H.

    2012-04-01

    Case studies indicate a large variability of the involved atmospheric structures and physical processes responsible for cyclogenesis. Historical classifications focus on the relative importance of low-level baroclinicity and upper-level disturbances, and a more recent threefold classification also considers the role of diabatically produced low-tropospheric potential vorticity. In this study, a large set of potential precursors for cyclogenesis will be systematically investigated on a statistical basis. Cyclones are objectively identified during 2010 in the operational analyses and deterministic forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) and then tracked along their life cycle. The starting points of these tracks are considered as the location of cyclogenesis. In the environment of these locations a set of about 20 precursors is determined. The set includes the following parameters: (a) temperature and heat fluxes at the surface; (b) characteristic conditions in the troposphere (e.g., integrated water vapor, amplitude of low-level potential vorticity); (c) measures of baroclinic and convective stability (e.g., Eady growth rate and CAPE); and (d) flow patterns at and forcing from the tropopause level (e.g., jet streams and streaks, potential vorticity anomalies, height of the tropopause). In addition to these relatively simple Eulerian characteristics, more advanced diagnostic approaches will be applied, including a Lagrangian moisture source diagnostic and quasigeostrophic omega forcing. These parameters will be determined for a multitude of cyclones and build the basis for an in-depth statistical analysis in this precursor phase space. A clustering approach will be applied to this precursor phase space in order to determine the main categories of cyclogenesis, and their geographical and seasonal variability.

  19. Earthquake source inversion for moderate magnitude seismic events based on GPS simulated high-rate data

    NASA Astrophysics Data System (ADS)

    Psimoulis, Panos; Dalguer, Luis; Houlie, Nicolas; Zhang, Youbing; Clinton, John; Rothacher, Markus; Giardini, Domenico

    2013-04-01

    The development of GNSS technology with the potential of high-rate (up to 100Hz) GNSS (GPS, GLONASS, Galileo, Compass) records allows the monitoring of the seismic ground motions. In this study we show the potential of estimating the earthquake magnitude (Mw) and the fault geometry parameters (slip, depth, length, rake, dip, strike) during the propagation of seismic waves based on high-rate GPS network data and using a non-linear inversion algorithm. The examined area is the Valais (South-West Switzerland) where a permanent GPS network of 15 stations (COGEAR and AGNES GPS networks) is operational and where the occurrence of an earthquake of Mw≈6 is possible every 80 years. We test our methodology using synthetic events of magnitude 6.0-6.5 corresponding to normal fault according to most of the fault mechanisms of the area, for surface and buried rupture. The epicentres are located in the Valais close to the epicentre of previous historical earthquakes. For each earthquake, synthetic seismic data (velocity records) of 15 sites, corresponding to the current GPS network sites in Valais, were produced. The synthetic seismic data were integrated into displacement time-series. By jointly using these time-series with the Bernese GNSS Software 5.1 (modified), 10Hz sampling rate GPS records were generated assuming a noise of peak-to-peak amplitudes of ±1cm and ±3cm for the horizontal and for the vertical components, respectively. The GPS records were processed and resulted in kinematic time series from where the seismic displacements were derived and inverted for the magnitude and the fault geometry parameters. The inversion results indicate that it is possible to estimate both, the earthquake magnitudes and the fault geometry parameters in real-time (~10 seconds after the fault rupture). The accuracy of the results depends on the geometry of the GPS network and of the position of the earthquake epicentre.

  20. Issues in Informal Education: Event-Based Science Communication Involving Planetaria and the Internet

    NASA Technical Reports Server (NTRS)

    Adams, M.; Gallagher, D. L.; Whitt, A.; Six, N. Frank (Technical Monitor)

    2002-01-01

    For the past four years the Science Directorate at Marshall Space Flight Center has carried out a diverse program of science communication through the web resources on the Internet. The program includes extended stories about NAS.4 science, a curriculum resource for teachers tied to national education standards, on-line activities for students, and webcasts of real-time events. Events have involved meteor showers, solar eclipses, natural very low frequency radio emissions, and amateur balloon flights. In some cases broadcasts accommodate active feedback and questions from Internet participants. We give here, examples of events, problems, and lessons learned from these activities.

  1. A study of preservice elementary teachers enrolled in a discrepant-event-based physical science class

    NASA Astrophysics Data System (ADS)

    Lilly, James Edward

    This research evaluated the POWERFUL IDEAS IN PHYSICAL SCIENCE (PIiPS) curriculum model used to develop a physical science course taken by preservice elementary teachers. The focus was on the evaluation of discrepant events used to induce conceptual change in relation to students' ideas concerning heat, temperature, and specific heat. Both quantitative and qualitative methodologies were used for the analysis. Data was collected during the 1998 Fall semester using two classes of physical science for elementary school teachers. The traditionally taught class served as the control group and the class using the PIiPS curriculum model was the experimental group. The PIiPS curriculum model was evaluated quantitatively for its influence on students' attitude toward science, anxiety towards teaching science, self efficacy toward teaching science, and content knowledge. An analysis of covariance was performed on the quantitative data to test for significant differences between the means of the posttests for the control and experimental groups while controlling for pretest. It was found that there were no significant differences between the means of the control and experimental groups with respect to changes in their attitude toward science, anxiety toward teaching science and self efficacy toward teaching science. A significant difference between the means of the content examination was found (F(1,28) = 14.202 and p = 0.001), however, the result is questionable. The heat and energy module was the target for qualitative scrutiny. Coding for discrepant events was adapted from Appleton's 1996 work on student's responses to discrepant event science lessons. The following qualitative questions were posed for the investigation: (1) what were the ideas of the preservice elementary students prior to entering the classroom regarding heat and energy, (2) how effective were the discrepant events as presented in the PIiPS heat and energy module, and (3) how much does the "risk taking factor" associated with not telling the students the answer right away, affect the learning of the material. It was found that preservice elementary teachers harbor similar preconceptions as the general population according to the literature. The discrepant events used in this module of the PIiPS curriculum model met with varied results. It appeared that those students who had not successfully confronted their preconceptions were less likely to accept the new concepts that were to be developed using the discrepant events. Lastly, students had shown great improvement in content understanding and developed the ability to ask deep and probing questions.

  2. Event-based Modeling of Fecal Coliform Concentrations in Runoff from Manured Fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative evaluation of the effect of field manure application on bacterial concentrations in creeks adjacent to the field requires developing microbial transport models. Reliable testing of such models with bacteria monitoring data requires a better understanding and estimation of the uncertaint...

  3. Event-Based Monitoring of Sediment Flux Following Removal of Oregon's Marmot Dam

    NASA Astrophysics Data System (ADS)

    Major, J. J.; O'Connor, J. E.; Spicer, K. R.; Bragg, H. M.; Wallick, J. R.; Kittleson, R. L.; Lee, K. K.; Cushman, D.; Piatt, D.; Tanner, D. Q.; Hale, T.; Uhrich, M. A.; Rhode, A.

    2008-12-01

    Breaching of Oregon's Marmot Dam in October 2007 allowed the 80-km-long Sandy River to flow freely from Mount Hood to the Columbia River for the first time in nearly 100 years. When breached, the dam was brimful with sediment. As part of an analysis examining the redistribution of ~730,000 m3 of stored sediment following the dam removal, we measured suspended-sediment load and bedload at sites 10 km upstream and 0.5 to 18 km downstream of the dam before, during and after breaching, and during five subsequent high-water events. Prior to breaching of the dam, suspended-sediment and bedload mass fluxes along the Sandy River both upstream and downstream of the dam were of the order of a few to a few tens of kg/s. Suspended sediment upstream was composed chiefly of sand in contrast to mostly silt and clay passing measurement sites 0.5 and 18 km below the dam. In all reaches bedload consisted chiefly (>90%) of sand. Breaching of the dam released a pulse of turbid water having an instantaneous suspended-sediment flux of 5200 kg/s. The initial sediment pulse consisted predominantly of silt and clay, presumably eroded from thin, fine-grained topset beds at the downstream end of the reservoir. However, the suspended load coarsened rapidly as the Sandy River incised into the stored sand and gravel that filled the former reservoir. Following the initial peak value, median fluxes of sandy suspended sediment 0.5 km below the dam site hovered around several tens to hundreds of kg/s for at least 24 hours, whereas the median suspended- sediment flux remained about 30 kg/s both 10 km upstream and 18 km downstream. Bedload transport also increased following breaching, but its response was slower than for suspended sediment. Bedload flux 0.5 km below the dam site increased from ~1 kg/s before breaching to 60 kg/s by 6 hours and to about 70 kg/s by 18 hours after breaching, in contrast to the steady, low (<10 kg/s) flux of sandy bedload passing upstream and farther downstream before and after breaching. Initially, the near-field bedload consisted predominantly of sand transported in large dunes. Significant gravel transport did not begin until 18 to 20 hours after breaching, in conjunction with rapid bed aggradation and downstream propagation of mid- channel gravel bars. This enhanced sediment transport occurred under a median flow just 30% greater than the river's mean annual flow at Marmot Dam. Within 3 months of breaching, the near-field high-flow-driven bedload flux remained significantly elevated above both upstream and downstream fluxes, but the suspended-sediment flux had declined substantially. Near-field bedload flux was persistently 10 to 100 times greater than that upstream and farther downstream, and remained gravel-rich compared to the sandy bedload passing stations upstream and 18 km distant. In contrast, near-field suspended-sediment concentrations declined approximately logarithmically, and by January 2008 the associated sandy suspended-sediment flux was comparable in both composition and magnitude to the suspended-sediment flux 18 km distant. The newly energetic Sandy River thus rapidly flushed sandy suspended-sediment downstream. Gravel-rich bedload continues to disperse downstream, but has yet to reach distal reaches of the river system. The majority of gravel transported thus far is stored chiefly along the 2-km-long channel reach below the dam site and within the Sandy River gorge 2-8 km downstream from the dam site.

  4. Folk Theorems on the Correspondence between State-Based and Event-Based Systems

    NASA Astrophysics Data System (ADS)

    Reniers, Michel A.; Willemse, Tim A. C.

    Kripke Structures and Labelled Transition Systems are the two most prominent semantic models used in concurrency theory. Both models are commonly believed to be equi-expressive. One can find many ad-hoc embeddings of one of these models into the other. We build upon the seminal work of De Nicola and Vaandrager that firmly established the correspondence between stuttering equivalence in Kripke Structures and divergence-sensitive branching bisimulation in Labelled Transition Systems. We show that their embeddings can also be used for a range of other equivalences of interest, such as strong bisimilarity, simulation equivalence, and trace equivalence. Furthermore, we extend the results by De Nicola and Vaandrager by showing that there are additional translations that allow one to use minimisation techniques in one semantic domain to obtain minimal representatives in the other semantic domain for these equivalences.

  5. Team-Teaching a Current Events-Based Biology Course for Nonmajors

    ERIC Educational Resources Information Center

    Bondos, Sarah E.; Phillips, Dereth

    2008-01-01

    Rice University has created a team-taught interactive biology course for nonmajors with a focus on cutting edge biology in the news--advances in biotechnology, medicine, and science policy, along with the biological principles and methodology upon which these advances are based. The challenges inherent to teaching current topics were minimized by…

  6. A Mobile Robots Experimental Environment with Event-Based Wireless Communication

    PubMed Central

    Guinaldo, María; Fábregas, Ernesto; Farias, Gonzalo; Dormido-Canto, Sebastián; Chaos, Dictino; Sánchez, José; Dormido, Sebastián

    2013-01-01

    An experimental platform to communicate between a set of mobile robots through a wireless network has been developed. The mobile robots get their position through a camera which performs as sensor. The video images are processed in a PC and a Waspmote card sends the corresponding position to each robot using the ZigBee standard. A distributed control algorithm based on event-triggered communications has been designed and implemented to bring the robots into the desired formation. Each robot communicates to its neighbors only at event times. Furthermore, a simulation tool has been developed to design and perform experiments with the system. An example of usage is presented. PMID:23881139

  7. Co-design of H∞ jump observers for event-based measurements over networks

    NASA Astrophysics Data System (ADS)

    Peñarrocha, Ignacio; Dolz, Daniel; Romero, Julio Ariel; Sanchis, Roberto

    2016-01-01

    This work presents a strategy to minimise the network usage and the energy consumption of wireless battery-powered sensors in the observer problem over networks. The sensor nodes implement a periodic send-on-delta approach, sending new measurements when a measure deviates considerably from the previous sent one. The estimator node implements a jump observer whose gains are computed offline and depend on the combination of available new measurements. We bound the estimator performance as a function of the sending policies and then state the design procedure of the observer under fixed sending thresholds as a semidefinite programming problem. We address this problem first in a deterministic way and, to reduce conservativeness, in a stochastic one after obtaining bounds on the probabilities of having new measurements and applying robust optimisation problem over the possible probabilities using sum of squares decomposition. We relate the network usage with the sending thresholds and propose an iterative procedure for the design of those thresholds, minimising the network usage while guaranteeing a prescribed estimation performance. Simulation results and experimental analysis show the validity of the proposal and the reduction of network resources that can be achieved with the stochastic approach.

  8. An events based algorithm for distributing concurrent tasks on multi-core architectures

    NASA Astrophysics Data System (ADS)

    Holmes, David W.; Williams, John R.; Tilke, Peter

    2010-02-01

    In this paper, a programming model is presented which enables scalable parallel performance on multi-core shared memory architectures. The model has been developed for application to a wide range of numerical simulation problems. Such problems involve time stepping or iteration algorithms where synchronization of multiple threads of execution is required. It is shown that traditional approaches to parallelism including message passing and scatter-gather can be improved upon in terms of speed-up and memory management. Using spatial decomposition to create orthogonal computational tasks, a new task management algorithm called H-Dispatch is developed. This algorithm makes efficient use of memory resources by limiting the need for garbage collection and takes optimal advantage of multiple cores by employing a "hungry" pull strategy. The technique is demonstrated on a simple finite difference solver and results are compared to traditional MPI and scatter-gather approaches. The H-Dispatch approach achieves near linear speed-up with results for efficiency of 85% on a 24-core machine. It is noted that the H-Dispatch algorithm is quite general and can be applied to a wide class of computational tasks on heterogeneous architectures involving multi-core and GPGPU hardware.

  9. Event-Based Computation of Motion Flow on a Neuromorphic Analog Neural Platform

    PubMed Central

    Giulioni, Massimiliano; Lagorce, Xavier; Galluppi, Francesco; Benosman, Ryad B.

    2016-01-01

    Estimating the speed and direction of moving objects is a crucial component of agents behaving in a dynamic world. Biological organisms perform this task by means of the neural connections originating from their retinal ganglion cells. In artificial systems the optic flow is usually extracted by comparing activity of two or more frames captured with a vision sensor. Designing artificial motion flow detectors which are as fast, robust, and efficient as the ones found in biological systems is however a challenging task. Inspired by the architecture proposed by Barlow and Levick in 1965 to explain the spiking activity of the direction-selective ganglion cells in the rabbit's retina, we introduce an architecture for robust optical flow extraction with an analog neuromorphic multi-chip system. The task is performed by a feed-forward network of analog integrate-and-fire neurons whose inputs are provided by contrast-sensitive photoreceptors. Computation is supported by the precise time of spike emission, and the extraction of the optical flow is based on time lag in the activation of nearby retinal neurons. Mimicking ganglion cells our neuromorphic detectors encode the amplitude and the direction of the apparent visual motion in their output spiking pattern. Hereby we describe the architectural aspects, discuss its latency, scalability, and robustness properties and demonstrate that a network of mismatched delicate analog elements can reliably extract the optical flow from a simple visual scene. This work shows how precise time of spike emission used as a computational basis, biological inspiration, and neuromorphic systems can be used together for solving specific tasks. PMID:26909015

  10. Event-Based Modeling of Driver Yielding Behavior at Unsignalized Crosswalks

    PubMed Central

    Schroeder, Bastian J.; Rouphail, Nagui M.

    2011-01-01

    This research explores factors associated with driver yielding behavior at unsignalized pedestrian crossings and develops predictive models for yielding using logistic regression. It considers the effect of variables describing driver attributes, pedestrian characteristics and concurrent conditions at the crosswalk on the yield response. Special consideration is given to ‘vehicle dynamics constraints’ that form a threshold for the potential to yield. Similarities are identified to driver reaction in response to the ‘amber’ indication at a signalized intersection. The logit models were developed from data collected at two unsignalized mid-block crosswalks in North Carolina. The data include ‘before’ and ‘after’ observations of two pedestrian safety treatments, an in-street pedestrian crossing sign and pedestrian-actuated in-roadway warning lights. The analysis suggests that drivers are more likely to yield to assertive pedestrians who walk briskly in their approach to the crosswalk. In turn, the yield probability is reduced with higher speeds, deceleration rates and if vehicles are traveling in platoons. The treatment effects proved to be significant and increased the propensity of drivers to yield, but their effectiveness may be dependent on whether the pedestrian activates the treatment. The results of this research provide new insights on the complex interaction of pedestrians and vehicles at unsignalized intersections and have implications for future work towards predictive models for driver yielding behavior. The developed logit models can provide the basis for representing driver yielding behavior in a microsimulation modeling environment. PMID:21852892

  11. Event based analysis of Chlorothalonil concentrations following application to managed turf

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorothalonil concentrations exceeding acute toxicity levels for certain organisms have been measured in surface water discharge events from managed turf watersheds. However, the duration of exceedence and the timing of those events with respect to precipitation/runoff and time since application ha...

  12. The cognitive cost of event-based prospective memory in children.

    PubMed

    Leigh, Janet; Marcovitch, Stuart

    2014-11-01

    Prospective memory is the act of remembering to perform an action in the future, often after the presentation of a cue. However, processes involved in remembering the future intention might hinder performance on activities leading up to and surrounding the event in which an intention must be carried out. The current study was designed to assess whether young children who were asked to engage in prospective memory do so at a cost to current cognitive processing. Participants (4-, 5-, and 6-year-olds) either performed a simple ongoing selection task only (control condition) or performed the selection task with an embedded prospective memory task (experimental condition). Results revealed that children in the experimental condition were slower in the execution of the ongoing task relative to children in the control condition, lending support to the theory that children as young as 4 ears selectively allocate resources in an effort to succeed in multiple tasks. PMID:24853249

  13. Probing the possible trigger mechanisms of an equatorial plasma bubble event based on multistation optical data

    NASA Astrophysics Data System (ADS)

    Taori, A.; Parihar, N.; Ghodpage, R.; Dashora, N.; Sripathi, S.; Kherani, E. A.; Patil, P. T.

    2015-10-01

    We analyze an equatorial plasma bubble (EPB) event observed in optical 630 nm image data simultaneously from Gadanki (13.5°N, 79.2°E), Kolhapur (16.8°N, 74.2°E), India. The total electron content data from Gadanki together with the ionosonde data from an equatorial Indian station, Tirunelveli (8.7°N, 77.8°E) confirmed the association of observed EPB event with equatorial spread F (ESF). The optical 630 nm images from a farther low-latitude Indian station Ranchi (23.3°N, 85.3°E) show clear signatures of tilted east-west wave structures propagating toward equator. Further, the upward wave energy noted in mesospheric airglow data was found to be negligible. These data suggest that possibly the off-equatorial tilted east-west structures triggered the observed EPB/ESF event.

  14. Prediction problem for target events based on the inter-event waiting time

    NASA Astrophysics Data System (ADS)

    Shapoval, A.

    2010-11-01

    In this paper we address the problem of forecasting the target events of a time series given the distribution ξ of time gaps between target events. Strong earthquakes and stock market crashes are the two types of such events that we are focusing on. In the series of earthquakes, as McCann et al. show [W.R. Mc Cann, S.P. Nishenko, L.R. Sykes, J. Krause, Seismic gaps and plate tectonics: seismic potential for major boundaries, Pure and Applied Geophysics 117 (1979) 1082-1147], there are well-defined gaps (called seismic gaps) between strong earthquakes. On the other hand, usually there are no regular gaps in the series of stock market crashes [M. Raberto, E. Scalas, F. Mainardi, Waiting-times and returns in high-frequency financial data: an empirical study, Physica A 314 (2002) 749-755]. For the case of seismic gaps, we analytically derive an upper bound of prediction efficiency given the coefficient of variation of the distribution ξ. For the case of stock market crashes, we develop an algorithm that predicts the next crash within a certain time interval after the previous one. We show that this algorithm outperforms random prediction. The efficiency of our algorithm sets up a lower bound of efficiency for effective prediction of stock market crashes.

  15. Event-based aquifer-to-atmosphere modeling over the European CORDEX domain

    NASA Astrophysics Data System (ADS)

    Keune, J.; Goergen, K.; Sulis, M.; Shrestha, P.; Springer, A.; Kusche, J.; Ohlwein, C.; Kollet, S. J.

    2014-12-01

    Despite the fact that recent studies focus on the impact of soil moisture on climate and especially land-energy feedbacks, groundwater dynamics are often neglected or conceptual groundwater flow models are used. In particular, in the context of climate change and the occurrence of droughts and floods, a better understanding and an improved simulation of the physical processes involving groundwater on continental scales is necessary. This requires the implementation of a physically consistent terrestrial modeling system, which explicitly incorporates groundwater dynamics and the connection with shallow soil moisture. Such a physics-based system enables simulations and monitoring of groundwater storage and enhanced representations of the terrestrial energy and hydrologic cycles over long time periods. On shorter timescales, the prediction of groundwater-related extremes, such as floods and droughts, are expected to improve, because of the improved simulation of components of the hydrological cycle. In this study, we present a fully coupled aquifer-to-atmosphere modeling system over the European CORDEX domain. The integrated Terrestrial Systems Modeling Platform, TerrSysMP, consisting of the three-dimensional subsurface model ParFlow, the Community Land Model CLM3.5 and the numerical weather prediction model COSMO of the German Weather Service, is used. The system is set up with a spatial resolution of 0.11° (12.5km) and closes the terrestrial water and energy cycles from aquifers into the atmosphere. Here, simulations of the fully coupled system are performed over events, such as the 2013 flood in Central Europe and the 2003 European heat wave, and over extended time periods on the order of 10 years. State and flux variables of the terrestrial hydrologic and energy cycle are analyzed and compared to both in situ (e.g. stream and water level gauge networks, FLUXNET) and remotely sensed observations (e.g. GRACE, ESA ICC ECV soil moisture and SMOS). Additionally, the presented modeling system may be useful in the assessment of groundwater-related uncertainties in virtual reality and scenario simulations.

  16. Tsunami Source Identification on the 1867 Tsunami Event Based on the Impact Intensity

    NASA Astrophysics Data System (ADS)

    Wu, T. R.

    2014-12-01

    The 1867 Keelung tsunami event has drawn significant attention from people in Taiwan. Not only because the location was very close to the 3 nuclear power plants which are only about 20km away from the Taipei city but also because of the ambiguous on the tsunami sources. This event is unique in terms of many aspects. First, it was documented on many literatures with many languages and with similar descriptions. Second, the tsunami deposit was discovered recently. Based on the literatures, earthquake, 7-meter tsunami height, volcanic smoke, and oceanic smoke were observed. Previous studies concluded that this tsunami was generated by an earthquake with a magnitude around Mw7.0 along the Shanchiao Fault. However, numerical results showed that even a Mw 8.0 earthquake was not able to generate a 7-meter tsunami. Considering the steep bathymetry and intense volcanic activities along the Keelung coast, one reasonable hypothesis is that different types of tsunami sources were existed, such as the submarine landslide or volcanic eruption. In order to confirm this scenario, last year we proposed the Tsunami Reverse Tracing Method (TRTM) to find the possible locations of the tsunami sources. This method helped us ruling out the impossible far-field tsunami sources. However, the near-field sources are still remain unclear. This year, we further developed a new method named 'Impact Intensity Analysis' (IIA). In the IIA method, the study area is divided into a sequence of tsunami sources, and the numerical simulations of each source is conducted by COMCOT (Cornell Multi-grid Coupled Tsunami Model) tsunami model. After that, the resulting wave height from each source to the study site is collected and plotted. This method successfully helped us to identify the impact factor from the near-field potential sources. The IIA result (Fig. 1) shows that the 1867 tsunami event was a multi-source event. A mild tsunami was trigged by a Mw7.0 earthquake, and then followed by the submarine landslide or volcanic events. A near-field submarine landslide and landslide at Mien-Hwa Canyon were the most possible scenarios. As for the volcano scenarios, the volcanic eruption located about 10 km away from Keelung with 2.5x108 m3 disturbed water volume might be a candidate. The detailed scenario results will be presented in the full paper.

  17. Conduction Velocity of the Uterine Contraction in Serial Magnetomyogram (MMG) Data: Event Based Simulation and Validation

    PubMed Central

    Preissl, Hubert; Lowery, Curtis L.; Eswaran, Hari; Govindan, Rathinaswamy B.

    2012-01-01

    We propose a novel approach to calculate the conduction velocity (CV) of the uterine contraction bursts in magnetomyogram (MMG) signals measured using a multichannel SQUID array. For this purpose, we partition the sensor coordinates into four different quadrants and identify the contractile bursts using a previously proposed Hilbert-wavelet transform approach. If contractile burst is identified in more than one quadrant, we calculate the center of gravity (CoG) in each quadrant for each time point as the sum of the product of the sensor coordinates with the Hilbert amplitude of the MMG signals normalized by the sum of the Hilbert amplitude of the signals over all sensors. Following this we compute the delay between the CoGs of all (six) possible quadrant pairs combinations. As a first step, we validate this approach by simulating a stochastic model based on independent second-order autoregressive processes (AR2) and we divide them into 30 second disjoint windows and insert burst activity at specific time instances in preselected sensors. Also we introduce a lag of 5 ± 1 seconds between different quadrants. Using our approach we calculate the CoG of the signals in a quadrant. To this end, we compute the delay between CoGs obtained from different quadrants and show that our approach is able to reliably capture the delay incorporated in the model. We apply the proposed approach to 19 serial MMG data obtained from two subjects and show an increase in the CV as the subjects approached labor. PMID:22255713

  18. A mobile robots experimental environment with event-based wireless communication.

    PubMed

    Guinaldo, María; Fábregas, Ernesto; Farias, Gonzalo; Dormido-Canto, Sebastián; Chaos, Dictino; Sánchez, José; Dormido, Sebastián

    2013-01-01

    An experimental platform to communicate between a set of mobile robots through a wireless network has been developed. The mobile robots get their position through a camera which performs as sensor. The video images are processed in a PC and a Waspmote card sends the corresponding position to each robot using the ZigBee standard. A distributed control algorithm based on event-triggered communications has been designed and implemented to bring the robots into the desired formation. Each robot communicates to its neighbors only at event times. Furthermore, a simulation tool has been developed to design and perform experiments with the system. An example of usage is presented. PMID:23881139

  19. Sentiment Diffusion of Public Opinions about Hot Events: Based on Complex Network.

    PubMed

    Hao, Xiaoqing; An, Haizhong; Zhang, Lijia; Li, Huajiao; Wei, Guannan

    2015-01-01

    To study the sentiment diffusion of online public opinions about hot events, we collected people's posts through web data mining techniques. We calculated the sentiment value of each post based on a sentiment dictionary. Next, we divided those posts into five different orientations of sentiments: strongly positive (P), weakly positive (p), neutral (o), weakly negative (n), and strongly negative (N). These sentiments are combined into modes through coarse graining. We constructed sentiment mode complex network of online public opinions (SMCOP) with modes as nodes and the conversion relation in chronological order between different types of modes as edges. We calculated the strength, k-plex clique, clustering coefficient and betweenness centrality of the SMCOP. The results show that the strength distribution obeys power law. Most posts' sentiments are weakly positive and neutral, whereas few are strongly negative. There are weakly positive subgroups and neutral subgroups with ppppp and ooooo as the core mode, respectively. Few modes have larger betweenness centrality values and most modes convert to each other with these higher betweenness centrality modes as mediums. Therefore, the relevant person or institutes can take measures to lead people's sentiments regarding online hot events according to the sentiment diffusion mechanism. PMID:26462230

  20. Event based uncertainty assessment in urban drainage modelling, applying the GLUE methodology

    NASA Astrophysics Data System (ADS)

    Thorndahl, S.; Beven, K. J.; Jensen, J. B.; Schaarup-Jensen, K.

    2008-08-01

    SummaryIn the present paper an uncertainty analysis on an application of the commercial urban drainage model MOUSE is conducted. Applying the Generalized Likelihood Uncertainty Estimation (GLUE) methodology the model is conditioned on observation time series from two flow gauges as well as the occurrence of combined sewer overflow. The GLUE methodology is used to test different conceptual setups in order to determine if one model setup gives a better goodness of fit conditional on the observations than the other. Moreover, different methodological investigations of GLUE are conducted in order to test if the uncertainty analysis is unambiguous. It is shown that the GLUE methodology is very applicable in uncertainty analysis of this application of an urban drainage model, although it was shown to be quite difficult to get good fits of the whole time series.

  1. Alcohol Use to Facilitate a Suicide Attempt: An Event-Based Examination

    PubMed Central

    Bagge, Courtney L.; Conner, Kenneth R.; Reed, Louren; Dawkins, Milton; Murray, Kevin

    2015-01-01

    Objective: The current study is based on the hypothesis that alcohol-involved suicide attempts are characterized by lower premeditation and intent, but only when the use of alcohol is not motivated by the desire to facilitate the attempt. Test of this idea was conducted by comparing proximal suicide premeditation and intent of suicide attempts among three groups: individuals who (a) drank to facilitate the attempt (e.g., to “numb fears” about attempting), (b) drank for nonfacilitative motives, and (c) did not use alcohol before the attempt. Method: Participants included 324 (62% female) recent suicide attempters presenting to a Level 1 trauma hospital. The Timeline Followback Interview for Suicide Attempts and a novel Suicide Facilitative Drinking Motives Scale were used to assess facilitative motives for drinking and characteristics of the attempt. Results: One third of participants drank before the attempt, and most (73%) who used alcohol did not do so to facilitate the attempt. As hypothesized, attempts carried out by this group had shorter proximal suicide premeditation and lower suicide intent compared with the other study groups; in contrast, individuals who drank to facilitate the attempt were similar to non–alcohol users on these indices. Conclusions: Alcohol-involved suicide attempts are heterogeneous. Motives for drinking are a key source of heterogeneity insofar as fundamental characteristics of attempts (proximal premeditation, intent) differ as a function of drinking motivation. Clinical implications include that individuals making suicide attempts with facilitative motives for drinking cannot be assumed to be at lowered risk upon a drop in blood alcohol level. PMID:25978835

  2. Task Interference in Time-Based, Event-Based, and Dual Intention Prospective Memory Conditions

    ERIC Educational Resources Information Center

    Hicks, Jason L.; Marsh, Richard L.; Cook, Gabriel I.

    2005-01-01

    Forming the intention to complete an activity later is the standard definition of a prospective memory task. Recently, a debate has arisen concerning the degree to which near-term intentions usurp resources away from other ongoing activities. In four experiments the authors tested how much interference was caused by holding a variety of different…

  3. Loss Modeling with a Data-Driven Approach in Event-Based Rainfall-Runoff Analysis

    NASA Astrophysics Data System (ADS)

    Chua, L. H. C.

    2012-04-01

    Mathematical models require the estimation of rainfall abstractions for accurate predictions of runoff. Although loss models such as the constant loss and exponential loss models are commonly used, these methods are based on simplified assumptions of the physical process. A new approach based on the data driven paradigm to estimate rainfall abstractions is proposed in this paper. The proposed data driven model, based on the artificial neural network (ANN) does not make any assumptions on the loss behavior. The estimated discharge from a physically-based model, obtained from the kinematic wave (KW) model assuming zero losses, was used as the only input to the ANN. The output is the measured discharge. Thus, the ANN functions as a black-box loss model. Two sets of data were analyzed for this study. The first dataset consists of rainfall and runoff data, measured from an artificial catchment (area = 25 m2) comprising two overland planes (slope = 11%), 25m long, transversely inclined towards a rectangular channel (slope = 2%) which conveyed the flow, recorded using calibrated weigh tanks, to the outlet. Two rain gauges, each placed 6.25 m from either ends of the channel, were used to record rainfall. Data for six storm events over the period between October 2002 and December 2002 were analyzed. The second dataset was obtained from the Upper Bukit Timah catchment (area = 6.4 km2) instrumented with two rain gauges and a flow measuring station. A total of six events recorded between November 1987 and July 1988 were selected for this study. The runoff predicted by the ANN was compared with the measured runoff. In addition, results from KW models developed for both the catchments were used as a benchmark. The KW models were calibrated assuming the loss rate for an average event for each of the datasets. The results from both the ANN and KW models agreed well with the runoff measured from the artificial catchment. The KW model is expected to perform well since the catchment is completely impervious and the losses are small. Thus, the good agreement of results between the ANN with the KW model results demonstrates the applicability of the ANN model in modeling the loss rate. Comparing the modeled runoff with the measured runoff for the Upper Bukit Timah catchment, it was found that the KW model was not able to produce the runoff from the catchment accurately due to the improper prescription of the loss rate. This is because the loss rate varies over a wide range of values in a real catchment and using the loss rate for an average event did not provide truly representative values for the catchment. Although the same dataset was used in the training of the ANN model, the ANN model was able to produce hydrographs with significantly higher Nash-Sutcliffe coefficients compared to the KW model. This analysis demonstrates that the ANN model is better able to model the highly variable loss rate during storm events, especially if the data used for calibration is limited. ACKNOWLEDGEMENT Funding received from the DHI-NTU Water & Environment Research Centre and Education Hub is gratefully acknowledged.

  4. Event-Based Modeling of Driver Yielding Behavior to Pedestrians at Two-Lane Roundabout Approaches

    PubMed Central

    Salamati, Katayoun; Schroeder, Bastian J.; Geruschat, Duane R.; Rouphail, Nagui M.

    2013-01-01

    Unlike other types of controlled intersections, drivers do not always comply with the “yield to pedestrian” sign at the roundabouts. This paper aims to identify the contributing factors affecting the likelihood of driver yielding to pedestrians at two-lane roundabouts. It further models the likelihood of driver yielding based on these factors using logistic regression. The models have been applied to 1150 controlled pedestrian crossings at entry and exit legs of two-lane approaches of six roundabouts across the country. The logistic regression models developed support prior research that the likelihood of driver yielding at the entry leg of roundabouts is higher than at the exit. Drivers tend to yield to pedestrians carrying a white cane more often than to sighted pedestrians. Drivers traveling in the far lane, relative to pedestrian location, have a lower probability of yielding to a pedestrian. As the speed increases the probability of driver yielding decreases. At the exit leg of the roundabout, drivers turning right from the adjacent lane have a lower propensity of yielding than drivers coming from other directions. The findings of this paper further suggest that although there has been much debate on pedestrian right-of-way laws and distinction between pedestrian waiting positions (in the street versus at the curb), this factor does not have a significant impact on driver yielding rate. The logistic regression models also quantify the effect of each of these factors on propensity of driver yielding. The models include variables which are specific to each study location and explain the impact size of each study location on probability of yielding. The models generated in this research will be useful to transportation professionals and researchers interested in understanding the factors that impact driver yielding at modern roundabouts. The results of the research can be used to isolate factors that may increase yielding (such as lower roundabout approach speeds), and can feasibly be incorporated into microsimulation algorithms to model driver yielding at roundabouts. PMID:24619314

  5. Issues in Informal Education: Event-Based Science Communication Involving Planetaria and the Internet

    NASA Technical Reports Server (NTRS)

    Adams, Mitzi L.; Gallagher, D. L.; Whitt, A.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    For the last several years the Science Directorate at Marshall Space Flight Center has carried out a diverse program of Internet-based science communication. The program includes extended stories about NASA science, a curriculum resource for teachers tied to national education standards, on-line activities for students, and webcasts of real-time events. The focus of sharing real-time science related events has been to involve and excite students and the public about science. Events have involved meteor showers, solar eclipses, natural very low frequency radio emissions, and amateur balloon flights. In some cases broadcasts accommodate active feedback and questions from Internet participants. Panel participation will be used to communicate the problems and lessons learned from these activities over the last three years.

  6. Sentiment Diffusion of Public Opinions about Hot Events: Based on Complex Network

    PubMed Central

    Hao, Xiaoqing; An, Haizhong; Zhang, Lijia; Li, Huajiao; Wei, Guannan

    2015-01-01

    To study the sentiment diffusion of online public opinions about hot events, we collected people’s posts through web data mining techniques. We calculated the sentiment value of each post based on a sentiment dictionary. Next, we divided those posts into five different orientations of sentiments: strongly positive (P), weakly positive (p), neutral (o), weakly negative (n), and strongly negative (N). These sentiments are combined into modes through coarse graining. We constructed sentiment mode complex network of online public opinions (SMCOP) with modes as nodes and the conversion relation in chronological order between different types of modes as edges. We calculated the strength, k-plex clique, clustering coefficient and betweenness centrality of the SMCOP. The results show that the strength distribution obeys power law. Most posts’ sentiments are weakly positive and neutral, whereas few are strongly negative. There are weakly positive subgroups and neutral subgroups with ppppp and ooooo as the core mode, respectively. Few modes have larger betweenness centrality values and most modes convert to each other with these higher betweenness centrality modes as mediums. Therefore, the relevant person or institutes can take measures to lead people’s sentiments regarding online hot events according to the sentiment diffusion mechanism. PMID:26462230

  7. Motion Entropy Feature and Its Applications to Event-Based Segmentation of Sports Video

    NASA Astrophysics Data System (ADS)

    Chen, Chen-Yu; Wang, Jia-Ching; Wang, Jhing-Fa; Hu, Yu-Hen

    2008-12-01

    An entropy-based criterion is proposed to characterize the pattern and intensity of object motion in a video sequence as a function of time. By applying a homoscedastic error model-based time series change point detection algorithm to this motion entropy curve, one is able to segment the corresponding video sequence into individual sections, each consisting of a semantically relevant event. The proposed method is tested on six hours of sports videos including basketball, soccer, and tennis. Excellent experimental results are observed.

  8. Probabilistic forecasting of extreme weather events based on extreme value theory

    NASA Astrophysics Data System (ADS)

    Van De Vyver, Hans; Van Schaeybroeck, Bert

    2016-04-01

    Extreme events in weather and climate such as high wind gusts, heavy precipitation or extreme temperatures are commonly associated with high impacts on both environment and society. Forecasting extreme weather events is difficult, and very high-resolution models are needed to describe explicitly extreme weather phenomena. A prediction system for such events should therefore preferably be probabilistic in nature. Probabilistic forecasts and state estimations are nowadays common in the numerical weather prediction community. In this work, we develop a new probabilistic framework based on extreme value theory that aims to provide early warnings up to several days in advance. We consider the combined events when an observation variable Y (for instance wind speed) exceeds a high threshold y and its corresponding deterministic forecasts X also exceeds a high forecast threshold y. More specifically two problems are addressed:} We consider pairs (X,Y) of extreme events where X represents a deterministic forecast, and Y the observation variable (for instance wind speed). More specifically two problems are addressed: Given a high forecast X=x_0, what is the probability that Y>y? In other words: provide inference on the conditional probability: [ Pr{Y>y|X=x_0}. ] Given a probabilistic model for Problem 1, what is the impact on the verification analysis of extreme events. These problems can be solved with bivariate extremes (Coles, 2001), and the verification analysis in (Ferro, 2007). We apply the Ramos and Ledford (2009) parametric model for bivariate tail estimation of the pair (X,Y). The model accommodates different types of extremal dependence and asymmetry within a parsimonious representation. Results are presented using the ensemble reforecast system of the European Centre of Weather Forecasts (Hagedorn, 2008). Coles, S. (2001) An Introduction to Statistical modelling of Extreme Values. Springer-Verlag.Ferro, C.A.T. (2007) A probability model for verifying deterministic forecasts of extreme events. Wea. Forecasting {22}, 1089-1100.Hagedorn, R. (2008) Using the ECMWF reforecast dataset to calibrate EPS forecasts. ECMWF Newsletter, {117}, 8-13.Ramos, A., Ledford, A. (2009) A new class of models for bivariate joint tails. J.R. Statist. Soc. B {71}, 219-241.

  9. Quantifying Future Changes in Extreme Precipitation Events Based on Resolved Synoptic Atmospheric Patterns

    NASA Astrophysics Data System (ADS)

    Gao, X.; Schlosser, C. A.; Monier, E.; Entekhabi, D.

    2012-12-01

    An important question for climate change science is possible shifts in the extremes of regional water cycle, especially changes in patterns, intensity and/or frequency of extreme precipitation events. In this study, an analogue method is developed to help detect extreme precipitation events and their potential changes under future climate regimes without relying on the highly uncertain modeled precipitation. Our approach is based on the use of composite maps to identify the distinct synoptic and large-scale atmospheric conditions that lead to extreme precipitation events at local scales. The analysis of extreme daily precipitation events, exemplified in the south-central United States, is carried out using 62-yr (1948-2010) CPC gridded station data and NASA's Modern Era Retrospective-analysis for Research and Applications (MERRA). Various aspects of the daily extremes are examined, including their historical ranking, associated common circulation features at upper and lower levels of the atmosphere, and moisture plumes. The scheme is first evaluated for the multiple climate model simulations of the 20th century from Coupled Model Intercomparison Project Phase 5 (CMIP5) archive to determine whether the statistical nature of modeled precipitation events (i.e. the numbers of occurrences over each season) could well correspond to that of the observed. Further, the approach will be applied to the CMIP5 multi-model projections of various climate change scenarios (i.e. Representative Concentration Pathways (RCP) scenarios) in the next century to assess the potential changes in the probability of extreme precipitation events. The research results from this study should be of particular significance to help society develop adaptive strategies and prevent catastrophic losses.

