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Sample records for md trajectory analysis

  1. Trajectory Analysis

    NASA Technical Reports Server (NTRS)

    Burke, Laura M.

    2004-01-01

    The Systems Analysis Branch performs trajectory and systems analysis for next-generation launch vehicle and space transportation technologies. Currently the branch is supporting the Project Prometheus with analysis of nuclear electric and nuclear thermal propulsion missions to a variety of destinations. Within Project Prometheus a proposed mission to Jupiter and three of the planet sized icy moons that orbit it is developing. The Jupiter Icy Moons Orbiter (JIMO) as the project is being called will enable detailed scientific investigation of Jupiter's moons Callisto, Ganymede, and Europa. These moons were choose to orbit for intensive study in particular because they are each believed to have water, energy, and organic material. The JIMO mission will utilize nuclear fission power and electric propulsion in order to allow the spacecraft to orbit the moons at close range for long durations of time. My assignment this summer was to assist in developing a trajectory analysis for the spacecraft system the Jupiter Icy Moons Orbiter by rewriting an inefficient Excel file into a more efficient FORTRAN program. This program has been created for use planning the trajectory of the Jupiter Icy Moons Orbiter Mission. The program uses a database of thousands of data points representing flight time, burn time, thrust, mass of the propellant used, final mass of the spacecraft, ratio of finals mass to initial mass, and change in velocity that a spacecraft experiences during each phase in the Jupiter Icy Moons Orbiter Mission. The trajectory program is capable of taking a specific user entered specific impulse (isp), final mass fraction, and thrust (P(sub J)/m0) and through the use of cubic splines to fit specific data curves, the program can locate the exact flight time linked to the user specified values of specific impulse and final over initial mass fraction. Currently, the database used by the program to calculate flight times for a given thrust is only for isps in the range of

  2. Ascent trajectory dispersion analysis

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The results of a Space Transportation System ascent trajectory dispersion analysis are documented. Critical trajectory parameter values useful for the definition of lightweight external tank insulation requirements are provided. This analysis was conducted using two of the critical missions specified for the Space Transportation System: a 28.5 deg inclination trajectory launched from the Eastern Test Range (ETR) and a Western Test Range (WTR) trajectory launched into a 104 deg orbital inclination.

  3. TrackTable Trajectory Analysis

    SciTech Connect

    Wilson, Andrew T.

    2014-08-25

    Tracktable is designed for analysis and rendering of the trajectories of moving objects such as planes, trains, automobiles and ships. Its purpose is to operate on large sets of trajectories (millions) to help a user detect, analyze and display patterns. It will also be used to disseminate trajectory research results from Sandia's PANTHER Grand Challenge LDRD.

  4. PANTHER. Trajectory Analysis

    SciTech Connect

    Rintoul, Mark Daniel; Wilson, Andrew T.; Valicka, Christopher G.; Kegelmeyer, W. Philip; Shead, Timothy M.; Newton, Benjamin D.; Czuchlewski, Kristina Rodriguez

    2015-09-01

    We want to organize a body of trajectories in order to identify, search for, classify and predict behavior among objects such as aircraft and ships. Existing compari- son functions such as the Fr'echet distance are computationally expensive and yield counterintuitive results in some cases. We propose an approach using feature vectors whose components represent succinctly the salient information in trajectories. These features incorporate basic information such as total distance traveled and distance be- tween start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally, these features can generally be mapped easily to behaviors of interest to humans that are searching large databases. Most of these geometric features are invariant under rigid transformation. We demonstrate the use of different subsets of these features to iden- tify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories, predict destination and apply unsupervised machine learning algorithms.

  5. MDTraj: A Modern Open Library for the Analysis of Molecular Dynamics Trajectories

    PubMed Central

    McGibbon, Robert T.; Beauchamp, Kyle A.; Harrigan, Matthew P.; Klein, Christoph; Swails, Jason M.; Hernández, Carlos X.; Schwantes, Christian R.; Wang, Lee-Ping; Lane, Thomas J.; Pande, Vijay S.

    2015-01-01

    As molecular dynamics (MD) simulations continue to evolve into powerful computational tools for studying complex biomolecular systems, the necessity of flexible and easy-to-use software tools for the analysis of these simulations is growing. We have developed MDTraj, a modern, lightweight, and fast software package for analyzing MD simulations. MDTraj reads and writes trajectory data in a wide variety of commonly used formats. It provides a large number of trajectory analysis capabilities including minimal root-mean-square-deviation calculations, secondary structure assignment, and the extraction of common order parameters. The package has a strong focus on interoperability with the wider scientific Python ecosystem, bridging the gap between MD data and the rapidly growing collection of industry-standard statistical analysis and visualization tools in Python. MDTraj is a powerful and user-friendly software package that simplifies the analysis of MD data and connects these datasets with the modern interactive data science software ecosystem in Python. PMID:26488642

  6. 14 CFR 417.207 - Trajectory analysis.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... a programmed thrust termination. (3) For launch vehicles flown with a flight safety system, a... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.207 Trajectory analysis. (a) General. A flight safety analysis must include a trajectory analysis that establishes: (1) For any...

  7. 14 CFR 417.207 - Trajectory analysis.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... a programmed thrust termination. (3) For launch vehicles flown with a flight safety system, a... OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.207 Trajectory analysis. (a) General. A flight safety analysis must include a trajectory analysis that establishes: (1) For any...

  8. Flight test trajectory control analysis

    NASA Technical Reports Server (NTRS)

    Walker, R.; Gupta, N.

    1983-01-01

    Recent extensions to optimal control theory applied to meaningful linear models with sufficiently flexible software tools provide powerful techniques for designing flight test trajectory controllers (FTTCs). This report describes the principal steps for systematic development of flight trajectory controllers, which can be summarized as planning, modeling, designing, and validating a trajectory controller. The techniques have been kept as general as possible and should apply to a wide range of problems where quantities must be computed and displayed to a pilot to improve pilot effectiveness and to reduce workload and fatigue. To illustrate the approach, a detailed trajectory guidance law is developed and demonstrated for the F-15 aircraft flying the zoom-and-pushover maneuver.

  9. Soccer ball lift coefficients via trajectory analysis

    NASA Astrophysics Data System (ADS)

    Goff, John Eric; Carré, Matt J.

    2010-07-01

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

  10. ST-analyzer: a web-based user interface for simulation trajectory analysis.

    PubMed

    Jeong, Jong Cheol; Jo, Sunhwan; Wu, Emilia L; Qi, Yifei; Monje-Galvan, Viviana; Yeom, Min Sun; Gorenstein, Lev; Chen, Feng; Klauda, Jeffery B; Im, Wonpil

    2014-05-05

    Molecular dynamics (MD) simulation has become one of the key tools to obtain deeper insights into biological systems using various levels of descriptions such as all-atom, united-atom, and coarse-grained models. Recent advances in computing resources and MD programs have significantly accelerated the simulation time and thus increased the amount of trajectory data. Although many laboratories routinely perform MD simulations, analyzing MD trajectories is still time consuming and often a difficult task. ST-analyzer, http://im.bioinformatics.ku.edu/st-analyzer, is a standalone graphical user interface (GUI) toolset to perform various trajectory analyses. ST-analyzer has several outstanding features compared to other existing analysis tools: (i) handling various formats of trajectory files from MD programs, such as CHARMM, NAMD, GROMACS, and Amber, (ii) intuitive web-based GUI environment--minimizing administrative load and reducing burdens on the user from adapting new software environments, (iii) platform independent design--working with any existing operating system, (iv) easy integration into job queuing systems--providing options of batch processing either on the cluster or in an interactive mode, and (v) providing independence between foreground GUI and background modules--making it easier to add personal modules or to recycle/integrate pre-existing scripts utilizing other analysis tools. The current ST-analyzer contains nine main analysis modules that together contain 18 options, including density profile, lipid deuterium order parameters, surface area per lipid, and membrane hydrophobic thickness. This article introduces ST-analyzer with its design, implementation, and features, and also illustrates practical analysis of lipid bilayer simulations.

  11. 14 CFR 417.207 - Trajectory analysis.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the requirements of paragraph (a) of this section. (c) Wind effects. A trajectory analysis must account for all wind effects, including profiles of winds that are no less severe than the worst wind conditions under which flight might be attempted, and must account for uncertainty in the wind conditions....

  12. 14 CFR 417.207 - Trajectory analysis.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the requirements of paragraph (a) of this section. (c) Wind effects. A trajectory analysis must account for all wind effects, including profiles of winds that are no less severe than the worst wind conditions under which flight might be attempted, and must account for uncertainty in the wind conditions....

  13. 14 CFR 417.207 - Trajectory analysis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the requirements of paragraph (a) of this section. (c) Wind effects. A trajectory analysis must account for all wind effects, including profiles of winds that are no less severe than the worst wind conditions under which flight might be attempted, and must account for uncertainty in the wind conditions....

  14. Analysis and prediction of stratospheric balloons trajectories

    NASA Astrophysics Data System (ADS)

    Cardillo, A.; Memmo, A.; Musso, I.; Ibba, R.; Spoto, D.

    The first step to manage a balloon flight from a trajectory point of view is the definition of launch location and period. Analysis data are used to realize a statistical study of the trajectories that can be obtained. The goal is define the conditions able to maximize the probability to respect mission objectives and constrains. Ones started with operations the balloon control centre has to manage the flight respecting safety and science. To predict stratospheric balloon trajectories we must utilize data from different forecast models and real-time measurements of wind and other meteorological entities. These sources of information have to be merged along the simulation of the balloon flight. Great attention has be paid for long duration flight from Pole and Equator, where QBO plays an important role.

  15. Ascent trajectory dispersion analysis for WTR heads-up space shuttle trajectory

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The results of a Space Transportation System ascent trajectory dispersion analysis are discussed. The purpose is to provide critical trajectory parameter values for assessing the Space Shuttle in a heads-up configuration launched from the Western Test Range (STR). This analysis was conducted using a trajectory profile based on a launch from the WTR in December. The analysis consisted of the following steps: (1) nominal trajectories were simulated under the conditions as specified by baseline reference mission guidelines; (2) dispersion trajectories were simulated using predetermined parametric variations; (3) requirements for a system-related composite trajectory were determined by a root-sum-square (RSS) analysis of the positive deviations between values of the aerodynamic heating indicator (AHI) generated by the dispersion and nominal trajectories; (4) using the RSS assessment as a guideline, the system related composite trajectory was simulated by combinations of dispersion parameters which represented major contributors; (5) an assessment of environmental perturbations via a RSS analysis was made by the combination of plus or minus 2 sigma atmospheric density variation and 95% directional design wind dispersions; (6) maximum aerodynamic heating trajectories were simulated by variation of dispersion parameters which would emulate the summation of the system-related RSS and environmental RSS values of AHI. The maximum aerodynamic heating trajectories were simulated consistent with the directional winds used in the environmental analysis.

  16. TAOS. Trajectory Analysis and Optimization System

    SciTech Connect

    Salguero, D.E.

    1995-12-09

    TAOS is a general-purpose software tool capable of analyzing nearly any type of three degree-of-freedom point-mass, high-speed trajectory. Input files contain aerodynamic coefficients, propulsion data, and a trajectory description. The trajectory description divides the trajectory into segments, and within each segment, guidance rules provided by the user describe how the trajectory is computed. Output files contain tabulated trajectory information such as position, velocity, and acceleration. Parametric optimization provides a powerful method for satisfying mission-planning constraints, and trajectories involving more than one vehicle can be computed within a single problem.

  17. The ESA's Space Trajectory Analysis software suite

    NASA Astrophysics Data System (ADS)

    Ortega, Guillermo

    The European Space Agency (ESA) initiated in 2005 an internal activity to develop an open source software suite involving university science departments and research institutions all over the world. This project is called the "Space Trajectory Analysis" or STA. This article describes the birth of STA and its present configuration. One of the STA aims is to promote the exchange of technical ideas, and raise knowledge and competence in the areas of applied mathematics, space engineering, and informatics at University level. Conceived as a research and education tool to support the analysis phase of a space mission, STA is able to visualize a wide range of space trajectories. These include among others ascent, re-entry, descent and landing trajectories, orbits around planets and moons, interplanetary trajectories, rendezvous trajectories, etc. The article explains that STA project is an original idea of the Technical Directorate of ESA. It was born in August 2005 to provide a framework in astrodynamics research at University level. As research and education software applicable to Academia, a number of Universities support this development by joining ESA in leading the development. ESA and Universities partnership are expressed in the STA Steering Board. Together with ESA, each University has a chair in the board whose tasks are develop, control, promote, maintain, and expand the software suite. The article describes that STA provides calculations in the fields of spacecraft tracking, attitude analysis, coverage and visibility analysis, orbit determination, position and velocity of solar system bodies, etc. STA implements the concept of "space scenario" composed of Solar system bodies, spacecraft, ground stations, pads, etc. It is able to propagate the orbit of a spacecraft where orbital propagators are included. STA is able to compute communication links between objects of a scenario (coverage, line of sight), and to represent the trajectory computations and

  18. Trajectory analysis and optimization system (TAOS) user`s manual

    SciTech Connect

    Salguero, D.E.

    1995-12-01

    The Trajectory Analysis and Optimization System (TAOS) is software that simulates point--mass trajectories for multiple vehicles. It expands upon the capabilities of the Trajectory Simulation and Analysis program (TAP) developed previously at Sandia National Laboratories. TAOS is designed to be a comprehensive analysis tool capable of analyzing nearly any type of three degree-of-freedom, point-mass trajectory. Trajectories are broken into segments, and within each segment, guidance rules provided by the user control how the trajectory is computed. Parametric optimization provides a powerful method for satisfying mission-planning constraints. Althrough TAOS is not interactive, its input and output files have been designed for ease of use. When compared to TAP, the capability to analyze trajectories for more than one vehicle is the primary enhancement, although numerous other small improvements have been made. This report documents the methods used in TAOS as well as the input and output file formats.

  19. Antenna trajectory error analysis in backprojection-based SAR images

    NASA Astrophysics Data System (ADS)

    Wang, Ling; Yazıcı, Birsen; Yanik, H. Cagri

    2014-06-01

    We present an analysis of the positioning errors in Backprojection (BP)-based Synthetic Aperture Radar (SAR) images due to antenna trajectory errors for a monostatic SAR traversing a straight linear trajectory. Our analysis is developed using microlocal analysis, which can provide an explicit quantitative relationship between the trajectory error and the positioning error in BP-based SAR images. The analysis is applicable to arbitrary trajectory errors in the antenna and can be extended to arbitrary imaging geometries. We present numerical simulations to demonstrate our analysis.

  20. Stochastic and fractal analysis of fracture trajectories

    NASA Technical Reports Server (NTRS)

    Bessendorf, Michael H.

    1987-01-01

    Analyses of fracture trajectories are used to investigate structures that fall between 'micro' and 'macro' scales. It was shown that fracture trajectories belong to the class of nonstationary processes. It was also found that correlation distance, which may be related to a characteristic size of a fracture process, increases with crack length. An assemblage of crack trajectory processes may be considered as a diffusive process. Chudnovsky (1981-1985) introduced a 'crack diffusion coefficient' d which reflects the ability of the material to deviate the crack trajectory from the most energetically efficient path and thus links the material toughness to its structure. For the set of fracture trajectories in AISI 304 steel, d was found to be equal to 1.04 microns. The fractal dimension D for the same set of trajectories was found to be 1.133.

  1. Trajectory analysis of a soccer ball

    NASA Astrophysics Data System (ADS)

    Goff, John Eric; Carré, Matt J.

    2009-11-01

    We performed experiments in which a soccer ball was launched from a machine while two cameras recorded portions of its trajectory. Drag coefficients were obtained from range measurements for no-spin trajectories, for which the drag coefficient does not vary appreciably during the ball's flight. Lift coefficients were obtained from the trajectories immediately following the ball's launch, in which Reynolds number and spin parameter do not vary much. We obtain two values of the lift coefficient for spin parameters that had not been obtained previously. Our codes for analyzing the trajectories are freely available to educators and students.

  2. Essential dynamics/factor analysis for the interpretation of molecular dynamics trajectories

    NASA Astrophysics Data System (ADS)

    Kaźmierkiewicz, R.; Czaplewski, C.; Lammek, B.; Ciarkowski, J.

    1999-01-01

    Subject of this work is the analysis of molecular dynamics (MD) trajectories of neurophysins I (NPI) and II (NPII) and their complexes with the neurophyseal nonapeptide hormones oxytocin (OT) and vasopresssin (VP), respectively, simulated in water. NPs serve in the neurosecretory granules as carrier proteins for the hormones before their release to the blood. The starting data consisted of two pairs of different trajectories for each of the (NPII/VP)2 and (NPI/OT)2 heterotetramers and two more trajectories for the NPII2 and NPI2 homodimers (six trajectories in total). Using essential dynamics which, to our judgement, is equivalent to factor analysis, we found that only about 10 degrees of freedom per trajectory are necessary and sufficient to describe in full the motions relevant for the function of the protein. This is consistent with these motions to explain about 90% of the total variance of the system. These principal degrees of freedom represent slow anharmonic motional modes, clearly pointing at distinguished mobility of the atoms involved in the protein's functionality.

  3. Soccer Ball Lift Coefficients via Trajectory Analysis

    ERIC Educational Resources Information Center

    Goff, John Eric; Carre, Matt J.

    2010-01-01

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

  4. Trajectory Based Behavior Analysis for User Verification

    NASA Astrophysics Data System (ADS)

    Pao, Hsing-Kuo; Lin, Hong-Yi; Chen, Kuan-Ta; Fadlil, Junaidillah

    Many of our activities on computer need a verification step for authorized access. The goal of verification is to tell apart the true account owner from intruders. We propose a general approach for user verification based on user trajectory inputs. The approach is labor-free for users and is likely to avoid the possible copy or simulation from other non-authorized users or even automatic programs like bots. Our study focuses on finding the hidden patterns embedded in the trajectories produced by account users. We employ a Markov chain model with Gaussian distribution in its transitions to describe the behavior in the trajectory. To distinguish between two trajectories, we propose a novel dissimilarity measure combined with a manifold learnt tuning for catching the pairwise relationship. Based on the pairwise relationship, we plug-in any effective classification or clustering methods for the detection of unauthorized access. The method can also be applied for the task of recognition, predicting the trajectory type without pre-defined identity. Given a trajectory input, the results show that the proposed method can accurately verify the user identity, or suggest whom owns the trajectory if the input identity is not provided.

  5. Mars Ascent Propulsion Trades with Trajectory Analysis

    SciTech Connect

    Whitehead, J

    2004-04-22

    Optimized trajectories to a 500 km circular orbit are calculated for vehicles having a 100 kg Mars launch mass. Staging trades, thrust optimization, and the importance of vehicle shape for drag are all taken into consideration. The high acceleration of solid rockets requires a steep trajectory for drag avoidance, followed by a relatively large circularization burn, appropriate for a second stage. Liquid thrust reduces drag, resulting in less steep trajectories which have small circularization burns. Liquid propulsion requires less total {Delta}v, and offers options for multiple stages or just one. Graphs of payload mass versus stage propellant fractions are compared for liquid and solid propulsion.

  6. Interdisciplinary Learning in Pharmacology: Analysis of M.D. and P.A. Student Performance.

    ERIC Educational Resources Information Center

    Andrus, Peter L.; And Others

    1981-01-01

    An analysis of M.D. and physician's assistant (P.A.) student comparative performances at Baylor College of Medicine is presented. The analysis was seen as being appropriate in view of the P.A.'s increasing involvement with the implementation and monitoring of therapeutic programs. (Author/MLW)

  7. Cell mechanics through analysis of cell trajectories in microfluidic channel

    NASA Astrophysics Data System (ADS)

    Bowie, Samuel; Alexeev, Alexander; Sulchek, Todd

    The understanding of dynamic cell behavior can aid in research ranging from the mechanistic causes of diseases to the development of microfluidic devices for cancer detection. Through analysis of trajectories captured from video of the cells moving in a specially designed microfluidic device, insight into the dynamic viscoelastic nature of cells can be found. The microfluidic device distinguishes cells viscoelastic properties through the use of angled ridges causing a series of compressions, resulting in differences in trajectories based on cell stiffness. Trajectories of cell passing through the device are collected using image processing methods and data mining techniques are used to relate the trajectories to cell properties obtained from experiments. Furthermore, numerical simulation of the cell and microfluidic device are used to match the experimental results from the trajectory analysis. Combination of the modeling and experimental data help to uncover how changes in cellular structures result in changes in mechanical properties.

  8. Analysis of trajectory entropy for continuous stochastic processes at equilibrium.

    PubMed

    Haas, Kevin R; Yang, Haw; Chu, Jhih-Wei

    2014-07-17

    The analytical expression for the trajectory entropy of the overdamped Langevin equation is derived via two approaches. The first route goes through the Fokker-Planck equation that governs the propagation of the conditional probability density, while the second method goes through the path integral of the Onsager-Machlup action. The agreement of these two approaches in the continuum limit underscores the equivalence between the partial differential equation and the path integral formulations for stochastic processes in the context of trajectory entropy. The values obtained using the analytical expression are also compared with those calculated with numerical solutions for arbitrary time resolutions of the trajectory. Quantitative agreement is clearly observed consistently across different models as the time interval between snapshots in the trajectories decreases. Furthermore, analysis of different scenarios illustrates how the deterministic and stochastic forces in the Langevin equation contribute to the variation in dynamics measured by the trajectory entropy.

  9. Quantifying ataxia: ideal trajectory analysis--a technical note

    NASA Technical Reports Server (NTRS)

    McPartland, M. D.; Krebs, D. E.; Wall, C. 3rd

    2000-01-01

    We describe a quantitative method to assess repeated stair stepping stability. In both the mediolateral (ML) and anterioposterior (AP) directions, the trajectory of the subject's center of mass (COM) was compared to an ideal sinusoid. The two identified sinusoids were unique in each direction but coupled. Two dimensionless numbers-the mediolateral instability index (IML) and AP instability index (IAP)-were calculated using the COM trajectory and ideal sinusoids for each subject with larger index values resulting from less stable performance. The COM trajectories of nine nonimpaired controls and six patients diagnosed with unilateral or bilateral vestibular labyrinth hypofunction were analyzed. The average IML and IAP values of labyrinth disorder patients were respectively 127% and 119% greater than those of controls (p<0.014 and 0.006, respectively), indicating that the ideal trajectory analysis distinguishes persons with labyrinth disorder from those without. The COM trajectories also identify movement inefficiencies attributable to vestibulopathy.

  10. Trajectory analysis for magnetic particle imaging.

    PubMed

    Knopp, T; Biederer, S; Sattel, T; Weizenecker, J; Gleich, B; Borgert, J; Buzug, T M

    2009-01-21

    Recently a new imaging technique called magnetic particle imaging was proposed. The method uses the nonlinear response of magnetic nanoparticles when a time varying magnetic field is applied. Spatial encoding is achieved by moving a field-free point through an object of interest while the field strength in the vicinity of the point is high. A resolution in the submillimeter range is provided even for fast data acquisition sequences. In this paper, a simulation study is performed on different trajectories moving the field-free point through the field of view. The purpose is to provide mandatory information for the design of a magnetic particle imaging scanner. Trajectories are compared with respect to density, speed and image quality when applied in data acquisition. Since simulation of the involved physics is a time demanding task, moreover, an efficient implementation is presented utilizing caching techniques.

  11. Conformational and functional analysis of molecular dynamics trajectories by Self-Organising Maps

    PubMed Central

    2011-01-01

    Background Molecular dynamics (MD) simulations are powerful tools to investigate the conformational dynamics of proteins that is often a critical element of their function. Identification of functionally relevant conformations is generally done clustering the large ensemble of structures that are generated. Recently, Self-Organising Maps (SOMs) were reported performing more accurately and providing more consistent results than traditional clustering algorithms in various data mining problems. We present a novel strategy to analyse and compare conformational ensembles of protein domains using a two-level approach that combines SOMs and hierarchical clustering. Results The conformational dynamics of the α-spectrin SH3 protein domain and six single mutants were analysed by MD simulations. The Cα's Cartesian coordinates of conformations sampled in the essential space were used as input data vectors for SOM training, then complete linkage clustering was performed on the SOM prototype vectors. A specific protocol to optimize a SOM for structural ensembles was proposed: the optimal SOM was selected by means of a Taguchi experimental design plan applied to different data sets, and the optimal sampling rate of the MD trajectory was selected. The proposed two-level approach was applied to single trajectories of the SH3 domain independently as well as to groups of them at the same time. The results demonstrated the potential of this approach in the analysis of large ensembles of molecular structures: the possibility of producing a topological mapping of the conformational space in a simple 2D visualisation, as well as of effectively highlighting differences in the conformational dynamics directly related to biological functions. Conclusions The use of a two-level approach combining SOMs and hierarchical clustering for conformational analysis of structural ensembles of proteins was proposed. It can easily be extended to other study cases and to conformational ensembles from

  12. Hodograph analysis in aircraft trajectory optimization

    NASA Technical Reports Server (NTRS)

    Cliff, Eugene M.; Seywald, Hans; Bless, Robert R.

    1993-01-01

    An account is given of key geometrical concepts involved in the use of a hodograph as an optimal control theory resource which furnishes a framework for geometrical interpretation of the minimum principle. Attention is given to the effects of different convexity properties on the hodograph, which bear on the existence of solutions and such types of controls as chattering controls, 'bang-bang' control, and/or singular control. Illustrative aircraft trajectory optimization problems are examined in view of this use of the hodograph.

  13. Dust trajectory sensor: accuracy and data analysis.

    PubMed

    Xie, J; Sternovsky, Z; Grün, E; Auer, S; Duncan, N; Drake, K; Le, H; Horanyi, M; Srama, R

    2011-10-01

    The Dust Trajectory Sensor (DTS) instrument is developed for the measurement of the velocity vector of cosmic dust particles. The trajectory information is imperative in determining the particles' origin and distinguishing dust particles from different sources. The velocity vector also reveals information on the history of interaction between the charged dust particle and the magnetospheric or interplanetary space environment. The DTS operational principle is based on measuring the induced charge from the dust on an array of wire electrodes. In recent work, the DTS geometry has been optimized [S. Auer, E. Grün, S. Kempf, R. Srama, A. Srowig, Z. Sternovsky, and V Tschernjawski, Rev. Sci. Instrum. 79, 084501 (2008)] and a method of triggering was developed [S. Auer, G. Lawrence, E. Grün, H. Henkel, S. Kempf, R. Srama, and Z. Sternovsky, Nucl. Instrum. Methods Phys. Res. A 622, 74 (2010)]. This article presents the method of analyzing the DTS data and results from a parametric study on the accuracy of the measurements. A laboratory version of the DTS has been constructed and tested with particles in the velocity range of 2-5 km/s using the Heidelberg dust accelerator facility. Both the numerical study and the analyzed experimental data show that the accuracy of the DTS instrument is better than about 1% in velocity and 1° in direction.

  14. Dust trajectory sensor: Accuracy and data analysis

    SciTech Connect

    Xie, J.; Horanyi, M.; Sternovsky, Z.; Gruen, E.; Duncan, N.; Drake, K.; Le, H.; Auer, S.; Srama, R.

    2011-10-15

    The Dust Trajectory Sensor (DTS) instrument is developed for the measurement of the velocity vector of cosmic dust particles. The trajectory information is imperative in determining the particles' origin and distinguishing dust particles from different sources. The velocity vector also reveals information on the history of interaction between the charged dust particle and the magnetospheric or interplanetary space environment. The DTS operational principle is based on measuring the induced charge from the dust on an array of wire electrodes. In recent work, the DTS geometry has been optimized [S. Auer, E. Gruen, S. Kempf, R. Srama, A. Srowig, Z. Sternovsky, and V Tschernjawski, Rev. Sci. Instrum. 79, 084501 (2008)] and a method of triggering was developed [S. Auer, G. Lawrence, E. Gruen, H. Henkel, S. Kempf, R. Srama, and Z. Sternovsky, Nucl. Instrum. Methods Phys. Res. A 622, 74 (2010)]. This article presents the method of analyzing the DTS data and results from a parametric study on the accuracy of the measurements. A laboratory version of the DTS has been constructed and tested with particles in the velocity range of 2-5 km/s using the Heidelberg dust accelerator facility. Both the numerical study and the analyzed experimental data show that the accuracy of the DTS instrument is better than about 1% in velocity and 1 deg. in direction.

  15. The Best Estimated Trajectory Analysis for Pad Abort One

    NASA Technical Reports Server (NTRS)

    Kutty, Prasad; Noonan, Meghan; Karlgaard, Christopher; Beck, Roger

    2011-01-01

    I. Best Estimated Trajectory (BET) objective: a) Produce reconstructed trajectory of the PA-1 flight to understand vehicle dynamics and aid other post flight analyses. b) Leverage all measurement sources taken of vehicle during flight to produce the most accurate estimate of vehicle trajectory. c) Generate trajectory reconstructions of the Crew Module (CM), Launch Abort System (LAS), and Forward Bay Cover (FBC). II. BET analysis was started immediately following the PA-1 mission and was completed in September, 2010 a) Quick look version of BET released 5/25/2010: initial repackaging of SIGI data. b) Preliminary version of BET released 7/6/2010: first blended solution using available sources of external measurements. c) Final version of BET released 9/1/2010: final blended solution using all available sources of data.

  16. Visual traffic jam analysis based on trajectory data.

    PubMed

    Wang, Zuchao; Lu, Min; Yuan, Xiaoru; Zhang, Junping; van de Wetering, Huub

    2013-12-01

    In this work, we present an interactive system for visual analysis of urban traffic congestion based on GPS trajectories. For these trajectories we develop strategies to extract and derive traffic jam information. After cleaning the trajectories, they are matched to a road network. Subsequently, traffic speed on each road segment is computed and traffic jam events are automatically detected. Spatially and temporally related events are concatenated in, so-called, traffic jam propagation graphs. These graphs form a high-level description of a traffic jam and its propagation in time and space. Our system provides multiple views for visually exploring and analyzing the traffic condition of a large city as a whole, on the level of propagation graphs, and on road segment level. Case studies with 24 days of taxi GPS trajectories collected in Beijing demonstrate the effectiveness of our system.

  17. Analysis of alternative-fuel price trajectories

    SciTech Connect

    Not Available

    1980-12-31

    Findings are presented from a study to (1) acquire, analyze, and report alternative published price projections including both oil- and coal-price trajectories, and to (2) apply the fixed-annuity formula to the updated primary source projections (Energy Information Administration; Data Resources, Inc.; and Wharton Econometric Forecasting Associates, Inc.) and to the newly acquired price projections. This report also encompasses: comparisons of key assumptions underlying the price projections, and a discussion of the applicability of the fixed-annuity formula as used in the alternative-cost calculation. Section II contains graphic presentations of all updated and newly acquired coal and oil price forecasts and the corresponding calculated annuity equivalents, tabulated presentations and discussions of each forecast and underlying assumptions, and a description of how each forecast price series was transformed into input for the present-value formulas. Section III presents the fixed-annuity formula employed and discusses its appropriateness for this application. Section IV discusses the applicability of the net present value approach for comparing alternate-fuel price trajectories. Appendix A contains a listing of contacts as potential sources of price forecasts. Appendix B contains the raw forecast data from each forecast source and the coal and oil price series derived from the raw data which were actually input into the cost calculation procedure. Appendix C contains a description and listing of the computer program developed to implement the cost calculation procedure. Finally, Appendix D contains tabulations and discussions of other alternative world crude price forecasts that were identified, but for which no corresponding coal-price projections were available. (MCW)

  18. Analysis and Interpretation of Superresolution Single-Particle Trajectories

    PubMed Central

    Holcman, D.; Hoze, N.; Schuss, Z.

    2015-01-01

    A large number (tens of thousands) of single molecular trajectories on a cell membrane can now be collected by superresolution methods. The data contains information about the diffusive motion of molecule, proteins, or receptors and here we review methods for its recovery by statistical analysis of the data. The information includes the forces, organization of the membrane, the diffusion tensor, the long-time behavior of the trajectories, and more. To recover the long-time behavior and statistics of long trajectories, a stochastic model of their nonequilibrium motion is required. Modeling and data analysis serve extracting novel biophysical features at an unprecedented spatiotemporal resolution. The review presents data analysis, modeling, and stochastic simulations applied in particular on surface receptors evolving in neuronal cells. PMID:26536253

  19. IBiSA_Tools: A Computational Toolkit for Ion-Binding State Analysis in Molecular Dynamics Trajectories of Ion Channels

    PubMed Central

    Kasahara, Kota; Kinoshita, Kengo

    2016-01-01

    Ion conduction mechanisms of ion channels are a long-standing conundrum. Although the molecular dynamics (MD) method has been extensively used to simulate ion conduction dynamics at the atomic level, analysis and interpretation of MD results are not straightforward due to complexity of the dynamics. In our previous reports, we proposed an analytical method called ion-binding state analysis to scrutinize and summarize ion conduction mechanisms by taking advantage of a variety of analytical protocols, e.g., the complex network analysis, sequence alignment, and hierarchical clustering. This approach effectively revealed the ion conduction mechanisms and their dependence on the conditions, i.e., ion concentration and membrane voltage. Here, we present an easy-to-use computational toolkit for ion-binding state analysis, called IBiSA_tools. This toolkit consists of a C++ program and a series of Python and R scripts. From the trajectory file of MD simulations and a structure file, users can generate several images and statistics of ion conduction processes. A complex network named ion-binding state graph is generated in a standard graph format (graph modeling language; GML), which can be visualized by standard network analyzers such as Cytoscape. As a tutorial, a trajectory of a 50 ns MD simulation of the Kv1.2 channel is also distributed with the toolkit. Users can trace the entire process of ion-binding state analysis step by step. The novel method for analysis of ion conduction mechanisms of ion channels can be easily used by means of IBiSA_tools. This software is distributed under an open source license at the following URL: http://www.ritsumei.ac.jp/~ktkshr/ibisa_tools/ PMID:27907142

  20. CFD Analysis of Swing of Cricket Ball and Trajectory Prediction

    NASA Astrophysics Data System (ADS)

    G, Jithin; Tom, Josin; Ruishikesh, Kamat; Jose, Jyothish; Kumar, Sanjay

    2013-11-01

    This work aims to understand the aerodynamics associated with the flight and swing of a cricket ball and predict its flight trajectory over the course of the game: at start (smooth ball) and as the game progresses (rough ball). Asymmetric airflow over the ball due to seam orientation and surface roughness can cause flight deviation (swing). The values of Drag, Lift and Side forces which are crucial for determining the trajectory of the ball were found with the help of FLUENT using the standard K- ɛ model. Analysis was done to study how the ball velocity, spin imparted to be ball and the tilt of the seam affects the movement of the ball through air. The governing force balance equations in 3 dimensions in combination a MATLAB code which used Heun's method was used for obtaining the trajectory of the ball. The conditions for the conventional swing and reverse swing to occur were deduced from the analysis and found to be in alignment with the real life situation. Critical seam angle for maximum swing and transition speed for normal to reverse swing were found out. The obtained trajectories were compared to real life hawk eye trajectories for validation. The analysis results were in good agreement with the real life situation.

  1. Wettability of graphitic-carbon and silicon surfaces: MD modeling and theoretical analysis

    SciTech Connect

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G. P.

    2015-07-28

    The wettability of graphitic carbon and silicon surfaces was numerically and theoretically investigated. A multi-response method has been developed for the analysis of conventional molecular dynamics (MD) simulations of droplets wettability. The contact angle and indicators of the quality of the computations are tracked as a function of the data sets analyzed over time. This method of analysis allows accurate calculations of the contact angle obtained from the MD simulations. Analytical models were also developed for the calculation of the work of adhesion using the mean-field theory, accounting for the interfacial entropy changes. A calibration method is proposed to provide better predictions of the respective contact angles under different solid-liquid interaction potentials. Estimations of the binding energy between a water monomer and graphite match those previously reported. In addition, a breakdown in the relationship between the binding energy and the contact angle was observed. The macroscopic contact angles obtained from the MD simulations were found to match those predicted by the mean-field model for graphite under different wettability conditions, as well as the contact angles of Si(100) and Si(111) surfaces. Finally, an assessment of the effect of the Lennard-Jones cutoff radius was conducted to provide guidelines for future comparisons between numerical simulations and analytical models of wettability.

  2. Novel 3D/VR interactive environment for MD simulations, visualization and analysis.

    PubMed

    Doblack, Benjamin N; Allis, Tim; Dávila, Lilian P

    2014-12-18

    The increasing development of computing (hardware and software) in the last decades has impacted scientific research in many fields including materials science, biology, chemistry and physics among many others. A new computational system for the accurate and fast simulation and 3D/VR visualization of nanostructures is presented here, using the open-source molecular dynamics (MD) computer program LAMMPS. This alternative computational method uses modern graphics processors, NVIDIA CUDA technology and specialized scientific codes to overcome processing speed barriers common to traditional computing methods. In conjunction with a virtual reality system used to model materials, this enhancement allows the addition of accelerated MD simulation capability. The motivation is to provide a novel research environment which simultaneously allows visualization, simulation, modeling and analysis. The research goal is to investigate the structure and properties of inorganic nanostructures (e.g., silica glass nanosprings) under different conditions using this innovative computational system. The work presented outlines a description of the 3D/VR Visualization System and basic components, an overview of important considerations such as the physical environment, details on the setup and use of the novel system, a general procedure for the accelerated MD enhancement, technical information, and relevant remarks. The impact of this work is the creation of a unique computational system combining nanoscale materials simulation, visualization and interactivity in a virtual environment, which is both a research and teaching instrument at UC Merced.

  3. Novel 3D/VR Interactive Environment for MD Simulations, Visualization and Analysis

    PubMed Central

    Doblack, Benjamin N.; Allis, Tim; Dávila, Lilian P.

    2014-01-01

    The increasing development of computing (hardware and software) in the last decades has impacted scientific research in many fields including materials science, biology, chemistry and physics among many others. A new computational system for the accurate and fast simulation and 3D/VR visualization of nanostructures is presented here, using the open-source molecular dynamics (MD) computer program LAMMPS. This alternative computational method uses modern graphics processors, NVIDIA CUDA technology and specialized scientific codes to overcome processing speed barriers common to traditional computing methods. In conjunction with a virtual reality system used to model materials, this enhancement allows the addition of accelerated MD simulation capability. The motivation is to provide a novel research environment which simultaneously allows visualization, simulation, modeling and analysis. The research goal is to investigate the structure and properties of inorganic nanostructures (e.g., silica glass nanosprings) under different conditions using this innovative computational system. The work presented outlines a description of the 3D/VR Visualization System and basic components, an overview of important considerations such as the physical environment, details on the setup and use of the novel system, a general procedure for the accelerated MD enhancement, technical information, and relevant remarks. The impact of this work is the creation of a unique computational system combining nanoscale materials simulation, visualization and interactivity in a virtual environment, which is both a research and teaching instrument at UC Merced. PMID:25549300

  4. Spectral Analysis of the Bounded Linear Operator in the Reproducing Kernel Space W2m(D)

    PubMed Central

    Guo, Lihua; Li, Songsong; Wu, Boying; Zhang, Dazhi

    2014-01-01

    We first introduce some related definitions of the bounded linear operator L in the reproducing kernel space W2m(D). Then we show spectral analysis of L and derive several property theorems. PMID:25250385

  5. The symbolic computation and automatic analysis of trajectories

    NASA Technical Reports Server (NTRS)

    Grossman, Robert

    1991-01-01

    Research was generally done on computation of trajectories of dynamical systems, especially control systems. Algorithms were further developed for rewriting expressions involving differential operators. The differential operators involved arise in the local analysis of nonlinear control systems. An initial design was completed of the system architecture for software to analyze nonlinear control systems using data base computing.

  6. Spacecraft Trajectory Analysis and Mission Planning Simulation (STAMPS) Software

    NASA Technical Reports Server (NTRS)

    Puckett, Nancy; Pettinger, Kris; Hallstrom,John; Brownfield, Dana; Blinn, Eric; Williams, Frank; Wiuff, Kelli; McCarty, Steve; Ramirez, Daniel; Lamotte, Nicole; Vu, Tuan

    2014-01-01

    STAMPS simulates either three- or six-degree-of-freedom cases for all spacecraft flight phases using translated HAL flight software or generic GN&C models. Single or multiple trajectories can be simulated for use in optimization and dispersion analysis. It includes math models for the vehicle and environment, and currently features a "C" version of shuttle onboard flight software. The STAMPS software is used for mission planning and analysis within ascent/descent, rendezvous, proximity operations, and navigation flight design areas.

  7. Efficiency estimation of liquid-liquid hydrocyclones using trajectory analysis

    SciTech Connect

    Wolbert, D.; Ma, B.F.; Aurelle, Y.; Seureau, J.

    1995-06-01

    As the use of hydrocyclones for liquid-liquid separation becomes increasingly common, the need for a satisfactory method to assess their efficiency increases. Currently available efficiency theories were developed for liquid-solid separations, based on the velocity distributions inside a hydrocyclone. These theories, however, appear less suitable for emulsions where the dispersed phase is slightly lighter than the continuous phase, such as oil/water emulsions. An efficiency computations based on the analysis of the trajectories of the droplets is presented. Trajectories are characterized through a differential equation combining models for the three bulk velocity distributions (axial, radial, and tangential) and the settling velocity defined by Stokes` law. From the critical trajectory and given operating conditions, a characteristic droplet diameter d{sub 100} can be deduced that corresponds to the smallest droplet with a 100% efficiency. Other efficiencies are obtained by changing the initial condition for the trajectory equation. The efficiency results of different hydrocyclone configurations are compared with experimental results, and residual emulsion distributions are estimated.

  8. Trajectory Browser: An Online Tool for Interplanetary Trajectory Analysis and Visualization

    NASA Technical Reports Server (NTRS)

    Foster, Cyrus James

    2013-01-01

    The trajectory browser is a web-based tool developed at the NASA Ames Research Center for finding preliminary trajectories to planetary bodies and for providing relevant launch date, time-of-flight and (Delta)V requirements. The site hosts a database of transfer trajectories from Earth to planets and small-bodies for various types of missions such as rendezvous, sample return or flybys. A search engine allows the user to find trajectories meeting desired constraints on the launch window, mission duration and (Delta)V capability, while a trajectory viewer tool allows the visualization of the heliocentric trajectory and the detailed mission itinerary. The anticipated user base of this tool consists primarily of scientists and engineers designing interplanetary missions in the context of pre-phase A studies, particularly for performing accessibility surveys to large populations of small-bodies.

  9. Analysis of flight trajectories of a ramjet-powered vehicle

    NASA Astrophysics Data System (ADS)

    Fomin, V. M.; Aulchenko, S. M.; Zvegintsev, V. I.; Ustinov, L. A.

    2014-11-01

    Based on numerical simulations of flight trajectories with ramjet-powered flying vehicles, it is found that all possible flight trajectories can be classified into three groups: ballistic trajectories, trajectories with a horizontal segment, and skipping trajectories. Trajectories of each group can be optimized, for instance, to ensure the maximum flight range under given initial conditions and constraints. Examples of optimal trajectories for a given amount of available fuel are presented as functions of the initial slope of the trajectory, angle of attack of the vehicle, instants of engine actuation, and engine operation time.

  10. Trajectory Browser: An online tool for interplanetary trajectory analysis and visualization

    NASA Astrophysics Data System (ADS)

    Foster, C.

    The Trajectory Browser is a web-based tool developed at the NASA Ames Research Center for finding preliminary trajectories to planetary bodies and for providing relevant launch date, time-of-flight and Δ V requirements. The site hosts a database of transfer trajectories from Earth to planets and small-bodies for various types of missions such as rendezvous, sample return or flybys. A search engine allows the user to find trajectories meeting desired constraints on the launch window, mission duration and Δ V capability, while a trajectory viewer tool allows the visualization of the heliocentric trajectory and the detailed mission itinerary. The anticipated user base of this tool consists primarily of scientists and engineers designing interplanetary missions in the context of pre-phase A studies, particularly for performing accessibility surveys to large populations of small-bodies. The educational potential of the website is also recognized for academia and the public with regards to trajectory design, a field that has generally been poorly understood by the public. The website is currently hosted on NASA-internal URL http://trajbrowser.arc.nasa.gov/ with plans for a public release in early 2013.

  11. Developmental trajectories of adolescent popularity: a growth curve modelling analysis.

    PubMed

    Cillessen, Antonius H N; Borch, Casey

    2006-12-01

    Growth curve modelling was used to examine developmental trajectories of sociometric and perceived popularity across eight years in adolescence, and the effects of gender, overt aggression, and relational aggression on these trajectories. Participants were 303 initially popular students (167 girls, 136 boys) for whom sociometric data were available in Grades 5-12. The popularity and aggression constructs were stable but non-overlapping developmental dimensions. Growth curve models were run with SAS MIXED in the framework of the multilevel model for change [Singer, J. D., & Willett, J. B. (2003). Applied longitudinal data analysis. Oxford, UK: Oxford University Press]. Sociometric popularity showed a linear change trajectory; perceived popularity showed nonlinear change. Overt aggression predicted low sociometric popularity but an increase in perceived popularity in the second half of the study. Relational aggression predicted a decrease in sociometric popularity, especially for girls, and continued high-perceived popularity for both genders. The effect of relational aggression on perceived popularity was the strongest around the transition from middle to high school. The importance of growth curve models for understanding adolescent social development was discussed, as well as specific issues and challenges of growth curve analyses with sociometric data.

  12. Estimation of Hydrogen-Exchange Protection Factors from MD Simulation Based on Amide Hydrogen Bonding Analysis.

    PubMed

    Park, In-Hee; Venable, John D; Steckler, Caitlin; Cellitti, Susan E; Lesley, Scott A; Spraggon, Glen; Brock, Ansgar

    2015-09-28

    Hydrogen exchange (HX) studies have provided critical insight into our understanding of protein folding, structure, and dynamics. More recently, hydrogen exchange mass spectrometry (HX-MS) has become a widely applicable tool for HX studies. The interpretation of the wealth of data generated by HX-MS experiments as well as other HX methods would greatly benefit from the availability of exchange predictions derived from structures or models for comparison with experiment. Most reported computational HX modeling studies have employed solvent-accessible-surface-area based metrics in attempts to interpret HX data on the basis of structures or models. In this study, a computational HX-MS prediction method based on classification of the amide hydrogen bonding modes mimicking the local unfolding model is demonstrated. Analysis of the NH bonding configurations from molecular dynamics (MD) simulation snapshots is used to determine partitioning over bonded and nonbonded NH states and is directly mapped into a protection factor (PF) using a logistics growth function. Predicted PFs are then used for calculating deuteration values of peptides and compared with experimental data. Hydrogen exchange MS data for fatty acid synthase thioesterase (FAS-TE) collected for a range of pHs and temperatures was used for detailed evaluation of the approach. High correlation between prediction and experiment for observable fragment peptides is observed in the FAS-TE and additional benchmarking systems that included various apo/holo proteins for which literature data were available. In addition, it is shown that HX modeling can improve experimental resolution through decomposition of in-exchange curves into rate classes, which correlate with prediction from MD. Successful rate class decompositions provide further evidence that the presented approach captures the underlying physical processes correctly at the single residue level. This assessment is further strengthened in a comparison of

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

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

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

  14. Analysis of vertical and horizontal circular C-arm trajectories

    NASA Astrophysics Data System (ADS)

    Maier, A.; Choi, J.-H.; Keil, A.; Niebler, C.; Sarmiento, M.; Fieselmann, A.; Gold, G.; Delp, S.; Fahrig, R.

    2011-03-01

    C-arm angiography systems offer great flexibility in the acquisition of trajectories for computed tomography. Theoretically, these systems are able to scan patients while standing in an upright position. This would allow novel insights into structural changes of the human anatomy while weight bearing. However, this would require a scan on a horizontal trajectory parallel to the ground floor which is currently not supported by standard C-arm CT acquisition protocols. In this paper, we compared the standard vertical and the new horizontal scanning trajectories by analysis of the source positions and source to detector distances during the scan. We employed a C-arm calibration phantom to compute the exact scan geometry. Based on the analysis of the projection matrices, we computed the source position in 3D and the source to detector distance for each projection. We then used the calibrated scan geometries to reconstruct the calibration phantom. Based on this reconstruction in comparison to the ideal phantom geometry we also evaluated the geometric reconstruction error. As expected, both the vertical and the horizontal scan trajectories exhibit a significant C-arm "wobble". But in both kinds of trajectories, the reproducibility over several scans was comparable. We were able to reconstruct the calibration phantom with satisfactory geometric reconstruction accuracy. With a reconstruction error of 0.2 mm, we conclude that horizontal C-arm scans are possible and show properties similar to those of vertical C-arm scans. The remaining challenge is compensation for the involuntary movement of the standing subject during a weight-bearing acquisition. We investigated this using an optical tracking system and found that the average movement at the knee while standing upright for 5 seconds is between 0.42 mm and 0.54 mm, and goes up to as much as 12 mm when the subject is holding a 60° squat. This involuntary motion is much larger than the reconstruction accuracy. Hence, we

  15. Spin system trajectory analysis under optimal control pulses

    NASA Astrophysics Data System (ADS)

    Kuprov, Ilya

    2013-08-01

    Several methods are proposed for the analysis, visualization and interpretation of high-dimensional spin system trajectories produced by quantum mechanical simulations. It is noted that expectation values of specific observables in large spin systems often feature fast, complicated and hard-to-interpret time dynamics and suggested that populations of carefully selected subspaces of states are much easier to analyze and interpret. As an illustration of the utility of the proposed methods, it is demonstrated that the apparent "noisy" appearance of many optimal control pulses in NMR and EPR spectroscopy is an illusion - the underlying spin dynamics is shown to be smooth, orderly and very tightly controlled.

  16. Singular perturbation analysis of AOTV-related trajectory optimization problems

    NASA Technical Reports Server (NTRS)

    Calise, Anthony J.; Bae, Gyoung H.

    1990-01-01

    The problem of real time guidance and optimal control of Aeroassisted Orbit Transfer Vehicles (AOTV's) was addressed using singular perturbation theory as an underlying method of analysis. Trajectories were optimized with the objective of minimum energy expenditure in the atmospheric phase of the maneuver. Two major problem areas were addressed: optimal reentry, and synergetic plane change with aeroglide. For the reentry problem, several reduced order models were analyzed with the objective of optimal changes in heading with minimum energy loss. It was demonstrated that a further model order reduction to a single state model is possible through the application of singular perturbation theory. The optimal solution for the reduced problem defines an optimal altitude profile dependent on the current energy level of the vehicle. A separate boundary layer analysis is used to account for altitude and flight path angle dynamics, and to obtain lift and bank angle control solutions. By considering alternative approximations to solve the boundary layer problem, three guidance laws were derived, each having an analytic feedback form. The guidance laws were evaluated using a Maneuvering Reentry Research Vehicle model and all three laws were found to be near optimal. For the problem of synergetic plane change with aeroglide, a difficult terminal boundary layer control problem arises which to date is found to be analytically intractable. Thus a predictive/corrective solution was developed to satisfy the terminal constraints on altitude and flight path angle. A composite guidance solution was obtained by combining the optimal reentry solution with the predictive/corrective guidance method. Numerical comparisons with the corresponding optimal trajectory solutions show that the resulting performance is very close to optimal. An attempt was made to obtain numerically optimized trajectories for the case where heating rate is constrained. A first order state variable inequality

  17. Eucb: A C++ program for molecular dynamics trajectory analysis

    NASA Astrophysics Data System (ADS)

    Tsoulos, Ioannis G.; Stavrakoudis, Athanassios

    2011-03-01

    Eucb is a standalone program for geometrical analysis of molecular dynamics trajectories of protein systems. The program is written in GNU C++ and it can be installed in any operating system running a C++ compiler. The program performs its analytical tasks based on user supplied keywords. The source code is freely available from http://stavrakoudis.econ.uoi.gr/eucb under LGPL 3 license. Program summaryProgram title:Eucb Catalogue identifier: AEIC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEIC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 31 169 No. of bytes in distributed program, including test data, etc.: 297 364 Distribution format: tar.gz Programming language: GNU C++ Computer: The tool is designed and tested on GNU/Linux systems Operating system: Unix/Linux systems RAM: 2 MB Supplementary material: Sample data files are available Classification: 3 Nature of problem: Analysis of molecular dynamics trajectories. Solution method: The program finds all possible interactions according to input files and the user instructions. Then it reads all the trajectory frames and finds those frames in which these interactions occur, under certain geometrical criteria. This is a blind search, without a priori knowledge if a certain interaction occurs or not. The program exports time series of these quantities (distance, angles, etc.) and appropriate descriptive statistics. Running time: Depends on the input data and the required options.

  18. Database Driven 6-DOF Trajectory Simulation for Debris Transport Analysis

    NASA Technical Reports Server (NTRS)

    West, Jeff

    2008-01-01

    Debris mitigation and risk assessment have been carried out by NASA and its contractors supporting Space Shuttle Return-To-Flight (RTF). As a part of this assessment, analysis of transport potential for debris that may be liberated from the vehicle or from pad facilities prior to tower clear (Lift-Off Debris) is being performed by MSFC. This class of debris includes plume driven and wind driven sources for which lift as well as drag are critical for the determination of the debris trajectory. As a result, NASA MSFC has a need for a debris transport or trajectory simulation that supports the computation of lift effect in addition to drag without the computational expense of fully coupled CFD with 6-DOF. A database driven 6-DOF simulation that uses aerodynamic force and moment coefficients for the debris shape that are interpolated from a database has been developed to meet this need. The design, implementation, and verification of the database driven six degree of freedom (6-DOF) simulation addition to the Lift-Off Debris Transport Analysis (LODTA) software are discussed in this paper.

  19. Quantitative multivariate analysis of dynamic multicellular morphogenic trajectories.

    PubMed

    White, Douglas E; Sylvester, Jonathan B; Levario, Thomas J; Lu, Hang; Streelman, J Todd; McDevitt, Todd C; Kemp, Melissa L

    2015-07-01

    Interrogating fundamental cell biology principles that govern tissue morphogenesis is critical to better understanding of developmental biology and engineering novel multicellular systems. Recently, functional micro-tissues derived from pluripotent embryonic stem cell (ESC) aggregates have provided novel platforms for experimental investigation; however elucidating the factors directing emergent spatial phenotypic patterns remains a significant challenge. Computational modelling techniques offer a unique complementary approach to probe mechanisms regulating morphogenic processes and provide a wealth of spatio-temporal data, but quantitative analysis of simulations and comparison to experimental data is extremely difficult. Quantitative descriptions of spatial phenomena across multiple systems and scales would enable unprecedented comparisons of computational simulations with experimental systems, thereby leveraging the inherent power of computational methods to interrogate the mechanisms governing emergent properties of multicellular biology. To address these challenges, we developed a portable pattern recognition pipeline consisting of: the conversion of cellular images into networks, extraction of novel features via network analysis, and generation of morphogenic trajectories. This novel methodology enabled the quantitative description of morphogenic pattern trajectories that could be compared across diverse systems: computational modelling of multicellular structures, differentiation of stem cell aggregates, and gastrulation of cichlid fish. Moreover, this method identified novel spatio-temporal features associated with different stages of embryo gastrulation, and elucidated a complex paracrine mechanism capable of explaining spatiotemporal pattern kinetic differences in ESC aggregates of different sizes.

  20. Ares I-X Best Estimated Trajectory Analysis and Results

    NASA Technical Reports Server (NTRS)

    Karlgaard, Christopher D.; Beck, Roger E.; Starr, Brett R.; Derry, Stephen D.; Brandon, Jay; Olds, Aaron D.

    2011-01-01

    The Ares I-X trajectory reconstruction produced best estimated trajectories of the flight test vehicle ascent through stage separation, and of the first and upper stage entries after separation. The trajectory reconstruction process combines on-board, ground-based, and atmospheric measurements to produce the trajectory estimates. The Ares I-X vehicle had a number of on-board and ground based sensors that were available, including inertial measurement units, radar, air-data, and weather balloons. However, due to problems with calibrations and/or data, not all of the sensor data were used. The trajectory estimate was generated using an Iterative Extended Kalman Filter algorithm, which is an industry standard processing algorithm for filtering and estimation applications. This paper describes the methodology and results of the trajectory reconstruction process, including flight data preprocessing and input uncertainties, trajectory estimation algorithms, output transformations, and comparisons with preflight predictions.

  1. Mars Hybrid Propulsion System Trajectory Analysis. Part II; Cargo Missions

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

    NASA's Human Spaceflight Architecture Team is developing a reusable hybrid transportation architecture in which both chemical and electric propulsion systems are used to send crew and cargo to Mars destinations such as Phobos, Deimos, the surface of Mars, and other orbits around Mars. By combining chemical and electrical propulsion into a single spaceship and applying each where it is more effective, the hybrid architecture enables a series of Mars trajectories that are more fuel-efficient than an all chemical architecture without significant increases in flight times. This paper shows the feasibility of the hybrid transportation architecture to pre-deploy cargo to Mars and Phobos in support of the Evolvable Mars Campaign crew missions. The analysis shows that the hybrid propulsion stage is able to deliver all of the current manifested payload to Phobos and Mars through the first three crew missions. The conjunction class trajectory also allows the hybrid propulsion stage to return to Earth in a timely fashion so it can be reused for additional cargo deployment. The 1,100 days total trip time allows the hybrid propulsion stage to deliver cargo to Mars every other Earth-Mars transit opportunity. For the first two Mars surface mission in the Evolvable Mars Campaign, the short trip time allows the hybrid propulsion stage to be reused for three round-trip journeys to Mars, which matches the hybrid propulsion stage's designed lifetime for three round-trip crew missions to the Martian sphere of influence.

  2. Dynamic analysis and trajectory tracking of a tethered space robot

    NASA Astrophysics Data System (ADS)

    Soltani, Mehrzad; Keshmiri, Mehdi; Misra, Arun K.

    2016-11-01

    Dynamic analysis and trajectory tracking of a Tethered Space Robot (TSR) is investigated in this paper. A hybrid controller is used to perform the control task. It consists of two components, the first one deals with librational motion of the tether, while the second one takes care of the manipulator motion. A Nonlinear Model Predictive Control (NMPC) approach is used to control the tether libration; for this purpose, the libration is described by a single degree of freedom and the tether length rate is employed as the input to suppress the librational motion. A modified Computed Torque Method (CTM) is used to control the manipulator motion. The dynamic interaction between the manipulator motion and the librational motion is considered both in the system dynamics and control of the system. Using numerical simulations, performance of the proposed control system is evaluated for end-effector positioning as well as for trajectory tracking for two cases: a Low Earth Orbit (LEO) and the Geostationary Earth Orbit (GEO).

  3. Methodologies for the Analysis of Instantaneous Lipid Diffusion in MD Simulations of Large Membrane Systems

    PubMed Central

    Chavent, Matthieu; Reddy, Tyler; Goose, Joseph; Dahl, Anna Caroline E.; Stone, John E.; Jobard, Bruno; Sansom, Mark S.P.

    2014-01-01

    Interactions between lipids and membrane proteins play a key role in determining the nanoscale dynamic and structural properties of biological membranes. Molecular dynamics (MD) simulations provide a valuable tool for studying membrane models, complementing experimental approaches. It is now possible to simulate large membrane systems, such as simplified models of bacterial and viral envelope membranes. Consequently, there is a pressing need to develop tools to visualize and quantify the dynamics of these immense systems, which typically are comprised of millions of particles. To tackle this issue, we have developed visual and quantitative analyses of molecular positions and their velocity field using path line, vector field and streamline techniques. This allows us to highlight large, transient flow-like movements of lipids and to better understand crowding within the lipid bilayer. The current study focuses on visualization and analysis of lipid dynamics. However, the methods are flexible and can be readily applied to e.g. proteins and nanoparticles within large complex membranes. The protocols developed here are readily accessible both as a plugin for the molecular visualization program VMD and as a module for the MDAnalysis library. PMID:25341001

  4. Beam Optics Analysis - An Advanced 3D Trajectory Code

    SciTech Connect

    Ives, R. Lawrence; Bui, Thuc; Vogler, William; Neilson, Jeff; Read, Mike; Shephard, Mark; Bauer, Andrew; Datta, Dibyendu; Beal, Mark

    2006-01-03

    Calabazas Creek Research, Inc. has completed initial development of an advanced, 3D program for modeling electron trajectories in electromagnetic fields. The code is being used to design complex guns and collectors. Beam Optics Analysis (BOA) is a fully relativistic, charged particle code using adaptive, finite element meshing. Geometrical input is imported from CAD programs generating ACIS-formatted files. Parametric data is inputted using an intuitive, graphical user interface (GUI), which also provides control of convergence, accuracy, and post processing. The program includes a magnetic field solver, and magnetic information can be imported from Maxwell 2D/3D and other programs. The program supports thermionic emission and injected beams. Secondary electron emission is also supported, including multiple generations. Work on field emission is in progress as well as implementation of computer optimization of both the geometry and operating parameters. The principle features of the program and its capabilities are presented.

  5. Hi-G electronic gated camera for precision trajectory analysis

    NASA Astrophysics Data System (ADS)

    Snyder, Donald R.; Payne, Scott; Keller, Ed; Longo, Salvatore; Caudle, Dennis E.; Walker, Dennis C.; Sartor, Mark A.; Keeler, Joe E.; Kerr, David A.; Fail, R. Wallace; Gannon, Jim; Carrol, Ernie; Jamison, Todd A.

    1997-12-01

    It is extremely difficult and expensive to determine the flight attitude and aimpoint of small maneuvering miniature air vehicles from ground based fixed or tracking photography. Telemetry alone cannot provide sufficient information bandwidth on 'what' the ground tracking is seeing and consequently 'why' it did or did not function properly. Additionally, it is anticipated that 'smart' and 'brilliant' guided vehicles now in development will require a high resolution imaging support system to determine which target and which part of a ground feature is being used for navigation or targeting. Other requirements include support of sub-component separation from developmental supersonic vehicles, where the clean separation from the container is not determinable from ground based film systems and film cameras do not survive vehicle breakup and impact. Hence, the requirement is to develop and demonstrate an imaging support system for development/testing that can provide the flight vehicle developer/analyst with imagery (combined with miniature telemetry sources) sufficient to recreate the trajectory, terminal navigation, and flight termination events. This project is a development and demonstration of a real-time, launch-rated, shuttered, electronic imager, transmitter, and analysis system. This effort demonstrated boresighted imagery from inside small flight vehicles for post flight analysis of trajectory, and capture of ground imagery during random triggered vehicle functions. The initial studies for this capability have been accomplished by the Experimental Dynamics Section of the Air Force Wright Laboratory, Armament Directorate, Eglin AFB, Florida, and the Telemetry Support Branch of the Army Material Research and Development Center at Picatinny Arsenal, New Jersey. It has been determined that at 1/10,000 of a second exposure time, new ultra-miniature CCD sensors have sufficient sensitivity to image key ground target features without blur, thereby providing data for

  6. A similarity analysis of the droplet trajectory equation

    NASA Technical Reports Server (NTRS)

    Bragg, M. B.

    1982-01-01

    A procedure is established to reduce the number of similarity parameters in the trajectory equation for particles in a moving fluid. This is accomplished by the use of an approximate sphere drag law to derive a new trajectory scaling parameter. The modified inertia parameter proposed by Langmuir specifically for the aircraft icing problem is analyzed and for the first time a closed-form solution is obtained. Both experimental and analytical results are presented to verify this new trajectory scaling parameter.

  7. The trajectory analysis of bevel planetary gear trains

    SciTech Connect

    Lin, Chen-Chou; Tsai, Lung-Wen

    1991-12-31

    In this paper, the trajectory of bevel planetary wear trains has been studied. The parametric equations of trajectory are derived. It is shown that the trajectory generated by a tracer point on the planet of a bevel planetary gear train is analogous to that of a spur planetary gear train. Two cases, gear ratio equal to one and two, are presented in detail including the geometric description, plane of symmetry, extent of trajectory, number of nodes (cusps) their locations. The criteria for the existence of cusps are verified algebraically, and interpreted from geometrical point of view.

  8. The trajectory analysis of bevel planetary gear trains

    SciTech Connect

    Lin, Chen-Chou; Tsai, Lung-Wen.

    1991-01-01

    In this paper, the trajectory of bevel planetary wear trains has been studied. The parametric equations of trajectory are derived. It is shown that the trajectory generated by a tracer point on the planet of a bevel planetary gear train is analogous to that of a spur planetary gear train. Two cases, gear ratio equal to one and two, are presented in detail including the geometric description, plane of symmetry, extent of trajectory, number of nodes (cusps) their locations. The criteria for the existence of cusps are verified algebraically, and interpreted from geometrical point of view.

  9. The trajectory analysis of bevel planetary gear trains

    NASA Astrophysics Data System (ADS)

    Lin, Chen-Chou; Tsai, Lung-Wen

    In this paper, the trajectory of bevel planetary wear trains has been studied. The parametric equations of trajectory are derived. It is shown that the trajectory generated by a tracer point on the planet of a bevel planetary gear train is analogous to that of a spur planetary gear train. Two cases, gear ratio equal to one and two, are presented in detail including the geometric description, plane of symmetry, extent of trajectory, number of nodes (cusps), and their locations. The criteria for the existence of cusps are verified algebraically, and interpreted from geometrical point of view.

  10. Towards analysis of growth trajectory through multimodal longitudinal MR imaging

    NASA Astrophysics Data System (ADS)

    Sadeghi, Neda; Prastawa, Marcel; Gilmore, John H.; Lin, Weili; Gerig, Guido

    2010-03-01

    The human brain undergoes significant changes in the first few years after birth, but knowledge about this critical period of development is quite limited. Previous neuroimaging studies have been mostly focused on morphometric measures such as volume and shape, although tissue property measures related to the degree of myelination and axon density could also add valuable information to our understanding of brain maturation. Our goal is to complement brain growth analysis via morphometry with the study of longitudinal tissue property changes as reflected in patterns observed in multi-modal structural MRI and DTI. Our preliminary study includes eight healthy pediatric subjects with repeated scans at the age of two weeks, one year, and two years with T1, T2, PD, and DT MRI. Analysis is driven by the registration of multiple modalities and time points within and between subjects into a common coordinate frame, followed by image intensity normalization. Quantitative tractography with diffusion and structural image parameters serves for multi-variate tissue analysis. Different patterns of rapid changes were observed in the corpus callosum and the posterior and anterior internal capsule, structures known for distinctly different myelination growth. There are significant differences in central versus peripheral white matter. We demonstrate that the combined longitudinal analysis of structural and diffusion MRI proves superior to individual modalities and might provide a better understanding of the trajectory of early neurodevelopment.

