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Sample records for accurate timely information

  1. The utility of accurate mass and LC elution time information in the analysis of complex proteomes

    SciTech Connect

    Norbeck, Angela D.; Monroe, Matthew E.; Adkins, Joshua N.; Anderson, Kevin K.; Daly, Don S.; Smith, Richard D.

    2005-08-01

    Theoretical tryptic digests of all predicted proteins from the genomes of three organisms of varying complexity were evaluated for specificity and possible utility of combined peptide accurate mass and predicted LC normalized elution time (NET) information. The uniqueness of each peptide was evaluated using its combined mass (+/- 5 ppm and 1 ppm) and NET value (no constraint, +/- 0.05 and 0.01 on a 0-1 NET scale). The set of peptides both underestimates actual biological complexity due to the lack of specific modifications, and overestimates the expected complexity since many proteins will not be present in the sample or observable on the mass spectrometer because of dynamic range limitations. Once a peptide is identified from an LCMS/MS experiment, its mass and elution time is representative of a unique fingerprint for that peptide. The uniqueness of that fingerprint in comparison to that for the other peptides present is indicative of the ability to confidently identify that peptide based on accurate mass and NET measurements. These measurements can be made using HPLC coupled with high resolution MS in a high-throughput manner. Results show that for organisms with comparatively small proteomes, such as Deinococcus radiodurans, modest mass and elution time accuracies are generally adequate for peptide identifications. For more complex proteomes, increasingly accurate easurements are required. However, the majority of proteins should be uniquely identifiable by using LC-MS with mass accuracies within +/- 1 ppm and elution time easurements within +/- 0.01 NET.

  2. The utility of accurate mass and LC elution time information in the analysis of complex proteomes

    PubMed Central

    Norbeck, Angela D.; Monroe, Matthew E.; Adkins, Joshua N.; Smith, Richard D.

    2007-01-01

    Theoretical tryptic digests of all predicted proteins from the genomes of three organisms of varying complexity were evaluated for specificity and possible utility of combined peptide accurate mass and predicted LC normalized elution time (NET) information. The uniqueness of each peptide was evaluated using its combined mass (+/− 5 ppm and 1 ppm) and NET value (no constraint, +/− 0.05 and 0.01 on a 0–1 NET scale). The set of peptides both underestimates actual biological complexity due to the lack of specific modifications, and overestimates the expected complexity since many proteins will not be present in the sample or observable on the mass spectrometer because of dynamic range limitations. Once a peptide is identified from an LC-MS/MS experiment, its mass and elution time is representative of a unique fingerprint for that peptide. The uniqueness of that fingerprint in comparison to that for the other peptides present is indicative of the ability to confidently identify that peptide based on accurate mass and NET measurements. These measurements can be made using HPLC coupled with high resolution MS in a high-throughput manner. Results show that for organisms with comparatively small proteomes, such as Deinococcus radiodurans, modest mass and elution time accuracies are generally adequate for peptide identifications. For more complex proteomes, increasingly accurate measurements are required. However, the majority of proteins should be uniquely identifiable by using LC-MS with mass accuracies within +/− 1 ppm and elution time measurements within +/− 0.01 NET. PMID:15979333

  3. Computational Time-Accurate Body Movement: Methodology, Validation, and Application

    DTIC Science & Technology

    1995-10-01

    used that had a leading-edge sweep angle of 45 deg and a NACA 64A010 symmetrical airfoil section. A cross section of the pylon is a symmetrical...25 2. Information Flow for the Time-Accurate Store Trajectory Prediction Process . . . . . . . . . 26 3. Pitch Rates for NACA -0012 Airfoil...section are comparisons of the computational results to data for a NACA -0012 airfoil following a predefined pitching motion. Validation of the

  4. Automated utilization review is timely, accurate, efficient.

    PubMed

    Schmitz, H H; Schoenhard, W C

    1976-07-01

    Federal utilization review regulations require that hospitals establish admission and extended stay certification processes and conduct medical care evaluation studies. The computerized review system in use at Deaconess Hospital, St. Louis, has satisfied these regulations with minimum expenditure of time, effort, and money while insuring maximum accuracy and timeliness and consistency of reporting.

  5. Approaching system equilibrium with accurate or not accurate feedback information in a two-route system

    NASA Astrophysics Data System (ADS)

    Zhao, Xiao-mei; Xie, Dong-fan; Li, Qi

    2015-02-01

    With the development of intelligent transport system, advanced information feedback strategies have been developed to reduce traffic congestion and enhance the capacity. However, previous strategies provide accurate information to travelers and our simulation results show that accurate information brings negative effects, especially in delay case. Because travelers prefer to the best condition route with accurate information, and delayed information cannot reflect current traffic condition but past. Then travelers make wrong routing decisions, causing the decrease of the capacity and the increase of oscillations and the system deviating from the equilibrium. To avoid the negative effect, bounded rationality is taken into account by introducing a boundedly rational threshold BR. When difference between two routes is less than the BR, routes have equal probability to be chosen. The bounded rationality is helpful to improve the efficiency in terms of capacity, oscillation and the gap deviating from the system equilibrium.

  6. Student Information Systems Demystified: The Increasing Demand for Accurate, Timely Data Means Schools and Districts Are Relying Heavily on SIS Technologies

    ERIC Educational Resources Information Center

    McIntire, Todd

    2004-01-01

    Student information systems, one of the first applications of computer technology in education, are undergoing a significant transition yet again. The first major shift in SIS technologies occurred about 15 years ago when they evolved from mainframe programs to client-server solutions. Now, vendors across the board are offering centralized…

  7. Accurate Fiber Length Measurement Using Time-of-Flight Technique

    NASA Astrophysics Data System (ADS)

    Terra, Osama; Hussein, Hatem

    2016-06-01

    Fiber artifacts of very well-measured length are required for the calibration of optical time domain reflectometers (OTDR). In this paper accurate length measurement of different fiber lengths using the time-of-flight technique is performed. A setup is proposed to measure accurately lengths from 1 to 40 km at 1,550 and 1,310 nm using high-speed electro-optic modulator and photodetector. This setup offers traceability to the SI unit of time, the second (and hence to meter by definition), by locking the time interval counter to the Global Positioning System (GPS)-disciplined quartz oscillator. Additionally, the length of a recirculating loop artifact is measured and compared with the measurement made for the same fiber by the National Physical Laboratory of United Kingdom (NPL). Finally, a method is proposed to relatively correct the fiber refractive index to allow accurate fiber length measurement.

  8. Multigrid time-accurate integration of Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Arnone, Andrea; Liou, Meng-Sing; Povinelli, Louis A.

    1993-01-01

    Efficient acceleration techniques typical of explicit steady-state solvers are extended to time-accurate calculations. Stability restrictions are greatly reduced by means of a fully implicit time discretization. A four-stage Runge-Kutta scheme with local time stepping, residual smoothing, and multigridding is used instead of traditional time-expensive factorizations. Some applications to natural and forced unsteady viscous flows show the capability of the procedure.

  9. Time-Accurate Numerical Simulations of Synthetic Jet Quiescent Air

    NASA Technical Reports Server (NTRS)

    Rupesh, K-A. B.; Ravi, B. R.; Mittal, R.; Raju, R.; Gallas, Q.; Cattafesta, L.

    2007-01-01

    The unsteady evolution of three-dimensional synthetic jet into quiescent air is studied by time-accurate numerical simulations using a second-order accurate mixed explicit-implicit fractional step scheme on Cartesian grids. Both two-dimensional and three-dimensional calculations of synthetic jet are carried out at a Reynolds number (based on average velocity during the discharge phase of the cycle V(sub j), and jet width d) of 750 and Stokes number of 17.02. The results obtained are assessed against PIV and hotwire measurements provided for the NASA LaRC workshop on CFD validation of synthetic jets.

  10. Extracting Time-Accurate Acceleration Vectors From Nontrivial Accelerometer Arrangements.

    PubMed

    Franck, Jennifer A; Blume, Janet; Crisco, Joseph J; Franck, Christian

    2015-09-01

    Sports-related concussions are of significant concern in many impact sports, and their detection relies on accurate measurements of the head kinematics during impact. Among the most prevalent recording technologies are videography, and more recently, the use of single-axis accelerometers mounted in a helmet, such as the HIT system. Successful extraction of the linear and angular impact accelerations depends on an accurate analysis methodology governed by the equations of motion. Current algorithms are able to estimate the magnitude of acceleration and hit location, but make assumptions about the hit orientation and are often limited in the position and/or orientation of the accelerometers. The newly formulated algorithm presented in this manuscript accurately extracts the full linear and rotational acceleration vectors from a broad arrangement of six single-axis accelerometers directly from the governing set of kinematic equations. The new formulation linearizes the nonlinear centripetal acceleration term with a finite-difference approximation and provides a fast and accurate solution for all six components of acceleration over long time periods (>250 ms). The approximation of the nonlinear centripetal acceleration term provides an accurate computation of the rotational velocity as a function of time and allows for reconstruction of a multiple-impact signal. Furthermore, the algorithm determines the impact location and orientation and can distinguish between glancing, high rotational velocity impacts, or direct impacts through the center of mass. Results are shown for ten simulated impact locations on a headform geometry computed with three different accelerometer configurations in varying degrees of signal noise. Since the algorithm does not require simplifications of the actual impacted geometry, the impact vector, or a specific arrangement of accelerometer orientations, it can be easily applied to many impact investigations in which accurate kinematics need to

  11. Ultra-accurate collaborative information filtering via directed user similarity

    NASA Astrophysics Data System (ADS)

    Guo, Q.; Song, W.-J.; Liu, J.-G.

    2014-07-01

    A key challenge of the collaborative filtering (CF) information filtering is how to obtain the reliable and accurate results with the help of peers' recommendation. Since the similarities from small-degree users to large-degree users would be larger than the ones in opposite direction, the large-degree users' selections are recommended extensively by the traditional second-order CF algorithms. By considering the users' similarity direction and the second-order correlations to depress the influence of mainstream preferences, we present the directed second-order CF (HDCF) algorithm specifically to address the challenge of accuracy and diversity of the CF algorithm. The numerical results for two benchmark data sets, MovieLens and Netflix, show that the accuracy of the new algorithm outperforms the state-of-the-art CF algorithms. Comparing with the CF algorithm based on random walks proposed by Liu et al. (Int. J. Mod. Phys. C, 20 (2009) 285) the average ranking score could reach 0.0767 and 0.0402, which is enhanced by 27.3% and 19.1% for MovieLens and Netflix, respectively. In addition, the diversity, precision and recall are also enhanced greatly. Without relying on any context-specific information, tuning the similarity direction of CF algorithms could obtain accurate and diverse recommendations. This work suggests that the user similarity direction is an important factor to improve the personalized recommendation performance.

  12. RTbox: a device for highly accurate response time measurements.

    PubMed

    Li, Xiangrui; Liang, Zhen; Kleiner, Mario; Lu, Zhong-Lin

    2010-02-01

    Although computer keyboards and mice are frequently used in measuring response times (RTs), the accuracy of these measurements is quite low. Specialized RT collection devices must be used to obtain more accurate measurements. However, all the existing devices have some shortcomings. We have developed and implemented a new, commercially available device, the RTbox, for highly accurate RT measurements. The RTbox has its own microprocessor and high-resolution clock. It can record the identities and timing of button events with high accuracy, unaffected by potential timing uncertainty or biases during data transmission and processing in the host computer. It stores button events until the host computer chooses to retrieve them. The asynchronous storage greatly simplifies the design of user programs. The RTbox can also receive and record external signals as triggers and can measure RTs with respect to external events. The internal clock of the RTbox can be synchronized with the computer clock, so the device can be used without external triggers. A simple USB connection is sufficient to integrate the RTbox with any standard computer and operating system.

  13. Accurate finite difference methods for time-harmonic wave propagation

    NASA Technical Reports Server (NTRS)

    Harari, Isaac; Turkel, Eli

    1994-01-01

    Finite difference methods for solving problems of time-harmonic acoustics are developed and analyzed. Multidimensional inhomogeneous problems with variable, possibly discontinuous, coefficients are considered, accounting for the effects of employing nonuniform grids. A weighted-average representation is less sensitive to transition in wave resolution (due to variable wave numbers or nonuniform grids) than the standard pointwise representation. Further enhancement in method performance is obtained by basing the stencils on generalizations of Pade approximation, or generalized definitions of the derivative, reducing spurious dispersion, anisotropy and reflection, and by improving the representation of source terms. The resulting schemes have fourth-order accurate local truncation error on uniform grids and third order in the nonuniform case. Guidelines for discretization pertaining to grid orientation and resolution are presented.

  14. Quantitative proteomic analysis by accurate mass retention time pairs.

    PubMed

    Silva, Jeffrey C; Denny, Richard; Dorschel, Craig A; Gorenstein, Marc; Kass, Ignatius J; Li, Guo-Zhong; McKenna, Therese; Nold, Michael J; Richardson, Keith; Young, Phillip; Geromanos, Scott

    2005-04-01

    Current methodologies for protein quantitation include 2-dimensional gel electrophoresis techniques, metabolic labeling, and stable isotope labeling methods to name only a few. The current literature illustrates both pros and cons for each of the previously mentioned methodologies. Keeping with the teachings of William of Ockham, "with all things being equal the simplest solution tends to be correct", a simple LC/MS based methodology is presented that allows relative changes in abundance of proteins in highly complex mixtures to be determined. Utilizing a reproducible chromatographic separations system along with the high mass resolution and mass accuracy of an orthogonal time-of-flight mass spectrometer, the quantitative comparison of tens of thousands of ions emanating from identically prepared control and experimental samples can be made. Using this configuration, we can determine the change in relative abundance of a small number of ions between the two conditions solely by accurate mass and retention time. Employing standard operating procedures for both sample preparation and ESI-mass spectrometry, one typically obtains under 5 ppm mass precision and quantitative variations between 10 and 15%. The principal focus of this paper will demonstrate the quantitative aspects of the methodology and continue with a discussion of the associated, complementary qualitative capabilities.

  15. Approaches for the accurate definition of geological time boundaries

    NASA Astrophysics Data System (ADS)

    Schaltegger, Urs; Baresel, Björn; Ovtcharova, Maria; Goudemand, Nicolas; Bucher, Hugo

    2015-04-01

    Which strategies lead to the most precise and accurate date of a given geological boundary? Geological units are usually defined by the occurrence of characteristic taxa and hence boundaries between these geological units correspond to dramatic faunal and/or floral turnovers and they are primarily defined using first or last occurrences of index species, or ideally by the separation interval between two consecutive, characteristic associations of fossil taxa. These boundaries need to be defined in a way that enables their worldwide recognition and correlation across different stratigraphic successions, using tools as different as bio-, magneto-, and chemo-stratigraphy, and astrochronology. Sedimentary sequences can be dated in numerical terms by applying high-precision chemical-abrasion, isotope-dilution, thermal-ionization mass spectrometry (CA-ID-TIMS) U-Pb age determination to zircon (ZrSiO4) in intercalated volcanic ashes. But, though volcanic activity is common in geological history, ashes are not necessarily close to the boundary we would like to date precisely and accurately. In addition, U-Pb zircon data sets may be very complex and difficult to interpret in terms of the age of ash deposition. To overcome these difficulties we use a multi-proxy approach we applied to the precise and accurate dating of the Permo-Triassic and Early-Middle Triassic boundaries in South China. a) Dense sampling of ashes across the critical time interval and a sufficiently large number of analysed zircons per ash sample can guarantee the recognition of all system complexities. Geochronological datasets from U-Pb dating of volcanic zircon may indeed combine effects of i) post-crystallization Pb loss from percolation of hydrothermal fluids (even using chemical abrasion), with ii) age dispersion from prolonged residence of earlier crystallized zircon in the magmatic system. As a result, U-Pb dates of individual zircons are both apparently younger and older than the depositional age

  16. Accurate and Timely Forecasting of CME-Driven Geomagnetic Storms

    NASA Astrophysics Data System (ADS)

    Chen, J.; Kunkel, V.; Skov, T. M.

    2015-12-01

    Wide-spread and severe geomagnetic storms are primarily caused by theejecta of coronal mass ejections (CMEs) that impose long durations ofstrong southward interplanetary magnetic field (IMF) on themagnetosphere, the duration and magnitude of the southward IMF (Bs)being the main determinants of geoeffectiveness. Another importantquantity to forecast is the arrival time of the expected geoeffectiveCME ejecta. In order to accurately forecast these quantities in atimely manner (say, 24--48 hours of advance warning time), it isnecessary to calculate the evolving CME ejecta---its structure andmagnetic field vector in three dimensions---using remote sensing solardata alone. We discuss a method based on the validated erupting fluxrope (EFR) model of CME dynamics. It has been shown using STEREO datathat the model can calculate the correct size, magnetic field, and theplasma parameters of a CME ejecta detected at 1 AU, using the observedCME position-time data alone as input (Kunkel and Chen 2010). Onedisparity is in the arrival time, which is attributed to thesimplified geometry of circular toroidal axis of the CME flux rope.Accordingly, the model has been extended to self-consistently includethe transverse expansion of the flux rope (Kunkel 2012; Kunkel andChen 2015). We show that the extended formulation provides a betterprediction of arrival time even if the CME apex does not propagatedirectly toward the earth. We apply the new method to a number of CMEevents and compare predicted flux ropes at 1 AU to the observed ejectastructures inferred from in situ magnetic and plasma data. The EFRmodel also predicts the asymptotic ambient solar wind speed (Vsw) foreach event, which has not been validated yet. The predicted Vswvalues are tested using the ENLIL model. We discuss the minimum andsufficient required input data for an operational forecasting systemfor predicting the drivers of large geomagnetic storms.Kunkel, V., and Chen, J., ApJ Lett, 715, L80, 2010. Kunkel, V., Ph

  17. A new accurate pill recognition system using imprint information

    NASA Astrophysics Data System (ADS)

    Chen, Zhiyuan; Kamata, Sei-ichiro

    2013-12-01

    Great achievements in modern medicine benefit human beings. Also, it has brought about an explosive growth of pharmaceuticals that current in the market. In daily life, pharmaceuticals sometimes confuse people when they are found unlabeled. In this paper, we propose an automatic pill recognition technique to solve this problem. It functions mainly based on the imprint feature of the pills, which is extracted by proposed MSWT (modified stroke width transform) and described by WSC (weighted shape context). Experiments show that our proposed pill recognition method can reach an accurate rate up to 92.03% within top 5 ranks when trying to classify more than 10 thousand query pill images into around 2000 categories.

  18. Building accurate geometric models from abundant range imaging information

    SciTech Connect

    Diegert, C.; Sackos, J.; Nellums, R.

    1997-05-01

    The authors define two simple metrics for accuracy of models built from range imaging information. They apply the metric to a model built from a recent range image taken at the Laser Radar Development and Evaluation Facility (LDERF), Eglin AFB, using a Scannerless Range Imager (SRI) from Sandia National Laboratories. They also present graphical displays of the residual information produced as a byproduct of this measurement, and discuss mechanisms that these data suggest for further improvement in the performance of this already impressive SRI.

  19. The Good, the Strong, and the Accurate: Preschoolers' Evaluations of Informant Attributes

    ERIC Educational Resources Information Center

    Fusaro, Maria; Corriveau, Kathleen H.; Harris, Paul L.

    2011-01-01

    Much recent evidence shows that preschoolers are sensitive to the accuracy of an informant. Faced with two informants, one of whom names familiar objects accurately and the other inaccurately, preschoolers subsequently prefer to learn the names and functions of unfamiliar objects from the more accurate informant. This study examined the inference…

  20. It's About Time: How Accurate Can Geochronology Become?

    NASA Astrophysics Data System (ADS)

    Harrison, M.; Baldwin, S.; Caffee, M. W.; Gehrels, G. E.; Schoene, B.; Shuster, D. L.; Singer, B. S.

    2015-12-01

    As isotope ratio precisions have improved to as low as ±1 ppm, geochronologic precision has remained essentially unchanged. This largely reflects the nature of radioactivity whereby the parent decays into a different chemical species thus putting as much emphasis on the determining inter-element ratios as isotopic. Even the best current accuracy grows into errors of >0.6 m.y. during the Paleozoic - a span of time equal to ¼ of the Pleistocene. If we are to understand the nature of Paleozoic species variation and climate change at anything like the Cenozoic, we need a 10x improvement in accuracy. The good news is that there is no physical impediment to realizing this. There are enough Pb* atoms in the outer few μm's of a Paleozoic zircon grown moments before eruption to permit ±0.01% accuracy in the U-Pb system. What we need are the resources to synthesize the spikes, enhance ionization yields, exploit microscale sampling, and improve knowledge of λ correspondingly. Despite advances in geochronology over the past 40 years (multicollection, multi-isotope spikes, in situ dating), our ability to translate a daughter atom into a detected ion has remained at the level of 1% or so. This means that a ~102 increase in signal can be achieved before we approach a physical limit. Perhaps the most promising approach is use of broad spectrum lasers that can ionize all neutrals. Radical new approaches to providing mass separation of such signals are emerging, including trapped ion cyclotron resonance and multi-turn, sputtered neutral TOF spectrometers capable of mass resolutions in excess of 105. These innovations hold great promise in geochronology but are largely being developed for cosmochemistry. This may make sense at first glance as cosmochemists are classically atom-limited (IDPs, stardust) but can be a misperception as the outer few μm's of a zircon may represent no more mass than a stardust mote. To reach the fundamental limits of geochronologic signals we need to

  1. Calibrating GPS With TWSTFT For Accurate Time Transfer

    DTIC Science & Technology

    2008-12-01

    and O. Koudelka, 2008, “Time transfer with nanosecond accuracy for the realization of International Atomic Time,” Metrologia , 45, 185- 198. [4] Z...468-475. [7] Z. Jiang, 2008, “Towards a TWSTFT Network Time Transfer,” Metrologia , 45, S6-S11.

  2. WARP: accurate retrieval of shapes using phase of fourier descriptors and time warping distance.

    PubMed

    Bartolini, Ilaria; Ciaccia, Paolo; Patella, Marco

    2005-01-01

    Effective and efficient retrieval of similar shapes from large image databases is still a challenging problem in spite of the high relevance that shape information can have in describing image contents. In this paper, we propose a novel Fourier-based approach, called WARP, for matching and retrieving similar shapes. The unique characteristics of WARP are the exploitation of the phase of Fourier coefficients and the use of the Dynamic Time Warping (DTW) distance to compare shape descriptors. While phase information provides a more accurate description of object boundaries than using only the amplitude of Fourier coefficients, the DTW distance permits us to accurately match images even in the presence of (limited) phase shiftings. In terms of classical precision/recall measures, we experimentally demonstrate that WARP can gain, say, up to 35 percent in precision at a 20 percent recall level with respect to Fourier-based techniques that use neither phase nor DTW distance.

  3. Fast and Accurate Estimates of Divergence Times from Big Data.

    PubMed

    Mello, Beatriz; Tao, Qiqing; Tamura, Koichiro; Kumar, Sudhir

    2017-01-01

    Ongoing advances in sequencing technology have led to an explosive expansion in the molecular data available for building increasingly larger and more comprehensive timetrees. However, Bayesian relaxed-clock approaches frequently used to infer these timetrees impose a large computational burden and discourage critical assessment of the robustness of inferred times to model assumptions, influence of calibrations, and selection of optimal data subsets. We analyzed eight large, recently published, empirical datasets to compare time estimates produced by RelTime (a non-Bayesian method) with those reported by using Bayesian approaches. We find that RelTime estimates are very similar to Bayesian approaches, yet RelTime requires orders of magnitude less computational time. This means that the use of RelTime will enable greater rigor in molecular dating, because faster computational speeds encourage more extensive testing of the robustness of inferred timetrees to prior assumptions (models and calibrations) and data subsets. Thus, RelTime provides a reliable and computationally thrifty approach for dating the tree of life using large-scale molecular datasets.

  4. Time-accurate Navier-Stokes calculations with multigrid acceleration

    NASA Technical Reports Server (NTRS)

    Melson, N. D.; Sanetrik, Mark D.; Atkins, Harold L.

    1993-01-01

    An efficient method for calculating unsteady flows is presented, with emphasis on a modified version of the thin-layer Navier-Stokes equations. Fourier stability analysis is used to illustrate the effect of treating the source term implicitly instead of explicity, as well as to illustrate other algorithmic choices. A 2D circular cylinder (with a Reynolds number of 1200 and a Mach number of 0.3) is calculated. The present scheme requires only about 10 percent of the computer time required by global minimum time stepping.

  5. Simple tunnel diode circuit for accurate zero crossing timing

    NASA Technical Reports Server (NTRS)

    Metz, A. J.

    1969-01-01

    Tunnel diode circuit, capable of timing the zero crossing point of bipolar pulses, provides effective design for a fast crossing detector. It combines a nonlinear load line with the diode to detect the zero crossing of a wide range of input waveshapes.

  6. Accurate and stable time stepping in ice sheet modeling

    NASA Astrophysics Data System (ADS)

    Cheng, Gong; Lötstedt, Per; von Sydow, Lina

    2017-01-01

    In this paper we introduce adaptive time step control for simulation of the evolution of ice sheets. The discretization error in the approximations is estimated using "Milne's device" by comparing the result from two different methods in a predictor-corrector pair. Using a predictor-corrector pair the expensive part of the procedure, the solution of the velocity and pressure equations, is performed only once per time step and an estimate of the local error is easily obtained. The stability of the numerical solution is maintained and the accuracy is controlled by keeping the local error below a given threshold using PI-control. Depending on the threshold, the time step Δt is bound by stability requirements or accuracy requirements. Our method takes a shorter Δt than an implicit method but with less work in each time step and the solver is simpler. The method is analyzed theoretically with respect to stability and applied to the simulation of a 2D ice slab and a 3D circular ice sheet. The stability bounds in the experiments are explained by and agree well with the theoretical results.

  7. Application of the accurate mass and time tag approach in studies of the human blood lipidome

    PubMed Central

    Ding, Jie; Sorensen, Christina M.; Jaitly, Navdeep; Jiang, Hongliang; Orton, Daniel J.; Monroe, Matthew E.; Moore, Ronald J.; Smith, Richard D.; Metz, Thomas O.

    2008-01-01

    We report a preliminary demonstration of the accurate mass and time (AMT) tag approach for lipidomics. Initial data-dependent LC-MS/MS analyses of human plasma, erythrocyte, and lymphocyte lipids were performed in order to identify lipid molecular species in conjunction with complementary accurate mass and isotopic distribution information. Identified lipids were used to populate initial lipid AMT tag databases containing 250 and 45 entries for those species detected in positive and negative electrospray ionization (ESI) modes, respectively. The positive ESI database was then utilized to identify human plasma, erythrocyte, and lymphocyte lipids in high-throughput LC-MS analyses based on the AMT tag approach. We were able to define the lipid profiles of human plasma, erythrocytes, and lymphocytes based on qualitative and quantitative differences in lipid abundance. PMID:18502191

  8. Numerical Methodology for Coupled Time-Accurate Simulations of Primary and Secondary Flowpaths in Gas Turbines

    NASA Technical Reports Server (NTRS)

    Przekwas, A. J.; Athavale, M. M.; Hendricks, R. C.; Steinetz, B. M.

    2006-01-01

    Detailed information of the flow-fields in the secondary flowpaths and their interaction with the primary flows in gas turbine engines is necessary for successful designs with optimized secondary flow streams. Present work is focused on the development of a simulation methodology for coupled time-accurate solutions of the two flowpaths. The secondary flowstream is treated using SCISEAL, an unstructured adaptive Cartesian grid code developed for secondary flows and seals, while the mainpath flow is solved using TURBO, a density based code with capability of resolving rotor-stator interaction in multi-stage machines. An interface is being tested that links the two codes at the rim seal to allow data exchange between the two codes for parallel, coupled execution. A description of the coupling methodology and the current status of the interface development is presented. Representative steady-state solutions of the secondary flow in the UTRC HP Rig disc cavity are also presented.

  9. Joint accurate time and stable frequency distribution infrastructure sharing fiber footprint with research network

    NASA Astrophysics Data System (ADS)

    Vojtech, Josef; Slapak, Martin; Skoda, Pavel; Radil, Jan; Havlis, Ondrej; Altmann, Michal; Munster, Petr; Smotlacha, Vladimir; Kundrat, Jan; Velc, Radek; Altmannova, Lada; Hula, Miloslav

    2016-09-01

    In this paper, we present infrastructure for accurate time and stable frequency distribution. It is based on sharing of fibers of research and educational network carrying data traffic. Accurate time and stable frequency transmission uses mainly created dark channels amplified by special bidirectional amplifiers with the same propagation path for both directions. Paper also targets challenges joined with bidirectional transmission, which represents directional non-reciprocities and interaction with parallel data transmissions.

  10. Single-sideband modulator accurately reproduces phase information in 2-Mc signals

    NASA Technical Reports Server (NTRS)

    Strenglein, H. F.

    1966-01-01

    Phase-locked oscillator system employing solid state components acts as a single-sideband modulator to accurately reproduce phase information in 2-Mc signals. This system is useful in telemetry, aircraft communications and position-finding stations, and VHF test circuitry.

  11. Time-accurate unsteady aerodynamic and aeroelastic calculations for wings using Euler equations

    NASA Technical Reports Server (NTRS)

    Guruswamy, Guru P.

    1988-01-01

    A time-accurate approach to simultaneously solve the Euler flow equations and modal structural equations of motion is presented for computing aeroelastic responses of wings. The Euler flow eauations are solved by a time-accurate finite difference scheme with dynamic grids. The coupled aeroelastic equations of motion are solved using the linear acceleration method. The aeroelastic configuration adaptive dynamic grids are time accurately generated using the aeroelastically deformed shape of the wing. The unsteady flow calculations are validated wih experiment, both for a semi-infinite wing and a wall-mounted cantilever rectangular wings. Aeroelastic responses are computed for a rectangular wing using the modal data generated by the finite-element method. The robustness of the present approach in computing unsteady flows and aeroelastic responses that are beyond the capability of earlier approaches using the potential equations are demonstrated.

  12. Highly Accurate Prediction of Protein-Protein Interactions via Incorporating Evolutionary Information and Physicochemical Characteristics

    PubMed Central

    Li, Zheng-Wei; You, Zhu-Hong; Chen, Xing; Gui, Jie; Nie, Ru

    2016-01-01

    Protein-protein interactions (PPIs) occur at almost all levels of cell functions and play crucial roles in various cellular processes. Thus, identification of PPIs is critical for deciphering the molecular mechanisms and further providing insight into biological processes. Although a variety of high-throughput experimental techniques have been developed to identify PPIs, existing PPI pairs by experimental approaches only cover a small fraction of the whole PPI networks, and further, those approaches hold inherent disadvantages, such as being time-consuming, expensive, and having high false positive rate. Therefore, it is urgent and imperative to develop automatic in silico approaches to predict PPIs efficiently and accurately. In this article, we propose a novel mixture of physicochemical and evolutionary-based feature extraction method for predicting PPIs using our newly developed discriminative vector machine (DVM) classifier. The improvements of the proposed method mainly consist in introducing an effective feature extraction method that can capture discriminative features from the evolutionary-based information and physicochemical characteristics, and then a powerful and robust DVM classifier is employed. To the best of our knowledge, it is the first time that DVM model is applied to the field of bioinformatics. When applying the proposed method to the Yeast and Helicobacter pylori (H. pylori) datasets, we obtain excellent prediction accuracies of 94.35% and 90.61%, respectively. The computational results indicate that our method is effective and robust for predicting PPIs, and can be taken as a useful supplementary tool to the traditional experimental methods for future proteomics research. PMID:27571061

  13. Accurate GPS Time-Linked data Acquisition System (ATLAS II) user's manual.

    SciTech Connect

    Jones, Perry L.; Zayas, Jose R.; Ortiz-Moyet, Juan

    2004-02-01

    The Accurate Time-Linked data Acquisition System (ATLAS II) is a small, lightweight, time-synchronized, robust data acquisition system that is capable of acquiring simultaneous long-term time-series data from both a wind turbine rotor and ground-based instrumentation. This document is a user's manual for the ATLAS II hardware and software. It describes the hardware and software components of ATLAS II, and explains how to install and execute the software.

  14. Accurate protein structure modeling using sparse NMR data and homologous structure information.

    PubMed

    Thompson, James M; Sgourakis, Nikolaos G; Liu, Gaohua; Rossi, Paolo; Tang, Yuefeng; Mills, Jeffrey L; Szyperski, Thomas; Montelione, Gaetano T; Baker, David

    2012-06-19

    While information from homologous structures plays a central role in X-ray structure determination by molecular replacement, such information is rarely used in NMR structure determination because it can be incorrect, both locally and globally, when evolutionary relationships are inferred incorrectly or there has been considerable evolutionary structural divergence. Here we describe a method that allows robust modeling of protein structures of up to 225 residues by combining (1)H(N), (13)C, and (15)N backbone and (13)Cβ chemical shift data, distance restraints derived from homologous structures, and a physically realistic all-atom energy function. Accurate models are distinguished from inaccurate models generated using incorrect sequence alignments by requiring that (i) the all-atom energies of models generated using the restraints are lower than models generated in unrestrained calculations and (ii) the low-energy structures converge to within 2.0 Å backbone rmsd over 75% of the protein. Benchmark calculations on known structures and blind targets show that the method can accurately model protein structures, even with very remote homology information, to a backbone rmsd of 1.2-1.9 Å relative to the conventional determined NMR ensembles and of 0.9-1.6 Å relative to X-ray structures for well-defined regions of the protein structures. This approach facilitates the accurate modeling of protein structures using backbone chemical shift data without need for side-chain resonance assignments and extensive analysis of NOESY cross-peak assignments.

  15. Time-Accurate Solutions of Incompressible Navier-Stokes Equations for Potential Turbopump Applications

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Kwak, Dochan

    2001-01-01

    Two numerical procedures, one based on artificial compressibility method and the other pressure projection method, are outlined for obtaining time-accurate solutions of the incompressible Navier-Stokes equations. The performance of the two method are compared by obtaining unsteady solutions for the evolution of twin vortices behind a at plate. Calculated results are compared with experimental and other numerical results. For an un- steady ow which requires small physical time step, pressure projection method was found to be computationally efficient since it does not require any subiterations procedure. It was observed that the artificial compressibility method requires a fast convergence scheme at each physical time step in order to satisfy incompressibility condition. This was obtained by using a GMRES-ILU(0) solver in our computations. When a line-relaxation scheme was used, the time accuracy was degraded and time-accurate computations became very expensive.

  16. Watershed mean residence times and travel time distributions: how accurately can they be characterized?

    NASA Astrophysics Data System (ADS)

    Godsey, S. E.; Kirchner, J. W.

    2006-12-01

    The average time that rainfall takes to reach the stream - the mean residence time - is a basic parameter used to characterize watersheds. Watersheds are also characterized by the distribution of travel times for individual parcels of precipitation that fall on different points across the catchment. This travel time distribution is an important control on catchment response to contamination events. Catchments with shorter residence times or narrower distributions will have a flashier response to contamination events, whereas catchments with longer residence times or longer-tailed distributions will have a more persistent response to those same contamination events. Catchments' travel time distributions are typically inferred from time series of passive tracers (such as water isotopes, chloride, or bromide) in rainfall and streamflow. Tracer fluctuations in streamflow are typically damped compared to those in preciptation, because precipitation inputs of different ages (and different tracer signatures) are mixed within the catchment. Mathematically, this mixing process is modeled by the convolution of the travel time distribution and the precipitation tracer inputs to generate the stream tracer outputs. The parameters describing the travel time distribution are typically estimated by maximizing the goodness of fit between the modeled and measured tracer outputs. This approach is potentially subject to at least two sources of uncertainty. First, both the input and output tracer concentrations are subject to measurement error. Second, although the catchment mixing process is continuous, the inputs and outputs are only sampled at discrete points in time. Here we test how these two sources of uncertainty may affect travel time distributions that are estimated from catchment monitoring data. We begin by generating synthetic tracer input time series, and convolve these with a specified travel-time distribution to generate a synthetic output time series. We then subsample

  17. A time-accurate implicit method for chemical non-equilibrium flows at all speeds

    NASA Technical Reports Server (NTRS)

    Shuen, Jian-Shun

    1992-01-01

    A new time accurate coupled solution procedure for solving the chemical non-equilibrium Navier-Stokes equations over a wide range of Mach numbers is described. The scheme is shown to be very efficient and robust for flows with velocities ranging from M less than or equal to 10(exp -10) to supersonic speeds.

  18. A fluorescence-based quantitative real-time PCR assay for accurate Pocillopora damicornis species identification

    NASA Astrophysics Data System (ADS)

    Thomas, Luke; Stat, Michael; Evans, Richard D.; Kennington, W. Jason

    2016-09-01

    Pocillopora damicornis is one of the most extensively studied coral species globally, but high levels of phenotypic plasticity within the genus make species identification based on morphology alone unreliable. As a result, there is a compelling need to develop cheap and time-effective molecular techniques capable of accurately distinguishing P. damicornis from other congeneric species. Here, we develop a fluorescence-based quantitative real-time PCR (qPCR) assay to genotype a single nucleotide polymorphism that accurately distinguishes P. damicornis from other morphologically similar Pocillopora species. We trial the assay across colonies representing multiple Pocillopora species and then apply the assay to screen samples of Pocillopora spp. collected at regional scales along the coastline of Western Australia. This assay offers a cheap and time-effective alternative to Sanger sequencing and has broad applications including studies on gene flow, dispersal, recruitment and physiological thresholds of P. damicornis.

  19. Enabling high grayscale resolution displays and accurate response time measurements on conventional computers.

    PubMed

    Li, Xiangrui; Lu, Zhong-Lin

    2012-02-29

    Display systems based on conventional computer graphics cards are capable of generating images with 8-bit gray level resolution. However, most experiments in vision research require displays with more than 12 bits of luminance resolution. Several solutions are available. Bit++ (1) and DataPixx (2) use the Digital Visual Interface (DVI) output from graphics cards and high resolution (14 or 16-bit) digital-to-analog converters to drive analog display devices. The VideoSwitcher (3) described here combines analog video signals from the red and blue channels of graphics cards with different weights using a passive resister network (4) and an active circuit to deliver identical video signals to the three channels of color monitors. The method provides an inexpensive way to enable high-resolution monochromatic displays using conventional graphics cards and analog monitors. It can also provide trigger signals that can be used to mark stimulus onsets, making it easy to synchronize visual displays with physiological recordings or response time measurements. Although computer keyboards and mice are frequently used in measuring response times (RT), the accuracy of these measurements is quite low. The RTbox is a specialized hardware and software solution for accurate RT measurements. Connected to the host computer through a USB connection, the driver of the RTbox is compatible with all conventional operating systems. It uses a microprocessor and high-resolution clock to record the identities and timing of button events, which are buffered until the host computer retrieves them. The recorded button events are not affected by potential timing uncertainties or biases associated with data transmission and processing in the host computer. The asynchronous storage greatly simplifies the design of user programs. Several methods are available to synchronize the clocks of the RTbox and the host computer. The RTbox can also receive external triggers and be used to measure RT with respect

  20. Cas9-chromatin binding information enables more accurate CRISPR off-target prediction

    PubMed Central

    Singh, Ritambhara; Kuscu, Cem; Quinlan, Aaron; Qi, Yanjun; Adli, Mazhar

    2015-01-01

    The CRISPR system has become a powerful biological tool with a wide range of applications. However, improving targeting specificity and accurately predicting potential off-targets remains a significant goal. Here, we introduce a web-based CRISPR/Cas9 Off-target Prediction and Identification Tool (CROP-IT) that performs improved off-target binding and cleavage site predictions. Unlike existing prediction programs that solely use DNA sequence information; CROP-IT integrates whole genome level biological information from existing Cas9 binding and cleavage data sets. Utilizing whole-genome chromatin state information from 125 human cell types further enhances its computational prediction power. Comparative analyses on experimentally validated datasets show that CROP-IT outperforms existing computational algorithms in predicting both Cas9 binding as well as cleavage sites. With a user-friendly web-interface, CROP-IT outputs scored and ranked list of potential off-targets that enables improved guide RNA design and more accurate prediction of Cas9 binding or cleavage sites. PMID:26032770

  1. Accurate early-time and late-time modeling of countercurrent spontaneous imbibition

    NASA Astrophysics Data System (ADS)

    March, Rafael; Doster, Florian; Geiger, Sebastian

    2016-08-01

    Spontaneous countercurrent imbibition into a finite porous medium is an important physical mechanism for many applications, included but not limited to irrigation, CO2 storage, and oil recovery. Symmetry considerations that are often valid in fractured porous media allow us to study the process in a one-dimensional domain. In 1-D, for incompressible fluids and homogeneous rocks, the onset of imbibition can be captured by self-similar solutions and the imbibed volume scales with √t. At later times, the imbibition rate decreases and the finite size of the medium has to be taken into account. This requires numerical solutions. Here we present a new approach to approximate the whole imbibition process semianalytically. The onset is captured by a semianalytical solution. We also provide an a priori estimate of the time until which the imbibed volume scales with √t. This time is significantly longer than the time it takes until the imbibition front reaches the model boundary. The remainder of the imbibition process is obtained from a self-similarity solution. We test our approach against numerical solutions that employ parametrizations relevant for oil recovery and CO2 sequestration. We show that this concept improves common first-order approaches that heavily underestimate early-time behavior and note that it can be readily included into dual-porosity models.

  2. A time accurate finite volume high resolution scheme for three dimensional Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing; Hsu, Andrew T.

    1989-01-01

    A time accurate, three-dimensional, finite volume, high resolution scheme for solving the compressible full Navier-Stokes equations is presented. The present derivation is based on the upwind split formulas, specifically with the application of Roe's (1981) flux difference splitting. A high-order accurate (up to the third order) upwind interpolation formula for the inviscid terms is derived to account for nonuniform meshes. For the viscous terms, discretizations consistent with the finite volume concept are described. A variant of second-order time accurate method is proposed that utilizes identical procedures in both the predictor and corrector steps. Avoiding the definition of midpoint gives a consistent and easy procedure, in the framework of finite volume discretization, for treating viscous transport terms in the curvilinear coordinates. For the boundary cells, a new treatment is introduced that not only avoids the use of 'ghost cells' and the associated problems, but also satisfies the tangency conditions exactly and allows easy definition of viscous transport terms at the first interface next to the boundary cells. Numerical tests of steady and unsteady high speed flows show that the present scheme gives accurate solutions.

  3. A Three Dimensional Parallel Time Accurate Turbopump Simulation Procedure Using Overset Grid Systems

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Chan, William; Kwak, Dochan

    2001-01-01

    The objective of the current effort is to provide a computational framework for design and analysis of the entire fuel supply system of a liquid rocket engine, including high-fidelity unsteady turbopump flow analysis. This capability is needed to support the design of pump sub-systems for advanced space transportation vehicles that are likely to involve liquid propulsion systems. To date, computational tools for design/analysis of turbopump flows are based on relatively lower fidelity methods. An unsteady, three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available for real-world engineering applications. The present effort provides developers with information such as transient flow phenomena at start up, and non-uniform inflows, and will eventually impact on system vibration and structures. In the proposed paper, the progress toward the capability of complete simulation of the turbo-pump for a liquid rocket engine is reported. The Space Shuttle Main Engine (SSME) turbo-pump is used as a test case for evaluation of the hybrid MPI/Open-MP and MLP versions of the INS3D code. CAD to solution auto-scripting capability is being developed for turbopump applications. The relative motion of the grid systems for the rotor-stator interaction was obtained using overset grid techniques. Unsteady computations for the SSME turbo-pump, which contains 114 zones with 34.5 million grid points, are carried out on Origin 3000 systems at NASA Ames Research Center. Results from these time-accurate simulations with moving boundary capability will be presented along with the performance of parallel versions of the code.

  4. A Three-Dimensional Parallel Time-Accurate Turbopump Simulation Procedure Using Overset Grid System

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Chan, William; Kwak, Dochan

    2002-01-01

    The objective of the current effort is to provide a computational framework for design and analysis of the entire fuel supply system of a liquid rocket engine, including high-fidelity unsteady turbopump flow analysis. This capability is needed to support the design of pump sub-systems for advanced space transportation vehicles that are likely to involve liquid propulsion systems. To date, computational tools for design/analysis of turbopump flows are based on relatively lower fidelity methods. An unsteady, three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available for real-world engineering applications. The present effort provides developers with information such as transient flow phenomena at start up, and nonuniform inflows, and will eventually impact on system vibration and structures. In the proposed paper, the progress toward the capability of complete simulation of the turbo-pump for a liquid rocket engine is reported. The Space Shuttle Main Engine (SSME) turbo-pump is used as a test case for evaluation of the hybrid MPI/Open-MP and MLP versions of the INS3D code. CAD to solution auto-scripting capability is being developed for turbopump applications. The relative motion of the grid systems for the rotor-stator interaction was obtained using overset grid techniques. Unsteady computations for the SSME turbo-pump, which contains 114 zones with 34.5 million grid points, are carried out on Origin 3000 systems at NASA Ames Research Center. Results from these time-accurate simulations with moving boundary capability are presented along with the performance of parallel versions of the code.

  5. Time Accurate Unsteady Pressure Loads Simulated for the Space Launch System at a Wind Tunnel Condition

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.; Brauckmann, Gregory J.; Kleb, Bil; Streett, Craig L; Glass, Christopher E.; Schuster, David M.

    2015-01-01

    Using the Fully Unstructured Three-Dimensional (FUN3D) computational fluid dynamics code, an unsteady, time-accurate flow field about a Space Launch System configuration was simulated at a transonic wind tunnel condition (Mach = 0.9). Delayed detached eddy simulation combined with Reynolds Averaged Naiver-Stokes and a Spallart-Almaras turbulence model were employed for the simulation. Second order accurate time evolution scheme was used to simulate the flow field, with a minimum of 0.2 seconds of simulated time to as much as 1.4 seconds. Data was collected at 480 pressure taps at locations, 139 of which matched a 3% wind tunnel model, tested in the Transonic Dynamic Tunnel (TDT) facility at NASA Langley Research Center. Comparisons between computation and experiment showed agreement within 5% in terms of location for peak RMS levels, and 20% for frequency and magnitude of power spectral densities. Grid resolution and time step sensitivity studies were performed to identify methods for improved accuracy comparisons to wind tunnel data. With limited computational resources, accurate trends for reduced vibratory loads on the vehicle were observed. Exploratory methods such as determining minimized computed errors based on CFL number and sub-iterations, as well as evaluating frequency content of the unsteady pressures and evaluation of oscillatory shock structures were used in this study to enhance computational efficiency and solution accuracy. These techniques enabled development of a set of best practices, for the evaluation of future flight vehicle designs in terms of vibratory loads.

  6. Time-Accurate, Unstructured-Mesh Navier-Stokes Computations with the Space-Time CESE Method

    NASA Technical Reports Server (NTRS)

    Chang, Chau-Lyan

    2006-01-01

    Application of the newly emerged space-time conservation element solution element (CESE) method to compressible Navier-Stokes equations is studied. In contrast to Euler equations solvers, several issues such as boundary conditions, numerical dissipation, and grid stiffness warrant systematic investigations and validations. Non-reflecting boundary conditions applied at the truncated boundary are also investigated from the stand point of acoustic wave propagation. Validations of the numerical solutions are performed by comparing with exact solutions for steady-state as well as time-accurate viscous flow problems. The test cases cover a broad speed regime for problems ranging from acoustic wave propagation to 3D hypersonic configurations. Model problems pertinent to hypersonic configurations demonstrate the effectiveness of the CESE method in treating flows with shocks, unsteady waves, and separations. Good agreement with exact solutions suggests that the space-time CESE method provides a viable alternative for time-accurate Navier-Stokes calculations of a broad range of problems.

  7. Accurate ampacity determination: Temperature-Sag Model for operational real time ratings

    SciTech Connect

    Seppa, T.O.

    1995-07-01

    This report presents a method for determining transmission line ratings based on the relationship between the conductor`s temperature and its sag. The method is based on the Ruling Span principle and the use of transmission line tension monitoring systems. The report also presents a method of accurately calibrating the final sag of the conductor and determining the actual Ruling Span length of the line sections between deadend structures. Main error sources for two other real time methods are also examined.

  8. Life, Information, Entropy, and Time

    PubMed Central

    Crofts, Antony R.

    2008-01-01

    Attempts to understand how information content can be included in an accounting of the energy flux of the biosphere have led to the conclusion that, in information transmission, one component, the semantic content, or “the meaning of the message,” adds no thermodynamic burden over and above costs arising from coding, transmission and translation. In biology, semantic content has two major roles. For all life forms, the message of the genotype encoded in DNA specifies the phenotype, and hence the organism that is tested against the real world through the mechanisms of Darwinian evolution. For human beings, communication through language and similar abstractions provides an additional supra-phenotypic vehicle for semantic inheritance, which supports the cultural heritages around which civilizations revolve. The following three postulates provide the basis for discussion of a number of themes that demonstrate some important consequences. (i) Information transmission through either pathway has thermodynamic components associated with data storage and transmission. (ii) The semantic content adds no additional thermodynamic cost. (iii) For all semantic exchange, meaning is accessible only through translation and interpretation, and has a value only in context. (1) For both pathways of semantic inheritance, translational and copying machineries are imperfect. As a consequence both pathways are subject to mutation and to evolutionary pressure by selection. Recognition of semantic content as a common component allows an understanding of the relationship between genes and memes, and a reformulation of Universal Darwinism. (2) The emergent properties of life are dependent on a processing of semantic content. The translational steps allow amplification in complexity through combinatorial possibilities in space and time. Amplification depends on the increased potential for complexity opened by 3D interaction specificity of proteins, and on the selection of useful variants

  9. Time Accurate Unsteady Simulation of the Stall Inception Process in the Compression System of a US Army Helicopter Gas Turbine Engine

    DTIC Science & Technology

    2004-06-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP023843 TITLE: Time Accurate Unsteady Simulation of the Stall Inception...report: ADP023820 thru ADP023869 UNCLASSIFIED Time Accurate Unsteady Simulation of the Stall Inception Process in the Compression System of a US Army...surface ships, tanks, manned and Improved understanding of the stall inception process and unmanned fixed-wing and rotary-wing combat aircraft, how stall

  10. An accurate assay for HCV based on real-time fluorescence detection of isothermal RNA amplification.

    PubMed

    Wu, Xuping; Wang, Jianfang; Song, Jinyun; Li, Jiayan; Yang, Yongfeng

    2016-09-01

    Hepatitis C virus (HCV) is one of the common reasons of liver fibrosis and hepatocellular carcinoma (HCC). Early, rapid and accurate HCV RNA detection is important to prevent and control liver disease. A simultaneous amplification and testing (SAT) assay, which is based on isothermal amplification of RNA and real-time fluorescence detection, was designed to optimize routine HCV RNA detection. In this study, HCV RNA and an internal control (IC) were amplified and analyzed simultaneously by SAT assay and detection of fluorescence using routine real-time PCR equipment. The assay detected as few as 10 copies of HCV RNA transcripts. We tested 705 serum samples with SAT, among which 96.4% (680/705) showed consistent results compared with routine real-time PCR. About 92% (23/25) discordant samples were confirmed to be same results as SAT-HCV by using a second real-time PCR. The sensitivity and specificity of SAT-HCV assay were 99.6% (461/463) and 100% (242/242), respectively. In conclusion, the SAT assay is an accurate test with a high specificity and sensitivity which may increase the detection rate of HCV. It is therefore a promising tool to diagnose HCV infection.

  11. Time accurate application of the MacCormack 2-4 scheme on massively parallel computers

    NASA Technical Reports Server (NTRS)

    Hudson, Dale A.; Long, Lyle N.

    1995-01-01

    Many recent computational efforts in turbulence and acoustics research have used higher order numerical algorithms. One popular method has been the explicit MacCormack 2-4 scheme. The MacCormack 2-4 scheme is second order accurate in time and fourth order accurate in space, and is stable for CFL's below 2/3. Current research has shown that the method can give accurate results but does exhibit significant Gibbs phenomena at sharp discontinuities. The impact of adding Jameson type second, third, and fourth order artificial viscosity was examined here. Category 2 problems, the nonlinear traveling wave and the Riemann problem, were computed using a CFL number of 0.25. This research has found that dispersion errors can be significantly reduced or nearly eliminated by using a combination of second and third order terms in the damping. Use of second and fourth order terms reduced the magnitude of dispersion errors but not as effectively as the second and third order combination. The program was coded using Thinking Machine's CM Fortran, a variant of Fortran 90/High Performance Fortran, and was executed on a 2K CM-200. Simple extrapolation boundary conditions were used for both problems.

  12. Time resolved diffuse optical spectroscopy with geometrically accurate models for bulk parameter recovery

    PubMed Central

    Guggenheim, James A.; Bargigia, Ilaria; Farina, Andrea; Pifferi, Antonio; Dehghani, Hamid

    2016-01-01

    A novel straightforward, accessible and efficient approach is presented for performing hyperspectral time-domain diffuse optical spectroscopy to determine the optical properties of samples accurately using geometry specific models. To allow bulk parameter recovery from measured spectra, a set of libraries based on a numerical model of the domain being investigated is developed as opposed to the conventional approach of using an analytical semi-infinite slab approximation, which is known and shown to introduce boundary effects. Results demonstrate that the method improves the accuracy of derived spectrally varying optical properties over the use of the semi-infinite approximation. PMID:27699137

  13. Nonlinear Aeroelastic Analysis Using a Time-Accurate Navier-Stokes Equations Solver

    NASA Technical Reports Server (NTRS)

    Kuruvila, Geojoe; Bartels, Robert E.; Hong, Moeljo S.; Bhatia, G.

    2007-01-01

    A method to simulate limit cycle oscillation (LCO) due to control surface freeplay using a modified CFL3D, a time-accurate Navier-Stokes computational fluid dynamics (CFD) analysis code with structural modeling capability, is presented. This approach can be used to analyze aeroelastic response of aircraft with structural behavior characterized by nonlinearity in the force verses displacement curve. A limited validation of the method, using very low Mach number experimental data for a three-degrees-of-freedom (pitch/plunge/flap deflection) airfoil model with flap freeplay, is also presented.

  14. Evaluating the capability of time-of-flight cameras for accurately imaging a cyclically loaded beam

    NASA Astrophysics Data System (ADS)

    Lahamy, Hervé; Lichti, Derek; El-Badry, Mamdouh; Qi, Xiaojuan; Detchev, Ivan; Steward, Jeremy; Moravvej, Mohammad

    2015-05-01

    Time-of-flight cameras are used for diverse applications ranging from human-machine interfaces and gaming to robotics and earth topography. This paper aims at evaluating the capability of the Mesa Imaging SR4000 and the Microsoft Kinect 2.0 time-of-flight cameras for accurately imaging the top surface of a concrete beam subjected to fatigue loading in laboratory conditions. Whereas previous work has demonstrated the success of such sensors for measuring the response at point locations, the aim here is to measure the entire beam surface in support of the overall objective of evaluating the effectiveness of concrete beam reinforcement with steel fibre reinforced polymer sheets. After applying corrections for lens distortions to the data and differencing images over time to remove systematic errors due to internal scattering, the periodic deflections experienced by the beam have been estimated for the entire top surface of the beam and at witness plates attached. The results have been assessed by comparison with measurements from highly-accurate laser displacement transducers. This study concludes that both the Microsoft Kinect 2.0 and the Mesa Imaging SR4000s are capable of sensing a moving surface with sub-millimeter accuracy once the image distortions have been modeled and removed.

  15. Accurate Time/Frequency Transfer Method Using Bi-Directional WDM Transmission

    NASA Technical Reports Server (NTRS)

    Imaoka, Atsushi; Kihara, Masami

    1996-01-01

    An accurate time transfer method is proposed using b-directional wavelength division multiplexing (WDM) signal transmission along a single optical fiber. This method will be used in digital telecommunication networks and yield a time synchronization accuracy of better than 1 ns for long transmission lines over several tens of kilometers. The method can accurately measure the difference in delay between two wavelength signals caused by the chromatic dispersion of the fiber in conventional simple bi-directional dual-wavelength frequency transfer methods. We describe the characteristics of this difference in delay and then show that the accuracy of the delay measurements can be obtained below 0.1 ns by transmitting 156 Mb/s times reference signals of 1.31 micrometer and 1.55 micrometers along a 50 km fiber using the proposed method. The sub-nanosecond delay measurement using the simple bi-directional dual-wavelength transmission along a 100 km fiber with a wavelength spacing of 1 nm in the 1.55 micrometer range is also shown.

  16. An Accurate Timing Alignment Method with Time-to-Digital Converter Linearity Calibration for High-Resolution TOF PET.

    PubMed

    Li, Hongdi; Wang, Chao; An, Shaohui; Lu, Xingyu; Dong, Yun; Liu, Shitao; Baghaei, Hossain; Zhang, Yuxuan; Ramirez, Rocio; Wong, Wai-Hoi

    2015-06-01

    Accurate PET system timing alignment minimizes the coincidence time window and therefore reduces random events and improves image quality. It is also critical for time-of-flight (TOF) image reconstruction. Here, we use a thin annular cylinder (shell) phantom filled with a radioactive source and located axially and centrally in a PET camera for the timing alignment of a TOF PET system. This timing alignment method involves measuring the time differences between the selected coincidence detector pairs, calibrating the differential and integral nonlinearity of the time-to-digital converter (TDC) with the same raw data and deriving the intrinsic time biases for each detector using an iterative algorithm. The raw time bias for each detector is downloaded to the front-end electronics and the residual fine time bias can be applied during the TOF list-mode reconstruction. Our results showed that a timing alignment accuracy of better than ±25 ps can be achieved, and a preliminary timing resolution of 473 ps (full width at half maximum) was measured in our prototype TOF PET/CT system.

  17. An Accurate Timing Alignment Method with Time-to-Digital Converter Linearity Calibration for High-Resolution TOF PET

    PubMed Central

    Li, Hongdi; Wang, Chao; An, Shaohui; Lu, Xingyu; Dong, Yun; Liu, Shitao; Baghaei, Hossain; Zhang, Yuxuan; Ramirez, Rocio; Wong, Wai-Hoi

    2015-01-01

    Accurate PET system timing alignment minimizes the coincidence time window and therefore reduces random events and improves image quality. It is also critical for time-of-flight (TOF) image reconstruction. Here, we use a thin annular cylinder (shell) phantom filled with a radioactive source and located axially and centrally in a PET camera for the timing alignment of a TOF PET system. This timing alignment method involves measuring the time differences between the selected coincidence detector pairs, calibrating the differential and integral nonlinearity of the time-to-digital converter (TDC) with the same raw data and deriving the intrinsic time biases for each detector using an iterative algorithm. The raw time bias for each detector is downloaded to the front-end electronics and the residual fine time bias can be applied during the TOF list-mode reconstruction. Our results showed that a timing alignment accuracy of better than ±25 ps can be achieved, and a preliminary timing resolution of 473 ps (full width at half maximum) was measured in our prototype TOF PET/CT system. PMID:26543243

  18. Accuracy in Recalling Interest Inventory Information at Three Time Intervals

    ERIC Educational Resources Information Center

    Swanson, Jane L.; Gore, Paul A., Jr.; Leuwerke, Wade; D'Achiardi, Catalina; Edwards, Jorie Hitch; Edwards, Jared

    2006-01-01

    Rates of accurate recall of the Strong Interest Inventory (SII; L. W. Harmon, J. C. Hansen, F. H. Borgen, & A. L. Hammer, 1994) profile information varied with the amount of time elapsed since the interpretation, the type of SII scale, and whether immediate recall was elicited, but rates did not vary with the strategy used to provide the…

  19. Accurate Behavioral Simulator of All-Digital Time-Domain Smart Temperature Sensors by Using SIMULINK.

    PubMed

    Chen, Chun-Chi; Chen, Chao-Lieh; Lin, You-Ting

    2016-08-08

    This study proposes a new behavioral simulator that uses SIMULINK for all-digital CMOS time-domain smart temperature sensors (TDSTSs) for performing rapid and accurate simulations. Inverter-based TDSTSs offer the benefits of low cost and simple structure for temperature-to-digital conversion and have been developed. Typically, electronic design automation tools, such as HSPICE, are used to simulate TDSTSs for performance evaluations. However, such tools require extremely long simulation time and complex procedures to analyze the results and generate figures. In this paper, we organize simple but accurate equations into a temperature-dependent model (TDM) by which the TDSTSs evaluate temperature behavior. Furthermore, temperature-sensing models of a single CMOS NOT gate were devised using HSPICE simulations. Using the TDM and these temperature-sensing models, a novel simulator in SIMULINK environment was developed to substantially accelerate the simulation and simplify the evaluation procedures. Experiments demonstrated that the simulation results of the proposed simulator have favorable agreement with those obtained from HSPICE simulations, showing that the proposed simulator functions successfully. This is the first behavioral simulator addressing the rapid simulation of TDSTSs.

  20. Accurate Behavioral Simulator of All-Digital Time-Domain Smart Temperature Sensors by Using SIMULINK

    PubMed Central

    Chen, Chun-Chi; Chen, Chao-Lieh; Lin, You-Ting

    2016-01-01

    This study proposes a new behavioral simulator that uses SIMULINK for all-digital CMOS time-domain smart temperature sensors (TDSTSs) for performing rapid and accurate simulations. Inverter-based TDSTSs offer the benefits of low cost and simple structure for temperature-to-digital conversion and have been developed. Typically, electronic design automation tools, such as HSPICE, are used to simulate TDSTSs for performance evaluations. However, such tools require extremely long simulation time and complex procedures to analyze the results and generate figures. In this paper, we organize simple but accurate equations into a temperature-dependent model (TDM) by which the TDSTSs evaluate temperature behavior. Furthermore, temperature-sensing models of a single CMOS NOT gate were devised using HSPICE simulations. Using the TDM and these temperature-sensing models, a novel simulator in SIMULINK environment was developed to substantially accelerate the simulation and simplify the evaluation procedures. Experiments demonstrated that the simulation results of the proposed simulator have favorable agreement with those obtained from HSPICE simulations, showing that the proposed simulator functions successfully. This is the first behavioral simulator addressing the rapid simulation of TDSTSs. PMID:27509507

  1. Responsible reporting of health research studies: transparent, complete, accurate and timely

    PubMed Central

    Altman, Douglas G.; Simera, Iveta

    2010-01-01

    Complete, accurate and transparent reporting is an integral part of responsible research conduct. However, many studies have shown that health research publications frequently lack crucial information. Reporting guidelines like the CONSORT Statement help to improve the quality of research reports. Unfortunately, their uptake by journals and authors is still limited and does not maximize their potential. The EQUATOR Network, a new international initiative, leads the effort to promote transparent reporting of research and the use of reporting guidelines. It provides online resources and training relating to the reporting of health research, and assists in the development, dissemination and implementation of reporting guidelines (www.equator-network.org). Poor reporting practices can be decreased only through close collaboration of all parties involved in research and its publication; EQUATOR can facilitate the process. PMID:19900949

  2. Time Accurate CFD Simulations of the Orion Launch Abort Vehicle in the Transonic Regime

    NASA Technical Reports Server (NTRS)

    Ruf, Joseph; Rojahn, Josh

    2011-01-01

    Significant asymmetries in the fluid dynamics were calculated for some cases in the CFD simulations of the Orion Launch Abort Vehicle through its abort trajectories. The CFD simulations were performed steady state with symmetric boundary conditions and geometries. The trajectory points at issue were in the transonic regime, at 0 and 5 angles of attack with the Abort Motors with and without the Attitude Control Motors (ACM) firing. In some of the cases the asymmetric fluid dynamics resulted in aerodynamic side forces that were large enough that would overcome the control authority of the ACMs. MSFC s Fluid Dynamics Group supported the investigation into the cause of the flow asymmetries with time accurate CFD simulations, utilizing a hybrid RANS-LES turbulence model. The results show that the flow over the vehicle and the subsequent interaction with the AB and ACM motor plumes were unsteady. The resulting instantaneous aerodynamic forces were oscillatory with fairly large magnitudes. Time averaged aerodynamic forces were essentially symmetric.

  3. In-Band Asymmetry Compensation for Accurate Time/Phase Transport over Optical Transport Network

    PubMed Central

    Siu, Sammy; Hu, Hsiu-fang; Lin, Shinn-Yan; Liao, Chia-Shu; Lai, Yi-Liang

    2014-01-01

    The demands of precise time/phase synchronization have been increasing recently due to the next generation of telecommunication synchronization. This paper studies the issues that are relevant to distributing accurate time/phase over optical transport network (OTN). Each node and link can introduce asymmetry, which affects the adequate time/phase accuracy over the networks. In order to achieve better accuracy, protocol level full timing support is used (e.g., Telecom-Boundary clock). Due to chromatic dispersion, the use of different wavelengths consequently causes fiber link delay asymmetry. The analytical result indicates that it introduces significant time error (i.e., phase offset) within 0.3397 ns/km in C-band or 0.3943 ns/km in L-band depending on the wavelength spacing. With the proposed scheme in this paper, the fiber link delay asymmetry can be compensated relying on the estimated mean fiber link delay by the Telecom-Boundary clock, while the OTN control plane is responsible for processing the fiber link delay asymmetry to determine the asymmetry compensation in the timing chain. PMID:24982948

  4. Time-Accurate Unsteady Pressure Loads Simulated for the Space Launch System at Wind Tunnel Conditions

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.; Brauckmann, Gregory J.; Kleb, William L.; Glass, Christopher E.; Streett, Craig L.; Schuster, David M.

    2015-01-01

    A transonic flow field about a Space Launch System (SLS) configuration was simulated with the Fully Unstructured Three-Dimensional (FUN3D) computational fluid dynamics (CFD) code at wind tunnel conditions. Unsteady, time-accurate computations were performed using second-order Delayed Detached Eddy Simulation (DDES) for up to 1.5 physical seconds. The surface pressure time history was collected at 619 locations, 169 of which matched locations on a 2.5 percent wind tunnel model that was tested in the 11 ft. x 11 ft. test section of the NASA Ames Research Center's Unitary Plan Wind Tunnel. Comparisons between computation and experiment showed that the peak surface pressure RMS level occurs behind the forward attach hardware, and good agreement for frequency and power was obtained in this region. Computational domain, grid resolution, and time step sensitivity studies were performed. These included an investigation of pseudo-time sub-iteration convergence. Using these sensitivity studies and experimental data comparisons, a set of best practices to date have been established for FUN3D simulations for SLS launch vehicle analysis. To the author's knowledge, this is the first time DDES has been used in a systematic approach and establish simulation time needed, to analyze unsteady pressure loads on a space launch vehicle such as the NASA SLS.

  5. A solution for measuring accurate reaction time to visual stimuli realized with a programmable microcontroller.

    PubMed

    Ohyanagi, Toshio; Sengoku, Yasuhito

    2010-02-01

    This article presents a new solution for measuring accurate reaction time (SMART) to visual stimuli. The SMART is a USB device realized with a Cypress Programmable System-on-Chip (PSoC) mixed-signal array programmable microcontroller. A brief overview of the hardware and firmware of the PSoC is provided, together with the results of three experiments. In Experiment 1, we investigated the timing accuracy of the SMART in measuring reaction time (RT) under different conditions of operating systems (OSs; Windows XP or Vista) and monitor displays (a CRT or an LCD). The results indicated that the timing error in measuring RT by the SMART was less than 2 msec, on average, under all combinations of OS and display and that the SMART was tolerant to jitter and noise. In Experiment 2, we tested the SMART with 8 participants. The results indicated that there was no significant difference among RTs obtained with the SMART under the different conditions of OS and display. In Experiment 3, we used Microsoft (MS) PowerPoint to present visual stimuli on the display. We found no significant difference in RTs obtained using MS DirectX technology versus using the PowerPoint file with the SMART. We are certain that the SMART is a simple and practical solution for measuring RTs accurately. Although there are some restrictions in using the SMART with RT paradigms, the SMART is capable of providing both researchers and health professionals working in clinical settings with new ways of using RT paradigms in their work.