  10. Event-based stormwater quality and quantity loadings from elevated urban infrastructure affected by transportation.

    PubMed

    Sansalone, John J; Hird, Jonathan P; Cartledge, Frank K; Tittlebaum, Marty E

    2005-01-01

    Urban-rainfall runoff affected by transportation is a complex matrix of a very wide gradation of particulate matter (< 1 to > 10 000 microm) and dissolved inorganic and organic constituents. Particulate matter transported by rainfall runoff can be a significant vector for many reactive particulate-bound constituents, particularly metal elements. The water quality and hydrology of nine events from a representative elevated section of Interstate 10 (I-10) (eastbound average daily traffic load of 70 400 vehicles) in Baton Rouge, Louisiana, were characterized and compared with respect to the passage of each hydrograph. Residence time on the paved concrete surface was less than 30 minutes for all events. Results indicate that event-mean concentrations (EMCs) of particulate matter as total-suspended solids (TSS) (138 to 561 mg/L) and chemical-oxygen demand (COD) (128 to 1440 mg/L) were greater than those found in untreated municipal wastewater from the same service area. Particulate-matter dissolution and COD partitioned as a function of pH, pavement residence time, and organic content. In general, delivery of mass for aggregate indices, such as particulate matter (measured as TSS) and COD mass, were driven by the hydrology of the event, while concentrations of aggregate-constituent measurements, such as total-dissolved solids (TDS), illustrated an exponential-type decline during the rising limb of the hydrograph. Despite the short residence times, wide solids gradation, partitioning, and complexity of the rainfall-runoff chemistry, conductivity and dissolved solids were strongly correlated. Characterization of the transport and loads of constituents in urban-rainfall runoff, as a function of hydrology, is a necessary first step when considering treatability, structural or nonstructural controls, and mass trading for discharges from paved infrastructure. PMID:16121503

  11. Event-Based Computation of Motion Flow on a Neuromorphic Analog Neural Platform.

    PubMed

    Giulioni, Massimiliano; Lagorce, Xavier; Galluppi, Francesco; Benosman, Ryad B

    2016-01-01

    Estimating the speed and direction of moving objects is a crucial component of agents behaving in a dynamic world. Biological organisms perform this task by means of the neural connections originating from their retinal ganglion cells. In artificial systems the optic flow is usually extracted by comparing activity of two or more frames captured with a vision sensor. Designing artificial motion flow detectors which are as fast, robust, and efficient as the ones found in biological systems is however a challenging task. Inspired by the architecture proposed by Barlow and Levick in 1965 to explain the spiking activity of the direction-selective ganglion cells in the rabbit's retina, we introduce an architecture for robust optical flow extraction with an analog neuromorphic multi-chip system. The task is performed by a feed-forward network of analog integrate-and-fire neurons whose inputs are provided by contrast-sensitive photoreceptors. Computation is supported by the precise time of spike emission, and the extraction of the optical flow is based on time lag in the activation of nearby retinal neurons. Mimicking ganglion cells our neuromorphic detectors encode the amplitude and the direction of the apparent visual motion in their output spiking pattern. Hereby we describe the architectural aspects, discuss its latency, scalability, and robustness properties and demonstrate that a network of mismatched delicate analog elements can reliably extract the optical flow from a simple visual scene. This work shows how precise time of spike emission used as a computational basis, biological inspiration, and neuromorphic systems can be used together for solving specific tasks. PMID:26909015

  12. Event-Based Plausibility Immediately Influences On-Line Language Comprehension

    ERIC Educational Resources Information Center

    Matsuki, Kazunaga; Chow, Tracy; Hare, Mary; Elman, Jeffrey L.; Scheepers, Christoph; McRae, Ken

    2011-01-01

    In some theories of sentence comprehension, linguistically relevant lexical knowledge, such as selectional restrictions, is privileged in terms of the time-course of its access and influence. We examined whether event knowledge computed by combining multiple concepts can rapidly influence language understanding even in the absence of selectional…

  13. Event-Based Media Enrichment Using an Adaptive Probabilistic Hypergraph Model.

    PubMed

    Liu, Xueliang; Wang, Meng; Yin, Bao-Cai; Huet, Benoit; Li, Xuelong

    2015-11-01

    Nowadays, with the continual development of digital capture technologies and social media services, a vast number of media documents are captured and shared online to help attendees record their experience during events. In this paper, we present a method combining semantic inference and multimodal analysis for automatically finding media content to illustrate events using an adaptive probabilistic hypergraph model. In this model, media items are taken as vertices in the weighted hypergraph and the task of enriching media to illustrate events is formulated as a ranking problem. In our method, each hyperedge is constructed using the K-nearest neighbors of a given media document. We also employ a probabilistic representation, which assigns each vertex to a hyperedge in a probabilistic way, to further exploit the correlation among media data. Furthermore, we optimize the hypergraph weights in a regularization framework, which is solved as a second-order cone problem. The approach is initiated by seed media and then used to rank the media documents using a transductive inference process. The results obtained from validating the approach on an event dataset collected from EventMedia demonstrate the effectiveness of the proposed approach. PMID:26470061

  14. Conduction velocity of the uterine contraction in serial magnetomyogram (MMG) data: event based simulation and validation.

    PubMed

    Furdea, Adrian; Preissl, Hubert; Lowery, Curtis L; Eswaran, Hari; Govindan, Rathinaswamy B

    2011-01-01

    We propose a novel approach to calculate the conduction velocity (CV) of the uterine contraction bursts in magnetomyogram (MMG) signals measured using a multichannel SQUID array. For this purpose, we partition the sensor coordinates into four different quadrants and identify the contractile bursts using a previously proposed Hilbert-wavelet transform approach. If contractile burst is identified in more than one quadrant, we calculate the center of gravity (CoG) in each quadrant for each time point as the sum of the product of the sensor coordinates with the Hilbert amplitude of the MMG signals normalized by the sum of the Hilbert amplitude of the signals over all sensors. Following this we compute the delay between the CoGs of all (six) possible quadrant pairs combinations. As a first step, we validate this approach by simulating a stochastic model based on independent second-order autoregressive processes (AR2) and we divide them into 30 second disjoint windows and insert burst activity at specific time instances in preselected sensors. Also we introduce a lag of 5 ± 1 seconds between different quadrants. Using our approach we calculate the CoG of the signals in a quadrant. To this end, we compute the delay between CoGs obtained from different quadrants and show that our approach is able to reliably capture the delay incorporated in the model. We apply the proposed approach to 19 serial MMG data obtained from two subjects and show an increase in the CV as the subjects approached labor. PMID:22255713

  15. Bonsai: an event-based framework for processing and controlling data streams.

    PubMed

    Lopes, Gonçalo; Bonacchi, Niccolò; Frazão, João; Neto, Joana P; Atallah, Bassam V; Soares, Sofia; Moreira, Luís; Matias, Sara; Itskov, Pavel M; Correia, Patrícia A; Medina, Roberto E; Calcaterra, Lorenza; Dreosti, Elena; Paton, Joseph J; Kampff, Adam R

    2015-01-01

    The design of modern scientific experiments requires the control and monitoring of many different data streams. However, the serial execution of programming instructions in a computer makes it a challenge to develop software that can deal with the asynchronous, parallel nature of scientific data. Here we present Bonsai, a modular, high-performance, open-source visual programming framework for the acquisition and online processing of data streams. We describe Bonsai's core principles and architecture and demonstrate how it allows for the rapid and flexible prototyping of integrated experimental designs in neuroscience. We specifically highlight some applications that require the combination of many different hardware and software components, including video tracking of behavior, electrophysiology and closed-loop control of stimulation. PMID:25904861

  16. Bonsai: an event-based framework for processing and controlling data streams

    PubMed Central

    Lopes, Gonçalo; Bonacchi, Niccolò; Frazão, João; Neto, Joana P.; Atallah, Bassam V.; Soares, Sofia; Moreira, Luís; Matias, Sara; Itskov, Pavel M.; Correia, Patrícia A.; Medina, Roberto E.; Calcaterra, Lorenza; Dreosti, Elena; Paton, Joseph J.; Kampff, Adam R.

    2015-01-01

    The design of modern scientific experiments requires the control and monitoring of many different data streams. However, the serial execution of programming instructions in a computer makes it a challenge to develop software that can deal with the asynchronous, parallel nature of scientific data. Here we present Bonsai, a modular, high-performance, open-source visual programming framework for the acquisition and online processing of data streams. We describe Bonsai's core principles and architecture and demonstrate how it allows for the rapid and flexible prototyping of integrated experimental designs in neuroscience. We specifically highlight some applications that require the combination of many different hardware and software components, including video tracking of behavior, electrophysiology and closed-loop control of stimulation. PMID:25904861

  17. Iterative and Event-Based Frameworks for University and School District Technology Professional Development Partnerships

    ERIC Educational Resources Information Center

    Winslow, Joseph; Dickerson, Jeremy; Weaver, Carmen; Josey, Fair

    2016-01-01

    Forming technology partnerships between universities and public schools in an era of competition and economic difficulty is a challenge. However, when these partnerships are formed and sustained, the benefits for both are extremely valuable. For a university instructional technology graduate program and school partnership to be successful, the…

  18. Prediction of consequences of meteor events based on atmospheric trajectory analysis

    NASA Astrophysics Data System (ADS)

    Kuznetsova, D.; Gritsevich, M.; Christou, A.

    2014-07-01

    In this study, we develop a model which describes how meteoroid enter the atmosphere of a planet, and categorize different consequences of the collisions of cosmic bodies with the atmosphere and the surface of a planet. We focus on two types of possible results: (1) meteorite fall, when a fragment of a meteoroid can be found on the surface, and (2) full ablation, when meteoroid does not reach the ground. The model is based on the analytical solution of the classical equations of meteor-body deceleration [1,2]. The dimensionless solution for the mass-velocity dependence and the height-velocity dependence can be expressed using two main dimensionless parameters: the ballistic coefficient, which shows the ratio between the mass of the atmospheric column along the trajectory and the body's pre-entry mass, and the mass loss parameter, which is proportional to the ratio between the initial kinetic energy of the body and energy required to insure total mass loss of the body due to ablation and fragmentation. Thus, every given meteoroid case is described by a pair of these parameters. To distinguish the two possible impact consequences (meteorite fall or full ablation) we use the meteorite fall condition: the terminal mass of a meteoroid exceeds or is equal to a certain chosen value. This condition can be written using the parameters introduced above. Thus, we get a boundary curve in the parameter plane and associate different events with the location of the point relative to this curve. This theory is applied in the classification of collisions of cosmic bodies with the Earth's atmosphere and surface. The observational data are used to calculate the values of the parameters used in current study, and these values are shown in the parameter plane and their locations are compared against the location of boundary curve in each case. The obtained results show a good agreement with the known consequences for the observed fireballs, including ones registered by the Canadian, Prairie and European Fireball Networks [3,4]. As an extension of this theory, we model the meteoroid entry into the Martian atmosphere using introduced parameters. A number of investigations by different authors show an increasing interest to this subject, e.g. [5--9]. To apply our theory, we take two meteoroid types as an example: a chondrite with the entry velocity 10 km/s, and an iron meteoroid with the entry velocity 15 km/s. For each type, we take several pre-entry mass values and show the impact consequences by constructing the boundary curve on the parameter plane and the point corresponding to the meteoroid. These results are also compared with the meteoroid entries into the terrestrial atmosphere with the same pre-entry characteristics. It is shown that for some pre-entry mass range, a meteoroid would be fully ablated for the case of Earth, but a fraction of it would reach the surface for the case of Mars.

  19. An event-based neural network architecture with an asynchronous programmable synaptic memory.

    PubMed

    Moradi, Saber; Indiveri, Giacomo

    2014-02-01

    We present a hybrid analog/digital very large scale integration (VLSI) implementation of a spiking neural network with programmable synaptic weights. The synaptic weight values are stored in an asynchronous Static Random Access Memory (SRAM) module, which is interfaced to a fast current-mode event-driven DAC for producing synaptic currents with the appropriate amplitude values. These currents are further integrated by current-mode integrator synapses to produce biophysically realistic temporal dynamics. The synapse output currents are then integrated by compact and efficient integrate and fire silicon neuron circuits with spike-frequency adaptation and adjustable refractory period and spike-reset voltage settings. The fabricated chip comprises a total of 32 × 32 SRAM cells, 4 × 32 synapse circuits and 32 × 1 silicon neurons. It acts as a transceiver, receiving asynchronous events in input, performing neural computation with hybrid analog/digital circuits on the input spikes, and eventually producing digital asynchronous events in output. Input, output, and synaptic weight values are transmitted to/from the chip using a common communication protocol based on the Address Event Representation (AER). Using this representation it is possible to interface the device to a workstation or a micro-controller and explore the effect of different types of Spike-Timing Dependent Plasticity (STDP) learning algorithms for updating the synaptic weights values in the SRAM module. We present experimental results demonstrating the correct operation of all the circuits present on the chip. PMID:24681923

  20. Historical Chronology of ENSO Events Based Upon Documentary Data From South America: Strengths and Limitations

    NASA Astrophysics Data System (ADS)

    Luc, O.

    2007-05-01

    The first reconstructions of past El Niño occurrences were proposed by W. Quinn twenty years ago. They were based on documentary evidence of anomalous rainfall episodes, destructive floods and other possible impacts of El Niño conditions in Peru and other South-American countries. It has been shown, later, that the El Niño chronological sequence covering the last four and a half centuries produced by Quinn needed a thorough revision since many so-called EN events had not occurred while some others had been overlooked. Beside the classical methodological problems met in historical climatology studies (reliability of data, confidence in the sources, primary and secondary information), the reconstruction of former EN events faces specific difficulties dealing with the significance of the indicators and their spatial location. For instance, strong precipitation anomalies during summer in Southern Ecuador and northern Peru and precipitation excess recorded in the preceding winter in central Chile constitute quite reliable proxies of El Niño conditions, in modern times. However this observed teleconnection pattern, which is useful to reinforce the interpretation of past EN occurrences, seems to have been inoperative before the early nineteenth century. It is interpreted that atmospheric circulation features during the Little Ice Age interfered with the teleconnection system linking the EN impacts in northern Peru and central Chile. As a consequence, how should be evaluated the significance of documented winter precipitation excess in central Chile in years during which there is drought evidence in northern Peru, during the sixteenth to eighteenth century? And vice versa, are former evidences for precipitation excess in northern Peru (prior to the nineteenth century) quite reliable indicators for EN conditions, even if the preceding winter was dry in the Valparaiso-Santiago region? Other specific problems met in the building-up of a consolidated EN chronological sequence deal with the non-homogeneity of the documentary records, the reconstruction of the paleo-events strength and the difficulty to cross check documentary data with other annually resolved records (corals, tree-rings and ice-core data). In spite of all these limitations, the documentation of former EN occurrences based upon written archives from colonial South-America remains an unavoidable and powerful tool to reconstruct a solid El Niño chronology for the last half millennium and to better understand the interplay of the different modes (at the interannual, decadal, multidecadal and centennial scales) of climate variations in this part of the world.

  1. You Never Walk Alone: Recommending Academic Events Based on Social Network Analysis

    NASA Astrophysics Data System (ADS)

    Klamma, Ralf; Cuong, Pham Manh; Cao, Yiwei

    Combining Social Network Analysis and recommender systems is a challenging research field. In scientific communities, recommender systems have been applied to provide useful tools for papers, books as well as expert finding. However, academic events (conferences, workshops, international symposiums etc.) are an important driven forces to move forwards cooperation among research communities. We realize a SNA based approach for academic events recommendation problem. Scientific communities analysis and visualization are performed to provide an insight into the communities of event series. A prototype is implemented based on the data from DBLP and EventSeer.net, and the result is observed in order to prove the approach.

  2. Projected changes in extreme temperature events based on the NARCCAP model suite

    NASA Astrophysics Data System (ADS)

    Horton, Radley M.; Coffel, Ethan D.; Winter, Jonathan M.; Bader, Daniel A.

    2015-09-01

    Once-per-year (annual) maximum temperature extremes in North American Regional Climate Change Assessment Program (NARCCAP) models are projected to increase more (less) than mean daily maximum summer temperatures over much of the eastern (western) United States. In contrast, the models almost everywhere project greater warming of once-per-year minimum temperatures as compared to mean daily minimum winter temperatures. Under projected changes associated with extremes of the temperature distribution, Baltimore's maximum temperature that was met or exceeded once per year historically is projected to occur 17 times per season by midcentury, a 28% increase relative to projections based on summer mean daily maximum temperature change. Under the same approach, historical once-per-year cold events in Baltimore are projected to occur once per decade. The models are generally able to capture observed geopotential height anomalies associated with temperature extremes in two subregions. Projected changes in extreme temperature events cannot be explained by geopotential height anomalies or lower boundary conditions as reflected by soil moisture anomalies or snow water equivalent.

  3. Simulation of the ATIC-2 Silicon Matrix for Protons and Helium GCR Primaries at 0.3, 10, and 25 TeV/Nucleon

    NASA Technical Reports Server (NTRS)

    Watts, J.; Adams, J. H.; Bashindzhagyan, G.; Batkov, K. E.; Chang, J.; Christl, M.; Fazely, A. R.; Ganel, O.; Gunasingha R. M.; Guzik, T. G.

    2005-01-01

    The energy deposition distribution for protons and helium galactic cosmic ray primaries at 0.3, 10, and 25 TeV/nucleon in the ATIC-2 silicon matrix detector are simulated with GEANT4. The GEANT3 geometrical model of ATIC developed by the University of Maryland was combined with a GEANT4 application developed for the Deep Space Test Bed (DSTB) detector package. The new code included relatively minor modifications to completely describe the ATIC materials and a more detailed model of the Silicon Matrix detector. For this analysis all particles were started as a unidirectional beam at a single point near the center of the Silicon Matrix front surface. The point was selected such that each primary passed through at least two of the overlapping silicon pixels.

  4. Transcriptional regulatory analysis reveals PDR3 and GCR1 as regulators of significantly induced genes by 5-hydroxymethylfurfural stress involved in bioethanol conversion for ethanologenic yeast Saccharomyces cerevisiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    5-Hydroxymethylfurfural (HMF) is one of major inhibitory compounds derived from dehydration of hexoses during biomass degradation using dilute acid hydrolysis. It inhibits yeast growth, reduces enzymatic activities, breaks down DNA, and represses protein and RNA synthesis. We study stress toleranc...

  5. A latent class analysis of adolescent adverse life events based on a Danish national youth probability sample.

    PubMed

    Shevlin, Mark; Elklit, Ask

    2008-01-01

    The aim of this study was to determine if there are meaningful clusters of individuals with similar experiences of adverse life events in a nationally representative sample of Danish adolescents. Latent class analysis (LCA) was used to identify such clusters or latent classes. In addition, the relationships between the latent classes and living arrangements and diagnosis of post-traumatic stress disorder (PTSD) were estimated. A four-class solution was found to be the best description of multiple adverse life events, and the classes were labelled "Low Risk", "Intermediate Risk", "Pregnancy" and "High Risk". Compared with the Low Risk class, the other classes were found to be significantly more likely to have a diagnosis PTSD and live with only one parent. This paper demonstrated how trauma research can focus on the individual as the unit of analysis rather than traumatic events. PMID:18609032

  6. Integrated Data Products to Forecast, Mitigate, and Educate for Natural Hazard Events Based on Recent and Historical Observations

    NASA Astrophysics Data System (ADS)

    McCullough, H. L.; Dunbar, P. K.; Varner, J. D.

    2011-12-01

    Immediately following a damaging or fatal natural hazard event there is interest to access authoritative data and information. The National Geophysical Data Center (NGDC) maintains and archives a comprehensive collection of natural hazards data. The NGDC global historic event database includes all tsunami events, regardless of intensity, as well as earthquakes and volcanic eruptions that caused fatalities, moderate damage, or generated a tsunami. Examining the past record provides clues to what might happen in the future. NGDC also archives tide gauge data from stations operated by the NOAA/NOS Center for Operational Oceanographic Products and Services and the NOAA Tsunami Warning Centers. In addition to the tide gauge data, NGDC preserves deep-ocean water-level, 15-second sampled data as collected by the Deep-ocean Assessment and Reporting of Tsunami (DART) buoys. Water-level data provide evidence of sea-level fluctuation and possible inundation events. NGDC houses an extensive collection of geologic hazards photographs available online as digital images. Visual media provide invaluable pre- and post-event data for natural hazards. Images can be used to illustrate inundation and possible damage or effects. These images are organized by event or hazard type (earthquake, volcano, tsunami, landslide, etc.), along with description and location. They may be viewed via interactive online maps and are integrated with historic event details. The planning required to achieve collection and dissemination of hazard event data is extensive. After a damaging or fatal event, NGDC begins to collect and integrate data and information from many people and organizations into the hazards databases. Sources of data include the U.S. NOAA Tsunami Warning Centers, the U.S. Geological Survey, the U.S. NOAA National Data Buoy Center, the UNESCO Intergovernmental Oceanographic Commission (IOC), Smithsonian Institution's Global Volcanism Program, news organizations, etc. NGDC then works to promptly distribute data and information for the appropriate audience. For example, when a major tsunami occurs, all of the related tsunami data are combined into one timely resource. NGDC posts a publicly accessible online report which includes: 1) event summary; 2) eyewitness and instrumental recordings from preliminary field surveys; 3) regional historical observations including similar past events and effects; 4) observed water heights and calculated tsunami travel times; and 5) near-field effects. This report is regularly updated to incorporate the most recent news and observations. Providing timely access to authoritative data and information ultimately benefits researchers, state officials, the media and the public.

  7. Evaluation of Event-Based Algorithms for Optical Flow with Ground-Truth from Inertial Measurement Sensor

    PubMed Central

    Rueckauer, Bodo; Delbruck, Tobi

    2016-01-01

    In this study we compare nine optical flow algorithms that locally measure the flow normal to edges according to accuracy and computation cost. In contrast to conventional, frame-based motion flow algorithms, our open-source implementations compute optical flow based on address-events from a neuromorphic Dynamic Vision Sensor (DVS). For this benchmarking we created a dataset of two synthesized and three real samples recorded from a 240 × 180 pixel Dynamic and Active-pixel Vision Sensor (DAVIS). This dataset contains events from the DVS as well as conventional frames to support testing state-of-the-art frame-based methods. We introduce a new source for the ground truth: In the special case that the perceived motion stems solely from a rotation of the vision sensor around its three camera axes, the true optical flow can be estimated using gyro data from the inertial measurement unit integrated with the DAVIS camera. This provides a ground-truth to which we can compare algorithms that measure optical flow by means of motion cues. An analysis of error sources led to the use of a refractory period, more accurate numerical derivatives and a Savitzky-Golay filter to achieve significant improvements in accuracy. Our pure Java implementations of two recently published algorithms reduce computational cost by up to 29% compared to the original implementations. Two of the algorithms introduced in this paper further speed up processing by a factor of 10 compared with the original implementations, at equal or better accuracy. On a desktop PC, they run in real-time on dense natural input recorded by a DAVIS camera. PMID:27199639

  8. Robotic goalie with 3 ms reaction time at 4% CPU load using event-based dynamic vision sensor.

    PubMed

    Delbruck, Tobi; Lang, Manuel

    2013-01-01

    Conventional vision-based robotic systems that must operate quickly require high video frame rates and consequently high computational costs. Visual response latencies are lower-bound by the frame period, e.g., 20 ms for 50 Hz frame rate. This paper shows how an asynchronous neuromorphic dynamic vision sensor (DVS) silicon retina is used to build a fast self-calibrating robotic goalie, which offers high update rates and low latency at low CPU load. Independent and asynchronous per pixel illumination change events from the DVS signify moving objects and are used in software to track multiple balls. Motor actions to block the most "threatening" ball are based on measured ball positions and velocities. The goalie also sees its single-axis goalie arm and calibrates the motor output map during idle periods so that it can plan open-loop arm movements to desired visual locations. Blocking capability is about 80% for balls shot from 1 m from the goal even with the fastest-shots, and approaches 100% accuracy when the ball does not beat the limits of the servo motor to move the arm to the necessary position in time. Running with standard USB buses under a standard preemptive multitasking operating system (Windows), the goalie robot achieves median update rates of 550 Hz, with latencies of 2.2 ± 2 ms from ball movement to motor command at a peak CPU load of less than 4%. Practical observations and measurements of USB device latency are provided. PMID:24311999

  9. The natural oscillation of two types of ENSO events based on analyses of CMIP5 model control runs

    NASA Astrophysics Data System (ADS)

    Xu, Kang; Su, Jingzhi; Zhu, Congwen

    2014-07-01

    The eastern- and central-Pacific El Niño-Southern Oscillation (EP- and CP-ENSO) have been found to be dominant in the tropical Pacific Ocean, and are characterized by interannual and decadal oscillation, respectively. In the present study, we defined the EP- and CP-ENSO modes by singular value decomposition (SVD) between SST and sea level pressure (SLP) anomalous fields. We evaluated the natural features of these two types of ENSO modes as simulated by the pre-industrial control runs of 20 models involved in phase five of the Coupled Model Intercomparison Project (CMIP5). The results suggested that all the models show good skill in simulating the SST and SLP anomaly dipolar structures for the EP-ENSO mode, but only 12 exhibit good performance in simulating the tripolar CP-ENSO modes. Wavelet analysis suggested that the ensemble principal components in these 12 models exhibit an interannual and multi-decadal oscillation related to the EP- and CP-ENSO, respectively. Since there are no changes in external forcing in the pre-industrial control runs, such a result implies that the decadal oscillation of CP-ENSO is possibly a result of natural climate variability rather than external forcing.

  10. The identification and analysis of risk for sudden accidental water pollution events based on the water resources monitoring system

    NASA Astrophysics Data System (ADS)

    Chen, Jiannan

    2016-04-01

    There are always various types of sudden accidental Water Pollution Events under the development of modern Chinese economy society, leading to serious economic losses and casualties. Water resources monitoring system, a real-time monitoring system, was built to monitor water quantity and quality of the important rivers and lakes over the country. Based on the system, we had brought up an idea to calculate the possibility of pollution and the risk of pollution in the watershed, and to deal with the threat of water pollution incidents effectively. It was proposed to build the greatest possible contamination with the most serious pollution values over the past years, and similarity test was carried on over the real-time monitoring of possible contamination value and the calculated value. In our study, taking Taihu River Basin as an example, we detailed the application progress of this method in water pollution incidents, the result shows that the method has a certain timeliness for the early warning of sudden water pollution incidents.

  11. Detection of water-quality contamination events based on multi-sensor fusion using an extented Dempster-Shafer method

    NASA Astrophysics Data System (ADS)

    Hou, Dibo; He, Huimei; Huang, Pingjie; Zhang, Guangxin; Loaiciga, Hugo

    2013-05-01

    This study presents a method for detecting contamination events of sources of drinking water based on the Dempster-Shafer (D-S) evidence theory. The detection method has the purpose of protecting water supply systems against accidental and intentional contamination events. This purpose is achieved by first predicting future water-quality parameters using an autoregressive (AR) model. The AR model predicts future water-quality parameters using recent measurements of these parameters made with automated (on-line) water-quality sensors. Next, a probabilistic method assigns probabilities to the time series of residuals formed by comparing predicted water-quality parameters with threshold values. Finally, the D-S fusion method searches for anomalous probabilities of the residuals and uses the result of that search to determine whether the current water quality is normal (that is, free of pollution) or contaminated. The D-S fusion method is extended and improved in this paper by weighted averaging of water-contamination evidence and by the analysis of the persistence of anomalous probabilities of water-quality parameters. The extended D-S fusion method makes determinations that have a high probability of being correct concerning whether or not a source of drinking water has been contaminated. This paper's method for detecting water-contamination events was tested with water-quality time series from automated (on-line) water quality sensors. In addition, a small-scale, experimental, water-pipe network was tested to detect water-contamination events. The two tests demonstrated that the extended D-S fusion method achieves a low false alarm rate and high probabilities of detecting water contamination events.

  12. Event-based surveillance of food- and waterborne diseases in Europe: urgent inquiries (outbreak alerts) during 2008 to 2013.

    PubMed

    Gossner, C M; de Jong, B; Hoebe, C J; Coulombier, D

    2015-01-01

    During 2008 to 2013, 215 outbreak alerts, also known as 'urgent inquiries' (UI), for food- and waterborne diseases were launched in Europe, the majority of them (135; 63%) being related to salmonellosis. For 110 (51%) UI, a potential food vehicle of infection was identified, with vegetables being the most reported category (34;31%). A total of 28% (n = 60) of the outbreaks reported had an international dimension, involving at least two countries (mean: 4; standard deviation: 2; range:2–14). Participating countries posted 2,343 messages(initial posts and replies, excluding updates), with a median of 11 messages per urgent inquiry (range:1–28). Of 60 multicountry UI, 50 involved between two and four countries. The UI allowed early detection of multicountry outbreaks, facilitated the identification of the suspected vehicles and consequently contributed to the timely implementation of control measures. The introduction of an epidemic intelligence information system platform in 2010 has strengthened the role of the Food- and Waterborne Diseases and Zoonoses network in facilitating timely exchange of information between public health authorities of the participating countries. PMID:26132769

  13. Event-based quantification of emerging pollutant removal for an open stormwater retention basin - loads, efficiency and importance of uncertainties.

    PubMed

    Sébastian, C; Becouze-Lareure, C; Lipeme Kouyi, G; Barraud, S

    2015-04-01

    Up to now, emerging contaminants have not been further-studied in in-situ stormwater best management practices and especially in detention basins. In this article, the efficiency of a dry stormwater detention basin was investigated regarding the removal of 7 alkylphenols and alkylphenol ethoxylates, 9 polybrominated diphenyl ethers, 45 pesticides and bisphenol A. Concentrations of contaminants were obtained by chemical analysis on dissolved and particulate phase distinctly. The removal efficiency was assessed on total, dissolved and particulate phase accounting for the global chain of uncertainty with a 95% confidence interval. Results showed that pesticides (rather hydrophilic) are not trapped in the detention basin but are released contrarily to B209 which is mostly in particulate phase. Alkylphenols and alkylphenol ethoxylates are present in both phases and the efficiency is storm event-dependent. Uncertainty consideration in efficiency determination revealed efficiency data, usually presented by raw values are not relevant to conclude on the performance of a detention basin. In this case study, efficiency data with a 95% confidence interval indicate that only 35%, 50% and 41% of campaigns showed an impact (in trapping or releasing) of the detention basin on alkylphenols and ethoxylates, polybrominated diphenyl ethers and pesticides respectively. PMID:25683631

  14. Building a knowledge base of severe adverse drug events based on AERS reporting data using semantic web technologies.

    PubMed

    Jiang, Guoqian; Wang, Liwei; Liu, Hongfang; Solbrig, Harold R; Chute, Christopher G

    2013-01-01

    A semantically coded knowledge base of adverse drug events (ADEs) with severity information is critical for clinical decision support systems and translational research applications. However it remains challenging to measure and identify the severity information of ADEs. The objective of the study is to develop and evaluate a semantic web based approach for building a knowledge base of severe ADEs based on the FDA Adverse Event Reporting System (AERS) reporting data. We utilized a normalized AERS reporting dataset and extracted putative drug-ADE pairs and their associated outcome codes in the domain of cardiac disorders. We validated the drug-ADE associations using ADE datasets from SIDe Effect Resource (SIDER) and the UMLS. We leveraged the Common Terminology Criteria for Adverse Event (CTCAE) grading system and classified the ADEs into the CTCAE in the Web Ontology Language (OWL). We identified and validated 2,444 unique Drug-ADE pairs in the domain of cardiac disorders, of which 760 pairs are in Grade 5, 775 pairs in Grade 4 and 2,196 pairs in Grade 3. PMID:23920604

  15. Pre-Processing Effect on the Accuracy of Event-Based Activity Segmentation and Classification through Inertial Sensors.

    PubMed

    Fida, Benish; Bernabucci, Ivan; Bibbo, Daniele; Conforto, Silvia; Schmid, Maurizio

    2015-01-01

    Inertial sensors are increasingly being used to recognize and classify physical activities in a variety of applications. For monitoring and fitness applications, it is crucial to develop methods able to segment each activity cycle, e.g., a gait cycle, so that the successive classification step may be more accurate. To increase detection accuracy, pre-processing is often used, with a concurrent increase in computational cost. In this paper, the effect of pre-processing operations on the detection and classification of locomotion activities was investigated, to check whether the presence of pre-processing significantly contributes to an increase in accuracy. The pre-processing stages evaluated in this study were inclination correction and de-noising. Level walking, step ascending, descending and running were monitored by using a shank-mounted inertial sensor. Raw and filtered segments, obtained from a modified version of a rule-based gait detection algorithm optimized for sequential processing, were processed to extract time and frequency-based features for physical activity classification through a support vector machine classifier. The proposed method accurately detected >99% gait cycles from raw data and produced >98% accuracy on these segmented gait cycles. Pre-processing did not substantially increase classification accuracy, thus highlighting the possibility of reducing the amount of pre-processing for real-time applications. PMID:26378544

  16. Pre-Processing Effect on the Accuracy of Event-Based Activity Segmentation and Classification through Inertial Sensors

    PubMed Central

    Fida, Benish; Bernabucci, Ivan; Bibbo, Daniele; Conforto, Silvia; Schmid, Maurizio

    2015-01-01

    Inertial sensors are increasingly being used to recognize and classify physical activities in a variety of applications. For monitoring and fitness applications, it is crucial to develop methods able to segment each activity cycle, e.g., a gait cycle, so that the successive classification step may be more accurate. To increase detection accuracy, pre-processing is often used, with a concurrent increase in computational cost. In this paper, the effect of pre-processing operations on the detection and classification of locomotion activities was investigated, to check whether the presence of pre-processing significantly contributes to an increase in accuracy. The pre-processing stages evaluated in this study were inclination correction and de-noising. Level walking, step ascending, descending and running were monitored by using a shank-mounted inertial sensor. Raw and filtered segments, obtained from a modified version of a rule-based gait detection algorithm optimized for sequential processing, were processed to extract time and frequency-based features for physical activity classification through a support vector machine classifier. The proposed method accurately detected >99% gait cycles from raw data and produced >98% accuracy on these segmented gait cycles. Pre-processing did not substantially increase classification accuracy, thus highlighting the possibility of reducing the amount of pre-processing for real-time applications. PMID:26378544

  17. Event based recharge assessment from soil moisture monitoring sites under a steep Mediterranean - semi-arid climatic gradient

    NASA Astrophysics Data System (ADS)

    Ries, Fabian; Sauter, Martin; Lange, Jens

    2014-05-01

    The unsaturated soil zone is of fundamental importance for the understanding of temporal and spatial variability of groundwater recharge. This is especially true for the Mediterranean region where a large fraction of long-term groundwater recharge occurs during above-average wet winters. To improve process knowledge, a dense monitoring network consisting of rainfall gauges, meteorological stations and soil moisture plots was installed along a steep climatic gradient in the Jordan Valley region. Ten-minute soil moisture dynamics of two entire years were modelled by Hydrus-1D whose parameters were calibrated with the help of the Shuffled Complex Evolution algorithm. The scrutinized model was applied to four locations with entirely different soil depth and annual rainfall. During high intensity rainfall events, saturation of deep soil layers was observed for several hours. The continuously modelled water balance yielded percolation pulses that depended on rainfall amounts and occurred simultaneously to a cooling of karst groundwater in a nearby groundwater well. Overall, a strong correlation between the magnitude of deep percolation and soil depth was observed. When the model was applied to a 40-year time series of rainfall data, a mean annual percolation fraction of 40% resulted. This value varied by up to 30% between years with similar (average) rainfall but different rainfall distribution. Here the length of dry spells between single recharge events was one important factor. Percolation fraction of exceptional wet years reached up to 69% of rainfall while for very dry years no percolation was modelled at all. A focused view on the unsaturated soil zone in areas with highly variable annual rainfall can provide valuable insights into recharge heterogeneity under Mediterranean and semi-arid climates.

  18. Robotic goalie with 3 ms reaction time at 4% CPU load using event-based dynamic vision sensor

    PubMed Central

    Delbruck, Tobi; Lang, Manuel

    2013-01-01

    Conventional vision-based robotic systems that must operate quickly require high video frame rates and consequently high computational costs. Visual response latencies are lower-bound by the frame period, e.g., 20 ms for 50 Hz frame rate. This paper shows how an asynchronous neuromorphic dynamic vision sensor (DVS) silicon retina is used to build a fast self-calibrating robotic goalie, which offers high update rates and low latency at low CPU load. Independent and asynchronous per pixel illumination change events from the DVS signify moving objects and are used in software to track multiple balls. Motor actions to block the most “threatening” ball are based on measured ball positions and velocities. The goalie also sees its single-axis goalie arm and calibrates the motor output map during idle periods so that it can plan open-loop arm movements to desired visual locations. Blocking capability is about 80% for balls shot from 1 m from the goal even with the fastest-shots, and approaches 100% accuracy when the ball does not beat the limits of the servo motor to move the arm to the necessary position in time. Running with standard USB buses under a standard preemptive multitasking operating system (Windows), the goalie robot achieves median update rates of 550 Hz, with latencies of 2.2 ± 2 ms from ball movement to motor command at a peak CPU load of less than 4%. Practical observations and measurements of USB device latency are provided1. PMID:24311999

  19. Controls of event-based pesticide leaching in natural soils: A systematic study based on replicated field scale irrigation experiments

    NASA Astrophysics Data System (ADS)

    Klaus, Julian; Zehe, Erwin; Elsner, Martin; Palm, Juliane; Schneider, Dorothee; Schröder, Boris; Steinbeiss, Sibylle; van Schaik, Loes; West, Stephanie

    2014-05-01

    Tile drains strongly influence the water cycle in agricultural catchment in terms of water quantity and quality. The connectivity of preferential flow to tile drains can create shortcuts for rapid transport of solutes into surface waters. The leaching of pesticides can be linked to a set of main factors including, rainfall characteristics, soil moisture, chemical properties of the pesticides, soil properties, and preferential flow paths. The connectivity of the macropore system to the tile drain is crucial for pesticide leaching. Concurring influences of the main factors, threshold responses and the role of flow paths are still poorly understood. The objective of this study is to investigate these influences by a replica series of three irrigation experiments on a tile drain field site using natural and artificial tracers together with applied pesticides. We found a clear threshold behavior in the initialization of pesticide transport that was different between the replica experiments. Pre-event soil water contributed significantly to the tile drain flow, and creates a flow path for stored pesticides from the soil matrix to the tile drain. This threshold is controlled by antecedent soil moisture and precipitation characteristics, and the interaction between the soil matrix and preferential flow system. Fast transport of pesticides without retardation and the remobilization could be attributed to this threshold and the interaction between the soil matrix and the preferential flow system. Thus, understanding of the detailed preferential flow processes clearly enhances the understanding of pesticide leaching on event and long term scale, and can further improve risk assessment and modeling approaches.

  20. An event-based comparison of two types of automated-recording, weighing bucket rain gauges 1890

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multi-year, multi-gage comparison of two types of automated-recording weighing-bucket raingages was conducted using precipitation data collected at the United States Department of Agriculture, Agricultural Research Service’s Walnut Gulch Experimental Watershed in Southeast Arizona. The compariso...

  1. Monitoring of event based mobilization of hydrophobic pollutants in rivers: Calibration of turbidity as a proxy for particle facilitated transport

    NASA Astrophysics Data System (ADS)

    Rügner, Hermann; Schwientek, Marc; Grathwohl, Peter

    2014-05-01

    Transport of many pollutants in rivers is coupled to transport of suspended particles which is typically enhanced during events such as floods, snow melts etc. As the amount of total suspended solids (TSS) in rivers can be monitored by turbidity measurements this may be used as a proxy for the total concentration of particle associated pollutants in rivers such as polycyclic aromatic hydrocarbons (PAHs), PCBs, etc. and several heavy metals. On-line turbidity measurements (e.g. by optical backscattering sensors) then allow for an assessment of particle and pollutant flux dynamics. In this study, pronounced flood and thus turbidity events were sampled at high temporal resolution in three contrasting catchments in Southwest Germany (Rivers Ammer, Goldersbach, Steinlach) as well as in the River Neckar. Samples were analyzed for turbidity, the total amount of PAH and total suspended solids (TSS) in water. Additionally, the grain size distributions of suspended solids were determined. Discharge and turbidity were measured on-line at gauging stations in three of the catchments. Results showed that turbidity and TSS were linearly correlated over an extended turbidity range up to 2000 NTU for the flood samples (i.e. independent on grain size). This also holds for total PAH concentrations which can be reasonably well predicted based on the turbidity measurements and TSS versus PAH relationships - even for very high turbidity or TSS values (> 2000 NTU or mg l-1, respectively). From these linear regressions concentrations of PAHs on suspended particles were obtained which varied by catchment. The values comprise a robust measure of the average sediment quality in a river network and may be correlated to the degree of urbanization represented by the number of inhabitants per total flux of suspended particles. Based on long-term on-line turbidity measurements mass flow rates of particle bound pollutants over time could be calculated. Results showed that by far the largest amount of pollutant loads occur at relative high turbidities > 100 NTU which are observed only during very short time periods. Therefore it is of particular importance not to miss these pronounced but rare events.

  2. Event-based estimation of water budget components using the network of multi-sensor capacitance probes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A time-scale-free approach was developed for estimation of water fluxes at boundaries of monitoring soil profile using water content time series. The approach uses the soil water budget to compute soil water budget components, i.e. surface-water excess (Sw), infiltration less evapotranspiration (I-E...

  3. Medical mitigation strategies for acute radiation exposure during spaceflight.

    PubMed

    Epelman, Slava; Hamilton, Douglas R

    2006-02-01

    The United States Government has recently refocused their space program on manned missions to the Moon by 2018 and later to Mars. While there are many potential risks associated with exploration-class missions, one of the most serious and unpredictable is the effect of acute space radiation exposure, and the space program must make every reasonable effort to mitigate this risk. The two cosmic sources of radiation that could impact a mission outside the Earth's magnetic field are solar particle events (SPE) and galactic cosmic radiation (GCR). Either can cause acute and chronic medical illness. Numerous researchers are currently examining the ability of GCR exposure to induce the development of genetic changes that lead to malignancies and other delayed effects. However, relatively little has been published on the medical management of an acute SPE event and the potential impact on the mission and crew. This review paper will provide the readers with medical management options for an acute radiation event based on recommendations from the Department of Homeland Security (DHS), Centers for Disease Control (CDC), and evidence-based critical analysis of the scientific literature. It is the goal of this paper to stimulate debate regarding the definition of safety parameters for exploration-class missions to determine the level of medical care necessary to provide for the crew that will undertake such missions. PMID:16491581

  4. Executive and Theory-of-Mind Contributions to Event-Based Prospective Memory in Children: Exploring the Self-Projection Hypothesis

    ERIC Educational Resources Information Center

    Ford, Ruth M.; Driscoll, Timothy; Shum, David; Macaulay, Catrin E.

    2012-01-01

    In two studies, 4- to 6-year-olds were asked to name pictures of animals for the benefit of a watching hand puppet (the ongoing task) but to refrain from naming and to remove from view any pictures of dogs (the prospective memory [PM] task). Children also completed assessments of verbal ability, cognitive inhibition, working memory, and…

  5. Reconstruction of flood events based on documentary data and transnational flood risk analysis of the Upper Rhine and its French and German tributaries since AD 1480

    NASA Astrophysics Data System (ADS)

    Himmelsbach, I.; Glaser, R.; Schoenbein, J.; Riemann, D.; Martin, B.

    2015-10-01

    This paper presents the long-term analysis of flood occurrence along the southern part of the Upper Rhine River system and of 14 of its tributaries in France and Germany covering the period starting from 1480 BC. Special focus is given on the temporal and spatial variations of flood events and their underlying meteorological causes over time. Examples are presented of how long-term information about flood events and knowledge about the historical aspect of flood protection in a given area can help to improve the understanding of risk analysis and therefor transnational risk management. Within this context, special focus is given to flood vulnerability while comparing selected historical and modern extreme events, establishing a common evaluation scheme. The transnational aspect becomes especially evident analyzing the tributaries: on this scale, flood protection developed impressively different on the French and German sides. We argue that comparing high technological standards of flood protection, which were initiated by the dukes of Baden on the German side starting in the early 19th century, misled people to the common belief that the mechanical means of flood protection like dams and barrages can guarantee the security from floods and their impacts. This lead to widespread settlements and the establishment of infrastructure as well as modern industries in potentially unsafe areas until today. The legal status in Alsace on the French side of the Rhine did not allow for continuous flood protection measurements, leading to a constant - and probably at last annoying - reminder that the floodplains are a potentially unsafe place to be. From a modern perspective of flood risk management, this leads to a significant lower aggregation of value in the floodplains of the small rivers in Alsace compared to those on the Baden side - an interesting fact - especially if the modern European Flood directive is taken into account.

  6. Monitoring of event-based mobilization of hydrophobic pollutants in rivers: calibration of turbidity as a proxy for particle facilitated transport in field and laboratory.