  11. Developmental Trajectories of Adolescent Popularity: A Growth Curve Modelling Analysis

    ERIC Educational Resources Information Center

    Cillessen, Antonius H. N.; Borch, Casey

    2006-01-01

    Growth curve modelling was used to examine developmental trajectories of sociometric and perceived popularity across eight years in adolescence, and the effects of gender, overt aggression, and relational aggression on these trajectories. Participants were 303 initially popular students (167 girls, 136 boys) for whom sociometric data were…

  12. Trajectory analysis via a geometric feature space approach

    SciTech Connect

    Rintoul, Mark D.; Wilson, Andrew T.

    2015-10-05

    This study aimed to organize a body of trajectories in order to identify, search for and classify both common and uncommon behaviors among objects such as aircraft and ships. Existing comparison functions such as the Fréchet distance are computationally expensive and yield counterintuitive results in some cases. We propose an approach using feature vectors whose components represent succinctly the salient information in trajectories. These features incorporate basic information such as the total distance traveled and the distance between start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally, these features can generally be mapped easily to behaviors of interest to humans who are searching large databases. Most of these geometric features are invariant under rigid transformation. Furthermore, we demonstrate the use of different subsets of these features to identify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories and identify outliers.

  13. Re-entry aerodynamics derived from space debris trajectory analysis

    NASA Astrophysics Data System (ADS)

    Crowther, R.

    1992-05-01

    This paper considers the technique of orbital analysis as a means of determining the ill-defined gas-surface interaction between spacecraft and atmospheric molecules in low earth orbit. The interaction is a major uncertainty in trajectory predictions for a body moving within an atmosphere. The rate of change of the orbital period of a debris object, the uncontrolled Salyut 7/Kosmos 1686 space station, is analyzed in order to determine the free molecular drag coefficient. The results are compared with theoretical values for the drag coefficient calculated using a complex representation of the vehicle configuration and motion and applying the Monte Carlo Test Particle method. Results suggest a nature of re-emission very close to the classical diffuse, totally accommodated case was occurring at the surface of the debris object as it approached re-entry. However, the determined drag coefficient and therefore the derived interaction are found to be very sensitive to the neutral density and therefore the atmospheric model used in the analysis.

  14. H5MD: A structured, efficient, and portable file format for molecular data

    NASA Astrophysics Data System (ADS)

    de Buyl, Pierre; Colberg, Peter H.; Höfling, Felix

    2014-06-01

    We propose a new file format named "H5MD" for storing molecular simulation data, such as trajectories of particle positions and velocities, along with thermodynamic observables that are monitored during the course of the simulation. H5MD files are HDF5 (Hierarchical Data Format) files with a specific hierarchy and naming scheme. Thus, H5MD inherits many benefits of HDF5, e.g., structured layout of multi-dimensional datasets, data compression, fast and parallel I/O, and portability across many programming languages and hardware platforms. H5MD files are self-contained, and foster the reproducibility of scientific data and the interchange of data between researchers using different simulation programs and analysis software. In addition, the H5MD specification can serve for other kinds of data (e.g. experimental data) and is extensible to supplemental data, or may be part of an enclosing file structure.

  15. The analysis of control trajectories using symbolic and database computing

    NASA Technical Reports Server (NTRS)

    Grossman, Robert

    1995-01-01

    This final report comprises the formal semi-annual status reports for this grant for the periods June 30-December 31, 1993, January 1-June 30, 1994, and June 1-December 31, 1994. The research supported by this grant is broadly concerned with the symbolic computation, mixed numeric-symbolic computation, and database computation of trajectories of dynamical systems, especially control systems. A review of work during the report period covers: trajectories and approximating series, the Cayley algebra of trees, actions of differential operators, geometrically stable integration algorithms, hybrid systems, trajectory stores, PTool, and other activities. A list of publications written during the report period is attached.

  16. Analysis of Capture Trajectories to the Vicinity of Libration Points

    NASA Technical Reports Server (NTRS)

    Nakamiya, M.; Scheeres, D. J.; Yamakawa, H.; Yoshikawa, M.

    2007-01-01

    Spacecraft capture trajectories to the periodic orbits of the L1 and L2 points in the restricted Hill three-body problem are studied. The specific focus is on transfer to these vicinities from interplanetary trajectories. This application is motivated by future proposals to place "Deep Space ports" at the Earth and Mars L1 or L2 points. These spaceports are considered as candidate gateways for interplanetary transfers in the future. We utilize stable manifolds for capture trajectories to periodic orbits around the libration points. As a result, the cost of capture into a periodic orbit is also reduced relative to direct capture into a parabolic orbit. The way of linking between interplanetary transfer trajectories and the stable manifold is also discussed.

  17. mdRNA-Seq analysis of marine microbial communities from the northern Red Sea

    PubMed Central

    Hou, Shengwei; Pfreundt, Ulrike; Miller, Dan; Berman-Frank, Ilana; Hess, Wolfgang R.

    2016-01-01

    Metatranscriptomic differential RNA-Seq (mdRNA-Seq) identifies the suite of active transcriptional start sites at single-nucleotide resolution through enrichment of primary transcript 5′ ends. Here we analyzed the microbial community at 45 m depth at Station A in the northern Gulf of Aqaba, Red Sea, during 500 m deep mixing in February 2012 using mdRNA-Seq and a parallel classical RNA-Seq approach. We identified promoters active in situ for five different pico-planktonic genera (the SAR11 clade of Alphaproteobacteria, Synechococcus of Cyanobacteria, Euryarchaeota, Thaumarchaeota, and Micromonas as an example for picoeukaryotic algae), showing the applicability of this approach to highly diverse microbial communities. 16S rDNA quantification revealed that 24% of the analyzed community were group II marine Euryarchaeota in which we identified a highly abundant non-coding RNA, Tan1, and detected very high expression of genes encoding intrinsically disordered proteins, as well as enzymes for the synthesis of specific B vitamins, extracellular peptidases, carbohydrate-active enzymes, and transport systems. These results highlight previously unknown functions of Euryarchaeota with community-wide relevance. The complementation of metatranscriptomic studies with mdRNA-Seq provides substantial additional information regarding transcriptional start sites, promoter activities, and the identification of non-coding RNAs. PMID:27759035

  18. Applications of analysis of dynamic adaptations in parameter trajectories

    PubMed Central

    van Riel, Natal A. W.; Tiemann, Christian A.; Vanlier, Joep; Hilbers, Peter A. J.

    2013-01-01

    Metabolic profiling in combination with pathway-based analyses and computational modelling are becoming increasingly important in clinical and preclinical research. Modelling multi-factorial, progressive diseases requires the integration of molecular data at the metabolome, proteome and transcriptome levels. Also the dynamic interaction of organs and tissues needs to be considered. The processes involved cover time scales that are several orders of magnitude different. We report applications of a computational approach to bridge the scales and different levels of biological detail. Analysis of dynamic adaptations in parameter trajectories (ADAPTs) aims to investigate phenotype transitions during disease development and after a therapeutic intervention. ADAPT is based on a time-dependent evolution of model parameters to describe the dynamics of metabolic adaptations. The progression of metabolic adaptations is predicted by identifying necessary dynamic changes in the model parameters to describe the transition between experimental data obtained during different stages. To get a better understanding of the concept, the ADAPT approach is illustrated in a theoretical study. Its application in research on progressive changes in lipoprotein metabolism is also discussed. PMID:23853705

  19. Detailed analysis of structure and particle trajectories in sheared suspensions

    NASA Astrophysics Data System (ADS)

    Morris, Jeffrey; Katyal, Bhavana

    1999-11-01

    The structure and particle dynamics of sheared suspensions of hard spheres over a range of shear strength to Brownain motion (Péclet number, Pe) have been studied by detailed analysis of extended sampling of Stokesian Dynamics simulations of simple shear. The emphasis is upon large Pe. The structure has been analyzed by decomposition of the pair distribution function, g(r), into spherical harmonics; the harmonics are a complete set for the decompositon. The results indicate a profound and very marked change in structure due to shearing. It is shown that as Pe increases, the structure is increasingly distorted from teh equilibrium spherical symmetry and the number of harmonics required to recompose the original data to within an arbitrary accuracy increases, and this variation depends upon particle fraction. We present information on the content of the dominant harmonics as a function of radial distance for a pair, and interpret the results in terms of preferred directions in the material. Dynamic particle trajectories at time scales long relative to that used for the Brownian step are analyzed in a novel fashion by simple differential geometric measures, such as root mean square path curvature and torsion. Preliminary results illustrate that the path variation from mean flow correlates with the particle stress.

  20. Trajectory Planning by Preserving Flexibility: Metrics and Analysis

    NASA Technical Reports Server (NTRS)

    Idris, Husni R.; El-Wakil, Tarek; Wing, David J.

    2008-01-01

    In order to support traffic management functions, such as mitigating traffic complexity, ground and airborne systems may benefit from preserving or optimizing trajectory flexibility. To help support this hypothesis trajectory flexibility metrics have been defined in previous work to represent the trajectory robustness and adaptability to the risk of violating safety and traffic management constraints. In this paper these metrics are instantiated in the case of planning a trajectory with the heading degree of freedom. A metric estimation method is presented based on simplifying assumptions, namely discrete time and heading maneuvers. A case is analyzed to demonstrate the estimation method and its use in trajectory planning in a situation involving meeting a time constraint and avoiding loss of separation with nearby traffic. The case involves comparing path-stretch trajectories, in terms of adaptability and robustness along each, deduced from a map of estimated flexibility metrics over the solution space. The case demonstrated anecdotally that preserving flexibility may result in enhancing certain factors that contribute to traffic complexity, namely reducing proximity and confrontation.

  1. Particle trajectory computer program for icing analysis of axisymmetric bodies

    NASA Technical Reports Server (NTRS)

    Frost, Walter; Chang, Ho-Pen; Kimble, Kenneth R.

    1982-01-01

    General aviation aircraft and helicopters exposed to an icing environment can accumulate ice resulting in a sharp increase in drag and reduction of maximum lift causing hazardous flight conditions. NASA Lewis Research Center (LeRC) is conducting a program to examine, with the aid of high-speed computer facilities, how the trajectories of particles contribute to the ice accumulation on airfoils and engine inlets. This study, as part of the NASA/LeRC research program, develops a computer program for the calculation of icing particle trajectories and impingement limits relative to axisymmetric bodies in the leeward-windward symmetry plane. The methodology employed in the current particle trajectory calculation is to integrate the governing equations of particle motion in a flow field computed by the Douglas axisymmetric potential flow program. The three-degrees-of-freedom (horizontal, vertical, and pitch) motion of the particle is considered. The particle is assumed to be acted upon by aerodynamic lift and drag forces, gravitational forces, and for nonspherical particles, aerodynamic moments. The particle momentum equation is integrated to determine the particle trajectory. Derivation of the governing equations and the method of their solution are described in Section 2.0. General features, as well as input/output instructions for the particle trajectory computer program, are described in Section 3.0. The details of the computer program are described in Section 4.0. Examples of the calculation of particle trajectories demonstrating application of the trajectory program to given axisymmetric inlet test cases are presented in Section 5.0. For the examples presented, the particles are treated as spherical water droplets. In Section 6.0, limitations of the program relative to excessive computer time and recommendations in this regard are discussed.

  2. Bulimic Symptom Onset in Young Girls: A Longitudinal Trajectory Analysis

    PubMed Central

    Pearson, Carolyn M.; Smith, Gregory T.

    2015-01-01

    To investigate whether there are different patterns of development for binge eating and purging behavior among pre-adolescent and early adolescent girls, we conducted trajectory analyses of those behaviors in 938 girls across eight waves of data from the spring of 5th grade (the last year of elementary school) through the spring of 9th grade (the first year of high school). Analyses revealed four separate developmental trajectories for binge eating behavior (labeled none, increasing, decreasing, and high steady) and three separate developmental trajectories for purging behavior (labeled none, dabble, and increasing). Fifth grade scores on risk factors that were both transdiagnostic (negative affect and negative urgency) and eating disorder specific (expectancies for reinforcement from eating and from thinness) differentiated among the trajectory groups, in some cases before the groups differed in the target behaviors. These findings are the first, to our knowledge, to examine developmental trajectories for bulimic symptom onset in youth as young as elementary school. Clinical implications are discussed. PMID:26595477

  3. Trajectory analysis via a geometric feature space approach

    DOE PAGES

    Rintoul, Mark D.; Wilson, Andrew T.

    2015-10-05

    This study aimed to organize a body of trajectories in order to identify, search for and classify both common and uncommon behaviors among objects such as aircraft and ships. Existing comparison functions such as the Fréchet distance are computationally expensive and yield counterintuitive results in some cases. We propose an approach using feature vectors whose components represent succinctly the salient information in trajectories. These features incorporate basic information such as the total distance traveled and the distance between start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally,more » these features can generally be mapped easily to behaviors of interest to humans who are searching large databases. Most of these geometric features are invariant under rigid transformation. Furthermore, we demonstrate the use of different subsets of these features to identify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories and identify outliers.« less

  4. Bohmian-trajectory analysis of high-order-harmonic generation: Ensemble averages, nonlocality, and quantitative aspects

    NASA Astrophysics Data System (ADS)

    Wu, J.; Augstein, B. B.; Figueira de Morisson Faria, C.

    2013-12-01

    We perform a Bohmian-trajectory analysis of high-order-harmonic generation (HHG), focusing on the fact that typical HHG spectra are best reproduced by the Bohmian trajectory starting at the innermost part of the core [J. Wu, B. B. Augstein, and C. Figueira de Morisson Faria, Phys. Rev. A 88, 023415 (2013), 10.1103/PhysRevA.88.023415]. Using ensemble averages around this central trajectory, we show that for the high-plateau and cutoff harmonics, small ensembles of Bohmian trajectories are sufficient for a quantitative agreement with the numerical solution of the time-dependent Schrödinger equation (TDSE), while larger ensembles are necessary in the low-plateau region. Furthermore, we relate the Bohmian trajectories to the short and long trajectories encountered in the strong-field approximation (SFA) and show that the time-frequency maps from the central Bohmian trajectory overestimate the contributions of the long SFA trajectory, in comparison to the outcome of the TDSE computations. We also discuss how the time-frequency profile of the central trajectory may be influenced nonlocally by degrading the wave-packet propagation far from the core.

  5. Shock induced alpha-epsilon phase transition in iron: Analysis of MD simulations and experimental data

    NASA Astrophysics Data System (ADS)

    Hawreliak, James; Belak, J. F.; Davies, H. M.; Germann, T. C.; Meyers, M. A.

    2005-07-01

    Multi-million atom non-equilibrium molecular dynamics (MD) simulations for shock compressed iron are analyzed using Fourier methods to determine the long scale ordering of the crystal. By analyzing the location of the maxima in k-space we can determine the crystal structure and compression due to the shock. This poster will present results from different shock pressures and compare them to recent experiments of shock compressed iron where the crystal structure was determined using in-situ wide angle x-ray diffraction.

  6. Aerodynamic, structural, and trajectory analysis of ASTRID-1 vehicle

    SciTech Connect

    Glover, L.S.; Iwaskiw, A.P.; Oursler, M.A.; Perini, L.L.; Schaefer, E.D.

    1994-02-10

    The Johns Hopkins University/Applied Physics Laboratory, JHU/API, in support of Lawrence Livermore National Laboratory, LLNL, is conducting aerodynamic, trajectory, and structural analysis of the Advanced Single Stage Technology Rapid Insertion Demonstration (ASTRID) vehicle, being launched out of Vandenberg Air Force Base (VAFB) in February 1994. The launch is designated ASTRID-1 and is the first in a series of three that will be launched out of VAFB. Launch dates for the next two flights have not been identified, but they are scheduled for the 1994-1995 time frame. The primary goal of the ASTRID-1 flight is to test the LLNL light weight thrust on demand bi-propellant pumped divert propulsion system. The system is employed as the main thrusters for the ASTRID-1 vehicle and uses hydrazine as the mono-propellant. The major conclusions are: (1) The vehicle is very stable throughout flight (stability margin = 17 to 24 inches); (2) The aerodynamic frequency and the roll rate are such that pitch-roll interactions will be small; (3) The high stability margin combined with the high launcher elevation angle makes the vehicle flight path highly sensitive to perturbations during the initial phase of flight, i.e., during the first second of flight after leaving the rail; (4) The major impact dispersions for the test flight are due to winds. The wind impact dispersions are 90% dictated by the low altitude, 0 to 1000 ft., wind conditions; and (5) In order to minimize wind dispersions, head wind conditions are favored for the launch as November VAFB mean tail winds result in land impacts. The ballistic wind methodology can be employed to assess the impact points of winds at the launch site.

  7. Space Trajectory Error Analysis Program (STEAP) for halo orbit missions. Volume 2: Programmer's manual

    NASA Technical Reports Server (NTRS)

    Byrnes, D. V.; Carney, P. C.; Underwood, J. W.; Vogt, E. D.

    1974-01-01

    The six month effort was responsible for the development, test, conversion, and documentation of computer software for the mission analysis of missions to halo orbits about libration points in the earth-sun system. The software consisting of two programs called NOMNAL and ERRAN is part of the Space Trajectories Error Analysis Programs. The program NOMNAL targets a transfer trajectory from earth on a given launch date to a specified halo orbit on a required arrival date. Either impulsive or finite thrust insertion maneuvers into halo orbit are permitted by the program. The transfer trajectory is consistent with a realistic launch profile input by the user. The second program ERRAN conducts error analyses of the targeted transfer trajectory. Measurements including range, doppler, star-planet angles, and apparent planet diameter are processed in a Kalman-Schmidt filter to determine the trajectory knowledge uncertainty.

  8. Design and Analysis of Optimal Ascent Trajectories for Stratospheric Airships

    NASA Astrophysics Data System (ADS)

    Mueller, Joseph Bernard

    Stratospheric airships are lighter-than-air vehicles that have the potential to provide a long-duration airborne presence at altitudes of 18-22 km. Designed to operate on solar power in the calm portion of the lower stratosphere and above all regulated air traffic and cloud cover, these vehicles represent an emerging platform that resides between conventional aircraft and satellites. A particular challenge for airship operation is the planning of ascent trajectories, as the slow moving vehicle must traverse the high wind region of the jet stream. Due to large changes in wind speed and direction across altitude and the susceptibility of airship motion to wind, the trajectory must be carefully planned, preferably optimized, in order to ensure that the desired station be reached within acceptable performance bounds of flight time and energy consumption. This thesis develops optimal ascent trajectories for stratospheric airships, examines the structure and sensitivity of these solutions, and presents a strategy for onboard guidance. Optimal ascent trajectories are developed that utilize wind energy to achieve minimum-time and minimum-energy flights. The airship is represented by a three-dimensional point mass model, and the equations of motion include aerodynamic lift and drag, vectored thrust, added mass effects, and accelerations due to mass flow rate, wind rates, and Earth rotation. A representative wind profile is developed based on historical meteorological data and measurements. Trajectory optimization is performed by first defining an optimal control problem with both terminal and path constraints, then using direct transcription to develop an approximate nonlinear parameter optimization problem of finite dimension. Optimal ascent trajectories are determined using SNOPT for a variety of upwind, downwind, and crosswind launch locations. Results of extensive optimization solutions illustrate definitive patterns in the ascent path for minimum time flights across

  9. Advanced methods of structural and trajectory analysis for transport aircraft

    NASA Technical Reports Server (NTRS)

    Ardema, Mark D.

    1995-01-01

    This report summarizes the efforts in two areas: (1) development of advanced methods of structural weight estimation, and (2) development of advanced methods of trajectory optimization. The majority of the effort was spent in the structural weight area. A draft of 'Analytical Fuselage and Wing Weight Estimation of Transport Aircraft', resulting from this research, is included as an appendix.

  10. The analysis of control trajectories using symbolic and database computing

    NASA Technical Reports Server (NTRS)

    Grossman, Robert

    1991-01-01

    The research broadly concerned the symbolic computation, mixed numeric-symbolic computation, and data base computation of trajectories of dynamical systems, especially control systems. It was determined that trees can be used to compute symbolically series which approximate solutions to differential equations.

  11. Molecular cloning and functional analysis of a UV-B photoreceptor gene, MdUVR8 (UV Resistance Locus 8), from apple.

    PubMed

    Zhao, Cheng; Mao, Ke; You, Chun-Xiang; Zhao, Xian-Yan; Wang, Shu-Hui; Li, Yuan-Yuan; Hao, Yu-Jin

    2016-06-01

    UVR8 (UV Resistance Locus 8) is an ultraviolet-B (UV-B; 280-315nm) light receptor that is involved in regulating many aspects of plant growth and development. UV-B irradiation can increase the development of flower and fruit coloration in many fruit trees, such as grape, pear and apple. Previous investigations of the structure and functions of UVR8 in plants have largely focused on Arabidopsis. Here, we isolated the UVR8 gene from apple (Malus domestica) and analyzed its function in transgenic Arabidopsis. Genomic and protein sequence analysis showed that MdUVR8 shares high similarity with the AtUVR8 protein from Arabidopsis, including the conserved seven-bladed β-propeller, the C27 region, the 3 "GWRHT" motifs and crucial amino-acid residues (14 Trps, 2 Args). A point mutation prediction and three-dimensional structural analysis of MdUVR8 indicated that it has a similar structure to AtUVR8 and that the crucial residues are also important in MdUVR8. In terms of transcript levels, MdUVR8 expression was up-regulated by UV-B light, which suggests that its expression follows a 24-h circadian rhythm. Using heterologous expression of MdUVR8 in both uvr8-1 mutant and wild-type (WT) Arabidopsis, we found that MdUVR8 regulates hypocotyl elongation and gene expression under UV-B light. These data provide functional evidence for a role of MdUVR8 in controlling photomorphogenesis under UV-B light and indicate that the function of UVR8 is conserved between Arabidopsis and apple. Furthermore, we examined the interaction between MdUVR8 and MdCOP1 (constitutive photomorphogenic1) using a yeast two-hybrid assay and a co-immunoprecipitation assay. This interaction provides a direction for investigating the regulatory mechanisms of the UV-B-light pathway in apple.

  12. Overview of the Development for a Suite of Low-Thrust Trajectory Analysis Tools

    NASA Technical Reports Server (NTRS)

    Kos, Larry D.; Polsgrove, Tara; Hopkins, Randall; Thomas, Dan; Sims, Jon A.

    2006-01-01

    A NASA intercenter team has developed a suite of low-thrust trajectory analysis tools to make a significant improvement in three major facets of low-thrust trajectory and mission analysis. These are: 1) ease of use, 2) ability to more robustly converge to solutions, and 3) higher fidelity modeling and accuracy of results. Due mostly to the short duration of the development, the team concluded that a suite of tools was preferred over having one integrated tool. This tool-suite, their characteristics, and their applicability will be described. Trajectory analysts can read this paper and determine which tool is most appropriate for their problem.

  13. Analysis of the forward-backward trajectory solution for the mixed quantum-classical Liouville equation.

    PubMed

    Hsieh, Chang-Yu; Kapral, Raymond

    2013-04-07

    Mixed quantum-classical methods provide powerful algorithms for the simulation of quantum processes in large and complex systems. The forward-backward trajectory solution of the mixed quantum-classical Liouville equation in the mapping basis [C.-Y. Hsieh and R. Kapral, J. Chem. Phys. 137, 22A507 (2012)] is one such scheme. It simulates the dynamics via the propagation of forward and backward trajectories of quantum coherent state variables, and the propagation of bath trajectories on a mean-field potential determined jointly by the forward and backward trajectories. An analysis of the properties of this solution, numerical tests of its validity and an investigation of its utility for the study of nonadiabtic quantum processes are given. In addition, we present an extension of this approximate solution that allows one to systematically improve the results. This extension, termed the jump forward-backward trajectory solution, is analyzed and tested in detail and its various implementations are discussed.

  14. Trajectory analysis and performance for SEP Comet Encke missions

    NASA Technical Reports Server (NTRS)

    Sauer, C. G., Jr.

    1973-01-01

    A summary of the performance of Solar Electric Propulsion spacecraft for Comet Encke missions for the 1980, 1984 and 1987 mission opportunities is presented together with a description of the spacecraft trajectory for each opportunity. Included is data for rendezvous trajectories for all three opportunities and data for a slow flyby mission during the 1980 opportunity. A range of propulsion system input powers of 10 to 20 kW are considered together with a constant spacecraft power requirement of 400 watts. The performance presented in this paper is indicative of that using 30 cm Mercury electron bombardment thrusters that are currently being developed. Performance is given in terms of final spacecraft mass and is thus independent of any particular spacecraft design concept.

  15. Trajectory planning and mechanic's analysis of lower limb rehabilitation robot.

    PubMed

    Zhiyong, Tang; Xiaodong, Xu; Zhongcai, Pei

    2015-01-01

    A new rehabilitation robot was designed. The robot included a suspension mechanism, a drive unit, and an adjustment mechanism. Additionally, innovative weight loss mechanism increased the dynamical device so that it could be used with patients of varying lower extremity muscle strengths. The relationship of hip and knee angles with height, step length, and gait cycle was studied. It was developed to generate different trajectories for different patients. Kinematics and dynamics were studied to lay the foundation for control.

  16. Trajectory Hunting: Analysis of UARS Measurements showing Rapid Chlorine Activation

    NASA Technical Reports Server (NTRS)

    Danilin, M.Y.; Santee, M. L.; Rodriquez, J. M.; Ko, M. K. W.; Mergenthaler, J. M.; Kumer, J. B.; Tabazadeh, A.

    1998-01-01

    Trajectory hunting (i.e., a technique to find air parcels sampled at least twice over the course of a few days) is applied to analyze Upper Atmosphere Research Satellite (UARS) measurements in conjunction with the AER photochemical box model. In this study, we investigate rapid chlorine activation in the Arctic lower stratosphere on 29 Dec 1992 associated with a polar stratospheric cloud (PSC) event. Six air parcels that have been sampled twice were followed along 5-day trajectories at the 465 K (approximately 46 mb) and 585 K (approximately 22 mb) levels. A detailed sensitivity study with the AER. photochemical box model along these trajectories leads to the following conclusions for the episode considered: (1) model results are in better agreement with UARS measurements at these levels if the UKMO temperature is decreased by at least 1-2 K; (2) the NAT (nitric acid trihydrate) PSC formation scheme produces results in better agreement with observations than the STS (supercooled ternary solution) scheme; (3) the model can explain the UARS measurements at 585 K, but under-estimates the ClO abundance at 465 K, suggesting some inconsistency between the UARS measurements at this level.

  17. Trajectory Hunting: Analysis of UARS Measurements Showing Rapid Chlorine Activation

    NASA Technical Reports Server (NTRS)

    Danilin, M. Y.; Santee, M. L.; Rodriquez, J. M.; Ko, M. K. W.; Mergenthaler, J. M.; Kumer, J. B.; Tabazadeh, A.

    1998-01-01

    Trajectory hunting (i.e., a technique to find air parcels sampled at least twice over the course of a few days) is applied to analyze Upper Atmosphere Research Satellite (UARS) measurements in conjunction with the AER photochemical box model. In this study, we investigate rapid chlorine activation in the Arctic lower stratosphere on 29 Dec. 1992 associated with a polar stratospheric cloud (PSC) event. Six air parcels that have been sampled twice were followed along 5-day trajectories at the 465 K (approx. 46 mb) and 585 K (approxi. 22 mb) levels. A detailed sensitivity study with the AER photochemical box model along these trajectories leads to the following conclusions for the episode considered: 1) model results are in better agreement with UARS measurements at these levels if the U.K. Meteorological Office (UKMO) temperature is decreased by at least 1-2 K; 2) the NAT (nitric acid trihydrate) PSC formation scheme produces results in better agreement with observations than the STS (supercooled ternary solution) scheme; 3) the model can explain the UARS measurements at 585 K, but under-estimates the ClO abundance at 465 K, suggesting some inconsistency between the UARS measurements at this level.

  18. Performance analysis of bullet trajectory estimation: Approach, simulation, and experiments

    SciTech Connect

    Ng, L.C.; Karr, T.J.

    1994-11-08

    This paper describes an approach to estimate a bullet`s trajectory from a time sequence of angles-only observations from a high-speed camera, and analyzes its performance. The technique is based on fitting a ballistic model of a bullet in flight along with unknown source location parameters to a time series of angular observations. The theory is developed to precisely reconstruct, from firing range geometry, the actual bullet trajectory as it appeared on the focal plane array and in real space. A metric for measuring the effective trajectory track error is also presented. Detailed Monte-Carlo simulations assuming different bullet ranges, shot-angles, camera frame rates, and angular noise show that angular track error can be as small as 100 {mu}rad for a 2 mrad/pixel sensor. It is also shown that if actual values of bullet ballistic parameters were available, the bullet s source location variables, and the angles of flight information could also be determined.

  19. Analysis of Trajectory Flexibility Preservation Impact on Traffic Complexity

    NASA Technical Reports Server (NTRS)

    Idris, Husni; El-Wakil, Tarek; Wing, David J.

    2009-01-01

    The growing demand for air travel is increasing the need for mitigation of air traffic congestion and complexity problems, which are already at high levels. At the same time new information and automation technologies are enabling the distribution of tasks and decisions from the service providers to the users of the air traffic system, with potential capacity and cost benefits. This distribution of tasks and decisions raises the concern that independent user actions will decrease the predictability and increase the complexity of the traffic system, hence inhibiting and possibly reversing any potential benefits. In answer to this concern, the authors proposed the introduction of decision-making metrics for preserving user trajectory flexibility. The hypothesis is that such metrics will make user actions naturally mitigate traffic complexity. In this paper, the impact of using these metrics on traffic complexity is investigated. The scenarios analyzed include aircraft in en route airspace with each aircraft meeting a required time of arrival in a one-hour time horizon while mitigating the risk of loss of separation with the other aircraft, thus preserving its trajectory flexibility. The experiments showed promising results in that the individual trajectory flexibility preservation induced self-separation and self-organization effects in the overall traffic situation. The effects were quantified using traffic complexity metrics, namely dynamic density indicators, which indicated that using the flexibility metrics reduced aircraft density and the potential of loss of separation.

  20. Preliminary analysis on the MD-4® plasma-sprayed titanium acetabular component☆

    PubMed Central

    de Araújo Loures, Elmano; Simoni, Leandro Furtado; Leite, Isabel Cristina Gonçalves; Loures, Daniel Naya; Loures, Clarice Naya

    2015-01-01

    Objectives To evaluate the short-term performance of a type of implant manufactured in Brazil. Methods This study analyzed a cohort of 60 patients who underwent implantation of MD-4® acetabular components during primary hip arthroplasty procedures performed between January 1, 2010, and August 1, 2012. The patients were studied retrospectively with regard to clinical behavior, stability and radiological osseointegration. The patients were followed up for a minimum of 12 months and a maximum of 42 months (mean: 27) and were evaluated by means of the Harris Hip Score, SF-36 questionnaire and serial conventional radiographs. Results All the components were radiologically stable, without evidence of migration or progressive radiolucency lines. On average, the Harris Hip Score evolved from 36.1 to 92.1 (p < 0.001) and the SF-36 showed significant increases in all its domains (p < 0.001). No differences were observed among patients with osteoarthrosis, osteonecrosis, hip dysplasia or other conditions. Conclusions The short-term results showed clinical and radiological signs of stability and osseointegration of the implants, which may represent a predictive factor regarding medium-term survival of this acetabular component. PMID:26229918

  1. A Comparative Analysis of Two Full-Scale MD-500 Helicopter Crash Tests

    NASA Technical Reports Server (NTRS)

    Littell, Justin D.

    2011-01-01

    Two full scale crash tests were conducted on a small MD-500 helicopter at NASA Langley Research Center fs Landing and Impact Research Facility. One of the objectives of this test series was to compare airframe impact response and occupant injury data between a test which outfitted the airframe with an external composite passive energy absorbing honeycomb and a test which had no energy absorbing features. In both tests, the nominal impact velocity conditions were 7.92 m/sec (26 ft/sec) vertical and 12.2 m/sec (40 ft/sec) horizontal, and the test article weighed approximately 1315 kg (2900 lbs). Airframe instrumentation included accelerometers and strain gages. Four Anthropomorphic Test Devices were also onboard; three of which were standard Hybrid II and III, while the fourth was a specialized torso. The test which contained the energy absorbing honeycomb showed vertical impact acceleration loads of approximately 15 g, low risk for occupant injury probability, and minimal airframe damage. These results were contrasted with the test conducted without the energy absorbing honeycomb. The test results showed airframe accelerations of approximately 40 g in the vertical direction, high risk for injury probability in the occupants, and substantial airframe damage.

  2. Low-thrust trajectory analysis for the geosynchronous mission

    NASA Technical Reports Server (NTRS)

    Jasper, T. P.

    1973-01-01

    Methodology employed in development of a computer program designed to analyze optimal low-thrust trajectories is described, and application of the program to a Solar Electric Propulsion Stage (SEPS) geosynchronous mission is discussed. To avoid the zero inclination and eccentricity singularities which plague many small-force perturbation techniques, a special set of state variables (equinoctial) is used. Adjoint equations are derived for the minimum time problem and are also free from the singularities. Solutions to the state and adjoint equations are obtained by both orbit averaging and precision numerical integration; an evaluation of these approaches is made.

  3. Analysis of Suborbital Launch Trajectories for Satellite Delivery

    DTIC Science & Technology

    1991-12-01

    trajectory, the transition point occurs at a. speed ratio of .876 and an altitude ratio of .279. These values correspond to a velocity of 22403 ft/sec...Transition Altitude 146,404 ft3 Transition Velocity 22403 ft/sec .AV segment 1 22,61 ift/sec Orbit Altitude 100 nm AV segment 2 3,718 ft/sec Dynamic...Consumption during 186,271 Ibm Air Breathing phase Propellant Consumption during 52,831 lbm Rocket Powered phase Transition Velocity 22403 ft/sec (Mach

  4. Hayabusa Re-Entry: Trajectory Analysis and Observation Mission Design

    NASA Technical Reports Server (NTRS)

    Cassell, Alan M.; Winter, Michael W.; Allen, Gary A.; Grinstead, Jay H.; Antimisiaris, Manny E.; Albers, James; Jenniskens, Peter

    2011-01-01

    On June 13th, 2010, the Hayabusa sample return capsule successfully re-entered Earth s atmosphere over the Woomera Prohibited Area in southern Australia in its quest to return fragments from the asteroid 1998 SF36 Itokawa . The sample return capsule entered at a super-orbital velocity of 12.04 km/sec (inertial), making it the second fastest human-made object to traverse the atmosphere. The NASA DC-8 airborne observatory was utilized as an instrument platform to record the luminous portion of the sample return capsule re-entry (60 sec) with a variety of on-board spectroscopic imaging instruments. The predicted sample return capsule s entry state information at 200 km altitude was propagated through the atmosphere to generate aerothermodynamic and trajectory data used for initial observation flight path design and planning. The DC- 8 flight path was designed by considering safety, optimal sample return capsule viewing geometry and aircraft capabilities in concert with key aerothermodynamic events along the predicted trajectory. Subsequent entry state vector updates provided by the Deep Space Network team at NASA s Jet Propulsion Laboratory were analyzed after the planned trajectory correction maneuvers to further refine the DC-8 observation flight path. Primary and alternate observation flight paths were generated during the mission planning phase which required coordination with Australian authorities for pre-mission approval. The final observation flight path was chosen based upon trade-offs between optimal viewing requirements, ground based observer locations (to facilitate post-flight trajectory reconstruction), predicted weather in the Woomera Prohibited Area and constraints imposed by flight path filing deadlines. To facilitate sample return capsule tracking by the instrument operators, a series of two racetrack flight path patterns were performed prior to the observation leg so the instruments could be pointed towards the region in the star background where

  5. Simulated trajectories error analysis program, version 2. Volume 2: Programmer's manual

    NASA Technical Reports Server (NTRS)

    Vogt, E. D.; Adams, G. L.; Working, M. M.; Ferguson, J. B.; Bynum, M. R.

    1971-01-01

    A series of three computer programs for the mathematical analysis of navigation and guidance of lunar and interplanetary trajectories was developed. All three programs require the integration of n-body trajectories for both interplanetary and lunar missions. The virutal mass technique is used in all three programs. The user's manual contains the information necessary to operate the programs. The input and output quantities of the programs are described. Sample cases are given and discussed.

  6. Orbiter/carrier separation for the ALT free flight no. 1 reference trajectories. Mission planning, mission analysis and software formulation

    NASA Technical Reports Server (NTRS)

    Glenn, G. M.

    1976-01-01

    Details of the generation of the separation trajectories are discussed. The analysis culminated in definition of separation trajectories between physical separation and orbiter/carrier vortex clearance. Specifications, assumptions and analytical approach used to generate the separation trajectories are presented. Results of the analytical approach are evaluated. Conclusions and recommendations are summarized. Supporting references are listed.

  7. Orbiter Trajectory Analysis for a Two-Stage Reusable Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Cowling, Adam L.

    2011-01-01

    Trajectory analysis performed on NASA's reference two-stage-to-orbit launch vehicle upper stage will be presented. The work was completed in support of the Hypersonics Multidisciplinary Analysis and Optimization effort for the NASA-Air Force Joint System Study. Three degree-of-freedom (3-DOF) untrimmed trajectory analysis was performed for the orbiter ascent, closure and re-entry. An iterative closure process resulted in a 333,000 lb initial mass for the orbiter. The re-entry trajectory satisfied heating constraints for all payload out cases and met the constraints with reduced margins for payload in cases. Abort trajectories for engine out at staging, engine out during ascent, and failure to circularize in orbit, gave insight to the robustness of the orbiter. A trimmed ascent trajectory defined an engine gimbal location and the body flap angle best suited for maximizing injected mass. A trimmed re-entry trajectory revealed a need to update the trim routine to accommodate full flap aerodynamic data.

  8. Monte Carlo Analysis as a Trajectory Design Driver for the TESS Mission

    NASA Technical Reports Server (NTRS)

    Nickel, Craig; Lebois, Ryan; Lutz, Stephen; Dichmann, Donald; Parker, Joel

    2016-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will be injected into a highly eccentric Earth orbit and fly 3.5 phasing loops followed by a lunar flyby to enter a mission orbit with lunar 2:1 resonance. Through the phasing loops and mission orbit, the trajectory is significantly affected by lunar and solar gravity. We have developed a trajectory design to achieve the mission orbit and meet mission constraints, including eclipse avoidance and a 30-year geostationary orbit avoidance requirement. A parallelized Monte Carlo simulation was performed to validate the trajectory after injecting common perturbations, including launch dispersions, orbit determination errors, and maneuver execution errors. The Monte Carlo analysis helped identify mission risks and is used in the trajectory selection process.

  9. Monte Carlo Analysis as a Trajectory Design Driver for the Transiting Exoplanet Survey Satellite (TESS) Mission

    NASA Technical Reports Server (NTRS)

    Nickel, Craig; Parker, Joel; Dichmann, Don; Lebois, Ryan; Lutz, Stephen

    2016-01-01

    The Transiting Exoplanet Survey Satellite (TESS) will be injected into a highly eccentric Earth orbit and fly 3.5 phasing loops followed by a lunar flyby to enter a mission orbit with lunar 2:1 resonance. Through the phasing loops and mission orbit, the trajectory is significantly affected by lunar and solar gravity. We have developed a trajectory design to achieve the mission orbit and meet mission constraints, including eclipse avoidance and a 30-year geostationary orbit avoidance requirement. A parallelized Monte Carlo simulation was performed to validate the trajectory after injecting common perturbations, including launch dispersions, orbit determination errors, and maneuver execution errors. The Monte Carlo analysis helped identify mission risks and is used in the trajectory selection process.

  10. Space Trajectory Error Analysis Program (STEAP) for halo orbit missions. Volume 1: Analytic and user's manual

    NASA Technical Reports Server (NTRS)

    Byrnes, D. V.; Carney, P. C.; Underwood, J. W.; Vogt, E. D.

    1974-01-01

    Development, test, conversion, and documentation of computer software for the mission analysis of missions to halo orbits about libration points in the earth-sun system is reported. The software consisting of two programs called NOMNAL and ERRAN is part of the Space Trajectories Error Analysis Programs (STEAP). The program NOMNAL targets a transfer trajectory from Earth on a given launch date to a specified halo orbit on a required arrival date. Either impulsive or finite thrust insertion maneuvers into halo orbit are permitted by the program. The transfer trajectory is consistent with a realistic launch profile input by the user. The second program ERRAN conducts error analyses of the targeted transfer trajectory. Measurements including range, doppler, star-planet angles, and apparent planet diameter are processed in a Kalman-Schmidt filter to determine the trajectory knowledge uncertainty. Execution errors at injection, midcourse correction and orbit insertion maneuvers are analyzed along with the navigation uncertainty to determine trajectory control uncertainties and fuel-sizing requirements. The program is also capable of generalized covariance analyses.

  11. An analysis and comparison of several trajectory optimization methods

    NASA Technical Reports Server (NTRS)

    Lewallen, J. M.

    1971-01-01

    The sensitivities of the convergence characteristics of the methods to initially assumed parameters and trial solution, convergence times, computer logic, and storage requirements are discussed. Numerical comparison of the convergence characteristics is made by considering a minimum time, low thrust, Earth-Mars transfer trajectory. A modified quasi-linearization method reduces convergence time by approximately 70% when compared with the generalized Newton-Raphson method and allows the terminal boundary to be specified by a general function of the problem variables. A uniquely specified and easily determined, time dependent weighting matrix for the gradient techniques accelerates the shaping of the optimal control program and improves the convergence characteristics during the terminal iterations. Convergence envelopes, indicating how sensitive the convergence characteristics are to initially assumed parameters, are plotted for the perturbation and quasi-linearization methods. Several iteration schemes are proposed which increase the size of the convergence envelopes and decrease the sensitivity of the method to initially assumed parameters.

  12. Analysis of Electron Trajectories in Magnetized High Power Plasmas

    NASA Astrophysics Data System (ADS)

    Krueger, Dennis; Gallian, Sara; Trieschmann, Jan; Brinkmann, Ralf Peter

    2015-09-01

    High Power Impulse Magnetron Sputtering (HiPIMS) is an important example of magnetized technological plasmas. With HiPIMS the focus lies on the generation of a high density plasma with a remarkably high degree of ionization. It can be used for the deposition of thin films with superior density and quality. Theoretical approaches to the regime of magnetized low temperature plasmas encounter some fundamental difficulties, for example concerning the details of the magnetic field configuration, the strongly varying degree of magnetization, and the frequent wall interactions. A kinetic single particle model is used for the investigations. Single electron trajectories are analyzed with the widely used Boris algorithm within the magnetized zone above the target (racetrack). We further examine a configuration where symmetry breaking occurs due to a potential bump, which is rotating azimuthally around the racetrack (spoke). Observing the effects of this structure on the single electron motion may allow us to obtain further insight into this phenomenon. This work is supported by the German Research Foundation in the frame of the Collaborative Research Centre TRR 87.

  13. Regional Influences of Marcellus Shale Natural Gas Activity: Back-trajectory Analysis of Baltimore/Washington Ethane Concentrations

    NASA Astrophysics Data System (ADS)

    Vinciguerra, T.; Chittams, A.; Dadzie, J.; Deskins, T.; Goncalves, V.; M'Bagui Matsanga, C.; Zakaria, R.; Ehrman, S.; Dickerson, R. R.

    2015-12-01

    Over the past several years, the combined utilization of hydraulic fracturing and horizontal drilling has led to a rapid increase in natural gas production, especially from the Marcellus Shale. To explore the impact of this activity downwind on regions with no natural gas production, the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model was used to generate 48-hour back-trajectories for summer, daytime hours from the years 2007-2014 in the Baltimore, MD and Washington, D.C. areas where hourly ethane measurements are available from Photochemical Assessment Monitoring Stations (PAMS). For each of the years investigated, unconventional well counts were obtained for counties in the surrounding states of Pennsylvania, Ohio, West Virginia, and Virginia, and counties exceeding a threshold of 0.05 wells/km2 were designated as counties with a high density of wells. The back-trajectories for each year were separated into two groups: those which passed through counties containing a high density of wells, and those which did not. Back-trajectories passing through high-density counties were further screened by applying a height criterion where trajectories beyond 10% above the mixing layer were excluded. Preliminary results indicate that air parcels with back-trajectories passing within the boundary layer of counties with a high density of unconventional natural gas wells correspond to significantly greater concentrations of observed ethane at these downwind monitors.

  14. FATSLiM: a fast and robust software to analyze MD simulations of membranes.

    PubMed

    Buchoux, Sébastien

    2017-01-01

    When studying biological membranes, Molecular Dynamics (MD) simulations reveal to be quite complementary to experimental techniques. Because the simulated systems keep increasing both in size and complexity, the analysis of MD trajectories need to be computationally efficient while being robust enough to perform analysis on membranes that may be curved or deformed due to their size and/or protein-lipid interactions. This work presents a new software named FATSLiM ('Fast Analysis Toolbox for Simulations of Lipid Membranes') that can extract physical properties from MD simulations of membranes (with or without interacting proteins). Because it relies on the calculation of local normals, FATSLiM does not depend of the bilayer morphology and thus can handle with the same accuracy vesicles for instance. Thanks to an efficiency-driven development, it is also fast and consumes a rather low amount of memory.

  15. Trajectory Correction and Locomotion Analysis of a Hexapod Walking Robot with Semi-Round Rigid Feet

    PubMed Central

    Zhu, Yaguang; Jin, Bo; Wu, Yongsheng; Guo, Tong; Zhao, Xiangmo

    2016-01-01

    Aimed at solving the misplaced body trajectory problem caused by the rolling of semi-round rigid feet when a robot is walking, a legged kinematic trajectory correction methodology based on the Least Squares Support Vector Machine (LS-SVM) is proposed. The concept of ideal foothold is put forward for the three-dimensional kinematic model modification of a robot leg, and the deviation value between the ideal foothold and real foothold is analyzed. The forward/inverse kinematic solutions between the ideal foothold and joint angular vectors are formulated and the problem of direct/inverse kinematic nonlinear mapping is solved by using the LS-SVM. Compared with the previous approximation method, this correction methodology has better accuracy and faster calculation speed with regards to inverse kinematics solutions. Experiments on a leg platform and a hexapod walking robot are conducted with multi-sensors for the analysis of foot tip trajectory, base joint vibration, contact force impact, direction deviation, and power consumption, respectively. The comparative analysis shows that the trajectory correction methodology can effectively correct the joint trajectory, thus eliminating the contact force influence of semi-round rigid feet, significantly improving the locomotion of the walking robot and reducing the total power consumption of the system. PMID:27589766

  16. Trajectory Correction and Locomotion Analysis of a Hexapod Walking Robot with Semi-Round Rigid Feet.

    PubMed

    Zhu, Yaguang; Jin, Bo; Wu, Yongsheng; Guo, Tong; Zhao, Xiangmo

    2016-08-31

    Aimed at solving the misplaced body trajectory problem caused by the rolling of semi-round rigid feet when a robot is walking, a legged kinematic trajectory correction methodology based on the Least Squares Support Vector Machine (LS-SVM) is proposed. The concept of ideal foothold is put forward for the three-dimensional kinematic model modification of a robot leg, and the deviation value between the ideal foothold and real foothold is analyzed. The forward/inverse kinematic solutions between the ideal foothold and joint angular vectors are formulated and the problem of direct/inverse kinematic nonlinear mapping is solved by using the LS-SVM. Compared with the previous approximation method, this correction methodology has better accuracy and faster calculation speed with regards to inverse kinematics solutions. Experiments on a leg platform and a hexapod walking robot are conducted with multi-sensors for the analysis of foot tip trajectory, base joint vibration, contact force impact, direction deviation, and power consumption, respectively. The comparative analysis shows that the trajectory correction methodology can effectively correct the joint trajectory, thus eliminating the contact force influence of semi-round rigid feet, significantly improving the locomotion of the walking robot and reducing the total power consumption of the system.

  17. Trajectory analysis of acid deposition data from the new jersey pine barrens

    NASA Astrophysics Data System (ADS)

    Budd, William W.

    This research provides an example of the application of a simple method for evaluating regional interrelationships using air parcel trajectory analysis. An assessment of trajectories associated with storms affecting McDonald's Branch watershed (39°50'N, 74°30'W) is presented. A simple classification system is used to examine regional contributions of acid precursors. The results of the work suggest that major regional sources of acid precursor emissions dominated precipitation acidity for the Pine Barrens region from 1978 to 1981. An incremental approach to acid precipitation policy is suggested.

  18. Analysis of self-overlap reveals trade-offs in plankton swimming trajectories.

    PubMed

    Bianco, Giuseppe; Mariani, Patrizio; Visser, Andre W; Mazzocchi, Maria Grazia; Pigolotti, Simone

    2014-07-06

    Movement is a fundamental behaviour of organisms that not only brings about beneficial encounters with resources and mates, but also at the same time exposes the organism to dangerous encounters with predators. The movement patterns adopted by organisms should reflect a balance between these contrasting processes. This trade-off can be hypothesized as being evident in the behaviour of plankton, which inhabit a dilute three-dimensional environment with few refuges or orienting landmarks. We present an analysis of the swimming path geometries based on a volumetric Monte Carlo sampling approach, which is particularly adept at revealing such trade-offs by measuring the self-overlap of the trajectories. Application of this method to experimentally measured trajectories reveals that swimming patterns in copepods are shaped to efficiently explore volumes at small scales, while achieving a large overlap at larger scales. Regularities in the observed trajectories make the transition between these two regimes always sharper than in randomized trajectories or as predicted by random walk theory. Thus, real trajectories present a stronger separation between exploration for food and exposure to predators. The specific scale and features of this transition depend on species, gender and local environmental conditions, pointing at adaptation to state and stage-dependent evolutionary trade-offs.

  19. Action Recognition Using Rate-Invariant Analysis of Skeletal Shape Trajectories.

    PubMed

    Ben Amor, Boulbaba; Su, Jingyong; Srivastava, Anuj

    2016-01-01

    We study the problem of classifying actions of human subjects using depth movies generated by Kinect or other depth sensors. Representing human body as dynamical skeletons, we study the evolution of their (skeletons’) shapes as trajectories on Kendall’s shape manifold. The action data is typically corrupted by large variability in execution rates within and across subjects and, thus, causing major problems in statistical analyses. To address that issue, we adopt a recently-developed framework of Su et al. [1], [2] to this problem domain. Here, the variable execution rates correspond to re-parameterizations of trajectories, and one uses a parameterization-invariant metric for aligning, comparing, averaging, and modeling trajectories. This is based on a combination of transported square-root vector fields (TSRVFs) of trajectories and the standard Euclidean norm, that allows computational efficiency. We develop a comprehensive suite of computational tools for this application domain: smoothing and denoising skeleton trajectories using median filtering, up- and down-sampling actions in time domain, simultaneous temporal-registration of multiple actions, and extracting invertible Euclidean representations of actions. Due to invertibility these Euclidean representations allow both discriminative and generative models for statistical analysis. For instance, they can be used in a SVM-based classification of original actions, as demonstrated here using MSR Action-3D, MSR Daily Activity and 3D Action Pairs datasets. Using only the skeletal information, we achieve state-of-the-art classification results on these datasets.

  20. Analysis of self-overlap reveals trade-offs in plankton swimming trajectories

    PubMed Central

    Bianco, Giuseppe; Mariani, Patrizio; Visser, Andre W.; Mazzocchi, Maria Grazia; Pigolotti, Simone

    2014-01-01

    Movement is a fundamental behaviour of organisms that not only brings about beneficial encounters with resources and mates, but also at the same time exposes the organism to dangerous encounters with predators. The movement patterns adopted by organisms should reflect a balance between these contrasting processes. This trade-off can be hypothesized as being evident in the behaviour of plankton, which inhabit a dilute three-dimensional environment with few refuges or orienting landmarks. We present an analysis of the swimming path geometries based on a volumetric Monte Carlo sampling approach, which is particularly adept at revealing such trade-offs by measuring the self-overlap of the trajectories. Application of this method to experimentally measured trajectories reveals that swimming patterns in copepods are shaped to efficiently explore volumes at small scales, while achieving a large overlap at larger scales. Regularities in the observed trajectories make the transition between these two regimes always sharper than in randomized trajectories or as predicted by random walk theory. Thus, real trajectories present a stronger separation between exploration for food and exposure to predators. The specific scale and features of this transition depend on species, gender and local environmental conditions, pointing at adaptation to state and stage-dependent evolutionary trade-offs. PMID:24789560

  1. Separating the Air Quality Impact of a Major Highway and Nearby Sources by Nonparametric Trajectory Analysis

    EPA Science Inventory

    Nonparametric Trajectory Analysis (NTA), a receptor-oriented model, was used to assess the impact of local sources of air pollution at monitoring sites located adjacent to highway I-15 in Las Vegas, NV. Measurements of black carbon, carbon monoxide, nitrogen oxides, and sulfur di...

  2. Analysis of video-based microscopic particle trajectories using Kalman filtering.

    PubMed

    Wu, Pei-Hsun; Agarwal, Ashutosh; Hess, Henry; Khargonekar, Pramod P; Tseng, Yiider

    2010-06-16

    The fidelity of the trajectories obtained from video-based particle tracking determines the success of a variety of biophysical techniques, including in situ single cell particle tracking and in vitro motility assays. However, the image acquisition process is complicated by system noise, which causes positioning error in the trajectories derived from image analysis. Here, we explore the possibility of reducing the positioning error by the application of a Kalman filter, a powerful algorithm to estimate the state of a linear dynamic system from noisy measurements. We show that the optimal Kalman filter parameters can be determined in an appropriate experimental setting, and that the Kalman filter can markedly reduce the positioning error while retaining the intrinsic fluctuations of the dynamic process. We believe the Kalman filter can potentially serve as a powerful tool to infer a trajectory of ultra-high fidelity from noisy images, revealing the details of dynamic cellular processes.

  3. Stereoscopic Analysis of STEREO/SECCHI Data for CME Trajectory Determination

    NASA Technical Reports Server (NTRS)

    Liewer, P. C.; Hall, J. R.; Howard, R. A.; DeJong, E. M.; Thompson, W. T.; Thernisten, A.

    2010-01-01

    The Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) coronagraphs on the twin Solar TErrestrial RElations Observatory (STEREO) spacecraft provide simultaneous views of the corona and coronal mass ejections from two view points. Here, we analyze simultaneous image pairs using the technique of tie-pointing and triangulation (T&T) to determine the three-dimensional trajectory of seven coronal mass ejections (CMEs). The bright leading edge of a CME seen in coronagraph images results from line-of-sight integration through the CME front; the two STEREO coronagraphs see different apparent leading edges, leading to a systematic error in its three-dimensional reconstruction. We analyze this systematic error using a simple geometric model of a CME front. We validate the technique and analysis by comparing T&T trajectory determinations for seven CMEs with trajectories determined by Thernisien et al. (2009) using a forward modeling technique not susceptible to this systematic effect.

  4. ProtoMD: A prototyping toolkit for multiscale molecular dynamics

    NASA Astrophysics Data System (ADS)

    Somogyi, Endre; Mansour, Andrew Abi; Ortoleva, Peter J.

    2016-05-01

    ProtoMD is a toolkit that facilitates the development of algorithms for multiscale molecular dynamics (MD) simulations. It is designed for multiscale methods which capture the dynamic transfer of information across multiple spatial scales, such as the atomic to the mesoscopic scale, via coevolving microscopic and coarse-grained (CG) variables. ProtoMD can be also be used to calibrate parameters needed in traditional CG-MD methods. The toolkit integrates 'GROMACS wrapper' to initiate MD simulations, and 'MDAnalysis' to analyze and manipulate trajectory files. It facilitates experimentation with a spectrum of coarse-grained variables, prototyping rare events (such as chemical reactions), or simulating nanocharacterization experiments such as terahertz spectroscopy, AFM, nanopore, and time-of-flight mass spectroscopy. ProtoMD is written in python and is freely available under the GNU General Public License from github.com/CTCNano/proto_md.

  5. Substance Use and Abuse Trajectories across Adolescence: A Latent Trajectory Analysis of a Community-Recruited Sample of Girls

    ERIC Educational Resources Information Center

    Marti, C. Nathan; Stice, Eric; Springer, David W.

    2010-01-01

    We used data from a school-based study of 496 adolescent girls to identify qualitatively distinct substance use and substance abuse developmental trajectory groups and tested whether the problematic groups differed from the non-problematic groups on baseline and outcome validation variables. Results identified four substance use groups (late…

  6. Space Trajectories Error Analysis (STEAP) Programs. Volume 1: Analytic manual, update

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Manual revisions are presented for the modified and expanded STEAP series. The STEAP 2 is composed of three independent but related programs: NOMAL for the generation of n-body nominal trajectories performing a number of deterministic guidance events; ERRAN for the linear error analysis and generalized covariance analysis along specific targeted trajectories; and SIMUL for testing the mathematical models used in the navigation and guidance process. The analytic manual provides general problem description, formulation, and solution and the detailed analysis of subroutines. The programmers' manual gives descriptions of the overall structure of the programs as well as the computational flow and analysis of the individual subroutines. The user's manual provides information on the input and output quantities of the programs. These are updates to N69-36472 and N69-36473.

  7. Mode Analysis for Long-Term Behavior in a Resonant Earth-Moon Trajectory

    NASA Astrophysics Data System (ADS)

    Short, Cody; Howell, Kathleen; Haapala, Amanda; Dichmann, Donald

    2016-11-01

    Trajectory design in chaotic regimes allows for the exploitation of system dynamics to achieve certain behaviors. For example, for the Transiting Exoplanet Survey Satellite (TESS) mission, the selected science orbit represents a stable option well-suited to meet the mission objectives. Extended analysis of particular solutions nearby in the phase space reveals transitions into desirable terminal modes induced by natural dynamics. This investigation explores the trajectory behavior and borrows from flow-based analysis strategies to characterize modes of such a motion. Perturbed initial states from a TESS-like orbit are evolved to supply motion suitable for contingency analysis. Through the associated analysis, mechanisms are identified that drive the spacecraft into particular modes and supply conditions necessary for such transitions.

  8. Data Flow Analysis and Visualization for Spatiotemporal Statistical Data without Trajectory Information.

    PubMed

    Kim, Seokyeon; Jeong, Seongmin; Woo, Insoo; Jang, Yun; Maciejewski, Ross; Ebert, David

    2017-02-08

    Geographic visualization research has focused on a variety of techniques to represent and explore spatiotemporal data. The goal of those techniques is to enable users to explore events and interactions over space and time in order to facilitate the discovery of patterns, anomalies and relationships within the data. However, it is difficult to extract and visualize data flow patterns over time for non-directional statistical data without trajectory information. In this work, we develop a novel flow analysis technique to extract, represent, and analyze flow maps of non-directional spatiotemporal data unaccompanied by trajectory information. We estimate a continuous distribution of these events over space and time, and extract flow fields for spatial and temporal changes utilizing a gravity model. Then, we visualize the spatiotemporal patterns in the data by employing flow visualization techniques. The user is presented with temporal trends of geo-referenced discrete events on a map. As such, overall spatiotemporal data flow patterns help users analyze geo-referenced temporal events, such as disease outbreaks, crime patterns, etc. To validate our model, we discard the trajectory information in an origin-destination dataset and apply our technique to the data and compare the derived trajectories and the original. Finally, we present spatiotemporal trend analysis for statistical datasets including twitter data, maritime search and rescue events, and syndromic surveillance.

  9. Two-year trajectory of fall risk in people with Parkinson’s disease: a latent class analysis

    PubMed Central

    Paul, Serene S; Thackeray, Anne; Duncan, Ryan P; Cavanaugh, James T; Ellis, Theresa D; Earhart, Gammon M; Ford, Matthew P; Foreman, K Bo; Dibble, Leland E

    2015-01-01

    Objective To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson’s disease (PD). Design Latent class analysis, specifically growth mixture modeling (GMM) of longitudinal fall risk trajectories. Setting Not applicable. Participants 230 community-dwelling PD participants of a longitudinal cohort study who attended at least two of five assessments over a two year period. Interventions Not applicable. Main Outcome Measures Fall risk trajectory (low, medium or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6-monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed. Results The GMM optimally grouped participants into three fall risk trajectories that closely mirrored baseline fall risk status (p=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium risk trajectories (p<.001). Fluctuating fall risk (posterior probability <0.8 of belonging to any trajectory) was found in only 22.6% of the sample, most commonly among individuals who were transitioning to PIGD predominance. Conclusions Regardless of their baseline characteristics, most participants had clear and stable fall risk trajectories over two years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD. PMID:26606871

  10. Trajectory analysis for solar electric propulsion stage /SEPS/ planetary missions

    NASA Technical Reports Server (NTRS)

    Dazzo, E. J.; Nagorski, R. P.

    1973-01-01

    This paper summarizes a portion of the planetary mission analysis results of past and present studies conducted by Rockwell International for NASA-MSFC (Contract NAS8-27360) dealing with the feasibility of a Solar Electric Propulsion Stage (SEPS). The SEPS is envisioned as an upper stage of a transportation system capable of delivering either separable payload spacecraft or attached science packages to various planetary targets. The purpose of the paper is to demonstrate that, from a payload performance capability standpoint, a common SEP Stage can deliver various payloads to a host of planetary targets including inner and outer planets, asteroids, and comets.

  11. Crew Exploration Vehicle Ascent Abort Trajectory Analysis and Optimization

    NASA Technical Reports Server (NTRS)

    Falck, Robert D.; Gefert, Leon P.

    2007-01-01

    The Orion Crew Exploration Vehicle is the first crewed capsule design to be developed by NASA since Project Apollo. Unlike Apollo, however, the CEV is being designed for service in both Lunar and International Space Station missions. Ascent aborts pose some issues that were not present for Apollo, due to its launch azimuth, nor Space Shuttle, due to its cross range capability. The requirement that a North Atlantic splashdown following an abort be avoidable, in conjunction with the requirement for overlapping abort modes to maximize crew survivability, drives the thrust level of the service module main engine. This paper summarizes 3DOF analysis conducted by NASA to aid in the determination of the appropriate propulsion system for the service module, and the appropriate propellant loading for ISS missions such that crew survivability is maximized.

  12. Trajectory and Aeroheating Environment Development and Sensitivity Analysis for Capsule-shaped Vehicles

    NASA Technical Reports Server (NTRS)

    Robinson, Jeffrey S.; Wurster, Kathryn E.

    2006-01-01

    Recently, NASA's Exploration Systems Research and Technology Project funded several tasks that endeavored to develop and evaluate various thermal protection systems and high temperature material concepts for potential use on the crew exploration vehicle. In support of these tasks, NASA Langley's Vehicle Analysis Branch generated trajectory information and associated aeroheating environments for more than 60 unique entry cases. Using the Apollo Command Module as the baseline entry system because of its relevance to the favored crew exploration vehicle design, trajectories for a range of lunar and Mars return, direct and aerocapture Earth-entry scenarios were developed. For direct entry, a matrix of cases was created that reflects reasonably expected minimum and maximum values of vehicle ballistic coefficient, inertial velocity at entry interface, and inertial flight path angle at entry interface. For aerocapture, trajectories were generated for a range of values of initial velocity and ballistic coefficient that, when combined with proper initial flight path angles, resulted in achieving a low Earth orbit either by employing a full lift vector up or full lift vector down attitude. For each trajectory generated, aeroheating environments were generated which were intended to bound the thermal protection system requirements for likely crew exploration vehicle concepts. The trades examined clearly pointed to a range of missions / concepts that will require ablative systems as well as a range for which reusable systems may be feasible. In addition, the results clearly indicated those entry conditions and modes suitable for manned flight, considering vehicle deceleration levels experienced during entry. This paper presents an overview of the analysis performed, including the assumptions, methods, and general approach used, as well as a summary of the trajectory and aerothermal environment information that was generated.

  13. Spatial variability of hailfalls in France: an analysis of air mass retro-trajectories

    NASA Astrophysics Data System (ADS)

    Hermida, Lucía; Merino, Andrés; Sánchez, José Luis; Berthet, Claude; Dessens, Jean; López, Laura; Fernández-González, Sergio; Gascón, Estíbaliz; García-Ortega, Eduardo

    2014-05-01

    Hail is the main meteorological risk in south-west France, with the strongest hailfalls being concentrated in just a few days. Specifically, this phenomenon occurs most often and with the greatest severity in the Midi-Pyrénées area. Previous studies have revealed the high spatial variability of hailfall in this part of France, even leading to different characteristics being recorded on hailpads that were relatively close together. For this reason, an analysis of the air mass trajectories was carried out at ground level and at altitude, which subsequently led to the formation of the hail recorded by these hailpads. It is already known that in the study zone, the trajectories of the storms usually stretch for long distances and are oriented towards the east, leading to hailstones with diameters in excess of 3 cm, and without any change in direction above 3 km. We analysed different days with hail precipitation where there was at least one stone with a diameter of 3 cm or larger. Using the simulations from these days, an analysis of the backward trajectories of the air masses was carried out. We used the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory Model) to determine the origin of the air masses, and tracked them toward each of the hailpads that were hit during the day studied. The height of the final points was the height of the impacted hailpads. Similarly, the backward trajectories for different heights were also established. Finally, the results show how storms that affect neighbouring hailpads come from very different air masses; and provide a deeper understanding of the high variability that affects the characteristics of hailfalls. Acknowledgements The authors would like to thank the Regional Government of Castile-León for its financial support through the project LE220A11-2. This study was supported by the following grants: GRANIMETRO (CGL2010-15930); MICROMETEO (IPT-310000-2010-22).

  14. Combining propensity score matching and group-based trajectory analysis in an observational study.

    PubMed

    Haviland, Amelia; Nagin, Daniel S; Rosenbaum, Paul R

    2007-09-01

    In a nonrandomized or observational study, propensity scores may be used to balance observed covariates and trajectory groups may be used to control baseline or pretreatment measures of outcome. The trajectory groups also aid in characterizing classes of subjects for whom no good matches are available and to define substantively interesting groups between which treatment effects may vary. These and related methods are illustrated using data from a Montreal-based study. The effects on subsequent violence of gang joining at age 14 are studied while controlling for measured characteristics of boys prior to age 14. The boys are divided into trajectory groups based on violence from ages 11 to 13. Within trajectory group, joiners are optimally matched to a variable number of controls using propensity scores, Mahalanobis distances, and a combinatorial optimization algorithm. Use of variable ratio matching results in greater efficiency than pair matching and also greater bias reduction than matching at a fixed ratio. The possible impact of failing to adjust for an important but unmeasured covariate is examined using sensitivity analysis.