  6. The Space-Time Conservative Schemes for Large-Scale, Time-Accurate Flow Simulations with Tetrahedral Meshes

    NASA Technical Reports Server (NTRS)

    Venkatachari, Balaji Shankar; Streett, Craig L.; Chang, Chau-Lyan; Friedlander, David J.; Wang, Xiao-Yen; Chang, Sin-Chung

    2016-01-01

    Despite decades of development of unstructured mesh methods, high-fidelity time-accurate simulations are still predominantly carried out on structured, or unstructured hexahedral meshes by using high-order finite-difference, weighted essentially non-oscillatory (WENO), or hybrid schemes formed by their combinations. In this work, the space-time conservation element solution element (CESE) method is used to simulate several flow problems including supersonic jet/shock interaction and its impact on launch vehicle acoustics, and direct numerical simulations of turbulent flows using tetrahedral meshes. This paper provides a status report for the continuing development of the space-time conservation element solution element (CESE) numerical and software framework under the Revolutionary Computational Aerosciences (RCA) project. Solution accuracy and large-scale parallel performance of the numerical framework is assessed with the goal of providing a viable paradigm for future high-fidelity flow physics simulations.

  7. Time-Accurate Simulations and Acoustic Analysis of Slat Free-Shear-Layer. Part 2

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.; Singer, Bart A.; Lockard, David P.

    2002-01-01

    Unsteady computational simulations of a multi-element, high-lift configuration are performed. Emphasis is placed on accurate spatiotemporal resolution of the free shear layer in the slat-cove region. The excessive dissipative effects of the turbulence model, so prevalent in previous simulations, are circumvented by switching off the turbulence-production term in the slat cove region. The justifications and physical arguments for taking such a step are explained in detail. The removal of this excess damping allows the shear layer to amplify large-scale structures, to achieve a proper non-linear saturation state, and to permit vortex merging. The large-scale disturbances are self-excited, and unlike our prior fully turbulent simulations, no external forcing of the shear layer is required. To obtain the farfield acoustics, the Ffowcs Williams and Hawkings equation is evaluated numerically using the simulated time-accurate flow data. The present comparison between the computed and measured farfield acoustic spectra shows much better agreement for the amplitude and frequency content than past calculations. The effect of the angle-of-attack on the slat's flow features radiated acoustic field are also simulated presented.

  8. 42 CFR 414.806 - Penalties associated with the failure to submit timely and accurate ASP data.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... timely and accurate ASP data. 414.806 Section 414.806 Public Health CENTERS FOR MEDICARE & MEDICAID... Penalties associated with the failure to submit timely and accurate ASP data. Section 1847A(d)(4) specifies the penalties associated with misrepresentations associated with ASP data. If the Secretary...

  9. 42 CFR 414.806 - Penalties associated with the failure to submit timely and accurate ASP data.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... timely and accurate ASP data. 414.806 Section 414.806 Public Health CENTERS FOR MEDICARE & MEDICAID... associated with the failure to submit timely and accurate ASP data. Section 1847A(d)(4) specifies the penalties associated with misrepresentations associated with ASP data. If the Secretary determines that...

  10. 42 CFR 414.806 - Penalties associated with the failure to submit timely and accurate ASP data.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... timely and accurate ASP data. 414.806 Section 414.806 Public Health CENTERS FOR MEDICARE & MEDICAID... Penalties associated with the failure to submit timely and accurate ASP data. Section 1847A(d)(4) specifies the penalties associated with misrepresentations associated with ASP data. If the Secretary...

  11. 42 CFR 414.806 - Penalties associated with the failure to submit timely and accurate ASP data.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... timely and accurate ASP data. 414.806 Section 414.806 Public Health CENTERS FOR MEDICARE & MEDICAID... associated with the failure to submit timely and accurate ASP data. Section 1847A(d)(4) specifies the penalties associated with misrepresentations associated with ASP data. If the Secretary determines that...

  12. 42 CFR 414.806 - Penalties associated with the failure to submit timely and accurate ASP data.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... timely and accurate ASP data. 414.806 Section 414.806 Public Health CENTERS FOR MEDICARE & MEDICAID... Penalties associated with the failure to submit timely and accurate ASP data. Section 1847A(d)(4) specifies the penalties associated with misrepresentations associated with ASP data. If the Secretary...

  13. Cartesian Off-Body Grid Adaption for Viscous Time- Accurate Flow Simulation

    NASA Technical Reports Server (NTRS)

    Buning, Pieter G.; Pulliam, Thomas H.

    2011-01-01

    An improved solution adaption capability has been implemented in the OVERFLOW overset grid CFD code. Building on the Cartesian off-body approach inherent in OVERFLOW and the original adaptive refinement method developed by Meakin, the new scheme provides for automated creation of multiple levels of finer Cartesian grids. Refinement can be based on the undivided second-difference of the flow solution variables, or on a specific flow quantity such as vorticity. Coupled with load-balancing and an inmemory solution interpolation procedure, the adaption process provides very good performance for time-accurate simulations on parallel compute platforms. A method of using refined, thin body-fitted grids combined with adaption in the off-body grids is presented, which maximizes the part of the domain subject to adaption. Two- and three-dimensional examples are used to illustrate the effectiveness and performance of the adaption scheme.

  14. Time-Accurate Simulations and Acoustic Analysis of Slat Free-Shear Layer

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.; Singer, Bart A.; Berkman, Mert E.

    2001-01-01

    A detailed computational aeroacoustic analysis of a high-lift flow field is performed. Time-accurate Reynolds Averaged Navier-Stokes (RANS) computations simulate the free shear layer that originates from the slat cusp. Both unforced and forced cases are studied. Preliminary results show that the shear layer is a good amplifier of disturbances in the low to mid-frequency range. The Ffowcs-Williams and Hawkings equation is solved to determine the acoustic field using the unsteady flow data from the RANS calculations. The noise radiated from the excited shear layer has a spectral shape qualitatively similar to that obtained from measurements in a corresponding experimental study of the high-lift system.

  15. Accurate mass - time tag library for LC/MS-based metabolite profiling of medicinal plants

    PubMed Central

    Cuthbertson, Daniel J.; Johnson, Sean R.; Piljac-Žegarac, Jasenka; Kappel, Julia; Schäfer, Sarah; Wüst, Matthias; Ketchum, Raymond E. B.; Croteau, Rodney B.; Marques, Joaquim V.; Davin, Laurence B.; Lewis, Norman G.; Rolf, Megan; Kutchan, Toni M.; Soejarto, D. Doel; Lange, B. Markus

    2013-01-01

    We report the development and testing of an accurate mass – time (AMT) tag approach for the LC/MS-based identification of plant natural products (PNPs) in complex extracts. An AMT tag library was developed for approximately 500 PNPs with diverse chemical structures, detected in electrospray and atmospheric pressure chemical ionization modes (both positive and negative polarities). In addition, to enable peak annotations with high confidence, MS/MS spectra were acquired with three different fragmentation energies. The LC/MS and MS/MS data sets were integrated into online spectral search tools and repositories (Spektraris and MassBank), thus allowing users to interrogate their own data sets for the potential presence of PNPs. The utility of the AMT tag library approach is demonstrated by the detection and annotation of active principles in 27 different medicinal plant species with diverse chemical constituents. PMID:23597491

  16. A time-accurate algorithm for chemical non-equilibrium viscous flows at all speeds

    NASA Technical Reports Server (NTRS)

    Shuen, J.-S.; Chen, K.-H.; Choi, Y.

    1992-01-01

    A time-accurate, coupled solution procedure is described for the chemical nonequilibrium Navier-Stokes equations over a wide range of Mach numbers. This method employs the strong conservation form of the governing equations, but uses primitive variables as unknowns. Real gas properties and equilibrium chemistry are considered. Numerical tests include steady convergent-divergent nozzle flows with air dissociation/recombination chemistry, dump combustor flows with n-pentane-air chemistry, nonreacting flow in a model double annular combustor, and nonreacting unsteady driven cavity flows. Numerical results for both the steady and unsteady flows demonstrate the efficiency and robustness of the present algorithm for Mach numbers ranging from the incompressible limit to supersonic speeds.

  17. A Fully Implicit Time Accurate Method for Hypersonic Combustion: Application to Shock-induced Combustion Instability

    NASA Technical Reports Server (NTRS)

    Yungster, Shaye; Radhakrishnan, Krishnan

    1994-01-01

    A new fully implicit, time accurate algorithm suitable for chemically reacting, viscous flows in the transonic-to-hypersonic regime is described. The method is based on a class of Total Variation Diminishing (TVD) schemes and uses successive Gauss-Siedel relaxation sweeps. The inversion of large matrices is avoided by partitioning the system into reacting and nonreacting parts, but still maintaining a fully coupled interaction. As a result, the matrices that have to be inverted are of the same size as those obtained with the commonly used point implicit methods. In this paper we illustrate the applicability of the new algorithm to hypervelocity unsteady combustion applications. We present a series of numerical simulations of the periodic combustion instabilities observed in ballistic-range experiments of blunt projectiles flying at subdetonative speeds through hydrogen-air mixtures. The computed frequencies of oscillation are in excellent agreement with experimental data.

  18. Using Focused Regression for Accurate Time-Constrained Scaling of Scientific Applications

    SciTech Connect

    Barnes, B; Garren, J; Lowenthal, D; Reeves, J; de Supinski, B; Schulz, M; Rountree, B

    2010-01-28

    Many large-scale clusters now have hundreds of thousands of processors, and processor counts will be over one million within a few years. Computational scientists must scale their applications to exploit these new clusters. Time-constrained scaling, which is often used, tries to hold total execution time constant while increasing the problem size along with the processor count. However, complex interactions between parameters, the processor count, and execution time complicate determining the input parameters that achieve this goal. In this paper we develop a novel gray-box, focused median prediction errors are less than 13%. regression-based approach that assists the computational scientist with maintaining constant run time on increasing processor counts. Combining application-level information from a small set of training runs, our approach allows prediction of the input parameters that result in similar per-processor execution time at larger scales. Our experimental validation across seven applications showed that median prediction errors are less than 13%.

  19. A time-accurate finite volume method valid at all flow velocities

    NASA Astrophysics Data System (ADS)

    Kim, S.-W.

    1993-07-01

    A finite volume method to solve the Navier-Stokes equations at all flow velocities (e.g., incompressible, subsonic, transonic, supersonic and hypersonic flows) is presented. The numerical method is based on a finite volume method that incorporates a pressure-staggered mesh and an incremental pressure equation for the conservation of mass. Comparison of three generally accepted time-advancing schemes, i.e., Simplified Marker-and-Cell (SMAC), Pressure-Implicit-Splitting of Operators (PISO), and Iterative-Time-Advancing (ITA) scheme, are made by solving a lid-driven polar cavity flow and self-sustained oscillatory flows over circular and square cylinders. Calculated results show that the ITA is the most stable numerically and yields the most accurate results. The SMAC is the most efficient computationally and is as stable as the ITA. It is shown that the PISO is the most weakly convergent and it exhibits an undesirable strong dependence on the time-step size. The degenerated numerical results obtained using the PISO are attributed to its second corrector step that cause the numerical results to deviate further from a divergence free velocity field. The accurate numerical results obtained using the ITA is attributed to its capability to resolve the nonlinearity of the Navier-Stokes equations. The present numerical method that incorporates the ITA is used to solve an unsteady transitional flow over an oscillating airfoil and a chemically reacting flow of hydrogen in a vitiated supersonic airstream. The turbulence fields in these flow cases are described using multiple-time-scale turbulence equations. For the unsteady transitional over an oscillating airfoil, the fluid flow is described using ensemble-averaged Navier-Stokes equations defined on the Lagrangian-Eulerian coordinates. It is shown that the numerical method successfully predicts the large dynamic stall vortex (DSV) and the trailing edge vortex (TEV) that are periodically generated by the oscillating airfoil

  20. A conservative finite volume scheme with time-accurate local time stepping for scalar transport on unstructured grids

    NASA Astrophysics Data System (ADS)

    Cavalcanti, José Rafael; Dumbser, Michael; Motta-Marques, David da; Fragoso Junior, Carlos Ruberto

    2015-12-01

    In this article we propose a new conservative high resolution TVD (total variation diminishing) finite volume scheme with time-accurate local time stepping (LTS) on unstructured grids for the solution of scalar transport problems, which are typical in the context of water quality simulations. To keep the presentation of the new method as simple as possible, the algorithm is only derived in two space dimensions and for purely convective transport problems, hence neglecting diffusion and reaction terms. The new numerical method for the solution of the scalar transport is directly coupled to the hydrodynamic model of Casulli and Walters (2000) that provides the dynamics of the free surface and the velocity vector field based on a semi-implicit discretization of the shallow water equations. Wetting and drying is handled rigorously by the nonlinear algorithm proposed by Casulli (2009). The new time-accurate LTS algorithm allows a different time step size for each element of the unstructured grid, based on an element-local Courant-Friedrichs-Lewy (CFL) stability condition. The proposed method does not need any synchronization between different time steps of different elements and is by construction locally and globally conservative. The LTS scheme is based on a piecewise linear polynomial reconstruction in space-time using the MUSCL-Hancock method, to obtain second order of accuracy in both space and time. The new algorithm is first validated on some classical test cases for pure advection problems, for which exact solutions are known. In all cases we obtain a very good level of accuracy, showing also numerical convergence results; we furthermore confirm mass conservation up to machine precision and observe an improved computational efficiency compared to a standard second order TVD scheme for scalar transport with global time stepping (GTS). Then, the new LTS method is applied to some more complex problems, where the new scalar transport scheme has also been coupled to

  1. Mass spectrometry in Earth sciences: the precise and accurate measurement of time.

    PubMed

    Schaltegger, Urs; Wotzlaw, Jörn-Frederik; Ovtcharova, Maria; Chiaradia, Massimo; Spikings, Richard

    2014-01-01

    Precise determinations of the isotopic compositions of a variety of elements is a widely applied tool in Earth sciences. Isotope ratios are used to quantify rates of geological processes that occurred during the previous 4.5 billion years, and also at the present time. An outstanding application is geochronology, which utilizes the production of radiogenic daughter isotopes by the radioactive decay of parent isotopes. Geochronological tools, involving isotopic analysis of selected elements from smallest volumes of minerals by thermal ionization mass spectrometry, provide precise and accurate measurements of time throughout the geological history of our planet over nine orders of magnitude, from the accretion of the proto-planetary disk, to the timing of the last glaciation. This article summarizes the recent efforts of the Isotope Geochemistry, Geochronology and Thermochronology research group at the University of Geneva to advance the U-Pb geochronological tool to achieve unprecedented precision and accuracy, and presents two examples of its application to two significant open questions in Earth sciences: what are the triggers and timescales of volcanic supereruptions, and what were the causes of mass extinctions in the geological past, driven by global climatic and environmental deterioration?

  2. Approximate but accurate quantum dynamics from the Mori formalism. II. Equilibrium time correlation functions.

    PubMed

    Montoya-Castillo, Andrés; Reichman, David R

    2017-02-28

    The ability to efficiently and accurately calculate equilibrium time correlation functions of many-body condensed phase quantum systems is one of the outstanding problems in theoretical chemistry. The Nakajima-Zwanzig-Mori formalism coupled to the self-consistent solution of the memory kernel has recently proven to be highly successful for the computation of nonequilibrium dynamical averages. Here, we extend this formalism to treat symmetrized equilibrium time correlation functions for the spin-boson model. Following the first paper in this series [A. Montoya-Castillo and D. R. Reichman, J. Chem. Phys. 144, 184104 (2016)], we use a Dyson-type expansion of the projected propagator to obtain a self-consistent solution for the memory kernel that requires only the calculation of normally evolved auxiliary kernels. We employ the approximate mean-field Ehrenfest method to demonstrate the feasibility of this approach. Via comparison with numerically exact results for the correlation function Czz(t)=Re⟨σz(0)σz(t)⟩, we show that the current scheme affords remarkable boosts in accuracy and efficiency over bare Ehrenfest dynamics. We further explore the sensitivity of the resulting dynamics to the choice of kernel closures and the accuracy of the initial canonical density operator.

  3. Time Accurate CFD Simulations of the Orion Launch Abort Vehicle in the Transonic Regime

    NASA Technical Reports Server (NTRS)

    Rojahn, Josh; Ruf, Joe

    2011-01-01

    Significant asymmetries in the fluid dynamics were calculated for some cases in the CFD simulations of the Orion Launch Abort Vehicle through its abort trajectories. The CFD simulations were performed steady state and in three dimensions with symmetric geometries, no freestream sideslip angle, and motors firing. The trajectory points at issue were in the transonic regime, at 0 and +/- 5 angles of attack with the Abort Motors with and without the Attitude Control Motors (ACM) firing. In some of the cases the asymmetric fluid dynamics resulted in aerodynamic side forces that were large enough that would overcome the control authority of the ACMs. MSFC's Fluid Dynamics Group supported the investigation into the cause of the flow asymmetries with time accurate CFD simulations, utilizing a hybrid RANS-LES turbulence model. The results show that the flow over the vehicle and the subsequent interaction with the AB and ACM motor plumes were unsteady. The resulting instantaneous aerodynamic forces were oscillatory with fairly large magnitudes. Time averaged aerodynamic forces were essentially symmetric.

  4. Explicit off-line criteria for stable accurate time filtering of strongly unstable spatially extended systems.

    PubMed

    Majda, Andrew J; Grote, Marcus J

    2007-01-23

    Many contemporary problems in science involve making predictions based on partial observation of extremely complicated spatially extended systems with many degrees of freedom and physical instabilities on both large and small scales. Various new ensemble filtering strategies have been developed recently for these applications, and new mathematical issues arise. Here, explicit off-line test criteria for stable accurate discrete filtering are developed for use in the above context and mimic the classical stability analysis for finite difference schemes. First, constant coefficient partial differential equations, which are randomly forced and damped to mimic mesh scale energy spectra in the above problems are developed as off-line filtering test problems. Then mathematical analysis is used to show that under natural suitable hypothesis the time filtering algorithms for general finite difference discrete approximations to an sxs partial differential equation system with suitable observations decompose into much simpler independent s-dimensional filtering problems for each spatial wave number separately; in other test problems, such block diagonal models rigorously provide upper and lower bounds on the filtering algorithm. In this fashion, elementary off-line filtering criteria can be developed for complex spatially extended systems. The theory is illustrated for time filters by using both unstable and implicit difference scheme approximations to the stochastically forced heat equation where the combined effects of filter stability and model error are analyzed through the simpler off-line criteria.

  5. Information-time based futures pricing

    NASA Astrophysics Data System (ADS)

    Yen, Simon; Wang, Jai Jen

    2009-09-01

    This study follows Clark [P.K. Clark, A subordinated stochastic process model with finite variance for speculative prices, Econometrica 41 (1973) 135-155] and Chang, Chang and Lim [C.W. Chang, S.K. Chang, K.G. Lim, Information-time option pricing: Theory and empirical evidence, Journal of Financial Economics 48 (1998) 211-242] to subordinate an information-time based directing process into calendar-time based parent processes. A closed-form futures pricing formula is derived after taking into account the information-time setting and the stochasticity of the spot price, interest rate, and convenience yield. According to the empirical results on the TAIEX and TFETX data from 1998/7/21 to 2003/12/31, the information-time based model performs better than its calendar-time based counterpart and the cost of carry model, especially when the information arrival intensity estimates become larger.

  6. A time-accurate adaptive grid method and the numerical simulation of a shock-vortex interaction

    NASA Technical Reports Server (NTRS)

    Bockelie, Michael J.; Eiseman, Peter R.

    1990-01-01

    A time accurate, general purpose, adaptive grid method is developed that is suitable for multidimensional steady and unsteady numerical simulations. The grid point movement is performed in a manner that generates smooth grids which resolve the severe solution gradients and the sharp transitions in the solution gradients. The temporal coupling of the adaptive grid and the PDE solver is performed with a grid prediction correction method that is simple to implement and ensures the time accuracy of the grid. Time accurate solutions of the 2-D Euler equations for an unsteady shock vortex interaction demonstrate the ability of the adaptive method to accurately adapt the grid to multiple solution features.

  7. High-accurate nonlocal timing and positioning using entangled photon pairs

    NASA Astrophysics Data System (ADS)

    Valencia Gonzalez, Alejandra C.

    One of the most surprising consequences of quantum mechanics is the concept of entanglement. This concept has intrigued the scientific community since it was first proposed by Einstein, Podolsky and Rosen in 1935 because of its connection to fundamental aspects regarding our conception of the universe. Nowadays, there are still open questions about the fundamental issues of quantum mechanics. Nevertheless, the unique characteristics of entanglement have been proposed for practical applications in the last years. Spontaneous Parametric Down Conversion (SPDC) has been recognized as a convenient source of entangled photon pairs. SPDC is a nonlinear optical process in which a pump laser beam is shone into a nonlinear crystal and occasionally one pump photon is down-converted to a pair of lower frequency photons that are entangled. Two photons in an entangled state are characterized by a single two-photon effective wavefunction, or Biphoton. They cannot be considered as the simple juxtaposition of two individual systems. This is a consequence of the quantum correlations between the two photons and implies that a measurement in one of the subsystems affects the total state of the composite system and, therefore, affects the output of a measurement performed in the other photon. The purpose of this dissertation is to show the potential of entangled photon pairs for high-accurate timing and positioning measurements. The entangled nature of the two-photon states allows, in principle, precise space-time correlation measurements to the femtosecond level, providing the physical foundations for high-accurate nonlocal distant clock synchronization. In this dissertation, the proof-of-principle demonstration of a "one-way" distant clock synchronization protocol is presented. The novel method is based on the measurements of the second order correlation function of entangled photon pairs. An experimental study of the behavior of the Biphoton when it travels through a dispersive

  8. A versatile assay for the accurate, time-resolved determination of cellular viability.

    PubMed

    Amano, Toyoki; Hirasawa, Ken ichi; O'Donohue, Michael J; Pernolle, Jean Claude; Shioi, Yuzo

    2003-03-01

    A convenient and versatile method for the accurate, time-resolved determination of cellular viability has been developed. The conventional viability indicator fluorescein diacetate (FDA), which is converted to the fluorescent compound fluorescein in living cells, was employed as a viability probe. Fluorescence emission from cells was measured using a spectrofluorimeter equipped with a magnetic stirrer. Using this assay cell suspensions exhibiting densities in the range 0.5 x 10(5) to 2.0 x 10(5) cells displayed a linear response when FDA concentrations less than 12 micro M were employed. To calibrate the method, viability standards were elaborated using different proportions of living and dead cells, and a correlation coefficient for the viability of tobacco BY-2 suspensions was calculated as 0.998. This viability assay was also found to be applicable to Chlamydomonas reinhardtii and Arabidopsis thaliana cultured cells. Using this cell viability assay, kinetic analyses of cell death could be performed. Using the proteinaceous elicitor from Phytophthora cryptogea, cryptogein, to induce cell death in tobacco cell suspensions, values for the maximum velocity of death induction rate (V(max)) and the LD50 (half-maximal velocity or k(1/2)) were calculated as 17.2 (% death/h) and 65 nM, respectively.

  9. Honey bees can perform accurately directed waggle dances based solely on information from a homeward trip.

    PubMed

    Edrich, Wolfgang

    2015-10-01

    Honey bees were displaced several 100 m from their hive to an unfamiliar site and provisioned with honey. After feeding, almost two-thirds of the bees flew home to their hive within a 50 min observation time. About half of these returning, bees signalled the direction of the release site in waggle dances thus demonstrating that the dance can be guided entirely by information gathered on a single homeward trip. The likely reason for the bees' enthusiastic dancing on their initial return from this new site was the highly rewarding honeycomb that they were given there. The attractive nature of the site is confirmed by many of these bees revisiting the site and continuing to forage there.

  10. PACE: Pattern Accurate Computationally Efficient Bootstrapping for Timely Discovery of Cyber-Security Concepts

    SciTech Connect

    McNeil, Nikki C; Bridges, Robert A; Iannacone, Michael D; Czejdo, Bogdan; Perez, Nicolas E; Goodall, John R

    2013-01-01

    Public disclosure of important security information, such as knowledge of vulnerabilities or exploits, often occurs in blogs, tweets, mailing lists, and other online sources significantly before proper classification into structured databases. In order to facilitate timely discovery of such knowledge, we propose a novel semi-supervised learning algorithm, PACE, for identifying and classifying relevant entities in text sources. The main contribution of this paper is an enhancement of the traditional bootstrapping method for entity extraction by employing a time-memory trade-off that simultaneously circumvents a costly corpus search while strengthening pattern nomination, which should increase accuracy. An implementation in the cyber-security domain is discussed as well as challenges to Natural Language Processing imposed by the security domain.

  11. Time-Accurate Computational Fluid Dynamics Simulation of a Pair of Moving Solid Rocket Boosters

    NASA Technical Reports Server (NTRS)

    Strutzenberg, Louise L.; Williams, Brandon R.

    2011-01-01

    Since the Columbia accident, the threat to the Shuttle launch vehicle from debris during the liftoff timeframe has been assessed by the Liftoff Debris Team at NASA/MSFC. In addition to engineering methods of analysis, CFD-generated flow fields during the liftoff timeframe have been used in conjunction with 3-DOF debris transport methods to predict the motion of liftoff debris. Early models made use of a quasi-steady flow field approximation with the vehicle positioned at a fixed location relative to the ground; however, a moving overset mesh capability has recently been developed for the Loci/CHEM CFD software which enables higher-fidelity simulation of the Shuttle transient plume startup and liftoff environment. The present work details the simulation of the launch pad and mobile launch platform (MLP) with truncated solid rocket boosters (SRBs) moving in a prescribed liftoff trajectory derived from Shuttle flight measurements. Using Loci/CHEM, time-accurate RANS and hybrid RANS/LES simulations were performed for the timeframe T0+0 to T0+3.5 seconds, which consists of SRB startup to a vehicle altitude of approximately 90 feet above the MLP. Analysis of the transient flowfield focuses on the evolution of the SRB plumes in the MLP plume holes and the flame trench, impingement on the flame deflector, and especially impingment on the MLP deck resulting in upward flow which is a transport mechanism for debris. The results show excellent qualitative agreement with the visual record from past Shuttle flights, and comparisons to pressure measurements in the flame trench and on the MLP provide confidence in these simulation capabilities.

  12. Accurately decoding visual information from fMRI data obtained in a realistic virtual environment

    PubMed Central

    Floren, Andrew; Naylor, Bruce; Miikkulainen, Risto; Ress, David

    2015-01-01

    Three-dimensional interactive virtual environments (VEs) are a powerful tool for brain-imaging based cognitive neuroscience that are presently under-utilized. This paper presents machine-learning based methods for identifying brain states induced by realistic VEs with improved accuracy as well as the capability for mapping their spatial topography on the neocortex. VEs provide the ability to study the brain under conditions closer to the environment in which humans evolved, and thus to probe deeper into the complexities of human cognition. As a test case, we designed a stimulus to reflect a military combat situation in the Middle East, motivated by the potential of using real-time functional magnetic resonance imaging (fMRI) in the treatment of post-traumatic stress disorder. Each subject experienced moving through the virtual town where they encountered 1–6 animated combatants at different locations, while fMRI data was collected. To analyze the data from what is, compared to most studies, more complex and less controlled stimuli, we employed statistical machine learning in the form of Multi-Voxel Pattern Analysis (MVPA) with special attention given to artificial Neural Networks (NN). Extensions to NN that exploit the block structure of the stimulus were developed to improve the accuracy of the classification, achieving performances from 58 to 93% (chance was 16.7%) with six subjects. This demonstrates that MVPA can decode a complex cognitive state, viewing a number of characters, in a dynamic virtual environment. To better understand the source of this information in the brain, a novel form of sensitivity analysis was developed to use NN to quantify the degree to which each voxel contributed to classification. Compared with maps produced by general linear models and the searchlight approach, these sensitivity maps revealed a more diverse pattern of information relevant to the classification of cognitive state. PMID:26106315

  13. Providing accurate near real-time fire alerts for Protected Areas through NASA FIRMS: Opportunities and Challenges

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    The NASA Fire Information for Resource Management System (FIRMS) is at the forefront of providing global near real-time (NRT) MODIS thermal anomalies / hotspot location data to end-users . FIRMS serves the data via an interactive Web GIS named Web Fire Mapper, downloads of NRT active fire, archive data downloads for MODIS hotspots dating back to 1999 and a hotspot email alert system The FIRMS Email Alerts system has been successfully alerting users of fires in their area of interest in near real-time and/or via daily and weekly email summaries, with an option to receive MODIS hotspot data as a text file (CSV) attachment. Currently, there are more than 7000 email alert subscriptions from more than 100 countries. Specifically, the email alerts system is designed to generate and send an email alert for any region or area on the globe, with a special focus on providing alerts for protected areas worldwide. For many protected areas, email alerts are particularly useful for early fire detection, monitoring on going fires, as well as allocating resources to protect wildlife and natural resources of particular value. For protected areas, FIRMS uses the World Database on Protected Areas (WDPA) supplied by United Nations Environment Program - World Conservation Monitoring Centre (UNEP-WCMC). Maintaining the most up-to-date, accurate boundary geometry for the protected areas for the email alerts is a challenge as the WDPA is continuously updated due to changing boundaries, merging or delisting of certain protected areas. Because of this dynamic nature of the protected areas database, the FIRMS protected areas database is frequently out-of-date with the most current version of WDPA database. To maintain the most up-to-date boundary information for protected areas and to be in compliance with the WDPA terms and conditions, FIRMS needs to constantly update its database of protected areas. Currently, FIRMS strives to keep its database up to date by downloading the most recent

  14. Time-accurate unstructured grid algorithms for the compressible Navier-Stokes equations

    NASA Astrophysics Data System (ADS)

    Okong'o, Nora Anyango

    Unstructured grid algorithms for the solution of the finite volume form of the unsteady compressible Navier-Stokes equations have been developed. The algorithms employ triangular cells in two-dimensions and tetrahedral cells in three-dimensions. Cell-averaged values are stored at the centroid of each cell, in a cell-centered storage scheme. Inviscid flux computations are performed by applying a Riemann solver across each face, the values at the points on the faces being obtained by function reconstruction from the cell-averaged values. The viscous fluxes and heat transfer are obtained by application of Gauss' theorem. The first unstructured grid algorithm is a two-dimensional implicit algorithm for laminar flows. Tests using flow into a supersonic compression comer showed that preconditioning in the iterative linear solver dramatically reduced the CPU time. Computations were then performed for a NACA0012 airfoil pitching about the quarter-chord at a freestream Mach number Minfinity=0.2 and Reynolds numbers Rec=104 and 2 x 104 at a dimensionless pitching rate W+o=0.2 . The results for Rec=104 are in excellent agreement with previous computations using an explicit unstructured Navier-Stokes algorithm. New results for Rec=2x104 indicate that the principal effect of increasing Reynolds number is to reduce the angle at which the primary recirculation region appears, and to cause it to form closer to the leading edge. This trend, confirmed by a grid refinement study, is consistent with previous results obtained at Minfinity=0.5 . The second unstructured grid algorithm is a three-dimensional explicit algorithm for turbulent flows. Function reconstruction via a least squares method capable of second- or third-order accuracy was implemented. Tests on the nonlinear propagation of an acoustic wave showed improved accuracy using third-order schemes but a substantial CPU-time cost. However, the second-order least squares is more accurate than the previous second-order scheme

  15. Continuous real-time water information: an important Kansas resource

    USGS Publications Warehouse

    Loving, Brian L.; Putnam, James E.; Turk, Donita M.

    2014-01-01

    Continuous real-time information on streams, lakes, and groundwater is an important Kansas resource that can safeguard lives and property, and ensure adequate water resources for a healthy State economy. The U.S. Geological Survey (USGS) operates approximately 230 water-monitoring stations at Kansas streams, lakes, and groundwater sites. Most of these stations are funded cooperatively in partnerships with local, tribal, State, or other Federal agencies. The USGS real-time water-monitoring network provides long-term, accurate, and objective information that meets the needs of many customers. Whether the customer is a water-management or water-quality agency, an emergency planner, a power or navigational official, a farmer, a canoeist, or a fisherman, all can benefit from the continuous real-time water information gathered by the USGS.

  16. The challenges of accurately estimating time of long bone injury in children.

    PubMed

    Pickett, Tracy A

    2015-07-01

    The ability to determine the time an injury occurred can be of crucial significance in forensic medicine and holds special relevance to the investigation of child abuse. However, dating paediatric long bone injury, including fractures, is nuanced by complexities specific to the paediatric population. These challenges include the ability to identify bone injury in a growing or only partially-calcified skeleton, different injury patterns seen within the spectrum of the paediatric population, the effects of bone growth on healing as a separate entity from injury, differential healing rates seen at different ages, and the relative scarcity of information regarding healing rates in children, especially the very young. The challenges posed by these factors are compounded by a lack of consistency in defining and categorizing healing parameters. This paper sets out the primary limitations of existing knowledge regarding estimating timing of paediatric bone injury. Consideration and understanding of the multitude of factors affecting bone injury and healing in children will assist those providing opinion in the medical-legal forum.

  17. A Weight-Averaged Interpolation Method for Coupling Time-Accurate Rarefied and Continuum Flows

    NASA Astrophysics Data System (ADS)

    Diaz, Steven William

    A novel approach to coupling rarefied and continuum flow regimes as a single, hybrid model is introduced. The method borrows from techniques used in the simulation of spray flows to interpolate Lagrangian point-particles onto an Eulerian grid in a weight-averaged sense. A brief overview of traditional methods for modeling both rarefied and continuum domains is given, and a review of the literature regarding rarefied/continuum flow coupling is presented. Details of the theoretical development of the method of weighted interpolation are then described. The method evaluates macroscopic properties at the nodes of a CFD grid via the weighted interpolation of all simulated molecules in a set surrounding the node. The weight factor applied to each simulated molecule is the inverse of the linear distance between it and the given node. During development, the method was applied to several preliminary cases, including supersonic flow over an airfoil, subsonic flow over tandem airfoils, and supersonic flow over a backward facing step; all at low Knudsen numbers. The main thrust of the research centered on the time-accurate expansion of a rocket plume into a near-vacuum. The method proves flexible enough to be used with various flow solvers, demonstrated by the use of Fluent as the continuum solver for the preliminary cases and a NASA-developed Large Eddy Simulation research code, WRLES, for the full lunar model. The method is applicable to a wide range of Mach numbers and is completely grid independent, allowing the rarefied and continuum solvers to be optimized for their respective domains without consideration of the other. The work presented demonstrates the validity, and flexibility of the method of weighted interpolation as a novel concept in the field of hybrid flow coupling. The method marks a significant divergence from current practices in the coupling of rarefied and continuum flow domains and offers a kernel on which to base an ongoing field of research. It has the

  18. Radioisotopic Tie Points of the Quaternary Geomagnetic Instability Time Scale (GITS): How Accurate and Precise?

    NASA Astrophysics Data System (ADS)

    Singer, B. S.

    2014-12-01

    Reversals and excursions of the geomagnetic field are recorded globally by sedimentary and volcanic rocks. These geodynamo instabilities provide a rich set of chronostratigraphic tie points for the Quaternary period that can provide tests of age models central to paleoclimate studies. Radioisotopic dating of volcanic rocks, mainly 40Ar/39Ar dating of lava flows, coupled with astronomically-dated deep sea sediments, reveals 10 polarity reversals and 27 field excursions during the Quaternary (Singer, 2014). A key question concerns the uncertainties associated with radioisotopic dates of those geodynamo instabilities that have been identified both in terrestrial volcanic rocks and in deep sea sediments. These particular features offer the highest confidence in linking 40Ar/39Ar dates to the global marine climate record. Geological issues aside, for rocks in which the build-up of 40Ar by decay of 40K may be overwhelmed by atmospheric 40Ar at the time of eruption, the uncertainty in 40Ar/39Ar dates derives from three sources: (1) analytical uncertainty associated with measurement of the isotopes; this is straightforward to estimate; (2) systematic uncertainties stemming from the age of standard minerals, such as the Fish Canyon sanidine, and in the 40K decay constant; and (3) systematic uncertainty introduced during analysis, mainly the size and reproducibility of procedural blanks. Whereas 1 and 2 control the precision of an age determination, 2 and 3 also control accuracy. In parallel with an astronomical calibration of 28.201 Ma for the Fish Canyon sanidine standard, awareness of the importance of procedural blanks, and a new generation multi-collector mass spectrometer capable of exceptionally low-blank and isobar-free analysis, are improving both accuracy and precision of 40Ar/39Ar dates. Results from lavas recording the Matuyama-Brunhes reversal, the Santa Rosa excursion, and the reversal at the top of the Cobb Mtn subchron demonstrate these advances. Current best

  19. Calibration of time-of-flight cameras for accurate intraoperative surface reconstruction

    SciTech Connect

    Mersmann, Sven; Seitel, Alexander; Maier-Hein, Lena; Erz, Michael; Jähne, Bernd; Nickel, Felix; Mieth, Markus; Mehrabi, Arianeb

    2013-08-15

    Purpose: In image-guided surgery (IGS) intraoperative image acquisition of tissue shape, motion, and morphology is one of the main challenges. Recently, time-of-flight (ToF) cameras have emerged as a new means for fast range image acquisition that can be used for multimodal registration of the patient anatomy during surgery. The major drawbacks of ToF cameras are systematic errors in the image acquisition technique that compromise the quality of the measured range images. In this paper, we propose a calibration concept that, for the first time, accounts for all known systematic errors affecting the quality of ToF range images. Laboratory and in vitro experiments assess its performance in the context of IGS.Methods: For calibration the camera-related error sources depending on the sensor, the sensor temperature and the set integration time are corrected first, followed by the scene-specific errors, which are modeled as function of the measured distance, the amplitude and the radial distance to the principal point of the camera. Accounting for the high accuracy demands in IGS, we use a custom-made calibration device to provide reference distance data, the cameras are calibrated too. To evaluate the mitigation of the error, the remaining residual error after ToF depth calibration was compared with that arising from using the manufacturer routines for several state-of-the-art ToF cameras. The accuracy of reconstructed ToF surfaces was investigated after multimodal registration with computed tomography (CT) data of liver models by assessment of the target registration error (TRE) of markers introduced in the livers.Results: For the inspected distance range of up to 2 m, our calibration approach yielded a mean residual error to reference data ranging from 1.5 ± 4.3 mm for the best camera to 7.2 ± 11.0 mm. When compared to the data obtained from the manufacturer routines, the residual error was reduced by at least 78% from worst calibration result to most accurate

  20. Two Accurate Time-delay Distances from Strong Lensing: Implications for Cosmology

    NASA Astrophysics Data System (ADS)

    Suyu, S. H.; Auger, M. W.; Hilbert, S.; Marshall, P. J.; Tewes, M.; Treu, T.; Fassnacht, C. D.; Koopmans, L. V. E.; Sluse, D.; Blandford, R. D.; Courbin, F.; Meylan, G.

    2013-04-01

    Strong gravitational lenses with measured time delays between the multiple images and models of the lens mass distribution allow a one-step determination of the time-delay distance, and thus a measure of cosmological parameters. We present a blind analysis of the gravitational lens RXJ1131-1231 incorporating (1) the newly measured time delays from COSMOGRAIL, the COSmological MOnitoring of GRAvItational Lenses, (2) archival Hubble Space Telescope imaging of the lens system, (3) a new velocity-dispersion measurement of the lens galaxy of 323 ± 20 km s-1 based on Keck spectroscopy, and (4) a characterization of the line-of-sight structures via observations of the lens' environment and ray tracing through the Millennium Simulation. Our blind analysis is designed to prevent experimenter bias. The joint analysis of the data sets allows a time-delay distance measurement to 6% precision that takes into account all known systematic uncertainties. In combination with the Wilkinson Microwave Anisotropy Probe seven-year (WMAP7) data set in flat wCDM cosmology, our unblinded cosmological constraints for RXJ1131-1231 are H_0=80.0^{+5.8}_{-5.7} km s^{-1} Mpc^{-1}, Ωde = 0.79 ± 0.03, and w=-1.25^{+0.17}_{-0.21}. We find the results to be statistically consistent with those from the analysis of the gravitational lens B1608+656, permitting us to combine the inferences from these two lenses. The joint constraints from the two lenses and WMAP7 are H_0=75.2^{+4.4}_{-4.2} km s^{-1} Mpc^{-1}, Ω _de=0.76^{+0.02}_{-0.03}, and w = -1.14^{+0.17}_{-0.20} in flat wCDM, and H_0=73.1^{+2.4}_{-3.6} km s^{-1} Mpc^{-1}, Ω_{Λ}= 0.75^{+0.01}_{-0.02}, and Ω_k=0.003^{+0.005}_{-0.006} in open ΛCDM. Time-delay lenses constrain especially tightly the Hubble constant H 0 (5.7% and 4.0% respectively in wCDM and open ΛCDM) and curvature of the universe. The overall information content is similar to that of Baryon Acoustic Oscillation experiments. Thus, they complement well other cosmological probes

  1. Accurate refinement of docked protein complexes using evolutionary information and deep learning.

    PubMed

    Akbal-Delibas, Bahar; Farhoodi, Roshanak; Pomplun, Marc; Haspel, Nurit

    2016-06-01

    One of the major challenges for protein docking methods is to accurately discriminate native-like structures from false positives. Docking methods are often inaccurate and the results have to be refined and re-ranked to obtain native-like complexes and remove outliers. In a previous work, we introduced AccuRefiner, a machine learning based tool for refining protein-protein complexes. Given a docked complex, the refinement tool produces a small set of refined versions of the input complex, with lower root-mean-square-deviation (RMSD) of atomic positions with respect to the native structure. The method employs a unique ranking tool that accurately predicts the RMSD of docked complexes with respect to the native structure. In this work, we use a deep learning network with a similar set of features and five layers. We show that a properly trained deep learning network can accurately predict the RMSD of a docked complex with 1.40 Å error margin on average, by approximating the complex relationship between a wide set of scoring function terms and the RMSD of a docked structure. The network was trained on 35000 unbound docking complexes generated by RosettaDock. We tested our method on 25 different putative docked complexes produced also by RosettaDock for five proteins that were not included in the training data. The results demonstrate that the high accuracy of the ranking tool enables AccuRefiner to consistently choose the refinement candidates with lower RMSD values compared to the coarsely docked input structures.

  2. Precisely Timing Dissipative Quantum Information Processing

    NASA Astrophysics Data System (ADS)

    Kastoryano, M. J.; Wolf, M. M.; Eisert, J.

    2013-03-01

    Dissipative engineering constitutes a framework within which quantum information processing protocols are powered by system-environment interaction rather than by unitary dynamics alone. This framework embraces noise as a resource and, consequently, offers a number of advantages compared to one based on unitary dynamics alone, e.g., that the protocols are typically independent of the initial state of the system. However, the time independent nature of this scheme makes it difficult to imagine precisely timed sequential operations, conditional measurements, or error correction. In this work, we provide a path around these challenges, by introducing basic dissipative gadgets which allow us to precisely initiate, trigger, and time dissipative operations while keeping the system Liouvillian time independent. These gadgets open up novel perspectives for thinking of timed dissipative quantum information processing. As an example, we sketch how measurement-based computation can be simulated in the dissipative setting.

  3. Precisely timing dissipative quantum information processing.

    PubMed

    Kastoryano, M J; Wolf, M M; Eisert, J

    2013-03-15

    Dissipative engineering constitutes a framework within which quantum information processing protocols are powered by system-environment interaction rather than by unitary dynamics alone. This framework embraces noise as a resource and, consequently, offers a number of advantages compared to one based on unitary dynamics alone, e.g., that the protocols are typically independent of the initial state of the system. However, the time independent nature of this scheme makes it difficult to imagine precisely timed sequential operations, conditional measurements, or error correction. In this work, we provide a path around these challenges, by introducing basic dissipative gadgets which allow us to precisely initiate, trigger, and time dissipative operations while keeping the system Liouvillian time independent. These gadgets open up novel perspectives for thinking of timed dissipative quantum information processing. As an example, we sketch how measurement-based computation can be simulated in the dissipative setting.

  4. Polyallelic structural variants can provide accurate, highly informative genetic markers focused on diagnosis and therapeutic targets: Accuracy vs. Precision.

    PubMed

    Roses, A D

    2016-02-01

    Structural variants (SVs) include all insertions, deletions, and rearrangements in the genome, with several common types of nucleotide repeats including single sequence repeats, short tandem repeats, and insertion-deletion length variants. Polyallelic SVs provide highly informative markers for association studies with well-phenotyped cohorts. SVs can influence gene regulation by affecting epigenetics, transcription, splicing, and/or translation. Accurate assays of polyallelic SV loci are required to define the range and allele frequency of variable length alleles.

  5. A time accurate prediction of the viscous flow in a turbine stage including a rotor in motion

    NASA Astrophysics Data System (ADS)

    Shavalikul, Akamol

    in the relative frame of reference; the boundary conditions for the computations were obtained from inlet flow measurements performed in the AFTRF. A complete turbine stage, including an NGV and a rotor row was simulated using the RANS solver with the SST kappa -- o turbulence model, with two different computational models for the interface between the rotating component and the stationary component. The first interface model, the circumferentially averaged mixing plane model, was solved for a fixed position of the rotor blades relative to the NGV in the stationary frame of reference. The information transferred between the NGV and rotor domains is obtained by averaging across the entire interface. The quasi-steady state flow characteristics of the AFTRF can be obtained from this interface model. After the model was validated with the existing experimental data, this model was not only used to investigate the flow characteristics in the turbine stage but also the effects of using pressure side rotor tip extensions. The tip leakage flow fields simulated from this model and from the linear cascade model show similar trends. More detailed understanding of unsteady characteristics of a turbine flow field can be obtained using the second type of interface model, the time accurate sliding mesh model. The potential flow interactions, wake characteristics, their effects on secondary flow formation, and the wake mixing process in a rotor passage were examined using this model. Furthermore, turbine stage efficiency and effects of tip clearance height on the turbine stage efficiency were also investigated. A comparison between the results from the circumferential average model and the time accurate flow model results is presented. It was found that the circumferential average model cannot accurately simulate flow interaction characteristics on the interface plane between the NGV trailing edge and the rotor leading edge. However, the circumferential average model does give

  6. 16 CFR 1101.32 - Reasonable steps to assure information is accurate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Reasonable steps to assure information is... to the best of the submitter's knowledge and belief, provided that: (i) The confirmation is made by... physician; or (v) The confirmation is made by a parent or guardian of a child involved in an...

  7. 16 CFR 1101.32 - Reasonable steps to assure information is accurate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Reasonable steps to assure information is... to the best of the submitter's knowledge and belief, provided that: (i) The confirmation is made by... physician; or (v) The confirmation is made by a parent or guardian of a child involved in an...

  8. 16 CFR 1101.32 - Reasonable steps to assure information is accurate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Reasonable steps to assure information is... to the best of the submitter's knowledge and belief, provided that: (i) The confirmation is made by... physician; or (v) The confirmation is made by a parent or guardian of a child involved in an...

  9. 16 CFR 1101.32 - Reasonable steps to assure information is accurate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Reasonable steps to assure information is... to the best of the submitter's knowledge and belief, provided that: (i) The confirmation is made by... physician; or (v) The confirmation is made by a parent or guardian of a child involved in an...

  10. 16 CFR 1101.32 - Reasonable steps to assure information is accurate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Reasonable steps to assure information is... to the best of the submitter's knowledge and belief, provided that: (i) The confirmation is made by... physician; or (v) The confirmation is made by a parent or guardian of a child involved in an...

  11. Extracting information in spike time patterns with wavelets and information theory

    PubMed Central

    Lopes-dos-Santos, Vítor; Panzeri, Stefano; Kayser, Christoph; Diamond, Mathew E.

    2014-01-01

    We present a new method to assess the information carried by temporal patterns in spike trains. The method first performs a wavelet decomposition of the spike trains, then uses Shannon information to select a subset of coefficients carrying information, and finally assesses timing information in terms of decoding performance: the ability to identify the presented stimuli from spike train patterns. We show that the method allows: 1) a robust assessment of the information carried by spike time patterns even when this is distributed across multiple time scales and time points; 2) an effective denoising of the raster plots that improves the estimate of stimulus tuning of spike trains; and 3) an assessment of the information carried by temporally coordinated spikes across neurons. Using simulated data, we demonstrate that the Wavelet-Information (WI) method performs better and is more robust to spike time-jitter, background noise, and sample size than well-established approaches, such as principal component analysis, direct estimates of information from digitized spike trains, or a metric-based method. Furthermore, when applied to real spike trains from monkey auditory cortex and from rat barrel cortex, the WI method allows extracting larger amounts of spike timing information. Importantly, the fact that the WI method incorporates multiple time scales makes it robust to the choice of partly arbitrary parameters such as temporal resolution, response window length, number of response features considered, and the number of available trials. These results highlight the potential of the proposed method for accurate and objective assessments of how spike timing encodes information. PMID:25392163

  12. Extracting information in spike time patterns with wavelets and information theory.

    PubMed

    Lopes-dos-Santos, Vítor; Panzeri, Stefano; Kayser, Christoph; Diamond, Mathew E; Quian Quiroga, Rodrigo

    2015-02-01

    We present a new method to assess the information carried by temporal patterns in spike trains. The method first performs a wavelet decomposition of the spike trains, then uses Shannon information to select a subset of coefficients carrying information, and finally assesses timing information in terms of decoding performance: the ability to identify the presented stimuli from spike train patterns. We show that the method allows: 1) a robust assessment of the information carried by spike time patterns even when this is distributed across multiple time scales and time points; 2) an effective denoising of the raster plots that improves the estimate of stimulus tuning of spike trains; and 3) an assessment of the information carried by temporally coordinated spikes across neurons. Using simulated data, we demonstrate that the Wavelet-Information (WI) method performs better and is more robust to spike time-jitter, background noise, and sample size than well-established approaches, such as principal component analysis, direct estimates of information from digitized spike trains, or a metric-based method. Furthermore, when applied to real spike trains from monkey auditory cortex and from rat barrel cortex, the WI method allows extracting larger amounts of spike timing information. Importantly, the fact that the WI method incorporates multiple time scales makes it robust to the choice of partly arbitrary parameters such as temporal resolution, response window length, number of response features considered, and the number of available trials. These results highlight the potential of the proposed method for accurate and objective assessments of how spike timing encodes information.

  13. Joint iris boundary detection and fit: a real-time method for accurate pupil tracking.

    PubMed

    Barbosa, Marconi; James, Andrew C

    2014-08-01

    A range of applications in visual science rely on accurate tracking of the human pupil's movement and contraction in response to light. While the literature for independent contour detection and fitting of the iris-pupil boundary is vast, a joint approach, in which it is assumed that the pupil has a given geometric shape has been largely overlooked. We present here a global method for simultaneously finding and fitting of an elliptic or circular contour against a dark interior, which produces consistently accurate results even under non-ideal recording conditions, such as reflections near and over the boundary, droopy eye lids, or the sudden formation of tears. The specific form of the proposed optimization problem allows us to write down closed analytic formulae for the gradient and the Hessian of the objective function. Moreover, both the objective function and its derivatives can be cast into vectorized form, making the proposed algorithm significantly faster than its closest relative in the literature. We compare methods in multiple ways, both analytically and numerically, using real iris images as well as idealizations of the iris for which the ground truth boundary is precisely known. The method proposed here is illustrated under challenging recording conditions and it is shown to be robust.

  14. Robust and Accurate Anomaly Detection in ECG Artifacts Using Time Series Motif Discovery

    PubMed Central

    Sivaraks, Haemwaan

    2015-01-01

    Electrocardiogram (ECG) anomaly detection is an important technique for detecting dissimilar heartbeats which helps identify abnormal ECGs before the diagnosis process. Currently available ECG anomaly detection methods, ranging from academic research to commercial ECG machines, still suffer from a high false alarm rate because these methods are not able to differentiate ECG artifacts from real ECG signal, especially, in ECG artifacts that are similar to ECG signals in terms of shape and/or frequency. The problem leads to high vigilance for physicians and misinterpretation risk for nonspecialists. Therefore, this work proposes a novel anomaly detection technique that is highly robust and accurate in the presence of ECG artifacts which can effectively reduce the false alarm rate. Expert knowledge from cardiologists and motif discovery technique is utilized in our design. In addition, every step of the algorithm conforms to the interpretation of cardiologists. Our method can be utilized to both single-lead ECGs and multilead ECGs. Our experiment results on real ECG datasets are interpreted and evaluated by cardiologists. Our proposed algorithm can mostly achieve 100% of accuracy on detection (AoD), sensitivity, specificity, and positive predictive value with 0% false alarm rate. The results demonstrate that our proposed method is highly accurate and robust to artifacts, compared with competitive anomaly detection methods. PMID:25688284

  15. Accurate real-time depth control for CP-SSOCT distal sensor based handheld microsurgery tools

    PubMed Central

    Cheon, Gyeong Woo; Huang, Yong; Cha, Jaepyeng; Gehlbach, Peter L.; Kang, Jin U.

    2015-01-01

    This paper presents a novel intuitive targeting and tracking scheme that utilizes a common-path swept source optical coherence tomography (CP-SSOCT) distal sensor integrated handheld microsurgical tool. To achieve micron-order precision control, a reliable and accurate OCT distal sensing method is required; simultaneously, a prediction algorithm is necessary to compensate for the system delay associated with the computational, mechanical and electronic latencies. Due to the multi-layered structure of retina, it is necessary to develop effective surface detection methods rather than simple peak detection. To achieve this, a shifted cross-correlation method is applied for surface detection in order to increase robustness and accuracy in distal sensing. A predictor based on Kalman filter was implemented for more precise motion compensation. The performance was first evaluated using an established dry phantom consisting of stacked cellophane tape. This was followed by evaluation in an ex-vivo bovine retina model to assess system accuracy and precision. The results demonstrate highly accurate depth targeting with less than 5 μm RMSE depth locking. PMID:26137393

  16. Joint iris boundary detection and fit: a real-time method for accurate pupil tracking

    PubMed Central

    Barbosa, Marconi; James, Andrew C.

    2014-01-01

    A range of applications in visual science rely on accurate tracking of the human pupil’s movement and contraction in response to light. While the literature for independent contour detection and fitting of the iris-pupil boundary is vast, a joint approach, in which it is assumed that the pupil has a given geometric shape has been largely overlooked. We present here a global method for simultaneously finding and fitting of an elliptic or circular contour against a dark interior, which produces consistently accurate results even under non-ideal recording conditions, such as reflections near and over the boundary, droopy eye lids, or the sudden formation of tears. The specific form of the proposed optimization problem allows us to write down closed analytic formulae for the gradient and the Hessian of the objective function. Moreover, both the objective function and its derivatives can be cast into vectorized form, making the proposed algorithm significantly faster than its closest relative in the literature. We compare methods in multiple ways, both analytically and numerically, using real iris images as well as idealizations of the iris for which the ground truth boundary is precisely known. The method proposed here is illustrated under challenging recording conditions and it is shown to be robust. PMID:25136477

  17. Robust and accurate anomaly detection in ECG artifacts using time series motif discovery.

    PubMed

    Sivaraks, Haemwaan; Ratanamahatana, Chotirat Ann

    2015-01-01

    Electrocardiogram (ECG) anomaly detection is an important technique for detecting dissimilar heartbeats which helps identify abnormal ECGs before the diagnosis process. Currently available ECG anomaly detection methods, ranging from academic research to commercial ECG machines, still suffer from a high false alarm rate because these methods are not able to differentiate ECG artifacts from real ECG signal, especially, in ECG artifacts that are similar to ECG signals in terms of shape and/or frequency. The problem leads to high vigilance for physicians and misinterpretation risk for nonspecialists. Therefore, this work proposes a novel anomaly detection technique that is highly robust and accurate in the presence of ECG artifacts which can effectively reduce the false alarm rate. Expert knowledge from cardiologists and motif discovery technique is utilized in our design. In addition, every step of the algorithm conforms to the interpretation of cardiologists. Our method can be utilized to both single-lead ECGs and multilead ECGs. Our experiment results on real ECG datasets are interpreted and evaluated by cardiologists. Our proposed algorithm can mostly achieve 100% of accuracy on detection (AoD), sensitivity, specificity, and positive predictive value with 0% false alarm rate. The results demonstrate that our proposed method is highly accurate and robust to artifacts, compared with competitive anomaly detection methods.

  18. Real-time preprocessing of holographic information

    NASA Astrophysics Data System (ADS)

    Schilling, Bradley W.; Poon, Ting-Chung

    1995-11-01

    Optical scanning holography (OSH) is a holographic recording technique that uses active optical heterodyne scanning to generate holographic information pertaining to an object. The holographic information manifests itself as an electrical signal suitable for real-time image reconstruction using a spatial light modulator. The electrical signal that carries the holographic information can also be digitized for computer storage and processing, allowing the image reconstruction to be performed numerically. In previous experiments with this technique, holographic information has been recorded using the interference pattern of a plane wave and a spherical wave of different temporal frequencies to scan an object. However, the proper manipulation of the pupil functions in the recording stage can result in real-time processing of the holographic edge extraction technique as an important example of real-time preprocessing of holographic information that utilizes alternate pupils in the OSH recording stage. We investigate the theory of holographic preprocessing using a spatial frequency-domain analysis based on the recording system's optical transfer function. The theory is reinforced through computer simulation.

  19. Timing crisis information release via television.

    PubMed

    Wei, Jiuchang; Zhao, Dingtao; Yang, Feng; Du, Shaofu; Marinova, Dora

    2010-10-01

    When and how often to release information on television are important issues in crisis and emergency risk communication. There is a lot of crisis information, including warnings and news, to which people should have access, but most of it is not significantly urgent to interrupt the broadcasting of television programmes. Hence, the right timing for the release of crisis information should be selected based on the importance of the crisis and any associated communication requirements. Using recursive methods, this paper builds an audience coverage model of crisis information release. Based on 2007 Household Using TV (HUT) data for Hefei City, China, the optimal combination of broadcasting sequence (with frequencies between one and eight times) is obtained using the implicit enumeration method. The developed model is applicable to effective transmission of crisis information, with the aim of reducing interference with the normal television transmission process and decreasing the psychological effect on audiences. The same model can be employed for other purposes, such as news coverage and weather and road information.

  20. Relativistic quantum information and time machines

    NASA Astrophysics Data System (ADS)

    Ralph, Timothy C.; Downes, Tony G.

    2012-01-01

    Relativistic quantum information combines the informational approach to understanding and using quantum mechanical systems - quantum information - with the relativistic view of the Universe. In this introductory review we examine key results to emerge from this new field of research in physics and discuss future directions. A particularly active area recently has been the question of what happens when quantum systems interact with general relativistic closed timelike curves - effectively time machines. We discuss two different approaches that have been suggested for modelling such situations. It is argued that the approach based on matching the density operator of the quantum state between the future and past most consistently avoids the paradoxes usually associated with time travel.

  1. Exploratory Movement Generates Higher-Order Information That Is Sufficient for Accurate Perception of Scaled Egocentric Distance

    PubMed Central

    Mantel, Bruno; Stoffregen, Thomas A.; Campbell, Alain; Bardy, Benoît G.

    2015-01-01

    Body movement influences the structure of multiple forms of ambient energy, including optics and gravito-inertial force. Some researchers have argued that egocentric distance is derived from inferential integration of visual and non-visual stimulation. We suggest that accurate information about egocentric distance exists in perceptual stimulation as higher-order patterns that extend across optics and inertia. We formalize a pattern that specifies the egocentric distance of a stationary object across higher-order relations between optics and inertia. This higher-order parameter is created by self-generated movement of the perceiver in inertial space relative to the illuminated environment. For this reason, we placed minimal restrictions on the exploratory movements of our participants. We asked whether humans can detect and use the information available in this higher-order pattern. Participants judged whether a virtual object was within reach. We manipulated relations between body movement and the ambient structure of optics and inertia. Judgments were precise and accurate when the higher-order optical-inertial parameter was available. When only optic flow was available, judgments were poor. Our results reveal that participants perceived egocentric distance from the higher-order, optical-inertial consequences of their own exploratory activity. Analysis of participants’ movement trajectories revealed that self-selected movements were complex, and tended to optimize availability of the optical-inertial pattern that specifies egocentric distance. We argue that accurate information about egocentric distance exists in higher-order patterns of ambient energy, that self-generated movement can generate these higher-order patterns, and that these patterns can be detected and used to support perception of egocentric distance that is precise and accurate. PMID:25856410

  2. Real-time Accurate Surface Reconstruction Pipeline for Vision Guided Planetary Exploration Using Unmanned Ground and Aerial Vehicles

    NASA Technical Reports Server (NTRS)

    Almeida, Eduardo DeBrito

    2012-01-01

    This report discusses work completed over the summer at the Jet Propulsion Laboratory (JPL), California Institute of Technology. A system is presented to guide ground or aerial unmanned robots using computer vision. The system performs accurate camera calibration, camera pose refinement and surface extraction from images collected by a camera mounted on the vehicle. The application motivating the research is planetary exploration and the vehicles are typically rovers or unmanned aerial vehicles. The information extracted from imagery is used primarily for navigation, as robot location is the same as the camera location and the surfaces represent the terrain that rovers traverse. The processed information must be very accurate and acquired very fast in order to be useful in practice. The main challenge being addressed by this project is to achieve high estimation accuracy and high computation speed simultaneously, a difficult task due to many technical reasons.

  3. Species Distribution 2.0: An Accurate Time- and Cost-Effective Method of Prospection Using Street View Imagery

    PubMed Central

    Schwoertzig, Eugénie; Millon, Alexandre

    2016-01-01

    Species occurrence data provide crucial information for biodiversity studies in the current context of global environmental changes. Such studies often rely on a limited number of occurrence data collected in the field and on pseudo-absences arbitrarily chosen within the study area, which reduces the value of these studies. To overcome this issue, we propose an alternative method of prospection using geo-located street view imagery (SVI). Following a standardised protocol of virtual prospection using both vertical (aerial photographs) and horizontal (SVI) perceptions, we have surveyed 1097 randomly selected cells across Spain (0.1x0.1 degree, i.e. 20% of Spain) for the presence of Arundo donax L. (Poaceae). In total we have detected A. donax in 345 cells, thus substantially expanding beyond the now two-centuries-old field-derived record, which described A. donax only 216 cells. Among the field occurrence cells, 81.1% were confirmed by SVI prospection to be consistent with species presence. In addition, we recorded, by SVI prospection, 752 absences, i.e. cells where A. donax was considered absent. We have also compared the outcomes of climatic niche modeling based on SVI data against those based on field data. Using generalized linear models fitted with bioclimatic predictors, we have found SVI data to provide far more compelling results in terms of niche modeling than does field data as classically used in SDM. This original, cost- and time-effective method provides the means to accurately locate highly visible taxa, reinforce absence data, and predict species distribution without long and expensive in situ prospection. At this time, the majority of available SVI data is restricted to human-disturbed environments that have road networks. However, SVI is becoming increasingly available in natural areas, which means the technique has considerable potential to become an important factor in future biodiversity studies. PMID:26751565

  4. Are portable bladder scanning and real-time ultrasound accurate measures of bladder volume in postnatal women?

    PubMed

    Mathew, S; Horne, A W; Murray, L S; Tydeman, G; McKinley, C A

    2007-08-01

    Real-time ultrasound and portable bladder scanners are commonly used instead of catheterisation to determine bladder volumes in postnatal women but it is not known whether these are accurate. Change in bladder volumes measured by ultrasound and portable scanners were compared with actual voided volume (VV) in 100 postnatal women. The VV was on average 41 ml (CI 29 - 54 ml) higher than that measured by ultrasound, and 33 ml (CI 17 - 48 ml) higher than that measured by portable scanners. Portable scanner volumes were 9 ml (CI -8 - 26 ml) higher than those measured by ultrasound. Neither method is an accurate tool for detecting bladder volume in postnatal women.

  5. A novel class of highly efficient and accurate time-integrators in nonlinear computational mechanics

    NASA Astrophysics Data System (ADS)

    Wang, Xuechuan; Atluri, Satya N.

    2017-01-01

    A new class of time-integrators is presented for strongly nonlinear dynamical systems. These algorithms are far superior to the currently common time integrators in computational efficiency and accuracy. These three algorithms are based on a local variational iteration method applied over a finite interval of time. By using Chebyshev polynomials as trial functions and Dirac-Delta functions as the test functions over the finite time interval, the three algorithms are developed into three different discrete time-integrators through the collocation method. These time integrators are labeled as Chebyshev local iterative collocation methods. Through examples of the forced Duffing oscillator, the Lorenz system, and the multiple coupled Duffing equations (which arise as semi-discrete equations for beams, plates and shells undergoing large deformations), it is shown that the new algorithms are far superior to the 4th order Runge-Kutta and ODE45 of MATLAB, in predicting the chaotic responses of strongly nonlinear dynamical systems.

  6. Some applications of GPS timing information

    NASA Technical Reports Server (NTRS)

    Zhang, Yinbai

    1994-01-01

    GPS Satellites transmit two independent signals. One is C/A code (course acquisition signal) which could be utilized by all civilian users. This service is called a Standard Positioning Service (SPS). Another is P code (precise signal) that could be only accessed by those authorized users. The service is called a precise positioning service (PPS). SPS C/A code users can navigate with accuracy of approximately 100 m and timing accuracy of about 250-300 ns (1 sigma). Such timing accuracy is not enough for precision time and frequency value transfer. For this reason we must do some research work to improve the SPS C/A code accuracy which SPS users can get. This paper presents our recent progress on timing information analysis, its data processing and its timing and frequency measurement applications.

  7. TTVFast: An efficient and accurate code for transit timing inversion problems

    SciTech Connect

    Deck, Katherine M.; Agol, Eric; Holman, Matthew J.; Nesvorný, David

    2014-06-01

    Transit timing variations (TTVs) have proven to be a powerful technique for confirming Kepler planet candidates, for detecting non-transiting planets, and for constraining the masses and orbital elements of multi-planet systems. These TTV applications often require the numerical integration of orbits for computation of transit times (as well as impact parameters and durations); frequently tens of millions to billions of simulations are required when running statistical analyses of the planetary system properties. We have created a fast code for transit timing computation, TTVFast, which uses a symplectic integrator with a Keplerian interpolator for the calculation of transit times. The speed comes at the expense of accuracy in the calculated times, but the accuracy lost is largely unnecessary, as transit times do not need to be calculated to accuracies significantly smaller than the measurement uncertainties on the times. The time step can be tuned to give sufficient precision for any particular system. We find a speed-up of at least an order of magnitude relative to dynamical integrations with high precision using a Bulirsch-Stoer integrator.

  8. TTVFast: An Efficient and Accurate Code for Transit Timing Inversion Problems

    NASA Astrophysics Data System (ADS)

    Deck, Katherine M.; Agol, Eric; Holman, Matthew J.; Nesvorný, David

    2014-06-01

    Transit timing variations (TTVs) have proven to be a powerful technique for confirming Kepler planet candidates, for detecting non-transiting planets, and for constraining the masses and orbital elements of multi-planet systems. These TTV applications often require the numerical integration of orbits for computation of transit times (as well as impact parameters and durations); frequently tens of millions to billions of simulations are required when running statistical analyses of the planetary system properties. We have created a fast code for transit timing computation, TTVFast, which uses a symplectic integrator with a Keplerian interpolator for the calculation of transit times. The speed comes at the expense of accuracy in the calculated times, but the accuracy lost is largely unnecessary, as transit times do not need to be calculated to accuracies significantly smaller than the measurement uncertainties on the times. The time step can be tuned to give sufficient precision for any particular system. We find a speed-up of at least an order of magnitude relative to dynamical integrations with high precision using a Bulirsch-Stoer integrator.