    PubMed

    Rügner, Hermann; Schwientek, Marc; Egner, Marius; Grathwohl, Peter

    2014-08-15

    Transport of many pollutants in rivers is coupled to mobilization of suspended particles which typically occurs during floods. Since the amount of total suspended solids (TSS) in rivers can be monitored by turbidity measurements this may be used as a proxy for the total concentration of particle associated pollutants such as PAHs, PCBs, etc. and several heavy metals. Online turbidity measurements (e.g. by optical backscattering sensors) would then also allow for an assessment of particle and pollutant flux dynamics if once calibrated against TSS and total pollutant concentrations for a given catchment. In this study, distinct flood and thus turbidity events were sampled at high temporal resolution in three contrasting sub-catchments of the River Neckar in Southwest Germany (Ammer, Goldersbach, Steinlach) as well as in the River Neckar itself and investigated for the total amount of PAHs and TSS in water; turbidity (NTU) and grain size distributions of suspended solids were determined as well. Laboratory experiments were performed with natural river bed sediments from different locations (Ammer) to investigate PAH concentrations, TSS and turbidity during sedimentation of suspended particles under controlled conditions (yielding smaller and smaller suspended particles and TSS with time). Laboratory and field results agreed very well and showed that turbidity and TSS were linearly correlated over an extended turbidity range up to 2000 NTU for the field samples and up to 8000 NTU in lab experiments. This also holds for total PAH concentrations which can be reasonably well predicted based on turbidity measurements and TSS vs. PAHs relationships - even for high turbidity values observed during flood events (>2000 NTU). Total PAH concentrations on suspended solids were independent of grain size of suspended particles. This implies that for the rivers investigated the sorption capacity of particles did not change significantly during the observed events. PMID:24858216

  7. Event-based distributed set-membership filtering for a class of time-varying non-linear systems over sensor networks with saturation effects

    NASA Astrophysics Data System (ADS)

    Wei, Guoliang; Liu, Shuai; Wang, Licheng; Wang, Yongxiong

    2016-07-01

    In this paper, based on the event-triggered mechanism, the problem of distributed set-membership filtering is concerned for a class of time-varying non-linear systems over sensor networks subject to saturation effects. Different from the traditional periodic sample-data approach, the filter is updated only when the predefined event is satisfied, which the event is defined according to the measurement output. For each node, the proposed novel event-triggered mechanism can reduce the unnecessary information transmission between sensors and filters. The purpose of the addressed problem is to design a series of distributed set-membership filters, for all the admissible unknown but bounded noises, non-linearities and sensor saturation, such that the set of all possible states can be determined. The desired filter parameters are obtained by solving a recursive linear matrix inequality that can be computed recursively using the available MATLAB toolbox. Finally, a simulation example is exploited to show the effectiveness of the proposed design approach in this paper.

  8. Precipitation induced stream flow: An event based chemical and isotopic study of a small stream in the Great Plains region of the USA

    USGS Publications Warehouse

    Machavaram, M.V.; Whittemore, D.O.; Conrad, M.E.; Miller, N.L.

    2006-01-01

    A small stream in the Great Plains of USA was sampled to understand the streamflow components following intense precipitation and the influence of water storage structures in the drainage basin. Precipitation, stream, ponds, ground-water and soil moisture were sampled for determination of isotopic (D, 18O) and chemical (Cl, SO4) composition before and after two intense rain events. Following the first storm event, flow at the downstream locations was generated primarily through shallow subsurface flow and runoff whereas in the headwaters region - where a pond is located in the stream channel - shallow ground-water and pond outflow contributed to the flow. The distinct isotopic signatures of precipitation and the evaporated pond water allowed separation of the event water from the other sources that contributed to the flow. Similarly, variations in the Cl and SO4 concentrations helped identify the relative contributions of ground-water and soil moisture to the streamflow. The relationship between deuterium excess and Cl or SO4 content reveals that the early contributions from a rain event to streamflow depend upon the antecedent climatic conditions and the position along the stream channel within the watershed. The design of this study, in which data from several locations within a watershed were collected, shows that in small streams changes in relative contributions from ground water and soil moisture complicate hydrograph separation, with surface-water bodies providing additional complexity. It also demonstrates the usefulness of combined chemical and isotopic methods in hydrologic investigations, especially the utility of the deuterium excess parameter in quantifying the relative contributions of various source components to the stream flow. ?? 2006 Elsevier B.V. All rights reserved.

  9. Executive and theory-of-mind contributions to event-based prospective memory in children: exploring the self-projection hypothesis.

    PubMed

    Ford, Ruth M; Driscoll, Timothy; Shum, David; Macaulay, Catrin E

    2012-03-01

    In two studies, 4- to 6-year-olds were asked to name pictures of animals for the benefit of a watching hand puppet (the ongoing task) but to refrain from naming and to remove from view any pictures of dogs (the prospective memory [PM] task). Children also completed assessments of verbal ability, cognitive inhibition, working memory, and false-belief understanding (both studies), empathy (Study 1 only), and performance on false-sign tests that matched the false-belief tests in narrative content and structure (Study 2 only). Both studies found that inhibition and false-belief performance made unique contributions to the variance in PM, although in Study 1 the influence of inhibition was evident only when children needed to withhold naming. Study 2 further demonstrated that false-belief performance was the only reliable predictor of whether children remembered to return to the researcher an object that had been loaned to them prior to the picture-naming game. Both experiments uncovered moderate relations between PM and chronological age, but such relations were rarely significant after taking account of cognitive ability. We consider the implications of the findings for (a) current views regarding frontal/executive contributions to PM development and (b) the suggestion that the same brain network underlies various forms of mental self-projection, including envisioning the future and understanding the minds of other people. PMID:22169353

  10. Galactic Cosmic Ray Simulator at the NASA Space Radiation Laboratory

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Slaba, Tony C.; Rusek, Adam

    2015-01-01

    The external Galactic Cosmic Ray (GCR) spectrum is significantly modified when it passes through spacecraft shielding and astronauts. One approach for simulating the GCR space radiation environment is to attempt to reproduce the unmodified, external GCR spectrum at a ground based accelerator. A possibly better approach would use the modified, shielded tissue spectrum, to select accelerator beams impinging on biological targets. NASA plans for implementation of a GCR simulator at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory will be discussed.

  11. 14 CFR 399.41 - Zones of limited suspension for international cargo rates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (GCR's and SCR's) in the Atlantic region, 20 percent above the standard foreign rate level. (2) For all bulk rates (GCR's and SCR's) in the Pacific region, 15 percent above the standard foreign rate level. (3) For all bulk rates (GCR's and SCR's) in the Western Hemisphere region (except Mexico and...

  12. International Collaboration for Galactic Cosmic Ray Simulation at the NASA Space Radiation Laboratory

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Slaba, Tony C.; Rusek, Adam; Durante, Marco; Reitz, Guenther

    2015-01-01

    An international collaboration on Galactic Cosmic Ray (GCR) simulation is being formed to make recommendations on how to best simulate the GCR spectrum at ground based accelerators. The external GCR spectrum is significantly modified when it passes through spacecraft shielding and astronauts. One approach for simulating the GCR space radiation environment at ground based accelerators would use the modified spectrum, rather than the external spectrum, in the accelerator beams impinging on biological targets. Two recent workshops have studied such GCR simulation. The first workshop was held at NASA Langley Research Center in October 2014. The second workshop was held at the NASA Space Radiation Investigators' workshop in Galveston, Texas in January 2015. The anticipated outcome of these and other studies may be a report or journal article, written by an international collaboration, making accelerator beam recommendations for GCR simulation. This poster describes the status of GCR simulation at the NASA Space Radiation Laboratory and encourages others to join the collaboration.

  13. Characterizing seasonal variability of storm events based on very high frequency monitoring of hydrological and chemical variables: comparing patterns in hot spots and hot moments for nutrient and sediment export

    NASA Astrophysics Data System (ADS)

    Fovet, Ophelie; Thelusma, Gilbert; Humbert, Guillaume; Dupas, Rémi; Faucheux, Mikael; Gilliet, Nicolas; Hamon, Yannick; Jaffrezic, Anne; Grimaldi, Catherine; Gruau, Gerard

    2016-04-01

    Storm events are critical hot moments of emission for several dissolved and particulate chemical species at major stake for water quality (e.g. dissolved organic carbon DOC, suspended sediments, phosphorus). During such events, the solutes or particles are exported from heterogeneous sources through various pathways to stream leading to specific integrated signals at the outlet characterized by very short dynamics. This is merely true in headwater catchments where the total duration of such events ranges over 10h to 3 days, with very quick variations in stream flow and concentrations at the outlet occurring in a few hours. Thus for investigating properly event processes, high frequency monitoring of flow and water quality is required. We analysed 103 storm events in a 5 km2 agricultural headwater catchment, part of the AgrHys Observatory, on the basis of a 3-year-long data set which combined meterological (Rainfall), hydrological (flow and piezometry), and water quality (turbidity, conductivity, DOC and NO3 concentrations) data recorded at very high frequencies (from 1 to 20 min) thanks to dedicated sensors. We proposed a range of quantitative storm descriptors for characterizing input (rainfall), antecedent and initial conditions (groundwater levels and saturated area), and stream response in terms of level and dynamics of flow (Q), groundwater levels, and concentrations (C) but also the C-Q relationships. Three intra annual periods have been previously defined for base flow dynamic according to shallow groundwater table variations so that they correspond to different connectivity status in the catchment. The seasonal and inter-annual variability of the storm events have been analysed using the descriptors and based on these predefined periods. Results show that the hydrological flowpaths and the consequent storm chemistry were controlled by the hydrological base flow regime rather than by the rain input characteristics. This highlights that the exports of NO3, DOC and sediments during storms may be either synchronized or desynchronized depending on the season. This temporal dynamic of the ratios between species may be at major stake for the aquatic ecosystems response and structure.

  14. Aromatase inhibitors alone or sequentially combined with tamoxifen in postmenopausal early breast cancer compared with tamoxifen or placebo - Meta-analyses on efficacy and adverse events based on randomized clinical trials.

    PubMed

    Rydén, Lisa; Heibert Arnlind, Marianne; Vitols, Sigurd; Höistad, Malin; Ahlgren, Johan

    2016-04-01

    Tamoxifen (TAM) and aromatase inhibitors (AI) are adjuvant therapy options for postmenopausal women with estrogen receptor positive (ER+) breast cancer. This systematic review of seven randomized controlled studies comparing TAM and AI, and one study comparing extended therapy with an AI with placebo after about 5 years of tamoxifen, aims to assess long-term clinical efficacy and adverse events. The literature review was performed according to the principles of the Cochrane Collaboration. The search included common databases up to 2013-01-14. Studies of high or moderate quality were used for grading of evidence. Revman™ software was utilized for meta-analyses of published data. Disease free survival (DFS) and overall survival (OS) were improved with AI monotherapy compared to TAM with high and moderate quality of evidence respectively. Sequenced therapy with AI → TAM (or vice versa) improved DFS compared with TAM with moderate quality of evidence, but did not improve OS (low quality of evidence). However, if only studies on sequenced AI therapy with randomization before endocrine therapy were considered, no improvement of DFS could be found. Fractures are more frequently associated with AI whereas the risk of endometrial cancer and venous thromboembolism are higher with TAM. For cardiovascular events no difference was found between AI (mono- or sequenced therapy) and TAM, whereas sequenced therapy compared with AI had lower risk of cardiovascular events (moderate level of evidence). AIs are superior to TAM as adjuvant hormonal therapy for postmenopausal ER-positive breast cancer. TAM can be considered for individual patients due to the different toxicity profile compared with AI. Cardiovascular events related to AI treatment deserve further attention. PMID:27017249

  15. Do plants contain g protein-coupled receptors?

    PubMed

    Taddese, Bruck; Upton, Graham J G; Bailey, Gregory R; Jordan, Siân R D; Abdulla, Nuradin Y; Reeves, Philip J; Reynolds, Christopher A

    2014-01-01

    Whether G protein-coupled receptors (GPCRs) exist in plants is a fundamental biological question. Interest in deorphanizing new GPCRs arises because of their importance in signaling. Within plants, this is controversial, as genome analysis has identified 56 putative GPCRs, including G protein-coupled receptor1 (GCR1), which is reportedly a remote homolog to class A, B, and E GPCRs. Of these, GCR2 is not a GPCR; more recently, it has been proposed that none are, not even GCR1. We have addressed this disparity between genome analysis and biological evidence through a structural bioinformatics study, involving fold recognition methods, from which only GCR1 emerges as a strong candidate. To further probe GCR1, we have developed a novel helix-alignment method, which has been benchmarked against the class A-class B-class F GPCR alignments. In addition, we have presented a mutually consistent set of alignments of GCR1 homologs to class A, class B, and class F GPCRs and shown that GCR1 is closer to class A and/or class B GPCRs than class A, class B, or class F GPCRs are to each other. To further probe GCR1, we have aligned transmembrane helix 3 of GCR1 to each of the six GPCR classes. Variability comparisons provide additional evidence that GCR1 homologs have the GPCR fold. From the alignments and a GCR1 comparative model, we have identified motifs that are common to GCR1, class A, B, and E GPCRs. We discuss the possibilities that emerge from this controversial evidence that GCR1 has a GPCR fold. PMID:24246381

  16. Low Clouds and Cosmic Rays: Possible Reasons for Correlation Changes

    NASA Astrophysics Data System (ADS)

    Veretenenko, S. V.; Ogurtsov, M. G.

    2015-03-01

    In this work we investigated the nature of correlations between low cloud cover anomalies (LCA) and galactic cosmic ray (GCR) variations detected on the decadal time scale, as well as possible reasons for the violation of these correlations in the early 2000s. It was shown that the link between cloud cover at middle latitudes and GCR fluxes is not direct, but it is realized through GCR influence on the development of extratropical baric systems (cyclones and troughs) which form cloud field. As the sign of GCR effects on the troposphere dynamics seems to depend on the strength of the stratospheric polar vortex, a possible reason for the violation of a positive correlation between LCA and GCR fluxes in the early 2000s may be the change of the vortex state which resulted in the reversal of GCR effects on extratropical cyclone development.

  17. Galactic cosmic ray currents and magnetic field irregularity degree in high-speed solar wind streams

    NASA Technical Reports Server (NTRS)

    Kuzmin, A. I.; Samsonov, I. S.; Samsonova, Z. N.

    1985-01-01

    Currents of galactic cosmic rays (GCR) obtained by global survey method are analyzed. The cases of almost total disappearance of GCR currents are compared with the results of direct measurements of the solar wind parameters. The conclusion is made on a restricted application of the convective-diffusive mechanism of the GCR modulation by the solar wind during the occurrence of stationary and regular magnetic fields in the interplanetary medium.

  18. An inhibitor of viral RNA replication is encoded by a plant resistance gene.

    PubMed

    Ishibashi, Kazuhiro; Masuda, Kiyoshi; Naito, Satoshi; Meshi, Tetsuo; Ishikawa, Masayuki

    2007-08-21

    The tomato Tm-1 gene confers resistance to tomato mosaic virus (ToMV). Here, we report that the extracts of Tm-1 tomato cells (GCR237) have properties that inhibit the in vitro RNA replication of WT ToMV more strongly than that of the Tm-1-resistance-breaking mutant of ToMV, LT1. We purified this inhibitory activity and identified a polypeptide of approximately 80 kDa (p80(GCR237)) using LC-tandem MS. The amino acid sequence of p80(GCR237) had no similarity to any characterized proteins. The p80(GCR237) gene cosegregated with Tm-1; transgenic expression of p80(GCR237) conferred resistance to ToMV within tomato plants; and the knockdown of p80(GCR237) sensitized Tm-1 tomato plants to ToMV, indicating that Tm-1 encodes p80(GCR237) itself. We further show that in vitro-synthesized Tm-1 (p80(GCR237)) protein binds to the replication proteins of WT ToMV and inhibits their function at a step before, but not after, the viral replication complex is formed on the membrane surfaces. Such binding was not observed for the replication proteins of LT1. These results suggest that Tm-1 (p80(GCR237)) inhibits the replication of WT ToMV RNA through binding to the replication proteins. PMID:17699618

  19. An inhibitor of viral RNA replication is encoded by a plant resistance gene

    PubMed Central

    Ishibashi, Kazuhiro; Masuda, Kiyoshi; Naito, Satoshi; Meshi, Tetsuo; Ishikawa, Masayuki

    2007-01-01

    The tomato Tm-1 gene confers resistance to tomato mosaic virus (ToMV). Here, we report that the extracts of Tm-1 tomato cells (GCR237) have properties that inhibit the in vitro RNA replication of WT ToMV more strongly than that of the Tm-1-resistance-breaking mutant of ToMV, LT1. We purified this inhibitory activity and identified a polypeptide of ≈80 kDa (p80GCR237) using LC–tandem MS. The amino acid sequence of p80GCR237 had no similarity to any characterized proteins. The p80GCR237 gene cosegregated with Tm-1; transgenic expression of p80GCR237 conferred resistance to ToMV within tomato plants; and the knockdown of p80GCR237 sensitized Tm-1 tomato plants to ToMV, indicating that Tm-1 encodes p80GCR237 itself. We further show that in vitro-synthesized Tm-1 (p80GCR237) protein binds to the replication proteins of WT ToMV and inhibits their function at a step before, but not after, the viral replication complex is formed on the membrane surfaces. Such binding was not observed for the replication proteins of LT1. These results suggest that Tm-1 (p80GCR237) inhibits the replication of WT ToMV RNA through binding to the replication proteins. PMID:17699618

  20. Inversion of Moraxella lacunata type 4 pilin gene sequences by a Neisseria gonorrhoeae site-specific recombinase.

    PubMed Central

    Rozsa, F W; Meyer, T F; Fussenegger, M

    1997-01-01

    A plasmid library of Neisseria gonorrhoeae sequences was screened for the ability to mediate recombinations on a sequence containing the Moraxella lacunata type 4 pilin gene invertible region in Escherichia coli. A plasmid containing the N. gonorrhoeae sequence encoding the putative recombinase (gcr) was identified and sequenced. Plasmids containing gcr were able to mediate site-specific recombinations despite a weak amino acid homology to Piv, the native M. lacunata pilin gene invertase. The gcr gene is present only in pathogenic strains of Neisseria tested; however, in our assays gene knockouts of gcr did not alter the variation of surface features that play a role in the pathogenesis of N. gonorrhoeae. PMID:9079926

  1. Real Distribution of the Coronal Green Line Intensity and Modelling Study of Galactic Cosmic Ray Propagation

    NASA Astrophysics Data System (ADS)

    Gushchina, R. T.; Alania, M. V.; Gil, A.; Iskra, K.; Siluszyk, M.

    2003-07-01

    transport equation of galactic cosmic rays (GCR) has been numerically solved for different qA>0 (1996) and qA<0 (1987) epochs assuming that free path of GCR scattering in the interplanetary space is controlled by the Sun's coronal green line intensity (CGLI). We found some distinctions in the distribution of the expected heliolatitudinal gradients of GCR for two and three dimensional interplanetary magnetic field. INTRODUCTION. modulation of GCR in the interplanetary space is generally determined by four processesdiffusion, convection, drift and energy change of GCR particles due to interaction with the solar wind. The joint effect of all above mentioned processes result the 11year variation of GCR. In papers [1-3] are assumed that the general reason of the 11-year variation of GCR in the energy range more than 1 GeV is different structure of the irregularities of the IMF in the maxima and minima epochs of solar activity (SA) caused the radical changes of the dependence of diffusion coefficient on the rigidity of GCR particles. EXPERIMENTAL DATA AND METHOD OF INVESTIGATION. experimental data of sunspot numbers, sunspots' areas and CGLI (λ = 5303˚) show a considerable changes during the 11-year cycle of SA, while e.g. A the changes of the solar wind velocity are not so noticeable [4, 5]. An attempt to take into account influences of the real distributions of the sunspot's areas and the Sun's CGLI on the modulation of GCR considering delay time of the phenomena in the interplanetary space with respect to the processes on the Sun have been undertaken in papers [6-8]. One of parameters of SA contentiously observed on the Earth is the Sun's CGLI. One can suppose that a modulation of GCR by some means is controlled by the changes of the CGLI; particularly there is assumed that a scattering free path of GCR transport is related with the

  2. Glucocorticoid receptors in the retina, Müller glia and the formation of Müller glia-derived progenitors

    PubMed Central

    Gallina, Donika; Zelinka, Christopher; Fischer, Andy J.

    2014-01-01

    Identification of the signaling pathways that influence the reprogramming of Müller glia into neurogenic retinal progenitors is key to harnessing the potential of these cells to regenerate the retina. Glucocorticoid receptor (GCR) signaling is commonly associated with anti-inflammatory responses and GCR agonists are widely used to treat inflammatory diseases of the eye, even though the cellular targets and mechanisms of action in the retina are not well understood. We find that signaling through GCR has a significant impact upon the ability of Müller glia to become proliferating Müller glia-derived progenitor cells (MGPCs). The primary amino acid sequence and pattern of GCR expression in the retina is highly conserved across vertebrate species, including chickens, mice, guinea pigs, dogs and humans. In all of these species we find GCR expressed by the Müller glia. In the chick retina, we find that GCR is expressed by progenitors in the circumferential marginal zone (CMZ) and is upregulated by Müller glia in acutely damaged retinas. Activation of GCR signaling inhibits the formation of MGPCs and antagonizes FGF2/MAPK signaling in the Müller glia. By contrast, we find that inhibition of GCR signaling stimulates the formation of proliferating MGPCs in damaged retinas, and enhances the neuronal differentiation while diminishing glial differentiation. Given the conserved expression pattern of GCR in different vertebrate retinas, we propose that the functions and mechanisms of GCR signaling are highly conserved and are mediated through the Müller glia. We conclude that GCR signaling directly inhibits the formation of MGPCs, at least in part, by interfering with FGF2/MAPK signaling. PMID:25085975

  3. Development of a Miniaturized Hollow-Waveguide Gas Correlation Radiometer for Trace Gas Measurements in the Martian Atmosphere

    NASA Technical Reports Server (NTRS)

    Wilson, Emily L.; Georgieva, E. M.; Blalock, G. W.; Marx, C. T.; Heaps, W. S.

    2012-01-01

    We present preliminary results in the development of a miniaturized gas correlation radiometer (GCR) for column trace gas measurements in the Martian atmosphere. The GCR is designed as an orbiting instrument capable of mapping multiple trace gases and identifying active regions on the Mars surface.

  4. Antimicrobial-resistant fecal bacteria from ceftiofur-treated and non-antimicrobial-treated co-mingled beef cows at a cow-calf operation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We compared the occurrences of 3rd-generation cephalosporin-resistant (3GCr ), tetracycline-resistant (TETr) and trimethoprim-sulfamethoxazole-resistant (COTr ) Escherichia coli, 3GCr Salmonella enterica, nalidixic acid-resistant (NALr) S. enterica and erythromycin-resistant (ERYr) enterococci from ...

  5. Flaviaesturariibacter amylovorans gen. nov., sp. nov., a starch-hydrolysing bacterium, isolated from estuarine water.

    PubMed

    Kang, Ji Young; Chun, Jeesun; Seo, Jeong-Woo; Kim, Chul Ho; Jahng, Kwang Yeop

    2015-07-01

    A novel bacterial strain, designated GCR0105(T), was isolated from a water sample of the Mangyung estuary enclosed by the Saemangeum Embankment, located in JEOLlabuk-do, South Korea. Cells of strain GCR0105(T) were Gram-stain-negative, non-motile and rod-shaped. Colonies of strain GCR0105(T) were pale yellow-pigmented on R2A agar and nutrient agar media, and were able to grow at 15-30 °C (optimum 25 °C) and pH 6.5-8.5 (optimum pH 7.5). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GCR0105(T) was related most closely to Flavisolibacter ginsengisoli Gsoil 643(T) (93.14% similarity). The polar lipid profile of strain GCR0105(T) comprised phosphatidylethanolamine, two unknown aminolipids, an unknown aminophospholipid and four unknown lipids. The DNA G+C content of strain GCR0105(T) was 42.9 mol% and the respiratory quinone was MK-7.On the basis of phenotypic, chemotaxonomic and phylogenetic properties, strain GCR0105(T) represents a novel species in a new genus within the family Chitinophagaceae, for which the name Flaviaesturariibacter amylovorans gen. nov., sp. nov. is proposed. The type strain of Flaviaesturariibacter amylovorans is GCR0105(T) ( = KACC 16454(T) = JCM 17919(T)). PMID:25858251

  6. Guiding Preservice Teachers to Critically Reflect: Towards a Renewed Sense about English Learners

    ERIC Educational Resources Information Center

    Markos, Amy Michele

    2011-01-01

    The purpose of this practitioner inquiry was to explore the use of Guided Critical Reflection (GCR) in preparing preservice teachers for English learners (ELs). As a teacher researcher, I documented, analyzed, and discussed the ways in which students in my course used the process of GCR to transform their passively held understandings about ELs.…

  7. Corotating interaction regions and the 27 day variation of galactic cosmic rays intensity at 1 AU during the cycle 23/24 solar minimum

    NASA Astrophysics Data System (ADS)

    Guo, X.; Florinski, V.

    2014-04-01

    We investigate the formation and evolution of corotating interaction regions (CIRs) in the solar wind and their effects on galactic cosmic rays (GCR) during the recent solar cycle 23/24 solar minimum. The output from a three-dimensional MHD model serves as background for kinetic time-dependent simulations of GCR transport based on the Parker equation. The results show that the CIR forward/reverse shock pairs or compression/rarefaction regions play important roles in the transport of GCR particles and directly control the observed 27 day periodic intensity variations. We find that stream interfaces (SIs) in CIRs and the heliospheric current sheet (HCS) are both closely associated with the GCR depression onset, in agreement with the observations at 1 AU. The HCS is more important when its tilt angle becomes small during the declining phase of the solar minimum, while the passages of SIs control the onset of GCR depressions for larger HCS tilt angles. The mechanism of GCR intensity variation near 1 AU can be explained through an interplay between the effects of particle drift and diffusion. The simulated plasma background and GCR intensity are compared with the observations from spacecraft and a neutron monitor on the ground, to find good qualitative agreement. Evidently, CIRs had a substantial modulational effect on GCR during the recent solar minimum.

  8. Occurrence of antimicrobial-resistant Escherichia coli and Salmonella enterica in the beef cattle production and processing continuum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Specific concerns have been raised that 3rd-generation cephalosporin-resistant (3GCr) Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COTr) E. coli, 3GCr Salmonella enterica, and nalidixic acid-resistant (NALr) S. enterica, may be present in cattle production environments, persist through...

  9. Astrophysical Li-7 as a product of big bang nucleosynthesis and galactic cosmic-ray spallation

    NASA Technical Reports Server (NTRS)

    Olive, Keith A.; Schramm, David N.

    1992-01-01

    The astrophysical Li-7 abundance is considered to be largely primordial, while the Be and B abundances are thought to be due to galactic cosmic ray (GCR) spallation reactions on top of a much smaller big bang component. But GCR spallation should also produce Li-7. As a consistency check on the combination of big bang nucleosynthesis and GCR spallation, the Be and B data from a sample of hot population II stars is used to subtract from the measured Li-7 abundance an estimate of the amount generated by GCR spallation for each star in the sample, and then to add to this baseline an estimate of the metallicity-dependent augmentation of Li-7 due to spallation. The singly reduced primordial Li-7 abundance is still consistent with big bang nucleosynthesis, and a single GCR spallation model can fit the Be, B, and corrected Li-7 abundances for all the stars in the sample.

  10. Three dimensional solar anisotropy of galactic cosmic rays near the recent solar minimum 23/24

    NASA Astrophysics Data System (ADS)

    Modzelewska, R.; Alania, M. V.

    2015-08-01

    Three dimensional (3D) galactic cosmic ray (GCR) anisotropy has been studied for 2006-2012. The GCR anisotropy, both in the ecliptic plane and in polar direction, were obtained based on the neutron monitors (NMs) and Nagoya muon telescopes (MT) data. We analyze two dimensional (2D) GCR anisotropy in the ecliptic plane and north-south anisotropy normal to the ecliptic plane. We reveal quasi-periodicities - the annual and 27-days waves in the GCR anisotropy in 2006-2012. We investigate the relationship of the 27-day variation of the GCR anisotropy in the ecliptic plane and in the polar direction with the parameters of solar activity and solar wind.

  11. Galactic cosmic ray simulation at the NASA Space Radiation Laboratory.

    PubMed

    Norbury, John W; Schimmerling, Walter; Slaba, Tony C; Azzam, Edouard I; Badavi, Francis F; Baiocco, Giorgio; Benton, Eric; Bindi, Veronica; Blakely, Eleanor A; Blattnig, Steve R; Boothman, David A; Borak, Thomas B; Britten, Richard A; Curtis, Stan; Dingfelder, Michael; Durante, Marco; Dynan, William S; Eisch, Amelia J; Robin Elgart, S; Goodhead, Dudley T; Guida, Peter M; Heilbronn, Lawrence H; Hellweg, Christine E; Huff, Janice L; Kronenberg, Amy; La Tessa, Chiara; Lowenstein, Derek I; Miller, Jack; Morita, Takashi; Narici, Livio; Nelson, Gregory A; Norman, Ryan B; Ottolenghi, Andrea; Patel, Zarana S; Reitz, Guenther; Rusek, Adam; Schreurs, Ann-Sofie; Scott-Carnell, Lisa A; Semones, Edward; Shay, Jerry W; Shurshakov, Vyacheslav A; Sihver, Lembit; Simonsen, Lisa C; Story, Michael D; Turker, Mitchell S; Uchihori, Yukio; Williams, Jacqueline; Zeitlin, Cary J

    2016-02-01

    Most accelerator-based space radiation experiments have been performed with single ion beams at fixed energies. However, the space radiation environment consists of a wide variety of ion species with a continuous range of energies. Due to recent developments in beam switching technology implemented at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL), it is now possible to rapidly switch ion species and energies, allowing for the possibility to more realistically simulate the actual radiation environment found in space. The present paper discusses a variety of issues related to implementation of galactic cosmic ray (GCR) simulation at NSRL, especially for experiments in radiobiology. Advantages and disadvantages of different approaches to developing a GCR simulator are presented. In addition, issues common to both GCR simulation and single beam experiments are compared to issues unique to GCR simulation studies. A set of conclusions is presented as well as a discussion of the technical implementation of GCR simulation. PMID:26948012

  12. Exploring the relationships of between land surface temperature, ground coverage ratio and building volume density in an urbanized environment

    NASA Astrophysics Data System (ADS)

    Zhan, Q.; Meng, F.; Xiao, Y.

    2015-04-01

    The objective of this study is to explore and compare the relationships between urban land surface temperature (LST), ground coverage ratio (GCR) and building volume density (BVD). Landsat ETM+ data of August 2011 and August 2013 are used to estimate the LST for Wuhan, China, metropolitan area, and maps of GCR and BVD are generated using building census data of 2011 and 2013. Our analysis indicates there is a strong linear relationship between LST and GCR, and when GCR is lower, the linear correlation is more prominent, whereas the relationship between LST and BVD is not straightforward, but seems some underlying pattern. The result suggests GCR and BVD provide complementary metrics to the traditionally applied land use/land cover (LULC) for analysing LST quantitatively for surface urban heat island studies using thermal infrared remote sensing in an urbanized environment. This study is of positive significance to understand today's urban heat island issues, and contributes to the planning work of urban architectural space.

  13. Determining solar effects in Neptune's atmosphere.

    PubMed

    Aplin, K L; Harrison, R G

    2016-01-01

    Long-duration observations of Neptune's brightness at two visible wavelengths provide a disk-averaged estimate of its atmospheric aerosol. Brightness variations were previously associated with the 11-year solar cycle, through solar-modulated mechanisms linked with either ultraviolet or galactic cosmic ray (GCR) effects on atmospheric particles. Here, we use a recently extended brightness data set (1972-2014), with physically realistic modelling to show, rather than alternatives, ultraviolet and GCR are likely to be modulating Neptune's atmosphere in combination. The importance of GCR is further supported by the response of Neptune's atmosphere to an intermittent 1.5- to 1.9-year periodicity, which occurred preferentially in GCR (not ultraviolet) during the mid-1980s. This periodicity was detected both at Earth, and in GCR measured by Voyager 2, then near Neptune. A similar coincident variability in Neptune's brightness suggests nucleation onto GCR ions. Both GCR and ultraviolet mechanisms may occur more rapidly than the subsequent atmospheric particle transport. PMID:27417301

  14. Determining solar effects in Neptune's atmosphere

    PubMed Central

    Aplin, K. L.; Harrison, R. G.

    2016-01-01

    Long-duration observations of Neptune's brightness at two visible wavelengths provide a disk-averaged estimate of its atmospheric aerosol. Brightness variations were previously associated with the 11-year solar cycle, through solar-modulated mechanisms linked with either ultraviolet or galactic cosmic ray (GCR) effects on atmospheric particles. Here, we use a recently extended brightness data set (1972–2014), with physically realistic modelling to show, rather than alternatives, ultraviolet and GCR are likely to be modulating Neptune's atmosphere in combination. The importance of GCR is further supported by the response of Neptune's atmosphere to an intermittent 1.5- to 1.9-year periodicity, which occurred preferentially in GCR (not ultraviolet) during the mid-1980s. This periodicity was detected both at Earth, and in GCR measured by Voyager 2, then near Neptune. A similar coincident variability in Neptune's brightness suggests nucleation onto GCR ions. Both GCR and ultraviolet mechanisms may occur more rapidly than the subsequent atmospheric particle transport. PMID:27417301

  15. Are there persistent physical atmospheric responses to galactic cosmic rays?

    NASA Astrophysics Data System (ADS)

    Benestad, Rasmus E.

    2013-09-01

    Variations in the annual mean of the galactic cosmic ray flux (GCR) are compared with annual variations in the most common meteorological variables: temperature, mean sea-level barometric pressure, and precipitation statistics. A multiple regression analysis was used to explore the potential for a GCR response on timescales longer than a year and to identify ‘fingerprint’ patterns in time and space associated with GCR as well as greenhouse gas (GHG) concentrations and the El Niño-Southern Oscillation (ENSO). The response pattern associated with GCR consisted of a negative temperature anomaly that was limited to parts of eastern Europe, and a weak anomaly in the sea-level pressure (SLP), but coincided with higher pressure over the Norwegian Sea. It had a similarity to the North Atlantic Oscillation (NAO) in the northern hemisphere and a wave train in the southern hemisphere. A set of Monte Carlo simulations nevertheless indicated that the weak amplitude of the global mean temperature response associated with GCR could easily be due to chance (p-value = 0.6), and there has been no trend in the GCR. Hence, there is little empirical evidence that links GCR to the recent global warming.

  16. Determining solar effects in Neptune's atmosphere

    NASA Astrophysics Data System (ADS)

    Aplin, K. L.; Harrison, R. G.

    2016-07-01

    Long-duration observations of Neptune's brightness at two visible wavelengths provide a disk-averaged estimate of its atmospheric aerosol. Brightness variations were previously associated with the 11-year solar cycle, through solar-modulated mechanisms linked with either ultraviolet or galactic cosmic ray (GCR) effects on atmospheric particles. Here, we use a recently extended brightness data set (1972-2014), with physically realistic modelling to show, rather than alternatives, ultraviolet and GCR are likely to be modulating Neptune's atmosphere in combination. The importance of GCR is further supported by the response of Neptune's atmosphere to an intermittent 1.5- to 1.9-year periodicity, which occurred preferentially in GCR (not ultraviolet) during the mid-1980s. This periodicity was detected both at Earth, and in GCR measured by Voyager 2, then near Neptune. A similar coincident variability in Neptune's brightness suggests nucleation onto GCR ions. Both GCR and ultraviolet mechanisms may occur more rapidly than the subsequent atmospheric particle transport.

  17. MODULATION OF GALACTIC COSMIC RAYS OBSERVED AT L1 IN SOLAR CYCLE 23

    SciTech Connect

    Fludra, A.

    2015-01-20

    We analyze a unique 15 yr record of galactic cosmic-ray (GCR) measurements made by the SOHO Coronal Diagnostic Spectrometer NIS detectors, recording integrated GCR numbers with energies above 1.0 GeV between 1996 July and 2011 June. We are able to closely reproduce the main features of the SOHO/CDS GCR record using the modulation potential calculated from neutron monitor data by Usoskin et al. The GCR numbers show a clear solar cycle modulation: they decrease by 50% from the 1997 minimum to the 2000 maximum of the solar cycle, then return to the 1997 level in 2007 and continue to rise, in 2009 December reaching a level 25% higher than in 1997. This 25% increase is in contrast with the behavior of Ulysses/KET GCR protons extrapolated to 1 AU in the ecliptic plane, showing the same level in 2008-2009 as in 1997. The GCR numbers are inversely correlated with the tilt angle of the heliospheric current sheet. In particular, the continued increase of SOHO/CDS GCRs from 2007 until 2009 is correlated with the decrease of the minimum tilt angle from 30° in mid-2008 to 5° in late 2009. The GCR level then drops sharply from 2010 January, again consistent with a rapid increase of the tilt angle to over 35°. This shows that the extended 2008 solar minimum was different from the 1997 minimum in terms of the structure of the heliospheric current sheet.

  18. Modulation of Galactic Cosmic Rays Observed at L1 in Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Fludra, A.

    2015-01-01

    We analyze a unique 15 yr record of galactic cosmic-ray (GCR) measurements made by the SOHO Coronal Diagnostic Spectrometer NIS detectors, recording integrated GCR numbers with energies above 1.0 GeV between 1996 July and 2011 June. We are able to closely reproduce the main features of the SOHO/CDS GCR record using the modulation potential calculated from neutron monitor data by Usoskin et al. The GCR numbers show a clear solar cycle modulation: they decrease by 50% from the 1997 minimum to the 2000 maximum of the solar cycle, then return to the 1997 level in 2007 and continue to rise, in 2009 December reaching a level 25% higher than in 1997. This 25% increase is in contrast with the behavior of Ulysses/KET GCR protons extrapolated to 1 AU in the ecliptic plane, showing the same level in 2008-2009 as in 1997. The GCR numbers are inversely correlated with the tilt angle of the heliospheric current sheet. In particular, the continued increase of SOHO/CDS GCRs from 2007 until 2009 is correlated with the decrease of the minimum tilt angle from 30° in mid-2008 to 5° in late 2009. The GCR level then drops sharply from 2010 January, again consistent with a rapid increase of the tilt angle to over 35°. This shows that the extended 2008 solar minimum was different from the 1997 minimum in terms of the structure of the heliospheric current sheet.

  19. Peculiarities of cosmic ray modulation in the solar minimum 23/24

    NASA Astrophysics Data System (ADS)

    Alania, M. V.; Modzelewska, R.; Wawrzynczak, A.

    2014-06-01

    We study changes of the galactic cosmic ray (GCR) intensity for the ending period of the solar cycle 23 and the beginning of the solar cycle 24 using neutron monitors experimental data. We show that an increase of the GCR intensity in 2009 is generally related with decrease of the solar wind velocity U, the strength B of the interplanetary magnetic field (IMF), and the drift in negative (A < 0) polarity epoch. We present that temporal changes of rigidity dependence of the GCR intensity variation, before reaching maximum level in 2009 and after it, do not noticeably differ from each other. The rigidity spectrum of the GCR intensity variations calculated based on neutron monitors data (for rigidities > 10 GV) is hard in the minimum and near-minimum epoch. We do not recognize any nonordinary changes in the physical mechanism of modulation of the GCR intensity in the rigidity range of GCR particles to which neutron monitors respond. We compose 2-D nonstationary model of transport equation to describe variations of the GCR intensity for 1996-2012 including the A > 0 (1996-2001) and the A < 0 (2002-2012) periods; diffusion coefficient of cosmic rays for rigidity 10-15 GV is increased by ~ 30% in 2009 (A < 0) comparing with 1996 (A > 0). We believe that the proposed model is relatively realistic, and obtained results are satisfactorily compatible with neutron monitors data.

  20. Despiking of spacecraft energetic proton flux to study galactic cosmic ray modulation

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Qin, G.; Chen, H.

    2012-12-01

    Galactic cosmic ray (GCR) is usually considered as a stable "background," with solar influence assumed as a modulation. The solar energetic particle (SEP) events associated with solar activities change particle fluxes by several orders of magnitude in a few minutes. Thus, the flux observation of GCR provided by satellite may be contaminated by spurious spikes due to SEPs. In addition, the GCR fluxes provided by ground-based neutron monitors may be contaminated by the system error spikes and the ground level enhancement effect. For modulation research, "pure" background GCR flux from the removal of spikes is needed. In this work, we use an automatic despiking algorithm based on the Poincare map thresholding method (Goring and Nikora 2002) for "purification" of the GCR flux observations. We can show that the algorithm is good at reducing the various kinds of spikes of GCR intensity rates measured by both spacecraft and neutron monitors without artificial parameters. In addition, using the algorithm to despike the spacecraft observations of relatively lower energy energetic proton flux, we get both 11-year and 27-day period cycles comparable to the much higher energy GCR flux data measured by the ground-based neutron monitors.

  1. Solar activity, the QBO, and tropospheric responses

    NASA Technical Reports Server (NTRS)

    Tinsley, Brian A.; Brown, Geoffrey M.; Scherrer, Philip H.

    1989-01-01

    The suggestion that galactic cosmic rays (GCR) as modulated by the solar wind are the carriers of the component of solar variability that affects weather and climate has been discussed in the literature for 30 years, and there is now a considerable body of evidence that supports it. Variations of GCR occur with the 11 year solar cycle, matching the time scale of recent results for atmospheric variations, as modulated by the quasibiennial oscillation of equatorial stratospheric winds (the QBO). Variations in GCR occur on the time scale of centuries with a well defined peak in the coldest decade of the little ice age. New evidence is presented on the meteorological responses to GCR variations on the time scale of a few days. These responses include changes in the vertical temperature profile in the troposphere and lower stratosphere in the two days following solar flare related high speed plasma streams and associated GCR decreases, and in decreases in Vorticity Area Index (VAI) following Forbush decreases of GCR. The occurrence of correlations of GCR and meteorological responses on all three time scales strengthens the hypothesis of GCR as carriers of solar variability to the lower atmosphere. Both short and long term tropospheric responses are understandable as changes in the intensity of cyclonic storms initiated by mechanisms involving cloud microphysical and cloud electrification processes, due to changes in local ion production from changes in GCR fluxes and other high energy particles in the MeV to low GeV range. The nature of these mechanisms remains undetermined. Possible stratospheric wind (particularly QBO) effects on the transport of HNO3 and other constituents incorporated in cluster ions and possible condensation and freezing nuclei are considered as relevant to the long term variations.

  2. Multiplex Assay for Protein Profiling and Potency Measurement of German Cockroach Allergen Extracts

    PubMed Central

    Khurana, Taruna; Dobrovolskaia, Ekaterina; Shartouny, Jessica R.; Slater, Jay E.