  15. Multidimensional Recurrence Quantification Analysis (MdRQA) for the Analysis of Multidimensional Time-Series: A Software Implementation in MATLAB and Its Application to Group-Level Data in Joint Action.

    PubMed

    Wallot, Sebastian; Roepstorff, Andreas; Mønster, Dan

    2016-01-01

    We introduce Multidimensional Recurrence Quantification Analysis (MdRQA) as a tool to analyze multidimensional time-series data. We show how MdRQA can be used to capture the dynamics of high-dimensional signals, and how MdRQA can be used to assess coupling between two or more variables. In particular, we describe applications of the method in research on joint and collective action, as it provides a coherent analysis framework to systematically investigate dynamics at different group levels-from individual dynamics, to dyadic dynamics, up to global group-level of arbitrary size. The Appendix in Supplementary Material contains a software implementation in MATLAB to calculate MdRQA measures.

  16. Multidimensional Recurrence Quantification Analysis (MdRQA) for the Analysis of Multidimensional Time-Series: A Software Implementation in MATLAB and Its Application to Group-Level Data in Joint Action

    PubMed Central

    Wallot, Sebastian; Roepstorff, Andreas; Mønster, Dan

    2016-01-01

    We introduce Multidimensional Recurrence Quantification Analysis (MdRQA) as a tool to analyze multidimensional time-series data. We show how MdRQA can be used to capture the dynamics of high-dimensional signals, and how MdRQA can be used to assess coupling between two or more variables. In particular, we describe applications of the method in research on joint and collective action, as it provides a coherent analysis framework to systematically investigate dynamics at different group levels—from individual dynamics, to dyadic dynamics, up to global group-level of arbitrary size. The Appendix in Supplementary Material contains a software implementation in MATLAB to calculate MdRQA measures. PMID:27920748

  17. Space safety trajectory optimization and debris analysis using ASTOS at ESA

    NASA Astrophysics Data System (ADS)

    Ortega, Guillermo; Blasco, Ana; Weikert, Sven

    This paper describes the coupling of the space trajectory optimization software ASTOS with a tool for splashdown analysis of separated spacecraft stages and debris called DARS (Destructive Analysis for Re-entry Spacecraft), and a Risk Analysis Module called RAM. ASTOS is a main reference tool for space trajectory optimization at ESA. It is also used to compute demise and break up of rocket stages and re-entry vehicles and analyze the risk to populated areas. ASTOS software is a simulation and optimization environment to compute optimal trajectories for a variety of complex multi-phase optimal control problems. It consists of fast and powerful optimization programs, PROMIS, CAMTOS, SOCS and TROPIC, that handle large and highly discretized problems, a user interface with multiple plot capability, and GISMO, an integrated graphical iteration monitor to review the optimization process and plot the state and control histories at intermediate steps during the optimization. The optimization programs used by ASTOS use Non-Linear Programming (NLP) mathematical solvers like NPSOL, SLSQP, SLLSQP, and SNOPT. These solvers use Sequential Quadratic Programming (SQP) mathematical algorithms to find the solution of the non-linear programming problems in trajectory optimization. ASTOS comprises an extensive model library, which allows launcher and re-entry spacecraft trajectory optimization without programming work. DARS considers not only a stage break-up, but also ablation and melting of the fragments, taking diverse materials and shapes into account. The paper discusses hazard due to stage and debris impact, considering the ESA launchers and re-entry vehicles as examples. Previous approaches for the impact point calculation during trajectory optimization are presented. Subsequently the results of these approaches are compared to DARS results. This paper shows that ASTOS and the DARS and RAM extensions can calculate impact points with satisfactory accuracy and calculation time

  18. Design of cycler trajectories and analysis of solar influences on radioactive decay rates during space missions

    NASA Astrophysics Data System (ADS)

    Rogers, Blake A.

    investigated to determine if they can be used to find new cycler trajectories, as well as those previously discovered. First order approximations to the relative motion equations are unfruitful for Earth-Mars cyclers because the variation in radial distance from the Sun is too large. However, using optimization techniques, cycling trajectories are found for the Earth-Mars, Earth-Ceres, and Mars-Ceres systems. Experiments showing a seasonal variation of the nuclear decay rates of a number of different nuclei and decay anomalies--- apparently related to solar flares and solar rotation--- have suggested that the Sun may somehow be influencing nuclear decay processes. Recently, there have been searches for such an effect in 238Pu nuclei contained in the radioisotope thermoelectric generators on board the Cassini spacecraft. In this work, that analysis is modified and extended to obtain constraints on anomalous decays of 238Pu over a wider range of models, but these limits cannot be applied to other nuclei if the anomaly is composition-dependent. It is also shown that it may require very high sensitivity for terrestrial experiments to discriminate among some models if such a decay anomaly exists, motivating the consideration of future spacecraft experiments which would require less precision. A mission on which such an experiment could be run is proposed. The proposed mission will take various isotopes on a spacecraft that has a large variation in radial distance and return them to Earth. Two different types of trajectories are considered: one with intermediate Venus flybys and one that injects directly into an Earth-resonant orbit. It is shown that each of these types of trajectories have their relative merits with regards to the scientific objective. The suitability of the upcoming Solar Probe Plus and Solar Orbiter missions to perform this experiment is also investigated.

  19. The application of trajectory analysis for an early warning system in STEM courses

    NASA Astrophysics Data System (ADS)

    Lee, Un Jung

    The retention of STEM (science, technology, engineering, and mathematics) majors has become a national concern. "Early warning systems" (EWS) are being developed to identify students who perform poorly early in the semester so that interventions can be implemented. The research reported here utilizes clicker scores and review quiz scores collected in every class session for the longitudinal analysis, as well as pre-course concept inventory scores and self-reported student characteristics. Pre course concept inventory scores were significantly predictive of final course grade. Student demographic characteristics had a smaller fraction of final course grade explained. The cumulative average student clicker score was highly predictive of final course grade. The cumulative average student review quiz score was also highly predictive of final course grade in spring 2014 semester, but was less predictive and less correlated with final course grade in the fall 2014 semester. The trajectories of transformed clicker and review quiz scores identified student longitudinal patterns of scores. Students with scores that were high at the beginning of the semester had consistently higher scores through the semester. In addition, the Bayesian Posterior Probabilities (BPPs) of clicker score trajectory were significant predictors of final course grade. In a trajectory analysis of ACF and PACF, the number of zero clicker scores was associated with final course grade. In conclusion, pre-course concept inventory scores and clicker scores were effective predictive variables for an EWS.

  20. Integrating graph partitioning and matching for trajectory analysis in video surveillance.

    PubMed

    Lin, Liang; Lu, Yongyi; Pan, Yan; Chen, Xiaowu

    2012-12-01

    In order to track moving objects in long range against occlusion, interruption, and background clutter, this paper proposes a unified approach for global trajectory analysis. Instead of the traditional frame-by-frame tracking, our method recovers target trajectories based on a short sequence of video frames, e.g., 15 frames. We initially calculate a foreground map at each frame obtained from a state-of-the-art background model. An attribute graph is then extracted from the foreground map, where the graph vertices are image primitives represented by the composite features. With this graph representation, we pose trajectory analysis as a joint task of spatial graph partitioning and temporal graph matching. The task can be formulated by maximizing a posteriori under the Bayesian framework, in which we integrate the spatio-temporal contexts and the appearance models. The probabilistic inference is achieved by a data-driven Markov chain Monte Carlo algorithm. Given a period of observed frames, the algorithm simulates an ergodic and aperiodic Markov chain, and it visits a sequence of solution states in the joint space of spatial graph partitioning and temporal graph matching. In the experiments, our method is tested on several challenging videos from the public datasets of visual surveillance, and it outperforms the state-of-the-art methods.

  1. An oilspill trajectory analysis model with a variable wind deflection angle

    USGS Publications Warehouse

    Samuels, W.B.; Huang, N.E.; Amstutz, D.E.

    1982-01-01

    The oilspill trajectory movement algorithm consists of a vector sum of the surface drift component due to wind and the surface current component. In the U.S. Geological Survey oilspill trajectory analysis model, the surface drift component is assumed to be 3.5% of the wind speed and is rotated 20 degrees clockwise to account for Coriolis effects in the Northern Hemisphere. Field and laboratory data suggest, however, that the deflection angle of the surface drift current can be highly variable. An empirical formula, based on field observations and theoretical arguments relating wind speed to deflection angle, was used to calculate a new deflection angle at each time step in the model. Comparisons of oilspill contact probabilities to coastal areas calculated for constant and variable deflection angles showed that the model is insensitive to this changing angle at low wind speeds. At high wind speeds, some statistically significant differences in contact probabilities did appear. ?? 1982.

  2. TRAJECTORY SENSITIVITY ANALYSIS FOR DYNAMIC SECURITY ASSESSMENT AND OTHER APPLICATIONS IN POWER SYSTEMS

    SciTech Connect

    Nguyen, Tony B.; Pai, M. A.

    2014-07-10

    Real time stability evaluation and preventive scheduling in power systems offer many challenges in a stressed power system. Trajectory sensitivity analysis (TSA) is a useful tool for this and other applications in the emerging smart grid area. In this chapter we outline the basic approach of TSA, to extract suitable information from the data and develop reliable metrics or indices to evaluate proximity of the system to an unstable condition. Trajectory sensitivities can be used to compute critical parameters such as clearing time of circuit breakers, tie line flow, etc. in a power system by developing suitable norms for ease of interpretation. The TSA technique has the advantage that model complexity is not a limitation, and the sensitivities can be computed numerically. Suitable metrics are developed from these sensitivities. The TSA technique can be extended to do preventive rescheduling. A brief discussion of other applications of TSA in placement of distributed generation is indicated.

  3. In silico thermodynamics stability change analysis involved in BH4 responsive mutations in phenylalanine hydroxylase: QM/MM and MD simulations analysis.

    PubMed

    Chadha, Nidhi; Tiwari, Anjani K; Kumar, Vikas; Milton, Marilyn D; Mishra, Anil K

    2015-01-01

    The mammalian tetrahydrobiopterin (BH4)-dependent phenylalanine hydroxylases (PAH), involved in important metabolic pathways of phenylalanine, belong to non-heme iron-containing aromatic acid hydroxylases' enzyme (AAH) family. AAHs utilize BH4 as protein co-factor and thus promote hydroxylation reactions of their substrates. Any alterations in BH4 -mediated AAH's pathway or mutations in these enzymes are responsible for various disorders, and thus highlights the importance of mutational analysis to assess the effect on their biosynthetic pathways. Our present studies are aimed at single-site mutations in PAH that lead to thermodynamic stability change upon folding and further validation of designed non-reduced BH2 designed co-factors. We have presented single-site mutational analysis of PAH where single-site mutations have been identified from known literature. Further, in silico studies with the PAH, in silico mutant PAH, and crystallized known mutant A313T forms, involved QM/MM and Molecular Dynamics (MD) simulations analysis. The modified co-factor A showed high affinity with PAH and all mutant PAH with high G-score of -14.851. The best pose high affinity co-factor A subjected to QM/MM optimization which leads to square-pyramidal coordination of non-heme active site. The structural and energetic information obtained from the production phase of 20 ns MD simulation of co-factor-metalloprotein complex results helped to understand the binding mode and involvement of three molecules throughout the reaction pathways' catalysis of PAH. The free energies of binding (dG) of A were found to be -68.181 kcal/mol and -72.249 for 1DMW and 1TDW for A313T mutant. Binding of Co-factor A do not perturb the coordination environment of iron at the active site which resides in 2-Histdine and 1-Glutamate triad, and may enhance the percentage response towards co-factor-mediated therapy.

  4. Trajectory analysis of Polar Patrol Balloon (PPB) flights in the stratosphere over Antarctica in summer and spring: A preliminary result

    NASA Technical Reports Server (NTRS)

    Kanzawa, Hiroshi; Fujii, Ryoichi; Yamazaki, Koji; Yamanaka, Manabu D.

    1994-01-01

    Actual trajectories of two PPB's which flew in the Antarctic stratosphere in austral summer and spring are compared with those calculated based on objective analysis data of Japan Meteorological Agency (JMA). The differences between the actual and calculated trajectories are discussed to check reliability of the JMA objective analysis data for the stratosphere, and to detect subsynoptic scale variability due to gravity waves and others.

  5. Trajectory analysis of winds and vesicular stomatitis in North America, 1982-5.

    PubMed

    Sellers, R F; Maarouf, A R

    1990-04-01

    Outbreaks of vesicular stomatitis, serotype New Jersey, during epidemics in the United States and northern Mexico, 1982-5, were examined by backward trajectories of winds to investigate spread and possible sources. The outbreaks selected for analysis did not involve introduction of disease by infected animals. The findings indicate that wind could have been responsible for carrying infection from northern Mexico to Arizona and New Mexico and thence to Colorado and Utah and on to Wyoming, Idaho and Montana. The results of these analyses are consistent with the findings from T1 RNAse fingerprinting of virus isolates from outbreaks during the epidemics. The arrival of the trajectories was associated with the passage of a front and rain or passage of a front alone or rain alone. At the time of the trajectories temperatures of 10 degrees C and higher were recorded at heights up to 2500-3500 m. Introduction by airborne particles would appear unlikely as it would have required a source of at least 10(5) infectious units per minute per animal. Vesicular stomatitis virus had been isolated from Simulium and Culicoides during the epidemic with amounts of virus from Simulium sufficient to suggest biological transmission. The possibility of Simulium infected with vesicular stomatitis virus being carried downwind to introduce disease is discussed in relation to the behaviour of Simulium and the pathogenesis of vesicular stomatitis in large animals.

  6. Programmer's manual for the Mission Analysis Evaluation and Space Trajectory Operations program (MAESTRO)

    NASA Technical Reports Server (NTRS)

    Lutzky, D.; Bjorkman, W. S.

    1973-01-01

    The Mission Analysis Evaluation and Space Trajectory Operations program known as MAESTRO is described. MAESTRO is an all FORTRAN, block style, computer program designed to perform various mission control tasks. This manual is a guide to MAESTRO, providing individuals the capability of modifying the program to suit their needs. Descriptions are presented of each of the subroutines descriptions consist of input/output description, theory, subroutine description, and a flow chart where applicable. The programmer's manual also contains a detailed description of the common blocks, a subroutine cross reference map, and a general description of the program structure.

  7. Optimum Three Impulse Trajectory Generator with Patched Conic Trajectory Model

    NASA Technical Reports Server (NTRS)

    Payne, M. H.; Pines, S.; Horsewood, J. L.

    1972-01-01

    Optimal multi-impulse trajectories were investigated as a nominal about which asymptotic expansion was used to obtain approximations of optimal low thrust trajectories. The work consisted of the analysis and description of an optimal 3-impulse trajectory program. A patched-conic trajectory model was specifically designed for compatibility with the subsequent addition of the low thrust expansion approximation.

  8. MD-2 binds cholesterol.

    PubMed

    Choi, Soo-Ho; Kim, Jungsu; Gonen, Ayelet; Viriyakosol, Suganya; Miller, Yury I

    2016-02-19

    Cholesterol is a structural component of cellular membranes, which is transported from liver to peripheral cells in the form of cholesterol esters (CE), residing in the hydrophobic core of low-density lipoprotein. Oxidized CE (OxCE) is often found in plasma and in atherosclerotic lesions of subjects with cardiovascular disease. Our earlier studies have demonstrated that OxCE activates inflammatory responses in macrophages via toll-like receptor-4 (TLR4). Here we demonstrate that cholesterol binds to myeloid differentiation-2 (MD-2), a TLR4 ancillary molecule, which is a binding receptor for bacterial lipopolysaccharide (LPS) and is indispensable for LPS-induced TLR4 dimerization and signaling. Cholesterol binding to MD-2 was competed by LPS and by OxCE-modified BSA. Furthermore, soluble MD-2 in human plasma and MD-2 in mouse atherosclerotic lesions carried cholesterol, the finding supporting the biological significance of MD-2 cholesterol binding. These results help understand the molecular basis of TLR4 activation by OxCE and mechanisms of chronic inflammation in atherosclerosis.

  9. MD-2 binds cholesterol

    PubMed Central

    Choi, Soo-Ho; Kim, Jungsu; Gonen, Ayelet; Viriyakosol, Suganya; Miller, Yury I.

    2016-01-01

    Cholesterol is a structural component of cellular membranes, which is transported from liver to peripheral cells in the form of cholesterol esters (CE), residing in the hydrophobic core of low-density lipoprotein. Oxidized CE (OxCE) is often found in plasma and in atherosclerotic lesions of subjects with cardiovascular disease. Our earlier studies have demonstrated that OxCE activates inflammatory responses in macrophages via toll-like receptor-4 (TLR4). Here we demonstrate that cholesterol binds to myeloid differentiation-2 (MD-2), a TLR4 ancillary molecule, which is a binding receptor for bacterial lipopolysaccharide (LPS) and is indispensable for LPS-induced TLR4 dimerization and signaling. Cholesterol binding to MD-2 was competed by LPS and by OxCE-modified BSA. Furthermore, soluble MD-2 in human plasma and MD-2 in mouse atherosclerotic lesions carried cholesterol, the finding supporting the biological significance of MD-2 cholesterol binding. These results help understand the molecular basis of TLR4 activation by OxCE and mechanisms of chronic inflammation in atherosclerosis. PMID:26806306

  10. Identification of synoptic precursors to extreme precipitation events in the Swiss Alps by the analysis of backward trajectories

    NASA Astrophysics Data System (ADS)

    Nguyen, L.; Horton, P.; Jaboyedoff, M.

    2015-12-01

    One of the most expensive natural disasters in Switzerland consists in floods related to heavy precipitation. The occurrence of heavy rainfall may induce landslides and debris flows, as observed during three major precipitation events that occurred recently in the Swiss Alps (August 1987, September 1993 and October 2000). Even though all these events took place under a southerly circulation, especially in autumn, not all southerly circulations lead to heavy precipitation. Although many studies tried to understand them, they are still difficult to forecast. Therefore, this work aims to identify synoptic precursors to such events throughout backward trajectories analysis. Part one tests as many combinations of tools, datasets and methods as possible in order to compare the trajectories in the case of heavy precipitations in the Alps and to reduce the number of models to be assessed for the second part by selecting the most relevant. As a result, we removed models yielding to similar results by using an absolute horizontal transport deviation measure (ATEH). The trajectories were processed with tools (HYSPLIT, a Matlab script developed at the University of Lausanne, and METEX) based on different Reanalysis (NCEP/NCAR, ECMWF, Japanese and NASA). Moreover, different types of trajectories (3D, isobaric, isentropic, isosigma, and constant density) have been used. As a result, 21 trajectory models were compared, and 9 were selected. Results show that most of the differences between trajectories are mainly related to the dataset rather than to the model. In part two, the 9 selected models were used to search precursors leading to heavy precipitations. 10-days backward trajectories were processed for the Binn station at different pressure levels, for all the days between 1961 and 2014 characterized by a southerly circulation in autumn. Based on these trajectories, two analysis for the identification of precursors were conducted. First, the ATEH was used to assess

  11. Spatio-Temporal Distribution Characteristics and Trajectory Similarity Analysis of Tuberculosis in Beijing, China

    PubMed Central

    Li, Lan; Xi, Yuliang; Ren, Fu

    2016-01-01

    Tuberculosis (TB) is an infectious disease with one of the highest reported incidences in China. The detection of the spatio-temporal distribution characteristics of TB is indicative of its prevention and control conditions. Trajectory similarity analysis detects variations and loopholes in prevention and provides urban public health officials and related decision makers more information for the allocation of public health resources and the formulation of prioritized health-related policies. This study analysed the spatio-temporal distribution characteristics of TB from 2009 to 2014 by utilizing spatial statistics, spatial autocorrelation analysis, and space-time scan statistics. Spatial statistics measured the TB incidence rate (TB patients per 100,000 residents) at the district level to determine its spatio-temporal distribution and to identify characteristics of change. Spatial autocorrelation analysis was used to detect global and local spatial autocorrelations across the study area. Purely spatial, purely temporal and space-time scan statistics were used to identify purely spatial, purely temporal and spatio-temporal clusters of TB at the district level. The other objective of this study was to compare the trajectory similarities between the incidence rates of TB and new smear-positive (NSP) TB patients in the resident population (NSPRP)/new smear-positive TB patients in the TB patient population (NSPTBP)/retreated smear-positive (RSP) TB patients in the resident population (RSPRP)/retreated smear-positive TB patients in the TB patient population (RSPTBP) to detect variations and loopholes in TB prevention and control among the districts in Beijing. The incidence rates in Beijing exhibited a gradual decrease from 2009 to 2014. Although global spatial autocorrelation was not detected overall across all of the districts of Beijing, individual districts did show evidence of local spatial autocorrelation: Chaoyang and Daxing were Low-Low districts over the six

  12. A Six Degree of Freedom Trajectory Analysis of Spin-Stabilized Projectiles

    NASA Astrophysics Data System (ADS)

    Gkritzapis, Dimitrios N.; Panagiotopoulos, Elias E.; Margaris, Dionissios P.; Papanikas, Dimitrios G.

    2007-12-01

    A full six degrees of freedom (6-DOF) flight dynamics model is proposed for the accurate prediction of short and long-range trajectories of high and low spin-stabilized projectiles via atmospheric flight to final impact point. The projectile is assumed to be both rigid (non-flexible), and rotationally symmetric about its spin axis launched at low and high pitch angles. The projectile maneuvering motion depends on the most significant force and moment variations in addition to gravity and Magnus Effect. The computational flight analysis takes into consideration the Mach number and total angle of attack effects by means of the variable aerodynamic coefficients. For the purposes of the present work, linear interpolation has been applied from the tabulated database of McCoy's book. The aforementioned variable flight model is compared with a trajectory atmospheric motion based on appropriate constant mean values of the aerodynamic projectile coefficients. Static stability, also called gyroscopic stability, is examined as a necessary condition for stable flight motion in order to locate the initial spinning projectile rotation. Static stability examination takes into account the overturning moment variations with Mach number flight motion. The developed method gives satisfactory results compared with published data of verified experiments and computational codes on atmospheric dynamics model analysis.

  13. Statistically optimal analysis of state-discretized trajectory data from multiple thermodynamic states.

    PubMed

    Wu, Hao; Mey, Antonia S J S; Rosta, Edina; Noé, Frank

    2014-12-07

    We propose a discrete transition-based reweighting analysis method (dTRAM) for analyzing configuration-space-discretized simulation trajectories produced at different thermodynamic states (temperatures, Hamiltonians, etc.) dTRAM provides maximum-likelihood estimates of stationary quantities (probabilities, free energies, expectation values) at any thermodynamic state. In contrast to the weighted histogram analysis method (WHAM), dTRAM does not require data to be sampled from global equilibrium, and can thus produce superior estimates for enhanced sampling data such as parallel/simulated tempering, replica exchange, umbrella sampling, or metadynamics. In addition, dTRAM provides optimal estimates of Markov state models (MSMs) from the discretized state-space trajectories at all thermodynamic states. Under suitable conditions, these MSMs can be used to calculate kinetic quantities (e.g., rates, timescales). In the limit of a single thermodynamic state, dTRAM estimates a maximum likelihood reversible MSM, while in the limit of uncorrelated sampling data, dTRAM is identical to WHAM. dTRAM is thus a generalization to both estimators.

  14. Trajectories of acute low back pain: a latent class growth analysis.

    PubMed

    Downie, Aron S; Hancock, Mark J; Rzewuska, Magdalena; Williams, Christopher M; Lin, Chung-Wei Christine; Maher, Christopher G

    2016-01-01

    Characterising the clinical course of back pain by mean pain scores over time may not adequately reflect the complexity of the clinical course of acute low back pain. We analysed pain scores over 12 weeks for 1585 patients with acute low back pain presenting to primary care to identify distinct pain trajectory groups and baseline patient characteristics associated with membership of each cluster. This was a secondary analysis of the PACE trial that evaluated paracetamol for acute low back pain. Latent class growth analysis determined a 5 cluster model, which comprised 567 (35.8%) patients who recovered by week 2 (cluster 1, rapid pain recovery); 543 (34.3%) patients who recovered by week 12 (cluster 2, pain recovery by week 12); 222 (14.0%) patients whose pain reduced but did not recover (cluster 3, incomplete pain recovery); 167 (10.5%) patients whose pain initially decreased but then increased by week 12 (cluster 4, fluctuating pain); and 86 (5.4%) patients who experienced high-level pain for the whole 12 weeks (cluster 5, persistent high pain). Patients with longer pain duration were more likely to experience delayed recovery or nonrecovery. Belief in greater risk of persistence was associated with nonrecovery, but not delayed recovery. Higher pain intensity, longer duration, and workers' compensation were associated with persistent high pain, whereas older age and increased number of episodes were associated with fluctuating pain. Identification of discrete pain trajectory groups offers the potential to better manage acute low back pain.

  15. APL@Voro: a Voronoi-based membrane analysis tool for GROMACS trajectories.

    PubMed

    Lukat, Gunther; Krüger, Jens; Sommer, Björn

    2013-11-25

    APL@Voro is a new program developed to aid in the analysis of GROMACS trajectories of lipid bilayer simulations. It can read a GROMACS trajectory file, a PDB coordinate file, and a GROMACS index file to create a two-dimensional geometric representation of a bilayer. Voronoi diagrams and Delaunay triangulations--generated for different selection models of lipids--support the analysis of the bilayer. The values calculated on the geometric structures can be visualized in a user-friendly interactive environment and, then, plotted and exported to different file types. APL@Voro supports complex bilayers with a mix of various lipids and proteins. For the calculation of the projected area per lipid, a modification of the well-known Voronoi approach is presented as well as the presentation of a new approach for including atoms into an existing triangulation. The application of the developed software is discussed for three example systems simulated with GROMACS. The program is written in C++, is open source, and is available free of charge.

  16. A combined Eulerian-Lagrangian two-phase flow analysis of SSME HPOTP nozzle plug trajectories. I - Methodology

    NASA Technical Reports Server (NTRS)

    De Jong, Frederik J.; Sabnis, Jayant S.; Mcconnaughey, Paul K.

    1989-01-01

    A computer code has been developed for the analysis of SSME (Space Shuttle Main Engine) HPOTP (High Pressure Oxidizer Turbo Pump) nozzle plug trajectories in the turnaround duct downstream of the turbine. The algorithm is based on a combined Eulerian-Lagrangian analysis originally developed for the study of two-phase flows. The Lagrangian part of this analysis has been enhanced to include three-dimensional particle motion and the effect of particle-wall collisions in complex geometries (with a large number of boundaries). The sensitivity of the nozzle plug trajectories to a variety of parameters has been determined, via the qualitative analysis of a select number of computed trajectories. The results of extensive parametric studies have been reported in a companion paper.

  17. Elevated Ozone Levels in Denmark: Analysis Employing Trajectory and Chemical Transport Modelling

    NASA Astrophysics Data System (ADS)

    Mahura, A.; Gross, A.; Petrova, I.

    2009-09-01

    In our study, among 9 Danish measurement sites, 3 sites having long-term ozone measurement (with a time resolution of 1 hour and starting in early 1990s) records were selected - Ulborg (DK31; 56.28°N, 8.43°E) and Frederiksborg (DK32; 55.97°N, 12.33°E) and Lille Valby (DK41; 55.69°N, 12.13°E) located on Jutland Peninsula and Zealand Island of Denmark, respectively. After pre-screening of the time series (covering almost 15 year period and including almost 543 thousand valid observations), the measurements with high ozone level (using threshold as 150 µg/m3) were selected accounting in total for 508 cases for these 3 locations. Among these, 42 (for DK41) and 59 (for DK31 and DK32) cases showed very high ozone concentrations (i.e. above 180 µg/m3). For all these cases, at first, the trajectory modelling approach was applied in order to estimate atmospheric transport pathway of air mass arrival at the measurement sites and potential source regions from where the elevated ozone level can be associated. In our study the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) model using REANALYSIS meteorological dataset (global, 1948-present) was run to calculate a set of backward trajectories (in total 508, with duration of 5 day backward in time and arriving at altitude of 100 m) and divide into groups with respect to potential source regions and dominating atmospheric transport pathways using cluster analysis technique. Several relatively long-term episodes with continuous elevated ozone were identified in the analyzed time series; in particular, for DK31 - 7 episodes (having longest duration and observed in Jun 1996 and Jun 2000), DK32 - 5 (Jul 1992 and Jun 2000), and DK41 - 4 (Jul 1992 and Jun 2000). For selected episodes the off-line Eulerian Chemistry-Aerosol-Cloud (CAC) model was run over the European domain. As meteorological driver, the High Resolution Limited Area Model (HIRLAM) generated output with 3D meteorological fields was used

  18. A Genome-Wide Analysis of the LBD (LATERAL ORGAN BOUNDARIES Domain) Gene Family in Malus domestica with a Functional Characterization of MdLBD11

    PubMed Central

    Su, Ling; Liu, Xin; Hao, Yujin

    2013-01-01

    The plant-specific LBD (LATERAL ORGAN BOUNDARIES domain) genes belong to a major family of transcription factor that encode a zinc finger-like domain. It has been shown that LBD genes play crucial roles in the growth and development of Arabidopsis and other plant species. However, no detailed information concerning this family is available for apple. In the present study, we analyzed the apple (Malus domestica) genome and identified 58 LBD genes. This gene family was tested for its phylogenetic relationships with homologous genes in the Arabidopsis genome, as well as its location in the genome, structure and expression. We also transformed one MdLBD gene into Arabidopsis to evaluate its function. Like Arabidopsis, apple LBD genes also have a conserved CX2CX6CX3C zinc finger-like domain in the N terminus and can be divided into two classes. The expression profile indicated that apple LBD genes exhibited a variety of expression patterns, suggesting that they have diverse functions. At the same time, the expression analysis implied that members of this apple gene family were responsive to hormones and stress and that they may participate in hormone-mediated plant organogenesis, which was demonstrated with the overexpression of the apple LBD gene MdLBD11, resulting in an abnormal phenotype. This phenotype included upward curling leaves, delayed flowering, downward-pointing flowers, siliques and other abnormal traits. Based on these data, we concluded that the MdLBD genes may play an important role in apple growth and development as in Arabidopsis and other species. PMID:23468909

  19. Entry trajectory, entry environment, and analysis of spacecraft motion for the RAM C-3 flight experiment

    NASA Technical Reports Server (NTRS)

    Weaver, W. L.; Bowen, J. T.

    1972-01-01

    The RAM C-3 flight experiment was launched to study the problem of radiofrequency blackout at an entry velocity of 24,300 ft/sec. The flight is described, and data for the entry trajectory and environment, which include the effects of actual temperature measured the day of launch, are presented. An analysis of entry spacecraft motions was performed. This analysis included the determination of wind angles from measured accelerations and estimates of wind angles at high altitudes from gyro-measured rotation rates. The maximum wind angles were found to be less than 5 deg to the point of pitch-roll resonance where the total wind angle increased to 8.5 deg and the roll rate started decreasing. A plausible cause for the decrease in roll rate was shown to be a combination of trim angle and an offset center of gravity.

  20. User's guide to the Mission Analysis Evaluation and Space Trajectory Operations program (MAESTRO)

    NASA Technical Reports Server (NTRS)

    Lutzky, D.; Schafer, J.

    1973-01-01

    The MAESTRO system is a mission analysis tool designed to present to the user information necessary to make the various decisions required in the design and execution of a spaceflight mission. The system was designed so that it can be used in both the pre-launch mission planning phase of a mission and during the flight as an in-flight decision making tool. A description of each of the following modes is presented: (1) trajectory propagation mode; (2) retro-fire determination mode; (3) midcourse analysis determination mode; (4) Monte Carlo mode; (5) verification mode; (6) orbit stability mode; and (7) post injection trim mode. A description of the inputs necessary to run the program mode is given along with a sample case.

  1. Reaction trajectory revealed by a joint analysis of protein data bank.

    PubMed

    Ren, Zhong

    2013-01-01

    Structural motions along a reaction pathway hold the secret about how a biological macromolecule functions. If each static structure were considered as a snapshot of the protein molecule in action, a large collection of structures would constitute a multidimensional conformational space of an enormous size. Here I present a joint analysis of hundreds of known structures of human hemoglobin in the Protein Data Bank. By applying singular value decomposition to distance matrices of these structures, I demonstrate that this large collection of structural snapshots, derived under a wide range of experimental conditions, arrange orderly along a reaction pathway. The structural motions along this extensive trajectory, including several helical transformations, arrive at a reverse engineered mechanism of the cooperative machinery (Ren, companion article), and shed light on pathological properties of the abnormal homotetrameric hemoglobins from α-thalassemia. This method of meta-analysis provides a general approach to structural dynamics based on static protein structures in this post genomics era.

  2. Reaction Trajectory Revealed by a Joint Analysis of Protein Data Bank

    PubMed Central

    Ren, Zhong

    2013-01-01

    Structural motions along a reaction pathway hold the secret about how a biological macromolecule functions. If each static structure were considered as a snapshot of the protein molecule in action, a large collection of structures would constitute a multidimensional conformational space of an enormous size. Here I present a joint analysis of hundreds of known structures of human hemoglobin in the Protein Data Bank. By applying singular value decomposition to distance matrices of these structures, I demonstrate that this large collection of structural snapshots, derived under a wide range of experimental conditions, arrange orderly along a reaction pathway. The structural motions along this extensive trajectory, including several helical transformations, arrive at a reverse engineered mechanism of the cooperative machinery (Ren, companion article), and shed light on pathological properties of the abnormal homotetrameric hemoglobins from α-thalassemia. This method of meta-analysis provides a general approach to structural dynamics based on static protein structures in this post genomics era. PMID:24244274

  3. Student trajectories in physics: the need for analysis through a socio-cultural lens

    NASA Astrophysics Data System (ADS)

    Zapata, Mara

    2010-09-01

    An analysis of student connections through time and space relative to the core discipline of physics is attempted, as viewed through the lens of actor-network-theory, by Antonia Candela. Using lenses of cultural realities, networks, and perceived power in the discourse of one specific university in the capital city of Mexico and one undergraduate physics classroom, the trajectories and itineraries of students are analyzed, relative to a physics professor's pedagogical practices. This ethnographic study then yields comparisons between Mexican undergraduate students and students from the United States. Actor network theory recognizes that the symbiotic relationship existing between an actor and a continuum of space and time is defined by the symbiotic yet interdependent relationships and networks of practice (Lemke in Downward causation: Minds, bodies, and matter 2000). As part of this study and in line with actor-network-theory, human actors and non-human participants were viewed in relation to how subjects acted and were acted upon within networks of practice. Through this forum I reflect on this work with particular focus on the issues of situatedness of actors from a sociocultural perspective and how established networks viewed within this perspective frame and subsequently impact student trajectories and itineraries. In essence I argue for a need to look at a myriad of further complexities driving the symbiotic relationships being analyzed.

  4. Separating the air quality impact of a major highway and nearby sources by nonparametric trajectory analysis.

    PubMed

    Henry, Ronald C; Vette, Alan; Norris, Gary; Vedantham, Ram; Kimbrough, Sue; Shores, Richard C

    2011-12-15

    Nonparametric Trajectory Analysis (NTA), a receptor-oriented model, was used to assess the impact of local sources of air pollution at monitoring sites located adjacent to highway I-15 in Las Vegas, NV. Measurements of black carbon, carbon monoxide, nitrogen oxides, and sulfur dioxide concentrations were collected from December 2008 to December 2009. The purpose of the study was to determine the impact of the highway at three downwind monitoring stations using an upwind station to measure background concentrations. NTA was used to precisely determine the contribution of the highway to the average concentrations measured at the monitoring stations accounting for the spatially heterogeneous contributions of other local urban sources. NTA uses short time average concentrations, 5 min in this case, and constructed local back-trajectories from similarly short time average wind speed and direction to locate and quantify contributions from local source regions. Averaged over an entire year, the decrease of concentrations with distance from the highway was found to be consistent with previous studies. For this study, the NTA model is shown to be a reliable approach to quantify the impact of the highway on local air quality in an urban area with other local sources.

  5. Comparative Analysis of VLF Signal Variation along Trajectory Induced by X-ray Solar Flares

    NASA Astrophysics Data System (ADS)

    Kolarski, A.; Grubor, D.

    2015-12-01

    Comparative qualitative analysis of amplitude and phase delay variations was carried out along the trajectory of GQD/22.1 kHz and NAA/24.0 kHz VLF signal traces, propagating from Skelton (UK) and Maine (USA) toward Belgrade, induced by four isolated solar X-ray flare events occurred during the period from September 2005 to December 2006. For monitoring, recording and for storage of VLF data at the Institute of Physics in Belgrade, Serbia, the AbsPAL system was used. For modeling purposes of propagating conditions along GQD and NAA signal propagation paths, LWPCv21 program code was used. Occurred solar flare events induced lower ionosphere electron density height profile changes, causing perturbations in VLF wave propagation within Earth-ionosphere waveguides. As analyzed VLF signals characterize by different propagation parameters along trajectories from their transmitters to the Belgrade receiver site, their propagation is affected in different ways for different solar flare events and also for the same solar flare events.

  6. Coral population trajectories, increased disturbance and management intervention: a sensitivity analysis

    PubMed Central

    Riegl, Bernhard; Berumen, Michael; Bruckner, Andrew

    2013-01-01

    Coral reefs distant from human population were sampled in the Red Sea and one-third showed degradation by predator outbreaks (crown-of-thorns-starfish = COTS observed in all regions in all years) or bleaching (1998, 2010). Models were built to assess future trajectories. They assumed variable coral types (slow/fast growing), disturbance frequencies (5,10,20 years), mortality (equal or not), and connectivity (un/connected to un/disturbed community). Known disturbances were used to parameterize models. Present and future disturbances were estimated from remote-sensing chlorophyll and temperature data. Simulations and sensitivity analysis suggest community resilience at >20-year disturbance frequency, but degradation at higher frequency. Trajectories move from fast-grower to slow-grower dominance at intermediate disturbance frequency, then again to fast-grower dominance. A similar succession was observed in the field: Acropora to Porites to Stylophora/Pocillopora dominance on shallow reefs, and a transition from large poritids to small faviids on deep reefs. Synthesis and application: Even distant reefs are impacted by global changes. COTS impacts and bleaching were key driver of coral degradation, coral population decline could be reduced if these outbreaks and bleaching susceptibility were managed by maintaining water quality and by other interventions. Just leaving reefs alone, seems no longer a satisfactory option. PMID:23610643

  7. Single-cell analysis delineates a trajectory toward the human early otic lineage

    PubMed Central

    Ealy, Megan; Ellwanger, Daniel C.; Kosaric, Nina; Stapper, Andres P.; Heller, Stefan

    2016-01-01

    Efficient pluripotent stem cell guidance protocols for the production of human posterior cranial placodes such as the otic placode that gives rise to the inner ear do not exist. Here we use a systematic approach including defined monolayer culture, signaling modulation, and single-cell gene expression analysis to delineate a developmental trajectory for human otic lineage specification in vitro. We found that modulation of bone morphogenetic protein (BMP) and WNT signaling combined with FGF and retinoic acid treatments over the course of 18 days generates cell populations that develop chronological expression of marker genes of non-neural ectoderm, preplacodal ectoderm, and early otic lineage. Gene expression along this differentiation path is distinct from other lineages such as endoderm, mesendoderm, and neural ectoderm. Single-cell analysis exposed the heterogeneity of differentiating cells and allowed discrimination of non-neural ectoderm and otic lineage cells from off-target populations. Pseudotemporal ordering of human embryonic stem cell and induced pluripotent stem cell-derived single-cell gene expression profiles revealed an initially synchronous guidance toward non-neural ectoderm, followed by comparatively asynchronous occurrences of preplacodal and otic marker genes. Positive correlation of marker gene expression between both cell lines and resemblance to mouse embryonic day 10.5 otocyst cells implied reasonable robustness of the guidance protocol. Single-cell trajectory analysis further revealed that otic progenitor cell types are induced in monolayer cultures, but further development appears impeded, likely because of lack of a lineage-stabilizing microenvironment. Our results provide a framework for future exploration of stabilizing microenvironments for efficient differentiation of stem cell-generated human otic cell types. PMID:27402757

  8. Expression analysis and functional characterization of apple MdVHP1 gene reveals its involvement in Na(+), malate and soluble sugar accumulation.

    PubMed

    Yao, Yu-Xin; Dong, Qing-Long; You, Chun-Xiang; Zhai, Heng; Hao, Yu-Jin

    2011-10-01

    The vacuolar H(+)-pyrophosphatase (VHP) is a proton pump, which energizes transport across the tonoplast. The contributions of VHP to ion, organic acid and sugar storage are unclear in fruit. Here we characterized the role of an apple vacuolar H(+)-pyrophosphatase gene (MdVHP1) in Na(+), malate and soluble sugar accumulation. MdVHP1 expression was consistent with VHP activities in apple fruits at most developmental stages, and highly significantly correlated with Na(+) concentration during fruit development. In apple fruits treated in vitro (i.e., fruit-bearing branches were cultured in Hoagland solution containing each of salt, malate and sucrose, respectively, or irradiated by blue light), MdVHP1 expression was significantly correlated with Na(+) and malate transporter genes MdNHX1 and MdtDT, while subunit A of the vacuolar H(+)-ATPase (MdVHA-A) was significantly correlated with MdtDT and sucrose transporter gene (MdSUT1). In addition, MdVHP1 overexpression noticeably promoted Na(+) and malate accumulation, but slightly increased soluble sugar accumulation in transgenic apple callus and tomato fruit, partially by regulating transporter genes MdNHX1, MdtDT and MdSUT1. Taken together, it appears that MdVHP1 favorably contributes to Na(+), malate and soluble sugar accumulation in apple fruit.

  9. Gunshot wound trajectory analysis using forensic animation to establish relative positions of shooter and victim.

    PubMed

    Galligan, Aisling A; Fries, Craig; Melinek, Judy

    2017-02-01

    Forensic pathologists who autopsy the victims of gun violence are often called upon to answer questions in both criminal and civil proceedings about the relative position of the shooter and the victim. In this case report of an officer-involved shooting incident, the statement of the police officer appeared to be in direct contradiction to the statements of other eyewitnesses, the evidence at the scene, and the final resting position of the decedent's body. Trajectory analysis of two gunshot wound pathways (only one of which was instantaneously incapacitating) was performed to assess the veracity of the officer's statement and forensic animation was used to create a court exhibit. A discussion of the current peer-reviewed literature is included.

  10. Fast analysis of molecular dynamics trajectories with graphics processing units-Radial distribution function histogramming

    SciTech Connect

    Levine, Benjamin G.; Stone, John E.; Kohlmeyer, Axel

    2011-05-01

    The calculation of radial distribution functions (RDFs) from molecular dynamics trajectory data is a common and computationally expensive analysis task. The rate limiting step in the calculation of the RDF is building a histogram of the distance between atom pairs in each trajectory frame. Here we present an implementation of this histogramming scheme for multiple graphics processing units (GPUs). The algorithm features a tiling scheme to maximize the reuse of data at the fastest levels of the GPU's memory hierarchy and dynamic load balancing to allow high performance on heterogeneous configurations of GPUs. Several versions of the RDF algorithm are presented, utilizing the specific hardware features found on different generations of GPUs. We take advantage of larger shared memory and atomic memory operations available on state-of-the-art GPUs to accelerate the code significantly. The use of atomic memory operations allows the fast, limited-capacity on-chip memory to be used much more efficiently, resulting in a fivefold increase in performance compared to the version of the algorithm without atomic operations. The ultimate version of the algorithm running in parallel on four NVIDIA GeForce GTX 480 (Fermi) GPUs was found to be 92 times faster than a multithreaded implementation running on an Intel Xeon 5550 CPU. On this multi-GPU hardware, the RDF between two selections of 1,000,000 atoms each can be calculated in 26.9 s per frame. The multi-GPU RDF algorithms described here are implemented in VMD, a widely used and freely available software package for molecular dynamics visualization and analysis.

  11. Fast Analysis of Molecular Dynamics Trajectories with Graphics Processing Units-Radial Distribution Function Histogramming.

    PubMed

    Levine, Benjamin G; Stone, John E; Kohlmeyer, Axel

    2011-05-01

    The calculation of radial distribution functions (RDFs) from molecular dynamics trajectory data is a common and computationally expensive analysis task. The rate limiting step in the calculation of the RDF is building a histogram of the distance between atom pairs in each trajectory frame. Here we present an implementation of this histogramming scheme for multiple graphics processing units (GPUs). The algorithm features a tiling scheme to maximize the reuse of data at the fastest levels of the GPU's memory hierarchy and dynamic load balancing to allow high performance on heterogeneous configurations of GPUs. Several versions of the RDF algorithm are presented, utilizing the specific hardware features found on different generations of GPUs. We take advantage of larger shared memory and atomic memory operations available on state-of-the-art GPUs to accelerate the code significantly. The use of atomic memory operations allows the fast, limited-capacity on-chip memory to be used much more efficiently, resulting in a fivefold increase in performance compared to the version of the algorithm without atomic operations. The ultimate version of the algorithm running in parallel on four NVIDIA GeForce GTX 480 (Fermi) GPUs was found to be 92 times faster than a multithreaded implementation running on an Intel Xeon 5550 CPU. On this multi-GPU hardware, the RDF between two selections of 1,000,000 atoms each can be calculated in 26.9 seconds per frame. The multi-GPU RDF algorithms described here are implemented in VMD, a widely used and freely available software package for molecular dynamics visualization and analysis.

  12. Video-tracker trajectory analysis: who meets whom, when and where

    NASA Astrophysics Data System (ADS)

    Jäger, U.; Willersinn, D.

    2010-04-01

    Unveiling unusual or hostile events by observing manifold moving persons in a crowd is a challenging task for human operators, especially when sitting in front of monitor walls for hours. Typically, hostile events are rare. Thus, due to tiredness and negligence the operator may miss important events. In such situations, an automatic alarming system is able to support the human operator. The system incorporates a processing chain consisting of (1) people tracking, (2) event detection, (3) data retrieval, and (4) display of relevant video sequence overlaid by highlighted regions of interest. In this paper we focus on the event detection stage of the processing chain mentioned above. In our case, the selected event of interest is the encounter of people. Although being based on a rather simple trajectory analysis, this kind of event embodies great practical importance because it paves the way to answer the question "who meets whom, when and where". This, in turn, forms the basis to detect potential situations where e.g. money, weapons, drugs etc. are handed over from one person to another in crowded environments like railway stations, airports or busy streets and places etc.. The input to the trajectory analysis comes from a multi-object video-based tracking system developed at IOSB which is able to track multiple individuals within a crowd in real-time [1]. From this we calculate the inter-distances between all persons on a frame-to-frame basis. We use a sequence of simple rules based on the individuals' kinematics to detect the event mentioned above to output the frame number, the persons' IDs from the tracker and the pixel coordinates of the meeting position. Using this information, a data retrieval system may extract the corresponding part of the recorded video image sequence and finally allows for replaying the selected video clip with a highlighted region of interest to attract the operator's attention for further visual inspection.

  13. A Spatiotemporal Analysis of Brazilian Science from the Perspective of Researchers' Career Trajectories.

    PubMed

    Furtado, Caio Alves; Davis, Clodoveu A; Gonçalves, Marcos André; de Almeida, Jussara Marques

    2015-01-01

    The growth of Brazilian scientific production in recent years is remarkable, which motivates an investigation on the factors, inside and outside the country, that helped shape this wealthy research environment. This article provides a thorough analysis of the education of researchers that constitute the main Brazilian research groups, using data on about 6,000 researchers involved in the country's National Institutes of Science and Technology (INCT) initiative. Data on the steps taken by each researcher in her education, from the bachelor's degree to doctorate, including a possible postdoctoral experience, and employment, are extracted from an official curriculum vitae repository. The location and the time at which each career step occurred define spatiotemporal career trajectories. We then analyze such trajectories considering additional data, including the area of knowledge of the INCTs to which each researcher is associated. We found an increasing prevalence of Brazilian institutions in the education of Brazilian scientists, as the number of doctorates earned abroad is decreasing over time. Postdoctoral stages, on the other hand, often take place in Europe or in the United States. Taking an international postdoctoral position after a full education in Brazil suggests a drive towards seeking higher-level exchange and cooperation with foreign groups in a more advanced career stage. Results also show that Brazilian researchers tend to seek employment in regions that are close to the institutions at which they received their bachelor's degrees, suggesting low mobility within the country. This study can be instrumental in defining public policies for correcting distortions, and can help other developing countries that aim to improve their national science systems.

  14. Analysis of Spatio-Temporal Traffic Patterns Based on Pedestrian Trajectories

    NASA Astrophysics Data System (ADS)

    Busch, S.; Schindler, T.; Klinger, T.; Brenner, C.

    2016-06-01

    For driver assistance and autonomous driving systems, it is essential to predict the behaviour of other traffic participants. Usually, standard filter approaches are used to this end, however, in many cases, these are not sufficient. For example, pedestrians are able to change their speed or direction instantly. Also, there may be not enough observation data to determine the state of an object reliably, e.g. in case of occlusions. In those cases, it is very useful if a prior model exists, which suggests certain outcomes. For example, it is useful to know that pedestrians are usually crossing the road at a certain location and at certain times. This information can then be stored in a map which then can be used as a prior in scene analysis, or in practical terms to reduce the speed of a vehicle in advance in order to minimize critical situations. In this paper, we present an approach to derive such a spatio-temporal map automatically from the observed behaviour of traffic participants in everyday traffic situations. In our experiments, we use one stationary camera to observe a complex junction, where cars, public transportation and pedestrians interact. We concentrate on the pedestrians trajectories to map traffic patterns. In the first step, we extract trajectory segments from the video data. These segments are then clustered in order to derive a spatial model of the scene, in terms of a spatially embedded graph. In the second step, we analyse the temporal patterns of pedestrian movement on this graph. We are able to derive traffic light sequences as well as the timetables of nearby public transportation. To evaluate our approach, we used a 4 hour video sequence. We show that we are able to derive traffic light sequences as well as time tables of nearby public transportation.

  15. A Spatiotemporal Analysis of Brazilian Science from the Perspective of Researchers’ Career Trajectories

    PubMed Central

    Furtado, Caio Alves; Davis, Clodoveu A.; Gonçalves, Marcos André; de Almeida, Jussara Marques

    2015-01-01

    The growth of Brazilian scientific production in recent years is remarkable, which motivates an investigation on the factors, inside and outside the country, that helped shape this wealthy research environment. This article provides a thorough analysis of the education of researchers that constitute the main Brazilian research groups, using data on about 6,000 researchers involved in the country’s National Institutes of Science and Technology (INCT) initiative. Data on the steps taken by each researcher in her education, from the bachelor’s degree to doctorate, including a possible postdoctoral experience, and employment, are extracted from an official curriculum vitae repository. The location and the time at which each career step occurred define spatiotemporal career trajectories. We then analyze such trajectories considering additional data, including the area of knowledge of the INCTs to which each researcher is associated. We found an increasing prevalence of Brazilian institutions in the education of Brazilian scientists, as the number of doctorates earned abroad is decreasing over time. Postdoctoral stages, on the other hand, often take place in Europe or in the United States. Taking an international postdoctoral position after a full education in Brazil suggests a drive towards seeking higher-level exchange and cooperation with foreign groups in a more advanced career stage. Results also show that Brazilian researchers tend to seek employment in regions that are close to the institutions at which they received their bachelor’s degrees, suggesting low mobility within the country. This study can be instrumental in defining public policies for correcting distortions, and can help other developing countries that aim to improve their national science systems. PMID:26513743

  16. Combining Propensity Score Matching and Group-Based Trajectory Analysis in an Observational Study

    ERIC Educational Resources Information Center

    Haviland, Amelia; Nagin, Daniel S.; Rosenbaum, Paul R.

    2007-01-01

    In a nonrandomized or observational study, propensity scores may be used to balance observed covariates and trajectory groups may be used to control baseline or pretreatment measures of outcome. The trajectory groups also aid in characterizing classes of subjects for whom no good matches are available and to define substantively interesting groups…

  17. Uncertainty Optimization Applied to the Monte Carlo Analysis of Planetary Entry Trajectories

    NASA Technical Reports Server (NTRS)

    Olds, John; Way, David

    2001-01-01

    Recently, strong evidence of liquid water under the surface of Mars and a meteorite that might contain ancient microbes have renewed interest in Mars exploration. With this renewed interest, NASA plans to send spacecraft to Mars approx. every 26 months. These future spacecraft will return higher-resolution images, make precision landings, engage in longer-ranging surface maneuvers, and even return Martian soil and rock samples to Earth. Future robotic missions and any human missions to Mars will require precise entries to ensure safe landings near science objective and pre-employed assets. Potential sources of water and other interesting geographic features are often located near hazards, such as within craters or along canyon walls. In order for more accurate landings to be made, spacecraft entering the Martian atmosphere need to use lift to actively control the entry. This active guidance results in much smaller landing footprints. Planning for these missions will depend heavily on Monte Carlo analysis. Monte Carlo trajectory simulations have been used with a high degree of success in recent planetary exploration missions. These analyses ascertain the impact of off-nominal conditions during a flight and account for uncertainty. Uncertainties generally stem from limitations in manufacturing tolerances, measurement capabilities, analysis accuracies, and environmental unknowns. Thousands of off-nominal trajectories are simulated by randomly dispersing uncertainty variables and collecting statistics on forecast variables. The dependability of Monte Carlo forecasts, however, is limited by the accuracy and completeness of the assumed uncertainties. This is because Monte Carlo analysis is a forward driven problem; beginning with the input uncertainties and proceeding to the forecasts outputs. It lacks a mechanism to affect or alter the uncertainties based on the forecast results. If the results are unacceptable, the current practice is to use an iterative, trial

  18. Semi-Automated Trajectory Analysis of Deep Ballistic Penetrating Brain Injury

    PubMed Central

    Folio, Les; Solomon, Jeffrey; Biassou, Nadia; Fischer, Tatjana; Dworzak, Jenny; Raymont, Vanessa; Sinaii, Ninet; Wassermann, Eric M.; Grafman, Jordan

    2016-01-01

    Background Penetrating head injuries (PHIs) are common in combat operations and most have visible wound paths on computed tomography (CT). Objective We assess agreement between an automated trajectory analysis-based assessment of brain injury and manual tracings of encephalomalacia on CT. Methods We analyzed 80 head CTs with ballistic PHI from the Institutional Review Board approved Vietnam head injury registry. Anatomic reports were generated from spatial coordinates of projectile entrance and terminal fragment location. These were compared to manual tracings of the regions of encephalomalacia. Dice’s similarity coefficients, kappa, sensitivities, and specificities were calculated to assess agreement. Times required for case analysis were also compared. Results Results show high specificity of anatomic regions identified on CT with semiautomated anatomical estimates and manual tracings of tissue damage. Radiologist’s and medical students’ anatomic region reports were similar (Kappa 0.8, t-test p < 0.001). Region of probable injury modeling of involved brain structures was sensitive (0.7) and specific (0.9) compared with manually traced structures. Semiautomated analysis was 9-fold faster than manual tracings. Conclusion Our region of probable injury spatial model approximates anatomical regions of encephalomalacia from ballistic PHI with time-saving over manual methods. Results show potential for automated anatomical reporting as an adjunct to current practice of radiologist/neurosurgical review of brain injury by penetrating projectiles. PMID:23707123

  19. HBonanza: A Computer Algorithm for Molecular-Dynamics-Trajectory Hydrogen-Bond Analysis

    PubMed Central

    Durrant, Jacob D.; McCammon, J. Andrew

    2011-01-01

    In the current work, we present a hydrogen-bond analysis of 2,673 ligand-receptor complexes that suggests the total number of hydrogen bonds formed between a ligand and its protein receptor is a poor predictor of ligand potency; furthermore, even that poor prediction does not suggest a statistically significant correlation between hydrogen-bond formation and potency. While we are not the first to suggest that hydrogen bonds on average do not generally contribute to ligand binding affinities, this additional evidence is nevertheless interesting. The primary role of hydrogen bonds may instead be to ensure specificity, to correctly position the ligand within the active site, and to hold the protein active site in a ligand-friendly conformation. We also present a new computer program called HBonanza (hydrogen-bond analyzer) that aids the analysis and visualization of hydrogen-bond networks. HBonanza, which can be used to analyze single structures or the many structures of a molecular dynamics trajectory, is open source and python implemented, making it easily editable, customizable, and platform independent. Unlike many other freely available hydrogen-bond analysis tools, HBonanza provides not only a text-based table describing the hydrogen-bond network, but also a Tcl script to facilitate visualization in VMD, a popular molecular visualization program. Visualization in other programs is also possible. A copy of HBonanza can be obtained free of charge from http://www.nbcr.net/hbonanza. PMID:21880522

  20. Air-breathing hypersonic vehicle guidance and control studies; An integrated trajectory/control analysis methodology: Phase 1

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1991-01-01

    A tool which generates optimal trajectory/control histories in an integrated manner is generically adapted to the treatment of single-stage-to-orbit air-breathing hypersonic vehicles. The methodology is implemented as a two point boundary value problem solution technique. Its use permits an assessment of an entire near-minimum-fuel trajectory and desired control strategy from takeoff to orbit while satisfying physically derived inequality constraints and while achieving efficient propulsive mode phasing. A simpler analysis strategy that partitions the trajectory into several boundary condition matched segments is also included to construct preliminary trajectory and control history representations with less computational burden than is required for the overall flight profile assessment. A demonstration was accomplished using a tabulated example (winged-cone accelerator) vehicle model that is combined with a newly developed multidimensional cubic spline data smoothing routine. A constrained near-fuel-optimal trajectory, imposing a dynamic pressure limit of 1000 psf, was developed from horizontal takeoff to 20,000 ft/sec relative air speed while aiming for a polar orbit. Previously unspecified propulsive discontinuities were located. Flight regimes demanding rapid attitude changes were identified, dictating control effector and closed-loop controller authority was ascertained after evaluating effector use for vehicle trim. Also, inadequacies in vehicle model representations and specific subsystem models with insufficient fidelity were determined based on unusual control characteristics and/or excessive sensitivity to uncertainty.

  1. General Growth Mixture Analysis of Adolescents' Developmental Trajectories of Anxiety: The Impact of Untested Invariance Assumptions on Substantive Interpretations

    ERIC Educational Resources Information Center

    Morin, Alexandre J. S.; Maiano, Christophe; Nagengast, Benjamin; Marsh, Herbert W.; Morizot, Julien; Janosz, Michel

    2011-01-01

    Substantively, this study investigates potential heterogeneity in the developmental trajectories of anxiety in adolescence. Methodologically, this study demonstrates the usefulness of general growth mixture analysis (GGMA) in addressing these issues and illustrates the impact of untested invariance assumptions on substantive interpretations. This…

  2. Barrier scattering with complex-valued quantum trajectories: Taxonomy and analysis of isochrones

    SciTech Connect

    David, Julianne K.; Wyatt, Robert E.

    2008-03-07

    To facilitate the search for isochrones when using complex-valued trajectory methods for quantum barrier scattering calculations, the structure and shape of isochrones in the complex plane were studied. Isochrone segments were categorized based on their distinguishing features, which are shared by each situation studied: High and low energy wave packets, scattering from both thick and thin Gaussian and Eckart barriers of varying height. The characteristic shape of the isochrone is a trifurcated system: Trajectories that transmit the barrier are launched from the lower branch (T), while the middle and upper branches form the segments for reflected trajectories (F and B). In addition, a model is presented for the curved section of the lower branch (from which transmitted trajectories are launched), and important features of the complex extension of the initial wave packet are identified.

  3. Feature point tracking and trajectory analysis for video imaging in cell biology.

    PubMed

    Sbalzarini, I F; Koumoutsakos, P

    2005-08-01

    This paper presents a computationally efficient, two-dimensional, feature point tracking algorithm for the automated detection and quantitative analysis of particle trajectories as recorded by video imaging in cell biology. The tracking process requires no a priori mathematical modeling of the motion, it is self-initializing, it discriminates spurious detections, and it can handle temporary occlusion as well as particle appearance and disappearance from the image region. The efficiency of the algorithm is validated on synthetic video data where it is compared to existing methods and its accuracy and precision are assessed for a wide range of signal-to-noise ratios. The algorithm is well suited for video imaging in cell biology relying on low-intensity fluorescence microscopy. Its applicability is demonstrated in three case studies involving transport of low-density lipoproteins in endosomes, motion of fluorescently labeled Adenovirus-2 particles along microtubules, and tracking of quantum dots on the plasma membrane of live cells. The present automated tracking process enables the quantification of dispersive processes in cell biology using techniques such as moment scaling spectra.

  4. Two Aspects of the Rural-Urban Divide and Educational Stratification in China: A Trajectory Analysis.

    PubMed

    Hao, Lingxin; Hu, Alfred; Lo, Jamie

    2014-08-01

    Contextualized in China's social change of the past half-century, this paper develops the notion of dichotomous inequality to conceptualize the two aspects of China's rural-urban divide in educational inequality-the household registration system (hukou) assigns people to a top-bottom hierarchy, and the rural-urban schooling system institutionalizes unequal resource distribution and diverse school mission. Based on this conceptualization, we formulate a Chinese version of the maximally maintained inequality (MMI) hypothesis. We capitalize on individual educational history data from the China General Social Survey (CGSS) 2008 and conduct a trajectory analysis using the generalized mixture modeling to estimate the differential effects of the two aspects of rural-urban divide on educational inequality in China. Findings indicate that (1) the sorting mechanism of the rural hukou places rural-hukou people in the very bottom of educational stratification, (2) the penalty of attending rural pre-tertiary school increases with educational stages, and (3) there is a cumulative disadvantage of rural hukou and rural school. Overall, our findings attest to the Chinese-version MMI and the behind principle of inequality reproduction.

  5. Trajectory analysis for the nucleus and dust of comet C/2013 A1 (Siding Spring)

    SciTech Connect

    Farnocchia, Davide; Chesley, Steven R.; Chodas, Paul W.; Tricarico, Pasquale; Kelley, Michael S. P.; Farnham, Tony L.

    2014-08-01

    Comet C/2013 A1 (Siding Spring) will experience a high velocity encounter with Mars on 2014 October 19 at a distance of 135,000 km ± 5000 km from the planet center. We present a comprehensive analysis of the trajectory of both the comet nucleus and the dust tail. The nucleus of C/2013 A1 cannot impact on Mars even in the case of unexpectedly large nongravitational perturbations. Furthermore, we compute the required ejection velocities for the dust grains of the tail to reach Mars as a function of particle radius and density and heliocentric distance of the ejection. A comparison between our results and the most current modeling of the ejection velocities suggests that impacts are possible only for millimeter to centimeter size particles released more than 13 AU from the Sun. However, this level of cometary activity that far from the Sun is considered extremely unlikely. The arrival time of these particles spans a 20-minute time interval centered at 2014 October 19 at 20:09 TDB, i.e., around the time that Mars crosses the orbital plane of C/2013 A1. Ejection velocities larger than currently estimated by a factor >2 would allow impacts for smaller particles ejected as close as 3 AU from the Sun. These particles would reach Mars from 19:13 TDB to 20:40 TDB.

  6. Characteristics of motive force derived from trajectory analysis of Amoeba proteus.

    PubMed

    Masaki, Noritaka; Miyoshi, Hiromi; Tsuchiya, Yoshimi

    2007-01-01

    We used a monochromatic charge-coupled-device camera to observe the migration behavior of Amoeba proteus every 5 s over a time course of 10000 s in order to investigate the characteristics of its centroid movement (cell velocity) over the long term. Fourier transformation of the time series of the cell velocity revealed that its power spectrum exhibits a Lorentz type profile with a relaxation time of a few hundred seconds. Moreover, some sharp peaks were found in the power spectrum, where the ratios of any two frequencies corresponding to the peaks were expressed as simple rational numbers. Analysis of the trajectory using a Langevin equation showed that the power spectrum reflects characteristics of the cell's motive force. These results suggest that some phenomena relating to the cell's motility, such as protoplasmic streaming and the sol-gel transformation of actin filaments, which seem to be independent phenomena and have different relaxation times, interact with each other and cooperatively participate in the generation process of the motive force.

  7. Uncertainty analysis and robust trajectory linearization control of a flexible air-breathing hypersonic vehicle

    NASA Astrophysics Data System (ADS)

    Pu, Zhiqiang; Tan, Xiangmin; Fan, Guoliang; Yi, Jianqiang

    2014-08-01

    Flexible air-breathing hypersonic vehicles feature significant uncertainties which pose huge challenges to robust controller designs. In this paper, four major categories of uncertainties are analyzed, that is, uncertainties associated with flexible effects, aerodynamic parameter variations, external environmental disturbances, and control-oriented modeling errors. A uniform nonlinear uncertainty model is explored for the first three uncertainties which lumps all uncertainties together and consequently is beneficial for controller synthesis. The fourth uncertainty is additionally considered in stability analysis. Based on these analyses, the starting point of the control design is to decompose the vehicle dynamics into five functional subsystems. Then a robust trajectory linearization control (TLC) scheme consisting of five robust subsystem controllers is proposed. In each subsystem controller, TLC is combined with the extended state observer (ESO) technique for uncertainty compensation. The stability of the overall closed-loop system with the four aforementioned uncertainties and additional singular perturbations is analyzed. Particularly, the stability of nonlinear ESO is also discussed from a Liénard system perspective. At last, simulations demonstrate the great control performance and the uncertainty rejection ability of the robust scheme.

  8. Characterizing the Atmospheric Circulation over the Colombian Orinoquia through Lagrangian Back-Trajectory Analysis

    NASA Astrophysics Data System (ADS)

    Orjuela, H. R.; Leon, G. E.; Jimenez-Pizarro, R.

    2012-12-01

    The ongoing transformation of the Colombian Orinoquia (Eastern Plains) due to the rapid expansion of the agricultural frontier and oil production implies a series of new atmospheric emissions, which might negatively impact human health and ecosystems in different ways. Some air pollutants have already been detected in the region. This is the case of Persistent Organic Pollutants (POPs), which are sampled in a site of the Global Atmospheric Passive Sampling (GAPS) network located in Arauca, Colombia. The current understanding on the origin and transport of pollutants is limited due to the lack of information on the atmospheric circulation in the Colombian Orinoquia. This research aims at generating new knowledge on the meteorology of this region mainly for weather forecasting and atmospheric pollution impact assessment. We present a conceptual model of the atmospheric circulation in the Colombian Orinoquia, including the main synoptic and mesoscale factors governing its meteorology. In order to identify the source of air masses and synoptic scale disturbances, we used Lagrangian back trajectories obtained with the model HYSPLIT 4.9 over the period 2000-2010. NCEP/NCAR and Global Data Assimilation System (GDAS) reanalysis results were used as meteorological input to HYSPLIT. Prior to the Lagrangian simulation, these global datasets were evaluated for their capability to reproduce meteorological observations in the region, particularly for rain and flood-triggering conditions. The observational data included satellite images and ground level network measurements by the Colombian Institute of Hydrology, Meteorology and Environmental Research (IDEAM). Windgridds and other data analysis tools were used.