  9. How Accurate Are German Work-Time Data? A Comparison of Time-Diary Reports and Stylized Estimates

    ERIC Educational Resources Information Center

    Otterbach, Steffen; Sousa-Poza, Alfonso

    2010-01-01

    This study compares work time data collected by the German Time Use Survey (GTUS) using the diary method with stylized work time estimates from the GTUS, the German Socio-Economic Panel, and the German Microcensus. Although on average the differences between the time-diary data and the interview data is not large, our results show that significant…

  10. Accurate Detection of Interaural Time Differences by a Population of Slowly Integrating Neurons

    NASA Astrophysics Data System (ADS)

    Vasilkov, Viacheslav A.; Tikidji-Hamburyan, Ruben A.

    2012-03-01

    For localization of a sound source, animals and humans process the microsecond interaural time differences of arriving sound waves. How nervous systems, consisting of elements with time constants of about and more than 1 ms, can reach such high precision is still an open question. In this Letter we present a hypothesis and show theoretical and computational evidence that a rather large population of slowly integrating neurons with inhibitory and excitatory inputs (EI neurons) can detect minute temporal disparities in input signals which are significantly less than any time constant in the system.

  11. Timing is everything. Time-oriented clinical information systems.

    PubMed Central

    Shahar, Y; Combi, C

    1998-01-01

    Time is important in clinical information systems. Representing, maintaining, querying, and reasoning about time-oriented clinical data is a major theoretical and practical research area in medical informatics. In this nonexhaustive overview, we present a brief synopsis of research efforts in designing and developing time-oriented information systems in medicine. These efforts can be viewed from either an application point of view, distinguishing between different clinical tasks (such as diagnosis versus therapy) and clinical areas (such as infectious diseases versus oncology), or a methodological point of view, distinguishing between different theoretical approaches. We also explore the two primary methodological and theoretical paths research has taken in the past decade: temporal reasoning and temporal data maintenance. Both of these research areas include efforts to model time, temporal entities, and temporal queries. Collaboration between the two areas is possible, through tasks such as the abstraction of raw time-oriented clinical data into higher-level meaningful clinical concepts and the management of different levels of temporal granularity. Such collaboration could provide a common ground and useful areas for future research and development. We conclude with our view of future research directions. PMID:9499744

  12. Quantum Brachistochrone Curves as Geodesics: Obtaining Accurate Minimum-Time Protocols for the Control of Quantum Systems

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoting; Allegra, Michele; Jacobs, Kurt; Lloyd, Seth; Lupo, Cosmo; Mohseni, Masoud

    2015-05-01

    Most methods of optimal control cannot obtain accurate time-optimal protocols. The quantum brachistochrone equation is an exception, and has the potential to provide accurate time-optimal protocols for a wide range of quantum control problems. So far, this potential has not been realized, however, due to the inadequacy of conventional numerical methods to solve it. Here we show that the quantum brachistochrone problem can be recast as that of finding geodesic paths in the space of unitary operators. We expect this brachistochrone-geodesic connection to have broad applications, as it opens up minimal-time control to the tools of geometry. As one such application, we use it to obtain a fast numerical method to solve the brachistochrone problem, and apply this method to two examples demonstrating its power.

  13. A Time-Accurate Upwind Unstructured Finite Volume Method for Compressible Flow with Cure of Pathological Behaviors

    NASA Technical Reports Server (NTRS)

    Loh, Ching Y.; Jorgenson, Philip C. E.

    2007-01-01

    A time-accurate, upwind, finite volume method for computing compressible flows on unstructured grids is presented. The method is second order accurate in space and time and yields high resolution in the presence of discontinuities. For efficiency, the Roe approximate Riemann solver with an entropy correction is employed. In the basic Euler/Navier-Stokes scheme, many concepts of high order upwind schemes are adopted: the surface flux integrals are carefully treated, a Cauchy-Kowalewski time-stepping scheme is used in the time-marching stage, and a multidimensional limiter is applied in the reconstruction stage. However even with these up-to-date improvements, the basic upwind scheme is still plagued by the so-called "pathological behaviors," e.g., the carbuncle phenomenon, the expansion shock, etc. A solution to these limitations is presented which uses a very simple dissipation model while still preserving second order accuracy. This scheme is referred to as the enhanced time-accurate upwind (ETAU) scheme in this paper. The unstructured grid capability renders flexibility for use in complex geometry; and the present ETAU Euler/Navier-Stokes scheme is capable of handling a broad spectrum of flow regimes from high supersonic to subsonic at very low Mach number, appropriate for both CFD (computational fluid dynamics) and CAA (computational aeroacoustics). Numerous examples are included to demonstrate the robustness of the methods.

  14. Near real time accurate bacterial enumeration in aquatic environment using an all-fibre optical system

    NASA Astrophysics Data System (ADS)

    Bogomolny, E.; Swift, S.; Patel, A.; Cheng, M.; Vanholsbeeck, F.

    2013-06-01

    We developed a computerized optical probe for near real time bacterial detection in water. This microorganism detection technique, based on fluorescence enhanced by nucleic acids staining, shows promising results compared to conventional methods.

  15. Neural computation by concentrating information in time.

    PubMed Central

    Tank, D W; Hopfield, J J

    1987-01-01

    An analog model neural network that can solve a general problem of recognizing patterns in a time-dependent signal is presented. The networks use a patterned set of delays to collectively focus stimulus sequence information to a neural state at a future time. The computational capabilities of the circuit are demonstrated on tasks somewhat similar to those necessary for the recognition of words in a continuous stream of speech. The network architecture can be understood from consideration of an energy function that is being minimized as the circuit computes. Neurobiological mechanisms are known for the generation of appropriate delays. PMID:3470765

  16. Accurate determination of screw position in treating fifth metatarsal base fractures to shorten radiation exposure time

    PubMed Central

    Wang, Xu; Zhang, Chao; Wang, Chen; Huang, Jia Zhang; Ma, Xin

    2016-01-01

    INTRODUCTION Anatomical markers can help to guide lag screw placement during surgery for internal fixation of fifth metatarsal base fractures. This study aimed to identify the optimal anatomical markers and thus reduce radiation exposure. METHODS A total of 50 patients in Huashan Hospital, Shanghai, China, who underwent oblique foot radiography in the lateral position were randomly selected. The angles between the fifth metatarsal axis and cuboid articular surface were measured to determine the optimal lag screw placement relative to anatomical markers. RESULTS The line connecting the styloid process of the fifth metatarsal base with the second metatarsophalangeal (MTP) joint intersected with the fifth metatarsal base fracture line at an angle of 86.85° ± 5.44°. The line connecting the fifth metatarsal base styloid with the third and fourth MTP joints intersected with the fracture line at angles of 93.28° ± 5.24° and 100.95° ± 5.00°, respectively. The proximal articular surface of the fifth metatarsal base intersected with the line connecting the styloid process of the fifth metatarsal base with the second, third and fourth MTP joints at angles of 24.02° ± 4.77°, 30.79° ± 4.53° and 38.08° ± 4.54°, respectively. CONCLUSION The fifth metatarsal base styloid and third MTP joint can be used as anatomical markers for lag screw placement in fractures involving the fifth tarsometatarsal joint. The connection line, which is normally perpendicular to the fracture line, provides sufficient mechanical stability to facilitate accurate screw placement. The use of these anatomical markers could help to reduce unnecessary radiation exposure for patients and medical staff. PMID:26767892

  17. Accurate measurement of the sticking time and sticking probability of Rb atoms on a polydimethylsiloxane coating

    SciTech Connect

    Atutov, S. N. Plekhanov, A. I.

    2015-01-15

    We present the results of a systematic study of Knudsen’s flow of Rb atoms in cylindrical capillary cells coated with a polydimethylsiloxane (PDMS) compound. The purpose of the investigation is to determine the characterization of the coating in terms of the sticking probability and sticking time of Rb on the two types of coating of high and medium viscosities. We report the measurement of the sticking probability of a Rb atom to the coating equal to 4.3 × 10{sup −5}, which corresponds to the number of bounces 2.3 × 10{sup 4} at room temperature. These parameters are the same for the two kinds of PDMS used. We find that at room temperature, the respective sticking times for high-viscosity and medium-viscosity PDMS are 22 ± 3 μs and 49 ± 6 μs. These sticking times are about million times larger than the sticking time derived from the surface Rb atom adsorption energy and temperature of the coating. A tentative explanation of this surprising result is proposed based on the bulk diffusion of the atoms that collide with the surface and penetrate inside the coating. The results can be important in many resonance cell experiments, such as the efficient magnetooptical trapping of rare elements or radioactive isotopes and in experiments on the light-induced drift effect.

  18. Genomic inference accurately predicts the timing and severity of a recent bottleneck in a non-model insect population

    PubMed Central

    McCoy, Rajiv C.; Garud, Nandita R.; Kelley, Joanna L.; Boggs, Carol L.; Petrov, Dmitri A.

    2015-01-01

    The analysis of molecular data from natural populations has allowed researchers to answer diverse ecological questions that were previously intractable. In particular, ecologists are often interested in the demographic history of populations, information that is rarely available from historical records. Methods have been developed to infer demographic parameters from genomic data, but it is not well understood how inferred parameters compare to true population history or depend on aspects of experimental design. Here we present and evaluate a method of SNP discovery using RNA-sequencing and demographic inference using the program δaδi, which uses a diffusion approximation to the allele frequency spectrum to fit demographic models. We test these methods in a population of the checkerspot butterfly Euphydryas gillettii. This population was intentionally introduced to Gothic, Colorado in 1977 and has since experienced extreme fluctuations including bottlenecks of fewer than 25 adults, as documented by nearly annual field surveys. Using RNA-sequencing of eight individuals from Colorado and eight individuals from a native population in Wyoming, we generate the first genomic resources for this system. While demographic inference is commonly used to examine ancient demography, our study demonstrates that our inexpensive, all-in-one approach to marker discovery and genotyping provides sufficient data to accurately infer the timing of a recent bottleneck. This demographic scenario is relevant for many species of conservation concern, few of which have sequenced genomes. Our results are remarkably insensitive to sample size or number of genomic markers, which has important implications for applying this method to other non-model systems. PMID:24237665

  19. Enabling fast, stable and accurate peridynamic computations using multi-time-step integration

    SciTech Connect

    Lindsay, P.; Parks, M. L.; Prakash, A.

    2016-04-13

    Peridynamics is a nonlocal extension of classical continuum mechanics that is well-suited for solving problems with discontinuities such as cracks. This paper extends the peridynamic formulation to decompose a problem domain into a number of smaller overlapping subdomains and to enable the use of different time steps in different subdomains. This approach allows regions of interest to be isolated and solved at a small time step for increased accuracy while the rest of the problem domain can be solved at a larger time step for greater computational efficiency. Lastly, performance of the proposed method in terms of stability, accuracy, and computational cost is examined and several numerical examples are presented to corroborate the findings.

  20. Enabling fast, stable and accurate peridynamic computations using multi-time-step integration

    DOE PAGES

    Lindsay, P.; Parks, M. L.; Prakash, A.

    2016-04-13

    Peridynamics is a nonlocal extension of classical continuum mechanics that is well-suited for solving problems with discontinuities such as cracks. This paper extends the peridynamic formulation to decompose a problem domain into a number of smaller overlapping subdomains and to enable the use of different time steps in different subdomains. This approach allows regions of interest to be isolated and solved at a small time step for increased accuracy while the rest of the problem domain can be solved at a larger time step for greater computational efficiency. Lastly, performance of the proposed method in terms of stability, accuracy, andmore » computational cost is examined and several numerical examples are presented to corroborate the findings.« less

  1. Time-Accurate Local Time Stepping and High-Order Time CESE Methods for Multi-Dimensional Flows Using Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Chang, Chau-Lyan; Venkatachari, Balaji Shankar; Cheng, Gary

    2013-01-01

    With the wide availability of affordable multiple-core parallel supercomputers, next generation numerical simulations of flow physics are being focused on unsteady computations for problems involving multiple time scales and multiple physics. These simulations require higher solution accuracy than most algorithms and computational fluid dynamics codes currently available. This paper focuses on the developmental effort for high-fidelity multi-dimensional, unstructured-mesh flow solvers using the space-time conservation element, solution element (CESE) framework. Two approaches have been investigated in this research in order to provide high-accuracy, cross-cutting numerical simulations for a variety of flow regimes: 1) time-accurate local time stepping and 2) highorder CESE method. The first approach utilizes consistent numerical formulations in the space-time flux integration to preserve temporal conservation across the cells with different marching time steps. Such approach relieves the stringent time step constraint associated with the smallest time step in the computational domain while preserving temporal accuracy for all the cells. For flows involving multiple scales, both numerical accuracy and efficiency can be significantly enhanced. The second approach extends the current CESE solver to higher-order accuracy. Unlike other existing explicit high-order methods for unstructured meshes, the CESE framework maintains a CFL condition of one for arbitrarily high-order formulations while retaining the same compact stencil as its second-order counterpart. For large-scale unsteady computations, this feature substantially enhances numerical efficiency. Numerical formulations and validations using benchmark problems are discussed in this paper along with realistic examples.

  2. Radiation Boundary Conditions for Maxwell’s Equations: A Review of Accurate Time-Domain Formulations

    DTIC Science & Technology

    2007-01-01

    lightcone belonging to the spacetime point (0, y, z, t). 2.2. Spherical boundary. 2.2.1. Vector spherical harmonics. We consider both pure–spin and pure...notation we write B(T − t, t) for the intersection of time level t < T and the past lightcone of the spacetime point (0, 0, 0, T ). The artificial boundary Γ...some foliation of R 3 into R2 planes. Let M represent the solid past null cone (or conoid) of the spacetime point (0, 0, 0, T ). For a generic time t < T

  3. Time-accurate simulations of a shear layer forced at a single frequency

    NASA Technical Reports Server (NTRS)

    Claus, R. W.; Huang, P. G.; Macinnes, J. M.

    1988-01-01

    Calculations are presented for the forced shear layer studied experimentally by Oster and Wygnanski, and Weisbrot. Two different computational approaches are examined: Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES). The DNS approach solves the full three dimensional Navier-Stokes equations for a temporally evolving mixing layer, while the LES approach solves the two dimensional Navier-Stokes equations with a subgrid scale turbulence model. While the comparison between these calculations and experimental data was hampered by a lack of information on the inflow boundary conditions, the calculations are shown to qualitatively agree with several aspects of the experiment. The sensitivity of these calculations to factors such as mesh refinement and Reynolds number is illustrated.

  4. WWVB: A Half Century of Delivering Accurate Frequency and Time by Radio

    PubMed Central

    Lombardi, Michael A; Nelson, Glenn K

    2014-01-01

    In commemoration of its 50th anniversary of broadcasting from Fort Collins, Colorado, this paper provides a history of the National Institute of Standards and Technology (NIST) radio station WWVB. The narrative describes the evolution of the station, from its origins as a source of standard frequency, to its current role as the source of time-of-day synchronization for many millions of radio controlled clocks. PMID:26601026

  5. Accurate 2D/3D electromagnetic modeling for time-domain airborne EM systems

    NASA Astrophysics Data System (ADS)

    Yin, C.; Hodges, G.

    2012-12-01

    The existing industry software cannot deliver correct results for 3D time-domain airborne EM responses. In this paper, starting from the Fourier transform and convolution, we compare the stability of different modeling techniques and analyze the reason for instable calculations of the time-domain airborne EM responses. We find that the singularity of the impulse responses of EM systems at very early time that are used in the convolution is responsible for the instability of the modeling (Fig.1). Based on this finding, we put forward an algorithm that uses step response rather than impulse response of the airborne EM system for the convolution and create a stable algorithm that delivers precise results and maintains well the integral/derivative relationship between the magnetic field B and the magnetic induction dB/dt. A three-step transformation procedure for the modeling is proposed: 1) output the frequency-domain EM response data from the existing software; 2) transform into step-response by digital Fourier/Hankel transform; 3) convolve the step response with the transmitting current or its derivatives. The method has proved to be working very well (Fig. 2). The algorithm can be extended to the modeling of other time-domain ground and airborne EM system responses.Fig. 1: Comparison of impulse and step responses for an airborne EM system Fig. 2: Bz and dBz/dt calculated from step (middle panel) and impulse responses (lower panel) for the same 3D model as in Fig.1.

  6. Accurate finite-difference time-domain simulation of anisotropic media by subpixel smoothing.

    PubMed

    Oskooi, Ardavan F; Kottke, Chris; Johnson, Steven G

    2009-09-15

    Finite-difference time-domain methods suffer from reduced accuracy when discretizing discontinuous materials. We previously showed that accuracy can be significantly improved by using subpixel smoothing of the isotropic dielectric function, but only if the smoothing scheme is properly designed. Using recent developments in perturbation theory that were applied to spectral methods, we extend this idea to anisotropic media and demonstrate that the generalized smoothing consistently reduces the errors and even attains second-order convergence with resolution.

  7. WWVB: A Half Century of Delivering Accurate Frequency and Time by Radio.

    PubMed

    Lombardi, Michael A; Nelson, Glenn K

    2014-01-01

    In commemoration of its 50th anniversary of broadcasting from Fort Collins, Colorado, this paper provides a history of the National Institute of Standards and Technology (NIST) radio station WWVB. The narrative describes the evolution of the station, from its origins as a source of standard frequency, to its current role as the source of time-of-day synchronization for many millions of radio controlled clocks.

  8. Accurate time delay technology in simulated test for high precision laser range finder

    NASA Astrophysics Data System (ADS)

    Chen, Zhibin; Xiao, Wenjian; Wang, Weiming; Xue, Mingxi

    2015-10-01

    With the continuous development of technology, the ranging accuracy of pulsed laser range finder (LRF) is higher and higher, so the maintenance demand of LRF is also rising. According to the dominant ideology of "time analog spatial distance" in simulated test for pulsed range finder, the key of distance simulation precision lies in the adjustable time delay. By analyzing and comparing the advantages and disadvantages of fiber and circuit delay, a method was proposed to improve the accuracy of the circuit delay without increasing the count frequency of the circuit. A high precision controllable delay circuit was designed by combining the internal delay circuit and external delay circuit which could compensate the delay error in real time. And then the circuit delay accuracy could be increased. The accuracy of the novel circuit delay methods proposed in this paper was actually measured by a high sampling rate oscilloscope actual measurement. The measurement result shows that the accuracy of the distance simulated by the circuit delay is increased from +/- 0.75m up to +/- 0.15m. The accuracy of the simulated distance is greatly improved in simulated test for high precision pulsed range finder.

  9. Fast and accurate numerical method for predicting gas chromatography retention time.

    PubMed

    Claumann, Carlos Alberto; Wüst Zibetti, André; Bolzan, Ariovaldo; Machado, Ricardo A F; Pinto, Leonel Teixeira

    2015-08-07

    Predictive modeling for gas chromatography compound retention depends on the retention factor (ki) and on the flow of the mobile phase. Thus, different approaches for determining an analyte ki in column chromatography have been developed. The main one is based on the thermodynamic properties of the component and on the characteristics of the stationary phase. These models can be used to estimate the parameters and to optimize the programming of temperatures, in gas chromatography, for the separation of compounds. Different authors have proposed the use of numerical methods for solving these models, but these methods demand greater computational time. Hence, a new method for solving the predictive modeling of analyte retention time is presented. This algorithm is an alternative to traditional methods because it transforms its attainments into root determination problems within defined intervals. The proposed approach allows for tr calculation, with accuracy determined by the user of the methods, and significant reductions in computational time; it can also be used to evaluate the performance of other prediction methods.

  10. Study of time-accurate integration of the variable-density Navier-Stokes equations

    NASA Astrophysics Data System (ADS)

    Lu, Xiaoyi; Pantano, Carlos

    2015-11-01

    We present several theoretical elements that affect time-consistent integration of the low-Mach number approximation of variable-density Navier-Stokes equations. The goal is for velocity, pressure, density, and scalars to achieve uniform order of accuracy, consistent with the time integrator being used. We show examples of second-order (using Crank-Nicolson and Adams-Bashforth) and third-order (using additive semi-implicit Runge-Kutta) uniform convergence with the proposed conceptual framework. Furthermore, the consistent approach can be extended to other time integrators. In addition, the method is formulated using approximate/incomplete factorization methods for easy incorporation in existing solvers. One of the observed benefits of the proposed approach is improved stability, even for large density difference, in comparison with other existing formulations. A linearized stability analysis is also carried out for some test problems to better understand the behavior of the approach. This work was supported in part by the Department of Energy, National Nuclear Security Administration, under award no. DE-NA0002382 and the California Institute of Technology.

  11. Accurate modeling of SiPM detectors coupled to FE electronics for timing performance analysis

    NASA Astrophysics Data System (ADS)

    Ciciriello, F.; Corsi, F.; Licciulli, F.; Marzocca, C.; Matarrese, G.; Del Guerra, A.; Bisogni, M. G.

    2013-08-01

    It has already been shown how the shape of the current pulse produced by a SiPM in response to an incident photon is sensibly affected by the characteristics of the front-end electronics (FEE) used to read out the detector. When the application requires to approach the best theoretical time performance of the detection system, the influence of all the parasitics associated to the coupling SiPM-FEE can play a relevant role and must be adequately modeled. In particular, it has been reported that the shape of the current pulse is affected by the parasitic inductance of the wiring connection between SiPM and FEE. In this contribution, we extend the validity of a previously presented SiPM model to account for the wiring inductance. Various combinations of the main performance parameters of the FEE (input resistance and bandwidth) have been simulated in order to evaluate their influence on the time accuracy of the detection system, when the time pick-off of each single event is extracted by means of a leading edge discriminator (LED) technique.

  12. Direct Coupling Method for Time-Accurate Solution of Incompressible Navier-Stokes Equations

    NASA Technical Reports Server (NTRS)

    Soh, Woo Y.

    1992-01-01

    A noniterative finite difference numerical method is presented for the solution of the incompressible Navier-Stokes equations with second order accuracy in time and space. Explicit treatment of convection and diffusion terms and implicit treatment of the pressure gradient give a single pressure Poisson equation when the discretized momentum and continuity equations are combined. A pressure boundary condition is not needed on solid boundaries in the staggered mesh system. The solution of the pressure Poisson equation is obtained directly by Gaussian elimination. This method is tested on flow problems in a driven cavity and a curved duct.

  13. Hardware and Software Developments for the Accurate Time-Linked Data Acquisition System

    SciTech Connect

    BERG,DALE E.; RUMSEY,MARK A.; ZAYAS,JOSE R.

    1999-11-09

    Wind-energy researchers at Sandia National Laboratories have developed a new, light-weight, modular data acquisition system capable of acquiring long-term, continuous, multi-channel time-series data from operating wind-turbines. New hardware features have been added to this system to make it more flexible and permit programming via telemetry. User-friendly Windows-based software has been developed for programming the hardware and acquiring, storing, analyzing, and archiving the data. This paper briefly reviews the major components of the system, summarizes the recent hardware enhancements and operating experiences, and discusses the features and capabilities of the software programs that have been developed.

  14. An accurate air temperature measurement system based on an envelope pulsed ultrasonic time-of-flight technique

    NASA Astrophysics Data System (ADS)

    Huang, Y. S.; Huang, Y. P.; Huang, K. N.; Young, M. S.

    2007-11-01

    A new microcomputer based air temperature measurement system is presented. An accurate temperature measurement is derived from the measurement of sound velocity by using an ultrasonic time-of-flight (TOF) technique. The study proposes a novel algorithm that combines both amplitude modulation (AM) and phase modulation (PM) to get the TOF measurement. The proposed system uses the AM and PM envelope square waveform (APESW) to reduce the error caused by inertia delay. The APESW ultrasonic driving waveform causes an envelope zero and phase inversion phenomenon in the relative waveform of the receiver. To accurately achieve a TOF measurement, the phase inversion phenomenon was used to sufficiently identify the measurement pulse in the received waveform. Additionally, a counter clock technique was combined to compute the phase shifts of the last incomplete cycle for TOF. The presented system can obtain 0.1% TOF resolution for the period corresponding to the 40kHz frequency ultrasonic wave. Consequently, with the integration of a humidity compensation algorithm, a highly accurate and high resolution temperature measurement can be achieved using the accurate TOF measurement. Experimental results indicate that the combined standard uncertainty of the temperature measurement is approximately 0.39°C. The main advantages of this system are high resolution measurements, narrow bandwidth requirements, and ease of implementation.

  15. Multigrid Acceleration of Time-Accurate DNS of Compressible Turbulent Flow

    NASA Technical Reports Server (NTRS)

    Broeze, Jan; Geurts, Bernard; Kuerten, Hans; Streng, Martin

    1996-01-01

    An efficient scheme for the direct numerical simulation of 3D transitional and developed turbulent flow is presented. Explicit and implicit time integration schemes for the compressible Navier-Stokes equations are compared. The nonlinear system resulting from the implicit time discretization is solved with an iterative method and accelerated by the application of a multigrid technique. Since we use central spatial discretizations and no artificial dissipation is added to the equations, the smoothing method is less effective than in the more traditional use of multigrid in steady-state calculations. Therefore, a special prolongation method is needed in order to obtain an effective multigrid method. This simulation scheme was studied in detail for compressible flow over a flat plate. In the laminar regime and in the first stages of turbulent flow the implicit method provides a speed-up of a factor 2 relative to the explicit method on a relatively coarse grid. At increased resolution this speed-up is enhanced correspondingly.

  16. Spectroscopic study of the environment of two time-delay lenses for accurate cosmology

    NASA Astrophysics Data System (ADS)

    Treu, Tommaso; Suyu, Sherry; Fassnacht, Chris; Hilbert, Stefan; Sluse, Dominique; Courbin, Frederic

    2013-02-01

    We are conducting a program to achieve compelling and robust cosmographic measurements from five gravitationally lensed quasars with exquisite time-delays and HST images. We aim with this analysis to measure H_0 with an accuracy better than 3.8%, resulting in constraints on cosmological parameters comparable to the one from current BAO and SN work when combined with CMB data. To reach this goal, we need to track any source of errors. The analysis of the first two systems has shown that H_0 can be derived from a single lens with better than 7% accuracy, and that the main source of uncertainty come from the lens environment. In this proposal, we propose to obtain multi-object spectroscopy of the galaxies in the field of two time-delays lenses in order to measure their redshift (spread over 2013A/B). This will pin down the error from the environment to a few percent, allowing us to deliver state of the art constraints on cosmological parameters.

  17. Time-accurate anisotropic mesh adaptation for three-dimensional time-dependent problems with body-fitted moving geometries

    NASA Astrophysics Data System (ADS)

    Barral, N.; Olivier, G.; Alauzet, F.

    2017-02-01

    Anisotropic metric-based mesh adaptation has proved its efficiency to reduce the CPU time of steady and unsteady simulations while improving their accuracy. However, its extension to time-dependent problems with body-fitted moving geometries is far from straightforward. This paper establishes a well-founded framework for multiscale mesh adaptation of unsteady problems with moving boundaries. This framework is based on a novel space-time analysis of the interpolation error, within the continuous mesh theory. An optimal metric field, called ALE metric field, is derived, which takes into account the movement of the mesh during the adaptation. Based on this analysis, the global fixed-point adaptation algorithm for time-dependent simulations is extended to moving boundary problems, within the range of body-fitted moving meshes and ALE simulations. Finally, three dimensional adaptive simulations with moving boundaries are presented to validate the proposed approach.

  18. Real-Time Traffic Information for Emergency Evacuations

    SciTech Connect

    Franzese, Oscar; Zhang, Li; Mahmoud, Anas M.

    2010-01-01

    There are many instances in which it is possible to plan ahead for an emergency evacuation (e.g., a chemical processing facility explosion). For those cases, if an accident were to happen, then the best evacuation plan for the prevailing network and weather conditions would be deployed. In other cases (e.g., the derailment of a train transporting hazardous materials), there may not be any previously developed plan to be implemented, and decisions must be made ad-hoc on how to proceed with an emergency evacuation. In both situations, the availability of real-time traffic information plays a critical role in the management of the evacuation operations. Due to cost constraints, only large urban areas have traffic sensor deployments that permit access to some sort of real-time traffic information; an evacuation taking place in other areas of the country would have to proceed without real-time traffic information. In order to improve operations during a vehicular emergency evacuation anywhere, a system of sensors that uses newly developed real-time traffic-information-gathering technologies to assess traffic conditions and to detect incidents on the main evacuation routes is presented in this paper. A series of tests, both in a controlled environment and in the field, were conducted to study the feasibility of such a system of traffic sensors and to assess its ability to provide real-time traffic information during an emergency evacuation. The results of these tests indicated that the prototype sensors are reliable and accurate for the type of application that is the focus of this paper.

  19. Simultaneous transmission of accurate time and stable frequency through bidirectional channel over telecommunication infrastructure with excessive spans

    NASA Astrophysics Data System (ADS)

    Vojtech, Josef; Smotlacha, Vladimir; Skoda, Pavel

    2015-09-01

    In this paper, we present simultaneous transmission of accurate time and stable frequency over 306 km long fiber link. The fiber link belongs to the Time and Frequency infrastructure that is being gradually developed and which shares fiber footprint with data network. The link had been originally deployed with wavelength division multiplexing systems for C and L band systems. But it has been recently upgraded to support 800 GHz wide super-channel with single signal path for both directions. This bidirectional super-channel spans over two extensive segments with attenuation of 28 and 25 dB.

  20. Accurate treatment of total photoabsorption cross sections by an ab initio time-dependent method

    NASA Astrophysics Data System (ADS)

    Daud, Mohammad Noh

    2014-09-01

    A detailed discussion of parallel and perpendicular transitions required for the photoabsorption of a molecule is presented within a time-dependent view. Total photoabsorption cross sections for the first two ultraviolet absorption bands of the N2O molecule corresponding to transitions from the X1 A' state to the 21 A' and 11 A'' states are calculated to test the reliability of the method. By fully considering the property of the electric field polarization vector of the incident light, the method treats the coupling of angular momentum and the parity differently for two kinds of transitions depending on the direction of the vector whether it is: (a) situated parallel in a molecular plane for an electronic transition between states with the same symmetry; (b) situated perpendicular to a molecular plane for an electronic transition between states with different symmetry. Through this, for those transitions, we are able to offer an insightful picture of the dynamics involved and to characterize some new aspects in the photoabsorption process of N2O. Our calculations predicted that the parallel transition to the 21 A' state is the major dissociation pathway which is in qualitative agreement with the experimental observations. Most importantly, a significant improvement in the absolute value of the total cross section over previous theoretical results [R. Schinke, J. Chem. Phys. 134, 064313 (2011), M.N. Daud, G.G. Balint-Kurti, A. Brown, J. Chem. Phys. 122, 054305 (2005), S. Nanbu, M.S. Johnson, J. Phys. Chem. A 108, 8905 (2004)] was obtained.

  1. Accurate treatment of total photoabsorption cross sections by an ab initio time-dependent method

    NASA Astrophysics Data System (ADS)

    Noh Daud, Mohammad

    2014-09-01

    A detailed discussion of parallel and perpendicular transitions required for the photoabsorption of a molecule is presented within a time-dependent view. Total photoabsorption cross sections for the first two ultraviolet absorption bands of the N2O molecule corresponding to transitions from the X1A' state to the 21A' and 11A'' states are calculated to test the reliability of the method. By fully considering the property of the electric field polarization vector of the incident light, the method treats the coupling of angular momentum and the parity differently for two kinds of transitions depending on the direction of the vector whether it is: (a) situated parallel in a molecular plane for an electronic transition between states with the same symmetry; (b) situated perpendicular to a molecular plane for an electronic transition between states with different symmetry. Through this, for those transitions, we are able to offer an insightful picture of the dynamics involved and to characterize some new aspects in the photoabsorption process of N2O. Our calculations predicted that the parallel transition to the 21A' state is the major dissociation pathway which is in qualitative agreement with the experimental observations. Most importantly, a significant improvement in the absolute value of the total cross section over previous theoretical results [R. Schinke, J. Chem. Phys. 134, 064313 (2011), M.N. Daud, G.G. Balint-Kurti, A. Brown, J. Chem. Phys. 122, 054305 (2005), S. Nanbu, M.S. Johnson, J. Phys. Chem. A 108, 8905 (2004)] was obtained.

  2. Accurate characterization of carcinogenic DNA adducts using MALDI tandem time-of-flight mass spectrometry

    NASA Astrophysics Data System (ADS)

    Barnes, Charles A.; Chiu, Norman H. L.

    2009-01-01

    Many chemical carcinogens and their in vivo activated metabolites react readily with genomic DNA, and form covalently bound carcinogen-DNA adducts. Clinically, carcinogen-DNA adducts have been linked to various cancer diseases. Among the current methods for DNA adduct analysis, mass spectroscopic method allows the direct measurement of unlabeled DNA adducts. The goal of this study is to explore the use of matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF MS) to determine the identity of carcinogen-DNA adducts. Two of the known carcinogenic DNA adducts, namely N-(2'-deoxyguanosin-8-yl)-2-amino-1-methyl-6-phenyl-imidazo [4,5-b] pyridine (dG-C8-PhIP) and N-(2'-deoxyguanosin-8yl)-4-aminobiphenyl (dG-C8-ABP), were selected as our models. In MALDI-TOF MS measurements, the small matrix ion and its cluster ions did not interfere with the measurements of both selected dG adducts. To achieve a higher accuracy for the characterization of selected dG adducts, 1 keV collision energy in MALDI-TOF/TOF MS/MS was used to measure the adducts. In comparison to other MS/MS techniques with lower collision energies, more extensive precursor ion dissociations were observed. The detection of the corresponding fragment ions allowed the identities of guanine, PhIP or ABP, and the position of adduction to be confirmed. Some of the fragment ions of dG-C8-PhIP have not been reported by other MS/MS techniques.

  3. Simulation of Accurate Vibrationally Resolved Electronic Spectra: the Integrated Time-Dependent and Time-Independent Framework

    NASA Astrophysics Data System (ADS)

    Baiardi, Alberto; Barone, Vincenzo; Biczysko, Malgorzata; Bloino, Julien

    2014-06-01

    Two parallel theories including Franck-Condon, Herzberg-Teller and Duschinsky (i.e., mode mixing) effects, allowing different approximations for the description of excited state PES have been developed in order to simulate realistic, asymmetric, electronic spectra line-shapes taking into account the vibrational structure: the so-called sum-over-states or time-independent (TI) method and the alternative time-dependent (TD) approach, which exploits the properties of the Fourier transform. The integrated TI-TD procedure included within a general purpose QM code [1,2], allows to compute one photon absorption, fluorescence, phosphorescence, electronic circular dichroism, circularly polarized luminescence and resonance Raman spectra. Combining both approaches, which use a single set of starting data, permits to profit from their respective advantages and minimize their respective limits: the time-dependent route automatically includes all vibrational states and, possibly, temperature effects, while the time-independent route allows to identify and assign single vibronic transitions. Interpretation, analysis and assignment of experimental spectra based on integrated TI-TD vibronic computations will be illustrated for challenging cases of medium-sized open-shell systems in the gas and condensed phases with inclusion of leading anharmonic effects. 1. V. Barone, A. Baiardi, M. Biczysko, J. Bloino, C. Cappelli, F. Lipparini Phys. Chem. Chem. Phys, 14, 12404, (2012) 2. A. Baiardi, V. Barone, J. Bloino J. Chem. Theory Comput., 9, 4097-4115 (2013)

  4. Preferential access to genetic information from endogenous hominin ancient DNA and accurate quantitative SNP-typing via SPEX

    PubMed Central

    Brotherton, Paul; Sanchez, Juan J.; Cooper, Alan; Endicott, Phillip

    2010-01-01

    The analysis of targeted genetic loci from ancient, forensic and clinical samples is usually built upon polymerase chain reaction (PCR)-generated sequence data. However, many studies have shown that PCR amplification from poor-quality DNA templates can create sequence artefacts at significant levels. With hominin (human and other hominid) samples, the pervasive presence of highly PCR-amplifiable human DNA contaminants in the vast majority of samples can lead to the creation of recombinant hybrids and other non-authentic artefacts. The resulting PCR-generated sequences can then be difficult, if not impossible, to authenticate. In contrast, single primer extension (SPEX)-based approaches can genotype single nucleotide polymorphisms from ancient fragments of DNA as accurately as modern DNA. A single SPEX-type assay can amplify just one of the duplex DNA strands at target loci and generate a multi-fold depth-of-coverage, with non-authentic recombinant hybrids reduced to undetectable levels. Crucially, SPEX-type approaches can preferentially access genetic information from damaged and degraded endogenous ancient DNA templates over modern human DNA contaminants. The development of SPEX-type assays offers the potential for highly accurate, quantitative genotyping from ancient hominin samples. PMID:19864251

  5. PRO*CAST: Providing Timely Information to Monitor Progress Toward University Goals.

    ERIC Educational Resources Information Center

    Jackson, Tad; And Others

    1995-01-01

    In the University of Massachusetts' multicampus system, an integrated suite of technologies called PRO*CAST provides administrators, planners, and policymakers with access to timely, accurate information to support decision making and monitor progress toward established goals. The system is structured as an information warehouse with executive…

  6. Development and Validation of a Highly Accurate Quantitative Real-Time PCR Assay for Diagnosis of Bacterial Vaginosis

    PubMed Central

    Smith, William L.; Chadwick, Sean G.; Toner, Geoffrey; Mordechai, Eli; Adelson, Martin E.; Aguin, Tina J.; Sobel, Jack D.

    2016-01-01

    Bacterial vaginosis (BV) is the most common gynecological infection in the United States. Diagnosis based on Amsel's criteria can be challenging and can be aided by laboratory-based testing. A standard method for diagnosis in research studies is enumeration of bacterial morphotypes of a Gram-stained vaginal smear (i.e., Nugent scoring). However, this technique is subjective, requires specialized training, and is not widely available. Therefore, a highly accurate molecular assay for the diagnosis of BV would be of great utility. We analyzed 385 vaginal specimens collected prospectively from subjects who were evaluated for BV by clinical signs and Nugent scoring. We analyzed quantitative real-time PCR (qPCR) assays on DNA extracted from these specimens to quantify nine organisms associated with vaginal health or disease: Gardnerella vaginalis, Atopobium vaginae, BV-associated bacteria 2 (BVAB2, an uncultured member of the order Clostridiales), Megasphaera phylotype 1 or 2, Lactobacillus iners, Lactobacillus crispatus, Lactobacillus gasseri, and Lactobacillus jensenii. We generated a logistic regression model that identified G. vaginalis, A. vaginae, and Megasphaera phylotypes 1 and 2 as the organisms for which quantification provided the most accurate diagnosis of symptomatic BV, as defined by Amsel's criteria and Nugent scoring, with 92% sensitivity, 95% specificity, 94% positive predictive value, and 94% negative predictive value. The inclusion of Lactobacillus spp. did not contribute sufficiently to the quantitative model for symptomatic BV detection. This molecular assay is a highly accurate laboratory tool to assist in the diagnosis of symptomatic BV. PMID:26818677

  7. On the accurate long-time solution of the wave equation in exterior domains: Asymptotic expansions and corrected boundary conditions

    NASA Technical Reports Server (NTRS)

    Hagstrom, Thomas; Hariharan, S. I.; Maccamy, R. C.

    1993-01-01

    We consider the solution of scattering problems for the wave equation using approximate boundary conditions at artificial boundaries. These conditions are explicitly viewed as approximations to an exact boundary condition satisfied by the solution on the unbounded domain. We study the short and long term behavior of the error. It is provided that, in two space dimensions, no local in time, constant coefficient boundary operator can lead to accurate results uniformly in time for the class of problems we consider. A variable coefficient operator is developed which attains better accuracy (uniformly in time) than is possible with constant coefficient approximations. The theory is illustrated by numerical examples. We also analyze the proposed boundary conditions using energy methods, leading to asymptotically correct error bounds.

  8. Dynamic force matching: Construction of dynamic coarse-grained models with realistic short time dynamics and accurate long time dynamics

    NASA Astrophysics Data System (ADS)

    Davtyan, Aram; Voth, Gregory A.; Andersen, Hans C.

    2016-12-01

    We recently developed a dynamic force matching technique for converting a coarse-grained (CG) model of a molecular system, with a CG potential energy function, into a dynamic CG model with realistic dynamics [A. Davtyan et al., J. Chem. Phys. 142, 154104 (2015)]. This is done by supplementing the model with additional degrees of freedom, called "fictitious particles." In that paper, we tested the method on CG models in which each molecule is coarse-grained into one CG point particle, with very satisfactory results. When the method was applied to a CG model of methanol that has two CG point particles per molecule, the results were encouraging but clearly required improvement. In this paper, we introduce a new type (called type-3) of fictitious particle that exerts forces on the center of mass of two CG sites. A CG model constructed using type-3 fictitious particles (as well as type-2 particles previously used) gives a much more satisfactory dynamic model for liquid methanol. In particular, we were able to construct a CG model that has the same self-diffusion coefficient and the same rotational relaxation time as an all-atom model of liquid methanol. Type-3 particles and generalizations of it are likely to be useful in converting more complicated CG models into dynamic CG models.

  9. Accurate Enumeration of Aspergillus brasiliensis in Hair Color and Mascara by Time-Lapse Shadow Image Analysis.

    PubMed

    Ogawa, Hiroyuki; Matsuoka, Hideaki; Saito, Mikako

    2015-01-01

    The growth of black mold (Aspergillus brasiliensis) in black-colored samples such as hair color and mascara was measured with an automatic count system based on time-lapse shadow image analysis (TSIA). A. brasiliensis suspended in a lecithin and polysorbate (LP) solution of each sample (hair color or mascara) was spread on a potato dextrose agar medium plate containing LP. The background image darkness of the agar plate could be adjusted to attain accurate colony counts. 95 colonies in hair color and 22 colonies in mascara could be automatically determined at 48 h. The accuracy of the colony counts could be confirmed from the timelapse image data. In contrast, conventional visual counting at a specified time could not determine the number of colonies or led to false colony counts.

  10. Development and Validation of a Highly Accurate Quantitative Real-Time PCR Assay for Diagnosis of Bacterial Vaginosis.

    PubMed

    Hilbert, David W; Smith, William L; Chadwick, Sean G; Toner, Geoffrey; Mordechai, Eli; Adelson, Martin E; Aguin, Tina J; Sobel, Jack D; Gygax, Scott E

    2016-04-01

    Bacterial vaginosis (BV) is the most common gynecological infection in the United States. Diagnosis based on Amsel's criteria can be challenging and can be aided by laboratory-based testing. A standard method for diagnosis in research studies is enumeration of bacterial morphotypes of a Gram-stained vaginal smear (i.e., Nugent scoring). However, this technique is subjective, requires specialized training, and is not widely available. Therefore, a highly accurate molecular assay for the diagnosis of BV would be of great utility. We analyzed 385 vaginal specimens collected prospectively from subjects who were evaluated for BV by clinical signs and Nugent scoring. We analyzed quantitative real-time PCR (qPCR) assays on DNA extracted from these specimens to quantify nine organisms associated with vaginal health or disease:Gardnerella vaginalis,Atopobium vaginae, BV-associated bacteria 2 (BVAB2, an uncultured member of the orderClostridiales),Megasphaeraphylotype 1 or 2,Lactobacillus iners,Lactobacillus crispatus,Lactobacillus gasseri, andLactobacillus jensenii We generated a logistic regression model that identifiedG. vaginalis,A. vaginae, andMegasphaeraphylotypes 1 and 2 as the organisms for which quantification provided the most accurate diagnosis of symptomatic BV, as defined by Amsel's criteria and Nugent scoring, with 92% sensitivity, 95% specificity, 94% positive predictive value, and 94% negative predictive value. The inclusion ofLactobacillusspp. did not contribute sufficiently to the quantitative model for symptomatic BV detection. This molecular assay is a highly accurate laboratory tool to assist in the diagnosis of symptomatic BV.

  11. MRI-aided tissues interface characterization: An accurate signal propagation time calculation method for UWB breast tumor imaging

    NASA Astrophysics Data System (ADS)

    Wang, Liang; Xiao, Xia; Kikkawa, Takamaro

    2016-12-01

    Radar-based ultrawideband (UWB) microwave imaging is expected to be a safe, low-cost tool for breast cancer detection. However, since radar wave travels at different speeds in different tissues, propagation time is hard to be estimated in heterogeneous breast. Wrongly estimated propagation time leads to error of tumor location in resulting image, aka imaging error. In this paper, we develop a magnetic resonance imaging-aided (MRI-aided) propagation time calculation technique which is independent from radar imaging system but can help decrease the imaging error. The technique can eliminate the influence of the rough interface between fat layer and gland layer in breast and get relative accurate thicknesses of two layers. The propagation time in each layer is calculated and summed. The summed propagation time is used in Confocal imaging algorithm to increase the accuracy of resulting image. 25 patients' breast models with glands of varying size are classified into four categories for imaging simulation tests. Imaging accuracy in terms of tumor location along x-direction has been improved for 21 among 25 cases, as a result, overall around 50% improvement compared to conventional UWB imaging.

  12. On the use of spring baseflow recession for a more accurate parameterization of aquifer transit time distribution functions

    NASA Astrophysics Data System (ADS)

    Farlin, J.; Maloszewski, P.

    2013-05-01

    Baseflow recession analysis and groundwater dating have up to now developed as two distinct branches of hydrogeology and have been used to solve entirely different problems. We show that by combining two classical models, namely the Boussinesq equation describing spring baseflow recession, and the exponential piston-flow model used in groundwater dating studies, the parameters describing the transit time distribution of an aquifer can be in some cases estimated to a far more accurate degree than with the latter alone. Under the assumption that the aquifer basis is sub-horizontal, the mean transit time of water in the saturated zone can be estimated from spring baseflow recession. This provides an independent estimate of groundwater transit time that can refine those obtained from tritium measurements. The approach is illustrated in a case study predicting atrazine concentration trend in a series of springs draining the fractured-rock aquifer known as the Luxembourg Sandstone. A transport model calibrated on tritium measurements alone predicted different times to trend reversal following the nationwide ban on atrazine in 2005 with different rates of decrease. For some of the springs, the actual time of trend reversal and the rate of change agreed extremely well with the model calibrated using both tritium measurements and the recession of spring discharge during the dry season. The agreement between predicted and observed values was however poorer for the springs displaying the most gentle recessions, possibly indicating a stronger influence of continuous groundwater recharge during the summer months.

  13. On the use of spring baseflow recession for a more accurate parameterization of aquifer transit time distribution functions

    NASA Astrophysics Data System (ADS)

    Farlin, J.; Maloszewski, P.

    2012-12-01

    Baseflow recession analysis and groundwater dating have up to now developed as two distinct branches of hydrogeology and were used to solve entirely different problems. We show that by combining two classical models, namely Boussinesq's Equation describing spring baseflow recession and the exponential piston-flow model used in groundwater dating studies, the parameters describing the transit time distribution of an aquifer can be in some cases estimated to a far more accurate degree than with the latter alone. Under the assumption that the aquifer basis is sub-horizontal, the mean residence time of water in the saturated zone can be estimated from spring baseflow recession. This provides an independent estimate of groundwater residence time that can refine those obtained from tritium measurements. This approach is demonstrated in a case study predicting atrazine concentration trend in a series of springs draining the fractured-rock aquifer known as the Luxembourg Sandstone. A transport model calibrated on tritium measurements alone predicted different times to trend reversal following the nationwide ban on atrazine in 2005 with different rates of decrease. For some of the springs, the best agreement between observed and predicted time of trend reversal was reached for the model calibrated using both tritium measurements and the recession of spring discharge during the dry season. The agreement between predicted and observed values was however poorer for the springs displaying the most gentle recessions, possibly indicating the stronger influence of continuous groundwater recharge during the dry period.

  14. Chamber for indirect calorimetry with accurate measurement and time discrimination of metabolic plateaus of over 20 min.

    PubMed

    Nguyen, T; de Jonge, L; Smith, S R; Bray, G A

    2003-09-01

    A robust algorithm for pull-calorimeters that provides a rapid response to changes in respiratory gas exchange has been implemented. Metabolic plateaus (over 20 min), such as that generated by steady treadmill exercise, can be measured accurately (< 2.0% error for an energy expenditure level of 16.7 kJ min(-1)). The time resolution for changes between plateaus can be accurately found with 1 min discrimination. Implementation required only software changes but no structural or instrumentation changes to the chamber. The algorithm was based on the one developed for the push-calorimeter at the Sahlgrenska Hospital in Sweden. The method utilises published equations for the rate of O2 consumption and CO2 production in the chamber, along with techniques for suppressing noise and identifying trends. Using the exact solution of the equations for steady state, the O2 concentrations from the preceding 30 min period are fitted to two connected exponential segments, of variable length, using the least-squares method. The smoothed O2 concentration and associated time derivative are then determined for the time point 15 min earlier and substituted into the respiration equations. The CO2 concentrations are subjected to the same analysis. The process is repeated every minute, and the newly computed rates of O2 consumption and CO2 production, as well as metabolic rate, are then presented. Gas injection tests proved that the chamber can respond instantaneously to a change from one steady state of respiration to another and correctly averages repeated changes in respiration with periods less than 15min (< 1.4% error for simulated, alternating O2 consumption levels of 0.81 min (-1) and 0.01 min). The successful integration of the algorithm into the Pennington chambers allows for traditional 24 h energy expenditure measurements and various metabolic experiments requiring rapid responses.

  15. Accurate retention time determination of co-eluting proteins in analytical chromatography by means of spectral data.

    PubMed

    Dismer, Florian; Hansen, Sigrid; Oelmeier, Stefan Alexander; Hubbuch, Jürgen

    2013-03-01

    Chromatography is the method of choice for the separation of proteins, at both analytical and preparative scale. Orthogonal purification strategies for industrial use can easily be implemented by combining different modes of adsorption. Nevertheless, with flexibility comes the freedom of choice and optimal conditions for consecutive steps need to be identified in a robust and reproducible fashion. One way to address this issue is the use of mathematical models that allow for an in silico process optimization. Although this has been shown to work, model parameter estimation for complex feedstocks becomes the bottleneck in process development. An integral part of parameter assessment is the accurate measurement of retention times in a series of isocratic or gradient elution experiments. As high-resolution analytics that can differentiate between proteins are often not readily available, pure protein is mandatory for parameter determination. In this work, we present an approach that has the potential to solve this problem. Based on the uniqueness of UV absorption spectra of proteins, we were able to accurately measure retention times in systems of up to four co-eluting compounds. The presented approach is calibration-free, meaning that prior knowledge of pure component absorption spectra is not required. Actually, pure protein spectra can be determined from co-eluting proteins as part of the methodology. The approach was tested for size-exclusion chromatograms of 38 mixtures of co-eluting proteins. Retention times were determined with an average error of 0.6 s (1.6% of average peak width), approximated and measured pure component spectra showed an average coefficient of correlation of 0.992.

  16. BOOK REVIEW: Time, Quantum and Information

    NASA Astrophysics Data System (ADS)

    Turner, Leaf

    2004-04-01

    Time, Quantum and Information, a paean to Professor Carl Friedrich von Weizsäcker, commemorates his 90th birthday. The range of Professor Weizsäcker’s endeavours is an exhilarating example of what can be accomplished by one freely-soaring human spirit, who is at the same time a physicist, a philosopher, and a humanitarian. The editors, Lutz Castell and Otfried Ischebeck, have assembled an admirable collection of essays and articles written by Weizsäcker’s past students, collaborators, colleagues and acquaintances. Time, Quantum and Information offers the reader a panoply of unique insights into twentieth century science and history. Entangled with the stories about Weizsäcker’s influence on the lives of some of the contributors are discussions of the activities of German scientists during and following World War II, emphasizing their reluctance to work on atomic weapons following the war. By outlining Weizsäcker’s role in the early development of numerous tributaries of physical science, the book gives us a new glimpse into the origins of some of its disparate domains, such as nuclear physics, the physics of stellar nucleosynthesis, cosmic ray physics, fluid turbulence, and the formation of the solar system. We physicists have all studied Weizsäcker’s semi-empirical mass formula describing the binding energy of nuclei. We are aware too that both he and Hans Bethe independently discovered the nuclear cycles that provide stars with their enduring energy output. We have studied the Weizsäcker--Williams technique of calculating the bremsstrahlung of relativistic electrons. But how many of us know of Weizsäcker’s work in fluid turbulence that he, like Werner Heisenberg under whom he had earned his doctorate, pursued while holed up in Farm Hall? And how many of us are aware of his introduction of turbulent viscosity to account for the origin of planetary orbits, involving the migration of mass inwards and angular momentum outwards? Moreover, before

  17. 76 FR 42536 - Real-Time System Management Information Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-19

    ... Federal Highway Administration 23 CFR Part 511 RIN 2125-AF19 Real-Time System Management Information... available and share traffic and travel conditions information via real-time information programs as required... additional comments relating to the costs and benefits of the Real-Time System Management Information...

  18. Estimating the state of a geophysical system with sparse observations: time delay methods to achieve accurate initial states for prediction

    NASA Astrophysics Data System (ADS)

    An, Zhe; Rey, Daniel; Ye, Jingxin; Abarbanel, Henry D. I.

    2017-01-01

    The problem of forecasting the behavior of a complex dynamical system through analysis of observational time-series data becomes difficult when the system expresses chaotic behavior and the measurements are sparse, in both space and/or time. Despite the fact that this situation is quite typical across many fields, including numerical weather prediction, the issue of whether the available observations are "sufficient" for generating successful forecasts is still not well understood. An analysis by Whartenby et al. (2013) found that in the context of the nonlinear shallow water equations on a β plane, standard nudging techniques require observing approximately 70 % of the full set of state variables. Here we examine the same system using a method introduced by Rey et al. (2014a), which generalizes standard nudging methods to utilize time delayed measurements. We show that in certain circumstances, it provides a sizable reduction in the number of observations required to construct accurate estimates and high-quality predictions. In particular, we find that this estimate of 70 % can be reduced to about 33 % using time delays, and even further if Lagrangian drifter locations are also used as measurements.

  19. Third-order-accurate numerical methods for efficient, large time-step solutions of mixed linear and nonlinear problems

    SciTech Connect

    Cobb, J.W.

    1995-02-01

    There is an increasing need for more accurate numerical methods for large-scale nonlinear magneto-fluid turbulence calculations. These methods should not only increase the current state of the art in terms of accuracy, but should also continue to optimize other desired properties such as simplicity, minimized computation, minimized memory requirements, and robust stability. This includes the ability to stably solve stiff problems with long time-steps. This work discusses a general methodology for deriving higher-order numerical methods. It also discusses how the selection of various choices can affect the desired properties. The explicit discussion focuses on third-order Runge-Kutta methods, including general solutions and five examples. The study investigates the linear numerical analysis of these methods, including their accuracy, general stability, and stiff stability. Additional appendices discuss linear multistep methods, discuss directions for further work, and exhibit numerical analysis results for some other commonly used lower-order methods.

  20. An accurate, flexible and small optical fiber sensor: a novel technological breakthrough for real-time analysis of dynamic blood flow data in vivo.

    PubMed

    Yuan, Qiao-ying; Zhang, Ling; Xiao, Dan; Zhao, Kun; Lin, Chun; Si, Liang-yi

    2014-01-01

    Because of the limitations of existing methods and techniques for directly obtaining real-time blood data, no accurate microflow in vivo real-time analysis method exists. To establish a novel technical platform for real-time in vivo detection and to analyze average blood pressure and other blood flow parameters, a small, accurate, flexible, and nontoxic Fabry-Perot fiber sensor was designed. The carotid sheath was implanted through intubation of the rabbit carotid artery (n = 8), and the blood pressure and other detection data were determined directly through the veins. The fiber detection results were compared with test results obtained using color Doppler ultrasound and a physiological pressure sensor recorder. Pairwise comparisons among the blood pressure results obtained using the three methods indicated that real-time blood pressure information obtained through the fiber sensor technique exhibited better correlation than the data obtained with the other techniques. The highest correlation (correlation coefficient of 0.86) was obtained between the fiber sensor and pressure sensor. The blood pressure values were positively related to the total cholesterol level, low-density lipoprotein level, number of red blood cells, and hemoglobin level, with correlation coefficients of 0.033, 0.129, 0.358, and 0.373, respectively. The blood pressure values had no obvious relationship with the number of white blood cells and high-density lipoprotein and had a negative relationship with triglyceride levels, with a correlation coefficient of -0.031. The average ambulatory blood pressure measured by the fiber sensor exhibited a negative correlation with the quantity of blood platelets (correlation coefficient of -0.839, P<0.05). The novel fiber sensor can thus obtain in vivo blood pressure data accurately, stably, and in real time; the sensor can also determine the content and status of the blood flow to some extent. Therefore, the fiber sensor can obtain partially real-time

  1. An Accurate, Flexible and Small Optical Fiber Sensor: A Novel Technological Breakthrough for Real-Time Analysis of Dynamic Blood Flow Data In Vivo

    PubMed Central

    Yuan, Qiao-ying; Zhang, Ling; Xiao, Dan; Zhao, Kun; Lin, Chun; Si, Liang-yi

    2014-01-01

    Because of the limitations of existing methods and techniques for directly obtaining real-time blood data, no accurate microflow in vivo real-time analysis method exists. To establish a novel technical platform for real-time in vivo detection and to analyze average blood pressure and other blood flow parameters, a small, accurate, flexible, and nontoxic Fabry-Perot fiber sensor was designed. The carotid sheath was implanted through intubation of the rabbit carotid artery (n = 8), and the blood pressure and other detection data were determined directly through the veins. The fiber detection results were compared with test results obtained using color Doppler ultrasound and a physiological pressure sensor recorder. Pairwise comparisons among the blood pressure results obtained using the three methods indicated that real-time blood pressure information obtained through the fiber sensor technique exhibited better correlation than the data obtained with the other techniques. The highest correlation (correlation coefficient of 0.86) was obtained between the fiber sensor and pressure sensor. The blood pressure values were positively related to the total cholesterol level, low-density lipoprotein level, number of red blood cells, and hemoglobin level, with correlation coefficients of 0.033, 0.129, 0.358, and 0.373, respectively. The blood pressure values had no obvious relationship with the number of white blood cells and high-density lipoprotein and had a negative relationship with triglyceride levels, with a correlation coefficient of –0.031. The average ambulatory blood pressure measured by the fiber sensor exhibited a negative correlation with the quantity of blood platelets (correlation coefficient of −0.839, P<0.05). The novel fiber sensor can thus obtain in vivo blood pressure data accurately, stably, and in real time; the sensor can also determine the content and status of the blood flow to some extent. Therefore, the fiber sensor can obtain partially real-time

  2. Accurate Time-Dependent Traveling-Wave Tube Model Developed for Computational Bit-Error-Rate Testing

    NASA Technical Reports Server (NTRS)

    Kory, Carol L.

    2001-01-01

    The phenomenal growth of the satellite communications industry has created a large demand for traveling-wave tubes (TWT's) operating with unprecedented specifications requiring the design and production of many novel devices in record time. To achieve this, the TWT industry heavily relies on computational modeling. However, the TWT industry's computational modeling capabilities need to be improved because there are often discrepancies between measured TWT data and that predicted by conventional two-dimensional helical TWT interaction codes. This limits the analysis and design of novel devices or TWT's with parameters differing from what is conventionally manufactured. In addition, the inaccuracy of current computational tools limits achievable TWT performance because optimized designs require highly accurate models. To address these concerns, a fully three-dimensional, time-dependent, helical TWT interaction model was developed using the electromagnetic particle-in-cell code MAFIA (Solution of MAxwell's equations by the Finite-Integration-Algorithm). The model includes a short section of helical slow-wave circuit with excitation fed by radiofrequency input/output couplers, and an electron beam contained by periodic permanent magnet focusing. A cutaway view of several turns of the three-dimensional helical slow-wave circuit with input/output couplers is shown. This has been shown to be more accurate than conventionally used two-dimensional models. The growth of the communications industry has also imposed a demand for increased data rates for the transmission of large volumes of data. To achieve increased data rates, complex modulation and multiple access techniques are employed requiring minimum distortion of the signal as it is passed through the TWT. Thus, intersymbol interference (ISI) becomes a major consideration, as well as suspected causes such as reflections within the TWT. To experimentally investigate effects of the physical TWT on ISI would be

  3. Real-Time Nonlinear Optical Information Processing.

    DTIC Science & Technology

    1979-06-01

    operations aree presented. One approach realizes the halftone method of nonlinear optical processing in real time by replacing the conventional...photographic recording medium with a real-time image transducer. In the second approach halftoning is eliminated and the real-time device is used directly

  4. Accurate estimation of entropy in very short physiological time series: the problem of atrial fibrillation detection in implanted ventricular devices.

    PubMed

    Lake, Douglas E; Moorman, J Randall

    2011-01-01

    Entropy estimation is useful but difficult in short time series. For example, automated detection of atrial fibrillation (AF) in very short heart beat interval time series would be useful in patients with cardiac implantable electronic devices that record only from the ventricle. Such devices require efficient algorithms, and the clinical situation demands accuracy. Toward these ends, we optimized the sample entropy measure, which reports the probability that short templates will match with others within the series. We developed general methods for the rational selection of the template length m and the tolerance matching r. The major innovation was to allow r to vary so that sufficient matches are found for confident entropy estimation, with conversion of the final probability to a density by dividing by the matching region volume, 2r(m). The optimized sample entropy estimate and the mean heart beat interval each contributed to accurate detection of AF in as few as 12 heartbeats. The final algorithm, called the coefficient of sample entropy (COSEn), was developed using the canonical MIT-BIH database and validated in a new and much larger set of consecutive Holter monitor recordings from the University of Virginia. In patients over the age of 40 yr old, COSEn has high degrees of accuracy in distinguishing AF from normal sinus rhythm in 12-beat calculations performed hourly. The most common errors are atrial or ventricular ectopy, which increase entropy despite sinus rhythm, and atrial flutter, which can have low or high entropy states depending on dynamics of atrioventricular conduction.

  5. Accurate and rapid identification of the Burkholderia pseudomallei near-neighbour, Burkholderia ubonensis, using real-time PCR.

    PubMed

    Price, Erin P; Sarovich, Derek S; Webb, Jessica R; Ginther, Jennifer L; Mayo, Mark; Cook, James M; Seymour, Meagan L; Kaestli, Mirjam; Theobald, Vanessa; Hall, Carina M; Busch, Joseph D; Foster, Jeffrey T; Keim, Paul; Wagner, David M; Tuanyok, Apichai; Pearson, Talima; Currie, Bart J

    2013-01-01

    Burkholderia ubonensis is an environmental bacterium belonging to the Burkholderia cepacia complex (Bcc), a group of genetically related organisms that are associated with opportunistic but generally nonfatal infections in healthy individuals. In contrast, the near-neighbour species Burkholderia pseudomallei causes melioidosis, a disease that can be fatal in up to 95% of cases if left untreated. B. ubonensis is frequently misidentified as B. pseudomallei from soil samples using selective culturing on Ashdown's medium, reflecting both the shared environmental niche and morphological similarities of these species. Additionally, B. ubonensis shows potential as an important biocontrol agent in B. pseudomallei-endemic regions as certain strains possess antagonistic properties towards B. pseudomallei. Current methods for characterising B. ubonensis are laborious, time-consuming and costly, and as such this bacterium remains poorly studied. The aim of our study was to develop a rapid and inexpensive real-time PCR-based assay specific for B. ubonensis. We demonstrate that a novel B. ubonensis-specific assay, Bu550, accurately differentiates B. ubonensis from B. pseudomallei and other species that grow on selective Ashdown's agar. We anticipate that Bu550 will catalyse research on B. ubonensis by enabling rapid identification of this organism from Ashdown's-positive colonies that are not B. pseudomallei.

  6. Path integrals for Fokker-Planck dynamics with singular diffusion: Accurate factorization for the time evolution operator

    NASA Astrophysics Data System (ADS)

    Drozdov, Alexander N.; Talkner, Peter

    1998-08-01

    Fokker-Planck processes with a singular diffusion matrix are quite frequently met in Physics and Chemistry. For a long time the resulting noninvertability of the diffusion matrix has been looked as a serious obstacle for treating these Fokker-Planck equations by various powerful numerical methods of quantum and statistical mechanics. In this paper, a path-integral method is presented that takes advantage of the singularity of the diffusion matrix and allows one to solve such problems in a simple and economic way. The basic idea is to split the Fokker-Planck equation into one of a linear system and an anharmonic correction and then to employ a symmetric decomposition of the short time propagator, which is exact up to a high order in the time step. Just because of the singularity of the diffusion matrix, the factors of the resulting product formula consist of well behaved propagators. In this way one obtains a highly accurate propagation scheme, which is simultaneously fast, stable, and computationally simple. Because it allows much larger time steps, it is more efficient than the standard propagation scheme based on the Trotter splitting formula. The proposed method is tested for Brownian motion in different types of potentials. For a harmonic potential we compare to the known analytic results. For a symmetric double well potential we determine the transition rates between the two wells for different friction strengths and compare them with the crossover theories of Mel'nikov and Meshkov and Pollak, Grabert, and Hänggi. Using a properly defined energy loss of the deterministic particle dynamics, we obtain excellent agreement. The methodology is outlined for a large class of processes defined by generalized Langevin equations and processes driven by colored noise.

  7. Accurate Identification of Candida parapsilosis (Sensu Lato) by Use of Mitochondrial DNA and Real-Time PCR

    PubMed Central

    Souza, Ana Carolina R.; Ferreira, Renata C.; Gonçalves, Sarah S.; Quindós, Guillermo; Eraso, Elena; Bizerra, Fernando C.; Briones, Marcelo R. S.