    2015-01-01

    Background German cockroach (GCr) allergens induce IgE responses and may cause asthma. Commercial GCr allergen extracts are variable and existing assays may not be appropriate for determining extract composition and potency. Objective Our aim was to develop a multiplex antibody/bead-based assay for assessment of GCr allergen extracts. Methods Single chain fragment variable (scFv) antibodies against GCr were obtained by screening libraries derived from naïve human lymphocytes and hyperimmunized chicken splenocytes and bone marrow. Selected clones were sequenced and characterized by immunoblotting. Eighteen scFv antibodies (17 chicken, 1 human) coupled to polystyrene beads were used in this suspension assay; binding of targeted GCr allergens to antibody-coated beads was detected using rabbit antisera against GCr, and against specific allergens rBla g 1, rBla g 2, and rBla g 4. The assay was tested for specificity, accuracy, and precision. Extracts were also compared by IgE competition ELISA. Results Chicken scFv’s generated eight different binding patterns to GCr proteins from 14 to 150 kDa molecular weight. Human scFv’s recognized a 100 kDa GCr protein. The multiplex assay was found to be specific and reproducible with intra-assay coefficient of variation (CV) of 2.64% and inter-assay CV of 10.0%. Overall potencies of various GCr extracts were calculated using mean logEC50s for eight selected scFvs. Overall potency measures were also analyzed by assessing the contributions to potency of each target. Conclusions An scFv antibody-based multiplex assay has been developed capable of simultaneously measuring different proteins in a complex mixture, and to determine the potencies and compositions of allergen extracts. PMID:26444288

  3. Practical Applications of Cosmic Ray Science: Spacecraft, Aircraft, Ground-Based Computation and Control Systems, Exploration, and Human Health and Safety

    NASA Technical Reports Server (NTRS)

    Koontz, Steve

    2015-01-01

    In this presentation a review of galactic cosmic ray (GCR) effects on microelectronic systems and human health and safety is given. The methods used to evaluate and mitigate unwanted cosmic ray effects in ground-based, atmospheric flight, and space flight environments are also reviewed. However not all GCR effects are undesirable. We will also briefly review how observation and analysis of GCR interactions with planetary atmospheres and surfaces and reveal important compositional and geophysical data on earth and elsewhere. About 1000 GCR particles enter every square meter of Earth’s upper atmosphere every second, roughly the same number striking every square meter of the International Space Station (ISS) and every other low- Earth orbit spacecraft. GCR particles are high energy ionized atomic nuclei (90% protons, 9% alpha particles, 1% heavier nuclei) traveling very close to the speed of light. The GCR particle flux is even higher in interplanetary space because the geomagnetic field provides some limited magnetic shielding. Collisions of GCR particles with atomic nuclei in planetary atmospheres and/or regolith as well as spacecraft materials produce nuclear reactions and energetic/highly penetrating secondary particle showers. Three twentieth century technology developments have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools needed to design, test, and verify the safety and reliability of modern complex technological systems and assess effects on human health and safety effects. The key technology developments are: 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems. Space and geophysical exploration needs drove the development of the instruments and analytical tools needed to recover compositional and structural data from GCR induced nuclear reactions and secondary particle showers. Finally, the

  4. Glucocorticoid (GC) sensitivity and GC receptor expression differ in thymocyte subpopulations.

    PubMed

    Berki, Timea; Pálinkás, László; Boldizsár, Ferenc; Németh, Péter

    2002-05-01

    Positive and negative selection steps in the thymus prevent non-functional or harmful T cells from reaching the periphery. To examine the role of glucocorticoid (GC) hormone and its intracellular receptor (GCR) in thymocyte development we measured the GCR expression in different thymocyte subpopulations of BALB/c mice with or without previous dexamethasone (DX), anti-CD3 mAb, RU-486 and RU-43044 treatment. Four-color labeling of thymocytes allowed detection of surface CD4/CD8/CD69 expression in parallel with intracellular GCR molecules by flow cytometry. Double-positive (DP) CD4+CD8+ thymocytes showed the lowest GCR expression compared to double-negative (DN) CD4-CD8- thymocytes and mature single-positive (SP) cells. DX treatment caused a concentration-dependent depletion of the DP cell population and increased appearance of mature SP cells with reduced GCR levels. GCR antagonists (RU-486 or RU-43044) did not influence the effect of DX on thymocyte composition; however, RU-43044 inhibited the high-dose GC-induced GCR down-regulation in SP and DN cells. GCR antagonists alone did not influence the maturation of thymocytes and receptor numbers. Combined low-dose anti-CD3 mAb and DX treatment caused an enhanced maturation (positive selection) of thymocytes followed by the elevation of CD69+ DP cells. The sensitivity of DP thymocytes with a GCRlow phenotype to GC action and the ineffectiveness of the GCR antagonist treatment may reflect a non-genomic GC action in the thymic selection steps. PMID:11978776

  5. Galactic Cosmic Ray Simulation at the NASA Space Radiation Laboratory

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Slaba, Tony C.; Rusek, Adam

    2015-01-01

    The external Galactic Cosmic Ray (GCR) spectrum is significantly modified when it passes through spacecraft shielding and astronauts. One approach for simulating the GCR space radiation environment at ground based accelerators would use the modified spectrum, rather than the external spectrum, in the accelerator beams impinging on biological targets. Two recent workshops have studied such GCR simulation. The first workshop was held at NASA Langley Research Center in October 2014. The second workshop was held at the NASA Space Radiation Investigators' workshop in Galveston, Texas in January 2015. The results of these workshops will be discussed in this paper.

  6. Particle Radiation Environments and Their Effects at Planetary Surfaces of Airless Bodies: Remote Sensing Lessons Learned at the Moon by LRO/CRaTER and Extension to Other Planetary Objects

    NASA Astrophysics Data System (ADS)

    Spence, H. E.; Schwadron, N. A.; Wilson, J. K.; Jordan, A. P.; Winslow, R.; Joyce, C.; Looper, M. D.; Case, A. W.; Stubbs, T. J.; Zeitlin, C.; Blake, J. B.; Kasper, J. C.; Mazur, J. E.; Smith, S. S.; Townsend, L. W.

    2015-11-01

    We summarize the physics of GCR and SEP interactions with the Moon's surface and quantify how these same processes operate at similar airless objects throughout the solar system, including at Mercury, Mars' moons, asteroids, and the Pluto system.

  7. Comparison of Space Radiation Calculations from Deterministic and Monte Carlo Transport Codes

    NASA Technical Reports Server (NTRS)

    Adams, J. H.; Lin, Z. W.; Nasser, A. F.; Randeniya, S.; Tripathi, r. K.; Watts, J. W.; Yepes, P.

    2010-01-01

    The presentation outline includes motivation, radiation transport codes being considered, space radiation cases being considered, results for slab geometry, results from spherical geometry, and summary. ///////// main physics in radiation transport codes hzetrn uprop fluka geant4, slab geometry, spe, gcr,

  8. Observations of the Li, Be, and B isotopes and Constraints on Cosmic-ray Propagation

    SciTech Connect

    de Nolfo, Georgia A.; Moskalenko, I.V.; Binns, W.R.; Christian, E.R.; Cummings, A.C.; Davis, A.J.; George, J.S.; Hink, P.L.; Israel, M.H.; Leske, R.A.; Lijowski, M.; Mewaldt, R.A.; Stone, E.C.; Strong, A.W.; von Rosenvinge, T.T.; Wiedenbeck, M.E.; Yanasak, N.E.; /NASA, Goddard /Stanford U., HEPL /Washington U., St. Louis /NASA, Headquarters /Caltech, SRL /Aerospace Corp. /Garching, Max Planck Inst., MPE /Caltech, JPL

    2006-11-15

    The abundance of Li, Be, and B isotopes in galactic cosmic rays (GCR) between E=50-200 MeV/nucleon has been observed by the Cosmic Ray Isotope Spectrometer (CRIS) on NASA's ACE mission since 1997 with high statistical accuracy. Precise observations of Li, Be, B can be used to constrain GCR propagation models. We find that a diffusive reacceleration model with parameters that best match CRIS results (e.g. B/C, Li/C, etc) are also consistent with other GCR observations. A {approx}15-20% overproduction of Li and Be in the model predictions is attributed to uncertainties in the production cross-section data. The latter becomes a significant limitation to the study of rare GCR species that are generated predominantly via spallation.

  9. Observations of the Li, Be, and B Isotopes and Constraints on Cosmic-ray Propagation

    NASA Technical Reports Server (NTRS)

    deNolfo, G. A.; Moskalenko, I. V.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; George, J. S.; Hink, P. L.; Israel, M. H.; Leske, R. A.; Lijowski, M.; Mewaldt, R. A.; Stone, E. C.; Strong, A. W.; vonRosenvinge, T. T.; Wiedenbeck, M. E.; Yanasak, N. E.

    2007-01-01

    The abundance of Li, Be, and B isotopes in galactic cosmic rays (GCR) between E=50-200 MeV/nucleon has been observed by the Cosmic Ray Isotope Spectrometer (CRIS) on NASA's ACE mission since 1997 with high statistical accuracy. Precise observations of Li, Be, B can be used to constrain GCR propagation models. We find that a diffusive reacceleration model with parameters that best match CRIS results (e.g. B/C, Li/C, etc) are also consistent with other GCR observations. A approx. 15-20% overproduction of Li and Be in the model predictions is attributed to uncertainties in the production cross-section data. The latter becomes a significant limitation to the study of rare GCR species that are generated predominantly via spallation.

  10. Validation of Cosmic Ray Ionization Model CORIMIA applied for solar energetic particles and Anomalous Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Asenovski, S.; Velinov, P.; Mateev, L.

    2016-02-01

    Based on the electromagnetic interaction between the cosmic ray (CR) and the atmospheric neutral constituents, CORIMIA (COsmic Ray Ionization Model) gives an estimation of the dynamical ionization condition of the lower ionosphere and middle atmosphere (about 30-120 km). Galactic Cosmic Rays (GCR), modified by solar wind and later by geomagnetic and atmospheric cut offs, produce ionization in the entire atmosphere. In this paper we show the GCR ionization in periods of solar minimum and maximum. Despite the considerably lower energies than GCR, Anomalous Cosmic Rays (ACR) contribute to the ionization state mostly over the polar regions and as we present here this contribution is comparable with those of GCR. Solar energetic particles (SEP), which differ vastly from one another for different solar events, can be responsible for significant ionization over the high latitude regions. Here we compare flows of SEP caused by two of the most powerful solar proton events at February 23, 1956 and January 20, 2005.

  11. Galactic cosmic ray flux in the mid of 1700 from 44Ti activity of Agen meteorite

    NASA Astrophysics Data System (ADS)

    Taricco, Carla; Sinha, Neeharika; Bhandari, Narendra; Colombetti, Paolo; Mancuso, Salvatore; Rubinetti, Sara; Barghini, Dario

    2016-04-01

    Cosmogenic isotopes produced by galactic cosmic rays (GCR) in meteorites offer the opportunity to reveal the heliospheric magnetic field modulation in the interplanetary space between heliocentric distances of 1 and 3 AU. We present the gamma-activity measurement of Agen meteorite, a H5 chondrite that fell on September 5, 1814 in Aquitaine, France. Its 44Ti activity reflects GCR flux integrated since the mid of 1700 to the time of fall and confirms the decreasing trend of GCR flux that we previously suggested on the basis of measurements of other meteorites which fell in the last 250 years as well as the centennial modulation of GCR due to the Gleissberg solar cycle This result was obtained thanks to the high-efficiency and selective configuration of the gamma-ray spectrometer (HPGe+NaI) operating at the underground Laboratory of Monte dei Cappuccini (OATo, INAF) in Torino, Italy.

  12. Energy, water, and carbon fluxes in a loblolly pine stand: Results from uniform and gappy canopy models with comparisons to eddy flux data

    NASA Astrophysics Data System (ADS)

    Song, Conghe; Katul, Gabriel; Oren, Ram; Band, Lawrence E.; Tague, Christina L.; Stoy, Paul C.; McCarthy, Heather R.

    2009-12-01

    This study investigates the impacts of canopy structure specification on modeling net radiation (Rn), latent heat flux (LE) and net photosynthesis (An) by coupling two contrasting radiation transfer models with a two-leaf photosynthesis model for a maturing loblolly pine stand near Durham, North Carolina, USA. The first radiation transfer model is based on a uniform canopy representation (UCR) that assumes leaves are randomly distributed within the canopy, and the second radiation transfer model is based on a gappy canopy representation (GCR) in which leaves are clumped into individual crowns, thereby forming gaps between the crowns. To isolate the effects of canopy structure on model results, we used identical model parameters taken from the literature for both models. Canopy structure has great impact on energy distribution between the canopy and the forest floor. Comparing the model results, UCR produced lower Rn, higher LE and higher An than GCR. UCR intercepted more shortwave radiation inside the canopy, thus producing less radiation absorption on the forest floor and in turn lower Rn. There is a higher degree of nonlinearity between An estimated by UCR and by GCR than for LE. Most of the difference for LE and An between UCR and GCR occurred around noon, when gaps between crowns can be seen from the direction of the incident sunbeam. Comparing with eddy-covariance measurements in the same loblolly pine stand from May to September 2001, based on several measures GCR provided more accurate estimates for Rn, LE and An than UCR. The improvements when using GCR were much clearer when comparing the daytime trend of LE and An for the growing season. Sensitivity analysis showed that UCR produces higher LE and An estimates than GCR for canopy cover ranging from 0.2 to 0.8. There is a high degree of nonlinearity in the relationship between UCR estimates for An and those of GCR, particularly when canopy cover is low, and suggests that simple scaling of UCR parameters

  13. Galactic cosmic ray radiation levels in spacecraft on interplanetary missions

    NASA Technical Reports Server (NTRS)

    Shinn, J. L.; Nealy, J. E.; Townsend, L. W.; Wilson, J. W.; Wood, J.S.

    1994-01-01

    Using the Langley Research Center Galactic Cosmic Ray (GCR) transport computer code (HZETRN) and the Computerized Anatomical Man (CAM) model, crew radiation levels inside manned spacecraft on interplanetary missions are estimated. These radiation-level estimates include particle fluxes, LET (Linear Energy Transfer) spectra, absorbed dose, and dose equivalent within various organs of interest in GCR protection studies. Changes in these radiation levels resulting from the use of various different types of shield materials are presented.

  14. Activation of glucocorticoid receptors in Müller glia is protective to retinal neurons and suppresses microglial reactivity.

    PubMed

    Gallina, Donika; Zelinka, Christopher Paul; Cebulla, Colleen M; Fischer, Andy J

    2015-11-01

    Reactive microglia and macrophages are prevalent in damaged retinas. Glucocorticoid signaling is known to suppress inflammation and the reactivity of microglia and macrophages. In the vertebrate retina, the glucocorticoid receptor (GCR) is known to be activated and localized to the nuclei of Müller glia (Gallina et al., 2014). Accordingly, we investigated how signaling through GCR influences the survival of neurons using the chick retina in vivo as a model system. We applied intraocular injections of GCR agonist or antagonist, assessed microglial reactivity, and the survival of retinal neurons following different damage paradigms. Microglial reactivity was increased in retinas from eyes that were injected with vehicle, and this reactivity was decreased by GCR-agonist dexamethasone (Dex) and increased by GCR-antagonist RU486. We found that activation of GCR suppresses the reactivity of microglia and inhibited the loss of retinal neurons resulting from excitotoxicity. We provide evidence that the protection-promoting effects of Dex were maintained when the microglia were selectively ablated. Similarly, intraocular injections of Dex protected ganglion cells from colchicine-treatment and protected photoreceptors from damage caused by retinal detachment. We conclude that activation of GCR promotes the survival of ganglion cells in colchicine-damaged retinas, promotes the survival of amacrine and bipolar cells in excitotoxin-damaged retinas, and promotes the survival of photoreceptors in detached retinas. We propose that suppression of microglial reactivity is secondary to activation of GCR in Müller glia, and this mode of signaling is an effective means to lessen the damage and vision loss resulting from different types of retinal damage. PMID:26272753

  15. Radiation environment during the long space mission (Mars) due to galactic cosmic rays

    SciTech Connect

    Pissarenko, N.F. ||

    1993-12-31

    Galactic cosmic radiation (GCR) mostly determines dose equivalents inside the spacecraft during long-term manned missions in space. In this paper some new results are collected concerning different characteristics of GCR`s. Together with earlier obtained data they show that during most part of the solar cycle such spacecflights are not possible. Attention is drawn to very great errors in the estimates of dose equivalent and shielding thickness.

  16. Rigidity Spectra of Primary Protons and Different Classes of Galactic Cosmic Ray Variations

    NASA Astrophysics Data System (ADS)

    Alania, Michael; Modzelewska, Renata; Siluszyk, Marek; Gil, Agnieszka; Wawrzynczak-Szaban, Anna; Iskra, Krzysztof

    We study changes of proton spectra of Galactic Cosmic Ray (GCR) in free space for various minimum and near minimum epochs of 21/22, 22/23/ and 23/24 solar activity using data of different space probes. There are distinctions for positive (A>0) and negative (A<0) polarity epochs demonstrating a soft proton spectra for A<0 polarity epochs. We ascribe it to the increase of parallel and drift diffusion coefficients for the A<0 minimum epochs. We calculate rigidity spectra of long period variations of the GCR intensity using neutron monitors (NMs) and muon telescopes (MTs) data. We find that rigidity spectra of the GCR intensity variations are gradually hardening before and after reaching the maximum of the GCR intensity for all considered 21/22, 22/23/ and 23/24 minimum epochs of solar activity. In these periods an increase of the exponent nu of the Power Spectral Density (PSD) of the Interplanetary Magnetic Field (IMF) turbulence is observed confirming a validity of the quasi linear theory to describe a propagation of GCR to which NMs and MTs respond. We also study rigidity dependencies of the amplitudes of Forbush degreases and 27-day variations of the GCR intensity. We compare results of 2-D and 3-D modeling of GCR transport with the experimental data in free space (interplanetary space) and at earth orbit. We conclude that in formation of the rigidity spectrum of 11-year, 27-days and Forbush decreases measured by NMs and MTs at earth’s orbit a crucial role belongs to the character of the dependence of diffusion coefficient on the GCR particle’s rigidity, i.e. to the structure of the IMF turbulence.

  17. History of the solar environment

    NASA Astrophysics Data System (ADS)

    Marti, Kurt; Lavielle, Bernard

    2009-03-01

    Galactic cosmic rays (GCR) provide information on the solar neighborhood during the sun's motion in the galaxy. There is now considerable evidence for GCR acceleration by shock waves of supernova in active star-forming regions (OB associations) in the galactic spiral arms. During times of passage into star-forming regions increases in the GCR-flux are expected. Recent data from the Spitzer Space Telescope (SST) are shedding light on the structure of the Milky Way and of its star-forming-regions in spiral arms. Records of flux variations may be found in solar system detectors, and iron meteorites with GCR-exposure times of several hundred million years have long been considered to be potential detectors (Voshage, 1962). Variable concentration ratios of GCR-produced stable and radioactive nuclides, with varying half-lives and therefore integration times, were reported by Lavielle et al. (1999), indicating a recent 38% GCR-flux increase. Potential flux recorders consisting of different pairs of nuclides can measure average fluxes over different time scales (Lavielle et al., 2007; Mathew and Marti, 2008). Specific characteristics of two pairs of recorders (81Kr-Kr and 129I-129Xe) are the properties of self-correction for GCR-shielding (flux variability within meteorites of varying sizes). The 81Kr-Kr method (Marti, 1967) is based on Kr isotope ratios, while stable 129Xe is the decay product of the radionuclide 129I, which is produced by secondary neutron reactions on Te in troilites of iron meteorites. The two chronometers provide records of the average GCR flux over 1 and 100 million year time scales, respectively.

  18. Grey Component Replacement Research, Modelling Tone And Color Reproduction

    NASA Astrophysics Data System (ADS)

    Fisch, Richard S.

    1990-06-01

    Four different scanning Color Electronic Pagination System (CEPS) devices were tested to study their conventional and Grey Component Replacement/Undercolor Addition (GCR/UCA) tone and color response in the 4 color Positive Acting Offset Lithographic printing process. A common transparency input and ganged printing output was used. Inter and intra machine differences are disclosed. A new depiction of the full tone reproduction characteristics is presented for several different levels of GCR/UCA and conventional printing.

  19. Galactic cosmic ray radiation levels in spacecraft on interplanetary missions.

    PubMed

    Shinn, J L; Nealy, J E; Townsend, L W; Wilson, J W; Wood, J S

    1994-01-01

    Using the Langley Research Center galactic cosmic ray (GCR) transport computer code (HZETRN) and the computerized anatomical man (CAM) model, crew radiation levels inside manned spacecraft on interplanetary missions are estimated. These radiation-level estimates include particle fluxes, LET (linear energy transfer) spectra, absorbed dose, and dose equivalent within various organs of interest in GCR protection studies. Changes in these radiation levels resulting from the use of various different types of shield materials are presented. PMID:11538037

  20. The influence of galactic cosmic ray on all India annual rainfall and temperature

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Sutapa; Pal, Jayanti; Guhathakurta, Suchandra

    2015-02-01

    The inverse relation between galactic cosmic ray (GCR) and sunspot numbers (SSN) suggests that the increase (decrease) in GCR count is linked with low (high) solar activity. The present study attempts to reveal the influence of GCR on all India annual rainfall and temperature during the period from 1953 to 2005. The inter-annual variation depicts that during the transition from maximum to minimum count of GCR, the rainfall anomaly shows alternative variation over India. Similar variation has also been observed for maximum temperature. Implementation of Fourier analysis shows an 11 year cycle of cosmic ray and depicts an increase in GCR count in the 11 year interval during the study period. The Fourier analysis of all India annual rainfall (AIR) and temperature also shows an 11 year cycle with a decreasing trend during the 11 year interval. The inter-decadal variation shows that during high GCR count there is a possibility of decrease in rainfall and minimum temperature but an increase in maximum temperature. The seasonal correlation shows a possible proportional association between cosmic ray and rainfall during the post monsoon season. The result further depicts that the sunspot number and temperature is positively correlated during the post-monsoon season. The correlation map of rainfall and temperature shows a meager but significant correlation with cosmic ray over some parts of West and East Indian coasts.

  1. NASA Galactic Cosmic Radiation Environment Model: Badhwar-O'Neill (2014)

    NASA Technical Reports Server (NTRS)

    O'Neill, P. M.; Golge, S.; Slaba, T. C.

    2015-01-01

    The Badhwar-O'Neill (BON) Galactic Cosmic Ray (GCR) flux model is used by NASA to certify microelectronic systems and in the analysis of radiation health risks for human space flight missions. Of special interest to NASA is the kinetic energy region below 4.0 GeV/n due to the fact that exposure from GCR behind shielding (e.g., inside a space vehicle) is heavily influenced by the GCR particles from this energy domain. The BON model numerically solves the Fokker-Planck differential equation to account for particle transport in the heliosphere due to diffusion, convection, and adiabatic deceleration under the assumption of a spherically symmetric heliosphere. The model utilizes a GCR measurements database from various particle detectors to determine the boundary conditions. By using an updated GCR database and improved model fit parameters, the new BON model (BON14) is significantly improved over the previous BON models for describing the GCR radiation environment of interest to human space flight.

  2. NASA Galactic Cosmic Radiation Environment Model: Badhwar - O'Neill (2014)

    NASA Technical Reports Server (NTRS)

    Golge, S.; O'Neill, P. M.; Slaba, T. C.

    2015-01-01

    The Badhwar-O'Neill (BON) Galactic Cosmic Ray (GCR) flux model has been used by NASA to certify microelectronic systems and in the analysis of radiation health risks for human space flight missions. Of special interest to NASA is the kinetic energy region below 4.0 GeV/n due to the fact that exposure from GCR behind shielding (e.g., inside a space vehicle) is heavily influenced by the GCR particles from this energy domain. The BON model numerically solves the Fokker-Planck differential equation to account for particle transport in the heliosphere due to diffusion, convection, and adiabatic deceleration under the assumption of a spherically symmetric heliosphere. The model utilizes a comprehensive database of GCR measurements from various particle detectors to determine boundary conditions. By using an updated GCR database and improved model fit parameters, the new BON model (BON14) is significantly improved over the previous BON models for describing the GCR radiation environment of interest to human space flight.

  3. Effects of Cutoffs on Galactic Cosmic-Ray Interactions in Solar-System Matter

    NASA Technical Reports Server (NTRS)

    Kim, K. J.; Reedy, R. C.; Masarik, J.

    2005-01-01

    The energetic particles in the galactic cosmic rays (GCR) induce many interactions in a variety of solar-system matter. Cosmogenic nuclides are used to study the histories of meteorites and lunar samples. Gamma rays and neutrons are used to map the compositions of planetary surfaces, such as Mars, the Moon, and asteroids. In almost all of these cases, the spectra of incident GCR particles are fairly similar, with only some modulation by the Sun over an 11-year cycle. Strong magnetic fields can seriously affect the energy spectrum of GCR particles hitting the surface of objects inside the magnetic fields. The Earth s geomagnetic field is strong enough that only GCR particles with magnetic rigidities above approx. 17 GV (a proton energy of approx. 17 GeV) reach the atmosphere over certain regions near the equator. This effect of removing lower-energy GCR particles is called a cutoff. The jovian magnetic fields are so strong that the fluxes of GCR particles hitting the 4 large Galilean satellites are similarly affected. The cutoff at Europa is estimated to be similar to or a little higher than at the Earth s equator.

  4. Computational and Genetic Reduction of a Cell Cycle to Its Simplest, Primordial Components

    PubMed Central

    Fumeaux, Coralie; Viollier, Patrick H.; Howard, Martin

    2013-01-01

    What are the minimal requirements to sustain an asymmetric cell cycle? Here we use mathematical modelling and forward genetics to reduce an asymmetric cell cycle to its simplest, primordial components. In the Alphaproteobacterium Caulobacter crescentus, cell cycle progression is believed to be controlled by a cyclical genetic circuit comprising four essential master regulators. Unexpectedly, our in silico modelling predicted that one of these regulators, GcrA, is in fact dispensable. We confirmed this experimentally, finding that ΔgcrA cells are viable, but slow-growing and elongated, with the latter mostly due to an insufficiency of a key cell division protein. Furthermore, suppressor analysis showed that another cell cycle regulator, the methyltransferase CcrM, is similarly dispensable with simultaneous gcrA/ccrM disruption ameliorating the cytokinetic and growth defect of ΔgcrA cells. Within the Alphaproteobacteria, gcrA and ccrM are consistently present or absent together, rather than either gene being present alone, suggesting that gcrA/ccrM constitutes an independent, dispensable genetic module. Together our approaches unveil the essential elements of a primordial asymmetric cell cycle that should help illuminate more complex cell cycles. PMID:24415923

  5. DESPIKING OF SPACECRAFT ENERGETIC PROTON FLUX TO STUDY GALACTIC COSMIC-RAY MODULATION

    SciTech Connect

    Qin, G.; Zhao, L.-L.; Chen, H.-C. E-mail: llzhao@spaceweather.ac.cn

    2012-06-20

    Galactic cosmic ray (GCR) is usually assumed as a stable 'background', with solar influence considered as a modulation. The violent solar energetic particle (SEP) events associated with solar activities change particle fluxes by several orders of magnitude in a few minutes. Thus, the flux observation of GCR provided by satellites may be heavily contaminated by spurious spikes due to SEPs, and that provided by ground-based neutron monitors (NMs) may be contaminated by the system error spikes and the ground level enhancement effect. To obtain the 'pure' background GCR flux for modulation research, the removal of multifarious spikes is necessary. In this article, we use a robust automatic despiking algorithm based on the Poincare map thresholding method provided by Goring and Nikora for 'purification' of the time-series GCR flux observations. We can show that the algorithm is good at cleaning up the heavily contaminated GCR intensity rates measured by both spacecraft and NMs without artificial parameters. In addition, using the algorithm to despike the spacecraft observations of relatively lower energetic proton flux, we get both 11 year and 27 day period cycles comparable to the much higher energy GCR flux data measured by the ground-based NMs.

  6. Near-Earth Cosmic Ray Decreases Associated with Remote Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Thomas, S. R.; Owens, M. J.; Lockwood, M.; Barnard, L.; Scott, C. J.

    2015-03-01

    Galactic cosmic ray (GCR) flux is modulated by both particle drift patterns and solar wind structures on a range of timescales. Over solar cycles, GCR flux varies as a function of the total open solar magnetic flux and the latitudinal extent of the heliospheric current sheet. Over hours, drops of a few percent in near-Earth GCR flux (Forbush decreases, FDs) are well known to be associated with the near-Earth passage of solar wind structures resulting from corotating interaction regions (CIRs) and transient coronal mass ejections (CMEs). We report on four FDs seen at ground-based neutron monitors which cannot be immediately associated with significant structures in the local solar wind. Similarly, there are significant near-Earth structures which do not produce any corresponding GCR variation. Three of the FDs are during the STEREO era, enabling in situ and remote observations from three well-separated heliospheric locations. Extremely large CMEs passed the STEREO-A spacecraft, which was behind the West limb of the Sun, approximately 2-3 days before each near-Earth FD. Solar wind simulations suggest that the CMEs combined with pre-existing CIRs, enhancing the pre-existing barriers to GCR propagation. Thus these observations provide strong evidence for the modulation of GCR flux by remote solar wind structures.

  7. The boron-to-beryllium ratio in halo stars - A signature of cosmic-ray nucleosynthesis in the early Galaxy

    NASA Technical Reports Server (NTRS)

    Walker, T. P.; Steigman, G.; Schramm, D. N.; Olive, K. A.; Fields, B.

    1993-01-01

    We discuss Galactic cosmic-ray (GCR) spallation production of Li, Be, and B in the early Galaxy with particular attention to the uncertainties in the predictions of this model. The observed correlation between the Be abundance and the metallicity in metal-poor Population II stars requires that Be was synthesized in the early Galaxy. We show that the observations and such Population II GCR synthesis of Be are quantitatively consistent with the big bang nucleosynthesis production of Li-7. We find that there is a nearly model independent lower bound to B/Be of about 7 for GCR synthesis. Recent measurements of B/Be about 10 in HD 140283 are in excellent agreement with the predictions of Population II GCR nucleosynthesis. Measurements of the boron abundance in additional metal-poor halo stars is a key diagnostic of the GCR spallation mechanism. We also show that Population II GCR synthesis can produce amounts of Li-6 which may be observed in the hottest halo stars.

  8. Monitoring Short-term Cosmic-ray Spectral Variations Using Neutron Monitor Time-delay Measurements

    NASA Astrophysics Data System (ADS)

    Ruffolo, D.; Sáiz, A.; Mangeard, P.-S.; Kamyan, N.; Muangha, P.; Nutaro, T.; Sumran, S.; Chaiwattana, C.; Gasiprong, N.; Channok, C.; Wuttiya, C.; Rujiwarodom, M.; Tooprakai, P.; Asavapibhop, B.; Bieber, J. W.; Clem, J.; Evenson, P.; Munakata, K.

    2016-01-01

    Neutron monitors (NMs) are ground-based detectors of cosmic-ray showers that are widely used for high-precision monitoring of changes in the Galactic cosmic-ray (GCR) flux due to solar storms and solar wind variations. In the present work, we show that a single neutron monitor station can also monitor short-term changes in the GCR spectrum, avoiding the systematic uncertainties in comparing data from different stations, by means of NM time-delay histograms. Using data for 2007-2014 from the Princess Sirindhorn Neutron Monitor, a station at Doi Inthanon, Thailand, with the world’s highest vertical geomagnetic cutoff rigidity of 16.8 GV, we have developed an analysis of time-delay histograms that removes the chance coincidences that can dominate conventional measures of multiplicity. We infer the “leader fraction” L of neutron counts that do not follow a previous neutron count in the same counter from the same atmospheric secondary, which is inversely related to the actual multiplicity and increases for increasing GCR spectral index. After correction for atmospheric pressure and water vapor, we find that L indicates substantial short-term GCR spectral hardening during some but not all Forbush decreases in GCR flux due to solar storms. Such spectral data from Doi Inthanon provide information about cosmic-ray energies beyond the Earth’s maximum geomagnetic cutoff, extending the reach of the worldwide NM network and opening a new avenue in the study of short-term GCR decreases.

  9. Heliospheric and geomagnetic modulation of galactic cosmic rays under quiet and disturbed interplanetary conditions during solar cycles 20-23

    NASA Astrophysics Data System (ADS)

    Chukwudi Okpala, Kingsley

    2015-08-01

    The modulation of galactic cosmic rays (GCR) within the heliosphere leads to a reduction in the GCR count rates during period of high solar activity and conversely. Data from three geomagnetic observatories and three Neutron monitors (in close proximity to the geomagnetic stations) have been studied. The monthly residuals of the geomagnetic field components with respect to quiet time conditions from these three stations have been computed and compared with the cosmic ray count rates. The modulations of the GCR during quiet and disturbed interplanetary conditions have been investigated with a view to better understand the role of the global merged interaction regions and intense magnetic fields to the GCR modulation. From first-order partial correlation, we found that removing the influence of the total IMF-B, (especially during quiet conditions) and the influence of SW dynamic pressure (during disturbed conditions) generally enhances the correlation of the residual geomagnetic field with the GCR significantly. The influence of the more subtle parameters like speed, Bz component and proton density were masked by these dominant parameters. Results from this work are important for the modeling of long term GCR variability.

  10. Implementing Badhwar-O'Neill Galactic Cosmic Ray Model for the Analysis of Space Radiation Exposure

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; O'Neill, Patrick M.; Slaba, Tony C.

    2014-01-01

    For the analysis of radiation risks to astronauts and planning exploratory space missions, accurate energy spectrum of galactic cosmic radiation (GCR) is necessary. Characterization of the ionizing radiation environment is challenging because the interplanetary plasma and radiation fields are modulated by solar disturbances and the radiation doses received by astronauts in interplanetary space are likewise influenced. A model of the Badhwar-O'Neill 2011 (BO11) GCR environment, which is represented by GCR deceleration potential theta, has been derived by utilizing all of the GCR measurements from balloons, satellites, and the newer NASA Advanced Composition Explorer (ACE). In the BO11 model, the solar modulation level is derived from the mean international sunspot numbers with time-delay, which has been calibrated with actual flight instrument measurements to produce better GCR flux data fit during solar minima. GCR fluxes provided by the BO11 model were compared with various spacecraft measurements at 1 AU, and further comparisons were made for the tissue equivalent proportional counters measurements at low Earth orbits using the high-charge and energy transport (HZETRN) code and various GCR models. For the comparison of the absorbed dose and dose equivalent calculations with the measurements by Radiation Assessment Detector (RAD) at Gale crater on Mars, the intensities and energies of GCR entering the heliosphere were calculated by using the BO11 model, which accounts for time-dependent attenuation of the local interstellar spectrum of each element. The BO11 model, which has emphasized for the last 24 solar minima, showed in relatively good agreement with the RAD data for the first 200 sols, but it was resulted in to be less well during near the solar maximum of solar cycle 24 due to subtleties in the changing heliospheric conditions. By performing the error analysis of the BO11 model and the optimization in reducing overall uncertainty, the resultant BO13 model

  11. Comparison of collection and land use efficiency for various solar concentrating field geometries

    NASA Astrophysics Data System (ADS)

    Stephens, Kyle; Angel, J. Roger P.

    2012-10-01

    In this paper we analyze the effects of neighbor shadowing of tracking solar photovoltaic arrays when they are set out in solar farms for large scale generation. Closer tracker spacing yields more power per unit area of land, but less power per tracking unit because of shadowing. A model has been developed to quantify and compare efficiencies for different tracker aspect ratios and field layouts, on an hourly, daily and annual basis. The model accounts for atmospheric absorption as well as neighbor shadowing at low solar altitude angles. We have focused on the case of CPV arrays which are oriented normal to the rays from the sun. The field layout is best characterized by the ratio of total array area to land area (the ground cover ratio or GCR). We explore as a function of GCR both the fraction of all the direct sunlight energy that is intercepted by the arrays (the irradiance collection efficiency) and the energy lost by each array because of shadowing. Examples are worked out for rectangular arrays on dual axis trackers at 33° latitude. We find that for a ground cover ratio of 30% the annual irradiance collection efficiency is 50%, almost independent of the layout pattern or the array aspect ratio. For a ground cover ratio of 40%, the irradiance collection efficiency rises to 65%. The corresponding shadowing losses do depend on aspect ratio, thus for 30% GCR the annual average of shadowing loss is 7.2% for 3:1 aspect ratio, rising to 7.8% for 2:1 aspect ratio. High GCR is not realizable for higher aspect ratios, which lead to large swing radius, but for 2:1 aspect ratio 40% GCR results in shadowing loss of 11.5%. One conclusion is that a solar farm with arrays of 2:1 aspect ratio set out with 40% GCR is good compromise when land is scarce: 64% of all the direct sunlight energy incident on the land is harvested by the arrays, with only 11.5% shadowing loss. We have compared these efficiencies with those for trough CSP systems, which also harvest direct sunlight

  12. Badhwar-O'Neill 2011 Galactic Cosmic Ray Model Update and Future Improvements

    NASA Technical Reports Server (NTRS)

    O'Neill, Pat M.; Kim, Myung-Hee Y.

    2014-01-01

    The Badhwar-O'Neill Galactic Cosmic Ray (GCR) Model based on actual GCR measurements is used by deep space mission planners for the certification of microelectronic systems and the analysis of radiation health risks to astronauts in space missions. The BO GCR Model provides GCR flux in deep space (outside the earth's magnetosphere) for any given time from 1645 to present. The energy spectrum from 50 MeV/n - 20 GeV/n is provided for ions from hydrogen to uranium. This work describes the most recent version of the BO GCR model (BO'11). BO'11 determined the GCR flux at a given time applying an emperical time delay function to past sunspot activity. We describe the GCR measurement data used in the BO'11 update - modern data from BESS, PAMELA, CAPRICE, and ACE emphasized more than the older balloon data used for the previous BO model (BO'10). We look at the GCR flux for the last 24 solar minima and show how much greater the flux was for the cycle 24 minimum in 2010. The BO'11 Model uses the traditional, steady-state Fokker-Planck differential equation to account for particle transport in the heliosphere due to diffusion, convection, and adiabatic deceleration. It assumes a radially symmetrical diffusion coefficient derived from magnetic disturbances caused by sunspots carried outward by a constant solar wind. A more complex differential equation is now being tested to account for particle transport in the heliosphere in the next generation BO model. This new model is time-dependent (no longer a steady state model). In the new model, the dynamics and anti-symmetrical features of the actual heliosphere are accounted for so emperical time delay functions will no longer be required. The new model will be capable of simulating the more subtle features of modulation - such as the Sun's polarity and modulation dependence on gradient and curvature drift. This improvement is expected to significantly improve the fidelity of the BO GCR model. Preliminary results of its

  13. Depth-dose equivalent relationship for cosmic rays at various solar minima

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Cucinotta, F. A.; O'Neill, P. M.

    1993-01-01

    Galactic cosmic rays (GCR) pose a serious radiation hazard for long-duration missions. In designing a lunar habitat or a Mars transfer vehicle, the radiation exposure determines the GCR shielding thickness, and hence the weight of spacecraft. Using the spherically symmetric diffusion theory of the solar modulation of GCR, and data on the differential energy spectra of H, He, O, and Fe, from 1965 to 1989, it has been shown that (1) the flux is determined by the diffusion parameter which is a function of the time in the solar cycle, and (2) the fluxes in the 1954 and 1976-1977 solar minima were similar and higher than those in 1965. In this paper, we have extended the spherical solar modulation theory back to 1954. The 1954-1955 GCR flux was nearly the same as that from 1976 to 1977; the 1965 flux values were nearly the same as those in 1986. Using this theory we have obtained the GCR spectra for all the nuclei, and calculated the depth dose as a function of Al thickness. It is shown that the shielding required to stay below 0.5 Sv is 17.5 -3/+8 g/sq cm of Al, and 9 -1.5/+5 g/sq cm to stay below 0.6 Sv. The calculated dose equivalent using the ICRP 60 values for quality factors is about 15 percent higher than that calculated using the ICRP 26 value.

  14. Breast Cancer by Age at Diagnosis in the Gharbiah, Egypt, Population-Based Registry Compared to the United States Surveillance, Epidemiology, and End Results Program, 2004–2008

    PubMed Central

    Schlichting, Jennifer A.; Soliman, Amr S.; Schairer, Catherine; Harford, Joe B.; Hablas, Ahmed; Ramadan, Mohamed; Seifeldin, Ibrahim; Merajver, Sofia D.

    2015-01-01

    Objective. Although breast cancers (BCs) in young women often display more aggressive features, younger women are generally not screened for early detection. It is important to understand the characteristics of young onset breast cancer to increase awareness in this population. This analysis includes all ages, with emphasis placed on younger onset BC in Egypt as compared to the United States. Methods. BC cases in the Gharbiah cancer registry (GCR), Egypt, were compared to those in the Surveillance, Epidemiology, and End Results (SEER) database. This analysis included 3,819 cases from the GCR and 273,019 from SEER diagnosed 2004–2008. Results. GCR cases were diagnosed at later stages, with <5% diagnosed at Stage I and 12% diagnosed at Stage IV. 48% of all SEER cases were diagnosed at Stage I, dropping to 30% among those ≤40. Significant differences in age, tumor grade, hormone receptor status, histology, and stage exist between GCR and SEER BCs. After adjustment, GCR cases were nearly 45 times more likely to be diagnosed at stage III and 16 times more likely to be diagnosed at stage IV than SEER cases. Conclusions. Future research should examine ways to increase literacy about early detection and prompt therapy in young cases. PMID:26495294

  15. Galactic Cosmic-Ray Intensity Modulation by Corotating Interaction Region Stream Interfaces at 1 au

    NASA Astrophysics Data System (ADS)

    Guo, X.; Florinski, V.

    2016-07-01

    We present a new model that couples galactic cosmic-ray (GCR) propagation with magnetic turbulence transport and the MHD background evolution in the heliosphere. The model is applied to the problem of the formation of corotating interaction regions (CIRs) during the last solar minimum from the period between 2007 and 2009. The numerical model simultaneously calculates the large-scale supersonic solar wind properties and its small-scale turbulent content from 0.3 au to the termination shock. Cosmic rays are then transported through the background, and thus computed, with diffusion coefficients derived from the solar wind turbulent properties, using a stochastic Parker approach. Our results demonstrate that GCR variations depend on the ratio of diffusion coefficients in the fast and slow solar winds. Stream interfaces inside the CIRs always lead to depressions of the GCR intensity. On the other hand, heliospheric current sheet (HCS) crossings do not appreciably affect GCR intensities in the model, which is consistent with the two observations under quiet solar wind conditions. Therefore, variations in diffusion coefficients associated with CIR stream interfaces are more important for GCR propagation than the drift effects of the HCS during a negative solar minimum.

  16. The Decadal Variability of Cosmic Ray Flux Outside of a Grand Solar Maximum

    NASA Astrophysics Data System (ADS)

    Thomas, Simon; Owens, Mathew; Lockwood, Mike

    2016-04-01

    Galactic cosmic ray (GCR) flux is modulated by changes in the Sun's magnetic field. In the long-term, GCRs flux at Earth varies in a 22-year cycle. Observing time-series of GCR flux we see a pattern of 'flat topped' and 'spiked topped' peaks. It is thought that differing drift patterns for when the northern solar pole is predominantly positive (qA>0) to when the northern pole is negative (qA<0) cause this difference in modulation. We demonstrate a link between GCR modulation and long-term changes in the intensity and structure of the large-scale heliospheric magnetic field, particularly during the declining phase of consecutive solar cycles. Using reconstructions of the heliospheric field from geomagnetic data, we demonstrate that this cause of GCR modulation is only present in cycles during the recent Grand Solar Maximum and not during the weaker period of activity prior to it. We therefore suggest that the current decline in solar activity will result in different long-term patterns in GCR data to those observed during the space-age which would be important for the planning of space-based missions. Finally, we compare our results to ice-core data (found to display the 22-year variation) to further explore how the 22-year cycle varies between different solar activity periods.

  17. Nuclide production by primary cosmic-ray protons

    SciTech Connect

    Reedy, R.C.

    1986-01-01

    The production rates of cosmogenic nuclides in the solar system and in interstellar space were calculated for the primary protons in the galactic and solar cosmic rays. At 1 AU, the long-term average fluxes of solar protons usually produce many more atoms of a cosmogenic nuclide than the primary protons in the galactic cosmic rays (GCR), the exceptions being nuclides made only by high-energy reactions (like /sup 10/Be). Because the particle fluxes inside meteorites and other large objects in space include many secondary neutrons, the production rates are much higher and ratios inside large objects are often very different from those by just the primary GCR protons in small objects. The production rates of cosmogenic nuclides are calculated to vary by about factors of 2.5 during at typical 11-year solar cycle, in agreement with measurements of short-lived radionuclides in recently fallen meteorites. The production of cosmogenic nuclides by the GCR particles outside the heliosphere is higher than that by the modulated GCR primaries normally in the solar system. However, there is considerable uncertainty in the fluxes of interstellar protons and, therefore, in the production rates of cosmogenic nuclides in interstellar space. Production rates and ratios for cosmogenic nuclides would be able to identify particles that were small in space or that were exposed to an unmodulated spectrum of GCR particles. 25 refs., 2 figs., 2 tabs.