  9. Two Aspects of the Rural-Urban Divide and Educational Stratification in China: A Trajectory Analysis*

    PubMed Central

    Hao, Lingxin; Hu, Alfred; Lo, Jamie

    2015-01-01

    Contextualized in China’s social change of the past half-century, this paper develops the notion of dichotomous inequality to conceptualize the two aspects of China’s rural-urban divide in educational inequality—the household registration system (hukou) assigns people to a top-bottom hierarchy, and the rural-urban schooling system institutionalizes unequal resource distribution and diverse school mission. Based on this conceptualization, we formulate a Chinese version of the maximally maintained inequality (MMI) hypothesis. We capitalize on individual educational history data from the China General Social Survey (CGSS) 2008 and conduct a trajectory analysis using the generalized mixture modeling to estimate the differential effects of the two aspects of rural-urban divide on educational inequality in China. Findings indicate that (1) the sorting mechanism of the rural hukou places rural-hukou people in the very bottom of educational stratification, (2) the penalty of attending rural pre-tertiary school increases with educational stages, and (3) there is a cumulative disadvantage of rural hukou and rural school. Overall, our findings attest to the Chinese-version MMI and the behind principle of inequality reproduction. PMID:26166835

  10. Trajectories of male sexual aggression from adolescence through college: A latent class growth analysis.

    PubMed

    Swartout, Kevin M; Swartout, Ashlyn G; Brennan, Carolyn L; White, Jacquelyn W

    2015-01-01

    Approximately 25% of male college students report engaging in some form of sexual coercion by the end of their fourth year of college. White and Smith (2004) found that negative childhood experiences-childhood sexual abuse, childhood physical abuse, and witnessing domestic violence-predicted sexual aggression perpetrated before college, but not during the subsequent college years, a puzzling finding in view of the reasonably consistent rates of sexual aggression from adolescence to the first 2 years of college. The current study takes a person-centered approach to sexual aggression in an attempt to resolve this discrepancy. We examined the possibility of cohesive subgroups of men in terms of their frequency of sexual aggression across the pre-college and college years. A series of latent class growth models were fit to an existing longitudinal dataset of sexual experiences collected across four time points-pre-college through year 3 of college. A four-trajectory model fit the data well, exhibiting significantly better fit than a three-trajectory model. The four trajectories are interpreted as men who perpetrate sexual aggression at (1) low (71.5% of the sample), (2) moderate (21.2%), (3) decreasing (4.2%), and (4) increasing (3.1%) frequencies across time. Negative childhood experiences predicted membership of the decreasing trajectory, relative to the low trajectory, but did not predict membership of the increasing trajectory, explaining the discrepancy uncovered by White and Smith. Implications for primary prevention of sexual aggression are discussed.

  11. Air-breathing hypersonic vehicle guidance and control studies: An integrated trajectory/control analysis methodology, phase 2

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1992-01-01

    An integrated trajectory/control analysis algorithm has been used to generate trajectories and desired control strategies for two different hypersonic air-breathing vehicle models and orbit targets. Both models used cubic spline curve fit tabulated winged-cone accelerator vehicle representations. Near-fuel-optimal, horizontal takeoff trajectories, imposing a dynamic pressure limit of 1000 psf, were developed. The first model analysis case involved a polar orbit and included the dynamic effects of using elevons to maintain longitudinal trim. Analysis results indicated problems with the adequacy of the propulsion model and highlighted dynamic pressure/altitude instabilities when using vehicle angle of attack as a control variable. Also, the magnitude of computed elevon deflections to maintain trim suggested a need for alternative pitch moment management strategies. The second analysis case was reformulated to use vehicle pitch attitude relative to the local vertical as the control variable. A new, more realistic, air-breathing propulsion model was incorporated. Pitch trim calculations were dropped and an equatorial orbit was specified. Changes in flight characteristics due to the new propulsion model have been identified. Flight regimes demanding rapid attitude changes have been noted. Also, some issues that would affect design of closed-loop controllers were ascertained.

  12. On trajectory generation for flexible space crane: Inverse dynamics analysis by LATDYN

    NASA Technical Reports Server (NTRS)

    Chen, G.-S.; Housner, J. M.; Wu, S.-C.; Chang, C.-W.

    1989-01-01

    For future in-space construction facility, one or more space cranes capable of manipulating and positioning large and massive spacecraft components will be needed. Inverse dynamics was extensively studied as a basis for trajectory generation and control of robot manipulators. The focus here is on trajectory generation in the gross-motion phase of space crane operation. Inverse dynamics of the flexible crane body is much more complex and intricate as compared with rigid robot link. To model and solve the space crane's inverse dynamics problem, LATDYN program which employs a three-dimensional finite element formulation for the multibody truss-type structures will be used. The formulation is oriented toward a joint dominated structure which is suitable for the proposed space crane concept. To track a planned trajectory, procedures will be developed to obtain the actuation profile and dynamics envelope which are pertinent to the design and performance requirements of the space crane concept.

  13. A Modification and Analysis of Lagrangian Trajectory Modeling and Granular Dynamics of Lunar Dust Particles

    NASA Technical Reports Server (NTRS)

    Long, Jason M.; Lane, John E.; Metzger, Philip T.

    2008-01-01

    A previously developed mathematical model is amended to more accurately incorporate the effects of lift and drag on single dust particles in order to predict their behavior in the wake of high velocity gas flow. The model utilizes output from a CFD or DSMC simulation of exhaust from a rocket nozzle hot gas jet. An extension of the Saffman equation for lift based on the research of McLaughlin (1991) and Mei (1992) is used, while an equation for the Magnus force modeled after the work of Oesterle (1994) and Tsuji et al (1985) is applied. A relationship for drag utilizing a particle shape factor (phi = 0.8) is taken from the work of Haider and Levenspiel (1989) for application to non-spherical particle dynamics. The drag equation is further adjusted to account for rarefaction and compressibility effects in rarefied and high Mach number flows according to the work of Davies (1945) and Loth (2007) respectively. Simulations using a more accurate model with the correction factor (Epsilon = 0.8 in a 20% particle concentration gas flow) given by Richardson and Zaki (1954) and Rowe (1961) show that particles have lower ejection angles than those that were previously calculated. This is more prevalent in smaller particles, which are shown through velocity and trajectory comparison to be more influenced by the flow of the surrounding gas. It is shown that particles are more affected by minor changes to drag forces than larger adjustments to lift forces, demanding a closer analysis of the shape and behavior of lunar dust particles and the composition of the surrounding gas flow.

  14. Verina Morton Jones, MD.

    PubMed

    Rishworth, Susan K

    2012-01-01

    The purpose of this historical article is to demonstrate, as the biography of Verina Morton Jones, MD, is uncovered, the difficulties inherent in researching original source material on the lives of 19th- and early 20th-century African American physicians as well as the great benefits derived from doing this research. The procedures used include basic archival research and close examination of published materials about her in the past, in conjunction with oral history. Original correspondence from Dr Morton Jones to her niece and nephew is used to illustrate events in her life and the thoughts and attitudes she expressed. Some of these thoughts and attitudes reflect those current situations in which African Americans found themselves, and others are quite unique, no doubt owing to her privileged position in the African American community. The principle conclusions reached include the great benefits derived from doing this kind of research, as difficult and time-consuming as that may be, with the enhanced knowledge and appreciation of the heritage of African American physicians, and insights into American social history during this period.

  15. John M. Eisenberg, MD.

    PubMed

    Eisenberg, J M

    1995-08-01

    The complicated interaction between government, academic medical centers, health care payers, and burgeoning market forces has tested the leadership skills of a generation of academicians with little formal training in economics. The emergence of a new breed of physician investigator with solid business credentials has therefore proved attractive to many segments of the medical community. John M. Eisenberg received his MD from Washington University in 1972, his MBA from the Wharton School in 1976, and shortly thereafter headed the division of general internal medicine at the University of Pennsylvania. In addition to championing the role of the generalist in health care delivery, Eisenberg has also played a major part in the reformation of Medicare reimbursement. He has been a commissioner on the Congressional Physician Payment Review Commission since 1986, serving as chairman since 1993. After assuming the chairmanship of the department of medicine at Georgetown University in 1992, Eisenberg served as an advisor to the Clinton administration during its efforts towards national health care reform. Interviewed in his office in Georgetown, Eisenberg reflected on the economic forces twisting post-graduate medical education, the role of non-physician providers in future health care delivery, and the evolving relationship between specialists and generalists.

  16. OPTIMUM TRAJECTORIES

    DTIC Science & Technology

    trajectory and the transient trajectories from the steady-state path to the endpoints could be computed separately. The results using this method agreed well with the exact solution and gave a tremendous savings in computing time....described the motion of a body similar to the one under study. The nature of the REAC solutions suggested that the steady-state, or mid-path

  17. Energies and 2'-Hydroxyl Group Orientations of RNA Backbone Conformations. Benchmark CCSD(T)/CBS Database, Electronic Analysis, and Assessment of DFT Methods and MD Simulations.

    PubMed

    Mládek, Arnošt; Banáš, Pavel; Jurečka, Petr; Otyepka, Michal; Zgarbová, Marie; Šponer, Jiří

    2014-01-14

    Sugar-phosphate backbone is an electronically complex molecular segment imparting RNA molecules high flexibility and architectonic heterogeneity necessary for their biological functions. The structural variability of RNA molecules is amplified by the presence of the 2'-hydroxyl group, capable of forming multitude of intra- and intermolecular interactions. Bioinformatics studies based on X-ray structure database revealed that RNA backbone samples at least 46 substates known as rotameric families. The present study provides a comprehensive analysis of RNA backbone conformational preferences and 2'-hydroxyl group orientations. First, we create a benchmark database of estimated CCSD(T)/CBS relative energies of all rotameric families and test performance of dispersion-corrected DFT-D3 methods and molecular mechanics in vacuum and in continuum solvent. The performance of the DFT-D3 methods is in general quite satisfactory. The B-LYP-D3 method provides the best trade-off between accuracy and computational demands. B3-LYP-D3 slightly outperforms the new PW6B95-D3 and MPW1B95-D3 and is the second most accurate density functional of the study. The best agreement with CCSD(T)/CBS is provided by DSD-B-LYP-D3 double-hybrid functional, although its large-scale applications may be limited by high computational costs. Molecular mechanics does not reproduce the fine energy differences between the RNA backbone substates. We also demonstrate that the differences in the magnitude of the hyperconjugation effect do not correlate with the energy ranking of the backbone conformations. Further, we investigated the 2'-hydroxyl group orientation preferences. For all families, we conducted a QM and MM hydroxyl group rigid scan in gas phase and solvent. We then carried out set of explicit solvent MD simulations of folded RNAs and analyze 2'-hydroxyl group orientations of different backbone families in MD. The solvent energy profiles determined primarily by the sugar pucker match well with the

  18. Space shuttle engineering and operations support. ALT separation reference trajectories for tailcone on orbiter forward and aft CG configurations. Mission planning, mission analysis and software formulation

    NASA Technical Reports Server (NTRS)

    Glenn, G. M.

    1977-01-01

    A preflight analysis of the ALT separation reference trajectories for the tailcone on, forward, and aft cg orbiter configurations is documented. The ALT separation reference trajectories encompass the time from physical separation of the orbiter from the carrier to orbiter attainment of the maximum ALT interface airspeed. The trajectories include post separation roll maneuvers by both vehicles and are generated using the final preflight data base. The trajectories so generated satisfy all known separation design criteria and violate no known constraints. The requirement for this analysis is given along with the specifications, assumptions, and analytical approach used to generate the separation trajectories. The results of the analytical approach are evaluated, and conclusions and recommendations are summarized.

  19. Simulation analysis of grinding wheel motion trajectory on SiC ceramics aspheric surface grinding

    NASA Astrophysics Data System (ADS)

    Zhang, Feihu; Liu, Lifei; Li, Chunhui

    2014-08-01

    In grinding process of SiC ceramics aspheric surface, the motion trajectory of grinding wheel has great influence on the surface forming. The paper provides mathematical models of grinding wheel movements; analytical simulation was done to describe the trajectories of the grinding wheel in manufacturing an aspherical workpiece. The effect of grinding parameters (including the rotation speed of the workpiece, the feed rate of grinding wheel etc.) on the aspheric surface coverage rate was conducted and discussed in detail. An experimental study was done according to the simulation results and an aspheric surface with form error less than 10μm was gained.

  20. Oncologic Patients' Knowledge Expectations and Cognitive Capacities During Illness Trajectory: Analysis of Critical Moments and Factors.

    PubMed

    Heli, Vaartio-Rajalin; Helena, Leino-Kilpi; Liisa, Iire; Kimmo, Lehtonen; Heikki, Minn

    2015-01-01

    Cancer and its management affect patients' cognitive resources and education needs in several ways. The objective of this study is to identify significant factors affecting cognitive resources and knowledge expectations of adult patients with cancer during the course of their illness trajectory. Current or former patients with cancer (n = 53) were recruited to focus group interviews and individual in-depth interviews. The informants' knowledge expectations vary during their illness trajectory and are affected by personal, situational, and clinical factors. These should be acknowledged to provide person-centered, holistic nursing care and patient education.

  1. A Hamiltonian Replica Exchange Molecular Dynamics (MD) Method for the Study of Folding, Based on the Analysis of the Stabilization Determinants of Proteins

    PubMed Central

    Meli, Massimiliano; Colombo, Giorgio

    2013-01-01

    Herein, we present a novel Hamiltonian replica exchange protocol for classical molecular dynamics simulations of protein folding/unfolding. The scheme starts from the analysis of the energy-networks responsible for the stabilization of the folded conformation, by means of the energy-decomposition approach. In this framework, the compact energetic map of the native state is generated by a preliminary short molecular dynamics (MD) simulation of the protein in explicit solvent. This map is simplified by means of an eigenvalue decomposition. The highest components of the eigenvector associated with the lowest eigenvalue indicate which sites, named “hot spots”, are likely to be responsible for the stability and correct folding of the protein. In the Hamiltonian replica exchange protocol, we use modified force-field parameters to treat the interparticle non-bonded potentials of the hot spots within the protein and between protein and solvent atoms, leaving unperturbed those relative to all other residues, as well as solvent-solvent interactions. We show that it is possible to reversibly simulate the folding/unfolding behavior of two test proteins, namely Villin HeadPiece HP35 (35 residues) and Protein A (62 residues), using a limited number of replicas. We next discuss possible implications for the study of folding mechanisms via all atom simulations. PMID:23743827

  2. Identification of synoptic precursors to extreme precipitation events in the Swiss Alps by the analysis of backward trajectories

    NASA Astrophysics Data System (ADS)

    Nguyen, Liliane; Horton, Pascal; Jaboyedoff, Michel

    2015-04-01

    combinations of tools, datasets and methods as possible. For the second part, in order to reduce the number of models to be assessed, we removed those models yielding to similar results. Then, the selected models were used to search simple precursors leading to heavy precipitations. Based on deviations analysis, we preliminary observed that the larger differences between trajectories result mainly from the dataset used rather than the model. Then, we processed 10 days backward trajectories for the Binn station (Wallis, Switzerland), which is a gauging station that often measures big amount of rain. As for the validity domain, we selected all the days between 1961 and 2014 that were characterized by a southerly circulation in autumn. Backward trajectories offer a way to understand some characteristics of air masses inducing heavy precipitation. For example, specific humidity can be retrieved all along the trajectories. Therefore, the origin of moisture contributing to heavy precipitation, and the role of the different weather systems in transporting moisture towards the Alps can be determined with the help of a Lagrangian moisture source diagnostic. According to the first results, moisture sources for heavy precipitation in autumn are mainly located on the western Mediterranean. An identification of simple synoptic precursors is by then attempted throughout analysis made on the resulting trajectories.

  3. Reflexive Language and Ethnic Minority Activism in Hong Kong: A Trajectory-Based Analysis

    ERIC Educational Resources Information Center

    Pérez-Milans, Miguel; Soto, Carlos

    2016-01-01

    This article engages with Archer's call to further research on reflexivity and social change under conditions of late modernity (2007, 2010, 2012) from the perspective of existing work on reflexive discourse in the language disciplines (Silverstein 1976, Lucy 1993). Drawing from a linguistic ethnography of the networked trajectories of a group of…

  4. LONG-DISTANCE GM POLLEN MOVEMENT OF CREEPING BENTGRASS USING MODELED WIND TRAJECTORY ANALYSIS

    EPA Science Inventory

    The importance of understanding the role of atmospheric conditions in pollen dispersal has grown in recent years with increased field-testing of genetically modified (GM) crop plants. An atmospheric model was used to characterize wind trajectories at 10 m and 100 m above GM polle...

  5. Trajectory analysis of low-energy and hyperthermal ions scattered from Cu(110)

    SciTech Connect

    McEachern, R.L.; Goodstein, D.M.; Cooper, B.H.

    1989-05-15

    Trajectories of Na{sup +} ions scattered from the Cu(110) surface in the <1 1bar 0> and <001> azimuths were studied for a range of incident energies from 56 eV to 4 keV. The goal is to explain the trends observed in the energy spectra and determine what types of trajectories contribute to these spectra. Using the computer program SAFARI, simulations were performed with trajectory analyses for 100-, 200-, and 400-eV scattering. We show results from the 100-eV simulations in both azimuths and compare them with the experimental data. The simulated energy spectra are in excellent agreement with the data. Ion trajectories and impact parameter plots from the simulations are used to determine the relative importance of different types of ion-surface-atom collisions. The simulations have shown that the striking differences observed in comparing the <1 1bar 0> and <001> spectra are mostly due to ions which scatter from second-layer atoms. This system exhibits strong focusing onto the second-layer atoms by the first-layer rows, and the focusing is very sensitive to the spacing between the rows. At the lower beam energies, scattering from the second layer dominates the measured spectra.

  6. Analysis of free text in electronic health records for identification of cancer patient trajectories.

    PubMed

    Jensen, Kasper; Soguero-Ruiz, Cristina; Oyvind Mikalsen, Karl; Lindsetmo, Rolv-Ole; Kouskoumvekaki, Irene; Girolami, Mark; Olav Skrovseth, Stein; Magne Augestad, Knut

    2017-04-07

    With an aging patient population and increasing complexity in patient disease trajectories, physicians are often met with complex patient histories from which clinical decisions must be made. Due to the increasing rate of adverse events and hospitals facing financial penalties for readmission, there has never been a greater need to enforce evidence-led medical decision-making using available health care data. In the present work, we studied a cohort of 7,741 patients, of whom 4,080 were diagnosed with cancer, surgically treated at a University Hospital in the years 2004-2012. We have developed a methodology that allows disease trajectories of the cancer patients to be estimated from free text in electronic health records (EHRs). By using these disease trajectories, we predict 80% of patient events ahead in time. By control of confounders from 8326 quantified events, we identified 557 events that constitute high subsequent risks (risk > 20%), including six events for cancer and seven events for metastasis. We believe that the presented methodology and findings could be used to improve clinical decision support and personalize trajectories, thereby decreasing adverse events and optimizing cancer treatment.

  7. Analysis of individual cell trajectories in lattice-gas cellular automaton models for migrating cell populations.

    PubMed

    Mente, Carsten; Voss-Böhme, Anja; Deutsch, Andreas

    2015-04-01

    Collective dynamics of migrating cell populations drive key processes in tissue formation and maintenance under normal and diseased conditions. Collective cell behavior at the tissue level is typically characterized by considering cell density patterns such as clusters and moving cell fronts. However, there are also important observables of collective dynamics related to individual cell behavior. In particular, individual cell trajectories are footprints of emergent behavior in populations of migrating cells. Lattice-gas cellular automata (LGCA) have proven successful to model and analyze collective behavior arising from interactions of migrating cells. There are well-established methods to analyze cell density patterns in LGCA models. Although LGCA dynamics are defined by cell-based rules, individual cells are not distinguished. Therefore, individual cell trajectories cannot be analyzed in LGCA so far. Here, we extend the classical LGCA framework to allow labeling and tracking of individual cells. We consider cell number conserving LGCA models of migrating cell populations where cell interactions are regulated by local cell density and derive stochastic differential equations approximating individual cell trajectories in LGCA. This result allows the prediction of complex individual cell trajectories emerging in LGCA models and is a basis for model-experiment comparisons at the individual cell level.

  8. Trajectories of Parenting and Child Negative Emotionality during Infancy and Toddlerhood: A Longitudinal Analysis

    ERIC Educational Resources Information Center

    Lipscomb, Shannon Tierney; Leve, Leslie D.; Harold, Gordon T.; Neiderhiser, Jenae M.; Shaw, Daniel S.; Ge, Xiaojia; Reiss, David

    2011-01-01

    The current longitudinal study examined trajectories of child negative emotionality, parenting efficacy, and overreactive parenting among 382 adoptive families during infancy and toddlerhood. Data were collected from adoptive parents when the children were 9-, 18-, and 27-month-old. Latent growth curve modeling indicated age-related increases in…

  9. Latent Class Analysis of Early Developmental Trajectory in Baby Siblings of Children with Autism

    ERIC Educational Resources Information Center

    Landa, Rebecca J.; Gross, Alden L.; Stuart, Elizabeth A.; Bauman, Margaret

    2012-01-01

    Background: Siblings of children with autism (sibs-A) are at increased genetic risk for autism spectrum disorders (ASD) and milder impairments. To elucidate diversity and contour of early developmental trajectories exhibited by sibs-A, regardless of diagnostic classification, latent class modeling was used. Methods: Sibs-A (N = 204) were assessed…

  10. First-Grade Predictors of Mathematical Learning Disability: A Latent Class Trajectory Analysis

    ERIC Educational Resources Information Center

    Geary, David C.; Bailey, Drew H.; Littlefield, Andrew; Wood, Phillip; Hoard, Mary K.; Nugent, Lara

    2009-01-01

    Kindergarten to third grade mathematics achievement scores from a prospective study of mathematical development (n = 306) were subjected to latent growth trajectory analyses. The four corresponding classes included children with mathematical learning disability (MLD, 6% of sample), and low (LA, 50%), typically (TA, 39%) and high (HA, 5%) achieving…

  11. Trajectory analysis of wet and dry deposited pollens from distant sources

    SciTech Connect

    Raynor, G S; Hayes, J V; Lewis, D M

    1981-01-01

    The purposes of this study are to determine if an available trajectory model calculates reasonable pathways from probable source regions to the sampling site and to determine the pathways and travel times involved in selected cases of long distance pollen transport. (PSB)

  12. Understanding the Gender Gap in School Performance among Low-Income Children: A Developmental Trajectory Analysis

    ERIC Educational Resources Information Center

    Kingdon, Danielle; Serbin, Lisa A.; Stack, Dale M.

    2017-01-01

    Internationally, girls outperform boys in overall school performance. The gender gap is particularly large among those in at-risk groups, such as children from families at economic disadvantage. This study modeled the academic trajectories of a low-income sample of boys and girls from the Concordia Longitudinal Risk Project across the full course…

  13. Analysis of free text in electronic health records for identification of cancer patient trajectories

    PubMed Central

    Jensen, Kasper; Soguero-Ruiz, Cristina; Oyvind Mikalsen, Karl; Lindsetmo, Rolv-Ole; Kouskoumvekaki, Irene; Girolami, Mark; Olav Skrovseth, Stein; Magne Augestad, Knut

    2017-01-01

    With an aging patient population and increasing complexity in patient disease trajectories, physicians are often met with complex patient histories from which clinical decisions must be made. Due to the increasing rate of adverse events and hospitals facing financial penalties for readmission, there has never been a greater need to enforce evidence-led medical decision-making using available health care data. In the present work, we studied a cohort of 7,741 patients, of whom 4,080 were diagnosed with cancer, surgically treated at a University Hospital in the years 2004–2012. We have developed a methodology that allows disease trajectories of the cancer patients to be estimated from free text in electronic health records (EHRs). By using these disease trajectories, we predict 80% of patient events ahead in time. By control of confounders from 8326 quantified events, we identified 557 events that constitute high subsequent risks (risk > 20%), including six events for cancer and seven events for metastasis. We believe that the presented methodology and findings could be used to improve clinical decision support and personalize trajectories, thereby decreasing adverse events and optimizing cancer treatment. PMID:28387314

  14. Trajectory analysis of transfers between L4 and L5 and low lunar orbit

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The flight characteristics and spacecraft performance during missions involving flight between the equilateral libration points and the Moon are discussed. The conclusions drawn will show that a minimum energy trajectory is the most efficient transfer technique for this type of flight.

  15. Space shuttle launch vehicle performance trajectory, exchange ratios, and dispersion analysis

    NASA Technical Reports Server (NTRS)

    Toelle, R. G.; Blackwell, D. L.; Lott, L. N.

    1973-01-01

    A baseline space shuttle performance trajectory for Mission 3A launched from WTR has been generated. Design constraints of maximum dynamic pressure, longitudinal acceleration, and delivered payload were satisfied. Payload exchange ratios are presented with explanation on use. Design envelopes of dynamic pressure, SRB staging point, aerodynamic heating and flight performance reserves are calculated and included.

  16. The Earth-Moon Transfer Trajectory Design and Analysis using Intermediate Loop Orbits

    NASA Astrophysics Data System (ADS)

    Song, Young-Joo; Woo, Jin; Park, Sang-Young; Kyu-Hong Choi; Sim, Eun-Sup

    2009-06-01

    Various Earth-Moon transfer trajectories are designed and analyzed to prepare the future Korea's Lunar missions. Minimum fuel trajectory solutions are obtained for the departure year of 2017, 2020, 2022, and every required mission phases are analyzed from Earth departure to the final lunar mission orbit. N-body equations of motion are formulated which include the gravitational effect of the Sun, Earth and Moon. In addition, accelerations due to geopotential harmonics, Lunar J2 and solar radiation pressures are considered. Impulsive high thrust is assumed as the main thrusting method of spacecraft with launcher capability of KSLV-2 which is planned to be developed. For the method of injecting a spacecraft into a trans Lunar trajectory, both direct shooting from circular parking orbit and shooting from the multiple elliptical intermediate orbits are adapted, and their design results are compared and analyzed. In addition, spacecraft's visibility from Deajeon ground station are constrained to see how they affect the magnitude of TLI (Trans Lunar Injection) maneuver. The results presented in this paper includes launch opportunities, required optimal maneuver characteristics for each mission phase as well as the trajectory characteristics and numerous related parameters. It is confirmed that the final mass of Korean lunar explorer strongly depends onto the initial parking orbit's altitude and launcher's capability, rather than mission start time.

  17. HEAVY DRINKING TRAJECTORIES AMONG MEN WHO HAVE SEX WITH MEN: A LONGITUDINAL, GROUP-BASED ANALYSIS

    PubMed Central

    Marshall, Brandon DL; Shoveller, Jean A.; Kahler, Christopher W.; Koblin, Beryl A.; Mayer, Kenneth H.; Mimiaga, Matthew J.; van den Berg, Jacob J.; Zaller, Nickolas D.; Operario, Don

    2014-01-01

    Background Heavy episodic drinking (HED) is associated with sexual risk behavior and HIV seroconversion among men who have sex with men (MSM), yet few studies have examined heavy drinking typologies in this population. Methods We analyzed data from 4,075 HIV-uninfected MSM (aged 16 to 88) participating in EXPLORE, a 48-month behavioral intervention trial, to determine the patterns and predictors of HED trajectories. Heavy episodic drinking was defined as the number of days in which ≥5 alcohol drinks were consumed in the past 6 months. Longitudinal group-based mixture models were used to identify HED trajectories, and multinomial logistic regression was used to determine correlates of membership in each group. Results We identified five distinct HED trajectories: non-heavy drinkers (31.9%); infrequent heavy drinkers (i.e., <10 heavy drinking days per 6 month period, 54.3%); regular heavy drinkers (30-45 heavy drinking days per 6 months, 8.4%); drinkers who increased HED over time (average 33 days in the past six months to 77 days at end of follow-up, 3.6%); and very frequent heavy drinkers (>100 days per 6 months, 1.7%). Intervention arm did not predict drinking trajectory patterns. Younger age, self-identifying as white, lower educational attainment, depressive symptoms, and stimulant use were also associated with reporting heavier drinking trajectories. Compared to non-heavy drinkers, participants who increased HED more often experienced a history of childhood sexual abuse. Over the study period, depressive symptomatology increased significantly among very frequent heavy drinkers. Conclusions Socioeconomic factors, substance use, depression, and childhood sexual abuse were associated with heavier drinking patterns among MSM. Multi-component interventions to reduce HED should seek to mitigate the adverse impacts of low educational attainment, depression, and early traumatic life events on the initiation, continuation or escalation of frequent HED among MSM. PMID

  18. Pitch and Yaw Trajectory Measurement Comparison Between Automated Video Analysis and Onboard Sensor Data Analysis Techniques

    DTIC Science & Technology

    2013-09-01

    captured by the video (first two nutation cycles). Included in the report is a general introduction of both analysis methods, as well as a brief...exhibiting the two mode (i.e., precession and nutation ) epicyclic yawing motion that is typical of spinning symmetric bodies. The precession motion is...cover a long enough interval to characterize the precessional motion. Two periods of the initial nutation motion were captured by the video method

  19. Mortality trajectory analysis reveals the drivers of sex-specific epidemiology in natural wildlife-disease interactions.

    PubMed

    McDonald, Jennifer L; Smith, Graham C; McDonald, Robbie A; Delahay, Richard J; Hodgson, Dave

    2014-09-07

    In animal populations, males are commonly more susceptible to disease-induced mortality than females. However, three competing mechanisms can cause this sex bias: weak males may simultaneously be more prone to exposure to infection and mortality; being 'male' may be an imperfect proxy for the underlying driver of disease-induced mortality; or males may experience increased severity of disease-induced effects compared with females. Here, we infer the drivers of sex-specific epidemiology by decomposing fixed mortality rates into mortality trajectories and comparing their parameters. We applied Bayesian survival trajectory analysis to a 22-year longitudinal study of a population of badgers (Meles meles) naturally infected with bovine tuberculosis (bTB). At the point of infection, infected male and female badgers had equal mortality risk, refuting the hypothesis that acquisition of infection occurs in males with coincidentally high mortality. Males and females exhibited similar levels of heterogeneity in mortality risk, refuting the hypothesis that maleness is only a proxy for disease susceptibility. Instead, sex differences were caused by a more rapid increase in male mortality rates following infection. Males are indeed more susceptible to bTB, probably due to immunological differences between the sexes. We recommend this mortality trajectory approach for the study of infection in animal populations.

  20. A tracer calibration of back trajectory analysis at the Grand Canyon

    NASA Astrophysics Data System (ADS)

    Vasconcelos, Luis A. de P.; Kahl, Jonathan D. W.; Liu, Desong; Macias, Edward S.; White, Warren H.

    1996-08-01

    The potential of routine back trajectory analyses to locate sources of contaminants in air at Grand Canyon is investigated with data on methylchloroform (CH3CCl3) concentrations collected during the Subregional Cooperative Electric Utility, Department of Defense, National Park Service, and Environmental Protection Agency Study (SCENES). Following a now-standard approach, the distribution of back trajectory segment endpoints over a latitude longitude grid is examined as a function of measured concentrations at the fixed monitoring site. Grid cells in which segment endpoints are preferentially associated with high concentrations are then identified as candidate emissions sources. The method correctly identifies southern California as a source of CH3CCl3. An objective rationale is developed for screening out chance associations, attributable to statistical fluctuations, and the results are evaluated for real and hypothetical tracers with known, simple distributions.

  1. Optimal trajectories for the aeroassisted flight experiment. Part 3: Formulation, results, and analysis

    NASA Technical Reports Server (NTRS)

    Miele, A.; Wang, T.; Lee, W. Y.; Zhao, Z. G.

    1989-01-01

    The determination of optimal trajectories for the aero-assisted flight experiment (AFE) is investigated. The intent of this experiment is to simulate a GEO-to-LEO transfer, where GEO denotes a geosynchronous Earth orbit and LEO denotes a low Earth orbit. The trajectories of an AFE spacecraft are analyzed in a 3D-space, employing the full system of 6 ODEs describing the atmospheric pass. The atmospheric entry conditions are given, and the atmospheric exit conditions are adjusted in such a way that the following conditions are satisfied: (1) the atmospheric velocity depletion is such that, after exiting, the AFE spacecraft first ascends to a specified apogee and then descends to a specified perigee; and (2) the exit orbital plane is identical with the entry orbital plane. The final maneuver, not analyzed here, includes the rendezvous with and the capture by the space shuttle.

  2. Optimal trajectories for the aeroassisted flight experiment. Part 3: Formulation, results, and analysis

    NASA Astrophysics Data System (ADS)

    Miele, A.; Wang, T.; Lee, W. Y.; Zhao, Z. G.

    1989-10-01

    The determination of optimal trajectories for the aero-assisted flight experiment (AFE) is investigated. The intent of this experiment is to simulate a GEO-to-LEO transfer, where GEO denotes a geosynchronous Earth orbit and LEO denotes a low Earth orbit. The trajectories of an AFE spacecraft are analyzed in a 3D-space, employing the full system of 6 ODEs describing the atmospheric pass. The atmospheric entry conditions are given, and the atmospheric exit conditions are adjusted in such a way that the following conditions are satisfied: (1) the atmospheric velocity depletion is such that, after exiting, the AFE spacecraft first ascends to a specified apogee and then descends to a specified perigee; and (2) the exit orbital plane is identical with the entry orbital plane. The final maneuver, not analyzed here, includes the rendezvous with and the capture by the space shuttle.

  3. Trajectory and System Analysis For Outer-Planet Solar-Electric Propulsion Missions

    NASA Technical Reports Server (NTRS)

    Cupples, Michael; Woo, Byoungsam; Coverstone, Victoria L.; Hartmann, John W.

    2004-01-01

    Outer-planet mission and systems analyses are performed using three next generation solar-electric ion thruster models. The impact of variations in thruster model, flight time, launch vehicle, propulsion and power systems characteristics is investigated. All presented trajectories have a single Venus gravity assist and maximize the delivered mass to Saturn or Neptune. The effect of revolution ratio - the ratio of Venusian orbital period to the flight time between launch and flyby dates - is also discussed.

  4. Binding Analysis of Some Classical Acetylcholinesterase Inhibitors: Insights for a Rational Design Using Free Energy Perturbation Method Calculations with QM/MM MD Simulations.

    PubMed

    Nascimento, Érica C M; Oliva, Mónica; Świderek, Katarzyna; Martins, João B L; Andrés, Juan

    2017-04-13

    In the present study, the binding free energy of some classical inhibitors (DMT, DNP, GNT, HUP, THA) with acetylcholinesterase (AChE) is calculated by means of the free energy perturbation (FEP) method based on hybrid quantum mechanics and molecular mechanics (QM/MM) potentials. The results highlight the key role of the van der Waals interaction for the inhibition process, since the contribution of this term to the binding free energy is almost as decisive as the electrostatic one. The analysis of the geometrical parameters and the interaction energy per residue along the QM/MM molecular dynamics (MD) simulations highlights the most relevant interactions in the different AChE-ligand systems, showing that the charged residues with a more prominent contribution to the interaction energy are Asp72 and Glu199, although the relative importance depends on the molecular size of the ligand. A correlation between the binding free energy and the number of cation-π interactions present in the systems has been established, DMT being the most potent inhibitor, capable of forming four cation-π interactions. A layer of water molecules surrounding the inhibitors has been observed, which act as bridges along a network formed by the ligands and the residues of the gorge and also between different residues. Although several hydrogen bonds between ligands and AChE do appear, no significant values of BIEs have been recorded. This behavior can be accounted for by the special features of AChE, such as the presence of several subsites of different natures in the gorge or the existence of several water molecules that act as bridges in the electrostatic interactions.

  5. Assessing randomness and complexity in human motion trajectories through analysis of symbolic sequences

    PubMed Central

    Peng, Zhen; Genewein, Tim; Braun, Daniel A.

    2014-01-01

    Complexity is a hallmark of intelligent behavior consisting both of regular patterns and random variation. To quantitatively assess the complexity and randomness of human motion, we designed a motor task in which we translated subjects' motion trajectories into strings of symbol sequences. In the first part of the experiment participants were asked to perform self-paced movements to create repetitive patterns, copy pre-specified letter sequences, and generate random movements. To investigate whether the degree of randomness can be manipulated, in the second part of the experiment participants were asked to perform unpredictable movements in the context of a pursuit game, where they received feedback from an online Bayesian predictor guessing their next move. We analyzed symbol sequences representing subjects' motion trajectories with five common complexity measures: predictability, compressibility, approximate entropy, Lempel-Ziv complexity, as well as effective measure complexity. We found that subjects' self-created patterns were the most complex, followed by drawing movements of letters and self-paced random motion. We also found that participants could change the randomness of their behavior depending on context and feedback. Our results suggest that humans can adjust both complexity and regularity in different movement types and contexts and that this can be assessed with information-theoretic measures of the symbolic sequences generated from movement trajectories. PMID:24744716

  6. Trajectory-Based Analysis of Urban Land-Cover Change Detection

    NASA Astrophysics Data System (ADS)

    Zhang, Y. H.; Liu, H. P.

    2016-06-01

    China have occurred unprecedented urban growth over the last two decades. It is reported that the level of China's urbanization increased from 18 % in 1978 to 41 % in 2003, and this figure may exceed 65 % by 2050. The change detection of long time serious remote sensing images is the effective way to acquire the data of urban land-cover change to understand the pattern of urbanization. In this paper, we proposed the similarity index (SI) and apply it in long time series urban land-cover change detection. First of all, we built possible change trajectories in four times based on the normalized difference vegetation index (NDVI) and modified normalized difference water index (MNDWI) that extracted from time series Landsat images. Secondly, we applied SI in similarity comparison between the observed change trajectory and the possible trajectories. Lastly, verifying the accuracy of the results. The overall accuracy in four periods is 85.7 % and the overall accuracy of each two years is about 90 % and kappa statistic is about 0.85. The results show that this method is effective for time series land-cover change detection.

  7. An interplanetary mission to Neptune System I: Analysis of trajectories to Neptune using gravity assists

    NASA Astrophysics Data System (ADS)

    Solórzano, C.; Sukhanov, A.; Prado, A.

    At the present time the search for the knowledge of our Solar System continues effective So in July 1st 2004 the international Cassini-Huygens Mission spacecraft entered into orbit around the planet Saturn and in January 2005 send data from the Huygens probe which is studing Saturn s largest moon Titan On January 19 2006 occurred the launch of the New Horizons spacecraft to Pluto and Charon NASA s Solar System Exploration theme listed a Neptune mission as one of its top priorities for the mid-term 2008-2013 The gravity assist is a proven technique in interplanetary exploration as exemplified by the missions Voyager Galileo Cassini etc Here a mission to Neptune for the mid-term 2008-2020 is proposed with the goal of studiyng several schemes for the mission A direct transfer to Neptune is considered and also Venus Earth Jupiter and Saturn gravity assists are used for the transfer to Neptune which represent new contributions for a possible real mission We show several schemes with and without braking near Neptune in order to find a good compromise between the Delta V and time of flight to Neptune Besides taking advantage of asteroid flyby opportunities when the spacecraft passes through the asteroid belt To incorporta as asteroid flyby we first need to optimize a trajectory to Neptune with planetary flybys and then search for asteroids that pass close to this trajectory to finally reoptimize the trajectory including one or more asteroid flybys

  8. SU-E-T-144: Effective Analysis of VMAT QA Generated Trajectory Log Files for Medical Accelerator Predictive Maintenance

    SciTech Connect

    Able, CM; Baydush, AH; Nguyen, C; Munley, MT; Gersh, J; Ndlovu, A; Rebo, I; Booth, J; Perez, M; Sintay, B

    2014-06-01

    Purpose: To determine the effectiveness of SPC analysis for a model predictive maintenance process that uses accelerator generated parameter and performance data contained in trajectory log files. Methods: Each trajectory file is decoded and a total of 131 axes positions are recorded (collimator jaw position, gantry angle, each MLC, etc.). This raw data is processed and either axis positions are extracted at critical points during the delivery or positional change over time is used to determine axis velocity. The focus of our analysis is the accuracy, reproducibility and fidelity of each axis. A reference positional trace of the gantry and each MLC is used as a motion baseline for cross correlation (CC) analysis. A total of 494 parameters (482 MLC related) were analyzed using Individual and Moving Range (I/MR) charts. The chart limits were calculated using a hybrid technique that included the use of the standard 3σ limits and parameter/system specifications. Synthetic errors/changes were introduced to determine the initial effectiveness of I/MR charts in detecting relevant changes in operating parameters. The magnitude of the synthetic errors/changes was based on: TG-142 and published analysis of VMAT delivery accuracy. Results: All errors introduced were detected. Synthetic positional errors of 2mm for collimator jaw and MLC carriage exceeded the chart limits. Gantry speed and each MLC speed are analyzed at two different points in the delivery. Simulated Gantry speed error (0.2 deg/sec) and MLC speed error (0.1 cm/sec) exceeded the speed chart limits. Gantry position error of 0.2 deg was detected by the CC maximum value charts. The MLC position error of 0.1 cm was detected by the CC maximum value location charts for every MLC. Conclusion: SPC I/MR evaluation of trajectory log file parameters may be effective in providing an early warning of performance degradation or component failure for medical accelerator systems.

  9. Trajectories of recovery among homeless adults with mental illness who participated in a randomised controlled trial of Housing First: a longitudinal, narrative analysis

    PubMed Central

    Patterson, Michelle L; Rezansoff, Stefanie; Currie, Lauren; Somers, Julian M

    2013-01-01

    Objectives This study used longitudinal, narrative data to identify trajectories of recovery among homeless adults with mental illness alongside the factors that contribute to positive, negative, mixed or neutral trajectories over time. We expected that participants who received Housing First (HF) would describe more positive trajectories of recovery than those who were assigned to Treatment as Usual (TAU; no housing or support provided through the study). Design Narrative interview data were collected from participants at baseline and 18 months after random assignment to HF or TAU. Setting Participants were sampled from the community in Vancouver, British Columbia. Participants Fifty-four participants were randomly and purposively selected from the larger trial; 52 were interviewed at baseline and 43 were reinterviewed 18 months after randomisation. Method Semistructured interviews were conducted at both time points. For each participant, paired baseline and follow-up narratives were classified as positive, negative, mixed or neutral trajectories of recovery, and thematic analysis was used to identify the factors underlying different trajectories. Results Participants assigned to HF (n=28) were generally classified as positive or mixed trajectories; those assigned to TAU (n=15) were generally classified as neutral or negative trajectories. Positive trajectories were characterised by a range of benefits associated with good-quality, stable housing (eg, reduced substance use, greater social support), positive expressions of identity and the willingness to self-reflect. Negative, neutral and mixed trajectories were characterised by hopelessness (‘things will never get better’) related to continued hardship (eg, eviction, substance use problems), perceived failures and loss. Conclusions HF is associated with positive trajectories of recovery among homeless adults with mental illness. Those who did not receive housing or support continued to struggle across a

  10. Trajectories of Suicidal Ideation in People Seeking Web-Based Help for Suicidality: Secondary Analysis of a Dutch Randomized Controlled Trial

    PubMed Central

    van Spijker, Bregje; Karstoft, Karen-Inge; Nordentoft, Merete; Kerkhof, Ad JFM

    2016-01-01

    Background Suicidal ideation (SI) is a common mental health problem. Variability in intensity of SI over time has been linked to suicidal behavior, yet little is known about the temporal course of SI. Objective The primary aim was to identify prototypical trajectories of SI in the general population and, secondarily, to examine whether receiving Web-based self-help for SI, psychiatric symptoms, or sociodemographics predicted membership in the identified SI trajectories. Methods We enrolled 236 people, from the general Dutch population seeking Web-based help for SI, in a randomized controlled trial comparing a Web-based self-help for SI group with a control group. We assessed participants at inclusion and at 2, 4, and 6 weeks. The Beck Scale for Suicide Ideation was applied at all assessments and was included in latent growth mixture modeling analysis to empirically identify trajectories. Results We identified 4 SI trajectories. The high stable trajectory represented 51.7% (122/236) of participants and was characterized by constant high level of SI. The high decreasing trajectory (50/236, 21.2%) consisted of people with a high baseline SI score followed by a gradual decrease to a very low score. The third trajectory, high increasing (12/236, 5.1%), also had high initial SI score, followed by an increase to the highest level of SI at 6 weeks. The fourth trajectory, low stable (52/236, 22.0%) had a constant low level of SI. Previous attempted suicide and having received Web-based self-help for SI predicted membership in the high decreasing trajectory. Conclusions Many adults experience high persisting levels of SI, though results encouragingly indicate that receiving Web-based self-help for SI increased membership in a decreasing trajectory of SI. PMID:27363482

  11. Analysis of particle trajectories in both low and intense bed-load regimes in flume tests

    NASA Astrophysics Data System (ADS)

    Fraccarollo, L.; Hassan, M. A.

    2012-12-01

    Sediment transport in streams consists of the statistics of individual grains movements, paths and rest periods associated to the forcing hydrodynamics and to the bed morphology. In this paper we present results from experimental work to obtain statistical information for the grain movements under wide range of sediment transport regimes, that is from low to high transport intensities. We use image techniques to track the particles and to identify also the particle at rest, laying on the bed surface. Using the method, almost all particles are identified, so that consistent statistics is obtained for theoretical analysis. In our flumes we are able to observe the particle movements from either the transparent sidewall of from the top. Side view is opportune when the bed load layer is thicker than one grain diameter, as in this case the movements of most of the grains is precluded from the top view. This is the case of intense sediment transport rates. Vice versa, at low sediment transport intensity, the isolated and irregular movement of grains may be better looked from above, if the image distortion and blur induced by the presence of free surface is acceptable. Short runs of a few seconds are useful to identify 104-105 trajectories. On the contrary, we need long lasting runs to describe the statistics of the rest periods. This part has been performed by image comparison after removal of the footprint of particles under motion. Our results concern, at the moment, experiments where the bed surface is about flat, i.e. without clear bed form appearance. From low to intense bed load we document how the main statistical features of grain movements and rest periods are characterized qualitatively and quantitatively, including the interesting transitional stage. In the field we observe an increasing effort in tracking a relatively high number of tagged clasts. This activity is recently performed mainly by exploiting magnetically tagged tracers. In spite of all the

  12. Mission objectives and trajectories

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The present state of the knowledge of asteroids was assessed to identify mission and target priorities for planning asteroidal flights in the 1980's and beyond. Mission objectives, mission analysis, trajectory studies, and cost analysis are discussed. A bibliography of reports and technical memoranda is included.

  13. RadNet Air Data From Baltimore, MD

    EPA Pesticide Factsheets

    This page presents radiation air monitoring and air filter analysis data for Baltimore, MD from EPA's RadNet system. RadNet is a nationwide network of monitoring stations that measure radiation in air, drinking water and precipitation.

  14. Statistical analysis of piloted simulation of real time trajectory optimization algorithms

    NASA Technical Reports Server (NTRS)

    Price, D. B.

    1982-01-01

    A simulation of time-optimal intercept algorithms for on-board computation of control commands is described. The effects of three different display modes and two different computation modes on the pilots' ability to intercept a moving target in minimum time were tested. Both computation modes employed singular perturbation theory to help simplify the two-point boundary value problem associated with trajectory optimization. Target intercept time was affected by both the display and computation modes chosen, but the display mode chosen was the only significant influence on the miss distance.

  15. Analysis of total least squares in estimating the parameters of a mortar trajectory

    SciTech Connect

    Lau, D.L.; Ng, L.C.

    1994-12-01

    Least Squares (LS) is a method of curve fitting used with the assumption that error exists in the observation vector. The method of Total Least Squares (TLS) is more useful in cases where there is error in the data matrix as well as the observation vector. This paper describes work done in comparing the LS and TLS results for parameter estimation of a mortar trajectory based on a time series of angular observations. To improve the results, we investigated several derivations of the LS and TLS methods, and early findings show TLS provided slightly, 10%, improved results over the LS method.

  16. Theoretical analysis for critical fluctuations of relaxation trajectory near a saddle-node bifurcation.

    PubMed

    Iwata, Mami; Sasa, Shin-ichi

    2010-07-01

    A Langevin equation whose deterministic part undergoes a saddle-node bifurcation is investigated theoretically. It is found that statistical properties of relaxation trajectories in this system exhibit divergent behaviors near a saddle-node bifurcation point in the weak-noise limit, while the final value of the deterministic solution changes discontinuously at the point. A systematic formulation for analyzing a path probability measure is constructed on the basis of a singular perturbation method. In this formulation, the critical nature turns out to originate from the neutrality of exiting time from a saddle point. The theoretical calculation explains results of numerical simulations.

  17. [The trajectory towards alternative medicines: an analysis of health professionals' social representations].

    PubMed

    Queiroz, M S

    2000-01-01

    This article focuses on social representations of alternative medicines by a group of professors from the School of Medicine and health professionals from the public health system in the city of Campinas, São Paulo, basically physicians and nurses. The article also emphasizes personal trajectories by which these health professionals opted for a dissident theoretical and practical perspective vis-à-vis the hegemonic positivist scientific medical paradigm. The research methods were mainly ethnographic, from a phenomenological perspective. The article concludes by sustaining (in theoretical terms) the importance of these dissident perspectives for scientific development.

  18. Kinematic analysis and fault-tolerant trajectory planning of space manipulator under a single joint failure.

    PubMed

    Mu, Zonggao; Han, Liang; Xu, Wenfu; Li, Bing; Liang, Bin

    2016-01-01

    A space manipulator plays an important role in spacecraft capturing, repairing, maintenance, and so on. However, the harsh space environment will cause its joints fail to work. For a non-redundant manipulator, single joint locked failure will cause it to lose one degree of freedom (DOF), hence reducing its movement ability. In this paper, the key problems related to the fault-tolerant including kinematics, workspace, and trajectory planning of a non-redundant space manipulator under single joint failure are handled. First, the analytical inverse kinematics equations are derived for the 5-DOF manipulator formed by locking the failure joint of the original 6-DOF manipulator. Then, the reachable end-effector pose (position and orientation) is determined. Further, we define the missions can be completed by the 5-DOF manipulator. According to the constraints of the on-orbital mission, we determine the grasp envelope required for the end-effector. Combining the manipulability of the manipulator and the performance of its end-effector, a fault tolerance parameter is defined and a planning method is proposed to generate the reasonable trajectory, based on which the 5-DOF manipulator can complete the desired tasks. Finally, typical cases are simulated and the simulation results verify the proposed method.

  19. Multiple trajectory analysis of MLS observed stratospheric chemical ozone loss in Arctic winter 1995/96

    NASA Astrophysics Data System (ADS)

    Lemmen, C.; Riese, R.; Grooss, J.-U.; Mueller, R.

    2003-04-01

    Daily ozone loss rates and total chemical ozone depletion during Arctic winter 1995/96 were evaluated based on ozone measurements by the Microwave Limb Sounder (MLS) instrument onboard the Upper Atmosphere Research Satellite (UARS). Employing the 3-dimensional transport scheme of the Chemical Lagrangian Model of the Stratosphere (CLaMS), trajectories from successive satellite measurements were compared with each other using a variation of the Match technique, such that ozone concentration differences between double sounded (``matched'') air parcels represent chemical ozone loss. The ensemble average of many (typically 30--150) matches yields an average ozone depletion rate for the area covered by the trajectories. Total ozone loss from late December to early March was 1.4 ppmv at the 475 K isentropic level within the vortex core (PV > 45 PVU at 475 K). Ozone loss decreased towards the edge of the vortex, no significant ozone loss could be observed in the outer vortex edge (between ≈ 27 and ≈ 35 PVU). Daily ozone loss was found to average 10 ppbv/day throughout January and throughout the extended vortex area. For the month of February daily ozone loss rates were highly variable and peaked at 40 ppbv/day in the vortex (≈ 35 PVU). In this study, no chemical ozone loss could be observed in the outer vortex edge region during February, which suggests that the dynamically defined vortex boundary separated two different chemical regimes during February, but not in January.

  20. Trajectory Reconstruction and Uncertainty Analysis Using Mars Science Laboratory Pre-Flight Scale Model Aeroballistic Testing

    NASA Technical Reports Server (NTRS)

    Lugo, Rafael A.; Tolson, Robert H.; Schoenenberger, Mark

    2013-01-01

    As part of the Mars Science Laboratory (MSL) trajectory reconstruction effort at NASA Langley Research Center, free-flight aeroballistic experiments of instrumented MSL scale models was conducted at Aberdeen Proving Ground in Maryland. The models carried an inertial measurement unit (IMU) and a flush air data system (FADS) similar to the MSL Entry Atmospheric Data System (MEADS) that provided data types similar to those from the MSL entry. Multiple sources of redundant data were available, including tracking radar and on-board magnetometers. These experimental data enabled the testing and validation of the various tools and methodologies that will be used for MSL trajectory reconstruction. The aerodynamic parameters Mach number, angle of attack, and sideslip angle were estimated using minimum variance with a priori to combine the pressure data and pre-flight computational fluid dynamics (CFD) data. Both linear and non-linear pressure model terms were also estimated for each pressure transducer as a measure of the errors introduced by CFD and transducer calibration. Parameter uncertainties were estimated using a "consider parameters" approach.

  1. Development of Advanced Methods of Structural and Trajectory Analysis for Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Ardema, Mark D.; Windhorst, Robert; Phillips, James

    1998-01-01

    This paper develops a near-optimal guidance law for generating minimum fuel, time, or cost fixed-range trajectories for supersonic transport aircraft. The approach uses a choice of new state variables along with singular perturbation techniques to time-scale decouple the dynamic equations into multiple equations of single order (second order for the fast dynamics). Application of the maximum principle to each of the decoupled equations, as opposed to application to the original coupled equations, avoids the two point boundary value problem and transforms the problem from one of a functional optimization to one of multiple function optimizations. It is shown that such an approach produces well known aircraft performance results such as minimizing the Brequet factor for minimum fuel consumption and the energy climb path. Furthermore, the new state variables produce a consistent calculation of flight path angle along the trajectory, eliminating one of the deficiencies in the traditional energy state approximation. In addition, jumps in the energy climb path are smoothed out by integration of the original dynamic equations at constant load factor. Numerical results performed for a supersonic transport design show that a pushover dive followed by a pullout at nominal load factors are sufficient maneuvers to smooth the jump.

  2. The evaluation of several agility metrics for fighter aircraft using optimal trajectory analysis

    NASA Technical Reports Server (NTRS)

    Ryan, George W., III; Downing, David R.

    1993-01-01

    Several functional agility metrics, including the combat cycle time metric, dynamic speed turn plots, and relative energy state metric, are used to compare turning performance for generic F-18, X-29, and X-31-type aircraft models. These three-degree-of-freedom models have characteristics similar to the real aircraft. The performance comparisons are made using data from optimal test trajectories to reduce sensitivities to different pilot input techniques and to reduce the effects of control system limiters. The turn performance for all three aircraft is calculated for simulated minimum time 180 deg heading captures from simulation data. Comparisons of the three aircraft give more insight into turn performance than would be available from traditional measures of performance. Using the optimal test technique yields significant performance improvements as measured by the metrics. These performance improvements were found without significant increases in turn radius.

  3. Optimal trajectories for an aerospace plane. Part 1: Formulation, results, and analysis

    NASA Technical Reports Server (NTRS)

    Miele, Angelo; Lee, W. Y.; Wu, G. D.

    1990-01-01

    The optimization of the trajectories of an aerospace plane is discussed. This is a hypervelocity vehicle capable of achieving orbital speed, while taking off horizontally. The vehicle is propelled by four types of engines: turbojet engines for flight at subsonic speeds/low supersonic speeds; ramjet engines for flight at moderate supersonic speeds/low hypersonic speeds; scramjet engines for flight at hypersonic speeds; and rocket engines for flight at near-orbital speeds. A single-stage-to-orbit (SSTO) configuration is considered, and the transition from low supersonic speeds to orbital speeds is studied under the following assumptions: the turbojet portion of the trajectory has been completed; the aerospace plane is controlled via the angle of attack and the power setting; the aerodynamic model is the generic hypersonic aerodynamics model example (GHAME). Concerning the engine model, three options are considered: (EM1), a ramjet/scramjet combination in which the scramjet specific impulse tends to a nearly-constant value at large Mach numbers; (EM2), a ramjet/scramjet combination in which the scramjet specific impulse decreases monotonically at large Mach numbers; and (EM3), a ramjet/scramjet/rocket combination in which, owing to stagnation temperature limitations, the scramjet operates only at M approx. less than 15; at higher Mach numbers, the scramjet is shut off and the aerospace plane is driven only by the rocket engines. Under the above assumptions, four optimization problems are solved using the sequential gradient-restoration algorithm for optimal control problems: (P1) minimization of the weight of fuel consumed; (P2) minimization of the peak dynamic pressure; (P3) minimization of the peak heating rate; and (P4) minimization of the peak tangential acceleration.

  4. Measurement of the Md3+/Md2+ reduction potential studied with flow electrolytic chromatography.

    PubMed

    Toyoshima, Atsushi; Li, Zijie; Asai, Masato; Sato, Nozomi; Sato, Tetsuya K; Kikuchi, Takahiro; Kaneya, Yusuke; Kitatsuji, Yoshihiro; Tsukada, Kazuaki; Nagame, Yuichiro; Schädel, Matthias; Ooe, Kazuhiro; Kasamatsu, Yoshitaka; Shinohara, Atsushi; Haba, Hiromitsu; Even, Julia

    2013-11-04

    The reduction behavior of mendelevium (Md) was studied using a flow electrolytic chromatography apparatus. By application of the appropriate potentials on the chromatography column, the more stable Md(3+) is reduced to Md(2+). The reduction potential of the Md(3+) + e(-) → Md(2+) couple was determined to be -0.16 ± 0.05 V versus a normal hydrogen electrode.

  5. Orbital Disturbance Analysis due to the Lunar Gravitational Potential and Deviation Minimization through the Trajectory Control in Closed Loop

    NASA Astrophysics Data System (ADS)

    Gonçalves, L. D.; Rocco, E. M.; de Moraes, R. V.

    2013-10-01

    A study evaluating the influence due to the lunar gravitational potential, modeled by spherical harmonics, on the gravity acceleration is accomplished according to the model presented in Konopliv (2001). This model provides the components x, y and z for the gravity acceleration at each moment of time along the artificial satellite orbit and it enables to consider the spherical harmonic degree and order up to100. Through a comparison between the gravity acceleration from a central field and the gravity acceleration provided by Konopliv's model, it is obtained the disturbing velocity increment applied to the vehicle. Then, through the inverse problem, the Keplerian elements of perturbed orbit of the satellite are calculated allowing the orbital motion analysis. Transfer maneuvers and orbital correction of lunar satellites are simulated considering the disturbance due to non-uniform gravitational potential of the Moon, utilizing continuous thrust and trajectory control in closed loop. The simulations are performed using the Spacecraft Trajectory Simulator-STRS, Rocco (2008), which evaluate the behavior of the orbital elements, fuel consumption and thrust applied to the satellite over the time.

  6. A novel theoretical framework for the dynamic stability analysis, movement control, and trajectory generation in a multisegment biomechanical model.

    PubMed

    Iqbal, Kamran; Roy, Anindo

    2009-01-01

    We consider a simplified characterization of the postural control system that embraces two broad components: one representing the musculoskeletal dynamics in the sagittal plane and the other representing proprioceptive feedback and the central nervous system (CNS). Specifically, a planar four-segment neuromusculoskeletal model consisting of the ankle, knee, and hip degrees-of-freedom (DOFs) is described in this paper. The model includes important physiological constructs such as Hill-type muscle model, active and passive muscle stiffnesses, force feedback from the Golgi tendon organ, muscle length and rate feedback from the muscle spindle, and transmission latencies in the neural pathways. A proportional-integral-derivative (PID) controller for each individual DOF is assumed to represent the CNS analog in the modeling paradigm. Our main hypothesis states that all stabilizing PID controllers for such multisegment biomechanical models can be parametrized and analytically synthesized. Our analytical and simulation results show that the proposed representation adequately shapes a postural control that (a) possesses good disturbance rejection and trajectory tracking, (b) is robust against feedback latencies and torque perturbations, and (c) is flexible to embrace changes in the musculoskeletal parameters. We additionally present detailed sensitivity analysis to show that control under conditions of limited or no proprioceptive feedback results in (a) significant reduction in the stability margins, (b) substantial decrease in the available stabilizing parameter set, and (c) oscillatory movement trajectories. Overall, these results suggest that anatomical arrangement, active muscle stiffness, force feedback, and physiological latencies play a major role in shaping motor control processes in humans.

  7. The Trajectory, Orbit, and Acoustical analysis of the Park Forest Fireball

    NASA Astrophysics Data System (ADS)

    Edwards, W. N.; Brown, P. G.; Pack, D.; Revelle, D. O.; Yoo, B. B.; Spalding, R. E.; Tagliaferri, E.

    2004-05-01

    The Park Forest meteorite fall of March 27th, 2003 was the first large bolide to occur over a major urban area in modern history. As such, characterizing various aspects of the event has been the subject of particular interest. This has been made possible due to the wide array of different instrument detections. Instrumental recordings of the Park Forest fireball include eyewitness video, optical and infrared light observations by orbiting satellites and acoustic recordings by audible sound, infrasonic and seismic instruments. Optical and infrared satellite observations fused with data from ground based video have allowed an accurate determination of the fireball's trajectory and velocity. The trajectory along with modelled atmospheric conditions has in turn allowed the source regions for audible acoustic and seismic recordings of the fireball's sound waves to be identified. These sources are consistent with the sound waves originating from several major fragmentation points along the fireball's path. Infrasonic recordings appear to be typical of stratospherically ducted waves. The best estimates of the original size of Park Forest is ~1.5m with an observed entry velocity of 20 km/s implying an energy of ~0.5 kTon TNT equivalent. Finally by employing the same model atmosphere, dark flight paths of the soon-to-be meteorites were modelled using the major fragmentation altitudes as possible ejection points. Results show that fragments ranging in size from 5 kg to 2 g agree very well with recovery observations, falling within and around the known meteorite strewn field and being released at altitudes from ~38 - 22 km. This suggests that fragments may have ejected at wide a range of altitudes and that the bolide travelled through the atmosphere as a conglomeration of fragments and not as a single large stone. The observed fragmentation occurred under ram pressures of 2-7 MPa, with early minor disruption under at less than 1 MPa. This provides an estimate for the

  8. Optimal solar sail planetocentric trajectories

    NASA Technical Reports Server (NTRS)

    Sackett, L. L.

    1977-01-01

    The analysis of solar sail planetocentric optimal trajectory problem is described. A computer program was produced to calculate optimal trajectories for a limited performance analysis. A square sail model is included and some consideration is given to a heliogyro sail model. Orbit to a subescape point and orbit to orbit transfer are considered. Trajectories about the four inner planets can be calculated and shadowing, oblateness, and solar motion may be included. Equinoctial orbital elements are used to avoid the classical singularities, and the method of averaging is applied to increase computational speed. Solution of the two-point boundary value problem which arises from the application of optimization theory is accomplished with a Newton procedure. Time optimal trajectories are emphasized, but a penalty function has been considered to prevent trajectories which intersect a planet's surface.

  9. Parameter estimation supplement to the Mission Analysis Evaluation and Space Trajectory Operations program (MAESTRO)

    NASA Technical Reports Server (NTRS)

    Bjorkman, W. S.; Uphoff, C. W.

    1973-01-01

    This Parameter Estimation Supplement describes the PEST computer program and gives instructions for its use in determination of lunar gravitation field coefficients. PEST was developed for use in the RAE-B lunar orbiting mission as a means of lunar field recovery. The observations processed by PEST are short-arc osculating orbital elements. These observations are the end product of an orbit determination process obtained with another program. PEST's end product it a set of harmonic coefficients to be used in long-term prediction of the lunar orbit. PEST employs some novel techniques in its estimation process, notably a square batch estimator and linear variational equations in the orbital elements (both osculating and mean) for measurement sensitivities. The program's capabilities are described, and operating instructions and input/output examples are given. PEST utilizes MAESTRO routines for its trajectory propagation. PEST's program structure and subroutines which are not common to MAESTRO are described. Some of the theoretical background information for the estimation process, and a derivation of linear variational equations for the Method 7 elements are included.

  10. Determination of upwind and downwind areas of Seoul, Korea using trajectory analysis.

    SciTech Connect

    Oh, H. S.; Ghim, Y. S.; Kim, J. Y.; Chang, Y. S.

    2010-09-01

    To identify the domains that have the greatest impacts on air quality at the surface, both the upwind and downwind areas of Seoul were determined by season using refined wind fields. Four consecutive days were selected as the study period typical of each season. The mesoscale meteorology of the study period was reproduced by using the MM5 prognostic meteorological model (PSU/NCAR Mesoscale Model) with horizontally nested grids. The gridded meteorological field, which was used on the study area of 242 km x 226 km with grid spacing of 2 km, was generated by using the CALMET diagnostic meteorological model. Upwind and downwind areas of Seoul were determined by calculating 24-hour backward and forward air parcel trajectories, respectively, with u, v, and w velocity vectors. The results showed that the upwind and downwind areas were extended far to the northwest and the southeast as a result of high wind speeds in the spring and winter, while they were restricted on the fringe of Seoul in the summer and fall.

  11. Vibrational nonequilibrium in chain branching reactions of hydrogen combustion using quasi-classical trajectory analysis

    NASA Astrophysics Data System (ADS)

    Voelkel, Stephen; Raman, Venkat; Varghese, Philip

    2015-11-01

    In high-speed reactive flows in scramjets, thermal nonequilibrium is introduced in the flow via shock waves. Though rotational and translational energy modes relax back to equilibrium quickly, vibrational relaxation is comparable to the bulk mixing and reaction timescales. The discrepancy between vibration and rotation/translation energy distributions can dramatically alter on the initiation of the fuel oxidation process. For continuum-scale applications, thermal nonequilibrium effects are derived from the rovibrational state-specific reaction and scattering rates associated with the chemical mechanism. In this work, the state-specific reaction rates are calculated for the chain branching reactions in the hydrogen combustion mechanism using a quasi-classical trajectory (QCT) framework. The state-specific rates are incorporated into a multiple temperature continuum-scale model whereby each species is characterized by a Boltzmann distribution parametrized by its own vibrational temperature. The flame ignition rates are implemented in a CFD code to simulate a reactive coflow. Funded by AFOSR FA9550-12-1-0460.

