Science.gov

Sample records for effective resistance metric

  1. Comparison of mixed effects models of antimicrobial resistance metrics of livestock and poultry Salmonella isolates from a national monitoring system.

    PubMed

    Bjork, K E; Kopral, C A; Wagner, B A; Dargatz, D A

    2015-12-01

    Antimicrobial use in agriculture is considered a pathway for the selection and dissemination of resistance determinants among animal and human populations. From 1997 through 2003 the U.S. National Antimicrobial Resistance Monitoring System (NARMS) tested clinical Salmonella isolates from multiple animal and environmental sources throughout the United States for resistance to panels of 16-19 antimicrobials. In this study we applied two mixed effects models, the generalized linear mixed model (GLMM) and accelerated failure time frailty (AFT-frailty) model, to susceptible/resistant and interval-censored minimum inhibitory concentration (MIC) metrics, respectively, from Salmonella enterica subspecies enterica serovar Typhimurium isolates from livestock and poultry. Objectives were to compare characteristics of the two models and to examine the effects of time, species, and multidrug resistance (MDR) on the resistance of isolates to individual antimicrobials, as revealed by the models. Fixed effects were year of sample collection, isolate source species and MDR indicators; laboratory study site was included as a random effect. MDR indicators were significant for every antimicrobial and were dominant effects in multivariable models. Temporal trends and source species influences varied by antimicrobial. In GLMMs, the intra-class correlation coefficient ranged up to 0.8, indicating that the proportion of variance accounted for by laboratory study site could be high. AFT models tended to be more sensitive, detecting more curvilinear temporal trends and species differences; however, high levels of left- or right-censoring made some models unstable and results uninterpretable. Results from GLMMs may be biased by cutoff criteria used to collapse MIC data into binary categories, and may miss signaling important trends or shifts if the series of antibiotic dilutions tested does not span a resistance threshold. Our findings demonstrate the challenges of measuring the AMR

  2. Nano-artifact metrics based on random collapse of resist

    PubMed Central

    Matsumoto, Tsutomu; Hoga, Morihisa; Ohyagi, Yasuyuki; Ishikawa, Mikio; Naruse, Makoto; Hanaki, Kenta; Suzuki, Ryosuke; Sekiguchi, Daiki; Tate, Naoya; Ohtsu, Motoichi

    2014-01-01

    Artifact metrics is an information security technology that uses the intrinsic characteristics of a physical object for authentication and clone resistance. Here, we demonstrate nano-artifact metrics based on silicon nanostructures formed via an array of resist pillars that randomly collapse when exposed to electron-beam lithography. The proposed technique uses conventional and scalable lithography processes, and because of the random collapse of resist, the resultant structure has extremely fine-scale morphology with a minimum dimension below 10 nm, which is less than the resolution of current lithography capabilities. By evaluating false match, false non-match and clone-resistance rates, we clarify that the nanostructured patterns based on resist collapse satisfy the requirements for high-performance security applications. PMID:25142401

  3. Nano-artifact metrics based on random collapse of resist

    NASA Astrophysics Data System (ADS)

    Matsumoto, Tsutomu; Hoga, Morihisa; Ohyagi, Yasuyuki; Ishikawa, Mikio; Naruse, Makoto; Hanaki, Kenta; Suzuki, Ryosuke; Sekiguchi, Daiki; Tate, Naoya; Ohtsu, Motoichi

    2014-08-01

    Artifact metrics is an information security technology that uses the intrinsic characteristics of a physical object for authentication and clone resistance. Here, we demonstrate nano-artifact metrics based on silicon nanostructures formed via an array of resist pillars that randomly collapse when exposed to electron-beam lithography. The proposed technique uses conventional and scalable lithography processes, and because of the random collapse of resist, the resultant structure has extremely fine-scale morphology with a minimum dimension below 10 nm, which is less than the resolution of current lithography capabilities. By evaluating false match, false non-match and clone-resistance rates, we clarify that the nanostructured patterns based on resist collapse satisfy the requirements for high-performance security applications.

  4. Inspecting baby Skyrmions with effective metrics

    NASA Astrophysics Data System (ADS)

    Gibbons, G. W.; Goulart, E.

    2014-05-01

    In the present paper we investigate the causal structure of the baby Skyrme model using appropriate geometrical tools. We discuss several features of excitations propagating on top of background solutions and show that the evolution of high frequency waves is governed by a curved effective geometry. Examples are given for which the effective metric describes the interaction between waves and solitonic solutions such as kinks, antikinks, and hedgehogs. In particular, it is shown how violent processes involving the collisions of solitons and antisolitons may induce metrics which are not globally hyperbolic. We argue that it might be illuminating to calculate the effective metric as a diagnostic test for pathological regimes in numerical simulations.

  5. Effectively nonlocal metric-affine gravity

    NASA Astrophysics Data System (ADS)

    Golovnev, Alexey; Koivisto, Tomi; Sandstad, Marit

    2016-03-01

    In metric-affine theories of gravity such as the C-theories, the spacetime connection is associated to a metric that is nontrivially related to the physical metric. In this article, such theories are rewritten in terms of a single metric, and it is shown that they can be recast as effectively nonlocal gravity. With some assumptions, known ghost-free theories with nonsingular and cosmologically interesting properties may be recovered. Relations between different formulations are analyzed at both perturbative and nonperturbative levels, taking carefully into account subtleties with boundary conditions in the presence of integral operators in the action, and equivalences between theories related by nonlocal redefinitions of the fields are verified at the level of equations of motion. This suggests a possible geometrical interpretation of nonlocal gravity as an emergent property of non-Riemannian spacetime structure.

  6. An Attentional Effect of Musical Metrical Structure

    PubMed Central

    Katz, Jonah; Chemla, Emmanuel; Pallier, Christophe

    2015-01-01

    Theories of metrical structure postulate the existence of several degrees of beat strength. While previous work has clearly established that humans are sensitive to the distinction between strong beats and weak ones, there is little evidence for a more fine grained distinction between intermediate levels. Here, we present experimental data showing that attention can be allocated to an intermediate level of beat strength. Comparing the effects of short exposures to 6/8 and 3/4 metrical structures on a tone detection task, we observe that subjects respond differently to beats of intermediate strength than to weak beats. PMID:26600180

  7. An Attentional Effect of Musical Metrical Structure.

    PubMed

    Katz, Jonah; Chemla, Emmanuel; Pallier, Christophe

    2015-01-01

    Theories of metrical structure postulate the existence of several degrees of beat strength. While previous work has clearly established that humans are sensitive to the distinction between strong beats and weak ones, there is little evidence for a more fine grained distinction between intermediate levels. Here, we present experimental data showing that attention can be allocated to an intermediate level of beat strength. Comparing the effects of short exposures to 6/8 and 3/4 metrical structures on a tone detection task, we observe that subjects respond differently to beats of intermediate strength than to weak beats. PMID:26600180

  8. Metrics. [measurement for effective software development and management

    NASA Technical Reports Server (NTRS)

    Mcgarry, Frank

    1991-01-01

    A development status evaluation is presented for practical software performance measurement, or 'metrics', in which major innovations have recently occurred. Metrics address such aspects of software performance as whether a software project is on schedule, how many errors can be expected from it, whether the methodology being used is effective and the relative quality of the software employed. Metrics may be characterized as explicit, analytical, and subjective. Attention is given to the bases for standards and the conduct of metrics research.

  9. Assessment of OPC effectiveness using two-dimensional metrics

    NASA Astrophysics Data System (ADS)

    Wiaux, Vincent; Philipsen, Vicky; Jonckheere, Rik M.; Vandenberghe, Geert; Verhaegen, Staf; Hoffmann, Thomas; Ronse, Kurt G.; Howard, William B.; Maurer, Wilhelm; Preil, Moshe E.

    2002-07-01

    A complete evaluation of the optical proximity effects (OPE) and of their corrections (OPC) requires a quantitative description of two-dimensional (2D) parameters, both at resist- and at reticle-level. Because the 2D behaviour at line-ends and at line-corners can become a limiting factor for the yield, it should be taken into account when characterising a process, just as the CD- and pitch-linearity are already kept under control. This implies the measurement of 2D-metrics in a precise way. We used an SEM Image Analysis tool (ProDATA SIAM) to define and measure various OPC-relevant metrics for a C013 process. For the METAL (M1) process, we show that the overlap between line-ends of M1-trenches and underlying nominal contacts is a relevant metric to describe the effectiveness of hammerheads. Moreover, it is an interesting metric to combine with the CD process window. For the GATE process, we demonstrate that for a given set of metrics there is a degree of OPC aggressiveness beyond which it is not worth to go. We considered both line-end shortening (LES) and corner rounding affecting the poly linewidth close to a contact pad, and this on various logic circuits having received different degrees of fragmentation. Finally the knowledge of the actual line-end contour on the reticle allows one to simulate separately the printing effect of that area loss at reticle line-ends. The area loss measured by comparing the extracted contour to the target one is regarded as a combination of pull-back and area loss at corners. For our C013 gate process, and for the 130nm lines at a 1:1.25 duty cycle, those two parameters contribute together to approximetely 40% of the measured LES in the resist. This fact raises the question of specifications on 2D reticle parameters. We also find a linear correlation between the area loss at reticle line-end corners and the corresponding increase of LES on the wafer, which suggests a way towards putting specifications on the reticle line-ends.

  10. Comparative study of line roughness metrics of chemically amplified and inorganic resists for EUV

    NASA Astrophysics Data System (ADS)

    Fallica, Roberto; Buitrago, Elizabeth; Ekinci, Yasin

    2016-03-01

    We present a comprehensive study of the roughness metrics of different resists. Dense line/space (L/S) images of polymethyl methacrylate (PMMA), hydrogen silsesquioxane (HSQ), different chemically amplified resists (CARs), and metal oxide based resists have been patterned by extreme ultraviolet interference lithography (EUV-IL). The three line width roughness metrics: r.m.s. value σLWR, correlation length ξ and roughness exponent α, were measured by metrological analysis of top down SEM images and compared for the different resists imaged here. It was found, that all metrics are required to fully describe the roughness of each resist. Our measurements indicate that few of the state-of-the- art resists tested here can meet the International Technology Roadmap for Semiconductors (ITRS) requirements for σLWR. The correlation length ξ has been found to be considerably higher in polymer-based materials in comparison to non-polymers. The roughness exponent α, interpreted using the concept of fractal geometry, is mainly affected by acid diffusion in CARs where it produces line edges with a higher complexity than in non-CAR resists. These results indicate that different resists platforms show very different LWR resist metrics and roughness is not only manifested in the σLWR but in all parameters. Therefore, all roughness metrics should be taken into account in the performance comparison of the resist, since they can have a substantial impact on the device performance.

  11. Coverage Metrics for Requirements-Based Testing: Evaluation of Effectiveness

    NASA Technical Reports Server (NTRS)

    Staats, Matt; Whalen, Michael W.; Heindahl, Mats P. E.; Rajan, Ajitha

    2010-01-01

    In black-box testing, the tester creates a set of tests to exercise a system under test without regard to the internal structure of the system. Generally, no objective metric is used to measure the adequacy of black-box tests. In recent work, we have proposed three requirements coverage metrics, allowing testers to objectively measure the adequacy of a black-box test suite with respect to a set of requirements formalized as Linear Temporal Logic (LTL) properties. In this report, we evaluate the effectiveness of these coverage metrics with respect to fault finding. Specifically, we conduct an empirical study to investigate two questions: (1) do test suites satisfying a requirements coverage metric provide better fault finding than randomly generated test suites of approximately the same size?, and (2) do test suites satisfying a more rigorous requirements coverage metric provide better fault finding than test suites satisfying a less rigorous requirements coverage metric? Our results indicate (1) only one coverage metric proposed -- Unique First Cause (UFC) coverage -- is sufficiently rigorous to ensure test suites satisfying the metric outperform randomly generated test suites of similar size and (2) that test suites satisfying more rigorous coverage metrics provide better fault finding than test suites satisfying less rigorous coverage metrics.

  12. An unbiased metric of antiproliferative drug effect in vitro.

    PubMed

    Harris, Leonard A; Frick, Peter L; Garbett, Shawn P; Hardeman, Keisha N; Paudel, B Bishal; Lopez, Carlos F; Quaranta, Vito; Tyson, Darren R

    2016-06-01

    In vitro cell proliferation assays are widely used in pharmacology, molecular biology, and drug discovery. Using theoretical modeling and experimentation, we show that current metrics of antiproliferative small molecule effect suffer from time-dependent bias, leading to inaccurate assessments of parameters such as drug potency and efficacy. We propose the drug-induced proliferation (DIP) rate, the slope of the line on a plot of cell population doublings versus time, as an alternative, time-independent metric. PMID:27135974

  13. Effective Coverage: A Metric for Monitoring Universal Health Coverage

    PubMed Central

    Ng, Marie; Fullman, Nancy; Dieleman, Joseph L.; Flaxman, Abraham D.; Murray, Christopher J. L.; Lim, Stephen S.

    2014-01-01

    A major challenge in monitoring universal health coverage (UHC) is identifying an indicator that can adequately capture the multiple components underlying the UHC initiative. Effective coverage, which unites individual and intervention characteristics into a single metric, offers a direct and flexible means to measure health system performance at different levels. We view effective coverage as a relevant and actionable metric for tracking progress towards achieving UHC. In this paper, we review the concept of effective coverage and delineate the three components of the metric — need, use, and quality — using several examples. Further, we explain how the metric can be used for monitoring interventions at both local and global levels. We also discuss the ways that current health information systems can support generating estimates of effective coverage. We conclude by recognizing some of the challenges associated with producing estimates of effective coverage. Despite these challenges, effective coverage is a powerful metric that can provide a more nuanced understanding of whether, and how well, a health system is delivering services to its populations. PMID:25243780

  14. Defining Attributes and Metrics of Effective Research Mentoring Relationships.

    PubMed

    Pfund, Christine; Byars-Winston, Angela; Branchaw, Janet; Hurtado, Sylvia; Eagan, Kevin

    2016-09-01

    Despite evidence of mentoring's importance in training researchers, studies to date have not yet determined which mentoring relationships have the most impact and what specific factors in those mentoring relationships contribute to key outcomes, such as the commitment to and persistence in research career paths for emerging researchers from diverse populations. Efforts to broaden participation and persistence in biomedical research careers require an understanding of why and how mentoring relationships work and their impact, not only to research training but also to promoting career advancement. This paper proposes core attributes of effective mentoring relationships, as supported by the literature and suggested by theoretical models of academic persistence. In addition, both existing and developing metrics for measuring the effectiveness of these attributes within mentoring relationships across diverse groups are presented, as well as preliminary data on these metrics from the authors' work. PMID:27062425

  15. Effects of subsampling of passive acoustic recordings on acoustic metrics.

    PubMed

    Thomisch, Karolin; Boebel, Olaf; Zitterbart, Daniel P; Samaran, Flore; Van Parijs, Sofie; Van Opzeeland, Ilse

    2015-07-01

    Passive acoustic monitoring is an important tool in marine mammal studies. However, logistics and finances frequently constrain the number and servicing schedules of acoustic recorders, requiring a trade-off between deployment periods and sampling continuity, i.e., the implementation of a subsampling scheme. Optimizing such schemes to each project's specific research questions is desirable. This study investigates the impact of subsampling on the accuracy of two common metrics, acoustic presence and call rate, for different vocalization patterns (regimes) of baleen whales: (1) variable vocal activity, (2) vocalizations organized in song bouts, and (3) vocal activity with diel patterns. To this end, above metrics are compared for continuous and subsampled data subject to different sampling strategies, covering duty cycles between 50% and 2%. The results show that a reduction of the duty cycle impacts negatively on the accuracy of both acoustic presence and call rate estimates. For a given duty cycle, frequent short listening periods improve accuracy of daily acoustic presence estimates over few long listening periods. Overall, subsampling effects are most pronounced for low and/or temporally clustered vocal activity. These findings illustrate the importance of informed decisions when applying subsampling strategies to passive acoustic recordings or analyses for a given target species. PMID:26233026

  16. The effect of measurement error on surveillance metrics

    SciTech Connect

    Weaver, Brian Phillip; Hamada, Michael S.

    2012-04-24

    The purpose of this manuscript is to describe different simulation studies that CCS-6 has performed for the purpose of understanding the effects of measurement error on the surveillance metrics. We assume that the measured items come from a larger population of items. We denote the random variable associate with an item's value of an attribute of interest as X and that X {approx} N({mu}, {sigma}{sup 2}). This distribution represents the variability in the population of interest and we wish to make inference on the parameters {mu} and {sigma} or on some function of these parameters. When an item X is selected from the larger population, a measurement is made on some attribute of it. This measurement is made with error and the true value of X is not observed. The rest of this section presents simulation results for different measurement cases encountered.

  17. Effects of quantum fluctuations of metric on the universe

    NASA Astrophysics Data System (ADS)

    Yang, Rongjia

    2016-09-01

    We consider a model of modified gravity from the nonperturbative quantization of a metric. We obtain the modified gravitational field equations and the modified conservational equations. We apply it to the FLRW spacetime and find that due to the quantum fluctuations a bounce universe can be obtained and a decelerated expansion can also possibly be obtained in a dark energy dominated epoch. We also discuss the effects of quantum fluctuations on inflation parameters (such as slow-roll parameters, spectral index, and the spectrum of the primordial curvature perturbation) and find values of parameters in the comparing the predictions of inflation can also work to drive the current epoch of acceleration. We obtain the constraints on the parameter of the theory from the observation of the big bang nucleosynthesis.

  18. Effecting IT infrastructure culture change: management by processes and metrics

    NASA Technical Reports Server (NTRS)

    Miller, R. L.

    2001-01-01

    This talk describes the processes and metrics used by Jet Propulsion Laboratory to bring about the required IT infrastructure culture change to update and certify, as Y2K compliant, thousands of computers and millions of lines of code.

  19. Making Metrics Matter: How to Use Indicators to Govern Effectively

    ERIC Educational Resources Information Center

    Allen, Clyde; Bacow, Lawrence S.; Trombley, Laura Skandera

    2011-01-01

    Many institutions develop specific measures or indicators--often called "dashboards"--to inform boards and top administrators about the college or university's current situation and performance and assist them in moving the institution ahead strategically. And, increasingly, institutions are using metrics not only to assess internal progress but…

  20. An effective theory of metrics with maximal proper acceleration

    NASA Astrophysics Data System (ADS)

    Gallego Torromé, Ricardo

    2015-12-01

    A geometric theory for spacetimes whose world lines associated with physical particles have an upper bound for the proper acceleration is developed. After some fundamental remarks on the requirements that the classical dynamics for point particles should hold, the notion of a generalized metric and a theory of maximal proper acceleration are introduced. A perturbative approach to metrics of maximal proper acceleration is discussed and we show how it provides a consistent theory where the associated Lorentzian metric corresponds to the limit when the maximal proper acceleration goes to infinity. Then several of the physical and kinematical properties of the maximal acceleration metric are investigated, including a discussion of the rudiments of the causal theory and the introduction of the notions of radar distance and celerity function. We discuss the corresponding modification of the Einstein mass-energy relation when the associated Lorentzian geometry is flat. In such a context it is also proved that the physical dispersion relation is relativistic. Two possible physical scenarios where the modified mass-energy relation could be confronted against the experiment are briefly discussed.

  1. Hamiltonians for the Quantum Hall Effect on Spaces with Non-Constant Metrics

    NASA Astrophysics Data System (ADS)

    Bracken, Paul Francis

    2007-01-01

    The problem of studying the quantum Hall effect on manifolds with non constant metric is addressed. The Hamiltonian on a space with hyperbolic metric is determined, and the spectrum and eigenfunctions are calculated in closed form. The hyperbolic disk is also considered and some other applications of this approach are discussed as well.

  2. Think Metric

    USGS Publications Warehouse

    U.S. Geological Survey

    1978-01-01

    The International System of Units, as the metric system is officially called, provides for a single "language" to describe weights and measures over the world. We in the United States together with the people of Brunei, Burma, and Yemen are the only ones who have not put this convenient system into effect. In the passage of the Metric Conversion Act of 1975, Congress determined that we also will adopt it, but the transition will be voluntary.

  3. Using community-level metrics to monitor the effects of marine protected areas on biodiversity.

    PubMed

    Soykan, Candan U; Lewison, Rebecca L

    2015-06-01

    Marine protected areas (MPAs) are used to protect species, communities, and their associated habitats, among other goals. Measuring MPA efficacy can be challenging, however, particularly when considering responses at the community level. We gathered 36 abundance and 14 biomass data sets on fish assemblages and used meta-analysis to evaluate the ability of 22 distinct community diversity metrics to detect differences in community structure between MPAs and nearby control sites. We also considered the effects of 6 covariates-MPA size and age, MPA size and age interaction, latitude, total species richness, and level of protection-on each metric. Some common metrics, such as species richness and Shannon diversity, did not differ consistently between MPA and control sites, whereas other metrics, such as total abundance and biomass, were consistently different across studies. Metric responses derived from the biomass data sets were more consistent than those based on the abundance data sets, suggesting that community-level biomass differs more predictably than abundance between MPA and control sites. Covariate analyses indicated that level of protection, latitude, MPA size, and the interaction between MPA size and age affect metric performance. These results highlight a handful of metrics, several of which are little known, that could be used to meet the increasing demand for community-level indicators of MPA effectiveness. PMID:25572325

  4. [Applicability of traditional landscape metrics in evaluating urban heat island effect].

    PubMed

    Chen, Ai-Lian; Sun, Ran-Hao; Chen, Li-Ding

    2012-08-01

    By using 24 landscape metrics, this paper evaluated the urban heat island effect in parts of Beijing downtown area. QuickBird (QB) images were used to extract the landscape type information, and the thermal bands from Landsat Enhanced Thematic Mapper Plus (ETM+) images were used to extract the land surface temperature (LST) in four seasons of the same year. The 24 landscape pattern metrics were calculated at landscape and class levels in a fixed window with 120 mx 120 m in size, with the applicability of these traditional landscape metrics in evaluating the urban heat island effect examined. Among the 24 landscape metrics, only the percentage composition of landscape (PLAND), patch density (PD), largest patch index (LPI), coefficient of Euclidean nearest-neighbor distance variance (ENN_CV), and landscape division index (DIVISION) at landscape level were significantly correlated with the LST in March, May, and November, and the PLAND, LPI, DIVISION, percentage of like adjacencies, and interspersion and juxtaposition index at class level showed significant correlations with the LST in March, May, July, and December, especially in July. Some metrics such as PD, edge density, clumpiness index, patch cohesion index, effective mesh size, splitting index, aggregation index, and normalized landscape shape index showed varying correlations with the LST at different class levels. The traditional landscape metrics could not be appropriate in evaluating the effects of river on LST, while some of the metrics could be useful in characterizing urban LST and analyzing the urban heat island effect, but screening and examining should be made on the metrics. PMID:23189682

  5. Effective metrics in the non-minimal Einstein-Yang-Mills-Higgs theory

    SciTech Connect

    Balakin, A.B. Dehnen, H. Zayats, A.E.

    2008-09-15

    We formulate a self-consistent non-minimal five-parameter Einstein-Yang-Mills-Higgs (EYMH) model and analyse it in terms of effective (associated, color and color-acoustic) metrics. We use a formalism of constitutive tensors in order to reformulate master equations for the gauge, scalar and gravitational fields and reconstruct in the algebraic manner the so-called associated metrics for the Yang-Mills field. Using WKB-approximation we find color metrics for the Yang-Mills field and color-acoustic metric for the Higgs field in the framework of five-parameter EYMH model. Based on explicit representation of these effective metrics for the EYMH system with uniaxial symmetry, we consider cosmological applications for Bianchi-I, FLRW and de Sitter models. We focus on the analysis of the obtained expressions for velocities of propagation of longitudinal and transversal color and color-acoustic waves in a (quasi)vacuum interacting with curvature; we show that curvature coupling results in time variations of these velocities. We show, that the effective metrics can be regular or can possess singularities depending on the choice of the parameters of non-minimal coupling in the cosmological models under discussion. We consider a physical interpretation of such singularities in terms of phase velocities of color and color-acoustic waves, using the terms 'wave stopping' and 'trapped surface'.

  6. Effective gravitational mass of the Ayón-Beato and García metric

    NASA Astrophysics Data System (ADS)

    Sinha, A. K.; Pandey, G. K.; Bhaskar, A. K.; Rai, B. C.; Jha, A. K.; Kumar, S.; Xulu, S. S.

    2015-06-01

    In this paper, we calculate the effective gravitational mass of Ayón-Beato and García (AG) regular (nonsingular) static spherically symmetric asymptotically Minkowskian metric that is a solution to Einstein’s equations coupled with a nonlinear electromagnetic field. The effective gravitational mass is negative, zero, or positive that depends on the ratio of magnitude of electric charge to the ADM mass and the ratio of the radial distance to the ADM mass. As expected, at large values of radial distance, our result gives effective gravitational mass of the Reissner-Nordström metric.

  7. Time-dependent Elastic Deformation in Crystal: Insights from Metric Description and Berry Phase Effect

    NASA Astrophysics Data System (ADS)

    Dong, Liang; Niu, Qian

    2015-03-01

    It is well known that elastic deformation in crystal can be described in the language of a metric. However, how the metric couples to the one-electron Hamiltonian in a deformed crystal is not very clear. By coordinate transformation from a Cartesian frame to lattice frame where all coordinates of ions are fixed, the metric emerges naturally both in the kinetic energy and potential energy of an electron. Besides, the velocity field of ions is also manifested in the Hamiltonian, which resembles the role of a vector potential. When the deformation slowly varies both in space and time, the wave-packet method can be used to study the Berry phase effect of deformation. This method applies to finite-strain cases and is accurate up to the first order of strain gradient. Different deformation effects are discussed, such as piezoelectricity, flexoelectricity and curving effect of a two-dimensional material

  8. Time-Indexed Effect Size Metric for K-12 Reading and Math Education Evaluation

    ERIC Educational Resources Information Center

    Lee, Jaekyung; Finn, Jeremy; Liu, Xiaoyan

    2011-01-01

    Through a synthesis of test publisher norms and national longitudinal datasets, this study provides new national norms of academic growth in K-12 reading and math that can be used to reinterpret conventional effect sizes in time units. We propose d' a time-indexed effect size metric to estimate how long it would take for an "untreated" control…

  9. On the Doppler effect for light from orbiting sources in Kerr-type metrics

    NASA Astrophysics Data System (ADS)

    Cisneros, S.; Goedecke, G.; Beetle, C.; Engelhardt, M.

    2015-04-01

    A formula is derived for the combined motional and gravitational Doppler effect in general stationary axisymmetric metrics for a photon emitted parallel or antiparallel to the assumed circular orbital motion of its source. The same formula is derived by both the eikonal approximation and Killing vector approaches to elucidate connections between observational astronomy and modern relativity. The formula yields expected results in the limits of a moving or stationary source in the exterior Kerr and Schwarzschild metrics and is useful for broad range astrophysical analyses.

  10. Surface adhesive forces: a metric describing the drag-reducing effects of superhydrophobic coatings.

    PubMed

    Cheng, Mengjiao; Song, Mengmeng; Dong, Hongyu; Shi, Feng

    2015-04-01

    Nanomaterials with superhydrophobic properties are promising as drag-reducing coatings. However, debates regarding whether superhydrophobic surfaces are favorable for drag reduction require further clarification. A quantified water adhesive force measurement is proposed as a metric and its effectiveness demonstrated using three typical superhydrophobic coatings on model ships with in situ sailing tests. PMID:25418808

  11. Metric Madness

    ERIC Educational Resources Information Center

    Kroon, Cindy D.

    2007-01-01

    Created for a Metric Day activity, Metric Madness is a board game for two to four players. Students review and practice metric vocabulary, measurement, and calculations by playing the game. Playing time is approximately twenty to thirty minutes.

  12. Effectively identifying user profiles in network and host metrics

    NASA Astrophysics Data System (ADS)

    Murphy, John P.; Berk, Vincent H.; Gregorio-de Souza, Ian

    2010-04-01

    This work presents a collection of methods that is used to effectively identify users of computers systems based on their particular usage of the software and the network. Not only are we able to identify individual computer users by their behavioral patterns, we are also able to detect significant deviations in their typical computer usage over time, or compared to a group of their peers. For instance, most people have a small, and relatively unique selection of regularly visited websites, certain email services, daily work hours, and typical preferred applications for mandated tasks. We argue that these habitual patterns are sufficiently specific to identify fully anonymized network users. We demonstrate that with only a modest data collection capability, profiles of individual computer users can be constructed so as to uniquely identify a profiled user from among their peers. As time progresses and habits or circumstances change, the methods presented update each profile so that changes in user behavior can be reliably detected over both abrupt and gradual time frames, without losing the ability to identify the profiled user. The primary benefit of our methodology allows one to efficiently detect deviant behaviors, such as subverted user accounts, or organizational policy violations. Thanks to the relative robustness, these techniques can be used in scenarios with very diverse data collection capabilities, and data privacy requirements. In addition to behavioral change detection, the generated profiles can also be compared against pre-defined examples of known adversarial patterns.

  13. Metrics to describe the effects of landscape pattern on hydrology in a lotic peatland

    NASA Astrophysics Data System (ADS)

    Yuan, J.; Cohen, M. J.; Kaplan, D. A.; Acharya, S.; Larsen, L.; Nungesser, M.

    2013-12-01

    Strong reciprocal interactions exist between landscape patterns and ecological processes. Hydrology is the dominant abiotic driver of ecological processes in wetlands, particularly flowing wetlands, but is both the control on and controlled by the geometry of vegetation patterning. Landscape metrics are widely used to quantitatively link pattern and process. Our goal here was to use several candidate spatial pattern metrics to predict the effects of wetland vegetation pattern on hydrologic regime, specifically hydroperiod, in the ridge-slough patterned landscape of the Everglades. The metrics focus on the capacity for longitudinally connected flow, and thus the ability of this low-gradient patterned landscape to route water from upstream. We first explored flow friction cost (FFC), a weighted spatial distance procedure wherein ridges have a high flow cost than sloughs by virtue of their elevation and vegetation structure, to evaluate water movement through different landscape configurations. We also investigated existing published flow metrics, specifically the Directional Connectivity Index (DCI) and Landscape Discharge Competence (LDC), that seek to quantify connectivity, one of the sentinel targets of ecological restoration. Hydroperiod was estimated using a numerical hydrologic model (SWIFT 2D) in real and synthetic landscapes with varying vegetation properties ( patch anisotropy, ridge density). Synthetic landscapes were constrained by the geostatistical properties of the best conserved patterned, and contained five anisotropy levels and seven ridge density levels. These were used to construct the relationship between landscape metrics and hydroperiod. Then, using historical images from 1940 to 2004, we applied the metrics toback-cast hydroperiod. Current vegetation maps were used to test scale dependency for each metric. Our results suggest that both FFC and DCI are good predictors of hydroperiod under free flowing conditions, and that they can be used

  14. Effect of respiratory and cardiac gating on the major diffusion-imaging metrics.

    PubMed

    Hamaguchi, Hiroyuki; Tha, Khin Khin; Sugimori, Hiroyuki; Nakanishi, Mitsuhiro; Nakagawa, Shin; Fujiwara, Taro; Yoshida, Hirokazu; Takamori, Sayaka; Shirato, Hiroki

    2016-08-01

    The effect of respiratory gating on the major diffusion-imaging metrics and that of cardiac gating on mean kurtosis (MK) are not known. For evaluation of whether the major diffusion-imaging metrics-MK, fractional anisotropy (FA), and mean diffusivity (MD) of the brain-varied between gated and non-gated acquisitions, respiratory-gated, cardiac-gated, and non-gated diffusion-imaging of the brain were performed in 10 healthy volunteers. MK, FA, and MD maps were constructed for all acquisitions, and the histograms were constructed. The normalized peak height and location of the histograms were compared among the acquisitions by use of Friedman and post hoc Wilcoxon tests. The effect of the repetition time (TR) on the diffusion-imaging metrics was also tested, and we corrected for its variation among acquisitions, if necessary. The results showed a shift in the peak location of the MK and MD histograms to the right with an increase in TR (p ≤ 0.01). The corrected peak location of the MK histograms, the normalized peak height of the FA histograms, the normalized peak height and the corrected peak location of the MD histograms varied significantly between the gated and non-gated acquisitions (p < 0.05). These results imply an influence of respiration and cardiac pulsation on the major diffusion-imaging metrics. The gating conditions must be kept identical if reproducible results are to be achieved. PMID:27073115

  15. Effects of certain key metrics of hydroentanglement system on properties of nonwoven fabrics made with commercially cleaned greige cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research was conducted to determine the effects of certain key process metrics of a commercial-grade hydroentanglement system on properties of the nonwoven fabrics made with cleaned Upland greige cotton lint. The metrics studied, among others, were the hydroentangling water pressure, the strip orif...