  18. Evaluating Shielding Effectiveness for Reducing Space Radiation Cancer Risks

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Kim, Myung-Hee Y.; Ren, Lei

    2007-01-01

    We discuss calculations of probability distribution functions (PDF) representing uncertainties in projecting fatal cancer risk from galactic cosmic rays (GCR) and solar particle events (SPE). The PDF s are used in significance tests of the effectiveness of potential radiation shielding approaches. Uncertainties in risk coefficients determined from epidemiology data, dose and dose-rate reduction factors, quality factors, and physics models of radiation environments are considered in models of cancer risk PDF s. Competing mortality risks and functional correlations in radiation quality factor uncertainties are treated in the calculations. We show that the cancer risk uncertainty, defined as the ratio of the 95% confidence level (CL) to the point estimate is about 4-fold for lunar and Mars mission risk projections. For short-stay lunar missions (<180 d), SPE s present the most significant risk, however one that is mitigated effectively by shielding, especially for carbon composites structures with high hydrogen content. In contrast, for long duration lunar (>180 d) or Mars missions, GCR risks may exceed radiation risk limits, with 95% CL s exceeding 10% fatal risk for males and females on a Mars mission. For reducing GCR cancer risks, shielding materials are marginally effective because of the penetrating nature of GCR and secondary radiation produced in tissue by relativistic particles. At the present time, polyethylene or carbon composite shielding can not be shown to significantly reduce risk compared to aluminum shielding based on a significance test that accounts for radiobiology uncertainties in GCR risk projection.

  19. Modeling of the recurrent Forbush effect of the galactic cosmic ray intensity and comparison with the experimental data

    NASA Astrophysics Data System (ADS)

    Wawrzynczak, A.; Alania, M. V.

    We developed a new three dimensional 3-D steady-state model of the recurrent Forbush effect of the galactic cosmic ray GCR intensity using Parker s transport equation New code for the solution of the transport equation is realized by C and needs less time for computations than the FORTRAN variant Convection diffusion drift and energy change of the GCR particles in the diverged solar wind are taken into account in the modeling Changes of the strength of the interplanetary magnetic field IMF and the power spectral density PSD of the IMF s turbulence in the range of frequencies sim 10 -6 -- 10 -5 Hz versus the radial distance heliolatitudes and heliolongitudes are the sources of the recurrent Forbush effect of the GCR intensity The state of this range of the frequencies sim 10 -6 -- 10 -5 Hz of the IMF s turbulence is responsible for the intensive diffusion of the GCR particles of the energy 5-50 GeV responding by neutron monitors and for a peculiarities of the rigidity spectrum of the Forbush effect Results of the modeling calculations time profile amplitude rigidity spectrum are compatible with the experimental data of the Forbush effects of the GCR intensity observed by neutron monitors in the positive A 0 and in the negative A 0 periods of solar magnetic cycle

  20. Movement patterns of wintering lesser scaup in Grand Calumet River - Indiana Harbor Canal, Indiana

    USGS Publications Warehouse

    Custer, Christine M.; Custer, T.W.; Sparks, D.W.; Hines, Randy K.; Kochanny, C.O.

    1996-01-01

    Lesser scaup (Aythya affinis) winter in the Grand Calumet River-Indiana Harbor Canal (GCR-IHC) drainage into southern Lake Michigan, a polluted oasis in the highly urban and industrial corridor of northern Illinois and Indiana. The GCR-IHC is an important wintering area for lesser scaup in northwestern Indiana, especially after Lake Michigan freezes, because of the lack of other wildlife habitat in the area. We investigated the feeding and movement patterns of these wintering lesser scaup to better understand the ecological significance of this area to wintering waterfowl and to interpret contaminant levels in these lesser scaup. We implanted radio transmitters in 20 individuals in January 1994 and tracked them until early March 1994. Four lesser scaup disappeared and four died within the first 2 weeks after implantation; 12 lesser scaup remained in the GCR-IHC for the next 6-7 weeks. Individual radio-marked scaup (n = 12) were located in the GCR-IHC on an average of 62.2% (extreme values = 25-87%) of the searches. No radio-marked lesser scaup were located outside the GCR-IHC. Lesser scaup were feeding during 23% of the radio fixes.

  1. Search for cosmogenic Ar-42 in meteorites

    NASA Astrophysics Data System (ADS)

    Cini Castagnoli, G.; Cane, D.; Taricco, C.; Bhandari, N.

    2003-04-01

    We have evidence for decreasing galactic cosmic ray (GCR) flux in the past 3 centuries by a factor about two [1]. The measurements of the activity of cosmogenic 44Ti (T1/2 = 59.2 y) produced by GCR in stony meteorites that fell during the last two centuries are in good agreement with the calculated values and validate the decreasing trend of GCR flux. The measurements were obtained by an hyperpure (372 cm3) Ge-NaI(Tl) spectrometer operating in the Monte dei Cappuccini laboratory in Torino[2]. To further improve upon statistical precision of 44Ti data and also to be able to measure the 42Ar (T1/2 = 33 y) which is produced in even smaller amounts by GCR in meteorites, we have set up in the same laboratory a larger (581 cm3) hyperpure Ge detector operating in coincidence with a 100 kg NaI(Tl) crystal assembly. This should enable us to confirm the above results about GCR variations. We wish to acknowledge our deep gratitude to professor Bonino, deceased on September 29, 2002, to whom the assemblage of the new equipment is due. [1] G. Bonino, G. Cini Castagnoli, D. Cane, C. Taricco and N. Bhandari,Proc. XXVII Intern. Cosmic Ray Conf. (Hamburg, 2001) 3769-3772. [2] Bonino G., Cini Castagnoli G., Cane D., Taricco C., Bhandari N, textit {34th COSPAR Sci. Ass. Houston 2002 (Adv. Space Res.)}, in press

  2. Interstellar propagation and electron capture processes of galactic cosmic ray heavy ions in space

    NASA Technical Reports Server (NTRS)

    Miltra, B.; Biswas, S.; Goswami, J. N.

    1995-01-01

    The new information on galactic cosmic rays (GCR) derived from the Spacelab-3 cosmic ray experiment 'Anuradha' shows that at 25-125 MeV/N GCR sub-iron and iron (Z = 21-28) particles consists of a mixture of partially ionized and fully ionized ions. Computation of electron capture and loss cross sections in hydrogen in 1-50 MeV/N energy range are made for Fe, Cr, Ti and Ni. From these it is concluded that: (1) these GCR particles must have captured orbital electrons at energies of about 1-5 MeV/N and (2) these particles are then reaccelerated to 300-500 MeV/N most probably in interstellar medium by collision with SNR shock fronts. Some reacceleration may take place also in heliospheric boundary region. It is suggested that these observations of partially ionized GCR ions of about 100 MeV/N in Spacelab-3 provide a direct evidence of reacceleration of GCR.

  3. Super-TIGER: A Balloon-Borne Instrument to Probe Galactic Cosmic Ray Origins

    NASA Astrophysics Data System (ADS)

    Rauch, Brian

    2012-07-01

    Super-TIGER (Super Trans-Iron Galactic Element Recorder) is a balloon-borne instrument under construction for a long-duration flight from Antarctica in 2012. It is designed to measure the relative abundances of the ultra-heavy (UH) Galactic cosmic rays (GCR) with individual-element resolution from _{30}Zn to _{42}Mo and make exploratory measurements through _{56}Ba, as well as the energy spectra of the GCR from _{10}Ne to _{29}Cu between 0.8 and 10 GeV/nucleon. The UH measurements will test the OB association origin model of the GCR, as well as the model of preferential acceleration of refractory elements. The GCR spectrum measurements will probe for microquasars or other sources that could superpose spectral features. Super-TIGER is a ˜ 4 × larger evolution of the preceding TIGER instrument, and is comprised of two independent modules with a total area of 5.4 m^{2}. A combination of plastic scintillation detectors, acrylic and silica-aerogel Cherenkov detectors, and scintillating fiber hodoscopes are used to resolve particle charge, kinetic energy per nucleon, and trajectory. Refinements in the Super-TIGER design over TIGER, including reduced material in the beam, give it a collecting power that is ˜ 6.4× larger. This paper will report on the instrument development status, the expected flight performance, and the scientific impact of the anticipated Super-TIGER GCR measurements. This research was supported by NASA under Grant NNX09AC17G

  4. Generation of a Chinese Hamster Ovary Cell Line Producing Recombinant Human Glucocerebrosidase

    PubMed Central

    Novo, Juliana Branco; Morganti, Ligia; Moro, Ana Maria; Paes Leme, Adriana Franco; Serrano, Solange Maria de Toledo; Raw, Isaias; Ho, Paulo Lee

    2012-01-01

    Impaired activity of the lysosomal enzyme glucocerebrosidase (GCR) results in the inherited metabolic disorder known as Gaucher disease. Current treatment consists of enzyme replacement therapy by administration of exogenous GCR. Although effective, it is exceptionally expensive, and patients worldwide have a limited access to this medicine. In Brazil, the public healthcare system provides the drug free of charge for all Gaucher's patients, which reaches the order of $ 84 million per year. However, the production of GCR by public institutions in Brazil would reduce significantly the therapy costs. Here, we describe a robust protocol for the generation of a cell line producing recombinant human GCR. The protein was expressed in CHO-DXB11 (dhfr−) cells after stable transfection and gene amplification with methotrexate. As expected, glycosylated GCR was detected by immunoblotting assay both as cell-associated (~64 and 59 kDa) and secreted (63–69 kDa) form. Analysis of subclones allowed the selection of stable CHO cells producing a secreted functional enzyme, with a calculated productivity of 5.14 pg/cell/day for the highest producer. Although being laborious, traditional methods of screening high-producing recombinant cells may represent a valuable alternative to generate expensive biopharmaceuticals in countries with limited resources. PMID:23091360

  5. Simulated Response of a Tissue-equivalent Proportional Counter on the Surface of Mars.

    PubMed

    Northum, Jeremy D; Guetersloh, Stephen B; Braby, Leslie A; Ford, John R

    2015-10-01

    Uncertainties persist regarding the assessment of the carcinogenic risk associated with galactic cosmic ray (GCR) exposure during a mission to Mars. The GCR spectrum peaks in the range of 300(-1) MeV n to 700 MeV n(-1) and is comprised of elemental ions from H to Ni. While Fe ions represent only 0.03% of the GCR spectrum in terms of particle abundance, they are responsible for nearly 30% of the dose equivalent in free space. Because of this, radiation biology studies focusing on understanding the biological effects of GCR exposure generally use Fe ions. Acting as a thin shield, the Martian atmosphere alters the GCR spectrum in a manner that significantly reduces the importance of Fe ions. Additionally, albedo particles emanating from the regolith complicate the radiation environment. The present study uses the Monte Carlo code FLUKA to simulate the response of a tissue-equivalent proportional counter on the surface of Mars to produce dosimetry quantities and microdosimetry distributions. The dose equivalent rate on the surface of Mars was found to be 0.18 Sv y(-1) with an average quality factor of 2.9 and a dose mean lineal energy of 18.4 keV μm(-1). Additionally, albedo neutrons were found to account for 25% of the dose equivalent. It is anticipated that these data will provide relevant starting points for use in future risk assessment and mission planning studies. PMID:26313586

  6. Time-dependent radiation dose simulations during interplanetary space flights

    NASA Astrophysics Data System (ADS)

    Dobynde, Mikhail; Shprits, Yuri; Drozdov, Alexander; Hoffman, Jeffrey; Li, Ju

    2016-07-01

    Space radiation is one of the main concerns in planning long-term interplanetary human space missions. There are two main types of hazardous radiation - Solar Energetic Particles (SEP) and Galactic Cosmic Rays (GCR). Their intensities and evolution depend on the solar activity. GCR activity is most enhanced during solar minimum, while the most intense SEPs usually occur during the solar maximum. SEPs are better shielded with thick shields, while GCR dose is less behind think shields. Time and thickness dependences of the intensity of these two components encourage looking for a time window of flight, when radiation intensity and dose of SEP and GCR would be minimized. In this study we combine state-of-the-art space environment models with GEANT4 simulations to determine the optimal shielding, geometry of the spacecraft, and launch time with respect to the phase of the solar cycle. The radiation environment was described by the time-dependent GCR model, and the SEP spectra that were measured during the period from 1990 to 2010. We included gamma rays, electrons, neutrons and 27 fully ionized elements from hydrogen to nickel. We calculated the astronaut's radiation doses during interplanetary flights using the Monte-Carlo code that accounts for the primary and the secondary radiation. We also performed sensitivity simulations for the assumed spacecraft size and thickness to find an optimal shielding. In conclusion, we present the dependences of the radiation dose as a function of launch date from 1990 to 2010, for flight durations of up to 3 years.

  7. Study the effect of gray component replacement level on reflectance spectra and color reproduction accuracy

    NASA Astrophysics Data System (ADS)

    Spiridonov, I.; Shopova, M.; Boeva, R.

    2013-03-01

    The aim of this study is investigation of gray component replacement (GCR) levels on reflectance spectrum for different overprints of the inks and color reproduction accuracy. The most commonly implemented method in practice for generation of achromatic composition is gray component replacement (GCR). The experiments in this study, have been performed in real production conditions with special test form generated by specialized software. The measuring of reflection spectrum of printed colors, gives a complete conception for the effect of different gray component replacement levels on color reproduction accuracy. For better data analyses and modeling of processes, we have calculated (converted) the CIEL*a*b* color coordinates from the reflection spectra data. The assessment of color accuracy by using different GCR amount has been made by calculation of color difference ΔE* ab. In addition for the specific printing conditions we have created ICC profiles with different GCR amounts. A comparison of the color gamuts has been performed. For a first time a methodology is implemented for examination and estimation of effect of GCR levels on color reproduction accuracy by studying a big number of colors in entire visible spectrum. Implementation in practice of the results achieved in this experiment, will lead to improved gray balance and better color accuracy. Another important effect of this research is reduction of financial costs of printing production by decreasing of ink consumption, indirect reduction of emissions during the manufacture of inks and facilitates the process of deinking during the recycling paper.

  8. Neutron yields and effective doses produced by Galactic Cosmic Ray interactions in shielded environments in space.

    PubMed

    Heilbronn, Lawrence H; Borak, Thomas B; Townsend, Lawrence W; Tsai, Pi-En; Burnham, Chelsea A; McBeth, Rafe A

    2015-11-01

    In order to define the ranges of relevant neutron energies for the purposes of measurement and dosimetry in space, we have performed a series of Monte Carlo transport model calculations that predict the neutron field created by Galactic Cosmic Ray interactions inside a variety of simple shielding configurations. These predictions indicate that a significant fraction of the neutron fluence and neutron effective dose lies in the region above 20 MeV up to several hundred MeV. These results are consistent over thicknesses of shielding that range from very thin (2.7 g/cm(2)) to thick (54 g/cm(2)), and over both shielding materials considered (aluminum and water). In addition to these results, we have also investigated whether simplified Galactic Cosmic Ray source terms can yield predictions that are equivalent to simulations run with a full GCR source term. We found that a source using a GCR proton and helium spectrum together with a scaled oxygen spectrum yielded nearly identical results to a full GCR spectrum, and that the scaling factor used for the oxygen spectrum was independent of shielding material and thickness. Good results were also obtained using a GCR proton spectrum together with a scaled helium spectrum, with the helium scaling factor also independent of shielding material and thickness. Using a proton spectrum alone was unable to reproduce the full GCR results. PMID:26553642

  9. Mars surface radiation exposure for solar maximum conditions and 1989 solar proton events.

    NASA Astrophysics Data System (ADS)

    Simonsen, L. C.; Nealy, J. E.

    1993-02-01

    The Langley heavy-ion/nucleon and the high-energy nucleon transport codes are used to predict the propagation of galactic cosmic rays (GCR's) and solar flare protons through the carbon dioxide atmosphere of Mars. Particle fluences and the resulting doses are estimated on the surface of Mars for GCR's during solar maximum conditions and the August, September, and October 1989 solar proton events. Surface doses are estimated with both a low-density and a high-density carbon dioxide model of the atmosphere for altitudes of 0, 4, 8, and 12 km above the surface. A solar modulation function is incorporated to estimate the GCR dose variation between solar minimum and maximum conditions over the 11-year solar cycle. By using current Mars mission scenarios, doses to the skin, eye, and blood-forming organs are predicted for short- and long-duration stay times on the Martian surface throughout the solar cycle.

  10. Cellular track model of biological damage to mammalian cell cultures from galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Katz, Robert; Wilson, John W.; Townsend, Lawrence W.; Nealy, John E.; Shinn, Judy L.

    1991-01-01

    The assessment of biological damage from the galactic cosmic rays (GCR) is a current interest for exploratory class space missions where the highly ionizing, high-energy, high-charge ions (HZE) particles are the major concern. The relative biological effectiveness (RBE) values determined by ground-based experiments with HZE particles are well described by a parametric track theory of cell inactivation. Using the track model and a deterministic GCR transport code, the biological damage to mammalian cell cultures is considered for 1 year in free space at solar minimum for typical spacecraft shielding. Included are the effects of projectile and target fragmentation. The RBE values for the GCR spectrum which are fluence-dependent in the track model are found to be more severe than the quality factors identified by the International Commission on Radiological Protection publication 26 and seem to obey a simple scaling law with the duration period in free space.

  11. A genetic network that suppresses genome rearrangements in Saccharomyces cerevisiae and contains defects in cancers.

    PubMed

    Putnam, Christopher D; Srivatsan, Anjana; Nene, Rahul V; Martinez, Sandra L; Clotfelter, Sarah P; Bell, Sara N; Somach, Steven B; E S de Souza, Jorge; Fonseca, André F; de Souza, Sandro J; Kolodner, Richard D

    2016-01-01

    Gross chromosomal rearrangements (GCRs) play an important role in human diseases, including cancer. The identity of all Genome Instability Suppressing (GIS) genes is not currently known. Here multiple Saccharomyces cerevisiae GCR assays and query mutations were crossed into arrays of mutants to identify progeny with increased GCR rates. One hundred eighty two GIS genes were identified that suppressed GCR formation. Another 438 cooperatively acting GIS genes were identified that were not GIS genes, but suppressed the increased genome instability caused by individual query mutations. Analysis of TCGA data using the human genes predicted to act in GIS pathways revealed that a minimum of 93% of ovarian and 66% of colorectal cancer cases had defects affecting one or more predicted GIS gene. These defects included loss-of-function mutations, copy-number changes associated with reduced expression, and silencing. In contrast, acute myeloid leukaemia cases did not appear to have defects affecting the predicted GIS genes. PMID:27071721

  12. A genetic network that suppresses genome rearrangements in Saccharomyces cerevisiae and contains defects in cancers

    PubMed Central

    Putnam, Christopher D.; Srivatsan, Anjana; Nene, Rahul V.; Martinez, Sandra L.; Clotfelter, Sarah P.; Bell, Sara N.; Somach, Steven B.; E.S. de Souza, Jorge; Fonseca, André F.; de Souza, Sandro J.; Kolodner, Richard D.

    2016-01-01

    Gross chromosomal rearrangements (GCRs) play an important role in human diseases, including cancer. The identity of all Genome Instability Suppressing (GIS) genes is not currently known. Here multiple Saccharomyces cerevisiae GCR assays and query mutations were crossed into arrays of mutants to identify progeny with increased GCR rates. One hundred eighty two GIS genes were identified that suppressed GCR formation. Another 438 cooperatively acting GIS genes were identified that were not GIS genes, but suppressed the increased genome instability caused by individual query mutations. Analysis of TCGA data using the human genes predicted to act in GIS pathways revealed that a minimum of 93% of ovarian and 66% of colorectal cancer cases had defects affecting one or more predicted GIS gene. These defects included loss-of-function mutations, copy-number changes associated with reduced expression, and silencing. In contrast, acute myeloid leukaemia cases did not appear to have defects affecting the predicted GIS genes. PMID:27071721

  13. A model of galactic cosmic rays for use in calculating linear energy transfer spectra

    NASA Technical Reports Server (NTRS)

    Chen, J.; Chenette, D.; Clark, R.; Garcia-Munoz, M.; Guzik, T. G.; Pyle, K. R.; Sang, Y.; Wefel, J. P.

    1994-01-01

    The Galactic Cosmic Rays (GCR) contain fully stripped nuclei, from Hydrogen to beyond the Iron group, accelerated to high energies and are a major component of the background radiation encountered by satellites and interplanetary spacecraft. This paper presents a GCR model which is based upon our current understanding of the astrophysics of GCR transport through interstellar and interplanetary space. The model can be used to predict the energy spectra for all stable and long-lived radioactive species from H to Ni over an energy range from 50 to 50,000 MeV/nucleon as a function of a single parameter, the solar modulation level phi. The details of this model are summarized, phi is derived for the period 1974 to present, and results from this model during the 1990/1991 Combined Release and Radiation Effects Satellite (CRRES) mission are presented.

  14. Experimental Plans for Subsystems of a Shock Wave Driven Gas Core Reactor

    NASA Technical Reports Server (NTRS)

    Kazeminezhad, F.; Anghai, S.

    2008-01-01

    This Contractor Report proposes a number of plans for experiments on subsystems of a shock wave driven pulsed magnetic induction gas core reactor (PMI-GCR, or PMD-GCR pulsed magnet driven gas core reactor). Computer models of shock generation and collision in a large-scale PMI-GCR shock tube have been performed. Based upon the simulation results a number of issues arose that can only be addressed adequately by capturing experimental data on high pressure (approx.1 atmosphere or greater) partial plasma shock wave effects in large bore shock tubes ( 10 cm radius). There are three main subsystems that are of immediate interest (for appraisal of the concept viability). These are (1) the shock generation in a high pressure gas using either a plasma thruster or pulsed high magnetic field, (2) collision of MHD or gas dynamic shocks, their interaction time, and collision pile-up region thickness, and (3) magnetic flux compression power generation (not included here).

  15. Stopping powers and cross sections due to two-photon processes in relativistic nucleus-nucleus collision

    NASA Technical Reports Server (NTRS)

    Cheung, Wang K.; Norbury, John W.

    1992-01-01

    The radiation dose received from high energy galactic cosmic rays (GCR) is a limiting factor in the design of long duration space flights and the building of lunar and martian habitats. It is of vital importance to have an accurate understanding of the interactions of GCR in order to assess the radiation environment that the astronauts will be exposed to. Although previous studies have concentrated on the strong interaction process in GCR, there are also very large effects due to electromagnetic (EM) interactions. In this report we describe our first efforts at understanding these EM production processes due to two-photon collisions. More specifically, we shall consider particle production processes in relativistic heavy ion collisions (RHICs) through two-photon exchange.

  16. Revised Production Rates for Na-22 and Mn-54 in Meteorites Using Cross Sections Measured for Neutron-induced Reactions

    NASA Technical Reports Server (NTRS)

    Sisterson, J. M.; Kim, K. J.; Reedy, R. C.

    2004-01-01

    The interactions of galactic cosmic rays (GCR) with extraterrestrial bodies produce small amounts of radionuclides and stable isotopes. The production rates of many relatively short-lived radionuclides, including 2.6-year Na-22 and 312-day Mn-54, have been measured in several meteorites collected very soon after they fell. Theoretical models used to calculate production rates for comparison with the measured values rely on input data containing good cross section measurements for all relevant reactions. Most GCR particles are protons, but secondary neutrons make most cosmogenic nuclides. Calculated production rates using only cross sections for proton-induced reactions do not agree well with measurements. One possible explanation is that the contribution to the production rate from reactions initiated by secondary neutrons produced in primary GCR interactions should be included explicitly. This, however, is difficult to do because so few of the relevant cross sections for neutron-induced reactions have been measured.

  17. Updated Computational Model of Cosmic Rays Near Earth

    NASA Technical Reports Server (NTRS)

    ONeill, Patrick M.

    2006-01-01

    An updated computational model of the galactic-cosmic-ray (GCR) environment in the vicinity of the Earth, Earth s Moon, and Mars has been developed, and updated software has been developed to implement the updated model. This model accounts for solar modulation of the cosmic-ray contribution for each element from hydrogen through iron by computationally propagating the local interplanetary spectrum of each element through the heliosphere. The propagation is effected by solving the Fokker-Planck diffusion, convection, energy-loss boundary-value problem. The Advanced Composition Explorer NASA satellite has provided new data on GCR energy spectra. These new data were used to update the original model and greatly improve the accuracy of prediction of interplanetary GCR.

  18. Implications of the observations of partially ionised states in the low energy galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Mitra, Banashree; Biswas, S.; Durgaprasad, N.; Dutta, A.; Goswami, J. N.; Ramadurai, S.

    1991-01-01

    Of the low energy (30-100 MeV/N)Fe-group nuclei of Galactic cosmic rays (GCRs) a fraction of about 20 percent of these are in partially ionized states. The origin of these particles are not known at present. From the considerations of relevant cross-sections, the following two important processes of the phenomena are given: (1) these GCR Fe-group nuclei must have captured the orbital electrons at energies of 1-5 MeV/N, while traversing matter; and (2) that these GCR ions of 1-5 MeV/N are then reaccelerated to energies of at least 30-100 MeV/N, most probably in the heliospheric boundary region. Three possible scenarios of the electron-capture processes are briefly discussed: (1) electron capture in a large molecular cloud; (2) GCR equilibrium spectra in ISM and their equilibrium charge; and (3) electron capture in the Oort's cloud.

  19. Modulation of UK lightning by heliospheric magnetic field polarity

    NASA Astrophysics Data System (ADS)

    Owens, M. J.; Scott, C. J.; Lockwood, M.; Barnard, L.; Harrison, R. G.; Nicoll, K.; Watt, C.; Bennett, A. J.

    2014-11-01

    Observational studies have reported solar magnetic modulation of terrestrial lightning on a range of time scales, from days to decades. The proposed mechanism is two-step: lightning rates vary with galactic cosmic ray (GCR) flux incident on Earth, either via changes in atmospheric conductivity and/or direct triggering of lightning. GCR flux is, in turn, primarily controlled by the heliospheric magnetic field (HMF) intensity. Consequently, global changes in lightning rates are expected. This study instead considers HMF polarity, which doesn't greatly affect total GCR flux. Opposing HMF polarities are, however, associated with a 40-60% difference in observed UK lightning and thunder rates. As HMF polarity skews the terrestrial magnetosphere from its nominal position, this perturbs local ionospheric potential at high latitudes and local exposure to energetic charged particles from the magnetosphere. We speculate as to the mechanism(s) by which this may, in turn, redistribute the global location and/or intensity of thunderstorm activity.

  20. Modulation of UK lightning and the atmospheric electric circuit by heliospheric magnetic field polarity

    NASA Astrophysics Data System (ADS)

    Owens, Mathew; Scott, Chris; Lockwood, Mike; Barnard, Luke; Harrison, Giles; Nicoll, Keri; Watt, Clare; Bennett, Alec

    2015-04-01

    Observational studies have reported solar magnetic modulation of terrestrial lightning on a range of time scales, from days to decades. The proposed mechanism is two-step: lightning rates vary with galactic cosmic ray (GCR) flux incident on Earth, either via changes in atmospheric conductivity and/or direct triggering of lightning. GCR flux is, in turn, primarily controlled by the heliospheric magnetic field (HMF) intensity. Consequently, global changes in lightning rates are expected. This study instead considers HMF polarity, which doesn't greatly affect total GCR flux. Opposing HMF polarities are, however, associated with a 40 to 60% difference in observed UK lightning and thunder rates. As HMF polarity skews the terrestrial magnetosphere from its nominal position, this perturbs local ionospheric potential at high latitudes and local exposure to energetic charged particles from the magnetosphere. We speculate as to the mechanism(s) by which this may, in turn, redistribute the global location and/or intensity of thunderstorm activity.

  1. Solar flare neon and solar cosmic ray fluxes in the past using gas-rich meteorites

    NASA Technical Reports Server (NTRS)

    Nautiyal, C. M.; Rao, M. N.

    1986-01-01

    Methods were developed earlier to deduce the composition of solar flare neon and to determine the solar cosmic ray proton fluxes in the past using etched lunar samples and at present, these techniques are extended to gas rich meteorites. By considering high temperature Ne data points for Pantar, Fayetteville and other gas rich meteorites and by applying the three component Ne-decomposition methods, the solar cosmic ray and galactic cosmic ray produced spallation Ne components from the trapped SF-Ne was resolved. Using appropiate SCR and GCR production rates, in the case of Pantar, for example, a GCR exposure age of 2 m.y. was estimated for Pantar-Dark while Pantar-Light yielded a GCR age of approx. 3 m.y. However the SCR exposure age of Pantar-Dark is two orders of magnitude higher than the average surface exposure ages of lunar soils. The possibility of higher proton fluxes in the past is discussed.

  2. Radiation shielding requirements for manned deep space missions

    SciTech Connect

    Santoro, R.T.; Ingersoll, D.T.

    1991-04-01

    Galactic cosmic rays (GCR) and, particularly, solar flares (SF) constitute the major radiation hazards in deep space. The dose to astronauts from these radiation sources and the shielding required to mitigate its effect during a 480 day Mars mission is estimated here for a simplistic spacecraft geometry. The intent is to ball park'' the magnitude of the doses for the constant GCR background and for SF's that occur randomly during the mission. The spacecraft shielding and dose data are given only for primary GCR and SF radiation, recognizing that secondary particles produced by primary particle reactions in the spacecraft and High Z-High Energy particles will also contribute to the dose suffered by the astronauts. 22 refs., 7 figs., 2 tabs.

  3. The Development of Materials for Structures and Radiation Shielding in Aerospace

    NASA Technical Reports Server (NTRS)

    Kiefer, Richard L.; Orwoll, Robert A.

    2001-01-01

    Polymeric materials on space vehicles and high-altitude aircraft win be exposed to highly penetrating radiations. These radiations come from solar flares and galactic cosmic rays (GCR). Radiation from solar flares consists primarily of protons with energies less than 1 GeV. On the other hand, GCR consist of nuclei with energies as high as 10(exp 10) GeV. Over 90% of the nuclei in GCR are protons and alpha particles, however there is a small but significant component of particles with atomic numbers greater than ten. Particles with high atomic number (Z) and high energy interact with very high specific ionization and thus represent a serious hazard for humans and electronic equipment on a spacecraft or on high-altitude commercial aircraft (most importantly for crew members who would have long exposures). Neutrons generated by reactions with the high energy particles also represent a hazard both for humans and electronic equipment.

  4. Occurrence of Antimicrobial-Resistant Escherichia coli and Salmonella enterica in the Beef Cattle Production and Processing Continuum.

    PubMed

    Schmidt, John W; Agga, Getahun E; Bosilevac, Joseph M; Brichta-Harhay, Dayna M; Shackelford, Steven D; Wang, Rong; Wheeler, Tommy L; Arthur, Terrance M

    2015-01-01

    Specific concerns have been raised that third-generation cephalosporin-resistant (3GC(r)) Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COT(r)) E. coli, 3GC(r) Salmonella enterica, and nalidixic acid-resistant (NAL(r)) S. enterica may be present in cattle production environments, persist through beef processing, and contaminate final products. The prevalences and concentrations of these organisms were determined in feces and hides (at feedlot and processing plant), pre-evisceration carcasses, and final carcasses from three lots of fed cattle (n = 184). The prevalences and concentrations were further determined for strip loins from 103 of the carcasses. 3GC(r) Salmonella was detected on 7.6% of hides during processing and was not detected on the final carcasses or strip loins. NAL(r) S. enterica was detected on only one hide. 3GC(r) E. coli and COT(r) E. coli were detected on 100.0% of hides during processing. Concentrations of 3GC(r) E. coli and COT(r) E. coli on hides were correlated with pre-evisceration carcass contamination. 3GC(r) E. coli and COT(r) E. coli were each detected on only 0.5% of final carcasses and were not detected on strip loins. Five hundred and 42 isolates were screened for extraintestinal pathogenic E. coli (ExPEC) virulence-associated markers. Only two COT(r) E. coli isolates from hides were ExPEC, indicating that fed cattle products are not a significant source of ExPEC causing human urinary tract infections. The very low prevalences of these organisms on final carcasses and their absence on strip loins demonstrate that current sanitary dressing procedures and processing interventions are effective against antimicrobial-resistant bacteria. PMID:25398858

  5. North-south component of galactic cosmic ray anisotropy at 1 AU

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    2015-12-01

    The galactic cosmic ray (GCR) solar diurnal anisotropy (SDA) may be represented by a vector (A; Ar, Aφ, Aθ) in a spherical polar coordinate system centered on the sun. We reported (elsewhere) the results of a detailed study of time variations of yearly radial (Ar) and east-west (Aφ) components recorded by the global network of the neutron monitors (NMs) with a long track record for 1963-2013, for four sunspot number (SSN) cycles (20-23) and the rising phase of cycle 24. A powerful new technique is used to compute and study time variations of the transverse component (Aθ) due to off-ecliptic GCR contributions, with the same NM data; GCR radial particle density gradient (Gr) drives all three components. The north-south anisotropy (Aθ) is computed from yearly NM data (Gϕ = 0), a flat heliospheric current sheet (HCS) model and the concept of GCR isotropic hard sphere scattering in the solar wind plasma. Relationships to SSN, rigidity and solar polarity intervals are studied. For a positive (p-) polarity the solar magnetic field in the northern hemisphere points outward and GCRs drift from polar regions toward equatorial plane and out along HCS, setting up a symmetric gradient (Gθs) pointing away from HCS (there is a local GCR density minimum on HCS); for n-polarity interval Gθs points towards HCS (there is a local GCR density maximum on HCS). Also, there exists a heliospheric asymmetric density gradient (Gθa) perpendicular to the ecliptic plane, it is the main contributor to Aθ for the period of our analysis. This is the most interesting and significant insight.

  6. Near-Earth Cosmic Ray Decreases Associated with Remote Coronal Mass Ejection

    NASA Astrophysics Data System (ADS)

    Thomas, Simon; Owens, Mathew; Lockwood, Mike; Barnard, Luke; Scott, Chris; Owen, Chris

    2015-04-01

    Galactic cosmic ray (GCR) flux is modulated by both particle drift patterns and solar wind structures on a range of time scales. Over solar cycles, GCR flux varies as a function of the total open solar magnetic flux and the latitudinal extent of the heliospheric current sheet. Over time-scales of hours, drops of a few percent in near-Earth GCR flux (Forbush decreases, FDs) are well known to be associated with the near-Earth passage of solar wind structures resulting from corotating interaction regions (CIRs) and transient coronal mass ejections (CMEs). We present four FDs seen at ground-based neutron monitors which cannot be immediately associated with significant structures in the local solar wind. Similarly, there are significant near-Earth structures which do not produce any corresponding GCR variation. Three of the FDs are shown to be during the STEREO era, enabling in-situ and remote observations from three well-separated heliospheric locations. Extremely large CMEs passed the STEREO-A spacecraft, which was behind the West limb of the Sun, approximately 2-3 days before each near-Earth FD. Solar wind simulations suggest that the CMEs combined with pre-existing CIRs, enhancing the pre-existing barriers to GCR propagation. These events are compared to the well-documented extreme event of July 2012 as a good comparison. Our observations provide strong evidence for the modulation of GCR flux by remote solar wind structures and a potential to detect these remote structures using neutron monitor data.

  7. An Improved Analytic Model for Microdosimeter Response

    NASA Technical Reports Server (NTRS)

    Shinn, Judy L.; Wilson, John W.; Xapsos, Michael A.

    2001-01-01

    An analytic model used to predict energy deposition fluctuations in a microvolume by ions through direct events is improved to include indirect delta ray events. The new model can now account for the increase in flux at low lineal energy when the ions are of very high energy. Good agreement is obtained between the calculated results and available data for laboratory ion beams. Comparison of GCR (galactic cosmic ray) flux between Shuttle TEPC (tissue equivalent proportional counter) flight data and current calculations draws a different assessment of developmental work required for the GCR transport code (HZETRN) than previously concluded.

  8. Twenty years of space radiation physics at the BNL AGS and NASA Space Radiation Laboratory.

    PubMed

    Miller, J; Zeitlin, C

    2016-06-01

    Highly ionizing atomic nuclei HZE in the GCR will be a significant source of radiation exposure for humans on extended missions outside low Earth orbit. Accelerators such as the LBNL Bevalac and the BNL AGS, designed decades ago for fundamental nuclear and particle physics research, subsequently found use as sources of GCR-like particles for ground-based physics and biology research relevant to space flight. The NASA Space Radiation Laboratory at BNL was constructed specifically for space radiation research. Here we review some of the space-related physics results obtained over the first 20 years of NASA-sponsored research at Brookhaven. PMID:27345198

  9. Twenty years of space radiation physics at the BNL AGS and NASA Space Radiation Laboratory

    NASA Astrophysics Data System (ADS)

    Miller, J.; Zeitlin, C.

    2016-06-01

    Highly ionizing atomic nuclei HZE in the GCR will be a significant source of radiation exposure for humans on extended missions outside low Earth orbit. Accelerators such as the LBNL Bevalac and the BNL AGS, designed decades ago for fundamental nuclear and particle physics research, subsequently found use as sources of GCR-like particles for ground-based physics and biology research relevant to space flight. The NASA Space Radiation Laboratory at BNL was constructed specifically for space radiation research. Here we review some of the space-related physics results obtained over the first 20 years of NASA-sponsored research at Brookhaven.

  10. Accelerator experiments on the contribution of secondary particles to the production of cosmogenic nuclides in meteorites

    NASA Technical Reports Server (NTRS)

    Dragovitsch, P.; Englert, P.

    1985-01-01

    Through the interaction of galactic cosmic particle radiation (GCR) a wide variety of cosmogenic nuclides is produced in meteorites. They provide historical information about the cosmic radiation and the bombarded meteorites. An important way to understand the production mechanisms of cosmogenic nuclides in meteorites is to gather information about the depth and size dependence of the build-up of Galactic Rays Cosmic-secondary particles within meteorites of different sizes and chemical compositions. Simulation experiments with meteorite models offer an alternative to direct observation providing a data basis to describe the development and action of the secondary cascade induced by the GCR in meteorites.

  11. Modeling and Experimental Study of Forbush Effects of Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Alania, Michael V.; Szabelski, J.; Wawrzynczak, A.

    2003-07-01

    temporal changes of the rigidity spectrum of the sporadic and recurrent Forbush effects of galactic cosmic rays (GCR) have been studied using neutron monitors data. An attempt to find a relationship between the rigidity spectrum exponent γ of the Forbush effects (δD/D(R) ∝ R-γ , where R is the rigidity of GCR particles) and an exponent ν of the power spectral density (PSD) of the fluctuations of the strength of the interplanetary magnetic field (IMF) (PSD ∝ f-ν , where f is the frequency) has been made. EXPERIMENTAL DATA AND METHOD OF INVESTIGATION. An attempt to find a relationship between the rigidity spectrum exponent γ of the Forbush effects [1] (δ D/D(R) ∝ R-γ , where R is the rigidity of GCR particles) and an exponent ν of the PSD of the fluctuations of the strength of the IMF has been made. Data of neutron super monitors and the IMF's Bx , By , and Bz components have been used to study peculiarities of two great sporadic Forbush effects (9-23 July 1982 and 9-29 July 2000) and one recurrent Forbush effect of the 1-16 September 1996 (figures 1ab c). It is well known that one of the ma jor parameters for the characterizing of the Forbush effects of GCR is the rigidity spectrum of the GCR intensity variations, hereafter called the rigidity spectrum of Forbush effect (δ D(R)/D(R ) = A R-γ , where R is the rigidity of GCR particles and A is the power). The rigidity spectrum of the Forbush effects has been calculated using the data of neutron super monitors and the method presented, e.g. in [2,3]. There was assumed: δ D(R)/D(R) = A R-γ for R≤Rmax . And δ D(R)/D(R) = 0 for R>Rmax. Here Rmax is the upper limiting rigidity beyond which the Forbush effect of GCR intensity vanishes. Results of calculations of γ based on daily means of data for the sporadic Forbush effects, 9-23 July 1982 (14 stations), 9-29 July 2000 (11 stations) and for the recurrent Forbush effect of 1-16 September 1996 (7 stations) are presented in the figures 1def. RESULTS

  12. Issues in deep space radiation protection.

    PubMed

    Wilson, J W; Shinn, J L; Tripathi, R K; Singleterry, R C; Clowdsley, M S; Thibeault, S A; Cheatwood, F M; Schimmerling, W; Cucinotta, F A; Badhwar, G D; Noor, A K; Kim, M Y; Badavi, F F; Heinbockel, J H; Miller, J; Zeitlin, C; Heilbronn, L

    2001-01-01

    The exposures in deep space are largely from the Galactic Cosmic Rays (GCR) for which there is as yet little biological experience. Mounting evidence indicates that conventional linear energy transfer (LET) defined protection quantities (quality factors) may not be appropriate for GCR ions. The available biological data indicates that aluminum alloy structures may generate inherently unhealthy internal spacecraft environments in the thickness range for space applications. Methods for optimization of spacecraft shielding and the associated role of materials selection are discussed. One material which may prove to be an important radiation protection material is hydrogenated carbon nanofibers. PMID:11669118

  13. Badhwar-O'Neill 2011 Galactic Cosmic Ray Model Update and Future Improvements

    NASA Technical Reports Server (NTRS)

    O'Neill, Pat M.; Kim, Myung-Hee Y.

    2014-01-01

    The Badhwar-O'Neill Galactic Cosmic Ray (GCR) Model based on actual GR measurements is used by deep space mission planners for the certification of micro-electronic systems and the analysis of radiation health risks to astronauts in space missions. The BO GCR Model provides GCR flux in deep space (outside the earth's magnetosphere) for any given time from 1645 to present. The energy spectrum from 50 MeV/n-20 GeV/n is provided for ions from hydrogen to uranium. This work describes the most recent version of the BO GCR model (BO'11). BO'11 determines the GCR flux at a given time applying an empirical time delay function to past sunspot activity. We describe the GCR measurement data used in the BO'11 update - modern data from BESS, PAMELA, CAPRICE, and ACE emphasized for than the older balloon data used for the previous BO model (BO'10). We look at the GCR flux for the last 24 solar minima and show how much greater the flux was for the cycle 24 minimum in 2010. The BO'11 Model uses the traditional, steady-state Fokker-Planck differential equation to account for particle transport in the heliosphere due to diffusion, convection, and adiabatic deceleration. It assumes a radially symmetrical diffusion coefficient derived from magnetic disturbances caused by sunspots carried onward by a constant solar wind. A more complex differential equation is now being tested to account for particle transport in the heliosphere in the next generation BO model. This new model is time-dependent (no longer a steady state model). In the new model, the dynamics and anti-symmetrical features of the actual heliosphere are accounted for so empirical time delay functions will no longer be required. The new model will be capable of simulating the more subtle features of modulation - such as the Sun's polarity and modulation dependence on the gradient and curvature drift. This improvement is expected to significantly improve the fidelity of the BO GCR model. Preliminary results of its

  14. Issues in deep space radiation protection

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Shinn, J. L.; Tripathi, R. K.; Singleterry, R. C.; Clowdsley, M. S.; Thibeault, S. A.; Cheatwood, F. M.; Schimmerling, W.; Cucinotta, F. A.; Badhwar, G. D.; Noor, A. K.; Kim, M. Y.; Badavi, F. F.; Heinbockel, J. H.; Miller, J.; Zeitlin, C.; Heilbronn, L.

    2001-01-01

    The exposures in deep space are largely from the Galactic Cosmic Rays (GCR) for which there is as yet little biological experience. Mounting evidence indicates that conventional linear energy transfer (LET) defined protection quantities (quality factors) may not be appropriate for GCR ions. The available biological data indicates that aluminum alloy structures may generate inherently unhealthy internal spacecraft environments in the thickness range for space applications. Methods for optimization of spacecraft shielding and the associated role of materials selection are discussed. One material which may prove to be an important radiation protection material is hydrogenated carbon nanofibers. c 2001. Elsevier Science Ltd. All rights reserved.