    2012-01-01

    Candida parapsilosis is the Candida species isolated the second most frequently from blood cultures in South America and some European countries, such as Spain. Since 2005, this species has been considered a complex of 3 closely related species: C. parapsilosis, Candida metapsilosis, and Candida orthopsilosis. Here, we describe a real-time TaqMan-MGB PCR assay, using mitochondrial DNA (mtDNA) as the target, which readily distinguishes these 3 species. We first used comparative genomics to locate syntenic regions between these 3 mitochondrial genomes and then selected NADH5 as the target for the real-time PCR assay. Probes were designed to include a combination of different single-nucleotide polymorphisms that are able to differentiate each species within the C. parapsilosis complex. This new methodology was first tested using mtDNA and then genomic DNA from 4 reference and 5 clinical strains. For assay validation, a total of 96 clinical isolates and 4 American Type Culture Collection (ATCC) isolates previously identified by internal transcribed spacer (ITS) ribosomal DNA (rDNA) sequencing were tested. Real-time PCR using genomic DNA was able to differentiate the 3 species with 100% accuracy. No amplification was observed when DNA from other species was used as the template. We observed 100% congruence with ITS rDNA sequencing identification, including for 30 strains used in blind testing. This novel method allows a quick and accurate intracomplex identification of C. parapsilosis and saves time compared with sequencing, which so far has been considered the “gold standard” for Candida yeast identification. In addition, this assay provides a useful tool for epidemiological and clinical studies of these emergent species. PMID:22535986

  8. Three-dimensional accurate detection of lung emphysema in rats using ultra-short and zero echo time MRI.

    PubMed

    Bianchi, Andrea; Tibiletti, Marta; Kjørstad, Åsmund; Birk, Gerald; Schad, Lothar R; Stierstorfer, Birgit; Rasche, Volker; Stiller, Detlef

    2015-11-01

    Emphysema is a life-threatening pathology that causes irreversible destruction of alveolar walls. In vivo imaging techniques play a fundamental role in the early non-invasive pre-clinical and clinical detection and longitudinal follow-up of this pathology. In the present study, we aimed to evaluate the feasibility of using high resolution radial three-dimensional (3D) zero echo time (ZTE) and 3D ultra-short echo time (UTE) MRI to accurately detect lung pathomorphological changes in a rodent model of emphysema.Porcine pancreas elastase (PPE) was intratracheally administered to the rats to produce the emphysematous changes. 3D ZTE MRI, low and high definition 3D UTE MRI and micro-computed tomography images were acquired 4 weeks after the PPE challenge. Signal-to-noise ratios (SNRs) were measured in PPE-treated and control rats. T2* values were computed from low definition 3D UTE MRI. Histomorphometric measurements were made after euthanizing the animals. Both ZTE and UTE MR images showed a significant decrease in the SNR measured in PPE-treated lungs compared with controls, due to the pathomorphological changes taking place in the challenged lungs. A significant decrease in T2* values in PPE-challenged animals compared with controls was measured using UTE MRI. Histomorphometric measurements showed a significant increase in the mean linear intercept in PPE-treated lungs. UTE yielded significantly higher SNR compared with ZTE (14% and 30% higher in PPE-treated and non-PPE-treated lungs, respectively).This study showed that optimized 3D radial UTE and ZTE MRI can provide lung images of excellent quality, with high isotropic spatial resolution (400 µm) and SNR in parenchymal tissue (>25) and negligible motion artifacts in freely breathing animals. These techniques were shown to be useful non-invasive instruments to accurately and reliably detect the pathomorphological alterations taking place in emphysematous lungs, without incurring the risks of cumulative radiation

  9. Accurate, fast and cost-effective diagnostic test for monosomy 1p36 using real-time quantitative PCR.

    PubMed

    Cunha, Pricila da Silva; Pena, Heloisa B; D'Angelo, Carla Sustek; Koiffmann, Celia P; Rosenfeld, Jill A; Shaffer, Lisa G; Stofanko, Martin; Gonçalves-Dornelas, Higgor; Pena, Sérgio Danilo Junho

    2014-01-01

    Monosomy 1p36 is considered the most common subtelomeric deletion syndrome in humans and it accounts for 0.5-0.7% of all the cases of idiopathic intellectual disability. The molecular diagnosis is often made by microarray-based comparative genomic hybridization (aCGH), which has the drawback of being a high-cost technique. However, patients with classic monosomy 1p36 share some typical clinical characteristics that, together with its common prevalence, justify the development of a less expensive, targeted diagnostic method. In this study, we developed a simple, rapid, and inexpensive real-time quantitative PCR (qPCR) assay for targeted diagnosis of monosomy 1p36, easily accessible for low-budget laboratories in developing countries. For this, we have chosen two target genes which are deleted in the majority of patients with monosomy 1p36: PRKCZ and SKI. In total, 39 patients previously diagnosed with monosomy 1p36 by aCGH, fluorescent in situ hybridization (FISH), and/or multiplex ligation-dependent probe amplification (MLPA) all tested positive on our qPCR assay. By simultaneously using these two genes we have been able to detect 1p36 deletions with 100% sensitivity and 100% specificity. We conclude that qPCR of PRKCZ and SKI is a fast and accurate diagnostic test for monosomy 1p36, costing less than 10 US dollars in reagent costs.

  10. A Support Vector Machine model for the prediction of proteotypic peptides for accurate mass and time proteomics

    SciTech Connect

    Webb-Robertson, Bobbie-Jo M.; Cannon, William R.; Oehmen, Christopher S.; Shah, Anuj R.; Gurumoorthi, Vidhya; Lipton, Mary S.; Waters, Katrina M.

    2008-07-01

    Motivation: The standard approach to identifying peptides based on accurate mass and elution time (AMT) compares these profiles obtained from a high resolution mass spectrometer to a database of peptides previously identified from tandem mass spectrometry (MS/MS) studies. It would be advantageous, with respect to both accuracy and cost, to only search for those peptides that are detectable by MS (proteotypic). Results: We present a Support Vector Machine (SVM) model that uses a simple descriptor space based on 35 properties of amino acid content, charge, hydrophilicity, and polarity for the quantitative prediction of proteotypic peptides. Using three independently derived AMT databases (Shewanella oneidensis, Salmonella typhimurium, Yersinia pestis) for training and validation within and across species, the SVM resulted in an average accuracy measure of ~0.8 with a standard deviation of less than 0.025. Furthermore, we demonstrate that these results are achievable with a small set of 12 variables and can achieve high proteome coverage. Availability: http://omics.pnl.gov/software/STEPP.php

  11. Accurate time-dependent wave packet study of the Li + H₂⁺ reaction and its isotopic variants.

    PubMed

    Aslan, E; Bulut, N; Castillo, J F; Bañares, L; Roncero, O; Aoiz, F J

    2012-01-12

    The dynamics and kinetics of the Li + H₂⁺ reaction and its isotopic variants (D₂⁺ and T₂⁺) have been studied by using a time-dependent wave packet (TDWP) coupled-channel (CC) method on the ab initio potential energy surface (PES) of Martinazzo et al. [J. Chem. Phys. 2003, 119, 21]. Total initial v = 0, j = 0 state-selected reaction probabilities for the Li + H₂⁺ reaction and its isotopic variants have been calculated from the threshold up to 1 eV for total angular momenta J from 0 to 90. Integral cross sections have been evaluated from the reaction probabilities at collision energies from threshold (≈0.2 eV) up to 1.0 eV collision. The calculated rate constants as a function of temperature show an Arrhenius type behavior in the 200 ≤ T ≤ 1000 K temperature interval. It has been found to be a considerable large intermolecular kinetic isotope effect. The TDWP-CC results are in overall good agreement with those obtained applying the TDWP Centrifugal-Sudden (CS) approximation, showing that the CS approximation is rather accurate for the title reaction.

  12. Accurate, Fast and Cost-Effective Diagnostic Test for Monosomy 1p36 Using Real-Time Quantitative PCR

    PubMed Central

    Cunha, Pricila da Silva; Pena, Heloisa B.; D'Angelo, Carla Sustek; Koiffmann, Celia P.; Rosenfeld, Jill A.; Shaffer, Lisa G.; Stofanko, Martin; Gonçalves-Dornelas, Higgor; Pena, Sérgio Danilo Junho

    2014-01-01

    Monosomy 1p36 is considered the most common subtelomeric deletion syndrome in humans and it accounts for 0.5–0.7% of all the cases of idiopathic intellectual disability. The molecular diagnosis is often made by microarray-based comparative genomic hybridization (aCGH), which has the drawback of being a high-cost technique. However, patients with classic monosomy 1p36 share some typical clinical characteristics that, together with its common prevalence, justify the development of a less expensive, targeted diagnostic method. In this study, we developed a simple, rapid, and inexpensive real-time quantitative PCR (qPCR) assay for targeted diagnosis of monosomy 1p36, easily accessible for low-budget laboratories in developing countries. For this, we have chosen two target genes which are deleted in the majority of patients with monosomy 1p36: PRKCZ and SKI. In total, 39 patients previously diagnosed with monosomy 1p36 by aCGH, fluorescent in situ hybridization (FISH), and/or multiplex ligation-dependent probe amplification (MLPA) all tested positive on our qPCR assay. By simultaneously using these two genes we have been able to detect 1p36 deletions with 100% sensitivity and 100% specificity. We conclude that qPCR of PRKCZ and SKI is a fast and accurate diagnostic test for monosomy 1p36, costing less than 10 US dollars in reagent costs. PMID:24839341

  13. Time-accurate unsteady flow simulations supporting the SRM T+68-second pressure spike anomaly investigation (STS-54B)

    NASA Astrophysics Data System (ADS)

    Dougherty, N. S.; Burnette, D. W.; Holt, J. B.; Matienzo, Jose

    1993-07-01

    Time-accurate unsteady flow simulations are being performed supporting the SRM T+68sec pressure 'spike' anomaly investigation. The anomaly occurred in the RH SRM during the STS-54 flight (STS-54B) but not in the LH SRM (STS-54A) causing a momentary thrust mismatch approaching the allowable limit at that time into the flight. Full-motor internal flow simulations using the USA-2D axisymmetric code are in progress for the nominal propellant burn-back geometry and flow conditions at T+68-sec--Pc = 630 psi, gamma = 1.1381, T(sub c) = 6200 R, perfect gas without aluminum particulate. In a cooperative effort with other investigation team members, CFD-derived pressure loading on the NBR and castable inhibitors was used iteratively to obtain nominal deformed geometry of each inhibitor, and the deformed (bent back) inhibitor geometry was entered into this model. Deformed geometry was computed using structural finite-element models. A solution for the unsteady flow has been obtained for the nominal flow conditions (existing prior to the occurrence of the anomaly) showing sustained standing pressure oscillations at nominally 14.5 Hz in the motor IL acoustic mode that flight and static test data confirm to be normally present at this time. Average mass flow discharged from the nozzle was confirmed to be the nominal expected (9550 lbm/sec). The local inlet boundary condition is being perturbed at the location of the presumed reconstructed anomaly as identified by interior ballistics performance specialist team members. A time variation in local mass flow is used to simulate sudden increase in burning area due to localized propellant grain cracks. The solution will proceed to develop a pressure rise (proportional to total mass flow rate change squared). The volume-filling time constant (equivalent to 0.5 Hz) comes into play in shaping the rise rate of the developing pressure 'spike' as it propagates at the speed of sound in both directions to the motor head end and nozzle. The

  14. Predicting application run times using historical information.

    SciTech Connect

    Foster, I.; Smith, W.; Taylor, V.

    1999-06-25

    The authors present a technique for deriving predictions for the run times of parallel applications from the run times of similar applications that have executed in the past. The novel aspect of the work is the use of search techniques to determine those application characteristics that yield the best definition of similarity for the purpose of making predictions. They use four workloads recorded from parallel computers at Argonne National Laboratory, the Cornell Theory Center, and the San Diego Supercomputer Center to evaluate the effectiveness of the approach.They show that on these workloads the techniques achieve predictions that are between 14 and 60% better than those achieved by other researchers; the approach achieves mean prediction errors that are between 41 and 65% of mean application run times.

  15. Accurate Time-Dependent Wave Packet Calculations for the O(+) + H2 → OH(+) + H Ion-Molecule Reaction.

    PubMed

    Bulut, N; Castillo, J F; Jambrina, P G; Kłos, J; Roncero, O; Aoiz, F J; Bañares, L

    2015-12-17

    Accurate quantum reactive scattering time-dependent wave packet close-coupling calculations have been carried out to determine total reaction probabilities and integral cross sections for the O(+) + H2 → OH(+) + H reaction in a range of collision energies from 10(-3) eV up to 1.0 eV for the H2 rovibrational states (v = 0; j = 0, 1, 2) and (v = 1; j = 0) using the potential energy surface (PES) by Martı́nez et al. As expected for a barrierless reaction, the reaction cross section decays rapidly with collision energy, Ec, following a behavior that nearly corresponds to that predicted by the Langevin model. Rotational excitation of H2 into j = 1, 2 has a very moderate effect on reactivity, similarly to what happens with vibrational excitation below Ec ≈ 0.3 eV. However, at higher collision energies the cross section increases notably when H2 is promoted to v = 1. This effect is explained by resorting to the effective potentials in the entrance channel. The integral cross sections have been used to calculate rate constants in the temperature range 200-1000 K. A good overall agreement has been found with the available experimental data on integral cross sections and rate constants. In addition, time-independent quantum mechanical and quasi-classical trajectory (QCT) calculations have been performed on the same PES aimed to compare the various methodologies and to discern the detailed mechanism of the title reaction. In particular, the analysis of individual trajectories has made it possible to explain, in terms of the coupling between reagent relative velocity and the topography of the PES, the presence of a series of alternating maxima and minima in the collision energy dependence of the QCT reaction probabilities for the reactions with H2(v=0,1,j=0), which are absent in the quantum mechanical calculations.

  16. A Proteomic Study of the HUPO Plasma Proteome Project's Pilot Samples using an Accurate Mass and Time Tag Strategy

    SciTech Connect

    Adkins, Joshua N.; Monroe, Matthew E.; Auberry, Kenneth J.; Shen, Yufeng; Jacobs, Jon M.; Camp, David G.; Vitzthum, Frank; Rodland, Karin D.; Zangar, Richard C.; Smith, Richard D.; Pounds, Joel G.

    2005-08-01

    Characterization of the human blood plasma proteome is critical to the discovery of routinely useful clinical biomarkers. We used an Accurate Mass and Time (AMT) tag strategy with high-resolution mass accuracy capillary liquid chromatography Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (cLC-FTICR MS) to perform a global proteomic analysis of pilot study samples as part of the HUPO Plasma Proteome Project. HUPO reference serum and citrated plasma samples from African Americans, Asian Americans, and Caucasian Americans were analyzed, in addition to a Pacific Northwest National Laboratory reference serum and plasma. The AMT tag strategy allowed us to leverage two previously published “shotgun” proteomics experiments to perform global analyses on these samples in triplicate in less than 4 days total analysis time. A total of 722 (22% with multiple peptide identifications) International Protein Index (IPI) redundant proteins, or 377 protein families by ProteinProphet, were identified over the 6 individual HUPO serum and plasma samples. The samples yielded a similar number of identified redundant proteins in the plasma samples (average 446 +/-23) as found in the serum samples (average 440+/-20). These proteins were identified by an average of 956+/-35 unique peptides in plasma and 930+/-11 unique peptides in serum. In addition to this high-throughput analysis, the AMT tag approach was used with a Z-score normalization to compare relative protein abundances. This analysis highlighted both known differences in serum and citrated plasma such as fibrinogens, and reproducible differences in peptide abundances from proteins such as soluble activin receptor-like kinase 7b and glycoprotein m6b. The AMT tag strategy not only improved our sample throughput, and provided a basis for estimated quantitation.

  17. Information theories for time-dependent harmonic oscillator

    SciTech Connect

    Choi, Jeong Ryeol; Kim, Min-Soo; Kim, Daeyeoul; Maamache, Mustapha; Menouar, Salah; Nahm, In Hyun

    2011-06-15

    Highlights: > Information theories for the general time-dependent harmonic oscillator based on invariant operator method. > Time dependence of entropies and entropic uncertainty relation. > Characteristics of Shannon information and Fisher information. > Application of information theories to particular systems that have time-dependent behavior. - Abstract: Information theories for the general time-dependent harmonic oscillator are described on the basis of invariant operator method. We obtained entropic uncertainty relation of the system and discussed whether it is always larger than or equal to the physically allowed minimum value. Shannon information and Fisher information are derived by means of density operator that satisfies Liouville-von Neumann equation and their characteristics are investigated. Shannon information is independent of time, but Fisher information is explicitly dependent on time as the time functions of the Hamiltonian vary. We can regard that the Fisher information is a local measure since its time behavior is largely affected by local arrangements of the density, whilst the Shannon information plays the role of a global measure of the spreading of density. To promote the understanding, our theory is applied to special systems, the so-called quantum oscillator with time-dependent frequency and strongly pulsating mass system.

  18. High-Throughput Accurate Single-Cell Screening of Euglena gracilis with Fluorescence-Assisted Optofluidic Time-Stretch Microscopy.

    PubMed

    Guo, Baoshan; Lei, Cheng; Ito, Takuro; Jiang, Yiyue; Ozeki, Yasuyuki; Goda, Keisuke

    2016-01-01

    The development of reliable, sustainable, and economical sources of alternative fuels is an important, but challenging goal for the world. As an alternative to liquid fossil fuels, algal biofuel is expected to play a key role in alleviating global warming since algae absorb atmospheric CO2 via photosynthesis. Among various algae for fuel production, Euglena gracilis is an attractive microalgal species as it is known to produce wax ester (good for biodiesel and aviation fuel) within lipid droplets. To date, while there exist many techniques for inducing microalgal cells to produce and accumulate lipid with high efficiency, few analytical methods are available for characterizing a population of such lipid-accumulated microalgae including E. gracilis with high throughout, high accuracy, and single-cell resolution simultaneously. Here we demonstrate high-throughput, high-accuracy, single-cell screening of E. gracilis with fluorescence-assisted optofluidic time-stretch microscopy-a method that combines the strengths of microfluidic cell focusing, optical time-stretch microscopy, and fluorescence detection used in conventional flow cytometry. Specifically, our fluorescence-assisted optofluidic time-stretch microscope consists of an optical time-stretch microscope and a fluorescence analyzer on top of a hydrodynamically focusing microfluidic device and can detect fluorescence from every E. gracilis cell in a population and simultaneously obtain its image with a high throughput of 10,000 cells/s. With the multi-dimensional information acquired by the system, we classify nitrogen-sufficient (ordinary) and nitrogen-deficient (lipid-accumulated) E. gracilis cells with a low false positive rate of 1.0%. This method holds promise for evaluating cultivation techniques and selective breeding for microalgae-based biofuel production.

  19. High-Throughput Accurate Single-Cell Screening of Euglena gracilis with Fluorescence-Assisted Optofluidic Time-Stretch Microscopy

    PubMed Central

    Guo, Baoshan; Lei, Cheng; Ito, Takuro; Jiang, Yiyue; Ozeki, Yasuyuki; Goda, Keisuke

    2016-01-01

    The development of reliable, sustainable, and economical sources of alternative fuels is an important, but challenging goal for the world. As an alternative to liquid fossil fuels, algal biofuel is expected to play a key role in alleviating global warming since algae absorb atmospheric CO2 via photosynthesis. Among various algae for fuel production, Euglena gracilis is an attractive microalgal species as it is known to produce wax ester (good for biodiesel and aviation fuel) within lipid droplets. To date, while there exist many techniques for inducing microalgal cells to produce and accumulate lipid with high efficiency, few analytical methods are available for characterizing a population of such lipid-accumulated microalgae including E. gracilis with high throughout, high accuracy, and single-cell resolution simultaneously. Here we demonstrate high-throughput, high-accuracy, single-cell screening of E. gracilis with fluorescence-assisted optofluidic time-stretch microscopy–a method that combines the strengths of microfluidic cell focusing, optical time-stretch microscopy, and fluorescence detection used in conventional flow cytometry. Specifically, our fluorescence-assisted optofluidic time-stretch microscope consists of an optical time-stretch microscope and a fluorescence analyzer on top of a hydrodynamically focusing microfluidic device and can detect fluorescence from every E. gracilis cell in a population and simultaneously obtain its image with a high throughput of 10,000 cells/s. With the multi-dimensional information acquired by the system, we classify nitrogen-sufficient (ordinary) and nitrogen-deficient (lipid-accumulated) E. gracilis cells with a low false positive rate of 1.0%. This method holds promise for evaluating cultivation techniques and selective breeding for microalgae-based biofuel production. PMID:27846239

  20. The Lunar Laser Ranging Experiment: Accurate ranges have given a large improvement in the lunar orbit and new selenophysical information.

    PubMed

    Bender, P L; Currie, D G; Poultney, S K; Alley, C O; Dicke, R H; Wilkinson, D T; Eckhardt, D H; Faller, J E; Kaula, W M; Mulholland, J D; Plotkin, H H; Silverberg, E C; Williams, J G

    1973-10-19

    The lunar ranging measurements now being made at the McDonald Observatory have an accuracy of 1 nsec in round-trip travel time. This corresponds to 15 cm in the one-way distance. The use of lasers with pulse-lengths of less than 1 nsec is expected to give an accuracy of 2 to 3 cm in the next few years. A new station is under construction in Hawaii, and additional stations in other countries are either in operation or under development. It is hoped that these stations will form the basis for a worldwide network to determine polar motion and earth rotation on a regular basis, and will assist in providing information about movement of the tectonic plates making up the earth's surface. Several mobile lunar ranging stations with telescopes having diameters of 1.0 m or less could, in the future, greatly extend the information obtainable about motions within and between the tectonic plates. The data obtained so far by the McDonald Observatory have been used to generate a new lunar ephemeris based on direct numerical integration of the equations of motion for the moon and planets. With this ephemeris, the range to the three Apollo retro-reflectors can be fit to an accuracy of 5 m by adjusting the differences in moments of inertia of the moon about its principal axes, the selenocentric coordinates of the reflectors, and the McDonald longitude. The accuracy of fitting the results is limited currently by errors of the order of an arc second in the angular orientation of the moon, as derived from the best available theory of how the moon rotates in response to the torques acting on it. Both a new calculation of the moon's orientation as a function of time based on direct numerical integration of the torque equations and a new analytic theory of the moon's orientation are expected to be available soon, and to improve considerably the accuracy of fitting the data. The accuracy already achieved routinely in lunar laser ranging represents a hundredfold improvement over any

  1. IrisPlex: a sensitive DNA tool for accurate prediction of blue and brown eye colour in the absence of ancestry information.

    PubMed

    Walsh, Susan; Liu, Fan; Ballantyne, Kaye N; van Oven, Mannis; Lao, Oscar; Kayser, Manfred

    2011-06-01

    A new era of 'DNA intelligence' is arriving in forensic biology, due to the impending ability to predict externally visible characteristics (EVCs) from biological material such as those found at crime scenes. EVC prediction from forensic samples, or from body parts, is expected to help concentrate police investigations towards finding unknown individuals, at times when conventional DNA profiling fails to provide informative leads. Here we present a robust and sensitive tool, termed IrisPlex, for the accurate prediction of blue and brown eye colour from DNA in future forensic applications. We used the six currently most eye colour-informative single nucleotide polymorphisms (SNPs) that previously revealed prevalence-adjusted prediction accuracies of over 90% for blue and brown eye colour in 6168 Dutch Europeans. The single multiplex assay, based on SNaPshot chemistry and capillary electrophoresis, both widely used in forensic laboratories, displays high levels of genotyping sensitivity with complete profiles generated from as little as 31pg of DNA, approximately six human diploid cell equivalents. We also present a prediction model to correctly classify an individual's eye colour, via probability estimation solely based on DNA data, and illustrate the accuracy of the developed prediction test on 40 individuals from various geographic origins. Moreover, we obtained insights into the worldwide allele distribution of these six SNPs using the HGDP-CEPH samples of 51 populations. Eye colour prediction analyses from HGDP-CEPH samples provide evidence that the test and model presented here perform reliably without prior ancestry information, although future worldwide genotype and phenotype data shall confirm this notion. As our IrisPlex eye colour prediction test is capable of immediate implementation in forensic casework, it represents one of the first steps forward in the creation of a fully individualised EVC prediction system for future use in forensic DNA intelligence.

  2. The application of intraoperative transit time flow measurement to accurately assess anastomotic quality in sequential vein grafting

    PubMed Central

    Yu, Yang; Zhang, Fan; Gao, Ming-Xin; Li, Hai-Tao; Li, Jing-Xing; Song, Wei; Huang, Xin-Sheng; Gu, Cheng-Xiong

    2013-01-01

    OBJECTIVES Intraoperative transit time flow measurement (TTFM) is widely used to assess anastomotic quality in coronary artery bypass grafting (CABG). However, in sequential vein grafting, the flow characteristics collected by the conventional TTFM method are usually associated with total graft flow and might not accurately indicate the quality of every distal anastomosis in a sequential graft. The purpose of our study was to examine a new TTFM method that could assess the quality of each distal anastomosis in a sequential graft more reliably than the conventional TTFM approach. METHODS Two TTFM methods were tested in 84 patients who underwent sequential saphenous off-pump CABG in Beijing An Zhen Hospital between April and August 2012. In the conventional TTFM method, normal blood flow in the sequential graft was maintained during the measurement, and the flow probe was placed a few centimetres above the anastomosis to be evaluated. In the new method, blood flow in the sequential graft was temporarily reduced during the measurement by placing an atraumatic bulldog clamp at the graft a few centimetres distal to the anastomosis to be evaluated, while the position of the flow probe remained the same as in the conventional method. This new TTFM method was named the flow reduction TTFM. Graft flow parameters measured by both methods were compared. RESULTS Compared with the conventional TTFM, the flow reduction TTFM resulted in significantly lower mean graft blood flow (P < 0.05); in contrast, yielded significantly higher pulsatility index (P < 0.05). Diastolic filling was not significantly different between the two methods and was >50% in both cases. Interestingly, the flow reduction TTFM identified two defective middle distal anastomoses that the conventional TTFM failed to detect. Graft flows near the defective distal anastomoses were improved substantially after revision. CONCLUSIONS In this study, we found that temporary reduction of graft flow during TTFM seemed to

  3. Identification of Novel Perfluoroalkyl Ether Carboxylic Acids (PFECAs) and Sulfonic Acids (PFESAs) in Natural Waters Using Accurate Mass Time-of-Flight Mass Spectrometry (TOFMS).

    PubMed

    Strynar, Mark; Dagnino, Sonia; McMahen, Rebecca; Liang, Shuang; Lindstrom, Andrew; Andersen, Erik; McMillan, Larry; Thurman, Michael; Ferrer, Imma; Ball, Carol

    2015-10-06

    Recent scientific scrutiny and concerns over exposure, toxicity, and risk have led to international regulatory efforts resulting in the reduction or elimination of certain perfluorinated compounds from various products and waste streams. Some manufacturers have started producing shorter chain per- and polyfluorinated compounds to try to reduce the potential for bioaccumulation in humans and wildlife. Some of these new compounds contain central ether oxygens or other minor modifications of traditional perfluorinated structures. At present, there has been very limited information published on these "replacement chemistries" in the peer-reviewed literature. In this study we used a time-of-flight mass spectrometry detector (LC-ESI-TOFMS) to identify fluorinated compounds in natural waters collected from locations with historical perfluorinated compound contamination. Our workflow for discovery of chemicals included sequential sampling of surface water for identification of potential sources, nontargeted TOFMS analysis, molecular feature extraction (MFE) of samples, and evaluation of features unique to the sample with source inputs. Specifically, compounds were tentatively identified by (1) accurate mass determination of parent and/or related adducts and fragments from in-source collision-induced dissociation (CID), (2) in-depth evaluation of in-source adducts formed during analysis, and (3) confirmation with authentic standards when available. We observed groups of compounds in homologous series that differed by multiples of CF2 (m/z 49.9968) or CF2O (m/z 65.9917). Compounds in each series were chromatographically separated and had comparable fragments and adducts produced during analysis. We detected 12 novel perfluoroalkyl ether carboxylic and sulfonic acids in surface water in North Carolina, USA using this approach. A key piece of evidence was the discovery of accurate mass in-source n-mer formation (H(+) and Na(+)) differing by m/z 21.9819, corresponding to the

  4. Isotopic Ratio Outlier Analysis of the S. cerevisiae Metabolome Using Accurate Mass Gas Chromatography/Time-of-Flight Mass Spectrometry: A New Method for Discovery.

    PubMed

    Qiu, Yunping; Moir, Robyn; Willis, Ian; Beecher, Chris; Tsai, Yu-Hsuan; Garrett, Timothy J; Yost, Richard A; Kurland, Irwin J

    2016-03-01

    Isotopic ratio outlier analysis (IROA) is a (13)C metabolomics profiling method that eliminates sample to sample variance, discriminates against noise and artifacts, and improves identification of compounds, previously done with accurate mass liquid chromatography/mass spectrometry (LC/MS). This is the first report using IROA technology in combination with accurate mass gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS), here used to examine the S. cerevisiae metabolome. S. cerevisiae was grown in YNB media, containing randomized 95% (13)C, or 5%(13)C glucose as the single carbon source, in order that the isotopomer pattern of all metabolites would mirror the labeled glucose. When these IROA experiments are combined, the abundance of the heavy isotopologues in the 5%(13)C extracts, or light isotopologues in the 95%(13)C extracts, follows the binomial distribution, showing mirrored peak pairs for the molecular ion. The mass difference between the (12)C monoisotopic and the (13)C monoisotopic equals the number of carbons in the molecules. The IROA-GC/MS protocol developed, using both chemical and electron ionization, extends the information acquired from the isotopic peak patterns for formulas generation. The process that can be formulated as an algorithm, in which the number of carbons, as well as the number of methoximations and silylations are used as search constraints. In electron impact (EI/IROA) spectra, the artifactual peaks are identified and easily removed, which has the potential to generate "clean" EI libraries. The combination of chemical ionization (CI) IROA and EI/IROA affords a metabolite identification procedure that enables the identification of coeluting metabolites, and allowed us to characterize 126 metabolites in the current study.

  5. Real-Time Dynamic Modeling - Data Information Requirements and Flight Test Results

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.; Smith, Mark S.

    2008-01-01

    Practical aspects of identifying dynamic models for aircraft in real time were studied. Topics include formulation of an equation-error method in the frequency domain to estimate non-dimensional stability and control derivatives in real time, data information content for accurate modeling results, and data information management techniques such as data forgetting, incorporating prior information, and optimized excitation. Real-time dynamic modeling was applied to simulation data and flight test data from a modified F-15B fighter aircraft, and to operational flight data from a subscale jet transport aircraft. Estimated parameter standard errors and comparisons with results from a batch output-error method in the time domain were used to demonstrate the accuracy of the identified real-time models.

  6. Real-Time Dynamic Modeling - Data Information Requirements and Flight Test Results

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.; Smith, Mark S.

    2010-01-01

    Practical aspects of identifying dynamic models for aircraft in real time were studied. Topics include formulation of an equation-error method in the frequency domain to estimate non-dimensional stability and control derivatives in real time, data information content for accurate modeling results, and data information management techniques such as data forgetting, incorporating prior information, and optimized excitation. Real-time dynamic modeling was applied to simulation data and flight test data from a modified F-15B fighter aircraft, and to operational flight data from a subscale jet transport aircraft. Estimated parameter standard errors, prediction cases, and comparisons with results from a batch output-error method in the time domain were used to demonstrate the accuracy of the identified real-time models.

  7. Accurate and in situ monitoring of bacterial concentration using a real time all-fibre spectroscopic device

    NASA Astrophysics Data System (ADS)

    Tao, W.; McGoverin, C.; Lydiard, S.; Song, Y.; Cheng, M.; Swift, S.; Singhal, N.; Vanholsbeeck, F.

    2015-07-01

    Accurate in situ monitoring of bacterial transport is important for increased understanding and improvement of bioremediation processes where microorganisms convert toxic compounds to more benign compounds. Bioremediation methods have become the preferred mechanism for the rehabilitation of hard to reach contaminated environments. In this study, we have used fluorescence spectroscopy to monitor the movement of fluorescently labelled bacteria (Rhodococcus erythropolis and Pseudomonas putida) within a bench-top column filled with a porous medium. In situ fluorescence measurements made using a fibre optic based instrument (`optrode') were compared to ex situ measurements made using a plate reader. In situ monitoring using this fibre optic based instrument is a promising alternative to ex situ measurements as the initial flow of bacteria is reliably observed. However, a greater understanding of the effect of the porous medium on fluorescence measurements is required to develop an accurate calibration for bacterial concentration based in situ measurements.

  8. 78 FR 21246 - Definition of Factual Information and Time Limits for Submission of Factual Information

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-10

    ... International Trade Administration 19 CFR Part 351 RIN 0625-AA91 Definition of Factual Information and Time...) is modifying its regulations, which define ``factual information'' and establish time limits for the.... The modifications to the time limits enable the Department to efficiently determine the type...

  9. Mapping Rise Time Information with Down-Shift Analysis

    SciTech Connect

    Tunnell, T. W., Machorro, E. A., Diaz, A. B.

    2011-11-01

    These viewgraphs summarize the application of recent developments in digital down-shift (DDS) analysis of up converted PDV data to map out how well the PDV diagnostic would capture rise time information (mid point and rise time) in short rise time (<1 ns) shock events. The mapping supports a PDV vs VISAR challenge. The analysis concepts are new (~September FY 2011), simple, and run quickly, which makes them good tools to map out (with ~1 million Monte Carlo simulations) how well PDV captures rise time information as function of baseline velocity, rise time, velocity jump, and signal-to-noise ratios.

  10. The role of cognitive switching in head-up displays. [to determine pilot ability to accurately extract information from either of two sources

    NASA Technical Reports Server (NTRS)

    Fischer, E.

    1979-01-01

    The pilot's ability to accurately extract information from either one or both of two superimposed sources of information was determined. Static, aerial, color 35 mm slides of external runway environments and slides of corresponding static head-up display (HUD) symbology were used as the sources. A three channel tachistoscope was utilized to show either the HUD alone, the scene alone, or the two slides superimposed. Cognitive performance of the pilots was assessed by determining the percentage of correct answers given to two HUD related questions, two scene related questions, or one HUD and one scene related question.

  11. Real-time alerts and reminders using information systems.

    PubMed

    Wanderer, Jonathan P; Sandberg, Warren S; Ehrenfeld, Jesse M

    2011-09-01

    Adoption of information systems throughout the hospital environment has enabled the development of real-time physiologic alerts and clinician reminder systems. These clinical tools can be made available through the deployment of anesthesia information management systems (AIMS). Creating usable alert systems requires understanding of technical considerations. Various successful implementations are reviewed, encompassing cost reduction, improved revenue capture, timely antibiotic administration, and postoperative nausea and vomiting prophylaxis. Challenges to the widespread use of real-time alerts and reminders include AIMS adoption rates and the difficulty in choosing appropriate areas and approaches for information systems support.

  12. Downdating a time-varying square root information filter

    NASA Technical Reports Server (NTRS)

    Muellerschoen, Ronald J.

    1990-01-01

    A new method to efficiently downdate an estimate and covariance generated by a discrete time Square Root Information Filter (SRIF) is presented. The method combines the QR factor downdating algorithm of Gill and the decentralized SRIF algorithm of Bierman. Efficient removal of either measurements or a priori information is possible without loss of numerical integrity. Moreover, the method includes features for detecting potential numerical degradation. Performance on a 300 parameter system with 5800 data points shows that the method can be used in real time and hence is a promising tool for interactive data analysis. Additionally, updating a time-varying SRIF filter with either additional measurements or a priori information proceeds analogously.

  13. Children's Processing and Comprehension of Complex Sentences Containing Temporal Connectives: The Influence of Memory on the Time Course of Accurate Responses

    ERIC Educational Resources Information Center

    Blything, Liam P.; Cain, Kate

    2016-01-01

    In a touch-screen paradigm, we recorded 3- to 7-year-olds' (N = 108) accuracy and response times (RTs) to assess their comprehension of 2-clause sentences containing "before" and "after". Children were influenced by order: performance was most accurate when the presentation order of the 2 clauses matched the chronological order…

  14. Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Can Accurately Differentiate between Mycobacterium masilliense (M. abscessus subspecies bolletti) and M. abscessus (Sensu Stricto)

    PubMed Central

    Teng, Shih-Hua; Chen, Chung-Ming; Lee, Meng-Rui; Lee, Tai-Fen; Chien, Kun-Yi; Teng, Lee-Jene

    2013-01-01

    Among 36 Mycobacterium masilliense and 22 M. abscessus isolates identified by erm(41) PCR and sequencing analysis of rpoB and 23S rRNA genes, the rate of accurate differentiation between these two subspecies was 100% by cluster analysis of spectra generated by Bruker Biotyper matrix-assisted laser desorption ionization–time of flight mass spectrometry. PMID:23824775

  15. Accurate prediction of unsteady and time-averaged pressure loads using a hybrid Reynolds-Averaged/large-eddy simulation technique

    NASA Astrophysics Data System (ADS)

    Bozinoski, Radoslav

    Significant research has been performed over the last several years on understanding the unsteady aerodynamics of various fluid flows. Much of this work has focused on quantifying the unsteady, three-dimensional flow field effects which have proven vital to the accurate prediction of many fluid and aerodynamic problems. Up until recently, engineers have predominantly relied on steady-state simulations to analyze the inherently three-dimensional ow structures that are prevalent in many of today's "real-world" problems. Increases in computational capacity and the development of efficient numerical methods can change this and allow for the solution of the unsteady Reynolds-Averaged Navier-Stokes (RANS) equations for practical three-dimensional aerodynamic applications. An integral part of this capability has been the performance and accuracy of the turbulence models coupled with advanced parallel computing techniques. This report begins with a brief literature survey of the role fully three-dimensional, unsteady, Navier-Stokes solvers have on the current state of numerical analysis. Next, the process of creating a baseline three-dimensional Multi-Block FLOw procedure called MBFLO3 is presented. Solutions for an inviscid circular arc bump, laminar at plate, laminar cylinder, and turbulent at plate are then presented. Results show good agreement with available experimental, numerical, and theoretical data. Scalability data for the parallel version of MBFLO3 is presented and shows efficiencies of 90% and higher for processes of no less than 100,000 computational grid points. Next, the description and implementation techniques used for several turbulence models are presented. Following the successful implementation of the URANS and DES procedures, the validation data for separated, non-reattaching flows over a NACA 0012 airfoil, wall-mounted hump, and a wing-body junction geometry are presented. Results for the NACA 0012 showed significant improvement in flow predictions

  16. Atypical late-time singular regimes accurately diagnosed in stagnation-point-type solutions of 3D Euler flows

    NASA Astrophysics Data System (ADS)

    Mulungye, Rachel M.; Lucas, Dan; Bustamante, Miguel D.

    2016-02-01

    We revisit, both numerically and analytically, the finite-time blowup of the infinite-energy solution of 3D Euler equations of stagnation-point-type introduced by Gibbon et al. (1999). By employing the method of mapping to regular systems, presented in Bustamante (2011) and extended to the symmetry-plane case by Mulungye et al. (2015), we establish a curious property of this solution that was not observed in early studies: before but near singularity time, the blowup goes from a fast transient to a slower regime that is well resolved spectrally, even at mid-resolutions of $512^2.$ This late-time regime has an atypical spectrum: it is Gaussian rather than exponential in the wavenumbers. The analyticity-strip width decays to zero in a finite time, albeit so slowly that it remains well above the collocation-point scale for all simulation times $t < T^* - 10^{-9000}$, where $T^*$ is the singularity time. Reaching such a proximity to singularity time is not possible in the original temporal variable, because floating point double precision ($\\approx 10^{-16}$) creates a `machine-epsilon' barrier. Due to this limitation on the \\emph{original} independent variable, the mapped variables now provide an improved assessment of the relevant blowup quantities, crucially with acceptable accuracy at an unprecedented closeness to the singularity time: $T^*- t \\approx 10^{-140}.$

  17. Alignment of leading-edge and peak-picking time of arrival methods to obtain accurate source locations

    SciTech Connect

    Roussel-Dupre, R.; Symbalisty, E.; Fox, C.; and Vanderlinde, O.

    2009-08-01

    The location of a radiating source can be determined by time-tagging the arrival of the radiated signal at a network of spatially distributed sensors. The accuracy of this approach depends strongly on the particular time-tagging algorithm employed at each of the sensors. If different techniques are used across the network, then the time tags must be referenced to a common fiducial for maximum location accuracy. In this report we derive the time corrections needed to temporally align leading-edge, time-tagging techniques with peak-picking algorithms. We focus on broadband radio frequency (RF) sources, an ionospheric propagation channel, and narrowband receivers, but the final results can be generalized to apply to any source, propagation environment, and sensor. Our analytic results are checked against numerical simulations for a number of representative cases and agree with the specific leading-edge algorithm studied independently by Kim and Eng (1995) and Pongratz (2005 and 2007).

  18. Probability of Intrinsic Time-Arrow from Information Loss

    NASA Astrophysics Data System (ADS)

    Diósi, Lajos

    Time-arrow s=±, intrinsic to a concrete physical system, is associated with the direction of information loss I displayed by the random evolution of the given system. When the information loss tends to zero the intrinsic time-arrow becomes uncertain. We propose the heuristic relationship for the probability of the intrinsic time-arrow. The main parts of the present work are trying to confirm this heuristic equation. The probability of intrinsic time arrow is defined by Bayesian inference from the observed random process. From irreversible thermodynamic systems, the proposed heuristic probabilities follow via the Gallavotti-Cohen relations between time-reversed random processes. In order to explore the underlying microscopic mechanism, a trivial microscopic process is analyzed and an obvious discrepancy is identified. It can be resolved by quantum theory. The corresponding trivial quantum process will exactly confirm the proposed heuristic time-arrow probability.

  19. A rapid and accurate quantification method for real-time dynamic analysis of cellular lipids during microalgal fermentation processes in Chlorella protothecoides with low field nuclear magnetic resonance.

    PubMed

    Wang, Tao; Liu, Tingting; Wang, Zejian; Tian, Xiwei; Yang, Yi; Guo, Meijin; Chu, Ju; Zhuang, Yingping

    2016-05-01

    The rapid and real-time lipid determination can provide valuable information on process regulation and optimization in the algal lipid mass production. In this study, a rapid, accurate and precise quantification method of in vivo cellular lipids of Chlorella protothecoides using low field nuclear magnetic resonance (LF-NMR) was newly developed. LF-NMR was extremely sensitive to the algal lipids with the limits of the detection (LOD) of 0.0026g and 0.32g/L in dry lipid samples and algal broth, respectively, as well as limits of quantification (LOQ) of 0.0093g and 1.18g/L. Moreover, the LF-NMR signal was specifically proportional to the cellular lipids of C. protothecoides, thus the superior regression curves existing in a wide detection range from 0.02 to 0.42g for dry lipids and from 1.12 to 8.97gL(-1) of lipid concentration for in vivo lipid quantification were obtained with all R(2) higher than 0.99, irrespective of the lipid content and fatty acids profile variations. The accuracy of this novel method was further verified to be reliable by comparing lipid quantification results to those obtained by GC-MS. And the relative standard deviation (RSD) of LF-NMR results were smaller than 2%, suggesting the precision of this method. Finally, this method was successfully used in the on-line lipid monitoring during the algal lipid fermentation processes, making it possible for better understanding of the lipid accumulation mechanism and dynamic bioprocess control.

  20. Designing Information Measures for Real-time Lightcurve Classification

    NASA Astrophysics Data System (ADS)

    Jones, David Edward; Chen, Yang; Meng, Xiao-Li; Siemiginowska, Aneta; Kashyap, Vinay

    2016-01-01

    Since telescope time is limited, real-time lightcurve classification involves carefully selecting future time points at which sources must be observed in order to maximize the information that will be gained for classification. We propose a framework for constructing measures of information for testing/classification/model-selection and demonstrate their use in experimental design. Degroot (1962) developed a general framework for constructing Bayesian measures of the expected information that an experiment will provide for estimation, and our framework analogously constructs measures of information for hypothesis testing. Such test information measures are most useful for model selection and classification problems. Indeed, our framework suggests a probability based measure of test information, which in decision problems has more appealing properties than variance based measures. In the case of lightcurve classification, we adapt our designs to penalize long waits until the next observation time. Lastly, we consider ways to address other aspects of the problem, such as uncertainty estimation arising due to contamination from nearby contaminating sources or background diffuse emission. We acknowledge support from Smithsonian Competitive Grants Fund 40488100HH0043 and NSF grant DMS 1208791.

  1. Rényi’s information transfer between financial time series

    NASA Astrophysics Data System (ADS)

    Jizba, Petr; Kleinert, Hagen; Shefaat, Mohammad

    2012-05-01

    In this paper, we quantify the statistical coherence between financial time series by means of the Rényi entropy. With the help of Campbell’s coding theorem, we show that the Rényi entropy selectively emphasizes only certain sectors of the underlying empirical distribution while strongly suppressing others. This accentuation is controlled with Rényi’s parameter q. To tackle the issue of the information flow between time series, we formulate the concept of Rényi’s transfer entropy as a measure of information that is transferred only between certain parts of underlying distributions. This is particularly pertinent in financial time series, where the knowledge of marginal events such as spikes or sudden jumps is of a crucial importance. We apply the Rényian information flow to stock market time series from 11 world stock indices as sampled at a daily rate in the time period 02.01.1990-31.12.2009. Corresponding heat maps and net information flows are represented graphically. A detailed discussion of the transfer entropy between the DAX and S&P500 indices based on minute tick data gathered in the period 02.04.2008-11.09.2009 is also provided. Our analysis shows that the bivariate information flow between world markets is strongly asymmetric with a distinct information surplus flowing from the Asia-Pacific region to both European and US markets. An important yet less dramatic excess of information also flows from Europe to the US. This is particularly clearly seen from a careful analysis of Rényi information flow between the DAX and S&P500 indices.

  2. A non-contact method based on multiple signal classification algorithm to reduce the measurement time for accurately heart rate detection.

    PubMed

    Bechet, P; Mitran, R; Munteanu, M

    2013-08-01

    Non-contact methods for the assessment of vital signs are of great interest for specialists due to the benefits obtained in both medical and special applications, such as those for surveillance, monitoring, and search and rescue. This paper investigates the possibility of implementing a digital processing algorithm based on the MUSIC (Multiple Signal Classification) parametric spectral estimation in order to reduce the observation time needed to accurately measure the heart rate. It demonstrates that, by proper dimensioning the signal subspace, the MUSIC algorithm can be optimized in order to accurately assess the heart rate during an 8-28 s time interval. The validation of the processing algorithm performance was achieved by minimizing the mean error of the heart rate after performing simultaneous comparative measurements on several subjects. In order to calculate the error the reference value of heart rate was measured using a classic measurement system through direct contact.

  3. A non-contact method based on multiple signal classification algorithm to reduce the measurement time for accurately heart rate detection

    NASA Astrophysics Data System (ADS)

    Bechet, P.; Mitran, R.; Munteanu, M.

    2013-08-01

    Non-contact methods for the assessment of vital signs are of great interest for specialists due to the benefits obtained in both medical and special applications, such as those for surveillance, monitoring, and search and rescue. This paper investigates the possibility of implementing a digital processing algorithm based on the MUSIC (Multiple Signal Classification) parametric spectral estimation in order to reduce the observation time needed to accurately measure the heart rate. It demonstrates that, by proper dimensioning the signal subspace, the MUSIC algorithm can be optimized in order to accurately assess the heart rate during an 8-28 s time interval. The validation of the processing algorithm performance was achieved by minimizing the mean error of the heart rate after performing simultaneous comparative measurements on several subjects. In order to calculate the error the reference value of heart rate was measured using a classic measurement system through direct contact.

  4. Optimal Numerical Schemes for Time Accurate Compressible Large Eddy Simulations: Comparison of Artificial Dissipation and Filtering Schemes

    DTIC Science & Technology

    2014-11-01

    content (ie: low- pass response) 1) compare damping character of Artificial Dissipation and Filtering 2) formulate filter as an equivalent...Artificial Dissipation scheme - consequence of filter damping for stiff problems 3) insight on achieving “ideal” low- pass response for general...require very high order for low- pass response –  overly dissipative for small time-steps •  Implicit filters can be efficiently designed for low- pass

  5. Choice certainty is informed by both evidence and decision time.

    PubMed

    Kiani, Roozbeh; Corthell, Leah; Shadlen, Michael N

    2014-12-17

    "Degree of certainty" refers to the subjective belief, prior to feedback, that a decision is correct. A reliable estimate of certainty is essential for prediction, learning from mistakes, and planning subsequent actions when outcomes are not immediate. It is generally thought that certainty is informed by a neural representation of evidence at the time of a decision. Here we show that certainty is also informed by the time taken to form the decision. Human subjects reported simultaneously their choice and confidence about the direction of a noisy display of moving dots. Certainty was inversely correlated with reaction times and directly correlated with motion strength. Moreover, these correlations were preserved even for error responses, a finding that contradicts existing explanations of certainty based on signal detection theory. We also contrived a stimulus manipulation that led to longer decision times without affecting choice accuracy, thus demonstrating that deliberation time itself informs the estimate of certainty. We suggest that elapsed decision time informs certainty because it serves as a proxy for task difficulty.

  6. Choice certainty is informed by both evidence and decision time

    PubMed Central

    Kiani, Roozbeh; Corthell, Leah; Shadlen, Michael N.

    2014-01-01

    “Degree of certainty” refers to the subjective belief, prior to feedback, that a decision is correct. A reliable estimate of certainty is essential for prediction, learning from mistakes, and planning subsequent actions when outcomes are not immediate. It is generally thought that certainty is informed by a neural representation of evidence at the time of a decision. Here we show that certainty is also informed by the time taken to form the decision. Human subjects reported simultaneously their choice and confidence about the direction of a noisy display of moving dots. Certainty was inversely correlated with reaction times and directly correlated with motion strength. Moreover, these correlations were preserved even for error responses, a finding that contradicts existing explanations of certainty based on signal detection theory. We also contrived a stimulus manipulation that led to longer decision times without affecting choice accuracy, thus demonstrating that deliberation time itself informs the estimate of certainty. We suggest that elapsed decision time informs certainty because it serves as a proxy for task difficulty. PMID:25521381

  7. Wavelet analysis of molecular dynamics: efficient extraction of time-frequency information in ultrafast optical processes.

    PubMed

    Prior, Javier; Castro, Enrique; Chin, Alex W; Almeida, Javier; Huelga, Susana F; Plenio, Martin B

    2013-12-14

    New experimental techniques based on nonlinear ultrafast spectroscopies have been developed over the last few years, and have been demonstrated to provide powerful probes of quantum dynamics in different types of molecular aggregates, including both natural and artificial light harvesting complexes. Fourier transform-based spectroscopies have been particularly successful, yet "complete" spectral information normally necessitates the loss of all information on the temporal sequence of events in a signal. This information though is particularly important in transient or multi-stage processes, in which the spectral decomposition of the data evolves in time. By going through several examples of ultrafast quantum dynamics, we demonstrate that the use of wavelets provide an efficient and accurate way to simultaneously acquire both temporal and frequency information about a signal, and argue that this greatly aids the elucidation and interpretation of physical process responsible for non-stationary spectroscopic features, such as those encountered in coherent excitonic energy transport.

  8. Wavelet analysis of molecular dynamics: Efficient extraction of time-frequency information in ultrafast optical processes

    SciTech Connect

    Prior, Javier; Castro, Enrique; Chin, Alex W.; Almeida, Javier; Huelga, Susana F.; Plenio, Martin B.

    2013-12-14

    New experimental techniques based on nonlinear ultrafast spectroscopies have been developed over the last few years, and have been demonstrated to provide powerful probes of quantum dynamics in different types of molecular aggregates, including both natural and artificial light harvesting complexes. Fourier transform-based spectroscopies have been particularly successful, yet “complete” spectral information normally necessitates the loss of all information on the temporal sequence of events in a signal. This information though is particularly important in transient or multi-stage processes, in which the spectral decomposition of the data evolves in time. By going through several examples of ultrafast quantum dynamics, we demonstrate that the use of wavelets provide an efficient and accurate way to simultaneously acquire both temporal and frequency information about a signal, and argue that this greatly aids the elucidation and interpretation of physical process responsible for non-stationary spectroscopic features, such as those encountered in coherent excitonic energy transport.

  9. Relations between information, time, and value of water

    NASA Astrophysics Data System (ADS)

    Weijs, S. V.; Galindo, L. C.

    2015-12-01

    This research uses with stochastic dynamic programming (SDP) as a tool to reveal economic information about managed water resources. An application to the operation of an example hydropower reservoir is presented. SDP explicitly balances the marginal value of water for immediate use and its expected opportunity cost of not having more water available for future use. The result of an SDP analysis is a steady state policy, which gives the optimal decision as a function of the state. A commonly applied form gives the optimal release as a function of the month, current reservoir level and current inflow to the reservoir. The steady state policy can be complemented with a real-time management strategy, that can depend on more real-time information. An information-theoretical perspective is given on how this information influences the value of water, and how to deal with that influence in hydropower reservoir optimization. This results in some conjectures about how the information gain from real-time operation could affect the optimal long term policy. Another issue is the sharing of increased benefits that result from this information gain in a multi-objective setting. It is argued that this should be accounted for in negotiations about an operation policy.

  10. A Non-Dissipative Staggered Fourth-Order Accurate Explicit Finite Difference Scheme for the Time-Domain Maxwell's Equations

    NASA Technical Reports Server (NTRS)

    Yefet, Amir; Petropoulos, Peter G.

    1999-01-01

    We consider a divergence-free non-dissipative fourth-order explicit staggered finite difference scheme for the hyperbolic Maxwell's equations. Special one-sided difference operators are derived in order to implement the scheme near metal boundaries and dielectric interfaces. Numerical results show the scheme is long-time stable, and is fourth-order convergent over complex domains that include dielectric interfaces and perfectly conducting surfaces. We also examine the scheme's behavior near metal surfaces that are not aligned with the grid axes, and compare its accuracy to that obtained by the Yee scheme.

  11. Decision peptide-driven: a free software tool for accurate protein quantification using gel electrophoresis and matrix assisted laser desorption ionization time of flight mass spectrometry.

    PubMed

    Santos, Hugo M; Reboiro-Jato, Miguel; Glez-Peña, Daniel; Nunes-Miranda, J D; Fdez-Riverola, Florentino; Carvallo, R; Capelo, J L

    2010-09-15

    The decision peptide-driven tool implements a software application for assisting the user in a protocol for accurate protein quantification based on the following steps: (1) protein separation through gel electrophoresis; (2) in-gel protein digestion; (3) direct and inverse (18)O-labeling and (4) matrix assisted laser desorption ionization time of flight mass spectrometry, MALDI analysis. The DPD software compares the MALDI results of the direct and inverse (18)O-labeling experiments and quickly identifies those peptides with paralleled loses in different sets of a typical proteomic workflow. Those peptides are used for subsequent accurate protein quantification. The interpretation of the MALDI data from direct and inverse labeling experiments is time-consuming requiring a significant amount of time to do all comparisons manually. The DPD software shortens and simplifies the searching of the peptides that must be used for quantification from a week to just some minutes. To do so, it takes as input several MALDI spectra and aids the researcher in an automatic mode (i) to compare data from direct and inverse (18)O-labeling experiments, calculating the corresponding ratios to determine those peptides with paralleled losses throughout different sets of experiments; and (ii) allow to use those peptides as internal standards for subsequent accurate protein quantification using (18)O-labeling. In this work the DPD software is presented and explained with the quantification of protein carbonic anhydrase.

  12. Rapid and Accurate Identification by Real-Time PCR of Biotoxin-Producing Dinoflagellates from the Family Gymnodiniaceae

    PubMed Central

    Smith, Kirsty F.; de Salas, Miguel; Adamson, Janet; Rhodes, Lesley L.

    2014-01-01

    The identification of toxin-producing dinoflagellates for monitoring programmes and bio-compound discovery requires considerable taxonomic expertise. It can also be difficult to morphologically differentiate toxic and non-toxic species or strains. Various molecular methods have been used for dinoflagellate identification and detection, and this study describes the development of eight real-time polymerase chain reaction (PCR) assays targeting the large subunit ribosomal RNA (LSU rRNA) gene of species from the genera Gymnodinium, Karenia, Karlodinium, and Takayama. Assays proved to be highly specific and sensitive, and the assay for G. catenatum was further developed for quantification in response to a bloom in Manukau Harbour, New Zealand. The assay estimated cell densities from environmental samples as low as 0.07 cells per PCR reaction, which equated to three cells per litre. This assay not only enabled conclusive species identification but also detected the presence of cells below the limit of detection for light microscopy. This study demonstrates the usefulness of real-time PCR as a sensitive and rapid molecular technique for the detection and quantification of micro-algae from environmental samples. PMID:24608972

  13. An efficient and accurate approximation to time-dependent density functional theory for systems of weakly coupled monomers

    NASA Astrophysics Data System (ADS)

    Liu, Jie; Herbert, John M.

    2015-07-01

    A novel formulation of time-dependent density functional theory (TDDFT) is derived, based on non-orthogonal, absolutely-localized molecular orbitals (ALMOs). We call this approach TDDFT(MI), in reference to ALMO-based methods for describing molecular interactions (MI) that have been developed for ground-state applications. TDDFT(MI) is intended for efficient excited-state calculations in systems composed of multiple, weakly interacting chromophores. The efficiency is based upon (1) a local excitation approximation; (2) monomer-based, singly-excited basis states; (3) an efficient localization procedure; and (4) a one-step Davidson method to solve the TDDFT(MI) working equation. We apply this methodology to study molecular dimers, water clusters, solvated chromophores, and aggregates of naphthalene diimide that form the building blocks of self-assembling organic nanotubes. Absolute errors of 0.1-0.3 eV with respect to supersystem methods are achievable for these systems, especially for cases involving an excited chromophore that is weakly coupled to several explicit solvent molecules. Excited-state calculations in an aggregate of nine naphthalene diimide monomers are ˜40 times faster than traditional TDDFT calculations.

  14. An efficient and accurate approximation to time-dependent density functional theory for systems of weakly coupled monomers.

    PubMed

    Liu, Jie; Herbert, John M

    2015-07-21

    A novel formulation of time-dependent density functional theory (TDDFT) is derived, based on non-orthogonal, absolutely-localized molecular orbitals (ALMOs). We call this approach TDDFT(MI), in reference to ALMO-based methods for describing molecular interactions (MI) that have been developed for ground-state applications. TDDFT(MI) is intended for efficient excited-state calculations in systems composed of multiple, weakly interacting chromophores. The efficiency is based upon (1) a local excitation approximation; (2) monomer-based, singly-excited basis states; (3) an efficient localization procedure; and (4) a one-step Davidson method to solve the TDDFT(MI) working equation. We apply this methodology to study molecular dimers, water clusters, solvated chromophores, and aggregates of naphthalene diimide that form the building blocks of self-assembling organic nanotubes. Absolute errors of 0.1-0.3 eV with respect to supersystem methods are achievable for these systems, especially for cases involving an excited chromophore that is weakly coupled to several explicit solvent molecules. Excited-state calculations in an aggregate of nine naphthalene diimide monomers are ∼40 times faster than traditional TDDFT calculations.

  15. Time and Category Information in Pattern-Based Codes

    PubMed Central

    Eyherabide, Hugo Gabriel; Samengo, Inés

    2010-01-01

    Sensory stimuli are usually composed of different features (the what) appearing at irregular times (the when). Neural responses often use spike patterns to represent sensory information. The what is hypothesized to be encoded in the identity of the elicited patterns (the pattern categories), and the when, in the time positions of patterns (the pattern timing). However, this standard view is oversimplified. In the real world, the what and the when might not be separable concepts, for instance, if they are correlated in the stimulus. In addition, neuronal dynamics can condition the pattern timing to be correlated with the pattern categories. Hence, timing and categories of patterns may not constitute independent channels of information. In this paper, we assess the role of spike patterns in the neural code, irrespective of the nature of the patterns. We first define information-theoretical quantities that allow us to quantify the information encoded by different aspects of the neural response. We also introduce the notion of synergy/redundancy between time positions and categories of patterns. We subsequently establish the relation between the what and the when in the stimulus with the timing and the categories of patterns. To that aim, we quantify the mutual information between different aspects of the stimulus and different aspects of the response. This formal framework allows us to determine the precise conditions under which the standard view holds, as well as the departures from this simple case. Finally, we study the capability of different response aspects to represent the what and the when in the neural response. PMID:21151371

  16. Towards Efficient and Accurate Description of Many-Electron Problems: Developments of Static and Time-Dependent Electronic Structure Methods

    NASA Astrophysics Data System (ADS)

    Ding, Feizhi

    Understanding electronic behavior in molecular and nano-scale systems is fundamental to the development and design of novel technologies and materials for application in a variety of scientific contexts from fundamental research to energy conversion. This dissertation aims to provide insights into this goal by developing novel methods and applications of first-principle electronic structure theory. Specifically, we will present new methods and applications of excited state multi-electron dynamics based on the real-time (RT) time-dependent Hartree-Fock (TDHF) and time-dependent density functional theory (TDDFT) formalism, and new development of the multi-configuration self-consist field theory (MCSCF) for modeling ground-state electronic structure. The RT-TDHF/TDDFT based developments and applications can be categorized into three broad and coherently integrated research areas: (1) modeling of the interaction between moleculars and external electromagnetic perturbations. In this part we will first prove both analytically and numerically the gauge invariance of the TDHF/TDDFT formalisms, then we will present a novel, efficient method for calculating molecular nonlinear optical properties, and last we will study quantum coherent plasmon in metal namowires using RT-TDDFT; (2) modeling of excited-state charge transfer in molecules. In this part, we will investigate the mechanisms of bridge-mediated electron transfer, and then we will introduce a newly developed non-equilibrium quantum/continuum embedding method for studying charge transfer dynamics in solution; (3) developments of first-principles spin-dependent many-electron dynamics. In this part, we will present an ab initio non-relativistic spin dynamics method based on the two-component generalized Hartree-Fock approach, and then we will generalized it to the two-component TDDFT framework and combine it with the Ehrenfest molecular dynamics approach for modeling the interaction between electron spins and nuclear

  17. Accurate Ground-State Energies of Solids and Molecules from Time-Dependent Density-Functional Theory

    NASA Astrophysics Data System (ADS)

    Olsen, Thomas; Thygesen, Kristian S.

    2014-05-01

    We demonstrate that ground-state energies approaching chemical accuracy can be obtained by combining the adiabatic-connection fluctuation-dissipation theorem with time-dependent density-functional theory. The key ingredient is a renormalization scheme, which eliminates the divergence of the correlation hole characteristic of any local kernel. This new class of renormalized kernels gives a significantly better description of the short-range correlations in covalent bonds compared to the random phase approximation (RPA) and yields a fourfold improvement of RPA binding energies in both molecules and solids. We also consider examples of barrier heights in chemical reactions, molecular adsorption, and graphene interacting with metal surfaces, which are three examples where the RPA has been successful. In these cases, the renormalized kernel provides results that are of equal quality or even slightly better than the RPA, with a similar computational cost.

  18. Toward Dynamic Real-Time Informative Warning Systems

    NASA Astrophysics Data System (ADS)

    Pahle, Robert; Ozel, Filiz

    A great deal of research has been done to improve safety in the built environment. Disaster preparedness plans have been developed for a variety of situations; however, these plans often fail to convey sufficient information flow to the target audience. The literature discusses a variety of arguments that both support and limit giving information to the target audience. One of the arguments for limiting information is the assumption that people could panic and increase the difficulties at hand. Yet, a literature search for this paper indicates that target audience panics only in very rare situations. Furthermore, it shows that most people seek information about the event and that they actually try to make good decisions to ensure their survival. A system that could bring information to persons during an emergency could therefore address a variety of decision-making challenges in these tense situations. The handling of information could encompass a variety of scales: from national to urban to building scale. This paper looks into the realm of dynamic, real-time informative warning systems that deliver information to occupants of buildings during emergencies. It builds on a cognitive model for navigation in the built environment. A theoretical approach for the design of the warning message is discussed. Since this is an ongoing research project, only the results of the initial assessment will be presented here.

  19. Psychological time as information: the case of boredom†

    PubMed Central

    Zakay, Dan

    2014-01-01

    The flow of time is experienced by humans although the exact nature of time is not well understood. The importance of time in humans’ life is not in dispute and is reflected by several dimensions like duration, which is best representing the naïve meaning of time. Psychological time serves several important functions which are essential for being able to act and survive in a dynamic environment. In the present paper we argue that psychological time in the form of sensing the pace of the flow of time provides important information to the executive system which control and monitor behavior. When information processing load is below an optimal level for a specific Individual a feeling of boredom is raised. Boredom is accompanied by a slowing of the felt pace of the flow of time. Boredom is a unique mental state which is linked with decreasing efficiency in cognitive and perceptual performance and is correlated with low job satisfaction and general well-being. As such, boredom poses a threat to normal functioning. We suggest that the felt slowing in the flow of time is a signal which, similarly to pain, is aimed at alerting the executive system that resources should be recruited in order to cope with the hazardous state. PMID:25191296

  20. DELIVERING TIMELY ENVIRONMENTAL INFORMATION TO YOUR COMMUNITY: THE BOULDER AREA SUSTAINABILITY INFORMATION NETWORK: OTHER

    EPA Science Inventory

    NRMRL-CIN-1577 Petersen*, D., Barber, L., Dilworth, G, Fiebelkorn, T., McCaffrey, M., Murphy, S., Rudkin, C., Scott, D., and Waterman, J. Delivering Timely Environmental Information to your Community: The Boulder Area Sustainability Information Network. EPA/625/C-01/010. The Te...

  1. ACCURATE TIME-DEPENDENT WAVE PACKET STUDY OF THE H{sup +}+LiH REACTION AT EARLY UNIVERSE CONDITIONS

    SciTech Connect

    Aslan, E.; Bulut, N.; Castillo, J. F.; Banares, L.; Aoiz, F. J.; Roncero, O.

    2012-11-01

    The dynamics and kinetics of the H{sup +} + LiH reaction have been studied using a quantum reactive time-dependent wave packet (TDWP) coupled-channel quantum mechanical method on an ab initio potential energy surface at conditions of the early universe. The total reaction probabilities for the H{sup +} + LiH(v = 0, j = 0) {yields} H{sup +} {sub 2} + Li process have been calculated from 5 Multiplication-Sign 10{sup -3} eV up to 1 eV for total angular momenta J from 0 to 110. Using a Langevin model, integral cross sections have been calculated in that range of collision energies and extrapolated for energies below 5 Multiplication-Sign 10{sup -3} eV. The calculated rate constants are found to be nearly independent of temperature in the 10-1000 K interval with a value of Almost-Equal-To 10{sup -9} cm{sup 3} s{sup -1}, which is in good agreement with estimates used in evolutionary models of the early universe lithium chemistry.

  2. Improved hybrid information filtering based on limited time window

    NASA Astrophysics Data System (ADS)

    Song, Wen-Jun; Guo, Qiang; Liu, Jian-Guo

    2014-12-01

    Adopting the entire collecting information of users, the hybrid information filtering of heat conduction and mass diffusion (HHM) (Zhou et al., 2010) was successfully proposed to solve the apparent diversity-accuracy dilemma. Since the recent behaviors are more effective to capture the users' potential interests, we present an improved hybrid information filtering of adopting the partial recent information. We expand the time window to generate a series of training sets, each of which is treated as known information to predict the future links proven by the testing set. The experimental results on one benchmark dataset Netflix indicate that by only using approximately 31% recent rating records, the accuracy could be improved by an average of 4.22% and the diversity could be improved by 13.74%. In addition, the performance on the dataset MovieLens could be preserved by considering approximately 60% recent records. Furthermore, we find that the improved algorithm is effective to solve the cold-start problem. This work could improve the information filtering performance and shorten the computational time.

  3. [Real time information. A necessary tool in epidemiological surveillance].

    PubMed

    González Morán, Francisco; Muñoz Criado, Isabel; Vanaclocha, Hermelinda

    2008-01-01

    Since 2004 an electronic epidemiological surveillance system (AVE) has been developed and implemented for infectious diseases in the autonomous region of Valencia that allows data collection from notifiable diseases in real time concerning outbreaks and alerts, as well as analysis and dissemination of the information. Within the autonomous region of Valencia, the system is used by 17 epidemiology units, which act as the first level of specialized surveillance. The electronic surveillance system is used by all these units, as well as by physicians working in primary and specialized care, who can introduce information from the ambulatory information system while the patient is in the practice room. The system is able to capture the demographic data from the patient and the physician can add any other information that is considered important for the case detected. The system receives new laboratory test results overnight from the Microbiological Surveillance Network (RedMIVA). AVE can record outbreaks of notifiable diseases as well as any unusual clusters or changing patterns of any disease. The department of epidemiology has access to the whole system for analysis of the information and for quality control of the epidemiological surveillance. The system provides timely and comprehensive information to facilitate public health action in individual cases of infectious disease.

  4. Determination of the presence or absence of sulfur materials in drywall using direct analysis in real time in conjunction with an accurate-mass time-of-flight mass spectrometer.

    PubMed

    Curtis, Matthew E; Jones, Patrick R; Sparkman, O David; Cody, Robert B

    2009-11-01

    Based on the concern about the presence of sulfur materials being in drywall (wallboard), a quick and reliable test to confirm the presence or absence of these materials using direct analysis in real time (DART) mass spectrometry in conjunction with an accurate-mass time-of-flight (TOF) mass spectrometer has been developed and is described here.

  5. 75 FR 68418 - Real-Time System Management Information Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-08

    ... comment (or signing the comment, if submitted on behalf of an association, business, or labor union). You... technology-dependent application, or any particular business approach for establishing a real-time... technology, technology- dependent application, and business approach options that yield information...