  12. Heliocentric trajectory analysis of Sun-pointing smart dust with electrochromic control

    NASA Astrophysics Data System (ADS)

    Mengali, Giovanni; Quarta, Alessandro A.

    2016-02-01

    A smart dust is a micro spacecraft, with a characteristic side length on the order of a few millimeters, whose surface is coated with electrochromic material. Its orbital dynamics is controlled by exploiting the differential force due to the solar radiation pressure, which is obtained by modulating the reflectivity coefficient of the electrochromic material within a range of admissible values. A significant thrust level can be reached due to the high values of area-to-mass ratio of such a spacecraft configuration. Assuming that the smart dust is designed to achieve a passive Sun-pointing attitude, the propulsive acceleration due to the solar radiation pressure lies along the Sun-spacecraft direction. The aim of this paper is to study the smart dust heliocentric dynamics in order to find a closed form, analytical solution of its trajectory when the reflectivity coefficient of the electrochromic material can assume two values only. The problem is addressed by introducing a suitable transformation that regularizes the spacecraft motion and translates the smart-dust dynamics into that of a linear harmonic oscillator with unitary frequency, whose forcing input is a boxcar function. The solution is found using the Laplace transform method, and afterwards the problem is generalized by accounting for the degradation of the electrochromic material due to its exposition to the solar radiation. Three spacecraft configurations, corresponding to low, medium and high performance smart dusts, are finally used to quantify the potentialities of these advanced devices in an interplanetary mission scenario.

  13. Using Lidar, in-situ measurements and Trajectory Analysis to observe air pollution in Beijing, 2014

    NASA Astrophysics Data System (ADS)

    Chen, Zhenyi; Liu, Wenqing; Liu, Jianguo; Zhang, Tianshu; Dong, Yunsheng

    2016-06-01

    We present combined Mie lidar, ozone lidar and wide-range particle spectrometer observations that were carried out in Beijing, north China during two periods—one haze period before the Asia-Pacific Economic Cooperation (APEC) meeting and one moderate pollution period during the meeting in 2014. High extinction coefficient, moderate ozone concentration and variable particle number concentration were obtained throughout the first haze observation period. The mean extinction coefficients in the two pollution periods were 0.52 km-1 and 0.23 km-1, respectively, at 532 nm. The ozone concentration during the first haze phase was more various with higher average value of 49 ppb compared to that in the second pollution observations (32 ppb). The comparison of aerosols and ozone in different heights indicate different pollution sources and complicated ozone process of generation and disappearance. The four-day back trajectories from a HYSPLIT model indicate that the air masses in the lower boundary layer were advected from the densely populated south regions of China and the long pollution transportation passing through northern China.

  14. Design of Quiet Rotorcraft Approach Trajectories: Verification Phase

    NASA Technical Reports Server (NTRS)

    Padula, Sharon L.

    2010-01-01

    Flight testing that is planned for October 2010 will provide an opportunity to evaluate rotorcraft trajectory optimization techniques. The flight test will involve a fully instrumented MD-902 helicopter, which will be flown over an array of microphones. In this work, the helicopter approach trajectory is optimized via a multiobjective genetic algorithm to improve community noise, passenger comfort, and pilot acceptance. Previously developed optimization strategies are modified to accommodate new helicopter data and to increase pilot acceptance. This paper describes the MD-902 trajectory optimization plus general optimization strategies and modifications that are needed to reduce the uncertainty in noise predictions. The constraints that are imposed by the flight test conditions and characteristics of the MD-902 helicopter limit the testing possibilities. However, the insights that will be gained through this research will prove highly valuable.

  15. Investigating trajectories of social recovery in individuals with first-episode psychosis: a latent class growth analysis

    PubMed Central

    Hodgekins, Jo; Birchwood, Max; Christopher, Rose; Marshall, Max; Coker, Sian; Everard, Linda; Lester, Helen; Jones, Peter; Amos, Tim; Singh, Swaran; Sharma, Vimal; Freemantle, Nick; Fowler, David

    2015-01-01

    Background Social disability is a hallmark of severe mental illness yet individual differences and factors predicting outcome are largely unknown. Aim To explore trajectories and predictors of social recovery following a first episode of psychosis (FEP). Method A sample of 764 individuals with FEP were assessed on entry into early intervention in psychosis (EIP) services and followed up over 12 months. Social recovery profiles were examined using latent class growth analysis. Results Three types of social recovery profile were identified: Low Stable (66%), Moderate-Increasing (27%), and High-Decreasing (7%). Poor social recovery was predicted by male gender, ethnic minority status, younger age at onset of psychosis, increased negative symptoms, and poor premorbid adjustment. Conclusions Social disability is prevalent in FEP, although distinct recovery profiles are evident. Where social disability is present on entry into EIP services it can remain stable, highlighting a need for targeted intervention. PMID:26294371

  16. Complexity analysis of the Next Gen Air Traffic Management System: trajectory based operations.

    PubMed

    Lyons, Rhonda

    2012-01-01

    According to Federal Aviation Administration traffic predictions currently our Air Traffic Management (ATM) system is operating at 150 percent capacity; forecasting that within the next two decades, the traffic with increase to a staggering 250 percent [17]. This will require a major redesign of our system. Today's ATM system is complex. It is designed to safely, economically, and efficiently provide air traffic services through the cost-effective provision of facilities and seamless services in collaboration with multiple agents however, contrary the vision, the system is loosely integrated and is suffering tremendously from antiquated equipment and saturated airways. The new Next Generation (Next Gen) ATM system is designed to transform the current system into an agile, robust and responsive set of operations that are designed to safely manage the growing needs of the projected increasingly complex, diverse set of air transportation system users and massive projected worldwide traffic rates. This new revolutionary technology-centric system is dynamically complex and is much more sophisticated than it's soon to be predecessor. ATM system failures could yield large scale catastrophic consequences as it is a safety critical system. This work will attempt to describe complexity and the complex nature of the NextGen ATM system and Trajectory Based Operational. Complex human factors interactions within Next Gen will be analyzed using a proposed dual experimental approach designed to identify hazards, gaps and elicit emergent hazards that would not be visible if conducted in isolation. Suggestions will be made along with a proposal for future human factors research in the TBO safety critical Next Gen environment.

  17. Aircraft Conflict Analysis and Real-Time Conflict Probing Using Probabilistic Trajectory Modeling

    NASA Technical Reports Server (NTRS)

    Yang, Lee C.; Kuchar, James K.

    2000-01-01

    Methods for maintaining separation between aircraft in the current airspace system have been built from a foundation of structured routes and evolved procedures. However, as the airspace becomes more congested and the chance of failures or operational error become more problematic, automated conflict alerting systems have been proposed to help provide decision support and to serve as traffic monitoring aids. The problem of conflict detection and resolution has been tackled from a number of different ways, but in this thesis, it is recast as a problem of prediction in the presence of uncertainties. Much of the focus is concentrated on the errors and uncertainties from the working trajectory model used to estimate future aircraft positions. The more accurate the prediction, the more likely an ideal (no false alarms, no missed detections) alerting system can be designed. Additional insights into the problem were brought forth by a review of current operational and developmental approaches found in the literature. An iterative, trial and error approach to threshold design was identified. When examined from a probabilistic perspective, the threshold parameters were found to be a surrogate to probabilistic performance measures. To overcome the limitations in the current iterative design method, a new direct approach is presented where the performance measures are directly computed and used to perform the alerting decisions. The methodology is shown to handle complex encounter situations (3-D, multi-aircraft, multi-intent, with uncertainties) with relative ease. Utilizing a Monte Carlo approach, a method was devised to perform the probabilistic computations in near realtime. Not only does this greatly increase the method's potential as an analytical tool, but it also opens up the possibility for use as a real-time conflict alerting probe. A prototype alerting logic was developed and has been utilized in several NASA Ames Research Center experimental studies.

  18. Determining Survey Satisficing of Online Longitudinal Survey Data in the Multicenter AIDS Cohort Study: A Group-Based Trajectory Analysis

    PubMed Central

    Di, Junrui; Li, Ying; Friedman, M Reuel; Reddy, Susheel; Surkan, Pamela J; Shoptaw, Steven

    2016-01-01

    Background Survey satisficing occurs when participants respond to survey questions rapidly without carefully reading or comprehending them. Studies have demonstrated the occurrence of survey satisficing, which can degrade survey quality, particularly in longitudinal studies. Objective The aim of this study is to use a group-based trajectory analysis method to identify satisficers when similar survey questions were asked periodically in a long-standing cohort, and to examine factors associated with satisficing in the surveys having sensitive human immunodeficiency virus (HIV)-related behavioral questions. Methods Behavioral data were collected semiannually online at all four sites of the Multicenter AIDS Cohort Study (MACS) from October 2008 through March 2013. Based on the start and end times, and the word counts per variable, response speed (word counts per second) for each participant visit was calculated. Two-step group-based trajectory analyses of the response speed across 9 study visits were performed to identify potential survey satisficing. Generalized linear models with repeated measures were used to investigate the factors associated with satisficing on HIV-related behavioral surveys. Results Among the total 2138 male participants, the median baseline age was 51 years (interquartile range, 45-58); most of the participants were non-Hispanic white (62.72%, 1341/2138) and college graduates (46.59%, 996/2138), and half were HIV seropositive (50.00%, 1069/2138). A total of 543 men (25.40%, 543/2138) were considered potential satisficers with respect to their increased trajectory tendency of response speed. In the multivariate analysis, being 10 years older at the baseline visit increased the odds of satisficing by 44% (OR 1.44, 95% CI 1.27-1.62, P<.001). Compared with the non-Hispanic white participants, non-Hispanic black participants were 122% more likely to satisfice the HIV-related behavioral survey (OR 2.22, 95% CI 1.69-2.91, P<.001), and 99% more likely

  19. Seismic analysis of clinoform depositional sequences and shelf-margin trajectories in Lower Cretaceous (Albian) strata, Alaska North Slope

    USGS Publications Warehouse

    Houseknecht, D.W.; Bird, K.J.; Schenk, C.J.

    2009-01-01

    Lower Cretaceous strata beneath the Alaska North Slope include clinoform depositional sequences that filled the western Colville foreland basin and overstepped the Beaufort rift shoulder. Analysis of Albian clinoform sequences with two-dimensional (2D) seismic data resulted in the recognition of seismic facies inferred to represent lowstand, transgressive and highstand systems tracts. These are stacked to produce shelf-margin trajectories that appear in low-resolution seismic data to alternate between aggradational and progradational. Higher-resolution seismic data reveal shelf-margin trajectories that are more complex, particularly in net-aggradational areas, where three patterns commonly are observed: (1) a negative (downward) step across the sequence boundary followed by mostly aggradation in the lowstand systems tract (LST), (2) a positive (upward) step across the sequence boundary followed by mostly progradation in the LST and (3) an upward backstep across a mass-failure d??collement. These different shelf-margin trajectories are interpreted as (1) fall of relative sea level below the shelf edge, (2) fall of relative sea level to above the shelf edge and (3) mass-failure removal of shelf-margin sediment. Lowstand shelf margins mapped using these criteria are oriented north-south in the foreland basin, indicating longitudinal filling from west to east. The shelf margins turn westward in the north, where the clinoform depositional system overstepped the rift shoulder, and turn eastward in the south, suggesting progradation of depositional systems from the ancestral Brooks Range into the foredeep. Lowstand shelf-margin orientations are consistently perpendicular to clinoform-foreset-dip directions. Although the Albian clinoform sequences of the Alaska North Slope are generally similar in stratal geometry to clinoform sequences elsewhere, they are significantly thicker. Clinoform-sequence thickness ranges from 600-1000 m in the north to 1700-2000 m in the south

  20. Galileo's Trajectory with Mild Resistance

    ERIC Educational Resources Information Center

    Groetsch, C. W.

    2012-01-01

    An aspect of Galileo's classical trajectory that persists in a simple resistance model is noted. The resistive model provides a case study for the classroom analysis of limiting behaviour of an implicitly defined function. (Contains 1 note.)

  1. Reaction analysis and visualization of ReaxFF molecular dynamics simulations.

    PubMed

    Liu, Jian; Li, Xiaoxia; Guo, Li; Zheng, Mo; Han, Junyi; Yuan, Xiaolong; Nie, Fengguang; Liu, Xiaolong

    2014-09-01

    ReaxFF MD (Reactive Force Field Molecular Dynamics) is a promising method for investigating complex chemical reactions in relatively larger scale molecular systems. The existing analysis tools for ReaxFF MD lack the capability of capturing chemical reactions directly by analyzing the simulation trajectory, which is critical in exploring reaction mechanisms. This paper presents the algorithms, implementation strategies, features, and applications of VARxMD, a tool for Visualization and Analysis of Reactive Molecular Dynamics. VARxMD is dedicated to detailed chemical reaction analysis and visualization from the trajectories obtained in ReaxFF MD simulations. The interrelationships among the atoms, bonds, fragments, species and reactions are analyzed directly from the three-dimensional (3D) coordinates and bond orders of the atoms in a trajectory, which are accomplished by determination of atomic connectivity for recognizing connected molecular fragments, perception of bond types in the connected fragments for molecules or radicals, indexing of all these molecules or radicals (chemical species) based on their 3D coordinates and recognition of bond breaking or forming in the chemical species for reactions. Consequently, detailed chemical reactions taking place between two sampled frames can be generated automatically. VARxMD is the first tool specialized for reaction analysis and visualization in ReaxFF MD simulations. Applications of VARxMD in ReaxFF MD simulations of coal and HDPE (high-density polyethylene) pyrolysis show that VARxMD provides the capabilities in exploring the reaction mechanism in large systems with complex chemical reactions involved that are difficult to access manually.

  2. 76 FR 53346 - Airworthiness Directives; The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ... Model DC-9-81 (MD- 81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes AGENCY... Jersey Avenue, SE., Washington, DC 20590. Hand Delivery: Deliver to Mail address above between 9 a.m. and...) This AD applies to The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83),...

  3. 76 FR 41651 - Airworthiness Directives; The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-15

    ... Model DC-9-81 (MD- 81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes AGENCY... Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590. FOR FURTHER INFORMATION...) This AD applies to The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83),...

  4. 78 FR 14547 - Praxedes E. Alverez Santiago, M.D., Daniel Perez Brisebois, M.D., Jorge Grillasca Palou, M.D...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... Garcia Nieves, M.D., Francis M. Vazques Roura, M.D., Angel B. Rivera Santos, M.D., Cosme D. Santos Torres... M. V zquez Roura, M.D., Angel B. Rivera Santos, M.D., Cosme D. Santos Torres, M.D., and Juan...

  5. Cluster Analysis as a Method of Recovering Types of Intraindividual Growth Trajectories: A Monte Carlo Study.

    ERIC Educational Resources Information Center

    Dumenci, Levent; Windle, Michael

    2001-01-01

    Used Monte Carlo methods to evaluate the adequacy of cluster analysis to recover group membership based on simulated latent growth curve (LCG) models. Cluster analysis failed to recover growth subtypes adequately when the difference between growth curves was shape only. Discusses circumstances under which it was more successful. (SLD)

  6. 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

  7. Classification of Aerosol over Central Europe by Cluster Analysis of Aerosol Columnar Optical Properties and Backward Trajectory Statistics

    NASA Astrophysics Data System (ADS)

    Szkop, Artur; Pietruczuk, Aleksander; Posyniak, Michał

    2016-12-01

    A cluster analysis is applied to the Aerosol Robotic Network (AERONET) data obtained at Belsk, Poland, as well as three nearby Central European stations (Leipzig, Minsk and Moldova) for estimation of atmospheric aerosol types. Absorption Ångstrom exponent (AAE), aerosol optical thickness (AOT) and extinction Ångstrom exponent (EAE) parameters are used. Clustering in both 2D (AOT, EAE) and 3D (AOT, EAE, AAE) is investigated. A method of air mass backward trajectory analysis is then proposed, with the receptor site at Belsk, to determine possible source regions for each cluster. Four dominant aerosol source regions are identified. The biomass burning aerosol source is localized in the vicinity of Belarusian-Ukrainian border. Slovakia and northern Hungary are found to be the source of urban/industrial pollutants. Western Poland and eastern Germany are the main sources of polluted continental aerosols. The most differentiated source region of Scandinavia, Baltic Sea and Northern Atlantic, associated with lowest values of AOT, corresponds to clean continental and possibly maritime type aerosols.

  8. GEODYN system support program, volume 4. [computer program for trajectory analysis of artificial satellites

    NASA Technical Reports Server (NTRS)

    Mullins, N. E.

    1972-01-01

    The GEODYN Orbit Determination and Geodetic Parameter Estimation System consists of a set of computer programs designed to determine and analyze definitive satellite orbits and their associated geodetic and measurement parameters. This manual describes the Support Programs used by the GEODYN System. The mathematics and programming descriptions are detailed. The operational procedures of each program are presented. GEODYN ancillary analysis programs may be grouped into three different categories: (1) orbit comparison - DELTA (2) data analysis using reference orbits - GEORGE, and (3) pass geometry computations - GROUNDTRACK. All of the above three programs use one or more tapes written by the GEODYN program in either a data reduction or orbit generator run.

  9. Student Trajectories in Physics: The Need for Analysis through a Socio-Cultural Lens

    ERIC Educational Resources Information Center

    Zapata, Mara

    2010-01-01

    An analysis of student connections through time and space relative to the core discipline of physics is attempted, as viewed through the lens of actor-network-theory, by Antonia Candela. Using lenses of cultural realities, networks, and perceived power in the discourse of one specific university in the capital city of Mexico and one undergraduate…

  10. Walter Moxon, MD, FCRP (1836-1886): the cerebro-vascular system and the syndrome of "congestion of the brain": an analysis of his 1881 Croonian Lectures.

    PubMed

    Buckingham, Hugh W

    2008-01-01

    Walter Moxon, MD, FRCP lived, practiced medicine, taught and wrote in the mid- to late- nineteenth-century Victorian England, mostly at Guy's Hospital, London. He was widely informed in the "Art of Physic," writing on a range of issues from cerebral lateralization of articulate speech to angina pectoris. The present paper will trace briefly his contributions to the newly discovered asymmetry of articulate speech in the left frontal lobe (1866) and will in more detail trace and analyze his 1881 Croonian Lectures at the Royal College of Physicians on a medical shibboleth referred to as "congestion of the brain." In a series of ingenious and rhetorically creative arguments with imaginative tropes, demonstrations, evolutionary accounts of cognition and blood metabolism for human/biped cognition, and cogent citations from the medical literature of the day, Moxon skillfully instructs his medical audience against the misleading notion of cerebral "congestion" as an underlying pathology for cognitive, motor, and sensory deficits seen in the clinic. In so doing, he provides the medical community with an in-depth glimpse at the circulatory system, its flow dynamics, and how they serve to meet the cognitive, motor, and sensory demands of upright bipedal man.

  11. Resistance Prediction in AML: Analysis of 4,601 Patients from MRC/NCRI, HOVON/SAKK, SWOG, and MD Anderson Cancer Center

    PubMed Central

    Walter, Roland B.; Othus, Megan; Burnett, Alan K.; Löwenberg, Bob; Kantarjian, Hagop M.; Ossenkoppele, Gert J.; Hills, Robert K.; Ravandi, Farhad; Pabst, Thomas; Evans, Anna; Pierce, Sherry R.; Vekemans, Marie-Christiane; Appelbaum, Frederick R.; Estey, Elihu H.

    2014-01-01

    Therapeutic resistance remains the principal problem in acute myeloid leukemia (AML). We used area under receiver operator characteristic curves (AUC) to quantify our ability to predict therapeutic resistance in individual patients where AUC=1.0 denotes perfect prediction and AUC=0.5 denotes a coin flip, using data from 4,601 patients with newly diagnosed AML given induction therapy with 3+7 or more intense standard regimens in MRC/NCRI, HOVON, SWOG, and MD Anderson Cancer Center studies. Age, performance status, white blood cell count, secondary disease, cytogenetic risk, and FLT3-ITD/NPM1 mutation status were each independently associated with failure to achieve complete remission despite no early death (“primary refractoriness”). However, the AUC of a bootstrap-corrected multivariable model predicting this outcome was only 0.78, indicating only fair predictive ability. Removal of FLT3-ITD and NPM1 information only slightly decreased the AUC (0.76). Prediction of resistance, defined as primary refractoriness or short relapse-free survival (RFS), was even more difficult. Our ability to forecast resistance based on routinely available pre-treatment covariates provides a rationale for continued randomization between standard and new therapies and supports further examination of genetic and post-treatment data to optimize resistance prediction in AML. PMID:25113226

  12. Resistance prediction in AML: analysis of 4601 patients from MRC/NCRI, HOVON/SAKK, SWOG and MD Anderson Cancer Center.

    PubMed

    Walter, R B; Othus, M; Burnett, A K; Löwenberg, B; Kantarjian, H M; Ossenkoppele, G J; Hills, R K; Ravandi, F; Pabst, T; Evans, A; Pierce, S R; Vekemans, M-C; Appelbaum, F R; Estey, E H

    2015-02-01

    Therapeutic resistance remains the principal problem in acute myeloid leukemia (AML). We used area under receiver-operating characteristic curves (AUCs) to quantify our ability to predict therapeutic resistance in individual patients, where AUC=1.0 denotes perfect prediction and AUC=0.5 denotes a coin flip, using data from 4601 patients with newly diagnosed AML given induction therapy with 3+7 or more intense standard regimens in UK Medical Research Council/National Cancer Research Institute, Dutch-Belgian Cooperative Trial Group for Hematology/Oncology/Swiss Group for Clinical Cancer Research, US cooperative group SWOG and MD Anderson Cancer Center studies. Age, performance status, white blood cell count, secondary disease, cytogenetic risk and FLT3-ITD/NPM1 mutation status were each independently associated with failure to achieve complete remission despite no early death ('primary refractoriness'). However, the AUC of a bootstrap-corrected multivariable model predicting this outcome was only 0.78, indicating only fair predictive ability. Removal of FLT3-ITD and NPM1 information only slightly decreased the AUC (0.76). Prediction of resistance, defined as primary refractoriness or short relapse-free survival, was even more difficult. Our limited ability to forecast resistance based on routinely available pretreatment covariates provides a rationale for continued randomization between standard and new therapies and supports further examination of genetic and posttreatment data to optimize resistance prediction in AML.

  13. Automatic Vehicle Trajectory Extraction for Traffic Analysis from Aerial Video Data

    NASA Astrophysics Data System (ADS)

    Apeltauer, J.; Babinec, A.; Herman, D.; Apeltauer, T.

    2015-03-01

    This paper presents a new approach to simultaneous detection and tracking of vehicles moving through an intersection in aerial images acquired by an unmanned aerial vehicle (UAV). Detailed analysis of spatial and temporal utilization of an intersection is an important step for its design evaluation and further traffic inspection. Traffic flow at intersections is typically very dynamic and requires continuous and accurate monitoring systems. Conventional traffic surveillance relies on a set of fixed cameras or other detectors, requiring a high density of the said devices in order to monitor the intersection in its entirety and to provide data in sufficient quality. Alternatively, a UAV can be converted to a very agile and responsive mobile sensing platform for data collection from such large scenes. However, manual vehicle annotation in aerial images would involve tremendous effort. In this paper, the proposed combination of vehicle detection and tracking aims to tackle the problem of automatic traffic analysis at an intersection from visual data. The presented method has been evaluated in several real-life scenarios.

  14. 76 FR 1993 - Airworthiness Directives; The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-12

    ... Model DC-9-81 (MD- 81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes AGENCY... Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590. FOR FURTHER INFORMATION.... Applicability (c) This AD applies to The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83...

  15. 76 FR 13543 - Airworthiness Directives; The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-14

    ... Model DC-9-81 (MD- 81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes AGENCY... Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590. Hand Delivery: Deliver to Mail... stabilizer is similar in design and loading to that of the Model DC-9-81 (MD-81), DC- 9-82 (MD-82),...

  16. 76 FR 39251 - Airworthiness Directives; The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... Model DC-9-81 (MD- 81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes AGENCY... Jersey Avenue, SE., Washington, DC 20590. FOR FURTHER INFORMATION CONTACT: Roger Durbin, Aerospace.... Applicability (c) This AD applies to all The Boeing Company Model DC-9-81 (MD- 81), DC-9-82 (MD-82), DC-9-83...

  17. A Topical Trajectory on Survival: an Analysis of Link-Making in a Sequence of Lessons on Evolution

    NASA Astrophysics Data System (ADS)

    Rocksén, Miranda; Olander, Clas

    2016-04-01

    This study explores the concept of link-making in relation to communicative strategies applied in the teaching and studying of biological evolution. The analysis focused on video recordings of 11 lessons on biological evolution conducted in a Swedish 9th grade class of students aged 15 years. It reveals how the teacher and students connected classroom conversations, the frequency of references to conversations in whole-class settings, and the development of a theme focusing on species survival and extinction. Detailed examples from the data illustrate how this theme developed from its initiation during the first lesson, through discussion and clarification, to its wrapping up during the last lesson. They further illustrate how students made sense of what the teacher said and wrote, and how the teacher postponed issues, explained and developed topics, provided opportunities for link-making, organised the class, motivated students, and checked their understanding. The study's methodological approach offers a way of including several time dimensions within research. Based on our findings, we conclude that the excerpts examined here did succeed in building `islands of coherence' in the co-construction of curricular content. Moreover, the topical trajectory in relation to species survival provided opportunities for constructing a `scientific story' in the classroom.

  18. Uncertainty optimization applied to the Monte Carlo analysis of planetary entry trajectories

    NASA Astrophysics Data System (ADS)

    Way, David Wesley

    2001-10-01

    Future robotic missions to Mars, as well as any human missions, will require precise entries to ensure safe landings near science objectives and pre-deployed assets. Planning for these missions will depend heavily on Monte Carlo analyses to evaluate active guidance algorithms, assess the impact of off-nominal conditions, and account for uncertainty. The dependability of Monte Carlo forecasts, however, is limited by the accuracy and completeness of the assumed uncertainties. This is because Monte Carlo analysis is a forward driven problem; beginning with the input uncertainties and proceeding to the forecast output statistics. An improvement to the Monte Carlo analysis is needed that will allow the problem to be worked in reverse. In this way, the largest allowable dispersions that achieve the required mission objectives can be determined quantitatively. This thesis proposes a methodology to optimize the uncertainties in the Monte Carlo analysis of spacecraft landing footprints. A metamodel is used to first write polynomial expressions for the size of the landing footprint as functions of the independent uncertainty extrema. The coefficients of the metamodel are determined by performing experiments. The metamodel is then used in a constrained optimization procedure to minimize a cost-tolerance function. First, a two-dimensional proof-of-concept problem was used to evaluate the feasibility of this optimization method. Next, the optimization method was further demonstrated on the Mars Surveyor Program 2001 Lander. The purpose of this example was to demonstrate that the methodology developed during the proof-of-concept could be scaled to solve larger, more complicated, "real world" problems. This research has shown that is possible to control the size of the landing footprint and establish tolerances for mission uncertainties. A simplified metamodel was developed, which is enabling for realistic problems with more than just a few uncertainties. A confidence interval on

  19. Analysis of Debris Trajectories at the Scaled Wind Farm Technology (SWiFT) Facility

    SciTech Connect

    White, Jonathan R.; Burnett, Damon J.

    2016-01-01

    Sandia National Laboratories operates the Scaled Wind Farm Technology Facility (SWiFT) on behalf of the Department of Energy Wind and Water Power Technologies Office. An analysis was performed to evaluate the hazards associated with debris thrown from one of SWiFT’s operating wind turbines, assuming a catastrophic failure. A Monte Carlo analysis was conducted to assess the complex variable space associated with debris throw hazards that included wind speed, wind direction, azimuth and pitch angles of the blade, and percentage of the blade that was separated. In addition, a set of high fidelity explicit dynamic finite element simulations were performed to determine the threshold impact energy envelope for the turbine control building located on-site. Assuming that all of the layered, independent, passive and active engineered safety systems and administrative procedures failed (a 100% failure rate of the safety systems), the likelihood of the control building being struck was calculated to be less than 5/10,000 and ballistic simulations showed that the control building would not provide passive protection for the majority of impact scenarios. Although options exist to improve the ballistic resistance of the control building, the recommendation is not to pursue them because there is a low probability of strike and there is an equal likelihood personnel could be located at similar distances in other areas of the SWiFT facility which are not passively protected, while the turbines are operating. A fenced exclusion area has been created around the turbines which restricts access to the boundary of the 1/100 strike probability. The overall recommendation is to neither relocate nor improve passive protection of the control building as the turbine safety systems have been improved to have no less than two independent, redundant, high quality engineered safety systems. Considering this, in combination with a control building strike probability of less than 5/10,000, the

  20. Development of Advanced Methods of Structural and Trajectory Analysis for Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Ardema, Mark D.

    1996-01-01

    In this report the author describes: (1) development of advanced methods of structural weight estimation, and (2) development of advanced methods of flight path optimization. A method of estimating the load-bearing fuselage weight and wing weight of transport aircraft based on fundamental structural principles has been developed. This method of weight estimation represents a compromise between the rapid assessment of component weight using empirical methods based on actual weights of existing aircraft and detailed, but time-consuming, analysis using the finite element method. The method was applied to eight existing subsonic transports for validation and correlation. Integration of the resulting computer program, PDCYL, has been made into the weights-calculating module of the AirCraft SYNThesis (ACSYNT) computer program. ACSYNT bas traditionally used only empirical weight estimation methods; PDCYL adds to ACSYNT a rapid, accurate means of assessing the fuselage and wing weights of unconventional aircraft. PDCYL also allows flexibility in the choice of structural concept, as well as a direct means of determining the impact of advanced materials on structural weight.

  1. [Bloodstain pattern analysis on examples from practice: Are calculations with application parabolic trajectory usable?].

    PubMed

    Makovický, Peter; Matlach, Radek; Pokorná, Olga; Mošna, František; Makovický, Pavol

    2015-01-01

    The bloodstain pattern analysis (BPA) is useful in the forensic medicine. In Czechoslovakian criminology is this method not commonly used. The objective of this work is to calculate the impact length, height and distance splashing of blood drops. The results are compared with the real values for specific cases. It is also compared to calculate the angle of incidence of blood drops, using sinα with a form using tgα. For this purposes we used two different character cases from practice with well-preserved condition and readable blood stains. Selected blood stains were documented in order to calculate the angle of incidence of blood drops and to calculateorigin splashes. For this drop of blood, the distance of impact of the drops of blood (x), the height of the sprayed blood drops (y) and the length of the flight path the drop of blood (l). The obtained data was retrospectively analysed for the two models. The first straight line is represented by the triangle (M1) and the other is the parabolic model (M2). The formulae were derived using the Euler substitution. The results show that the angle of incidence of the drop of blood can be calculated as sinα and the tgα. When applying, the triangle is appropriate to consider the application and sinα parabolic requires the calculation of the angle of incidence drops of blood tgα. Parabola is useful for the BPA. In Czechoslovakian should be providing workplace training seminars BPA primarily intended for forensic investigators.We recommend the use of this method during investigations, verification of acts in forensic practice.

  2. Eye safety analysis for non-uniform retinal scanning laser trajectories

    NASA Astrophysics Data System (ADS)

    Schelinski, Uwe; Dallmann, Hans-Georg; Grüger, Heinrich; Knobbe, Jens; Pügner, Tino; Reinig, Peter; Woittennek, Franziska

    2016-03-01

    Scanning the retinae of the human eyes with a laser beam is an approved diagnosis method in ophthalmology; moreover the retinal blood vessels form a biometric modality for identifying persons. Medical applied Scanning Laser Ophthalmoscopes (SLOs) usually contain galvanometric mirror systems to move the laser spot with a defined speed across the retina. Hence, the load of laser radiation is uniformly distributed and eye safety requirements can be easily complied. Micro machined mirrors also known as Micro Electro Mechanical Systems (MEMS) are interesting alternatives for designing retina scanning systems. In particular double-resonant MEMS are well suited for mass fabrication at low cost. However, their Lissajous-shaped scanning figure requires a particular analysis and specific measures to meet the requirements for a Class 1 laser device, i.e. eye-safe operation. The scanning laser spot causes a non-uniform pulsing radiation load hitting the retinal elements within the field of view (FoV). The relevant laser safety standards define a smallest considerable element for eye-related impacts to be a point source that is visible with an angle of maximum 1.5 mrad. For non-uniform pulsing expositions onto retinal elements the standard requires to consider all particular impacts, i.e. single pulses, pulse sequences in certain time intervals and cumulated laser radiation loads. As it may be expected, a Lissajous scanning figure causes the most critical radiation loads at its edges and borders. Depending on the applied power the laser has to be switched off here to avoid any retinal injury.

  3. Genomic analysis reveals distinct concentration-dependent evolutionary trajectories for antibiotic resistance in Escherichia coli.

    PubMed

    Mogre, Aalap; Sengupta, Titas; Veetil, Reshma T; Ravi, Preethi; Seshasayee, Aswin Sai Narain

    2014-12-01

    Evolution of bacteria under sublethal concentrations of antibiotics represents a trade-off between growth and resistance to the antibiotic. To understand this trade-off, we performed in vitro evolution of laboratory Escherichia coli under sublethal concentrations of the aminoglycoside kanamycin over short time durations. We report that fixation of less costly kanamycin-resistant mutants occurred earlier in populations growing at lower sublethal concentration of the antibiotic, compared with those growing at higher sublethal concentrations; in the latter, resistant mutants with a significant growth defect persisted longer. Using deep sequencing, we identified kanamycin resistance-conferring mutations, which were costly or not in terms of growth in the absence of the antibiotic. Multiple mutations in the C-terminal end of domain IV of the translation elongation factor EF-G provided low-cost resistance to kanamycin. Despite targeting the same or adjacent residues of the protein, these mutants differed from each other in the levels of resistance they provided. Analysis of one of these mutations showed that it has little defect in growth or in synthesis of green fluorescent protein (GFP) from an inducible plasmid in the absence of the antibiotic. A second class of mutations, recovered only during evolution in higher sublethal concentrations of the antibiotic, deleted the C-terminal end of the ATP synthase shaft. This mutation confers basal-level resistance to kanamycin while showing a strong growth defect in the absence of the antibiotic. In conclusion, the early dynamics of the development of resistance to an aminoglycoside antibiotic is dependent on the levels of stress (concentration) imposed by the antibiotic, with the evolution of less costly variants only a matter of time.

  4. Potential emission flux to aerosol pollutants over Bengal Gangetic plain through combined trajectory clustering and aerosol source fields analysis

    NASA Astrophysics Data System (ADS)

    Kumar, D. Bharath; Verma, S.

    2016-09-01

    A hybrid source-receptor analysis was carried out to evaluate the potential emission flux to winter monsoon (WinMon) aerosols over Bengal Gangetic plain urban (Kolkata, Kol) and semi-urban atmospheres (Kharagpur, Kgp). This was done through application of fuzzy c-mean clustering to back-trajectory data combined with emission flux and residence time weighted aerosols analysis. WinMon mean aerosol optical depth (AOD) and angstrom exponent (AE) at Kol (AOD: 0.77; AE: 1.17) were respectively slightly higher than and nearly equal to that at Kgp (AOD: 0.71; AE: 1.18). Out of six source region clusters over Indian subcontinent and two over Indian oceanic region, the cluster mean AOD was the highest when associated with the mean path of air mass originating from the Bay of Bengal and the Arabian sea clusters at Kol and that from the Indo-Gangetic plain (IGP) cluster at Kgp. Spatial distribution of weighted AOD fields showed the highest potential source of aerosols over the IGP, primarily over upper IGP (e.g. Punjab, Haryana), lower IGP (e.g. Uttarpradesh) and eastern region (e.g. west Bengal, Bihar, northeast India) clusters. The emission flux contribution potential (EFCP) of fossil fuel (FF) emissions at surface (SL) of Kol/Kgp, elevated layer (EL) of Kol, and of biomass burning (BB) emissions at SL of Kol were primarily from upper, lower, upper/lower IGP clusters respectively. The EFCP of FF/BB emissions at Kgp-EL/SL, and that of BB at EL of Kol/Kgp were mainly from eastern region and Africa (AFR) clusters respectively. Though the AFR cluster was constituted of significantly high emission flux source potential of dust emissions, the EFCP of dust from northwest India (NWI) was comparable to that from AFR at Kol SL/EL.

  5. Inferring the Observed PSC Composition Using the Improved Limb Atmospheric Spectrometer (ILAS) Data Along With Trajectory Analysis

    NASA Astrophysics Data System (ADS)

    Saitoh, N.; Hayashida, S.; Sasano, Y.

    2001-12-01

    The Improved Limb Atmospheric Spectrometer (ILAS) captured many polar stratospheric cloud (PSC) events in the Northern Hemisphere during the winter and early spring of 1997. We identified about 250 events in 65 profiles as PSCs in the Arctic. Preliminary analysis made it clear that the ILAS also observed many PSC events during the early winter of 1997 in the Southern Hemisphere. The ILAS aerosol extinction coefficient and nitric acid data were compared with the theoretically predicted values for supercooled ternary solution (STS), nitric acid dihydrate (NAD), and nitric acid trihydrate (NAT) particles at thermodynamic equilibrium to infer the chemical composition of the observed PSC particles. In mid-January of 1997, both the extinction coefficient and nitric acid values of some of the observed PSC events showed better agreement with the theoretical values for STS than with those of NAT or NAD. Although a few PSCs were observed in March, most of the PSCs observed late in the PSC season had features of nitric-acid-containing hydrates. An intensive analysis of the temperature histories suggested that most of the STS particles observed in January had experienced the thermal conditions necessary for the formation of liquid particles. The nitric-acid-containing solid PSC events observed in early March experienced temperatures below TNAT for more than several days, and sometimes fell below Tice during the 20-day period. They had not passed over typical mountainous area before their measurements, so the formation mechanisms of these solid particles should be explained from their synoptic scale temperature histories, without considering lee waves. They maintained relatively high nitric acid hydrate saturation ratios along their trajectory, which suggests their homogeneous nucleation.

  6. Rapid Design of Gravity Assist Trajectories

    NASA Technical Reports Server (NTRS)

    Carrico, J.; Hooper, H. L.; Roszman, L.; Gramling, C.

    1991-01-01

    Several International Solar Terrestrial Physics (ISTP) missions require the design of complex gravity assisted trajectories in order to investigate the interaction of the solar wind with the Earth's magnetic field. These trajectories present a formidable trajectory design and optimization problem. The philosophy and methodology that enable an analyst to design and analyse such trajectories are discussed. The so called 'floating end point' targeting, which allows the inherently nonlinear multiple body problem to be solved with simple linear techniques, is described. The combination of floating end point targeting with analytic approximations with a Newton method targeter to achieve trajectory design goals quickly, even for the very sensitive double lunar swingby trajectories used by the ISTP missions, is demonstrated. A multiconic orbit integration scheme allows fast and accurate orbit propagation. A prototype software tool, Swingby, built for trajectory design and launch window analysis, is described.

  7. BIGNASim: a NoSQL database structure and analysis portal for nucleic acids simulation data

    PubMed Central

    Hospital, Adam; Andrio, Pau; Cugnasco, Cesare; Codo, Laia; Becerra, Yolanda; Dans, Pablo D.; Battistini, Federica; Torres, Jordi; Goñi, Ramón; Orozco, Modesto; Gelpí, Josep Ll.

    2016-01-01

    Molecular dynamics simulation (MD) is, just behind genomics, the bioinformatics tool that generates the largest amounts of data, and that is using the largest amount of CPU time in supercomputing centres. MD trajectories are obtained after months of calculations, analysed in situ, and in practice forgotten. Several projects to generate stable trajectory databases have been developed for proteins, but no equivalence exists in the nucleic acids world. We present here a novel database system to store MD trajectories and analyses of nucleic acids. The initial data set available consists mainly of the benchmark of the new molecular dynamics force-field, parmBSC1. It contains 156 simulations, with over 120 μs of total simulation time. A deposition protocol is available to accept the submission of new trajectory data. The database is based on the combination of two NoSQL engines, Cassandra for storing trajectories and MongoDB to store analysis results and simulation metadata. The analyses available include backbone geometries, helical analysis, NMR observables and a variety of mechanical analyses. Individual trajectories and combined meta-trajectories can be downloaded from the portal. The system is accessible through http://mmb.irbbarcelona.org/BIGNASim/. Supplementary Material is also available on-line at http://mmb.irbbarcelona.org/BIGNASim/SuppMaterial/. PMID:26612862

  8. BIGNASim: a NoSQL database structure and analysis portal for nucleic acids simulation data.

    PubMed

    Hospital, Adam; Andrio, Pau; Cugnasco, Cesare; Codo, Laia; Becerra, Yolanda; Dans, Pablo D; Battistini, Federica; Torres, Jordi; Goñi, Ramón; Orozco, Modesto; Gelpí, Josep Ll

    2016-01-04

    Molecular dynamics simulation (MD) is, just behind genomics, the bioinformatics tool that generates the largest amounts of data, and that is using the largest amount of CPU time in supercomputing centres. MD trajectories are obtained after months of calculations, analysed in situ, and in practice forgotten. Several projects to generate stable trajectory databases have been developed for proteins, but no equivalence exists in the nucleic acids world. We present here a novel database system to store MD trajectories and analyses of nucleic acids. The initial data set available consists mainly of the benchmark of the new molecular dynamics force-field, parmBSC1. It contains 156 simulations, with over 120 μs of total simulation time. A deposition protocol is available to accept the submission of new trajectory data. The database is based on the combination of two NoSQL engines, Cassandra for storing trajectories and MongoDB to store analysis results and simulation metadata. The analyses available include backbone geometries, helical analysis, NMR observables and a variety of mechanical analyses. Individual trajectories and combined meta-trajectories can be downloaded from the portal. The system is accessible through http://mmb.irbbarcelona.org/BIGNASim/. Supplementary Material is also available on-line at http://mmb.irbbarcelona.org/BIGNASim/SuppMaterial/.

  9. Identifying Neurocognitive Decline at 36 Months among HIV-Positive Participants in the CHARTER Cohort Using Group-Based Trajectory Analysis

    PubMed Central

    Brouillette, Marie-Josée; Fellows, Lesley K.; Cysique, Lucette A.; Heaton, Robert K.

    2016-01-01

    Introduction While HIV-associated neurocognitive impairment remains common despite the widespread use of combined antiretroviral therapy (cART), there have been relatively few studies investigating the trajectories of neurocognitive change in longitudinal NeuroAIDS studies. Objective To estimate the magnitude and pattern of neurocognitive change over the first 3 years of follow-up using Group-Based Trajectory Analysis (GBTA) applied to participants in the longitudinal arm of the CHARTER cohort. Method The study population consisted of 701 CHARTER participants who underwent neuropsychological (NP) testing on at least 2 occasions. Raw test scores on 15 NP measures were modeled using GBTA. Each trajectory was categorized as stable, improved or declined, according to two different criteria for change (whether the magnitude of the estimated change at 36 months differed ≥ 0.5 standard deviations from baseline value or changed by > the standard error of measurement estimated at times 1 and 2). Individuals who declined on one or more NP measures were categorized as decliners. Results Overall, 111 individuals (15.8%) declined on at least one NP test over 36 months, with the vast majority showing decline on a single NP test (93/111-83.8%). The posterior probability of group assignment was high in most participants (71%) after only 2 sessions, and in the overwhelming majority of those with 3+ sessions. Heterogeneity of trajectories was the norm rather than the exception. Individuals who declined had, on average, worse baseline NP performance on every test, were older, had a longer duration of HIV infection and more follow-up sessions. Conclusion The present study identified heterogeneous trajectories over 3 years across 15 NP raw test scores using GBTA. Cognitive decline was observed in only a small subset of this study cohort. Decliners had demographics and HIV characteristics that have been previously associated with cognitive decline, suggesting clinical validity for the

  10. Trajectories and magnitude of change in coral reef fish populations in Philippine marine reserves: a meta-analysis

    NASA Astrophysics Data System (ADS)

    Maliao, R. J.; White, A. T.; Maypa, A. P.; Turingan, R. G.

    2009-12-01

    Marine reserves are widely implemented worldwide to meet both conservation and fisheries management goals. This study examines the efficacy of Philippine marine reserves using meta-analysis by comparing variations in fish density (1) between reserves and adjacent fished reefs (spatial comparison), (2) within reserves before establishment relative to years following the establishment (temporal comparison), and (3) among reserves classified based on size, age, and enforcement capacity. A grand (total) mean of nineteen 22.3 ha coral reef reserves, protected for a mean duration of 8.2 years, were included in the meta-analyses. The overall density of fishes was higher in the reserves compared with the fished reefs and this difference was largely accounted for by exploited fishes. However, the overall density of fishes within the same reserves remained similar from the period before its establishment to several years following its establishment. Only the density of nonexploited fishes increased significantly during years subsequent to the establishment of the reserves. Neither age nor size of reserves correlated with pattern of change in fish density following the establishment of the reserves; however, fish density was consistently higher in larger and older reserves relative to smaller and younger reserves in the spatial comparison. Furthermore, well-enforced reserves had higher density of exploited fishes relative to less-enforced reserves in both spatial and temporal comparisons. In general, the magnitude and trajectory of change in fish density following the establishment of Philippine marine reserves are influenced by (1) functional groups of fishes under consideration, (2) size and age of the reserve, and (3) level of enforcement of the regulatory mechanisms necessary to sustain a marine reserve.

  11. 3D bloodstain pattern analysis: ballistic reconstruction of the trajectories of blood drops and determination of the centres of origin of the bloodstains.

    PubMed

    Buck, Ursula; Kneubuehl, Beat; Näther, Silvio; Albertini, Nicola; Schmidt, Lars; Thali, Michael

    2011-03-20

    For crime scene investigation in cases of homicide, the pattern of bloodstains at the incident site is of critical importance. The morphology of the bloodstain pattern serves to determine the approximate blood source locations, the minimum number of blows and the positioning of the victim. In the present work, the benefits of the three-dimensional bloodstain pattern analysis, including the ballistic approximation of the trajectories of the blood drops, will be demonstrated using two illustrative cases. The crime scenes were documented in 3D, using the non-contact methods digital photogrammetry, tachymetry and laser scanning. Accurate, true-to-scale 3D models of the crime scenes, including the bloodstain pattern and the traces, were created. For the determination of the areas of origin of the bloodstain pattern, the trajectories of up to 200 well-defined bloodstains were analysed in CAD and photogrammetry software. The ballistic determination of the trajectories was performed using ballistics software. The advantages of this method are the short preparation time on site, the non-contact measurement of the bloodstains and the high accuracy of the bloodstain analysis. It should be expected that this method delivers accurate results regarding the number and position of the areas of origin of bloodstains, in particular the vertical component is determined more precisely than using conventional methods. In both cases relevant forensic conclusions regarding the course of events were enabled by the ballistic bloodstain pattern analysis.

  12. Analysis of fuel-conservative curved decelerating approach trajectories for powered-lift and CTOL jet aircraft

    NASA Technical Reports Server (NTRS)

    Neuman, F.

    1980-01-01

    A method for determining fuel conservative terminal approaches that include changes in altitude, speed, and heading are described. Three different guidance system concepts for STOL aircraft were evaluated in flight: (1) a fixed trajectory system; (2) a system that included a fixed path and a real time synthesized capture flight path; and (3) a trajectory synthesizing system. Simulation results for the augmentor wing jet STOL research aircraft and for the Boeing 727 aircraft are discussed. The results indicate that for minimum fuel consumption, two guidance deceleration segments are required.

  13. Application of Brownian motion theory to the analysis of membrane channel ionic trajectories calculated by molecular dynamics.

    PubMed Central

    Jakobsson, E; Chiu, S W

    1988-01-01

    This paper shows how Brownian motion theory can be used to analyze features of individual ion trajectories in channels as calculated by molecular dynamics, and that its use permits more precise determinations of diffusion coefficients than would otherwise be possible. We also show how a consideration of trajectories of single particles can distinguish between effects due to the magnitude of the diffusion coefficient and effects due to barriers and wells in the potential profile, effects which can not be distinguished by consideration of average fluxes. PMID:2465032

  14. 76 FR 52225 - Airworthiness Directives; The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ... Model DC-9-81 (MD- 81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes AGENCY... Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590. FOR FURTHER INFORMATION... ADs (b) None. Applicability (c) This AD applies to The Boeing Company Model DC-9-81 (MD-81),...

  15. Cluster analysis of the impact of air back-trajectories on aerosol optical properties at Hornsund, Spitsbergen

    NASA Astrophysics Data System (ADS)

    Rozwadowska, A.; Zieliński, T.; Petelski, T.; Sobolewski, P.

    2010-02-01

    In this paper, spectra of aerosol optical thickness from the AERONET (AErosol RObotic NETwork) station at Hornsund in the southern part of Spitsbergen were employed to study the impact of air mass history on aerosol optical thickness for wavelength λ=500 nm - AOT(500) - and the Ångström exponent. Backward trajectories computed, using the NOAA HYSPLIT model, were used to trace air history. It was found that in spring, the changes in AOT values over the Hornsund station were strongly influenced by air mass trajectories 8 days or longer in duration, arriving both in the free troposphere and at an altitude of 1 km above sea level. Nevertheless, free tropospheric advection was dominant. AOT variability in summer was best explained by the local direction and speed of advection (1-day trajectories) and was dominated by the effectiveness of cleansing processes. During the ASTAR 2007 campaign, the aerosols near Hornsund displayed low AOT values ranging from 0.06 to 0.09, which is lower than the mean AOT(500) for spring seasons from 2005 to 2007 (0.110±0.007; mean ± standard deviation of mean). 9 April 2007 with AOT(500)=0.147 was exceptional. The back-trajectories belonged to clusters with low and average cluster mean AOT. Apart from the maximum AOT of 9 April 2007, the observed AOT values were close to or lower than the means for the clusters to which they belonged.

  16. The Longitudinal Interplay of Adolescents' Self-Esteem and Body Image: A Conditional Autoregressive Latent Trajectory Analysis

    ERIC Educational Resources Information Center

    Morin, Alexandre J. S.; Maiano, Christophe; Marsh, Herbert W.; Janosz, Michel; Nagengast, Benjamin

    2011-01-01

    Self-esteem and body image are central to coping successfully with the developmental challenges of adolescence. However, the current knowledge surrounding self-esteem and body image is fraught with controversy. This study attempts to clarify some of them by addressing three questions: (1) Are the intraindividual developmental trajectories of…

  17. Anomaly Detection and Modeling of Trajectories

    DTIC Science & Technology

    2012-08-01

    unsupervised fashion using support vector machines (SVMs) and various spatial representations of trajectories. This thesis will also focus on...empirically to provide a rich analysis of trajectory datasets. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as...based on the rest of the dataset. This thesis develops a technique for detecting anoma- lous trajectories in a dataset in an unsupervised fashion using

  18. Jettison Engineering Trajectory Tool

    NASA Technical Reports Server (NTRS)

    Zaczek, Mariusz; Walter, Patrick; Pascucci, Joseph; Armstrong, Phyllis; Hallbick, Patricia; Morgan, Randal; Cooney, James

    2013-01-01

    The Jettison Engineering Trajectory Tool (JETT) performs the jettison analysis function for any orbiting asset. It provides a method to compute the relative trajectories between an orbiting asset and any jettisoned item (intentional or unintentional) or sublimating particles generated by fluid dumps to assess whether an object is safe to jettison, or if there is a risk with an item that was inadvertently lost overboard. The main concern is the interaction and possible recontact of the jettisoned object with an asset. This supports the analysis that jettisoned items will safely clear the vehicle, ensuring no collisions. The software will reduce the jettison analysis task from one that could take days to complete to one that can be completed in hours, with an analysis that is more comprehensive than the previous method. It provides the ability to define the jettison operation relative to International Space Station (ISS) structure, and provides 2D and 3D plotting capability to allow an analyst to perform a subjective clearance assessment with ISS structures. The developers followed the SMP to create the code and all supporting documentation. The code makes extensive use of the object-oriented format of Java and, in addition, the Model-View-Controller architecture was used in the organization of the code, allowing each piece to be independent of updates to the other pieces. The model category is for maintaining data entered by the user and generated by the analysis. The view category provides capabilities for data entry and displaying all or a portion of the analysis data in tabular, 2D, and 3D representation. The controller category allows for handling events that affect the model or view(s). The JETT utilizes orbital mechanics with complex algorithms. Since JETT is written in JAVA, it is essentially platform-independent.

  19. Trajectories of depressive symptoms after hip fracture

    PubMed Central

    Cristancho, P.; Lenze, E. J.; Avidan, M. S.; Rawson, K. S.

    2016-01-01

    Background Hip fracture is often complicated by depressive symptoms in older adults. We sought to characterize trajectories of depressive symptoms arising after hip fracture and examine their relationship with functional outcomes and walking ability. We also investigated clinical and psychosocial predictors of these trajectories. Method We enrolled 482 inpatients, aged ≥60 years, who were admitted for hip fracture repair at eight St Louis, MO area hospitals between 2008 and 2012. Participants with current depression diagnosis and/or notable cognitive impairment were excluded. Depressive symptoms and functional recovery were assessed with the Montgomery–Asberg Depression Rating Scale and Functional Recovery Score, respectively, for 52 weeks after fracture. Health, cognitive, and psychosocial variables were gathered at baseline. We modeled depressive symptoms using group-based trajectory analysis and subsequently identified correlates of trajectory group membership. Results Three trajectories emerged according to the course of depressive symptoms, which we termed ‘resilient’, ‘distressed’, and ‘depressed’. The depressed trajectory (10% of participants) experienced a persistently high level of depressive symptoms and a slower time to recover mobility than the other trajectory groups. Stressful life events prior to the fracture, current smoking, higher anxiety, less social support, antidepressant use, past depression, and type of implant predicted membership of the depressed trajectory. Conclusions Depressive symptoms arising after hip fracture are associated with poorer functional status. Clinical and psychosocial variables predicted membership of the depression trajectory. Early identification and intervention of patients in a depressive trajectory may improve functional outcomes after hip fracture. PMID:27032698

  20. Finite-Time Lagrangian Transport Analysis: Stable and Unstable Manifolds of Hyperbolic Trajectories and Finite-Time Lyapunov Exponents

    DTIC Science & Technology

    2009-08-01

    Wang, G. Haller, A. Banaszuk, and G. Tadmor, Closed-loop Lagrangian separation control in a bluff body shear flow model, Physics of Fluids 15 (2003... separation which depends, in general, on the time interval chosen for assessment of such a measure. Conse- quently, in flows undergoing transitions...straightforward diagnostic tool for uncovering time-dependent flow structures characterised by locally strongest separation of nearby trajectories. Note how

  1. The Longitudinal Interplay of Adolescents' Self-Esteem and Body Image: A Conditional Autoregressive Latent Trajectory Analysis.

    PubMed

    Morin, Alexandre J S; Maïano, Christophe; Marsh, Herbert W; Janosz, Michel; Nagengast, Benjamin

    2011-04-11

    Self-esteem and body image are central to coping successfully with the developmental challenges of adolescence. However, the current knowledge surrounding self-esteem and body image is fraught with controversy. This study attempts to clarify some of them by addressing three questions: (1) Are the intraindividual developmental trajectories of self-esteem and body image stable across adolescence? (2) What is the direction of the relations between body image and self-esteem over time? (3) What is the role of gender, ethnicity, and pubertal development on those trajectories? This study relies on Autoregressive Latent Trajectory analyses based on data from a 4-year, 6-wave, prospective longitudinal study of 1,001 adolescents. Self-esteem and body image levels remained high and stable over time, although body image levels also tended to increase slightly. The results show that levels of self-esteem were positively influenced by levels of body image. However, these effects remained small and most of the observed associations were cross-sectional. Finally, the effects of pubertal development on body image and self-esteem levels were mostly limited to non-Caucasian females who appeared to benefit from more advanced pubertal development. Conversely, Caucasian females presented the lowest self-esteem and body image levels of all, although for them more advanced pubertal development levels were associated with a slight rise in body image over time.

  2. Patterns of risk and trajectories of preschool problem behaviors: a person-oriented analysis of attachment in context.

    PubMed

    Keller, Thomas E; Spieker, Susan J; Gilchrist, Lewayne

    2005-01-01

    A small proportion of children exhibit extreme and persistent conduct problems through childhood. The present study employed the multiple-domain model of Greenberg and colleagues as the framework for person-oriented analyses examining whether parent-child attachment combines with parenting, family ecology, and child characteristics in particular configurations of risk that are linked to this problematic developmental pathway. Using prospective data from a community sample of adolescent mothers and their children, latent variable growth mixture modeling identified a normative trajectory with declining problem behaviors during the preschool period. Consistent with research on early-starter pathways, a distinct group of children featured a higher intercept and a positive slope, indicating an escalation in disruptive behaviors. Attachment security played a role in defining specific risk profiles associated with the probability of exhibiting this problem trajectory. Given particular patterns of risk exposure, secure attachment served a protective function. Avoidant, but not disorganized, attachment was associated with significantly higher likelihood of the disruptive problem trajectory. The results also indicated the general accumulation of risk was detrimental, but the particular configuration of risk made a difference. Overall, the findings suggest early attachment operates in conjunction with personal and contextual risk to distinguish the development of later problem behaviors.

  3. The organic analysis and carbon chemistry of lunar samples: Their significance for exobiology; Proceedings of the Conference, University of Maryland, College Park, Md., October 26-28, 1971.

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Various methods used in the organic analysis of lunar samples are reviewed. The scope, advantages, and limitations of these methods are discussed, with particular emphasis on possible sources of contamination and experimental artifacts inherent in their use. A broad survey of the organogenic elements and compounds found in lunar samples covers the search for biogenic structures and viable organisms; the abundance and isotopic composition of various elements and compounds; the search for porphyrins, amino acids, or amino acid precursors; and the presence of heterocylics, aromatic hydrocarbons, and other organic compounds. The sources of the organogenic elements and compounds detected in lunar samples are discussed. The significance of the lunar organic analysis for exobiology is discussed in terms of its relevance to and implications for the studies of chemical evolution and terrestrial organic geochemistry. Individual items are announced in this issue.

  4. Ballute Aerocapture Trajectories at Neptune

    NASA Technical Reports Server (NTRS)

    Lyons, Daniel T.; Johnson, Wyatt

    2004-01-01

    Using an inflatable ballute system for aerocapture at planets and moons with atmospheres has the potential to provide significant performance benefits compared not only to traditional all propulsive capture, but also to aeroshell based aerocapture technologies. This paper discusses the characteristics of entry trajectories for ballute aerocapture at Neptune. These trajectories are the first steps in a larger systems analysis effort that is underway to characterize and optimize the performance of a ballute aerocapture system for future missions not only at Neptune, but also the other bodies with atmospheres.

  5. Particle Trajectory and Icing Analysis of the E(sup 3) Turbofan Engine Using LEWICE3D Version 3

    NASA Technical Reports Server (NTRS)

    Bidwell, Colin S.

    2011-01-01

    Particle trajectory and ice shape calculations were made for the Energy Efficient Engine (E(sup 3)) using the LEWICE3D Version 3 software. The particle trajectory and icing computations were performed using the new "block-to-block" collection efficiency method which has been incorporated into the LEWICE3D Version 3 software. The E(sup 3) was developed by NASA and GE in the early 1980 s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The E(sup 3) flow field was calculated using the NASA Glenn ADPAC turbomachinery flow solver. Computations were performed for the low pressure compressor of the E(sup 3) for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for three drop sizes and two drop distributions typically used in aircraft design and certification. Particle trajectory computations were made for water drop sizes of 5, 20, and 100 microns. Particle trajectory and ice shape predictions were made for a 20 micron Langmuir-D distribution and for a 92 mm Super-cooled Large Droplet (SLD) distribution with and without splashing effects for a Liquid Water Content (LWC) of 0.3 g/cu m and an icing time of 30 min. The E3 fan and spinner combination proved to be an effective ice removal mechanism as they removed greater than 36 percent of the mass entering the inlet for the icing cases. The maximum free stream catch fraction for the fan and spinner combination was 0.60 while that on the elements downstream of the fan was 0.03. The non-splashing trajectory and collection efficiency results showed that as drop size increased impingement rates increased on the spinner and fan leaving less mass to impinge on downstream components. The SLD splashing case yielded more mass downstream of the fan than the SLD non-splashing case due to mass being splashed from the upstream inlet lip, spinner and fan components. The ice shapes generated downstream of the fan were either small or nonexistent due to the small available mass

  6. Orbital ATK – Elkton, MD MDD003067121

    EPA Pesticide Factsheets

    The EPA is announcing its environmental remediation and draft corrective action permit under the Resource Conservation and Recovery Act, as amended (RCRA), as complete with Controls for the Orbital ATK Inc. Facility (ATK), Elkton MD, (EPA ID: MDD0030671)

  7. Obituary of Philip H. Cooper, MD.

    PubMed

    Patterson, James W; Wick, Mark R; Mills, Stacey E

    2015-08-01

    Dermatopathology lost a giant in the field with the death of Philip H. Cooper, MD, on Friday, January 30, 2015. The following obituary represents a celebration of his life and his contributions to our field.

  8. Enhanced Allergic Inflammation of Der p 2 Affected by Polymorphisms of MD-2 Promoter

    PubMed Central

    Liao, En-Chih; Hsieh, Chia-Wei; Chang, Ching-Yun; Yu, Sheng-Jie; Sheu, Meei-Ling; Wu, Sheng-Mao

    2015-01-01

    Purpose Myeloid differentiation-2 (MD-2) has been associated with endotoxin and inflammatory disorders because it can recognize lipopolysaccharide (LPS) binding and attenuate Toll-like receptor 4 (TLR4)-mediated signaling. However, its role in allergic inflammation has yet to be clarified. We examined whether single nucleotide polymorphisms (SNPs) in MD-2 promoter can affect MD-2 expression and aimed to clarify the relationship between Der p 2 allergy and SNPs of MD-2 promoter. Methods The function of SNPs of MD-2 promoter and the effects of cytokines and immunoglobulin on the secretion and mRNA expression were investigated in 73 allergic subjects with different MD-2 gene promoter variants. Peripheral blood mononuclear cells were cultured with or without LPS in the presence of Dermatophagoides pteronyssinus group 2 allergen (Der p 2), followed by mRNA extraction and cytokine expression analysis. The culture supernatants were collected for cytokine measurement. Results Patients with the MD-2 promoter SNPs (rs1809441/rs1809442) had increased mRNA expressions of MD-2, ε heavy chain of IgE (Cε), and interleukin (IL)-8; however, only MD-2 and IL-8 were further up-regulated after Der p 2 stimulation. Patients with SNPs of MD-2 promoter tended to have high levels of IL-1β, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α after Der p 2 and LPS stimulation. Increased secretions of IL-6, IL-8, and IL-10 were found to be up-regulated by Der p 2 stimulation, and an increased secretion of IFN-γ and decreased secretion of IL-4 were noted after LPS stimulation. Conclusions The high levels of proinflammatory cytokines secreted by Der p 2 were predetermined by MD-2 promoter SNPs (rs1809441/rs1809442). Through cytokine secretion by Der p 2 and LPS, these SNPs may serve as an indicator of the pathological phenotype of Der p 2-induced allergic inflammation. PMID:26122509

  9. Solvation structure and dynamics of K+ in aqueous ammonia solution: Insights from an ONIOM-XS MD simulation

    NASA Astrophysics Data System (ADS)

    Kabbalee, Pilailuk; Sripa, Pattrawan; Tongraar, Anan; Kerdcharoen, Teerakiat

    2015-07-01

    An ONIOM-XS MD simulation has been performed to investigate the solvation structure and dynamics of K+ in aqueous ammonia solution. Detailed analyses on the ONIOM-XS MD trajectories clearly reveal that the K+ solvation is rather flexible, forming numerous possible K+-ligand species, ranging from 4- to 10-fold coordinated complexes. The average coordination number of K+ in such a solvent mixture is predicted to be 7.0, consisting of 4.8 water and 2.2 ammonia molecules. The results obtained by the ONIOM-XS MD simulation have provided more insights into the characteristics of this solvated ion, i.e., when compared to the previous QM/MM MD study.

  10. Back-trajectory analysis of African dust outbreaks at a coastal city in southern Spain: Selection of starting heights and assessment of African and concurrent Mediterranean contributions

    NASA Astrophysics Data System (ADS)

    Cabello, M.; Orza, J. A. G.; Dueñas, C.; Liger, E.; Gordo, E.; Cañete, S.

    2016-09-01

    The present study uses a back-trajectory analysis at multiple heights for better interpretation of the impact of the African dust outbreaks in the coastal Mediterranean city of Málaga (Spain), the southernmost large city in Europe. Throughout a 3-year period, 363 days were identified as dusty days by atmospheric transport models. During these events, PM10, SO2, O3, temperature, AOD and Ångström exponent showed statistically significant differences compared to days with no African dust. It was found that under African dust events, the study site was influenced by Mediterranean air masses at the lowermost heights and by Atlantic advections at high altitudes, while African air masses mostly reached Málaga at intermediate levels. Specifically, the lowest heights at which air masses reached the study site after having resided over Africa are confined into the 1000-2000 m range. The decoupling between the lowest heights and the ones for dust transport may explain the presence of aged air masses at the time of the African outbreak. Additionally, with the aim of studying the influence of the air mass origin and history on air quality, a new procedure based on Principal component analysis (PCA) is proposed to determine which altitudes are best suited as starting points for back-trajectory calculations, as they maximize the differences in residence time over different areas. Its application to Málaga identifies three altitudes (750, 2250 and 4500 m) and a subsequent analysis of back-trajectories for African dust days provided the main source areas over Africa as well as further insight on the Mediterranean contribution.

  11. Using synoptic classification and trajectory analysis to assess air quality during the winter heating period in Ürümqi, China

    NASA Astrophysics Data System (ADS)

    Wang, Lili; Wang, Yuesi; Sun, Yang; Li, Yuanyuan

    2012-03-01

    Synoptic patterns identified by an automated procedure employing principal-component analysis and a two-stage cluster analysis, and backward trajectory analysis clustered by the HYSPLIT4.9 model were used to examine air quality patterns over Ürümqi, China, one of the most heavily polluted cities in the world. Six synoptic patterns representing different atmospheric circulation patterns and air-mass characteristics were classified during the winter heating periods from 2001 to 2008, and seven trajectory clusters representing different paths of air masses arriving at Ürümqi were calculated during the winter heating periods from 2005 to 2008. Then air quality was evaluated using these two approaches, and significant variations were found across both synoptic patterns and trajectory clusters. The heaviest air-pollution episodes occurred when Ürümqi was either in an extremely cold, strong anticyclone or at the front of a migrating cyclone. Both conditions were characterized by with light winds, cold, wet surface air, and relatively dry upper air. Ürümqi was predominately influenced by air masses from the southwest and from local areas. Air pollution index (API) levels were highest for air masses originating from the southwest with a longer path or for the local area, because of transport from semi-desert/desert regions by strong winds and because of local heavy pollution emissions, respectively. The interactions between these two analytical approaches showed that poor diffusion conditions, together with local circulation, enhanced air pollution, besides, regional air-mass transport caused by strong winds contributed to serious air quality under relatively good diffusion conditions.