  15. Preparing nurses to use standardized nursing language in the electronic health record.

    PubMed

    Müller-Staub, Maria

    2009-01-01

    Research demonstrated nurses' education needs to be able to document nursing diagnoses, interventions and patient outcomes in the EHR. The aim of this study is to investigate the effect of Guided Clinical Reasoning, a learning method to foster nurses' abilities in using standardized language. In a cluster randomized experimental study, nurses from 3 wards received Guided Clinical Reasoning (GCR), a learning method to foster nurses in stating nursing diagnoses, related interventions and outcomes. Three wards, receiving Classic Case Discussions, functioned as control group. The learning effect was measured by assessing the quality of 225 nursing documentations by applying 18 Likert-type items with a 0-4 scale of the measurement instrument "Quality of Nursing Diagnoses, Interventions and Outcomes" (Q-DIO). T-tests were applied to analyze pre-post intervention scores. GCR led to significantly higher quality of nursing diagnosis documentation; to etiology-specific nursing interventions and to enhanced nursing-sensitive patient outcomes. Before GCR, the pre-intervention mean in quality of nursing documentation was = 2.69 (post-intervention = 3.70; p<.0001). Similar results were found for nursing interventions and outcomes. In the control group, the quality remained unchanged. GCR supported nurses' abilities to state accurate nursing diagnoses, to select effective nursing interventions and to reach enhanced patient outcomes. Nursing diagnoses (NANDA-I) with related interventions and patient outcomes provide a knowledgebase for nurses to use standardized language in the EHR. PMID:19592861

  16. The Phosphorus, Sulfur, Argon, and Calcium Isotopic Composition of the Galactic Cosmic Ray Source

    NASA Astrophysics Data System (ADS)

    Ogliore, R. C.; Stone, E. C.; Leske, R. A.; Mewaldt, R. A.; Wiedenbeck, M. E.; Binns, W. R.; Israel, M. H.; von Rosenvinge, T. T.; de Nolfo, G. A.; Moskalenko, I. V.

    2009-04-01

    Galactic cosmic ray (GCR) measurements of the phosphorus, sulfur, argon, and calcium isotopes made by the Cosmic Ray Isotope Spectrometer aboard the Advanced Composition Explorer are reported over the energy range from ~100 to ~400 MeV nucleon-1. The propagation of cosmic rays through the Galaxy and heliosphere is modeled with constraints imposed by measurements. Isotopic source abundance ratios 31P/32S, 34S/32S, 38Ar/36Ar, and 44Ca/40Ca are deduced. The derived 31P/32S ratio is 2.34 ± 0.34 times larger than the solar system value, lending further credence to the suggestion that refractory elements are enriched in the GCRs due to the sputtering of ions off grains in the cores of superbubbles. By determining the GCR source abundances of argon (a noble gas) and calcium (a refractory), it is determined that material in grains is accelerated to GCR energies a factor of 6.4 ± 0.3 more efficiently than gas-phase material in this charge range. With this information, the dust fraction of phosphorus and sulfur in the interstellar material that is mixed with stellar ejecta to form the GCR seed material is found to be consistent with astronomical observations.

  17. Commitment Predictors: Long-Distance versus Geographically Close Relationships

    ERIC Educational Resources Information Center

    Pistole, M. Carole; Roberts, Amber; Mosko, Jonathan E.

    2010-01-01

    In this web-based study, the authors examined long-distance relationships (LDRs) and geographically close relationships (GCRs). Two hierarchical multiple regressions (N = 138) indicated that attachment predicted LDR and GCR commitment in Step 1. Final equations indicated that high satisfaction and investments predicted LDR commitment, whereas low…

  18. Mars surface radiation exposure for solar maximum conditions and 1989 solar proton events

    NASA Astrophysics Data System (ADS)

    Simonsen, Lisa C.; Nealy, John E.

    1992-02-01

    The Langley heavy-ion/nucleon transport code, HZETRN, and the high-energy nucleon transport code, BRYNTRN, are used to predict the propagation of galactic cosmic rays (GCR's) and solar flare protons through the carbon dioxide atmosphere of Mars. Particle fluences and the resulting doses are estimated on the surface of Mars for GCR's during solar maximum conditions and the Aug., Sep., and Oct. 1989 solar proton events. These results extend previously calculated surface estimates for GCR's at solar minimum conditions and the Feb. 1956, Nov. 1960, and Aug. 1972 solar proton events. Surface doses are estimated with both a low-density and a high-density carbon dioxide model of the atmosphere for altitudes of 0, 4, 8, and 12 km above the surface. A solar modulation function is incorporated to estimate the GCR dose variation between solar minimum and maximum conditions over the 11-year solar cycle. By using current Mars mission scenarios, doses to the skin, eye, and blood-forming organs are predicted for short- and long-duration stay times on the Martian surface throughout the solar cycle.

  19. How Galactic Cosmic Ray models affect the estimation of radiation exposure in space

    NASA Astrophysics Data System (ADS)

    Mrigakshi, Alankrita Isha; Matthiä, Daniel; Berger, Thomas; Reitz, Günther; Wimmer-Schweingruber, Robert F.

    2013-03-01

    The radiation environment in space is a major concern for human spaceflight because of the adverse effects of high levels of radiation on astronauts' health. Therefore, it is essential to perform radiation risk assessments already during the concept studies of a manned mission. Galactic Cosmic Rays (GCR) have been identified to be one of the primary sources of radiation exposure in space.This work presents an evaluation of the radiation exposure caused by GCR between 1970 and 2011 in near-Earth interplanetary space and at the orbit of the International Space Station (ISS) by making numerical simulations with the Monte-Carlo framework GEANT4. Commonly used GCR models - CREME96, CREME2009 and Badhwar-O'Neill2010 are used to describe the GCR spectra and the differences arising from the application of these different models in terms of absorbed dose and dose equivalent rates are investigated. Additionally, the depth distribution of the dose quantities and the relative contribution of particles with different energies to the total exposure during solar maximum and minimum conditions are studied.The differences in the spectra, described by the models, result in considerable differences in the estimation of the radiation exposure.

  20. Impact of Consciousness-Raising Activities on Young English Language Learners' Grammar Performance

    ERIC Educational Resources Information Center

    Fatemipour, Hamidreza; Hemmati, Shiva

    2015-01-01

    Grammar Consciousness-Raising (GCR) is an approach to teaching of grammar which learners instead of being taught the given rules, experience language data. The data challenge them to rethink, restructure their existing mental grammar and construct an explicit rule to describe the grammatical feature which the data illustrate (Ellis, 2002). And…

  1. Managing Lunar and Mars Mission Radiation Risks. Part 1; Cancer Risks, Uncertainties, and Shielding Effectiveness

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Kim, Myung-Hee Y.; Ren, Lei

    2005-01-01

    This document addresses calculations of probability distribution functions (PDFs) representing uncertainties in projecting fatal cancer risk from galactic cosmic rays (GCR) and solar particle events (SPEs). PDFs are used to test the effectiveness of potential radiation shielding approaches. Monte-Carlo techniques are used to propagate uncertainties in risk coefficients determined from epidemiology data, dose and dose-rate reduction factors, quality factors, and physics models of radiation environments. Competing mortality risks and functional correlations in radiation quality factor uncertainties are treated in the calculations. The cancer risk uncertainty is about four-fold for lunar and Mars mission risk projections. For short-stay lunar missins (<180 d), SPEs present the most significant risk, but one effectively mitigated by shielding. For long-duration (>180 d) lunar or Mars missions, GCR risks may exceed radiation risk limits. While shielding materials are marginally effective in reducing GCR cancer risks because of the penetrating nature of GCR and secondary radiation produced in tissue by relativisitc particles, polyethylene or carbon composite shielding cannot be shown to significantly reduce risk compared to aluminum shielding. Therefore, improving our knowledge of space radiobiology to narrow uncertainties that lead to wide PDFs is the best approach to ensure radiation protection goals are met for space exploration.

  2. A heavy ion spectrometer system for the measurement of projectile fragmentation of relativistic heavy ions

    NASA Astrophysics Data System (ADS)

    Engelage, J.; Crawford, H. J.; Albergo, S.; Kuo, C.; Caccia, Z.; Chen, C.-X.; Costa, S.; Cronqvist, M.; Flores, L.; Fonte, R.; Greiner, L.; Guzik, T. G.; Insolia, A.; Mitchell, J. W.

    1996-06-01

    The Heavy Ion Spectrometer System (HISS) at the LBL Bevalac provided a unique facility for measuring projectile fragmentation cross sections important in deconvolving the Galactic Cosmic Ray (GCR) source composition. The general characteristics of the apparatus specific to this application are described and the main features of the event reconstruction and analysis used in the TRANSPORT experiment are discussed.

  3. Mars surface radiation exposure for solar maximum conditions and 1989 solar proton events

    NASA Technical Reports Server (NTRS)

    Simonsen, Lisa C.; Nealy, John E.

    1992-01-01

    The Langley heavy-ion/nucleon transport code, HZETRN, and the high-energy nucleon transport code, BRYNTRN, are used to predict the propagation of galactic cosmic rays (GCR's) and solar flare protons through the carbon dioxide atmosphere of Mars. Particle fluences and the resulting doses are estimated on the surface of Mars for GCR's during solar maximum conditions and the Aug., Sep., and Oct. 1989 solar proton events. These results extend previously calculated surface estimates for GCR's at solar minimum conditions and the Feb. 1956, Nov. 1960, and Aug. 1972 solar proton events. Surface doses are estimated with both a low-density and a high-density carbon dioxide model of the atmosphere for altitudes of 0, 4, 8, and 12 km above the surface. A solar modulation function is incorporated to estimate the GCR dose variation between solar minimum and maximum conditions over the 11-year solar cycle. By using current Mars mission scenarios, doses to the skin, eye, and blood-forming organs are predicted for short- and long-duration stay times on the Martian surface throughout the solar cycle.

  4. The Projection of Space Radiation Environments with a Solar Cycle Statistical Model

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee; Cucinotta, Francis A.; Wilson, John W.

    2006-01-01

    A solar cycle statistical model has been developed to project sunspot numbers which represent the variations in the space radiation environment. The resultant projection of sunspot numbers in near future were coupled to space-related quantities of interest in radiation protection, such as the galactic cosmic radiation (GCR) deceleration potential (f) and the mean occurrence frequency of solar particle event (SPE). Future GCR fluxes have been derived from a predictive model, in which GCR temporal dependence represented by f was derived from GCR flux and ground-based Climax neutron monitor rate measurements over the last four decades. Results showed that the point dose equivalent inside a typical spacecraft in interplanetary radiation fields was influenced by solar modulation up to a factor of three. One important characteristic of sporadic SPEs is their mean frequency of occurrence, which is dependent on solar activity. Projections of future mean frequency of SPE occurrence were estimated from a power law function of sunspot number. Furthermore, the cumulative probabilities of SPE during short-period missions were defined with the continuous database of proton fluences of SPE. The analytic representation of energy spectra of SPE was constructed by the Weibull distribution for different event sizes. The representative exposure level at each event size was estimated for the guideline of protection systems for astronauts during future space exploration missions.

  5. Comparison of CREME (Cosmic Ray Effects on Microelectronics) model LET (Linear Energy Transfer) spaceflight dosimetry data

    NASA Astrophysics Data System (ADS)

    Letaw, John R.; Adams, James H., Jr.

    1986-07-01

    The galactic cosmic radiation (GCR) component of space radiation is the dominant cause of single event phenomena in microelectronic circuits when Earth's magnetic shielding is low. Spaceflights outside the magnetosphere and in high inclination orbits are examples of such circumstances. In high inclination orbits, low energy (high LET) particles are transmitted through the field only at extreme latitudes, but can dominate the orbit-averaged dose. GCR is an important part of the radiation dose to astronauts under the same conditions. As a test of the CREME environmental model and particle transport codes used to estimate single event upsets, we have compiled existing measurements of HZE doses where GCR is expected to be important: Apollo 16 and 17, Skylab, Apollo Soyuz Test Project, and Kosmos 782. The LET spectra, due to direct ionization from GCR, for each of these missions has been estimated. The resulting comparisons with data validate the CREME model predictions of high LET galactic cosmic ray fluxes to within a factor of two. Some systematic differences between the model and data are identified.

  6. Special applications of gas-cooled reactors

    SciTech Connect

    Peinado, C.O.

    1981-02-01

    The HTGR technology has been demonstrated by Peach Bottom, Fort St. Vrain, and AVR. Another member of the GCR family is the GCFR. Energy requirements for process heat applications of the HTGR high-temperature nuclear heat source are tabulated. 2 tables. (DLC)

  7. Sex differences in operant responding and survivability following exposure to space radiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On exploratory class missions, such as a mission to Mars, astronauts will be exposed to types and doses of radiation (galactic cosmic rays [GCR]) which are not experienced in low earth orbit where the space shuttle and International Space Station operate. Despite the fact that the crew on such a mi...

  8. Initial conditions for radiation analysis: models of galactic cosmic rays and solar particle events

    NASA Astrophysics Data System (ADS)

    Nymmik, R. A.

    During interplanetary missions the radiation conditions are determined by fluxes of Galactic Cosmic Ray (GCR) particles and Solar Energetic Particles (SEP). The particle fluxes of these two high-energy radiation components differ fundamentally in energy spectra and have the opposite dependence on solar activity level. One of the key issues, associated with estimating flight conditions for missions to the Moon, various asteroids and Mars, is the relative balance between GCR and SCR, depending on the level of solar activity and the distance to the Sun for both open space conditions and conditions inside the spacecraft. This task can be solved with sufficient accuracy only when using such particle flux models (of the above mentioned radiation sources), which are based on unified parameters, describing the current solar activity level. Such models, employing smoothed Wolf numbers as the initial parameter, were developed at SINP MSU. These models are - the semi-empirical model of GCR fluxes, which has currently been approved as an international standard (ISO 15390), and the probabilistic model of SEP particle fluxes, which is currently under discussion as a draft international standard (ISO DRAFT 15391). The report presents a survey of experimental data on GCR and SEP fluxes in interplanetary space at various solar activity levels, and an analysis of the reliability and completeness of data on these fluxes, provided by various calculation models.

  9. How safe is safe enough? Radiation risk for a human mission to Mars.

    PubMed

    Cucinotta, Francis A; Kim, Myung-Hee Y; Chappell, Lori J; Huff, Janice L

    2013-01-01

    Astronauts on a mission to Mars would be exposed for up to 3 years to galactic cosmic rays (GCR)--made up of high-energy protons and high charge (Z) and energy (E) (HZE) nuclei. GCR exposure rate increases about three times as spacecraft venture out of Earth orbit into deep space where protection of the Earth's magnetosphere and solid body are lost. NASA's radiation standard limits astronaut exposures to a 3% risk of exposure induced death (REID) at the upper 95% confidence interval (CI) of the risk estimate. Fatal cancer risk has been considered the dominant risk for GCR, however recent epidemiological analysis of radiation risks for circulatory diseases allow for predictions of REID for circulatory diseases to be included with cancer risk predictions for space missions. Using NASA's models of risks and uncertainties, we predicted that central estimates for radiation induced mortality and morbidity could exceed 5% and 10% with upper 95% CI near 10% and 20%, respectively for a Mars mission. Additional risks to the central nervous system (CNS) and qualitative differences in the biological effects of GCR compared to terrestrial radiation may significantly increase these estimates, and will require new knowledge to evaluate. PMID:24146746

  10. How Safe Is Safe Enough? Radiation Risk for a Human Mission to Mars

    PubMed Central

    Cucinotta, Francis A.; Kim, Myung-Hee Y.; Chappell, Lori J.; Huff, Janice L.

    2013-01-01

    Astronauts on a mission to Mars would be exposed for up to 3 years to galactic cosmic rays (GCR) — made up of high-energy protons and high charge (Z) and energy (E) (HZE) nuclei. GCR exposure rate increases about three times as spacecraft venture out of Earth orbit into deep space where protection of the Earth's magnetosphere and solid body are lost. NASA's radiation standard limits astronaut exposures to a 3% risk of exposure induced death (REID) at the upper 95% confidence interval (CI) of the risk estimate. Fatal cancer risk has been considered the dominant risk for GCR, however recent epidemiological analysis of radiation risks for circulatory diseases allow for predictions of REID for circulatory diseases to be included with cancer risk predictions for space missions. Using NASA's models of risks and uncertainties, we predicted that central estimates for radiation induced mortality and morbidity could exceed 5% and 10% with upper 95% CI near 10% and 20%, respectively for a Mars mission. Additional risks to the central nervous system (CNS) and qualitative differences in the biological effects of GCR compared to terrestrial radiation may significantly increase these estimates, and will require new knowledge to evaluate. PMID:24146746

  11. ESBL Detection: Comparison of a Commercially Available Chromogenic Test for Third Generation Cephalosporine Resistance and Automated Susceptibility Testing in Enterobactericeae

    PubMed Central

    El-Jade, Mohamed Ramadan; Parcina, Marijo; Schmithausen, Ricarda Maria; Stein, Christoph; Meilaender, Alina; Hoerauf, Achim; Molitor, Ernst

    2016-01-01

    Rapid detection and reporting of third generation cephalosporine resistance (3GC-R) and of extended spectrum betalactamases in Enterobacteriaceae (ESBL-E) is a diagnostic and therapeutic priority to avoid inefficacy of the initial antibiotic regimen. In this study we evaluated a commercially available chromogenic screen for 3GC-R as a predictive and/or confirmatory test for ESBL and AmpC activity in clinical and veterinary Enterobacteriaceae isolates. The test was highly reliable in the prediction of cefotaxime and cefpodoxime resistance, but there was no correlation with ceftazidime and piperacillin/tazobactam minimal inhibitory concentrations. All human and porcine ESBL-E tested were detected with exception of one genetically positive but phenotypically negative isolate. By contrast, AmpC detection rates lay below 30%. Notably, exclusion of piperacillin/tazobactam resistant, 3GC susceptible K1+ Klebsiella isolates increased the sensitivity and specificity of the test for ESBL detection. Our data further imply that in regions with low prevalence of AmpC and K1 positive E. coli strains chromogenic testing for 3GC-R can substitute for more time consuming ESBL confirmative testing in E. coli isolates tested positive by Phoenix or VITEK2 ESBL screen. We, therefore, suggest a diagnostic algorithm that distinguishes 3GC-R screening from primary culture and species-dependent confirmatory ESBL testing by βLACTATM and discuss the implications of MIC distribution results on the choice of antibiotic regimen. PMID:27494134

  12. ESBL Detection: Comparison of a Commercially Available Chromogenic Test for Third Generation Cephalosporine Resistance and Automated Susceptibility Testing in Enterobactericeae.

    PubMed

    El-Jade, Mohamed Ramadan; Parcina, Marijo; Schmithausen, Ricarda Maria; Stein, Christoph; Meilaender, Alina; Hoerauf, Achim; Molitor, Ernst; Bekeredjian-Ding, Isabelle

    2016-01-01

    Rapid detection and reporting of third generation cephalosporine resistance (3GC-R) and of extended spectrum betalactamases in Enterobacteriaceae (ESBL-E) is a diagnostic and therapeutic priority to avoid inefficacy of the initial antibiotic regimen. In this study we evaluated a commercially available chromogenic screen for 3GC-R as a predictive and/or confirmatory test for ESBL and AmpC activity in clinical and veterinary Enterobacteriaceae isolates. The test was highly reliable in the prediction of cefotaxime and cefpodoxime resistance, but there was no correlation with ceftazidime and piperacillin/tazobactam minimal inhibitory concentrations. All human and porcine ESBL-E tested were detected with exception of one genetically positive but phenotypically negative isolate. By contrast, AmpC detection rates lay below 30%. Notably, exclusion of piperacillin/tazobactam resistant, 3GC susceptible K1+ Klebsiella isolates increased the sensitivity and specificity of the test for ESBL detection. Our data further imply that in regions with low prevalence of AmpC and K1 positive E. coli strains chromogenic testing for 3GC-R can substitute for more time consuming ESBL confirmative testing in E. coli isolates tested positive by Phoenix or VITEK2 ESBL screen. We, therefore, suggest a diagnostic algorithm that distinguishes 3GC-R screening from primary culture and species-dependent confirmatory ESBL testing by βLACTATM and discuss the implications of MIC distribution results on the choice of antibiotic regimen. PMID:27494134

  13. Computational trigonometry

    SciTech Connect

    Gustafson, K.

    1994-12-31

    By means of the author`s earlier theory of antieigenvalues and antieigenvectors, a new computational approach to iterative methods is presented. This enables an explicit trigonometric understanding of iterative convergence and provides new insights into the sharpness of error bounds. Direct applications to Gradient descent, Conjugate gradient, GCR(k), Orthomin, CGN, GMRES, CGS, and other matrix iterative schemes will be given.

  14. Comparison of CREME (cosmic-ray effects on microelectronics) model LET (linear energy transfer) spaceflight dosimetry data

    SciTech Connect

    Letaw, J.R.; Adams, J.H.

    1986-07-15

    The galactic cosmic radiation (GCR) component of space radiation is the dominant cause of single-event phenomena in microelectronic circuits when Earth's magnetic shielding is low. Spaceflights outside the magnetosphere and in high inclination orbits are examples of such circumstances. In high-inclination orbits, low-energy (high LET) particles are transmitted through the field only at extreme latitudes, but can dominate the orbit-averaged dose. GCR is an important part of the radiation dose to astronauts under the same conditions. As a test of the CREME environmental model and particle transport codes used to estimate single event upsets, we have compiled existing measurements of HZE doses were compiled where GCR is expected to be important: Apollo 16 and 17, Skylab, Apollo Soyuz Test Project, and Kosmos 782. The LET spectra, due to direct ionization from GCR, for each of these missions has been estimated. The resulting comparisons with data validate the CREME model predictions of high-LET galactic cosmic-ray fluxes to within a factor of two. Some systematic differences between the model and data are identified.

  15. Neutron production in the lunar subsurface from alpha particles in galactic cosmic rays

    NASA Astrophysics Data System (ADS)

    Ota, Shuya; Kobayashi, Shingo; Sihver, Lembit; Yamashita, Naoyuki; Hasebe, Nobuyuki

    2011-01-01

    The neutron production from alpha particles in galactic cosmic rays (GCR) in the lunar subsurface has not been estimated with reliable precision despite its importance for lunar nuclear spectroscopy and space dosimetry. Here, we report our estimation of neutron production from GCR nuclei (protons and alpha particles) with the Particle and Heavy Ion Transport code System (PHITS), which includes several heavy ion interaction models. PHITS simulations of the equilibrium neutron density profiles in the lunar subsurface are compared with experimental data obtained in the Apollo 17 Lunar Neutron Probe Experiment. Our calculations successfully reproduced the data within an experimental error of 15%. Our estimation of neutron production from GCR nuclei, estimated by scaling that from protons by a factor of 1.27, is in good agreement within an error of 1% with the calculations using two different alpha particle interaction models in PHITS during a period of average activity of the solar cycle. However, we show that the factor depends on the incident GCR spectrum model used in the simulation. Therefore, we conclude that the use of heavy ion interaction models is important for estimating neutron production in the lunar subsurface.

  16. Variations of cosmogenic radionuclide production rates along the meteorite orbits

    NASA Astrophysics Data System (ADS)

    Alexeev, V. A.; Laubenstein, M.; Povinec, P. P.; Ustinova, G. K.

    2015-08-01

    Cosmogenic radionuclides produced by galactic cosmic rays (GCR) in meteorites during their motion in space are natural detectors of the GCR intensity and variations along the meteorite orbits. On the basis of measured and calculated contents of cosmogenic radionuclides in the freshly fallen Chelyabinsk and Košice chondrites some peculiarities of generation of cosmogenic radionuclides of different half-lives in the chondrites of different orbits and dates of fall onto the Earth are demonstrated. Dependence of production rates of the radionuclides on the GCR variations in the heliosphere is analyzed. Using radionuclides with different half-lives it is possible to compare the average GCR intensity over various time periods. The measurement and theoretical analysis of cosmogenic radionuclides in consecutively fallen chondrites provide a unique information on the space-time continuum of the cosmogenic radionuclide production rates and their variations over a long time scale, which could be useful in correlative analyses of processes in the heliosphere. Some applications of cosmogenic radionuclide depth distribution in chondrites for estimation of their pre-atmospheric sizes are illustrated.

  17. Functional characterization of transcriptional regulatory elements in the upstream region of the yeast GLK1 gene.

    PubMed Central

    Herrero, P; Flores, L; de la Cera, T; Moreno, F

    1999-01-01

    The glucokinase gene GLK1 of the yeast Saccharomyces cerevisiae is transcriptionally regulated in response to the carbon source of the growth medium. Northern-blot analysis shows that the GLK1 gene is expressed at a basal level in the presence of glucose, de-repressed more than 6-fold under conditions of sugar limitation and more than 25-fold under conditions of ethanol induction. lacZ fusions of the GLK1 gene promoter were constructed and a deletion analysis was performed in order to identify the cis-acting regulatory elements of the promoter that controls GLK1 gene expression. First, the expression seemed to be mediated mainly by one GCR1 and three stress-responsive element (STRE) activating elements. Secondly, an ethanol repression autoregulation (ERA)/twelve-fold TA repeat (TAB) repressor element was identified within the promoter region of the GLK1 gene. A specific and differential protein binding to the STRE was observed with extracts from de-repressed and repressed cells. No differential binding to the GCR1 or ERA/TAB elements was observed with extracts from de-repressed and repressed cells, but, in both cases, the binding was competed for by an excess of the unlabelled GLK1(GCR1) and GLK1(ERA) sequence. The transcription factors Msn2 and Msn4, which bind to the GLK1 upstream region through the STRE, contribute to inductive activation. The transcription factor Gcr1, which binds through the GCR1 element, contributes to constitutive activation. In order to achieve the severe glucose repression of GLK1, constitutive repressor factors acting through the ERA/TAB element must counteract constitutive activation generated by Gcr1 binding to the GCR1 element. Full expression of the GLK1 gene is produced by inductive activation of three STRE when Msn2 and Msn4 proteins are translocated to the nucleus by covalent modification. The combinatorial effect of the entire region leads to the regulated transcription of GLK1, i.e., silent in media with glucose and other

  18. Studies on the Effect of Cloud Coverage and Galactic Cosmic Ray on Stratospheric Moistening

    NASA Astrophysics Data System (ADS)

    Maitra, Animesh; Saha, Upal; Das, Saurabh

    2012-07-01

    Increased stratospheric water vapor is one of the significant causes of global warming as increased stratospheric water vapor acts to cool the stratosphere but it warms the underlying troposphere. The sun can influence the clouds by mediating through Galactic cosmic rays (GCR) which controls the nucleation of water droplets in the atmosphere. The role of primary GCR in generating low-level cloud condensation nuclei reflects solar energy back into space affecting the temperature on earth. In the present study, variations of different types of cloud coverage (low, mid and high) are correlated with the intensity of GCR flux and their effects on the stratospheric moistening in the equatorial, mid- latitude and polar region have been investigated for the years 2004 and 2005 using the Aura's Microwave Limb Sounder (MLS) water vapor data, ISCCP cloud data and GCR from neutron monitor observations at Calgary (51.080 N, 245.870 E). The relation between GCR and stratospheric moistening is also investigated in this paper. Additionally, the latitudinal variation of different types of cloud coverage is also studied for the same period. The southern mid-latitudinal region has the highest coverage of low-level cloud, followed by the equatorial region. Both the Polar Regions are highly covered with mid-level cloud. The mid-latitudinal region shows highest coverage of high-cloud, followed by the equatorial region. Lower level clouds exert a large net cooling effect on the climate indicating an inter-relationship between cosmic ray and cloud coverage. However, the mid and high cloud coverage have no significant correlation with GCR flux. The stratospheric moistening is controlled by transport of water vapour from troposphere to stratosphere through the tropopause region and the oxidation of methane within the stratosphere. Water vapour plays a major role in the chemistry and radiative budget of the stratosphere. One possible water vapor source in the stratosphere is the advection of

  19. Physics of the Isotopic Dependence of Galactic Cosmic Ray Fluence Behind Shielding

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Saganti, Premkumar B.; Hu, Xiao-Dong; Kim, Myung-Hee Y.; Cleghorn, Timothy F.; Wilson, John W.; Tripathi, Ram K.; Zeitlin, Cary J.

    2003-01-01

    For over 25 years, NASA has supported the development of space radiation transport models for shielding applications. The NASA space radiation transport model now predicts dose and dose equivalent in Earth and Mars orbit to an accuracy of plus or minus 20%. However, because larger errors may occur in particle fluence predictions, there is interest in further assessments and improvements in NASA's space radiation transport model. In this paper, we consider the effects of the isotopic composition of the primary galactic cosmic rays (GCR) and the isotopic dependence of nuclear fragmentation cross-sections on the solution to transport models used for shielding studies. Satellite measurements are used to describe the isotopic composition of the GCR. Using NASA's quantum multiple-scattering theory of nuclear fragmentation (QMSFRG) and high-charge and energy (HZETRN) transport code, we study the effect of the isotopic dependence of the primary GCR composition and secondary nuclei on shielding calculations. The QMSFRG is shown to accurately describe the iso-spin dependence of nuclear fragmentation. The principal finding of this study is that large errors (plus or minus 100%) will occur in the mass-fluence spectra when comparing transport models that use a complete isotope grid (approximately 170 ions) to ones that use a reduced isotope grid, for example the 59 ion-grid used in the HZETRN code in the past, however less significant errors (less than 20%) occur in the elemental-fluence spectra. Because a complete isotope grid is readily handled on small computer workstations and is needed for several applications studying GCR propagation and scattering, it is recommended that they be used for future GCR studies.

  20. Radiation effects in space: The Clementine I mission

    SciTech Connect

    Guzik, T. G.; Clayton, E.; Wefel, J. P.

    1994-12-20

    The space radiation environment for the CLEMENTINE I mission was investigated using a new calculational model, CHIME, which includes the effects of galactic cosmic rays (GCR), anomalous component (AC) species and solar energetic particle (SEP) events and their variations as a function of time. Unlike most previous radiation environment models, CHIME is based upon physical theory and is {open_quotes}calibrated{close_quotes} with energetic particle measurements made over the last two decades. Thus, CHIME provides an advance in the accuracy of estimating the interplanetary radiation environment. Using this model we have calculated particle energy spectra, fluences and linear energy transfer (LET) spectra for all three major components of the CLEMENTINE I mission during 1994: (1) the spacecraft in lunar orbit, (2) the spacecraft during asteroid flyby, and (3) the interstate adapter USA in Earth orbit. Our investigations indicate that during 1994 the level of solar modulation, which dominates the variation in the GCR and AC flux as a function of time, will be decreasing toward solar minimum levels. Consequently the GCR and AC flux will be increasing during Y, the year and, potentially, will rise to levels seen during previous solar minimums. The estimated radiation environment also indicates that the AC will dominate the energetic particle spectra for energies below 30-50 MeV/nucleon, while the GCR have a peak flux at {approximately}300 MeV/nucleon and maintain a relatively high flux level up to >1000 MeV/nucleon. The AC significantly enhances the integrated flux for LET in the range 1 to 10 MeV/(mg/cm{sup 2}), but due to the steep energy spectra of the AC a relatively small amount of material ({approximately}50 mils of Al) can effectively shield against this component. The GCR are seen to be highly penetrating and require massive amounts of shielding before there is any appreciable decrease in the LET flux.

  1. Atmospheric changes caused by galactic cosmic rays over the period 1960-2010

    NASA Astrophysics Data System (ADS)

    Jackman, C. H.; Marsh, D. R.; Kinnison, D. E.; Mertens, C. J.; Fleming, E. L.

    2015-12-01

    The Specified Dynamics version of the Whole Atmosphere Community Climate Model (SD-WACCM) and the Goddard Space Flight Center two-dimensional (GSFC 2-D) models are used to investigate the effect of galactic cosmic rays (GCRs) on the atmosphere over the 1960-2010 time period. The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) computation of the GCR-caused ionization rates are used in these simulations. GCR-caused maximum NOx increases of 4-15 % are computed in the Southern polar troposphere with associated ozone increases of 1-2 %. NOx increases of ∼ 1-6 % are calculated for the lower stratosphere with associated ozone decreases of 0.2-1 %. The primary impact of GCRs on ozone was due to their production of NOx. The impact of GCRs varies with the atmospheric chlorine loading, sulfate aerosol loading, and solar cycle variation. Because of the interference between the NOx and ClOx ozone loss cycles (e.g., the ClO + NO2 + M → ClONO2 + M reaction) and the change in the importance of ClOx in the ozone budget, GCRs cause larger atmospheric impacts with less chlorine loading. GCRs also cause larger atmospheric impacts with less sulfate aerosol loading and for years closer to solar minimum. GCR-caused decreases of annual average global total ozone (AAGTO) were computed to be 0.2 % or less with GCR-caused tropospheric column ozone increases of 0.08 % or less and GCR-caused stratospheric column ozone decreases of 0.23 % or less. Although these computed ozone impacts are small, GCRs provide a natural influence on ozone and need to be quantified over long time periods.

  2. The Average Quality Factors by TEPC for Charged Particles

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Nikjoo, Hooshang; Cucinotta, Francis A.

    2004-01-01

    The quality factor used in radiation protection is defined as a function of LET, Q(sub ave)(LET). However, tissue equivalent proportional counters (TEPC) measure the average quality factors as a function of lineal energy (y), Q(sub ave)(Y). A model of the TEPC response for charged particles considers energy deposition as a function of impact parameter from the ion s path to the volume, and describes the escape of energy out of sensitive volume by delta-rays and the entry of delta rays from the high-density wall into the low-density gas-volume. A common goal for operational detectors is to measure the average radiation quality to within accuracy of 25%. Using our TEPC response model and the NASA space radiation transport model we show that this accuracy is obtained by a properly calibrated TEPC. However, when the individual contributions from trapped protons and galactic cosmic rays (GCR) are considered; the average quality factor obtained by TEPC is overestimated for trapped protons and underestimated for GCR by about 30%, i.e., a compensating error. Using TEPC's values for trapped protons for Q(sub ave)(y), we obtained average quality factors in the 2.07-2.32 range. However, Q(sub ave)(LET) ranges from 1.5-1.65 as spacecraft shielding depth increases. The average quality factors for trapped protons on STS-89 demonstrate that the model of the TEPC response is in good agreement with flight TEPC data for Q(sub ave)(y), and thus Q(sub ave)(LET) for trapped protons is overestimated by TEPC. Preliminary comparisons for the complete GCR spectra show that Q(sub ave)(LET) for GCR is approximately 3.2-4.1, while TEPC measures 2.9-3.4 for QQ(sub ave)(y), indicating that QQ(sub ave)(LET) for GCR is underestimated by TEPC.

  3. Ionizing Radiation Environments and Exposure Risks

    NASA Astrophysics Data System (ADS)

    Kim, M. H. Y.

    2015-12-01

    Space radiation environments for historically large solar particle events (SPE) and galactic cosmic rays (GCR) are simulated to characterize exposures to radio-sensitive organs for missions to low-Earth orbit (LEO), moon, near-Earth asteroid, and Mars. Primary and secondary particles for SPE and GCR are transported through the respective atmospheres of Earth or Mars, space vehicle, and astronaut's body tissues using NASA's HZETRN/QMSFRG computer code. Space radiation protection methods, which are derived largely from ground-based methods recommended by the National Council on Radiation Protection and Measurements (NCRP) or International Commission on Radiological Protections (ICRP), are built on the principles of risk justification, limitation, and ALARA (as low as reasonably achievable). However, because of the large uncertainties in high charge and energy (HZE) particle radiobiology and the small population of space crews, NASA develops distinct methods to implement a space radiation protection program. For the fatal cancer risks, which have been considered the dominant risk for GCR, the NASA Space Cancer Risk (NSCR) model has been developed from recommendations by NCRP; and undergone external review by the National Research Council (NRC), NCRP, and through peer-review publications. The NSCR model uses GCR environmental models, particle transport codes describing the GCR modification by atomic and nuclear interactions in atmospheric shielding coupled with spacecraft and tissue shielding, and NASA-defined quality factors for solid cancer and leukemia risk estimates for HZE particles. By implementing the NSCR model, the exposure risks from various heliospheric conditions are assessed for the radiation environments for various-class mission types to understand architectures and strategies of human exploration missions and ultimately to contribute to the optimization of radiation safety and well-being of space crewmembers participating in long-term space missions.

  4. A field assessment of long-term laboratory sediment toxicity tests with the amphipod Hyalella azteca

    USGS Publications Warehouse

    Ingersoll, C.G.; Wang, N.; Hayward, J.M.R.; Jones, J.R.; Jones, S.B.; Ireland, D.S.

    2005-01-01

    Response of the amphipod Hyalella azteca exposed to contaminated sediments for 10 to 42 d in laboratory toxicity tests was compared to responses observed in controlled three-month invertebrate colonization exposures conducted in a pond. Sediments evaluated included a sediment spiked with dichlorodiphenyldichloroethane (DDD) or dilutions of a field sediment collected from the Grand Calumet River (GCR) in Indiana (USA) (contaminated with organic compounds and metals). Consistent effects were observed at the highest exposure concentrations (400 ??g DDD/goc [DDD concentrations normalized to grams of organic carbon (goc) in sedimentl or 4% GCR sediment) on survival, length, and reproduction of amphipods in the laboratory and on abundance of invertebrates colonizing sediments in the field. Effect concentrations for DDD observed for 10-d length and 42-d reproduction of amphipods (e.g., chronic value [ChV] of 66 ??g DDD/goc and 25% inhibition concentration [IC25] of 68 ??g DDD/goc for reproduction) were similar to the lowest effect concentrations for DDD measured on invertebrates colonizing sediment the field. Effect concentrations for GCR sediment on 28-d survival and length and 42-d reproduction and length of amphipods (i.e., ChVs of 0.20-0.66% GCR sediment) provided more conservative effect concentrations compared to 10-d survival or length of amphipods in the laboratory or the response of invertebrates colonizing sediment in the field (e.g., ChVs of 2.2% GCR sediment). Results of this study indicate that use of chronic laboratory toxicity tests with H. azteca and benthic colonization studies should be used to provide conservative estimates of impacts on benthic communities exposed to contaminated sediments. Bioaccumulation of DDD by oligochaetes colonizing the DDD-spiked sediment was similar to results of laboratory sediment tests previously conducted with the oligochaete Lumbriculus variegates, confirming that laboratory exposures can be used to estimate

  5. Large Galactic Cosmic Ray Anisotropies in the Heliosheath

    NASA Astrophysics Data System (ADS)

    Hill, M. E.; Decker, R. B.; Hamilton, D. C.; Brown, L. E.; Krimigis, S. M.; Roelof, E. C.

    2013-12-01

    The angular distribution of galactic cosmic ray (GCR) intensities had been observed to be nearly isotropic throughout the space age, with even the largest anisotropies falling well short of 1%. Voyager 1, after the initial GCR intensity enhancement in May 2012 and upon sustainably entering a region depleted of hot plasma on 25 August 2012 (Burlaga et al. 2013; Krimigis et al. 2013; Stone et al. 2013; Webber & McDonald 2013), has uncovered a new regime where large GCR anisotropies prevail. We recently reported on the largest GCR anisotropies observed (Krimigis et al., 2013; Hill et al., 2013), with the second order anisotropy of >200 MeV GCRs reaching ~3.5%. We developed a new technique to extract bi-directional intensities from a double-ended particle telescope that has asymmetric viewing geometry (i.e., the geometric factor for particle detection with one end is unequal to the geometric factor of the other end). Applying this technique we report here on the variation of GCR anisotropies at Voyager 1 and 2 in the depletion region, in the hot heliosheath, and upstream of the termination shock. Burlaga, L.F. et al, 2013, Science 341, 147-150, DOI: 10.1126/science.1235451. Hill, M.E. et al, 2013, presented at the 12th Ann. Inter. Astrophys. Conf., Myrtle Beach, SC, 15-19 April 2013. Krimigis, S.M. et al., 2013, Science 341, 144-147, DOI: 10.1126/science.1235721. Stone, E.C. et al., 2013, Science 341, 150-153, DOI: 10.1126/science.1236408. Webber & McDonald, 2013, Geophys. Res. Let. 40, 1665-1668, DOI: 10.1002/grl.50383.

  6. Simulation and Comparison of Martian Surface Ionization Radiation

    NASA Technical Reports Server (NTRS)

    Kim, Myung-Hee Y.; Zeitlin, Cary; Hassler, Donald M.; Cucinotta, Francis A.

    2013-01-01

    The spectrum of energetic particle radiation and corresponding doses at the surface of Mars is being characterized by the Radiation Assessment Detector (RAD), one of ten science instruments on the Mars Science Laboratory (MSL) Curiosity Rover. The time series of dose rate for the first 300 Sols after landing on Mars on August 6, 2012 is presented here. For the comparison to RAD measurements of dose rate, Martian surface ionization radiation is simulated by utilizing observed space quantities. The GCR primary radiation spectrum is calculated by using the Badhwar-O'Neill 2011 (BO11) galactic cosmic ray (GCR) model, which has been developed by utilizing all balloon and satellite GCR measurements since 1955 and the newer 1997-2012 Advanced Composition Explorer (ACE) measurements. In the BO11 model, solar modulation of the GCR primary radiation spectrum is described in terms of the international smoothed sunspot number and a time delay function. For the transport of the impingent GCR primary radiation through Mars atmosphere, a vertical distribution of atmospheric thickness at each elevation is calculated using the vertical profiles of atmospheric temperature and pressure made by Mars Global Surveyor measurements. At Gale Crater in the southern hemisphere, the seasonal variation of atmospheric thickness is accounted for the daily atmospheric pressure measurements of the MSL Rover Environmental Monitoring Station (REMS) by using low- and high-density models for cool- and warm-season, respectively. The spherically distributed atmospheric distance is traced along the slant path, and the resultant directional shielding by Martian atmosphere is coupled with Curiosity vehicle for dose estimates. We present predictions of dose rate and comparison to the RAD measurements. The simulation agrees to within +/- 20% with the RAD measurements showing clearly the variation of dose rate by heliospheric conditions, and presenting the sensitivity of dose rate by atmospheric pressure

  7. May 2005 Halo CMEs and Galactic Cosmic Ray Flux Changes at Earth's Orbit

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.; Alania, M. V.; Wawrzynczak, A.; Ygbuhay, R. C.; Fikani, M. M.

    2014-05-01

    The pressure corrected hourly data from the global network of cosmic ray detectors, measurements of the interplanetary magnetic field (IMF) intensity ( B) at Earth's orbit and its components B x , B y , B z (in the geocentric solar ecliptic coordinates) are used to conduct a comprehensive study of the galactic cosmic ray (GCR) intensity fluctuations caused by the halo coronal mass ejection of 13 May 2005. Distinct differences exist in GCR timelines recorded by neutron monitors (NMs) and multidirectional muon telescopes (MTs), the latter respond to the high rigidity portion of the GCR differential rigidity spectrum. The Forbush decrease (FD) onset in MTs is delayed (˜5 h) with respect to the onset of a geomagnetic storm sudden commencement (SSC) and a large pre-increase is present in MT data before, during, and after the SSC onset, of unknown origin. The rigidity spectrum, for a range of GCR rigidities (≤200 GV), is a power law in rigidity (R) with a negative exponent ( γ=-1.05) at GCR minimum intensity, leading us to infer that the quasi-linear theory of modulation is inconsistent with observations at high rigidities (>1 GV); the results support the force field theory of modulation. At present, we do not have a comprehensive model for the FD explaining quantitatively all the observational features but we present a preliminary model listing physical processes that may contribute to a FD timeline. We explored the connections between different phases of the FD and the power spectra of IMF components but did not find a sustained relationship.

  8. Sunspot numbers, interplanetary magnetic field, and cosmic ray intensity at earth: Nexus for the twentieth century

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    2013-12-01

    The pivotal role played by the interplanetary magnetic field (B) in modulating galactic cosmic ray (GCR) intensity in the heliosphere is described. We show that the inverse correlation observed by Forbush (1958) between GCRs and sunspot numbers (SSNs) is reflected in high correlation between SSNs and B (cc = 0.94). The SSN data are available since 1700 and the derived B data since 1835. The paleo-cosmic ray data are available for several millennia in the form of 10Be radionuclide sequestered in polar ice. The data of the ion chambers (ICs) at the Cheltenham-Fredericksburg-Yakutsk (CFY) sites are combined to create a data string for 1937-1988. In turn, these data are used to extend the measurements of the low energy GCR ions (>0.1 GeV) at balloon altitudes at high latitudes in Russia to 1937. These data are then correlated to B and the fit parameters are used to extend the low energy ion data to 1900, creating the instrumental era GCR time series for the twentieth century. The derived GCR time series is compared to 10Be measured at two sites in Greenland, namely Dye 3 and NGRIP for 1900-2000 to check the internal consistency of datasets for the long-term trend. We find that the annual mean rate (%) for 1965 at NGRIP is an outlier. We replace it with the mean of 1964 and 1965 rates and construct a new re-normalized time series at NGIP, improving the agreement with the derived instrumental era GCR time series for the twentieth century as well. This should encourage its use by heliophysics community for varied applications.