  6. Practical measures of integrated information for time-series data.

    PubMed

    Barrett, Adam B; Seth, Anil K

    2011-01-20

    A recent measure of 'integrated information', Φ(DM), quantifies the extent to which a system generates more information than the sum of its parts as it transitions between states, possibly reflecting levels of consciousness generated by neural systems. However, Φ(DM) is defined only for discrete Markov systems, which are unusual in biology; as a result, Φ(DM) can rarely be measured in practice. Here, we describe two new measures, Φ(E) and Φ(AR), that overcome these limitations and are easy to apply to time-series data. We use simulations to demonstrate the in-practice applicability of our measures, and to explore their properties. Our results provide new opportunities for examining information integration in real and model systems and carry implications for relations between integrated information, consciousness, and other neurocognitive processes. However, our findings pose challenges for theories that ascribe physical meaning to the measured quantities.

  7. Extracting Low-Frequency Information from Time Attenuation in Elastic Waveform Inversion

    NASA Astrophysics Data System (ADS)

    Guo, Xuebao; Liu, Hong; Shi, Ying; Wang, Weihong

    2017-03-01

    Low-frequency information is crucial for recovering background velocity, but the lack of low-frequency information in field data makes inversion impractical without accurate initial models. Laplace-Fourier domain waveform inversion can recover a smooth model from real data without low-frequency information, which can be used for subsequent inversion as an ideal starting model. In general, it also starts with low frequencies and includes higher frequencies at later inversion stages, while the difference is that its ultralow frequency information comes from the Laplace-Fourier domain. Meanwhile, a direct implementation of the Laplace-transformed wavefield using frequency domain inversion is also very convenient. However, because broad frequency bands are often used in the pure time domain waveform inversion, it is difficult to extract the wavefields dominated by low frequencies in this case. In this paper, low-frequency components are constructed by introducing time attenuation into the recorded residuals, and the rest of the method is identical to the traditional time domain inversion. Time windowing and frequency filtering are also applied to mitigate the ambiguity of the inverse problem. Therefore, we can start at low frequencies and to move to higher frequencies. The experiment shows that the proposed method can achieve a good inversion result in the presence of a linear initial model and records without low-frequency information.

  8. Children’s Processing and Comprehension of Complex Sentences Containing Temporal Connectives: The Influence of Memory on the Time Course of Accurate Responses

    PubMed Central

    2016-01-01

    In a touch-screen paradigm, we recorded 3- to 7-year-olds’ (N = 108) accuracy and response times (RTs) to assess their comprehension of 2-clause sentences containing before and after. Children were influenced by order: performance was most accurate when the presentation order of the 2 clauses matched the chronological order of events: “She drank the juice, before she walked in the park” (chronological order) versus “Before she walked in the park, she drank the juice” (reverse order). Differences in RTs for correct responses varied by sentence type: accurate responses were made more speedily for sentences that afforded an incremental processing of meaning. An independent measure of memory predicted this pattern of performance. We discuss these findings in relation to children’s knowledge of connective meaning and the processing requirements of sentences containing temporal connectives. PMID:27690492

  9. An Advanced Real-Time Earthquake Information System in Japan

    NASA Astrophysics Data System (ADS)

    Takahashi, I.; Nakamura, H.; Suzuki, W.; Kunugi, T.; Aoi, S.; Fujiwara, H.

    2015-12-01

    J-RISQ (Japan Real-time Information System for earthquake) has been developing in NIED for appropriate first-actions to big earthquakes. When an earthquake occurs, seismic intensities (SI) are calculated first at each observation station and sent to the Data Management Center in different timing. The system begins the first estimation when the number of the stations observing the SI of 2.5 or larger exceeds the threshold amount. It estimates SI distribution, exposed population and earthquake damage on buildings by using basic data for estimation, such as subsurface amplification factors, population, and building information. It has been accumulated in J-SHIS (Japan Seismic Information Station) developed by NIED, a public portal for seismic hazard information across Japan. The series of the estimation is performed for each 250m square mesh and finally the estimated data is converted into information for each municipality. Since October 2013, we have opened estimated SI, exposed population etc. to the public through the website by making full use of maps and tables.In the previous system, we sometimes could not inspect the information of the surrounding areas out of the range suffered from strong motions, or the details of the focusing areas, and could not confirm whether the present information was the latest or not without accessing the website. J-RISQ has been advanced by introducing the following functions to settle those problems and promote utilization in local areas or in personal levels. In addition, the website in English has been released.・It has become possible to focus on the specific areas and inspect enlarged information.・The estimated information can be downloaded in the form of KML.・The estimated information can be updated automatically and be provided as the latest one.・The newest information can be inspected by using RSS readers or browsers corresponding to RSS.・Exclusive pages for smartphones have been prepared.The information estimated

  10. Time series characterization via horizontal visibility graph and Information Theory

    NASA Astrophysics Data System (ADS)

    Gonçalves, Bruna Amin; Carpi, Laura; Rosso, Osvaldo A.; Ravetti, Martín G.

    2016-12-01

    Complex networks theory have gained wider applicability since methods for transformation of time series to networks were proposed and successfully tested. In the last few years, horizontal visibility graph has become a popular method due to its simplicity and good results when applied to natural and artificially generated data. In this work, we explore different ways of extracting information from the network constructed from the horizontal visibility graph and evaluated by Information Theory quantifiers. Most works use the degree distribution of the network, however, we found alternative probability distributions, more efficient than the degree distribution in characterizing dynamical systems. In particular, we find that, when using distributions based on distances and amplitude values, significant shorter time series are required. We analyze fractional Brownian motion time series, and a paleoclimatic proxy record of ENSO from the Pallcacocha Lake to study dynamical changes during the Holocene.

  11. Financial time series analysis based on information categorization method

    NASA Astrophysics Data System (ADS)

    Tian, Qiang; Shang, Pengjian; Feng, Guochen

    2014-12-01

    The paper mainly applies the information categorization method to analyze the financial time series. The method is used to examine the similarity of different sequences by calculating the distances between them. We apply this method to quantify the similarity of different stock markets. And we report the results of similarity in US and Chinese stock markets in periods 1991-1998 (before the Asian currency crisis), 1999-2006 (after the Asian currency crisis and before the global financial crisis), and 2007-2013 (during and after global financial crisis) by using this method. The results show the difference of similarity between different stock markets in different time periods and the similarity of the two stock markets become larger after these two crises. Also we acquire the results of similarity of 10 stock indices in three areas; it means the method can distinguish different areas' markets from the phylogenetic trees. The results show that we can get satisfactory information from financial markets by this method. The information categorization method can not only be used in physiologic time series, but also in financial time series.

  12. Autonomous Information Fading and Provision to Achieve High Response Time in Distributed Information Systems

    NASA Astrophysics Data System (ADS)

    Lu, Xiaodong; Arfaoui, Helene; Mori, Kinji

    In highly dynamic electronic commerce environment, the need for adaptability and rapid response time to information service systems has become increasingly important. In order to cope with the continuously changing conditions of service provision and utilization, Faded Information Field (FIF) has been proposed. FIF is a distributed information service system architecture, sustained by push/pull mobile agents to bring high-assurance of services through a recursive demand-oriented provision of the most popular information closer to the users to make a tradeoff between the cost of information service allocation and access. In this paper, based on the analysis of the relationship that exists among the users distribution, information provision and access time, we propose the technology for FIF design to resolve the competing requirements of users and providers to improve users' access time. In addition, to achieve dynamic load balancing with changing users preference, the autonomous information reallocation technology is proposed. We proved the effectiveness of the proposed technology through the simulation and comparison with the conventional system.

  13. SU-D-18C-05: Variable Bolus Arterial Spin Labeling MRI for Accurate Cerebral Blood Flow and Arterial Transit Time Mapping

    SciTech Connect

    Johnston, M; Jung, Y

    2014-06-01

    Purpose: Arterial spin labeling (ASL) is an MRI perfusion imaging method from which quantitative cerebral blood flow (CBF) maps can be calculated. Acquisition with variable post-labeling delays (PLD) and variable TRs allows for arterial transit time (ATT) mapping and leads to more accurate CBF quantification with a scan time saving of 48%. In addition, T1 and M0 maps can be obtained without a separate scan. In order to accurately estimate ATT and T1 of brain tissue from the ASL data, variable labeling durations were invented, entitled variable-bolus ASL. Methods: All images were collected on a healthy subject with a 3T Siemens Skyra scanner. Variable-bolus Psuedo-continuous ASL (PCASL) images were collected with 7 TI times ranging 100-4300ms in increments of 700ms with TR ranging 1000-5200ms. All boluses were 1600ms when the TI allowed, otherwise the bolus duration was 100ms shorter than the TI. All TI times were interleaved to reduce sensitivity to motion. Voxel-wise T1 and M0 maps were estimated using a linear least squares fitting routine from the average singal from each TI time. Then pairwise subtraction of each label/control pair and averaging for each TI time was performed. CBF and ATT maps were created using the standard model by Buxton et al. with a nonlinear fitting routine using the T1 tissue map. Results: CBF maps insensitive to ATT were produced along with ATT maps. Both maps show patterns and averages consistent with literature. The T1 map also shows typical T1 contrast. Conclusion: It has been demonstrated that variablebolus ASL produces CBF maps free from the errors due to ATT and tissue T1 variations and provides M0, T1, and ATT maps which have potential utility. This is accomplished with a single scan in a feasible scan time (under 6 minutes) with low sensivity to motion.

  14. Argon Cluster Sputtering Source for ToF-SIMS Depth Profiling of Insulating Materials: High Sputter Rate and Accurate Interfacial Information.

    PubMed

    Wang, Zhaoying; Liu, Bingwen; Zhao, Evan W; Jin, Ke; Du, Yingge; Neeway, James J; Ryan, Joseph V; Hu, Dehong; Zhang, Kelvin H L; Hong, Mina; Le Guernic, Solenne; Thevuthasan, Suntharampilai; Wang, Fuyi; Zhu, Zihua

    2015-08-01

    The use of an argon cluster ion sputtering source has been demonstrated to perform superiorly relative to traditional oxygen and cesium ion sputtering sources for ToF-SIMS depth profiling of insulating materials. The superior performance has been attributed to effective alleviation of surface charging. A simulated nuclear waste glass (SON68) and layered hole-perovskite oxide thin films were selected as model systems because of their fundamental and practical significance. Our results show that high sputter rates and accurate interfacial information can be achieved simultaneously for argon cluster sputtering, whereas this is not the case for cesium and oxygen sputtering. Therefore, the implementation of an argon cluster sputtering source can significantly improve the analysis efficiency of insulating materials and, thus, can expand its applications to the study of glass corrosion, perovskite oxide thin film characterization, and many other systems of interest.

  15. Wave-Based Turing Machine: Time Reversal and Information Erasing.

    PubMed

    Perrard, S; Fort, E; Couder, Y

    2016-08-26

    The investigation of dynamical systems has revealed a deep-rooted difference between waves and objects regarding temporal reversibility and particlelike objects. In nondissipative chaos, the dynamic of waves always remains time reversible, unlike that of particles. Here, we explore the dynamics of a wave-particle entity. It consists in a drop bouncing on a vibrated liquid bath, self-propelled and piloted by the surface waves it generates. This walker, in which there is an information exchange between the particle and the wave, can be analyzed in terms of a Turing machine with waves as the information repository. The experiments reveal that in this system, the drop can read information backwards while erasing it. The drop can thus backtrack on its previous trajectory. A transient temporal reversibility, restricted to the drop motion, is obtained in spite of the system being both dissipative and chaotic.

  16. Judging the Probability of Hypotheses Versus the Impact of Evidence: Which Form of Inductive Inference Is More Accurate and Time-Consistent?

    PubMed

    Tentori, Katya; Chater, Nick; Crupi, Vincenzo

    2016-04-01

    Inductive reasoning requires exploiting links between evidence and hypotheses. This can be done focusing either on the posterior probability of the hypothesis when updated on the new evidence or on the impact of the new evidence on the credibility of the hypothesis. But are these two cognitive representations equally reliable? This study investigates this question by comparing probability and impact judgments on the same experimental materials. The results indicate that impact judgments are more consistent in time and more accurate than probability judgments. Impact judgments also predict the direction of errors in probability judgments. These findings suggest that human inductive reasoning relies more on estimating evidential impact than on posterior probability.

  17. SnowyOwl: accurate prediction of fungal genes by using RNA-Seq and homology information to select among ab initio models

    PubMed Central

    2014-01-01

    Background Locating the protein-coding genes in novel genomes is essential to understanding and exploiting the genomic information but it is still difficult to accurately predict all the genes. The recent availability of detailed information about transcript structure from high-throughput sequencing of messenger RNA (RNA-Seq) delineates many expressed genes and promises increased accuracy in gene prediction. Computational gene predictors have been intensively developed for and tested in well-studied animal genomes. Hundreds of fungal genomes are now or will soon be sequenced. The differences of fungal genomes from animal genomes and the phylogenetic sparsity of well-studied fungi call for gene-prediction tools tailored to them. Results SnowyOwl is a new gene prediction pipeline that uses RNA-Seq data to train and provide hints for the generation of Hidden Markov Model (HMM)-based gene predictions and to evaluate the resulting models. The pipeline has been developed and streamlined by comparing its predictions to manually curated gene models in three fungal genomes and validated against the high-quality gene annotation of Neurospora crassa; SnowyOwl predicted N. crassa genes with 83% sensitivity and 65% specificity. SnowyOwl gains sensitivity by repeatedly running the HMM gene predictor Augustus with varied input parameters and selectivity by choosing the models with best homology to known proteins and best agreement with the RNA-Seq data. Conclusions SnowyOwl efficiently uses RNA-Seq data to produce accurate gene models in both well-studied and novel fungal genomes. The source code for the SnowyOwl pipeline (in Python) and a web interface (in PHP) is freely available from http://sourceforge.net/projects/snowyowl/. PMID:24980894

  18. Accurate molecular dynamics and nuclear quantum effects at low cost by multiple steps in real and imaginary time: Using density functional theory to accelerate wavefunction methods

    NASA Astrophysics Data System (ADS)

    Kapil, V.; VandeVondele, J.; Ceriotti, M.

    2016-02-01

    The development and implementation of increasingly accurate methods for electronic structure calculations mean that, for many atomistic simulation problems, treating light nuclei as classical particles is now one of the most serious approximations. Even though recent developments have significantly reduced the overhead for modeling the quantum nature of the nuclei, the cost is still prohibitive when combined with advanced electronic structure methods. Here we present how multiple time step integrators can be combined with ring-polymer contraction techniques (effectively, multiple time stepping in imaginary time) to reduce virtually to zero the overhead of modelling nuclear quantum effects, while describing inter-atomic forces at high levels of electronic structure theory. This is demonstrated for a combination of MP2 and semi-local DFT applied to the Zundel cation. The approach can be seamlessly combined with other methods to reduce the computational cost of path integral calculations, such as high-order factorizations of the Boltzmann operator or generalized Langevin equation thermostats.

  19. Accurate molecular dynamics and nuclear quantum effects at low cost by multiple steps in real and imaginary time: Using density functional theory to accelerate wavefunction methods

    SciTech Connect

    Kapil, V.; Ceriotti, M.; VandeVondele, J.

    2016-02-07

    The development and implementation of increasingly accurate methods for electronic structure calculations mean that, for many atomistic simulation problems, treating light nuclei as classical particles is now one of the most serious approximations. Even though recent developments have significantly reduced the overhead for modeling the quantum nature of the nuclei, the cost is still prohibitive when combined with advanced electronic structure methods. Here we present how multiple time step integrators can be combined with ring-polymer contraction techniques (effectively, multiple time stepping in imaginary time) to reduce virtually to zero the overhead of modelling nuclear quantum effects, while describing inter-atomic forces at high levels of electronic structure theory. This is demonstrated for a combination of MP2 and semi-local DFT applied to the Zundel cation. The approach can be seamlessly combined with other methods to reduce the computational cost of path integral calculations, such as high-order factorizations of the Boltzmann operator or generalized Langevin equation thermostats.

  20. Phylogenetic informativeness reconciles ray-finned fish molecular divergence times

    PubMed Central

    2014-01-01

    Background Discordance among individual molecular age estimates, or between molecular age estimates and the fossil record, is observed in many clades across the Tree of Life. This discordance is attributed to a variety of variables including calibration age uncertainty, calibration placement, nucleotide substitution rate heterogeneity, or the specified molecular clock model. However, the impact of changes in phylogenetic informativeness of individual genes over time on phylogenetic inferences is rarely analyzed. Using nuclear and mitochondrial sequence data for ray-finned fishes (Actinopterygii) as an example, we extend the utility of phylogenetic informativeness profiles to predict the time intervals when nucleotide substitution saturation results in discordance among molecular ages estimated. Results We demonstrate that even with identical calibration regimes and molecular clock methods, mitochondrial based molecular age estimates are systematically older than those estimated from nuclear sequences. This discordance is most severe for highly nested nodes corresponding to more recent (i.e., Jurassic-Recent) divergences. By removing data deemed saturated, we reconcile the competing age estimates and highlight that the older mtDNA based ages were driven by nucleotide saturation. Conclusions Homoplasious site patterns in a DNA sequence alignment can systematically bias molecular divergence time estimates. Our study demonstrates that PI profiles can provide a non-arbitrary criterion for data exclusion to mitigate the influence of homoplasy on time calibrated branch length estimates. Analyses of actinopterygian molecular clocks demonstrate that scrutiny of the time scale on which sequence data is informative is a fundamental, but generally overlooked, step in molecular divergence time estimation. PMID:25103329

  1. Modelling the world in real time: how robots engineer information.

    PubMed

    Davison, Andrew J

    2003-12-15

    Programming robots and other autonomous systems to interact with the world in real time is bringing into sharp focus general questions about representation, inference and understanding. These artificial agents use digital computation to interpret the data gleaned from sensors and produce decisions and actions to guide their future behaviour. In a physical system, however, finite computational resources unavoidably impose the need to approximate and make selective use of the information available to reach prompt deductions. Recent research has led to widespread adoption of the methodology of Bayesian inference, which provides the absolute framework to understand this process fully via modelling as informed, fully acknowledged approximation. The performance of modern systems has improved greatly on the heuristic methods of the early days of artificial intelligence. We discuss the general problem of real-time inference and computation, and draw on examples from recent research in computer vision and robotics: specifically visual tracking and simultaneous localization and mapping.

  2. Spike timing and information transmission at retinogeniculate synapses

    PubMed Central

    Rathbun, Daniel L.; Warland, David K.; Usrey, W. Martin

    2010-01-01

    This study examines the rules governing the transfer of spikes between the retina and LGN with the goal of determining whether the most informative retinal spikes preferentially drive LGN responses and what role spike timing plays in the process. By recording from monosynaptically-connected pairs of retinal ganglion cells and LGN neurons in vivo in the cat, we show that relayed spikes are more likely than non-relayed spikes to be evoked by stimuli that match the recorded cells’ receptive fields and that an interspike interval (ISI)-based mechanism contributes to the process. Relayed spikes are also more reliable in their timing and number where they often achieve the theoretical limit of minimum variance. As a result, relayed spikes carry more visual information per spike. Based on these results, we conclude that retinogeniculate processing increases sparseness in the neural code by selectively relaying the highest fidelity spikes to the visual cortex. PMID:20943897

  3. Rapid and accurate identification of Mycobacterium tuberculosis complex and common non-tuberculous mycobacteria by multiplex real-time PCR targeting different housekeeping genes.

    PubMed

    Nasr Esfahani, Bahram; Rezaei Yazdi, Hadi; Moghim, Sharareh; Ghasemian Safaei, Hajieh; Zarkesh Esfahani, Hamid

    2012-11-01

    Rapid and accurate identification of mycobacteria isolates from primary culture is important due to timely and appropriate antibiotic therapy. Conventional methods for identification of Mycobacterium species based on biochemical tests needs several weeks and may remain inconclusive. In this study, a novel multiplex real-time PCR was developed for rapid identification of Mycobacterium genus, Mycobacterium tuberculosis complex (MTC) and the most common non-tuberculosis mycobacteria species including M. abscessus, M. fortuitum, M. avium complex, M. kansasii, and the M. gordonae in three reaction tubes but under same PCR condition. Genetic targets for primer designing included the 16S rDNA gene, the dnaJ gene, the gyrB gene and internal transcribed spacer (ITS). Multiplex real-time PCR was setup with reference Mycobacterium strains and was subsequently tested with 66 clinical isolates. Results of multiplex real-time PCR were analyzed with melting curves and melting temperature (T (m)) of Mycobacterium genus, MTC, and each of non-tuberculosis Mycobacterium species were determined. Multiplex real-time PCR results were compared with amplification and sequencing of 16S-23S rDNA ITS for identification of Mycobacterium species. Sensitivity and specificity of designed primers were each 100 % for MTC, M. abscessus, M. fortuitum, M. avium complex, M. kansasii, and M. gordonae. Sensitivity and specificity of designed primer for genus Mycobacterium was 96 and 100 %, respectively. According to the obtained results, we conclude that this multiplex real-time PCR with melting curve analysis and these novel primers can be used for rapid and accurate identification of genus Mycobacterium, MTC, and the most common non-tuberculosis Mycobacterium species.

  4. Performances and recent evolutions of EMSC Real Time Information services

    NASA Astrophysics Data System (ADS)

    Mazet-Roux, G.; Godey, S.; Bossu, R.

    2009-04-01

    The EMSC (http://www.emsc-csem.org) operates Real Time Earthquake Information services for the public and the scientific community which aim at providing rapid and reliable information on the seismic-ity of the Euro-Mediterranean region and on significant earthquakes worldwide. These services are based on parametric data rapidly provided by 66 seismological networks which are automatically merged and processed at EMSC. A web page which is updated every minute displays a list and a map of the latest earthquakes as well as additional information like location maps, moment tensors solutions or past regional seismicity. Since 2004, the performances and the popularity of these services have dramatically increased. The number of messages received from the contributors and the number of published events have been multiplied by 2 since 2004 and by 1.6 since 2005 respectively. The web traffic and the numbers of users of the Earthquake Notification Service (ENS) have been multiplied by 15 and 7 respectively. In terms of performances of the ENS, the median dissemination time for Euro-Med events is minutes in 2008. In order to further improve its performances and especially the speed and robustness of the reception of real time data, EMSC has recently implemented a software named QWIDS (Quake Watch Information Distribution System) which provides a quick and robust data exchange system through permanent TCP connections. At the difference with emails that can sometimes be delayed or lost, QWIDS is an actual real time communication system that ensures the data delivery. In terms of hardware, EMSC imple-mented a high availability, dynamic load balancing, redundant and scalable web servers infrastructure, composed of two SUN T2000 and one F5 BIG-IP switch. This will allow coping with constantly increas-ing web traffic and the occurrence of huge peaks of traffic after widely felt earthquakes.

  5. How a fly photoreceptor samples light information in time.

    PubMed

    Juusola, Mikko; Song, Zhuoyi

    2017-02-23

    A photoreceptor's information capture is constrained by the structure and function of its light-sensitive parts. Specifically, in a fly photoreceptor, this limit is set by the number of its photon sampling units (microvilli), constituting its light-sensor (the rhabdomere), and the speed and recoverability of their phototransduction reactions. In this mini-review, using an insightful constructionist viewpoint of a fly photoreceptor being an "imperfect" photon counting machine, we explain how these constraints give rise to adaptive quantal information sampling in time, which maximises information in responses to salient light changes while antialiasing visual signals. Interestingly, such sampling innately determines also why photoreceptors extract more information, and more economically, from naturalistic light contrast changes than Gaussian white-noise stimuli, and we explicate why this is so. Our main message is that stochasticity in quantal information sampling is less noise and more processing, representing an "evolutionary adaptation" to generate a reliable neural estimate of the variable world. This article is protected by copyright. All rights reserved.

  6. Transit light curves with finite integration time: Fisher information analysis

    SciTech Connect

    Price, Ellen M.; Rogers, Leslie A.

    2014-10-10

    Kepler has revolutionized the study of transiting planets with its unprecedented photometric precision on more than 150,000 target stars. Most of the transiting planet candidates detected by Kepler have been observed as long-cadence targets with 30 minute integration times, and the upcoming Transiting Exoplanet Survey Satellite will record full frame images with a similar integration time. Integrations of 30 minutes affect the transit shape, particularly for small planets and in cases of low signal to noise. Using the Fisher information matrix technique, we derive analytic approximations for the variances and covariances on the transit parameters obtained from fitting light curve photometry collected with a finite integration time. We find that binning the light curve can significantly increase the uncertainties and covariances on the inferred parameters when comparing scenarios with constant total signal to noise (constant total integration time in the absence of read noise). Uncertainties on the transit ingress/egress time increase by a factor of 34 for Earth-size planets and 3.4 for Jupiter-size planets around Sun-like stars for integration times of 30 minutes compared to instantaneously sampled light curves. Similarly, uncertainties on the mid-transit time for Earth and Jupiter-size planets increase by factors of 3.9 and 1.4. Uncertainties on the transit depth are largely unaffected by finite integration times. While correlations among the transit depth, ingress duration, and transit duration all increase in magnitude with longer integration times, the mid-transit time remains uncorrelated with the other parameters. We provide code in Python and Mathematica for predicting the variances and covariances at www.its.caltech.edu/∼eprice.

  7. Diurnal patterns of salivary cortisol and DHEA using a novel collection device: Electronic monitoring confirms accurate recording of collection time using this device

    PubMed Central

    Laudenslager, Mark L.; Calderone, Jacqueline; Philips, Sam; Natvig, Crystal; Carlson, Nichole E.

    2013-01-01

    The accurate indication of saliva collection time is important for defining the diurnal decline in salivary cortisol as well as characterizing the cortisol awakening response.. We tested a convenient and novel collection device for collecting saliva on strips of filter paper in a specially constructed booklet for determination of both cortisol and DHEA. In the present study, 31 healthy adults (mean age 43.5 yrs.) collected saliva samples four times a day on three consecutive days using filter paper collection devices (Saliva Procurement and Integrated Testing (SPIT) booklet) which were maintained during the collection period in a large plastic bottle with an electronic monitoring cap. Subjects were asked to collect saliva samples at awakening, 30 min. after awakening, before lunch and 600 min. after awakening. The time of awakening and the time of collection before lunch were allowed to vary by each subjects’ schedule. A reliable relationship was observed between the time recorded by the subject directly on the booklet and the time recorded by electronic collection device (n = 286 observations; r2 = 0.98). However, subjects did not consistently collect the saliva samples at the two specific times requested, 30 and 600 min. after awakening. Both cortisol and DHEA revealed diurnal declines.. In spite of variance in collection times at 30 min. and 600 min. after awakening, the slope of the diurnal decline in both salivary cortisol and DHEA were similar when we compared collection tolerances of ± 7.5 and ± 15 min. for each steroid.. These unique collection booklets proved to be a reliable method for recording collection times by subjects as well as for estimating diurnal salivary cortisol and DHEA patterns. PMID:23490073

  8. Characterizing Information Processing With a Mobile Device: Measurement of Simple and Choice Reaction Time.

    PubMed

    Burke, Daniel; Linder, Susan; Hirsch, Joshua; Dey, Tanujit; Kana, Daniel; Ringenbach, Shannon; Schindler, David; Alberts, Jay

    2016-03-01

    Information processing is typically evaluated using simple reaction time (SRT) and choice reaction time (CRT) paradigms in which a specific response is initiated following a given stimulus. The measurement of reaction time (RT) has evolved from monitoring the timing of mechanical switches to computerized paradigms. The proliferation of mobile devices with touch screens makes them a natural next technological approach to assess information processing. The aims of this study were to determine the validity and reliability of using of a mobile device (Apple iPad or iTouch) to accurately measure RT. Sixty healthy young adults completed SRT and CRT tasks using a traditional test platform and mobile platforms on two occasions. The SRT was similar across test modality: 300, 287, and 280 milliseconds (ms) for the traditional, iPad, and iTouch, respectively. The CRT was similar within mobile devices, though slightly faster on the traditional: 359, 408, and 384 ms for traditional, iPad, and iTouch, respectively. Intraclass correlation coefficients ranged from 0.79 to 0.85 for SRT and from 0.75 to 0.83 for CRT. The similarity and reliability of SRT across platforms and consistency of SRT and CRT across test conditions indicate that mobile devices provide the next generation of assessment platforms for information processing.

  9. Robust Algorithm for Alignment of Liquid Chromatography-Mass Spectrometry Analyses in an Accurate Mass and Time Tag Data Analysis Pipeline

    SciTech Connect

    Jaitly, Navdeep; Monroe, Matthew E.; Petyuk, Vladislav A.; Clauss, Therese RW; Adkins, Joshua N.; Smith, Richard D.

    2006-11-01

    Liquid chromatography coupled to mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS/MS) has become a standard technique for analyzing complex peptide mixtures to determine composition and relative quantity. Several high-throughput proteomics techniques attempt to combine complementary results from multiple LC-MS and LC-MS/MS analyses to provide more comprehensive and accurate results. To effectively collate results from these techniques, variations in mass and elution time measurements between related analyses are corrected by using algorithms designed to align the various types of results: LC-MS/MS vs. LC-MS/MS, LC-MS vs. LC-MS/MS, and LC-MS vs. LC-MS. Described herein are new algorithms referred to collectively as Liquid Chromatography based Mass Spectrometric Warping and Alignment of Retention times of Peptides (LCMSWARP) which use a dynamic elution time warping approach similar to traditional algorithms that correct variation in elution time using piecewise linear functions. LCMSWARP is compared to a linear alignment algorithm that assumes a linear transformation of elution time between analyses. LCMSWARP also corrects for drift in mass measurement accuracies that are often seen in an LC-MS analysis due to factors such as analyzer drift. We also describe the alignment of LC-MS results and provide examples of alignment of analyses from different chromatographic systems to demonstrate more complex transformation functions.

  10. Acting to gain information: Real-time reasoning meets real-time perception

    NASA Technical Reports Server (NTRS)

    Rosenschein, Stan

    1994-01-01

    Recent advances in intelligent reactive systems suggest new approaches to the problem of deriving task-relevant information from perceptual systems in real time. The author will describe work in progress aimed at coupling intelligent control mechanisms to real-time perception systems, with special emphasis on frame rate visual measurement systems. A model for integrated reasoning and perception will be discussed, and recent progress in applying these ideas to problems of sensor utilization for efficient recognition and tracking will be described.

  11. Optimal Perceived Timing: Integrating Sensory Information with Dynamically Updated Expectations

    PubMed Central

    Di Luca, Massimiliano; Rhodes, Darren

    2016-01-01

    The environment has a temporal structure, and knowing when a stimulus will appear translates into increased perceptual performance. Here we investigated how the human brain exploits temporal regularity in stimulus sequences for perception. We find that the timing of stimuli that occasionally deviate from a regularly paced sequence is perceptually distorted. Stimuli presented earlier than expected are perceptually delayed, whereas stimuli presented on time and later than expected are perceptually accelerated. This result suggests that the brain regularizes slightly deviant stimuli with an asymmetry that leads to the perceptual acceleration of expected stimuli. We present a Bayesian model for the combination of dynamically-updated expectations, in the form of a priori probability of encountering future stimuli, with incoming sensory information. The asymmetries in the results are accounted for by the asymmetries in the distributions involved in the computational process. PMID:27385184

  12. Accurate mass analysis of ethanesulfonic acid degradates of acetochlor and alachlor using high-performance liquid chromatography and time-of-flight mass spectrometry

    USGS Publications Warehouse

    Thurman, E.M.; Ferrer, Imma; Parry, R.

    2002-01-01

    Degradates of acetochlor and alachlor (ethanesulfonic acids, ESAs) were analyzed in both standards and in a groundwater sample using high-performance liquid chromatography-time-of-flight mass spectrometry with electrospray ionization. The negative pseudomolecular ion of the secondary amide of acetochlor ESA and alachlor ESA gave average masses of 256.0750+/-0.0049 amu and 270.0786+/-0.0064 amu respectively. Acetochlor and alachlor ESA gave similar masses of 314.1098+/-0.0061 amu and 314.1153+/-0.0048 amu; however, they could not be distinguished by accurate mass because they have the same empirical formula. On the other hand, they may be distinguished using positive-ion electrospray because of different fragmentation spectra, which did not occur using negative-ion electrospray.

  13. Accurate mass analysis of ethanesulfonic acid degradates of acetochlor and alachlor using high-performance liquid chromatography and time-of-flight mass spectrometry

    USGS Publications Warehouse

    Thurman, E.M.; Ferrer, I.; Parry, R.

    2002-01-01

    Degradates of acetochlor and alachlor (ethanesulfonic acids, ESAs) were analyzed in both standards and in a groundwater sample using high-performance liquid chromatography-time-of-flight mass spectrometry with electrospray ionization. The negative pseudomolecular ion of the secondary amide of acetochlor ESA and alachlor ESA gave average masses of 256.0750??0.0049 amu and 270.0786??0.0064 amu respectively. Acetochlor and alachlor ESA gave similar masses of 314.1098??0.0061 amu and 314.1153??0.0048 amu; however, they could not be distinguished by accurate mass because they have the same empirical formula. On the other hand, they may be distinguished using positive-ion electrospray because of different fragmentation spectra, which did not occur using negative-ion electrospray.

  14. A Provenance Model for Real-Time Water Information Systems

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Bai, Q.; Zednik, S.; Taylor, P.; Fox, P. A.; Taylor, K.; Kloppers, C.; Peters, C.; Terhorst, A.; West, P.; Compton, M.; Shu, Y.; Provenance Management Team

    2010-12-01

    Generating hydrological data products, such as flow forecasts, involves complex interactions among instruments, data simulation models, computational facilities and data providers. Correct interpretation of the data produced at various stages requires good understanding of how data was generated or processed. Provenance describes the lineage of a data product. Making provenance information accessible to hydrologists and decision makers not only helps to determine the data’s value, accuracy and authorship, but also enables users to determine the trustworthiness of the data product. In the water domain, WaterML2 [1] is an emerging standard which describes an information model and format for the publication of water observations data in XML. The W3C semantic sensor network incubator group (SSN-XG) [3] is producing ontologies for the description of sensor configurations. By integrating domain knowledge of this kind into the provenance information model, the integrated information model will enable water domain researchers and water resource managers to better analyse how observations and derived data products were generated. We first introduce the Proof Mark Language (PML2) [2], WaterML2 and the SSN-XG sensor ontology as the proposed provenance representation formalism. Then we describe some initial implementations how these standards could be integrated to represent the lineage of water information products. Finally we will highlight how the provenance model for a distributed real-time water information system assists the interpretation of the data product and establishing trust. Reference [1] Taylor, P., Walker, G., Valentine, D., Cox, Simon: WaterML2.0: Harmonising standards for water observation data. Geophysical Research Abstracts. Vol. 12. [2] da Silva, P.P., McGuinness, D.L., Fikes, R.: A proof markup language for semantic web services. Inf. Syst. 31(4) (2006), 381-395. [3] W3C Semantic Sensor Network Incubator Group http://www.w3.org/2005/Incubator

  15. Purification of pharmaceutical preparations using thin-layer chromatography to obtain mass spectra with Direct Analysis in Real Time and accurate mass spectrometry.

    PubMed

    Wood, Jessica L; Steiner, Robert R

    2011-06-01

    Forensic analysis of pharmaceutical preparations requires a comparative analysis with a standard of the suspected drug in order to identify the active ingredient. Purchasing analytical standards can be expensive or unattainable from the drug manufacturers. Direct Analysis in Real Time (DART™) is a novel, ambient ionization technique, typically coupled with a JEOL AccuTOF™ (accurate mass) mass spectrometer. While a fast and easy technique to perform, a drawback of using DART™ is the lack of component separation of mixtures prior to ionization. Various in-house pharmaceutical preparations were purified using thin-layer chromatography (TLC) and mass spectra were subsequently obtained using the AccuTOF™- DART™ technique. Utilizing TLC prior to sample introduction provides a simple, low-cost solution to acquiring mass spectra of the purified preparation. Each spectrum was compared against an in-house molecular formula list to confirm the accurate mass elemental compositions. Spectra of purified ingredients of known pharmaceuticals were added to an in-house library for use as comparators for casework samples. Resolving isomers from one another can be accomplished using collision-induced dissociation after ionization. Challenges arose when the pharmaceutical preparation required an optimized TLC solvent to achieve proper separation and purity of the standard. Purified spectra were obtained for 91 preparations and included in an in-house drug standard library. Primary standards would only need to be purchased when pharmaceutical preparations not previously encountered are submitted for comparative analysis. TLC prior to DART™ analysis demonstrates a time efficient and cost saving technique for the forensic drug analysis community. Copyright © 2011 John Wiley & Sons, Ltd.

  16. Fast and Accurate Data Extraction for Near Real-Time Registration of 3-D Ultrasound and Computed Tomography in Orthopedic Surgery.

    PubMed

    Brounstein, Anna; Hacihaliloglu, Ilker; Guy, Pierre; Hodgson, Antony; Abugharbieh, Rafeef

    2015-12-01

    Automatic, accurate and real-time registration is an important step in providing effective guidance and successful anatomic restoration in ultrasound (US)-based computer assisted orthopedic surgery. We propose a method in which local phase-based bone surfaces, extracted from intra-operative US data, are registered to pre-operatively segmented computed tomography data. Extracted bone surfaces are downsampled and reinforced with high curvature features. A novel hierarchical simplification algorithm is used to further optimize the point clouds. The final point clouds are represented as Gaussian mixture models and iteratively matched by minimizing the dissimilarity between them using an L2 metric. For 44 clinical data sets from 25 pelvic fracture patients and 49 phantom data sets, we report mean surface registration accuracies of 0.31 and 0.77 mm, respectively, with an average registration time of 1.41 s. Our results suggest the viability and potential of the chosen method for real-time intra-operative registration in orthopedic surgery.

  17. Advanced Fire Information System - A real time fire information system for Africa

    NASA Astrophysics Data System (ADS)

    Frost, P. E.; Roy, D. P.

    2012-12-01

    The Council for Scientific and Industrial Research (CSIR) lead by the Meraka Institute and supported by the South African National Space Agency (SANSA) developed the Advanced Fire Information System (AFIS) to provide near real time fire information to a variety of operational and science fire users including disaster managers, fire fighters, farmers and forest managers located across Southern and Eastern Africa. The AFIS combines satellite data with ground based observations and statistics and distributes the information via mobile phone technology. The system was launched in 2004, and Eskom (South Africa' and Africa's largest power utility) quickly became the biggest user and today more than 300 Eskom line managers and support staff receive cell phone and email fire alert messages whenever a wildfire is within 2km of any of the 28 000km of Eskom electricity transmission lines. The AFIS uses Earth observation satellites from NASA and Europe to detect possible actively burning fires and their fire radiative power (FRP). The polar orbiting MODIS Terra and Aqua satellites provide data at around 10am, 15pm, 22am and 3am daily, while the European Geostationary MSG satellite provides 15 minute updates at lower spatial resolution. The AFIS processing system ingests the raw satellite data and within minutes of the satellite overpass generates fire location and FRP based fire intensity information. The AFIS and new functionality are presented including an incident report and permiting system that can be used to differentiate between prescribed burns and uncontrolled wild fires, and the provision of other information including 5-day fire danger forecasts, vegetation curing information and historical burned area maps. A new AFIS mobile application for IOS and Android devices as well as a fire reporting tool are showcased that enable both the dissemination and alerting of fire information and enable user upload of geo tagged photographs and on the fly creation of fire reports

  18. Mitochondrial DNA as a non-invasive biomarker: Accurate quantification using real time quantitative PCR without co-amplification of pseudogenes and dilution bias

    SciTech Connect

    Malik, Afshan N.; Shahni, Rojeen; Rodriguez-de-Ledesma, Ana; Laftah, Abas; Cunningham, Phil

    2011-08-19

    Highlights: {yields} Mitochondrial dysfunction is central to many diseases of oxidative stress. {yields} 95% of the mitochondrial genome is duplicated in the nuclear genome. {yields} Dilution of untreated genomic DNA leads to dilution bias. {yields} Unique primers and template pretreatment are needed to accurately measure mitochondrial DNA content. -- Abstract: Circulating mitochondrial DNA (MtDNA) is a potential non-invasive biomarker of cellular mitochondrial dysfunction, the latter known to be central to a wide range of human diseases. Changes in MtDNA are usually determined by quantification of MtDNA relative to nuclear DNA (Mt/N) using real time quantitative PCR. We propose that the methodology for measuring Mt/N needs to be improved and we have identified that current methods have at least one of the following three problems: (1) As much of the mitochondrial genome is duplicated in the nuclear genome, many commonly used MtDNA primers co-amplify homologous pseudogenes found in the nuclear genome; (2) use of regions from genes such as {beta}-actin and 18S rRNA which are repetitive and/or highly variable for qPCR of the nuclear genome leads to errors; and (3) the size difference of mitochondrial and nuclear genomes cause a 'dilution bias' when template DNA is diluted. We describe a PCR-based method using unique regions in the human mitochondrial genome not duplicated in the nuclear genome; unique single copy region in the nuclear genome and template treatment to remove dilution bias, to accurately quantify MtDNA from human samples.

  19. A Review of Wearable Technologies for Elderly Care that Can Accurately Track Indoor Position, Recognize Physical Activities and Monitor Vital Signs in Real Time

    PubMed Central

    Wang, Zhihua; Yang, Zhaochu; Dong, Tao

    2017-01-01

    Rapid growth of the aged population has caused an immense increase in the demand for healthcare services. Generally, the elderly are more prone to health problems compared to other age groups. With effective monitoring and alarm systems, the adverse effects of unpredictable events such as sudden illnesses, falls, and so on can be ameliorated to some extent. Recently, advances in wearable and sensor technologies have improved the prospects of these service systems for assisting elderly people. In this article, we review state-of-the-art wearable technologies that can be used for elderly care. These technologies are categorized into three types: indoor positioning, activity recognition and real time vital sign monitoring. Positioning is the process of accurate localization and is particularly important for elderly people so that they can be found in a timely manner. Activity recognition not only helps ensure that sudden events (e.g., falls) will raise alarms but also functions as a feasible way to guide people’s activities so that they avoid dangerous behaviors. Since most elderly people suffer from age-related problems, some vital signs that can be monitored comfortably and continuously via existing techniques are also summarized. Finally, we discussed a series of considerations and future trends with regard to the construction of “smart clothing” system. PMID:28208620

  20. Accurate and sensitive real-time PCR assays using intergenic spacer 1 region to differentiate Cryptococcus gattii sensu lato and Cryptococcus neoformans sensu lato.

    PubMed

    Tavares, Eliandro Reis; Azevedo, Caroline Souza; Panagio, Luciano Aparecido; Pelisson, Marsileni; Pinge-Filho, Phileno; Venancio, Emerson José; Barros, Tânia Fraga; Yamada-Ogatta, Sueli Fumie; Yamauchi, Lucy Megumi

    2016-01-01

    In this work, two accurate and sensitive real-time polymerase chain reaction (PCR) assays to differentiate pathogenic Cryptococcus gattii sensu lato (s.l.) and C. neoformans sensu lato (s.l.) targeting the intergenic spacer 1 (IGS1) region from rDNA locus were developed. Specific primers were designed based on their IGS1 sequence analyses and the optimal real-time PCR assays showed that the dissociation curves generated two different melting peaks, at 82.8 and 84.2ºC for C. gattii s.l. and C. neoformans s.l., respectively. No amplifications were observed in the negative template control. The minimum limit of detection of both primers was 100 plasmid copies per reaction, and they were highly specific when tested with a range of fungal DNAs. Overall, the results showed that the designed primers completely differentiated C. gattii s.l. and C. neoformans s.l. from clinical and environmental sources with great accuracy when compared to phenotypic identification, with no cross-reactivity to other fungal DNA.

  1. Percutaneous Radiofrequency Ablation of Osteoid Osteomas with Use of Real-Time Needle Guidance for Accurate Needle Placement: A Pilot Study

    SciTech Connect

    Busser, Wendy M. H. Hoogeveen, Yvonne L.; Veth, Rene P. H.; Schreuder, H. W. Bart; Balguid, Angelique; Renema, W. KlaasJan; SchultzeKool, Leo J.

    2011-02-15

    Purpose: To evaluate the accuracy and technical success of positioning a radiofrequency ablation (RFA) electrode in osteoid osteomas by use of a new real-time needle guidance technology combining cone-beam computed tomography (CT) and fluoroscopy. Materials and Methods: Percutaneous RFA of osteoid osteomas was performed in five patients (median age 18 years), under general anesthesia, with the use of cone-beam CT and fluoroscopic guidance for electrode positioning. The outcome parameters were technical success, meaning correct needle placement in the nidus; accuracy defined as the deviation (in mm) from the center of the nidus; and clinical outcome at follow-up. Results: In all five cases, positioning was possible within 3 mm of the determined target location (median nidus size 6.8 mm; range 5-10.2 mm). All procedures were technically successful. All patients were free of pain at clinical follow-up. No complications were observed. Conclusion: Real-time fluoroscopy needle guidance based on cone-beam CT is a useful tool to accurately position radiofrequency needles for minimally invasive treatment of osteoid osteomas.

  2. A Review of Wearable Technologies for Elderly Care that Can Accurately Track Indoor Position, Recognize Physical Activities and Monitor Vital Signs in Real Time.

    PubMed

    Wang, Zhihua; Yang, Zhaochu; Dong, Tao

    2017-02-10

    Rapid growth of the aged population has caused an immense increase in the demand for healthcare services. Generally, the elderly are more prone to health problems compared to other age groups. With effective monitoring and alarm systems, the adverse effects of unpredictable events such as sudden illnesses, falls, and so on can be ameliorated to some extent. Recently, advances in wearable and sensor technologies have improved the prospects of these service systems for assisting elderly people. In this article, we review state-of-the-art wearable technologies that can be used for elderly care. These technologies are categorized into three types: indoor positioning, activity recognition and real time vital sign monitoring. Positioning is the process of accurate localization and is particularly important for elderly people so that they can be found in a timely manner. Activity recognition not only helps ensure that sudden events (e.g., falls) will raise alarms but also functions as a feasible way to guide people's activities so that they avoid dangerous behaviors. Since most elderly people suffer from age-related problems, some vital signs that can be monitored comfortably and continuously via existing techniques are also summarized. Finally, we discussed a series of considerations and future trends with regard to the construction of "smart clothing" system.

  3. A conceptual framework for intelligent real-time information processing

    NASA Technical Reports Server (NTRS)

    Schudy, Robert

    1987-01-01

    By combining artificial intelligence concepts with the human information processing model of Rasmussen, a conceptual framework was developed for real time artificial intelligence systems which provides a foundation for system organization, control and validation. The approach is based on the description of system processing terms of an abstraction hierarchy of states of knowledge. The states of knowledge are organized along one dimension which corresponds to the extent to which the concepts are expressed in terms of the system inouts or in terms of the system response. Thus organized, the useful states form a generally triangular shape with the sensors and effectors forming the lower two vertices and the full evaluated set of courses of action the apex. Within the triangle boundaries are numerous processing paths which shortcut the detailed processing, by connecting incomplete levels of analysis to partially defined responses. Shortcuts at different levels of abstraction include reflexes, sensory motor control, rule based behavior, and satisficing. This approach was used in the design of a real time tactical decision aiding system, and in defining an intelligent aiding system for transport pilots.

  4. Quantum Information, Entropy, ALPHA, Hubble Time, and Dark Energy, Linked?

    NASA Astrophysics Data System (ADS)

    Goradia, Shantilal

    2008-03-01

    The postulation of fundamental constants by Newton, Einstein and Planck gave us natural units at Planck scale. Additional postulates may explain coupling constants. About sixty orders of magnitude of Planck times equal Hubble time (W). Substitution of W in Boltzmann's entropy equation (S=k ln W; with Boltzmann constant k = 1 in natural units, and using the natural logarithm to probe nature) equates the statistical entropy (S) of the universe to about 137, the reciprocal of the fine-structure constant (α). Thermodynamic entropy (dS = δQ/T), a consequence of statistical entropy, implies that the fine-structure constant generates heat out of vacuum energy or dark energy. We draw support from the insights of Maxwell's demon (1867), Gamow (1967) and Eddington (1949). In information theory, entropy is linked to a measure of uncertainty, indicating that the fine-structure constant is greater than or equal to the reciprocal of the natural logarithm of the age of the universe: α>=1 / 1 lnW . - lnW. The postulation in [1] (a draft of a 2008 planned review paper) will address further issues. [1] S. Goradia, What is Fine Structure Constant? http://www.arxiv.org/abs/physics/0210040v3 (revised 1/6/2007)

  5. Accurate Finite Difference Algorithms

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  6. Use of Real-time Satellite Rainfall Information in a Global Flood Estimation System

    NASA Astrophysics Data System (ADS)

    Adler, R. F.; Wu, H.; Tian, Y.

    2012-12-01

    (FAR) is ~ 0.6. Limitations in the flood calculations that are related to the satellite rainfall estimates include space and time resolution limitations and underestimation of shallow orographic and monsoon system rainfall. Recent cases from 2012, mainly over Asia, are discussed as examples of the utility of the output information and the importance of accurate rainfall input. These calculations in their current form provide information useful to national and international agencies in understanding the location, intensity, timeline and impact on populations of these significant hazard events. Improvements in precipitation information from the coming Global Precipitation Measurement (GPM) mission (2014) will improve the flood model calculations, and improvements in hydrological model resolution and water routing will improve the utility of the results.

  7. 23 CFR 511.311 - Real-time information program establishment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... INFRASTRUCTURE MANAGEMENT REAL-TIME SYSTEM MANAGEMENT INFORMATION PROGRAM Real-Time System Management Information Program § 511.311 Real-time information program establishment. (a) Requirement. States shall establish... 23 Highways 1 2011-04-01 2011-04-01 false Real-time information program establishment....

  8. 23 CFR 511.313 - Metropolitan Area real-time information program supplement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... TRANSPORTATION INFRASTRUCTURE MANAGEMENT REAL-TIME SYSTEM MANAGEMENT INFORMATION PROGRAM Real-Time System Management Information Program § 511.313 Metropolitan Area real-time information program supplement. (a... 23 Highways 1 2011-04-01 2011-04-01 false Metropolitan Area real-time information...

  9. How Have Concepts of Informal Learning Developed over Time?

    ERIC Educational Resources Information Center

    Carliner, Saul

    2013-01-01

    Although the current interest in informal learning seems recent, performance improvement professionals have long had an interest in informal learning-the ways that people learn outside of formal structures. The earliest forms of learning for work were informal, including de facto and formal apprenticeship programs and the "school of…

  10. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry for fast and accurate identification of clinically relevant Aspergillus species.

    PubMed

    Alanio, A; Beretti, J-L; Dauphin, B; Mellado, E; Quesne, G; Lacroix, C; Amara, A; Berche, P; Nassif, X; Bougnoux, M-E

    2011-05-01

    New Aspergillus species have recently been described with the use of multilocus sequencing in refractory cases of invasive aspergillosis. The classical phenotypic identification methods routinely used in clinical laboratories failed to identify them adequately. Some of these Aspergillus species have specific patterns of susceptibility to antifungal agents, and misidentification may lead to inappropriate therapy. We developed a matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS)-based strategy to adequately identify Aspergillus species to the species level. A database including the reference spectra of 28 clinically relevant species from seven Aspergillus sections (five common and 23 unusual species) was engineered. The profiles of young and mature colonies were analysed for each reference strain, and species-specific spectral fingerprints were identified. The performance of the database was then tested on 124 clinical and 16 environmental isolates previously characterized by partial sequencing of the β-tubulin and calmodulin genes. One hundred and thirty-eight isolates of 140 (98.6%) were correctly identified. Two atypical isolates could not be identified, but no isolate was misidentified (specificity: 100%). The database, including species-specific spectral fingerprints of young and mature colonies of the reference strains, allowed identification regardless of the maturity of the clinical isolate. These results indicate that MALDI-TOF MS is a powerful tool for rapid and accurate identification of both common and unusual species of Aspergillus. It can give better results than morphological identification in clinical laboratories.

  11. A real-time PCR assay for accurate quantification of the individual members of the Altered Schaedler Flora microbiota in gnotobiotic mice.

    PubMed

    Gomes-Neto, João Carlos; Mantz, Sara; Held, Kyler; Sinha, Rohita; Segura Munoz, Rafael R; Schmaltz, Robert; Benson, Andrew K; Walter, Jens; Ramer-Tait, Amanda E

    2017-04-01

    Changes in the gastrointestinal microbial community are frequently associated with chronic diseases such as Inflammatory Bowel Diseases. However, understanding the relationship of any individual taxon within the community to host physiology is made complex due to the diversity and individuality of the gut microbiota. Defined microbial communities such as the Altered Schaedler Flora (ASF) help alleviate the challenges of a diverse microbiota by allowing one to interrogate the relationship between individual bacterial species and host responses. An important aspect of studying these relationships with defined microbial communities is the ability to measure the population abundance and dynamics of each member. Herein, we describe the development of an improved ASF species-specific and sensitive real-time quantitative polymerase chain reaction (qPCR) for use with SYBR Green chemistry to accurately assess individual ASF member abundance. This approach targets hypervariable regions V1 through V3 of the 16S rRNA gene of each ASF taxon to enhance assay specificity. We demonstrate the reproducibility, sensitivity and application of this new method by quantifying each ASF bacterium in two inbred mouse lines. We also used it to assess changes in ASF member abundance before and after acute antibiotic perturbation of the community as well as in mice fed two different diets. Additionally, we describe a nested PCR assay for the detection of lowly abundant ASF members. Altogether, this improved qPCR method will facilitate gnotobiotic research involving the ASF community by allowing for reproducible quantification of its members under various physiological conditions.

  12. Simultaneous and accurate real-time monitoring of glucose and ethanol in alcoholic drinks, must, and biomass by a dual-amperometric biosensor.

    PubMed

    Mentana, Annalisa; Palermo, Carmen; Nardiello, Donatella; Quinto, Maurizio; Centonze, Diego

    2013-01-09

    In this work the optimization and application of a dual-amperometric biosensor for simultaneous monitoring of glucose and ethanol content, as quality markers in drinks and alcoholic fermentation media, are described. The biosensor is based on glucose oxidase (GOD) and alcohol oxidase (AOD) immobilized by co-cross-linking with bovine serum albumin (BSA) and glutaraldehyde (GLU) both onto a dual gold electrode, modified with a permselective overoxidized polypyrrole film (PPYox). Response, rejection of interferents, and stability of the dual biosensor were optimized in terms of PPYox thickness, BSA, and enzyme loading. The biosensor was integrated in a flow injection system coupled with an at-line microdialysis fiber as a sampling tool. Flow rates inside and outside the fiber were optimized in terms of linear responses (0.01-1 and 0.01-1.5 M) and sensitivities (27.6 ± 0.4 and 31.0 ± 0.6 μA·M(-1)·cm(-2)) for glucose and ethanol. Excellent anti-interference characteristics, the total absence of "cross-talk", and good response stability under operational conditions allowed application of the dual biosensor in accurate real-time monitoring (at least 15 samples/h) of alcoholic drinks, white grape must, and woody biomass.

  13. Exploratory Data Analysis of Acceleration Signals to Select Light-Weight and Accurate Features for Real-Time Activity Recognition on Smartphones

    PubMed Central

    Khan, Adil Mehmood; Siddiqi, Muhammad Hameed; Lee, Seok-Won

    2013-01-01

    Smartphone-based activity recognition (SP-AR) recognizes users' activities using the embedded accelerometer sensor. Only a small number of previous works can be classified as online systems, i.e., the whole process (pre-processing, feature extraction, and classification) is performed on the device. Most of these online systems use either a high sampling rate (SR) or long data-window (DW) to achieve high accuracy, resulting in short battery life or delayed system response, respectively. This paper introduces a real-time/online SP-AR system that solves this problem. Exploratory data analysis was performed on acceleration signals of 6 activities, collected from 30 subjects, to show that these signals are generated by an autoregressive (AR) process, and an accurate AR-model in this case can be built using a low SR (20 Hz) and a small DW (3 s). The high within class variance resulting from placing the phone at different positions was reduced using kernel discriminant analysis to achieve position-independent recognition. Neural networks were used as classifiers. Unlike previous works, true subject-independent evaluation was performed, where 10 new subjects evaluated the system at their homes for 1 week. The results show that our features outperformed three commonly used features by 40% in terms of accuracy for the given SR and DW. PMID:24084108

  14. Resolving spectral information from time domain induced polarization data through 2-D inversion

    NASA Astrophysics Data System (ADS)

    Fiandaca, Gianluca; Ramm, James; Binley, Andrew; Gazoty, Aurélie; Christiansen, Anders Vest; Auken, Esben

    2013-02-01

    Field-based time domain (TD) induced polarization (IP) surveys are usually modelled by taking into account only the integral chargeability, thus disregarding spectral content. Furthermore, the effect of the transmitted waveform is commonly neglected, biasing inversion results. Given these limitations of conventional approaches, a new 2-D inversion algorithm has been developed using the full voltage decay of the IP response, together with an accurate description of the transmitter waveform and receiver transfer function. This allows reconstruction of the spectral information contained in the TD decay series. The inversion algorithm is based around a 2-D complex conductivity kernel that is computed over a range of frequencies and converted to the TD through a fast Hankel transform. Two key points in the implementation ensure that computation times are minimized. First, the speed of the Jacobian computation, time transformed from frequency domain through the same transformation adopted for the forward response is optimized. Secondly, the reduction of the number of frequencies where the forward response and Jacobian are calculated: cubic splines are used to interpolate the responses to the frequency sampling necessary in the fast Hankel transform. These features, together with parallel computation, ensure inversion times comparable with those of direct current algorithms. The algorithm has been developed in a laterally constrained inversion scheme, and handles both smooth and layered inversions; the latter being helpful in sedimentary environments, where quasi-layered models often represent the actual geology more accurately than smooth minimum-structure models. In the layered inversion approach, a general method to derive the thickness derivative from the complex conductivity Jacobian is also proposed. One synthetic example of layered inversion and one field example of smooth inversion show the capability of the algorithm and illustrates a complete uncertainty

  15. Life, Information, Entropy, and Time: Vehicles for Semantic Inheritance.

    PubMed

    Crofts, Antony R

    2007-01-01

    Attempts to understand how information content can be included in an accounting of the energy flux of the biosphere have led to the conclusion that, in information transmission, one component, the semantic content, or "the meaning of the message," adds no thermodynamic burden over and above costs arising from coding, transmission and translation. In biology, semantic content has two major roles. For all life forms, the message of the genotype encoded in DNA specifies the phenotype, and hence the organism that is tested against the real world through the mechanisms of Darwinian evolution. For human beings, communication through language and similar abstractions provides an additional supra-phenotypic vehicle for semantic inheritance, which supports the cultural heritages around which civilizations revolve. The following three postulates provide the basis for discussion of a number of themes that demonstrate some important consequences. (i) Information transmission through either pathway has thermodynamic components associated with data storage and transmission. (ii) The semantic content adds no additional thermodynamic cost. (iii) For all semantic exchange, meaning is accessible only through translation and interpretation, and has a value only in context. (1) For both pathways of semantic inheritance, translational and copying machineries are imperfect. As a consequence both pathways are subject to mutation and to evolutionary pressure by selection. Recognition of semantic content as a common component allows an understanding of the relationship between genes and memes, and a reformulation of Universal Darwinism. (2) The emergent properties of life are dependent on a processing of semantic content. The translational steps allow amplification in complexity through combinatorial possibilities in space and time. Amplification depends on the increased potential for complexity opened by 3D interaction specificity of proteins, and on the selection of useful variants by

  16. Identification and evaluation of new reference genes in Gossypium hirsutum for accurate normalization of real-time quantitative RT-PCR data

    PubMed Central

    2010-01-01

    Background Normalizing through reference genes, or housekeeping genes, can make more accurate and reliable results from reverse transcription real-time quantitative polymerase chain reaction (qPCR). Recent studies have shown that no single housekeeping gene is universal for all experiments. Thus, suitable reference genes should be the first step of any qPCR analysis. Only a few studies on the identification of housekeeping gene have been carried on plants. Therefore qPCR studies on important crops such as cotton has been hampered by the lack of suitable reference genes. Results By the use of two distinct algorithms, implemented by geNorm and NormFinder, we have assessed the gene expression of nine candidate reference genes in cotton: GhACT4, GhEF1α5, GhFBX6, GhPP2A1, GhMZA, GhPTB, GhGAPC2, GhβTUB3 and GhUBQ14. The candidate reference genes were evaluated in 23 experimental samples consisting of six distinct plant organs, eight stages of flower development, four stages of fruit development and in flower verticils. The expression of GhPP2A1 and GhUBQ14 genes were the most stable across all samples and also when distinct plants organs are examined. GhACT4 and GhUBQ14 present more stable expression during flower development, GhACT4 and GhFBX6 in the floral verticils and GhMZA and GhPTB during fruit development. Our analysis provided the most suitable combination of reference genes for each experimental set tested as internal control for reliable qPCR data normalization. In addition, to illustrate the use of cotton reference genes we checked the expression of two cotton MADS-box genes in distinct plant and floral organs and also during flower development. Conclusion We have tested the expression stabilities of nine candidate genes in a set of 23 tissue samples from cotton plants divided into five different experimental sets. As a result of this evaluation, we recommend the use of GhUBQ14 and GhPP2A1 housekeeping genes as superior references for normalization of gene

  17. Real-Time Traffic Information for Emergency Evacuation Operations: Phase A Final Report

    SciTech Connect

    Franzese, Oscar; Zhang, Li; Mahmoud, Anas M.; Lascurain, Mary Beth; Wen, Yi

    2010-05-01

    is also equipped with their own power supply and a GPS (Global Positioning System) device to auto-determine its spatial location on the transportation network under surveillance. The system is capable of assessing traffic parameters by identifying and re-identifying vehicles in the traffic stream as those vehicles pass over the sensors. The system of sensors transmits, through wireless communication, real-time traffic information (travel time and other parameters) to a command and control center via an NTCIP (National Transportation Communication for ITS Protocol) -compatible interface. As an alternative, an existing NTCIP-compatible system accepts the real-time traffic information mentioned and broadcasts the traffic information to emergency managers, the media and the public via the existing channels. A series of tests, both in a controlled environment and on the field, were conducted to study the feasibility of rapidly deploying the system of traffic sensors and to assess its ability to provide real-time traffic information during an emergency evacuation. The results of these tests indicated that the prototype sensors are reliable and accurate for the type of application that is the focus of this project.

  18. An Information Processing Approach to Skill Acquisition: Perception and Timing.

    ERIC Educational Resources Information Center

    Rothstein, Anne L.

    In order to understand learners and players in relation to environments typically found in sport, it is necessary to first understand the individual as an information processor who must sample information from the environment, interpret it, organize or select an appropriate motor response, and execute that response. One of the most difficult…

  19. Where Field Staff Get Information. Approaching the Electronic Times.

    ERIC Educational Resources Information Center

    Shih, Win-Yuan; Evans, James F.

    1991-01-01

    Top 3 information sources identified in a survey of 109 extension agents were extension publications, specialists, and personal files. Electronic sources such as satellite programing and bibliographic databases were used infrequently, because of lack of access, user friendliness, and ready applicability of information. (SK)

  20. Identification of protein O-glycosylation site and corresponding glycans using liquid chromatography-tandem mass spectrometry via mapping accurate mass and retention time shift.

    PubMed

    Huang, Li-Juan; Lin, Jen-Hui; Tsai, Jung-Heng; Chu, Yen-Yin; Chen, Yen-Wen; Chen, Shun-Li; Chen, Shu-Hui

    2014-12-05

    We reported an improved combinatorial approach for identifying site-specific O-glycosylation using both glycan cleaved and non-cleaved methods. In this approach, a non-reducing β-elimination kit coupled with non-specific enzymes performed efficient digestion, O-glycan cleavage, and partial dephosphorylation without significant side reactions, thus enabling an automatic database search for the cleaved O-glycosylation or serine/threonine (S/T) phosphorylation sites. From the same sample concurrently prepared without β-elimination, the corresponding intact O-glycopeptides were mapped by accurate precursor ion mass using an in-house glycan database majorly composed of GalNAc (mucin-type) core and the retention-time shift (ΔRt). Each glycopeptide assignment was verified by the detection of glycan-specific fragments using collision-induced dissociation (CID) to estimate False Discovery Rate (FDR). Using fetuin as a model, all identified S/T elimination sites were matched to multiple intact glycopeptides with a 31% FDR. This considerably reduced to 0% FDR by ΔRt filtering. This approach was then applied to a protein mixture composed of therapeutic Factor IX and Enbrel(®) mixed with fetuin and kappa-casein. A total of 26 glycosylation sites each of which corresponds to 1-4 glycans were positively mapped and confirmed. The FDR decreased from 33% to 3.3% by ΔRt filtering and exclusion of repeated peptide tags that covered the same glycosylation sites. Moreover, the phosphorylation and O-glycosylation on the same site such as T159 of Factor IX and T170 of kappa-casein were able to be unambiguously differentiated. Thus, our approach is useful for in-depth characterization of site-specific O-glycosylation of a simple mixture such as protein-based therapeutics.

  1. The Soviet applied information sciences in a time of change

    SciTech Connect

    Bengston, J.; Cronin, R.R.; Davidson, R.B.

    1991-07-01

    The Foreign Applied Sciences Assessment Center (FASAC) conducts reviews of selected areas of foreign basic and applied science by US scientists who are technically expert and active in the fields reviewed. Several of the FASAC assessments of Soviet science have involved various aspects of the information sciences, including enabling technologies and applications, as well as the core information sciences. This report draws upon those FASAC assessment reports, the expert judgment of some of the authors of those reports, and other public sources to characterize the current state of the information sciences in the Soviet Union and the effects of information science capabilities upon other areas of Soviet science and technology. This report also provides estimates of the likely effect of the political and social reforms underway in the Soviet Union on future Soviet progress in the information sciences and, at a more general level, in science and technology. 41 refs., 7 tabs.

  2. 30 CFR 48.3 - Training plans; time of submission; where filed; information required; time for approval; method...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... will be given for each course. (5) A description of the teaching methods and the course materials which...; information required; time for approval; method for disapproval; commencement of training; approval of....3 Training plans; time of submission; where filed; information required; time for approval;...

  3. Accurate Mass GC/LC-Quadrupole Time of Flight Mass Spectrometry Analysis of Fatty Acids and Triacylglycerols of Spicy Fruits from the Apiaceae Family

    PubMed Central

    Nguyen, Thao; Aparicio, Mario; Saleh, Mahmoud A.

    2016-01-01

    The triacylglycerol (TAG) structure and the regio-stereospecific distribution of fatty acids (FA) of seed oils from most of the Apiaceae family are not well documented. The TAG structure ultimately determines the final physical properties of the oils and the position of FAs in the TAG molecule affects the digestion; absorption and metabolism; and physical and technological properties of TAGs. Fixed oils from the fruits of dill (Anethum graveolens), caraway (Carum carvi), cumin (Cuminum cyminum), coriander (Coriandrum sativum), anise (Pimpinella anisum), carrot (Daucus carota), celery (Apium graveolens), fennel (Foeniculum vulgare), and Khella (Ammi visnaga), all from the Apiaceae family, were extracted at room temperature in chloroform/methanol (2:1 v/v) using percolators. Crude lipids were fractionated by solid phase extraction to separate neutral triacylglycerols (TAGs) from other lipids components. Neutral TAGs were subjected to transesterification process to convert them to their corresponding fatty acids methyl esters (FAMES) using 1% boron trifluoride (BF3) in methanol. FAMES were analyzed by gas chromatography-quadrupole time of flight (GC-QTOF) mass spectrometry. Triglycerides were analyzed using high performance liquid chromatography-quadrupole time of flight (LC-QTOF) mass spectrometry. Petroselinic acid was the major fatty acid in all samples ranging from 57% of the total fatty acids in caraway up to 82% in fennel. All samples contained palmitic (16:0), palmitoleic (C16:1n-9), stearic (C18:0), petroselinic (C18:1n-12), linoleic (C18:2n-6), linolinic (18:3n-3), and arachidic (C20:0) acids. TAG were analyzed using LC-QTOF for accurate mass identification and mass spectrometry/mass spectrometry (MS/MS) techniques for regiospesific elucidation of the identified TAGs. Five major TAGs were detected in all samples but with different relative concentrations in all of the tested samples. Several other TAGs were detected as minor components and were present in

  4. Accurate Mass GC/LC-Quadrupole Time of Flight Mass Spectrometry Analysis of Fatty Acids and Triacylglycerols of Spicy Fruits from the Apiaceae Family.