  16. The metric comparability of meta-analytic effect-size estimators from factorial designs.

    PubMed

    Gillett, Raphael

    2003-12-01

    The primary studies in a meta-analysis of standardized mean differences generally include a mixture of single-factor t tests and multifactor analysis of variance designs. Accordingly, there is a need for effect-size measures in multifactor designs that are metrically comparable with measures in single-factor t tests. Two models, the variance-preservation model and the variance-reduction model, provide a formal description of the 2 principal routes by which a single-factor design may evolve into a higher order factorial design. New metrically comparable effect-size measures and estimators are developed for designs that contain variance-preservation factors, variance-reduction factors, or a mixture of both types of factors. A statistical test for checking the validity of model assumptions is presented. PMID:14664680

  17. Status report on aerospace metrication

    NASA Astrophysics Data System (ADS)

    Peterson, A.

    1983-10-01

    Following passage of PL 94-168, the transition to the use of metric units within the United States has been very slow. The lack of a national plan with no clear understanding or agreement concerning the source of the funds required to effect the transition have been major impediments. There are international pressures from the international standards-making organizations, the ICAO and NATO, to proceed with the unification of standards. Within the commercial aviation field, the United States is resisting the pressure, but is participating in international standardization activities because of a general recognition of the need to support future market requirements and to assist in the resolution of a significant NATO logistics problem. The AIA, with the SAE and other standards-making organizations, is attempting to secure a harmonization of United States and AECMA metric standards. The future transition progress is not expected to accelerate significantly until metric standards are available.

  18. Comparing Exposure Metrics for the Effects of Fine Particulate Matter on Emergency Hospital Admissions

    PubMed Central

    Mannshardt, Elizabeth; Sucic, Katarina; Jiao, Wan; Dominici, Francesca; Frey, H. Christopher; Reich, Brian; Fuentes, Montserrat

    2013-01-01

    A crucial step in an epidemiological study of the effects of air pollution is to accurately quantify exposure of the population. In this paper, we investigate the sensitivity of the health effects estimates associated with short-term exposure to fine particulate matter with respect to three potential metrics for daily exposure: ambient monitor data, estimated values from a deterministic atmospheric chemistry model, and stochastic daily average human exposure simulation output. Each of these metrics has strengths and weaknesses when estimating the association between daily changes in ambient exposure to fine particulate matter and daily emergency hospital admissions. Monitor data is readily available, but is incomplete over space and time. The atmospheric chemistry model output is spatially and temporally complete, but may be less accurate than monitor data. The stochastic human exposure estimates account for human activity patterns and variability in pollutant concentration across microenvironments, but requires extensive input information and computation time. To compare these metrics, we consider a case study of the association between fine particulate matter and emergency hospital admissions for respiratory cases for the Medicare population across three counties in New York. Of particular interest is to quantify the impact and/or benefit to using the stochastic human exposure output to measure ambient exposure to fine particulate matter. Results indicate that the stochastic human exposure simulation output indicates approximately the same increase in relative risk associated with emergency admissions as using a chemistry model or monitoring data as exposure metrics. However, the stochastic human exposure simulation output and the atmospheric chemistry model both bring additional information which helps to reduce the uncertainly in our estimated risk. PMID:23942393

  19. Color Metric.

    ERIC Educational Resources Information Center

    Illinois State Office of Education, Springfield.

    This booklet was designed to convey metric information in pictoral form. The use of pictures in the coloring book enables the more mature person to grasp the metric message instantly, whereas the younger person, while coloring the picture, will be exposed to the metric information long enough to make the proper associations. Sheets of the booklet…

  20. Separability of test fields equations on the C -metric background. II. Rotating case and the Meissner effect

    NASA Astrophysics Data System (ADS)

    KofroÅ, David

    2016-05-01

    We present the separation of the Teukolsky master equation for the test field of arbitrary spin on the background of the rotating C -metric. We also summarize and simplify some known results about Debye potentials of these fields on type D background. The equation for the Debye potential is also separated. Solving for the Debye potential of the electromagnetic field we show that on the extremely rotating C -metric no magnetic field can penetrate through the outer black hole horizon—we thus recover the Meissner effect for the C -metric.

  1. Effects of metric change on safety in the workplace for selected occupations

    NASA Astrophysics Data System (ADS)

    Lefande, J. M.; Pokorney, J. L.

    1982-04-01

    The study assesses the potential safety issues of metric conversion in the workplace. A purposive sample of 35 occupations based on injury and illnesses indexes were assessed. After an analysis of workforce population, hazard analysis and measurement sensitivity of the occupations, jobs were analyzed to identify potential safety hazards by industrial hygienists, safety engineers and academia. The study's major findings were as follows: No metric hazard experience was identified. An increased exposure might occur when particular jobs and their job tasks are going the transition from customary measurement to metric measurement. Well planned metric change programs reduce hazard potential. Metric safety issues are unresolved in the aviation industry.

  2. Assessing the Effects of Data Compression in Simulations Using Physically Motivated Metrics

    DOE PAGESBeta

    Laney, Daniel; Langer, Steven; Weber, Christopher; Lindstrom, Peter; Wegener, Al

    2014-01-01

    This paper examines whether lossy compression can be used effectively in physics simulations as a possible strategy to combat the expected data-movement bottleneck in future high performance computing architectures. We show that, for the codes and simulations we tested, compression levels of 3–5X can be applied without causing significant changes to important physical quantities. Rather than applying signal processing error metrics, we utilize physics-based metrics appropriate for each code to assess the impact of compression. We evaluate three different simulation codes: a Lagrangian shock-hydrodynamics code, an Eulerian higher-order hydrodynamics turbulence modeling code, and an Eulerian coupled laser-plasma interaction code. Wemore » compress relevant quantities after each time-step to approximate the effects of tightly coupled compression and study the compression rates to estimate memory and disk-bandwidth reduction. We find that the error characteristics of compression algorithms must be carefully considered in the context of the underlying physics being modeled.« less

  3. Comparing Single Case Design Overlap-Based Effect Size Metrics From Studies Examining Speech Generating Device Interventions.

    PubMed

    Chen, Mo; Hyppa-Martin, Jolene K; Reichle, Joe E; Symons, Frank J

    2016-05-01

    Meaningfully synthesizing single case experimental data from intervention studies comprised of individuals with low incidence conditions and generating effect size estimates remains challenging. Seven effect size metrics were compared for single case design (SCD) data focused on teaching speech generating device use to individuals with intellectual and developmental disabilities (IDD) with moderate to profound levels of impairment. The effect size metrics included percent of data points exceeding the median (PEM), percent of nonoverlapping data (PND), improvement rate difference (IRD), percent of all nonoverlapping data (PAND), Phi, nonoverlap of all pairs (NAP), and Tau(novlap). Results showed that among the seven effect size metrics, PAND, Phi, IRD, and PND were more effective in quantifying intervention effects for the data sample (N = 285 phase or condition contrasts). Results are discussed with respect to issues concerning extracting and calculating effect sizes, visual analysis, and SCD intervention research in IDD. PMID:27119210

  4. Primary Metrics.

    ERIC Educational Resources Information Center

    Otto, Karen; And Others

    These 55 activity cards were created to help teachers implement a unit on metric measurement. They were designed for students aged 5 to 10, but could be used with older students. Cards are color-coded in terms of activities on basic metric terms, prefixes, length, and other measures. Both individual and small-group games and ideas are included.…

  5. Mastering Metrics

    ERIC Educational Resources Information Center

    Parrot, Annette M.

    2005-01-01

    By the time students reach a middle school science course, they are expected to make measurements using the metric system. However, most are not practiced in its use, as their experience in metrics is often limited to one unit they were taught in elementary school. This lack of knowledge is not wholly the fault of formal education. Although the…

  6. Metrics for the effectiveness and success of an Education and Public Outreach Program; the HST experience

    NASA Astrophysics Data System (ADS)

    Griffin, I. P.; Eisenhammer, B.; Kakadelis, S.; Stanley, M.; Stoke, J.; Teays, T.; Villard, R.; Voit, G. M.

    2002-05-01

    The Office of Public Outreach (OPO) at the STScI was created to share the amazing discoveries of the Hubble Space Telescope with the American public. During the last five years we have developed a multitude of products and programs that have capitalized on the intense interest in Hubble to inform and inspire millions of Americans and many others around the globe. Our Education and Public outreach program has five complementary strands that broadly define the communities we serve. These are News, Formal Education, Informal Science Education, Online Outreach, Origins Forum In this paper we present and discuss some of the metrics for effectiveness and success that we have developed and use in each area of our outreach program.

  7. Detecting the effects of cascade hydropower reservoirs on eco-flow metrics

    NASA Astrophysics Data System (ADS)

    Zhao, T.; Zhao, J.

    2012-12-01

    Over evolutionary time, the natural hydrological events of floods and droughts have become an integral component of riverine ecosystems. However, human activities, particularly reservoir operations, can greatly alter the natural flow regime and pose great impacts on riverine ecosystems. This study analyses the effects of cascade hydropower reservoir operation on eco-flow metrics based on inflow and release data of reservoirs in southwest China, with a focus on the Xiaowan reservoir (upper reservoir with multi-annual storage capacity) and the Jinghong reservoir (lower reservoir with weekly storage capacity). For the upper Xiaowan Reservoir, the analysis results show that the eco-surplus and eco-deficit (Vogel, et al, 2007; Gao, et al., 2009 ) can capture its impacts of hydropower operation on eco-flow metrics very well. However, comparative analysis of the lower Jinghong reservoir based on daily and hourly data shows that eco-surplus and eco-deficit measured with flow duration curve of daily and hourly flow data are not sensitive indices, which is attributed to the small regulating capacity of the Jinghong reservoir. It is shown that the negative impacts of hydropower operation of the Jinghong reservoir can be characterized by the changing rate of flow. These results indicate that eco-surplus and eco-deficit are good representative indices for evaluating seasonal reservoir operation, but more attention should be paid to the changing rate of flow for short term hydropower reservoir operation. This study implies that coordination of cascade reservoirs can be an effective way to mitigate the negative impacts of hydropower operation on ecosystem.

  8. Metric transition

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This report describes NASA's metric transition in terms of seven major program elements. Six are technical areas involving research, technology development, and operations; they are managed by specific Program Offices at NASA Headquarters. The final program element, Institutional Management, covers both NASA-wide functional management under control of NASA Headquarters and metric capability development at the individual NASA Field Installations. This area addresses issues common to all NASA program elements, including: Federal, state, and local coordination; standards; private industry initiatives; public-awareness initiatives; and employee training. The concluding section identifies current barriers and impediments to metric transition; NASA has no specific recommendations for consideration by the Congress.

  9. Do-It-Yourself Metrics

    ERIC Educational Resources Information Center

    Klubeck, Martin; Langthorne, Michael; Padgett, Don

    2006-01-01

    Something new is on the horizon, and depending on one's role on campus, it might be storm clouds or a cleansing shower. Either way, no matter how hard one tries to avoid it, sooner rather than later he/she will have to deal with metrics. Metrics do not have to cause fear and resistance. Metrics can, and should, be a powerful tool for improvement.…

  10. Comparing Single Case Design Overlap-Based Effect Size Metrics from Studies Examining Speech Generating Device Interventions

    ERIC Educational Resources Information Center

    Chen, Mo; Hyppa-Martin, Jolene K.; Reichle, Joe E.; Symons, Frank J.

    2016-01-01

    Meaningfully synthesizing single case experimental data from intervention studies comprised of individuals with low incidence conditions and generating effect size estimates remains challenging. Seven effect size metrics were compared for single case design (SCD) data focused on teaching speech generating device use to individuals with…

  11. Edible Metrics.

    ERIC Educational Resources Information Center

    Mecca, Christyna E.

    1998-01-01

    Presents an exercise that introduces students to scientific measurements using only metric units. At the conclusion of the exercise, students eat the experiment. Requires dried refried beans, crackers or chips, and dried instant powder for lemonade. (DDR)

  12. Evaluating Texture Compression Masking Effects Using Objective Image Quality Assessment Metrics.

    PubMed

    Griffin, Wesley; Olano, Marc

    2015-08-01

    Texture compression is widely used in real-time rendering to reduce storage and bandwidth requirements. Recent research in compression algorithms has explored both reduced fixed bit rate and variable bit rate algorithms. The results are evaluated at the individual texture level using mean square error, peak signal-to-noise ratio, or visual image inspection. We argue this is the wrong evaluation approach. Compression artifacts in individual textures are likely visually masked in final rendered images and this masking is not accounted for when evaluating individual textures. This masking comes from both geometric mapping of textures onto models and the effects of combining different textures on the same model such as diffuse, gloss, and bump maps. We evaluate final rendered images using rigorous perceptual error metrics. Our method samples the space of viewpoints in a scene, renders the scene from each viewpoint using variations of compressed textures, and then compares each to a ground truth using uncompressed textures from the same viewpoint. We show that masking has a significant effect on final rendered image quality, masking effects and perceptual sensitivity to masking varies by the type of texture, graphics hardware compression algorithms are too conservative, and reduced bit rates are possible while maintaining final rendered image quality. PMID:26357259

  13. Distributed series resistance effects in solar cells

    NASA Astrophysics Data System (ADS)

    Nielsen, L. D.

    1982-05-01

    A mathematical treatment is presented of the effects of one-dimensional distributed series resistance in solar cells. A general perturbation theory is developed, including consistently the induced spatial variation of diode current density and leading to a first-order equivalent lumped resistance of one third the total sheet resistance. For the case of diode characteristics of exponential type and distributed resistance of arbitrary size, unified numerical results are presented for both illuminated and dark characteristics. At high forward dark currents, the distributed series resistance is shown to cause an effective doubling of the 'diode quality factor'.

  14. Metric qualities of the cognitive behavioral assessment for outcome evaluation to estimate psychological treatment effects

    PubMed Central

    Bertolotti, Giorgio; Michielin, Paolo; Vidotto, Giulio; Sanavio, Ezio; Bottesi, Gioia; Bettinardi, Ornella; Zotti, Anna Maria

    2015-01-01

    Background Cognitive behavioral assessment for outcome evaluation was developed to evaluate psychological treatment interventions, especially for counseling and psychotherapy. It is made up of 80 items and five scales: anxiety, well-being, perception of positive change, depression, and psychological distress. The aim of the study was to present the metric qualities and to show validity and reliability of the five constructs of the questionnaire both in nonclinical and clinical subjects. Methods Four steps were completed to assess reliability and factor structure: criterion-related and concurrent validity, responsiveness, and convergent–divergent validity. A nonclinical group of 269 subjects was enrolled, as was a clinical group comprising 168 adults undergoing psychotherapy and psychological counseling provided by the Italian public health service. Results Cronbach’s alphas were between 0.80 and 0.91 for the clinical sample and between 0.74 and 0.91 in the nonclinical one. We observed an excellent structural validity for the five interrelated dimensions. The clinical group showed higher scores in the anxiety, depression, and psychological distress scales, as well as lower scores in well-being and perception of positive change scales than those observed in the nonclinical group. Responsiveness was large for the anxiety, well-being, and depression scales; the psychological distress and perception of positive change scales showed a moderate effect. Conclusion The questionnaire showed excellent psychometric properties, thus demonstrating that the questionnaire is a good evaluative instrument, with which to assess pre- and post-treatment outcomes. PMID:26442466

  15. Modeling motivation three ways: effects of MI metrics on treatment outcomes among adolescents.

    PubMed

    Hall, Brittany C; Stewart, David G; Arger, Chris; Athenour, Dylan R; Effinger, Jenell

    2014-03-01

    The purpose of this study was to determine how three different measures of motivation (cognitive motivation, taking steps, and self-efficacy for change and maintenance) predict substance use outcomes after engaging in a Motivational Interviewing intervention. Participants were 225 high school students enrolled in Project Reducing the Effects of Alcohol and Drugs on Youth (Project READY), a NIDA-funded intervention initially developed with Motivational Interviewing (MI) principles for adolescents identified by schools as having problems with alcohol or other drug use. We measured motivation at multiple time points during the intervention in multiple methods. Cognitive motivation was assessed using a Decisional Balance matrix at Session 3 of treatment. We measured self-efficacy with the Situational Confidence Questionnaire, administered at 4-, 8-, 12-, and 16-week follow-ups. A measure of taking steps (SOCRATES, v. 8) was administered at intake and Session 8. We hypothesized that motivation would follow the Transtheoretical Model (TTM) pathway, and we proposed a model where cognitive motivation would predict self-confidence for change and taking steps toward change, and self-confidence and taking steps would predict substance use outcomes. We tested our model using path analysis in AMOS and found support for a motivational continuum predicting percent days abstinent at 16-week follow-up [χ(2) = 2.75, df = 7, p = .90, CFI = 1, RMSEA (90% confidence interval) = .00 - .03]. This model demonstrates that motivational metrics predict unique outcomes at different time points and serve as important components of intervention. PMID:24467198

  16. Cyber threat metrics.

    SciTech Connect

    Frye, Jason Neal; Veitch, Cynthia K.; Mateski, Mark Elliot; Michalski, John T.; Harris, James Mark; Trevino, Cassandra M.; Maruoka, Scott

    2012-03-01

    Threats are generally much easier to list than to describe, and much easier to describe than to measure. As a result, many organizations list threats. Fewer describe them in useful terms, and still fewer measure them in meaningful ways. This is particularly true in the dynamic and nebulous domain of cyber threats - a domain that tends to resist easy measurement and, in some cases, appears to defy any measurement. We believe the problem is tractable. In this report we describe threat metrics and models for characterizing threats consistently and unambiguously. The purpose of this report is to support the Operational Threat Assessment (OTA) phase of risk and vulnerability assessment. To this end, we focus on the task of characterizing cyber threats using consistent threat metrics and models. In particular, we address threat metrics and models for describing malicious cyber threats to US FCEB agencies and systems.

  17. Metric System.

    ERIC Educational Resources Information Center

    Del Mod System, Dover, DE.

    This autoinstructional unit deals with the identification of units of measure in the metric system and the construction of relevant conversion tables. Students in middle school or in grade ten, taking a General Science course, can handle this learning activity. It is recommended that high, middle or low level achievers can use the program.…

  18. Effects of Stream and Elevation Resolution on Riparian Metrics and Restoration Identification

    EPA Science Inventory

    Even though riparian areas attenuate nutrients and sediments from agricultural runoff at the field scale, best management practices and locations for restoring riparian areas should be determined at watershed scales. Riparian metrics (e.g., percent forest within 100m of stream)...

  19. Metrication of the United States Lumber Industry and Its Effects on Wood Consuming Industrial Education Courses.

    ERIC Educational Resources Information Center

    Craemer, Peter J.

    A study investigated the direction United States lumber industries are moving concerning the implementation of the metric system and what implications this has concerning wood consuming industrial education courses. The procedure included a literature review and investigating the major producers of softwood dimensional lumber by a detailed survey…

  20. Effective detective quantum efficiency for two mammography systems: Measurement and comparison against established metrics

    SciTech Connect

    Salvagnini, Elena; Bosmans, Hilde; Marshall, Nicholas W.; Struelens, Lara

    2013-10-15

    Purpose: The aim of this paper was to illustrate the value of the new metric effective detective quantum efficiency (eDQE) in relation to more established measures in the optimization process of two digital mammography systems. The following metrics were included for comparison against eDQE: detective quantum efficiency (DQE) of the detector, signal difference to noise ratio (SdNR), and detectability index (d′) calculated using a standard nonprewhitened observer with eye filter.Methods: The two systems investigated were the Siemens MAMMOMAT Inspiration and the Hologic Selenia Dimensions. The presampling modulation transfer function (MTF) required for the eDQE was measured using two geometries: a geometry containing scattered radiation and a low scatter geometry. The eDQE, SdNR, and d′ were measured for poly(methyl methacrylate) (PMMA) thicknesses of 20, 40, 60, and 70 mm, with and without the antiscatter grid and for a selection of clinically relevant target/filter (T/F) combinations. Figures of merit (FOMs) were then formed from SdNR and d′ using the mean glandular dose as the factor to express detriment. Detector DQE was measured at energies covering the range of typical clinically used spectra.Results: The MTF measured in the presence of scattered radiation showed a large drop at low spatial frequency compared to the low scatter method and led to a corresponding reduction in eDQE. The eDQE for the Siemens system at 1 mm{sup −1} ranged between 0.15 and 0.27, depending on T/F and grid setting. For the Hologic system, eDQE at 1 mm{sup −1} varied from 0.15 to 0.32, again depending on T/F and grid setting. The eDQE results for both systems showed that the grid increased the system efficiency for PMMA thicknesses of 40 mm and above but showed only small sensitivity to T/F setting. While results of the SdNR and d′ based FOMs confirmed the eDQE grid position results, they were also more specific in terms of T/F selection. For the Siemens system at 20 mm PMMA

  1. Characterizing social media metrics of scholarly papers: the effect of document properties and collaboration patterns.

    PubMed

    Haustein, Stefanie; Costas, Rodrigo; Larivière, Vincent

    2015-01-01

    A number of new metrics based on social media platforms--grouped under the term "altmetrics"--have recently been introduced as potential indicators of research impact. Despite their current popularity, there is a lack of information regarding the determinants of these metrics. Using publication and citation data from 1.3 million papers published in 2012 and covered in Thomson Reuters' Web of Science as well as social media counts from Altmetric.com, this paper analyses the main patterns of five social media metrics as a function of document characteristics (i.e., discipline, document type, title length, number of pages and references) and collaborative practices and compares them to patterns known for citations. Results show that the presence of papers on social media is low, with 21.5% of papers receiving at least one tweet, 4.7% being shared on Facebook, 1.9% mentioned on blogs, 0.8% found on Google+ and 0.7% discussed in mainstream media. By contrast, 66.8% of papers have received at least one citation. Our findings show that both citations and social media metrics increase with the extent of collaboration and the length of the references list. On the other hand, while editorials and news items are seldom cited, it is these types of document that are the most popular on Twitter. Similarly, while longer papers typically attract more citations, an opposite trend is seen on social media platforms. Finally, contrary to what is observed for citations, it is papers in the Social Sciences and humanities that are the most often found on social media platforms. On the whole, these findings suggest that factors driving social media and citations are different. Therefore, social media metrics cannot actually be seen as alternatives to citations; at most, they may function as complements to other type of indicators. PMID:25780916

  2. Characterizing Social Media Metrics of Scholarly Papers: The Effect of Document Properties and Collaboration Patterns

    PubMed Central

    Haustein, Stefanie; Costas, Rodrigo; Larivière, Vincent

    2015-01-01

    A number of new metrics based on social media platforms—grouped under the term “altmetrics”—have recently been introduced as potential indicators of research impact. Despite their current popularity, there is a lack of information regarding the determinants of these metrics. Using publication and citation data from 1.3 million papers published in 2012 and covered in Thomson Reuters’ Web of Science as well as social media counts from Altmetric.com, this paper analyses the main patterns of five social media metrics as a function of document characteristics (i.e., discipline, document type, title length, number of pages and references) and collaborative practices and compares them to patterns known for citations. Results show that the presence of papers on social media is low, with 21.5% of papers receiving at least one tweet, 4.7% being shared on Facebook, 1.9% mentioned on blogs, 0.8% found on Google+ and 0.7% discussed in mainstream media. By contrast, 66.8% of papers have received at least one citation. Our findings show that both citations and social media metrics increase with the extent of collaboration and the length of the references list. On the other hand, while editorials and news items are seldom cited, it is these types of document that are the most popular on Twitter. Similarly, while longer papers typically attract more citations, an opposite trend is seen on social media platforms. Finally, contrary to what is observed for citations, it is papers in the Social Sciences and humanities that are the most often found on social media platforms. On the whole, these findings suggest that factors driving social media and citations are different. Therefore, social media metrics cannot actually be seen as alternatives to citations; at most, they may function as complements to other type of indicators. PMID:25780916

  3. The International Safeguards Technology Base: How is the Patient Doing? An Exploration of Effective Metrics

    SciTech Connect

    Schanfein, Mark J; Gouveia, Fernando S

    2010-07-01

    The term “Technology Base” is commonly used but what does it mean? Is there a common understanding of the components that comprise a technology base? Does a formal process exist to assess the health of a given technology base? These are important questions the relevance of which is even more pressing given the USDOE/NNSA initiatives to strengthen the safeguards technology base through investments in research & development and human capital development. Accordingly, the authors will establish a high-level framework to define and understand what comprises a technology base. Potential goal-driven metrics to assess the health of a technology base will also be explored, such as linear demographics and resource availability, in the hope that they can be used to better understand and improve the health of the U.S. safeguards technology base. Finally, through the identification of such metrics, the authors will offer suggestions and highlight choices for addressing potential shortfalls.

  4. When can we measure stress noninvasively? Postdeposition effects on a fecal stress metric confound a multiregional assessment.

    PubMed

    Wilkening, Jennifer L; Ray, Chris; Varner, Johanna

    2016-01-01

    Measurement of stress hormone metabolites in fecal samples has become a common method to assess physiological stress in wildlife populations. Glucocorticoid metabolite (GCM) measurements can be collected noninvasively, and studies relating this stress metric to anthropogenic disturbance are increasing. However, environmental characteristics (e.g., temperature) can alter measured GCM concentration when fecal samples cannot be collected immediately after defecation. This effect can confound efforts to separate environmental factors causing predeposition physiological stress in an individual from those acting on a fecal sample postdeposition. We used fecal samples from American pikas (Ochotona princeps) to examine the influence of environmental conditions on GCM concentration by (1) comparing GCM concentration measured in freshly collected control samples to those placed in natural habitats for timed exposure, and (2) relating GCM concentration in samples collected noninvasively throughout the western United States to local environmental characteristics measured before and after deposition. Our timed-exposure trials clarified the spatial scale at which exposure to environmental factors postdeposition influences GCM concentration in pika feces. Also, fecal samples collected from occupied pika habitats throughout the species' range revealed significant relationships between GCM and metrics of climate during the postdeposition period (maximum temperature, minimum temperature, and precipitation during the month of sample collection). Conversely, we found no such relationships between GCM and metrics of climate during the predeposition period (prior to the month of sample collection). Together, these results indicate that noninvasive measurement of physiological stress in pikas across the western US may be confounded by climatic conditions in the postdeposition environment when samples cannot be collected immediately after defecation. Our results reiterate the importance

  5. Probing the post-newtonian physics of semi-conservative metric theories through secular tidal effects in satellite gradiometry missions

    NASA Astrophysics Data System (ADS)

    Qiang, Li-E.; Xu, Peng

    2016-04-01

    The existence of relativistic secular tidal effects along orbit motions will largely improve the measurement accuracies of relativistic gravitational gradients with orbiting gradiometers. With the continuous advances in technologies related to gradiometry and the improvements in their resolutions, it is feasible for future satellite gradiometry missions to carry out precision relativistic experiments and impose constraints on modern theories of gravity. In this work, we study the theoretical principles of measuring directly the secular post-Newtonian (PN) tidal effects in semi-conservative metric theories with satellite gradiometry missions. The isolations of the related PN parameters in the readouts of an orbiting three-axis gradiometer is discussed.

  6. Metricize Yourself

    NASA Astrophysics Data System (ADS)

    Falbo, Maria K.

    2006-12-01

    In lab and homework, students should check whether or not their quantitative answers to physics questions make sense in the context of the problem. Unfortunately it is still the case in the US that many students don’t have a “feel” for oC, kg, cm, liters or Newtons. This problem contributes to the inability of students to check answers. It is also the case that just “going over” the tables in the text can be boring and dry. In this talk I’ll demonstrate some classroom activities that can be used throughout the year to give students a metric context in which quantitative answers can be interpreted.

  7. Prediction of junior faculty success in biomedical research: comparison of metrics and effects of mentoring programs

    PubMed Central

    Houmanfar, Ramona; Candido, Amber

    2015-01-01

    Measuring and predicting the success of junior faculty is of considerable interest to faculty, academic institutions, funding agencies and faculty development and mentoring programs. Various metrics have been proposed to evaluate and predict research success and impact, such as the h-index, and modifications of this index, but they have not been evaluated and validated side-by-side in a rigorous empirical study. Our study provides a retrospective analysis of how well bibliographic metrics and formulas (numbers of total, first- and co-authored papers in the PubMed database, numbers of papers in high-impact journals) would have predicted the success of biomedical investigators (n = 40) affiliated with the University of Nevada, Reno, prior to, and after completion of significant mentoring and research support (through funded Centers of Biomedical Research Excellence, COBREs), or lack thereof (unfunded COBREs), in 2000–2014. The h-index and similar indices had little prognostic value. Publishing as mid- or even first author in only one high-impact journal was poorly correlated with future success. Remarkably, junior investigators with >6 first-author papers within 10 years were significantly (p < 0.0001) more likely (93%) to succeed than those with ≤6 first-author papers (4%), regardless of the journal’s impact factor. The benefit of COBRE-support increased the success rate of junior faculty approximately 3-fold, from 15% to 47%. Our work defines a previously neglected set of metrics that predicted the success of junior faculty with high fidelity—thus defining the pool of faculty that will benefit the most from faculty development programs such as COBREs. PMID:26421238

  8. Handbook of aircraft noise metrics

    NASA Astrophysics Data System (ADS)

    Bennett, R. L.; Pearsons, K. S.

    1981-03-01

    Information is presented on 22 noise metrics that are associated with the measurement and prediction of the effects of aircraft noise. Some of the instantaneous frequency weighted sound level measures, such as A-weighted sound level, are used to provide multiple assessment of the aircraft noise level. Other multiple event metrics, such as day-night average sound level, were designed to relate sound levels measured over a period of time to subjective responses in an effort to determine compatible land uses and aid in community planning. The various measures are divided into: (1) instantaneous sound level metrics; (2) duration corrected single event metrics; (3) multiple event metrics; and (4) speech communication metrics. The scope of each measure is examined in terms of its: definition, purpose, background, relationship to other measures, calculation method, example, equipment, references, and standards.

  9. Handbook of aircraft noise metrics

    NASA Technical Reports Server (NTRS)

    Bennett, R. L.; Pearsons, K. S.