  12. Trajectories of Posttraumatic Stress Among Urban Residents

    PubMed Central

    Galea, Sandro; Uddin, Monica; Koenen, Karestan C.

    2014-01-01

    Urban residents experience a wide range of traumatic events and are at increased risk of assaultive violence. Although previous research has examined trajectories of posttraumatic stress (PTS) through latent class growth analysis (LCGA) among persons exposed to the same index events (e.g., a natural disaster), PTS trajectories have not been documented among urban residents. The aims of this study were to conduct LGCA with a sample of trauma survivors from Detroit, Michigan (N = 981), and to explore predictors of trajectory membership. Participants completed three annual telephone surveys, each of which included the posttraumatic stress disorder (PTSD) Check-list-Civilian Version. Four PTS trajectories were detected. Although the majority evidenced a trajectory of consistently few symptoms (Low: 72.5 %), 4.6 % were in a trajectory of chronic severe PTSD (High), and the remainder were in trajectories of consistently elevated, but generally subclinical, levels of PTS (Decreasing: 12.3 %; Increasing: 10.6 %). Socioeconomic disadvantage (e.g., lower income), more extensive trauma history (e.g., childhood abuse), and fewer social resources (e.g., lower social support) were associated with membership in higher PTS trajectories, relative to the Low trajectory. The results suggest that efforts to reduce PTS in urban areas need to attend to socioeconomic vulnerabilities in addition to trauma history and risk for ongoing trauma exposure. PMID:24469249

  13. Determination of Delta m(d) and absolute calibration of flavor taggers for the Delta m(s) analysis, in fully reconstructed decays at the CDF experiment

    SciTech Connect

    Gomez, Jonatan Piedra

    2005-04-21

    The new trigger processor, the Silicon Vertex Tracking (SVT), has dramatically improved the B physics capabilities of the upgraded CDF II Detector; for the first time in a hadron collider, the SVT has enabled the access to non-lepton-triggered B meson decays. Within the new available range of decay modes, the B$0\\atop{s}$ → D$-\\atop{s}$π+ signature is of paramount importance in the measurement of the Δms mixing frequency. The analysis reported here is a step towards the measurement of this frequency; two where our goals: carrying out the absolute calibration of the opposite side flavor taggers, used in the Δms measurement; and measuring the B$0\\atop{d}$ mixing frequency in a B → Dπ sample, establishing the feasibility of the mixing measurement in this sample whose decay-length is strongly biased by the selective SVT trigger. We analyze a total integrated luminosity of 355 pb-1 collected with the CDF II Detector. By triggering on muons, using the conventional di-muon trigger; or displaced tracks, using the SVT trigger, we gather a sample rich in bottom and charm mesons.

  14. Center of excellence for mobile sensor data-to-knowledge (MD2K)

    PubMed Central

    Kumar, Santosh; Abowd, Gregory D; Abraham, William T; al’Absi, Mustafa; Gayle Beck, J; Chau, Duen Horng; Condie, Tyson; Conroy, David E; Ertin, Emre; Estrin, Deborah; Ganesan, Deepak; Lam, Cho; Marlin, Benjamin; Marsh, Clay B; Murphy, Susan A; Nahum-Shani, Inbal; Patrick, Kevin; Rehg, James M; Sharmin, Moushumi; Shetty, Vivek; Sim, Ida; Spring, Bonnie; Srivastava, Mani; Wetter, David W

    2015-01-01

    Mobile sensor data-to-knowledge (MD2K) was chosen as one of 11 Big Data Centers of Excellence by the National Institutes of Health, as part of its Big Data-to-Knowledge initiative. MD2K is developing innovative tools to streamline the collection, integration, management, visualization, analysis, and interpretation of health data generated by mobile and wearable sensors. The goal of the big data solutions being developed by MD2K is to reliably quantify physical, biological, behavioral, social, and environmental factors that contribute to health and disease risk. The research conducted by MD2K is targeted at improving health through early detection of adverse health events and by facilitating prevention. MD2K will make its tools, software, and training materials widely available and will also organize workshops and seminars to encourage their use by researchers and clinicians. PMID:26555017

  15. Center of excellence for mobile sensor data-to-knowledge (MD2K).

    PubMed

    Kumar, Santosh; Abowd, Gregory D; Abraham, William T; al'Absi, Mustafa; Beck, J Gayle; Chau, Duen Horng; Condie, Tyson; Conroy, David E; Ertin, Emre; Estrin, Deborah; Ganesan, Deepak; Lam, Cho; Marlin, Benjamin; Marsh, Clay B; Murphy, Susan A; Nahum-Shani, Inbal; Patrick, Kevin; Rehg, James M; Sharmin, Moushumi; Shetty, Vivek; Sim, Ida; Spring, Bonnie; Srivastava, Mani; Wetter, David W

    2015-11-01

    Mobile sensor data-to-knowledge (MD2K) was chosen as one of 11 Big Data Centers of Excellence by the National Institutes of Health, as part of its Big Data-to-Knowledge initiative. MD2K is developing innovative tools to streamline the collection, integration, management, visualization, analysis, and interpretation of health data generated by mobile and wearable sensors. The goal of the big data solutions being developed by MD2K is to reliably quantify physical, biological, behavioral, social, and environmental factors that contribute to health and disease risk. The research conducted by MD2K is targeted at improving health through early detection of adverse health events and by facilitating prevention. MD2K will make its tools, software, and training materials widely available and will also organize workshops and seminars to encourage their use by researchers and clinicians.

  16. Calculating Trajectories And Orbits

    NASA Technical Reports Server (NTRS)

    Alderson, Daniel J.; Brady, Franklyn H.; Breckheimer, Peter J.; Campbell, James K.; Christensen, Carl S.; Collier, James B.; Ekelund, John E.; Ellis, Jordan; Goltz, Gene L.; Hintz, Gerarld R.; Legerton, Victor N.; Mccreary, Faith A.; Mitchell, Robert T.; Mottinger, Neil A.; Moultrie, Benjamin A.; Moyer, Theodore D.; Rinker, Sheryl L.; Ryne, Mark S.; Stavert, L. Robert; Sunseri, Richard F.

    1989-01-01

    Double-Precision Trajectory Analysis Program, DPTRAJ, and Orbit Determination Program, ODP, developed and improved over years to provide highly reliable and accurate navigation capability for deep-space missions like Voyager. Each collection of programs working together to provide desired computational results. DPTRAJ, ODP, and supporting utility programs capable of handling massive amounts of data and performing various numerical calculations required for solving navigation problems associated with planetary fly-by and lander missions. Used extensively in support of NASA's Voyager project. DPTRAJ-ODP available in two machine versions. UNIVAC version, NPO-15586, written in FORTRAN V, SFTRAN, and ASSEMBLER. VAX/VMS version, NPO-17201, written in FORTRAN V, SFTRAN, PL/1 and ASSEMBLER.

  17. VIEW IN OPPOSITE DIRECTION AS MD1351 AND MD1352. RAW MATERIAL ...

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

    VIEW IN OPPOSITE DIRECTION AS MD-135-1 AND MD-135-2. RAW MATERIAL CONVEYOR AT LEFT DEPOSITS SHELL INTO MILLING MACHINE AT LOWER LEFT. ENGINE IS AT LOWER RIGHT AND RADIATOR AT LOWER CENTER. ROLLER SORTER IS AT TOP OF CONVEYOR. - F. & H. Benning Company Oyster Mill, 14430 Solomons Island Road (moved from 1014 Benning Road, Galesville, Anne Arundel County, Maryland), Solomons, Calvert County, MD

  18. Trajectories of Martian Habitability

    PubMed Central

    2014-01-01

    Abstract Beginning from two plausible starting points—an uninhabited or inhabited Mars—this paper discusses the possible trajectories of martian habitability over time. On an uninhabited Mars, the trajectories follow paths determined by the abundance of uninhabitable environments and uninhabited habitats. On an inhabited Mars, the addition of a third environment type, inhabited habitats, results in other trajectories, including ones where the planet remains inhabited today or others where planetary-scale life extinction occurs. By identifying different trajectories of habitability, corresponding hypotheses can be described that allow for the various trajectories to be disentangled and ultimately a determination of which trajectory Mars has taken and the changing relative abundance of its constituent environments. Key Words: Mars—Habitability—Liquid water—Planetary science. Astrobiology 14, 182–203. PMID:24506485

  19. Soft-tissue volumetric changes following monobloc distraction procedure: analysis using digital three-dimensional photogrammetry system (3dMD).

    PubMed

    Chan, Fuan Chiang; Kawamoto, Henry K; Federico, Christina; Bradley, James P

    2013-03-01

    We have previously reported that monobloc advancement by distraction osteogenesis resulted in decreased morbidity and greater advancement with less relapse compared with acute monobloc advancement with bone grafting. In this study, we examine the three-dimensional (3D) volumetric soft-tissue changes in monobloc distraction.Patients with syndromic craniosynostosis who underwent monobloc distraction from 2002 to 2010 at University of California-Los Angeles Craniofacial Center were studied (n = 12). We recorded diagnosis, indications for the surgery, and volumetric changes for skeletal and soft-tissue midface structures (preoperative/postoperative [6 weeks]/follow-up [>1 year]). Computed tomography scans and a digital 3D photogrammetry system were used for image analysis.Patients ranged from 6 to 14 years of age (mean, 10.1 years) at the time of the operation (follow-up 2-11 years); mean distraction advancement was 19.4 mm (range, 14-25 mm). There was a mean increase in the 3D volumetric soft-tissue changes: 99.5 ± 4.0 cm(3) (P < 0.05) at 6 weeks and 94.9 ± 3.6 cm(3) (P < 0.05) at 1-year follow-up. When comparing soft-tissue changes at 6 weeks postoperative to 1-year follow-up, there were minimal relapse changes. The overall mean 3D skeletal change was 108.9 ± 4.2 cm. For every 1 cm of skeletal gain, there was 0.78 cm(3) of soft-tissue gain.Monobloc advancement by distraction osteogenesis using internal devices resulted in increased volumetric soft-tissue changes, which remained stable at 1 year. The positive linear correlation between soft-tissue increments and bony advancement can be incorporated during the planning of osteotomies to achieve optimum surgical outcomes with monobloc distraction.

  20. Crystal structure of the TLR4-MD-2 complex with bound endotoxin antagonist Eritoran.

    PubMed

    Kim, Ho Min; Park, Beom Seok; Kim, Jung-In; Kim, Sung Eun; Lee, Judong; Oh, Se Cheol; Enkhbayar, Purevjav; Matsushima, Norio; Lee, Hayyoung; Yoo, Ook Joon; Lee, Jie-Oh

    2007-09-07

    TLR4 and MD-2 form a heterodimer that recognizes LPS (lipopolysaccharide) from Gram-negative bacteria. Eritoran is an analog of LPS that antagonizes its activity by binding to the TLR4-MD-2 complex. We determined the structure of the full-length ectodomain of the mouse TLR4 and MD-2 complex. We also produced a series of hybrids of human TLR4 and hagfish VLR and determined their structures with and without bound MD-2 and Eritoran. TLR4 is an atypical member of the LRR family and is composed of N-terminal, central, and C-terminal domains. The beta sheet of the central domain shows unusually small radii and large twist angles. MD-2 binds to the concave surface of the N-terminal and central domains. The interaction with Eritoran is mediated by a hydrophobic internal pocket in MD-2. Based on structural analysis and mutagenesis experiments on MD-2 and TLR4, we propose a model of TLR4-MD-2 dimerization induced by LPS.

  1. Multivariate nonlinear regression analysis of trajectory tracking performance using force reflecting joystick in chronic stroke-induced hemiparesis.

    PubMed

    Feng, Xin; Winters, Jack M

    2011-01-01

    Individualizing a neurorehabilitation training protocol requires understanding the performance of subjects with various capabilities under different task settings. We use multivariate regression to evaluate the performance of subjects with stroke-induced hemiparesis in trajectory tracking tasks using a force-reflecting joystick. A nonlinear effect was consistently shown in both dimensions of force field strength and impairment level for selected kinematic performance measures, with greatest sensitivity at lower force fields. This suggests that the form of a force field may play a different "role" for subjects with various impairment levels, and confirms that to achieve optimized therapeutic benefit, it is necessary to personalize interfaces.

  2. An Examination of "The Martian" Trajectory

    NASA Technical Reports Server (NTRS)

    Burke, Laura

    2015-01-01

    This analysis was performed to support a request to examine the trajectory of the Hermes vehicle in the novel "The Martian" by Andy Weir. Weir developed his own tool to perform the analysis necessary to provide proper trajectory information for the novel. The Hermes vehicle is the interplanetary spacecraft that shuttles the crew to and from Mars. It is notionally a Nuclear powered vehicle utilizing VASIMR engines for propulsion. The intent of this analysis was the determine whether the trajectory as it was outlined in the novel is consistent with the rules of orbital mechanics.

  3. Optimization Of Simulated Trajectories

    NASA Technical Reports Server (NTRS)

    Brauer, Garry L.; Olson, David W.; Stevenson, Robert

    1989-01-01

    Program To Optimize Simulated Trajectories (POST) provides ability to target and optimize trajectories of point-mass powered or unpowered vehicle operating at or near rotating planet. Used successfully to solve wide variety of problems in mechanics of atmospheric flight and transfer between orbits. Generality of program demonstrated by its capability to simulate up to 900 distinct trajectory phases, including generalized models of planets and vehicles. VAX version written in FORTRAN 77 and CDC version in FORTRAN V.

  4. 75 FR 6162 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-81 (MD-81), DC-9-82 (MD-82...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... Corporation Model DC- 9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes... Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes. This... material fatigue from normal flap operating loads. We are proposing this AD to detect and correct...

  5. 75 FR 34661 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-81 (MD-81), DC-9-82 (MD-82...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ... Corporation Model DC- 9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9- 87 (MD-87), and MD-88 airplanes. This proposed AD would...

  6. 75 FR 80744 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-9-81 (MD-81), DC-9-82 (MD-82...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ... Corporation Model DC- 9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD- 87) and MD-88 airplanes. This proposed AD would require...

  7. Variation in Trajectories of Women's Marital Quality

    PubMed Central

    James, Spencer L.

    2014-01-01

    I examine variation in trajectories of women's marital quality across the life course. The analysis improves upon earlier research in three ways: (1) the analysis uses a sequential cohort design and data from the first 35 years of marriage; (2) I analyze rich data from a national sample; (3) I examine multiple dimensions of marital quality. Latent class growth analyses estimated on data from women in the National Longitudinal Survey of Youth-1979 (N = 2604) suggest multiple trajectories for each of three dimensions of marital quality, including two trajectories of marital happiness, two trajectories of marital communication, and three trajectories of marital conflict. Socioeconomic and demographic covariates are then used to illustrate how factors such as income, cohabitation, and race-ethnicity set individuals at risk of poor marital quality throughout the life course by differentiating between high and low trajectories of marital quality. Women on low marital quality trajectories are, as expected, at much greater risk of divorce. Taken together, these findings show how fundamental socioeconomic and demographic characteristics contribute to subsequent marital outcomes via their influence on trajectories of marital quality as well as providing a better picture of the complexity in contemporary patterns of marital quality. PMID:25432600

  8. Variation in trajectories of women's marital quality.

    PubMed

    James, Spencer L

    2015-01-01

    I examine variation in trajectories of women's marital quality across the life course. The analysis improves upon earlier research in three ways: (1) the analysis uses a sequential cohort design and data from the first 35years of marriage; (2) I analyze rich data from a national sample; (3) I examine multiple dimensions of marital quality. Latent class growth analyses estimated on data from women in the National Longitudinal Survey of Youth-1979 (N=2604) suggest multiple trajectories for each of three dimensions of marital quality, including two trajectories of marital happiness, two trajectories of marital communication, and three trajectories of marital conflict. Socioeconomic and demographic covariates are then used to illustrate how factors such as income, cohabitation, and race-ethnicity set individuals at risk of poor marital quality throughout the life course by differentiating between high and low trajectories of marital quality. Women on low marital quality trajectories are, as expected, at much greater risk of divorce. Taken together, these findings show how fundamental socioeconomic and demographic characteristics contribute to subsequent marital outcomes via their influence on trajectories of marital quality as well as providing a better picture of the complexity in contemporary patterns of marital quality.

  9. Evolutionary trajectory of channel planforms in the middle Garonne River (Toulouse, SW France) over a 130-year period: Contribution of mixed multiple factor analysis (MFAmix)

    NASA Astrophysics Data System (ADS)

    David, Mélodie; Labenne, Amaury; Carozza, Jean-Michel; Valette, Philippe

    2016-04-01

    The purpose of this study is to propose a methodological essay for defining evolutionary trajectories of channel planforms and to examine the channel change in the middle Garonne River (southwest France) over a 130-year period. The study focuses on a reach of ~ 90 km situated downstream from the city of Toulouse. A set of four historical maps (1868, 1940s, 1970s, and 2000s) is used to build a geomorphometric diachronic database. Data processing through mixed multiple factor analysis (MFAmix) and hierarchical cluster analysis (HCA) allows distinction between four homogeneous zones within the study reach, depending on their evolutionary trajectories. Channel behavior in the upstream and median zones evolved as of the beginning of the study period (narrowing of the fluvial area, colonization by vegetation, and removal of alluvial bars), likely owing to punctual anthropogenic actions. The downstream zone is characterized by stabilization of the channel and alluvial bar removal over the second half of the twentieth century, coinciding with the campaign undertaken by French local authorities between 1960 and 1984 to protect river banks. The role of climate transition between the Little Ice Age (LIA) and the onset of the Global Warming period (GW) is also discussed. Results generally are consistent with the chronology established for most European rivers.

  10. Zero- vs. one-dimensional, parametric vs. non-parametric, and confidence interval vs. hypothesis testing procedures in one-dimensional biomechanical trajectory analysis.

    PubMed

    Pataky, Todd C; Vanrenterghem, Jos; Robinson, Mark A

    2015-05-01

    Biomechanical processes are often manifested as one-dimensional (1D) trajectories. It has been shown that 1D confidence intervals (CIs) are biased when based on 0D statistical procedures, and the non-parametric 1D bootstrap CI has emerged in the Biomechanics literature as a viable solution. The primary purpose of this paper was to clarify that, for 1D biomechanics datasets, the distinction between 0D and 1D methods is much more important than the distinction between parametric and non-parametric procedures. A secondary purpose was to demonstrate that a parametric equivalent to the 1D bootstrap exists in the form of a random field theory (RFT) correction for multiple comparisons. To emphasize these points we analyzed six datasets consisting of force and kinematic trajectories in one-sample, paired, two-sample and regression designs. Results showed, first, that the 1D bootstrap and other 1D non-parametric CIs were qualitatively identical to RFT CIs, and all were very different from 0D CIs. Second, 1D parametric and 1D non-parametric hypothesis testing results were qualitatively identical for all six datasets. Last, we highlight the limitations of 1D CIs by demonstrating that they are complex, design-dependent, and thus non-generalizable. These results suggest that (i) analyses of 1D data based on 0D models of randomness are generally biased unless one explicitly identifies 0D variables before the experiment, and (ii) parametric and non-parametric 1D hypothesis testing provide an unambiguous framework for analysis when one׳s hypothesis explicitly or implicitly pertains to whole 1D trajectories.

  11. Cooling channels design analysis with chaotic laminar trajectory for closed cathode air-cooled PEM fuel cells using non-reacting numerical approach

    NASA Astrophysics Data System (ADS)

    N, W. Mohamed W. A.

    2015-09-01

    The thermal management of Polymer Electrolyte Membrane (PEM) fuel cells contributes directly to the overall power output of the system. For a closed cathode PEM fuel cell design, the use of air as a cooling agent is a non-conventional method due to the large heat load involved, but it offers a great advantage for minimizing the system size. Geometrical aspects of the cooling channels have been identified as the basic parameter for improved cooling performance. Numerical investigation using STAR-CCM computational fluid dynamics platform was applied for non-reacting cooling effectiveness study of various channel geometries for fuel cell application. The aspect ratio of channels and the flow trajectory are the parametric variations. A single cooling plate domain was selected with an applied heat flux of 2400 W/m2 while the cooling air are simulated at Reynolds number of 400 that corresponds to normal air flow velocities using standard 6W fans. Three channel designs of similar number of channels (20 channels) are presented here to analyze the effects of having chaotic laminar flow trajectory compared to the usual straight path trajectory. The total heat transfer between the cooling channel walls and coolant were translated into temperature distribution, maximum temperature gradient, average plate temperature and overall cooling effectiveness analyses. The numerical analysis shows that the chaotic flow promotes a 5% to 10% improvement in cooling effectiveness, depending on the single-axis or multi-axis flow paths applied. Plate temperature uniformity is also more realizable using the chaotic flow designs.

  12. Studies of the TLR4-associated protein MD-2 using yeast-display and mutational analyses

    PubMed Central

    Mattis, Daiva M.; Chervin, Adam; Ranoa, Diana; Kelley, Stacy; Tapping, Richard; Kranz, David M.

    2015-01-01

    Bacterial lipopolysaccharide (LPS) activates the innate immune system by forming a complex with myeloid differentiation factor 2 (MD-2) and Toll-like receptor 4 (TLR4), which is present on antigen presenting cells. MD-2 plays an essential role in this activation of the innate immune system as a member of the ternary complex, TLR4:MD-2:LPS. With the goal of further understanding the molecular details of the interaction of MD-2 with LPS and TLR4, and possibly toward engineering dominant negative regulators of the MD-2 protein, here we subjected MD-2 to a mutational analysis using yeast display. The approach included generation of site-directed alanine mutants, and ligand-driven selections of MD-2 mutant libraries. Our findings showed that: 1) proline mutations in the F119-K132 loop that binds LPS were strongly selected for enhanced yeast surface stability, 2) there was a preference for positive-charged side chains (R/K) at residue 120 for LPS binding, and negative-charged side chains (D/E) for TLR4 binding, 3) aromatic residues were strongly preferred at F119 and F121 for LPS binding, and 4) an MD-2 mutant (T84N/D101A/S118A/S120D/K122P) exhibited increased binding to TLR4 but decreased binding to LPS. These studies revealed the impact of specific residues and regions of MD-2 on the binding of LPS and TLR4, and they provide a framework for further directed evolution of the MD-2 protein. PMID:26320630

  13. Housing Trajectories of Forensic Psychiatric Patients.

    PubMed

    Salem, Leila; Crocker, Anne G; Charette, Yanick; Earls, Christopher M; Nicholls, Tonia L; Seto, Michael C

    2016-03-01

    The objectives of this study were to describe the disposition and housing trajectories of individuals found Not Criminally Responsible on account of Mental Disorder (NCRMD), and the factors that predict different trajectories. To do so, disposition and housing status were coded for 934 NCRMD patients over a 36-month follow-up period. Sequential data analysis resulted in four distinct trajectories: detention in hospital, conditional discharge in supportive housing, conditional discharge in independent housing, and absolute discharge to unknown housing. The likelihood of a placement in supportive housing compared with detention significantly decreased for individuals with a higher index offense severity. Less restrictive trajectories were significantly predicted by clinical factors. The results revealed little change in the disposition and housing trajectories of NCRMD patients. Furthermore, decisions about disposition and housing placement reflect a knowledge-practice gap between risk factors known to be predictive of community resources use in the forensic population. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Preliminary Analysis of Low-Thrust Gravity Assist Trajectories by An Inverse Method and a Global Optimization Technique.

    NASA Astrophysics Data System (ADS)

    de Pascale, P.; Vasile, M.; Casotto, S.

    The design of interplanetary trajectories requires the solution of an optimization problem, which has been traditionally solved by resorting to various local optimization techniques. All such approaches, apart from the specific method employed (direct or indirect), require an initial guess, which deeply influences the convergence to the optimal solution. The recent developments in low-thrust propulsion have widened the perspectives of exploration of the Solar System, while they have at the same time increased the difficulty related to the trajectory design process. Continuous thrust transfers, typically characterized by multiple spiraling arcs, have a broad number of design parameters and thanks to the flexibility offered by such engines, they typically turn out to be characterized by a multi-modal domain, with a consequent larger number of optimal solutions. Thus the definition of the first guesses is even more challenging, particularly for a broad search over the design parameters, and it requires an extensive investigation of the domain in order to locate the largest number of optimal candidate solutions and possibly the global optimal one. In this paper a tool for the preliminary definition of interplanetary transfers with coast-thrust arcs and multiple swing-bys is presented. Such goal is achieved combining a novel methodology for the description of low-thrust arcs, with a global optimization algorithm based on a hybridization of an evolutionary step and a deterministic step. Low thrust arcs are described in a 3D model in order to account the beneficial effects of low-thrust propulsion for a change of inclination, resorting to a new methodology based on an inverse method. The two-point boundary values problem (TPBVP) associated with a thrust arc is solved by imposing a proper parameterized evolution of the orbital parameters, by which, the acceleration required to follow the given trajectory with respect to the constraints set is obtained simply through

  15. Trajectory reconstruction through analysis of trace evidence in bullet-intermediate target interaction by SEM/EDX.

    PubMed

    Hu, Sunlin; Shen, Hui; Wang, Songcai; Fang, Chao

    2009-11-01

    A young male was shot to death by a police officer with a Chinese Type 64 7.62 mm pistol when he was dealing with an aggravated assault arising from a traffic accident. By using scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDX), trace deposits on the discharged bullet and the intermediate target, i.e., a concrete telegraph pole at the scene, were identified to be from each other. The result demonstrated the bullet causing the death ricocheted from the concrete telegraph pole before striking the victim, thus indicating the incident was accidental. The case report illustrates the evidential value of trace materials derived, respectively, from discharged bullets and intermediate targets in bullet-intermediate target interaction for trajectory reconstruction. In addition, it indicates that the SEM/EDX method with its nondestructive nature, compared to other methods, may be more helpful in certain situations in determining the origins of trace evidentially valuable deposits on substrates.

  16. Seasonal variability of tritium and ion concentrations in rain at Kumamoto, Japan and back-trajectory analysis of air mass

    SciTech Connect

    Momoshima, N.; Sugihara, S.; Toyoshima, T.; Nagao, Y.; Takahashi, M.; Nakamura, Y.

    2008-07-15

    Tritium and major ion concentrations in rain were analyzed in Kumamoto (Japan)) between 2001 and 2006 to examine present tritium concentration and seasonal variation. The average tritium concentration was 0.36 {+-} 0.19 Bq/L (n=104) and higher tritium concentrations were observed in spring than the other seasons. Among the ions, non-sea-salt (nss) SO{sub 4}{sup 2}'- showed higher concentration in winter while other ions did not show marked increase in winter. Based on the back-trajectory analyses of air masses, the increase in tritium concentrations in spring arises from downward movement of naturally produced tritium from stratosphere to troposphere, while the increase of the nss-SO{sub 4}{sup 2-} concentrations in winter is due to long range transport of pollutants from China to Japan. (authors)

  17. Registration of cotton germplasm line md 10-5

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MD 10-5 (Reg. No. ______, PI 675077) is a noncommercial breeding line of cotton (Gossypium hirsutum L.) released by the USDA-ARS at Stoneville, MS in 2015. MD 10-5 was selected in F4 progenies from a cross between MD 15 (PI 642769) and JJ 1145ne. MD 10-5 has a desirable combination between lint yi...

  18. Trajectory selection for the Mariner Jupiter/Saturn 1977 project

    NASA Technical Reports Server (NTRS)

    Dyer, J. S.; Miles, R. F., Jr.

    1974-01-01

    The use of decision analysis to facilitate a group decision-making problem in the selection of trajectories for the two spacecraft of the Mariner Jupiter/Saturn 1977 Project. A set of 32 candidate trajectory pairs was developed. Cardinal utility function values were assigned to the trajectory pairs, and the data and statistics derived from collective choice rules were used in selecting the science-preferred trajectory pair.

  19. SU-E-T-529: Is MFO-IMPT Robust Enough for the Treatment of Head and Neck Tumors? A 2-Year Outcome Analysis Following Proton Therapy On the First 50 Oropharynx Patients at the MD Anderson Cancer Center

    SciTech Connect

    Frank, S; Garden, A; Anderson, M; Rosenthal, D; Morrison, W; Gunn, B; Fuller, C; Phan, J; Zhang, X; Poenisch, F; Wu, R; Li, H; Gautam, A; Sahoo, N; Gillin, M; Zhu, X

    2015-06-15

    Purpose: Multi-field optimization intensity modulated proton therapy (MFO-IMPT) for oropharyngeal tumors has been established using robust planning, robust analysis, and robust optimization techniques. While there are inherent uncertainties in proton therapy treatment planning and delivery, outcome reporting are important to validate the proton treatment process. The purpose of this study is to report the first 50 oropharyngeal tumor patients treated de-novo at a single institution with MFO-IMPT. Methods: The data from the first 50 patients with squamous cell carcinoma of the oropharynx treated at MD Anderson Cancer Center from January 2011 to December 2014 on a prospective IRB approved protocol were analyzed. Outcomes were analyzed to include local, regional, and distant treatment failures. Acute and late toxicities were analyzed by CTCAE v4.0. Results: All patients were treated with definitive intent. The median follow-up time of the 50 patients was 25 months. Patients by gender were male (84%) and female (16%). The average age was 61 years. 50% of patients were never smokers and 4% were current smokers. Presentation by stage; I–1, II–0, III– 9, IVA–37 (74%), IVB–3. 88% of patients were HPV/p16+. Patients were treated to 66–70 CGE. One local failure was reported at 13 months following treatment. One neck failure was reported at 12 months. 94% of patients were alive with no evidence of disease. One patient died without evidence of disease. There were no Grade 4 or Grade 5 toxicities. Conclusion: MFO-IMPT for oropharyngeal tumors is robust and provides excellent outcomes 2 years after treatment. A randomized trial is underway to determine if proton therapy will reduce chronic late toxicities of IMRT.

  20. Dynamic drag force based on iterative density mapping: A new numerical tool for three-dimensional analysis of particle trajectories in a dielectrophoretic system.

    PubMed

    Knoerzer, Markus; Szydzik, Crispin; Tovar-Lopez, Francisco Javier; Tang, Xinke; Mitchell, Arnan; Khoshmanesh, Khashayar

    2016-02-01

    Dielectrophoresis is a widely used means of manipulating suspended particles within microfluidic systems. In order to efficiently design such systems for a desired application, various numerical methods exist that enable particle trajectory plotting in two or three dimensions based on the interplay of hydrodynamic and dielectrophoretic forces. While various models are described in the literature, few are capable of modeling interactions between particles as well as their surrounding environment as these interactions are complex, multifaceted, and computationally expensive to the point of being prohibitive when considering a large number of particles. In this paper, we present a numerical model designed to enable spatial analysis of the physical effects exerted upon particles within microfluidic systems employing dielectrophoresis. The model presents a means of approximating the effects of the presence of large numbers of particles through dynamically adjusting hydrodynamic drag force based on particle density, thereby introducing a measure of emulated particle-particle and particle-liquid interactions. This model is referred to as "dynamic drag force based on iterative density mapping." The resultant numerical model is used to simulate and predict particle trajectory and velocity profiles within a microfluidic system incorporating curved dielectrophoretic microelectrodes. The simulated data are compared favorably with experimental data gathered using microparticle image velocimetry, and is contrasted against simulated data generated using traditional "effective moment Stokes-drag method," showing more accurate particle velocity profiles for areas of high particle density.

  1. Analysis of Rainfall and PM2.5 Data Using Clustered Trajectory Analysis for National Park Sites in the Western U.S.

    NASA Astrophysics Data System (ADS)

    Solorzano, N. N.; Hafner, W.; Jaffe, D.

    2005-12-01

    We calculated daily kinematic back-trajectories using the NOAA-HYSPLIT model to analyze 7 years of PM2.5 data from National Park sites in the Western U.S. (Glacier N.P., Mount Rainier N.P., Sequoia N.P., Rocky Mountain N.P. and Denali N.P.) The back-trajectories were clustered using a k-means clustering algorithm to segregate the trajectories into 6 main transport patterns. We calculated trajectory clusters for 1, 5 and 10 days to represent short, medium and long-range flow patterns. Some trajectory types and clusters show marked seasonality. Generally faster flow patterns are more prevalent in winter and slower/stagnant patterns are more prevalent in summer. In addition, we found significant inter-annual variability that may be important for explaining variations in rainfall and/or pollutant concentrations. The 5 and 10-day analyses revealed that, for the 4 non-Alaskan sites, trajectories from Asia tend to be less frequent in the summer, compared to the rest of the year. The clusters of different duration show very different predictive power for rainfall and PM2.5. We found that the 1-day clusters are a better predictor for precipitation and PM2.5 concentrations, as compared to the 5 and 10-day clusters. At each of the sites, there is at least one cluster with an average PM2.5 concentration that is different than the average for the site, indicating distinctive transport patterns. The same is true for 5 and 10-day clusters. Interestingly, only one site, Mount Rainier N.P., shows seasonal differences in PM2.5 concentrations between the clusters that differ from the average.

  2. Trajectory Browser Website

    NASA Technical Reports Server (NTRS)

    Foster, Cyrus; Jaroux, Belgacem A.

    2012-01-01

    The Trajectory Browser is a web-based tool developed at the NASA Ames Research Center to be used for the preliminary assessment of trajectories to small-bodies and planets and for providing relevant launch date, time-of-flight and V requirements. The site hosts a database of transfer trajectories from Earth to asteroids and planets for various types of missions such as rendezvous, sample return or flybys. A search engine allows the user to find trajectories meeting desired constraints on the launch window, mission duration and delta V capability, while a trajectory viewer tool allows the visualization of the heliocentric trajectory and the detailed mission itinerary. The anticipated user base of this tool consists primarily of scientists and engineers designing interplanetary missions in the context of pre-phase A studies, particularly for performing accessibility surveys to large populations of small-bodies. The educational potential of the website is also recognized for academia and the public with regards to trajectory design, a field that has generally been poorly understood by the public. The website is currently hosted on NASA-internal URL http://trajbrowser.arc.nasa.gov/ with plans for a public release as soon as development is complete.

  3. Hybrid MC/MD Method For High Entropy Alloy

    NASA Astrophysics Data System (ADS)

    Feng, Bojun; Widom, Michael

    High entropy alloys (HEA) are materials that contain multiple components of elements consisting of a single solid solution phase which could make the entropy of mixing very high. From recent investigations, HEA's possess promising properties such as strength at high temperature, tensile strength, thermal stability and corrosion resistance. In this talk, a hybrid Molecular Dynamics (MD)/Monte Carlo (MC) simulation method is introduced to the computational analysis of HEA, treating atomic displacement by MD as well as swapping atomic species by MC. This method efficiently models the phase separation and short range order by swapping between different types of atoms, while structural deviation from the perfect lattice sites of atoms is equilibrated quickly by MD. We apply this method to HfNbTaZr HEA modeled using an embedded-atom potential. The result gives a strong phase separation of Hf-Zr and Nb-Ta pairs shown by the pair correlation function. Diffuse scattering patterns are predicted and compared to experiments. Doe Grant No. DE-SC0014506.

  4. Hazardous Waste Minimization Assessment: Fort Meade, MD

    DTIC Science & Technology

    1991-01-01

    Audit." in Wuem Mbdmi1zmim Mama (Govarmmu Inlmdu he.. Roeehdmf, MD. 19), pp 61-73 M.L R=. "Haudow Wons Mhbdms Aisu Usi4 a Two-Timed Appm." rw£nwwd...severe health problems (e.g.. gastric disorders, skin lesions. swollen limbs, cancers. tumors , eye problems. liver disorders, menstrual irregularities

  5. Modeling Nanocomposites for Molecular Dynamics (MD) Simulations

    DTIC Science & Technology

    2015-01-01

    Maximum 200 Words) The minimum energy configuration for Molecular Dynamics (MD) simulations is found for a carbon nanotube (CNT)/polymer...Carbon Nanotubes (CNTs), Molecular Dynamics Simulations 15. NUMBER OF PAGES 18 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT...fiber composites have shown success in improving mechanical properties. Carbon nanotube (CNT)-based nanocomposites have been studied for

  6. 78 FR 2707 - Maryland Disaster # MD-00026

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Maryland Disaster MD-00026 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... Deadline Date: 10/02/2013. ADDRESSES: Submit completed loan applications to: U.S. Small...

  7. Howard Parnes, MD | Division of Cancer Prevention

    Cancer.gov

    Dr. Howard Parnes received a BA from Cornell University in 1977 and an MD from the University of Medicine and Dentistry of New Jersey in 1981. He trained in internal medicine at the Johns Hopkins Bayview Medical Center from 1981 to 1984 followed by a medical oncology fellowship at the University of Maryland Cancer Center (UMCC) from 1984 to 1987. |

  8. 76 FR 77579 - Maryland Disaster #MD-00017

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-13

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Maryland Disaster MD-00017 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... INFORMATION CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409...

  9. Identifying anthropogenic and natural influences on extreme pollution of respirable suspended particulates in Beijing using backward trajectory analysis.

    PubMed

    Song, Yu; Miao, Weijie; Liu, Bing; Dai, Wei; Cai, Xuhui

    2008-06-15

    In China, daily respirable suspended particulate (RSP, particles with aerodynamic diameters less than 10 microm) concentrations exceeding 420 microg m(-3) are considered "hazardous" to health. These can lead to the premature onset of certain diseases and premature death of sick and elderly people; even healthy people are warned to avoid outdoor activity when RSP concentrations are high. Such high pollution levels are defined as extreme RSP pollution events. Recent epidemiological studies have shown that a distinct difference exists between the health effects caused by natural sources and anthropogenic sources, mandating knowledge of the source of extreme RSP pollution. Twenty-six extreme RSP pollution events were recorded in Beijing from January 2003 to December 2006. The HYSPLIT4 (Hybrid Single Particle Lagrangian Integrated Trajectory) model (Version 4) was used to discriminate the sources of these extreme RSP pollution events. The model found that twelve events were caused from natural sources (dust storms), nine events from anthropogenic sources (e.g., vehicles and industrial activities, etc.) under quasi-quiescent weather, and five events were from mixed causes. Identifying such events will be valuable in epidemiological studies on air pollution in Beijing.

  10. Risk analysis for rumor propagation in metropolises based on improved 8-state ICSAR model and dynamic personal activity trajectories

    NASA Astrophysics Data System (ADS)

    Zhang, N.; Huang, H.; Duarte, M.; Zhang, J.

    2016-06-01

    Social media has developed extremely fast in metropolises in recent years resulting in more and more rumors disturbing our daily lives. Knowing the characteristics of rumor propagation in metropolises can help the government make efficient rumor refutation plans. In this paper, we established a dynamic spatio-temporal comprehensive risk assessment model for rumor propagation based on an improved 8-state ICSAR model (Ignorant, Information Carrier, Information Spreader, Advocate, Removal), large personal activity trajectory data, and governmental rumor refutation (anti-rumor) scenarios. Combining these relevant data with the 'big' traffic data on the use of subways, buses, and taxis, we simulated daily oral communications among inhabitants in Beijing. In order to analyze rumor and anti-rumor competition in the actual social network, personal resistance, personal preference, conformity, rumor intensity, government rumor refutation and other influencing factors were considered. Based on the developed risk assessment model, a long-term dynamic rumor propagation simulation for a seven day period was conducted and a comprehensive rumor propagation risk distribution map was obtained. A set of the sensitivity analyses were conducted for different social media and propagation routes. We assessed different anti-rumor coverage ratios and the rumor-spreading thresholds at which the government started to launch anti-rumor actions. The results we obtained provide worthwhile references useful for governmental decision making towards control of social-disrupting rumors.

  11. MAVEN's Trajectory to Mars

    NASA Video Gallery

    This movie shows the cruise trajectory of NASA's Mars Atmosphere and Volatile Evolution (MAVEN) mission, which was launched on Nov. 18, 2013. It will arrive at Mars on Sept. 21, 2014, to explore th...

  12. [The health-disease-care process from the perspective of the users of a primary care clinic in Montevideo, Uruguay: An analysis of therapeutic trajectories].

    PubMed

    Evia Bertullo, Victoria

    2015-12-01

    The aim of this paper is to analyze, using an ethnographic approach, the health-disease-care experiences of the users of a multi-specialty clinic that forms part of the Metropolitan Primary Health Care Network of Uruguay's Public Health Services. The fieldwork was carried out in the northeast of Montevideo from July 2012 to November 2013, combining participant observation in social and care spaces and interviews with more than 20 users. In our analysis of care trajectories we found that people incorporate different practices and beliefs when facing their health problems. The use of biomedical health care services is predominant in Uruguay; nevertheless, people engage in self-care practices and in some cases, in the use of folk, religious/magical or alternative remedies. Medical pluralism is therefore observed in facing certain common ailments or significant experiences of disease.

  13. Automated Cooperative Trajectories

    NASA Technical Reports Server (NTRS)

    Hanson, Curt; Pahle, Joseph; Brown, Nelson

    2015-01-01

    This presentation is an overview of the Automated Cooperative Trajectories project. An introduction to the phenomena of wake vortices is given, along with a summary of past research into the possibility of extracting energy from the wake by flying close parallel trajectories. Challenges and barriers to adoption of civilian automatic wake surfing technology are identified. A hardware-in-the-loop simulation is described that will support future research. Finally, a roadmap for future research and technology transition is proposed.

  14. Hierarchical Control and Trajectory Planning

    NASA Technical Reports Server (NTRS)

    Martin, Clyde F.; Horn, P. W.

    1994-01-01

    Most of the time on this project was spent on the trajectory planning problem. The construction is equivalent to the classical spline construction in the case that the system matrix is nilpotent. If the dimension of the system is n then the spline of degree 2n-1 is constructed. This gives a new approach to the construction of splines that is more efficient than the usual construction and at the same time allows the construction of a much larger class of splines. All known classes of splines are reconstructed using the approach of linear control theory. As a numerical analysis tool control theory gives a very good tool for constructing splines. However, for the purposes of trajectory planning it is quite another story. Enclosed in this document are four reports done under this grant.

  15. Hybrid 3-D rocket trajectory program. Part 1: Formulation and analysis. Part 2: Computer programming and user's instruction. [computerized simulation using three dimensional motion analysis

    NASA Technical Reports Server (NTRS)

    Huang, L. C. P.; Cook, R. A.

    1973-01-01

    Models utilizing various sub-sets of the six degrees of freedom are used in trajectory simulation. A 3-D model with only linear degrees of freedom is especially attractive, since the coefficients for the angular degrees of freedom are the most difficult to determine and the angular equations are the most time consuming for the computer to evaluate. A computer program is developed that uses three separate subsections to predict trajectories. A launch rail subsection is used until the rocket has left its launcher. The program then switches to a special 3-D section which computes motions in two linear and one angular degrees of freedom. When the rocket trims out, the program switches to the standard, three linear degrees of freedom model.

  16. Origin of the Ion Foreshock in a Quasi-perpendicular Curved Collisionless Shock: Particles Trajectory Analysis in 2D PIC Simulations

    NASA Astrophysics Data System (ADS)

    Savoini, P.; Lembege, B.

    2015-12-01

    The ion foreshock located upstream of the Earth's shock wave is populated with ions having interacted with the shock, and then, reflected back with an high energy gain. Spacecrafts have clearly established the existence of two distinct populations in the quasi-perpendicular shock region (i.e. for 45° ≤ ΘBn ≤ 90°, where ΘBn is the angle between the shock normal and the upstream magnetic field) : (i) field-aligned ion beams or « FAB » characterized by a gyrotropic distribution, and (ii) gyro-phase bunched ions or « GPB » characterized by a NON gyrotropic distribution. One of the important unresolved problem is the exact origin of the particles contributing to these two populations. To our knowledge, it was the first time that full-particle simulations have been performed including self-consistently the shock front curvature and nonstationarity, and the time-of-flight effects. Our analysis evidences that these two backstreaming populations may be reflected by the front itself and can be differentiated both in terms of interaction time and trajectory within the shock front. In particular, simulations evidence that "GPB" population is characterized by a short interaction time (ΔTinter = 1 to 2 τci) while the "FAB" population corresponds to a much larger time range (from 1 τci to 10 τci), where tci is the upstream ion gyroperiod. Present individual ion trajectories evidence that "FAB" population shows a strong perpendicular drift at the shock front (i.e. strong dependence of the pitch angle to the perpendicular velocity) whereas the "GPB" population shows no perpendicular drift (i.e. its pitch angle is mainly driven by the parallel velocity). Such differences explain why the "FAB" population loses their gyro-phase coherency and become gyrotropic which is not the case for the "GPB". This important result was not expected and greatly simplifies the question of their origin.

  17. Comparative analysis of land use/cover change trajectories and their driving forces in two small watersheds in the western Loess Plateau of China

    NASA Astrophysics Data System (ADS)

    Wang, Dongchuan; Gong, Jianhua; Chen, Liding; Zhang, Lihui; Song, Yiquan; Yue, Yujuan

    2013-04-01

    To prevent soil loss and achieve better ecological environments, soil conservation measures have been taken during the past decades in the western Loess Plateau of China. In this paper, a case study was taken in Luoyu valley and Lver valley, two sub-watersheds of Xihe watershed and comparison was carried out between them. The main object of this study is to monitor land use/cover changes in the two similar small watersheds utilizing SPOT5 imageries by object-oriented human-computer interactive classification method, further develop the method of spatio-temporal analysis of land use/cover change by using pattern metrics of change trajectories and relative land use suitability index (R) in smaller watersheds, and make comparisons between the two similar small watersheds, taking water and soil conservation measures into consideration. Results show that combining GIS and RS, this method can be perfectly applied to make comparisons between different small watersheds with similar geographical backgrounds. And land use/cover spatiotemporal dynamic change characteristics can be preferably expressed by pattern metrics of change trajectories and R values based on topographical data. Different emphases have been laid according to their own geological backgrounds in the two watersheds and human activities have different effects on the landscapes of the two watersheds. The main change pattern is from slope farmland to terrace (322, the largest in Luoyu valley) or to economic fruit forest (344, the largest in Lver valley). R value of every slope grade in both of the two watersheds drops with the rising of slope degree on the whole and it shows that there is still much to do for people in the two watersheds in consideration that all the R values are still lower than 0.7.

  18. Toxic wastes discovered in Cecil County, MD

    SciTech Connect

    1994-12-31

    This report focuses on the clean-up activities following toxic waste contamination in Cecil County, MD. The potentially hazardous leakage from waste containers buried in a quarry was addressed before it was turned into a civil emergency of the magnitude of Love Canal. US Superfund is a federal government trust fund largely comprised of taxes on the chemical and petrochemical industries. Local governments share in the cost of removing the waste and other aspects of emergency management.

  19. Toxic wastes discovered in Cecil County, MD

    SciTech Connect

    Not Available

    1994-01-01

    This report focuses on the clean-up activities following toxic waste contamination in Cecil County, MD. The potentially hazardous leakage from waste containers buried in a quarry was addressed before it was turned into a civil emergency of the magnitude of Love Canal. US Superfund is a federal government trust fund largely comprised of taxes on the chemical and petrochemical industries. Local governments share in the cost of removing the waste and other aspects of emergency management.

  20. Eva Szabo, MD | Division of Cancer Prevention

    Cancer.gov

    Dr. Eva Szabo is Chief of the Lung and Upper Aerodigestive Cancer Research Group at the NCI Division of Cancer Prevention. She graduated from Yale University with a BS in Molecular Biophysics and Biochemistry, received her MD from Duke University, and completed her internal medicine residency at Bellevue-NYU Medical Center. After completing her medical oncology fellowship at the National Cancer Institute, Dr. |

  1. Graphs for Isotopes of 101-Md (Mendelevium)

    NASA Astrophysics Data System (ADS)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Subvolume B `Nuclei with Z = 55 - 100' of Volume 22 `Nuclear Binding Energies and Atomic Masses' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms', and additionally including data for nuclei with Z = 101 - 130. It provides a graphic representation of nucleon separation energies and residual interaction parameters for isotopes of the chemical element 101-Md (Mendelevium, atomic number Z = 101).

  2. Five-Year Growth Trajectories of Kindergarten Children with Learning Difficulties in Mathematics

    ERIC Educational Resources Information Center

    Morgan, Paul L.; Farkas, George; Wu, Qiong

    2009-01-01

    The investigators used data from the "Early Childhood Longitudinal Study-Kindergarten Cohort" (ECLS-K) to estimate whether and to what extent the timing and persistence of mathematics difficulties (MD) in kindergarten predicted children's first through fifth grade math growth trajectories. Results indicated that children persistently…

  3. Trajectories of Alcohol Consumption Following Liver Transplantation

    PubMed Central

    DiMartini, Andrea; Dew, Mary Amanda; Day, Nancy; Fitzgerald, Mary Grace; Jones, Bobby L.; deVera, Michael; Fontes, Paulo

    2010-01-01

    Any use of alcohol in the years following liver transplantation (LTX) approaches 50% of patients transplanted for alcoholic liver disease (ALD). We collected detailed prospective data on alcohol consumption following LTX for ALD to investigate ongoing patterns of use. Using trajectory modeling we identified four distinct alcohol use trajectories. One group had minimal use over time. Two other groups developed early onset moderate to heavy consumption and one group developed late onset moderate use. These trajectories demonstrate that alcohol use varies based on timing of onset, quantity, and duration. Using discriminant function analysis, we examine characteristics of recipient’s pre-LTX alcohol histories and early post-LTX psychological stressors to identify the profile of those at risk for these specific trajectories. We discuss the relevance of these findings to clinical care and preliminarily to outcomes. PMID:20726963

  4. Trajectory tracking control for underactuated stratospheric airship

    NASA Astrophysics Data System (ADS)

    Zheng, Zewei; Huo, Wei; Wu, Zhe

    2012-10-01

    Stratospheric airship is a new kind of aerospace system which has attracted worldwide developing interests for its broad application prospects. Based on the trajectory linearization control (TLC) theory, a novel trajectory tracking control method for an underactuated stratospheric airship is presented in this paper. Firstly, the TLC theory is described sketchily, and the dynamic model of the stratospheric airship is introduced with kinematics and dynamics equations. Then, the trajectory tracking control strategy is deduced in detail. The designed control system possesses a cascaded structure which consists of desired attitude calculation, position control loop and attitude control loop. Two sub-loops are designed for the position and attitude control loops, respectively, including the kinematics control loop and dynamics control loop. Stability analysis shows that the controlled closed-loop system is exponentially stable. Finally, simulation results for the stratospheric airship to track typical trajectories are illustrated to verify effectiveness of the proposed approach.

  5. A study of QM/Langevin-MD simulation for oxygen-evolving center of photosystem II

    SciTech Connect

    Uchida, Waka; Kimura, Yoshiro; Wakabayashi, Masamitsu; Hatakeyama, Makoto; Ogata, Koji; Nakamura, Shinichiro; Yokojima, Satoshi

    2013-12-10

    We have performed three QM/Langevin-MD simulations for oxygen-evolving complex (OEC) and surrounding residues, which are different configurations of the oxidation numbers on Mn atoms in the Mn{sub 4}O{sub 5}Ca cluster. By analyzing these trajectories, we have observed sensitivity of the change to the configuration of Mn oxidation state on O atoms of carboxyl on three amino acids, Glu354, Ala344, and Glu333. The distances from Mn to O atoms in residues contacting with the Mn{sub 4}O{sub 5}Ca cluster were analyzed for the three trajectories. We found the good correlation of the distances among the simulations. However, the distances with Glu354, Ala344, and Glu333 have not shown the correlation. These residues can be sensitive index of the changes of Mn oxidation numbers.

  6. Three-phase permeabilities and other characteristics of 260-mD fired Berea

    SciTech Connect

    Maloney, D.; Brinkmeyer, A.

    1992-04-01

    A laboratory investigation was conducted to determine relative permeabilities and other characteristics of a 260-mD fired Berea sandstone. The mineralogical and physical characteristics of the sample were characterized by XRD tests, thin section analyses, mercury injection tests, and centrifuge capillary pressure and wettability tests. Two-phase oil/water relative permeabilities were measured under several stress conditions. Resistivity characteristics of the sample were also evaluated during several of the oil/water tests. Oil/gas and gas/water relative permeabilities were measured during steady-state tests. Three-phase steady-state oil/gas/water tests were performed for six DDI saturation trajectories (decreasing brine and oil saturations, increasing gas saturation) in which the sample was not cleaned between saturation trajectories.

  7. Loudon Park Substation. Violetville, Baltimore City, MD. Sec. 1201, MP ...

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

    Loudon Park Substation. Violetville, Baltimore City, MD. Sec. 1201, MP 100.50. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  8. B & P Tunnel west portal. Baltimore, Baltimore City, MD. ...

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

    B & P Tunnel west portal. Baltimore, Baltimore City, MD. Sec. 1201, MP 97.43. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  9. Bacon Hill Substation. Bacon Hill, Cecil Co., MD. Sec. 1201, ...

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

    Bacon Hill Substation. Bacon Hill, Cecil Co., MD. Sec. 1201, MP 48.50. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  10. Using Synoptic Systems' Typical Wind Trajectories for the Analysis of Potential Atmospheric Long-Distance Dispersal of Lumpy Skin Disease Virus.

    PubMed

    Klausner, Z; Fattal, E; Klement, E

    2017-04-01

    Lumpy skin disease virus (LSDV) is an infectious, arthropod-borne virus that affects mostly cattle. Solitary outbreaks have occurred in Israel in 1989 and 2006. In both years, the outbreaks occurred parallel to a severe outbreak in Egypt, and LSDV was hypothesized to be transmitted from Egypt to Israel via long-distance dispersal (LDD) of infected vectors by wind. The aim of this study was to identify possible events of such transport. At the first stage, we identified the relevant synoptic systems that allowed wind transport from Egypt to Israel during the 3 months preceding each outbreak. Three-dimensional backwards Lagrangian trajectories were calculated from the receptor sites in Israel for each occurrence of such relevant synoptic system. The analysis revealed several events in which atmospheric connection routes between the affected locations in Egypt and Israel were established. Specifically, during the 1989, Damietta and Port Said stand out as likely sources for the outbreak in Israel. In 2006, different locations acted simultaneously as potential sources of the outbreak in Israel. These locations were situated in the Nile delta, the Suez Canal and in northern Sinai. The analysis pointed out Sharav low and Shallow Cyprus low to the North to be the most likely systems to enable windborne transport from Egypt to Israel. These findings are of high importance for the analysis of the risk of transmission of vectorborne viruses in the eastern Mediterranean region.

  11. 75 FR 81125 - Drawbridge Operation Regulation; Sassafras River, Georgetown, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Sassafras River, Georgetown, MD... of the Sassafras River (Route 213) Bridge, mile 10.0, in Georgetown, MD. The deviation is necessary... Sassafras River Bridge (Route 213), at mile 10.0, in Georgetown, MD has a vertical clearance in the...

  12. 77 FR 5201 - Drawbridge Operation Regulation; Bear Creek, Dundalk, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Bear Creek, Dundalk, MD... across Bear Creek, mile 3.4, between Dundalk and Sparrows Point, MD. The proposed change will alter the... Avenue across Bear Creek, mile 3.4 between Dundalk and Sparrows Point, MD. This change would require...

  13. 77 FR 73967 - Drawbridge Operation Regulation; Bear Creek, Dundalk, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-12

    ... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Bear Creek, Dundalk, MD... highway bridge at Wise Avenue across Bear Creek, mile 3.4, between Dundalk and Sparrows Point, MD. The... Regulation; Bear Creek, Dundalk, MD'' in the Federal Register (77 FR 5201). The rulemaking concerned...

  14. Remains of abutments for Bridge No. 1575 at MD Rt. ...

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

    Remains of abutments for Bridge No. 1575 at MD Rt. 51 in Spring Gap, Maryland, looking northeast. (Compare with HAER MD-115 photos taken 1988). - Western Maryland Railway, Cumberland Extension, Pearre to North Branch, from WM milepost 125 to 160, Pearre, Washington County, MD

  15. 75 FR 54069 - Drawbridge Operation Regulations; Curtis Creek, Baltimore, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-03

    ...-2010-0265] RIN 1625--AA09 Drawbridge Operation Regulations; Curtis Creek, Baltimore, MD AGENCY: Coast....9, across Curtis Creek at Baltimore, MD. The requested change would have allowed the bridge to... Regulation Curtis Creek, Baltimore, MD'' in the Federal Register (75 FR 30747-30750). The...

  16. The fastest evolutionary trajectory

    PubMed Central

    Traulsen, Arne; Iwasa, Yoh; Nowak, Martin A.

    2008-01-01

    Given two mutants, A and B, separated by n mutational steps, what is the evolutionary trajectory which allows a homogeneous population of A to reach B in the shortest time? We show that the optimum evolutionary trajectory (fitness landscape) has the property that the relative fitness increase between any two consecutive steps is constant. Hence, the optimum fitness landscape between A and B is given by an exponential function. Our result is precise for small mutation rates and excluding back mutations. We discuss deviations for large mutation rates and including back mutations. For very large mutation rates, the optimum fitness landscape is flat and has a single peak at type B. PMID:17900629

  17. Wordom: a user-friendly program for the analysis of molecular structures, trajectories, and free energy surfaces.

    PubMed

    Seeber, Michele; Felline, Angelo; Raimondi, Francesco; Muff, Stefanie; Friedman, Ran; Rao, Francesco; Caflisch, Amedeo; Fanelli, Francesca

    2011-04-30

    Wordom is a versatile, user-friendly, and efficient program for manipulation and analysis of molecular structures and dynamics. The following new analysis modules have been added since the publication of the original Wordom paper in 2007: assignment of secondary structure, calculation of solvent accessible surfaces, elastic network model, motion cross correlations, protein structure network, shortest intra-molecular and inter-molecular communication paths, kinetic grouping analysis, and calculation of mincut-based free energy profiles. In addition, an interface with the Python scripting language has been built and the overall performance and user accessibility enhanced. The source code of Wordom (in the C programming language) as well as documentation for usage and further development are available as an open source package under the GNU General Purpose License from http://wordom.sf.net.

  18. Discovery of /sup 260/Md and the decay properties of /sup 258/Fm, /sup 258m,g/Md, and /sup 259/Md

    SciTech Connect

    Lougheed, R.W.; Hulet, E.K.; Dougan, R.J.; Wild, J.F.; Dupzyk, R.J.; Henderson, C.M.; Moody, K.J.; Hahn, R.L.; Suemmerer, K.; Bethune, G.

    1985-08-01

    We have discovered a new neutron-rich isotope, /sup 260/Md, from /sup 18/O and /sup 22/Ne bombardments of /sup 254/Es. We observed a spontaneous-fission (SF) activity with a 32-day half-life in electromagnetically separated mass-260 fractions from these bombardments and we have measured the mass and kinetic energy distributions of this SF activity. The mass distribution was symmetric with the principal energy peak at 234-MeV total kinetic energy (TKE), similar to previous observations for heavy Fm isotopes. Surprisingly, we also observed a smaller symmetric component with 195-MeV TKE. We interpret these two peaks in the TKE distribution as arising from two types of fission in the same nucleus, or bimodal fission. The observed fission activity may be either from the SF decay of /sup 260/Md or /sup 260/Fm which would arise from electron capture (EC) decay of /sup 260/Md. We have eliminated the possible ..beta../sup -/ decay of /sup 260/Md by measuring ..beta../sup -/-SF time correlations for the decay of /sup 260/Md and we plan to determine if /sup 260/Md decays by EC by measuring time correlations between Fm x-rays and SF events. We also measured properties for heavy Fm and Md isotopes which include: (1) more accurate cross sections for the neutron-rich Md isotopes which we use to predict the production rates of yet undiscovered nuclides; (2) improved half-live measurements for /sup 258m,g/Md and /sup 259/Md; (3) confirmation of the EC decay of /sup 258m/Md by measuring Fm x-rays preceding the SF decay of /sup 258/Fm; and (4) very substantially improved mass and TKE distributions for the SF decay of /sup 258/Fm and /sup 259/Md.

  19. Comparison of ER-2 Aircraft and POAM-III, MLS, and SAGE-II Satellite Measurements During SOLVE Using Traditional Correlative Analysis and Trajectory Hunting Technique

    NASA Technical Reports Server (NTRS)

    Danilin, M. Y.; Ko, Malcolm K. W.; Bevilacqua, R. M.; Lyjak, L. V.; Froidevaux, L.; Santee, M. L.; Zawodny, J. M.; Hoppel, K. W.; Richard, E. C.; Spackman, J. R.; Jackman, Charles H. (Technical Monitor)

    2001-01-01

    We compared the version 5 Microwave Limb Sounder (MLS) aboard the Upper Atmosphere Research Satellite (UARS), version 3 Polar Ozone and Aerosol Measurement-III (POAM-111) aboard the French satellite SPOT-IV, version 6.0 Stratospheric Aerosol and Gas Experiment 11 (SAGE-II) aboard the Earth Radiation Budget Satellite, and NASA ER-2 aircraft measurements made in the northern hemisphere in January-February 2000 during the SAGE III Ozone Loss and Validation Experiment (SOLVE). This study addresses one of the key scientific objectives of the SOLVE campaign, namely, to validate multi-platform satellite measurements made in the polar stratosphere during winter. This intercomparison was performed using a traditional correlative analysis (TCA) and a trajectory hunting technique (THT). Launching backward and forward trajectories from the points of measurement, the THT identifies air parcels sampled at least twice within a prescribed match criterion during the course of 5 days. We found that the ozone measurements made by these four instruments agree most of the time within 110% in the stratosphere up to 1400 K (approximately 35 km). The water vapor measurements from POAM-III and the ER-2 Harvard Lyman-alpha hygrometer and JPL laser hygrometer agree to within 10.5 ppmv (or about +/-10%) in the lower stratosphere above 380 K. The MLS and ER-2 ClO measurements agree within their error bars for the TCA. The MLS and ER-2 nitric acid measurements near 17-20 km altitude agree within their uncertainties most of the time with a hint of a positive offset by MLS according to the TCA. We also applied the AER box model constrained by the ER-2 measurements for analysis of the ClO and HN03 measurements using the THT. We found that: (1) the model values of ClO are smaller by about 0.3-0.4 (0.2) ppbv below (above) 400 K than those by MLS and (2) the HN03 comparison shows a positive offset of MLS values by approximately 1 and 1-2 ppbv below 400 K and near 450 K, respectively. It is hard to

  20. A trajectory analysis of atmospheric transport of black carbon aerosols to Canadian high Arctic in winter and spring (1990-2005)

    NASA Astrophysics Data System (ADS)

    Huang, L.; Gong, S. L.; Sharma, S.; Lavoué, D.; Jia, C. Q.

    2010-06-01

    Black carbon (BC) particles accumulated in the Arctic troposphere and deposited on snow have been calculated to have significant effects on radiative forcing of the Arctic regional climate. Applying cluster analysis technique on 10-day backward trajectories, seven distinct transport pathways (or clusters) affecting Alert (82.5° N, 62.5° W), Nunavut in Canada are identified in this work. Transport frequency associated with each pathway is obtained as the fraction of trajectories in that cluster. Based on atmospheric transport frequency and BC surface flux from surrounding regions (i.e. North America, Europe, and former USSR), a linear regression model is constructed to investigate the inter-annual variations of BC observed at Alert in January and April, representative of winter and spring respectively, between 1990 and 2005. Strong correlations are found between BC concentrations predicted with the regression model and measurements at Alert for both seasons (R2 equals 0.77 and 0.81 for winter and spring, respectively). Results imply that atmospheric transport and BC emission are the major contributors to the inter-annual variations in BC concentrations observed at Alert in the cold seasons for the 16-year period. Other factors, such as deposition, could also contribute to the variability in BC concentrations but were not considered in this analysis. Based on the regression model the relative contributions of regional BC emissions affecting Alert are attributed to the Eurasian sector, composed of the European Union and the former USSR, and the North American sector. Considering both seasons, the model suggests that former USSR is the major contributor to the near-surface BC levels at the Canadian high Arctic site with an average contribution of about 67% during the 16-year period, followed by European Union (18%) and North America (15%). In winter, the atmospheric transport of BC aerosols from Eurasia is found to be even more predominant with a multi-year average

  1. A trajectory analysis of atmospheric transport of black carbon aerosols to Canadian high Arctic in winter and spring (1990-2005)

    NASA Astrophysics Data System (ADS)

    Huang, L.; Gong, S.; Sharma, S.; Lavoue, D.; Jia, C. Q.

    2010-12-01

    Black carbon (BC) particles accumulated in the Arctic troposphere and deposited on snow have been calculated to have significant effects on radiative forcing of the Arctic regional climate. Applying cluster analysis technique on 10-day backward trajectories, seven distinct transport pathways (or clusters) affecting Alert (82.5° N, 62.5° W), Nunavut in Canada are identified in this work. Transport frequency associated with each pathway is obtained as the fraction of trajectories in that cluster. Based on atmospheric transport frequency and BC surface flux from surrounding regions (i.e. North America, Europe, and former USSR), a linear regression model is constructed to investigate the inter-annual variations of BC observed at Alert in January and April, representative of winter and spring respectively, between 1990 and 2005. Strong correlations are found between BC concentrations predicted with the regression model and measurements at Alert for both seasons (R2 equals 0.77 and 0.81 for winter and spring, respectively). Results imply that atmospheric transport and BC emission are the major contributors to the inter-annual variations in BC concentrations observed at Alert in the cold seasons for the 16-year period. Other factors, such as deposition, could also contribute to the variability in BC concentrations but were not considered in this analysis. Based on the regression model the relative contributions of regional BC emissions affecting Alert are attributed to the Eurasian sector, composed of the European Union and the former USSR, and the North American sector. Considering both seasons, the model suggests that former USSR is the major contributor to the near-surface BC levels at the Canadian high Arctic site with an average contribution of about 67% during the 16-year period, followed by European Union (18%) and North America (15%). In winter, the atmospheric transport of BC aerosols from Eurasia is found to be even more predominant with a multi-year average

  2. Self-Esteem Trajectories among Ethnic Minority Adolescents: A Growth Curve Analysis of the Patterns and Predictors of Change

    ERIC Educational Resources Information Center

    Greene, Melissa L.; Way, Niobe

    2005-01-01

    The current study presents a growth curve analysis of self-esteem among Black, Latino, and Asian American high school students. A series of hierarchical linear models were used to examine patterns and predictors of change in self-esteem over time. Results revealed an average increase in self-esteem with age. Although boys and girls experienced…

  3. Optimizing interplanetary trajectories with deep space maneuvers

    NASA Astrophysics Data System (ADS)

    Navagh, John

    1993-09-01

    Analysis of interplanetary trajectories is a crucial area for both manned and unmanned missions of the Space Exploration Initiative. A deep space maneuver (DSM) can improve a trajectory in much the same way as a planetary swingby. However, instead of using a gravitational field to alter the trajectory, the on-board propulsion system of the spacecraft is used when the vehicle is not near a planet. The purpose is to develop an algorithm to determine where and when to use deep space maneuvers to reduce the cost of a trajectory. The approach taken to solve this problem uses primer vector theory in combination with a non-linear optimizing program to minimize Delta(V). A set of necessary conditions on the primer vector is shown to indicate whether a deep space maneuver will be beneficial. Deep space maneuvers are applied to a round trip mission to Mars to determine their effect on the launch opportunities. Other studies which were performed include cycler trajectories and Mars mission abort scenarios. It was found that the software developed was able to locate quickly DSM's which lower the total Delta(V) on these trajectories.