    PubMed

    Nguyen, Thao; Aparicio, Mario; Saleh, Mahmoud A

    2015-12-02

    The triacylglycerol (TAG) structure and the regio-stereospecific distribution of fatty acids (FA) of seed oils from most of the Apiaceae family are not well documented. The TAG structure ultimately determines the final physical properties of the oils and the position of FAs in the TAG molecule affects the digestion; absorption and metabolism; and physical and technological properties of TAGs. Fixed oils from the fruits of dill (Anethum graveolens), caraway (Carum carvi), cumin (Cuminum cyminum), coriander (Coriandrum sativum), anise (Pimpinella anisum), carrot (Daucus carota), celery (Apium graveolens), fennel (Foeniculum vulgare), and Khella (Ammi visnaga), all from the Apiaceae family, were extracted at room temperature in chloroform/methanol (2:1 v/v) using percolators. Crude lipids were fractionated by solid phase extraction to separate neutral triacylglycerols (TAGs) from other lipids components. Neutral TAGs were subjected to transesterification process to convert them to their corresponding fatty acids methyl esters (FAMES) using 1% boron trifluoride (BF₃) in methanol. FAMES were analyzed by gas chromatography-quadrupole time of flight (GC-QTOF) mass spectrometry. Triglycerides were analyzed using high performance liquid chromatography-quadrupole time of flight (LC-QTOF) mass spectrometry. Petroselinic acid was the major fatty acid in all samples ranging from 57% of the total fatty acids in caraway up to 82% in fennel. All samples contained palmitic (16:0), palmitoleic (C16:1n-9), stearic (C18:0), petroselinic (C18:1n-12), linoleic (C18:2n-6), linolinic (18:3n-3), and arachidic (C20:0) acids. TAG were analyzed using LC-QTOF for accurate mass identification and mass spectrometry/mass spectrometry (MS/MS) techniques for regiospesific elucidation of the identified TAGs. Five major TAGs were detected in all samples but with different relative concentrations in all of the tested samples. Several other TAGs were detected as minor components and were present in

  5. Eye proprioception may provide real time eye position information.

    PubMed

    Wang, Jing; Pan, Yujun

    2013-03-01

    Because of the frequency of eye movements, online knowledge of eye position is crucial for the accurate spatial perception and behavioral navigation. Both the internal monitoring signal (corollary discharge) of eye movements and the eye proprioception signal are thought to contribute to the localization of the eye position in the orbit. However, the functional role of these two eye position signals in spatial cognition has been disputed for more than a century. The predominant view proposes that the online analysis of eye position is exclusively provided by the corollary discharge signal, while the eye proprioception signal only plays a role in the long-term calibration of the oculomotor system. However, increasing evidence from recent behavioral and physiological studies suggests that the eye proprioception signal may play a role in the online monitoring of eye position. The purpose of this review is to discuss the feasibility and possible function of the eye proprioceptive signal for online monitoring of eye position.

  6. Assessing Change in High School Student Information Literacy Using the Tool for Real-Time Assessment of Information Literacy Skills

    ERIC Educational Resources Information Center

    Kovalik, Cindy L.; Yutzey, Susan D.; Piazza, Laura M.

    2012-01-01

    Change in high school student information literacy (IL) knowledge and skills, from freshman year to senior year in high school was the focus of this quasi-experimental research project. Researchers used a free information literacy skills assessment tool entitled TRAILS (Tool for Real-time Assessment of Information Literacy Skills) to measure…

  7. INFORMED CONSENT: THE MEDICAL AND LEGAL CHALLENGE OF OUR TIME

    PubMed Central

    Séllos Simões, Luiz Carlos

    2015-01-01

    Objective: To assess the real importance of obtaining informed consent, through an appropriate form, and its role in the outcome from civil liability claims. Methods: The wordings of the current Brazilian law and jurisprudence were compared with rulings from the State Court of the State of Rio de Janeiro, in 269 civil liability claims against healthcare professionals and hospitals. Results: Favorable and unfavorable outcomes (i.e. acquittals and convictions) were compared, and possible variations in the verdicts were discussed in relation to whether informed consent forms had been filled out or not. Conclusions: Obtaining informed consent, by means of appropriate forms, is still not a widespread practice in the Brazilian healthcare or judicial systems. It is recommended that this practice be adopted in the manner described in this paper, since this is prescribed in Brazilian law. PMID:27022541

  8. The Effect of Pressure and Time on Information Recall

    DTIC Science & Technology

    2008-04-01

    d’une plongée à 40 m de profondeur et du temps écoulé sur le traitement et la mémorisation de l’information. À six reprises, dix plongeurs ont vu des...deployed in deep water to make them more difficult to locate and less accessible to the divers. Thus MCM dives can be technically difficult...submersion in 6 to10°C water while wearing a wet suit) was associated with significant decrements in information processing. It is difficult to

  9. Effect of Information Load and Time on Observational Learning

    ERIC Educational Resources Information Center

    Breslin, Gavin; Hodges, Nicola J.; Williams, A. Mark

    2009-01-01

    We examined whether altering the amount of and moment when visual information is presented affected observational learning for participants practicing a bowling skill. On Day 1, four groups practiced a cricket bowling action. Three groups viewed a full-body point-light model, the model's bowling arm, or between-limb coordination of the model's…

  10. Time Course of Loss of Information Regarding Pattern Analyzing Operations

    ERIC Educational Resources Information Center

    Kolers, Paul A.; Ostry, David J.

    1974-01-01

    A study is reported in which subjects were shown sentences, some of which they had read previously, after intervals ranging from a few minutes to 32 days. Results show that information about typography can be recovered for at least 32 days after initial reading. Implications are discussed. (Author/RM)

  11. A Basis for Time and Cost Evaluation of Information Systems.

    ERIC Educational Resources Information Center

    Korfhage, R. R.; DeLutis, T. G.

    A general model for information storage and retrieval (IS&R) systems is proposed. The system is selected from the set of all available IS&R components. These components define the system's users and data sources; the hardware, software, and personnel performing the actual storage and retrieval activities; and the funder who acts as a filter in the…

  12. 30 CFR 48.23 - Training plans; time of submission; where filed; information required; time for approval; method...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...; information required; time for approval; method for disapproval; commencement of training; approval of... filed; information required; time for approval; method for disapproval; commencement of training... miners as a normal method of operation by the operator. The operator to be so excepted shall maintain...

  13. Gemini: Extending Information Management for Real Time Tactical Environments

    DTIC Science & Technology

    2008-03-01

    access to multiple other aircraft and the  Global  Information Grid (GIG). On these  UAS, Gemini may be installed in the form of a small payload or onto an...There are several technologies specifically designed for compressing XML data (for example XGrind,  XML‐ Xpress , and XMill). A general purpose...Future Force Warrior (US Army)  GIG  Global  Information Grid  GNOME  GNU Object Model Environment  GNU  GNU’s Not Unix  IDL  Interface Definition

  14. The Use of Auditory Output for Time-Critical Information

    DTIC Science & Technology

    1992-12-01

    that uses the auditory sense for alerts in the Combat Information Center (ClC). The immediate goal was to compare operator performance using voice ...tracking task on a scenario simulation of the ClC. Alerts were presented by voice , auditory icons, or buzzers. Four different causes for alerts were...alert so that three related sounds corresponded to three alerts of each alert cause. RESULTS 1. Overall, the results showed that both voice and

  15. Three-dimensional dose evaluation system using real-time wind field information for nuclear accidents in Taiwan

    NASA Astrophysics Data System (ADS)

    Wu, Jay; Lu, Chung-Hsin; Chang, Shu-Jun; Yang, Yung-Muh; Chang, Bor-Jing; Teng, Jen-Hsin

    2006-09-01

    In Taiwan, the three operating nuclear power plants are all built along the coast over complex terrain. Dose estimates after a nuclear accident with releases of radioactive materials, therefore, cannot be accurately calculated using simple dispersion models. We developed a three-dimensional dose evaluation system, which incorporates real-time prognostic wind field information with three-dimensional numerical models to predict dose results. The proposed system consists of three models: a three-dimensional mesoscale atmospheric model (HOTMAC), a three-dimensional transport and diffusion model (RAPTAD), and a dose calculation model (DOSE). The whole-body dose and thyroid dose as well as dose rates can be rapidly estimated and displayed on the three-dimensional terrain model constructed by satellite images. The developed three-dimensional dose evaluation system could accurately forecast the dose results and has been used in the annual nuclear emergency response exercise to provide suggestions for protective measures.

  16. Information Transfer by Reader Service Cards. A Response Time Analysis

    ERIC Educational Resources Information Center

    Bottle, Robert R.; Emery, Betty L.

    1971-01-01

    Some 80 percent of controlled circulation journals provide Reader Service Cards. The responses obtained with those from a sample of ten journals is reported and the data are analyzed in terms of yield, postal and other delays. Response times approximated a normal distribution with an overall mean of 5.8 weeks. (2 references) (Author/NH)

  17. Delayed High School Starting Times. Information Capsule. Volume 0908

    ERIC Educational Resources Information Center

    Blazer, Christie

    2009-01-01

    Educators around the nation are considering pushing high school starting times back until later in the morning, based on evidence suggesting that amount of sleep and circadian rhythms play a part in adolescents' academic performance. While research confirms that adolescents do not get enough sleep and that insufficient sleep can negatively…

  18. Modeling Information Accumulation in Psychological Tests Using Item Response Times

    ERIC Educational Resources Information Center

    Ranger, Jochen; Kuhn, Jörg-Tobias

    2015-01-01

    In this article, a latent trait model is proposed for the response times in psychological tests. The latent trait model is based on the linear transformation model and subsumes popular models from survival analysis, like the proportional hazards model and the proportional odds model. Core of the model is the assumption that an unspecified monotone…

  19. Development of information-movement couplings in a rhythmical ball-bouncing task: from space- to time-related information.

    PubMed

    Bazile, C; Benguigui, N; Siegler, I A

    2016-01-01

    We studied the development of information-movement couplings in a ball-bouncing task with a special interest in how space- and time-related information is used by people of different ages. Participants from four age groups (children aged 7-8, 9-10 and 11-12 years, and adults) performed a virtual ball-bouncing task in which space- and time-related information were independently manipulated. Task performance and information-movement couplings were analyzed. Our results confirm a clear use of time-related information in adults, while children demonstrated a predominant relationship between space-related information and the period of movement. In the course of development, however, the children become progressively more capable of using time-related information in order to control the rhythmic ball-bouncing task. A second and weaker coupling, between ball height information and racket velocity at impact, also appears in the course of development. The data seem to show that the development of children follows the freezing-freeing-exploiting sequence proposed by Savelsbergh and Van der Kamp (Int J Sport Psychol 31:467-484, 2000), with a significant change in how information is used to control movement related to age.

  20. Usage of Near Real-Time Climate Information.

    NASA Astrophysics Data System (ADS)

    Changnon, Stanley A., Jr.; Wendland, Wayne M.; Vogel, John L.

    1987-09-01

    Through a computer-based system, weather data from Illinois are collected daily, checked, and summarized into various climatic products within hours after collection. This system was controlled for two years to demonstrate system feasibility, determine user interest and product desires, and plan for statewide urge. This study focuses on usage of system products. The private sector (agribusiness news media, and private industry) was the most frequent and persistent user group, suggesting user-pay as a possible approach for funding such a system. State and federal agencies, farmers, and extension agents also use the system but primarily during weather stress periods. The characteristics of usage should help in the design and selection of products in other emerging state and regional systems for dissemination of climate data and information. The usage patterns also indicate how climate conditions impact various private and public sectors in a humid continental climate.

  1. A diagnostic one-step real-time reverse transcription polymerase chain reaction method for accurate detection of influenza virus type A

    PubMed Central

    Behzadi, Mohammad Amin; Alborzi, Abdolvahab

    2016-01-01

    Introduction Influenza A is known as a public health concern worldwide. In this study, a novel one-step real-time reverse transcription polymerase chain reaction (rtRT-PCR) assay was designed and optimized for the detection of influenza A viruses. Material and methods The primers and probe were designed based on the analysis of 90 matrix nucleotide sequence data of influenza type A subtypes from the GenBank database of the National Center for Biotechnology Information (NCBI). The influenza virus A/Tehran/5652/2010 (H1N1 pdm09) was used as a reference. The rtRT-PCR assay was optimized, compared with that of the World Health Organization (WHO), and its analytical sensitivity, specificity and reproducibility were evaluated. In total, 64 nasopharyngeal swabs from patients with influenza-like illness (ILI) and 41 samples without ILI symptoms were tested for the virus, using conventional cell culture, direct immunofluorescence antibody (DFA) methods, and one-step rtRT-PCR with the designed primer set and probe and the WHO’s. Results The optimized assay results were similar to the WHO’s. The optimized assay results were similar to WHO’s, with non-significant differences for 10–103 copies of viral RNA/reaction (p > 0.05). It detected 10 copies of viral RNA/reaction with high reproducibility and no cross reactivity with other respiratory viruses. A specific cytopathic effect was observed in 6/64 (9.37%) of the ILI group using conventional culture and DFA staining methods; however, it was not seen in non-ILI. Also, the results of our assay and the WHO’s were similar to those of viral isolation and DFA staining. Conclusions Given the high specificity, sensitivity and reproducibility of this novel assay, it can serve as a reliable diagnostic tool for the detection of influenza A viruses in clinical specimens and lab experiments. PMID:27904520

  2. Fourier information optics for the ultrafast time domain.

    PubMed

    Weiner, Andrew M

    2008-02-01

    Ultrafast photonic signal processing based on Fourier optics principles offers exciting possibilities to go beyond the processing speeds of electronics technologies for applications in high-speed fiber communications and ultrawideband wireless. I review our recent work on processing of ultrafast optical signals via conversion between time, space, and optical frequency (Fourier) domains. Specific topics include optical arbitrary waveform generation, application of optical pulse shaping technologies for wavelength-parallel compensation of fiber transmission impairments and for experimental studies of optical code-division multiple-access communications, and application of photonic methods for precompensation of dispersion effects in wireless transmission of radio-frequency signals over ultrawideband antenna links.

  3. Analysis of fMRI time series with mutual information.

    PubMed

    Gómez-Verdejo, Vanessa; Martínez-Ramón, Manel; Florensa-Vila, José; Oliviero, Antonio

    2012-02-01

    Neuroimaging plays a fundamental role in the study of human cognitive neuroscience. Functional magnetic resonance imaging (fMRI), based on the Blood Oxygenation Level Dependent signal, is currently considered as a standard technique for a system level understanding of the human brain. The problem of identifying regionally specific effects in neuroimaging data is usually solved by applying Statistical Parametric Mapping (SPM). Here, a mutual information (MI) criterion is used to identify regionally specific effects produced by a task. In particular, two MI estimators are presented for its use in fMRI data. The first one uses a Parzen probability density estimation, and the second one is based on a K Nearest Neighbours (KNN) estimation. Additionally, a statistical measure has been introduced to automatically detect the voxels which are relevant to the fMRI task. Experiments demonstrate the advantages of MI estimators over SPM maps; firstly, providing more significant differences between relevant and irrelevant voxels; secondly, presenting more focalized activation; and, thirdly, detecting small areas related to the task. These findings, and the improved performance of KNN MI estimator in multisubject and multistimuli studies, make the proposed methods a good alternative to SPM.

  4. Transfer mutual information: A new method for measuring information transfer to the interactions of time series

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaojun; Shang, Pengjian; Lin, Aijing

    2017-02-01

    In this paper, we propose a new method to measure the influence of a third variable on the interactions of two variables. The method called transfer mutual information (TMI) is defined by the difference between the mutual information and the partial mutual information. It is established on the assumption that if the presence or the absence of one variable does make change to the interactions of another two variables, then quantifying this change is supposed to be the influence from this variable to those two variables. Moreover, a normalized TMI and other derivatives of the TMI are introduced as well. The empirical analysis including the simulations as well as real-world applications is investigated to examine this measure and to reveal more information among variables.

  5. Binary versus non-binary information in real time series: empirical results and maximum-entropy matrix models

    NASA Astrophysics Data System (ADS)

    Almog, Assaf; Garlaschelli, Diego

    2014-09-01

    The dynamics of complex systems, from financial markets to the brain, can be monitored in terms of multiple time series of activity of the constituent units, such as stocks or neurons, respectively. While the main focus of time series analysis is on the magnitude of temporal increments, a significant piece of information is encoded into the binary projection (i.e. the sign) of such increments. In this paper we provide further evidence of this by showing strong nonlinear relations between binary and non-binary properties of financial time series. These relations are a novel quantification of the fact that extreme price increments occur more often when most stocks move in the same direction. We then introduce an information-theoretic approach to the analysis of the binary signature of single and multiple time series. Through the definition of maximum-entropy ensembles of binary matrices and their mapping to spin models in statistical physics, we quantify the information encoded into the simplest binary properties of real time series and identify the most informative property given a set of measurements. Our formalism is able to accurately replicate, and mathematically characterize, the observed binary/non-binary relations. We also obtain a phase diagram allowing us to identify, based only on the instantaneous aggregate return of a set of multiple time series, a regime where the so-called ‘market mode’ has an optimal interpretation in terms of collective (endogenous) effects, a regime where it is parsimoniously explained by pure noise, and a regime where it can be regarded as a combination of endogenous and exogenous factors. Our approach allows us to connect spin models, simple stochastic processes, and ensembles of time series inferred from partial information.

  6. Lost in translation: preclinical studies on 3,4-methylenedioxymethamphetamine provide information on mechanisms of action, but do not allow accurate prediction of adverse events in humans

    PubMed Central

    Green, AR; King, MV; Shortall, SE; Fone, KCF

    2012-01-01

    3,4-Methylenedioxymethamphetamine (MDMA) induces both acute adverse effects and long-term neurotoxic loss of brain 5-HT neurones in laboratory animals. However, when choosing doses, most preclinical studies have paid little attention to the pharmacokinetics of the drug in humans or animals. The recreational use of MDMA and current clinical investigations of the drug for therapeutic purposes demand better translational pharmacology to allow accurate risk assessment of its ability to induce adverse events. Recent pharmacokinetic studies on MDMA in animals and humans are reviewed and indicate that the risks following MDMA ingestion should be re-evaluated. Acute behavioural and body temperature changes result from rapid MDMA-induced monoamine release, whereas long-term neurotoxicity is primarily caused by metabolites of the drug. Therefore acute physiological changes in humans are fairly accurately mimicked in animals by appropriate dosing, although allometric dosing calculations have little value. Long-term changes require MDMA to be metabolized in a similar manner in experimental animals and humans. However, the rate of metabolism of MDMA and its major metabolites is slower in humans than rats or monkeys, potentially allowing endogenous neuroprotective mechanisms to function in a species specific manner. Furthermore acute hyperthermia in humans probably limits the chance of recreational users ingesting sufficient MDMA to produce neurotoxicity, unlike in the rat. MDMA also inhibits the major enzyme responsible for its metabolism in humans thereby also assisting in preventing neurotoxicity. These observations question whether MDMA alone produces long-term 5-HT neurotoxicity in human brain, although when taken in combination with other recreational drugs it may induce neurotoxicity. LINKED ARTICLES This article is commented on by Parrott, pp. 1518–1520 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2012.01941.x and to view the the

  7. Rapid automated screening, identification and quantification of organic micro-contaminants and their main transformation products in wastewater and river waters using liquid chromatography-quadrupole-time-of-flight mass spectrometry with an accurate-mass database.

    PubMed

    Gómez, M J; Gómez-Ramos, M M; Malato, O; Mezcua, M; Férnandez-Alba, A R

    2010-11-05

    In this study we have developed and evaluated an analytical method for a rapid automated screening and confirmation of a large number of organic micro-contaminants (almost 400) and also the quantification of the positive findings in water samples of different types (surface and wastewaters) using liquid chromatography-electrospray quadrupole-time-of-flight mass spectrometry (LC-QTOFMS) based on the use of an accurate-mass database. The created database includes data not only on the accurate masses of the target ions but also on the characteristic in-source fragment ions, isotopic pattern and retention time data. This customized database was linked to commercially available software which extracted all the potential compounds of interest from the LC-QTOFMS raw data of each sample and matched them against the database to search for targeted compounds in the sample. The detailed fragmentation information has also been used as a powerful tool for the automatic identification of unknown compounds and/or transformation products with similar structures to those of known organic contaminants included in the database. The database can be continually enlarged. To confirm identification of compounds which have no fragment ions (or fragments with low intensity/relative abundance) from in-source CID fragmentation or isomers which are not distinguished within full single mass spectra, a "Targeted MS/MS" method is developed. Thereafter, these compounds can be further analyzed using the collision energy (CE) in QTOF-MS/MS mode. Linearity and limits of detection were studied. Method detection limits (MDLs) in effluent wastewater and river waters were, in most cases, lowers or equal to 5 and 2 ng/L, respectively. Only 15 compounds had MDLs between 5 and 50 ng/L in effluent wastewater matrix. We obtained a linearity of the calibration curves over two orders of magnitude. The method has been applied to real samples and the results obtained reveal that most of the pharmaceutically

  8. Time course of information representation of macaque AIP neurons in hand manipulation task revealed by information analysis.

    PubMed

    Sakaguchi, Yutaka; Ishida, Fumihiko; Shimizu, Takashi; Murata, Akira

    2010-12-01

    We used mutual information analysis of neuronal activity in the macaque anterior intraparietal area (AIP) to examine information processing during a hand manipulation task. The task was to reach-to-grasp a three-dimensional (3D) object after presentation of a go signal. Mutual information was calculated between the spike counts of individual neurons in 50-ms-wide time bins and six unique shape classifications or 15 one-versus-one classifications of these shapes. The spatiotemporal distribution of mutual information was visualized as a two-dimensional image ("information map") to better observe global profiles of information representation. In addition, a nonnegative matrix factorization technique was applied for extracting its structure. Our major finding was that the time course of mutual information differed significantly according to different classes of task-related neurons. This strongly suggests that different classes of neurons were engaged in different information processing stages in executing the hand manipulation task. On the other hand, our analysis revealed the heterogeneous nature of information representation of AIP neurons. For example, "information latency" (or information onset) varied among individual neurons even in the same neuron class and the same shape classification. Further, some neurons changed "information preference" (i.e., shape classification with the largest amount of information) across different task periods. These suggest that neurons encode different information in the different task periods. Taking the present result together with previous findings, we used a Gantt chart to propose a hypothetical scheme of the dynamic interactions between different types of AIP neurons.

  9. DELIVERING TIMELY ENVIRONMENTAL INFORMATION TO YOUR COMMUNITY: THE BOULDER AREA SUSTAINABILITY INFORMATION NETWORK

    EPA Science Inventory

    The Technology Transfer and Support Division of the EPA Office of Research and Development's (ORD's) National Risk Management Laboratory in conjunction with the Boulder Area Sustainability Information Network (BASIN) has developed a "how-to" handbook to allow other community orga...

  10. Accurate measurement of the jitter time of GaAs photoconductive semiconductor switches triggered by a one-to-two optical fiber

    SciTech Connect

    Shi, Wei; Zhang, Lin; Gui, Huaimeng; Hou, Lei; Xu, Ming; Qu, Guanghui

    2013-04-15

    An improved method is proposed to measure the jitter time of the photoconductive semiconductor switches (PCSSs). A one-to-two fiber is utilized to separate and guide the 1053 nm laser beam to trigger two identical 3-mm-gap GaAs PCSSs synchronously. The jitter time is derived from the time lags of two switches turn-on by the error transfer theory. At a bias voltage of 1 kV, the jitter time is measured as 14.41 ps, which is the lowest jitter of GaAs PCSS that has been reported so far.

  11. Cross time-frequency analysis for combining information of several sources: application to estimation of spontaneous respiratory rate from photoplethysmography.

    PubMed

    Peláez-Coca, M D; Orini, M; Lázaro, J; Bailón, R; Gil, E

    2013-01-01

    A methodology that combines information from several nonstationary biological signals is presented. This methodology is based on time-frequency coherence, that quantifies the similarity of two signals in the time-frequency domain. A cross time-frequency analysis method, based on quadratic time-frequency distribution, has been used for combining information of several nonstationary biomedical signals. In order to evaluate this methodology, the respiratory rate from the photoplethysmographic (PPG) signal is estimated. The respiration provokes simultaneous changes in the pulse interval, amplitude, and width of the PPG signal. This suggests that the combination of information from these sources will improve the accuracy of the estimation of the respiratory rate. Another target of this paper is to implement an algorithm which provides a robust estimation. Therefore, respiratory rate was estimated only in those intervals where the features extracted from the PPG signals are linearly coupled. In 38 spontaneous breathing subjects, among which 7 were characterized by a respiratory rate lower than 0.15 Hz, this methodology provided accurate estimates, with the median error {0.00; 0.98} mHz ({0.00; 0.31}%) and the interquartile range error {4.88; 6.59} mHz ({1.60; 1.92}%). The estimation error of the presented methodology was largely lower than the estimation error obtained without combining different PPG features related to respiration.

  12. Archetypes and architecture of time: an artistic inquiry into the nature of time, space and information

    NASA Astrophysics Data System (ADS)

    Ast, Olga

    2013-09-01

    This paper and poster seek to address several fundamental questions about time. What are the natural phenomena and cognitive structures that underlie the human perception of time? What social constructs have evolved around questioning its nature? How did they arise and evolve over the ages? I have been exploring the subject of time merging my background as a conceptual artist with principles of scientific study. My focus has been on the changing visualizations of time through the evolution of human society, from the earliest depictions of the flowing river or the circular uroboros - a snake eating its own tail - to the linear arrow and the paintings of Dali and Magritte, who depict time with modern metaphors of a clock, a train, or the 4th dimension. How have these images influenced scientific, religious and philosophical thought surrounding time? Drawn by now from our collective subconscious, do they naturally bias us towards particular conventional models? And finally, how can an analysis of the visual metaphors of time contribute to the larger dialogue, one that involves scientists, technologists and philosophers, each with their own theories on the subject? This project attempts to answer these questions, and to propose that art is an essential voice in any discussion about time. Can artists and scientists working together bring us closer to an answer to the age-old question - what is time?

  13. Integrating trans-abdominal ultrasonography with fecal steroid metabolite monitoring to accurately diagnose pregnancy and predict the timing of parturition in the red panda (Ailurus fulgens styani).

    PubMed

    Curry, Erin; Browning, Lissa J; Reinhart, Paul; Roth, Terri L

    2017-02-23

    Red pandas (Ailurus fulgens styani) exhibit a variable gestation length and may experience a pseudopregnancy indistinguishable from true pregnancy; therefore, it is not possible to deduce an individual's true pregnancy status and parturition date based on breeding dates or fecal progesterone excretion patterns alone. The goal of this study was to evaluate the use of transabdominal ultrasonography for pregnancy diagnosis in red pandas. Two to three females were monitored over 4 consecutive years, generating a total of seven profiles (four pregnancies, two pseudopregnancies, and one lost pregnancy). Fecal samples were collected and assayed for progesterone (P4) and estrogen conjugate (EC) to characterize patterns associated with breeding activity and parturition events. Animals were trained for voluntary transabdominal ultrasound and examinations were performed weekly. Breeding behaviors and fecal EC data suggest that the estrus cycle of this species is 11-12 days in length. Fecal steroid metabolite analyses also revealed that neither P4 nor EC concentrations were suitable indicators of pregnancy in this species; however, a secondary increase in P4 occurred 69-71 days prior to parturition in all pregnant females, presumably coinciding with embryo implantation. Using ultrasonography, embryos were detected as early as 62 days post-breeding/50 days pre-partum and serial measurements of uterine lumen diameter were documented throughout four pregnancies. Advances in reproductive diagnostics, such as the implementation of ultrasonography, may facilitate improved husbandry of pregnant females and allow for the accurate prediction of parturition.

  14. Accurate mass determination, quantification and determination of detection limits in liquid chromatography-high-resolution time-of-flight mass spectrometry: challenges and practical solutions.

    PubMed

    Vergeynst, Leendert; Van Langenhove, Herman; Joos, Pieter; Demeestere, Kristof

    2013-07-30

    Uniform guidelines for the data processing and validation of qualitative and quantitative multi-residue analysis using full-spectrum high-resolution mass spectrometry are scarce. Through systematic research, optimal mass accuracy and sensitivity are obtained after refining the post-processing of the HRMS data. For qualitative analysis, transforming the raw profile spectra to centroid spectra is recommended resulting in a 2.3 fold improved precision on the accurate mass determination of spectrum peaks. However, processing centroid data for quantitative purposes could lead to signal interruption when too narrow mass windows are applied for the construction of extracted ion chromatograms. Therefore, peak integration on the raw profile data is recommended. An optimal width of the mass window of 50 ppm, which is a trade-off between sensitivity and selectivity, was obtained for a TOF instrument providing a resolving power of 20,000 at full width at half maximum (FWHM). For the validation of HRMS analytical methods, widespread concepts such as the signal-to-noise ratios for the determination of decision limits and detection capabilities have shown to be not always applicable because in some cases almost no noise can be detected anymore. A statistical methodology providing a reliable alternative is extended and applied.

  15. Modelling financial markets with agents competing on different time scales and with different amount of information

    NASA Astrophysics Data System (ADS)

    Wohlmuth, Johannes; Andersen, Jørgen Vitting

    2006-05-01

    We use agent-based models to study the competition among investors who use trading strategies with different amount of information and with different time scales. We find that mixing agents that trade on the same time scale but with different amount of information has a stabilizing impact on the large and extreme fluctuations of the market. Traders with the most information are found to be more likely to arbitrage traders who use less information in the decision making. On the other hand, introducing investors who act on two different time scales has a destabilizing effect on the large and extreme price movements, increasing the volatility of the market. Closeness in time scale used in the decision making is found to facilitate the creation of local trends. The larger the overlap in commonly shared information the more the traders in a mixed system with different time scales are found to profit from the presence of traders acting at another time scale than themselves.

  16. Validation of reference genes for accurate normalization of gene expression for real time-quantitative PCR in strawberry fruits using different cultivars and osmotic stresses.

    PubMed

    Galli, Vanessa; Borowski, Joyce Moura; Perin, Ellen Cristina; Messias, Rafael da Silva; Labonde, Julia; Pereira, Ivan dos Santos; Silva, Sérgio Delmar Dos Anjos; Rombaldi, Cesar Valmor

    2015-01-10

    The increasing demand of strawberry (Fragaria×ananassa Duch) fruits is associated mainly with their sensorial characteristics and the content of antioxidant compounds. Nevertheless, the strawberry production has been hampered due to its sensitivity to abiotic stresses. Therefore, to understand the molecular mechanisms highlighting stress response is of great importance to enable genetic engineering approaches aiming to improve strawberry tolerance. However, the study of expression of genes in strawberry requires the use of suitable reference genes. In the present study, seven traditional and novel candidate reference genes were evaluated for transcript normalization in fruits of ten strawberry cultivars and two abiotic stresses, using RefFinder, which integrates the four major currently available software programs: geNorm, NormFinder, BestKeeper and the comparative delta-Ct method. The results indicate that the expression stability is dependent on the experimental conditions. The candidate reference gene DBP (DNA binding protein) was considered the most suitable to normalize expression data in samples of strawberry cultivars and under drought stress condition, and the candidate reference gene HISTH4 (histone H4) was the most stable under osmotic stresses and salt stress. The traditional genes GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and 18S (18S ribosomal RNA) were considered the most unstable genes in all conditions. The expression of phenylalanine ammonia lyase (PAL) and 9-cis epoxycarotenoid dioxygenase (NCED1) genes were used to further confirm the validated candidate reference genes, showing that the use of an inappropriate reference gene may induce erroneous results. This study is the first survey on the stability of reference genes in strawberry cultivars and osmotic stresses and provides guidelines to obtain more accurate RT-qPCR results for future breeding efforts.

  17. Argon Cluster Sputtering Source for ToF-SIMS Depth Profiling of Insulating Materials: High Sputter Rate and Accurate Interfacial Information

    SciTech Connect

    Wang, Zhaoying; Liu, Bingwen; Zhao, Evan; Jin, Ke; Du, Yingge; Neeway, James J.; Ryan, Joseph V.; Hu, Dehong; Zhang, Hongliang; Hong, Mina; Le Guernic, Solenne; Thevuthasan, Suntharampillai; Wang, Fuyi; Zhu, Zihua

    2015-08-01

    For the first time, the use of an argon cluster ion sputtering source has been demonstrated to perform superiorly relative to traditional oxygen and cesium ion sputtering sources for ToF-SIMS depth profiling of insulating materials. The superior performance has been attributed to effective alleviation of surface charging. A simulated nuclear waste glass, SON68, and layered hole-perovskite oxide thin films were selected as model systems due to their fundamental and practical significance. Our study shows that if the size of analysis areas is same, the highest sputter rate of argon cluster sputtering can be 2-3 times faster than the highest sputter rates of oxygen or cesium sputtering. More importantly, high quality data and high sputter rates can be achieved simultaneously for argon cluster sputtering while this is not the case for cesium and oxygen sputtering. Therefore, for deep depth profiling of insulating samples, the measurement efficiency of argon cluster sputtering can be about 6-15 times better than traditional cesium and oxygen sputtering. Moreover, for a SrTiO3/SrCrO3 bi-layer thin film on a SrTiO3 substrate, the true 18O/16O isotopic distribution at the interface is better revealed when using the argon cluster sputtering source. Therefore, the implementation of an argon cluster sputtering source can significantly improve the measurement efficiency of insulating materials, and thus can expand the application of ToF-SIMS to the study of glass corrosion, perovskite oxide thin films, and many other potential systems.

  18. Online Discussion Compensates for Suboptimal Timing of Supportive Information Presentation in a Digitally Supported Learning Environment

    ERIC Educational Resources Information Center

    Noroozi, Omid; Busstra, Maria C.; Mulder, Martin; Biemans, Harm J. A.; Tobi, Hilde; Geelen, Anouk; van't Veer, Pieter; Chizari, Mohammad

    2012-01-01

    This study used a sequential set-up to investigate the consecutive effects of timing of supportive information presentation (information before vs. information during the learning task clusters) in interactive digital learning materials (IDLMs) and type of collaboration (personal discussion vs. online discussion) in computer-supported…

  19. Identifying the Critical Time Period for Information Extraction when Recognizing Sequences of Play

    ERIC Educational Resources Information Center

    North, Jamie S.; Williams, A. Mark

    2008-01-01

    The authors attempted to determine the critical time period for information extraction when recognizing play sequences in soccer. Although efforts have been made to identify the perceptual information underpinning such decisions, no researchers have attempted to determine "when" this information may be extracted from the display. The authors…

  20. Accurate spectral color measurements

    NASA Astrophysics Data System (ADS)

    Hiltunen, Jouni; Jaeaeskelaeinen, Timo; Parkkinen, Jussi P. S.

    1999-08-01

    Surface color measurement is of importance in a very wide range of industrial applications including paint, paper, printing, photography, textiles, plastics and so on. For a demanding color measurements spectral approach is often needed. One can measure a color spectrum with a spectrophotometer using calibrated standard samples as a reference. Because it is impossible to define absolute color values of a sample, we always work with approximations. The human eye can perceive color difference as small as 0.5 CIELAB units and thus distinguish millions of colors. This 0.5 unit difference should be a goal for the precise color measurements. This limit is not a problem if we only want to measure the color difference of two samples, but if we want to know in a same time exact color coordinate values accuracy problems arise. The values of two instruments can be astonishingly different. The accuracy of the instrument used in color measurement may depend on various errors such as photometric non-linearity, wavelength error, integrating sphere dark level error, integrating sphere error in both specular included and specular excluded modes. Thus the correction formulas should be used to get more accurate results. Another question is how many channels i.e. wavelengths we are using to measure a spectrum. It is obvious that the sampling interval should be short to get more precise results. Furthermore, the result we get is always compromise of measuring time, conditions and cost. Sometimes we have to use portable syste or the shape and the size of samples makes it impossible to use sensitive equipment. In this study a small set of calibrated color tiles measured with the Perkin Elmer Lamda 18 and the Minolta CM-2002 spectrophotometers are compared. In the paper we explain the typical error sources of spectral color measurements, and show which are the accuracy demands a good colorimeter should have.

  1. Evaluation of comprehensive two-dimensional gas chromatography with accurate mass time-of-flight mass spectrometry for the metabolic profiling of plant-fungus interaction in Aquilaria malaccensis.

    PubMed

    Wong, Yong Foo; Chin, Sung-Tong; Perlmutter, Patrick; Marriott, Philip J

    2015-03-27

    To explore the possible obligate interactions between the phytopathogenic fungus and Aquilaria malaccensis which result in generation of a complex array of secondary metabolites, we describe a comprehensive two-dimensional gas chromatography (GC × GC) method, coupled to accurate mass time-of-flight mass spectrometry (TOFMS) for the untargeted and comprehensive metabolic profiling of essential oils from naturally infected A. malaccensis trees. A polar/non-polar column configuration was employed, offering an improved separation pattern of components when compared to other column sets. Four different grades of the oils displayed quite different metabolic patterns, suggesting the evolution of a signalling relationship between the host tree (emergence of various phytoalexins) and fungi (activation of biotransformation). In total, ca. 550 peaks/metabolites were detected, of which tentative identification of 155 of these compounds was reported, representing between 20.1% and 53.0% of the total ion count. These are distributed over the chemical families of monoterpenic and sesquiterpenic hydrocarbons, oxygenated monoterpenes and sesquiterpenes (comprised of ketone, aldehyde, oxide, alcohol, lactone, keto-alcohol and diol), norterpenoids, diterpenoids, short chain glycols, carboxylic acids and others. The large number of metabolites detected, combined with the ease with which they are located in the 2D separation space, emphasises the importance of a comprehensive analytical approach for the phytochemical analysis of plant metabolomes. Furthermore, the potential of this methodology in grading agarwood oils by comparing the obtained metabolic profiles (pattern recognition for unique metabolite chemical families) is discussed. The phytocomplexity of the agarwood oils signified the production of a multitude of plant-fungus mediated secondary metabolites as chemical signals for natural ecological communication. To the best of our knowledge, this is the most complete

  2. Cognitive tasks in information analysis: Use of event dwell time to characterize component activities

    SciTech Connect

    Sanquist, Thomas F.; Greitzer, Frank L.; Slavich, Antoinette L.; Littlefield, Rik J.; Littlefield, Janis S.; Cowley, Paula J.

    2004-09-28

    Technology-based enhancement of information analysis requires a detailed understanding of the cognitive tasks involved in the process. The information search and report production tasks of the information analysis process were investigated through evaluation of time-stamped workstation data gathered with custom software. Model tasks simulated the search and production activities, and a sample of actual analyst data were also evaluated. Task event durations were calculated on the basis of millisecond-level time stamps, and distributions were plotted for analysis. The data indicate that task event time shows a cyclic pattern of variation, with shorter event durations (< 2 sec) reflecting information search and filtering, and longer event durations (> 10 sec) reflecting information evaluation. Application of cognitive principles to the interpretation of task event time data provides a basis for developing “cognitive signatures” of complex activities, and can facilitate the development of technology aids for information intensive tasks.

  3. 12 CFR 1024.6 - Special information booklet at time of loan application.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 8 2012-01-01 2012-01-01 false Special information booklet at time of loan application. 1024.6 Section 1024.6 Banks and Banking BUREAU OF CONSUMER FINANCIAL PROTECTION REAL ESTATE SETTLEMENT PROCEDURES ACT (REGULATION X) § 1024.6 Special information booklet at time of loan application....

  4. 76 FR 31682 - Agency Information Collection (Time Record (Work-Study Program)) Activity Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... AFFAIRS Agency Information Collection (Time Record (Work-Study Program)) Activity Under OMB Review AGENCY... INFORMATION: Title: Time Record (Work-Study Program), VA Form 22-8690. OMB Control Number: 2900-0379. Type of... 22-8690 to report the number of work-study hours a claimant has completed. When a claimant elects...

  5. Spectroscopy by Integration of Frequency and Time Domain Information (SIFT) for Fast Acquisition of High Resolution Dark Spectra

    PubMed Central

    Matsuki, Yoh; Eddy, Matthew T.; Herzfeld, Judith

    2009-01-01

    A simple and effective method, SIFT (Spectroscopy by Integrating Frequency and Time domain information) is introduced for processing non-uniformly sampled multidimensional NMR data. Applying the computationally efficient Gerchberg-Papoulis (G-P) algorithm, used previously in picture processing and medical imaging, SIFT supplements data at non-uniform points in the time domain with the information carried by known “dark” points (i.e. empty regions) in the frequency domain. We demonstrate that this rapid integration not only removes the severe pseudo-noise characteristic of the Fourier transforms of non-uniformly sampled data, but also provides a robust procedure for using frequency information to replace time measurements. The latter can be used to avoid unnecessary sampling in sampling-limited experiments and the former can be used to take advantage of the ability of non-uniformly sampled data to minimize trade-offs between the signal-to-noise ratio and the resolution in sensitivity-limited experiments. Processing 2D and 3D datasets takes about 0.1 and 2 min, respectively, on a personal computer. With these several attractive features, SIFT offers a novel, model-independent, flexible, and user-friendly tool for efficient and accurate processing of multidimensional NMR data. PMID:19284727

  6. Spectroscopy by integration of frequency and time domain information for fast acquisition of high-resolution dark spectra.

    PubMed

    Matsuki, Yoh; Eddy, Matthew T; Herzfeld, Judith

    2009-04-08

    A simple and effective method, SIFT (spectroscopy by integration of frequency and time domain information), is introduced for processing nonuniformly sampled multidimensional NMR data. Applying the computationally efficient Gerchberg-Papoulis (G-P) algorithm, used previously in picture processing and medical imaging, SIFT supplements data at nonuniform points in the time domain with the information carried by known "dark" points (i.e., empty regions) in the frequency domain. We demonstrate that this rapid integration not only removes the severe pseudonoise characteristic of the Fourier transforms of nonuniformly sampled data, but also provides a robust procedure for using frequency information to replace time measurements. The latter can be used to avoid unnecessary sampling in sampling-limited experiments, and the former can be used to take advantage of the ability of nonuniformly sampled data to minimize trade-offs between the signal-to-noise ratio and the resolution in sensitivity-limited experiments. Processing 2D and 3D data sets takes about 0.1 and 2 min, respectively, on a personal computer. With these several attractive features, SIFT offers a novel, model-independent, flexible, and user-friendly tool for efficient and accurate processing of multidimensional NMR data.

  7. A uniformly accurate multiscale time integrator spectral method for the Klein-Gordon-Zakharov system in the high-plasma-frequency limit regime

    NASA Astrophysics Data System (ADS)

    Bao, Weizhu; Zhao, Xiaofei

    2016-12-01

    A multiscale time integrator sine pseudospectral (MTI-SP) method is presented for discretizing the Klein-Gordon-Zakharov (KGZ) system with a dimensionless parameter 0 < ε ≤ 1, which is inversely proportional to the plasma frequency. In the high-plasma-frequency limit regime, i.e. 0 < ε ≪ 1, the solution of the KGZ system propagates waves with amplitude at O (1) and wavelength at O (ε2) in time and O (1) in space, which causes significantly numerical burdens due to the high oscillation in time. The main idea of the numerical method is to carry out a multiscale decomposition by frequency (MDF) to the electric field component of the solution at each time step and then apply the sine pseudospectral discretization for spatial derivatives followed by using the exponential wave integrator in phase space for integrating the MDF and the equation of the ion density component. The method is explicit and easy to be implemented. Extensive numerical results show that the MTI-SP method converges uniformly and optimally in space with exponential convergence rate if the solution is smooth, and uniformly in time with linear convergence rate at O (τ) for ε ∈ (0 , 1 ] with τ time step size and optimally with quadratic convergence rate at O (τ2) in the regime when either ε = O (1) or 0 < ε ≤ τ. Thus the meshing strategy requirement (or ε-scalability) of the MTI-SP for the KGZ system in the high-plasma-frequency limit regime is τ = O (1) and h = O (1) for 0 < ε ≪ 1, which is significantly better than classical methods in the literatures. Finally, we apply the MTI-SP method to study the convergence rates of the KGZ system to its limiting models in the high-plasma-frequency limit and the interactions of bright solitons of the KGZ system, and to identify certain parameter regimes that the solution of the KGZ system will be blow-up in one dimension.

  8. Development of a Rapid and Accurate Identification Method for Citrobacter Species Isolated from Pork Products Using a Matrix-Assisted Laser-Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS).

    PubMed

    Kwak, Hye-Lim; Han, Sun-Kyung; Park, Sunghoon; Park, Si Hong; Shim, Jae-Yong; Oh, Mihwa; Ricke, Steven C; Kim, Hae-Yeong

    2015-09-01

    Previous detection methods for Citrobacter are considered time consuming and laborious. In this study, we have developed a rapid and accurate detection method for Citrobacter species in pork products, using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). A total of 35 Citrobacter strains were isolated from 30 pork products and identified by both MALDI-TOF MS and 16S rRNA gene sequencing approaches. All isolates were identified to the species level by the MALDI-TOF MS, while 16S rRNA gene sequencing results could not discriminate them clearly. These results confirmed that MALDI-TOF MS is a more accurate and rapid detection method for the identification of Citrobacter species.

  9. Rapid and accurate typing of Bordetella pertussis targeting genes encoding acellular vaccine antigens using real time PCR and High Resolution Melt analysis.

    PubMed

    Chan, Wai-Fong; Maharjan, Ram P; Reeves, Peter R; Sintchenko, Vitali; Gilbert, Gwendolyn L; Lan, Ruiting

    2009-06-01

    Real Time-PCR (RT-PCR) and high resolution melt (HRM) analyses were used for rapid typing of genes encoding components of the pertussis acellular vaccine, namely prn, ptxA, fhaB, fim2 and fim3. The length polymorphisms in prn were detected by RT-PCR followed by HRM; single nucleotide polymorphisms in prn and other genes were detected by hairpin primer RT-PCR. These rapid methods are suitable for large-scale studies of vaccine-driven evolution of Bordetella pertussis.

  10. Time resolution dependence of information measures for spiking neurons: scaling and universality.

    PubMed

    Marzen, Sarah E; DeWeese, Michael R; Crutchfield, James P

    2015-01-01

    The mutual information between stimulus and spike-train response is commonly used to monitor neural coding efficiency, but neuronal computation broadly conceived requires more refined and targeted information measures of input-output joint processes. A first step toward that larger goal is to develop information measures for individual output processes, including information generation (entropy rate), stored information (statistical complexity), predictable information (excess entropy), and active information accumulation (bound information rate). We calculate these for spike trains generated by a variety of noise-driven integrate-and-fire neurons as a function of time resolution and for alternating renewal processes. We show that their time-resolution dependence reveals coarse-grained structural properties of interspike interval statistics; e.g., τ-entropy rates that diverge less quickly than the firing rate indicated by interspike interval correlations. We also find evidence that the excess entropy and regularized statistical complexity of different types of integrate-and-fire neurons are universal in the continuous-time limit in the sense that they do not depend on mechanism details. This suggests a surprising simplicity in the spike trains generated by these model neurons. Interestingly, neurons with gamma-distributed ISIs and neurons whose spike trains are alternating renewal processes do not fall into the same universality class. These results lead to two conclusions. First, the dependence of information measures on time resolution reveals mechanistic details about spike train generation. Second, information measures can be used as model selection tools for analyzing spike train processes.

  11. Visualization of Time-Series Sensor Data to Inform the Design of Just-In-Time Adaptive Stress Interventions.

    PubMed

    Sharmin, Moushumi; Raij, Andrew; Epstien, David; Nahum-Shani, Inbal; Beck, J Gayle; Vhaduri, Sudip; Preston, Kenzie; Kumar, Santosh

    2015-09-01

    We investigate needs, challenges, and opportunities in visualizing time-series sensor data on stress to inform the design of just-in-time adaptive interventions (JITAIs). We identify seven key challenges: massive volume and variety of data, complexity in identifying stressors, scalability of space, multifaceted relationship between stress and time, a need for representation at multiple granularities, interperson variability, and limited understanding of JITAI design requirements due to its novelty. We propose four new visualizations based on one million minutes of sensor data (n=70). We evaluate our visualizations with stress researchers (n=6) to gain first insights into its usability and usefulness in JITAI design. Our results indicate that spatio-temporal visualizations help identify and explain between- and within-person variability in stress patterns and contextual visualizations enable decisions regarding the timing, content, and modality of intervention. Interestingly, a granular representation is considered informative but noise-prone; an abstract representation is the preferred starting point for designing JITAIs.

  12. Multiplexed highly-accurate DNA sequencing of closely-related HIV-1 variants using continuous long reads from single molecule, real-time sequencing.

    PubMed

    Dilernia, Dario A; Chien, Jung-Ting; Monaco, Daniela C; Brown, Michael P S; Ende, Zachary; Deymier, Martin J; Yue, Ling; Paxinos, Ellen E; Allen, Susan; Tirado-Ramos, Alfredo; Hunter, Eric

    2015-11-16

    Single Molecule, Real-Time (SMRT) Sequencing (Pacific Biosciences, Menlo Park, CA, USA) provides the longest continuous DNA sequencing reads currently available. However, the relatively high error rate in the raw read data requires novel analysis methods to deconvolute sequences derived from complex samples. Here, we present a workflow of novel computer algorithms able to reconstruct viral variant genomes present in mixtures with an accuracy of >QV50. This approach relies exclusively on Continuous Long Reads (CLR), which are the raw reads generated during SMRT Sequencing. We successfully implement this workflow for simultaneous sequencing of mixtures containing up to forty different >9 kb HIV-1 full genomes. This was achieved using a single SMRT Cell for each mixture and desktop computing power. This novel approach opens the possibility of solving complex sequencing tasks that currently lack a solution.

  13. Multi-residue screening of veterinary drugs in egg, fish and meat using high-resolution liquid chromatography accurate mass time-of-flight mass spectrometry.

    PubMed

    Peters, R J B; Bolck, Y J C; Rutgers, P; Stolker, A A M; Nielen, M W F

    2009-11-13

    The last 2 years multi-compound methods are gaining ground as screening methods. In this study a high-resolution liquid chromatography combined with time-of-flight mass spectrometry (HRLC-ToF-MS) is tested for the screening of about 100 veterinary drugs in three matrices, meat, fish and egg. While the results are satisfactory for 70-90% of the veterinary drugs, a more efficient sample preparation or extract purification is required for quantitative analysis of all analytes in more difficult matrices like egg. The average mass measurement error of the ToF-MS for the veterinary drugs spiked at concentrations ranging from 4 to 400 microg/kg, is 3.0 ppm (median 2.5 ppm) with little difference between the three matrices, but slightly decreases with increasing concentration. The SigmaFit value, a new feature for isotope pattern matching, also decreases with increasing concentration and, in addition, shows an increase with increasing matrix complexity. While the average SigmaFit value is 0.04, the median is 0.01 indicating some high individual deviations. As with the mass measurement error, the highest deviations are found in those regions of the chromatogram where most compounds elute from the column, be it analytes or matrix compounds. The median repeatability of the method ranges from 8% to 15%, decreasing with increasing concentration, while the median reproducibility ranges from 15% to 20% with little difference between matrices and concentrations. The median accuracy is in between 70% and 100% with a few compounds showing higher values due to matrix interference. The squared regression coefficient is >0.99 for 92% of the compounds showing a good overall linearity for most compounds. The detection capability, CCbeta, is within 2 times the associated validation level for >90% of the compounds studied. By changing a few conditions in the analyses protocol and analysing a number of blank samples, it was determined that the method is robust as well as specific. Finally

  14. Accurate detection and quantification of the fish viral hemorrhagic Septicemia virus (VHSv) with a two-color fluorometric real-time PCR assay.

    PubMed

    Pierce, Lindsey R; Willey, James C; Palsule, Vrushalee V; Yeo, Jiyoun; Shepherd, Brian S; Crawford, Erin L; Stepien, Carol A

    2013-01-01

    Viral Hemorrhagic Septicemia virus (VHSv) is one of the world's most serious fish pathogens, infecting >80 marine, freshwater, and estuarine fish species from Eurasia and North America. A novel and especially virulent strain - IVb - appeared in the Great Lakes in 2003, has killed many game fish species in a series of outbreaks in subsequent years, and shut down interstate transport of baitfish. Cell culture is the diagnostic method approved by the USDA-APHIS, which takes a month or longer, lacks sensitivity, and does not quantify the amount of virus. We thus present a novel, easy, rapid, and highly sensitive real-time quantitative reverse transcription PCR (qRT-PCR) assay that incorporates synthetic competitive template internal standards for quality control to circumvent false negative results. Results demonstrate high signal-to-analyte response (slope = 1.00±0.02) and a linear dynamic range that spans seven orders of magnitude (R(2) = 0.99), ranging from 6 to 6,000,000 molecules. Infected fishes are found to harbor levels of virus that range to 1,200,000 VHSv molecules/10(6) actb1 molecules with 1,000 being a rough cut-off for clinical signs of disease. This new assay is rapid, inexpensive, and has significantly greater accuracy than other published qRT-PCR tests and traditional cell culture diagnostics.

  15. Rapid and accurate detection of the CFTR gene mutation 1811+1.6 kbA>G by real-time fluorescence resonance energy transfer PCR.

    PubMed

    Reboul, Marie-Pierre; Higueret, Laurent; Biteau, Nicolas; Iron, Albert

    2005-10-01

    The CFTR gene mutation 1811+1.6 kbA>G has been reported as associated with a severe phenotype of cystic fibrosis with pancreatic insufficiency. This mutation has been identified as a rather common one in the South West of France and in the Iberian Peninsula. Because of the precise geographical origin of the subjects and its frequency, the mutation has to be investigated with accuracy. We have developed an original real-time Fluorescence Resonance Energy Transfer (FRET) PCR assay for genotyping the mutation 1811+1.6 kbA>G. It is based on the amplification of a region spanning the mutation with simultaneous detection of the amplicon by hybridization with a bi-probe followed by a melting curve analysis. The results obtained are identical with those resulting from either restriction fragment length polymorphism analysis or sequencing. The distinction between the wild type and the mutation 1811+1.6 kbA>G is easy because the corresponding melting points shows a difference of 6 or 9.5 degrees C depending on the associated SNP A/T located 16 bp downstream. We demonstrated that a FRET assay showed enough sensitivity to discriminate between two nucleotide polymorphisms (SNPs) in the sequence of the sensor. In conclusion, this method is specific, fast, easy to perform, reproducible, inexpensive as it uses only one bi-probe and well adapted to daily practice.

  16. Accurate Detection and Quantification of the Fish Viral Hemorrhagic Septicemia virus (VHSv) with a Two-Color Fluorometric Real-Time PCR Assay

    PubMed Central

    Palsule, Vrushalee V.; Yeo, Jiyoun; Shepherd, Brian S.; Crawford, Erin L.; Stepien, Carol A.

    2013-01-01

    Viral Hemorrhagic Septicemia virus (VHSv) is one of the world's most serious fish pathogens, infecting >80 marine, freshwater, and estuarine fish species from Eurasia and North America. A novel and especially virulent strain – IVb – appeared in the Great Lakes in 2003, has killed many game fish species in a series of outbreaks in subsequent years, and shut down interstate transport of baitfish. Cell culture is the diagnostic method approved by the USDA-APHIS, which takes a month or longer, lacks sensitivity, and does not quantify the amount of virus. We thus present a novel, easy, rapid, and highly sensitive real-time quantitative reverse transcription PCR (qRT-PCR) assay that incorporates synthetic competitive template internal standards for quality control to circumvent false negative results. Results demonstrate high signal-to-analyte response (slope = 1.00±0.02) and a linear dynamic range that spans seven orders of magnitude (R2 = 0.99), ranging from 6 to 6,000,000 molecules. Infected fishes are found to harbor levels of virus that range to 1,200,000 VHSv molecules/106 actb1 molecules with 1,000 being a rough cut-off for clinical signs of disease. This new assay is rapid, inexpensive, and has significantly greater accuracy than other published qRT-PCR tests and traditional cell culture diagnostics. PMID:23977162

  17. 75 FR 1119 - Agency Information Collection (Survey of Appropriate and Timely Diagnosis of Infectious Diseases...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-08

    ... Timely Diagnosis of Infectious Diseases (Leishmaniasis), VA Form 10-0476. b. Survey of Appropriate and Timely Diagnosis of Infectious Diseases (Malaria), VA Form 10-0476a. OMB Control Number: 2900-New (VA... Information Collection (Survey of Appropriate and Timely Diagnosis of Infectious Diseases) Activity Under...

  18. 26 CFR 1.6081-8 - Automatic extension of time to file certain information returns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Automatic extension of time to file certain... TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Extension of Time for Filing Returns § 1.6081-8 Automatic extension of time to file certain information returns. (a) In general. Except as provided...

  19. Evaluation of reference genes for accurate normalization of gene expression for real time-quantitative PCR in Pyrus pyrifolia using different tissue samples and seasonal conditions.

    PubMed

    Imai, Tsuyoshi; Ubi, Benjamin E; Saito, Takanori; Moriguchi, Takaya

    2014-01-01

    We have evaluated suitable reference genes for real time (RT)-quantitative PCR (qPCR) analysis in Japanese pear (Pyrus pyrifolia). We tested most frequently used genes in the literature such as β-Tubulin, Histone H3, Actin, Elongation factor-1α, Glyceraldehyde-3-phosphate dehydrogenase, together with newly added genes Annexin, SAND and TIP41. A total of 17 primer combinations for these eight genes were evaluated using cDNAs synthesized from 16 tissue samples from four groups, namely: flower bud, flower organ, fruit flesh and fruit skin. Gene expression stabilities were analyzed using geNorm and NormFinder software packages or by ΔCt method. geNorm analysis indicated three best performing genes as being sufficient for reliable normalization of RT-qPCR data. Suitable reference genes were different among sample groups, suggesting the importance of validation of gene expression stability of reference genes in the samples of interest. Ranking of stability was basically similar between geNorm and NormFinder, suggesting usefulness of these programs based on different algorithms. ΔCt method suggested somewhat different results in some groups such as flower organ or fruit skin; though the overall results were in good correlation with geNorm or NormFinder. Gene expression of two cold-inducible genes PpCBF2 and PpCBF4 were quantified using the three most and the three least stable reference genes suggested by geNorm. Although normalized quantities were different between them, the relative quantities within a group of samples were similar even when the least stable reference genes were used. Our data suggested that using the geometric mean value of three reference genes for normalization is quite a reliable approach to evaluating gene expression by RT-qPCR. We propose that the initial evaluation of gene expression stability by ΔCt method, and subsequent evaluation by geNorm or NormFinder for limited number of superior gene candidates will be a practical way of finding out

  20. A system for accurate and automated injection of hyperpolarized substrate with minimal dead time and scalable volumes over a large range.

    PubMed

    Reynolds, Steven; Bucur, Adriana; Port, Michael; Alizadeh, Tooba; Kazan, Samira M; Tozer, Gillian M; Paley, Martyn N J

    2014-02-01

    Over recent years hyperpolarization by dissolution dynamic nuclear polarization has become an established technique for studying metabolism in vivo in animal models. Temporal signal plots obtained from the injected metabolite and daughter products, e.g. pyruvate and lactate, can be fitted to compartmental models to estimate kinetic rate constants. Modeling and physiological parameter estimation can be made more robust by consistent and reproducible injections through automation. An injection system previously developed by us was limited in the injectable volume to between 0.6 and 2.4ml and injection was delayed due to a required syringe filling step. An improved MR-compatible injector system has been developed that measures the pH of injected substrate, uses flow control to reduce dead volume within the injection cannula and can be operated over a larger volume range. The delay time to injection has been minimized by removing the syringe filling step by use of a peristaltic pump. For 100μl to 10.000ml, the volume range typically used for mice to rabbits, the average delivered volume was 97.8% of the demand volume. The standard deviation of delivered volumes was 7μl for 100μl and 20μl for 10.000ml demand volumes (mean S.D. was 9 ul in this range). In three repeat injections through a fixed 0.96mm O.D. tube the coefficient of variation for the area under the curve was 2%. For in vivo injections of hyperpolarized pyruvate in tumor-bearing rats, signal was first detected in the input femoral vein cannula at 3-4s post-injection trigger signal and at 9-12s in tumor tissue. The pH of the injected pyruvate was 7.1±0.3 (mean±S.D., n=10). For small injection volumes, e.g. less than 100μl, the internal diameter of the tubing contained within the peristaltic pump could be reduced to improve accuracy. Larger injection volumes are limited only by the size of the receiving vessel connected to the pump.

  1. A system for accurate and automated injection of hyperpolarized substrate with minimal dead time and scalable volumes over a large range☆

    PubMed Central

    Reynolds, Steven; Bucur, Adriana; Port, Michael; Alizadeh, Tooba; Kazan, Samira M.; Tozer, Gillian M.; Paley, Martyn N.J.

    2014-01-01

    Over recent years hyperpolarization by dissolution dynamic nuclear polarization has become an established technique for studying metabolism in vivo in animal models. Temporal signal plots obtained from the injected metabolite and daughter products, e.g. pyruvate and lactate, can be fitted to compartmental models to estimate kinetic rate constants. Modeling and physiological parameter estimation can be made more robust by consistent and reproducible injections through automation. An injection system previously developed by us was limited in the injectable volume to between 0.6 and 2.4 ml and injection was delayed due to a required syringe filling step. An improved MR-compatible injector system has been developed that measures the pH of injected substrate, uses flow control to reduce dead volume within the injection cannula and can be operated over a larger volume range. The delay time to injection has been minimized by removing the syringe filling step by use of a peristaltic pump. For 100 μl to 10.000 ml, the volume range typically used for mice to rabbits, the average delivered volume was 97.8% of the demand volume. The standard deviation of delivered volumes was 7 μl for 100 μl and 20 μl for 10.000 ml demand volumes (mean S.D. was 9 ul in this range). In three repeat injections through a fixed 0.96 mm O.D. tube the coefficient of variation for the area under the curve was 2%. For in vivo injections of hyperpolarized pyruvate in tumor-bearing rats, signal was first detected in the input femoral vein cannula at 3–4 s post-injection trigger signal and at 9–12 s in tumor tissue. The pH of the injected pyruvate was 7.1 ± 0.3 (mean ± S.D., n = 10). For small injection volumes, e.g. less than 100 μl, the internal diameter of the tubing contained within the peristaltic pump could be reduced to improve accuracy. Larger injection volumes are limited only by the size of the receiving vessel connected to the pump. PMID:24355621

  2. A system for accurate and automated injection of hyperpolarized substrate with minimal dead time and scalable volumes over a large range

    NASA Astrophysics Data System (ADS)

    Reynolds, Steven; Bucur, Adriana; Port, Michael; Alizadeh, Tooba; Kazan, Samira M.; Tozer, Gillian M.; Paley, Martyn N. J.

    2014-02-01

    Over recent years hyperpolarization by dissolution dynamic nuclear polarization has become an established technique for studying metabolism in vivo in animal models. Temporal signal plots obtained from the injected metabolite and daughter products, e.g. pyruvate and lactate, can be fitted to compartmental models to estimate kinetic rate constants. Modeling and physiological parameter estimation can be made more robust by consistent and reproducible injections through automation. An injection system previously developed by us was limited in the injectable volume to between 0.6 and 2.4 ml and injection was delayed due to a required syringe filling step. An improved MR-compatible injector system has been developed that measures the pH of injected substrate, uses flow control to reduce dead volume within the injection cannula and can be operated over a larger volume range. The delay time to injection has been minimized by removing the syringe filling step by use of a peristaltic pump. For 100 μl to 10.000 ml, the volume range typically used for mice to rabbits, the average delivered volume was 97.8% of the demand volume. The standard deviation of delivered volumes was 7 μl for 100 μl and 20 μl for 10.000 ml demand volumes (mean S.D. was 9 ul in this range). In three repeat injections through a fixed 0.96 mm O.D. tube the coefficient of variation for the area under the curve was 2%. For in vivo injections of hyperpolarized pyruvate in tumor-bearing rats, signal was first detected in the input femoral vein cannula at 3-4 s post-injection trigger signal and at 9-12 s in tumor tissue. The pH of the injected pyruvate was 7.1 ± 0.3 (mean ± S.D., n = 10). For small injection volumes, e.g. less than 100 μl, the internal diameter of the tubing contained within the peristaltic pump could be reduced to improve accuracy. Larger injection volumes are limited only by the size of the receiving vessel connected to the pump.

  3. The timing and sources of information for the adoption and implementation of production innovations

    NASA Technical Reports Server (NTRS)

    Ettlie, J. E.

    1976-01-01

    Two dimensions (personal-impersonal and internal-external) are used to characterize information sources as they become important during the interorganizational transfer of production innovations. The results of three studies are reviewed for the purpose of deriving a model of the timing and importance of different information sources and the utilization of new technology. Based on the findings of two retrospective studies, it was concluded that the pattern of information seeking behavior in user organizations during the awareness stage of adoption is not a reliable predictor of the eventual utilization rate. Using the additional findings of a real-time study, an empirical model of the relative importance of information sources for successful user organizations is presented. These results are extended and integrated into a theoretical model consisting of a time-profile of successful implementations and the relative importance of four types of information sources during seven stages of the adoption-implementation process.

  4. 75 FR 75725 - Financial Management Service; Proposed Collection of Information: Tax Time Card Account Pilot...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-06

    ... Fiscal Service Financial Management Service; Proposed Collection of Information: Tax Time Card Account Pilot, Screening, Focus Groups, and Study AGENCY: Financial Management Service, Fiscal Service, Treasury. ACTION: Notice and request for comments. SUMMARY: The Financial Management Service, as part of...

  5. 21 CFR 830.330 - Times for submission of unique device identification information.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Times for submission of unique device identification information. 830.330 Section 830.330 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... labeler shall submit to FDA the information required by § 830.310 no later than the date the label of...

  6. 76 FR 15052 - Proposed Information Collection (Time Record (Work-Study Program); Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-18

    ... AFFAIRS Proposed Information Collection (Time Record (Work-Study Program); Comment Request AGENCY... information needed to verify the actual number of hours worked by a work-study claimant. DATES: Written... Record (Work-Study Program)), VA Form 22-8690. OMB Control Number: 2900-0379. Type of Review:...

  7. Information Accumulation over Time in Monkey Inferior Temporal Cortex Neurons Explains Pattern Recognition Reaction Time under Visual Noise

    PubMed Central

    Kuboki, Ryosuke; Sugase-Miyamoto, Yasuko; Matsumoto, Narihisa; Richmond, Barry J.; Shidara, Munetaka

    2017-01-01

    We recognize objects even when they are partially degraded by visual noise. We studied the relation between the amount of visual noise (5, 10, 15, 20, or 25%) degrading 8 black-and-white stimuli and stimulus identification in 2 monkeys performing a sequential delayed match-to-sample task. We measured the accuracy and speed with which matching stimuli were identified. The performance decreased slightly (errors increased) as the amount of visual noise increased for both monkeys. The performance remained above 80% correct, even with 25% noise. However, the reaction times markedly increased as the noise increased, indicating that the monkeys took progressively longer to decide what the correct response would be as the amount of visual noise increased, showing that the monkeys trade time to maintain accuracy. Thus, as time unfolds the monkeys act as if they are accumulating the information and/or testing hypotheses about whether the test stimulus is likely to be a match for the sample being held in short-term memory. We recorded responses from 13 single neurons in area TE of the 2 monkeys. We found that stimulus-selective information in the neuronal responses began accumulating when the match stimulus appeared. We found that the greater the amount of noise obscuring the test stimulus, the more slowly stimulus-related information by the 13 neurons accumulated. The noise induced slowing was about the same for both behavior and information. These data are consistent with the hypothesis that area TE neuron population carries information about stimulus identity that accumulates over time in such a manner that it progressively overcomes the signal degradation imposed by adding visual noise. PMID:28127279

  8. Information Accumulation over Time in Monkey Inferior Temporal Cortex Neurons Explains Pattern Recognition Reaction Time under Visual Noise.