    1981-01-01

    Information is presented on 22 noise metrics that are associated with the measurement and prediction of the effects of aircraft noise. Some of the instantaneous frequency weighted sound level measures, such as A-weighted sound level, are used to provide multiple assessment of the aircraft noise level. Other multiple event metrics, such as day-night average sound level, were designed to relate sound levels measured over a period of time to subjective responses in an effort to determine compatible land uses and aid in community planning. The various measures are divided into: (1) instantaneous sound level metrics; (2) duration corrected single event metrics; (3) multiple event metrics; and (4) speech communication metrics. The scope of each measure is examined in terms of its: definition, purpose, background, relationship to other measures, calculation method, example, equipment, references, and standards.

  10. Conversion to the Metric System

    ERIC Educational Resources Information Center

    Crunkilton, John C.; Lee, Jasper S.

    1974-01-01

    The authors discuss background information about the metric system and explore the effect of metrication of agriculture in areas such as equipment calibration, chemical measurement, and marketing of agricultural products. Suggestions are given for possible leadership roles and approaches that agricultural education might take in converting to the…

  11. The metric system: An introduction

    SciTech Connect

    Lumley, S.M.

    1995-05-01

    On July 13, 1992, Deputy Director Duane Sewell restated the Laboratory`s policy on conversion to the metric system which was established in 1974. Sewell`s memo announced the Laboratory`s intention to continue metric conversion on a reasonable and cost effective basis. Copies of the 1974 and 1992 Administrative Memos are contained in the Appendix. There are three primary reasons behind the Laboratory`s conversion to the metric system. First, Public Law 100-418, passed in 1988, states that by the end of fiscal year 1992 the Federal Government must begin using metric units in grants, procurements, and other business transactions. Second, on July 25, 1991, President George Bush signed Executive Order 12770 which urged Federal agencies to expedite conversion to metric units. Third, the contract between the University of California and the Department of Energy calls for the Laboratory to convert to the metric system. Thus, conversion to the metric system is a legal requirement and a contractual mandate with the University of California. Public Law 100-418 and Executive Order 12770 are discussed in more detail later in this section, but first they examine the reasons behind the nation`s conversion to the metric system. The second part of this report is on applying the metric system.

  12. The metric system: An introduction

    NASA Astrophysics Data System (ADS)

    Lumley, Susan M.

    On 13 Jul. 1992, Deputy Director Duane Sewell restated the Laboratory's policy on conversion to the metric system which was established in 1974. Sewell's memo announced the Laboratory's intention to continue metric conversion on a reasonable and cost effective basis. Copies of the 1974 and 1992 Administrative Memos are contained in the Appendix. There are three primary reasons behind the Laboratory's conversion to the metric system. First, Public Law 100-418, passed in 1988, states that by the end of fiscal year 1992 the Federal Government must begin using metric units in grants, procurements, and other business transactions. Second, on 25 Jul. 1991, President George Bush signed Executive Order 12770 which urged Federal agencies to expedite conversion to metric units. Third, the contract between the University of California and the Department of Energy calls for the Laboratory to convert to the metric system. Thus, conversion to the metric system is a legal requirement and a contractual mandate with the University of California. Public Law 100-418 and Executive Order 12770 are discussed in more detail later in this section, but first they examine the reasons behind the nation's conversion to the metric system. The second part of this report is on applying the metric system.

  13. Quality metrics for product defectiveness at KCD

    SciTech Connect

    Grice, J.V.

    1993-07-01

    Metrics are discussed for measuring and tracking product defectiveness at AlliedSignal Inc., Kansas City Division (KCD). Three new metrics, the metric (percent defective) that preceded the new metrics, and several alternatives are described. The new metrics, Percent Parts Accepted, Percent Parts Accepted Trouble Free, and Defects Per Million Observations, (denoted by PPA, PATF, and DPMO, respectively) were implemented for KCD-manufactured product and purchased material in November 1992. These metrics replace the percent defective metric that had been used for several years. The PPA and PATF metrics primarily measure quality performance while DPMO measures the effects of continuous improvement activities. The new metrics measure product quality in terms of product defectiveness observed only during the inspection process. The metrics were originally developed for purchased product and were adapted to manufactured product to provide a consistent set of metrics plant- wide. The new metrics provide a meaningful tool to measure the quantity of product defectiveness in terms of the customer`s requirements and expectations for quality. Many valid metrics are available and all will have deficiencies. These three metrics are among the least sensitive to problems and are easily understood. They will serve as good management tools for KCD in the foreseeable future until new flexible data systems and reporting procedures can be implemented that can provide more detailed and accurate metric computations.

  14. Engineering performance metrics

    NASA Astrophysics Data System (ADS)

    Delozier, R.; Snyder, N.

    1993-03-01

    Implementation of a Total Quality Management (TQM) approach to engineering work required the development of a system of metrics which would serve as a meaningful management tool for evaluating effectiveness in accomplishing project objectives and in achieving improved customer satisfaction. A team effort was chartered with the goal of developing a system of engineering performance metrics which would measure customer satisfaction, quality, cost effectiveness, and timeliness. The approach to developing this system involved normal systems design phases including, conceptual design, detailed design, implementation, and integration. The lessons teamed from this effort will be explored in this paper. These lessons learned may provide a starting point for other large engineering organizations seeking to institute a performance measurement system accomplishing project objectives and in achieving improved customer satisfaction. To facilitate this effort, a team was chartered to assist in the development of the metrics system. This team, consisting of customers and Engineering staff members, was utilized to ensure that the needs and views of the customers were considered in the development of performance measurements. The development of a system of metrics is no different than the development of any type of system. It includes the steps of defining performance measurement requirements, measurement process conceptual design, performance measurement and reporting system detailed design, and system implementation and integration.

  15. Engineering performance metrics

    SciTech Connect

    DeLozier, R. ); Snyder, N. )

    1993-03-31

    Implementation of a Total Quality Management (TQM) approach to engineering work required the development of a system of metrics which would serve as a meaningful msinagement tool for evaluating effectiveness in accomplishing project objectives and in achieving improved customer satisfaction. A team effort was chartered with the goal of developing a system of engineering performance metrics which would measure customer satisfaction, quality, cost effectiveness, and timeliness. The approach to developing this system involved normal systems design phases including, conceptual design, detailed design, implementation, and integration. The lessons teamed from this effort will be explored in this paper. These lessons teamed may provide a starting point for other large engineering organizations seeking to institute a performance measurement system accomplishing project objectives and in achieving improved customer satisfaction. To facilitate this effort, a team was chartered to assist in the development of the metrics system. This team, consisting of customers and Engineering staff members, was utilized to ensure that the needs and views of the customers were considered in the development of performance measurements. The development of a system of metrics is no different than the development of any type of system. It includes the steps of defining performance measurement requirements, measurement process conceptual design, performance measurement and reporting system detailed design, and system implementation and integration.

  16. Make It Metric.

    ERIC Educational Resources Information Center

    Camilli, Thomas

    Measurement is perhaps the most frequently used form of mathematics. This book presents activities for learning about the metric system designed for upper intermediate and junior high levels. Discussions include: why metrics, history of metrics, changing to a metric world, teaching tips, and formulas. Activities presented are: metrics all around…

  17. Alternative ozone metrics and daily mortality in Suzhou: the China Air Pollution and Health Effects Study (CAPES).

    PubMed

    Yang, Chunxue; Yang, Haibing; Guo, Shu; Wang, Zongshuang; Xu, Xiaohui; Duan, Xiaoli; Kan, Haidong

    2012-06-01

    Controversy remains regarding the relationship between various metrics of ozone (O(3)) and mortality. In China, the largest developing country, there have been few studies investigating the acute effect of O(3) on death. We used three exposure metrics of O(3) (1-hour maximum, maximum 8-hour average and 24-hour average) to examine its short-term association with daily mortality in Suzhou, China. We used a Generalized Additive Model (GAM) with penalized splines to analyze the mortality, O(3), and covariate data. We examined the association by season, age group, sex and educational level. We found that the current level of O(3) in Suzhou is associated with death rates from all causes and cardiovascular diseases. Among various metrics of O(3), maximum 8-hour average and 1-hour maximum concentrations seem to be more strongly associated with increased mortality rate compared to 24-hour average concentrations. Using maximum 8-hour average, an inter-quartile range increase of 2-day average O(3) (lag 01) corresponds to 2.15% (95%CI, 0.36 to 3.93), 4.47% (95%CI, 1.43 to 7.51), -1.85% (95%CI, -6.91 to 3.22) increase in all-cause, cardiovascular, and respiratory mortality, respectively. The associations between O(3) and daily mortality appeared to be more evident in the cool season than in the warm season. In conclusion, maximum 8-hour average and 1-hour maximum concentrations of O(3) are associated with daily mortality in Suzhou. Our analyses strengthen the rationale for further limiting levels of O(3) pollution in the city. PMID:22521098

  18. The International Safeguards Technology Base: How is the Patient Doing? An Exploration of Effective Metrics

    SciTech Connect

    Schanfein, Mark; Gouveia, Fernando; Crawford, Cary E.; Pickett, Chris J.; Jay, Jeffrey

    2010-07-15

    The term “Technology Base” is commonly used but what does it mean? Is there a common understanding of the components that comprise a technology base? Does a formal process exist to assess the health of a given technology base? These are important questions the relevance of which is even more pressing given the USDOE/NNSA initiatives to strengthen the safeguards technology base through investments in research & development and human capital development. Accordingly, the authors will establish a high-level framework to define and understand what comprises a technology base. Potential goal-driven metrics to assess the health of a technology base will also be explored, such as linear demographics and resource availability, in the hope that they can be used to better understand and improve the health of the U.S. safeguards technology base. Finally, through the identification of such metrics, the authors will offer suggestions and highlight choices for addressing potential shortfalls. Introduction The U.S. safeguards technology base got its start almost half a century ago in the nuclear weapons program of the U.S. Department of Energy/National Nuclear Security Administration (DOE/NNSA) and their predecessors: AEC & ERDA. Due to nuclear materials’ strategic importance and value, and the risk associated with the public’s and worker’s health and the potential for theft, significant investments were made to develop techniques to measure nuclear materials using both destructive assay (DA) and non-destructive assay (NDA). Major investment within the U.S. DOE Domestic Safeguards Program continued over the next three decades, resulting in continuous improvements in the state-of-the-art of these techniques. This was particularly true in the area of NDA with its ability to use gamma rays, neutrons, and heat to identify and quantify nuclear materials without the need to take direct samples of the material. Most of these techniques were commercialized and transferred to

  19. Effective contrast of colored stimuli in the mesopic range: a metric for perceived contrast based on achromatic luminance contrast.

    PubMed

    Walkey, Helen C; Barbur, John L; Harlow, J Alister; Hurden, Antony; Moorhead, Ian R; Taylor, Julie A F

    2005-01-01

    Little is known about how color signals and cone- and rod-based luminance signals contribute to perceived contrast in the mesopic range. In this study the perceived contrast of colored, mesopic stimuli was matched with that of spatially equivalent achromatic stimuli. The objective was to develop a metric for perceived contrast in the mesopic range in terms of an equivalent achromatic luminance contrast, referred to here as effective contrast. Stimulus photopic luminance contrast, scotopic luminance contrast, and chromatic difference from the background all contributed to effective contrast over the mid-mesopic range, but their contributions were not independent and varied markedly with background luminance. Surprisingly, color made a significant contribution to effective contrast from 10 to approximately 0.003 cd m(-2). A model describing this relationship is introduced (R2 = 0.89) and compared with predictions of mesopic luminance contrast obtained from a number of models proposed as systems of mesopic photometry. PMID:15669611

  20. Effective contrast of colored stimuli in the mesopic range: a metric for perceived contrast based on achromatic luminance contrast

    NASA Astrophysics Data System (ADS)

    Walkey, Helen C.; Barbur, John L.; Harlow, J. Alister; Hurden, Antony; Moorhead, Ian R.; Taylor, Julie A. F.

    2005-01-01

    Little is known about how color signals and cone- and rod-based luminance signals contribute to perceived contrast in the mesopic range. In this study the perceived contrast of colored, mesopic stimuli was matched with that of spatially equivalent achromatic stimuli. The objective was to develop a metric for perceived contrast in the mesopic range in terms of an equivalent achromatic luminance contrast, referred to here as effective contrast. Stimulus photopic luminance contrast, scotopic luminance contrast, and chromatic difference from the background all contributed to effective contrast over the mid-mesopic range, but their contributions were not independent and varied markedly with background luminance. Surprisingly, color made a significant contribution to effective contrast from 10 to approximately 0.003 cd m-2. A model describing this relationship is introduced (R2=0.89) and compared with predictions of mesopic luminance contrast obtained from a number of models proposed as systems of mesopic photometry.

  1. Terrain effects in resistivity and magnetotelluric surveys

    SciTech Connect

    Holcombe, H.T.

    1982-12-01

    A three-dimensional finite element computer algorithm which can accommodate arbitrarily complex topography and subsurface structure, has been developed to model the resistivity response of the earth. The algorithm has undergone extensive evaluation and is believed to provide accurate results for realistic earth models. Testing included comparison to scale model measurements, analytically calculated solutions, and results calculated numerically by other independent means. Computer modeling experiments have demonstrated that it is possible to remove the effect of topography on resistivity data under conditions where such effects dominate the response. This can be done without resorting to lengthy and costly trial and error computer modeling. After correction, the data can be interpreted with confidence that the anomalies are due only to subsurface structure. The results of case studies on resistivity field data measured in high relief topography are discussed.

  2. NASA metrication activities

    NASA Technical Reports Server (NTRS)

    Vlannes, P. N.

    1978-01-01

    NASA's organization and policy for metrification, history from 1964, NASA participation in Federal agency activities, interaction with nongovernmental metrication organizations, and the proposed metrication assessment study are reviewed.

  3. Effecting Change in a Resistant Organization.

    ERIC Educational Resources Information Center

    Caldwell, Patricia F.; Gould, Edward

    In an effort to overcome organizational resistance to change, Victor Valley College, in Victorville, California, has utilized a seven-part strategy to enable leaders to empower others and effect change. Step 1 requires the development of a visionary plan, so that changes have a meaningful context. Step 2 calls for an assessment of the campus…

  4. Software Quality Assurance Metrics

    NASA Technical Reports Server (NTRS)

    McRae, Kalindra A.

    2004-01-01

    Software Quality Assurance (SQA) is a planned and systematic set of activities that ensures conformance of software life cycle processes and products conform to requirements, standards and procedures. In software development, software quality means meeting requirements and a degree of excellence and refinement of a project or product. Software Quality is a set of attributes of a software product by which its quality is described and evaluated. The set of attributes includes functionality, reliability, usability, efficiency, maintainability, and portability. Software Metrics help us understand the technical process that is used to develop a product. The process is measured to improve it and the product is measured to increase quality throughout the life cycle of software. Software Metrics are measurements of the quality of software. Software is measured to indicate the quality of the product, to assess the productivity of the people who produce the product, to assess the benefits derived from new software engineering methods and tools, to form a baseline for estimation, and to help justify requests for new tools or additional training. Any part of the software development can be measured. If Software Metrics are implemented in software development, it can save time, money, and allow the organization to identify the caused of defects which have the greatest effect on software development. The summer of 2004, I worked with Cynthia Calhoun and Frank Robinson in the Software Assurance/Risk Management department. My task was to research and collect, compile, and analyze SQA Metrics that have been used in other projects that are not currently being used by the SA team and report them to the Software Assurance team to see if any metrics can be implemented in their software assurance life cycle process.

  5. How Robust Are Malaria Parasite Clearance Rates as Indicators of Drug Effectiveness and Resistance?

    PubMed

    Hastings, Ian M; Kay, Katherine; Hodel, Eva Maria

    2015-10-01

    Artemisinin-based combination therapies (ACTs) are currently the first-line drugs for treating uncomplicated falciparum malaria, the most deadly of the human malarias. Malaria parasite clearance rates estimated from patients' blood following ACT treatment have been widely adopted as a measure of drug effectiveness and as surveillance tools for detecting the presence of potential artemisinin resistance. This metric has not been investigated in detail, nor have its properties or potential shortcomings been identified. Herein, the pharmacology of drug treatment, parasite biology, and human immunity are combined to investigate the dynamics of parasite clearance following ACT. This approach parsimoniously recovers the principal clinical features and dynamics of clearance. Human immunity is the primary determinant of clearance rates, unless or until artemisinin killing has fallen to near-ineffective levels. Clearance rates are therefore highly insensitive metrics for surveillance that may lead to overconfidence, as even quite substantial reductions in drug sensitivity may not be detected as lower clearance rates. Equally serious is the use of clearance rates to quantify the impact of ACT regimen changes, as this strategy will plausibly miss even very substantial increases in drug effectiveness. In particular, the malaria community may be missing the opportunity to dramatically increase ACT effectiveness through regimen changes, particularly through a switch to twice-daily regimens and/or increases in artemisinin dosing levels. The malaria community therefore appears overreliant on a single metric of drug effectiveness, the parasite clearance rate, that has significant and serious shortcomings. PMID:26239987

  6. How Robust Are Malaria Parasite Clearance Rates as Indicators of Drug Effectiveness and Resistance?

    PubMed Central

    Kay, Katherine; Hodel, Eva Maria

    2015-01-01

    Artemisinin-based combination therapies (ACTs) are currently the first-line drugs for treating uncomplicated falciparum malaria, the most deadly of the human malarias. Malaria parasite clearance rates estimated from patients' blood following ACT treatment have been widely adopted as a measure of drug effectiveness and as surveillance tools for detecting the presence of potential artemisinin resistance. This metric has not been investigated in detail, nor have its properties or potential shortcomings been identified. Herein, the pharmacology of drug treatment, parasite biology, and human immunity are combined to investigate the dynamics of parasite clearance following ACT. This approach parsimoniously recovers the principal clinical features and dynamics of clearance. Human immunity is the primary determinant of clearance rates, unless or until artemisinin killing has fallen to near-ineffective levels. Clearance rates are therefore highly insensitive metrics for surveillance that may lead to overconfidence, as even quite substantial reductions in drug sensitivity may not be detected as lower clearance rates. Equally serious is the use of clearance rates to quantify the impact of ACT regimen changes, as this strategy will plausibly miss even very substantial increases in drug effectiveness. In particular, the malaria community may be missing the opportunity to dramatically increase ACT effectiveness through regimen changes, particularly through a switch to twice-daily regimens and/or increases in artemisinin dosing levels. The malaria community therefore appears overreliant on a single metric of drug effectiveness, the parasite clearance rate, that has significant and serious shortcomings. PMID:26239987

  7. A Dynamic Testing Complexity Metric

    NASA Technical Reports Server (NTRS)

    Voas, Jeffrey

    1991-01-01

    This paper introduces a dynamic metric that is based on the estimated ability of a program to withstand the effects of injected "semantic mutants" during execution by computing the same function as if the semantic mutants had not been injected. Semantic mutants include: (1) syntactic mutants injected into an executing program and (2) randomly selected values injected into an executing program's internal states. The metric is a function of a program, the method used for injecting these two types of mutants, and the program's input distribution; this metric is found through dynamic executions of the program. A program's ability to withstand the effects of injected semantic mutants by computing the same function when executed is then used as a tool for predicting the difficulty that will be incurred during random testing to reveal the existence of faults, i.e., the metric suggests the likelihood that a program will expose the existence of faults during random testing assuming faults were to exist. If the metric is applied to a module rather than to a program, the metric can be used to guide the allocation of testing resources among a program's modules. In this manner the metric acts as a white-box testing tool for determining where to concentrate testing resources. Index Terms: Revealing ability, random testing, input distribution, program, fault, failure.

  8. Measuring in Metric.

    ERIC Educational Resources Information Center

    Sorenson, Juanita S.

    Eight modules for an in-service course on metric education for elementary teachers are included in this document. The modules are on an introduction to the metric system, length and basic prefixes, volume, mass, temperature, relationships within the metric system, and metric and English system relationships. The eighth one is on developing a…

  9. Joint learning of labels and distance metric.

    PubMed

    Liu, Bo; Wang, Meng; Hong, Richang; Zha, Zhengjun; Hua, Xian-Sheng

    2010-06-01

    Machine learning algorithms frequently suffer from the insufficiency of training data and the usage of inappropriate distance metric. In this paper, we propose a joint learning of labels and distance metric (JLLDM) approach, which is able to simultaneously address the two difficulties. In comparison with the existing semi-supervised learning and distance metric learning methods that focus only on label prediction or distance metric construction, the JLLDM algorithm optimizes the labels of unlabeled samples and a Mahalanobis distance metric in a unified scheme. The advantage of JLLDM is multifold: 1) the problem of training data insufficiency can be tackled; 2) a good distance metric can be constructed with only very few training samples; and 3) no radius parameter is needed since the algorithm automatically determines the scale of the metric. Extensive experiments are conducted to compare the JLLDM approach with different semi-supervised learning and distance metric learning methods, and empirical results demonstrate its effectiveness. PMID:19963702

  10. The Effects of Three Instructional Strategies on Prospective Teachers' Ability to Transfer Estimation Skills for Metric Length and Area.

    ERIC Educational Resources Information Center

    Attivo, Barbara; Trueblood, Cecil R.

    The purpose of this study was to investigate how the nature of metric estimation skill instruction affects prospective elementary and special education teachers' abilities to estimate metric length, area, and volume. Four types of estimation skills were identified by an estimation matrix. Three instructional strategies were selected: (1) a…

  11. Resistive switching effect in titanium oxides.

    PubMed

    Tang, Zhensen; Chi, Yaqing; Fang, Liang; Liu, Rulin; Yi, Xun

    2014-02-01

    Resistive switching (RS) phenomena have been vigorously investigated in a large variety of materials and highlighted for its preeminent potential for the future nonvolatile semiconductor memory applications or reconfigurable logic circuits. Among the various resistive switching materials, the binary metal oxides demonstrate more advantageous for micro- or nano-electronics applications due to their simpler fabrication process and compatibility with conventional CMOS technology, though the mechanisms are controversial due to the diversity of RS effects. This review mainly focuses on the current understanding of the microscopic nature of RS in titanium oxides, in which the working mechanisms can be categorized into thermochemical metallization mechanism, valence change mechanism, and electrostatic/electronic mechanism. The approaches developed to investigate the RS and the specific switching processes related to different mechanisms are addressed. Since titanium oxides are oxygen-vacancy doped semiconductors, the role of defects is analyzed in detail and possible effective strategies to improve the performance of RS are addressed. PMID:24749437

  12. Multi-site study of diffusion metric variability: characterizing the effects of site, vendor, field strength, and echo time using the histogram distance

    NASA Astrophysics Data System (ADS)

    Helmer, K. G.; Chou, M.-C.; Preciado, R. I.; Gimi, B.; Rollins, N. K.; Song, A.; Turner, J.; Mori, S.

    2016-03-01

    MRI-based multi-site trials now routinely include some form of diffusion-weighted imaging (DWI) in their protocol. These studies can include data originating from scanners built by different vendors, each with their own set of unique protocol restrictions, including restrictions on the number of available gradient directions, whether an externally generated list of gradient directions can be used, and restrictions on the echo time (TE). One challenge of multi-site studies is to create a common imaging protocol that will result in a reliable and accurate set of diffusion metrics. The present study describes the effect of site, scanner vendor, field strength, and TE on two common metrics: the first moment of the diffusion tensor field (mean diffusivity, MD), and the fractional anisotropy (FA). We have shown in earlier work that ROI metrics and the mean of MD and FA histograms are not sufficiently sensitive for use in site characterization. Here we use the distance between whole brain histograms of FA and MD to investigate within- and between-site effects. We concluded that the variability of DTI metrics due to site, vendor, field strength, and echo time could influence the results in multi-center trials and that histogram distance is sensitive metrics for each of these variables.

  13. More Than Numbers: Effects of Social Media Virality Metrics on Intention to Help Unknown Others in the Context of Bone Marrow Donation.

    PubMed

    Lee-Won, Roselyn J; Abo, Melissa M; Na, Kilhoe; White, Tiffany N

    2016-06-01

    A bone marrow transplant is often the only key to recovery and survival for patients suffering from blood cancers. Social media platforms have allowed nonprofit organizations as well as family members and friends of patients in need of a matching donor to make their solicitation messages go viral and reach out to the broadest possible audience to increase the likelihood of finding a matching donor. Noting that social media audiences are exposed not only to the content of a social media message but also to the metrics representing the virality of the message (i.e., how many times the content has been shared), we conducted an online experiment to investigate the effects of virality metrics on perceived social norms and behavioral intention to join a bone marrow registry. In doing so, we considered the potential moderating role of perceived threat posed by blood cancers. The experiment was conducted with 152 participants who met the general eligibility guidelines set by the National Marrow Donor Program (NMDP). The results of the experiment showed that exposure to high virality metrics led to greater perceived injunctive norms. The results also revealed that the effect of virality metrics on perceived injunctive norms was significant among those perceiving low levels of blood cancer threat. Furthermore, the results demonstrated that high virality metrics led to greater intention to join a bone marrow registry through perceived injunctive norms only when perceived threat of blood cancers was low. Theoretical and practical implications of these findings are discussed. PMID:27327068

  14. FY 2011 4th Quarter Metric: Estimate of Future Aerosol Direct and Indirect Effects

    SciTech Connect

    Koch, D

    2011-09-21

    The global and annual mean aerosol direct and indirect effects, relative to 1850 conditions, estimated from CESM simulations are 0.02 W m-2 and -0.39 W m-2, respectively, for emissions in year 2100 under the IPCC RCP8.5 scenario. The indirect effect is much smaller than that for 2000 emissions because of much smaller SO2 emissions in 2100; the direct effects are small due to compensation between warming by black carbon and cooling by sulfate.

  15. Aquatic Acoustic Metrics Interface

    Energy Science and Technology Software Center (ESTSC)

    2012-12-18

    Fishes and marine mammals may suffer a range of potential effects from exposure to intense underwater sound generated by anthropogenic activities such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording (USR) devices have been built to acquire samples of the underwater sound generated by anthropogenic activities. Software becomes indispensable for processing and analyzing the audio files recorded by these USRs. The new Aquatic Acoustic Metrics Interface Utility Software (AAMI) is specificallymore » designed for analysis of underwater sound recordings to provide data in metrics that facilitate evaluation of the potential impacts of the sound on aquatic animals. In addition to the basic functions, such as loading and editing audio files recorded by USRs and batch processing of sound files, the software utilizes recording system calibration data to compute important parameters in physical units. The software also facilitates comparison of the noise sound sample metrics with biological measures such as audiograms of the sensitivity of aquatic animals to the sound, integrating various components into a single analytical frame.« less

  16. Rotational clutter metric

    NASA Astrophysics Data System (ADS)

    Salem, Salem; Halford, Carl; Moyer, Steve; Gundy, Matthew

    2009-08-01

    A new approach to linear discriminant analysis (LDA), called orthogonal rotational LDA (ORLDA) is presented. Using ORLDA and properly accounting for target size allowed development of a new clutter metric that is based on the Laplacian pyramid (LP) decomposition of clutter images. The new metric achieves correlation exceeding 98% with expert human labeling of clutter levels in a set of 244 infrared images. Our clutter metric is based on the set of weights for the LP levels that best classify images into clutter levels as manually classified by an expert human observer. LDA is applied as a preprocessing step to classification. LDA suffers from a few limitations in this application. Therefore, we propose a new approach to LDA, called ORLDA, using orthonormal geometric rotations. Each rotation brings the LP feature space closer to the LDA solution while retaining orthogonality in the feature space. To understand the effects of target size on clutter, we applied ORLDA at different target sizes. The outputs are easily related because they are functions of orthogonal rotation angles. Finally, we used Bayesian decision theory to learn class boundaries for clutter levels at different target sizes.

  17. Aquatic Acoustic Metrics Interface

    SciTech Connect

    2012-12-18

    Fishes and marine mammals may suffer a range of potential effects from exposure to intense underwater sound generated by anthropogenic activities such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording (USR) devices have been built to acquire samples of the underwater sound generated by anthropogenic activities. Software becomes indispensable for processing and analyzing the audio files recorded by these USRs. The new Aquatic Acoustic Metrics Interface Utility Software (AAMI) is specifically designed for analysis of underwater sound recordings to provide data in metrics that facilitate evaluation of the potential impacts of the sound on aquatic animals. In addition to the basic functions, such as loading and editing audio files recorded by USRs and batch processing of sound files, the software utilizes recording system calibration data to compute important parameters in physical units. The software also facilitates comparison of the noise sound sample metrics with biological measures such as audiograms of the sensitivity of aquatic animals to the sound, integrating various components into a single analytical frame.

  18. NASA metric transition plan

    NASA Astrophysics Data System (ADS)

    NASA science publications have used the metric system of measurement since 1970. Although NASA has maintained a metric use policy since 1979, practical constraints have restricted actual use of metric units. In 1988, an amendment to the Metric Conversion Act of 1975 required the Federal Government to adopt the metric system except where impractical. In response to Public Law 100-418 and Executive Order 12770, NASA revised its metric use policy and developed this Metric Transition Plan. NASA's goal is to use the metric system for program development and functional support activities to the greatest practical extent by the end of 1995. The introduction of the metric system into new flight programs will determine the pace of the metric transition. Transition of institutional capabilities and support functions will be phased to enable use of the metric system in flight program development and operations. Externally oriented elements of this plan will introduce and actively support use of the metric system in education, public information, and small business programs. The plan also establishes a procedure for evaluating and approving waivers and exceptions to the required use of the metric system for new programs. Coordination with other Federal agencies and departments (through the Interagency Council on Metric Policy) and industry (directly and through professional societies and interest groups) will identify sources of external support and minimize duplication of effort.

  19. NASA metric transition plan

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA science publications have used the metric system of measurement since 1970. Although NASA has maintained a metric use policy since 1979, practical constraints have restricted actual use of metric units. In 1988, an amendment to the Metric Conversion Act of 1975 required the Federal Government to adopt the metric system except where impractical. In response to Public Law 100-418 and Executive Order 12770, NASA revised its metric use policy and developed this Metric Transition Plan. NASA's goal is to use the metric system for program development and functional support activities to the greatest practical extent by the end of 1995. The introduction of the metric system into new flight programs will determine the pace of the metric transition. Transition of institutional capabilities and support functions will be phased to enable use of the metric system in flight program development and operations. Externally oriented elements of this plan will introduce and actively support use of the metric system in education, public information, and small business programs. The plan also establishes a procedure for evaluating and approving waivers and exceptions to the required use of the metric system for new programs. Coordination with other Federal agencies and departments (through the Interagency Council on Metric Policy) and industry (directly and through professional societies and interest groups) will identify sources of external support and minimize duplication of effort.

  20. Effect of nonsymmetrical flow resistance upon orifice impedance resistance

    NASA Technical Reports Server (NTRS)

    Posey, J. W.; Compton, K. J.

    1974-01-01

    A nonreactive orifice in an infinite baffle is analyzed. The pressure difference delta across the orifice varies sinusoidally with amplitude 1.0 and average value -P. The orifice resistance, delta p is discontinuous at zero velocity and exhibits the constant values R sub + and R sub - for u 0 and u 0, respectively. The resultant velocity has power in all harmonics of the excitation frequency. A quasi-linear resistance is defined and found to be relatively insensitive to the presence or absence of a resonant backing cavity; however, it does vary from 1.33 R sub + to 0.67 R sub + for a resistance ratio R sub +/R sub - between 0.5 and 2.0.

  1. Mining metrics for buried treasure

    NASA Astrophysics Data System (ADS)

    Konkowski, D. A.; Helliwell, T. M.