  9. Corotating solar wind structures and recurrent trains of enhanced diurnal variation in galactic cosmic rays

    SciTech Connect

    Yeeram, T.; Ruffolo, D.; Sáiz, A.; Kamyan, N.; Nutaro, T. E-mail: david.ruf@mahidol.ac.th E-mail: p_chang24@hotmail.com

    2014-04-01

    Data from the Princess Sirindhorn Neutron Monitor at Doi Inthanon, Thailand, with a vertical cutoff rigidity of 16.8 GV, were utilized to determine the diurnal anisotropy (DA) of Galactic cosmic rays (GCRs) near Earth during solar minimum conditions between 2007 November and 2010 November. We identified trains of enhanced DA over several days, which often recur after a solar rotation period (∼27 days). By investigating solar coronal holes as identified from synoptic maps and solar wind parameters, we found that the intensity and anisotropy of cosmic rays are associated with the high-speed streams (HSSs) in the solar wind, which are in turn related to the structure and evolution of coronal holes. An enhanced DA was observed after the onset of some, but not all, HSSs. During time periods of recurrent trains, the DA was often enhanced or suppressed according to the sign of the interplanetary magnetic field B, which suggests a contribution from a mechanism involving a southward gradient in the GCR density, n, and a gradient anisotropy along B × ∇n. In one non-recurrent and one recurrent sequence, an HSS from an equatorial coronal hole was merged with that from a trailing mid-latitude extension of a polar coronal hole, and the slanted HSS structure in space with suppressed GCR density can account for the southward GCR gradient. We conclude that the gradient anisotropy is a source of temporary changes in the GCR DA under solar minimum conditions, and that the latitudinal GCR gradient can sometimes be explained by the coronal hole morphology.

  10. Image transformation into device-dependent color printer description using 4th-order polynomial regression and object-oriented programming development of image processing modules

    NASA Astrophysics Data System (ADS)

    Mongeon, Michael C.

    1996-03-01

    This paper investigates the development of printer device profiles used in color document printing system environments when devices with intrinsically different gamut capabilities communicate with one another in a common (CIELAB) color space. While the main thrust of this activity focuses on the output printer, namely the Xerox 5760 printer, and its rendition of some device independent image description, characterizations are provided which investigate relative areas of photographic, monitor, and printer gamuts using a visual hue leaf comparison between devices. The printer is modeled using 4th-order polynomial regression which maps the device independent CIELAB image representation into device dependent printer CMYK. This technique results in 1.89 AEEavg over the training data set. Some key properties of the proposed calibration method are as follows: (1) Linearized CMYK tone reproduction curves with respect to AEEpaper to improve the distribution of calibration data in color space. (2) Application of GCR strategy and linearization to the calibration target prior to the regression on the measured CIELAB and original CMY values. Each strategy employs a K addition/No CMY removal method which maximizes printer gamut and relies on the regression to determine the appropriate CMY removal. The following GCR strategies are explored: CMY only (0% K addition), 50% K addition, 100% K addition, and non-linear K addition. A library of image processing algorithms is included, using LabView object oriented programming, which provides a modular approach for key color processing tasks. In the user interface, an image is selected with appropriate GCR strategy, and the program operates on the image. In general, the pictorial image quality is excellent for each GCR strategy with subtle differences between GCR approaches. Quantitative analysis of Q60 color matching performance is included.

  11. Average Spatial Distribution of Cosmic Rays behind the Interplanetary Shock—Global Muon Detector Network Observations

    NASA Astrophysics Data System (ADS)

    Kozai, M.; Munakata, K.; Kato, C.; Kuwabara, T.; Rockenbach, M.; Dal Lago, A.; Schuch, N. J.; Braga, C. R.; Mendonça, R. R. S.; Jassar, H. K. Al; Sharma, M. M.; Duldig, M. L.; Humble, J. E.; Evenson, P.; Sabbah, I.; Tokumaru, M.

    2016-07-01

    We analyze the galactic cosmic ray (GCR) density and its spatial gradient in Forbush Decreases (FDs) observed with the Global Muon Detector Network (GMDN) and neutron monitors (NMs). By superposing the GCR density and density gradient observed in FDs following 45 interplanetary shocks (IP-shocks), each associated with an identified eruption on the Sun, we infer the average spatial distribution of GCRs behind IP-shocks. We find two distinct modulations of GCR density in FDs, one in the magnetic sheath and the other in the coronal mass ejection (CME) behind the sheath. The density modulation in the sheath is dominant in the western flank of the shock, while the modulation in the CME ejecta stands out in the eastern flank. This east–west asymmetry is more prominent in GMDN data responding to ∼60 GV GCRs than in NM data responding to ∼10 GV GCRs, because of the softer rigidity spectrum of the modulation in the CME ejecta than in the sheath. The geocentric solar ecliptic-y component of the density gradient, G y , shows a negative (positive) enhancement in FDs caused by the eastern (western) eruptions, while G z shows a negative (positive) enhancement in FDs caused by the northern (southern) eruptions. This implies that the GCR density minimum is located behind the central flank of IP-shocks and propagating radially outward from the location of the solar eruption. We also confirmed that the average G z changes its sign above and below the heliospheric current sheet, in accord with the prediction of the drift model for the large-scale GCR transport in the heliosphere.

  12. Anomalous and galactic cosmic ray intensities at 1 AU during the present solar minimum

    NASA Astrophysics Data System (ADS)

    Leske, Richard; Cummings, A. C.; Cohen, Christina; Mewaldt, R. A.; Stone, E. C.; Wiedenbeck, Mark; von Rosenvinge, Tycho

    Anomalous cosmic ray (ACR) intensities at 1 AU at solar minimum typically track galactic cosmic ray (GCR) intensities as measured by neutron monitors. Throughout the current A<0 cycle, however, the ACR intensities have consistently been a factor of 3-4 lower than expected from scaling neutron monitor rates; a similar discrepancy seems to have been present during the last A<0 period in the mid-1980's. Also, although the present solar minimum has been deep and long-lasting in terms of sunspot numbers and major solar particle events, ACR intensities remain almost a factor of 2 below their maximum values during each of the last two A>0 solar minima and have just barely reached the last A<0 levels. This is probably associated with the fact that ACRs drift inward along the heliospheric current sheet (HCS) during A<0 cycles, and the tilt of the current sheet has been relatively high, dropping below 15° for only 3 solar rotations starting in August 2009. However, while ACR intensities are typical or low, GCR intensities are at the highest levels recorded during the last 50 years, indicating these particles are not being as heavily modulated during their transport from the outer heliosphere. Using neutron monitor data along with ACR and GCR measurements from the ACE spacecraft, we find that both ACR and GCR intensities are actually much higher now for a given HCS tilt angle than they were during the last A<0 cycle. We present updated measurements of the ACR and GCR intensity variations at 1 AU through-out the solar cycle and discuss possible explanations for the different behavior between the present A<0 epoch and the previous one.

  13. Assessing the experience in complex hepatopancreatobiliary surgery among graduating chief residents: Is the operative experience enough?

    PubMed Central

    Sachs, Teviah E.; Ejaz, Aslam; Weiss, Matthew; Spolverato, Gaya; Ahuja, Nita; Makary, Martin A.; Wolfgang, Christopher L.; Hirose, Kenzo; Pawlik, Timothy M.

    2015-01-01

    Introduction Resident operative autonomy and case volume is associated with posttraining confidence and practice plans. Accreditation Council for Graduate Medical Education requirements for graduating general surgery residents are four liver and three pancreas cases. We sought to evaluate trends in resident experience and autonomy for complex hepatopancreatobiliary (HPB) surgery over time. Methods We queried the Accreditation Council for Graduate Medical Education General Surgery Case Log (2003–2012) for all cases performed by graduating chief residents (GCR) relating to liver, pancreas, and the biliary tract (HPB); simple cholecystectomy was excluded. Mean (±SD), median [10th–90th percentiles] and maximum case volumes were compared from 2003 to 2012 using R2 for all trends. Results A total of 252,977 complex HPB cases (36% liver, 43% pancreas, 21% biliary) were performed by 10,288 GCR during the 10-year period examined (Mean = 24.6 per GCR). Of these, 57% were performed during the chief year, whereas 43% were performed as postgraduate year 1–4. Only 52% of liver cases were anatomic resections, whereas 71% of pancreas cases were major resections. Total number of cases increased from 22,516 (mean = 23.0) in 2003 to 27,191 (mean = 24.9) in 2012. During this same time period, the percentage of HPB cases that were performed during the chief year decreased by 7% (liver: 13%, pancreas 8%, biliary 4%). There was an increasing trend in the mean number of operations (mean ± SD) logged by GCR on the pancreas (9.1 ± 5.9 to 11.3 ± 4.3; R2 = .85) and liver (8.0 ± 5.9 to 9.4 ± 3.4; R2 = .91), whereas those for the biliary tract decreased (5.9 ± 2.5 to 3.8 ± 2.1; R2 = .96). Although the median number of cases [10th:90th percentile] increased slightly for both pancreas (7.0 [4.0:15] to 8.0 [4:20]) and liver (7.0 [4:13] to 8.0 [5:14]), the maximum number of cases preformed by any given GCR remained stable for pancreas (51 to 53; R2 = .18), but increased for liver (38

  14. Time-dependent radiation hazard estimations during space flights

    NASA Astrophysics Data System (ADS)

    Dobynde, Mikhail; Shprits, Yuri; Drozdov, Alexander

    Cosmic particle radiation is a limiting factor for the out of magnetosphere crewed flights. The cosmic radiation uncrewed flights inside heliosphere and crewed flights inside of magnetosphere tend to become a routine procedure, whereas there have been only few shot time flights out of it (Apollo missions 1969-1972) with maximum duration less than a month. Long term crewed missions set much higher requirements to the radiation shielding, primarily because of long exposition term. Inside the helosphere there are two main sources of cosmic radiation: galactic cosmic rays (GCR) and coronal mass ejections (CME). GCR come from the outside of heliosphere forming a background of overall radiation that affects the spacecraft. The intensity of GCR is varied according to solar activity, increasing with solar activity decrease and backward, with the modulation time (time between nearest maxima) of 11 yeas. CME are shot term events, comparing to GCR modulation time, but are much more energetic. The probability of CME increases with the increase of solar activity. Time dependences of the intensity of these two components encourage looking for a time window of flight, when intensity and affection of CME and GCR would be minimized. Applying time dependent models of GCR spectra [1] and estimations of CME we show the time dependence of the radiation dose in a realistic human phantom [2] inside the shielding capsule. We pay attention to the shielding capsule design, looking for an optimal geometry parameters and materials. Different types of particles affect differently on the human providing more or less harm to the tissues. Incident particles provide a large amount of secondary particles while propagating through the shielding capsule. We make an attempt to find an optimal combination of shielding capsule parameters, namely material and thickness, that will effectively decrease the incident particle energy, at the same time minimizing flow of secondary induced particles and

  15. Integration of the QMSFRG Database into the HZETRN Code

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Shavers, M. R.; Tripathi, R. K.; Wilson, J. W.

    2001-01-01

    Accurate nuclear interaction data bases are needed for describing the transport of space radiation in matter including space craft structures, atmospheres, and tissues. Transport models support the identification and development of new material concepts for human and electronic part protection. Quantum effects are manifested in nuclear reactions in several ways including interference effects between terms in the multiple scattering series, the many-body nuclear wave functions (for e.g. the roles of shell structure and Fermi momentum) and nuclear clustering. The quantum multiple scattering fragmentation model (QMSFRG) is a comprehensive model for generating nuclear interaction databases for galactic cosmic ray (GCR) transport. Other nuclear databases including the NUCFRG model and Monte-Carlo simulation codes such as FLUKA, LAHET, HETC, and GEANT ignore quantum effects. These codes fail to describe many important features of nuclear reactions and are thus inaccurate for the evaluation of materials for radiation protection. Previously we have shown that quantum effects are manifested through constructive interference in forward production spectra, the effects of Fermi momentum on production spectra, cluster nuclei knockout, and the nuclear response function. Quantum effects are especially important for heavy ions with mass numbers less than 20 that dominate radiation transport in human tissues and for the materials that are expected to be superior in space radiation protection. We describe the integration of the QMSFRG model into the HZETRN transport code. Integration milestones include proper treatment of odd-even charge-mass effects in nuclear fragmentation and the momentum distribution of nucleon production from GCR primary heavy ions. We have also modified the two-body amplitudes in the model to include nuclear medium effects. In order to include a comprehensive description of the GCR isotopic composition in materials, we have described the isotopic composition

  16. An analytical model for the prediction of a micro-dosimeter response function

    NASA Astrophysics Data System (ADS)

    Badavi, Francis; Michael, Michael; Wilson, John W.

    A rapid analytical procedure for the prediction of a micro-dosimeter response function in Low Earth Orbit (LEO), correlated with the Space Transportation System (STS, shuttle) Tissue Equivalent Proportional Counter (TEPC) measurements is presented. The analytical model takes into consideration the energy loss straggling and chord length distribution of the detector, and is capable of predicting energy deposition fluctuations in a cylindrical micro-volume of arbitrary aspect ratio (height/diameter) by incoming ions through both direct and indirect (δ rays) events. At any designated (ray traced) target point within the vehicle, the model as input accepts the differential flux spectrum of Galactic Cosmic Rays (GCR) and/or trapped protons at LEO. On a desktop PC, the response function of TEPC for each ion in the GCR/trapped field is computed at the average rate of 30 seconds/ion. The ionizing radiation environment at LEO is represented by O'Neill's GCR model (2004), covering charge particles in the 1≤Z≤28 range. O'Neill's free space GCR model is coupled with the Langley Research Center (LaRC) cutoff model with angular dependency compensation to compute the transmission coefficient at LEO. The trapped proton environment is represented by a LaRC developed time dependent procedure which couples the AP8min/AP8max, Deep River Neutron Monitor (DRNM) and F10.7 solar radio frequency measurements. The albedo neutron environment is represented by the extrapolation of the Atmospheric Ionizing Radiation (AIR) measurements. The charged particle transport calculations correlated with STS 56, 51, 110 and 114 flights are accomplished by using the most recent version (2005) of LaRC's deterministic ionized particle transport code High charge (Z) and Energy TRaNsport (HZETRN). Herein, we present the correlations between the TEPC model predictions (response function) and TEPC measured differential/integral spectra in the lineal energy (y) domain for both GCR and trapped protons, with

  17. Validity of the Aluminum Equivalent Approximation in Space Radiation Shielding

    NASA Technical Reports Server (NTRS)

    Badavi, Francis F.; Adams, Daniel O.; Wilson, John W.

    2009-01-01

    The origin of the aluminum equivalent shield approximation in space radiation analysis can be traced back to its roots in the early years of the NASA space programs (Mercury, Gemini and Apollo) wherein the primary radiobiological concern was the intense sources of ionizing radiation causing short term effects which was thought to jeopardize the safety of the crew and hence the mission. Herein, it is shown that the aluminum equivalent shield approximation, although reasonably well suited for that time period and to the application for which it was developed, is of questionable usefulness to the radiobiological concerns of routine space operations of the 21 st century which will include long stays onboard the International Space Station (ISS) and perhaps the moon. This is especially true for a risk based protection system, as appears imminent for deep space exploration where the long-term effects of Galactic Cosmic Ray (GCR) exposure is of primary concern. The present analysis demonstrates that sufficiently large errors in the interior particle environment of a spacecraft result from the use of the aluminum equivalent approximation, and such approximations should be avoided in future astronaut risk estimates. In this study, the aluminum equivalent approximation is evaluated as a means for estimating the particle environment within a spacecraft structure induced by the GCR radiation field. For comparison, the two extremes of the GCR environment, the 1977 solar minimum and the 2001 solar maximum, are considered. These environments are coupled to the Langley Research Center (LaRC) deterministic ionized particle transport code High charge (Z) and Energy TRaNsport (HZETRN), which propagates the GCR spectra for elements with charges (Z) in the range I <= Z <= 28 (H -- Ni) and secondary neutrons through selected target materials. The coupling of the GCR extremes to HZETRN allows for the examination of the induced environment within the interior' of an idealized spacecraft

  18. Full Mission Astronaut Radiation Exposure Assessments for Long Duration Lunar Surface Missions

    NASA Technical Reports Server (NTRS)

    Adamczyk, Anne M.; Clowdsley, Martha S.; Qualls, Garry D.; Blattnig, Steve B.; Lee, Kerry T.; Fry, Dan J.; Stoffle, Nicholas N.; Simonsen, Lisa C.; Slaba, Tony C.; Walker, Steven A.; Zapp, Edward N.

    2010-01-01

    Risk to astronauts due to ionizing radiation exposure is a primary concern for missions beyond Low Earth Orbit (LEO) and will drive mission architecture requirements, mission timelines, and operational practices. Both galactic cosmic ray (GCR) and solar particle event (SPE) environments pose a risk to astronauts for missions beyond LEO. The GCR environment, which is made up of protons and heavier ions covering a broad energy spectrum, is ever present but varies in intensity with the solar cycle, while SPEs are sporadic events, consisting primarily of protons moving outward through the solar system from the sun. The GCR environment is more penetrating and is more difficult to shield than SPE environments, but lacks the intensity to induce acute effects. Large SPEs are rare, but they could result in a lethal dose, if adequate shielding is not provided. For short missions, radiation risk is dominated by the possibility of a large SPE. Longer missions also require planning for large SPEs; adequate shielding must be provided and operational constraints must allow astronauts to move quickly to shielded locations. The dominant risk for longer missions, however, is GCR exposure, which accumulates over time and can lead to late effects such as cancer. SPE exposure, even low level SPE exposure received in heavily shielded locations, will increase this risk. In addition to GCR and SPE environments, the lunar neutron albedo resulting mainly from the interaction of GCRs with regolith will also contribute to astronaut risk. Full mission exposure assessments were performed for proposed long duration lunar surface mission scenarios. In order to accomplish these assessments, radiation shielding models were developed for a proposed lunar habitat and rover. End-to-End mission exposure assessments were performed by first calculating exposure rates for locations in the habitat, rover, and during extra-vehicular activities (EVA). Subsequently, total mission exposures were evaluated for

  19. An Analytical Model for the Prediction of a Micro-Dosimeter Response Function

    NASA Technical Reports Server (NTRS)

    Badavi, Francis F.; Xapsos, Mike

    2008-01-01

    A rapid analytical procedure for the prediction of a micro-dosimeter response function in low Earth orbit (LEO), correlated with the Space Transportation System (STS, shuttle) Tissue Equivalent Proportional Counter (TEPC) measurements is presented. The analytical model takes into consideration the energy loss straggling and chord length distribution of the detector, and is capable of predicting energy deposition fluctuations in a cylindrical micro-volume of arbitrary aspect ratio (height/diameter) by incoming ions through both direct and indirect (ray) events. At any designated (ray traced) target point within the vehicle, the model accepts the differential flux spectrum of Galactic Cosmic Rays (GCR) and/or trapped protons at LEO as input. On a desktop PC, the response function of TEPC for each ion in the GCR/trapped field is computed at the average rate of 30 seconds/ion. The ionizing radiation environment at LEO is represented by O'Neill fs GCR model (2004), covering charged particles in the 1 less than or equal to Z less than or equal to 28. O'Neill's free space GCR model is coupled with the Langley Research Center (LaRC) angular dependent geomagnetic cutoff model to compute the transmission coefficient in LEO. The trapped proton environment is represented by a LaRC developed time dependent procedure which couples the AP8MIN/AP8MAX, Deep River Neutron Monitor (DRNM) and F10.7 solar radio frequency measurements. The albedo neutron environment is represented by the extrapolation of the Atmospheric Ionizing Radiation (AIR) measurements. The charged particle transport calculations correlated with STS 51 and 114 flights are accomplished by using the most recent version (2005) of the LaRC deterministic High charge (Z) and Energy TRaNsport (HZETRN) code. We present the correlations between the TEPC model predictions (response function) and TEPC measured differential/integral spectra in the lineal energy (y) domain for both GCR and trapped protons, with the conclusion

  20. Early Energetic Particle Irradiation of the HED Parent Body Regolith

    NASA Technical Reports Server (NTRS)

    Bogard, D. D.; Garrison, D. H.; Rao, M. N.

    1996-01-01

    Previous studies have shown that many individual grains within the dark phase of the Kapoeta howardite were irradiated with energetic particles while residing on the surface of the early HED regolith. Particle tracks in these grains vary in density by more than an order of magnitude and undoubtedly were formed by energetic heavy (Fe) ions associated with early solar flares. Early Irradiation of HED Regolith: Concentrations of excess Ne alone are not sufficient to decide between competing galactic and solar irradiation models. However, from recent studies of depth samples of oriented lunar rocks, we have shown that the cosmogenic 21-Ne/22-Ne ratio produced in feldspar differs substantially between Galactic Cosmic Radiation (GCR) and solar protons, and that this difference is exactly that predicted from cross-section data. Using Ne literature data and new isotopic data we obtained on acid-etched, separated feldspar from both the light and dark phases of Kapoeta, we derive 21-Ne/22-Ne = 0.80 for the recent GCR irradiation and 21-Ne/22-Ne = 0.68 for the early regolith irradiation. This derived ratio indicates that the early Ne production in the regolith occurred by both galactic and solar protons. If we adopt a likely one-component regolith model in which all grains were exposed to galactic protons but individual grains had variable exposure to solar protons, we estimate that this early GCR irradiation lasted for about 3-6 m.y. More complex two-component regolith models involving separate solar and galactic irradiation would permit this GCR age to be longer. Higher-energy solar protons would permit the GCR to be longer. Higher-energy solar protons would permit the GCR age to be shorter. Further, cosmogenic 126(Xe) in Kapoeta dark is no more than a factor of about 2 higher than that observed in Kapoeta light. Because 126(Xe) can only be formed by galactic protons and not solar protons, these data support a short GCR irradiation for the HED regolith. This would also be

  1. Study - Radiation Shielding Effectiveness of the Prototyped High Temperature Superconductivity (HTS) 'Artificial' Magnetosphere for Deep Space Missions

    NASA Technical Reports Server (NTRS)

    Denkins, Pamela

    2010-01-01

    The high temperature superconductor (HTS) is being used to develop the magnets for the Variable Specific Impulse Magneto-plasma Rocket (VASIMR ) propulsion system and may provide lightweight magnetic radiation shielding to protect spacecraft crews from radiation caused by GCR and SPEs on missions to Mars. A study is being planned to assess the radiation shielding effectiveness of the artificial magnetosphere produced by the HTS magnet. VASIMR is an advanced technology propulsion engine which is being touted as enabling one way transit to Mars in 90 days or less. This is extremely important to NASA. This technology would enable a significant reduction in the number of days in transit to and from Mars and significantly reduce the astronauts exposure to a major threat - high energy particles from solar storms and GCR during long term deep space missions. This paper summarizes the plans for the study and the subsequent testing of the VASIMR technology onboard the ISS slated for 2013.

  2. Solar cosmic ray produced neon in lunar soils and their implication for gas-rich meteorite studies

    NASA Technical Reports Server (NTRS)

    Nautiyal, C. M.; Rao, M. N.

    1984-01-01

    Characteristic neon isotopic ratios, produced due to solar cosmic ray spallation (SCR) in lunar soils, are useful in deciphering and estimating the relative contributions of SCR and GCR spallation. To delineate these features, etched mineral grains from mature and immature lunar soils (14148 and 61221 respectively) were analyzed using mass spectrometry. The SF-Ne composition deduced in this work agrees with that obtained from earlier etched lunar pyroxene studies. The data points for mature soil 14148 define a line which significantly deviates from the 61221 tie line. This deviation is attributed to the presence of SCR spallation component. In this context, neon isotopic compositions (step-wise heating) in Pantar and Leighton dark portions were studied and compared with that of Fayetteville. The meteorite data points deviate significantly from the tie line joining SF-Ne and GCR (pyroxene) end points. This deviation is attributed to SCR-spallation in gas-rich chondrites.

  3. Optimized Shielding for Space Radiation Protection

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Cucinotta, F. A.; Kim, M.-H. Y.; Schimmerling, W.

    2000-01-01

    Abstract. Future deep space mission and International Space Station exposures will be dominated by the high-charge and -energy (HZE) ions of the Galactic Cosmic Rays (GCR). A few mammalian systems have been extensively tested over a broad range of ion types and energies. For example, C3H10T1/2 cells, V79 cells, and Harderian gland tumors have been described by various track-structure dependent response models. The attenuation of GCR induced biological effects depends strongly on the biological endpoint, response model used, and material composition. Optimization of space shielding is then driven by the nature of the response model and the transmission characteristics of the given material.

  4. Light ion components of the galactic cosmic rays: Nuclear interactions and transport theory

    NASA Astrophysics Data System (ADS)

    Cucinotta, F. A.; Townsend, L. W.; Wilson, J. W.; Shinn, J. L.; Badhwar, G. D.; Dubey, R. R.

    Light nuclei are present in the primary galactic cosmic rays (GCR) and are produced in thick targets due to projectile or target fragmentation from both nucleon and heavy induced reactions. In the primary GCR, He-4 is the most abundant nucleus after H-1. However, there are also a substantial fluxes of H-2 and He-3. In this paper we describe theoretical models based on quantum multiple scattering theory for the description of light ion nuclear interactions. The energy dependence of the light ion fragmentation cross section is considered with comparisons of inclusive yields and secondary momentum distributions to experiments described. We also analyze the importance of a fast component of lights ions from proton and neutron induced target fragementation. These theoretical models have been incorporated into the cosmic ray transport code HZETRN and will be used to analyze the role of shielding materials in modulating the production and the energy spectrum of light ions.

  5. Emerging Radiation Health-Risk Mitigation Technologies

    SciTech Connect

    Wilson, J.W.; Cucinotta, F.A.; Schimmerling, W.

    2004-02-04

    Past space missions beyond the confines of the Earth's protective magnetic field have been of short duration and protection from the effects of solar particle events was of primary concern. The extension of operational infrastructure beyond low-Earth orbit to enable routine access to more interesting regions of space will require protection from the hazards of the accumulated exposures of Galactic Cosmic Rays (GCR). There are significant challenges in providing protection from the long-duration exposure to GCR: the human risks to the exposures are highly uncertain and safety requirements places unreasonable demands in supplying sufficient shielding materials in the design. A vigorous approach to future radiation health-risk mitigation requires a triage of techniques (using biological and technical factors) and reduction of the uncertainty in radiation risk models. The present paper discusses the triage of factors for risk mitigation with associated materials issues and engineering design methods.

  6. Cermet coating tribological behavior in high temperature helium

    SciTech Connect

    CACHON, Lionel; ALBALADEJO, Serge; TARAUD, Pascal; LAFFONT, G.

    2006-07-01

    As the CEA is highly involved in the Generation IV Forum, a comprehensive research and development program has been conducted for several years, in order to establish the feasibility of Gas Cooled Reactor (GCR) technology projects using helium as a cooling fluid. Within this framework, a tribology program was launched in order to select and qualify coatings and materials, and to provide recommendations for the sliding components operating in GCRs. The purpose of this paper is to describe the CEA Helium tribology study on several GCR components (thermal barriers, control rod drive mechanisms, reactor internals, ..) requiring protection against wear and bonding. Tests in helium atmosphere are necessary to be fully representative of tribological environments and to assess the material or coating candidates which can provide a reliable answer to these situations. This paper focuses on the tribology tests performed on CERMET (Cr{sub 3}C-2- NiCr) coatings within a temperature range of between 800 and 1000 deg C.

  7. Space Radiation and Exploration - Information for the Augustine Committee Review

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis; Semones, Edward; Kim, Myung-Hee; Jackson, Lori

    2009-01-01

    Space radiation presents significant health risks including mortality for Exploration missions: a) Galactic cosmic ray (GCR) heavy ions are distinct from radiation that occurs on Earth leading to different biological impacts. b) Large uncertainties in GCR risk projections impact ability to design and assess mitigation approaches and select crew. c) Solar Proton Events (SPEs) require new operational and shielding approaches and new biological data on risks. Risk estimates are changing as new scientific knowledge is gained: a) Research on biological effects of space radiation show qualitative and quantitative differences with X- or gamma-rays. b) Expert recommendations and regulatory policy are changing. c) New knowledge leads to changes in estimates for the number of days in space to stay below Permissible Exposure Limits (PELS).

  8. Cosmogenic 44Ti in meteorites and century scale solar modulation.

    PubMed

    Bonino, G; Cini Castagnoli, G; Taricco, C; Bhandari, N

    1994-10-01

    The galactic cosmic ray (GCR) flux is modulated by solar activity: 11 and 22 year cycles are well established. Meteorites offer the possibility of studying longer cycles in the interplanetary space, due to GCR nuclear interactions. 44Ti cosmogenic isotope produced in meteorites is suitable for detecting a century scale modulation. So far reliable measurements of 44Ti in the samples are scarce, the radioisotope concentration being very low. A gamma-ray sensitive spectrometer has been set up in the underground laboratory of Monte dei Cappuccini. The system consists of a 2 kg HPGe detector inside a 28 kg NaI well. The system has a background of approximately 1 count/day (in coincidence mode) in the 44Ti region. We present here the results obtained on the Rio Negro meteorite, which fell in the year 1934. PMID:11540026

  9. Radiological health risks

    NASA Technical Reports Server (NTRS)

    Nachtwey, D. Stuart

    1989-01-01

    The crew of a manned Mars mission will be unavoidably exposed to galactic cosmic ray (GCR) flux. The Mars mission crew shielded by 2 g/sq cm Al could receive about 0.7 Sv in a 460-day mission at solar minimum. However, three-fourths of this dose-equivalent in free space is contributed by high LET heavy ions (Z 3 or greater) and target fragments with average Q of 10.3 and 20, respectively. Such high quality factors for these particles may be inappropriate. Moreover, in a 460-day mission, less than half of the nuclei in the body of an astronaut will have been traversed by a single heavy particle. The entire concept of absorbed dose/quality factors/dose-equivalents as applied to GCR must be reconsidered.

  10. Galactic cosmic ray abundances and spectra behind defined shielding.

    PubMed

    Heinrich, W; Benton, E V; Wiegel, B; Zens, R; Rusch, G

    1994-10-01

    LET spectra have been measured for lunar missions and for several near Earth orbits ranging from 28 degrees to 83 degrees inclination. In some of the experiments the flux of GCR was determined separately from contributions caused by interactions in the detector material. Results of these experiments are compared to model calculations. The general agreement justifies the use of the model to calculate GCR fluxes. The magnitude of variations caused by solar modulation, geomagnetic shielding, and shielding by matter determined from calculated LET spectra is generally in agreement with experimental data. However, more detailed investigations show that there are some weak points in modeling solar modulation and shielding by material. These points are discussed in more detail. PMID:11540030

  11. Solar modulation and nuclear fragmentation effects in galactic cosmic ray transport through shielding

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.; Cucinotta, C. F.; Wilson, J. W.; Shinn, J. L.; Badhwar, G.

    1994-01-01

    Crews of manned interplanetary missions may accumulate significant radiation exposures from the Galactic Cosmic Ray (GCR) environment in space. Estimates of how these dose levels are affected by the assumed temporal and spatial variations in the composition of the GCR environment, and by the effects of the spacecraft and body self-shielding on the transported fields are presented. In this work, the physical processes through which shielding alters the transported radiation fields are described. We then present estimates of the effects on model calculations of (1) nuclear fragmentation model uncertainties, (2) solar modulation, (3) variations between solar cycles, and (4) proposed changes to the quality factors which relate dose equivalent to absorbed dose.

  12. Galactic cosmic ray abundances and spectra behind defined shielding

    NASA Technical Reports Server (NTRS)

    Heinrich, W.; Benton, E. V.; Wiegel, B.; Zens, R.; Rusch, G.

    1994-01-01

    Linear Energy Transfer (LET) spectra have been measured for lunar missions and for several near Earth orbits ranging from 28 deg to 83 deg inclination. In some of the experiments the flux of Galactic Cosmic Rays (GCR) was determined separately from contributions caused by interactions in the detector material. Results of these experiments are compared to model calculations. The general agreement justifies the use of the model to calculate GCR fluxes. The magnitude of variations caused by solar modulation, geomagnetic shielding, and shielding by matter determined from calculated LET spectra is generally in agreement with experimental data. However, more detailed investigations show that there are some weak points in modeling solar modulation and shielding by material. These points are discussed in more detail.

  13. A space radiation shielding model of the Martian radiation environment experiment (MARIE)

    NASA Technical Reports Server (NTRS)

    Atwell, W.; Saganti, P.; Cucinotta, F. A.; Zeitlin, C. J.

    2004-01-01

    The 2001 Mars Odyssey spacecraft was launched towards Mars on April 7, 2001. Onboard the spacecraft is the Martian radiation environment experiment (MARIE), which is designed to measure the background radiation environment due to galactic cosmic rays (GCR) and solar protons in the 20-500 MeV/n energy range. We present an approach for developing a space radiation-shielding model of the spacecraft that includes the MARIE instrument in the current mapping phase orientation. A discussion is presented describing the development and methodology used to construct the shielding model. For a given GCR model environment, using the current MARIE shielding model and the high-energy particle transport codes, dose rate values are compared with MARIE measurements during the early mapping phase in Mars orbit. The results show good agreement between the model calculations and the MARIE measurements as presented for the March 2002 dataset. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

  14. The fluxes and anisotropy of charged particles and the connection with the interplanetary space parameters in November 1973-February 1974 according to the Mars-7 and Prognoz-3 data

    NASA Astrophysics Data System (ADS)

    Mineev, Iu. V.; Spirkova, E. S.; Shestopalov, I. P.

    From November 1973 to February 1974, the distance between the Mars-7 space probe and the Prognoz-3 satellite varied from 0.3 AU to 1 AU, and the angle between Mars-7, the sun, and the earth changed from 6 deg to 50 deg. The proton and electron data observed during the four solar rotations of this period are compared with intensity variations of galactic cosmic rays (GCR), with changes of the solar wind velocity and with their effect on the interplanetary magnetic field (IMF) parameters. It was found that in each of the four recurrent solar events, the electron (greater than or equal to 40 MeV) and the proton (greater than or equal to 1 MeV) increase was accompanied by a GCR intensity decrease, by an increase in the solar wind velocity, and by changes in the IMF parameters (magnitude and sign).

  15. Effects of radiobiological uncertainty on vehicle and habitat shield design for missions to the moon and Mars

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Nealy, John E.; Schimmerling, Walter; Cucinotta, Francis A.; Wood, James S.

    1993-01-01

    Some consequences of uncertainties in radiobiological risk due to galactic cosmic ray (GCR) exposure are analyzed for their effect on engineering designs for the first lunar outpost and a mission to explore Mars. This report presents the plausible effect of biological uncertainties, the design changes necessary to reduce the uncertainties to acceptable levels for a safe mission, and an evaluation of the mission redesign cost. Estimates of the amount of shield mass required to compensate for radiobiological uncertainty are given for a simplified vehicle and habitat. The additional amount of shield mass required to provide a safety factor for uncertainty compensation is calculated from the expected response to GCR exposure. The amount of shield mass greatly increases in the estimated range of biological uncertainty, thus, escalating the estimated cost of the mission. The estimates are used as a quantitative example for the cost-effectiveness of research in radiation biophysics and radiation physics.

  16. Cosmic-ray record in solar system matter

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.; Arnold, J. R.; Lal, D.

    1983-01-01

    The interaction of galactic cosmic rays (GCR) and solar cosmic rays (SCR) with bodies in the solar system is discussed, and what the record of that interaction reveals about the history of the solar system is considered. The influence of the energy, charge, and mass of the particles on the interaction is addressed, showing long-term average fluxes of solar protons, predicted production rates for heavy-nuclei tracks and various radionuclides as a function of depth in lunar rock, and integral fluxes of protons emitted by solar flares. The variation of the earth's magnetic field, the gardening of the lunar surface, and the source of meteorites and cosmic dust are studied using the cosmic ray record. The time variation of GCR, SCR, and VH and VVH nuclei is discussed for both the short and the long term.

  17. Effects of the lunar environment on optical telescopes and instruments

    NASA Technical Reports Server (NTRS)

    Johnson, Charles L.; Dietz, Kurtis L.

    1991-01-01

    The effects of the hostile lunar environment are assessed, and potential techniques for adverse-effect mitigation are developed. The environmental concerns addressed include Galactic cosmic ray (GCR) effects on telescope electronics, lunar dust obscuration and damage to optical surfaces, and micrometeor cratering of the optics and support structure. The feasibility of shielding the electronics from the GCR flux and associated secondaries is investigated as one option for noise reduction. An alternative approach to noise reduction uses shorter integration ties and multiple images for background subtraction. Dust abatement techniques such as stabilizing the lunar soil at the launch and telescope sites and covering the optics during high contamination-risk times are evaluated. The micrometeorite flux and associated surface cratering are assessed for their impact on the lifetime and integrity of the telescope.

  18. Effects of the lunar environment on optical telescopes and instruments

    NASA Astrophysics Data System (ADS)

    Johnson, Charles L.; Dietz, Kurtis L.

    1991-09-01

    The effects of the hostile lunar environment are assessed, and potential techniques for adverse-effect mitigation are developed. The environmental concerns addressed include Galactic cosmic ray (GCR) effects on telescope electronics, lunar dust obscuration and damage to optical surfaces, and micrometeor cratering of the optics and support structure. The feasibility of shielding the electronics from the GCR flux and associated secondaries is investigated as one option for noise reduction. An alternative approach to noise reduction uses shorter integration ties and multiple images for background subtraction. Dust abatement techniques such as stabilizing the lunar soil at the launch and telescope sites and covering the optics during high contamination-risk times are evaluated. The micrometeorite flux and associated surface cratering are assessed for their impact on the lifetime and integrity of the telescope.

  19. Energy spectrum of the recurrent cosmic rays variation during the solar minimum 23/24

    NASA Astrophysics Data System (ADS)

    Gil, Agnieszka; Alania, Michael

    2016-07-01

    We study temporal changes of the power-law energy/ rigidity spectrum of the first three harmonics of the recurrent variation of the galactic cosmic rays (GCR) intensity during the unusual solar minimum 23/24 and compare with four previous minima. We show that the energy spectrum of the amplitudes of the recurrent variation is soft in the minimum 23/24. Moreover, while the energy spectrum of the amplitudes of the first harmonic of the recurrent variation of the GCR intensity practically behaves as during earlier four minima, the energy spectrum of the amplitudes of the second and the third harmonics demonstrate a valuable softening. We attribute this phenomenon to the decrease of an extension of heliosphere caused by the drop of the solar wind dynamic pressure during the solar minimum 23/24.

  20. Effects of Nuclear Cross Sections at Different Energies on the Radiation Hazard from Galactic Cosmic Rays

    NASA Technical Reports Server (NTRS)

    Lin, Z. W.; Adams, J. H., Jr.

    2006-01-01

    The radiation hazard for astronauts from galactic cosmic rays is a major obstacle in long duration human space explorations. Space radiation transport codes have been developed to calculate radiation environment on missions to the Moon, Mars or beyond. We have studied how uncertainties in fragmentation cross sections at different energies affect the accuracy of predictions from such radiation transport. We find that, in deep space, cross sections between 0.3 and 0.85 GeV/u usually have the largest effect on dose-equivalent behind shielding in solar minimum GCR environments, and cross sections between 0.85 and 1.2 GeV/u have the largest effect in solar maximum GCR environments. At the International Space Station, cross sections at higher energies have the largest effect due to the geomagnetic cutoff.

  1. Numerical Study of the Generation of Linear Energy Transfer Spectra for Space Radiation Applications

    NASA Technical Reports Server (NTRS)

    Badavi, Francis F.; Wilson, John W.; Hunter, Abigail

    2005-01-01

    In analyzing charged particle spectra in space due to galactic cosmic rays (GCR) and solar particle events (SPE), the conversion of particle energy spectra into linear energy transfer (LET) distributions is a convenient guide in assessing biologically significant components of these spectra. The mapping of LET to energy is triple valued and can be defined only on open energy subintervals where the derivative of LET with respect to energy is not zero. Presented here is a well-defined numerical procedure which allows for the generation of LET spectra on the open energy subintervals that are integrable in spite of their singular nature. The efficiency and accuracy of the numerical procedures is demonstrated by providing examples of computed differential and integral LET spectra and their equilibrium components for historically large SPEs and 1977 solar minimum GCR environments. Due to the biological significance of tissue, all simulations are done with tissue as the target material.

  2. A space radiation shielding model of the Martian radiationenvironment experiment (MARIE)

    SciTech Connect

    Atwell, William; Saganti, Premkumar; Cucinotta, Francis A.; Zeitlin, Cary J.

    2004-12-01

    The 2001 Mars Odyssey spacecraft was launched towards Mars on April 7, 2001. On board the spacecraft is the Martian radiation environment experiment (MARIE), which is designed to measure the background radiation environment due to galactic cosmic rays (GCR) and solar protons in the 20 500 MeV/n energy range. We present an approach for developing a space radiation-shielding model of the spacecraft that includes the MARIE instrument in the current mapping phase orientation. A discussion is presented describing the development and methodology used to construct the shielding model. For a given GCR model environment, using the current MARIE shielding model and the high-energy particle transport codes, dose rate values are compared with MARIE measurements during the early mapping phase in Mars orbit. The results show good agreement between the model calculations and the MARIE measurements as presented for the March 2002 dataset.

  3. A space radiation shielding model of the Martian radiation environment experiment (MARIE).

    PubMed

    Atwell, W; Saganti, P; Cucinotta, F A; Zeitlin, C J

    2004-01-01

    The 2001 Mars Odyssey spacecraft was launched towards Mars on April 7, 2001. Onboard the spacecraft is the Martian radiation environment experiment (MARIE), which is designed to measure the background radiation environment due to galactic cosmic rays (GCR) and solar protons in the 20-500 MeV/n energy range. We present an approach for developing a space radiation-shielding model of the spacecraft that includes the MARIE instrument in the current mapping phase orientation. A discussion is presented describing the development and methodology used to construct the shielding model. For a given GCR model environment, using the current MARIE shielding model and the high-energy particle transport codes, dose rate values are compared with MARIE measurements during the early mapping phase in Mars orbit. The results show good agreement between the model calculations and the MARIE measurements as presented for the March 2002 dataset. PMID:15791735

  4. Solar modulation of the neutron component of the radiation background observed simultaneously in different space missions

    NASA Astrophysics Data System (ADS)

    Litvak, Maxim; Mitrofanov, Igor; Nuzhdin, Igor; Sanin, Anton; Fedosov, Fedor; Golovin, Dmitry

    2016-04-01

    We have studied variability of neutron component of radiation environment at Earth, Moon and Mars vicinities over a long period of time produced by the solar modulation of the GCR flux in the 23rd and 24th solar cycles. The global behavior of the neutron flux is in relatively good agreement with different observations performed simultaneously onboard various space missions, including instruments HEND onboard Mars Odyssey orbiter, BTN onboard International Space Station and LEND onboard Lunar Reconnaissance Orbiter as well as with the modeled behavior of the GCR flux derived from a global network of neutron monitors on the Earth. The local differences in the time history and character of different observations have been also evaluated. The joint analysis of different data sets, where some of them are gathered far away from the Earth, reveals a multi-dimensional view and new patterns of the solar modulation of GCRs within current unusual solar cycle.