    PubMed

    Kuboki, Ryosuke; Sugase-Miyamoto, Yasuko; Matsumoto, Narihisa; Richmond, Barry J; Shidara, Munetaka

    2016-01-01

    We recognize objects even when they are partially degraded by visual noise. We studied the relation between the amount of visual noise (5, 10, 15, 20, or 25%) degrading 8 black-and-white stimuli and stimulus identification in 2 monkeys performing a sequential delayed match-to-sample task. We measured the accuracy and speed with which matching stimuli were identified. The performance decreased slightly (errors increased) as the amount of visual noise increased for both monkeys. The performance remained above 80% correct, even with 25% noise. However, the reaction times markedly increased as the noise increased, indicating that the monkeys took progressively longer to decide what the correct response would be as the amount of visual noise increased, showing that the monkeys trade time to maintain accuracy. Thus, as time unfolds the monkeys act as if they are accumulating the information and/or testing hypotheses about whether the test stimulus is likely to be a match for the sample being held in short-term memory. We recorded responses from 13 single neurons in area TE of the 2 monkeys. We found that stimulus-selective information in the neuronal responses began accumulating when the match stimulus appeared. We found that the greater the amount of noise obscuring the test stimulus, the more slowly stimulus-related information by the 13 neurons accumulated. The noise induced slowing was about the same for both behavior and information. These data are consistent with the hypothesis that area TE neuron population carries information about stimulus identity that accumulates over time in such a manner that it progressively overcomes the signal degradation imposed by adding visual noise.

  9. A novel mutual information-based Boolean network inference method from time-series gene expression data

    PubMed Central

    Barman, Shohag; Kwon, Yung-Keun

    2017-01-01

    Background Inferring a gene regulatory network from time-series gene expression data in systems biology is a challenging problem. Many methods have been suggested, most of which have a scalability limitation due to the combinatorial cost of searching a regulatory set of genes. In addition, they have focused on the accurate inference of a network structure only. Therefore, there is a pressing need to develop a network inference method to search regulatory genes efficiently and to predict the network dynamics accurately. Results In this study, we employed a Boolean network model with a restricted update rule scheme to capture coarse-grained dynamics, and propose a novel mutual information-based Boolean network inference (MIBNI) method. Given time-series gene expression data as an input, the method first identifies a set of initial regulatory genes using mutual information-based feature selection, and then improves the dynamics prediction accuracy by iteratively swapping a pair of genes between sets of the selected regulatory genes and the other genes. Through extensive simulations with artificial datasets, MIBNI showed consistently better performance than six well-known existing methods, REVEAL, Best-Fit, RelNet, CST, CLR, and BIBN in terms of both structural and dynamics prediction accuracy. We further tested the proposed method with two real gene expression datasets for an Escherichia coli gene regulatory network and a fission yeast cell cycle network, and also observed better results using MIBNI compared to the six other methods. Conclusions Taken together, MIBNI is a promising tool for predicting both the structure and the dynamics of a gene regulatory network. PMID:28178334

  10. Hydrologic consistency analysed through modeling at multiple time steps: does hydrological model performance benefit from finer time step information?

    NASA Astrophysics Data System (ADS)

    Ficchi, Andrea; Perrin, Charles; Andréassian, Vazken

    2015-04-01

    We investigate the operational utility of fine time step hydro-climatic information using a large catchment data set. The originality of this data set lies in the availability of precipitation data from the 6-minute rain gauges of Météo-France, and in the size of the catchment set (217 French catchments in total). The rainfall-runoff model used (GR4) has been adapted to hourly and sub-hourly time steps (up to 6-minute) from the daily time step version (Perrin et al., 2003). The model is applied at different time steps ranging from 6-minute to 1 day (6-, 12-, 30-minute, 1-, 3-, 6-, 12-hour and 1 day) and the evolution of model performance for each catchment is evaluated at the daily time step by aggregation of model outputs. Three classes of behavior are found according to the trend of model performance as the time step becomes finer: (i) catchments presenting an improvement of model performance; (ii) catchments with a model performance insensitive to the time step; (iii) catchments for which the performance even deteriorates as the time step becomes finer. The reasons behind these different trends are investigated from a hydrological point of view, by relating the model sensitivity to data at finer time step to catchment descriptors. References: Perrin, C., C. Michel and V. Andréassian (2003), "Improvement of a parsimonious model for streamflow simulation", Journal of Hydrology, 279(1-4): 275-289.

  11. Accurate mass measurements for the confirmation of Sudan azo-dyes in hot chilli products by capillary liquid chromatography-electrospray tandem quadrupole orthogonal-acceleration time of flight mass spectrometry.

    PubMed

    Calbiani, F; Careri, M; Elviri, L; Mangia, A; Zagnoni, I

    2004-11-26

    The potential of capillary liquid chromatography (microLC)-quadrupole/time-of-flight mass spectrometry (Q-TOF MS) for the confirmation of Sudan I, II, III and IV azo-dyes as contaminants in hot-chilli food products was demonstrated. Using the microLC-electrospray ionization (ESI)-Q-TOF MS technique, accurate mass measurements of Sudan dyes were performed both on standard solutions and on matrices. Precision of exact mass measurements was calculated taking into account the ion statistics according to the number of ion sampled in the measurement. Accurate mass measurements by MS/MS experiments were performed to elucidate azo-dye fragmentation patterns. Selectivity of the microLC-Q-TOF MS method was assessed by evaluating matrix suppression effects by pre-column injection of blank hot chilli tomato sauce matrices. The results were compared with those obtained on a LC-triple quadrupole-MS system. Confirmation of Sudan I present in hot chill tomato sauce samples was obtained by accurate mass measurements. In real samples trueness of exact mass measurements was estimated to be 1.6 and 4.4 ppm when calculated for hot chilli tomato sauce and hot chilli tomato with cheese sauce samples, respectively; precision was calculated around 9.5 ppm.

  12. Time accurate simulations of compressible shear flows

    NASA Technical Reports Server (NTRS)

    Givi, Peyman; Steinberger, Craig J.; Vidoni, Thomas J.; Madnia, Cyrus K.

    1993-01-01

    The objectives of this research are to employ direct numerical simulation (DNS) to study the phenomenon of mixing (or lack thereof) in compressible free shear flows and to suggest new means of enhancing mixing in such flows. The shear flow configurations under investigation are those of parallel mixing layers and planar jets under both non-reacting and reacting nonpremixed conditions. During the three-years of this research program, several important issues regarding mixing and chemical reactions in compressible shear flows were investigated.

  13. Status and Future of a Real-time Global Flood Detection and Forecasting System Using Satellite Rainfall Information

    NASA Astrophysics Data System (ADS)

    Adler, R. F.; Wu, H.; Hong, Y.; Policelli, F.; Pierce, H.

    2011-12-01

    Over the last several years a Global Flood Monitoring System (GFMS) has been running in real-time to detect the occurrence of floods (see trmm.gsfc.nasa.gov and click on "Floods and Landslides"). The system uses 3-hr resolution composite rainfall analyses (TRMM Multi-satellite Precipitation Analysis [TMPA]) as input into a hydrological model that calculates water depth at each grid (at 0.25 degree latitude-longitude) over the tropics and mid-latitudes. These calculations can provide information useful to national and international agencies in understanding the location, intensity, timeline and impact on populations of these significant hazard events. The status of these flood calculations will be shown by case study examples and a statistical comparison against a global flood event database. The validation study indicates that results improve with longer duration (> 3 days) floods and that the statistics are impacted by the presence of dams, which are not accounted for in the model calculations. Limitations in the flood calculations that are related to the satellite rainfall estimates include space and time resolution limitations and underestimation of shallow orographic and monsoon system rainfall. The current quality of these flood estimations is at the level of being useful, but there is a potential for significant improvement, mainly through improved and more timely satellite precipitation information and improvement in the hydrological models being used. NASA's Global Precipitation Measurement (GPM) program should lead to better precipitation analyses utilizing space-time interpolations that maintain accurate intensity distributions along with methods to disaggregate the rain information research should lead to improved rain estimation for shallow, orographic rainfall systems and some types of monsoon rainfall, a current problem area for satellite rainfall. Higher resolution flood models with accurate routing and regional calibration, and the use of satellite

  14. Time-to-contact estimation of accelerated stimuli is based on first-order information.

    PubMed

    Benguigui, Nicolas; Ripoll, Hubert; Broderick, Michael P

    2003-12-01

    The goal of this study was to test whether 1st-order information, which does not account for acceleration, is used (a) to estimate the time to contact (TTC) of an accelerated stimulus after the occlusion of a final part of its trajectory and (b) to indirectly intercept an accelerated stimulus with a thrown projectile. Both tasks require the production of an action on the basis of predictive information acquired before the arrival of the stimulus at the target and allow the experimenter to make quantitative predictions about the participants' use (or nonuse) of 1st-order information. The results show that participants do not use information about acceleration and that they commit errors that rely quantitatively on 1st-order information even when acceleration is psychophysically detectable. In the indirect interceptive task, action is planned about 200 ms before the initiation of the movement, at which time the 1st-order TTC attains a critical value.

  15. Isolating the Contributions of Familiarity and Source Information to Item Recognition: A Time Course Analysis

    PubMed Central

    McElree, Brian; Dolan, Patrick O.; Jacoby, Larry L.

    2012-01-01

    Recognition memory may be mediated by the retrieval of distinct types of information, notably, a general assessment of familiarity and the recovery of specific source information. A response-signal speed–accuracy trade-off variant of an exclusion procedure was used to isolate the retrieval time course for familiarity and source information. In 2 experiments, participants studied spoken and read lists (with various numbers of presentations) and then performed an exclusion task, judging an item as old only if it was in the heard list. Dual-process fits of the time course data indicated that familiarity information typically is retrieved before source information. The implications that these data have for models of recognition, including dual-process and global memory models, are discussed. PMID:10368927

  16. Development of a time-oriented data warehouse based on a medical information event model.

    PubMed

    Yamamoto, Yuichiro; Namikawa, Hirokazu; Inamura, Kiyonari

    2002-01-01

    We designed a new medical information event model and developed a time-oriented data warehouse based on the model. Here, the medical information event in a basic data unit is handled by a medical information system. The timing of decision making and treatment for a patient in the processing of his medical information is sometimes very critical. The time-oriented data warehouse was developed, to provide a search feature on the time axis. Our medical information event model has a unique simple data structure. PC-ORDERING2000 developed by NEC, which used Oracle, had about 600 pages of tables. However, we reduced these 600 complicated data structures to one unique and simple event model. By means of shifting clinical data from the old type order entry system into the new order entry system of the medical information event model, we produced a simple and flexible system, and the easy secondary use of clinical data of patients was realized. Evaluation of our system revealed heightened data retrieval efficiency and shortened response time 1:600 at a terminal, owing to the 1:600 reduction of the number of tables as mentioned above.

  17. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  18. Time resolution dependence of information measures for spiking neurons: scaling and universality

    PubMed Central

    Marzen, Sarah E.; DeWeese, Michael R.; Crutchfield, James P.

    2015-01-01

    The mutual information between stimulus and spike-train response is commonly used to monitor neural coding efficiency, but neuronal computation broadly conceived requires more refined and targeted information measures of input-output joint processes. A first step toward that larger goal is to develop information measures for individual output processes, including information generation (entropy rate), stored information (statistical complexity), predictable information (excess entropy), and active information accumulation (bound information rate). We calculate these for spike trains generated by a variety of noise-driven integrate-and-fire neurons as a function of time resolution and for alternating renewal processes. We show that their time-resolution dependence reveals coarse-grained structural properties of interspike interval statistics; e.g., τ-entropy rates that diverge less quickly than the firing rate indicated by interspike interval correlations. We also find evidence that the excess entropy and regularized statistical complexity of different types of integrate-and-fire neurons are universal in the continuous-time limit in the sense that they do not depend on mechanism details. This suggests a surprising simplicity in the spike trains generated by these model neurons. Interestingly, neurons with gamma-distributed ISIs and neurons whose spike trains are alternating renewal processes do not fall into the same universality class. These results lead to two conclusions. First, the dependence of information measures on time resolution reveals mechanistic details about spike train generation. Second, information measures can be used as model selection tools for analyzing spike train processes. PMID:26379538

  19. Using time-delayed mutual information to discover and interpret temporal correlation structure in complex populations

    NASA Astrophysics Data System (ADS)

    Albers, D. J.; Hripcsak, George

    2012-03-01

    This paper addresses how to calculate and interpret the time-delayed mutual information (TDMI) for a complex, diversely and sparsely measured, possibly non-stationary population of time-series of unknown composition and origin. The primary vehicle used for this analysis is a comparison between the time-delayed mutual information averaged over the population and the time-delayed mutual information of an aggregated population (here, aggregation implies the population is conjoined before any statistical estimates are implemented). Through the use of information theoretic tools, a sequence of practically implementable calculations are detailed that allow for the average and aggregate time-delayed mutual information to be interpreted. Moreover, these calculations can also be used to understand the degree of homo or heterogeneity present in the population. To demonstrate that the proposed methods can be used in nearly any situation, the methods are applied and demonstrated on the time series of glucose measurements from two different subpopulations of individuals from the Columbia University Medical Center electronic health record repository, revealing a picture of the composition of the population as well as physiological features.

  20. Transfer entropy coefficient: Quantifying level of information flow between financial time series

    NASA Astrophysics Data System (ADS)

    Teng, Yue; Shang, Pengjian

    2017-03-01

    In this paper, a new coefficient is proposed with the objective of quantifying the level of information flow between financial time series. This transfer entropy coefficient, which provides an assessment on the multiscale information flow between measurements, is defined in terms of the transfer entropy method and the multiscale method. The implementation of this transfer entropy coefficient is illustrated with simulated time series and financial time series. Examples taken from simulated and financial data demonstrate that the dynamic mechanism of a complex system cannot be detected solely on the basis of transfer entropy of single scale.

  1. Relation between physical time-energy cost of a quantum process and its information fidelity

    NASA Astrophysics Data System (ADS)

    Fung, Chi-Hang Fred; Chau, H. F.

    2014-08-01

    A quantum system can be described and characterized by at least two different concepts, namely, its physical and informational properties. Here, we explicitly connect these two concepts, by equating the time-energy cost which is the product of the largest energy of a Hamiltonian of quantum dynamics and the evolution time, and the entanglement fidelity which is the informational difference between an input state and the corresponding output state produced by a quantum channel characterized by the Hamiltonian. Specifically, the worst-case entanglement fidelity between the input and output states is exactly the cosine of the channel's time-energy cost (except when the fidelity is zero). The exactness of our relation makes a strong statement about the intimate connection between information and physics. Our exact result may also be regarded as a time-energy uncertainty relation for the fastest state that achieves a certain fidelity.

  2. Economy with the time delay of information flow—The stock market case

    NASA Astrophysics Data System (ADS)

    Miśkiewicz, Janusz

    2012-02-01

    Any decision process requires information about the past and present state of the system, but in an economy acquiring data and processing it is an expensive and time-consuming task. Therefore, the state of the system is often measured over some legal interval, analysed after the end of well defined time periods and the results announced much later before any strategic decision is envisaged. The various time delay roles have to be crucially examined. Here, a model of stock market coupled with an economy is investigated to emphasise the role of the time delay span on the information flow. It is shown that the larger the time delay the more important the collective behaviour of agents since one observes time oscillations in the absolute log-return autocorrelations.

  3. Visualization of Time-Series Sensor Data to Inform the Design of Just-In-Time Adaptive Stress Interventions

    PubMed Central

    Sharmin, Moushumi; Raij, Andrew; Epstien, David; Nahum-Shani, Inbal; Beck, J. Gayle; Vhaduri, Sudip; Preston, Kenzie; Kumar, Santosh

    2015-01-01

    We investigate needs, challenges, and opportunities in visualizing time-series sensor data on stress to inform the design of just-in-time adaptive interventions (JITAIs). We identify seven key challenges: massive volume and variety of data, complexity in identifying stressors, scalability of space, multifaceted relationship between stress and time, a need for representation at multiple granularities, interperson variability, and limited understanding of JITAI design requirements due to its novelty. We propose four new visualizations based on one million minutes of sensor data (n=70). We evaluate our visualizations with stress researchers (n=6) to gain first insights into its usability and usefulness in JITAI design. Our results indicate that spatio-temporal visualizations help identify and explain between- and within-person variability in stress patterns and contextual visualizations enable decisions regarding the timing, content, and modality of intervention. Interestingly, a granular representation is considered informative but noise-prone; an abstract representation is the preferred starting point for designing JITAIs. PMID:26539566

  4. Attitudes and Beliefs of Parents Concerned About Vaccines: Impact of Timing of Immunization Information

    PubMed Central

    Salmon, Daniel A.; Shui, Irene; Omer, Saad B.; Kissner, Jennifer; Edwards, Kathryn M.; Sparks, Robert; Dekker, Cornelia L.; Klein, Nicola P.; Gust, Deborah A.

    2011-01-01

    OBJECTIVES: To determine if giving vaccine-information materials before the 2-month vaccination visit to mothers with concerns about vaccine safety positively changed their attitudes and beliefs about vaccine safety. METHODS: Mothers who indicated concerns about infant vaccinations were recruited from 2 separate sites in Tennessee and California and were given vaccine information at 1 of 3 times: during a prenatal visit; a 1-week postpartum well-child visit; or a 2-month vaccination visit. A separate group of concerned mothers was assigned to be followed longitudinally at all 3 time points and was analyzed separately. The mothers reviewed a new vaccine-information pamphlet and Vaccine Information Statements (VIS) from the Centers for Disease Control and Prevention. Attitudes and beliefs about immunization were assessed both before and after the review of materials with written surveys. RESULTS: A total of 272 mothers with immunization concerns participated in the study. After review of the materials, mothers in all groups were significantly more likely to respond positively to questions and statements supporting the safety and importance of vaccines. Mothers who received this information at earlier visits were not significantly more likely to respond positively than mothers who received the information at the child's 2-month vaccination visit; however, participating mothers did indicate a preference for receiving vaccine information before the first vaccination visit. CONCLUSIONS: Distribution of the vaccine-information pamphlet and Vaccine Information Statements significantly improved attitudes about vaccination regardless of at what visit they were provided. Allowing adequate time to review vaccine information, even if done at the vaccination visit, may benefit concerned mothers. PMID:21502250

  5. Spike count, spike timing and temporal information in the cortex of awake, freely moving rats

    NASA Astrophysics Data System (ADS)

    Scaglione, Alessandro; Foffani, Guglielmo; Moxon, Karen A.

    2014-08-01

    Objective. Sensory processing of peripheral information is not stationary but is, in general, a dynamic process related to the behavioral state of the animal. Yet the link between the state of the behavior and the encoding properties of neurons is unclear. This report investigates the impact of the behavioral state on the encoding mechanisms used by cortical neurons for both detection and discrimination of somatosensory stimuli in awake, freely moving, rats. Approach. Neuronal activity was recorded from the primary somatosensory cortex of five rats under two different behavioral states (quiet versus whisking) while electrical stimulation of increasing stimulus strength was delivered to the mystacial pad. Information theoretical measures were then used to measure the contribution of different encoding mechanisms to the information carried by neurons in response to the whisker stimulation. Main results. We found that the behavioral state of the animal modulated the total amount of information conveyed by neurons and that the timing of individual spikes increased the information compared to the total count of spikes alone. However, the temporal information, i.e. information exclusively related to when the spikes occur, was not modulated by behavioral state. Significance. We conclude that information about somatosensory stimuli is modulated by the behavior of the animal and this modulation is mainly expressed in the spike count while the temporal information is more robust to changes in behavioral state.

  6. Spike count, spike timing and temporal information in the cortex of awake, freely moving rats

    PubMed Central

    Scaglione, Alessandro; Foffani, Guglielmo; Moxon, Karen A.

    2014-01-01

    Objective Sensory processing of peripheral information is not stationary but is, in general, a dynamic process related to the behavioral state of the animal. Yet the link between the state of the behavior and the encoding properties of neurons is unclear. This report investigates the impact of the behavioral state on the encoding mechanisms used by cortical neurons for both detection and discrimination of somatosensory stimuli in awake, freely moving, rats. Approach Neuronal activity was recorded from the primary somatosensory cortex of five rats under two different behavioral states (quiet vs. whisking) while electrical stimulation of increasing stimulus strength was delivered to the mystacial pad. Information theoretical measures were then used to measure the contribution of different encoding mechanisms to the information carried by neurons in response to the whisker stimulation. Main Results We found that the behavioral state of the animal modulated the total amount of information conveyed by neurons and that the timing of individual spikes increased the information compared to the total count of spikes alone. However, the temporal information, i.e. information exclusively related to when the spikes occur, was not modulated by behavioral state. Significance We conclude that information about somatosensory stimuli is modulated by the behavior of the animal and this modulation is mainly expressed in the spike count while the temporal information is more robust to changes in behavioral state. PMID:25024291

  7. Expansion and Compression of Time Correlate with Information Processing in an Enumeration Task

    PubMed Central

    Wutz, Andreas; Shukla, Anuj; Bapi, Raju S.; Melcher, David

    2015-01-01

    Perception of temporal duration is subjective and is influenced by factors such as attention and context. For example, unexpected or emotional events are often experienced as if time subjectively expands, suggesting that the amount of information processed in a unit of time can be increased. Time dilation effects have been measured with an oddball paradigm in which an infrequent stimulus is perceived to last longer than standard stimuli in the rest of the sequence. Likewise, time compression for the oddball occurs when the duration of the standard items is relatively brief. Here, we investigated whether the amount of information processing changes when time is perceived as distorted. On each trial, an oddball stimulus of varying numerosity (1–14 items) and duration was presented along with standard items that were either short (70 ms) or long (1050 ms). Observers were instructed to count the number of dots within the oddball stimulus and to judge its relative duration with respect to the standards on that trial. Consistent with previous results, oddballs were reliably perceived as temporally distorted: expanded for longer standard stimuli blocks and compressed for shorter standards. The occurrence of these distortions of time perception correlated with perceptual processing; i.e. enumeration accuracy increased when time was perceived as expanded and decreased with temporal compression. These results suggest that subjective time distortions are not epiphenomenal, but reflect real changes in sensory processing. Such short-term plasticity in information processing rate could be evolutionarily advantageous in optimizing perception and action during critical moments. PMID:26308546

  8. Expansion and Compression of Time Correlate with Information Processing in an Enumeration Task.

    PubMed

    Wutz, Andreas; Shukla, Anuj; Bapi, Raju S; Melcher, David

    2015-01-01

    Perception of temporal duration is subjective and is influenced by factors such as attention and context. For example, unexpected or emotional events are often experienced as if time subjectively expands, suggesting that the amount of information processed in a unit of time can be increased. Time dilation effects have been measured with an oddball paradigm in which an infrequent stimulus is perceived to last longer than standard stimuli in the rest of the sequence. Likewise, time compression for the oddball occurs when the duration of the standard items is relatively brief. Here, we investigated whether the amount of information processing changes when time is perceived as distorted. On each trial, an oddball stimulus of varying numerosity (1-14 items) and duration was presented along with standard items that were either short (70 ms) or long (1050 ms). Observers were instructed to count the number of dots within the oddball stimulus and to judge its relative duration with respect to the standards on that trial. Consistent with previous results, oddballs were reliably perceived as temporally distorted: expanded for longer standard stimuli blocks and compressed for shorter standards. The occurrence of these distortions of time perception correlated with perceptual processing; i.e. enumeration accuracy increased when time was perceived as expanded and decreased with temporal compression. These results suggest that subjective time distortions are not epiphenomenal, but reflect real changes in sensory processing. Such short-term plasticity in information processing rate could be evolutionarily advantageous in optimizing perception and action during critical moments.

  9. Optimum neural tuning curves for information efficiency with rate coding and finite-time window.

    PubMed

    Han, Fang; Wang, Zhijie; Fan, Hong; Sun, Xiaojuan

    2015-01-01

    An important question for neural encoding is what kind of neural systems can convey more information with less energy within a finite time coding window. This paper first proposes a finite-time neural encoding system, where the neurons in the system respond to a stimulus by a sequence of spikes that is assumed to be Poisson process and the external stimuli obey normal distribution. A method for calculating the mutual information of the finite-time neural encoding system is proposed and the definition of information efficiency is introduced. The values of the mutual information and the information efficiency obtained by using Logistic function are compared with those obtained by using other functions and it is found that Logistic function is the best one. It is further found that the parameter representing the steepness of the Logistic function has close relationship with full entropy, and that the parameter representing the translation of the function associates with the energy consumption and noise entropy tightly. The optimum parameter combinations for Logistic function to maximize the information efficiency are calculated when the stimuli and the properties of the encoding system are varied respectively. Some explanations for the results are given. The model and the method we proposed could be useful to study neural encoding system, and the optimum neural tuning curves obtained in this paper might exhibit some characteristics of a real neural system.

  10. Analysis of complex physiological systems by information flow: a time scale-specific complexity assessment.

    PubMed

    Hoyer, Dirk; Frank, Birgit; Pompe, Bernd; Schmidt, Hendrik; Werdan, Karl; Müller-Werdan, Ursula; Baranowski, Rafal; Zebrowski, Jan J; Meissner, Winfried; Kletzin, Ulf; Adler, Daniela; Adler, Steffen; Blickhan, Reinhard

    2006-07-01

    In the last two decades conventional linear methods for biosignal analysis have been substantially extended by non-stationary, non-linear, and complexity approaches. So far, complexity is usually assessed with regard to one single time scale, disregarding complex physiology organised on different time scales. This shortcoming was overcome and medically evaluated by information flow functions developed in our research group in collaboration with several theoretical, experimental, and clinical partners. In the present work, the information flow is introduced and typical information flow characteristics are demonstrated. The prognostic value of autonomic information flow (AIF), which reflects communication in the cardiovascular system, was shown in patients with multiple organ dysfunction syndrome and in patients with heart failure. Gait information flow (GIF), which reflects communication in the motor control system during walking, was introduced to discriminate between controls and elderly patients suffering from low back pain. The applications presented for the theoretically based approach of information flow confirm its value for the identification of complex physiological systems. The medical relevance has to be confirmed by comprehensive clinical studies. These information flow measures substantially extend the established linear and complexity measures in biosignal analysis.

  11. Western scrub-jays allocate longer observation time to more valuable information.

    PubMed

    Watanabe, Arii; Grodzinski, Uri; Clayton, Nicola S

    2014-07-01

    When humans mentally reconstruct past events and imagine future scenarios, their subjective experience of mentally time travelling is accompanied by the awareness of doing so. Despite recent popularity of studying episodic memory in animals, such phenomenological consciousness has been extremely difficult to demonstrate without agreed behavioural markers of consciousness in non-linguistic subjects. We presented western scrub-jays (Aphelocoma californica) with a task requiring them to allocate observing time between two peepholes to see food being hidden in either of two compartments, one where observing the hiding location was necessary to later relocate the food, and another where food could easily be found without watching. Jays first separately experienced these consequences of possessing information in each compartment and subsequently, once given a choice, made more looks and spent more time looking into the compartment where information was necessary than into the compartment where it was unnecessary. Thus, the jays can collect information to solve a future problem. Moreover, they can differentiate sources of information according to their potential value and modify behaviour to efficiently collect important, usable information. This is the first evidence of metacognition in a species that passes the behavioural criteria for both retrospective and prospective mental time travel.

  12. Information-sharing tendency on Twitter and time evolution of tweeting

    NASA Astrophysics Data System (ADS)

    Kwon, H. W.; Kim, H. S.; Lee, K.; Choi, M. Y.

    2013-03-01

    While topics on Twitter may be categorized according to their predictability and sustainability, some topics have characteristics depending on the time scale. Here we propose a good measure for the transition of sustainability, which we call the information-sharing tendency, and find that the unpredictability on Twitter is provoked by the exposure of Twitter users to external environments, e.g., mass media and other social network services. In addition, it is demonstrated that the numbers of articles and comments on on-line newspapers serve as plausible measures of exposure. From such measures of exposure, the time evolution of tweeting can be described, when the information-sharing tendency is known.

  13. A Strategy for Functional Interpretation of Metabolomic Time Series Data in Context of Metabolic Network Information

    PubMed Central

    Nägele, Thomas; Fürtauer, Lisa; Nagler, Matthias; Weiszmann, Jakob; Weckwerth, Wolfram

    2016-01-01

    The functional connection of experimental metabolic time series data with biochemical network information is an important, yet complex, issue in systems biology. Frequently, experimental analysis of diurnal, circadian, or developmental dynamics of metabolism results in a comprehensive and multidimensional data matrix comprising information about metabolite concentrations, protein levels, and/or enzyme activities. While, irrespective of the type of organism, the experimental high-throughput analysis of the transcriptome, proteome, and metabolome has become a common part of many systems biological studies, functional data integration in a biochemical and physiological context is still challenging. Here, an approach is presented which addresses the functional connection of experimental time series data with biochemical network information which can be inferred, for example, from a metabolic network reconstruction. Based on a time-continuous and variance-weighted regression analysis of experimental data, metabolic functions, i.e., first-order derivatives of metabolite concentrations, were related to time-dependent changes in other biochemically relevant metabolic functions, i.e., second-order derivatives of metabolite concentrations. This finally revealed time points of perturbed dependencies in metabolic functions indicating a modified biochemical interaction. The approach was validated using previously published experimental data on a diurnal time course of metabolite levels, enzyme activities, and metabolic flux simulations. To support and ease the presented approach of functional time series analysis, a graphical user interface including a test data set and a manual is provided which can be run within the numerical software environment Matlab®. PMID:27014700

  14. Real-time decision support and information gathering system for financial domain

    NASA Astrophysics Data System (ADS)

    Tseng, Chiu-Che; Gmytrasiewicz, Piotr J.

    2006-05-01

    The challenge of the investment domain is that a large amount of diverse information can be potentially relevant to an investment decision, and that, frequently, the decisions have to be made in a timely manner. This presents the potential for better decision support, but poses the challenge of building a decision support agent that gathers information from different sources and incorporates it for timely decision support. These problems motivate us to investigate ways in which the investors can be equipped with a flexible real-time decision support system to be practical in time-critical situations. The flexible real-time decision support system considers a tradeoff between decision quality and computation cost. For this purpose, we propose a system that uses the object oriented Bayesian knowledge base (OOBKB) design to create a decision model at the most suitable level of detail to guide the information gathering activities, and to produce an investment recommendation within a reasonable length of time. The decision models our system uses are implemented as influence diagrams. We validate our system with experiments in a simplified investment domain. The experiments show that our system produces a quality recommendation under different urgency situations. The contribution of our system is that it provides the flexible decision recommendation for an investor under time constraints in a complex environment.

  15. A Strategy for Functional Interpretation of Metabolomic Time Series Data in Context of Metabolic Network Information.

    PubMed

    Nägele, Thomas; Fürtauer, Lisa; Nagler, Matthias; Weiszmann, Jakob; Weckwerth, Wolfram

    2016-01-01

    The functional connection of experimental metabolic time series data with biochemical network information is an important, yet complex, issue in systems biology. Frequently, experimental analysis of diurnal, circadian, or developmental dynamics of metabolism results in a comprehensive and multidimensional data matrix comprising information about metabolite concentrations, protein levels, and/or enzyme activities. While, irrespective of the type of organism, the experimental high-throughput analysis of the transcriptome, proteome, and metabolome has become a common part of many systems biological studies, functional data integration in a biochemical and physiological context is still challenging. Here, an approach is presented which addresses the functional connection of experimental time series data with biochemical network information which can be inferred, for example, from a metabolic network reconstruction. Based on a time-continuous and variance-weighted regression analysis of experimental data, metabolic functions, i.e., first-order derivatives of metabolite concentrations, were related to time-dependent changes in other biochemically relevant metabolic functions, i.e., second-order derivatives of metabolite concentrations. This finally revealed time points of perturbed dependencies in metabolic functions indicating a modified biochemical interaction. The approach was validated using previously published experimental data on a diurnal time course of metabolite levels, enzyme activities, and metabolic flux simulations. To support and ease the presented approach of functional time series analysis, a graphical user interface including a test data set and a manual is provided which can be run within the numerical software environment Matlab®.

  16. Accurate quantum chemical calculations

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

  17. Can free energy calculations be fast and accurate at the same time? Binding of low-affinity, non-peptide inhibitors to the SH2 domain of the src protein

    NASA Astrophysics Data System (ADS)

    Chipot, Christophe; Rozanska, Xavier; Dixit, Surjit B.

    2005-11-01

    The usefulness of free-energy calculations in non-academic environments, in general, and in the pharmaceutical industry, in particular, is a long-time debated issue, often considered from the angle of cost/performance criteria. In the context of the rational drug design of low-affinity, non-peptide inhibitors to the SH2 domain of the pp60src tyrosine kinase, the continuing difficulties encountered in an attempt to obtain accurate free-energy estimates are addressed. free-energy calculations can provide a convincing answer, assuming that two key-requirements are fulfilled: (i) thorough sampling of the configurational space is necessary to minimize the statistical error, hence raising the question: to which extent can we sacrifice the computational effort, yet without jeopardizing the precision of the free-energy calculation? (ii) the sensitivity of binding free-energies to the parameters utilized imposes an appropriate parametrization of the potential energy function, especially for non-peptide molecules that are usually poorly described by multipurpose macromolecular force fields. Employing the free-energy perturbation method, accurate ranking, within ±0.7 kcal/mol, is obtained in the case of four non-peptide mimes of a sequence recognized by the pp60src SH2 domain.

  18. A brief description of the Medical Information Computer System (MEDICS). [real time minicomputer system

    NASA Technical Reports Server (NTRS)

    Moseley, E. C.

    1974-01-01

    The Medical Information Computer System (MEDICS) is a time shared, disk oriented minicomputer system capable of meeting storage and retrieval needs for the space- or non-space-related applications of at least 16 simultaneous users. At the various commercially available low cost terminals, the simple command and control mechanism and the generalized communication activity of the system permit multiple form inputs, real-time updating, and instantaneous retrieval capability with a full range of options.

  19. Social contagion process in informal warning networks to understand evacuation timing behavior.

    PubMed

    Hasan, Samiul; Ukkusuri, Satish V

    2013-01-01

    Individual evacuation decisions are often characterized by the influence of one's social network, referred to as informal warning network. In this article, a threshold model of social contagion, originally introduced in the network science literature, is proposed to characterize this social influence in the evacuation decision-making process, in particular the timing of evacuation decision. Simulation models are developed to investigate the effects of community mixing patterns and the strength of ties on timing of evacuation decision.

  20. Information-transmission rates in manual control of unstable systems with time delays.

    PubMed

    Lupu, Mircea F; Sun, Mingui; Wang, Fei-Yue; Mao, Zhi-Hong

    2015-01-01

    In analyzing the human-machine interaction (HMI), a human-centered approach is needed to address the potential and limitation of human control, especially in the control of high-order or unstable systems. However, there is no quantitative measure of the human performance or cognitive workload in these difficult HMI tasks. We propose to characterize the HMI as information flows quantified by the information-transmission rate in bits per second (b/s). Using information- and control-theoretic approaches, we derive the minimum rates of information transmission in manual control required by any deterministic controller to stabilize the feedback system. Furthermore, we suggest a method adopted from time-series analysis to estimate the information-transmission rate from human experiments. We show that the relationship between the empirically estimated information rates and the minimum bounds allows for the quantitative indication of the potential and limitation of human manual control. We illustrate our method in the control of an inverted pendulum with time delays.

  1. 16 CFR 803.21 - Additional information shall be supplied within reasonable time.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Additional information shall be supplied within reasonable time. 803.21 Section 803.21 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF...

  2. 16 CFR 803.21 - Additional information shall be supplied within reasonable time.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Additional information shall be supplied within reasonable time. 803.21 Section 803.21 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF...

  3. 16 CFR 803.21 - Additional information shall be supplied within reasonable time.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Additional information shall be supplied within reasonable time. 803.21 Section 803.21 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF...

  4. 16 CFR 803.21 - Additional information shall be supplied within reasonable time.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Additional information shall be supplied within reasonable time. 803.21 Section 803.21 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF...

  5. 16 CFR 803.21 - Additional information shall be supplied within reasonable time.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Additional information shall be supplied within reasonable time. 803.21 Section 803.21 Commercial Practices FEDERAL TRADE COMMISSION RULES, REGULATIONS, STATEMENTS AND INTERPRETATIONS UNDER THE HART-SCOTT-RODINO ANTITRUST IMPROVEMENTS ACT OF...

  6. OZONE MONITORING, MAPPING, AND PUBLIC OUTREACH: DELIVERING REAL-TIME OZONE INFORMATION TO YOUR COMMUNITY

    EPA Science Inventory

    The U.S. EPA had developed a handbook to help state and local government officials implement ozone monitoring, mapping, and outreach programs. The handbook, called Ozone Monitoring, Mapping, and Public Outreach: Delivering Real-Time Ozone Information to Your Community, provides ...

  7. Solving Word Problems about Time: The Effects of Speed and Space Information.

    ERIC Educational Resources Information Center

    Senechal, Monique

    This study investigated how preadolescents and adolescents solve problems involving three temporal dimensions. Specifically examined was the question of whether speed and space information would influence the time judgments of 90 subjects 9, 12, and 15 years of age who solved 16 word problems describing the displacements of two cars. The problems…

  8. Neural network incorporating meal information improves accuracy of short-time prediction of glucose concentration.

    PubMed

    Zecchin, Chiara; Facchinetti, Andrea; Sparacino, Giovanni; De Nicolao, Giuseppe; Cobelli, Claudio

    2012-06-01

    Diabetes mellitus is one of the most common chronic diseases, and a clinically important task in its management is the prevention of hypo/hyperglycemic events. This can be achieved by exploiting continuous glucose monitoring (CGM) devices and suitable short-term prediction algorithms able to infer future glycemia in real time. In the literature, several methods for short-time glucose prediction have been proposed, most of which do not exploit information on meals, and use past CGM readings only. In this paper, we propose an algorithm for short-time glucose prediction using past CGM sensor readings and information on carbohydrate intake. The predictor combines a neural network (NN) model and a first-order polynomial extrapolation algorithm, used in parallel to describe, respectively, the nonlinear and the linear components of glucose dynamics. Information on the glucose rate of appearance after a meal is described by a previously published physiological model. The method is assessed on 20 simulated datasets and on 9 real Abbott FreeStyle Navigator datasets, and its performance is successfully compared with that of a recently proposed NN glucose predictor. Results suggest that exploiting meal information improves the accuracy of short-time glucose prediction.

  9. Reconstruction of the cophylogenetic history of related phylogenetic trees with divergence timing information.

    PubMed

    Merkle, Daniel; Middendorf, Martin

    2005-04-01

    In this paper, we present a method and a corresponding tool called Tarzan for cophylogeny analysis of phylogenetic trees where the nodes are labelled with divergence timing information. The tool can be used for example to infer the common history of hosts and their parasites, of insect-plant relations or symbiotic relationships. Our method does the reconciliation analysis using an event-based concept where each event is assigned a cost and cost minimal solutions are sought. The events that are used by Tarzan are cospeciations, sortings, duplications, and (host) switches. Different from existing tools, Tarzan can handle more complex timing information of the phylogenetic trees for the analysis. This is important because several recent studies of cophylogenetic relationship have shown that timing information can be very important for the correct interpretation of results from cophylogenetic analysis. We present two examples (one host-parasite system and one insect-plant system) that show how divergence timing information can be integrated into reconciliation analysis and how this influences the results.

  10. Prospective and Retrospective Judgments of Time as a Function of Amount of Information Processed

    ERIC Educational Resources Information Center

    Hicks, Robert E.; And Others

    1976-01-01

    120 college students sorted cards with instructions to process bits of information per card (response uncertainty) and then made an absolute judgment of the interval's duration. Judged time was an inverse linear function of response uncertainty under the prospective paradigm, whereas no significant function was obtained under the retrospective…

  11. The Timing of Foreign Language Instruction and Related Issues. Information Capsule. Volume 0610

    ERIC Educational Resources Information Center

    Blazer, Christie

    2007-01-01

    In an effort to support the development of higher levels of foreign language proficiency among our nation's students, researchers have examined the effectiveness of foreign language programs based on the amount of time students receive instruction, the age at which instruction begins, and the course schedule utilized. This Information Capsule…

  12. 19 CFR 351.301 - Time limits for submission of factual information.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Time limits for submission of factual information. 351.301 Section 351.301 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE... to the Secretary's satisfaction that the alleged subsidy or subsidy program has been notified,...

  13. An Understanding Information Management System for a Real-Time Interactive Distance Education Environment

    ERIC Educational Resources Information Center

    He, Aiguo

    2009-01-01

    A real-time interactive distance lecture is a joint work that should be accomplished by the effort of the lecturer and his students in remote sites. It is important for the lecturer to get understanding information from the students which cannot be efficiently collected by only using video/audio channels between the lecturer and the students. This…

  14. Managing Information Technology as a Catalyst of Change. Track I: Leadership during Times of Change.

    ERIC Educational Resources Information Center

    CAUSE, Boulder, CO.

    Eight papers are presented from the 1993 CAUSE conference track on leadership challenges facing managers of information technology during times of change at colleges and universities. Papers include: (1) "ASURITE: How To Avoid Creating a Distributed Computing 'Tower of Babel'!" (Neil Armann and others), which discusses the Arizona State…

  15. Visual Design for Interactive Learning Tools: Representation of Time-Based Information.

    ERIC Educational Resources Information Center

    Boling, Elizabeth; Brown, J. P.; Ray, Sumitra Das; Erwin, Anthony; Kirkley, Sonny

    The development of potentially powerful computer-based tools within rich learning environments is hampered by the constraints of delivery systems (specifically low-resolution, low-real estate displays). In designing a World Wide Web-based tool for manipulating time-based information, the authors have encountered a lack of guidelines or empirical…

  16. Motor preparation is modulated by the resolution of the response timing information

    PubMed Central

    Carlsen, Anthony N.; MacKinnon, Colum D.

    2010-01-01

    In the present experiment, the temporal predictability of response time was systematically manipulated to examine its effect on the time course of motor pre-programming and release of the intended movement by an acoustic startle stimulus. Participants performed a ballistic right wrist extension task in four different temporal conditions: 1) a variable foreperiod simple RT task, 2) a fixed foreperiod simple RT task, 3) a low resolution countdown anticipation timing task, and 4) a high resolution anticipation-timing task. For each task, a startling acoustic stimulus (124 dB) was presented at several intervals prior to the “go” signal (“go” −150ms, −500 ms, and −1500 ms). Results from the startle trials showed that the time course of movement pre-programming was affected by the temporal uncertainty of the imperative “go” cue. These findings demonstrate that the resolution of the timing information regarding the response cue has a marked effect on the timing of movement preparation such that under conditions of low temporal resolution, participants plan the movement well in advance in accordance with the anticipated probability of onset of the cue, whereas movement preparation is delayed until less than 500 ms prior to response time when continuous temporal information is provided. PMID:20138165

  17. Codimension-Two Bifurcation, Chaos and Control in a Discrete-Time Information Diffusion Model

    NASA Astrophysics Data System (ADS)

    Ren, Jingli; Yu, Liping

    2016-12-01

    In this paper, we present a discrete model to illustrate how two pieces of information interact with online social networks and investigate the dynamics of discrete-time information diffusion model in three types: reverse type, intervention type and mutualistic type. It is found that the model has orbits with period 2, 4, 6, 8, 12, 16, 20, 30, quasiperiodic orbit, and undergoes heteroclinic bifurcation near 1:2 point, a homoclinic structure near 1:3 resonance point and an invariant cycle bifurcated by period 4 orbit near 1:4 resonance point. Moreover, in order to regulate information diffusion process and information security, we give two control strategies, the hybrid control method and the feedback controller of polynomial functions, to control chaos, flip bifurcation, 1:2, 1:3 and 1:4 resonances, respectively, in the two-dimensional discrete system.

  18. Just-in-Time Information Improved Decision-Making in Primary Care: A Randomized Controlled Trial

    PubMed Central

    McGowan, Jessie; Hogg, William; Campbell, Craig; Rowan, Margo

    2008-01-01

    Background The “Just-in-time Information” (JIT) librarian consultation service was designed to provide rapid information to answer primary care clinical questions during patient hours. This study evaluated whether information provided by librarians to answer clinical questions positively impacted time, decision-making, cost savings and satisfaction. Methods and Finding A randomized controlled trial (RCT) was conducted between October 2005 and April 2006. A total of 1,889 questions were sent to the service by 88 participants. The object of the randomization was a clinical question. Each participant had clinical questions randomly allocated to both intervention (librarian information) and control (no librarian information) groups. Participants were trained to send clinical questions via a hand-held device. The impact of the information provided by the service (or not provided by the service), additional resources and time required for both groups was assessed using a survey sent 24 hours after a question was submitted. The average time for JIT librarians to respond to all questions was 13.68 minutes/question (95% CI, 13.38 to 13.98). The average time for participants to respond their control questions was 20.29 minutes/question (95% CI, 18.72 to 21.86). Using an impact assessment scale rating cognitive impact, participants rated 62.9% of information provided to intervention group questions as having a highly positive cognitive impact. They rated 14.8% of their own answers to control question as having a highly positive cognitive impact, 44.9% has having a negative cognitive impact, and 24.8% with no cognitive impact at all. In an exit survey measuring satisfaction, 86% (62/72 responses) of participants scored the service as having a positive impact on care and 72% (52/72) indicated that they would use the service frequently if it were continued. Conclusions In this study, providing timely information to clinical questions had a highly positive impact on decision

  19. Real-Time Diffusion of Information on Twitter and the Financial Markets.

    PubMed

    Tafti, Ali; Zotti, Ryan; Jank, Wolfgang

    2016-01-01

    Do spikes in Twitter chatter about a firm precede unusual stock market trading activity for that firm? If so, Twitter activity may provide useful information about impending financial market activity in real-time. We study the real-time relationship between chatter on Twitter and the stock trading volume of 96 firms listed on the Nasdaq 100, during 193 days of trading in the period from May 21, 2012 to September 18, 2013. We identify observations featuring firm-specific spikes in Twitter activity, and randomly assign each observation to a ten-minute increment matching on the firm and a number of repeating time indicators. We examine the extent that unusual levels of chatter on Twitter about a firm portend an oncoming surge of trading of its stock within the hour, over and above what would normally be expected for the stock for that time of day and day of week. We also compare the findings from our explanatory model to the predictive power of Tweets. Although we find a compelling and potentially informative real-time relationship between Twitter activity and trading volume, our forecasting exercise highlights how difficult it can be to make use of this information for monetary gain.

  20. Real-Time Diffusion of Information on Twitter and the Financial Markets

    PubMed Central

    Tafti, Ali; Zotti, Ryan; Jank, Wolfgang

    2016-01-01

    Do spikes in Twitter chatter about a firm precede unusual stock market trading activity for that firm? If so, Twitter activity may provide useful information about impending financial market activity in real-time. We study the real-time relationship between chatter on Twitter and the stock trading volume of 96 firms listed on the Nasdaq 100, during 193 days of trading in the period from May 21, 2012 to September 18, 2013. We identify observations featuring firm-specific spikes in Twitter activity, and randomly assign each observation to a ten-minute increment matching on the firm and a number of repeating time indicators. We examine the extent that unusual levels of chatter on Twitter about a firm portend an oncoming surge of trading of its stock within the hour, over and above what would normally be expected for the stock for that time of day and day of week. We also compare the findings from our explanatory model to the predictive power of Tweets. Although we find a compelling and potentially informative real-time relationship between Twitter activity and trading volume, our forecasting exercise highlights how difficult it can be to make use of this information for monetary gain. PMID:27504639

  1. BIOACCESSIBILITY TESTS ACCURATELY ESTIMATE ...

    EPA Pesticide Factsheets

    Hazards of soil-borne Pb to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, we measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from five Pb-contaminated Superfund sites had relative bioavailabilities from 33%-63%, with a mean of about 50%. Treatment of two of the soils with P significantly reduced the bioavailability of Pb. The bioaccessibility of the Pb in the test soils was then measured in six in vitro tests and regressed on bioavailability. They were: the “Relative Bioavailability Leaching Procedure” (RBALP) at pH 1.5, the same test conducted at pH 2.5, the “Ohio State University In vitro Gastrointestinal” method (OSU IVG), the “Urban Soil Bioaccessible Lead Test”, the modified “Physiologically Based Extraction Test” and the “Waterfowl Physiologically Based Extraction Test.” All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the RBALP pH 2.5 and OSU IVG tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter 24%, or present as Pb sulfate 18%. Ad

  2. Sequential information processing using time-delay connections in ontogenic CALM networks.

    PubMed

    Tijsseling, Adriaan G

    2005-01-01

    In this paper, a variant of the categorization-and-learning-module (CALM) network is presented that is not only capable of categorizing sequential information with feedback, but can adapt its resources to the current training set. In other words, the modules of the network may grow or shrink depending on the complexity of the presented sequence-set. In the original CALM algorithm, modules did not have access to activations from earlier stimulus presentations. To bypass this limitation, we introduced time-delay connections in CALM. These connections allow for a delayed propagation of activation, such that information at a given time will be available to a module at a later timestep. In addition, modules can autonomously add and remove resources depending on the structure and complexity of the task domain. The performance of this ontogenic CALM network with time-delay connections is demonstrated and analyzed using a sample set of overlapping sequences from an existing problem domain.

  3. Techniques for optimizing human-machine information transfer related to real-time interactive display systems

    NASA Technical Reports Server (NTRS)

    Granaas, Michael M.; Rhea, Donald C.

    1989-01-01

    In recent years the needs of ground-based researcher-analysts to access real-time engineering data in the form of processed information has expanded rapidly. Fortunately, the capacity to deliver that information has also expanded. The development of advanced display systems is essential to the success of a research test activity. Those developed at the National Aeronautics and Space Administration (NASA), Western Aeronautical Test Range (WATR), range from simple alphanumerics to interactive mapping and graphics. These unique display systems are designed not only to meet basic information display requirements of the user, but also to take advantage of techniques for optimizing information display. Future ground-based display systems will rely heavily not only on new technologies, but also on interaction with the human user and the associated productivity with that interaction. The psychological abilities and limitations of the user will become even more important in defining the difference between a usable and a useful display system. This paper reviews the requirements for development of real-time displays; the psychological aspects of design such as the layout, color selection, real-time response rate, and interactivity of displays; and an analysis of some existing WATR displays.

  4. Response Timing Detection Using Prosodic and Linguistic Information for Human-friendly Spoken Dialog Systems

    NASA Astrophysics Data System (ADS)

    Kitaoka, Norihide; Takeuchi, Masashi; Nishimura, Ryota; Nakagawa, Seiichi

    If a dialog system can respond to the user as reasonably as a human, the interaction will become smoother. Timing of the response such as back-channels and turn-taking plays an important role in such a smooth dialog as in human-human interaction. We developed a response timing generator for such a dialog system. This generator uses a decision tree to detect the timing based on the features coming from some prosodic and linguistic information. The timing generator decides the action of the system at every 100 ms during the user's pause. In this paper, we describe a robust spoken dialog system using the timing generator. Subjective evaluation proved that almost all of the subjects experienced a friendly feeling from the system.

  5. Dynamics of traffic flows on crossing roads induced by real-time information

    NASA Astrophysics Data System (ADS)

    Fukui, Minoru; Ishibashi, Yoshihiro; Nishinari, Katsuhiro

    2013-02-01

    Traffic flows on crossing roads with an information board installed at the intersection have been simulated by a cellular automaton model. In the model, drivers have to enter the road with a shorter trip-time indicated on the information board, by making a turn at the intersection if necessary. The movement of drivers induces various traffic states, which are classified into six phases as a function of the car density. The dynamics of the traffic is expressed as the return map in the density-flow space, and analyzed on the basis of the car configuration on the roads.

  6. Information Gap Analysis: near real-time evaluation of disaster response

    NASA Astrophysics Data System (ADS)

    Girard, Trevor

    2014-05-01

    Disasters, such as major storm events or earthquakes, trigger an immediate response by the disaster management system of the nation in question. The quality of this response is a large factor in its ability to limit the impacts on the local population. Improving the quality of disaster response therefore reduces disaster impacts. Studying past disasters is a valuable exercise to understand what went wrong, identify measures which could have mitigated these issues, and make recommendations to improve future disaster planning and response. While such ex post evaluations can lead to improvements in the disaster management system, there are limitations. The main limitation that has influenced this research is that ex post evaluations do not have the ability to inform the disaster response being assessed for the obvious reason that they are carried out long after the response phase is over. The result is that lessons learned can only be applied to future disasters. In the field of humanitarian relief, this limitation has led to the development of real time evaluations. The key aspect of real time humanitarian evaluations is that they are completed while the operation is still underway. This results in findings being delivered at a time when they can still make a difference to the humanitarian response. Applying such an approach to the immediate disaster response phase requires an even shorter time-frame, as well as a shift in focus from international actors to the nation in question's government. As such, a pilot study was started and methodology developed, to analyze disaster response in near real-time. The analysis uses the information provided by the disaster management system within the first 0 - 5 days of the response. The data is collected from publicly available sources such as ReliefWeb and sorted under various categories which represent each aspect of disaster response. This process was carried out for 12 disasters. The quantity and timeliness of information

  7. Time-based self-spacing techniques using cockpit display of traffic information during approach to landing in a terminal area vectoring environment

    NASA Technical Reports Server (NTRS)

    Williams, D. H.

    1983-01-01

    A simulation study was undertaken to evaluate two time-based self-spacing techniques for in-trail following during terminal area approach. An electronic traffic display was provided in the weather radarscope location. The displayed self-spacing cues allowed the simulated aircraft to follow and to maintain spacing on another aircraft which was being vectored by air traffic control (ATC) for landing in a high-density terminal area. Separation performance data indicate the information provided on the traffic display was adequate for the test subjects to accurately follow the approach path of another aircraft without the assistance of ATC. The time-based technique with a constant-delay spacing criterion produced the most satisfactory spacing performance. Pilot comments indicate the workload associated with the self-separation task was very high and that additional spacing command information and/or aircraft autopilot functions would be desirable for operational implementational of the self-spacing task.

  8. Measuring information interactions on the ordinal pattern of stock time series.

    PubMed

    Zhao, Xiaojun; Shang, Pengjian; Wang, Jing

    2013-02-01

    The interactions among time series as individual components of complex systems can be quantified by measuring to what extent they exchange information among each other. In many applications, one focuses not on the original series but on its ordinal pattern. In such cases, trivial noises appear more likely to be filtered and the abrupt influence of extreme values can be weakened. Cross-sample entropy and inner composition alignment have been introduced as prominent methods to estimate the information interactions of complex systems. In this paper, we modify both methods to detect the interactions among the ordinal pattern of stock return and volatility series, and we try to uncover the information exchanges across sectors in Chinese stock markets.

  9. Measuring information interactions on the ordinal pattern of stock time series

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaojun; Shang, Pengjian; Wang, Jing

    2013-02-01

    The interactions among time series as individual components of complex systems can be quantified by measuring to what extent they exchange information among each other. In many applications, one focuses not on the original series but on its ordinal pattern. In such cases, trivial noises appear more likely to be filtered and the abrupt influence of extreme values can be weakened. Cross-sample entropy and inner composition alignment have been introduced as prominent methods to estimate the information interactions of complex systems. In this paper, we modify both methods to detect the interactions among the ordinal pattern of stock return and volatility series, and we try to uncover the information exchanges across sectors in Chinese stock markets.

  10. Real Time Alert System: A Disease Management System Leveraging Health Information Exchange

    PubMed Central

    Anand, Vibha; Sheley, Meena E.; Xu, Shawn; Downs, Stephen M.

    2012-01-01

    Background Rates of preventive and disease management services can be improved by providing automated alerts and reminders to primary care providers (PCPs) using of health information technology (HIT) tools. Methods: Using Adaptive Turnaround Documents (ATAD), an existing Health Information Exchange (HIE) infrastructure and office fax machines, we developed a Real Time Alert (RTA) system. RTA is a computerized decision support system (CDSS) that is able to deliver alerts to PCPs statewide for recommended services around the time of the patient visit. RTA is also able to capture structured clinical data from providers using existing fax technology. In this study, we evaluate RTA’s performance for alerting PCPs when their patients with asthma have an emergency room visit anywhere in the state. Results: Our results show that RTA was successfully able to deliver “just in time” patient-relevant alerts to PCPs across the state. Furthermore, of those ATADs faxed back and automatically interpreted by the RTA system, 35% reported finding the provided information helpful. The PCPs who reported finding information helpful also reported making a phone call, sending a letter or seeing the patient for follow up care. Conclusions: We have successfully demonstrated the feasibility of electronically exchanging important patient related information with the PCPs statewide. This is despite a lack of a link with their electronic health records. We have shown that using our ATAD technology, a PCP can be notified quickly of an important event such as a patient’s asthma related emergency room admission so further follow up can happen in near real time. PMID:23569648

  11. Simultaneous learning of instantaneous and time-delayed genetic interactions using novel information theoretic scoring technique

    PubMed Central

    2012-01-01

    Background Understanding gene interactions is a fundamental question in systems biology. Currently, modeling of gene regulations using the Bayesian Network (BN) formalism assumes that genes interact either instantaneously or with a certain amount of time delay. However in reality, biological regulations, both instantaneous and time-delayed, occur simultaneously. A framework that can detect and model both these two types of interactions simultaneously would represent gene regulatory networks more accurately. Results In this paper, we introduce a framework based on the Bayesian Network (BN) formalism that can represent both instantaneous and time-delayed interactions between genes simultaneously. A novel scoring metric having firm mathematical underpinnings is also proposed that, unlike other recent methods, can score both interactions concurrently and takes into account the reality that multiple regulators can regulate a gene jointly, rather than in an isolated pair-wise manner. Further, a gene regulatory network (GRN) inference method employing an evolutionary search that makes use of the framework and the scoring metric is also presented. Conclusion By taking into consideration the biological fact that both instantaneous and time-delayed regulations can occur among genes, our approach models gene interactions with greater accuracy. The proposed framework is efficient and can be used to infer gene networks having multiple orders of instantaneous and time-delayed regulations simultaneously. Experiments are carried out using three different synthetic networks (with three different mechanisms for generating synthetic data) as well as real life networks of Saccharomyces cerevisiae, E. coli and cyanobacteria gene expression data. The results show the effectiveness of our approach. PMID:22691450

  12. Effect of real-time information upon traffic flows on crossing roads

    NASA Astrophysics Data System (ADS)

    Fukui, Minoru; Nishinari, Katsuhiro; Yokoya, Yasushi; Ishibashi, Yoshihiro

    2009-04-01

    The effect of real-time information on the traffic flows of the crossing roads is studied by simulations based on a cellular automaton model. At the intersection, drivers have to enter a road of a shorter trip-time, by making a turn if necessary, as indicated on the information board. Dynamics of the traffic are expressed as a return map in the density-flow space. The traffic flow is classified into six phases, as a function of the car density. It is found that such a behavior of drivers induces too much concentration of cars on one road and, as a result, causes oscillation of the flow and the density of cars on both roads. The oscillation usually results in a reduced total flow, except for the cases of high car density.

  13. Time dependent Schrödinger equation for black hole evaporation: No information loss

    SciTech Connect

    Corda, Christian

    2015-02-15

    In 1976 S. Hawking claimed that “Because part of the information about the state of the system is lost down the hole, the final situation is represented by a density matrix rather than a pure quantum state”. This was the starting point of the popular “black hole (BH) information paradox”. In a series of papers, together with collaborators, we naturally interpreted BH quasi-normal modes (QNMs) in terms of quantum levels discussing a model of excited BH somewhat similar to the historical semi-classical Bohr model of the structure of a hydrogen atom. Here we explicitly write down, for the same model, a time dependent Schrödinger equation for the system composed by Hawking radiation and BH QNMs. The physical state and the correspondent wave function are written in terms of a unitary evolution matrix instead of a density matrix. Thus, the final state results to be a pure quantum state instead of a mixed one. Hence, Hawking’s claim is falsified because BHs result to be well defined quantum mechanical systems, having ordered, discrete quantum spectra, which respect ’t Hooft’s assumption that Schrödinger equations can be used universally for all dynamics in the universe. As a consequence, information comes out in BH evaporation in terms of pure states in a unitary time dependent evolution. In Section 4 of this paper we show that the present approach permits also to solve the entanglement problem connected with the information paradox.

  14. Effect of the time window on the heat-conduction information filtering model

    NASA Astrophysics Data System (ADS)

    Guo, Qiang; Song, Wen-Jun; Hou, Lei; Zhang, Yi-Lu; Liu, Jian-Guo

    2014-05-01

    Recommendation systems have been proposed to filter out the potential tastes and preferences of the normal users online, however, the physics of the time window effect on the performance is missing, which is critical for saving the memory and decreasing the computation complexity. In this paper, by gradually expanding the time window, we investigate the impact of the time window on the heat-conduction information filtering model with ten similarity measures. The experimental results on the benchmark dataset Netflix indicate that by only using approximately 11.11% recent rating records, the accuracy could be improved by an average of 33.16% and the diversity could be improved by 30.62%. In addition, the recommendation performance on the dataset MovieLens could be preserved by only considering approximately 10.91% recent records. Under the circumstance of improving the recommendation performance, our discoveries possess significant practical value by largely reducing the computational time and shortening the data storage space.

  15. On the implementation of a real-time information security architecture in frequency domain

    NASA Astrophysics Data System (ADS)

    Basu, Abhishek; Sarkar, Souvik; Sarkar, Subir Kumar

    2015-12-01

    This paper presents the real-time implementation of a watermarking-based information security architecture in frequency domain. The scheme emphasises on the human visual system (HVS)-supported watermarking approach using wavelet-lifting technique. In addition to HVS, image registration algorithm is also introduced in order to increase the resiliency as well as the security of the estimated recovered watermark image. The algorithmic steps with optimisation considerations about the real-time implementation on TMS320CDSK6416/6713 fixed/floating point digital signal processor are also projected.

  16. Nonexposure Accurate Location K-Anonymity Algorithm in LBS

    PubMed Central

    2014-01-01

    This paper tackles location privacy protection in current location-based services (LBS) where mobile users have to report their exact location information to an LBS provider in order to obtain their desired services. Location cloaking has been proposed and well studied to protect user privacy. It blurs the user's accurate coordinate and replaces it with a well-shaped cloaked region. However, to obtain such an anonymous spatial region (ASR), nearly all existent cloaking algorithms require knowing the accurate locations of all users. Therefore, location cloaking without exposing the user's accurate location to any party is urgently needed. In this paper, we present such two nonexposure accurate location cloaking algorithms. They are designed for K-anonymity, and cloaking is performed based on the identifications (IDs) of the grid areas which were reported by all the users, instead of directly on their accurate coordinates. Experimental results show that our algorithms are more secure than the existent cloaking algorithms, need not have all the users reporting their locations all the time, and can generate smaller ASR. PMID:24605060

  17. Nonexposure accurate location K-anonymity algorithm in LBS.

    PubMed

    Jia, Jinying; Zhang, Fengli

    2014-01-01

    This paper tackles location privacy protection in current location-based services (LBS) where mobile users have to report their exact location information to an LBS provider in order to obtain their desired services. Location cloaking has been proposed and well studied to protect user privacy. It blurs the user's accurate coordinate and replaces it with a well-shaped cloaked region. However, to obtain such an anonymous spatial region (ASR), nearly all existent cloaking algorithms require knowing the accurate locations of all users. Therefore, location cloaking without exposing the user's accurate location to any party is urgently needed. In this paper, we present such two nonexposure accurate location cloaking algorithms. They are designed for K-anonymity, and cloaking is performed based on the identifications (IDs) of the grid areas which were reported by all the users, instead of directly on their accurate coordinates. Experimental results show that our algorithms are more secure than the existent cloaking algorithms, need not have all the users reporting their locations all the time, and can generate smaller ASR.

  18. TIME Impact - a new user-friendly tuberculosis (TB) model to inform TB policy decisions.

    PubMed

    Houben, R M G J; Lalli, M; Sumner, T; Hamilton, M; Pedrazzoli, D; Bonsu, F; Hippner, P; Pillay, Y; Kimerling, M; Ahmedov, S; Pretorius, C; White, R G

    2016-03-24

    Tuberculosis (TB) is the leading cause of death from infectious disease worldwide, predominantly affecting low- and middle-income countries (LMICs), where resources are limited. As such, countries need to be able to choose the most efficient interventions for their respective setting. Mathematical models can be valuable tools to inform rational policy decisions and improve resource allocation, but are often unavailable or inaccessible for LMICs, particularly in TB. We developed TIME Impact, a user-friendly TB model that enables local capacity building and strengthens country-specific policy discussions to inform support funding applications at the (sub-)national level (e.g. Ministry of Finance) or to international donors (e.g. the Global Fund to Fight AIDS, Tuberculosis and Malaria).TIME Impact is an epidemiological transmission model nested in TIME, a set of TB modelling tools available for free download within the widely-used Spectrum software. The TIME Impact model reflects key aspects of the natural history of TB, with additional structure for HIV/ART, drug resistance, treatment history and age. TIME Impact enables national TB programmes (NTPs) and other TB policymakers to better understand their own TB epidemic, plan their response, apply for funding and evaluate the implementation of the response.The explicit aim of TIME Impact's user-friendly interface is to enable training of local and international TB experts towards independent use. During application of TIME Impact, close involvement of the NTPs and other local partners also builds critical understanding of the modelling methods, assumptions and limitations inherent to modelling. This is essential to generate broad country-level ownership of the modelling data inputs and results. In turn, it stimulates discussions and a review of the current evidence and assumptions, strengthening the decision-making process in general.TIME Impact has been effectively applied in a variety of settings. In South Africa, it

  19. Named entity recognition of follow-up and time information in 20 000 radiology reports

    PubMed Central

    Xu, Yan; Tsujii, Junichi

    2012-01-01

    Objective To develop a system to extract follow-up information from radiology reports. The method may be used as a component in a system which automatically generates follow-up information in a timely fashion. Methods A novel method of combining an LSP (labeled sequential pattern) classifier with a CRF (conditional random field) recognizer was devised. The LSP classifier filters out irrelevant sentences, while the CRF recognizer extracts follow-up and time phrases from candidate sentences presented by the LSP classifier. Measurements The standard performance metrics of precision (P), recall (R), and F measure (F) in the exact and inexact matching settings were used for evaluation. Results Four experiments conducted using 20 000 radiology reports showed that the CRF recognizer achieved high performance without time-consuming feature engineering and that the LSP classifier further improved the performance of the CRF recognizer. The performance of the current system is P=0.90, R=0.86, F=0.88 in the exact matching setting and P=0.98, R=0.93, F=0.95 in the inexact matching setting. Conclusion The experiments demonstrate that the system performs far better than a baseline rule-based system and is worth considering for deployment trials in an alert generation system. The LSP classifier successfully compensated for the inherent weakness of CRF, that is, its inability to use global information. PMID:22771530

  20. Using precise word timing information improves decoding accuracy in a multiband-accelerated multimodal reading experiment

    PubMed Central

    Vu, An T.; Phillips, Jeffrey S.; Kay, Kendrick; Phillips, Matthew E.; Johnson, Matthew R.; Shinkareva, Svetlana V.; Tubridy, Shannon; Millin, Rachel; Grossman, Murray; Gureckis, Todd; Bhattacharyya, Rajan; Yacoub, Essa

    2017-01-01

    The blood-oxygen-level-dependent (BOLD) signal measured in functional magnetic resonance imaging (fMRI) experiments is generally regarded as sluggish and poorly suited for probing neural function at the rapid timescales involved in sentence comprehension. However, recent studies have shown the value of acquiring data with very short repetition times (TRs), not merely in terms of improvements in contrast to noise ratio (CNR) through averaging, but also in terms of additional fine-grained temporal information. Using multiband-accelerated fMRI, we achieved whole-brain scans at 3-mm resolution with a TR of just 500 ms at both 3T and 7T field strengths. By taking advantage of word timing information, we found that word decoding accuracy across two separate sets of scan sessions improved significantly, with better overall performance at 7T than at 3T. The effect of TR was also investigated; we found that substantial word timing information can be extracted using fast TRs, with diminishing benefits beyond TRs of 1000 ms. PMID:27686111

  1. Using precise word timing information improves decoding accuracy in a multiband-accelerated multimodal reading experiment.