    2006-06-01

    The same but different: That might describe two metrics. On the surface CLASSI may show two metrics are locally equivalent, but buried beneath may be a wealth of further structure. This was beautifully described in a paper by Malcolm MacCallum in 1998. Here I will illustrate the effect with two flat metrics — one describing ordinary Minkowski spacetime and the other describing a threeparameter family of Gal'tsov-Letelier-Tod spacetimes. I will dig out the beautiful hidden classical singularity structure of the latter (a structure first noticed by Tod in 1994) and then show how quantum considerations can illuminate the riches. I will then discuss how quantum structure can help us understand classical singularities and metric parameters in a variety of exact solutions mined from the Exact Solutions book.

  2. Using Social Network Metrics to Assess the Effectiveness of Broad Based Admission Practices

    ERIC Educational Resources Information Center

    Dawson, Shane; Macfadyen, Leah; Lockyer, Lori; Mazzochi-Jones, David

    2011-01-01

    Notions of what it is to be knowledgeable and skilled in one's profession have evolved in recent decades. For instance, medical practitioners are expected to think critically and creatively, communicate effectively, and to be a professional and community leader. While these attributes have always been well regarded, it is only relatively recently…

  3. Effects of surface pressures and streamline metrics on the calculation of laminar heating rates

    NASA Technical Reports Server (NTRS)

    Riley, Christopher J.; Dejarnette, Fred R.; Zoby, Vincent

    1988-01-01

    The effect of streamline geometry and pressure distributions on surface heating rates is examined for slender, spherically blunted cones. The modifications to the approximate aeroheating code include a curve fit of pressures computed by an Euler solution over a range of Mach numbers and cone angles. The streamline geometry is then found using the surface pressures and inviscid surface properties. Previously, streamlines were determined using the inviscid properties at the edge of the boundary layer when accounting for the effects of entropy-layer swallowing. Streamline calculations are now based on inviscid surface conditions rather than boundary-layer edge properties. However, the heating rates are calculated using inviscid properties at the edge of the boundary layer. Resulting heating rates compare favorably with solutions from the viscous-shock-layer equations.

  4. Chronic effects of temperature on mortality in the Southeastern USA using satellite-based exposure metrics

    NASA Astrophysics Data System (ADS)

    Shi, Liuhua; Liu, Pengfei; Wang, Yan; Zanobetti, Antonella; Kosheleva, Anna; Koutrakis, Petros; Schwartz, Joel

    2016-07-01

    Climate change may affect human health, particularly for elderly individuals who are vulnerable to temperature changes. While many studies have investigated the acute effects of heat, only a few have dealt with the chronic ones. We have examined the effects of seasonal temperatures on survival of the elderly in the Southeastern USA, where a large fraction of subpopulation resides. We found that both seasonal mean temperature and its standard deviation (SD) affected long-term survival among the 13 million Medicare beneficiaries (aged 65+) in this region during 2000–2013. A 1 °C increase in summer mean temperature corresponded to an increase of 2.5% in death rate. Whereas, 1 °C increase in winter mean temperature was associated with a decrease of 1.5%. Increases in seasonal temperature SD also influence mortality. We decomposed seasonal mean temperature and its temperature SD into long-term geographic contrasts between ZIP codes and annual anomalies within ZIP code. Effect modifications by different subgroups were also examined to find out whether certain individuals are more vulnerable. Our findings will be critical to future efforts assessing health risks related to the future climate change.

  5. Chronic effects of temperature on mortality in the Southeastern USA using satellite-based exposure metrics.

    PubMed

    Shi, Liuhua; Liu, Pengfei; Wang, Yan; Zanobetti, Antonella; Kosheleva, Anna; Koutrakis, Petros; Schwartz, Joel

    2016-01-01

    Climate change may affect human health, particularly for elderly individuals who are vulnerable to temperature changes. While many studies have investigated the acute effects of heat, only a few have dealt with the chronic ones. We have examined the effects of seasonal temperatures on survival of the elderly in the Southeastern USA, where a large fraction of subpopulation resides. We found that both seasonal mean temperature and its standard deviation (SD) affected long-term survival among the 13 million Medicare beneficiaries (aged 65+) in this region during 2000-2013. A 1 °C increase in summer mean temperature corresponded to an increase of 2.5% in death rate. Whereas, 1 °C increase in winter mean temperature was associated with a decrease of 1.5%. Increases in seasonal temperature SD also influence mortality. We decomposed seasonal mean temperature and its temperature SD into long-term geographic contrasts between ZIP codes and annual anomalies within ZIP code. Effect modifications by different subgroups were also examined to find out whether certain individuals are more vulnerable. Our findings will be critical to future efforts assessing health risks related to the future climate change. PMID:27436237

  6. Chronic effects of temperature on mortality in the Southeastern USA using satellite-based exposure metrics

    PubMed Central

    Shi, Liuhua; Liu, Pengfei; Wang, Yan; Zanobetti, Antonella; Kosheleva, Anna; Koutrakis, Petros; Schwartz, Joel

    2016-01-01

    Climate change may affect human health, particularly for elderly individuals who are vulnerable to temperature changes. While many studies have investigated the acute effects of heat, only a few have dealt with the chronic ones. We have examined the effects of seasonal temperatures on survival of the elderly in the Southeastern USA, where a large fraction of subpopulation resides. We found that both seasonal mean temperature and its standard deviation (SD) affected long-term survival among the 13 million Medicare beneficiaries (aged 65+) in this region during 2000–2013. A 1 °C increase in summer mean temperature corresponded to an increase of 2.5% in death rate. Whereas, 1 °C increase in winter mean temperature was associated with a decrease of 1.5%. Increases in seasonal temperature SD also influence mortality. We decomposed seasonal mean temperature and its temperature SD into long-term geographic contrasts between ZIP codes and annual anomalies within ZIP code. Effect modifications by different subgroups were also examined to find out whether certain individuals are more vulnerable. Our findings will be critical to future efforts assessing health risks related to the future climate change. PMID:27436237

  7. Effects of Efflux Pump Inhibitors on Colistin Resistance in Multidrug-Resistant Gram-Negative Bacteria.

    PubMed

    Ni, Wentao; Li, Yanjun; Guan, Jie; Zhao, Jin; Cui, Junchang; Wang, Rui; Liu, Youning

    2016-05-01

    We tested the effects of various putative efflux pump inhibitors on colistin resistance in multidrug-resistant Gram-negative bacteria. Addition of 10 mg/liter cyanide 3-chlorophenylhydrazone (CCCP) to the test medium could significantly decrease the MICs of colistin-resistant strains. Time-kill assays showed CCCP could reverse colistin resistance and inhibit the regrowth of the resistant subpopulation, especially in Acinetobacter baumannii and Stenotrophomonas maltophilia These results suggest colistin resistance in Gram-negative bacteria can be suppressed and reversed by CCCP. PMID:26953203

  8. Metrics in Career Education.

    ERIC Educational Resources Information Center

    Lindbeck, John R.

    The United States is rapidly becoming a metric nation. Industry, education, business, and government are all studying the issue of metrication to learn how they can prepare for it. The book is designed to help teachers and students in career education programs learn something about metrics. Presented in an easily understood manner, the textbook's…

  9. Metrication for the Manager.

    ERIC Educational Resources Information Center

    Benedict, John T.

    The scope of this book covers metrication management. It was created to fill the middle management need for condensed, authoritative information about the metrication process and was conceived as a working tool and a prime reference source. Written from a management point of view, it touches on virtually all aspects of metrication and highlights…

  10. Using Fish Population Metrics to Compare the Effects of Artificial Reef Density

    PubMed Central

    2015-01-01

    Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1–190 culverts. Abundances of adults and species evenness of juvenile populations differed between the years. Fish communities did not significantly differ among density categories; however, highest species richness and total abundances were observed at intermediate culvert densities and at natural reefs. Whereas the abundance of L. campechanus did not differ among density categories, mean total lengths of L. campechanus were greatest at the lower density. Our findings suggest that reefs should be deployed with intermediate patch density of 71–120 culverts in a 30-m radius to yield the highest fish abundances. PMID:26422472

  11. Publication Track Records as a Metric of Clinical Research Training Effectiveness

    PubMed Central

    Knapke, Jacqueline M.; Tsevat, Joel; Succop, Paul A.; Djawe, Kpandja; Kuhnell, Pierce; Haynes, Erin N.

    2013-01-01

    Clinical research training programs exist across the country, but no quantitative studies have been performed to evaluate the effectiveness of these programs. The goal of this study was to evaluate the success of the clinical research training program at the University of Cincinnati by comparing the publication histories of pediatric fellows who graduated from the clinical and translational research master of science (MS) degree programs between 1995 and 2011 with fellows who did not pursue an MS degree. Among 296 pediatric fellows, 44 of 54 graduates (81%) published at least 1 first-authored paper, as compared with 149 of 242 (62%) fellows who did not obtain an MS degree (p<0.01). In multivariable analysis, 3-4 years after program completion, MS graduates published more papers overall (R2=0.10) and more first-authored papers than did non-MS graduates (R2=0.04). These findings suggest that graduate training in clinical and translational research is related to an increase in research productivity as assessed by publication rates. PMID:24330690

  12. Publication track records as a metric of clinical research training effectiveness.

    PubMed

    Knapke, Jacqueline M; Tsevat, Joel; Succop, Paul A; Djawe, Kpandja; Kuhnell, Pierce; Haynes, Erin N

    2013-12-01

    Clinical research training programs exist across the country, but no quantitative studies have been performed to evaluate the effectiveness of these programs. The goal of this study was to evaluate the success of the clinical research training program at the University of Cincinnati by comparing the publication histories of pediatric fellows who graduated from the clinical and translational research Master of Science (MS) degree programs between 1995 and 2011 with fellows who did not pursue an MS degree. Among 296 pediatric fellows, 44 of 54 graduates (81%) published at least 1 first-authored paper, as compared with 149 of 242 (62%) fellows who did not obtain an MS degree (P < 0.01). In multivariable analysis, 3-4 years after program completion, MS graduates published more papers overall (R(2) = 0.10) and more first-authored papers than did non-MS graduates (R(2) = 0.04). These findings suggest that graduate training in clinical and translational research is related to an increase in research productivity as assessed by publication rates. PMID:24330690

  13. NIH grant awards as a metric of clinical and translational research training effectiveness.

    PubMed

    Knapke, Jacqueline M; Haynes, Erin N; Kuhnell, Pierce; Tsevat, Joel

    2015-02-01

    The number of clinical research training programs has increased over the past 5-10 years, but few studies have quantitatively evaluated the effectiveness of these programs. The goal of this study was to evaluate the clinical and translational research training program at the University of Cincinnati by comparing the number of National Institutes of Health grants awarded to pediatric fellows who graduated from the MS degree program between 1995 and 2013 versus fellows who did not pursue an MS degree. Among 394 pediatric fellows, 16 of 81 (20%) MS alumni were awarded at least one NIH grant, as compared with 28 of 313 (9%) fellows who did not obtain an MS degree (p < 0.02). In multivariable analysis, MS alumni were more than three times as likely to have received at least one grant than were non-MS fellows (OR = 3.5, 95% CI [1.7-7.2]; C-statistic = 0.71) and MS alumni were more likely to obtain at least one K-series (OR = 4.1, 95% CI [1.6-10.2]; C-statistic = 0.74), M-series (OR = 11.8, 95% CI [3.4-41.4]; C-statistic = 0.81), or R-series (OR = 10.1, 95% CI [2.4-42.8]; C-statistic = 0.74) grant than were non-MS fellows. These findings suggest that graduate training in clinical and translational research prepares graduates for the highly competitive field of clinical and translational research. PMID:25377275

  14. Effect of Resistance Mechanisms on the Inoculum Effect of Carbapenem in Klebsiella pneumoniae Isolates with Borderline Carbapenem Resistance

    PubMed Central

    Ben-Dalak, Ma'ayan; Chmelnitsky, Ina; Carmeli, Yehuda

    2015-01-01

    We aimed to examine the effects of resistance mechanisms on several resistance phenotypes among carbapenem-resistant Klebsiella pneumoniae isolates with borderline carbapenem MICs. We compared carbapenemase-negative K. pneumoniae with carbapenemase-producing K. pneumoniae (CPKP) isolates with similar MICs. CPKP isolates exhibited a marked inoculum effect and were more resistant to the bactericidal effect of meropenem. This suggests that MIC measurements alone may not be sufficient in predicting the therapeutic efficacy of carbapenems against CPKP. PMID:25987630

  15. Effect of Resistance Mechanisms on the Inoculum Effect of Carbapenem in Klebsiella pneumoniae Isolates with Borderline Carbapenem Resistance.

    PubMed

    Adler, Amos; Ben-Dalak, Ma'ayan; Chmelnitsky, Ina; Carmeli, Yehuda

    2015-08-01

    We aimed to examine the effects of resistance mechanisms on several resistance phenotypes among carbapenem-resistant Klebsiella pneumoniae isolates with borderline carbapenem MICs. We compared carbapenemase-negative K. pneumoniae with carbapenemase-producing K. pneumoniae (CPKP) isolates with similar MICs. CPKP isolates exhibited a marked inoculum effect and were more resistant to the bactericidal effect of meropenem. This suggests that MIC measurements alone may not be sufficient in predicting the therapeutic efficacy of carbapenems against CPKP. PMID:25987630

  16. Multi-site study of diffusion metric variability: effects of site, vendor, field strength, and echo time on regions-of-interest and histogram-bin analyses

    NASA Astrophysics Data System (ADS)

    Helmer, K. G.; Chou, M.-C.; Preciado, R. I.; Gimi, B.; Rollins, N. K.; Song, A.; Turner, J.; Mori, S.

    2016-03-01

    It is now common for magnetic-resonance-imaging (MRI) based multi-site trials to include diffusion-weighted imaging (DWI) as part of the protocol. It is also common for these sites to possess MR scanners of different manufacturers, different software and hardware, and different software licenses. These differences mean that scanners may not be able to acquire data with the same number of gradient amplitude values and number of available gradient directions. Variability can also occur in achievable b-values and minimum echo times. The challenge of a multi-site study then, is to create a common protocol by understanding and then minimizing the effects of scanner variability and identifying reliable and accurate diffusion metrics. This study describes the effect of site, scanner vendor, field strength, and TE on two diffusion metrics: the first moment of the diffusion tensor field (mean diffusivity, MD), and the fractional anisotropy (FA) using two common analyses (region-of-interest and mean-bin value of whole brain histograms). The goal of the study was to identify sources of variability in diffusion-sensitized imaging and their influence on commonly reported metrics. The results demonstrate that the site, vendor, field strength, and echo time all contribute to variability in FA and MD, though to different extent. We conclude that characterization of the variability of DTI metrics due to site, vendor, field strength, and echo time is a worthwhile step in the construction of multi-center trials.

  17. Pyrethroid resistance in Phytoseiulus macropilis (Acari: Phytoseiidae): cross-resistance, stability and effect of synergists.

    PubMed

    Queiroz, Maria Cristina Vitelli; Sato, Mario Eidi

    2016-01-01

    Phytoseiulus macropilis Banks (Acari: Phytoseiidae) is an effective predator of Tetranychus urticae Koch (Acari: Tetranychidae). The objectives of this research were to study the stability of fenpropathrin resistance and the cross-resistance relationships with different pyrethroids, and also to evaluate the effect of synergists [piperonyl butoxide (PBO), diethyl maleate (DEM) and S,S,S-tributyl phosphorotrithioate (DEF)] on fenpropathrin resistant and susceptible strains of this predaceous mite. The stability of fenpropathrin resistance was studied under laboratory conditions, using P. macropilis populations with initial frequencies of 75 and 50% of resistant mites. The percentages of fenpropathrin resistant mites were evaluated monthly for a period of up to 12 months. A trend toward decreased resistance frequencies was observed only during the first 3-4 months. After this initial decrease, the fenpropathrin resistance was shown to be stable, maintaining constant resistance frequencies (around 30%) until the end of the evaluation period. Toxicity tests carried out using fenpropathrin resistant and susceptible strains of P. macropilis indicated strong positive cross-resistance between fenpropathrin and the pyrethroids bifenthrin and deltamethrin. Bioassays with the synergists DEM, DEF and PBO were also performed. The maximum synergism ratio (SR = LC50 without synergist/LC50 with synergist) detected for the three evaluated synergists (PBO, DEM, DEF) was 5.86 (for DEF), indicating low influence of enzyme detoxification processes in fenpropathrin resistance. PMID:26530989

  18. Metric Education and the Metrics Debate: A Perspective.

    ERIC Educational Resources Information Center

    Chappelet, Jean Loup

    A short history of the use of the metric system is given. The role of education in metrication is discussed. The metric activities of three groups of metrics advocates, the business community, private groups, and government agencies, are described. Arguments advanced by metric opponents are also included. The author compares the metric debate with…

  19. Metrics That Matter.

    PubMed

    Prentice, Julia C; Frakt, Austin B; Pizer, Steven D

    2016-04-01

    Increasingly, performance metrics are seen as key components for accurately measuring and improving health care value. Disappointment in the ability of chosen metrics to meet these goals is exemplified in a recent Institute of Medicine report that argues for a consensus-building process to determine a simplified set of reliable metrics. Overall health care goals should be defined and then metrics to measure these goals should be considered. If appropriate data for the identified goals are not available, they should be developed. We use examples from our work in the Veterans Health Administration (VHA) on validating waiting time and mental health metrics to highlight other key issues for metric selection and implementation. First, we focus on the need for specification and predictive validation of metrics. Second, we discuss strategies to maintain the fidelity of the data used in performance metrics over time. These strategies include using appropriate incentives and data sources, using composite metrics, and ongoing monitoring. Finally, we discuss the VA's leadership in developing performance metrics through a planned upgrade in its electronic medical record system to collect more comprehensive VHA and non-VHA data, increasing the ability to comprehensively measure outcomes. PMID:26951272

  20. Independent Metrics for Protein Backbone and Side-Chain Flexibility: Time Scales and Effects of Ligand Binding.

    PubMed

    Fuchs, Julian E; Waldner, Birgit J; Huber, Roland G; von Grafenstein, Susanne; Kramer, Christian; Liedl, Klaus R

    2015-03-10

    Conformational dynamics are central for understanding biomolecular structure and function, since biological macromolecules are inherently flexible at room temperature and in solution. Computational methods are nowadays capable of providing valuable information on the conformational ensembles of biomolecules. However, analysis tools and intuitive metrics that capture dynamic information from in silico generated structural ensembles are limited. In standard work-flows, flexibility in a conformational ensemble is represented through residue-wise root-mean-square fluctuations or B-factors following a global alignment. Consequently, these approaches relying on global alignments discard valuable information on local dynamics. Results inherently depend on global flexibility, residue size, and connectivity. In this study we present a novel approach for capturing positional fluctuations based on multiple local alignments instead of one single global alignment. The method captures local dynamics within a structural ensemble independent of residue type by splitting individual local and global degrees of freedom of protein backbone and side-chains. Dependence on residue type and size in the side-chains is removed via normalization with the B-factors of the isolated residue. As a test case, we demonstrate its application to a molecular dynamics simulation of bovine pancreatic trypsin inhibitor (BPTI) on the millisecond time scale. This allows for illustrating different time scales of backbone and side-chain flexibility. Additionally, we demonstrate the effects of ligand binding on side-chain flexibility of three serine proteases. We expect our new methodology for quantifying local flexibility to be helpful in unraveling local changes in biomolecular dynamics. PMID:26579739

  1. About Using the Metric System.

    ERIC Educational Resources Information Center

    Illinois State Office of Education, Springfield.

    This booklet contains a brief introduction to the use of the metric system. Topics covered include: (1) what is the metric system; (2) how to think metric; (3) some advantages of the metric system; (4) basics of the metric system; (5) how to measure length, area, volume, mass and temperature the metric way; (6) some simple calculations using…

  2. Geoelectrical behavior of a Fault Zone: the meaning of the electrical resistivity of metric-scale segments of the Liquiñe-Ofqui and the Arc-oblique Long-lived Fault Systems, Southern Andes

    NASA Astrophysics Data System (ADS)

    Roquer, T.; Arancibia, G.; Yanez, G. A.; Estay, N.; Rowland, J. V.; Figueroa, R.; Iturrieta, P. C.

    2015-12-01

    The geoelectrical behavior of blind fault zones has been studied by different authors at decametric-to-kilometric scales, and inferred to reveal the dimensions of the main structural domains of a fault zone (core vs. damage zone). However, there is still a lack in the application of electrical methods in exposed fault zones, despite the importance of validating the inferences based on electrical measurements with direct geologic observation. In this study we correlate the results of structural mapping and geoelectrical measurements in two metric-scale, very well exposed segments of the Liquiñe-Ofqui Fault System (LOFS) and the Arc-oblique Long-lived Fault System (ALFS), Southern Andes. The LOFS is an active dextral and dextral-normal ca. 1200-km-long Cenozoic intra-arc structure that strikes NNE to NE. Although the LOFS and the ALFS cross-cut each other, the ALFS is an apparently older basement NW-striking fault system where mainly sinistral movement is recorded. Two 22-m-long transects were mapped revealing in both examples a simple core and an assymetric damage zone with more frequency of fractures in the hanging wall than in the footwall. The LOFS outcrop showed a WNW-striking, 65°S-dipping core; the ALFS, a NW-striking, 60°SW-dipping core. A 2D direct-current electrical survey was made at each locality, orthogonal to the respective strike of the core. The field installation of the electrical survey used two electrode configurations for each outcrop: (1) electrodes were put in a vertical wall of rock, which gives a resistivity profile in plan view; and (2) electrodes were put in the ground, which gives a cross-section resistivity profile. The combined structural and electrical results suggest that: (1) it is possible to discriminate the geoelectrical response of the main metric-scale structural domains: the core and the fractured damage zones are relative conductors (20-200 ohm-m), whereas the less fractured damage zones are relative resistive volumes (500

  3. Frequency of Extreme Heat Event as a Surrogate Exposure Metric for Examining the Human Health Effects of Climate Change

    PubMed Central

    Romeo Upperman, Crystal; Parker, Jennifer; Jiang, Chengsheng; He, Xin; Murtugudde, Raghuram; Sapkota, Amir

    2015-01-01

    Epidemiological investigation of the impact of climate change on human health, particularly chronic diseases, is hindered by the lack of exposure metrics that can be used as a marker of climate change that are compatible with health data. Here, we present a surrogate exposure metric created using a 30-year baseline (1960–1989) that allows users to quantify long-term changes in exposure to frequency of extreme heat events with near unabridged spatial coverage in a scale that is compatible with national/state health outcome data. We evaluate the exposure metric by decade, seasonality, area of the country, and its ability to capture long-term changes in weather (climate), including natural climate modes. Our findings show that this generic exposure metric is potentially useful to monitor trends in the frequency of extreme heat events across varying regions because it captures long-term changes; is sensitive to the natural climate modes (ENSO events); responds well to spatial variability, and; is amenable to spatial/temporal aggregation, making it useful for epidemiological studies. PMID:26641244

  4. A neural net-based approach to software metrics

    NASA Technical Reports Server (NTRS)

    Boetticher, G.; Srinivas, Kankanahalli; Eichmann, David A.

    1992-01-01

    Software metrics provide an effective method for characterizing software. Metrics have traditionally been composed through the definition of an equation. This approach is limited by the fact that all the interrelationships among all the parameters be fully understood. This paper explores an alternative, neural network approach to modeling metrics. Experiments performed on two widely accepted metrics, McCabe and Halstead, indicate that the approach is sound, thus serving as the groundwork for further exploration into the analysis and design of software metrics.

  5. A Sensor-Independent Gust Hazard Metric

    NASA Technical Reports Server (NTRS)

    Stewart, Eric C.

    2001-01-01

    A procedure for calculating an intuitive hazard metric for gust effects on airplanes is described. The hazard metric is for use by pilots and is intended to replace subjective pilot reports (PIREPs) of the turbulence level. The hazard metric is composed of three numbers: the first describes the average airplane response to the turbulence, the second describes the positive peak airplane response to the gusts, and the third describes the negative peak airplane response to the gusts. The hazard metric is derived from any time history of vertical gust measurements and is thus independent of the sensor making the gust measurements. The metric is demonstrated for one simulated airplane encountering different types of gusts including those derived from flight data recorder measurements of actual accidents. The simulated airplane responses to the gusts compare favorably with the hazard metric.

  6. Effects of atmospheric moisture on rock resistivity.

    NASA Technical Reports Server (NTRS)

    Alvarez, R.

    1973-01-01

    This study examines the changes in resistivity of rock samples as induced by atmospheric moisture. Experiments were performed on samples of hematitic sandstone, pyrite, and galena. The sandstone underwent a change in resistivity of four orders of magnitude when it was measured in a vacuum of 500 ntorr and in air of 37% relative humidity. Pyrite and galena showed no variations in resistivity when they were measured under the same conditions. These results, plus others obtained elsewhere, indicate that rocks of the resistive type are affected in their electrical properties by atmospheric moisture, whereas rocks of the conductive type are not. The experimental evidence obtained is difficult to reconcile with a model of aqueous electrolytic conduction on the sample surface. It is instead suggested that adsorbed water molecules alter the surface resistivity in a manner similar to that observed in semiconductors and insulators.

  7. Powerful Metrics: Strategic and Transformative

    ERIC Educational Resources Information Center

    Butterfield, Barbara

    2006-01-01

    To be a valuable partner at the strategic level, human resources can and should contribute to both institutional effectiveness measurement and workforce metrics. In this article, the author examines how to link HR initiatives with key institutional strategies, clarifies essential HR responsibilities for workforce results, explores return on human…

  8. Exposure effects on deep-ultraviolet resist thickness

    NASA Astrophysics Data System (ADS)

    Baluswamy, Pary; Glass, Thomas R.

    1998-06-01

    Most deep ultraviolet (DUV) resist models available today utilize the Dill parameters to characterize resist exposure. These models assume that the thickness of the resist remains constant through exposure and post-exposure bake (PEB). The thickness is only affected by development in the models when resist is removed from the exposed or unexposed regions, depending on whether it is a positive or negative resist. It has been observed that a number of DUV resists change thickness upon exposure. This effect is expected to have an impact on the post-exposure acid profile calculated for modeling purposes. In this paper, we present data on the thickness changes for different resists and the effect of exposure to PEB delay on the change.

  9. Improved contact resistance in ReSe2 thin film field-effect transistors

    NASA Astrophysics Data System (ADS)

    Corbet, Chris M.; Sonde, Sushant S.; Tutuc, Emanuel; Banerjee, Sanjay K.

    2016-04-01

    We report the fabrication and device characteristics of exfoliated, few-layer, ReSe2 field effect transistors (FET) and a method to improve contact resistance by up to three orders of magnitude using ultra-high-vacuum annealing (UHV). Many devices were studied in the absence of light and we found an average contact of 750 Ω . cm after UHV treatment. The median FET metrics were similar to other transition metal dichalcogenides: field effect mobility ˜6.7 cm2/V . s, subthreshold swing ˜1.2 V/decade, and Ion/Ioff ˜ 105. In devices with low Rc current saturation was observed and is attributed to injection limited transport.

  10. Arbitrary Metrics in Psychology

    ERIC Educational Resources Information Center

    Blanton, Hart; Jaccard, James

    2006-01-01

    Many psychological tests have arbitrary metrics but are appropriate for testing psychological theories. Metric arbitrariness is a concern, however, when researchers wish to draw inferences about the true, absolute standing of a group or individual on the latent psychological dimension being measured. The authors illustrate this in the context of 2…

  11. Metrics for Cosmetology.

    ERIC Educational Resources Information Center

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of cosmetology students, this instructional package on cosmetology is part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational terminology, measurement terms, and tools currently in use. Each of the…

  12. Surveillance Metrics Sensitivity Study

    SciTech Connect

    Bierbaum, R; Hamada, M; Robertson, A

    2011-11-01

    In September of 2009, a Tri-Lab team was formed to develop a set of metrics relating to the NNSA nuclear weapon surveillance program. The purpose of the metrics was to develop a more quantitative and/or qualitative metric(s) describing the results of realized or non-realized surveillance activities on our confidence in reporting reliability and assessing the stockpile. As a part of this effort, a statistical sub-team investigated various techniques and developed a complementary set of statistical metrics that could serve as a foundation for characterizing aspects of meeting the surveillance program objectives. The metrics are a combination of tolerance limit calculations and power calculations, intending to answer level-of-confidence type questions with respect to the ability to detect certain undesirable behaviors (catastrophic defects, margin insufficiency defects, and deviations from a model). Note that the metrics are not intended to gauge product performance but instead the adequacy of surveillance. This report gives a short description of four metrics types that were explored and the results of a sensitivity study conducted to investigate their behavior for various inputs. The results of the sensitivity study can be used to set the risk parameters that specify the level of stockpile problem that the surveillance program should be addressing.

  13. Surveillance metrics sensitivity study.

    SciTech Connect

    Hamada, Michael S.; Bierbaum, Rene Lynn; Robertson, Alix A.

    2011-09-01

    In September of 2009, a Tri-Lab team was formed to develop a set of metrics relating to the NNSA nuclear weapon surveillance program. The purpose of the metrics was to develop a more quantitative and/or qualitative metric(s) describing the results of realized or non-realized surveillance activities on our confidence in reporting reliability and assessing the stockpile. As a part of this effort, a statistical sub-team investigated various techniques and developed a complementary set of statistical metrics that could serve as a foundation for characterizing aspects of meeting the surveillance program objectives. The metrics are a combination of tolerance limit calculations and power calculations, intending to answer level-of-confidence type questions with respect to the ability to detect certain undesirable behaviors (catastrophic defects, margin insufficiency defects, and deviations from a model). Note that the metrics are not intended to gauge product performance but instead the adequacy of surveillance. This report gives a short description of four metrics types that were explored and the results of a sensitivity study conducted to investigate their behavior for various inputs. The results of the sensitivity study can be used to set the risk parameters that specify the level of stockpile problem that the surveillance program should be addressing.

  14. Introduction to Metrics.

    ERIC Educational Resources Information Center

    Edgecomb, Philip L.; Shapiro, Marion

    Addressed to vocational, or academic middle or high school students, this book reviews mathematics fundamentals using metric units of measurement. It utilizes a common-sense approach to the degree of accuracy needed in solving actual trade and every-day problems. Stress is placed on reading off metric measurements from a ruler or tape, and on…

  15. Metrics for Agricultural Mechanics.

    ERIC Educational Resources Information Center

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of agricultural mechanics students, this instructional package is one of four for the agribusiness and natural resources occupations cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational…

  16. Metric Education Evaluation Package.

    ERIC Educational Resources Information Center

    Kansky, Bob; And Others

    This document was developed out of a need for a complete, carefully designed set of evaluation instruments and procedures that might be applied in metric inservice programs across the nation. Components of this package were prepared in such a way as to permit local adaptation to the evaluation of a broad spectrum of metric education activities.…

  17. What About Metric?

    ERIC Educational Resources Information Center

    Barbrow, Louis E.