  4. Patched Conic Trajectory Code

    NASA Technical Reports Server (NTRS)

    Park, Brooke Anderson; Wright, Henry

    2012-01-01

    PatCon code was developed to help mission designers run trade studies on launch and arrival times for any given planet. Initially developed in Fortran, the required inputs included launch date, arrival date, and other orbital parameters of the launch planet and arrival planets at the given dates. These parameters include the position of the planets, the eccentricity, semi-major axes, argument of periapsis, ascending node, and inclination of the planets. With these inputs, a patched conic approximation is used to determine the trajectory. The patched conic approximation divides the planetary mission into three parts: (1) the departure phase, in which the two relevant bodies are Earth and the spacecraft, and where the trajectory is a departure hyperbola with Earth at the focus; (2) the cruise phase, in which the two bodies are the Sun and the spacecraft, and where the trajectory is a transfer ellipse with the Sun at the focus; and (3) the arrival phase, in which the two bodies are the target planet and the spacecraft, where the trajectory is an arrival hyperbola with the planet as the focus.

  5. Trajectory structures and transport

    SciTech Connect

    Vlad, Madalina; Spineanu, Florin

    2004-11-01

    The special problem of transport in two-dimensional divergence-free stochastic velocity fields is studied by developing a statistical approach, the nested subensemble method. The nonlinear process of trapping determined by such fields generates trajectory structures whose statistical characteristics are determined. These structures strongly influence the transport.

  6. General order parameter based correlation analysis of protein backbone motions between experimental NMR relaxation measurements and molecular dynamics simulations.

    PubMed

    Liu, Qing; Shi, Chaowei; Yu, Lu; Zhang, Longhua; Xiong, Ying; Tian, Changlin

    2015-02-13

    Internal backbone dynamic motions are essential for different protein functions and occur on a wide range of time scales, from femtoseconds to seconds. Molecular dynamic (MD) simulations and nuclear magnetic resonance (NMR) spin relaxation measurements are valuable tools to gain access to fast (nanosecond) internal motions. However, there exist few reports on correlation analysis between MD and NMR relaxation data. Here, backbone relaxation measurements of (15)N-labeled SH3 (Src homology 3) domain proteins in aqueous buffer were used to generate general order parameters (S(2)) using a model-free approach. Simultaneously, 80 ns MD simulations of SH3 domain proteins in a defined hydrated box at neutral pH were conducted and the general order parameters (S(2)) were derived from the MD trajectory. Correlation analysis using the Gromos force field indicated that S(2) values from NMR relaxation measurements and MD simulations were significantly different. MD simulations were performed on models with different charge states for three histidine residues, and with different water models, which were SPC (simple point charge) water model and SPC/E (extended simple point charge) water model. S(2) parameters from MD simulations with charges for all three histidines and with the SPC/E water model correlated well with S(2) calculated from the experimental NMR relaxation measurements, in a site-specific manner.

  7. Gordon Fullerton in PCA (MD-11) Simulator

    NASA Technical Reports Server (NTRS)

    1998-01-01

    NASA research pilot Gordon Fullerton 'flying' in the MD-11 simulator during the Propulsion Controlled Aircraft (PCA) project. This investigation grew out of the crash of a DC-10 airliner on July 19, 1989, following an explosion in the rear engine which caused the loss of all manual flight controls. The flight crew attempted to control the airliner using only the thrust from the two remaining engines. Although the DC-10 crashed during the landing attempt, 184 of the 296 passengers and crew aboard survived. The PCA effort at the Dryden Flight Research Center grew out of the crash, and attempted to develop a means to successfully land an aircraft using only engine thrust. After more than five years of work, on August 29, 1995, Gordon Fullerton made the first PCA touchdown aboard an MD-11 airliner (a later version of the DC-10). The concept was further refined over the years that followed this first landing. Simulators were essential ingredients of the PCA development process. The feasibility of the concept was first tested with an F-15 simulator, then the results of actual flight tests in an F-15 were incorporated back into the simulator. Additional simulations were run on the Boeing 720 airliner simulator used in the Controlled Impact Demonstration project. After the MD-11 test landings, Boeing 747 and 757 simulators tested a wide range of possible situations. Simulations even helped develop a method of landing an airliner if it lost its complete hydraulic system as well as a wing engine, by transferring fuel to shift the center of gravity toward the working engine. The most extreme procedure was undertaken in a 747 simulator. The aircraft simulated the loss of the hydraulic system at 35,000 feet and rolled upside down. Then, the PCA mode was engaged, the airliner righted itself, leveled its wings, and made an approach nearly identical to that of a normal auto landing.

  8. Orlando C. Kirton, MD, FACS, FCCM, FCCP.

    PubMed Central

    Pyrtek, Ludwig J.

    2007-01-01

    The chair is named for Ludwig J. Pyrtek, MD, an esteemed surgeon at Hartford Hospital, who was devoted to the care of his patients and was an outstanding educator within his chosen field. A unique aspect of the chair is that its income is not used to support the salary of the director but is used to enhance the education activities of the department, such as the purchasing of state-of-the-art teaching devices, support of surgical resident research activities, educational travel for residents and honoraria for nationally/internationally known clinicians/scientists to speak at grand rounds. Images p1420-a PMID:18229781

  9. Orlando C. Kirton, MD, FACS, FCCM, FCCP.

    PubMed

    Pyrtek, Ludwig J

    2007-12-01

    The chair is named for Ludwig J. Pyrtek, MD, an esteemed surgeon at Hartford Hospital, who was devoted to the care of his patients and was an outstanding educator within his chosen field. A unique aspect of the chair is that its income is not used to support the salary of the director but is used to enhance the education activities of the department, such as the purchasing of state-of-the-art teaching devices, support of surgical resident research activities, educational travel for residents and honoraria for nationally/internationally known clinicians/scientists to speak at grand rounds.

  10. IRVE-II Post-Flight Trajectory Reconstruction

    NASA Technical Reports Server (NTRS)

    O'Keefe, Stephen A.; Bose, David M.

    2010-01-01

    NASA s Inflatable Re-entry Vehicle Experiment (IRVE) II successfully demonstrated an inflatable aerodynamic decelerator after being launched aboard a sounding rocket from Wallops Flight Facility (WFF). Preliminary day of flight data compared well with pre-flight Monte Carlo analysis, and a more complete trajectory reconstruction performed with an Extended Kalman Filter (EKF) approach followed. The reconstructed trajectory and comparisons to an attitude solution provided by NASA Sounding Rocket Operations Contract (NSROC) personnel at WFF are presented. Additional comparisons are made between the reconstructed trajectory and pre and post-flight Monte Carlo trajectory predictions. Alternative observations of the trajectory are summarized which leverage flight accelerometer measurements, the pre-flight aerodynamic database, and on-board flight video. Finally, analysis of the payload separation and aeroshell deployment events are presented. The flight trajectory is reconstructed to fidelity sufficient to assess overall project objectives related to flight dynamics and overall, IRVE-II flight dynamics are in line with expectations

  11. Huygens probe entry, descent, and landing trajectory reconstruction using the Program to Optimize Simulated Trajectories II

    NASA Astrophysics Data System (ADS)

    Striepe, Scott Allen

    The objectives of this research were to develop a reconstruction capability using the Program to Optimize Simulated Trajectories II (POST2), apply this capability to reconstruct the Huygens Titan probe entry, descent, and landing (EDL) trajectory, evaluate the newly developed POST2 reconstruction module, analyze the reconstructed trajectory, and assess the pre-flight simulation models used for Huygens EDL simulation. An extended Kalman filter (EKF) module was developed and integrated into POST2 to enable trajectory reconstruction (especially when using POST2-based mission specific simulations). Several validation cases, ranging from a single, constant parameter estimate to multivariable estimation cases similar to an actual mission flight, were executed to test the POST2 reconstruction module. Trajectory reconstruction of the Huygens entry probe at Titan was accomplished using accelerometer measurements taken during flight to adjust an estimated state (e.g., position, velocity, parachute drag, wind velocity, etc.) in a POST2-based simulation developed to support EDL analyses and design prior to entry. Although the main emphasis of the trajectory reconstruction was to evaluate models used in the NASA pre-entry trajectory simulation, the resulting reconstructed trajectory was also assessed to provide an independent evaluation of the ESA result. Major findings from this analysis include: Altitude profiles from this analysis agree well with other NASA and ESA results but not with Radar data, whereas a scale factor of about 0.93 would bring the radar measurements into compliance with these results; entry capsule aerodynamics predictions (axial component only) were well within 3-sigma bounds established pre-flight for most of the entry when compared to reconstructed values; Main parachute drag of 9% to 19% above ESA model was determined from the reconstructed trajectory; based on the tilt sensor and accelerometer data, the conclusion from this assessment was that the

  12. Five-year growth trajectories of kindergarten children with learning difficulties in mathematics.

    PubMed

    Morgan, Paul L; Farkas, George; Qiong Wu

    2009-01-01

    The investigators used data from the Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K) to estimate whether and to what extent the timing and persistence of mathematics difficulties (MD) in kindergarten predicted children's first through fifth grade math growth trajectories. Results indicated that children persistently displaying MD (i.e., those experiencing MD in both fall and spring of kindergarten) had the lowest subsequent growth rates, children with MD in spring only had the second-lowest growth rates, and children with MD in the fall only (and who had thus recovered from their MD by the spring of kindergarten) had the next-lowest growth rates. The children who did not have MD in either fall or spring of kindergarten had the highest growth rates. These results were observed prior to and after statistical control for additional variables. They indicate that measuring the timing and persistence of kindergarten children's mathematics learning difficulties may help identify those most at risk for failing to become mathematically proficient during elementary school.

  13. Scout trajectory error propagation computer program

    NASA Technical Reports Server (NTRS)

    Myler, T. R.

    1982-01-01

    Since 1969, flight experience has been used as the basis for predicting Scout orbital accuracy. The data used for calculating the accuracy consists of errors in the trajectory parameters (altitude, velocity, etc.) at stage burnout as observed on Scout flights. Approximately 50 sets of errors are used in Monte Carlo analysis to generate error statistics in the trajectory parameters. A covariance matrix is formed which may be propagated in time. The mechanization of this process resulted in computer program Scout Trajectory Error Propagation (STEP) and is described herein. Computer program STEP may be used in conjunction with the Statistical Orbital Analysis Routine to generate accuracy in the orbit parameters (apogee, perigee, inclination, etc.) based upon flight experience.

  14. Influence of injector geometry on particle trajectories: Analysis of particle dynamics in the injector and plasma jet

    SciTech Connect

    Vardelle, M.; Vardelle, A.; Dussoubs, B.; Fauchais, P.; Roemer, T.S.; Neiser, R.A.; Smith, M.F.

    1998-11-01

    The conditions of particle injection into the side of plasma jets play an important role in determining the microstructure and properties of sprayed deposits. However, few investigations have been carried out on this topic. The current work presents the results of an experimental and computational study of the influence of injector geometry and gas mass flow rate on particle dynamics at injector exit and in the plasma jet. Two injector geometries were tested: a straight tube and a curved tube with various radii of curvature. Zirconia powders with different particle size range and morphology were used. A possible size segregation effect in the injector was analyzed from the space distribution of particles collected on a stick tape. The spray patterns in the plasma jet was monitored from the thermal radiation emitted by particles. An analysis of the particle behavior in the injector and mixing of the carrier-gas flow with the plasma jet was carried out using a 3-D computational fluids dynamics code.

  15. Dissipative Bohmian mechanics within the Caldirola–Kanai framework: A trajectory analysis of wave-packet dynamics in viscid media

    SciTech Connect

    Sanz, A.S.; Martínez-Casado, R.; Peñate-Rodríguez, H.C.; Rojas-Lorenzo, G.; Miret-Artés, S.

    2014-08-15

    Classical viscid media are quite common in our everyday life. However, we are not used to find such media in quantum mechanics, and much less to analyze their effects on the dynamics of quantum systems. In this regard, the Caldirola–Kanai time-dependent Hamiltonian constitutes an appealing model, accounting for friction without including environmental fluctuations (as it happens, for example, with quantum Brownian motion). Here, a Bohmian analysis of the associated friction dynamics is provided in order to understand how a hypothetical, purely quantum viscid medium would act on a wave packet from a (quantum) hydrodynamic viewpoint. To this purpose, a series of paradigmatic contexts have been chosen, such as the free particle, the motion under the action of a linear potential, the harmonic oscillator, or the superposition of two coherent wave packets. Apart from their analyticity, these examples illustrate interesting emerging behaviors, such as localization by “quantum freezing” or a particular type of quantum–classical correspondence. The reliability of the results analytically determined has been checked by means of numerical simulations, which has served to investigate other problems lacking of such analyticity (e.g., the coherent superpositions). - Highlights: • A dissipative Bohmian approach is developed within the Caldirola–Kanai model. • Some simple yet physically insightful systems are then studied analytically. • Dissipation leads to spatial localization in free-force regimes. • Under the action of linear forces, dissipation leads to uniform motion. • In harmonic potentials, the system decays unavoidable to the well minimum.

  16. Developmental trajectories in toddlers' self-restraint predict individual differences in executive functions 14 years later: a behavioral genetic analysis.

    PubMed

    Friedman, Naomi P; Miyake, Akira; Robinson, JoAnn L; Hewitt, John K

    2011-09-01

    We examined whether self-restraint in early childhood predicted individual differences in 3 executive functions (EFs; inhibiting prepotent responses, updating working memory, and shifting task sets) in late adolescence in a sample of approximately 950 twins. At ages 14, 20, 24, and 36 months, the children were shown an attractive toy and told not to touch it for 30 s. Latency to touch the toy increased with age, and latent class growth modeling distinguished 2 groups of children that differed in their latencies to touch the toy at all 4 time points. Using confirmatory factor analysis, we decomposed the 3 EFs (measured with latent variables at age 17 years) into a Common EF factor (isomorphic to response inhibition ability) and 2 factors specific to updating and shifting. Less-restrained children had significantly lower scores on the Common EF factor, equivalent scores on the Updating-Specific factor, and higher scores on the Shifting-Specific factor than did the more-restrained children. The less-restrained group also had lower IQ scores, but this effect was entirely mediated by the EF components. Twin models indicated that the associations were primarily genetic in origin for the Common EF variable but split between genetics and nonshared environment for the Shifting-Specific variable. These results suggest a biological relation between individual differences in self-restraint and EFs, one that begins early in life and persists into late adolescence.

  17. Growth Trajectories of Health Behaviors from Adolescence through Young Adulthood

    PubMed Central

    Wiium, Nora; Breivik, Kyrre; Wold, Bente

    2015-01-01

    Based on nine waves of data collected during a period of 17 years (1990–2007), the present study explored different developmental trajectories of the following unhealthy behaviors: regular smoking, lack of regular exercise, lack of daily fruit intake, and drunkenness. A baseline sample of 1195 13-year-old pupils was from 22 randomly selected schools in the Hordaland County in western Norway. Latent class growth analysis revealed three developmental trajectories. The first trajectory was a conventional trajectory, comprising 36.3% of participants, who showed changes in smoking, physical exercise, fruit intake, and drunkenness consistent with the prevailing age specific norms of these behaviors in the Norwegian society at the time. The second trajectory was a passive trajectory, comprising 25.5% of participants, who reported low levels of both healthy and unhealthy behaviors during the 17-year period. The third trajectory was an unhealthy trajectory, comprising 38.2% of participants, who had high levels of unhealthy behaviors over time. Several covariates were examined, but only sex and mother’s and father’s educational levels were found to be significantly associated with the identified trajectories. While these findings need to be replicated in future studies, the identification of the different trajectories suggests the need to tailor intervention according to specific needs. PMID:26516889

  18. Trajectory Code Studies, 1987

    SciTech Connect

    Poukey, J.W.

    1988-01-01

    The trajectory code TRAJ has been used extensively to study nonimmersed foilless electron diodes. The basic goal of the research is to design low-emittance injectors for electron linacs and propagation experiments. Systems studied during 1987 include Delphi, Recirc, and Troll. We also discuss a partly successful attempt to extend the same techniques to high currents (tens of kA). 7 refs., 30 figs.

  19. Surrealistic Bohm Trajectories

    NASA Astrophysics Data System (ADS)

    Englert, Berthold-Georg; Scully, Marian O.; Süssmann, Georg; Walther, Herbert

    1992-12-01

    A study of interferometers with one-bit which-way detectors demonstrates that the trajectories, which David Bohm invented in his attempt at a realistic interpretation of quantum mechanics, are in fact surrealistic, because they may be macroscopically at variance with the observed track of the particle. We consider a two-slit interferometer and an incomplete Stern-Gerlach interferometer, and propose an experimentum crucis based on the latter.

  20. Flight Trajectory Control Investigation

    DTIC Science & Technology

    1981-03-01

    control algorithms for four-dimensional guidance of a transport air- craft were investigated for feasibility. Cost function constraints on the ptimal...21 3.1.6 Solution Constraints .... ............. ... 25 3.1.7 Trajectory Generator Review .. ......... .. 25 3.2 OPTIMAl CONTROLLER ALGORITHM...value formulation to a six-degree-of-freedom point mass aircraft with all the structural, maneuver, and mission constraints accounted for by using pelalty

  1. Modern precipitation δ18O and trajectory analysis over the Himalaya-Tibet Orogen from ECHAM5-wiso simulations

    NASA Astrophysics Data System (ADS)

    Li, Jingmin; Ehlers, Todd A.; Mutz, Sebastian G.; Steger, Christian; Paeth, Heiko; Werner, Martin; Poulsen, Christopher J.; Feng, Ran

    2016-09-01

    Variations in oxygen isotope ratios (δ18O) measured from modern precipitation and geologic archives provide a promising tool for understanding modern and past climate dynamics and tracking elevation changes over geologic time. In areas of extreme topography, such as the Tibetan Plateau, the interpretation of δ18O has proven challenging. This study investigates the climate controls on temporal (daily and 6 h intervals) and spatial variations in present-day precipitation δ18O (δ18Op) across the Tibetan Plateau using a 30 year record produced from the European Centre/Hamburg ECHAM5-wiso global atmospheric general circulation model (GCM). Results indicate spatial and temporal agreement between model-predicted δ18Op and observations. Large daily δ18Op variations of -25 to +5‰ occur over the Tibetan Plateau throughout the 30 simulation years, along with interannual δ18Op variations of 2‰. Analysis of extreme daily δ18Op indicates that extreme low values coincide with extreme highs in precipitation amount. During the summer, monsoon vapor transport from the north and southwest of the plateau generally corresponds with high δ18Op, whereas vapor transport from the Indian Ocean corresponds with average to low δ18Op. Thus, vapor source variations are one important cause of the spatial-temporal differences in δ18Op. Comparison of GCM and Rayleigh Distillation Model (RDM)-predicted δ18Op indicates a modest agreement for the Himalaya region (averaged over 86°-94°E), confirming application of the simpler RDM approach for estimating δ18Op lapse rates across Himalaya.

  2. Combined trajectory clustering and aerosol fields analysis to evaluate the potential emission flux to aerosol pollutants in an urban and semi-urban atmospheres in eastern India

    NASA Astrophysics Data System (ADS)

    Kumar, B. D.; Verma, S.

    2015-12-01

    A hybrid source-receptor analysis was carried out to evaluate the potential emission flux to winter monsoon (WinMon) aerosols over eastern India urban (Kolkata, Kol) and semi-urban atmospheres (Kharagpur, Kgp). This was done through application of fuzzy c-mean clustering to back-trajectory data combined with emission flux and residence time weighted aerosols analysis. WinMon mean aerosol optical depth (AOD) and angstrom exponent (AE) at Kol were respectively slightly higher than and nearly equal to that at Kgp. Out of six source region clusters over Indian subcontinent and two over Indian oceanic region, the cluster mean AOD was the highest when associated with the mean path of air mass originating from the Bay of Bengal (BoB) and the Arabian sea (AS) clusters at Kol and that from the Indo-Gangetic plain (IGP)cluster at Kgp. Spatial distribution of weighted AOD fields showed the highest potential source of aerosols over the IGP, majorly over upper IGP (IGP-U), lower IGP (IGP-L) and eastern region (ER) clusters. The emission flux contribution potential (EFCP) of fossil fuel (FF) emissions at surface (SL) of Kol/Kgp , elevated layer (EL) of Kol, and of biomass burning (BB) emissions at SL of Kol were majorly from IGP-U, IGP-L and IGP-U/L clusters respectively. The EFCP of FF/BB emissions at Kgp-EL/SL, and that of BB at EL of Kol/Kgp were mainly from ER and Africa (AFR) clusters respectively. Though the AFR cluster was constituted of significantly high emission flux source potential of dust emissions, the EFCP of dust from NWI was comparable to that from AFR at Kol SL/EL.

  3. On-line measurements of sulfur dioxide at the 3 km level over central Europe (Sonnblick observatory, Austria) and statistical trajectory source analysis

    NASA Astrophysics Data System (ADS)

    Tscherwenka, W.; Seibert, P.; Kasper, A.; Puxbaum, H.

    Continuous sulfur dioxide (SO 2) measurements were performed at the Sonnblick Observatory (SBO), Austria (3106 m a.s.l.) for several weeks during summer, autumn and spring 1995/96. The average SO 2 concentration was 0.30 μg m -3 standard temperature and pressure (STP; 273 K, 1013 hPa) (105 pptv), the median 0.10 μg m -3 STP (35 pptv). For 80% of the time sulfur dioxide concentrations were at "clean levels" (<0.30 μg m -3) interrupted by "episodes" lasting up to two days. During the episodes SO 2 levels rose generally above 0.5 μg m -3 and reached up to 8.0 μg m -3 in spring. Sulfur dioxide concentrations showed a strong seasonal variation with very low concentrations during summer and fall (means 0.11 and 0.17 μg m -3) and elevated concentrations during spring (mean 0.70 μg m -3). An analysis of the diurnal variation indicated that upslope winds are not responsible for the elevated SO 2 levels observed during SO 2 episodes; rather cloud transport appears to be the predominant process for lifting SO 2 from the boundary layer to the mid troposphere. For air and cloud transport across Western European countries hydrogen peroxide (H 2O 2) is apparently in excess and most SO 2 is removed by oxidation leading to "clean conditions". For the less frequent air and cloud transport from the East and Southeast SO 2 appears to be in excess leading to the "SO 2 episodes" at the 3 km level. These results are substantiated by in-cloud observations of elevated levels of SO 2 at SBO ( Brantner et al., 1994) and trajectory statistics for the SO 2 data set from SBO and analysis of the meteorological conditions during transport.

  4. Thrusters Pairing Guidelines for Trajectory Corrections of Projectiles

    DTIC Science & Technology

    2011-01-12

    distance traveled along flight path, cal V = projectile velocity, m s1 = pitch angle , rad = total incidence angle , rad = yaw angle , rad S, F...3) M Ad 3 2Iy CM (4) T Ad 2m CL md2 Ix CMp (5) Figure 1 shows that the complex incidence angle is the plane projection of the total... angle of attack. As the projectile travels along the trajectory, the complex incidence traces out a series of loops in the pitch-yaw plane, which is

  5. Interview with Steven J. Levin, MD.

    PubMed

    Levin, S J

    1997-11-01

    Steven J. Levin, MD, is the only full-time physician at St. John's Health Center in New Brunswick. The Center provides primary medical services to 3,000 uninsured people and has a waiting list of almost 600 more. Levin's workdays are consumed by procuring free medications, treating patients who are poor and possibly homeless, arranging specialty consults, seeking out grants and equipment donations, and training medical students. The family physician also helped create a statefunded sexually transmitted diseases clinic, a home safety program for inner-city children, a Latino diabetes support group, and a computer database to track indigent patients in need of immunizations and other followup services. St. John's is run under an arrangement with Catholic Charities, UMDNJ-Robert Wood Johnson Medical School, and St. Peter's Medical Center.

  6. Ashley W. Oughterson, MD: Surgeon, Soldier, Leader

    PubMed Central

    Kunstman, John W.; Longo, Walter E.

    2015-01-01

    Ashley W. Oughterson, MD, (1895-1956) was a longtime faculty surgeon at Yale University. He performed some of the earliest pancreatic resections in the United States. During World War II, Colonel Oughterson was the primary “Surgical Consultant” in the South Pacific and present at nearly every major battle. His meticulously kept diary is regarded as the foremost source detailing wartime surgical care. Colonel Oughterson led the initial Army team to survey Hiroshima and Nagasaki following the nuclear attacks. Thoughout his academic career at Yale, Oughterson was a key leader in several medical and surgical societies. As scientific director of the American Cancer Society, Oughterson lectured widely and guided research priorities in oncology following World War II. Oughterson also authored numerous benchmark papers in surgical oncology that continue to be cited today. These extensive contributions are examined here and demonstrate the wide-ranging impact Oughterson exerted during a formative period of American surgery. PMID:26029018

  7. On air motion trajectories in cold fronts

    NASA Technical Reports Server (NTRS)

    Reeder, Michael J.; Smith, Roger K.

    1988-01-01

    This paper examines air parcel trajectories in the two-dimensional model for a cold front by Reeder and Smith (1987). These are found to be in close agreement with trajectories deduced from analyses of summertime 'cool changes' in southeastern Australia, adding further support to the applicability of the numerical model to this kind of cold front. The favorable comparison points also to the dynamical consistency of the conceptual model for the cool change, which has evolved from the analysis of data from observational experiments.

  8. Posttraumatic stress symptoms and trajectories in child sexual abuse victims: an analysis of sex differences using the national survey of child and adolescent well-being.

    PubMed

    Maikovich, Andrea Kohn; Koenen, Karestan C; Jaffee, Sara R

    2009-07-01

    Very few studies have prospectively examined sex differences in posttraumatic stress symptoms and symptom trajectories in youth victimized by childhood sexual abuse. This study addresses that question in a relatively large sample of children, drawn from the National Survey of Child and Adolescent Well-Being, who were between the ages of 8-16 years and who were reported to Child Protective Services for alleged sexual abuse. Sex differences were examined using t tests, logistic regression, and latent trajectory modeling. Results revealed that there were not sex differences in victims' posttraumatic stress symptoms or trajectories. Whereas caseworkers substantiated girls' abuse at higher rates than boys' abuse and rated girls significantly higher than boys on level of harm, there were not sex differences in three more objective measures of abuse severity characteristics. Overall, higher caseworker ratings of harm predicted higher initial posttraumatic stress symptom levels, and substantiation status predicted shallower decreases in trauma symptoms over time. Implications for theory and intervention are discussed.

  9. How do we deal with multiple goals for care within an individual patient trajectory? A document content analysis of health service research papers on goals for care

    PubMed Central

    Berntsen, G K R; Gammon, D; Steinsbekk, A; Salamonsen, A; Foss, N; Ruland, C; Fønnebø, V

    2015-01-01

    Objectives Patients with complex long-term needs experience multiple parallel care processes, which may have conflicting or competing goals, within their individual patient trajectory (iPT). The alignment of multiple goals is often implicit or non-existent, and has received little attention in the literature. Research questions: (1) What goals for care relevant for the iPT can be identified from the literature? (2) What goal typology can be proposed based on goal characteristics? (3) How can professionals negotiate a consistent set of goals for the iPT? Design Document content analysis of health service research papers, on the topic of ‘goals for care’. Setting With the increasing prevalence of multimorbidity, guidance regarding the identification and alignment of goals for care across organisations and disciplines is urgently needed. Participants 70 papers that describe ‘goals for care’, ‘health’ or ‘the good healthcare process’ relevant to a general iPT, identified in a step-wise structured search of MEDLINE, Web of Science and Google Scholar. Results We developed a goal typology with four categories. Three categories are professionally defined: (1) Functional, (2) Biological/Disease and (3) Adaptive goals. The fourth category is the patient's personally defined goals. Professional and personal goals may conflict, in which case goal prioritisation by creation of a goal hierarchy can be useful. We argue that the patient has the moral and legal right to determine the goals at the top of such a goal hierarchy. Professionals can then translate personal goals into realistic professional goals such as standardised health outcomes linked to evidence-based guidelines. Thereby, when goals are aligned with one another, the iPT will be truly patient centred, while care follows professional guidelines. Conclusions Personal goals direct professional goals and define the success criteria of the iPT. However, making personal goals count requires brave and wide

  10. Robust Classification of Small-Molecule Mechanism of Action Using a Minimalist High-Content Microscopy Screen and Multidimensional Phenotypic Trajectory Analysis.

    PubMed

    Twarog, Nathaniel R; Low, Jonathan A; Currier, Duane G; Miller, Greg; Chen, Taosheng; Shelat, Anang A

    2016-01-01

    Phenotypic screening through high-content automated microscopy is a powerful tool for evaluating the mechanism of action of candidate therapeutics. Despite more than a decade of development, however, high content assays have yielded mixed results, identifying robust phenotypes in only a small subset of compound classes. This has led to a combinatorial explosion of assay techniques, analyzing cellular phenotypes across dozens of assays with hundreds of measurements. Here, using a minimalist three-stain assay and only 23 basic cellular measurements, we developed an analytical approach that leverages informative dimensions extracted by linear discriminant analysis to evaluate similarity between the phenotypic trajectories of different compounds in response to a range of doses. This method enabled us to visualize biologically-interpretable phenotypic tracks populated by compounds of similar mechanism of action, cluster compounds according to phenotypic similarity, and classify novel compounds by comparing them to phenotypically active exemplars. Hierarchical clustering applied to 154 compounds from over a dozen different mechanistic classes demonstrated tight agreement with published compound mechanism classification. Using 11 phenotypically active mechanism classes, classification was performed on all 154 compounds: 78% were correctly identified as belonging to one of the 11 exemplar classes or to a different unspecified class, with accuracy increasing to 89% when less phenotypically active compounds were excluded. Importantly, several apparent clustering and classification failures, including rigosertib and 5-fluoro-2'-deoxycytidine, instead revealed more complex mechanisms or off-target effects verified by more recent publications. These results show that a simple, easily replicated, minimalist high-content assay can reveal subtle variations in the cellular phenotype induced by compounds and can correctly predict mechanism of action, as long as the appropriate

  11. A trajectory analysis of atmospheric transport of black carbon aerosols to Canadian High Arctic in winter and spring (1990-2005)

    NASA Astrophysics Data System (ADS)

    Huang, L.; Gong, S. L.; Sharma, S.; Lavoué, D.; Jia, C. Q.

    2010-02-01

    Black carbon (BC) particles accumulated in the Arctic troposphere and deposited over snow have significant effects on radiative forcing of the Arctic regional climate. Applying cluster analysis technique on 10-day backward trajectories, transport pathways affecting Alert (82.5° N, 62.5° W), Nunavut in Canada are identified in this work, along with the associated transport frequency. Based on the atmospheric transport frequency and the estimated BC emission intensity from surrounding regions, a linear regression model is constructed to investigate the inter-annual variations of BC observed at Alert in January and April, representative of winter and spring respectively, between 1990 and 2005. Strong correlations are found between BC concentrations predicted with the regression model and measured at Alert for both seasons (R2 equals 0.77 and 0.81 for winter and spring, respectively). Results imply that atmospheric transport and BC emission are the major contributors to the inter-annual variations in BC concentrations observed at Alert in the cold seasons for the 16-year period. Based on the regression model the relative contributions of regional BC emissions affecting Alert are attributed to the Eurasian sector, composed of the European Union and the former USSR, and the North American sector. Considering both seasons, the model suggests that Eurasia is the major contributor to the near-surface BC levels at the Canadian High Arctic site with an average contribution of over 85% during the 16-year period. In winter, the atmospheric transport of BC aerosols from Eurasia is found to be even more predominant with a multi-year average of 94%. The model estimates smaller contribution from the Eurasian sector in spring (70%) than that in winter. It is also found that the change in Eurasian contributions depends mainly on the reduction of emission intensity, while the changes in both emission and atmospheric transport contributed to the inter-annual variation of North

  12. Romantic attraction and adolescent smoking trajectories.

    PubMed

    Pollard, Michael S; Tucker, Joan S; Green, Harold D; Kennedy, David P; Go, Myong-Hyun

    2011-12-01

    Research on sexual orientation and substance use has established that lesbian, gay, and bisexual (LGB) individuals are more likely to smoke than heterosexuals. This analysis furthers the examination of smoking behaviors across sexual orientation groups by describing how same- and opposite-sex romantic attraction, and changes in romantic attraction, are associated with distinct six-year developmental trajectories of smoking. The National Longitudinal Study of Adolescent Health dataset is used to test our hypotheses. Multinomial logistic regressions predicting smoking trajectory membership as a function of romantic attraction were separately estimated for men and women. Romantic attraction effects were found only for women. The change from self-reported heterosexual attraction to lesbian or bisexual attraction was more predictive of higher smoking trajectories than was a consistent lesbian or bisexual attraction, with potentially important differences between the smoking patterns of these two groups.

  13. Multiple Trajectories of Successful Aging of Older and Younger Cohorts

    ERIC Educational Resources Information Center

    Hsu, Hui-Chuan; Jones, Bobby L.

    2012-01-01

    Purpose: The purpose of this study was to apply group-based trajectory analysis to identify multiple successful aging trajectories by multiple indicators and to examine the factors related to successful aging among the elderly population in Taiwan. Design and Methods: Nation-representative longitudinal data collected from 1993 to 2007 and…

  14. Trajectory Optimization: OTIS 4

    NASA Technical Reports Server (NTRS)

    Riehl, John P.; Sjauw, Waldy K.; Falck, Robert D.; Paris, Stephen W.

    2010-01-01

    The latest release of the Optimal Trajectories by Implicit Simulation (OTIS4) allows users to simulate and optimize aerospace vehicle trajectories. With OTIS4, one can seamlessly generate optimal trajectories and parametric vehicle designs simultaneously. New features also allow OTIS4 to solve non-aerospace continuous time optimal control problems. The inputs and outputs of OTIS4 have been updated extensively from previous versions. Inputs now make use of objectoriented constructs, including one called a metastring. Metastrings use a greatly improved calculator and common nomenclature to reduce the user s workload. They allow for more flexibility in specifying vehicle physical models, boundary conditions, and path constraints. The OTIS4 calculator supports common mathematical functions, Boolean operations, and conditional statements. This allows users to define their own variables for use as outputs, constraints, or objective functions. The user-defined outputs can directly interface with other programs, such as spreadsheets, plotting packages, and visualization programs. Internally, OTIS4 has more explicit and implicit integration procedures, including high-order collocation methods, the pseudo-spectral method, and several variations of multiple shooting. Users may switch easily between the various methods. Several unique numerical techniques such as automated variable scaling and implicit integration grid refinement, support the integration methods. OTIS4 is also significantly more user friendly than previous versions. The installation process is nearly identical on various platforms, including Microsoft Windows, Apple OS X, and Linux operating systems. Cross-platform scripts also help make the execution of OTIS and post-processing of data easier. OTIS4 is supplied free by NASA and is subject to ITAR (International Traffic in Arms Regulations) restrictions. Users must have a Fortran compiler, and a Python interpreter is highly recommended.

  15. Identifying Patterns of FEES-Derived Swallowing Trajectories Using Group-Based Trajectory Model.

    PubMed

    Baijens, Laura W J; Pilz, Walmari; Kremer, Bernd; Passos, Valeria Lima

    2015-10-01

    The present study delineates and visualizes swallowing trajectories along seven swallow trials in dysphagic patients using group-based trajectory modeling (GBTM). This model facilitates the recognition of swallowing functional categories, estimates their frequency of occurrence, and enhances the understanding of swallowing dynamics. Two hundred and five dysphagic patients underwent a standardized FEES examination protocol. Five ordinal variables were blindly assessed for each swallow by two observers independently. GBTM analysis was conducted to find and characterize trajectories of FEES responses. For most FEES outcome variables, trajectories were qualitatively distinct in degree and kind (level of impairment and how this changed over the seven swallow trials). Two FEES outcome variables-delayed initiation of the pharyngeal reflex and postswallow pyriform sinus pooling-showed the highest prevalence of severe swallowing impairment. Highly impaired categories were more stable throughout the different swallow trials. Intermediate trajectories, by contrast, were erratic, responding more sensitively to shifts in bolus consistency. GBTM can identify distinct developmental trajectories of measured FEES variables in patients with oropharyngeal dysphagia. In clinical practice, classification into distinct groups would help to identify the subgroup of dysphagic patients who may need specific medical attention.

  16. Trajectories in parallel optics.

    PubMed

    Klapp, Iftach; Sochen, Nir; Mendlovic, David

    2011-10-01

    In our previous work we showed the ability to improve the optical system's matrix condition by optical design, thereby improving its robustness to noise. It was shown that by using singular value decomposition, a target point-spread function (PSF) matrix can be defined for an auxiliary optical system, which works parallel to the original system to achieve such an improvement. In this paper, after briefly introducing the all optics implementation of the auxiliary system, we show a method to decompose the target PSF matrix. This is done through a series of shifted responses of auxiliary optics (named trajectories), where a complicated hardware filter is replaced by postprocessing. This process manipulates the pixel confined PSF response of simple auxiliary optics, which in turn creates an auxiliary system with the required PSF matrix. This method is simulated on two space variant systems and reduces their system condition number from 18,598 to 197 and from 87,640 to 5.75, respectively. We perform a study of the latter result and show significant improvement in image restoration performance, in comparison to a system without auxiliary optics and to other previously suggested hybrid solutions. Image restoration results show that in a range of low signal-to-noise ratio values, the trajectories method gives a significant advantage over alternative approaches. A third space invariant study case is explored only briefly, and we present a significant improvement in the matrix condition number from 1.9160e+013 to 34,526.

  17. Posttraumatic Stress Symptoms and Trajectories in Child Sexual Abuse Victims: An Analysis of Sex Differences Using the National Survey of Child and Adolescent Well-Being

    ERIC Educational Resources Information Center

    Maikovich, Andrea Kohn; Koenen, Karestan C.; Jaffee, Sara R.

    2009-01-01

    Very few studies have prospectively examined sex differences in posttraumatic stress symptoms and symptom trajectories in youth victimized by childhood sexual abuse. This study addresses that question in a relatively large sample of children, drawn from the National Survey of Child and Adolescent Well-Being, who were between the ages of 8-16 years…

  18. Screening of UV-B-induced genes from apple peels by SSH: possible involvement of MdCOP1-mediated signaling cascade genes in anthocyanin accumulation.

    PubMed

    Peng, Ting; Saito, Takanori; Honda, Chikako; Ban, Yusuke; Kondo, Satoru; Liu, Ji-Hong; Hatsuyama, Yoshimichi; Moriguchi, Takaya

    2013-07-01

    Suppression subtractive hybridization (SSH) was employed to identify candidate genes involved in red coloration in apple peel with the ultraviolet (UV)-B-treated 'Mutsu'. After reverse Northern blotting verification, nearly 80 clones were successfully sequenced. Large portions of the expressed sequence tags (ESTs) are well characterized anthocyanin biosynthesis-related genes, such as chalcone synthase (11A5), flavonol synthase (12F3), anthocyanidin synthase (11H5) and UDP-glycosyl transferase (14A12) whose presence proved the success of SSH. Eight ESTs were selected for quantitative real-time polymerase chain reaction analysis and their expressions were all elevated in 'Induction', further confirming the reliability of the SSH library. One EST, 11F4 (CONSTITUTIVE PHOTOMORPHOGENIC 1: COP1) with putative function in light signal relay was further analyzed in 'Mutsu' and 'Tsugaru', along with MdHY5 (ELONGATED HYPOCOTYL 5: the downstream target of COP1), MdMYB22 (a possible flavonol-specific activator under the regulation of HY5, belonging to the SG7/PRODUCTION OF FLAVONOL GLYCOSIDES family) and MdMYBA. Results showed that MdCOP1, MdHY5, MdMYB22 and MdMYBA were all UV-B inducible genes and anthocyanin accumulation occurred after their increased expressions. Moreover, their expressions and anthocyanin content were enhanced under UV-B plus 17°C treatment. The presence of G box, a known consensus binding site of HY5, in the MdMYBA promoter region implicated that it could be regulated by MdHY5, which was verified by the result of the yeast one-hybrid analysis. Our data suggested that UV-B irradiation would induce the utmost upstream light signaling factor, MdCOP1, which activates MdHY5 signaling by binding to the promoter regions of MdMYBs, and finally leads to the red coloration of apple peels.

  19. A Distributed Trajectory-Oriented Approach to Managing Traffic Complexity

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Wing, David J.; Vivona, Robert; Garcia-Chico, Jose-Luis

    2007-01-01

    In order to handle the expected increase in air traffic volume, the next generation air transportation system is moving towards a distributed control architecture, in which ground-based service providers such as controllers and traffic managers and air-based users such as pilots share responsibility for aircraft trajectory generation and management. While its architecture becomes more distributed, the goal of the Air Traffic Management (ATM) system remains to achieve objectives such as maintaining safety and efficiency. It is, therefore, critical to design appropriate control elements to ensure that aircraft and groundbased actions result in achieving these objectives without unduly restricting user-preferred trajectories. This paper presents a trajectory-oriented approach containing two such elements. One is a trajectory flexibility preservation function, by which aircraft plan their trajectories to preserve flexibility to accommodate unforeseen events. And the other is a trajectory constraint minimization function by which ground-based agents, in collaboration with air-based agents, impose just-enough restrictions on trajectories to achieve ATM objectives, such as separation assurance and flow management. The underlying hypothesis is that preserving trajectory flexibility of each individual aircraft naturally achieves the aggregate objective of avoiding excessive traffic complexity, and that trajectory flexibility is increased by minimizing constraints without jeopardizing the intended ATM objectives. The paper presents conceptually how the two functions operate in a distributed control architecture that includes self separation. The paper illustrates the concept through hypothetical scenarios involving conflict resolution and flow management. It presents a functional analysis of the interaction and information flow between the functions. It also presents an analytical framework for defining metrics and developing methods to preserve trajectory flexibility and

  20. 77 FR 24838 - Safety Zone; Magothy River, Sillery Bay, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Magothy River, Sillery Bay, MD AGENCY... waters of the Magothy River, in Sillery Bay, Maryland. This safety zone is necessary to provide for the... ``Safety Zone; Magothy River, Sillery Bay, MD'' in the Federal Register (77 FR 11423). We received...

  1. MD simulation of cluster formation during sputtering

    NASA Astrophysics Data System (ADS)

    Muramoto, T.; Okai, M.; Yamashita, Y.; Yorizane, K.; Yamamura, Y.

    2001-06-01

    The cluster ejection due to cluster impact on a solid surface is studied through molecular dynamics (MD) simulations. Simulations are performed for Cu cluster impacts on the Cu(1 1 1) surface for cluster energy 100 eV/atom, and for clusters of 6, 13, 28 and 55 atoms. Interatomic interactions are described by the AMLJ-EAM potential. The vibration energy spectrum is independent of the incident cluster size and energy. This comes from the fact that sputtered clusters become stable through the successive fragmentation of nascent large sputtered clusters. The vibration energy spectra for large sputtered clusters have a peak, whose energy corresponds to the melting temperature of Cu. The exponent of the power-law fit of the abundance distribution and the total sputtering yield for the cluster impacts are higher than that for the monatomic ion impacts with the same total energy, where the exponent δ is given by Yn∝ nδ and Yn is the yield of sputtered n-atom cluster. The exponent δ follows a unified function of the total sputtering yield, which is a monotonic increase function, and it is nearly equal to δ ˜ -3 for larger yield.

  2. Leroy D Vandam, MD: an anesthesia journey.

    PubMed

    Ortega, Rafael A

    2005-08-01

    Leroy D Vandam, MD was a remarkable man--an intricate amalgamation of an artist, scientist, and physician. He was a bastion of medical historical knowledge. Dr Vandam became a most influential anesthesiologist, some say, a giant. He was an example of someone who, with resolve, overcame adversity. His artwork is displayed in countless places, and several of his paintings form part of the Wood Library Museum Heritage Series. Dr Vandam was first a surgeon, but he abandoned surgery and pursued a career in anesthesiology under the leadership of Robert Dripps. He completed his residency training at the University of Pennsylvania and joined its staff in 1949. When he arrived at Brigham and Women's Hospital in the 1950s as director of anesthesia, he embarked on one of the most illustrious careers in American anesthesiology. Dr Vandam published more than 250 original articles, chapters, abstracts, and other reports on a wide variety of subjects including history, art, and pharmacology. His classic article on the complications of neuroaxial blocks is a seminal work in anesthesiology. This article describes how an anesthesiologist who shared an interest with Dr Vandam in the history of anesthesiology came to produce a movie based on his career, the evolution of anesthesia equipment, and the transformation of our specialty.

  3. The JIM interview. David Korn, MD.

    PubMed

    Korn, D

    1995-04-01

    When David Korn, MD, was named dean of the Stanford University School of Medicine on October 9, 1984, he assumed leadership of a world class research institution. Stanford was at the forefront of medicine in the areas of transplantation and oncology, and the steady influx of privately insured patients had generated a net operating surplus of $17 million in that year alone. However, in the same issue of the Stanford University Hospital newsletter which announced the selection of Korn as Dean, a small article appeared on a new prospective payment system based on diagnosis-related groups (DRGs). The article stated that the new system had begun smoothly, though some payments for cost outliers had been delayed. Other cost containment measures soon followed, most notably the implementation of managed care, and by 1990, Stanford was $14 million in the red. Buffeted by changes in medical reimbursement, competition with less costly hospitals, and a nasty squabble with Congress over indirect research costs, Stanford has been on the frontlines of a struggle now confronting many academic medical centers. After successfully consolidating the university's clinical services into a unified Stanford Health System, Korn announced that he would be stepping down as Dean on April 1. Interviewed in his office in Palo Alto, Korn reflected on the difficulties of dealing with managed care, the current financial state of the institution, and what Stanford's experience may predict for other academic medical centers.

  4. Periodic billiard trajectories in polygons: generating mechanisms

    NASA Astrophysics Data System (ADS)

    Vorobets, Ya B.; Gal'perin, G. A.; Stepin, Anatolii M.

    1992-06-01

    CONTENTSIntroduction §1. Billiard trajectories in a plane domain §2. Fagnano's problem. Mechanical interpretations of periodic trajectories in triangles §3. An extremal property of billiard trajectories. Birkhoff's theorem. The non-existence of a unified construction of periodic trajectories in obtuse triangles §4. 'Perpendicular' trajectories in obtuse triangles of special shape §5. 'Perpendicular' trajectories in rational polygons and polyhedra §6. Stable trajectories §7. Stable perpendicular trajectories §8. Isolated trajectories §9. Isolated trajectories in acute and obtuse triangles. The bifurcation diagram of isolated trajectories (a 'hang-glider' configuration) §10. The density of F-triangles in a neighbourhood of (0, 0) §11. Generalization of the construction of isolated trajectories in obtuse triangles §12. Stable and unstable billiard trajectories in plane Weyl chambers §13. A criterion for the stability of periodic trajectories in a regular hexagonConclusionReferences

  5. Friendship networks and trajectories of adolescent tobacco use.

    PubMed

    Pollard, Michael S; Tucker, Joan S; Green, Harold D; Kennedy, David; Go, Myong-Hyun

    2010-07-01

    This article examines how friendship networks in adolescence are linked to tobacco use trajectories through a combination of analytic techniques that traditionally are located in separate literatures: social network analysis and developmental trajectory analysis. Using six years of longitudinal data from the National Longitudinal Study of Adolescent Health, we identify a set of six unique developmental trajectories of smoking (never smokers, steady lows, delayed increasers, early increasers, decreasers, and steady highs). Individuals' locations in their friendship networks were then linked to their trajectory group membership. Adolescents with a greater number of smoking friends were more likely to belong to the higher use trajectories. Beyond this exposure to smoking peers, individuals who at baseline were either members of a smoking group or liaisons to a smoking group were more likely than members of a nonsmoking group to belong to the higher use trajectories. Liaisons to a smoking group were particularly likely to belong to the delayed increaser trajectory group. Trajectory group membership for adolescents who belonged to a nonsmoking group did not significantly differ from those who were isolates or liaisons to a nonsmoking group. The study suggests features of an individual's social network have long-lasting associations with smoking behaviors.

  6. Parallel Aircraft Trajectory Optimization with Analytic Derivatives

    NASA Technical Reports Server (NTRS)

    Falck, Robert D.; Gray, Justin S.; Naylor, Bret

    2016-01-01

    Trajectory optimization is an integral component for the design of aerospace vehicles, but emerging aircraft technologies have introduced new demands on trajectory analysis that current tools are not well suited to address. Designing aircraft with technologies such as hybrid electric propulsion and morphing wings requires consideration of the operational behavior as well as the physical design characteristics of the aircraft. The addition of operational variables can dramatically increase the number of design variables which motivates the use of gradient based optimization with analytic derivatives to solve the larger optimization problems. In this work we develop an aircraft trajectory analysis tool using a Legendre-Gauss-Lobatto based collocation scheme, providing analytic derivatives via the OpenMDAO multidisciplinary optimization framework. This collocation method uses an implicit time integration scheme that provides a high degree of sparsity and thus several potential options for parallelization. The performance of the new implementation was investigated via a series of single and multi-trajectory optimizations using a combination of parallel computing and constraint aggregation. The computational performance results show that in order to take full advantage of the sparsity in the problem it is vital to parallelize both the non-linear analysis evaluations and the derivative computations themselves. The constraint aggregation results showed a significant numerical challenge due to difficulty in achieving tight convergence tolerances. Overall, the results demonstrate the value of applying analytic derivatives to trajectory optimization problems and lay the foundation for future application of this collocation based method to the design of aircraft with where operational scheduling of technologies is key to achieving good performance.

  7. Stratospheric ozone loss in the 1996/1997 Arctic winter: Evaluation based on multiple trajectory analysis for double-sounded air parcels by ILAS

    NASA Astrophysics Data System (ADS)

    Terao, Yukio; Sasano, Yasuhiro; Nakajima, Hideaki; Tanaka, H. L.; Yasunari, Tetsuzo

    2002-12-01

    Quantitative chemical ozone loss rates and amounts in the Arctic polar vortex for the spring of 1997 are analyzed based on ozone profile data obtained by the Improved Limb Atmospheric Spectrometer (ILAS) using an extension of the Match technique. In this study, we calculated additional multiple trajectories and set very strict criteria to overcome the weakness of the satellite sensor data (lower vertical resolution and larger sampling air mass volume) and to identify more accurately a double-sounded air mass. On the average inside the inner edge of the vortex boundary (north of about 70°N equivalent latitude), the local ozone loss rate was 50-80 ppbv/day at the maximum during late February between the levels of 450 and 500 K potential temperatures. The integrated ozone loss during February to March reached 2.0 ± 0.1 ppmv at 475-529 K levels, and the column ozone loss between 400 and 600 K during the 2 months was 96 ± 0.3 DU. Using a relative potential vorticity (rPV) scale, the vortex was divided into some rPV belts, and it was shown that the magnitude of the ozone loss increased gradually toward the vortex center from the edge. The maximum ozone loss rate of 6.0 ± 0.6 ppbv/sunlit hour near the vortex center was higher than near the vortex edge by a factor of 2-3. When we expanded the area of interest to include all the data obtained inside the vortex edge (north of about 65°N equivalent latitude), the local ozone loss rate was about 50 ppbv/day at the maximum. This value is slightly larger than that estimated by the Match analysis using ozonesondes for the same winter by ˜10 ppbv/day. Temperature histories of double-sounded air parcels indicated that the extreme ozone loss in the innermost part of the vortex was observed when the air parcel experienced temperatures below TNAT during the two soundings and had experienced temperatures near Tice in the 10 days prior to the first sounding. These facts suggest that the high ozone loss rate deep inside the vortex

  8. Mathematical difficulties as decoupling of expectation and developmental trajectories

    PubMed Central

    McLean, Janet F.; Rusconi, Elena

    2014-01-01

    Recent years have seen an increase in research articles and reviews exploring mathematical difficulties (MD). Many of these articles have set out to explain the etiology of the problems, the possibility of different subtypes, and potential brain regions that underlie many of the observable behaviors. These articles are very valuable in a research field, which many have noted, falls behind that of reading and language disabilities. Here will provide a perspective on the current understanding of MD from a different angle, by outlining the school curriculum of England and the US and connecting these to the skills needed at different stages of mathematical understanding. We will extend this to explore the cognitive skills which most likely underpin these different stages and whose impairment may thus lead to mathematics difficulties at all stages of mathematics development. To conclude we will briefly explore interventions that are currently available, indicating whether these can be used to aid the different children at different stages of their mathematical development and what their current limitations may be. The principal aim of this review is to establish an explicit connection between the academic discourse, with its research base and concepts, and the developmental trajectory of abstract mathematical skills that is expected (and somewhat dictated) in formal education. This will possibly help to highlight and make sense of the gap between the complexity of the MD range in real life and the state of its academic science. PMID:24567712

  9. 75 FR 12464 - Airworthiness Directives; McDonnell Douglas Corporation Model MD-11 and MD-11F Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ... Directives; McDonnell Douglas Corporation Model MD- 11 and MD-11F Airplanes AGENCY: Federal Aviation... Management, 3855 Lakewood Boulevard, MC D800-0019, Long Beach, California 90846- 0001; telephone 206-544-5000.... The FAA amends Sec. 39.13 by adding the following new AD: McDonnell Douglas Corporation: Docket...

  10. MD-1324 and MD-1324A 5kHz Modem Overview, Issues and Status

    DTIC Science & Technology

    2011-03-01

    Contactor providing TSN support on DMR , MD-1324 1 Mar 2011 "Sustaining the Tactical Edge through reliable C4ISR UHF SATCOM Support" Distribution...UHF SATCOM Antenna and an External HPA / Up Converter (like a UHF SATCOM AN/WSC-3, ARC-210, or DMR RFS). ▼ Supports 5kHz and 25kHz DAMA and Non...Low cost light weight comms to manpac radio users and low data rate reliable comms to disadvantaged users. ▼ Simultaneously supports two

  11. [Critical trajectories of female victims of gender violence: discourse analysis of women and staff professionals in Porto Alegre, Rio Grande do Sul State, Brazil].

    PubMed

    Meneghel, Stela Nazareth; Bairros, Fernanda; Mueller, Betânia; Monteiro, Débora; Oliveira, Lidiane Pellenz de; Collaziol, Marceli Emer

    2011-04-01

    This qualitative study aims to describe the trajectories of female victims of gender violence in Porto Alegre, Rio Grande do Sul State, Brazil. The methodology included in-depth interviews with women and staff, attempting to map the critical paths of women when they made the decision to seek professional help. We interviewed 21 women victims of gender violence and 25 professionals, including law enforcement officials, health and social workers, and nongovernmental organizations. The women's trajectories in the services were mapped, identifying facilitating factors and obstacles in the process of breaking with gender violence. The victims reported: pressure by professional staff to return to their marriages and police inefficiency in providing protection. The discourse of law enforcement officials and health and social workers showed a range of different concepts regarding violence, medicalization of violence, and network fragmentation.

  12. Does parenting help to explain socioeconomic inequalities in children's body mass index trajectories? Longitudinal analysis using the Growing Up in Scotland study

    PubMed Central

    Parkes, Alison; Sweeting, Helen; Young, Robert; Wight, Daniel

    2016-01-01

    Background Pathways leading to socioeconomic inequalities in young children's body mass index (BMI) are not well understood. This study examined whether parenting related to the physical and social context of children's food consumption helped to explain associations between maternal educational level and child BMI trajectory. Methods The study used data from 2957 families in a nationally representative birth cohort study surveyed from 2004 to 2011, with child BMI z-score measured 3 times (46, 70 and 94 months). Latent growth curve models examined associations between maternal education and BMI z-score trajectory, exploring mediating effects of parenting (positive mealtime interaction, informal meal setting and child bedroom TV) and unhealthy child diet. Results After adjusting for maternal BMI, maternal education predicted increased inequality in child BMI z-score trajectory slope over the study period. The slope index of inequality coefficient for maternal education, that is, the change in z-score associated with the lowest relative to the highest maternal education level, was 0.17, p<0.001. Indirect effects of lower maternal education on steeper BMI trajectory via parenting and/or unhealthy diet represented 89% of the total effect. Pathways via parenting and then unhealthy diet accounted for 68% of significant indirect pathways, with the remainder via unhealthy diet only. Bedroom TV was the most important parenting pathway, followed by informal meal setting. Conclusions Pathways via parenting helped to explain the emergence of inequalities in young children's BMI related to maternal education. Interventions targeting parental provision of child bedroom TV and informal meal setting might reduce these inequalities. PMID:27056682

  13. Analysis of planetary and solar-induced perturbations on trans-Martian trajectory of Mars missions before and after Mars orbit insertion

    NASA Astrophysics Data System (ADS)

    Nwankwo, V. U. J.; Chakrabarti, S. K.

    2015-12-01

    Interplanetary missions are susceptible to gravitational and nongravitational perturbing forces at every trajectory phase, assuming, of course, that the man made rockets and thrusters work as expected. These forces are mainly due to planetary and solar-forcing-induced perturbations during geocentric, heliocentric and Martian trajectories, and before orbit insertion. In this study, we review and/or analyze Mars orbiters mission associated perturbing forces and their possible impacts before Mars Orbit Insertion viz Earth's oblateness, Third body (solar and lunar), solar radiation pressure, solar energetic radiation environment and atmospheric drag forces. We also model the significance of atmospheric drag force on Mangalyaan Mars orbiter mission, as a function of appropriate space environmental parameters during its 28 days in Earth's orbit (around and during perigee passage), 300 days of heliocentric and 100 days of Martian trajectory. We have found that for a total perigee height boost of about 250 km, the cumulative orbit decay can be approximately 720 m. The approximate altitude variation could be up to 158 m with respect to the sun during 300 days of interplanetary journey toward Mars. After Mars orbit insertion, the total decay experienced by the spacecraft could be up to 701 m with decay rate of up to 9 m/day during 100 days of Martian trajectory, based on Mars-Earth atmosphere density ratio. In principle, resulting deviations due to perturbing forces are usually corrected before Earth departure (and/or Mars orbit insertion) and are beyond the scope of this work. However, the knowledge is important for mission planning, design, implementation and situational awareness. We find that the deviations are small enough and should be correctable.

  14. Ballistic projectile trajectory determining system

    DOEpatents

    Karr, T.J.

    1997-05-20

    A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile. 8 figs.

  15. Ballistic projectile trajectory determining system

    DOEpatents

    Karr, Thomas J.

    1997-01-01

    A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile.

  16. Iso-chemical potential trajectories in the P-T plane for He II

    NASA Technical Reports Server (NTRS)

    Maytal, B.; Nissen, J. A.; Van Sciver, S. W.

    1990-01-01

    Trajectories of constant chemical potential in the P-T plane serve as an integral formulation of London's equation. The trajectories are useful for analysis and synthesis of fountain effect pump performance. A family of trajectories is generated from available numerical codes.

  17. Generalization of the paraxial trajectory method for the analysis of non-paraxial rays: simulation program G-optk for electron gun characterization.

    PubMed

    Fujita, Shin; Takebe, Masahiro; Ushio, Wataru; Shimoyama, Hiroshi

    2010-01-01

    The paraxial trajectory method has been generalized for the application to the cathode rays inside electron guns. The generalized method can handle rays that initially make a large angle with the optical axis with a satisfactory accuracy. The key to success of the generalization is the adoption of the trigonometric function sine for the trajectory slope specification, instead of the conventional use of the tangent. Formulas have been derived to relate the ray conditions (position and slope of the ray at reference planes) on the cathode to those at the crossover plane using third-order polynomial functions. Some of the polynomial coefficients can be used as the optical parameters in the characterization of electron sources; the electron gun focal length gives a quantitative estimate of both the crossover size and the angular current intensity. An electron gun simulation program G-optk has been developed based on the mathematical formulations presented in the article. The program calculates the principal paraxial trajectories and the relevant optical parameters from axial potentials and fields. It gives the electron-optical-column designers a clear physical picture of the electron gun in a much more faster way than the conventional ray-tracing methods.

  18. Weighing in on the issue: a longitudinal analysis of the influence of selected individual factors and the sports context on the developmental trajectories of eating pathology among adolescents.

    PubMed

    Fay, Kristen; Lerner, Richard M

    2013-01-01

    Eating disorders, and related issues (e.g., body dissatisfaction, weight control behaviors), represent pressing and prevalent health problems that affect American adolescents with alarming frequency and potentially chronic consequences. However, more longitudinal research is needed to elucidate the developmental processes that increase or maintain risk for, and that protect against, eating- and weight-related problems among adolescents. Accordingly, the current study used longitudinal data from 1,050 male and female (68.0 %) adolescents (Grades 9-11)-the majority of whom were European Americans (72.2 %)-who participated in the 4-H Study of Positive Youth Development to (a) describe trajectories of adolescents' eating pathology and body dissatisfaction, (b) identify individual and contextual correlates of these pathways, (c) examine whether trajectories of eating pathology and body dissatisfaction related to adolescents' depressive symptoms, and (d) elucidate whether sports participation moderated associations between specific trajectories of eating pathology and body dissatisfaction and adolescents' depressive symptoms. Results suggest that the diverse pathways of eating pathology and body dissatisfaction that exist across middle adolescence, in combination with adolescents' sports participation, have important implications for the positive and problematic development of our youth. In addition, the findings underscore the need to evaluate the interindividual differences that exist in regard to how sports participation may relate positively and negatively to developmental outcomes.

  19. Lunar Cube Transfer Trajectory Options

    NASA Technical Reports Server (NTRS)

    Folta, David; Dichmann, Donald James; Clark, Pamela E.; Haapala, Amanda; Howell, Kathleen

    2015-01-01

    Numerous Earth-Moon trajectory and lunar orbit options are available for Cubesat missions. Given the limited Cubesat injection infrastructure, transfer trajectories are contingent upon the modification of an initial condition of the injected or deployed orbit. Additionally, these transfers can be restricted by the selection or designs of Cubesat subsystems such as propulsion or communication. Nonetheless, many trajectory options can b e considered which have a wide range of transfer duration, fuel requirements, and final destinations. Our investigation of potential trajectories highlights several options including deployment from low Earth orbit (LEO) geostationary transfer orbits (GTO) and higher energy direct lunar transfer and the use of longer duration Earth-Moon dynamical systems. For missions with an intended lunar orbit, much of the design process is spent optimizing a ballistic capture while other science locations such as Sun-Earth libration or heliocentric orbits may simply require a reduced Delta-V imparted at a convenient location along the trajectory.

  20. Lunar Cube Transfer Trajectory Options

    NASA Technical Reports Server (NTRS)

    Folta, David; Dichmann, Donald J.; Clark, Pamela; Haapala, Amanda; Howell, Kathleen

    2015-01-01

    Numerous Earth-Moon trajectory and lunar orbit options are available for Cubesat missions. Given the limited Cubesat injection infrastructure, transfer trajectories are contingent upon the modification of an initial condition of the injected or deployed orbit. Additionally, these transfers can be restricted by the selection or designs of Cubesat subsystems such as propulsion or communication. Nonetheless, many trajectory options can be considered which have a wide range of transfer durations, fuel requirements, and final destinations. Our investigation of potential trajectories highlights several options including deployment from low Earth orbit (LEO), geostationary transfer orbits (GTO), and higher energy direct lunar transfers and the use of longer duration Earth-Moon dynamical systems. For missions with an intended lunar orbit, much of the design process is spent optimizing a ballistic capture while other science locations such as Sun-Earth libration or heliocentric orbits may simply require a reduced Delta-V imparted at a convenient location along the trajectory.

  1. Hyper-X Mach 10 Trajectory Reconstruction

    NASA Technical Reports Server (NTRS)

    Karlgaard, Christopher D.; Martin, John G.; Tartabini, Paul V.; Thornblom, Mark N.

    2005-01-01

    This paper discusses the formulation and development of a trajectory reconstruction tool for the NASA X-43A/Hyper-X high speed research vehicle, and its implementation for the reconstruction and analysis of flight test data. Extended Kalman filtering techniques are employed to reconstruct the trajectory of the vehicle, based upon numerical integration of inertial measurement data along with redundant measurements of the vehicle state. The equations of motion are formulated in order to include the effects of several systematic error sources, whose values may also be estimated by the filtering routines. Additionally, smoothing algorithms have been implemented in which the final value of the state (or an augmented state that includes other systematic error parameters to be estimated) and covariance are propagated back to the initial time to generate the best-estimated trajectory, based upon all available data. The methods are applied to the problem of reconstructing the trajectory of the Hyper-X vehicle from data obtained during the Mach 10 test flight, which occurred on November 16th 2004.