    PubMed

    Vu, An T; Phillips, Jeffrey S; Kay, Kendrick; Phillips, Matthew E; Johnson, Matthew R; Shinkareva, Svetlana V; Tubridy, Shannon; Millin, Rachel; Grossman, Murray; Gureckis, Todd; Bhattacharyya, Rajan; Yacoub, Essa

    2016-01-01

    The blood-oxygen-level-dependent (BOLD) signal measured in functional magnetic resonance imaging (fMRI) experiments is generally regarded as sluggish and poorly suited for probing neural function at the rapid timescales involved in sentence comprehension. However, recent studies have shown the value of acquiring data with very short repetition times (TRs), not merely in terms of improvements in contrast to noise ratio (CNR) through averaging, but also in terms of additional fine-grained temporal information. Using multiband-accelerated fMRI, we achieved whole-brain scans at 3-mm resolution with a TR of just 500 ms at both 3T and 7T field strengths. By taking advantage of word timing information, we found that word decoding accuracy across two separate sets of scan sessions improved significantly, with better overall performance at 7T than at 3T. The effect of TR was also investigated; we found that substantial word timing information can be extracted using fast TRs, with diminishing benefits beyond TRs of 1000 ms.

  2. "Right Time, Right Place" Health Communication on Twitter: Value and Accuracy of Location Information

    PubMed Central

    Burton, Scott H; Tanner, Kesler W; West, Joshua H; Barnes, Michael D

    2012-01-01

    Background Twitter provides various types of location data, including exact Global Positioning System (GPS) coordinates, which could be used for infoveillance and infodemiology (ie, the study and monitoring of online health information), health communication, and interventions. Despite its potential, Twitter location information is not well understood or well documented, limiting its public health utility. Objective The objective of this study was to document and describe the various types of location information available in Twitter. The different types of location data that can be ascertained from Twitter users are described. This information is key to informing future research on the availability, usability, and limitations of such location data. Methods Location data was gathered directly from Twitter using its application programming interface (API). The maximum tweets allowed by Twitter were gathered (1% of the total tweets) over 2 separate weeks in October and November 2011. The final dataset consisted of 23.8 million tweets from 9.5 million unique users. Frequencies for each of the location options were calculated to determine the prevalence of the various location data options by region of the world, time zone, and state within the United States. Data from the US Census Bureau were also compiled to determine population proportions in each state, and Pearson correlation coefficients were used to compare each state’s population with the number of Twitter users who enable the GPS location option. Results The GPS location data could be ascertained for 2.02% of tweets and 2.70% of unique users. Using a simple text-matching approach, 17.13% of user profiles in the 4 continental US time zones were able to be used to determine the user’s city and state. Agreement between GPS data and data from the text-matching approach was high (87.69%). Furthermore, there was a significant correlation between the number of Twitter users per state and the 2010 US Census state

  3. End-User Applications of Real-Time Earthquake Information in Europe

    NASA Astrophysics Data System (ADS)

    Cua, G. B.; Gasparini, P.; Giardini, D.; Zschau, J.; Filangieri, A. R.; Reakt Wp7 Team

    2011-12-01

    The primary objective of European FP7 project REAKT (Strategies and Tools for Real-Time Earthquake Risk Reduction) is to improve the efficiency of real-time earthquake risk mitigation methods and their capability of protecting structures, infrastructures, and populations. REAKT aims to address the issues of real-time earthquake hazard and response from end-to-end, with efforts directed along the full spectrum of methodology development in earthquake forecasting, earthquake early warning, and real-time vulnerability systems, through optimal decision-making, and engagement and cooperation of scientists and end users for the establishment of best practices for use of real-time information. Twelve strategic test cases/end users throughout Europe have been selected. This diverse group of applications/end users includes civil protection authorities, railway systems, hospitals, schools, industrial complexes, nuclear plants, lifeline systems, national seismic networks, and critical structures. The scale of target applications covers a wide range, from two school complexes in Naples, to individual critical structures, such as the Rion Antirion bridge in Patras, and the Fatih Sultan Mehmet bridge in Istanbul, to large complexes, such as the SINES industrial complex in Portugal and the Thessaloniki port area, to distributed lifeline and transportation networks and nuclear plants. Some end-users are interested in in-depth feasibility studies for use of real-time information and development of rapid response plans, while others intend to install real-time instrumentation and develop customized automated control systems. From the onset, REAKT scientists and end-users will work together on concept development and initial implementation efforts using the data products and decision-making methodologies developed with the goal of improving end-user risk mitigation. The aim of this scientific/end-user partnership is to ensure that scientific efforts are applicable to operational

  4. Value of information of repair times for offshore wind farm maintenance planning

    NASA Astrophysics Data System (ADS)

    Seyr, Helene; Muskulus, Michael

    2016-09-01

    A large contribution to the total cost of energy in offshore wind farms is due to maintenance costs. In recent years research has focused therefore on lowering the maintenance costs using different approaches. Decision support models for scheduling the maintenance exist already, dealing with different factors influencing the scheduling. Our contribution deals with the uncertainty in the repair times. Given the mean repair times for different turbine components we make some assumptions regarding the underlying repair time distribution. We compare the results of a decision support model for the mean times to repair and those repair time distributions. Additionally, distributions with the same mean but different variances are compared under the same conditions. The value of lowering the uncertainty in the repair time is calculated and we find that using distributions significantly decreases the availability, when scheduling maintenance for multiple turbines in a wind park. Having detailed information about the repair time distribution may influence the results of maintenance modeling and might help identify cost factors.

  5. Incorporating Real-time Earthquake Information into Large Enrollment Natural Disaster Course Learning

    NASA Astrophysics Data System (ADS)

    Furlong, K. P.; Benz, H.; Hayes, G. P.; Villasenor, A.

    2010-12-01

    Although most would agree that the occurrence of natural disaster events such as earthquakes, volcanic eruptions, and floods can provide effective learning opportunities for natural hazards-based courses, implementing compelling materials into the large-enrollment classroom environment can be difficult. These natural hazard events derive much of their learning potential from their real-time nature, and in the modern 24/7 news-cycle where all but the most devastating events are quickly out of the public eye, the shelf life for an event is quite limited. To maximize the learning potential of these events requires that both authoritative information be available and course materials be generated as the event unfolds. Although many events such as hurricanes, flooding, and volcanic eruptions provide some precursory warnings, and thus one can prepare background materials to place the main event into context, earthquakes present a particularly confounding situation of providing no warning, but where context is critical to student learning. Attempting to implement real-time materials into large enrollment classes faces the additional hindrance of limited internet access (for students) in most lecture classrooms. In Earth 101 Natural Disasters: Hollywood vs Reality, taught as a large enrollment (150+ students) general education course at Penn State, we are collaborating with the USGS’s National Earthquake Information Center (NEIC) to develop efficient means to incorporate their real-time products into learning activities in the lecture hall environment. Over time (and numerous events) we have developed a template for presenting USGS-produced real-time information in lecture mode. The event-specific materials can be quickly incorporated and updated, along with key contextual materials, to provide students with up-to-the-minute current information. In addition, we have also developed in-class activities, such as student determination of population exposure to severe ground

  6. Using Concurrent Cardiovascular Information to Augment Survival Time Data from Orthostatic Tilt Tests

    NASA Technical Reports Server (NTRS)

    Feiveson, Alan H.; Fiedler, James; Lee, Stuart M. M.; Westby, Christian M.; Stenger, Michael B.; Platts, Steven H.

    2014-01-01

    Orthostatic Intolerance (OI) is the propensity to develop symptoms of fainting during upright standing. OI is associated with changes in heart rate, blood pressure and other measures of cardiac function. Problem: NASA astronauts have shown increased susceptibility to OI on return from space missions. Current methods for counteracting OI in astronauts include fluid loading and the use of compression garments. Multivariate trajectory spread is greater as OI increases. Pairwise comparisons at the same time within subjects allows incorporation of pass/fail outcomes. Path length, convex hull area, and covariance matrix determinant do well as statistics to summarize this spread Missing data problems Time series analysis need many more time points per OTT session treatment of trend? how incorporate survival information?

  7. The use of generalized information dimension in measuring fractal dimension of time series

    NASA Astrophysics Data System (ADS)

    Ashkenazy, Y.

    1999-09-01

    An algorithm for calculating generalized fractal dimension of a time series using the general information function is presented. The algorithm is based on a strings sort technique and requires O(N log2 N) computations. A rough estimate for the number of points needed for the fractal dimension calculation is given. The algorithm was tested on analytic example as well as well-known examples, such as, the Lorenz attractor, the Rossler attractor, the van der Pol oscillator, and the Mackey-Glass equation, and compared, successfully, with previous results published in the literature. The computation time for the algorithm suggested in this paper is much less than the computation time according to other methods.

  8. Self-Existing Objects and Auto-Generated Information in Chronology-Violating Space-Times

    NASA Astrophysics Data System (ADS)

    Romero, Gustavo E.; Torres, Diego F.

    Closed time-like curves (CTCs) naturally appear in a variety of chronology-violating space-times. In these space-times, the principle of self-consistency demands a harmony between local and global affairs that excludes grandfather-like paradoxes. However, self-existing objects trapped in CTCs are not seemingly avoided by the standard interpretation of this principle, usually constrained to a dynamical framework. In this letter we discuss whether we are committed to accept an ontology with self-existing objects if CTCs actually occur in the universe. In addition, the epistemological status of the principle of self-consistency is analyzed and a discussion on the information flux through CTCs is presented.

  9. Time-resolved X-ray PIV measurements of hemodynamic information of real pulsatile blood flows

    NASA Astrophysics Data System (ADS)

    Park, Hanwook; Yeom, Eunseop; Lee, Sang Joon

    2015-11-01

    X-ray imaging technique has been used to visualize various bio-fluid flow phenomena as a nondestructive manner. To obtain hemodynamic information related with circulatory vascular diseases, a time-resolved X-ray PIV technique with high temporal resolution was developed. In this study, to embody actual pulsatile blood flows in a circular conduit without changes in hemorheological properties, a bypass loop is established by connecting a microtube between the jugular vein and femoral artery of a rat. Biocompatible CO2 microbubbles are used as tracer particles. After mixing with whole blood, CO2 microbubbles are injected into the bypass loop. Particle images of the pulsatile blood flows in the bypass loop are consecutively captured by the time-resolved X-ray PIV system. The velocity field information are obtained with varying flow rate and pulsataility. To verify the feasibility of the use of CO2 microbubbles under in vivo conditions, the effects of the surrounding-tissues are also investigated, because these effects are crucial for deteriorating the image contrast of CO2 microbubbles. Therefore, the velocity information of blood flows in the abdominal aorta are obtained to demonstrate the visibility and usefulness of CO2 microbubbles under ex vivo conditions. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2008-0061991).

  10. Time dependent Schrödinger equation for black hole evaporation: No information loss

    NASA Astrophysics Data System (ADS)

    Corda, Christian

    2015-02-01

    In 1976 S. Hawking claimed that "Because part of the information about the state of the system is lost down the hole, the final situation is represented by a density matrix rather than a pure quantum state".1 In a series of papers, together with collaborators, we naturally interpreted BH quasi-normal modes (QNMs) in terms of quantum levels discussing a model of excited BH somewhat similar to the historical semi-classical Bohr model of the structure of a hydrogen atom. Here we explicitly write down, for the same model, a time dependent Schrödinger equation for the system composed by Hawking radiation and BH QNMs. The physical state and the correspondent wave function are written in terms of a unitary evolution matrix instead of a density matrix. Thus, the final state results to be a pure quantum state instead of a mixed one. Hence, Hawking's claim is falsified because BHs result to be well defined quantum mechanical systems, having ordered, discrete quantum spectra, which respect 't Hooft's assumption that Schrödinger equations can be used universally for all dynamics in the universe. As a consequence, information comes out in BH evaporation in terms of pure states in a unitary time dependent evolution. In Section 4 of this paper we show that the present approach permits also to solve the entanglement problem connected with the information paradox.

  11. Real time biomedical signal transmission of mixed ECG signal and patient information using visible light communication.

    PubMed

    Tan, Yee Yong; Jung, Sang-Joong; Chung, Wan-Young

    2013-01-01

    The utilization of radio-frequency (RF) communication technology in healthcare application, especially in the transmission of health-related data such as biomedical signal and patient information is often perturbed by electromagnetic interference (EMI). This will not only significantly reduce the accuracy and reliability of the data transmitted, but could also compromise the safety of the patients due to radio frequency (RF) radiation. In this paper, we propose a method which utilizes visible light communication technology as a platform for transmission and to provide real-time monitoring of heart rate and patient information. White LED beam is used as the illuminating source to simultaneously transmit biomedical signal as well as patient record. On-off Keying (OOK) modulation technique is used to modulate all the data onto the visible light beam. Both types of data will be transmitted using a single data packet. At the receiving end, a receiver circuit consisting of a high-speed PIN photodetector and a demodulation circuit is employed to demodulate the data from the visible light beam. The demodulated data is then serially transmitted to a personal computer where the biomedical signal, patient information and heart rate can be monitored in real-time.

  12. Whisper: Tracing the Spatiotemporal Process of Information Diffusion in Real Time.

    PubMed

    Cao, Nan; Lin, Yu-Ru; Sun, Xiaohua; Lazer, D; Liu, Shixia; Qu, Huamin

    2012-12-01

    When and where is an idea dispersed? Social media, like Twitter, has been increasingly used for exchanging information, opinions and emotions about events that are happening across the world. Here we propose a novel visualization design, "Whisper", for tracing the process of information diffusion in social media in real time. Our design highlights three major characteristics of diffusion processes in social media: the temporal trend, social-spatial extent, and community response of a topic of interest. Such social, spatiotemporal processes are conveyed based on a sunflower metaphor whose seeds are often dispersed far away. In Whisper, we summarize the collective responses of communities on a given topic based on how tweets were retweeted by groups of users, through representing the sentiments extracted from the tweets, and tracing the pathways of retweets on a spatial hierarchical layout. We use an efficient flux line-drawing algorithm to trace multiple pathways so the temporal and spatial patterns can be identified even for a bursty event. A focused diffusion series highlights key roles such as opinion leaders in the diffusion process. We demonstrate how our design facilitates the understanding of when and where a piece of information is dispersed and what are the social responses of the crowd, for large-scale events including political campaigns and natural disasters. Initial feedback from domain experts suggests promising use for today's information consumption and dispersion in the wild.

  13. The timing of the human circadian clock is accurately represented by the core body temperature rhythm following phase shifts to a three-cycle light stimulus near the critical zone

    NASA Technical Reports Server (NTRS)

    Jewett, M. E.; Duffy, J. F.; Czeisler, C. A.

    2000-01-01

    A double-stimulus experiment was conducted to evaluate the phase of the underlying circadian clock following light-induced phase shifts of the human circadian system. Circadian phase was assayed by constant routine from the rhythm in core body temperature before and after a three-cycle bright-light stimulus applied near the estimated minimum of the core body temperature rhythm. An identical, consecutive three-cycle light stimulus was then applied, and phase was reassessed. Phase shifts to these consecutive stimuli were no different from those obtained in a previous study following light stimuli applied under steady-state conditions over a range of circadian phases similar to those at which the consecutive stimuli were applied. These data suggest that circadian phase shifts of the core body temperature rhythm in response to a three-cycle stimulus occur within 24 h following the end of the 3-day light stimulus and that this poststimulus temperature rhythm accurately reflects the timing of the underlying circadian clock.

  14. Novel Accurate Bacterial Discrimination by MALDI-Time-of-Flight MS Based on Ribosomal Proteins Coding in S10-spc-alpha Operon at Strain Level S10-GERMS

    NASA Astrophysics Data System (ADS)

    Tamura, Hiroto; Hotta, Yudai; Sato, Hiroaki

    2013-08-01

    Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is one of the most widely used mass-based approaches for bacterial identification and classification because of the simple sample preparation and extremely rapid analysis within a few minutes. To establish the accurate MALDI-TOF MS bacterial discrimination method at strain level, the ribosomal subunit proteins coded in the S 10-spc-alpha operon, which encodes half of the ribosomal subunit protein and is highly conserved in eubacterial genomes, were selected as reliable biomarkers. This method, named the S10-GERMS method, revealed that the strains of genus Pseudomonas were successfully identified and discriminated at species and strain levels, respectively; therefore, the S10-GERMS method was further applied to discriminate the pathovar of P. syringae. The eight selected biomarkers (L24, L30, S10, S12, S14, S16, S17, and S19) suggested the rapid discrimination of P. syringae at the strain (pathovar) level. The S10-GERMS method appears to be a powerful tool for rapid and reliable bacterial discrimination and successful phylogenetic characterization. In this article, an overview of the utilization of results from the S10-GERMS method is presented, highlighting the characterization of the Lactobacillus casei group and discrimination of the bacteria of genera Bacillus and Sphingopyxis despite only two and one base difference in the 16S rRNA gene sequence, respectively.

  15. Classification and Verification of Handwritten Signatures with Time Causal Information Theory Quantifiers.

    PubMed

    Rosso, Osvaldo A; Ospina, Raydonal; Frery, Alejandro C

    2016-01-01

    We present a new approach for handwritten signature classification and verification based on descriptors stemming from time causal information theory. The proposal uses the Shannon entropy, the statistical complexity, and the Fisher information evaluated over the Bandt and Pompe symbolization of the horizontal and vertical coordinates of signatures. These six features are easy and fast to compute, and they are the input to an One-Class Support Vector Machine classifier. The results are better than state-of-the-art online techniques that employ higher-dimensional feature spaces which often require specialized software and hardware. We assess the consistency of our proposal with respect to the size of the training sample, and we also use it to classify the signatures into meaningful groups.

  16. Classification and Verification of Handwritten Signatures with Time Causal Information Theory Quantifiers

    PubMed Central

    Ospina, Raydonal; Frery, Alejandro C.

    2016-01-01

    We present a new approach for handwritten signature classification and verification based on descriptors stemming from time causal information theory. The proposal uses the Shannon entropy, the statistical complexity, and the Fisher information evaluated over the Bandt and Pompe symbolization of the horizontal and vertical coordinates of signatures. These six features are easy and fast to compute, and they are the input to an One-Class Support Vector Machine classifier. The results are better than state-of-the-art online techniques that employ higher-dimensional feature spaces which often require specialized software and hardware. We assess the consistency of our proposal with respect to the size of the training sample, and we also use it to classify the signatures into meaningful groups. PMID:27907014

  17. Time-Delayed Mutual Information of the Phase as a Measure of Functional Connectivity

    PubMed Central

    Wilmer, Andreas; de Lussanet, Marc; Lappe, Markus

    2012-01-01

    We propose a time-delayed mutual information of the phase for detecting nonlinear synchronization in electrophysiological data such as MEG. Palus already introduced the mutual information as a measure of synchronization [1]. To obtain estimates on small data-sets as reliably as possible, we adopt the numerical implementation as proposed by Kraskov and colleagues [2]. An embedding with a parametric time-delay allows a reconstruction of arbitrary nonstationary connective structures – so-called connectivity patterns – in a wide class of systems such as coupled oscillatory or even purely stochastic driven processes [3]. By using this method we do not need to make any assumptions about coupling directions, delay times, temporal dynamics, nonlinearities or underlying mechanisms. For verifying and refining the methods we generate synthetic data-sets by a mutual amplitude coupled network of Rössler oscillators with an a-priori known connective structure. This network is modified in such a way, that the power-spectrum forms a power law, which is also observed in electrophysiological recordings. The functional connectivity measure is tested on robustness to additive uncorrelated noise and in discrimination of linear mixed input data. For the latter issue a suitable de-correlation technique is applied. Furthermore, the compatibility to inverse methods for a source reconstruction in MEG such as beamforming techniques is controlled by dedicated dipole simulations. Finally, the method is applied on an experimental MEG recording. PMID:23028571

  18. Analysing the information flow between financial time series . An improved estimator for transfer entropy

    NASA Astrophysics Data System (ADS)

    Marschinski, R.; Kantz, H.

    2002-11-01

    Following the recently introduced concept of transfer entropy, we attempt to measure the information flow between two financial time series, the Dow Jones and DAX stock index. Being based on Shannon entropies, this model-free approach in principle allows us to detect statistical dependencies of all types, i.e. linear and nonlinear temporal correlations. However, when available data is limited and the expected effect is rather small, a straightforward implementation suffers badly from misestimation due to finite sample effects, making it basically impossible to assess the significance of the obtained values. We therefore introduce a modified estimator, called effective transfer entropy, which leads to improved results in such conditions. In the application, we then manage to confirm an information transfer on a time scale of one minute between the two financial time series. The different economic impact of the two indices is also recovered from the data. Numerical results are then interpreted on one hand as capability of one index to explain future observations of the other, and on the other hand within terms of coupling strengths in the framework of a bivariate autoregressive stochastic model. Evidence is given for a nonlinear character of the coupling between Dow Jones and DAX.

  19. Development and Implementation of Real-Time Information Delivery Systems for Emergency Management

    NASA Technical Reports Server (NTRS)

    Wegener, Steve; Sullivan, Don; Ambrosia, Vince; Brass, James; Dann, R. Scott

    2000-01-01

    The disaster management community has an on-going need for real-time data and information, especially during catastrophic events. Currently, twin engine or jet aircraft with limited altitude and duration capabilities collect much of the data. Flight safety is also an issue. Clearly, much of the needed data could be delivered via over-the-horizon transfer through a uninhabited aerial vehicles (UAV) platform to mission managers at various locations on the ground. In fact, because of the ability to stay aloft for long periods of time, and to fly above dangerous situations, UAV's are ideally suited for disaster missions. There are numerous situations that can be considered disastrous for the human population. Some, such as fire or flood, can continue over a period of days. Disaster management officials rely on data from the site to respond in an optimum way with warnings, evacuations, rescue, relief, and to the extent possible, damage control. Although different types of disasters call for different types of response, most situations can be improved by having visual images and other remotely sensed data available. "Disaster Management" is actually made up of a number of activities, including: - Disaster Prevention and Mitigation - Emergency Response Planning - Disaster Management (real-time deployment of resources, during an event) - Disaster / Risk Modeling All of these activities could benefit from real-time information, but a major focus for UAV-based technology is in real-time deployment of resources (i.e., emergency response teams), based on changing conditions at the location of the event. With all these potential benefits, it is desirable to demonstrate to user agencies the ability to perform disaster management missions as described. The following demonstration project is the first in a program designed to prove the feasibility of supporting disaster missions with UAV technology and suitable communications packages on-board. A several-year program is envisioned

  20. Accurate pointing of tungsten welding electrodes

    NASA Technical Reports Server (NTRS)

    Ziegelmeier, P.

    1971-01-01

    Thoriated-tungsten is pointed accurately and quickly by using sodium nitrite. Point produced is smooth and no effort is necessary to hold the tungsten rod concentric. The chemically produced point can be used several times longer than ground points. This method reduces time and cost of preparing tungsten electrodes.

  1. Time-Varying Distortions of Binaural Information by Bilateral Hearing Aids

    PubMed Central

    Rodriguez, Francisco A.; Portnuff, Cory D. F.; Goupell, Matthew J.; Tollin, Daniel J.

    2016-01-01

    In patients with bilateral hearing loss, the use of two hearing aids (HAs) offers the potential to restore the benefits of binaural hearing, including sound source localization and segregation. However, existing evidence suggests that bilateral HA users’ access to binaural information, namely interaural time and level differences (ITDs and ILDs), can be compromised by device processing. Our objective was to characterize the nature and magnitude of binaural distortions caused by modern digital behind-the-ear HAs using a variety of stimuli and HA program settings. Of particular interest was a common frequency-lowering algorithm known as nonlinear frequency compression, which has not previously been assessed for its effects on binaural information. A binaural beamforming algorithm was also assessed. Wide dynamic range compression was enabled in all programs. HAs were placed on a binaural manikin, and stimuli were presented from an arc of loudspeakers inside an anechoic chamber. Stimuli were broadband noise bursts, 10-Hz sinusoidally amplitude-modulated noise bursts, or consonant–vowel–consonant speech tokens. Binaural information was analyzed in terms of ITDs, ILDs, and interaural coherence, both for whole stimuli and in a time-varying sense (i.e., within a running temporal window) across four different frequency bands (1, 2, 4, and 6 kHz). Key findings were: (a) Nonlinear frequency compression caused distortions of high-frequency envelope ITDs and significantly reduced interaural coherence. (b) For modulated stimuli, all programs caused time-varying distortion of ILDs. (c) HAs altered the relationship between ITDs and ILDs, introducing large ITD–ILD conflicts in some cases. Potential perceptual consequences of measured distortions are discussed. PMID:27698258

  2. The Utility of the Real-Time NASA Land Information System Data for Drought Monitoring Applications

    NASA Technical Reports Server (NTRS)

    White, Kristopher D.; Case, Jonathan L.

    2013-01-01

    Measurements of soil moisture are a crucial component for the proper monitoring of drought conditions. The large spatial variability of soil moisture complicates the problem. Unfortunately, in situ soil moisture observing networks typically consist of sparse point observations, and conventional numerical model analyses of soil moisture used to diagnose drought are of coarse spatial resolution. Decision support systems such as the U.S. Drought Monitor contain drought impact resolution on sub-county scales, which may not be supported by the existing soil moisture networks or analyses. The NASA Land Information System, which is run with 3 km grid spacing over the eastern United States, has demonstrated utility for monitoring soil moisture. Some of the more useful output fields from the Land Information System are volumetric soil moisture in the 0-10 cm and 40-100 cm layers, column-integrated relative soil moisture, and the real-time green vegetation fraction derived from MODIS (Moderate Resolution Imaging Spectroradiometer) swath data that are run within the Land Information System in place of the monthly climatological vegetation fraction. While these and other variables have primarily been used in local weather models and other operational forecasting applications at National Weather Service offices, the use of the Land Information System for drought monitoring has demonstrated utility for feedback to the Drought Monitor. Output from the Land Information System is currently being used at NWS Huntsville to assess soil moisture, and to provide input to the Drought Monitor. Since feedback to the Drought Monitor takes place on a weekly basis, weekly difference plots of column-integrated relative soil moisture are being produced by the NASA Short-term Prediction Research and Transition Center and analyzed to facilitate the process. In addition to the Drought Monitor, these data are used to assess drought conditions for monthly feedback to the Alabama Drought Monitoring

  3. Information content of nonautonomous free fields in curved space-time

    SciTech Connect

    Parreira, J. E.; Nemes, M. C.; Fonseca-Romero, K. M.

    2011-03-15

    We show that it is possible to quantify the information content of a nonautonomous free field state in curved space-time. A covariance matrix is defined and it is shown that, for symmetric Gaussian field states, the matrix is connected to the entropy of the state. This connection is maintained throughout a quadratic nonautonomous (including possible phase transitions) evolution. Although particle-antiparticle correlations are dynamically generated, the evolution is isoentropic. If the current standard cosmological model for the inflationary period is correct, in absence of decoherence such correlations will be preserved, and could potentially lead to observable effects, allowing for a test of the model.

  4. Stabilization of the stochastically forced equilibria for nonlinear discrete-time systems with incomplete information

    NASA Astrophysics Data System (ADS)

    Ryashko, Lev

    2015-11-01

    A stabilization problem of the equilibrium of stochastically forced nonlinear discrete-time system with incomplete information is considered. Our approach uses a regulator which synthesizes the required stochastic sensitivity of the equilibrium. Mathematically, this problem is reduced to the solution of some quadratic matrix equations. A description of attainability sets and algorithms for regulators design is given. The general results are applied to the suppression of unwanted large-amplitude oscillations around the equilibria of the stochastically forced Verhulst model with noisy observations.

  5. Stabilization of the stochastically forced equilibria for nonlinear discrete-time systems with incomplete information

    SciTech Connect

    Ryashko, Lev

    2015-11-30

    A stabilization problem of the equilibrium of stochastically forced nonlinear discrete-time system with incomplete information is considered. Our approach uses a regulator which synthesizes the required stochastic sensitivity of the equilibrium. Mathematically, this problem is reduced to the solution of some quadratic matrix equations. A description of attainability sets and algorithms for regulators design is given. The general results are applied to the suppression of unwanted large-amplitude oscillations around the equilibria of the stochastically forced Verhulst model with noisy observations.

  6. Threats to information security of real-time disease surveillance systems.

    PubMed

    Henriksen, Eva; Johansen, Monika A; Baardsgaard, Anders; Bellika, Johan G

    2009-01-01

    This paper presents the main results from a qualitative risk assessment of information security aspects for a new real-time disease surveillance approach in general, and for the Snow surveillance system in particular. All possible security threats and acceptable solutions, and the implications these solutions had to the design of the system, were discussed. Approximately 30 threats were identified. None of these got an unacceptable high risk level originally, but two got medium risk level, of which one was concluded to be unacceptable after further investigation. Of the remaining low risk threats, some have severe consequence, thus requiring particular assessment. Since it is very important to identify and solve all security threats before real-time solutions can be used in a wide scale, additional investigations are needed.

  7. Spatial representation of temporal information through spike-timing-dependent plasticity

    NASA Astrophysics Data System (ADS)

    Nowotny, Thomas; Rabinovich, Misha I.; Abarbanel, Henry D.

    2003-07-01

    We suggest a mechanism based on spike-timing-dependent plasticity (STDP) of synapses to store, retrieve and predict temporal sequences. The mechanism is demonstrated in a model system of simplified integrate-and-fire type neurons densely connected by STDP synapses. All synapses are modified according to the so-called normal STDP rule observed in various real biological synapses. After conditioning through repeated input of a limited number of temporal sequences, the system is able to complete the temporal sequence upon receiving the input of a fraction of them. This is an example of effective unsupervised learning in a biologically realistic system. We investigate the dependence of learning success on entrainment time, system size, and presence of noise. Possible applications include learning of motor sequences, recognition and prediction of temporal sensory information in the visual as well as the auditory system, and late processing in the olfactory system of insects.

  8. Dark matter vs. neutrinos: the effect of astrophysical uncertainties and timing information on the neutrino floor

    SciTech Connect

    Davis, Jonathan H.

    2015-03-09

    Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments are said to run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that, using only spectral information, the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions it can still be surpassed using timing information, and so the neutrino floor is not an absolute limit on the sensitivity of Direct Detection experiments.

  9. Mapping emotions through time: how affective trajectories inform the language of emotion.

    PubMed

    Kirkland, Tabitha; Cunningham, William A

    2012-04-01

    The words used to describe emotions can provide insight into the basic processes that contribute to emotional experience. We propose that emotions arise partly from interacting evaluations of one's current affective state, previous affective state, predictions for how these may change in the future, and the experienced outcomes following these predictions. These states can be represented and inferred from neural systems that encode shifts in outcomes and make predictions. In two studies, we demonstrate that emotion labels are reliably differentiated from one another using only simple cues about these affective trajectories through time. For example, when a worse-than-expected outcome follows the prediction that something good will happen, that situation is labeled as causing anger, whereas when a worse-than-expected outcome follows the prediction that something bad will happen, that situation is labeled as causing sadness. Emotion categories are more differentiated when participants are required to think categorically than when participants have the option to consider multiple emotions and degrees of emotions. This work indicates that information about affective movement through time and changes in affective trajectory may be a fundamental aspect of emotion categories. Future studies of emotion must account for the dynamic way that we absorb and process information.

  10. The Development and Evaluation of the Climate Time Line Information Tool

    NASA Astrophysics Data System (ADS)

    McCaffrey, M. S.; Kowal, D.; Eakin, C. M.

    2002-12-01

    The Climate Time Line Information Tool or CTL (http://www.ngdc.noaa.gov/paleo/ctl) has been prototyped as a digital educational tool for conveying fundamental climatic processes and their human dimension for diverse audiences. Using a powers of ten approach to temporal scaling, the CTL website was developed through a CIRES Innovative Research Grant by Mark McCaffrey at the National Climatic Data Center's Paleoclimatology Program and Dan Kowal at the National Geophysical Data Center. CTL was specifcally designed as an interdisciplinary tool for conveying information about weather and climatic processes, such as the diurnal, annual and orbital cycles and ENSO. Moreover, the web site explores potential connections between climatic variability and human development over the past 100,000 years. Evaluation of the prototype examined issues of usability and navigation of the site as well as how its content and framework served the needs of undergraduate, middle and high school students, geoscience educators, and climate experts. The development and evaluation of the Climate Time Line provide a case study for other geoscience researchers and educators on: i) how objectives were set by developers; ii) how evaluators were involved in assessing the prototype; iii) the variety of evaluative methods available to test the viability of the product; and iv) how results from the evaluation can be used to finalize the prototype.

  11. Dark matter vs. neutrinos: the effect of astrophysical uncertainties and timing information on the neutrino floor

    SciTech Connect

    Davis, Jonathan H.

    2015-03-01

    Future multi-tonne Direct Detection experiments will be sensitive to solar neutrino induced nuclear recoils which form an irreducible background to light Dark Matter searches. Indeed for masses around 6 GeV the spectra of neutrinos and Dark Matter are so similar that experiments are said to run into a neutrino floor, for which sensitivity increases only marginally with exposure past a certain cross section. In this work we show that this floor can be overcome using the different annual modulation expected from solar neutrinos and Dark Matter. Specifically for cross sections below the neutrino floor the DM signal is observable through a phase shift and a smaller amplitude for the time-dependent event rate. This allows the exclusion power to be improved by up to an order of magnitude for large exposures. In addition we demonstrate that, using only spectral information, the neutrino floor exists over a wider mass range than has been previously shown, since the large uncertainties in the Dark Matter velocity distribution make the signal spectrum harder to distinguish from the neutrino background. However for most velocity distributions it can still be surpassed using timing information, and so the neutrino floor is not an absolute limit on the sensitivity of Direct Detection experiments.

  12. The duration of uncertain times: audiovisual information about intervals is integrated in a statistically optimal fashion.

    PubMed

    Hartcher-O'Brien, Jess; Di Luca, Massimiliano; Ernst, Marc O

    2014-01-01

    Often multisensory information is integrated in a statistically optimal fashion where each sensory source is weighted according to its precision. This integration scheme isstatistically optimal because it theoretically results in unbiased perceptual estimates with the highest precisionpossible.There is a current lack of consensus about how the nervous system processes multiple sensory cues to elapsed time.In order to shed light upon this, we adopt a computational approach to pinpoint the integration strategy underlying duration estimationof audio/visual stimuli. One of the assumptions of our computational approach is that the multisensory signals redundantly specify the same stimulus property. Our results clearly show that despite claims to the contrary, perceived duration is the result of an optimal weighting process, similar to that adopted for estimates of space. That is, participants weight the audio and visual information to arrive at the most precise, single duration estimate possible. The work also disentangles how different integration strategies - i.e. consideringthe time of onset/offset ofsignals - might alter the final estimate. As such we provide the first concrete evidence of an optimal integration strategy in human duration estimates.

  13. A real time pipeline to link meteorological information and TGFs detected by AGILE

    NASA Astrophysics Data System (ADS)

    Ursi, Alessandro; Tavani, Marco; Dietrich, Stefano; Marisaldi, Martino; Casella, Daniele; Sanò, Paolo; Petracca, Marco; Argan, Andrea

    2015-04-01

    Terrestrial Gamma-ray Flashes (TGFs) are brief (time" meteorological information about the detected TGFs. We take advantage of the Meteosat Second Generation (MSG) satellites data to promptly identify the possible individual thunderstorm or mesoscale convective system associated to the detected TGF event and to follow its evolution in space and time. Data from other meteorological satellites, for example the GPM mission, as well as ground measurements from lightning detection network, can be integrated in the pipeline. This allows us a prompt characterization of the ground meteorological conditions at TGF time which will provide instrument independent trigger validation, fill in a database for subsequent statistical analysis, and eventually, on a longer term perspective, serve as a real time alert system open to the community.

  14. Timing of preparatory landing responses as a function of availability of optic flow information.

    PubMed

    Liebermann, Dario G; Hoffman, Jay R

    2005-02-01

    This study investigated temporal patterns of EMG activity during self-initiated falls with different optic flow information ('gaze directions'). Onsets of EMG during the flight phase were monitored from five experienced volunteers that completed 72 landings in three gaze directions (downward, mid-range and horizontal) and six heights of fall (10-130 cm). EMG recordings were obtained from the right gastrocnemius, tibialis anterior, biceps femoris and rectus femoris muscles, and used to determine the latency of onset (L(o)) and the perceived time to contact (T(c)). Impacts at touchdown were also monitored using as estimates the major peak of the vertical ground reaction forces (F(max)) normalized to body mass, time to peak (T(max)), peak impulse (I(norm)) normalized to momentum, and rate of change of force (dF(max)/dt). Results showed that L(o) was longer as heights of fall increased, but remained within a narrow time-window at >50 cm landings. No significant differences in L(o) were observed when gaze direction was changed. The relationship between T(c) and flight time followed a linear trend regardless of gaze direction. Gaze direction did not significantly affect the landing impacts. In conclusion, availability of optic flow during landing does not play a major role in triggering the preparatory muscle actions in self-initiated falls. Once a structured landing plan has been acquired, the relevant muscles respond relative to the start of the fall.

  15. Separation of Stochastic and Deterministic Information from Seismological Time Series with Nonlinear Dynamics and Maximum Entropy Methods

    SciTech Connect

    Gutierrez, Rafael M.; Useche, Gina M.; Buitrago, Elias

    2007-11-13

    We present a procedure developed to detect stochastic and deterministic information contained in empirical time series, useful to characterize and make models of different aspects of complex phenomena represented by such data. This procedure is applied to a seismological time series to obtain new information to study and understand geological phenomena. We use concepts and methods from nonlinear dynamics and maximum entropy. The mentioned method allows an optimal analysis of the available information.

  16. Accurate Development of Thermal Neutron Scattering Cross Section Libraries

    SciTech Connect

    Hawari, Ayman; Dunn, Michael

    2014-06-10

    The objective of this project is to develop a holistic (fundamental and accurate) approach for generating thermal neutron scattering cross section libraries for a collection of important enutron moderators and reflectors. The primary components of this approach are the physcial accuracy and completeness of the generated data libraries. Consequently, for the first time, thermal neutron scattering cross section data libraries will be generated that are based on accurate theoretical models, that are carefully benchmarked against experimental and computational data, and that contain complete covariance information that can be used in propagating the data uncertainties through the various components of the nuclear design and execution process. To achieve this objective, computational and experimental investigations will be performed on a carefully selected subset of materials that play a key role in all stages of the nuclear fuel cycle.

  17. On recovering distributed IP information from inductive source time domain electromagnetic data

    NASA Astrophysics Data System (ADS)

    Kang, Seogi; Oldenburg, Douglas W.

    2016-10-01

    We develop a procedure to invert time domain induced polarization (IP) data for inductive sources. Our approach is based upon the inversion methodology in conventional electrical IP (EIP), which uses a sensitivity function that is independent of time. However, significant modifications are required for inductive source IP (ISIP) because electric fields in the ground do not achieve a steady state. The time-history for these fields needs to be evaluated and then used to define approximate IP currents. The resultant data, either a magnetic field or its derivative, are evaluated through the Biot-Savart law. This forms the desired linear relationship between data and pseudo-chargeability. Our inversion procedure has three steps: (1) Obtain a 3-D background conductivity model. We advocate, where possible, that this be obtained by inverting early-time data that do not suffer significantly from IP effects. (2) Decouple IP responses embedded in the observations by forward modelling the TEM data due to a background conductivity and subtracting these from the observations. (3) Use the linearized sensitivity function to invert data at each time channel and recover pseudo-chargeability. Post-interpretation of the recovered pseudo-chargeabilities at multiple times allows recovery of intrinsic Cole-Cole parameters such as time constant and chargeability. The procedure is applicable to all inductive source survey geometries but we focus upon airborne time domain EM (ATEM) data with a coincident-loop configuration because of the distinctive negative IP signal that is observed over a chargeable body. Several assumptions are adopted to generate our linearized modelling but we systematically test the capability and accuracy of the linearization for ISIP responses arising from different conductivity structures. On test examples we show: (1) our decoupling procedure enhances the ability to extract information about existence and location of chargeable targets directly from the data maps

  18. Accurate upper body rehabilitation system using kinect.

    PubMed

    Sinha, Sanjana; Bhowmick, Brojeshwar; Chakravarty, Kingshuk; Sinha, Aniruddha; Das, Abhijit

    2016-08-01

    The growing importance of Kinect as a tool for clinical assessment and rehabilitation is due to its portability, low cost and markerless system for human motion capture. However, the accuracy of Kinect in measuring three-dimensional body joint center locations often fails to meet clinical standards of accuracy when compared to marker-based motion capture systems such as Vicon. The length of the body segment connecting any two joints, measured as the distance between three-dimensional Kinect skeleton joint coordinates, has been observed to vary with time. The orientation of the line connecting adjoining Kinect skeletal coordinates has also been seen to differ from the actual orientation of the physical body segment. Hence we have proposed an optimization method that utilizes Kinect Depth and RGB information to search for the joint center location that satisfies constraints on body segment length and as well as orientation. An experimental study have been carried out on ten healthy participants performing upper body range of motion exercises. The results report 72% reduction in body segment length variance and 2° improvement in Range of Motion (ROM) angle hence enabling to more accurate measurements for upper limb exercises.

  19. Accurate, reproducible measurement of blood pressure.

    PubMed Central

    Campbell, N R; Chockalingam, A; Fodor, J G; McKay, D W

    1990-01-01

    The diagnosis of mild hypertension and the treatment of hypertension require accurate measurement of blood pressure. Blood pressure readings are altered by various factors that influence the patient, the techniques used and the accuracy of the sphygmomanometer. The variability of readings can be reduced if informed patients prepare in advance by emptying their bladder and bowel, by avoiding over-the-counter vasoactive drugs the day of measurement and by avoiding exposure to cold, caffeine consumption, smoking and physical exertion within half an hour before measurement. The use of standardized techniques to measure blood pressure will help to avoid large systematic errors. Poor technique can account for differences in readings of more than 15 mm Hg and ultimately misdiagnosis. Most of the recommended procedures are simple and, when routinely incorporated into clinical practice, require little additional time. The equipment must be appropriate and in good condition. Physicians should have a suitable selection of cuff sizes readily available; the use of the correct cuff size is essential to minimize systematic errors in blood pressure measurement. Semiannual calibration of aneroid sphygmomanometers and annual inspection of mercury sphygmomanometers and blood pressure cuffs are recommended. We review the methods recommended for measuring blood pressure and discuss the factors known to produce large differences in blood pressure readings. PMID:2192791

  20. Evaluation and validation of an accurate mass screening method for the analysis of pesticides in fruits and vegetables using liquid chromatography-quadrupole-time of flight-mass spectrometry with automated detection.

    PubMed

    López, Mónica García; Fussell, Richard J; Stead, Sara L; Roberts, Dominic; McCullagh, Mike; Rao, Ramesh

    2014-12-19

    This study reports the development and validation of a screening method for the detection of pesticides in 11 different fruit and vegetable commodities. The method was based on ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-QTOF-MS). The objective was to validate the method in accordance with the SANCO guidance document (12571/2013) on analytical quality control and validation procedures for pesticide residues analysis in food and feed. Samples were spiked with 199 pesticides, each at two different concentrations (0.01 and 0.05 mg kg(-1)) and extracted using the QuEChERS approach. Extracts were analysed by UPLC-QTOF-MS using generic acquisition parameters. Automated detection and data filtering were performed using the UNIFI™ software and the peaks detected evaluated against a proprietary scientific library containing information for 504 pesticides. The results obtained using different data processing parameters were evaluated for 4378 pesticide/commodities combinations at 0.01 and 0.05 mg kg(-1). Using mass accuracy (± 5 ppm) with retention time (± 0.2 min) and a low response threshold (100 counts) the validated Screening Detection Limits (SDLs) were 0.01 mg kg(-1) and 0.05 mg kg(-1) for 57% and 79% of the compounds tested, respectively, with an average of 10 false detects per sample analysis. Excluding the most complex matrices (onion and leek) the detection rates increased to 69% and 87%, respectively. The use of additional parameters such as isotopic pattern and fragmentation information further reduced the number of false detects but compromised the detection rates, particularly at lower residue concentrations. The challenges associated with the validation and subsequent implementation of a pesticide multi-residue screening method are also discussed.

  1. Planck 2015 results. VII. High Frequency Instrument data processing: Time-ordered information and beams

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Adam, R.; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bertincourt, B.; Bielewicz, P.; Bock, J. J.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chiang, H. C.; Christensen, P. R.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Fergusson, J.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Le Jeune, M.; Leahy, J. P.; Lellouch, E.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Moreno, R.; Morgante, G.; Mortlock, D.; Moss, A.; Mottet, S.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rowan-Robinson, M.; Rusholme, B.; Sandri, M.; Santos, D.; Sauvé, A.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vibert, L.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Wehus, I. K.; Yvon, D.; Zacchei, A.; Zonca, A.

    2016-09-01

    The Planck High Frequency Instrument (HFI) has observed the full sky at six frequencies (100, 143, 217, 353, 545, and 857 GHz) in intensity and at four frequencies in linear polarization (100, 143, 217, and 353 GHz). In order to obtain sky maps, the time-ordered information (TOI) containing the detector and pointing samples must be processed and the angular response must be assessed. The full mission TOI is included in the Planck 2015 release. This paper describes the HFI TOI and beam processing for the 2015 release. HFI calibration and map making are described in a companion paper. The main pipeline has been modified since the last release (2013 nominal mission in intensity only), by including a correction for the nonlinearity of the warm readout and by improving the model of the bolometer time response. The beam processing is an essential tool that derives the angular response used in all the Planck science papers and we report an improvement in the effective beam window function uncertainty of more than a factor of 10 relative to the2013 release. Noise correlations introduced by pipeline filtering function are assessed using dedicated simulations. Angular cross-power spectra using data sets that are decorrelated in time are immune to the main systematic effects.

  2. The effect of viewing time, time to encounter, and practice on perception of aircraft separation on a cockpit display of traffic information

    NASA Technical Reports Server (NTRS)

    Oconnor, S.; Palmer, E. A.; Baty, D.; Jago, S.

    1980-01-01

    The concept of a cockpit display of traffic information (CDTI) includes the integration of air traffic, navigation, and other pertinent information in a single electronic display in the cockpit. Two studies were conducted to develop a clear and concise display format for use in later full-mission simulator evaluations of the CDTI concept. Subjects were required to monitor a CDTI for specified periods of time and to make perceptual judgments concerning the future position of a single intruder aircraft in relationship to their own aircraft. Experimental variables included: type of predictor information displayed on the two aircraft symbols; time to encounter point; length of time subjects viewed the display; amount of practice; and type of encounter (straight or turning). Results show that length of viewing time had little or no effect on performance; time to encounter influenced performance with the straight predictor but did not with the curved predictor; and that learning occurred under all conditions.

  3. A Unified Computational Architecture for Preprocessing Visual Information in Space and Time.

    NASA Astrophysics Data System (ADS)

    Skrzypek, Josef

    1986-06-01

    The success of autonomous mobile robots depends on the ability to understand continuously changing scenery. Present techniques for analysis of images are not always suitable because in sequential paradigm, computation of visual functions based on absolute values of stimuli is inefficient. Important aspects of visual information are encoded in discontinuities of intensity, hence a representation in terms of relative values seems advantageous. We present the computing architecture of a massively parallel vision module which optimizes the detection of relative intensity changes in space and time. Visual information must remain constant despite variation in ambient light level or velocity of target and robot. Constancy can be achieved by normalizing motion and lightness scales. In both cases, basic computation involves a comparison of the center pixels with the context of surrounding values. Therefore, a similar computing architecture, composed of three functionally-different and hierarchically-arranged layers of overlapping operators, can be used for two integrated parts of the module. The first part maintains high sensitivity to spatial changes by reducing noise and normalizing the lightness scale. The result is used by the second part to maintain high sensitivity to temporal discontinuities and to compute relative motion information. Simulation results show that response of the module is proportional to contrast of the stimulus and remains constant over the whole domain of intensity. It is also proportional to velocity of motion limited to any small portion of the visual field. Uniform motion throughout the visual field results in constant response, independent of velocity. Spatial and temporal intensity changes are enhanced because computationally, the module resembles the behavior of a DOG function.

  4. Confirming PICC tip position during insertion with real-time information.

    PubMed

    Barton, Andrew

    2016-01-27

    Peripherally inserted central catheters (PICCs) play a fundamental role in patient care in a variety of clinical and healthcare settings. Tip location is important for both safety and efficacy. New technologies may offer the possibility of safer, more efficient and more effective insertion. A prospective evaluation was carried out of a system providing real-time information on the tip's location, direction, and depth during insertion in a total of 488 patients at a single centre (65 patients in the initial study, plus follow-on case series reports in 423 patients). No tip malpositions were reported and, as a result, the institution has been able to waive the requirement for confirmatory chest X-ray after PICC insertion, thus minimising the delay before the PICC can be used and increasing staff and patient confidence in the procedure.

  5. Confirming PICC tip position during insertion with real-time information.

    PubMed

    Barton, Andrew

    Peripherally inserted central catheters (PICCs) play a fundamental role in patient care in a variety of clinical and healthcare settings. Tip location is important for both safety and efficacy. New technologies may offer the possibility of safer, more efficient and more effective insertion. A prospective evaluation was carried out of a system providing real-time information on the tip’s location, direction, and depth during insertion in a total of 488 patients at a single centre (65 patients in the initial study, plus follow-on case series reports in 423 patients). No tip malpositions were reported and, as a result, the institution has been able to waive the requirement for confirmatory chest X-ray after PICC insertion, thus minimising the delay before the PICC can be used and increasing staff and patient confidence in the procedure.

  6. The research of security and real-time based on the control information network

    NASA Astrophysics Data System (ADS)

    Su, Xiao-hui; Xu, Shu-Ping

    2013-03-01

    Aiming at the security issues, the construction of the remote motor control server based on the Web is studied, the scheme of two server programs based on the virtual server technology is proposed. The safety and application occasion of the scheme are described respectively, and the encryption algorithm which Improve certification accuracy is proposed. Aiming at the real-time problem, a new control method is proposed, which is based on neural network predictive control to solve the existing closed-loop network control system random delay. The experiment verification and system simulated are completed. These methods provide a new way to integrate the control network and information network, and to lay a solid foundation for the development of the control network.

  7. Surgical training and the European Working Time Directive: The role of informal workplace learning.

    PubMed

    Giles, James A

    2010-01-01

    The introduction of European Working Time Directive, limiting doctors' working hours to 48 per week, has caused recent controversy within the profession. The Royal College of Surgeons of England in particular has been one of the loudest critics of the legislation. One of the main concerns is regarding the negative impact on training hours for those embarking on surgical careers. Simulation technology has been suggested as a method to overcome this reduction in hospital training hours, and research suggests that this is a good substitute for operative training in a theatre. However, modern educational theory emphasises the power of informal workplace learning in postgraduate education, and the essential role of experience in training future surgeons.

  8. Real time explosive hazard information sensing, processing, and communication for autonomous operation

    DOEpatents

    Versteeg, Roelof J.; Few, Douglas A.; Kinoshita, Robert A.; Johnson, Douglas; Linda, Ondrej

    2015-12-15

    Methods, computer readable media, and apparatuses provide robotic explosive hazard detection. A robot intelligence kernel (RIK) includes a dynamic autonomy structure with two or more autonomy levels between operator intervention and robot initiative A mine sensor and processing module (ESPM) operating separately from the RIK perceives environmental variables indicative of a mine using subsurface perceptors. The ESPM processes mine information to determine a likelihood of a presence of a mine. A robot can autonomously modify behavior responsive to an indication of a detected mine. The behavior is modified between detection of mines, detailed scanning and characterization of the mine, developing mine indication parameters, and resuming detection. Real time messages are passed between the RIK and the ESPM. A combination of ESPM bound messages and RIK bound messages cause the robot platform to switch between modes including a calibration mode, the mine detection mode, and the mine characterization mode.

  9. Real time explosive hazard information sensing, processing, and communication for autonomous operation

    DOEpatents

    Versteeg, Roelof J; Few, Douglas A; Kinoshita, Robert A; Johnson, Doug; Linda, Ondrej

    2015-02-24

    Methods, computer readable media, and apparatuses provide robotic explosive hazard detection. A robot intelligence kernel (RIK) includes a dynamic autonomy structure with two or more autonomy levels between operator intervention and robot initiative A mine sensor and processing module (ESPM) operating separately from the RIK perceives environmental variables indicative of a mine using subsurface perceptors. The ESPM processes mine information to determine a likelihood of a presence of a mine. A robot can autonomously modify behavior responsive to an indication of a detected mine. The behavior is modified between detection of mines, detailed scanning and characterization of the mine, developing mine indication parameters, and resuming detection. Real time messages are passed between the RIK and the ESPM. A combination of ESPM bound messages and RIK bound messages cause the robot platform to switch between modes including a calibration mode, the mine detection mode, and the mine characterization mode.

  10. On-line, on time. A centralized laboratory information system speeds the results.

    PubMed

    Cianciotto, J P

    1990-10-01

    Catholic Medical Center of Brooklyn and Queens (CMC), Jamaica, NY, is a multihospital system that is concerned with providing a more cost-effective method of delivering healthcare in an urban environment. To reach this goal CMC centralized its laboratory services to save time, cut costs, and ultimately improve patient care. The centralized laboratory's manual delivery and tracking system put in place at first appeared to hinder the success of the centralized laboratory concept. Through a detailed planning and review process, CMC then implemented a multihospital laboratory information system to allow the centralized laboratory (1) to electronically access patient information from any on-line hospital and (2) to transmit test results back to the originating hospital. CMC believed the automated system would improve the quality of care, reduce the number of duplicated tests, eliminate late charges, and reduce the length of a patient's hospital stay. Since the implementation of the laboratory management system, its member hospitals agree that CMC has finally begun to realize the full benefits of its centralized laboratory services.

  11. Energy beyond food: foraging theory informs time spent in thermals by a large soaring bird.

    PubMed

    Shepard, Emily L C; Lambertucci, Sergio A; Vallmitjana, Diego; Wilson, Rory P

    2011-01-01

    Current understanding of how animals search for and exploit food resources is based on microeconomic models. Although widely used to examine feeding, such constructs should inform other energy-harvesting situations where theoretical assumptions are met. In fact, some animals extract non-food forms of energy from the environment, such as birds that soar in updraughts. This study examined whether the gains in potential energy (altitude) followed efficiency-maximising predictions in the world's heaviest soaring bird, the Andean condor (Vultur gryphus). Animal-attached technology was used to record condor flight paths in three-dimensions. Tracks showed that time spent in patchy thermals was broadly consistent with a strategy to maximise the rate of potential energy gain. However, the rate of climb just prior to leaving a thermal increased with thermal strength and exit altitude. This suggests higher rates of energetic gain may not be advantageous where the resulting gain in altitude would lead to a reduction in the ability to search the ground for food. Consequently, soaring behaviour appeared to be modulated by the need to reconcile differing potential energy and food energy distributions. We suggest that foraging constructs may provide insight into the exploitation of non-food energy forms, and that non-food energy distributions may be more important in informing patterns of movement and residency over a range of scales than previously considered.

  12. Energy Beyond Food: Foraging Theory Informs Time Spent in Thermals by a Large Soaring Bird

    PubMed Central

    Shepard, Emily L. C.; Lambertucci, Sergio A.; Wilson, Rory P.

    2011-01-01

    Current understanding of how animals search for and exploit food resources is based on microeconomic models. Although widely used to examine feeding, such constructs should inform other energy-harvesting situations where theoretical assumptions are met. In fact, some animals extract non-food forms of energy from the environment, such as birds that soar in updraughts. This study examined whether the gains in potential energy (altitude) followed efficiency-maximising predictions in the world's heaviest soaring bird, the Andean condor (Vultur gryphus). Animal-attached technology was used to record condor flight paths in three-dimensions. Tracks showed that time spent in patchy thermals was broadly consistent with a strategy to maximise the rate of potential energy gain. However, the rate of climb just prior to leaving a thermal increased with thermal strength and exit altitude. This suggests higher rates of energetic gain may not be advantageous where the resulting gain in altitude would lead to a reduction in the ability to search the ground for food. Consequently, soaring behaviour appeared to be modulated by the need to reconcile differing potential energy and food energy distributions. We suggest that foraging constructs may provide insight into the exploitation of non-food energy forms, and that non-food energy distributions may be more important in informing patterns of movement and residency over a range of scales than previously considered. PMID:22087301

  13. Non-targeted analysis of electronics waste by comprehensive two-dimensional gas chromatography combined with high-resolution mass spectrometry: Using accurate mass information and mass defect analysis to explore the data.

    PubMed

    Ubukata, Masaaki; Jobst, Karl J; Reiner, Eric J; Reichenbach, Stephen E; Tao, Qingping; Hang, Jiliang; Wu, Zhanpin; Dane, A John; Cody, Robert B

    2015-05-22

    Comprehensive two-dimensional gas chromatography (GC×GC) and high-resolution mass spectrometry (HRMS) offer the best possible separation of their respective techniques. Recent commercialization of combined GC×GC-HRMS systems offers new possibilities for the analysis of complex mixtures. However, such experiments yield enormous data sets that require new informatics tools to facilitate the interpretation of the rich information content. This study reports on the analysis of dust obtained from an electronics recycling facility by using GC×GC in combination with a new high-resolution time-of-flight (TOF) mass spectrometer. New software tools for (non-traditional) Kendrick mass defect analysis were developed in this research and greatly aided in the identification of compounds containing chlorine and bromine, elements that feature in most persistent organic pollutants (POPs). In essence, the mass defect plot serves as a visual aid from which halogenated compounds are recognizable on the basis of their mass defect and isotope patterns. Mass chromatograms were generated based on specific ions identified in the plots as well as region of the plot predominantly occupied by halogenated contaminants. Tentative identification was aided by database searches, complementary electron-capture negative ionization experiments and elemental composition determinations from the exact mass data. These included known and emerging flame retardants, such as polybrominated diphenyl ethers (PBDEs), hexabromobenzene, tetrabromo bisphenol A and tris (1-chloro-2-propyl) phosphate (TCPP), as well as other legacy contaminants such as polychlorinated biphenyls (PCBs) and polychlorinated terphenyls (PCTs).

  14. Evaluation of the occurrence and biodegradation of parabens and halogenated by-products in wastewater by accurate-mass liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-QTOF-MS).

    PubMed

    González-Mariño, Iria; Quintana, José Benito; Rodríguez, Isaac; Cela, Rafael

    2011-12-15

    An assessment of the sewage occurrence and biodegradability of seven parabens and three halogenated derivatives of methyl paraben (MeP) is presented. Several wastewater samples were collected at three different wastewater treatment plants (WWTPs) during April and May 2010, concentrated by solid-phase extraction (SPE) and analysed by liquid chromatography-electrospray-quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS). The performance of the QTOF system proved to be comparable to triple-quadrupole instruments in terms of quantitative capabilities, with good linearity (R(2) > 0.99 in the 5-500 ng mL(-1) range), repeatability (RSD < 5.6%) and LODs (0.3-4.0 ng L(-1) after SPE). MeP and n-propyl paraben (n-PrP) were the most frequently detected and the most abundant analytes in raw wastewater (0.3-10 μg L(-1)), in accordance with the data displayed in the bibliography and reflecting their wider use in cosmetic formulations. Samples were also evaluated in search for potential halogenated by-products of parabens, formed as a result of their reaction with residual chlorine contained in tap water. Monochloro- and dichloro-methyl paraben (ClMeP and Cl(2)MeP) were found and quantified in raw wastewater at levels between 0.01 and 0.1 μg L(-1). Halogenated derivatives of n-PrP could not be quantified due to the lack of standards; nevertheless, the monochlorinated species (ClPrP) was identified in several samples from its accurate precursor and product ions mass/charge ratios (m/z). Removal efficiencies of parabens and MeP chlorinated by-products in WWTPs exceeded 90%, with the lowest percentages corresponding to the latter species. This trend was confirmed by an activated sludge biodegradation batch test, where non-halogenated parabens had half-lives lower than 4 days, whereas halogenated derivatives of MeP turned out to be more persistent, with up to 10 days of half-life in the case of dihalogenated derivatives. A further stability test performed with raw wastewater

  15. Just-in-Time Information Presentation: Improving Learning a Troubleshooting Skill

    ERIC Educational Resources Information Center

    Kester, Liesbeth; Kirschner, Paul A.; van Merrienboer, Jeroen J. G.

    2006-01-01

    Troubleshooting in a practice situation requires two types of information, namely for reasoning about the problem-cause and for finding an adequate solution ("declarative information") and for manipulating the environment ("procedural information"). It is hypothesized that presenting this information piece-by-piece during practice (i.e.,…

  16. Evacuation time estimate for total pedestrian evacuation using a queuing network model and volunteered geographic information

    NASA Astrophysics Data System (ADS)

    Kunwar, Bharat; Simini, Filippo; Johansson, Anders

    2016-02-01

    Estimating city evacuation time is a nontrivial problem due to the interaction between thousands of individual agents, giving rise to various collective phenomena, such as bottleneck formation, intermittent flow, and stop-and-go waves. We present a mean field approach to draw relationships between road network spatial attributes, the number of evacuees, and the resultant evacuation time estimate (ETE). Using volunteered geographic information, we divide 50 United Kingdom cities into a total of 704 catchment areas (CAs) which we define as an area where all agents share the same nearest exit node. 90% of the agents are within ≈6 ,847 m of CA exit nodes with ≈13 ,778 agents/CA. We establish a characteristic flow rate from catchment area attributes (population, distance to exit node, and exit node width) and a mean flow rate in a free-flow regime by simulating total evacuations using an agent based "queuing network" model. We use these variables to determine a relationship between catchment area attributes and resultant ETEs. This relationship could enable emergency planners to make a rapid appraisal of evacuation strategies and help support decisions in the run up to a crisis.

  17. Display Provides Pilots with Real-Time Sonic-Boom Information

    NASA Technical Reports Server (NTRS)

    Haering, Ed; Plotkin, Ken

    2013-01-01

    Supersonic aircraft generate shock waves that move outward and extend to the ground. As a cone of pressurized air spreads across the landscape along the flight path, it creates a continuous sonic boom along the flight track. Several factors can influence sonic booms: weight, size, and shape of the aircraft; its altitude and flight path; and weather and atmospheric conditions. This technology allows pilots to control the impact of sonic booms. A software system displays the location and intensity of shock waves caused by supersonic aircraft. This technology can be integrated into cockpits or flight control rooms to help pilots minimize sonic boom impact in populated areas. The system processes vehicle and flight parameters as well as data regarding current atmospheric conditions. The display provides real-time information regarding sonic boom location and intensity, enabling pilots to make the necessary flight adjustments to control the timing and location of sonic booms. This technology can be used on current-generation supersonic aircraft, which generate loud sonic booms, as well as future- generation, low-boom aircraft, anticipated to be quiet enough for populated areas.

  18. Accurate Evaluation of Quantum Integrals

    NASA Technical Reports Server (NTRS)

    Galant, D. C.; Goorvitch, D.; Witteborn, Fred C. (Technical Monitor)

    1995-01-01

    Combining an appropriate finite difference method with Richardson's extrapolation results in a simple, highly accurate numerical method for solving a Schrodinger's equation. Important results are that error estimates are provided, and that one can extrapolate expectation values rather than the wavefunctions to obtain highly accurate expectation values. We discuss the eigenvalues, the error growth in repeated Richardson's extrapolation, and show that the expectation values calculated on a crude mesh can be extrapolated to obtain expectation values of high accuracy.

  19. Systematic study of terahertz time-domain spectra of historically informed black inks.

    PubMed

    Bardon, Tiphaine; May, Robert K; Taday, Philip F; Strlič, Matija

    2013-09-07

    The potential of terahertz-time domain spectroscopy (THz-TDS) as a diagnostic tool for studies of inks in historical documents is investigated in this paper. Transmission mode THz-TDS was performed on historically informed model writing and drawing inks. Carbon black, bistre and sepia inks show featureless spectra between 5 and 75 cm(-1) (0.15-2.25 THz); however, their analysis still provided useful information on the interaction of terahertz radiation with amorphous materials. On the other hand, THz-TDS can be used to distinguish different iron gall inks with respect to the amount of iron(II) sulfate contained, as sharp spectral features are observed for inks containing different ratios of iron(II) sulfate to tannic or gallic acid. Additionally, copper sulfate was found to modify the structure of iron(II) precipitate. Furthermore, Principal Component Analysis (PCA) applied to THz-TDS spectra, highlights changes in iron gall inks during thermal degradation, during which a decrease in the sharp spectral bands associated with iron(II) sulfate is observed. ATR-FTIR spectroscopy combined with THz-TDS of dynamically heated ink samples indicate that this phenomenon is due to dehydration of iron(II) sulfate heptahydrate. While this research demonstrates the potential of THz-TDS to improve monitoring of the chemical state of historical documents, the outcomes go beyond the heritage field, as it also helps to develop the theoretical knowledge on interactions between terahertz radiation and matter, particularly in studies of long-range symmetry (polymorphism) in complex molecular structures and the role played by the surrounding matrix, and also indicates the potential of THz-TDS for the optimization of contrast in terahertz imaging.

  20. Combining Real-time Seismic and Geodetic Data to Improve Rapid Earthquake Information

    NASA Astrophysics Data System (ADS)

    Murray, M. H.; Neuhauser, D. S.; Gee, L. S.; Dreger, D. S.; Basset, A.; Romanowicz, B.

    2002-12-01

    The Berkeley Seismological Laboratory operates seismic and geodetic stations in the San Francisco Bay area and northern California for earthquake and deformation monitoring. The seismic systems, part of the Berkeley Digital Seismic Network (BDSN), include strong motion and broadband sensors, and 24-bit dataloggers. The data from 20 GPS stations, part of the Bay Area Regional Deformation (BARD) network of more than 70 stations in northern California, are acquired in real-time. We have developed methods to acquire GPS data at 12 stations that are collocated with the seismic systems using the seismic dataloggers, which have large on-site data buffer and storage capabilities, merge it with the seismic data stream in MiniSeed format, and continuously stream both data types using reliable frame relay and/or radio modem telemetry. Currently, the seismic data are incorporated into the Rapid Earthquake Data Integration (REDI) project to provide notification of earthquake magnitude, location, moment tensor, and strong motion information for hazard mitigation and emergency response activities. The geodetic measurements can provide complementary constraints on earthquake faulting, including the location and extent of the rupture plane, unambiguous resolution of the nodal plane, and distribution of slip on the fault plane, which can be used, for example, to refine strong motion shake maps. We are developing methods to rapidly process the geodetic data to monitor transient deformation, such as coseismic station displacements, and for combining this information with the seismic observations to improve finite-fault characterization of large earthquakes. The GPS data are currently processed at hourly intervals with 2-cm precision in horizontal position, and we are beginning a pilot project in the Bay Area in collaboration with the California Spatial Reference Center to do epoch-by-epoch processing with greater precision.