    Implications of the change to the metric system in our daily lives are discussed. Advantages of the metric system are presented, especially its decimal base and ease of calculation which are demonstrated by several worked examples. Some further sources of information are listed. A world map indicates the few remaining countries that have not yet…

  18. Metrics for Food Distribution.

    ERIC Educational Resources Information Center

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of students interested in food distribution, this instructional package is one of five for the marketing and distribution cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational…

  19. Metrics for Transportation.

    ERIC Educational Resources Information Center

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of students interested in transportation, this instructional package is one of five for the marketing and distribution cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational terminology,…

  20. Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

    PubMed Central

    Chudobova, Dagmar; Dostalova, Simona; Blazkova, Iva; Michalek, Petr; Ruttkay-Nedecky, Branislav; Sklenar, Matej; Nejdl, Lukas; Kudr, Jiri; Gumulec, Jaromir; Tmejova, Katerina; Konecna, Marie; Vaculovicova, Marketa; Hynek, David; Masarik, Michal; Kynicky, Jindrich; Kizek, Rene; Adam, Vojtech

    2014-01-01

    There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead) to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM) on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control) of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health. PMID:24651395

  1. SU-E-I-28: Introduction and Investigation of Effective Diameter Ratios as a New Patient Size Metric for Use in CT

    SciTech Connect

    Lamoureux, R; Sinclair, L; Mench, A; Lipnharski, I; Carranza, C; Bidari, S; Cormack, B; Rill, L; Arreola, M

    2015-06-15

    Purpose: To introduce and investigate effective diameter ratios as a new patient metric for use in computed tomography protocol selection as a supplement to patient-specific size parameter data. Methods: The metrics of outer effective diameter and inner effective diameter were measured for 7 post-mortem subjects scanned with a standardized chest/abdomen/pelvis (CAP) protocol on a 320-slice MDCT scanner. The outer effective diameter was calculated by obtaining the anterior/posterior and lateral dimensions of the imaged anatomy at the middle of the scan range using Effective Diameter= SQRT(AP height*Lat Width). The inner effective diameter was calculated with the same equation using the AP and Lat dimensions of the anatomy excluding the adipose tissue. The ratio of outer to inner effective diameter was calculated for each subject. A relationship to BMI, weight, and CTDI conversion coefficients was investigated. Results: For the largest subject with BMI of 43.85 kg/m2 and weight of 255 lbs the diameter ratio was calculated as 1.33. For the second largest subject with BMI of 33.5 kg/m2 and weight of 192.4 lbs the diameter ratio was measured as 1.43, indicating a larger percentage of adipose tissue in the second largest subject’s anatomical composition. For the smallest subject at BMI of 17.4 kg/m2 and weight of 86 lbs a similar tissue composition was indicated as a subject with BMI of 24.2 kg/m2 and weight of 136 lbs as they had the same diameter ratios of 1.11. Conclusion: The diameter ratio proves to contain information about anatomical composition that the BMI and weight alone do not. The utility of this metric is still being examined but could prove useful for determining MDCT techniques and for giving a more in depth detail of the composition of a patient’s body habitus.

  2. The effect of resist material composition on development behavior

    NASA Astrophysics Data System (ADS)

    Minegishi, Shinya; Itani, Toshiro

    2015-03-01

    The relation between resist composition and its development behavior was evaluated. The effect of a hydrophobic unit on a resist and on its development behavior was systematically investigated. The resist was exposed to extreme ultraviolet (EUV) or electron beam (EB) exposure, and the development behavior of the film was observed by high-speed atomic force microscopy (HS-AFM). The introduction of a hydrophobic group in the resist resulted in diminished swelling behavior and uniform dissolution. The resist resin cluster shape was also altered by the introduction of the hydrophobic group. These behaviors imply that the resin-resin and resin-tetramethylammonium hydroxide solution interactions differ. EUV lithography suffers from the photon issue that causes stochastic uniformity; however, in this study, we demonstrate the feasibility of achieving a better uniformity of resist patterning by altering the resist formulation.

  3. Unraveling the effect of resist composition on EUV optics contamination

    NASA Astrophysics Data System (ADS)

    Pollentier, I.; Neira, I.; Goethals, A.-M.; Gronheid, R.; Tarutani, S.; Tamaoki, H.; Tsubaki, H.; Takahashi, T.

    2011-04-01

    EUV lithography is the most promising new technology for the next node of semiconductor devices. Unfortunately, the high energy photons are likely to generate more contamination than observed with ArF or KrF light which can reduce the transmission of the EUV optics. Resist outgassing is considered to be an important contamination source, however, not enough is known about the way a resist composition influences the contamination growth rate, while this information is crucial to guide the development of EUV resists. To reduce the knowledge gap, FUJIFILM and imec started a joint effort aimed at systematically exploring the contribution of the different resist components and at understanding the effect of chemical modifications of the different components on the contamination tendency of resists. The project focuses on (1) the identification and quantification of the outgassing components from resist by RGA measurements, (2) on the quantification of the resist related contamination rate by witness sample (WS) testing, and (3) on the correlation between these two results knowing the details of the resist chemistry. To explore the effect of the resist composition upon contamination growth, the following approach was followed. The focus was put on chemically amplified resists (CAR), since this chemistry is mostly used in EUV lithography. Both PAG blended as well as PAG bound systems were explored, and the following resist components are individually varied: polymer matrix, blocking groups, PAG type and concentration. In this way the total contamination of a resist can be divided into the separate contributions of the different resist components upon the contamination growth rate, which is a huge step forward in the understanding of optics contamination due to resist.

  4. Effect of Tulathromycin on Colonization Resistance, Antimicrobial Resistance, and Virulence of Human Gut Microbiota in Chemostats

    PubMed Central

    Hao, Haihong; Zhou, Shengxi; Cheng, Guyue; Dai, Menghong; Wang, Xu; Liu, Zhenli; Wang, Yulian; Yuan, Zonghui

    2016-01-01

    To evaluate microbiological safety of tulathromycin on human intestinal bacteria, tulathromycin (0, 0.1, 1, 10, and 100 μg/mL) was added into Chemostats. Before and after drug exposure, we monitored (1) population, SCFA products, antimicrobial resistance, and colonization resistance of gut microbiota, and (2) the antimicrobial resistance genes, transferability, virulent genes, pathogenicity of Enterococus faecalis. Results showed that low level of tulathromycin did not exhibit microbiological hazard on resistance selection and colonization resistance. However, high level of tulathromycin (10 and 100 μg/mL) may disturb colonization resistance of human gut microbiota and select antimicrobial resistant E. faecalis. Most of the selected resistant E. faecalis carried resistant gene of ermB, transferable element of Tn1545 and three virulence genes (esp, cylA, and ace). One of them (E. faecalis 143) was confirmed to have higher horizontal transfer risk and higher pathogenicity. The calculated no observable adverse effect concentration (NOAEC) and microbiological acceptable daily intake (mADI) in our study was 1 μg/mL and 14.66 μg/kg.bw/day, respectively. PMID:27092131

  5. Radiation Effects of Commercial Resistive Random Access Memories

    NASA Technical Reports Server (NTRS)

    Chen, Dakai; LaBel, Kenneth; Berg, Melanie; Wilcox, Edward; Kim, Hak; Phan, Anthony; Figueiredo, Marco; Buchner, Stephen; Khachatrian, Ani; Roche, Nicolas

    2014-01-01

    We present results for the single-event effect response of commercial production-level resistive random access memories. We found that the resistive memory arrays are immune to heavy ion-induced upsets. However, the devices were susceptible to single-event functional interrupts, due to upsets from the control circuits. The intrinsic radiation tolerant nature of resistive memory makes the technology an attractive consideration for future space applications.

  6. An Arithmetic Metric

    ERIC Educational Resources Information Center

    Dominici, Diego

    2011-01-01

    This work introduces a distance between natural numbers not based on their position on the real line but on their arithmetic properties. We prove some metric properties of this distance and consider a possible extension.

  7. A metric for success

    NASA Astrophysics Data System (ADS)

    Carver, Gary P.

    1994-05-01

    The federal agencies are working with industry to ease adoption of the metric system. The goal is to help U.S. industry compete more successfully in the global marketplace, increase exports, and create new jobs. The strategy is to use federal procurement, financial assistance, and other business-related activities to encourage voluntary conversion. Based upon the positive experiences of firms and industries that have converted, federal agencies have concluded that metric use will yield long-term benefits that are beyond any one-time costs or inconveniences. It may be time for additional steps to move the Nation out of its dual-system comfort zone and continue to progress toward metrication. This report includes 'Metric Highlights in U.S. History'.

  8. Sustainability Indicators and Metrics

    EPA Science Inventory

    Sustainability is about preserving human existence. Indicators and metrics are absolutely necessary to provide at least a semi-quantitative assessment of progress towards or away from sustainability. Otherwise, it becomes impossible to objectively assess whether progress is bei...

  9. Metrication - Our Responsibility?

    ERIC Educational Resources Information Center

    Kroner, Klaus E.

    1972-01-01

    The metric system will soon be adopted in the United States. Engineering college educators can play a major role in this revision. Various suggestions are listed for teachers, authors and others. (PS)

  10. Neoclassical viscosity effects on resistive magnetohydrodynamic modes in toroidal geometry

    SciTech Connect

    Yang, J.G.; Oh, Y.H.; Choi, D.I. ); Kim, J.Y.; Horton, W. )

    1992-03-01

    The flux-surface-averaged linearized resistive magnetohydrodynamic (MHD) boundary-layer equations including the compressibility, diamagnetic drift, and neoclassical viscosity terms are derived in toroidal geometry. These equations describe the resistive layer dynamics of resistive MHD modes over the collisionality regime between the banana plateau and the Pfirsch--Schlueter. From the resulting equations, the effects of neoclassical viscosity on the stability of the tearing and resistive ballooning modes are investigated numerically. Also, a study is given for the problem of how the neoclassical resistive MHD mode is generated as the collisionality is reduced. It is shown that the neoclassical viscosity terms give a significant destabilizing effect for the tearing and resistive ballooning modes. This destabilization comes mainly from the reduction of the stabilizing effect of the parallel ion sound compression by the ion neoclassical viscosity. In the banana-plateau collisionality limit, where the compressibility is negligible, the dispersion relations of the tearing and resistive ballooning modes reduce to the same form, with the threshold value of the driving force given by {Delta}{sub {ital c}}=0. On the other hand, with the finite neoclassical effect it is found that the neoclassical resistive MHD instability is generated in agreement with previous results. Furthermore, it is shown that this later instability can be generated in a wide range of the collisionality including near the Pfirsch--Schlueter regime as well as the banana-plateau regime, suggesting that this mode is a probable cause of anomalous transport.

  11. Effects of Transgenic Glyphosate-Resistant Crops on Water Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate (N-[phosphonomethyl] glycine) is a highly effective, non-selective herbicide. Herbicide-resistant crop (HRC) has been the most successful trait used in transgenic crops throughout the world. Transgenic glyphosate-resistant crops (GRCs) have been commercialized and grown extensively in the...

  12. Effects of cost metric on cost-effectiveness of protected-area network design in urban landscapes.

    PubMed

    Burkhalter, J C; Lockwood, J L; Maslo, B; Fenn, K H; Leu, K

    2016-04-01

    A common goal in conservation planning is to acquire areas that are critical to realizing biodiversity goals in the most cost-effective manner. The way monetary acquisition costs are represented in such planning is an understudied but vital component to realizing cost efficiencies. We sought to design a protected-area network within a forested urban region that would protect 17 birds of conservation concern. We compared the total costs and spatial structure of the optimal protected-area networks produced using three acquisition-cost surrogates (area, agricultural land value, and tax-assessed land value). Using the tax-assessed land values there was a 73% and 78% cost savings relative to networks derived using area or agricultural land value, respectively. This cost reduction was due to the considerable heterogeneity in acquisition costs revealed in tax-assessed land values, especially for small land parcels, and the corresponding ability of the optimization algorithm to identify lower-cost parcels for inclusion that had equal value to our target species. Tax-assessed land values also reflected the strong spatial differences in acquisition costs (US$0.33/m(2)-$55/m(2)) and thus allowed the algorithm to avoid inclusion of high-cost parcels when possible. Our results add to a nascent but growing literature that suggests conservation planners must consider the cost surrogate they use when designing protected-area networks. We suggest that choosing cost surrogates that capture spatial- and size-dependent heterogeneity in acquisition costs may be relevant to establishing protected areas in urbanizing ecosystems. PMID:26395858

  13. Effect of thread pitch and frictional coefficient on the stress concentration in metric nut-bolt connections

    SciTech Connect

    Dragoni, E. . Dept. of Mechanics)

    1994-02-01

    By means of the finite element method, this paper establishes how much the stress state within standard metric nut-bolt connections is affected by variations of the thread pitch and of the frictional coefficient. Following a validated simplified approach, the actual three-dimensional geometry of each connection is replaced by an axisymmetric model which recreates the outline of the joint on an appropriate meridional section. The numerical data prove that, for prescribed nominal thread diameter and bolt load, The peak stress in the screw monotonically increases as the pitch decreases. Further, as far as complete sticking between nut and bolt is not achieved, the stress level linearly increases with the coefficient of friction, the rate of variations being higher at the lowest pitches.

  14. Marketing metrics for medical practices.

    PubMed

    Zahaluk, David; Baum, Neil

    2012-01-01

    There's a saying by John Wanamaker who pontificated, "Half the money I spend on advertising is wasted; the trouble is, I don't know which half". Today you have opportunities to determine which parts of your marketing efforts are effective and what is wasted. However, you have to measure your marketing results. This article will discuss marketing metrics and how to use them to get the best bang for your marketing buck. PMID:22834190

  15. Effect of flow twisting on hydraulic resistance and heat exchange

    NASA Astrophysics Data System (ADS)

    Suslov, V. Ya.; Makarov, N. A.

    1989-02-01

    On the basis of dimensional analysis through a differentiated approach to the dimensions of length we have obtained formulas for the effect of flow twisting in a circular tube on the hydraulic resistance and exchange of heat.

  16. Planck Constant Deduced from Metrical Results of Doppler Effect of Moving Particle— Uncertainty Principle Caused byCollision of a Particle with CMB Photons and Virtual Photons

    NASA Astrophysics Data System (ADS)

    Chen, Shao-Guang

    Put two counters at origin O and particle P respectively, the wave-number difference counted by two counters at same moment is the length x between P and O (as a rod). The metrical result of known Doppler effect is: x(θ) = x0 (1+ β cos θ) (1). β= v/c, v is the velocity of counter to light-source, c = c+ = c -is the metrical one-way velocity of light, v • n = v cos θ, θ is the angle between v and unit-vector n of light-beam pointing to counter from light-source, x0 is the metrical length when v = 0. The result counted by a counter in one second is the light-wave frequency: f(θ) = f0 (1 -β cos θ) (2). f0 is the metrical frequency when v = 0. From Eq.(1) and Eq (2): x 2 (θ) = x0 2 (1+2 β cos θ + β 2 cos2 θ); f 2 (θ) = f 0 2 (1-2 β cos θ + β 2 cos2 θ). Define the square-difference root of the metrical results in two contrary directions: ∆x = (x 2 (0) -x 2 (π)) 1/2 = 2 x0 β 1/2 (3); ∆f = (f 2 (0) -f 2 (π))1/2 = i 2 f0 β 1/2 (4); ∆x • ∆f = i 4 x0 f0 β (5). From p = m v and the variance in absolute average value of Eq.(2) ∆f= 2 f0 ∆v/π c, Eq.(5) changes into: ∆x•∆p= 2 π x0 p (6). Once a particle collides with CMB photon, its velocity will change as in a quasi-Brownian motion. Let S be the average space-distance between CMB photons, the time-interval between two collisions is S / v, v is the velocity of particle. Because x0 is the length of an imaginary resting rod, i.e., after every collision the origin O must be reset jumpily at a new position and the jumpy distance (S/v) • ∆v is just the displacement of particle x0 , ∆v is the variance in velocity caused by each collision. The variance in momentum of particle ∆p in each collision is the average momentum p0 of CMB photon, then we obtain: x0 = S ∆v / v = S ∆p /p = S p0 /p and Eq.(6) changes into: ∆x•∆p= 2 π p0 S (7). The average energy and average momentum of CMB photon in 2.7K are: e0 = k T= 3.72•10-16 erg; p0 = e0 /c =1.24•10 -26 g cm s -1 . The

  17. Effect of prolonged hypokinesia on resistance of resistive vessels in rats

    NASA Technical Reports Server (NTRS)

    Saltykova, V. A.

    1982-01-01

    Under the effect of prolonged hypokinesia, the perfusion pressure in resistive vessels, measured under conditions of deep anesthesia and complete denervation, increased by approximately the same degree as arterial pressure in non-anesthetized animals. The increase in arterial, perfusion pressure and the resistance of resistive vessels in animals subjected to prolonged hypokinesia was accompanied by an increase in adrenoreactivity. During prolonged hypokinesia, partial obliteration of the vascular bed of the skeletal muscles plays a significant role in the observed increase in resistance of vessels of the extremities. The increase in adrenoreactivity of the vessels during hypokinesia may be realized as a partial case of an increase in the adrenoreactivity of structures whose innervation is disturbed.

  18. Successful Experiences in Teaching Metric.

    ERIC Educational Resources Information Center

    Odom, Jeffrey V., Ed.

    In this publication are presentations on specific experiences in teaching metrics, made at a National Bureau of Standards conference. Ideas of value to teachers and administrators are described in reports on: SI units of measure; principles and practices of teaching metric; metric and the school librarian; teaching metric through television and…

  19. [Effect of Three Typical Disinfection Byproducts on Bacterial Antibiotic Resistance].

    PubMed

    Lü, Lu; Zhang, Meng-lu; Wang, Chun-ming; Lin, Hui-rong; Yu, Xin

    2015-07-01

    The effect of typical disinfection byproducts (DBPs) on bacterial antibiotic resistance was investigated in this study. chlorodibromomethane (CDBM), iodoacetic acid (IAA) and chloral hydrate (CH) were selected, which belong to trihalomethanes (THMs), haloacetic acids (HAAs) and aldehydes, respectively. After exposure to the selected DBPs, the resistance change of the tested strains to antibiotics was determined. As a result, all of the three DBPs induced Pseudomonas aeruginosa PAO1 to gain increased resistance to the five antibiotics tested, and the DBPs ranked as IAA > CH > CDBM according to their enhancement effects. Multidrug resistance could also be enhanced by treatment with IAA. The same result was observed in Escherichia coli K12, suggesting that the effect of DBPs on antibiotic resistance was a common phenomenon. The mechanism was probably that DBPs stimulated oxidative stress, which induced mutagenesis. And the antibiotic resistance mutation frequency could be increased along with mutagenesis. This study revealed that the acquisition of bacterial antibiotic resistance might be related to DBPs in drinking water systems. Besides the genotoxicological risks, the epidemiological risks of DBPs should not be overlooked. PMID:26489321

  20. Evaluation of a Metric Booklet as a Supplement to Teaching the Metric System to Undergraduate Non-Science Majors.

    ERIC Educational Resources Information Center

    Exum, Kenith Gene

    Examined is the effectiveness of a method of teaching the metric system using the booklet, Metric Supplement to Mathematics, in combination with a physical science textbook. The participants in the study were randomly selected undergraduates in a non-science oriented program of study. Instruments used included the Metric Supplement to Mathematics…

  1. Effects of tissue resistivities on electroencephalogram sensitivity distribution.

    PubMed

    Laarne, P; Kauppinen, P; Hyttinen, J; Malmivuo, J; Eskola, H

    1999-09-01

    The effects of tissue resistivities on EEG amplitudes were studied using an anatomically accurate computer model based on the finite difference method (FDM) and lead field analysis covering the whole brain area with 180,000 nodes. Five tissue types and three lead fields were considered for analysis. The changes in sensitivity distribution are directly comparable to changes in the potential distribution on the scalp. The results indicate that a 10% decrease in any tissue resistivity caused 3.0-4.1% differences in the sensitivity distributions of the selected EEG leads. The applied 10% decrease in the resistivity values covers only a fraction of the range of variation of 50% to 100% reported in the literature. The use of a 55% decreased skull resistivity value or a commonly applied three-compartment model increased the differences to 28% and 33%, respectively. In conclusion, both a realistic anatomy and accurate resistivity data are important in EEG head models. PMID:10723891

  2. Testing, Requirements, and Metrics

    NASA Technical Reports Server (NTRS)

    Rosenberg, Linda; Hyatt, Larry; Hammer, Theodore F.; Huffman, Lenore; Wilson, William

    1998-01-01

    The criticality of correct, complete, testable requirements is a fundamental tenet of software engineering. Also critical is complete requirements based testing of the final product. Modern tools for managing requirements allow new metrics to be used in support of both of these critical processes. Using these tools, potential problems with the quality of the requirements and the test plan can be identified early in the life cycle. Some of these quality factors include: ambiguous or incomplete requirements, poorly designed requirements databases, excessive or insufficient test cases, and incomplete linkage of tests to requirements. This paper discusses how metrics can be used to evaluate the quality of the requirements and test to avoid problems later. Requirements management and requirements based testing have always been critical in the implementation of high quality software systems. Recently, automated tools have become available to support requirements management. At NASA's Goddard Space Flight Center (GSFC), automated requirements management tools are being used on several large projects. The use of these tools opens the door to innovative uses of metrics in characterizing test plan quality and assessing overall testing risks. In support of these projects, the Software Assurance Technology Center (SATC) is working to develop and apply a metrics program that utilizes the information now available through the application of requirements management tools. Metrics based on this information provides real-time insight into the testing of requirements and these metrics assist the Project Quality Office in its testing oversight role. This paper discusses three facets of the SATC's efforts to evaluate the quality of the requirements and test plan early in the life cycle, thus preventing costly errors and time delays later.

  3. Effect of wall roughness on fluid transport resistance in nanopores

    NASA Astrophysics Data System (ADS)

    Xu, Baoxing; Li, Yibing; Park, Taehyo; Chen, Xi

    2011-10-01

    Using non-equilibrium molecular dynamics simulations, we investigate the effect of wall roughness on the transport resistance of water molecules inside modified carbon nanotubes. The effective shear stress, which characterizes the strong interaction between liquid molecules and solid wall, is a quantity that dominates the nanofluidic transport resistance. Both the effective shear stress and nominal viscosity arise with the increase of the amplitude or the decrease of the wavelength of roughness. The effect of roughness is also relatively more prominent in smaller nanotubes. The molecular mechanism is elucidated through the study of the radial density profile, hydrogen bonding, and velocity field of the confined water molecules.

  4. A filled duration illusion in music: Effects of metrical subdivision on the perception and production of beat tempo.

    PubMed Central

    Repp, Bruno H.; Bruttomesso, Meijin

    2010-01-01

    This study replicates and extends previous findings suggesting that metrical subdivision slows the perceived beat tempo (Repp, 2008). Here, musically trained participants produced the subdivisions themselves and were found to speed up, thus compensating for the perceived slowing. This was shown in a synchronization-continuation paradigm (Experiment 1) and in a reproduction task (Experiment 2a). Participants also judged the tempo of a subdivided sequence as being slower than that of a preceding simple beat sequence (Experiment 2b). Experiment 2 also included nonmusician participants, with similar results. Tempo measurements of famous pianists’ recordings of two variation movements from Beethoven sonatas revealed a strong tendency to play the first variation (subdivided beats) faster than the theme (mostly simple beats). A similar tendency was found in musicians’ laboratory performances of a simple theme and variations, despite instruc-tions to keep the tempo constant (Experiment 3a). When playing melodic sequences in which only one of three beats per measure was subdivided, musicians tended to play these beats faster and to perceive them as longer than adjacent beats, and they played the whole sequence faster than a sequence without any subdivisions (Experiments 3b and 3c). The results amply demonstrate a filled duration illusion in rhythm perception and music performance: Intervals containing events seem longer than empty intervals and thus must be shortened to be perceived as equal in duration. PMID:20689669

  5. Effect of mechanical surface and heat treatments on erosion resistance

    NASA Technical Reports Server (NTRS)

    Salik, J.; Buckley, D. H.

    1980-01-01

    The effects of mechanical surface treatments as well as heat treatments on the erosion resistance of 6061 aluminum alloy and 1045 steel were studied. Mechanical surface treatments were found to have little or no effect on the erosion resistance. This is due to the formation by particle impact of a work hardened surface layer regardless of the initial surface condition. The erosion resistance of Al single crystals is found to be independent of orientation. This is due to destruction of the surface microstructure and formation of a polycrystalline surface layer by the impact of erodant particles as observed by X-ray diffraction. While upon solution treatment of annealed 6061 aluminum the increase in hardness is accompanied by an increase in erosion resistance, precipitation treatment which causes a further increase in hardness results in slightly lower erosion resistance. Using two types of erodant particles, glass beads and crushed glass, the erosion rate is found to be strongly dependent on erodant particle shape, being an order of magnitude higher for erosion with crushed glass as compared to glass beads. While for erosion with glass beads heat treatment of 1045 steel had a profound effect on its erosion resistance, little or no such effect was observed for erosion with crushed glass.

  6. An Underwater Color Image Quality Evaluation Metric.

    PubMed

    Yang, Miao; Sowmya, Arcot

    2015-12-01

    Quality evaluation of underwater images is a key goal of underwater video image retrieval and intelligent processing. To date, no metric has been proposed for underwater color image quality evaluation (UCIQE). The special absorption and scattering characteristics of the water medium do not allow direct application of natural color image quality metrics especially to different underwater environments. In this paper, subjective testing for underwater image quality has been organized. The statistical distribution of the underwater image pixels in the CIELab color space related to subjective evaluation indicates the sharpness and colorful factors correlate well with subjective image quality perception. Based on these, a new UCIQE metric, which is a linear combination of chroma, saturation, and contrast, is proposed to quantify the non-uniform color cast, blurring, and low-contrast that characterize underwater engineering and monitoring images. Experiments are conducted to illustrate the performance of the proposed UCIQE metric and its capability to measure the underwater image enhancement results. They show that the proposed metric has comparable performance to the leading natural color image quality metrics and the underwater grayscale image quality metrics available in the literature, and can predict with higher accuracy the relative amount of degradation with similar image content in underwater environments. Importantly, UCIQE is a simple and fast solution for real-time underwater video processing. The effectiveness of the presented measure is also demonstrated by subjective evaluation. The results show better correlation between the UCIQE and the subjective mean opinion score. PMID:26513783

  7. Effect of mechanical surface and heat treatments on erosion resistance

    NASA Technical Reports Server (NTRS)

    Salik, J.; Buckley, D. H.

    1981-01-01

    The effect of erosion by glass beads and crushed glass and by heat treatments on the erosional resistance of 6061 aluminum alloy and 1045 steel were studied. The aluminum alloy's erosion resistance was found to be insensitive to mechanical surface treatment applied before testing, and was determined to depend on the properties of the work-hardened surface layer; this was also demonstrated for aluminum alloy single crystals. The aluminum alloy heat treatments included annealing, solution, and precipitation. Solution was found to increase erosion resistance but precipitation had the opposite effect. Hardness showed no correlation with erosion resistance for either aluminum alloy steel. The steel tests showed that crushed glass provides an order of magnitude more erosion than glass beads.

  8. Effect of surface fissure on apparent resistivity measurements

    NASA Astrophysics Data System (ADS)

    Sailhac, P.; Gance, J.; Malet, J.

    2013-12-01

    Fissures are features of interest, prone to create preferential flow path, modifying locally the soil hydrogeological behavior. Electrical Resistivity Tomography (ERT) is a suitable tool to monitor such preferential flow path. However, this technique is not efficient in the presence of surface fissure, due to a bad resistivity recovering around the fissure vicinity during the inversion process. Therefore, we propose a description of fissure effect on raw apparent resistivity on three resistivity arrays. The purposes of the study are multiple. First, we aim at making ERT users aware of surface fissure effect, and propose a first help to interpret basically resistivity pseudo sections. Second, we propose to ERT users to automatically conduct a surface fissure survey on the studied profile, in order to consider each fissure in a forward DC model and to suppress their effect. Finally, this study is only a first step toward 2D fissure shape inversion, and time-lapse monitoring of fissure drying and filling. In this study, we create a fissure model based on different geomorphological descriptors. After describing the FEM-DC forward modeling strategy, we investigate the fissure effect on pseudo section of apparent resistivity for a Wenner-Schlumberger (WS), a dipole-dipole (DD) and a gradient (GRAD) array. We determine a fissure detectability threshold for each array and perform a sensitivity analysis on the different fissure parameters (position, width, depth, dip angles...). The crack filling or drying effect is also investigated. The possibility to remove fissure effect and to propose a first interpretation of time-lapse data is illustrated on real data. This study show again the higher sensitivity of the DD array compared to the GRAD and WS arrays. Not only the maximal amplitude in the pseudo section is higher for the DD array, but also the anomaly pattern created by the fissure is much larger for this acquisition geometry. The minimal depth detectable for the DD

  9. Metrics and Sports.

    ERIC Educational Resources Information Center

    National Collegiate Athletic Association, Shawnee Mission, KS.

    Designed as a guide to aid the National Collegiate Athletic Association membership and others who must relate measurement of distances, weights, and volumes to athletic activity, this document presents diagrams of performance areas with measurements delineated in both imperial and metric terms. Illustrations are given for baseball, basketball,…

  10. Toll Gate Metrication Project

    ERIC Educational Resources Information Center

    Izzi, John

    1974-01-01

    The project director of the Toll Gate Metrication Project describes the project as the first structured United States public school educational experiment in implementing change toward the adoption of the International System of Units. He believes the change will simplify, rather than complicate, the educational task. (AG)

  11. Metrics of Scholarly Impact

    ERIC Educational Resources Information Center

    Cacioppo, John T.; Cacioppo, Stephanie

    2012-01-01

    Ruscio and colleagues (Ruscio, Seaman, D'Oriano, Stremlo, & Mahalchik, this issue) provide a thoughtful empirical analysis of 22 different measures of individual scholarly impact. The simplest metric is number of publications, which Simonton (1997) found to be a reasonable predictor of career trajectories. Although the assessment of the scholarly…

  12. Metric Style Guide.

    ERIC Educational Resources Information Center

    Canadian Council of Ministers of Education, Toronto (Ontario).

    This guide was designed to provide a measure of uniformity across Canada with respect to metric terminology and symbolism, and is designed to enable users to understand and apply Systeme International d'Unites (SI) to everyday life with ease and confidence. This document was written with the intent of being helpful to the greatest number of…

  13. Effects of raltegravir or elvitegravir resistance signature mutations on the barrier to dolutegravir resistance in vitro.