  5. Preliminary Design of a Galactic Cosmic Ray Shielding Materials Testbed for the International Space Station

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Berkebile, Stephen; Sechkar, Edward A.; Panko, Scott R.

    2012-01-01

    The preliminary design of a testbed to evaluate the effectiveness of galactic cosmic ray (GCR) shielding materials, the MISSE Radiation Shielding Testbed (MRSMAT) is presented. The intent is to mount the testbed on the Materials International Space Station Experiment-X (MISSE-X) which is to be mounted on the International Space Station (ISS) in 2016. A key feature is the ability to simultaneously test nine samples, including standards, which are 5.25 cm thick. This thickness will enable most samples to have an areal density greater than 5 g/sq cm. It features a novel and compact GCR telescope which will be able to distinguish which cosmic rays have penetrated which shielding material, and will be able to evaluate the dose transmitted through the shield. The testbed could play a pivotal role in the development and qualification of new cosmic ray shielding technologies.

  6. Results from the Martian Radiation Environment Experiment MARIE

    NASA Technical Reports Server (NTRS)

    Zeitlin, C.; Cleghorn, T.; Cucinotta, F.; Saganti, P.; Andersen, V.; Lee, K.; Pinsky, L.; Atwell, W.; Turner, R.

    2003-01-01

    One of the three science instruments aboard the 2001 Mars Odyssey spacecraft is the Martian Radiation Environment Experiment, MARIE. MARIE consists of a stack of silicon detectors, augmented by a Cerenkov detector. MARIE is designed to measure a portion of the particle spectrum of the Galactic Cosmic Rays (GCR), as well as the high fluxes of low-energy protons (energies less than about 100 MeV) that are intermittently produced by active regions on the sun in Solar Particle Events (SPE). MARIE is providing the first detailed information about the radiation environment near Mars.measurements. MARIE has been operating successfully for nearly a year. Solar particle events of considerable interest have been observed, and data have been obtained that will yield GCR spectra from a novel observation point in the solar system.

  7. Solar Particle Events Observed by the Odyssey MARIE Instrument at Mars: Dose and Model Calculations

    NASA Technical Reports Server (NTRS)

    Cleghorn, T. F.; Saganti, P. B.; Zeitlin, C. J.; Cucinotta, F. A.

    2003-01-01

    One of the primary concerns prior to human exploration of Mars is the need to accurately characterize the charged particle radiation environment both for the surface stay, and for the transit period to and from the planet. The Odyssey spacecraft, currently in Mars orbit includes a charged particle radiation detector, MARIE, which can measure particle fluxes with energies above approx. 30 MeV and charges between 1 and 10. Two classes of particles are of particular interest: the Galactic Cosmic Rays, (GCR), and those charged particles associated with Solar Particle Events, (SPE). The GCR are present continuously throughout the solar activity cycle, and their numbers vary inversely with the level of solar activity. They are characteristically more energetic than those particles originating from solar activity, and hence less influences by the solar magnetic field.

  8. MARIE: Current Status and Results from 20 Months of Observations at Mars

    NASA Technical Reports Server (NTRS)

    Zeitlin, C.; Andersen, V.; Atwell, W.; Cleghorn, T. F.; Cucinotta, F. A.; Lee, K. T.; Pinsky, L.; Saganti, P.

    2004-01-01

    The MARIE instrument aboard the 2001 Mars Odyssey spacecraft detects energetic charged particles in the Galactic Cosmic Radiation (GCR) and during solar particle events (SPE) [1]. As of this writing (January 2004), MARIE has been turned off, after losing communication with the spacecraft during the large SPE of October 28, 2003. However, during the prior 20 months, MARIE collected data almost continuously, observing several solar events and the nearly-constant GCR. There is still a possibility the instrument can be recovered, and troubleshooting efforts are scheduled to begin in May 2004, following the completion of the primary missions of MER-A (Spirit) and MER-B (Opportunity). At present, Odyssey is acting as a telecommunications relay for the rovers and only routine science operations are permitted in this mode.

  9. Effects of nuclear cross sections at different energies on the radiation hazard from galactic cosmic rays.

    PubMed

    Lin, Z W; Adams, J H

    2007-03-01

    The radiation hazard for astronauts from galactic cosmic rays (GCR) is a major obstacle to long-duration human space exploration. Space radiation transport codes have been developed to calculate the radiation environment on missions to the Moon, Mars, and beyond. We have studied how uncertainties in fragmentation cross sections at different energies affect the accuracy of predictions from such radiation transport calculations. We find that, in deep space, cross sections at energies between 0.3 and 0.85 GeV/nucleon have the largest effect in solar maximum GCR environments. At the International Space Station, cross sections at higher energies have the largest effect due to the geomagnetic cutoff. PMID:17316078

  10. The Heavy Nuclei eXplorer (HNX) Mission

    NASA Technical Reports Server (NTRS)

    Binns, W. R.; Adams, J. H.; Barbier, L. M.; Craig, N.; Cummings, A. C.; Cummings, J. R.; Doke, T.; Hasebe, N.; Hayashi, T.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    The primary scientific objectives of HNX, which was recently selected by NASA for a Small Explorer (SMEX) Mission Concept Study, are to measure the age of the galactic cosmic rays (GCR) since nucleosynthesis, determine the injection mechanism for the GCR accelerator (Volatility or FIP), and study the mix of nucleosynthetic processes that contribute to the source of GCRs. The experimental goal of HNX is to measure the elemental abundances of all individual stable nuclei from neon through the actinides and possibly beyond. HNX is composed of two instruments: ECCO, which measures elemental abundances of nuclei with Z greater than or equal to 72, and ENTICE. which measures elemental abundances of nuclei with Z between 10 and 82. We describe the mission and the science that can be addressed by HNX.

  11. The Heavy Nuclei Explorer (HNX) Mission

    NASA Technical Reports Server (NTRS)

    Binns, W. R.

    2001-01-01

    The Heavy Nuclei eXplorer (HNX) mission was recently selected by NASA for a Small Explorer (SMEX) Mission Concept Study to begin in 2001. The primary scientific objectives of HNX are to measure the age of the galactic cosmic rays (GCR) since nucleosynthesis, determine the injection mechanism for the GCR accelerator (Volatility or FIP), and study the mix of nucleosynthetic processes that contribute to the source of GCRs. The experimental goal of HNX is to measure the elemental abundances of all individual stable nuclei from neon through the actinides and possibly beyond. HNX is composed of two instruments: ECCO, which measures elemental abundances of nuclei with Z(sup 3)72, and ENTICE, which measures elemental abundances of nuclei with 10(f)Z(f)82. We will discuss the mission and the science that can be addressed by HNX.

  12. Badhwar - O'Neill 2014 Galactic Cosmic Ray Flux Model Description

    NASA Technical Reports Server (NTRS)

    O'Neill, P. M.; Golge, S.; Slaba, T. C.

    2014-01-01

    The Badhwar-O'Neill (BON) Galactic Cosmic Ray (GCR) model is based on GCR measurements from particle detectors. The model has mainly been used by NASA to certify microelectronic systems and the analysis of radiation health risks to astronauts in space missions. The BON14 model numerically solves the Fokker-Planck differential equation to account for particle transport in the heliosphere due to diffusion, convection, and adiabatic deceleration under the assumption of a spherically symmetric heliosphere. The model also incorporates an empirical time delay function to account for the lag of the solar activity to reach the boundary of the heliosphere. This technical paper describes the most recent improvements in parameter fits to the BON model (BON14). Using a comprehensive measurement database, it is shown that BON14 is significantly improved over the previous version, BON11.

  13. Cosmic Ray Modulation in the Outer Heliosphere During the Minimum of Solar Cycle 23/24

    NASA Technical Reports Server (NTRS)

    Adams, James H., Jr.; Florinski, V.; Washimi, H.; Pogorelov, N. V.

    2011-01-01

    We report a next generation model of galactic cosmic ray (GCR) transport in the three dimensional heliosphere. Our model is based on an accurate three-dimensional representation of the heliospheric interface. This representation is obtained by taking into account the interaction between partially ionized, magnetized plasma flows of the solar wind and the local interstellar medium. Our model reveals that after entering the heliosphere GCRs are stored in the heliosheath for several years. The preferred GCR entry locations are near the nose of the heliopause and at high latitudes. Low-energy (hundreds of MeV) galactic ions observed in the heliosheath have spent, on average, a longer time in the solar wind than those observed in the inner heliosphere, which would explain their cooled-off spectra at these energies. We also discuss radial gradients in the heliosheath and the implications for future Voyager observations.

  14. Radiation Physics for Space and High Altitude Air Travel

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Wilson, J. W.; Goldhagen, P.; Saganti, P.; Shavers, M. R.; McKay, Gordon A. (Technical Monitor)

    2000-01-01

    Galactic cosmic rays (GCR) are of extra-solar origin consisting of high-energy hydrogen, helium, and heavy ions. The GCR are modified by physical processes as they traverse through the solar system, spacecraft shielding, atmospheres, and tissues producing copious amounts of secondary radiation including fragmentation products, neutrons, mesons, and muons. We discuss physical models and measurements relevant for estimating biological risks in space and high-altitude air travel. Ambient and internal spacecraft computational models for the International Space Station and a Mars mission are discussed. Risk assessment is traditionally based on linear addition of components. We discuss alternative models that include stochastic treatments of columnar damage by heavy ion tracks and multi-cellular damage following nuclear fragmentation in tissue.

  15. Optimized shielding for space radiation protection

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Cucinotta, F. A.; Kim, M. H.; Schimmerling, W.

    2001-01-01

    Future deep space mission and International Space Station exposures will be dominated by the high-charge and -energy (HZE) ions of the Galactic Cosmic Rays (GCR). A few mammalian systems have been extensively tested over a broad range of ion types and energies. For example, C3H10T1/2 cells, V79 cells, and Harderian gland tumors have been described by various track-structure dependent response models. The attenuation of GCR induced biological effects depends strongly on the biological endpoint, response model used, and material composition. Optimization of space shielding is then driven by the nature of the response model and the transmission characteristics of the given material.

  16. Quiet-Time Spectra and Abundances of Energetic Particles During the 1996 Solar Minimum

    NASA Technical Reports Server (NTRS)

    Reames, Donald V.

    1999-01-01

    We report the energy spectra and abundances of ions with atomic number, Z, in the interval Z is greater than or equal to 2 and Z is less than or equal to 36 and energies approximately 3-20 MeV/amu for solar and interplanetary quiet periods between 1994 November and 1998 April as measured by the large-geometry Low Energy Matrix Telescope (LEMT) telescope on the Wind spacecraft near Earth. The energy spectra show the presence of galactic (GCR) and "anomalous" cosmic ray (ACR) components, depending on the element. ACR components are reported for Mg and Si for the first time at 1 AU and the previous observation of S and Ar is confirmed. However, only GCR components are clearly apparent for the elements Ca, Ti, Cr, Fe, as well as for C. New limits are placed on a possible ACR contribution for other elements, including Kr.

  17. Quiet-Time Spectra and Abundances of Energetic Particles During the 1996 Solar Minimum

    NASA Technical Reports Server (NTRS)

    Reames, Donald V.

    1998-01-01

    This report concerns the energy spectra and abundances of ions with atomic number, Z, in the interval 2 greater than or equal to Z and Z less than or equal to 36 and energies approximately 3-20 MeV/amu for solar and interplanetary quiet periods between November 1994 and April 1998 as measured by the large-geometry LEMT telescope on the Wind spacecraft near Earth. The energy spectra show the presence of galactic (GCR) and 'anomalous' cosmic ray (ACR) components, depending on the element. ACR components are reported for Mg and Si for the first time at 1 AU and the previous observation of S and Ar is confirmed. However, only GCR components are clearly apparent for the elements Ca, Ti, Cr, Fe, as well as for C. New limits are placed on a possible ACR contribution for other elements, including Kr.

  18. Galactic Cosmic Rays in the Outer Heliosphere

    NASA Technical Reports Server (NTRS)

    Florinski, V.; Washimi, H.; Pogorelov, N. V.; Adams, J. H.

    2010-01-01

    We report a next generation model of galactic cosmic ray (GCR) transport in the three dimensional heliosphere. Our model is based on an accurate three-dimensional representation of the heliospheric interface. This representation is obtained by taking into account the interaction between partially ionized, magnetized plasma flows of the solar wind and the local interstellar medium. Our model reveals that after entering the heliosphere GCRs are stored in the heliosheath for several years. The preferred GCR entry locations are near the nose of the heliopause and at high latitudes. Low-energy (hundreds of MeV) galactic ions observed in the heliosheath have spent, on average, a longer time in the solar wind than those observed in the inner heliosphere, which would explain their cooled-off spectra at these energies. We also discuss radial gradients in the heliosheath and the implications for future Voyager observations

  19. Radiation quality of cosmic ray nuclei studied with Geant4-based simulations

    NASA Astrophysics Data System (ADS)

    Burigo, Lucas N.; Pshenichnov, Igor A.; Mishustin, Igor N.; Bleicher, Marcus

    2014-04-01

    In future missions in deep space a space craft will be exposed to a non-negligible flux of high charge and energy (HZE) particles present in the galactic cosmic rays (GCR). One of the major concerns of manned missions is the impact on humans of complex radiation fields which result from the interactions of HZE particles with the spacecraft materials. The radiation quality of several ions representing GCR is investigated by calculating microdosimetry spectra. A Geant4-based Monte Carlo model for Heavy Ion Therapy (MCHIT) is used to simulate microdosimetry data for HZE particles in extended media where fragmentation reactions play a certain role. Our model is able to reproduce measured microdosimetry spectra for H, He, Li, C and Si in the energy range of 150-490 MeV/u. The effect of nuclear fragmentation on the relative biological effectiveness (RBE) of He, Li and C is estimated and found to be below 10%.

  20. Effects of radiobiological uncertainty on vehicle and habitat shield design for missions to the moon and Mars

    SciTech Connect

    Wilson, J.W.; Nealy, J.E.; Schimmerling, W.; Cucinotta, F.A.; Wood, J.S.

    1993-08-01

    Some consequences of uncertainties in radiobiological risk due to galactic cosmic ray (GCR) exposure are analyzed for their effect on engineering designs for the first lunar outpost and a mission to explore Mars. This report presents the plausible effect of biological uncertainties, the design changes necessary to reduce the uncertainties to acceptable levels for a safe mission, and an evaluation of the mission redesign cost. Estimates of the amount of shield mass required to compensate for radiobiological uncertainty are given for a simplified vehicle and habitat. The additional amount of shield mass required to provide a safety factor for uncertainty compensation is calculated from the expected response to GCR exposure. The amount of shield mass greatly increases in the estimated range of biological uncertainty, thus, escalating the estimated cost of the mission. The estimates are used as a quantitative example for the cost-effectiveness of research in radiation biophysics and radiation physics.

  1. Light ion components of the galactic cosmic rays: Nuclear interactions and transport theory

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Townsend, L. W.; Wilson, J. W.; Shinn, J. L.; Badhwar, G. D.; Dubey, R. R.

    1996-01-01

    Light nuclei are present in the primary galactic cosmic rays (GCR) and are produced in thick targets due to projectile or target fragmentation from both nucleon and heavy induced reactions. In the primary GCR, He-4 is the most abundant nucleus after H-1. However, there are also a substantial fluxes of H-2 and He-3. In this paper we describe theoretical models based on quantum multiple scattering theory for the description of light ion nuclear interactions. The energy dependence of the light ion fragmentation cross section is considered with comparisons of inclusive yields and secondary momentum distributions to experiments described. We also analyze the importance of a fast component of lights ions from proton and neutron induced target fragementation. These theoretical models have been incorporated into the cosmic ray transport code HZETRN and will be used to analyze the role of shielding materials in modulating the production and the energy spectrum of light ions.

  2. Radiation Measured with Different Dosimeters for ISS-Expedition 18-19/ULF2 on Board International Space Station during Solar Minimum

    NASA Astrophysics Data System (ADS)

    Zhou, Dazhuang

    Radiation field of particles in low Earth orbit (LEO) is mainly composed of galactic cosmic rays (GCR), solar energetic particles and particles in SAA (South Atlantic Anomaly). GCR are modulated by solar activity, at the period of solar minimum activity, GCR intensity is at maximum and the main contributor for space radiation is GCR. At present for space radiation measurements conducted by JSC (Johnson Space Center) -SRAG (Space Radiation Analysis Group), the preferred active dosimeter sensitive to all LET (Linear Energy Transfer) is the tissue equivalent proportional counter (TEPC); the preferred passive dosimeters are thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) sensitive to low LET as well as CR-39 plastic nuclear track detectors (PNTDs) sensitive to high LET. For the method using passive dosimeters, radiation quantities for all LET can be obtained by combining radiation results measured with TLDs/OSLDs and CR-39 PNTDs. TEPC, TLDs/OSLDs and CR-39 detectors were used to measure the radiation field for the ISS (International Space Station) -Expedition 18-19/ULF2 space mission which was conducted from 15 November 2008 to 31 July 2009 -near the period of the recent solar minimum activity. LET spectra (differential and integral fluence, absorbed dose and dose equivalent) and radiation quantities were measured for positions TEPC, TESS (Temporary Sleeping Station, inside the polyethylene lined sleep station), SM-P 327 and 442 (Service Module -Panel 327 and 442). This paper presents radiation LET spectra measured with TEPC and CR-39 PNTDs and radiation dose measured with TLDs/OSLDs as well as the radiation quantities combined from results measured with passive dosimeters.

  3. Electromagnetic Dissociation and Spacecraft Electronics Damage

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2016-01-01

    When protons or heavy ions from galactic cosmic rays (GCR) or solar particle events (SPE) interact with target nuclei in spacecraft, there can be two different types of interactions. The more familiar strong nuclear interaction often dominates and is responsible for nuclear fragmentation in either the GCR or SPE projectile nucleus or the spacecraft target nucleus. (Of course, the proton does not break up, except possibly to produce pions or other hadrons.) The less familiar, second type of interaction is due to the very strong electromagnetic fields that exist when two charged nuclei pass very close to each other. This process is called electromagnetic dissociation (EMD) and primarily results in the emission of neutrons, protons and light ions (isotopes of hydrogen and helium). The cross section for particle production is approximately defined as the number of particles produced in nucleus-nucleus collisions or other types of reactions. (There are various kinematic and other factors which multiply the particle number to arrive at the cross section.) Strong, nuclear interactions usually dominate the nuclear reactions of most interest that occur between GCR and target nuclei. However, for heavy nuclei (near Fe and beyond) at high energy the EMD cross section can be much larger than the strong nuclear interaction cross section. This paper poses a question: Are there projectile or target nuclei combinations in the interaction of GCR or SPE where the EMD reaction cross section plays a dominant role? If the answer is affirmative, then EMD mechanisms should be an integral part of codes that are used to predict damage to spacecraft electronics. The question can become more fine-tuned and one can ask about total reaction cross sections as compared to double differential cross sections. These issues will be addressed in the present paper.

  4. MCNP6 Cosmic-Source Option

    SciTech Connect

    McKinney, Gregg W; Armstrong, Hirotatsu; James, Michael R; Clem, John; Goldhagen, Paul

    2012-06-19

    MCNP is a Monte Carlo radiation transport code that has been under development for over half a century. Over the last decade, the development team of a high-energy offshoot of MCNP, called MCNPX, has implemented several physics and algorithm improvements important for modeling galactic cosmic-ray (GCR) interactions with matter. In this presentation, we discuss the latest of these improvements, a new Cosmic-Source option, that has been implemented in MCNP6.

  5. Radiation risk predictions for Space Station Freedom orbits

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Atwell, William; Weyland, Mark; Hardy, Alva C.; Wilson, John W.; Townsend, Lawrence W.; Shinn, Judy L.; Katz, Robert

    1991-01-01

    Risk assessment calculations are presented for the preliminary proposed solar minimum and solar maximum orbits for Space Station Freedom (SSF). Integral linear energy transfer (LET) fluence spectra are calculated for the trapped proton and GCR environments. Organ dose calculations are discussed using the computerized anatomical man model. The cellular track model of Katz is applied to calculate cell survival, transformation, and mutation rates for various aluminum shields. Comparisons between relative biological effectiveness (RBE) and quality factor (QF) values for SSF orbits are made.

  6. Application of real-time radiation dosimetry using a new silicon LET sensor

    NASA Technical Reports Server (NTRS)

    Doke, T.; Hayashi, T.; Kikuchi, J.; Nagaoka, S.; Nakano, T.; Sakaguchi, T.; Terasawa, K.; Badhwar, G. D.

    1999-01-01

    A new type of real-time radiation monitoring device, RRMD-III, consisting of three double-sided silicon strip detectors (DSSDs), has been developed and tested on-board the Space Shuttle mission STS-84. The test succeeded in measuring the linear energy transfer (LET) distribution over the range of 0.2 keV/micrometer to 600 keV/micrometer for 178 h. The Shuttle cruised at an altitude of 300 to 400 km and an inclination angle of 51.6 degrees for 221.3 h, which is equivalent to the International Space Station orbit. The LET distribution obtained for particles was investigated by separating it into galactic cosmic ray (GCR) particles and trapped particles in the South Atlantic Anomaly (SAA) region. The result shows that the contribution in dose-equivalent due to GCR particles is almost equal to that from trapped particles. The total absorbed dose rate during the mission was 0.611 mGy/day; the effective quality factor, 1.64; and the dose equivalent rate, 0.998 mSv/day. The average absorbed dose rates are 0.158 mGy/min for GCR particles and 3.67 mGy/min for trapped particles. The effective quality factors are 2.48 for GCR particles and 1.19 for trapped particles. The absorbed doses obtained by the RRMD-III and a conventional method using TLD (Mg(2)SiO(4)), which was placed around the RRMD-III were compared. It was found that the TLDs showed a lower efficiency, just 58% of absorbed dose registered by the RRMD-III.

  7. Comparisons of Integrated Radiation Transport Models with Microdosimetry Data in Spaceflight

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Nikjoo, H.; Kim, M. Y.; Hu, X.; Dicello, J. F.; Pisacane, V. L.

    2006-01-01

    Astronauts are exposed to galactic cosmic rays (GCR), trapped protons, and possible solar particle events (SPE) during spaceflight. For such complicated mixtures of radiation types and kinetic energies, tissue equivalent proportional counters (TEPC's) represent a simple time-dependent approach for radiation monitoring. Of interest in radiation protection is the average quality factor of a radiation field defined as a function of linear energy transfer, LET, Q(sub ave)(LET). However TEPC's measure the average quality factors as a function of lineal energy (y), Q(sub ave)(y) defined as the average energy deposition in a volume divided by the average chord length of the volume. Lineal energy, y deviates from LET due to energy straggling, delta-ray escape or entry, and nuclear fragments produced in the detector. Using integrated space radiation models that includes the transport code HZETRN/BRYNTRN, the quantum nuclear interaction model, QMSFRG, and results from Monte-Carlo track simulations of TEPC's response to ions, we consider comparisons of model calculations to TEPC results from NASA missions in low Earth orbit and make predictions for lunar and Mars missions. Good agreement between the model and measured spectra from past NASA missions is found. A finding of this work is that TEPC's values for trapped or solar protons of Q(sub ave)(y) range from 1.9-2.5, overestimating Q(sub ave)(LET), which ranges from 1.4-1.6 with both quantities increasing with shielding depth due to nuclear secondaries Comparisons for the complete GCR spectra show that Q(sub ave)(LET) for GCR is approximately 3.5-4.5, while TEPC's measure 2.9-3.4 for Q(sub ave)(y) with the GCR values decreasing with depth as heavy ions are absorbed in shielding material. Our results support the use of TEPC's for space radiation environmental monitoring when computational analysis is used for proper data interpretation.

  8. ISOLATED WOLF-RAYET STARS AND O SUPERGIANTS IN THE GALACTIC CENTER REGION IDENTIFIED VIA PASCHEN-{alpha} EXCESS

    SciTech Connect

    Mauerhan, J. C.; Stolovy, S. R.; Cotera, A.; Dong, H.; Wang, Q. D.; Morris, M. R.; Lang, C.

    2010-12-10

    We report the discovery of 19 hot, evolved, massive stars near the Galactic center region (GCR). These objects were selected for spectroscopy owing to their detection as strong sources of Paschen-{alpha} (P{alpha}) emission-line excess, following a narrowband imaging survey of the central 0.{sup 0}65 x 0.{sup 0}25 (l, b) around Sgr A* with the Hubble Space Telescope. Discoveries include six carbon-type (WC) and five nitrogen-type (WN) Wolf-Rayet stars, six O supergiants, and two B supergiants. Two of the O supergiants have X-ray counterparts having properties consistent with solitary O stars and colliding-wind binaries. The infrared photometry of 17 stars is consistent with the Galactic center distance, but 2 of them are located in the foreground. Several WC stars exhibit a relatively large infrared excess, which is possibly thermal emission from hot dust. Most of the stars appear scattered throughout the GCR, with no relation to the three known massive young clusters; several others lie near the Arches and Quintuplet clusters and may have originated within one of these systems. The results of this work bring the total sample of Wolf-Rayet (WR) stars in the GCR to 88. All sources of strong P{alpha} excess have been identified in the area surveyed with HST, which implies that the sample of WN stars in this region is near completion, and is dominated by late (WNL) types. The current WC sample, although probably not complete, is almost exclusively dominated by late (WCL) types. The observed WR subtype distribution in the GCR is a reflection of the intrinsic rarity of early subtypes (WNE and WCE) in the inner Galaxy, an effect that is driven by metallicity.

  9. Cosmic Ray Modulation Observed by the Princess Sirindhorn Neutron Monitor at High Rigidity Cutoff

    NASA Astrophysics Data System (ADS)

    Mangeard, Pierre-Simon; Pyle, Roger; Evenson, Paul; Ruffolo, David; Saiz, Alejandro; Clem, John; Madlee, Suttiwat; Nutaro, Tanin

    2016-07-01

    Neutron monitors (NMs) are the premier instruments for precisely tracking time variations in the Galactic cosmic ray (GCR) flux at the GV-range. For more than 60 years, the worldwide NM network has provided continuous measurements of the solar induced variations of the GCR flux impinging Earth and the data cover about six 11-year solar cycles. The recent rise of space exploration, with PAMELA and AMS-02 spacecraft, brings new energy sensitive measurements of GCR fluxes. Moreover since late 2007, the range of sensitivity of the worldwide NM network has been increased with the installation of the Princess Sirindhorn Neutron Monitor (PSNM), at the summit of Doi Inthanon, Thailand's highest mountain (2565 m altitude). PSNM records the GCR flux with the world's highest vertical rigidity cutoff for a fixed station, 16.8 GV. PSNM data now cover the period from the last solar minimum to the recent solar maximum and give us the opportunity to study the effect of the solar modulation at such high rigidity for the first time. We present here the observations of PSNM since 2007. The observed solar modulation is much weaker than predicted by the force field model with φ inferred from NM data at low cutoff. We compare measurements with those from NMs located at low rigidity cutoff and with spacecraft data. We discuss the solar modulation at high rigidity. Partially supported by a postdoctoral fellowship from Mahidol University, the Thailand Research Fund (BRG 5880009), the Science Achievement Scholarship of Thailand, and US National Science Foundation awards PLR-1341562, PLR-1245939, and their predecessors.

  10. Global clinical response in Cushing’s syndrome patients treated with mifepristone

    PubMed Central

    Katznelson, Laurence; Loriaux, D Lynn; Feldman, David; Braunstein, Glenn D; Schteingart, David E; Gross, Coleman

    2014-01-01

    Objective Mifepristone, a glucocorticoid receptor antagonist, improves clinical status in patients with Cushing’s syndrome (CS). We examined the pattern, reliability and correlates of global clinical response (GCR) assessments during a 6-month clinical trial of mifepristone in CS. Design Post hoc analysis of secondary end-point data from a 24-week multicentre, open-label trial of mifepristone (300–1200mg daily) in CS. Intraclass correlation coefficient (ICC) was used to examine rater concordance, and drivers of clinical improvement were determined by multivariate regression analysis. Patients Forty-six adult patients with refractory CS along with diabetes mellitus type 2 or impaired glucose tolerance, and/or a diagnosis of hypertension. Measurements Global clinical assessment made by three independent reviewers using a three-point ordinal scale (+1 = improvement; 0=no change; −1=worsening) based on eight broad clinical categories including glucose control, lipids, blood pressure, body composition, clinical appearance, strength, psychiatric/cognitive symptoms and quality of life at Weeks 6, 10, 16, and 24. Results Positive GCR increased progressively over time with 88% of patients having improved at Week 24 (P<0·001). The full concordance among reviewers occurred in 76·6% of evaluations resulting in an ICC of 0·652 (P<0·001). Changes in body weight (P<0·0001), diastolic blood pressure (P<0·0001), two-hour postoral glucose challenge glucose concentration (P = 0·0003), and Cushingoid appearance (P=0·022) were strong correlates of GCR. Conclusions Mifepristone treatment for CS results in progressive clinical improvement. Overall agreement among clinical reviewers was substantial and determinants of positive GCR included change in weight, blood pressure, glucose levels and appearance. PMID:24102404

  11. An Algorithm for the Transport of Anisotropic Neutrons

    NASA Technical Reports Server (NTRS)

    Tweed, J.

    2005-01-01

    One major obstacle to human space exploration is the possible limitations imposed by the adverse effect of long-term exposure to the space environment. Even before human spaceflight began, the potentially brief exposure of astronauts to the very intense random solar particle events (SPE) were of great concern. A new challenge appears in deep space exploration from exposure to the low-intensity heavy-ion flux of the galactic cosmic rays (GCR) since the missions are of long duration and the accumulated GCR exposures can be high. Because cancer induction rates increase behind low to rather large thicknesses of aluminum shielding, according to available biological data on mammalian exposures to GCR like ions, the shield requirements for a Mars mission are prohibitively expensive in terms of mission launch costs. Therefore, a critical issue in the Human Exploration and Development of Space enterprise is cost effective mitigation of risk associated with ionizing radiation exposure. In order to estimate astronaut risk to GCR exposure and associated cancer risks and health hazards, it is necessary to do shield material studies. To determine an optimum radiation shield material it is necessary to understand nuclear interaction processes such as fragmentation and secondary particle production which is a function of energy dependent cross sections. This requires knowledge of material transmission characteristics either through laboratory testing or improved theoretical modeling. Here ion beam transport theory is of importance in that testing of materials in the laboratory environment generated by particle accelerators is a necessary step in materials development and evaluation for space use. The approximations used in solving the Boltzmann transport equation for the space setting are often not sufficient for laboratory work and those issues are a major emphasis of the present work.

  12. Space Radiation Hazards on Human Missions to the Moon and Mars

    NASA Astrophysics Data System (ADS)

    Townsend, L.

    2004-12-01

    One of the most significant health risks for humans exploring Earth's moon and Mars is exposure to the harsh space radiation environment. Crews on these exploration missions will be exposed to a complex mixture of very energetic particles. Chronic exposures to the ever-present background galactic cosmic ray (GCR) spectrum consisting of various fluxes of all naturally - occurring chemical elements are combined with infrequent, possibly acute exposures to large fluxes of solar energetic particles, consisting of protons and heavier particles. The GCR environment is primarily a concern for stochastic effects, such as the induction of cancer, with subsequent mortality in many cases, and late deterministic effects, such as cataracts and possible damage to the central nervous system. An acute radiation syndrome response ("radiation sickness") is not possible from the GCR environment since the organ doses are well below levels of concern. Unfortunately, the actual risks of cancer induction and mortality for the very important high-energy heavy ion component of the GCR spectrum are essentially unknown. The sporadic occurrence of extremely large solar energetic particle events, usually associated with intense solar activity, is also a major concern for Lunar and Mars missions because of the possible manifestation of acute effects from the accompanying high doses of such radiations, especially acute radiation syndrome effects such as nausea, emesis, hemorrhaging or possibly even death. Large solar energetic particle events can also contribute significantly to crew risks from cancer mortality. In this presentation an overview of current estimates of critical organ doses and equivalent doses for crews of Lunar and Mars bases and on those on transits between Earth and Mars is presented. Possible methods of mitigating these radiation exposures by shielding, thereby reducing the associated health risks to crews, are also described.

  13. Fabrication of Regolith-Derived Radiation Shield Project

    NASA Technical Reports Server (NTRS)

    Zeitlin, Nancy; Mantovani, James G.; Townsend, Ivan

    2015-01-01

    Mars and asteroids have little or no atmosphere, and do not possess a magnetosphere that can protect humans, mechanisms and electronics from damaging Galactic Cosmic Radiation (GCR) and solar particle events (SPE) as does the Earth. These types of space radiation present one of the highest risks to a human crew during interplanetary journeys and to onboard electronics. This project aims to evaluate the effectiveness of carbonaceous asteroid materials as a potential radiation shielding material.

  14. Multi-Scale Model of Galactic Cosmic Ray Effects on the Hippocampus

    NASA Astrophysics Data System (ADS)

    Cucinotta, Francis

    An important concern for risk assessment from galactic cosmic ray (GCR) exposures is impacts to the central nervous systems including changes in cognition, and associations with increased risk of Alzheimer’s disease (AD). AD, which affects about 50 percent of the population above age 80-yr, is a degenerative disease that worsens with time after initial onset leading to death, and has no known cure. AD is difficult to detect at early stages, and the small number of epidemiology studies that have considered the possibility have not identified an association with low dose radiation. However, experimental studies in transgenic mice suggest the possibility exits. We discuss modeling approaches to consider mechanisms whereby GCR would accelerate the occurrence of AD to earlier ages. Biomarkers of AD include Amyloid beta plaques, and neurofibrillary tangles (NFT) made up of aggregates of the hyper-phosphorylated form of the micro-tubule associated, tau protein. Related markers include synaptic degeneration, dendritic spine loss, and neuronal cell loss through apoptosis. GCR may affect these processes by causing oxidative stress, aberrant signaling following DNA damage, and chronic neuro-inflammation. Cell types considered in multi-scale models are neurons, astrocytes, and microglia. We developed biochemical and cell kinetics models of DNA damage signaling related to glycogen synthase kinase-3 beta and neuro-inflammation, and considered approaches to develop computer simulations of GCR induced cell interactions and their relationships to Amyloid beta plaques and NFTs. Comparison of model results to experimental data for the age specific development of plaques in transgenic mice and predictions of space radiation effects will be discussed.

  15. Observation and prediction of SEU in Hitachi SRAMs in low altitude polar orbits

    SciTech Connect

    Harboe-Sorensen, R.; Daly, E.J.; Adams, L. ); Underwood, C.I. . Surrey Satellite Technology); Mueller, R. . Institut fuer Datenverarbeitungsanlagen)

    1993-12-01

    In-orbit SEU data from three microsatellites are separated into Galactic Cosmic Ray (GCR), South Atlantic Anomaly (SAA) and solar flare upsets. Heavy ion and proton testing of the same devices are reported and predictions using LET-dependent ion cross sections and a 2-parameter fit to proton cross section data are compared with in-flight data. SEU trends in memory devices from a single manufacturer, from 16 K-bit to 4 M-bit, are identified.

  16. Radiation Measured with Different Dosimeters for ISS-Expedition 18-19/ULF2 on Board International Space Station during Solar Minimum

    NASA Technical Reports Server (NTRS)

    Zhou, Dazhuang; Gaza, R.; Roed, Y.; Semones, E.; Lee, K.; Steenburgh, R.; Johnson, S.; Flanders, J.; Zapp, N.

    2010-01-01

    Radiation field of particles in low Earth orbit (LEO) is mainly composed of galactic cosmic rays (GCR), solar energetic particles and particles in SAA (South Atlantic Anomaly). GCR are modulated by solar activity, at the period of solar minimum activity, GCR intensity is at maximum and the main contributor for space radiation is GCR. At present for space radiation measurements conducted by JSC (Johnson Space Center) SRAG (Space Radiation Analysis Group), the preferred active dosimeter sensitive to all LET (Linear Energy Transfer) is the tissue equivalent proportional counter (TEPC); the preferred passive dosimeters are thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) sensitive to low LET as well as CR-39 plastic nuclear track detectors (PNTDs) sensitive to high LET. For the method using passive dosimeters, radiation quantities for all LET can be obtained by combining radiation results measured with TLDs/OSLDs and CR-39 PNTDs. TEPC, TLDs/OSLDs and CR-39 detectors were used to measure the radiation field for the ISS (International Space Station) - Expedition 18-19/ULF2 space mission which was conducted from 15 November 2008 to 31 July 2009 - near the period of the recent solar minimum activity. LET spectra (differential and integral fluence, absorbed dose and dose equivalent) and radiation quantities were measured for positions TEPC, TESS (Temporary Sleeping Station, inside the polyethylene lined sleep station), SM-P 327 and 442 (Service Module - Panel 327 and 442). This paper presents radiation LET spectra measured with TEPC and CR-39 PNTDs and radiation dose measured with TLDs/OSLDs as well as the radiation quantities combined from results measured with passive dosimeters.

  17. Radiation Transport Properties of Potential In Situ-Developed Regolith-Epoxy Materials for Martian Habitats

    NASA Technical Reports Server (NTRS)

    Miller, Jack; Heilbronn, Lawrence H.; Zeitlin, Cary J.; Wilson, John W.; Singleterry, Robert C., Jr.; Thibeault, Sheila Ann

    2003-01-01

    Mission crews in space outside the Earth s magnetic field will be exposed to high energy heavy charged particles in the galactic cosmic radiation (GCR). These highly ionizing particles will be a source of radiation risk to crews on extended missions to the Moon and Mars, and the biological effects of and countermeasures to the GCR have to be investigated as part of the planning of exploration-class missions. While it is impractical to shield spacecraft and planetary habitats against the entire GCR spectrum, biological and physical studies indicate that relatively modest amounts of shielding are effective at reducing the radiation dose. However, nuclear fragmentation in the shielding materials produces highly penetrating secondary particles, which complicates the problem: in some cases, some shielding is worse than none at all. Therefore the radiation transport properties of potential shielding materials need to be carefully investigated. One intriguing option for a Mars mission is the use of material from the Martian surface, in combination with chemicals carried from Earth and/or fabricated from elements found in the Martian atmosphere, to construct crew habitats. We have measured the transmission properties of epoxy-Martian regolith composites with respect to heavy charged particles characteristic of the GCR ions which bombard the Martian surface. The composites were prepared at NASA Langley Research Center using simulated Martian regolith, in the process also evaluating fabrication methods which could lead to technologies for in situ fabrication on Mars. Initial evaluation of the radiation shielding properties is made using radiation transport models developed at NASA-LaRC, and the results of these calculations are used to select the composites with the most favorable radiation transmission properties. These candidates are then evaluated at particle accelerators which produce beams of heavy charged particles representative in energy and charge of the radiation

  18. Sunspot activity and cosmic ray modulation at 1 a.u. for 1900-2013

    NASA Astrophysics Data System (ADS)

    Ahluwalia, H. S.

    2014-10-01

    The descent of sunspot cycle 23 to an unprecedented minimum of long duration in 2006-2009 led to a prolonged galactic cosmic ray (GCR) recovery to the highest level observed in the instrumental era for a variety of energetic charged particle species on Earth, over a wide range of rigidities. The remarkable GCR increase measured by several ground-based, balloon-borne, and detectors on a satellite is described and discussed. It is accompanied by a decrease in solar wind velocity and interplanetary magnetic field at 1 a.u., reaching the lowest values since measurements of the solar wind began in October 1963; the solar polar field strength (μT) measured at the Wilcox Solar Observatory (WSO) is also significantly reduced compared to prior cycles since the start of the program in 1976, the polar field in the northern hemisphere reversed in June 2012 and again in February 2014, that in the southern hemisphere reversed in July 2013. If updates of WSO data confirm the second reversal in northern solar hemisphere, it would pose a serious challenge to the Dynamo Theory. The long-term change in solar behavior may have begun in 1992, perhaps earlier. The physical underpinnings of these solar changes need to be understood and their effect on GCR modulation processes clarified. The study discusses the recent phenomena in the context of GCR modulation since 1900. These happenings affected our empirical predictions for the key parameters for the next two sunspot cycles (they may be progressively less active than sunspot cycle 24) but it enhanced support for our prediction that solar activity is descending into a Dalton-like grand minimum in the middle of the twentyfirst century, reducing the frequency of the coronal mass ejections; they determine the space weather affecting the quality of life on Earth, radiation dose for hardware and human activities in space as well as the frequency of large Forbush decreases at 1 a.u.

  19. Galactic Cosmic Ray Modulation near the Heliospheric Current Sheet

    NASA Astrophysics Data System (ADS)

    Thomas, S. R.; Owens, M. J.; Lockwood, M.; Scott, C. J.

    2014-07-01

    Galactic cosmic rays (GCRs) are modulated by the heliospheric magnetic field (HMF) both over decadal time scales (due to long-term, global HMF variations), and over time scales of a few hours (associated with solar wind structures such as coronal mass ejections or the heliospheric current sheet, HCS). Due to the close association between the HCS, the streamer belt, and the band of slow solar wind, HCS crossings are often associated with corotating interaction regions where fast solar wind catches up and compresses slow solar wind ahead of it. However, not all HCS crossings are associated with strong compressions. In this study we categorize HCS crossings in two ways: Firstly, using the change in magnetic polarity, as either away-to-toward (AT) or toward-to-away (TA) magnetic field directions relative to the Sun and, secondly, using the strength of the associated solar wind compression, determined from the observed plasma density enhancement. For each category, we use superposed epoch analyses to show differences in both solar wind parameters and GCR flux inferred from neutron monitors. For strong-compression HCS crossings, we observe a peak in neutron counts preceding the HCS crossing, followed by a large drop after the crossing, attributable to the so-called `snow-plough' effect. For weak-compression HCS crossings, where magnetic field polarity effects are more readily observable, we instead observe that the neutron counts have a tendency to peak in the away magnetic field sector. By splitting the data by the dominant polarity at each solar polar region, we find that the increase in GCR flux prior to the HCS crossing is primarily from strong compressions in cycles with negative north polar fields due to GCR drift effects. Finally, we report on unexpected differences in GCR behavior between TA weak compressions during opposing polarity cycles.

  20. A comparison of clinician-rated neuropsychological and self-rated cognitive assessments in patients with asthma and rheumatologic disorders.

    PubMed

    Frol, Alan B; Vasquez, Aracely; Getahun, Yonatan; Pacheco, Maria; Khan, David A; Brown, E Sherwood

    2013-01-01

    Although data are mixed, asthma and rheumatologic conditions may be associated with cognitive impairment. Medications may play a role because corticosteroids are associated with memory impairment. Therefore, an easily administered assessment of cognition would be useful in these patients. We assessed relationships between self-rated and clinician-rated cognitive performance and mood in patients with asthma and rheumatologic diseases. Participants included 31adults treated for asthma or rheumatologic disorders (17 receiving chronic prednisone therapy, and 14 not receiving prednisone). An objective assessment of a variety of cognitive domains was administered through clinician and patient-rated assessments of cognition. Composite scores for the objective (Global Clinical Rating [GCR]) and subjective (Neuropsychological Impairment Scale: Global Measure of Impairment [GMI]) measures of cognition were derived. Depression was assessed with the 17-item Hamilton Rating Scale for Depression (HRSD-17). A linear regression was conducted with GMI scores as dependent variable and GCR, HRSD-17 scores, and prednisone-use status, as independent variables. Significant differences between prednisone-treated patients and other patients were observed on the GCR, GMI, and HRSD-17. In the regression analysis, HRSD-17 scores, but not GCR scores, significantly predicted GMI scores. Prednisone-treated patients had higher levels of depressive symptoms and subjective and objective cognitive deficits than those not taking prednisone. In the combined patient groups, subjective cognitive assessment was more strongly related to depressive symptoms than objective cognition. Findings suggest physicians should be aware of the potential for cognitive deficits in patients taking corticosteroids and, when appropriate, should consider the use of objective neurocognitive tests or neuropsychology consultation to better characterize its presence and severity. PMID:23484893