  2. Six-year trajectories of post-traumatic stress and severe psychological distress symptoms and associations with timing of trauma exposure, ongoing adversity and sense of injustice: a latent transition analysis of a community cohort in conflict-affected Timor-Leste

    PubMed Central

    Rees, S; Steel, Z; Tam, N; Soares, Z; Soares, C; Silove, DM

    2016-01-01

    Objectives To identify the 6-year trajectories of post-traumatic stress symptoms (PTSS) and psychological distress symptoms, and examine for associations with timing of trauma exposure, ongoing adversity and with the sense of injustice in conflict-affected Timor-Leste. Setting A whole-of-household survey was conducted in 2004 and 2010 in Dili, the capital of Timor-Leste. Participants 1022 adults were followed up over 6 years (retention rate 84.5%). Interviews were conducted by field workers applying measures of traumatic events (TEs), ongoing adversity, a sense of injustice, PTS symptoms and psychological distress. Results Latent transition analysis supported a 3-class longitudinal model (psychological distress, comorbid symptoms and low symptoms). We derived 4 composite trajectories comprising recovery (20.8%), a persisting morbidity trajectory (7.2%), an incident trajectory (37.2%) and a low-symptom trajectory (34.7%). Compared with the low-symptom trajectory, the persistent and incident trajectories reported greater stress arising from poverty and family conflict, higher TE exposure for 2 historical periods, and a sense of injustice for 2 historical periods. The persistent trajectory was unique in reporting greater TE exposure in the Indonesian occupation, whereas the incident trajectory reported greater TE exposure during the later internal conflict that occurred between baseline and follow-up. Compared with the low-symptom trajectory, the incident trajectory reported a greater sense of injustice relating to the periods of the Indonesian occupation and independence. The persistent trajectory was characterised by a sense of injustice relating to the internal conflict and contemporary times. The recovery trajectory was characterised by the absence of these risk factors, the only difference from the low-symptom trajectory being that the former reported a sense of injustice for the period surrounding independence. Conclusions Our findings suggest that the timing

  3. MD-PhD training: looking back and looking forward.

    PubMed

    Bonham, Ann C

    2014-01-01

    MD-PhD programs provide rigorous, integrated training for physician-scientists, enabling them to frame scientific questions in unique ways and to apply clinical insight to fundamental science. Few would question the influential contributions of MD-PhD physician-scientists in advancing medical science. In this issue of Academic Medicine, Jeffe et al affirm high levels of excellence in educational outcomes from MD-PhD training programs at U.S. MD-granting medical schools, especially programs that receive funding from the NIH Medical Scientist Training Program (MSTP). The author of this commentary observes that, in the face of current economic pressures, comprehensive, longitudinal national outcomes data from MSTP- and non-MSTP-funded MD-PhD programs will help verify the value provided by MD-PhD physician-scientists. She proposes that MD-PhD programs should better prepare the next generation of physician-scientists for future research environments, which will provide new technologies, venues, and modalities. These research environments will be more closely integrated within health care delivery systems, extend into diverse communities and regions, and employ complex technologies. MD-PhD physician-scientists also will train and gain expertise in broadening areas of research, such as health policy, health economics, clinical epidemiology, and medical informatics. Program leaders are ideally situated to foster innovative learning environments and methodologies. By sharing their innovations, they can help ensure production of a diverse MD-PhD physician-scientist workforce, prepared to engage in myriad research opportunities to meet patient and population needs in a new environment.

  4. Development of a Mars Airplane Entry, Descent, and Flight Trajectory

    NASA Technical Reports Server (NTRS)

    Murray, James E.; Tartabini, Paul V.

    2001-01-01

    An entry, descent, and flight (EDF) trajectory profile for a Mars airplane mission is defined as consisting of the following elements: ballistic entry of an aeroshell; supersonic deployment of a decelerator parachute; subsonic release of a heat shield; release, unfolding, and orientation of an airplane to flight attitude; and execution of a pull up maneuver to achieve trimmed, horizontal flight. Using the Program to Optimize Simulated Trajectories (POST) a trajectory optimization problem was formulated. Model data representative of a specific Mars airplane configuration, current models of the Mars surface topography and atmosphere, and current estimates of the interplanetary trajectory, were incorporated into the analysis. The goal is to develop an EDF trajectory to maximize the surface-relative altitude of the airplane at the end of a pull up maneuver, while subject to the mission design constraints. The trajectory performance was evaluated for three potential mission sites and was found to be site-sensitive. The trajectory performance, examined for sensitivity to a number of design and constraint variables, was found to be most sensitive to airplane mass, aerodynamic performance characteristics, and the pull up Mach constraint. Based on the results of this sensitivity study, an airplane-drag optimized trajectory was developed that showed a significant performance improvement.

  5. Trajectories of health care service utilization and differences in patient characteristics among adults with specific chronic pain: analysis of health plan member claims

    PubMed Central

    Ruetsch, Charles; Tkacz, Joseph; Kardel, Peter G; Howe, Andrew; Pai, Helen; Levitan, Bennett

    2013-01-01

    Introduction The lack of consistency surrounding the diagnosis of chronic non-cancer pain, treatment approaches, and patient management suggests the need for further research to better characterize the chronic non-cancer pain population. Objective The purpose of this study was to identify distinct trajectories of health care service utilization of chronic non-cancer pain patients and describe the characteristic differences between trajectory groups. Patients and methods This study utilized the MarketScan claims databases. A total of 71,392 patients diagnosed with either low back pain or osteoarthritis between 2006 and 2009 served as the study sample. Each subject’s claims data were divided into three time periods around an initial diagnosis date: pre-period, post-Year 1, and post-Year 2. Subjects were categorized as either high (H) or low (L) cost at each post period, resulting in the creation of four trajectory groups based on the post-Year 1 and 2 cost pattern: H-H, H-L, L-H, and L-L. Multivariate statistical tests were used to predict and discriminate between trajectory group memberships. Results The H-H, L-H, and H-L groups each utilized significantly greater pre-period high-cost venue services, post-Year 1 outpatient services, and post-Year 1 opioids compared to the L-L group (P < 0.001). Additionally, the H-H and L-H groups displayed elevated Charlson comorbidity index scores compared with the L-L group (P < 0.001), with each showing increased odds of having both opioid dependence and cardiovascular disease diagnoses (P < 0.01). Conclusion This study identified patient characteristics among chronic pain patients that discriminated between different levels of post-index high-cost venue service utilization and trajectories of change in the same. With implications for managed care program implementation and resource management, this study highlights results from a developed algorithm that employed a variety of accessible data elements to effectively

  6. Michael S. Brown, MD and Joseph L. Goldstein, MD. 1985 Nobel laureates in medicine.

    PubMed

    Brown, M S; Goldstein, J L

    1996-02-01

    When Michael S. Brown, MD and Joseph L. Goldstein, MD first met as interns at the Massachusetts General Hospital in 1966, they could hardly have imagined that their careers would continue to be intertwined some 30 years later. It was shortly following their arrival as clinical associates at the National Institutes of Health in 1968 that the pair developed an interest in abnormalities of cholesterol metabolism. Bolstered by epidemiologic data that showed elevated cholesterol levels in many patients with myocardial infarction, Brown and Goldstein, who relocated to the University of Texas Southwestern Medical Center in 1972, began a search for receptors important in cholesterol homeostasis. These studies, performed in their early stages while juggling clinical duties at Parkland Hospital, culminated in a series of scientific achievements which merited among other honors the Hazen Award in 1982, the Lasker Award in 1985, and the Nobel Prize in Medicine in 1985. Today, as Regental Professors of the University of Texas, Brown and Goldstein head a laboratory group which continues to test the cutting edge of medical research. Although impressed with the pace of technological advances in biology, the declining role of clinically oriented physicians in biomedical research troubles the pair. Interviewed in their library in Dallas, Brown and Goldstein spoke about the complicated balance of science, medicine, and education necessary to produce another generation of successful investigators.

  7. Diagnostic throughput factor analysis for en-route airspace and optimal aircraft trajectory generation based on capacity prediction and controller workload

    NASA Astrophysics Data System (ADS)

    Shin, Sanghyun

    Today's National Airspace System (NAS) is approaching its limit to efficiently cope with the increasing air traffic demand. Next Generation Air Transportation System (NextGen) with its ambitious goals aims to make the air travel more predictable with fewer delays, less time sitting on the ground and holding in the air to improve the performance of the NAS. However, currently the performance of the NAS is mostly measured using delay-based metrics which do not capture a whole range of important factors that determine the quality and level of utilization of the NAS. The factors affecting the performance of the NAS are themselves not well defined to begin with. To address these issues, motivated by the use of throughput-based metrics in many areas such as ground transportation, wireless communication and manufacturing, this thesis identifies the different factors which majorly affect the performance of the NAS as demand (split into flight cancellation and flight rerouting), safe separation (split into conflict and metering) and weather (studied as convective weather) through careful comparison with other applications and performing empirical sensitivity analysis. Additionally, the effects of different factors on the NAS's performance are quantitatively studied using real traffic data with the Future ATM Concepts Evaluation Tool (FACET) for various sectors and centers of the NAS on different days. In this thesis we propose a diagnostic tool which can analyze the factors that have greater responsibility for regions of poor and better performances of the NAS. Based on the throughput factor analysis for en-route airspace, it was found that weather and controller workload are the major factors that decrease the efficiency of the airspace. Also, since resources such as air traffic controllers, infrastructure and airspace are limited, it is becoming increasingly important to use the available resources efficiently. To alleviate the impact of the weather and controller

  8. Preparing MD-PhD students for clinical rotations: navigating the interface between PhD and MD training.

    PubMed

    Goldberg, Charles; Insel, Paul A

    2013-06-01

    Many aspects of MD-PhD training are not optimally designed to prepare students for their future roles as translational clinician-scientists. The transition between PhD research efforts and clinical rotations is one hurdle that must be overcome. MD-PhD students have deficits in clinical skills compared with those of their MD-only colleagues at the time of this transition. Reimmersion programs (RPs) targeted to MD-PhD students have the potential to help them navigate this transition.The authors draw on their experience creating and implementing an RP that incorporates multiple types of activities (clinical exam review, objective structured clinical examination, and supervised practice in patient care settings) designed to enhance the participants' skills and readiness for clinical efforts. On the basis of this experience, they note that MD-PhD students' time away from the clinical environment negatively affects their clinical skills, causing them to feel underprepared for clinical rotations. The authors argue that participation in an RP can help students feel more comfortable speaking with and examining patients and decrease their anxiety regarding clinical encounters. The authors propose that RPs can have positive outcomes for improving the transition from PhD to clinical MD training in dual-degree programs. Identifying and addressing this and other transitions need to be considered to improve the educational experience of MD-PhD students.

  9. Trajectories of Marital Conflict across the Life Course: Predictors and Interactions with Marital Happiness Trajectories

    ERIC Educational Resources Information Center

    Kamp Dush, Claire M.; Taylor, Miles G.

    2012-01-01

    Using typologies outlined by Gottman and Fitzpatrick as well as institutional and companionate models of marriage, the authors conducted a latent class analysis of marital conflict trajectories using 20 years of data from the Marital Instability Over the Life Course study. Respondents were in one of three groups: high, medium (around the mean), or…

  10. [Photodensitometry: microdensitometry (MD): digital image processing method (DIP)].

    PubMed

    Ohama, K; Sanada, M; Nakagawa, H

    1994-09-01

    The principles of microdensitometry (MD) and digital image processing method (DIP), as well as the application of these methods to measure bone mineral density in clinical practice, were mentioned in the report. MD and DIP assess bone mineral content and bone mineral density by analyzing relative contrast of the metacarpus II on X-ray image. However, the parameters obtained by these methods have been reported to be closely related to lumber vertebral bone mineral density and whole-body bone mineral content as measured by dual energy X-ray absorptiometry (DXA). Being easy to use, MD and DIP are adequate for the screening of osteoporosis. Once any reduction in bone mineral content or bone mineral density is shown by MD or DIP, it is recommendable to measure bone mineral density of vertebrae and femoral neck by DXA.

  11. University of Texas M.D. Anderson Cancer Center

    MedlinePlus

    ... Facts & History Home Shared Governance Committee Institutional Profile Moon Shots Program Joint Commission Survey Who Was MD ... ORBIT Proteomics Translational Research Accelerator B-Cell Lymphoma Moon Shot™ The B-Cell Lymphoma Moon Shot is ...

  12. Eastman Specialties Corporation – Chestertown MD - MDD001890060

    EPA Pesticide Factsheets

    The U.S. EPA is announcing its proposed decision of Corrective Action Complete with Controls under the RCRA, for the Eastman Specialties Corporation Facility EPA ID: MDD001890060, located in Chestertown MD.

  13. Powercon Corp. settles hazardous waste violations at Severn, Md. facility

    EPA Pesticide Factsheets

    PHILADELPHIA (November 19, 2015) - Powercon Corporation has agreed to pay a $40,000 penalty to settle alleged violations of hazardous waste regulations at its manufacturing facility in Severn, Md., the U.S. Environmental Protection Agency announced today.

  14. Video partitioning by segmenting moving object trajectories

    NASA Astrophysics Data System (ADS)

    Badal, Tapas; Nain, Neeta; Ahmed, Mushtaq

    2015-02-01

    Video partitioning may be involve in a number of applications and present solutions for monitoring and tracking particular person trajectory and also helps in to generate semantic analysis of single entity or of entire video. Many recent advances in object detection and tracking concern about motion structure and data association used to be assigned a label to trajectories and analyze them independently. In this work we propose an approach for video portioning and a structure is given to store motion structure of target set to monitor in video. Spatio-temporal tubes separate individual objects that help to generate semantic analysis report for each object individually. The semantic analysis system for video based on this framework provides not only efficient synopsis generation but also spatial collision where the temporal consistency can be resolved for representation of semantic knowledge of each object. For keeping low computational complexity trajectories are generated online and classification, knowledge representation and arrangement over spatial domain are suggested to perform in offline manner.

  15. Young adults' trajectories of Ecstasy use: a population based study.

    PubMed

    Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

    2013-11-01

    Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns.

  16. High Altitude Venus Operations Concept Trajectory Design, Modeling and Simulation

    NASA Technical Reports Server (NTRS)

    Lugo, Rafael A.; Ozoroski, Thomas A.; Van Norman, John W.; Arney, Dale C.; Dec, John A.; Jones, Christopher A.; Zumwalt, Carlie H.

    2015-01-01

    A trajectory design and analysis that describes aerocapture, entry, descent, and inflation of manned and unmanned High Altitude Venus Operation Concept (HAVOC) lighter-than-air missions is presented. Mission motivation, concept of operations, and notional entry vehicle designs are presented. The initial trajectory design space is analyzed and discussed before investigating specific trajectories that are deemed representative of a feasible Venus mission. Under the project assumptions, while the high-mass crewed mission will require further research into aerodynamic decelerator technology, it was determined that the unmanned robotic mission is feasible using current technology.

  17. Trajectory Design Tools for Libration and Cis-Lunar Environments

    NASA Technical Reports Server (NTRS)

    Folta, David C.; Webster, Cassandra M.; Bosanac, Natasha; Cox, Andrew; Guzzetti, Davide; Howell, Kathleen C.

    2016-01-01

    Innovative trajectory design tools are required to support challenging multi-body regimes with complex dynamics, uncertain perturbations, and the integration of propulsion influences. Two distinctive tools, Adaptive Trajectory Design and the General Mission Analysis Tool have been developed and certified to provide the astrodynamics community with the ability to design multi-body trajectories. In this paper we discuss the multi-body design process and the capabilities of both tools. Demonstrable applications to confirmed missions, the Lunar IceCube Cubesat lunar mission and the Wide-Field Infrared Survey Telescope (WFIRST) Sun-Earth L2 mission, are presented.

  18. Trajectory Design Analysis over the Lunar Nodal Cycle for the Multi-Purpose Crew Vehicle (MPCV) Exploration Mission 2 (EM-2)

    NASA Technical Reports Server (NTRS)

    Gutkowski, Jeffrey P.; Dawn, Timothy F.; Jedrey, Richard M.

    2014-01-01

    The first crewed mission, Exploration Mission 2 (EM-2), for the MPCV Orion spacecraft is scheduled for August 2021, and its current mission is to orbit the Moon in a highly elliptical lunar orbit for 3 days. A 21-year scan was performed to identify feasible missions that satisfy the propulsive capabilities of the Interim Cryogenic Propulsion Stage (ICPS) and MPCV Service Module (SM). The mission is divided into 4 phases: (1) a lunar free return trajectory, (2) a hybrid maneuver, during the translunar coast, to lower the approach perilune altitude to 100 km, (3) lunar orbit insertion into a 100 x 10,000 km orbit, and (4) lunar orbit loiter and Earth return to a splashdown off the coast of Southern California. Trajectory data was collected for all feasible missions and converted to information that influence different subsystems including propulsion, power, thermal, communications, and mission operations. The complete 21-year scan data shows seasonal effects that are due to the Earth-Moon geometry and the initial Earth parking orbit. The data and information is also useful to identify mission opportunities around the current planned launch date for EM-2.

  19. ATP Hydrolysis Induced Conformational Changes in the Vitamin B12 Transporter BtuCD Revealed by MD Simulations

    PubMed Central

    Pan, Chao; Weng, Jingwei; Wang, Wenning

    2016-01-01

    ATP binding cassette (ABC) transporters utilize the energy of ATP hydrolysis to uni-directionally transport substrates across cell membrane. ATP hydrolysis occurs at the nucleotide-binding domain (NBD) dimer interface of ABC transporters, whereas substrate translocation takes place at the translocation pathway between the transmembrane domains (TMDs), which is more than 30 angstroms away from the NBD dimer interface. This raises the question of how the hydrolysis energy released at NBDs is “transmitted” to trigger the conformational changes at TMDs. Using molecular dynamics (MD) simulations, we studied the post-hydrolysis state of the vitamin B12 importer BtuCD. Totally 3-μs MD trajectories demonstrate a predominantly asymmetric arrangement of the NBD dimer interface, with the ADP-bound site disrupted and the ATP-bound site preserved in most of the trajectories. TMDs response to ATP hydrolysis by separation of the L-loops and opening of the cytoplasmic gate II, indicating that hydrolysis of one ATP could facilitate substrate translocation by opening the cytoplasmic end of translocation pathway. It was also found that motions of the L-loops and the cytoplasmic gate II are coupled with each other through a contiguous interaction network involving a conserved Asn83 on the extended stretch preceding TM3 helix plus the cytoplasmic end of TM2/6/7 helix bundle. These findings entail a TMD-NBD communication mechanism for type II ABC importers. PMID:27870912

  20. Four-body trajectory optimization

    NASA Technical Reports Server (NTRS)

    Pu, C. L.; Edelbaum, T. N.

    1973-01-01

    A collection of typical three-body trajectories from the L1 libration point on the sun-earth line to the earth is presented. These trajectories in the sun-earth system are grouped into four distinct families which differ in transfer time and delta V requirements. Curves showing the variations of delta V with respect to transfer time, and typical two and three-impulse primer vector histories, are included. The development of a four-body trajectory optimization program to compute fuel optimal trajectories between the earth and a point in the sun-earth-moon system are also discussed. Methods for generating fuel optimal two-impulse trajectories which originate at the earth or a point in space, and fuel optimal three-impulse trajectories between two points in space, are presented. A brief qualitative comparison of these methods is given. An example of a four-body two-impulse transfer from the Li libration point to the earth is included.

  1. Semi-Automatic Determination of Rockfall Trajectories

    PubMed Central

    Volkwein, Axel; Klette, Johannes

    2014-01-01

    In determining rockfall trajectories in the field, it is essential to calibrate and validate rockfall simulation software. This contribution presents an in situ device and a complementary Local Positioning System (LPS) that allow the determination of parts of the trajectory. An assembly of sensors (herein called rockfall sensor) is installed in the falling block recording the 3D accelerations and rotational velocities. The LPS automatically calculates the position of the block along the slope over time based on Wi-Fi signals emitted from the rockfall sensor. The velocity of the block over time is determined through post-processing. The setup of the rockfall sensor is presented followed by proposed calibration and validation procedures. The performance of the LPS is evaluated by means of different experiments. The results allow for a quality analysis of both the obtained field data and the usability of the rockfall sensor for future/further applications in the field. PMID:25268916

  2. Hermes emergency reentry trajectories consequences on the Ariane 5 trajectories

    NASA Astrophysics Data System (ADS)

    Delattre, Ph.; Wagner, A.

    1990-06-01

    Hermes emergency reentry trajectories occur in case of any failure during that part of the launch phase from jettisoning the burn-out solid propellant boosters till the ignition of the MPH. In that case the Crew Escape Module cannot be used because of high Mach numbers and very severe constraints that would result of its low lift coefficient. The maximum constraints on the Hermes space plane are obtained in the atmospheric reentry phase of the emergency trajectories. Their important level is due to the deep flight path angle attained during the ballistic arc of the trajectory. Their values are depending on the instant of launch abort. These maximum constraints are very depending on the launch trajectory. The maximum Hermes constraints were represented in the altitude-velocity plane as a maximum altitude boundary for the Ariane 5 launch trajectory. Unfortunately a performance loss is the result of the requirement for a reduction of the culmination altitude. This has lead to a launch trajectory optimization that will be detailed in this paper. As an out-come of this study two important decisions have been made by CNES: choice of a L6 for the Hermes propulsion module; and the choice of the boundary that constraints the launch trajectory. Important efforts were made on Hermes in order to reduce the maximum constraints, in the field of aerodynamics (moment coefficient reduction, increase of the maximum angle of attack), center of gravity location (in order to reduce control surfaces hinge-moments and temperatures) and elevon-body-flap differential deflection.

  3. Trajectory Control of Rendezvous with Maneuver Target Spacecraft

    NASA Technical Reports Server (NTRS)

    Zhou, Zhinqiang

    2012-01-01

    In this paper, a nonlinear trajectory control algorithm of rendezvous with maneuvering target spacecraft is presented. The disturbance forces on the chaser and target spacecraft and the thrust forces on the chaser spacecraft are considered in the analysis. The control algorithm developed in this paper uses the relative distance and relative velocity between the target and chaser spacecraft as the inputs. A general formula of reference relative trajectory of the chaser spacecraft to the target spacecraft is developed and applied to four different proximity maneuvers, which are in-track circling, cross-track circling, in-track spiral rendezvous and cross-track spiral rendezvous. The closed-loop differential equations of the proximity relative motion with the control algorithm are derived. It is proven in the paper that the tracking errors between the commanded relative trajectory and the actual relative trajectory are bounded within a constant region determined by the control gains. The prediction of the tracking errors is obtained. Design examples are provided to show the implementation of the control algorithm. The simulation results show that the actual relative trajectory tracks the commanded relative trajectory tightly. The predicted tracking errors match those calculated in the simulation results. The control algorithm developed in this paper can also be applied to interception of maneuver target spacecraft and relative trajectory control of spacecraft formation flying.

  4. Infant BMI trajectories are associated with young adult body composition

    PubMed Central

    Slining, M. M.; Herring, A. H.; Popkin, B. M.; Mayer-Davis, E. J.; Adair, L. S.

    2013-01-01

    The dynamic aspect of early life growth is not fully captured by typical analyses, which focus on one specific time period. To better understand how infant and young child growth relate to the development of adult body composition, the authors characterized body mass index (BMI) trajectories using latent class growth analysis (LCGA) and evaluated their association with adult body composition. Data are from the Cebu Longitudinal Health and Nutrition Survey, which followed a birth cohort to age 22 years (n=1749). In both males and females, LCGA identified seven subgroups of respondents with similar BMI trajectories from 0 to 24 months (assessed with bimonthly anthropometrics). Trajectory groups were compared with conventional approaches: (1) accelerated growth between two time points (0–4 months), (2) continuous BMI gain between two points (0–4 months and 0–24 months) and (3) BMI measured at one time point (24 months) as predictors of young adult body composition measures. The seven trajectory groups were distinguished by age-specific differences in tempo and timing of BMI gain in infancy. Infant BMI trajectories were better than accelerated BMI gain between 0 and 4 months at predicting young adult body composition. After controlling for BMI at age 2 years, infant BMI trajectories still explained variation in adult body composition. Using unique longitudinal data and methods, we find that distinct infant BMI trajectories have long-term implications for the development of body composition. PMID:24040489

  5. Preserving correlations between trajectories for efficient path sampling

    SciTech Connect

    Gingrich, Todd R.; Geissler, Phillip L.

    2015-06-21

    Importance sampling of trajectories has proved a uniquely successful strategy for exploring rare dynamical behaviors of complex systems in an unbiased way. Carrying out this sampling, however, requires an ability to propose changes to dynamical pathways that are substantial, yet sufficiently modest to obtain reasonable acceptance rates. Satisfying this requirement becomes very challenging in the case of long trajectories, due to the characteristic divergences of chaotic dynamics. Here, we examine schemes for addressing this problem, which engineer correlation between a trial trajectory and its reference path, for instance using artificial forces. Our analysis is facilitated by a modern perspective on Markov chain Monte Carlo sampling, inspired by non-equilibrium statistical mechanics, which clarifies the types of sampling strategies that can scale to long trajectories. Viewed in this light, the most promising such strategy guides a trial trajectory by manipulating the sequence of random numbers that advance its stochastic time evolution, as done in a handful of existing methods. In cases where this “noise guidance” synchronizes trajectories effectively, as the Glauber dynamics of a two-dimensional Ising model, we show that efficient path sampling can be achieved for even very long trajectories.

  6. MdSOS2L1 forms a complex with MdMYB1 to control vacuolar pH by transcriptionally regulating MdVHA-B1 in apples.

    PubMed

    Sun, Cui-Hui; Zhang, Quan-Yan; Sun, Mei-Hong; Hu, Da-Gang

    2016-01-01

    Vacuolar pH is important and involves in many different physiological processes in plants. A recent paper published in Plant Physiology reveals that MdMYB1 regulates vacuolar pH by directly transcriptionally regulating proton pump genes and malate transporters genes, such as V-ATPase subunit gene MdVHA-B1. Here, we found that MdSOS2L1 in vitro did not directly interact with MdMYB1, however, in vivo formed a complex with MdMYB1 in the nucleus to regulate MdVHA-B1-mediated vacuolar acidification. This finding shed light on the role of MdSOS2L1 in transcriptionally regulating MdVHA-B1 in addition to its post-modified function in apples.

  7. MdSOS2L1 forms a complex with MdMYB1 to control vacuolar pH by transcriptionally regulating MdVHA-B1 in apples

    PubMed Central

    Sun, Cui-Hui; Zhang, Quan-Yan; Sun, Mei-Hong; Hu, Da-Gang

    2016-01-01

    ABSTRACT Vacuolar pH is important and involves in many different physiological processes in plants. A recent paper published in Plant Physiology reveals that MdMYB1 regulates vacuolar pH by directly transcriptionally regulating proton pump genes and malate transporters genes, such as V-ATPase subunit gene MdVHA-B1. Here, we found that MdSOS2L1 in vitro did not directly interact with MdMYB1, however, in vivo formed a complex with MdMYB1 in the nucleus to regulate MdVHA-B1-mediated vacuolar acidification. This finding shed light on the role of MdSOS2L1 in transcriptionally regulating MdVHA-B1 in addition to its post-modified function in apples. PMID:26910596

  8. Observation of bow shock protons at the lunar orbit. M.S. Thesis; [particle trajectory analysis of solar protons in the lunar atmosphere

    NASA Technical Reports Server (NTRS)

    Benson, J. L.

    1974-01-01

    Protons with energies ranging from about 500 eV to 3,500 eV were observed by the Suprathermal Ion Detector Experiment (SIDE) on both the dusk and dawn sides of the magnetosphere. On each lunation these particles appeared as a rather continuous phenomenon for 3 to 5 days after crossing from the dawn-side magnetosheath into the solar wind and for about 2 days prior to entering the dusk-side magnetosheath. Data from the SIDE and from the Explorer 35 lunar orbiting magnetometer were analyzed and these data indicated that the transverse ion flows observed by the SIDE in the pre and post bow shock crossing regions of the lunar orbit are due to these deviated solar wind particles. A computer model based on drift trajectories for particles leaving the shock was developed and synthetic particle data produced by this model are in good agreement with the observed data.

  9. An Effective Approach for Clustering InhA Molecular Dynamics Trajectory Using Substrate-Binding Cavity Features.

    PubMed

    De Paris, Renata; Quevedo, Christian V; Ruiz, Duncan D A; Norberto de Souza, Osmar

    2015-01-01

    Protein receptor conformations, obtained from molecular dynamics (MD) simulations, have become a promising treatment of its explicit flexibility in molecular docking experiments applied to drug discovery and development. However, incorporating the entire ensemble of MD conformations in docking experiments to screen large candidate compound libraries is currently an unfeasible task. Clustering algorithms have been widely used as a means to reduce such ensembles to a manageable size. Most studies investigate different algorithms using pairwise Root-Mean Square Deviation (RMSD) values for all, or part of the MD conformations. Nevertheless, the RMSD only may not be the most appropriate gauge to cluster conformations when the target receptor has a plastic active site, since they are influenced by changes that occur on other parts of the structure. Hence, we have applied two partitioning methods (k-means and k-medoids) and four agglomerative hierarchical methods (Complete linkage, Ward's, Unweighted Pair Group Method and Weighted Pair Group Method) to analyze and compare the quality of partitions between a data set composed of properties from an enzyme receptor substrate-binding cavity and two data sets created using different RMSD approaches. Ensembles of representative MD conformations were generated by selecting a medoid of each group from all partitions analyzed. We investigated the performance of our new method for evaluating binding conformation of drug candidates to the InhA enzyme, which were performed by cross-docking experiments between a 20 ns MD trajectory and 20 different ligands. Statistical analyses showed that the novel ensemble, which is represented by only 0.48% of the MD conformations, was able to reproduce 75% of all dynamic behaviors within the binding cavity for the docking experiments performed. Moreover, this new approach not only outperforms the other two RMSD-clustering solutions, but it also shows to be a promising strategy to distill

  10. An Effective Approach for Clustering InhA Molecular Dynamics Trajectory Using Substrate-Binding Cavity Features

    PubMed Central

    Ruiz, Duncan D. A.; Norberto de Souza, Osmar

    2015-01-01

    Protein receptor conformations, obtained from molecular dynamics (MD) simulations, have become a promising treatment of its explicit flexibility in molecular docking experiments applied to drug discovery and development. However, incorporating the entire ensemble of MD conformations in docking experiments to screen large candidate compound libraries is currently an unfeasible task. Clustering algorithms have been widely used as a means to reduce such ensembles to a manageable size. Most studies investigate different algorithms using pairwise Root-Mean Square Deviation (RMSD) values for all, or part of the MD conformations. Nevertheless, the RMSD only may not be the most appropriate gauge to cluster conformations when the target receptor has a plastic active site, since they are influenced by changes that occur on other parts of the structure. Hence, we have applied two partitioning methods (k-means and k-medoids) and four agglomerative hierarchical methods (Complete linkage, Ward’s, Unweighted Pair Group Method and Weighted Pair Group Method) to analyze and compare the quality of partitions between a data set composed of properties from an enzyme receptor substrate-binding cavity and two data sets created using different RMSD approaches. Ensembles of representative MD conformations were generated by selecting a medoid of each group from all partitions analyzed. We investigated the performance of our new method for evaluating binding conformation of drug candidates to the InhA enzyme, which were performed by cross-docking experiments between a 20 ns MD trajectory and 20 different ligands. Statistical analyses showed that the novel ensemble, which is represented by only 0.48% of the MD conformations, was able to reproduce 75% of all dynamic behaviors within the binding cavity for the docking experiments performed. Moreover, this new approach not only outperforms the other two RMSD-clustering solutions, but it also shows to be a promising strategy to distill

  11. Trajectories in Operating a Handheld Tool

    ERIC Educational Resources Information Center

    Heuer, Herbert; Sulzenbruck, Sandra

    2009-01-01

    The authors studied the trajectories of the hand and of the tip of a handheld sliding first-order lever in aiming movements. With this kind of tool, straight trajectories of the hand are generally associated with curved trajectories of the tip of the lever and vice versa. Trajectories of the tip of the lever exhibited smaller deviations from…

  12. PoopMD, a Mobile Health Application, Accurately Identifies Infant Acholic Stools.

    PubMed

    Franciscovich, Amy; Vaidya, Dhananjay; Doyle, Joe; Bolinger, Josh; Capdevila, Montserrat; Rice, Marcus; Hancock, Leslie; Mahr, Tanya; Mogul, Douglas B

    2015-01-01

    Biliary atresia (BA) is the leading cause of pediatric end-stage liver disease in the United States. Education of parents in the perinatal period with stool cards depicting acholic and normal stools has been associated with improved time-to-diagnosis and survival in BA. PoopMD is a mobile application that utilizes a smartphone's camera and color recognition software to analyze an infant's stool and determine if additional follow-up is indicated. PoopMD was developed using custom HTML5/CSS3 and wrapped to work on iOS and Android platforms. In order to define the gold standard regarding stool color, seven pediatricians were asked to review 45 photographs of infant stool and rate them as acholic, normal, or indeterminate. Samples for which 6+ pediatricians demonstrated agreement defined the gold standard, and only these samples were included in the analysis. Accuracy of PoopMD was assessed using an iPhone 5s with incandescent lighting. Variability in analysis of stool photographs as acholic versus normal with intermediate rating weighted as 50% agreement (kappa) was compared between three laypeople and one expert user. Variability in output was also assessed between an iPhone 5s and a Samsung Galaxy S4, as well as between incandescent lighting and compact fluorescent lighting. Six-plus pediatricians agreed on 27 normal and 7 acholic photographs; no photographs were defined as indeterminate. The sensitivity was 7/7 (100%). The specificity was 24/27 (89%) with 3/27 labeled as indeterminate; no photos of normal stool were labeled as acholic. The Laplace-smoothed positive likelihood ratio was 6.44 (95% CI 2.52 to 16.48) and the negative likelihood ratio was 0.13 (95% CI 0.02 to 0.83). kappauser was 0.68, kappaphone was 0.88, and kappalight was 0.81. Therefore, in this pilot study, PoopMD accurately differentiates acholic from normal color with substantial agreement across users, and almost perfect agreement across two popular smartphones and ambient light settings. PoopMD

  13. Cummins MD & HD Accessory Hybridization CRADA -Annual Report FY15

    SciTech Connect

    Deter, Dean D.

    2015-10-01

    There are many areas of MD and HD vehicles that can be improved by new technologies and optimized control strategies. Component optimization and idle reduction need to be addressed, this is best done by a two part approach that includes selecting the best component technology, and/or architecture, and optimized controls that are vehicle focused. While this is a common focus in the light duty industry it has been gaining momentum in the MD and HD market as the market gets more competitive and the regulations become more stringent. When looking into systems optimization and idle reduction technologies, affected vehicle systems must first be considered, and if possible included in the new architecture to get the most benefit out of these new capabilities. Typically, when looking into idle reduction or component optimization for MD/HD, the vehicle s accessories become a prime candidate for electrification or hybridization. While this has already been studied on light duty vehicles (especially on hybrids and electric vehicles) it has not made any head way or market penetration in most MD and HD applications. If hybrids and electric MD and HD vehicles begin to break into the market this would be a necessary step into the ability to make those vehicles successful by allowing for independent, optimized operation separate from the engine.

  14. MD Family Medicine - Calicut experience: History is made here

    PubMed Central

    Roshni, M.

    2016-01-01

    Government Medical College, Calicut, Kerala - the first medical college in India to start Doctor of Medicine (MD) in family medicine as a postgraduate course. This was in the year 2012. Till date, this is the only medical college to have MD Family Medicine program in India. The college was allowed two MD Family Medicine seats per year by the Medical Council of India, and this is a 3 year course. The first batch of MD Family Medicine students has passed out from the Government Medical College, Calicut in July 2015. In this article, the author, who has been working as an assistant professor in the Department of Family Medicine, ever since the department started in the year 2012, shares her experiences in setting up the department, its functioning and the achievement of bringing out the first batch of successful MD Family Medicine specialists. Another laurel, of which the institution is proud of, is that they were able to incorporate family medicine teaching program in the MBBS curriculum. A brief introduction about Government Medical College, Calicut, is also given. PMID:27843820

  15. Academic trajectories of newcomer immigrant youth.

    PubMed

    Suárez-Orozco, Carola; Gaytán, Francisco X; Bang, Hee Jin; Pakes, Juliana; O'Connor, Erin; Rhodes, Jean

    2010-05-01

    Immigration to the United States presents both challenges and opportunities that affect students' academic achievement. Using a 5-year longitudinal, mixed-methods approach, we identified varying academic trajectories of newcomer immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve analysis revealed that although some newcomer students performed at high or improving levels over time, others showed diminishing performance. Multinomial logistic regressions identified significant group differences in academic trajectories, particularly between the high-achieving youth and the other groups. In keeping with ecological-developmental and stage-environment fit theories, School Characteristics (school segregation rate, school poverty rate, and student perceptions of school violence), Family Characteristics (maternal education, parental employment, and household structure), and Individual Characteristics (academic English proficiency, academic engagement, psychological symptoms, gender, and 2 age-related risk factors, number of school transitions and being overaged for grade placement) were associated with different trajectories of academic performance. A series of case studies triangulate many of the quantitative findings as well as illuminate patterns that were not detected in the quantitative data. Thus, the mixed-methods approach sheds light on the cumulative developmental challenges that immigrant students face as they adjust to their new educational settings.

  16. Hyper-X Post-Flight Trajectory Reconstruction

    NASA Technical Reports Server (NTRS)

    Karlgaard, Christopher D.; Tartabini, Paul V.; Blanchard, RobertC.; Kirsch, Michael; Toniolo, Matthew D.

    2004-01-01

    This paper discusses the formulation and development of a trajectory reconstruction tool for the NASA X{43A/Hyper{X high speed research vehicle, and its implementation for the reconstruction and analysis of ight test data. Extended Kalman ltering techniques are employed to reconstruct the trajectory of the vehicle, based upon numerical integration of inertial measurement data along with redundant measurements of the vehicle state. The equations of motion are formulated in order to include the effects of several systematic error sources, whose values may also be estimated by the ltering routines. Additionally, smoothing algorithms have been implemented in which the nal value of the state (or an augmented state that includes other systematic error parameters to be estimated) and covariance are propagated back to the initial time to generate the best-estimated trajectory, based upon all available data. The methods are applied to the problem of reconstructing the trajectory of the Hyper-X vehicle from ight data.

  17. Molecular cloning and functional characterization of MdSOS2 reveals its involvement in salt tolerance in apple callus and Arabidopsis.

    PubMed

    Hu, Da-Gang; Li, Ming; Luo, Hua; Dong, Qing-Long; Yao, Yu-Xin; You, Chun-Xiang; Hao, Yu-Jin

    2012-04-01

    Plants respond to various environmental stresses by activating "stress genes". CIPKs (CBL-interacting protein kinases) family genes play an important role in the process of stress response. In this study, a CIPK gene MdSOS2 was isolated from apple (Malus × Domestica). Sequence alignment and phylogenetic analysis showed that it is highly similar with Arabidopsis AtSOS2 and contained the conserved domains and motifs. Expression analysis demonstrated that MdSOS2 expressed in all tested organs at different levels, and positively in response to salt stress. Furthermore, the ectopic expression of MdSOS2 complemented the function of Arabidopsis sos2 mutant, and conferred enhanced salt tolerance to the transgenic Arabidopsis. Yeast two-hybrid assay indicated that the N-terminal of MdSOS2 protein physically interacted with MdSOS3 and AtSOS3, respectively, suggesting that SOS pathway operates in apple tree. Finally, MdSOS2 overexpression enhanced, while its suppression reduced the tolerance to salt in transgenic apple calluses, indicating that MdSOS2 acts as a positive regulator in response to salt stress in apple.

  18. A dsRNA-binding protein MdDRB1 associated with miRNA biogenesis modifies adventitious rooting and tree architecture in apple.

    PubMed

    You, Chun-Xiang; Zhao, Qiang; Wang, Xiao-Fei; Xie, Xing-Bin; Feng, Xiao-Ming; Zhao, Ling-Ling; Shu, Huai-Rui; Hao, Yu-Jin

    2014-02-01

    Although numerous miRNAs have been already isolated from fruit trees, knowledge about miRNA biogenesis is largely unknown in fruit trees. Double-strand RNA-binding (DRB) protein plays an important role in miRNA processing and maturation; however, its role in the regulation of economically important traits is not clear yet in fruit trees. EST blast and RACE amplification were performed to isolate apple MdDRB1 gene. Following expression analysis, RNA binding and protein interaction assays, MdDRB1 was transformed into apple callus and in vitro tissue cultures to characterize the functions of MdDRB1 in miRNA biogenesis, adventitious rooting, leaf development and tree growth habit. MdDRB1 contained two highly conserved DRB domains. Its transcripts existed in all tissues tested and are induced by hormones. It bound to double-strand RNAs and interacted with AtDCL1 (Dicer-Like 1) and MdDCL1. Chip assay indicated its role in miRNA biogenesis. Transgenic analysis showed that MdDRB1 controls adventitious rooting, leaf curvature and tree architecture by modulating the accumulation of miRNAs and the transcript levels of miRNA target genes. Our results demonstrated that MdDRB1 functions in the miRNA biogenesis in a conserved way and that it is a master regulator in the formation of economically important traits in fruit trees.

  19. 3MdB: the Mexican Million Models database

    NASA Astrophysics Data System (ADS)

    Morisset, C.; Delgado-Inglada, G.

    2014-10-01

    The 3MdB is an original effort to construct a large multipurpose database of photoionization models. This is a more modern version of a previous attempt based on Cloudy3D and IDL tools. It is accessed by MySQL requests. The models are obtained using the well known and widely used Cloudy photoionization code (Ferland et al, 2013). The database is aimed to host grids of models with different references to identify each project and to facilitate the extraction of the desired data. We present here a description of the way the database is managed and some of the projects that use 3MdB. Anybody can ask for a grid to be run and stored in 3MdB, to increase the visibility of the grid and the potential side applications of it.

  20. CoMD Implementation Suite in Emerging Programming Models

    SciTech Connect

    Haque, Riyaz; Reeve, Sam; Juallmes, Luc; Asal, Sameer Abu; Landmehr, Aaron; Gaffer, Sanian; Teodor Bercea, Gheorghe; Rubinstein, Zach

    2014-09-23

    CoMD-Em is a software implementation suite of the CoMD [4] proxy app using different emerging programming models. It is intended to analyze the features and capabilities of novel programming models that could help ensure code and performance portability and scalability across heterogeneous platforms while improving programmer productivity. Another goal is to provide the authors and venders with some meaningful feedback regarding the capabilities and limitations of their models. The actual application is a classical molecular dynamics (MD) simulation using either the Lennard-Jones method (LJ) or the embedded atom method (EAM) for primary particle interaction. The code can be extended to support alternate interaction models. The code is expected ro run on a wide class of heterogeneous hardware configurations like shard/distributed/hybrid memory, GPU's and any other platform supported by the underlying programming model.

  1. Trajectory-Based Loads for the Ares I-X Test Flight Vehicle

    NASA Technical Reports Server (NTRS)

    Vause, Roland F.; Starr, Brett R.

    2011-01-01

    In trajectory-based loads, the structural engineer treats each point on the trajectory as a load case. Distributed aero, inertial, and propulsion forces are developed for the structural model which are equivalent to the integrated values of the trajectory model. Free-body diagrams are then used to solve for the internal forces, or loads, that keep the applied aero, inertial, and propulsion forces in dynamic equilibrium. There are several advantages to using trajectory-based loads. First, consistency is maintained between the integrated equilibrium equations of the trajectory analysis and the distributed equilibrium equations of the structural analysis. Second, the structural loads equations are tied to the uncertainty model for the trajectory systems analysis model. Atmosphere, aero, propulsion, mass property, and controls uncertainty models all feed into the dispersions that are generated for the trajectory systems analysis model. Changes in any of these input models will affect structural loads response. The trajectory systems model manages these inputs as well as the output from the structural model over thousands of dispersed cases. Large structural models with hundreds of thousands of degrees of freedom would execute too slowly to be an efficient part of several thousand system analyses. Trajectory-based loads provide a means for the structures discipline to be included in the integrated systems analysis. Successful applications of trajectory-based loads methods for the Ares I-X vehicle are covered in this paper. Preliminary design loads were based on 2000 trajectories using Monte Carlo dispersions. Range safety loads were tied to 8423 malfunction turn trajectories. In addition, active control system loads were based on 2000 preflight trajectories using Monte Carlo dispersions.

  2. Apple MdACS6 Regulates Ethylene Biosynthesis During Fruit Development Involving Ethylene-Responsive Factor.

    PubMed

    Li, Tong; Tan, Dongmei; Liu, Zhi; Jiang, Zhongyu; Wei, Yun; Zhang, Lichao; Li, Xinyue; Yuan, Hui; Wang, Aide

    2015-10-01

    Ethylene biosynthesis in plants involves different 1-aminocyclopropane-1-carboxylic acid synthase (ACS) genes. The regulation of each ACS gene during fruit development is unclear. Here, we characterized another apple (Malus×domestica) ACS gene, MdACS6. The transcript of MdACS6 was observed not only in fruits but also in other tissues. During fruit development, MdACS6 was initiated at a much earlier stage, whereas MdACS3a and MdACS1 began to be expressed at 35 d before harvest and immediateley after harvest, respectively. Moreover, the enzyme activity of MdACS6 was significantly lower than that of MdACS3a and MdACS1, accounting for the low ethylene biosynthesis in young fruits. Overexpression of MdACS6 (MdACS6-OE) by transient assay in apple showed enhanced ethylene production, and MdACS3a was induced in MdACS6-OE fruits but not in control fruits. In MdACS6 apple fruits silenced by the virus-induced gene silencing (VIGS) system (MdACS6-AN), neither ethylene production nor MdACS3a transcript was detectable. In order to explore the mechanism through which MdACS3a was induced in MdACS6-OE fruits, we investigated the expression of apple ethylene-responsive factor (ERF) genes. The results showed that the expression of MdERF2 was induced in MdACS6-OE fruits and inhibited in MdACS6-AN fruits. Yeast one-hybrid assay showed that MdERF2 protein could bind to the promoter of MdACS3a. Moreover, down-regulation of MdERF2 in apple flesh callus led to a decrease of MdACS3a expression, demonstrating the regulation of MdERF2 on MdACS3a. The mechanism through which MdACS6 regulates the action of MdACS3a was discussed.

  3. Lunar Landing Trajectory Design for Onboard Hazard Detection and Avoidance

    NASA Technical Reports Server (NTRS)

    Paschall, Steve; Brady, Tye; Sostaric, Ron

    2009-01-01

    The Autonomous Landing and Hazard Avoidance Technology (ALHAT) Project is developing the software and hardware technology needed to support a safe and precise landing for the next generation of lunar missions. ALHAT provides this capability through terrain-relative navigation measurements to enhance global-scale precision, an onboard hazard detection system to select safe landing locations, and an Autonomous Guidance, Navigation, and Control (AGNC) capability to process these measurements and safely direct the vehicle to a landing location. This paper focuses on the key trajectory design issues relevant to providing an onboard Hazard Detection and Avoidance (HDA) capability for the lander. Hazard detection can be accomplished by the crew visually scanning the terrain through a window, a sensor system imaging the terrain, or some combination of both. For ALHAT, this hazard detection activity is provided by a sensor system, which either augments the crew s perception or entirely replaces the crew in the case of a robotic landing. Detecting hazards influences the trajectory design by requiring the proper perspective, range to the landing site, and sufficient time to view the terrain. Following this, the trajectory design must provide additional time to process this information and make a decision about where to safely land. During the final part of the HDA process, the trajectory design must provide sufficient margin to enable a hazard avoidance maneuver. In order to demonstrate the effects of these constraints on the landing trajectory, a tradespace of trajectory designs was created for the initial ALHAT Design Analysis Cycle (ALDAC-1) and each case evaluated with these HDA constraints active. The ALHAT analysis process, described in this paper, narrows down this tradespace and subsequently better defines the trajectory design needed to support onboard HDA. Future ALDACs will enhance this trajectory design by balancing these issues and others in an overall system

  4. Identifying Trajectories of Borderline Personality Features in Adolescence

    PubMed Central

    Haltigan, John D.

    2016-01-01

    Objective: To examine trajectories of adolescent borderline personality (BP) features in a normative-risk cohort (n = 566) of Canadian children assessed at ages 13, 14, 15, and 16 and childhood predictors of trajectory group membership assessed at ages 8, 10, 11, and 12. Method: Data were drawn from the McMaster Teen Study, an on-going study examining relations among bullying, mental health, and academic achievement. Participants and their parents completed a battery of mental health and peer relations questionnaires at each wave of the study. Academic competence was assessed at age 8 (Grade 3). Latent class growth analysis, analysis of variance, and logistic regression were used to analyze the data. Results: Three distinct BP features trajectory groups were identified: elevated or rising, intermediate or stable, and low or stable. Parent- and child-reported mental health symptoms, peer relations risk factors, and intra-individual risk factors were significant predictors of elevated or rising and intermediate or stable trajectory groups. Child-reported attention-deficit hyperactivity disorder (ADHD) and somatization symptoms uniquely predicted elevated or rising trajectory group membership, whereas parent-reported anxiety and child-reported ADHD symptoms uniquely predicted intermediate or stable trajectory group membership. Child-reported somatization symptoms was the only predictor to differentiate the intermediate or stable and elevated or rising trajectory groups (OR 1.15, 95% CI 1.04 to 1.28). Associations between child-reported reactive temperament and elevated BP features trajectory group membership were 10.23 times higher among children who were bullied, supporting a diathesis–stress pathway in the development of BP features for these youth. Conclusions: Findings demonstrate the heterogeneous course of BP features in early adolescence and shed light on the potential prodromal course of later borderline personality disorder. PMID:27254092

  5. Ion drive performance and trajectories

    NASA Technical Reports Server (NTRS)

    Yen, C. L.

    1978-01-01

    The use of Solar Electric Propulsion (SEP) for the Solar Probe Mission is addressed. The dependence of the payload mass on the site of the SEP and the flight time are described on the basis of preliminary data. The range of hardware expected to be available in the 1980's is summarized. There are several classes of optimal low-thrust trajectories for the Solar Probe Mission. These are trajectory types A, B, C corresponding to one, two, or three orbital revolutions, respectively. Plots of transfer trajectories corresponding to type-A, type-A with a Venus Swingby, type-B, and type-C with ab Icarus Rendezvous are shown. A summary of the SEP performance is given.

  6. Trajectory generation of space telerobots

    NASA Technical Reports Server (NTRS)

    Lumia, R.; Wavering, A. J.

    1989-01-01

    The purpose is to review a variety of trajectory generation techniques which may be applied to space telerobots and to identify problems which need to be addressed in future telerobot motion control systems. As a starting point for the development of motion generation systems for space telerobots, the operation and limitations of traditional path-oriented trajectory generation approaches are discussed. This discussion leads to a description of more advanced techniques which have been demonstrated in research laboratories, and their potential applicability to space telerobots. Examples of this work include systems that incorporate sensory-interactive motion capability and optimal motion planning. Additional considerations which need to be addressed for motion control of a space telerobot are described, such as redundancy resolution and the description and generation of constrained and multi-armed cooperative motions. A task decomposition module for a hierarchical telerobot control system which will serve as a testbed for trajectory generation approaches which address these issues is also discussed briefly.

  7. Single fiber electromyography (SFEMG) in mitochondrial diseases (MD).

    PubMed

    Cruz-Martínez, A; Arpa, J; Santiago, S; Pérez-Conde, C; Gutiérrez-Molina, M; Campos, Y

    2004-01-01

    Conventional EMG, nerve conduction studies and SFEMG were performed in 18 patients with various phenotypes of MD. 14 cases showed findings consistent with mild myopathy, 2 patients signs of sensory-motor axonal neuropathy and 2 cases a mixture of myopathy and axonal neuropathy. Motor unit fiber density was mild increased in 8 out of 13 tested cases. Jitter was abnormal in 10 out of 18 tested patients. Jitter abnormalities were not related to myopathic or neurogenic features in the EMG study, and may be observed in muscles without clinical weakness. The results suggest the existence of neuromuscular transmission disturbances in patients with MD.

  8. David Kasner, MD, and the Road to Pars Plana Vitrectomy

    PubMed Central

    Blodi, Christopher F.

    2016-01-01

    David Kasner, MD (1927–2001), used his extensive dissections of eye bank eyes and experiences in teaching cataract surgery to resident physicians to realize that excision of vitreous when present in the anterior chamber of eyes undergoing cataract surgery was preferable to prior intraoperative procedures. Noting that eyes tolerated his maneuvers, he then performed planned subtotal open-sky vitrectomies; first on a traumatized eye in 1961, then on two eyes of patients with amyloidosis (1966–1967). The success of these operations was noted by others, most particularly Robert Machemer, MD. Kasner’s work directly led to further surgical developments, including closed pars plana vitrectomy. PMID:27660504

  9. Rescheduling Child Sexual Trajectories

    ERIC Educational Resources Information Center

    Yuill, Richard

    2008-01-01

    The author comments on Diederik Janssen's essay "ReQueering Queer Youth Development: A Post-Developmental Approach to Childhood and Pedagogy," commenting that Janssen's analysis can inform both both materialist and post-structuralist understandings of children's sexuality by shifting focus from children as fetishized objects or as a group…

  10. Detection of germline BRCA1 mutations by Multiple-Dye Cleavase Fragment Length Polymorphism (MD-CFLP) method

    PubMed Central

    Casadei, S; Cortesi, L; Pensotti, V; Radice, P; Pierotti, M; Amadori, D; Calistri, D

    2001-01-01

    We describe the Multiple-Dye Cleavase Fragment Length Polymorphism (MD-CFLP) method set up for a sensitive and preliminary rapid screening of BRCA1 mutations. We analysed exons 11 and 16, which are known to cover slightly more than 70% of the whole coding region of the gene, subdivided into 4 amplicons and labelled with different fluorescent dUTPs. MD-CFLP was first utilised on a panel of 30 DNA samples in which the presence of single-base substitutions or small deletions/insertions had been previously identified by direct sequencing as gold standard, in order to define the optimal conditions in terms of PCR amplification and temperature of digestion. In a second step, we blindly analysed 21 DNA samples by MD-CFLP to verify its reliability. The sensitivity and specificity of MD-CFLP were both 100% in the first study, and 80% and 94%, respectively, in the blind sample assay. Our results demonstrate the capability of the MD-CFLP method to detect DNA sequence alterations in fragments of more than 1 kb. We conclude that CFLP is a powerful tool in mutational analysis, offering reliable results in a shorter time and at a lower cost than conventional methods, and its potential can be enhanced when internal fluorescent labelling and laser detection are used. © 2001 Cancer Research Campaignhttp://www.bjcancer.com PMID:11556835

  11. Predicting Adult Offenders' Criminal Trajectories from Their Juvenile Criminal Trajectories.

    ERIC Educational Resources Information Center

    Day, David M.; Bevc, Irene; Rosenthal, Jeffrey S.; Duchesne, Thierry; Rossman, Lianne; Theodor, Frances

    This study examined the relationship between adolescent (10-17 years) criminal offending and adult (18-33 years) offending. The sample comprised 378 Canadian male offenders whose criminal trajectory was tracked for an average of 12.1 years, from adolescence into adulthood. Their man age at the time of the most recent follow-up was 27.5 years. The…

  12. Locomotor Trajectories of Stroke Patients during Oriented Gait and Turning

    PubMed Central

    Van Hamme, Angele; Bensmail, Djamel

    2016-01-01

    Background The Timed Up and Go (TUG) test is widely used to assess locomotion in patients with stroke and is considered to predict the risk of falls. The analysis of locomotor trajectories during the TUG appears pertinent in stroke patients. The aims of this study were i) to analyze locomotor trajectories in patients with stroke during the walking and turning sub-tasks of the TUG, and to compare them with healthy subjects, ii) to determine whether trajectory parameters provide additional information to that provided by the conventional measure (performance time), iii) to compare the trajectory parameters of fallers and non-fallers with stroke and of patients with right and left hemisphere stroke, and iv) to evaluate correlations between trajectory parameters and Berg Balance Scale scores. Methods 29 patients with stroke (mean age 54.2±12.2 years, 18 men, 8 fallers) and 25 healthy subjects (mean age 51.6±8.7 years, 11 men) underwent three-dimensional analysis of the TUG. The trajectory of the center of mass was analyzed by calculation of the global trajectory length, Hausdorff distance and Dynamic Time Warping. The parameters were compared with a reference trajectory during the total task and each sub-task (Go, Turn, Return) of the TUG. Results Values of trajectory parameters were significantly higher for the stroke group during the total TUG and the Go and Turn sub-tasks (p<0.05). Moreover, logistic regression indicated that these parameters better discriminated stroke patients and healthy subjects than the conventional timed performance during the Go sub-task. In addition, fallers were distinguished by higher Dynamic Time Warping during the Go (p<0.05). There were no differences between patients with right and left hemisphere stroke. Discussion and Conclusion The trajectories of the stroke patients were longer and more deviated during the turn and the preceding phase. Trajectory parameters provided additional information to timed performance of this locomotor

  13. MdMYB9 and MdMYB11 are involved in the regulation of the JA-induced biosynthesis of anthocyanin and proanthocyanidin in apples.

    PubMed

    An, Xiu-Hong; Tian, Yi; Chen, Ke-Qin; Liu, Xiao-Juan; Liu, Dan-Dan; Xie, Xing-Bin; Cheng, Cun-Gang; Cong, Pei-Hua; Hao, Yu-Jin

    2015-04-01

    Anthocyanin and proanthocyanidin (PA) are important secondary metabolites and beneficial to human health. Their biosynthesis is induced by jasmonate (JA) treatment and regulated by MYB transcription factors (TFs). However, which and how MYB TFs regulate this process is largely unknown in apple. In this study, MdMYB9 and MdMYB11 which were induced by methyl jasmonate (MeJA) were functionally characterized. Overexpression of MdMYB9 or MdMYB11 promoted not only anthocyanin but also PA accumulation in apple calluses, and the accumulation was further enhanced by MeJA. Subsequently, yeast two-hybrid, pull-down and bimolecular fluorescence complementation assays showed that both MYB proteins interact with MdbHLH3. Moreover, Jasmonate ZIM-domain (MdJAZ) proteins interact with MdbHLH3. Furthermore, chromatin immunoprecipitation-quantitative PCR and yeast one-hybrid assays demonstrated that both MdMYB9 and MdMYB11 bind to the promoters of ANS, ANR and LAR, whereas MdbHLH3 is recruited to the promoters of MdMYB9 and MdMYB11 and regulates their transcription. In addition, transient expression assays indicated that overexpression of MdJAZ2 inhibits the recruitment of MdbHLH3 to the promoters of MdMYB9 and MdMYB11. Our findings provide new insight into the mechanism of how MeJA regulates anthocyanin and PA accumulation in apple.

  14. Novel plasmid conferring kanamycin and tetracycline resistance in the turkey-derived Campylobacter jejuni strain 11601MD.

    PubMed

    Crespo, M D; Altermann, E; Olson, J; Miller, W G; Chandrashekhar, K; Kathariou, S

    2016-07-01

    In Campylobacter spp., resistance to the antimicrobials kanamycin and tetracycline is frequently associated with plasmid-borne genes. However, relatively few plasmids of Campylobacter jejuni have been fully characterized to date. A novel plasmid (p11601MD; 44,095nt) harboring tet(O) was identified in C. jejuni strain 11601MD, which was isolated from the jejunum of a turkey produced conventionally in North Carolina. Analysis of the p11601MD sequence revealed the presence of a high-GC content cassette with four genes that included tet(O) and a putative aminoglycoside transferase gene (aphA-3) highly similar to kanamycin resistance determinants. Several genes putatively involved in conjugative transfer were also identified on the plasmid. These findings will contribute to a better understanding of the distribution of potentially self-mobilizing plasmids harboring antibiotic resistance determinants in Campylobacter spp. from turkeys and other sources.

  15. Trajectory Design Considerations for Exploration Mission 1

    NASA Technical Reports Server (NTRS)

    Dawn, Timothy F.; Gutkowski, Jeffrey P.; Batcha, Amelia L.

    2017-01-01

    Exploration Mission 1 (EM-1) will be the first mission to send an uncrewed Orion vehicle to cislunar space in 2018, targeted to a Distant Retrograde Orbit (DRO). Analysis of EM-1 DRO mission opportunities in 2018 help characterize mission parameters that are of interest to other subsystems (e.g., power, thermal, communications, flight operations, etc). Subsystems request mission design trades which include: landing lighting, addition of an Orion main engine checkout burn, and use of auxiliary thruster only cases. This paper examines the evolving trade studies that incorporate subsystem feedback and demonstrate the feasibility of these constrained mission trajectory designs and contingencies.

  16. Modulation of CD14 and TLR4.MD-2 activities by a synthetic lipid A mimetic

    PubMed Central

    Cighetti, Roberto; Ciaramelli, Carlotta; Sestito, Stefania Enza; Zanoni, Ivan; Kubik, Łukasz; Ardá-Freire, Ana; Calabrese, Valentina; Granucci, Francesca; Jerala, Roman; Martín-Santamaría, Sonsoles; Jiménez-Barbero, Jesus

    2014-01-01

    Monosaccharide lipid A mimetics composed by a glucosamine core linked to two fatty acid chains and bearing one or two phosphates have been synthesized. While compounds 1 and 2, with one phosphate group, were practically inactive in inhibiting LPS-induced TLR4 signaling and cytokine production in HEK-blue™ cells and murine macrophages, compound 3 with two phosphates was found to be active in efficiently inhibiting TLR4 signal in both cell types. The direct interaction of molecule 3 with MD-2 co-receptor has been investigated by means of NMR and molecular modeling/docking analysis. This compound also interacts directly with CD14 receptor, stimulating its internalization by endocytosis. Experiments on macrophages show that the effect on CD14 reinforces the activity on MD-2.TLR4, because compound 3 activity is higher when CD14 is important for TLR4 signaling i,e, at low LPS concentration. The dual MD-2 and CD14 targeting, accompanied by good solubility in water and lack of toxicity, suggests the use of monosaccharide 3 as a lead compound to develop drugs directed against TLR4-related syndromes. PMID:24339336

  17. Efficient quantum trajectory representation of wavefunctions evolving in imaginary time

    SciTech Connect

    Garashchuk, Sophya; Mazzuca, James; Vazhappilly, Tijo

    2011-07-21

    The Boltzmann evolution of a wavefunction can be recast as imaginary-time dynamics of the quantum trajectory ensemble. The quantum effects arise from the momentum-dependent quantum potential - computed approximately to be practical in high-dimensional systems - influencing the trajectories in addition to the external classical potential [S. Garashchuk, J. Chem. Phys. 132, 014112 (2010)]. For a nodeless wavefunction represented as {psi}(x, t) = exp ( -S(x, t)/({Dirac_h}/2{pi})) with the trajectory momenta defined by {nabla}S(x, t), analysis of the Lagrangian and Eulerian evolution shows that for bound potentials the former is more accurate while the latter is more practical because the Lagrangian quantum trajectories diverge with time. Introduction of stationary and time-dependent components into the wavefunction representation generates new Lagrangian-type dynamics where the trajectory spreading is controlled improving efficiency of the trajectory description. As an illustration, different types of dynamics are used to compute zero-point energy of a strongly anharmonic well and low-lying eigenstates of a high-dimensional coupled harmonic system.

  18. Survey and Method for Determination of Trajectory Predictor Requirements

    NASA Technical Reports Server (NTRS)

    Rentas, Tamika L.; Green, Steven M.; Cate, Karen Tung

    2009-01-01

    A survey of air-traffic-management researchers, representing a broad range of automation applications, was conducted to document trajectory-predictor requirements for future decision-support systems. Results indicated that the researchers were unable to articulate a basic set of trajectory-prediction requirements for their automation concepts. Survey responses showed the need to establish a process to help developers determine the trajectory-predictor-performance requirements for their concepts. Two methods for determining trajectory-predictor requirements are introduced. A fast-time simulation method is discussed that captures the sensitivity of a concept to the performance of its trajectory-prediction capability. A characterization method is proposed to provide quicker, yet less precise results, based on analysis and simulation to characterize the trajectory-prediction errors associated with key modeling options for a specific concept. Concept developers can then identify the relative sizes of errors associated with key modeling options, and qualitatively determine which options lead to significant errors. The characterization method is demonstrated for a case study involving future airport surface traffic management automation. Of the top four sources of error, results indicated that the error associated with accelerations to and from turn speeds was unacceptable, the error associated with the turn path model was acceptable, and the error associated with taxi-speed estimation was of concern and needed a higher fidelity concept simulation to obtain a more precise result

  19. A Final Approach Trajectory Model for Current Operations

    NASA Technical Reports Server (NTRS)

    Gong, Chester; Sadovsky, Alexander

    2010-01-01

    Predicting accurate trajectories with limited intent information is a challenge faced by air traffic management decision support tools in operation today. One such tool is the FAA's Terminal Proximity Alert system which is intended to assist controllers in maintaining safe separation of arrival aircraft during final approach. In an effort to improve the performance of such tools, two final approach trajectory models are proposed; one based on polynomial interpolation, the other on the Fourier transform. These models were tested against actual traffic data and used to study effects of the key final approach trajectory modeling parameters of wind, aircraft type, and weight class, on trajectory prediction accuracy. Using only the limited intent data available to today's ATM system, both the polynomial interpolation and Fourier transform models showed improved trajectory prediction accuracy over a baseline dead reckoning model. Analysis of actual arrival traffic showed that this improved trajectory prediction accuracy leads to improved inter-arrival separation prediction accuracy for longer look ahead times. The difference in mean inter-arrival separation prediction error between the Fourier transform and dead reckoning models was 0.2 nmi for a look ahead time of 120 sec, a 33 percent improvement, with a corresponding 32 percent improvement in standard deviation.

  20. Titan Explorer Entry, Descent and Landing Trajectory Design

    NASA Technical Reports Server (NTRS)

    Fisher, Jody L.; Lindberg, Robert E.; Lockwood, Mary Kae

    2006-01-01

    The Titan Explorer mission concept includes an orbiter, entry probe and inflatable airship designed to take remote and in-situ measurements of Titan's atmosphere. A modified entry, descent and landing trajectory at Titan that incorporates mid-air airship inflation (under a parachute) and separation is developed and examined for Titan Explorer. The feasibility of mid-air inflation and deployment of an airship under a parachute is determined by implementing and validating an airship buoyancy and inflation model in the trajectory simulation program, Program to Optimize Simulated Trajectories II (POST2). A nominal POST2 trajectory simulation case study is generated which examines different descent scenarios by varying airship inflation duration, orientation, and separation. The buoyancy model incorporation into POST2 is new to the software and may be used in future trajectory simulations. Each case from the nominal POST2 trajectory case study simulates a successful separation between the parachute and airship systems with sufficient velocity change as to alter their paths to avoid collision throughout their descent. The airship and heatshield also separate acceptably with a minimum distance of separation from the parachute system of 1.5 km. This analysis shows the feasibility of airship inflation on a parachute for different orientations, airship separation at various inflation times, and preparation for level-flight at Titan.