    PubMed

    Seki, Takahiro; Suyama-Kagitani, Akemi; Kawauchi-Miki, Shinobu; Miki, Shigeru; Wakasa-Morimoto, Chiaki; Akihisa, Erika; Nakahara, Koichiro; Kobayashi, Masanori; Underwood, Mark R; Sato, Akihiko; Fujiwara, Tamio; Yoshinaga, Tomokazu

    2015-05-01

    The recently approved HIV-1 integrase strand transfer inhibitor (INSTI) dolutegravir (DTG) (S/GSK1349572) has overall advantageous activity when tested in vitro against HIV-1 with raltegravir (RAL) and elvitegravir (EVG) resistance signature mutations. We conducted an in vitro resistance selection study using wild-type HIV-1 and mutants with the E92Q, Y143C, Y143R, Q148H, Q148K, Q148R, and N155H substitutions to assess the DTG in vitro barrier to resistance. No viral replication was observed at concentrations of ≥ 32 nM DTG, whereas viral replication was observed at 160 nM RAL or EVG in the mutants. In the Q148H, Q148K, or Q148R mutants, G140S/Q148H, E138K/Q148K, E138K/Q148R, and G140S/Q148R secondary mutations were identified with each INSTI and showed high resistance to RAL or EVG but limited resistance to DTG. E138K and G140S, as secondary substitutions to Q148H, Q148K, or Q148R, were associated with partial recovery in viral infectivity and/or INSTI resistance. In the E92Q, Y143C, Y143R, and N155H mutants, no secondary substitutions were associated with DTG. These in vitro results suggest that DTG has a high barrier to the development of resistance in the presence of RAL or EVG signature mutations other than Q148. One explanation for this high barrier to resistance is that no additional secondary substitution of E92Q, Y143C, Y143R, or N155H simultaneously increased the fold change in 50% effective concentration (EC50) to DTG and infectivity. Although increased DTG resistance via the Q148 pathway and secondary substitutions occurs at low concentrations, a higher starting concentration may reduce or eliminate the development of DTG resistance in this pathway in vitro. PMID:25691633

  14. The Warburg effect and drug resistance.

    PubMed

    Bhattacharya, Bhaskar; Mohd Omar, Mohd Feroz; Soong, Richie

    2016-03-01

    : The Warburg effect describes the increased utilization of glycolysis rather than oxidative phosphorylation by tumour cells for their energy requirements under physiological oxygen conditions. This effect has been the basis for much speculation on the survival advantage of tumour cells, tumourigenesis and the microenvironment of tumours. More recently, studies have begun to reveal how the Warburg effect could influence drug efficacy and how our understanding of tumour energetics could be exploited to improve drug development. In particular, evidence is emerging demonstrating how better modelling of the tumour metabolic microenvironment could lead to a better prediction of drug efficacy and the identification of new combination strategies. This review will provide details of the current understanding of the complex interplay between glucose metabolism and pharmacology and discuss opportunities for utilizing the Warburg effect in future drug development. PMID:26750865

  15. The Warburg effect and drug resistance

    PubMed Central

    Mohd Omar, Mohd Feroz; Soong, Richie

    2016-01-01

      The Warburg effect describes the increased utilization of glycolysis rather than oxidative phosphorylation by tumour cells for their energy requirements under physiological oxygen conditions. This effect has been the basis for much speculation on the survival advantage of tumour cells, tumourigenesis and the microenvironment of tumours. More recently, studies have begun to reveal how the Warburg effect could influence drug efficacy and how our understanding of tumour energetics could be exploited to improve drug development. In particular, evidence is emerging demonstrating how better modelling of the tumour metabolic microenvironment could lead to a better prediction of drug efficacy and the identification of new combination strategies. This review will provide details of the current understanding of the complex interplay between glucose metabolism and pharmacology and discuss opportunities for utilizing the Warburg effect in future drug development. PMID:26750865

  16. Origins of effective resistivity in collisionless magnetic reconnection

    SciTech Connect

    Singh, Nagendra

    2014-07-15

    The mechanisms that provide effective resistivity for supporting collisonless magnetic reconnection have remained unsettled despite numerous studies. Some of these studies demonstrated that the electron pressure nongyrotropy generates the resistivity (η{sub npg}) in the electron diffusion region (EDR). We derive an analytical relation for the effective resistivity (η{sub kin}) by momentum balance in a control volume in the EDR. Both η{sub npg} and η{sub kin} mutually compare well and they also compare well with the resistivity required to support reconnection electric field E{sub rec} in multi-dimensional particle-in-cell simulations as well as in satellite observations when reconnection occurs in an EDR. But they are about an order of magnitude or so smaller than that required when the reconnection occurred in a much wider reconnecting current sheet (RCS) of half width (w) of the order of the ion skin depth (d{sub i}), observed in the Earth magnetosphere. The chaos-induced resistivity reported in the literature is found to be even more deficient. We find that for reconnection in RCS with w ∼ d{sub i}, anomalous diffusion, such as the universal Bhom diffusion and/or that arising from kinetic Alfven waves, could fairly well account for the required resistivity.

  17. Out of band radiation effects on resist patterning

    SciTech Connect

    George, Simi A .; Naulleau, Patrick P.

    2011-03-11

    Our previous work estimated the expected out-of-band (OOB) flare contribution at the wafer level assuming that there is a given amount of OOB at the collector focus. We found that the OOB effects are wavelength, resist, and pattern dependent. In this paper, results from rigorous patterning evaluation of multiple OOB-exposed resists using the SEMATECH Berkeley 0.3-NA MET are presented. A controlled amount of OOB is applied to the resist films before patterning is completed with the MET. LER and process performance above the resolution limit and at the resolution limits are evaluated and presented. The results typically show a negative impact on LER and process performance after the OOB exposures except in the case of single resist formulation, where resolution and performance improvement was observed.

  18. Hypermultiplet metric and D-instantons

    NASA Astrophysics Data System (ADS)

    Alexandrov, Sergei; Banerjee, Sibasish

    2015-02-01

    We use the twistorial construction of D-instantons in Calabi-Yau compactifications of type II string theory to compute an explicit expression for the metric on the hypermultiplet moduli space affected by these non-perturbative corrections. In this way we obtain an exact quaternion-Kähler metric which is a non-trivial deformation of the local c-map. In the four-dimensional case corresponding to the universal hypermultiplet, our metric fits the Tod ansatz and provides an exact solution of the continuous Toda equation. We also analyze the fate of the curvature singularity of the perturbative metric by deriving an S-duality invariant equation which determines the singularity hypersurface after inclusion of the D(-1)-instanton effects.

  19. Effects of sleeve gastrectomy on insulin resistance

    PubMed Central

    CĂTOI, ADRIANA FLORINELA; PÂRVU, ALINA; MIRONIUC, AUREL; GALEA, ROMEO FLORIN; MUREŞAN, ADRIANA; BIDIAN, CRISTINA; POP, IOANA

    2016-01-01

    Background and aim Obesity is a major risk factor for the onset of insulin resistance (IR), hyperinsulinemia and type 2 diabetes mellitus (T2DM) Evidence data has proven that beyond important weight loss bariatric surgery especially Roux-en-Y gastric bypass (RYGB) and bilio-pancreatic diversion (BPD) leads to significant early reduction of insulinemia and of IR calculated through the homeostatic model assessment (HOMA-IR), independently of fat mass decrease. Sleeve gastrectomy (SG) is now used as a sole weight loss operation with good results. Therefore, the aim of the present study was to investigate the early changes of fasting blood glucose, insulin and HOMA-IR in a group of morbidly obese (MO) patients i.e. at 7, 30 and 90 days after SG. Methods The study included 20 MO patients (7 male and 13 female) submitted to SG. Anthropometrical (weight, body mass index –BMI, percent excess BMI loss -%EBMIL) and biochemical (plasma glucose, insulin and calculated HOMA-IR ) evaluation were performed before and at 7, 30 and 90 days after SG. In addition, a second group of 10 normal weight healthy subjects with a BMI ranging form 19 kg/m2 to 23.14 kg/m2, matched for age and gender was investigated. Results Plasma glucose (p=0.018), insulin (p=0.004) and HOMA-IR (p=0.006) values were statistically different between the studied groups. After surgery, at every follow-up point, there were statistically different weight and BMI mean values relative to the operation day (p<0.003). BMI, decreased at 7 days (estimated reduction=2.79; 95% CI:[2.12;3.45]), at 30 days (estimated reduction=5.65; 95% CI:[3.57;7.73]) and at 90 days (estimated reduction=10.88; 95% CI:[7.35;14.41]) respectively after SG. We noted a tendency toward statistical significant change of mean insulin values at 7 days after surgery (corrected p=0.075), no statistical change at 30 days (corrected p=0.327) and a significant change at 90 days (corrected p=0.027) after SG as compared to baseline. There was a

  20. Resist charging effect correction function qualification for photomasks production

    NASA Astrophysics Data System (ADS)

    Sidorkin, Vadim; Finken, Michael; Wandel, Timo; Nakayamada, Noriaki; Cantrell, G. R.

    2014-10-01

    We quantitatively evaluate Nuflare's latest resist charging effect correction (CEC) model for advanced photomask production using e-beam lithography. Functionality of this CEC model includes the simulation of static and timedependent charging effects together with an improved calibration method. CEC model calibration is performed by polynomial fitting of image placement distortions induced by various beam scattering effects on a special test design with writing density variations. CEC model parameters can be fine tuned for different photomask blank materials facilitating resist charging compensation maps for different product layers. Application of this CEC model into production yields a significant reduction in photomask image placement (IP), as well as improving photomask overlay between critical neighbouring layers. The correlations between IP improvement facilitated by this CEC model and single mask parameters are presented and discussed. The layer design specifics, resist and blank materials, coupled with their required exposure parameters are observed to be the major influences on CEC model performance.

  1. Quality metrics for sensor images

    NASA Technical Reports Server (NTRS)

    Ahumada, AL

    1993-01-01

    Methods are needed for evaluating the quality of augmented visual displays (AVID). Computational quality metrics will help summarize, interpolate, and extrapolate the results of human performance tests with displays. The FLM Vision group at NASA Ames has been developing computational models of visual processing and using them to develop computational metrics for similar problems. For example, display modeling systems use metrics for comparing proposed displays, halftoning optimizing methods use metrics to evaluate the difference between the halftone and the original, and image compression methods minimize the predicted visibility of compression artifacts. The visual discrimination models take as input two arbitrary images A and B and compute an estimate of the probability that a human observer will report that A is different from B. If A is an image that one desires to display and B is the actual displayed image, such an estimate can be regarded as an image quality metric reflecting how well B approximates A. There are additional complexities associated with the problem of evaluating the quality of radar and IR enhanced displays for AVID tasks. One important problem is the question of whether intruding obstacles are detectable in such displays. Although the discrimination model can handle detection situations by making B the original image A plus the intrusion, this detection model makes the inappropriate assumption that the observer knows where the intrusion will be. Effects of signal uncertainty need to be added to our models. A pilot needs to make decisions rapidly. The models need to predict not just the probability of a correct decision, but the probability of a correct decision by the time the decision needs to be made. That is, the models need to predict latency as well as accuracy. Luce and Green have generated models for auditory detection latencies. Similar models are needed for visual detection. Most image quality models are designed for static imagery

  2. Calculating effective resistances on underlying networks of association schemes

    NASA Astrophysics Data System (ADS)

    Jafarizadeh, M. A.; Sufiani, R.; Jafarizadeh, S.

    2008-07-01

    Recently, in the work of Jafarizadeh et al. [J. Phys, A: Math. Theor. 40, 4949 (2007); e-print arXiv:0705.2480], calculation of effective resistances on distance-regular networks was investigated, where in the first paper, the calculation was based on stratification and Stieltjes functions associated with the network, whereas in the latter one a recursive formula for effective resistances was given based on the Christoffel-Darboux identity. In this paper, evaluation of effective resistances on more general networks that are underlying networks of association schemes is considered, where by using the algebraic combinatoric structures of association schemes such as stratification and Bose-Mesner algebras, an explicit formula for effective resistances on these networks is given in terms of the parameters of the corresponding association schemes. Moreover, we show that for particular underlying networks of association schemes with diameter d such that the adjacency matrix A possesses d +1 distinct eigenvalues, all of the other adjacency matrices Ai, i ≠0, 1 can be written as polynomials of A, i.e., Ai=Pi(A), where Pi is not necessarily of degree i. Then, we use this property for these particular networks and assume that all of the conductances except for one of them, say, c ≡c1=1, are zero to give a procedure for evfor a galuating effective resistances on these networks. The preference of this procedure is that one can evaluate effective resistances by using the structure of their Bose-Mesner algebra without any need to know the spectrum of the adjacency matrices.

  3. Note on a new class of metrics: touching metrics

    NASA Astrophysics Data System (ADS)

    Starovoitov, Valery V.

    1996-09-01

    A new class of functions is studied. They are generalizations of the little-known `flower-shop distance'. We call them touching functions. Some of them are metrics, i.e. touching metrics (TM). Disks, circles and digital paths based on these metrics are also studied. The distance transform based on TMs is introduced and a scheme for the algorithm is given.

  4. Effects produced by CDU improvement of resist pattern with PEB temperature control for wiring resistance variation reduction

    NASA Astrophysics Data System (ADS)

    Tadokoro, Masahide; Shinozuka, Shinichi; Ogata, Kunie; Morimoto, Tamotsu

    2008-03-01

    Semiconductor manufacturing technology has shifted towards finer design rules, and demands for critical dimension uniformity (CDU) of resist patterns have become greater than ever. One of the methods for improving CDU of resist pattern is to control the temperature of post-exposure bake (PEB). When ArF resist is used, there is a certain relationship between critical dimension (CD) and PEB temperature. By utilizing this relationship, Resist Pattern CDU can be improved through control of within-wafer temperature distribution in the PEB process. We have already applied this method to Resist Pattern CDU improvement and have achieved these results. In this evaluation, we aim at: 1. Clarifying the relationship between the improvement in Resist Pattern CDU through PEB temperature control and the improvement in Etching Pattern CDU. 2. Verifying whether Resist Pattern CDU improvement through PEB temperature control has any effect on the reduction in wiring resistance variation. The evaluation procedure is: 1. Preparation of wafers with base film of doped Poly-Si (D-Poly). 2. Creation of two sets of samples on the base, a set of samples with good Resist Pattern CDU and a set of samples with poor Resist Pattern CDU. 3. Etching of the two sets under the same conditions. 4. Measurements of CD and wiring resistance. We used Optical CD Measurement (OCD) for measurement of resist pattern and etching pattern for the reason that OCD is minimally affected by Line Edge Roughness (LER). As a result, we found that; 1. The improvement in Resist Pattern CDU leads to the improvement in Etching Pattern CDU . 2. The improvement in Resist Pattern CDU has an effect on the reduction in wiring resistance variation. There is a cause-and-effect relationship between wiring resistance variation and transistor characteristics. From this relationship, we expect that the improvement in Resist Pattern CDU through PEB temperature control can contribute to device performance improvement.

  5. Combinatorial measurements of Hall effect and resistivity in oxide films.

    PubMed

    Clayhold, J A; Kerns, B M; Schroer, M D; Rench, D W; Logvenov, G; Bollinger, A T; Bozovic, I

    2008-03-01

    A system for the simultaneous measurement of the Hall effect in 31 different locations as well as the measurement of the resistivity in 30 different locations on a single oxide thin film grown with a composition gradient is described. Considerations for designing and operating a high-throughput system for characterizing highly conductive oxides with Hall coefficients as small as 10(-10) m3/C are discussed. Results from measurements on films grown using combinatorial molecular beam epitaxy show the usefulness of characterizing combinatorial libraries via both the resistivity and the Hall effect. PMID:18377026

  6. Corrections of surface fissure effect on apparent resistivity measurements

    NASA Astrophysics Data System (ADS)

    Gance, J.; Sailhac, P.; Malet, J.-P.

    2015-02-01

    Electrical resistivity tomography (ERT) is a useful tool to detect and track water flow paths in the subsoil. However, measurements are strongly affected by subsurface heterogeneities such as fissures of different sizes and genesis (shrinking-swelling, macropores and deformation). In this work, we focus on surface fissures characterized by dimensions lower than the interelectrode spacing and correct their effect on apparent resistivity pseudo-sections by incorporating fissure geometry in the topography. We show that fissures with depths greater than 0.10 times the interelectrode spacing for a dipole-dipole array and equal to 0.16 for the gradient array and the Wenner-Schlumberger arrays create significant anomalies (greater than 5 per cent) in the pseudo-section. Surface fissure widths and dip angles have little effect with respect to the fissure depths which can increase the apparent resistivity up to 200 per cent. The clogging of the fissures with water or soil material decreases the anomaly effect linearly with the percentage of filling. The correction of apparent resistivity values is possible for relatively simple fissure geometries and only requires a manual survey of the surface fissures. It allows to improve the quality of the inverted resistivity section by mitigating the inversion artefacts and therefore a better interpretation.

  7. The Kerr metric

    NASA Astrophysics Data System (ADS)

    Teukolsky, Saul A.

    2015-06-01

    This review describes the events leading up to the discovery of the Kerr metric in 1963 and the enormous impact the discovery has had in the subsequent 50 years. The review discusses the Penrose process, the four laws of black hole mechanics, uniqueness of the solution, and the no-hair theorems. It also includes Kerr perturbation theory and its application to black hole stability and quasi-normal modes. The Kerr metric's importance in the astrophysics of quasars and accreting stellar-mass black hole systems is detailed. A theme of the review is the ‘miraculous’ nature of the solution, both in describing in a simple analytic formula the most general rotating black hole, and in having unexpected mathematical properties that make many calculations tractable. Also included is a pedagogical derivation of the solution suitable for a first course in general relativity.

  8. Quality Metrics in Endoscopy

    PubMed Central

    Gurudu, Suryakanth R.

    2013-01-01

    Endoscopy has evolved in the past 4 decades to become an important tool in the diagnosis and management of many digestive diseases. Greater focus on endoscopic quality has highlighted the need to ensure competency among endoscopists. A joint task force of the American College of Gastroenterology and the American Society for Gastrointestinal Endoscopy has proposed several quality metrics to establish competence and help define areas of continuous quality improvement. These metrics represent quality in endoscopy pertinent to pre-, intra-, and postprocedural periods. Quality in endoscopy is a dynamic and multidimensional process that requires continuous monitoring of several indicators and benchmarking with local and national standards. Institutions and practices should have a process in place for credentialing endoscopists and for the assessment of competence regarding individual endoscopic procedures. PMID:24711767

  9. Bibliography on metrication

    NASA Astrophysics Data System (ADS)

    Smith, C. R.; Powel, M. B.

    1990-08-01

    This is a bibliography on metrication, the conversion to the International System of Units (SI), compiled from citations dated from January 1977 through July 1989. Citations include books, conference proceedings, newspapers, periodicals, government and civilian documents and reports. Subject indices for each type of citation and an author index for the entire work are included. A variety of subject categories such as legislation, construction, avionics, consumers, engineering, education, management, standards, agriculture, marketing and many others are available.

  10. Resistive switching effect and traps in partially fluorinated graphene films

    NASA Astrophysics Data System (ADS)

    Kurkina, Irina I.; Antonova, Irina V.; Nebogatikova, Nadezhda A.; Kapitonov, Albert N.; Smagulova, Svetlana A.

    2016-03-01

    A reversible resistive switching effect is detected in films created from the suspension of partially fluorinated graphene (more specifically, small graphene or few-layer graphene quantum dots in a fluorographene matrix), which makes them promising for resistive memory applications. This paper is focused on the investigation and comparison of the traps and transport in such films in both the low- and high-resistance state. The appearing set of traps for holes and electrons in the band gap of fluorinated graphene is revealed in the films at the low-resistance state, and their parameters (activation energy and trap density) are defined using charge spectroscopy. The minimum relaxation time of nonequilibrium carriers from different traps is found to be about 700 ns, and the energy level position of corresponding traps from the conduction band of a silicon substrate equals 0.08 eV. It has also been demonstrated that the carrier transport in the low-resistance state is determined by the same traps, and they form conductive channels in the film. Transport and non-equilibrium recharging processes in the state of high resistance are found to occur above all by means of carrier tunneling through the potential barriers in the films.

  11. Resistance training is medicine: effects of strength training on health.

    PubMed

    Westcott, Wayne L

    2012-01-01

    Inactive adults experience a 3% to 8% loss of muscle mass per decade, accompanied by resting metabolic rate reduction and fat accumulation. Ten weeks of resistance training may increase lean weight by 1.4 kg, increase resting metabolic rate by 7%, and reduce fat weight by 1.8 kg. Benefits of resistance training include improved physical performance, movement control, walking speed, functional independence, cognitive abilities, and self-esteem. Resistance training may assist prevention and management of type 2 diabetes by decreasing visceral fat, reducing HbA1c, increasing the density of glucose transporter type 4, and improving insulin sensitivity. Resistance training may enhance cardiovascular health, by reducing resting blood pressure, decreasing low-density lipoprotein cholesterol and triglycerides, and increasing high-density lipoprotein cholesterol. Resistance training may promote bone development, with studies showing 1% to 3% increase in bone mineral density. Resistance training may be effective for reducing low back pain and easing discomfort associated with arthritis and fibromyalgia and has been shown to reverse specific aging factors in skeletal muscle. PMID:22777332

  12. Metrics for Energy Resilience

    SciTech Connect

    Paul E. Roege; Zachary A. Collier; James Mancillas; John A. McDonagh; Igor Linkov

    2014-09-01

    Energy lies at the backbone of any advanced society and constitutes an essential prerequisite for economic growth, social order and national defense. However there is an Achilles heel to today?s energy and technology relationship; namely a precarious intimacy between energy and the fiscal, social, and technical systems it supports. Recently, widespread and persistent disruptions in energy systems have highlighted the extent of this dependence and the vulnerability of increasingly optimized systems to changing conditions. Resilience is an emerging concept that offers to reconcile considerations of performance under dynamic environments and across multiple time frames by supplementing traditionally static system performance measures to consider behaviors under changing conditions and complex interactions among physical, information and human domains. This paper identifies metrics useful to implement guidance for energy-related planning, design, investment, and operation. Recommendations are presented using a matrix format to provide a structured and comprehensive framework of metrics relevant to a system?s energy resilience. The study synthesizes previously proposed metrics and emergent resilience literature to provide a multi-dimensional model intended for use by leaders and practitioners as they transform our energy posture from one of stasis and reaction to one that is proactive and which fosters sustainable growth.

  13. Performance Metrics for Commercial Buildings

    SciTech Connect

    Fowler, Kimberly M.; Wang, Na; Romero, Rachel L.; Deru, Michael P.

    2010-09-30

    Commercial building owners and operators have requested a standard set of key performance metrics to provide a systematic way to evaluate the performance of their buildings. The performance metrics included in this document provide standard metrics for the energy, water, operations and maintenance, indoor environmental quality, purchasing, waste and recycling and transportation impact of their building. The metrics can be used for comparative performance analysis between existing buildings and industry standards to clarify the impact of sustainably designed and operated buildings.

  14. Evaluating Algorithm Performance Metrics Tailored for Prognostics

    NASA Technical Reports Server (NTRS)

    Saxena, Abhinav; Celaya, Jose; Saha, Bhaskar; Saha, Sankalita; Goebel, Kai

    2009-01-01

    Prognostics has taken a center stage in Condition Based Maintenance (CBM) where it is desired to estimate Remaining Useful Life (RUL) of the system so that remedial measures may be taken in advance to avoid catastrophic events or unwanted downtimes. Validation of such predictions is an important but difficult proposition and a lack of appropriate evaluation methods renders prognostics meaningless. Evaluation methods currently used in the research community are not standardized and in many cases do not sufficiently assess key performance aspects expected out of a prognostics algorithm. In this paper we introduce several new evaluation metrics tailored for prognostics and show that they can effectively evaluate various algorithms as compared to other conventional metrics. Specifically four algorithms namely; Relevance Vector Machine (RVM), Gaussian Process Regression (GPR), Artificial Neural Network (ANN), and Polynomial Regression (PR) are compared. These algorithms vary in complexity and their ability to manage uncertainty around predicted estimates. Results show that the new metrics rank these algorithms in different manner and depending on the requirements and constraints suitable metrics may be chosen. Beyond these results, these metrics offer ideas about how metrics suitable to prognostics may be designed so that the evaluation procedure can be standardized. 1

  15. Metrics for Offline Evaluation of Prognostic Performance

    NASA Technical Reports Server (NTRS)

    Saxena, Abhinav; Celaya, Jose; Saha, Bhaskar; Saha, Sankalita; Goebel, Kai

    2010-01-01

    Prognostic performance evaluation has gained significant attention in the past few years. Currently, prognostics concepts lack standard definitions and suffer from ambiguous and inconsistent interpretations. This lack of standards is in part due to the varied end-user requirements for different applications, time scales, available information, domain dynamics, etc. to name a few. The research community has used a variety of metrics largely based on convenience and their respective requirements. Very little attention has been focused on establishing a standardized approach to compare different efforts. This paper presents several new evaluation metrics tailored for prognostics that were recently introduced and were shown to effectively evaluate various algorithms as compared to other conventional metrics. Specifically, this paper presents a detailed discussion on how these metrics should be interpreted and used. These metrics have the capability of incorporating probabilistic uncertainty estimates from prognostic algorithms. In addition to quantitative assessment they also offer a comprehensive visual perspective that can be used in designing the prognostic system. Several methods are suggested to customize these metrics for different applications. Guidelines are provided to help choose one method over another based on distribution characteristics. Various issues faced by prognostics and its performance evaluation are discussed followed by a formal notational framework to help standardize subsequent developments.

  16. On Applying the Prognostic Performance Metrics

    NASA Technical Reports Server (NTRS)

    Saxena, Abhinav; Celaya, Jose; Saha, Bhaskar; Saha, Sankalita; Goebel, Kai

    2009-01-01

    Prognostics performance evaluation has gained significant attention in the past few years. As prognostics technology matures and more sophisticated methods for prognostic uncertainty management are developed, a standardized methodology for performance evaluation becomes extremely important to guide improvement efforts in a constructive manner. This paper is in continuation of previous efforts where several new evaluation metrics tailored for prognostics were introduced and were shown to effectively evaluate various algorithms as compared to other conventional metrics. Specifically, this paper presents a detailed discussion on how these metrics should be interpreted and used. Several shortcomings identified, while applying these metrics to a variety of real applications, are also summarized along with discussions that attempt to alleviate these problems. Further, these metrics have been enhanced to include the capability of incorporating probability distribution information from prognostic algorithms as opposed to evaluation based on point estimates only. Several methods have been suggested and guidelines have been provided to help choose one method over another based on probability distribution characteristics. These approaches also offer a convenient and intuitive visualization of algorithm performance with respect to some of these new metrics like prognostic horizon and alpha-lambda performance, and also quantify the corresponding performance while incorporating the uncertainty information.

  17. Say "Yes" to Metric Measure.

    ERIC Educational Resources Information Center

    Monroe, Eula Ewing; Nelson, Marvin N.

    2000-01-01

    Provides a brief history of the metric system. Discusses the infrequent use of the metric measurement system in the United States, why conversion from the customary system to the metric system is difficult, and the need for change. (Contains 14 resources.) (ASK)

  18. Metrication, American Style. Fastback 41.

    ERIC Educational Resources Information Center

    Izzi, John

    The purpose of this pamphlet is to provide a starting point of information on the metric system for any concerned or interested reader. The material is organized into five brief chapters: Man and Measurement; Learning the Metric System; Progress Report: Education; Recommended Sources; and Metrication, American Style. Appendixes include an…

  19. Metrication in a global environment

    NASA Technical Reports Server (NTRS)

    Aberg, J.

    1994-01-01

    A brief history about the development of the metric system of measurement is given. The need for the U.S. to implement the 'SI' metric system in the international markets, especially in the aerospace and general trade, is discussed. Development of metric implementation and experiences locally, nationally, and internationally are included.

  20. Some References on Metric Information.

    ERIC Educational Resources Information Center

    National Bureau of Standards (DOC), Washington, DC.

    This resource work lists metric information published by the U.S. Government and the American National Standards Institute. Also organizations marketing metric materials for education are given. A short table of conversions is included as is a listing of basic metric facts for everyday living. (LS)

  1. Resistive Memory for Harsh Electronics: Immunity to Surface Effect and High Corrosion Resistance via Surface Modification

    PubMed Central

    Huang, Teng-Han; Yang, Po-Kang; Lien, Der-Hsien; Kang, Chen-Fang; Tsai, Meng-Lin; Chueh, Yu-Lun; He, Jr-Hau

    2014-01-01

    The tolerance/resistance of the electronic devices to extremely harsh environments is of supreme interest. Surface effects and chemical corrosion adversely affect stability and operation uniformity of metal oxide resistive memories. To achieve the surrounding-independent behavior, the surface modification is introduced into the ZnO memristors via incorporating fluorine to replace the oxygen sites. F-Zn bonds is formed to prevent oxygen chemisorption and ZnO dissolution upon corrosive atmospheric exposure, which effectively improves switching characteristics against harmful surroundings. In addition, the fluorine doping stabilizes the cycling endurance and narrows the distribution of switching parameters. The outcomes provide valuable insights for future nonvolatile memory developments in harsh electronics. PMID:24638086

  2. Oral Antibiotics are Effective for Highly Resistant Hip Arthroplasty Infections

    PubMed Central

    Esteban, Jaime; García-Cimbrelo, Eduardo

    2009-01-01

    Infected arthroplasties reportedly have a lower eradication rate when caused by highly resistant and/or polymicrobial isolates and in these patients most authors recommend intravenous antibiotics. We asked whether two-stage revision with interim oral antibiotics could eradicate these infections. We prospectively followed 36 patients (mean age, 71.8 years) with late hip arthroplasty infections. Combinations of oral antibiotics were prescribed according to cultures, biofilm, and intracellular effectiveness. The minimum followup was 1 year (mean, 4.4 years; range, 1–12 years). We presumed eradication in the absence of clinical, serologic, and radiographic signs of infection. Infection was eradicated in all 13 patients with highly resistant bacteria who completed a two-stage protocol (10 with methicillin-resistant Staphylococci) and in eight of 11 patients treated with only the first stage (and six of nine with methicillin-resistant Staphylococci). Infection was eradicated in six of six patients with polymicrobial isolates (of sensitive and/or resistant bacteria) who completed a two-stage protocol and in five of seven with polymicrobial isolates treated with only the first surgery. The Harris hip score averaged 88.1 (range, 70–98) in patients who underwent reimplantation and 56.8 (range, 32–76) in patients who underwent resection arthroplasty. Long cycles of combined oral antibiotics plus a two-stage surgical exchange appear a promising alternative for infections by highly resistant bacteria, methicillin-resistant Staphylococci, and polymicrobial infections. Level of Evidence: Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence. PMID:19333670

  3. Microwave-Induced Resistance Oscillations as a Classical Memory Effect

    NASA Astrophysics Data System (ADS)

    Beltukov, Y. M.; Dyakonov, M. I.

    2016-04-01

    By numerical simulations and analytical studies, we show that the phenomenon of microwave-induced resistance oscillations can be understood as a classical memory effect caused by recollisions of electrons with scattering centers after a cyclotron period. We develop a Drude-like approach to magnetotransport in the presence of a microwave field, taking into account memory effects, and find an excellent agreement between numerical and analytical results, as well as a qualitative agreement with experiment.

  4. Optical metrics and projective equivalence

    SciTech Connect

    Casey, Stephen; Dunajski, Maciej; Gibbons, Gary; Warnick, Claude

    2011-04-15

    Trajectories of light rays in a static spacetime are described by unparametrized geodesics of the Riemannian optical metric associated with the Lorentzian spacetime metric. We investigate the uniqueness of this structure and demonstrate that two different observers, moving relative to one another, who both see the Universe as static may determine the geometry of the light rays differently. More specifically, we classify Lorentzian metrics admitting more than one hyper-surface orthogonal timelike Killing vector and analyze the projective equivalence of the resulting optical metrics. These metrics are shown to be projectively equivalent up to diffeomorphism if the static Killing vectors generate a group SL(2,R), but not projectively equivalent in general. We also consider the cosmological C metrics in Einstein-Maxwell theory and demonstrate that optical metrics corresponding to different values of the cosmological constant are projectively equivalent.

  5. Short Lived Climate Pollutants cause a Long Lived Effect on Sea-level Rise: Analyzing climate metrics for sea-level rise

    NASA Astrophysics Data System (ADS)

    Sterner, E.; Johansson, D. J.

    2013-12-01

    Climate change depends on the increase of several different atmospheric pollutants. While long term global warming will be determined mainly by carbon dioxide, warming in the next few decades will depend to a large extent on short lived climate pollutants (SLCP). Reducing emissions of SLCPs could contribute to lower the global mean surface temperature by 0.5 °C already by 2050 (Shindell et al. 2012). Furthermore, the warming effect of one of the most potent SLCPs, black carbon (BC), may have been underestimated in the past. Bond et al. (2013) presents a new best estimate of the total BC radiative forcing (RF) of 1.1 W/m2 (90 % uncertainty bounds of 0.17 to 2.1 W/m2) since the beginning of the industrial era. BC is however never emitted alone and cooling aerosols from the same sources offset a majority of this RF. In the wake of calls for mitigation of SLCPs it is important to study other aspects of the climate effect of SLCPs. One key impact of climate change is sea-level rise (SLR). In a recent study, the effect of SLCP mitigation scenarios on SLR is examined. Hu et al (2013) find a substantial effect on SLR from mitigating SLCPs sharply, reducing SLR by 22-42% by 2100. We choose a different approach focusing on emission pulses and analyse a metric based on sea level rise so as to further enlighten the SLR consequences of SLCPs. We want in particular to understand the time dynamics of SLR impacts caused by SLCPs compared to other greenhouse gases. The most commonly used physical based metrics are GWP and GTP. We propose and evaluate an additional metric: The global sea-level rise potential (GSP). The GSP is defined as the sea level rise after a time horizon caused by an emissions pulse of a forcer to the sea level rise after a time horizon caused by an emissions pulse of a CO2. GSP is evaluated and compared to GWP and GTP using a set of climate forcers chosen to cover the whole scale of atmospheric perturbation life times (BC, CH4, N2O, CO2 and SF6). The study

  6. Building a Metric

    NASA Technical Reports Server (NTRS)

    Spencer, Shakira

    2007-01-01

    Launch Services Program is a Kennedy Space Center based program whose job it is to undertake all the necessary roles required to successfully launch Expendable Launch Vehicles. This project was designed to help Launch Services Program accurately report how successful they have been at launching missions on time or +/- 2 days from the scheduled launch date and also if they weren't successful, why. This information will be displayed in the form of a metric, which answers these questions in a clear and accurate way.

  7. SI (Metric) handbook

    NASA Technical Reports Server (NTRS)

    Artusa, Elisa A.

    1994-01-01

    This guide provides information for an understanding of SI units, symbols, and prefixes; style and usage in documentation in both the US and in the international business community; conversion techniques; limits, fits, and tolerance data; and drawing and technical writing guidelines. Also provided is information of SI usage for specialized applications like data processing and computer programming, science, engineering, and construction. Related information in the appendixes include legislative documents, historical and biographical data, a list of metric documentation, rules for determining significant digits and rounding, conversion factors, shorthand notation, and a unit index.

  8. Ribonucleotide reductase is an effective target to overcome gemcitabine resistance in gemcitabine-resistant pancreatic cancer cells with dual resistant factors.

    PubMed

    Minami, Kentaro; Shinsato, Yoshinari; Yamamoto, Masatatsu; Takahashi, Homare; Zhang, Shaoxuan; Nishizawa, Yukihiko; Tabata, Sho; Ikeda, Ryuji; Kawahara, Kohich; Tsujikawa, Kazutake; Chijiiwa, Kazuo; Yamada, Katsushi; Akiyama, Shin-ichi; Pérez-Torras, Sandra; Pastor-Anglada, Marcal; Furukawa, Tatsuhiko; Yasuo, Takeda

    2015-03-01

    Gemcitabine is widely used for pancreatic, lung, and bladder cancer. However, drug resistance against gemcitabine is a large obstacle to effective chemotherapy. Nucleoside transporters, nucleoside and nucleotide metabolic enzymes, and efflux transporters have been reported to be involved in gemcitabine resistance. Although most of the resistant factors are supposed to be related to each other, it is unclear how one factor can affect the other one. In this study, we established gemcitabine-resistant pancreatic cancer cell lines. Gemcitabine resistance in these cells is caused by two major processes: a decrease in gemcitabine uptake and overexpression of ribonucleotide reductase large subunit (RRM1). Knockdown of RRM1, but not the overexpression of concentrative nucleoside transporter 1 (CNT1), could completely overcome the gemcitabine resistance. RRM1 knockdown in gemcitabine-resistant cells could increase the intracellular accumulation of gemcitabine by increasing the nucleoside transporter expression. Furthermore, a synergistic effect was observed between hydroxyurea, a ribonucleotide reductase (RR) inhibitor, and gemcitabine on the gemcitabine-resistant cells. Here we indicate that RR is one of the most promising targets to overcome gemcitabine resistance in gemcitabine-resistant cells with dual resistant factors. PMID:25837929

  9. PREDICTING THE ACUTE BEHAVIORAL EFFECTS OF TOLUENE INHALED FOR 24 HRS IN RATS: DOSE METRICS, METABOLISM AND BEHAVIORAL TOLERANCE

    EPA Science Inventory

    Purpose: Recent research on the acute effects of volatile organic compounds (VOCs) suggests that extrapolation from short (~ 1 h) to long durations (up to 4 h) is improved by using estimates of brain toluene concentration ( Br[ToI)] instead of cumulative inhaled dose (C x t) as a...

  10. Nonlinearity of resistive impurity effects on van der Pauw measurements

    SciTech Connect

    Koon, D. W.

    2006-09-15

    The dependence of van der Pauw resistivity measurements on local macroscopic inhomogeneities is shown to be nonlinear. A resistor grid network models a square laminar specimen, enabling the investigation of both positive and negative local perturbations in resistivity. The effect of inhomogeneity is measured both experimentally, for an 11x11 grid, and computationally, for both 11x11 and 101x101 grids. The maximum 'shortlike' perturbation produces 3.1{+-}0.2 times the effect predicted by the linear approximation, regardless of its position within the specimen, while all 'openlike' perturbations produce a smaller effect than predicted. An empirical nonlinear correction for f(x,y) is presented which provides excellent fit over the entire range of both positive and negative perturbations for the entire specimen.

  11. Exploring Metric Symmetry

    SciTech Connect

    Zwart, P.H.; Grosse-Kunstleve, R.W.; Adams, P.D.

    2006-07-31

    Relatively minor perturbations to a crystal structure can in some cases result in apparently large changes in symmetry. Changes in space group or even lattice can be induced by heavy metal or halide soaking (Dauter et al, 2001), flash freezing (Skrzypczak-Jankun et al, 1996), and Se-Met substitution (Poulsen et al, 2001). Relations between various space groups and lattices can provide insight in the underlying structural causes for the symmetry or lattice transformations. Furthermore, these relations can be useful in understanding twinning and how to efficiently solve two different but related crystal structures. Although (pseudo) symmetric properties of a certain combination of unit cell parameters and a space group are immediately obvious (such as a pseudo four-fold axis if a is approximately equal to b in an orthorhombic space group), other relations (e.g. Lehtio, et al, 2005) that are less obvious might be crucial to the understanding and detection of certain idiosyncrasies of experimental data. We have developed a set of tools that allows straightforward exploration of possible metric symmetry relations given unit cell parameters and a space group. The new iotbx.explore{_}metric{_}symmetry command produces an overview of the various relations between several possible point groups for a given lattice. Methods for finding relations between a pair of unit cells are also available. The tools described in this newsletter are part of the CCTBX libraries, which are included in the latest (versions July 2006 and up) PHENIX and CCI Apps distributions.

  12. Pure Lovelock Kasner metrics

    NASA Astrophysics Data System (ADS)

    Camanho, Xián O.; Dadhich, Naresh; Molina, Alfred

    2015-09-01

    We study pure Lovelock vacuum and perfect fluid equations for Kasner-type metrics. These equations correspond to a single Nth order Lovelock term in the action in d=2N+1,2N+2 dimensions, and they capture the relevant gravitational dynamics when aproaching the big-bang singularity within the Lovelock family of theories. Pure Lovelock gravity also bears out the general feature that vacuum in the critical odd dimension, d=2N+1, is kinematic, i.e. we may define an analogue Lovelock-Riemann tensor that vanishes in vacuum for d=2N+1, yet the Riemann curvature is non-zero. We completely classify isotropic and vacuum Kasner metrics for this class of theories in several isotropy types. The different families can be characterized by means of certain higher order 4th rank tensors. We also analyze in detail the space of vacuum solutions for five- and six dimensional pure Gauss-Bonnet theory. It possesses an interesting and illuminating geometric structure and symmetries that carry over to the general case. We also comment on a closely related family of exponential solutions and on the possibility of solutions with complex Kasner exponents. We show that the latter imply the existence of closed timelike curves in the geometry.

  13. Relating reconnection rate, exhaust structure and effective resistivity

    SciTech Connect

    Singh, Nagendra

    2014-03-15

    The magnetic reconnection structure consists of a central diffusion region (CDR) and a cone or wedge shaped reconnection exhaust containing accelerated plasma flows and electromagnetic fluctuations. We predict here the relationship among the exhaust half-cone angle (θ{sub e}), the half width (w) of the CDR, the outflow velocity V{sub o}, and the effective resistivity (η{sub eff}), which includes the effects of all the nonideal terms in the generalized Ohm's law. The effective resistivity is defined as the ratio of reconnection electric field E{sub rec} to the current density J{sub y} at the X point and it essentially represents the loss of momentum from the current-carrying plasma particles due to scattering by waves, their inertia or outflux from the CDR. The relation is checked against relevant results previously reported from laboratory experiments, space observations, and simulations, showing excellent agreement. The relation can be used for estimating the ad-hoc effective resistivity often used in magnetohydrodynamic modeling of reconnection.

  14. How inaccurate is weight as a metric for patient size? Comparing patient weight to effective diameter for size-specific dose estimation

    NASA Astrophysics Data System (ADS)

    Cook, Tessa S.; Chadalavada, Seetharam C.; Boonn, William W.

    2013-03-01

    One of the biggest challenges in dose monitoring is customization of CT dose estimates to the patient. Patient size remains a highly significant variable. One metric that has previously been used for patient size is patient weight, though this is often criticized as inaccurate. In this work, we compare patients' weight to their effective diameters obtained from a CT scan of the chest or the abdomen. CT exams of the chest (N=163) and abdomen/pelvis (N=168) performed on adult patients in July 2012 were randomly selected for analysis. The effective diameter of the patient for each exam was determined using the central slice of the scan region for each exam using eXposure™ (Radimetrics, Inc., Toronto, Canada). In some cases, the same patient had both a chest and abdominopelvic CT, so effective diameters from both regions were analyzed. In this small sample size, there appears to be a linear relationship between patient weight and effective diameter when measured in the mid-chest and mid-abdomen of adult patients. However, for each weight, patient effective diameter can vary by 5 cm from the regression line in both the chest and the abdomen. A 5-cm difference corresponds to a difference of approximately 0.2 in the chest and 0.3 in the abdomen/pelvis for the correction factors recommended for size-specific dose estimation by the AAPM. This preliminary data suggests that weight-based CT protocoling may in fact be appropriate for some adults. However, more work is needed to identify those patients in whom weight-based protocoling is not appropriate.

  15. A study for polarized illumination effects in photo resist

    NASA Astrophysics Data System (ADS)

    Lei, Junjiang; Bai, Min; Shiely, Jim; Zhang, Lin

    2005-06-01

    Using a polarized illumination source is a promising RET technique for improvement of wafer printability for features of 65 nm and below. Polarization effects could be considered in several different stages of lithography modeling and simulation. For example, light propagation in thin films, wave superstition and interference in the thin film stack, and mask-induced polarization all deserve special attention and delicate treatment because TE and TM waves have different behaviors through these stages. In this paper we consider effects of polarized illumination in photo resist, using the Kirchhoff approximation for masks. We discuss some theoretical aspects of our vector modeling methods and show an example of simulation for polarized illumination effects.

  16. Study of parasitic resistance effects in nanowire and nanoribbon biosensors.

    PubMed

    Zeimpekis, Ioannis; Sun, Kai; Hu, Chunxiao; Thomas, Owain; de Planque, Maurits Rr; Chong, Harold Mh; Morgan, Hywel; Ashburn, Peter

    2015-01-01

    In this work, we investigate sensor design approaches for eliminating the effects of parasitic resistance in nanowire and nanoribbon biosensors. Measurements of pH with polysilicon nanoribbon biosensors are used to demonstrate a reduction in sensitivity as the sensor length is reduced. The sensitivity (normalised conductance change) is reduced from 11% to 5.5% for a pH change from 9 to 3 as the sensing window length is reduced from 51 to 11 μm. These results are interpreted using a simple empirical model, which is also used to demonstrate how the sensitivity degradation can be alleviated by a suitable choice of sensor window length. Furthermore, a differential sensor design is proposed that eliminates the detrimental effects of parasitic resistance. Measurements on the differential sensor give a sensitivity of 15%, which is in good agreement with the predicted maximum sensitivity obtained from modeling. PMID:25852375

  17. Postactivation potentiation effects after heavy resistance exercise on running speed.

    PubMed

    Chatzopoulos, Dimitris E; Michailidis, Charalambos J; Giannakos, Athanasios K; Alexiou, Kostas C; Patikas, Dimitrios A; Antonopoulos, Christos B; Kotzamanidis, Christos M

    2007-11-01

    The purpose of this study was to investigate the postactivation potentiation effect after a heavy resistance stimulus (HRS) on running speed (RS). Fifteen amateur team game players (basketball, volleyball, handball, and soccer players), ages 18-23 years running the 30-m dash and the intermediate phase of 0-10 and 0-30 m sprints, were used to evaluate RS. Resistance training consisted of 10 single repetitions at 90% of 1 repetition maximum. The running tests were performed 3 times--(a) 3 minutes prior the HRS, (b) 3 minutes after the HRS, and (c) 5 minutes after the HRS--in separated training sessions. Results showed that RS was not affected 3 minutes after the resistance training, but it increased for both selected running phases (0-10 and 0-30 m) 5 minutes after the HRS (p < 0.05). These findings indicate that heavy resistance exercise improves 10- and 30-m sprint performance when performed 5 minutes after the exercise bout. PMID:18076255

  18. Application of the quantum Hall effect to resistance metrology

    NASA Astrophysics Data System (ADS)

    Poirier, Wilfrid; Schopfer, Félicien; Guignard, Jérémie; Thévenot, Olivier; Gournay, Pierre

    2011-05-01

    The quantum Hall effect (QHE) discovery has revolutionized metrology by providing with a representation of the unit of resistance, R, that can be reproduced within a relative uncertainty of one part in 10 9 and is theoretically only linked to Planck's constant h and the electron charge e. This breakthrough also results from the development of resistance comparison bridges using cryogenic current comparator (CCC). The QHE experimental know-how now allows the realization of perfectly quantized Quantum Hall Array Resistance Standards (QHARS) by combining a large number of single Hall bars. In the context of an evolution of the Système International (SI) of units by fixing some fundamental constants of physics, the determination of the von Klitzing constant R through the use of the so-called Thompson-Lampard calculable capacitor and the realization of refined universality tests of the QHE are of prime importance. Finally, the fascinating graphene material might be a new turning point in resistance metrology.

  19. [Effect of transgenic insect-resistant rice on biodiversity].

    PubMed

    Zhang, Lei; Zhu, Zhen

    2011-05-01

    Rice is the most important food crops in maintaining food security in China. The loss of China's annual rice production caused by pests is over ten million tons. Present studies showed that the transgenic insect-resistant rice can substantially reduce the application amount of chemical pesticides. In the case of no pesticide use, the pest density in transgenic rice field is significantly lower than that in non-transgenic field, and the neutral insects and natural enemies of pests increased significantly, indicating that the ecological environment and biodiversity toward the positive direction. The gene flow frequency from transgenic rice is dramatically reduced with the distance increases, reaching less than 0.01% at the distance of 6.2 m. Application of transgenic insect-resistant rice in China has an important significance for ensuring food security, maintaining sustainable agricultural development, and protecting the ecological environment and biodiversity. This review summarized the research progress in transgenic insect-resistant rice and its effect on biodiversity. The research directions and development trends of crop pest controlling in future are discussed. These help to promote better use of transgenic insect-resistant rice. PMID:21586387

  20. Effects of resistance exercise on cardiopulmonary factors in sedentary individuals

    PubMed Central

    Janyacharoen, Taweesak; Thayon, Methiya; Bushong, Wanwisa; Jaikla, Nussamol; Sawanyawisuth, Kittisak

    2016-01-01

    [Purpose] This study investigated the effects of resistance exercise on cardiopulmonary functions in young sedentary subjects. [Subjects] Forty-two young and healthy subjects with a sedentary lifestyle were included in this study. [Methods] The subjects were randomly divided into 2 groups: control and experimental. The control group (n=21) received health education and continued with normal activities of daily living. The experimental group (n=21) underwent resistance training, health education, and continued with normal activities of daily living. The resistance exercise program consisted of 3 postural exercises: chest press, dumbbell pullover, and flat-bench dumbbell fly. The subjects received this intervention 3 times/week for 8 weeks. [Results] The baseline characteristics were comparable between the 2 groups. The 6-minute-walk test score, peak expiratory flow, forced vital capacity, forced expiratory volume in 1 second, maximal voluntary ventilation, and chest expansions were significantly improved post-intervention in the experimental group and between the 2 groups. [Conclusion] Cardiopulmonary functions in young sedentary subjects were significantly improved with the 8-week resistance exercise program. PMID:26957760

  1. Effects of resistance exercise on cardiopulmonary factors in sedentary individuals.

    PubMed

    Janyacharoen, Taweesak; Thayon, Methiya; Bushong, Wanwisa; Jaikla, Nussamol; Sawanyawisuth, Kittisak

    2016-01-01

    [Purpose] This study investigated the effects of resistance exercise on cardiopulmonary functions in young sedentary subjects. [Subjects] Forty-two young and healthy subjects with a sedentary lifestyle were included in this study. [Methods] The subjects were randomly divided into 2 groups: control and experimental. The control group (n=21) received health education and continued with normal activities of daily living. The experimental group (n=21) underwent resistance training, health education, and continued with normal activities of daily living. The resistance exercise program consisted of 3 postural exercises: chest press, dumbbell pullover, and flat-bench dumbbell fly. The subjects received this intervention 3 times/week for 8 weeks. [Results] The baseline characteristics were comparable between the 2 groups. The 6-minute-walk test score, peak expiratory flow, forced vital capacity, forced expiratory volume in 1 second, maximal voluntary ventilation, and chest expansions were significantly improved post-intervention in the experimental group and between the 2 groups. [Conclusion] Cardiopulmonary functions in young sedentary subjects were significantly improved with the 8-week resistance exercise program. PMID:26957760

  2. The effects of solution resistance on electrochemical noise resistance measurements: A theoretical analysis

    SciTech Connect

    Cottis, R.A.; Turgoose, S.; Mendoza-Flores, J.

    1996-12-31

    The theoretical basis of electrochemical noise resistance measurements in the presence of significant solution resistance is examined with a simple linear circuit model. A shot noise model of the noise generation process is assumed to develop the dependence of electrochemical potential and current noise on corrosion rate, although the conclusions in respect to electrochemical noise resistance do not depend on this. It is concluded that the electrochemical noise resistance method measures essentially the same resistance as is measured by a conventional linear polarization resistance measurement, although it is found to be capable of making measurements in higher resistance systems.

  3. The metric on field space, functional renormalization, and metric-torsion quantum gravity

    NASA Astrophysics Data System (ADS)

    Reuter, Martin; Schollmeyer, Gregor M.

    2016-04-01

    Searching for new non-perturbatively renormalizable quantum gravity theories, functional renormalization group (RG) flows are studied on a theory space of action functionals depending on the metric and the torsion tensor, the latter parameterized by three irreducible component fields. A detailed comparison with Quantum Einstein-Cartan Gravity (QECG), Quantum Einstein Gravity (QEG), and "tetrad-only" gravity, all based on different theory spaces, is performed. It is demonstrated that, over a generic theory space, the construction of a functional RG equation (FRGE) for the effective average action requires the specification of a metric on the infinite-dimensional field manifold as an additional input. A modified FRGE is obtained if this metric is scale-dependent, as it happens in the metric-torsion system considered.

  4. Evaluation metrics for bone segmentation in ultrasound

    NASA Astrophysics Data System (ADS)

    Lougheed, Matthew; Fichtinger, Gabor; Ungi, Tamas

    2015-03-01

    Tracked ultrasound is a safe alternative to X-ray for imaging bones. The interpretation of bony structures is challenging as ultrasound has no specific intensity characteristic of bones. Several image segmentation algorithms have been devised to identify bony structures. We propose an open-source framework that would aid in the development and comparison of such algorithms by quantitatively measuring segmentation performance in the ultrasound images. True-positive and false-negative metrics used in the framework quantify algorithm performance based on correctly segmented bone and correctly segmented boneless regions. Ground-truth for these metrics are defined manually and along with the corresponding automatically segmented image are used for the performance analysis. Manually created ground truth tests were generated to verify the accuracy of the analysis. Further evaluation metrics for determining average performance per slide and standard deviation are considered. The metrics provide a means of evaluating accuracy of frames along the length of a volume. This would aid in assessing the accuracy of the volume itself and the approach to image acquisition (positioning and frequency of frame). The framework was implemented as an open-source module of the 3D Slicer platform. The ground truth tests verified that the framework correctly calculates the implemented metrics. The developed framework provides a convenient way to evaluate bone segmentation algorithms. The implementation fits in a widely used application for segmentation algorithm prototyping. Future algorithm development will benefit by monitoring the effects of adjustments to an algorithm in a standard evaluation framework.

  5. Cleanroom Energy Efficiency: Metrics and Benchmarks

    SciTech Connect

    International SEMATECH Manufacturing Initiative; Mathew, Paul A.; Tschudi, William; Sartor, Dale; Beasley, James

    2010-07-07

    Cleanrooms are among the most energy-intensive types of facilities. This is primarily due to the cleanliness requirements that result in high airflow rates and system static pressures, as well as process requirements that result in high cooling loads. Various studies have shown that there is a wide range of cleanroom energy efficiencies and that facility managers may not be aware of how energy efficient their cleanroom facility can be relative to other cleanroom facilities with the same cleanliness requirements. Metrics and benchmarks are an effective way to compare one facility to another and to track the performance of a given facility over time. This article presents the key metrics and benchmarks that facility managers can use to assess, track, and manage their cleanroom energy efficiency or to set energy efficiency targets for new construction. These include system-level metrics such as air change rates, air handling W/cfm, and filter pressure drops. Operational data are presented from over 20 different cleanrooms that were benchmarked with these metrics and that are part of the cleanroom benchmark dataset maintained by Lawrence Berkeley National Laboratory (LBNL). Overall production efficiency metrics for cleanrooms in 28 semiconductor manufacturing facilities in the United States and recorded in the Fabs21 database are also presented.

  6. Product Accuracy Effect of Oblique and Vertical Non-Metric Digital Camera Utilization in Uav-Photogrammetry to Determine Fault Plane

    NASA Astrophysics Data System (ADS)

    Amrullah, C.; Suwardhi, D.; Meilano, I.

    2016-06-01

    This study aims to see the effect of non-metric oblique and vertical camera combination along with the configuration of the ground control points to improve the precision and accuracy in UAV-Photogrammetry project. The field observation method is used for data acquisition with aerial photographs and ground control points. All data are processed by digital photogrammetric process with some scenarios in camera combination and ground control point configuration. The model indicates that the value of precision and accuracy increases with the combination of oblique and vertical camera at all control point configuration. The best products of the UAV-Photogrammetry model are produced in the form of Digital Elevation Model (DEM) compared to the LiDAR DEM. Furthermore, DEM from UAV-Photogrammetry and LiDAR are used to define the fault plane by using cross-section on the model and interpretation to determine the point at the extreme height of terrain changes. The result of the defined fault planes indicate that two models do not show any significant difference.

  7. Effect and Safety of Shihogyejitang for Drug Resistant Childhood Epilepsy.

    PubMed

    Lee, Jinsoo; Son, Kwanghyun; Hwang, Gwiseo; Kim, Moonju

    2016-01-01

    Objective. Herbal medicine has been widely used to treat drug resistant epilepsy. Shihogyejitang (SGT) has been commonly used to treat epilepsy. We investigated the effect and safety of SGT in children with drug resistant epilepsy. Design. We reviewed medical records of 54 patients with epilepsy, who failed to respond to at least two antiepileptic drugs and have been treated with SGT between April 2006 and June 2014 at the Department of Pediatric Neurology, I-Tomato Hospital, Korea. Effect was measured by the response rate, seizure-free rate, and retention rate at six months. We also checked adverse events, change in antiepileptic drugs use, and the variables related to the outcome. Results. Intent-to-treat analysis showed that, after six months, 44.4% showed a >50% seizure reduction, 24.1% including seizure-free, respectively, and 53.7% remained on SGT. Two adverse events were reported, mild skin rash and fever. Focal seizure type presented significantly more positive responses when compared with other seizure types at six months (p = 0.0284, Fisher's exact test). Conclusion. SGT is an effective treatment with excellent tolerability for drug resistant epilepsy patients. Our data provide evidence that SGT may be used as alternative treatment option when antiepileptic drug does not work in epilepsy children. PMID:27047568

  8. Effect and Safety of Shihogyejitang for Drug Resistant Childhood Epilepsy

    PubMed Central

    Lee, Jinsoo; Son, Kwanghyun; Hwang, Gwiseo

    2016-01-01

    Objective. Herbal medicine has been widely used to treat drug resistant epilepsy. Shihogyejitang (SGT) has been commonly used to treat epilepsy. We investigated the effect and safety of SGT in children with drug resistant epilepsy. Design. We reviewed medical records of 54 patients with epilepsy, who failed to respond to at least two antiepileptic drugs and have been treated with SGT between April 2006 and June 2014 at the Department of Pediatric Neurology, I-Tomato Hospital, Korea. Effect was measured by the response rate, seizure-free rate, and retention rate at six months. We also checked adverse events, change in antiepileptic drugs use, and the variables related to the outcome. Results. Intent-to-treat analysis showed that, after six months, 44.4% showed a >50% seizure reduction, 24.1% including seizure-free, respectively, and 53.7% remained on SGT. Two adverse events were reported, mild skin rash and fever. Focal seizure type presented significantly more positive responses when compared with other seizure types at six months (p = 0.0284, Fisher's exact test). Conclusion. SGT is an effective treatment with excellent tolerability for drug resistant epilepsy patients. Our data provide evidence that SGT may be used as alternative treatment option when antiepileptic drug does not work in epilepsy children. PMID:27047568

  9. Software metrics: Software quality metrics for distributed systems. [reliability engineering

    NASA Technical Reports Server (NTRS)

    Post, J. V.

    1981-01-01

    Software quality metrics was extended to cover distributed computer systems. Emphasis is placed on studying embedded computer systems and on viewing them within a system life cycle. The hierarchy of quality factors, criteria, and metrics was maintained. New software quality factors were added, including survivability, expandability, and evolvability.

  10. Implementing the Metric System in Business Occupations. Metric Implementation Guide.

    ERIC Educational Resources Information Center

    Retzer, Kenneth A.; And Others

    Addressed to the business education teacher, this guide is intended to provide appropriate information, viewpoints, and attitudes regarding the metric system and to make suggestions regarding presentation of the material in the classroom. An introductory section on teaching suggestions emphasizes the need for a "think metric" approach made up of…

  11. Antimicrobial Effects and Resistant Regulation of Magnolol and Honokiol on Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Kim, Su Young; Kim, Ju; Jeong, Seung-Il; Jahng, Kwang Yeop; Yu, Kang-Yeol

    2015-01-01

    The antimicrobial killing activity toward methicillin-resistant Staphylococcus aureus (MRSA) has been a serious emerging global issue. In a continuing search for compounds with antibacterial activity against several microorganisms including S. aureus and MRSA, an n-hexane extract of Magnolia officinalis was found to contain magnolol. This compound exhibited potent activity against S. aureus, standard methicillin-susceptible S. aureus (MSSA), and MRSA as well as clinical MRSA isolates. When combined with oxacillin, the antibacterial activities of magnolol and honokiol against the MRSA strain were increased compared to single treatment without antibiotics at 10 µg/mL and 25 µg/mL, respectively. These activities of magnolol and honokiol were dose dependent. Also, magnolol showed synergistic effects with oxacillin against 13 clinical isolates of MRSA. It was determined that magnolol and honokiol had a synergistic effect with oxacillin against MRSA strain. Furthermore, the magnolol inhibited the expression of the resistant genes, mecA, mecI, femA, and femB, in mRNA. We concluded that the antibacterial activity of magnolol against MRSA strain is more related to the mecI's pathway and components of the cell wall than mecR1. Therefore, the results obtained in this study suggest that the combination of magnolol and antibiotics could lead to the development of new combination antibiotics against MRSA infection. PMID:26357651

  12. Environmental Decision Support with Consistent Metrics

    EPA Science Inventory

    One of the most effective ways to pursue environmental progress is through the use of consistent metrics within a decision making framework. The US Environmental Protection Agency’s Sustainable Technology Division has developed TRACI, the Tool for the Reduction and Assessment of...

  13. The effects of systematic resistance training in the elderly.

    PubMed

    Wieser, M; Haber, P

    2007-01-01

    The aim of the study was to examine the effects of a maximal resistance training following the principles of the most effective resistance training known from sport adapted to elderly people. Twenty-four subjects were randomly assigned into a training group (10 females and 4 males, age; 76.2 +/- 3.2 years) that underwent a training program and a control group (6 females and 4 males, age; 76.6 +/- 2.7 years) that did not participate in the training program. Before and after the training period, both groups were identically examined (blood and urine sample, spiroergometric testing, morphological measurements). The training group underwent a 12-week training program. Eight different exercises for the largest muscle groups of the largest joints were defined as one training circle. Training took place twice a week and commenced with two training circles per week (one circle per training session). After every four weeks, one training circle per week was added until four training circles per week were reached. Before, after every four weeks (changes in training amount) and after the training period, the maximum strength was measured. Data was analysed by the independent T-test and the analysis of variance, in case of significance, the dependent T-test and the Scheffé-test were used. In the resistance training group, the fat-free body mass was increased by approximately 2.9 +/- 0.5 kg, with no significant difference between females and males. Ergometrical fitness was increased by approximately 15 %, while the maximum oxygen uptake was increased by approximately 12 %. Maximum strength was increased between 26 % (bench pull) and 38 % (leg press). Resistance training that consisted of two training sessions per week was found to be at least as efficient as resistance training that included three training sessions per week, provided that the number of sets performed were equal. Seventy-five-year-old females were found to have a significantly higher body fat content than males

  14. Chemically amplified resist using self-solubility acceleration effect

    NASA Astrophysics Data System (ADS)

    Kihara, Naoko; Ushirogouchi, Tohru; Tada, Tsukasa; Naito, Takuya; Saito, Satoshi; Nakase, Makoto

    1994-11-01

    This paper concerns a novel three-component chemically amplified positive tone resist system for EB lithography composed of a novolak resin, an acid generator, and a newly synthesized dissolution inhibitor. To obtain resist materials with high sensitivity and high contrast, the authors synthesized four 1-(3H)-isobenzofuranone derivatives as novel dissolution inhibitors, which contain a tert-butoxycarbonyl (t-Boc) group and a lactone ring. The t-Boc group of these dissolution inhibitors was effectively decomposed by an acid catalyzed thermal reaction. In addition to this decomposition, the lactone ring of the decomposed product was spontaneously cleft in an aqueous base to generate carboxylic acid. Among these synthesized substances, only the t-Boc derivative of o-cresolphthalein, named CP-TBOC, showed an excellent solubility in 1-acetoxy-2-ethoxyethane. The subsequent cleavage in an aqueous developer was investigated by UV-visible spectroscopy.

  15. Hall effect analysis in irradiated silicon samples with different resistivities

    SciTech Connect

    Borchi, E.; Bruzzi, M.; Pirollo, S. |; Dezillie, B.; Li, Z.; Lazanu, S.

    1999-08-01

    The changes induced by neutron irradiation in n- and p-type silicon samples with starting resistivities from 10 {Omega}-cm up to 30 K{Omega}-cm, grown using different techniques, as Float-Zone (FZ), Czochralski (CZ) and epitaxial, have been analyzed by Van der Pauw and Hall effect measurements. Increasing the fluence, each set of samples evolved toward a quasi-intrinsic p-type material. This behavior has been explained in the frame of a two-level model, that considers the introduction during irradiation of mainly two defects. A deep acceptor and a deep donor, probably related to the divacancy and to the C{sub i}O{sub i} complex, are placed in the upper and lower half of the forbidden gap, respectively. This simple model explains quantitatively the data on resistivity and Hall coefficient of each set of samples up to the fluence of {approx} 10{sup 14} n/cm{sup 2}.

  16. Measurable Control System Security through Ideal Driven Technical Metrics

    SciTech Connect

    Miles McQueen; Wayne Boyer; Sean McBride; Marie Farrar; Zachary Tudor

    2008-01-01

    The Department of Homeland Security National Cyber Security Division supported development of a small set of security ideals as a framework to establish measurable control systems security. Based on these ideals, a draft set of proposed technical metrics was developed to allow control systems owner-operators to track improvements or degradations in their individual control systems security posture. The technical metrics development effort included review and evaluation of over thirty metrics-related documents. On the bases of complexity, ambiguity, or misleading and distorting effects the metrics identified during the reviews were determined to be weaker than necessary to aid defense against the myriad threats posed by cyber-terrorism to human safety, as well as to economic prosperity. Using the results of our metrics review and the set of security ideals as a starting point for metrics development, we identified thirteen potential technical metrics - with at least one metric supporting each ideal. Two case study applications of the ideals and thirteen metrics to control systems were then performed to establish potential difficulties in applying both the ideals and the metrics. The case studies resulted in no changes to the ideals, and only a few deletions and refinements to the thirteen potential metrics. This led to a final proposed set of ten core technical metrics. To further validate the security ideals, the modifications made to the original thirteen potential metrics, and the final proposed set of ten core metrics, seven separate control systems security assessments performed over the past three years were reviewed for findings and recommended mitigations. These findings and mitigations were then mapped to the security ideals and metrics to assess gaps in their coverage. The mappings indicated that there are no gaps in the security ideals and that the ten core technical metrics provide significant coverage of standard security issues with 87% coverage. Based

  17. The effect of ceramic/metal gradient armor's components characteristic on its impact-resistant characteristic

    SciTech Connect

    Liu Lisheng; Zhang Qingjie; Zhai Pengcheng; Cao Dongfeng

    2008-02-15

    The effect of ceramic/metal gradient armor's components characteristic on its impact-resistant characteristic has been investigated by a new modified Alekseevskii-Tate equation. The following researching work is done by the former model [1]: the effect of ceramic layer on the impact-resistant characteristic, the effect of gradient layer on the impact-resistant characteristic and the effect of metal layer on the impact-resistant characteristic.

  18. The effect of a sitting versus supine posture on normative esophageal pressure topography metrics and Chicago Classification diagnosis of esophageal motility disorders

    PubMed Central

    Xiao, Yinglian; Read, Andrew; Nicodème, Frédéric; Roman, Sabine; Kahrilas, Peter J.; Pandolfino, John E.

    2013-01-01

    Background and aims Although, the current protocol for high resolution manometry (HRM) using the Chicago Classification is based on the supine posture, some practitioners prefer a sitting posture. Our aims were to establish normative esophageal pressure topography (EPT) data for the sitting position and to determine the effect of applying those norms to Chicago Classification diagnoses. Method EPT studies including test swallows in both a supine and sitting position of 75 healthy volunteers and 120 patients were reviewed. Integrated relaxation pressure (IRP), distal contractile integral (DCI), contractile front velocity (CFV) and distal latency (DL) were measured and compared between postures. Normative ranges were established from the healthy volunteers and the effect of applying sitting normative values to the patients was analyzed. Result Normative values of IRP, DCI and CFV all decreased significantly in the sitting posture. Applying normative sitting metrics to patient studies (27% reduction in IRP (15 to 11 mmHg), 69% reduction in DCI (8,000 to 2500 mmHg-s-cm)) reclassified 13/120 (11%) patients as having abnormal EGJ relaxation and 26/120 (22%) as hypercontractile. Three patients with an abnormal supine IRP normalized when sitting with elimination of a vascular artifact. Conclusion Clinical HRM studies should include both a supine and sitting position to minimize misdiagnoses attributable to anatomical factors. However, until outcome studies demonstrating the significance of isolated abnormalities of IRP or DCI in the sitting position are available, the Chicago Classification of esophageal motility disorders should continue to be based on supine swallows using normative data from the supine posture. PMID:22897486

  19. Metric Supplement to Technical Drawing.

    ERIC Educational Resources Information Center

    Henschel, Mark

    This manual is intended for use in training persons whose vocations involve technical drawing to use the metric system of measurement. It could be used in a short course designed for that purpose or for individual study. The manual begins with a brief discussion of the rationale for conversion to the metric system. It then provides a…

  20. Inching toward the Metric System.

    ERIC Educational Resources Information Center

    Moore, Randy

    1989-01-01

    Provides an overview and description of the metric system. Discusses the evolution of measurement systems and their early cultures, the beginnings of metric measurement, the history of measurement systems in the United States, the International System of Units, its general style and usage, and supplementary units. (RT)

  1. Metric Activities, Grades K-6.

    ERIC Educational Resources Information Center

    Draper, Bob, Comp.

    This pamphlet presents worksheets for use in fifteen activities or groups of activities designed for teaching the metric system to children in grades K through 6. The approach taken in several of the activities is one of conversion between metric and English units. The majority of the activities concern length, area, volume, and capacity. A…

  2. Metrication: A Guide for Consumers.

    ERIC Educational Resources Information Center

    Consumer and Corporate Affairs Dept., Ottawa (Ontario).

    The widespread use of the metric system by most of the major industrial powers of the world has prompted the Canadian government to investigate and consider use of the system. This booklet was developed to aid the consuming public in Canada in gaining some knowledge of metrication and how its application would affect their present economy.…

  3. What About Metric? Revised Edition.

    ERIC Educational Resources Information Center

    Barbrow, Louis E.

    Described are the advantages of using the metric system over the English system. The most common units of both systems are listed and compared. Pictures are used to exhibit use of the metric system in connection with giving prices or sizes of common items. Several examples provide computations of area, total weight of several objects, and volume;…

  4. Metrics for Soft Goods Merchandising.

    ERIC Educational Resources Information Center

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of students interested in soft goods merchandising, this instructional package is one of five for the marketing and distribution cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational…

  5. Metrics for Hard Goods Merchandising.

    ERIC Educational Resources Information Center

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of students interested in hard goods merchandising, this instructional package is one of five for the marketing and distribution cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational…

  6. Multimetric indices: How many metrics?

    EPA Science Inventory

    Multimetric indices (MMI’s) often include 5 to 15 metrics, each representing a different attribute of assemblage condition, such as species diversity, tolerant taxa, and nonnative taxa. Is there an optimal number of metrics for MMIs? To explore this question, I created 1000 9-met...

  7. Effects of resistance training fatigue on joint biomechanics.

    PubMed

    Hooper, David R; Szivak, Tunde K; Distefano, Lindsay J; Comstock, Brett A; Dunn-Lewis, Courtenay; Apicella, Jenna M; Kelly, Neil A; Creighton, Brent C; Volek, Jeff S; Maresh, Carl M; Kraemer, William J

    2013-01-01

    Resistance training has been found to have a multitude of benefits. However, when performed with short rest, resistance training can result in substantial fatigue, which may have a negative impact on exercise technique. The purpose of this study is to examine the effects of fatigue from resistance exercise on joint biomechanics to determine what residual movement effects may exist after the workout. Twelve men with at least 6 months of resistance training experience (age 24 ± 4.2 years, height 173.1 ± 3.6 cm, weight 76.9 ± 7.8 kg) performed 5 body weight squats before (pretest) and after (posttest) a highly fatiguing resistance training workout. Lower extremity biomechanics were assessed using a 3-dimensional motion analysis system during these squats. Peak angle, total displacement, and rate were assessed for knee flexion, trunk flexion, hip flexion, hip rotation, and hip adduction. Results showed a significant decrease in peak angle for knee flexion (Pre: 120.28 ± 11.93°, Post: 104.46 ± 9.85°), hip flexion (Pre: -109.42 ± 12.49°, Post: -95.8 ± 12.30°), and hip adduction (Pre: -23.32 ± 7.04°, Post: -17.30 ± 8.79°). There was a significant reduction in angular displacement for knee flexion (Pre: 115.56 ± 10.55°, Post: 103.35 ± 10.49°), hip flexion (Pre: 97.94 ± 10.69°, Post: 90.51 ± 13.22°), hip adduction (Pre: 17.79 ± 7.36°, Post: 11.89 ± 4.34°), and hip rotation (Pre: 30.72 ± 12.28, Post: 20.48 ± 10.12). There was also a significant reduction in displacement rate for knee flexion (Pre: 2.20 ± 0.20, Post: 1.98 ± 0.20), hip flexion (Pre: 1.92 ± 0.20, Post: 1.76 ± 0.27), hip adduction (Pre: -0.44 ± 0.17, Post: -0.31 ± 0.17), and hip rotation (Pre: 0.59 ± 0.23, Post: 0.38 ± 0.21). This study demonstrated that there are lasting residual effects on movement capabilities after a high-intensity short rest protocol. Thus, strength and conditioning coaches must be careful to monitor movements and exercise techniques after such workouts

  8. Edge effect on resistance scaling rules in graphene nanostructures.

    PubMed

    Xu, Guangyu; Torres, Carlos M; Tang, Jianshi; Bai, Jingwei; Song, Emil B; Huang, Yu; Duan, Xiangfeng; Zhang, Yuegang; Wang, Kang L

    2011-03-01

    We report an experimental investigation of the edge effect on the room-temperature transport in graphene nanoribbon and graphene sheet (both single-layer and bilayer). By measuring the resistance scaling behaviors at both low- and high-carrier densities, we show that the transport of single-layer nanoribbons lies in a strong localization regime, which can be attributed to an edge effect. We find that this edge effect can be weakened by enlarging the width, decreasing the carrier densities, or adding an extra layer. From graphene nanoribbon to graphene sheet, the data show a dimensional crossover of the transport regimes possibly due to the drastic change of the edge effect. PMID:21322591

  9. Space-time metrical fluctuations induced by cosmic turbulence

    NASA Technical Reports Server (NTRS)

    Rosen, G.

    1980-01-01

    For a stochastic stress-energy tensor associated with cosmic turbulence, it is observed that Einstein's equations imply fluctuations in the space-time metric tensor. Such metrical fluctuations are shown to engender modified values for the average effective proper density and total pressure and thus to alter the solutions to the Friedman equations.

  10. Effect of cements on fracture resistance of monolithic zirconia crowns

    PubMed Central

    Nakamura, Keisuke; Mouhat, Mathieu; Nergård, John Magnus; Lægreid, Solveig Jenssen; Kanno, Taro; Milleding, Percy; Örtengren, Ulf

    2016-01-01

    Abstract Objectives The present study investigated the effect of cements on fracture resistance of monolithic zirconia crowns in relation to their compressive strength. Materials and methods Four different cements were tested: zinc phosphate cement (ZPC), glass-ionomer cement (GIC), self-adhesive resin-based cement (SRC) and resin-based cement (RC). RC was used in both dual cure mode (RC-D) and chemical cure mode (RC-C). First, the compressive strength of each cement was tested according to a standard (ISO 9917-1:2004). Second, load-to-failure test was performed to analyze the crown fracture resistance. CAD/CAM-produced monolithic zirconia crowns with a minimal thickness of 0.5 mm were prepared and cemented to dies with each cement. The crown–die samples were loaded until fracture. Results The compressive strength of SRC, RC-D and RC-C was significantly higher than those of ZPC and GIC (p < 0.05). However, there was no significant difference in the fracture load of the crown between the groups. Conclusion The values achieved in the load-to-failure test suggest that monolithic zirconia crowns with a minimal thickness of 0.5 mm may have good resistance against fracture regardless of types of cements. PMID:27335900

  11. Effects of Ca antagonists on Ca fluxes in resistance vessels

    SciTech Connect

    Cauvin, C.; Saida, K.; van Breemen, C.

    1982-01-01

    Researchers have examined contractions and /sup 45/Ca fluxes induced by norepinephrine (NE) and 80 mM potassium (high K) depolarization and their inhibition by dilitazem in rabbit mesenteric resistance vessels. Contraction induced by both NE and high K depended almost completely on extracellular Ca. Dose-response curves for diltiazem inhibition of NE (10(-5) M) and high K contractions showed ED50 values of 1 X 10(-8) and 6 X 10(-7) M, respectively, indicating that the receptor-operated channel (ROC) was more sensitive than the potential-operated channel (POC) to the action of diltiazem. Diltiazem (10(-6) M) was shown to inhibit NE- and 80 mM K-stimulated /sup 45/Ca influx effectively by 87 +/- 15 and 85 +/- 10%, respectively. Comparison of these data to those obtained from aorta suggest that although the sensitivity of the POC is approximately the same in aorta and mesenteric resistance vessels, the sensitivity of the ROC is much greater in the latter. This increased sensitivity is paralleled by a greatly decreased role of intracellular Ca release in NE contraction in mesenteric resistance vessels.

  12. To Resist or Not to Resist? The Effect of Context and Crime Characteristics on Sex Offenders' Reaction to Victim Resistance

    ERIC Educational Resources Information Center

    Balemba, Samantha; Beauregard, Eric; Mieczkowski, Tom

    2012-01-01

    Circumstances under which a sexual assault takes place and how these circumstances affect offenders' reactions to victim resistance are not well understood. Previous studies have not thoroughly examined the interactions that take place between situational factors and resistance. Using a combination of logistic regression and Chi-square Automatic…

  13. The Effect of Resistance on Rocket Injector Acoustics

    NASA Technical Reports Server (NTRS)

    Morgan, C. J.

    2015-01-01

    Combustion instability, where unsteady heat release couples with acoustic modes, has long been an area of concern in liquid rocket engines. Accurate modeling of the acoustic normal modes of the combustion chamber is important to understanding and preventing combustion instability. This study evaluates the effect of injector resistance on the mode shapes and complex eigen-frequencies of an injector/combustion chamber system by defining a high Mach-flow form of the convective wave equation (see Eq. 1) in COMSOL Multiphysics' Coefficient Form PDE Mathematics Module.

  14. A multi-metric assessment of environmental contaminant exposure and effects in an urbanized reach of the Charles River near Watertown, Massachusetts

    USGS Publications Warehouse

    Smith, Stephen B.; Anderson, Patrick J.; Baumann, Paul C.; DeWeese, Lawrence R.; Goodbred, Steven L.; Coyle, James J.; Smith, David S.

    2012-01-01

    The Charles River Project provided an opportunity to simultaneously deploy a combination of biomonitoring techniques routinely used by the U.S. Geological Survey National Water Quality Assessment Program, the Biomonitoring of Environmental Status and Trends Project, and the Contaminant Biology Program at an urban site suspected to be contaminated with polycyclic aromatic hydrocarbons. In addition to these standardized methods, additional techniques were used to further elucidate contaminant exposure and potential impacts of exposure on biota. The purpose of the study was to generate a comprehensive, multi-metric data set to support assessment of contaminant exposure and effects at the site. Furthermore, the data set could be assessed to determine the relative performance of the standardized method suites typically used by the National Water Quality Assessment Program and the Biomonitoring of Environmental Status and Trends Project, as well as the additional biomonitoring methods used in the study to demonstrate ecological effects of contaminant exposure. The Contaminant Effects Workgroup, an advisory committee of the U.S. Geological Survey/Contaminant Biology Program, identified polycyclic aromatic hydrocarbons as the contaminant class of greatest concern in urban streams of all sizes. The reach of the Charles River near Watertown, Massachusetts, was selected as the site for this study based on the suspected presence of polycyclic aromatic hydrocarbon contamination and the presence of common carp (Cyprinus carpio), largemouth bass (Micropterus salmoides), and white sucker (Catostomus commersoni). All of these fish have extensive contaminant-exposure profiles related to polycyclic aromatic hydrocarbons and other environmental contaminants. This project represented a collaboration of universities, Department of the Interior bureaus including multiple components of the USGS (Biological Resources Discipline and Water Resources Discipline Science Centers, the

  15. Plasma stability theory including the resistive wall effects

    NASA Astrophysics Data System (ADS)

    Pustovitov, V. D.

    2015-12-01

    > Plasma stabilization due to a nearby conducting wall can provide access to better performance in some scenarios in tokamaks. This was proved by experiments with an essential gain in and demonstrated as a long-lasting effect at sufficiently fast plasma rotation in the DIII-D tokamak (see, for example, Strait et al., Nucl. Fusion, vol. 43, 2003, pp. 430-440). The rotational stabilization is the central topic of this review, though eventually the mode rotation gains significance. The analysis is based on the first-principle equations describing the energy balance with dissipation in the resistive wall. The method emphasizes derivation of the dispersion relations for the modes which are faster than the conventional resistive wall modes, but slower than the ideal magnetohydrodynamics modes. Both the standard thin wall and ideal-wall approximations are not valid in this range. Here, these are replaced by an approach incorporating the skin effect in the wall. This new element in the stability theory makes the energy sink a nonlinear function of the complex growth rate. An important consequence is that a mode rotating above a critical level can provide a damping effect sufficient for instability suppression. Estimates are given and applications are discussed.

  16. The Metric System--An Overview.

    ERIC Educational Resources Information Center

    Hovey, Larry; Hovey, Kathi

    1983-01-01

    Sections look at: (1) Historical Perspective; (2) Naming the New System; (3) The Metric Units; (4) Measuring Larger and Smaller Amounts; (5) Advantage of Using the Metric System; (6) Metric Symbols; (7) Conversion from Metric to Customary System; (8) General Hints for Helping Children Understand; and (9) Current Status of Metric Conversion. (MP)

  17. GPS Metric Tracking Unit

    NASA Technical Reports Server (NTRS)

    2008-01-01

    As Global Positioning Satellite (GPS) applications become more prevalent for land- and air-based vehicles, GPS applications for space vehicles will also increase. The Applied Technology Directorate of Kennedy Space Center (KSC) has developed a lightweight, low-cost GPS Metric Tracking Unit (GMTU), the first of two steps in developing a lightweight, low-cost Space-Based Tracking and Command Subsystem (STACS) designed to meet Range Safety's link margin and latency requirements for vehicle command and telemetry data. The goals of STACS are to improve Range Safety operations and expand tracking capabilities for space vehicles. STACS will track the vehicle, receive commands, and send telemetry data through the space-based asset, which will dramatically reduce dependence on ground-based assets. The other step was the Low-Cost Tracking and Data Relay Satellite System (TDRSS) Transceiver (LCT2), developed by the Wallops Flight Facility (WFF), which allows the vehicle to communicate with a geosynchronous relay satellite. Although the GMTU and LCT2 were independently implemented and tested, the design collaboration of KSC and WFF engineers allowed GMTU and LCT2 to be integrated into one enclosure, leading to the final STACS. In operation, GMTU needs only a radio frequency (RF) input from a GPS antenna and outputs position and velocity data to the vehicle through a serial or pulse code modulation (PCM) interface. GMTU includes one commercial GPS receiver board and a custom board, the Command and Telemetry Processor (CTP) developed by KSC. The CTP design is based on a field-programmable gate array (FPGA) with embedded processors to support GPS functions.

  18. Variable metric conjugate gradient methods

    SciTech Connect

    Barth, T.; Manteuffel, T.

    1994-07-01

    1.1 Motivation. In this paper we present a framework that includes many well known iterative methods for the solution of nonsymmetric linear systems of equations, Ax = b. Section 2 begins with a brief review of the conjugate gradient method. Next, we describe a broader class of methods, known as projection methods, to which the conjugate gradient (CG) method and most conjugate gradient-like methods belong. The concept of a method having either a fixed or a variable metric is introduced. Methods that have a metric are referred to as either fixed or variable metric methods. Some relationships between projection methods and fixed (variable) metric methods are discussed. The main emphasis of the remainder of this paper is on variable metric methods. In Section 3 we show how the biconjugate gradient (BCG), and the quasi-minimal residual (QMR) methods fit into this framework as variable metric methods. By modifying the underlying Lanczos biorthogonalization process used in the implementation of BCG and QMR, we obtain other variable metric methods. These, we refer to as generalizations of BCG and QMR.

  19. Epistasis between antibiotic resistance mutations and genetic background shape the fitness effect of resistance across species of Pseudomonas.

    PubMed

    Vogwill, T; Kojadinovic, M; MacLean, R C

    2016-05-11

    Antibiotic resistance often evolves by mutations at conserved sites in essential genes, resulting in parallel molecular evolution between divergent bacterial strains and species. Whether these resistance mutations are having parallel effects on fitness across bacterial taxa, however, is unclear. This is an important point to address, because the fitness effects of resistance mutations play a key role in the spread and maintenance of resistance in pathogen populations. We address this idea by measuring the fitness effect of a collection of rifampicin resistance mutations in the β subunit of RNA polymerase (rpoB) across eight strains that span the diversity of the genus Pseudomonas We find that almost 50% of rpoB mutations have background-dependent fitness costs, demonstrating that epistatic interactions between rpoB and the rest of the genome are common. Moreover, epistasis is typically strong, and it is the dominant genetic determinant of the cost of resistance mutations. To investigate the functional basis of epistasis, and because rpoB plays a central role in transcription, we measured the effects of common rpoB mutations on transcriptional efficiency across three strains of Pseudomonas Transcriptional efficiency correlates strongly to fitness across strains, and epistasis arises because individual rpoB mutations have differential effects on transcriptional efficiency in different genetic backgrounds. PMID:27170722

  20. Epistasis between antibiotic resistance mutations and genetic background shape the fitness effect of resistance across species of Pseudomonas

    PubMed Central

    Kojadinovic, M.; MacLean, R. C.

    2016-01-01

    Antibiotic resistance often evolves by mutations at conserved sites in essential genes, resulting in parallel molecular evolution between divergent bacterial strains and species. Whether these resistance mutations are having parallel effects on fitness across bacterial taxa, however, is unclear. This is an important point to address, because the fitness effects of resistance mutations play a key role in the spread and maintenance of resistance in pathogen populations. We address this idea by measuring the fitness effect of a collection of rifampicin resistance mutations in the β subunit of RNA polymerase (rpoB) across eight strains that span the diversity of the genus Pseudomonas. We find that almost 50% of rpoB mutations have background-dependent fitness costs, demonstrating that epistatic interactions between rpoB and the rest of the genome are common. Moreover, epistasis is typically strong, and it is the dominant genetic determinant of the cost of resistance mutations. To investigate the functional basis of epistasis, and because rpoB plays a central role in transcription, we measured the effects of common rpoB mutations on transcriptional efficiency across three strains of Pseudomonas. Transcriptional efficiency correlates strongly to fitness across strains, and epistasis arises because individual rpoB mutations have differential effects on transcriptional efficiency in different genetic backgrounds. PMID:27170722

  1. Double metric, generalized metric, and α' -deformed double field theory

    NASA Astrophysics Data System (ADS)

    Hohm, Olaf; Zwiebach, Barton

    2016-03-01

    We relate the unconstrained "double metric" of the "α' -geometry" formulation of double field theory to the constrained generalized metric encoding the spacetime metric and b -field. This is achieved by integrating out auxiliary field components of the double metric in an iterative procedure that induces an infinite number of higher-derivative corrections. As an application, we prove that, to first order in α' and to all orders in fields, the deformed gauge transformations are Green-Schwarz-deformed diffeomorphisms. We also prove that to first order in α' the spacetime action encodes precisely the Green-Schwarz deformation with Chern-Simons forms based on the torsionless gravitational connection. This seems to be in tension with suggestions in the literature that T-duality requires a torsionful connection, but we explain that these assertions are ambiguous since actions that use different connections are related by field redefinitions.

  2. Issues in Benchmark Metric Selection

    NASA Astrophysics Data System (ADS)

    Crolotte, Alain

    It is true that a metric can influence a benchmark but will esoteric metrics create more problems than they will solve? We answer this question affirmatively by examining the case of the TPC-D metric which used the much debated geometric mean for the single-stream test. We will show how a simple choice influenced the benchmark and its conduct and, to some extent, DBMS development. After examining other alternatives our conclusion is that the “real” measure for a decision-support benchmark is the arithmetic mean.

  3. Daylight metrics and energy savings

    SciTech Connect

    Mardaljevic, John; Heschong, Lisa; Lee, Eleanor

    2009-12-31

    The drive towards sustainable, low-energy buildings has increased the need for simple, yet accurate methods to evaluate whether a daylit building meets minimum standards for energy and human comfort performance. Current metrics do not account for the temporal and spatial aspects of daylight, nor of occupants comfort or interventions. This paper reviews the historical basis of current compliance methods for achieving daylit buildings, proposes a technical basis for development of better metrics, and provides two case study examples to stimulate dialogue on how metrics can be applied in a practical, real-world context.

  4. Truss Performance and Packaging Metrics

    NASA Technical Reports Server (NTRS)

    Mikulas, Martin M.; Collins, Timothy J.; Doggett, William; Dorsey, John; Watson, Judith

    2006-01-01

    In the present paper a set of performance metrics are derived from first principals to assess the efficiency of competing space truss structural concepts in terms of mass, stiffness, and strength, for designs that are constrained by packaging. The use of these performance metrics provides unique insight into the primary drivers for lowering structural mass and packaging volume as well as enabling quantitative concept performance evaluation and comparison. To demonstrate the use of these performance metrics, data for existing structural concepts are plotted and discussed. Structural performance data is presented for various mechanical deployable concepts, for erectable structures, and for rigidizable structures.

  5. The LSST metrics analysis framework (MAF)

    NASA Astrophysics Data System (ADS)

    Jones, R. L.; Yoachim, Peter; Chandrasekharan, Srinivasan; Connolly, Andrew J.; Cook, Kem H.; Ivezic, Željko; Krughoff, K. S.; Petry, Catherine; Ridgway, Stephen T.

    2014-07-01

    We describe the Metrics Analysis Framework (MAF), an open-source python framework developed to provide a user-friendly, customizable, easily-extensible set of tools for analyzing data sets. MAF is part of the Large Synoptic Survey Telescope (LSST) Simulations effort. Its initial goal is to provide a tool to evaluate LSST Operations Simulation (OpSim) simulated surveys to help understand the effects of telescope scheduling on survey performance, however MAF can be applied to a much wider range of datasets. The building blocks of the framework are Metrics (algorithms to analyze a given quantity of data), Slicers (subdividing the overall data set into smaller data slices as relevant for each Metric), and Database classes (to access the dataset and read data into memory). We describe how these building blocks work together, and provide an example of using MAF to evaluate different dithering strategies. We also outline how users can write their own custom Metrics and use these within the framework.

  6. Vehicle Integrated Prognostic Reasoner (VIPR) Metric Report

    NASA Technical Reports Server (NTRS)

    Cornhill, Dennis; Bharadwaj, Raj; Mylaraswamy, Dinkar

    2013-01-01

    This document outlines a set of metrics for evaluating the diagnostic and prognostic schemes developed for the Vehicle Integrated Prognostic Reasoner (VIPR), a system-level reasoner that encompasses the multiple levels of large, complex systems such as those for aircraft and spacecraft. VIPR health managers are organized hierarchically and operate together to derive diagnostic and prognostic inferences from symptoms and conditions reported by a set of diagnostic and prognostic monitors. For layered reasoners such as VIPR, the overall performance cannot be evaluated by metrics solely directed toward timely detection and accuracy of estimation of the faults in individual components. Among other factors, overall vehicle reasoner performance is governed by the effectiveness of the communication schemes between monitors and reasoners in the architecture, and the ability to propagate and fuse relevant information to make accurate, consistent, and timely predictions at different levels of the reasoner hierarchy. We outline an extended set of diagnostic and prognostics metrics that can be broadly categorized as evaluation measures for diagnostic coverage, prognostic coverage, accuracy of inferences, latency in making inferences, computational cost, and sensitivity to different fault and degradation conditions. We report metrics from Monte Carlo experiments using two variations of an aircraft reference model that supported both flat and hierarchical reasoning.

  7. Reuse metrics and measurement: A framework

    NASA Technical Reports Server (NTRS)

    Reifer, Donald J.

    1990-01-01

    The lessons learned and experience gleaned are described by those who have started to implement the reuse metrics and measurement framework used in controlling the development of common avionics and software for its affiliated aircraft programs. The framework was developed to permit the measurement of the long term cost/benefits resulting from the creation and use of Reusable Software Objects (RSOs). The framework also monitors the efficiency and effectiveness of the Software Reuse Library (SRL). The metrics and measurement framework is defined which was established to allow some determinations and findings to be made relative to software reuse. Seven criteria are discussed which were used to guide the establishment of the proposed reuse framework. Object recapture and creation metrics are explained along with their normalized use in effort, productivity, and quality determination. A single and multiple reuse instance version of a popular cost model is presented which uses these metrics and the measurement scheme proposed to predict the software effort and duration under various reuse assumptions. Studies in using this model to predict actuals taken from the RCI data base of over 1000 completed projects is discussed.

  8. Converting Residential Drawing Courses to Metric.

    ERIC Educational Resources Information Center

    Goetsch, David L.

    1980-01-01

    Describes the process of metric conversion in residential drafting courses. Areas of concern are metric paper sizes; metric scale; plot, foundation, floor and electric plans; wall sections; elevations; and heat loss/ heat gain calculations. (SK)

  9. Psychotropic placebos create resistance to the misinformation effect.

    PubMed

    Clifasefi, Seema L; Garry, Maryanne; Harper, David N; Sharman, Stefanie J; Sutherland, Rachel

    2007-02-01

    Can a placebo for a psychotropic drug help participants resist the misinformation effect? To answer this question, we gave participants a mixture of baking soda and water and told half of them that the mixture was a cognition-enhancing drug called R273 and told the other half that it was an inactive version of the drug. Shortly thereafter, all participants took part in a three-stage misinformation experiment. Compared with participants who were told that they had taken the placebo, the participants who were told that they had taken the drug reported improved cognitive abilities and were less susceptible to the misinformation effect. We provide source-monitoring and mindfulness accounts of our findings. PMID:17546740

  10. Scale-dependent effects of land cover on water physico-chemistry and diatom-based metrics in a major river system, the Adour-Garonne basin (South Western France).

    PubMed

    Tudesque, Loïc; Tisseuil, Clément; Lek, Sovan

    2014-01-01

    The scale dependence of ecological phenomena remains a central issue in ecology. Particularly in aquatic ecology, the consideration of the accurate spatial scale in assessing the effects of landscape factors on stream condition is critical. In this context, our study aimed at assessing the relationships between multi-spatial scale land cover patterns and a variety of water quality and diatom metrics measured at the stream reach level. This investigation was conducted in a major European river system, the Adour-Garonne river basin, characterized by a wide range of ecological conditions. Redundancy analysis (RDA) and variance partitioning techniques were used to disentangle the different relationships between land cover, water-chemistry and diatom metrics. Our results revealed a top-down "cascade effect" indirectly linking diatom metrics to land cover patterns through water physico-chemistry, which occurred at the largest spatial scales. In general, the strength of the relationships between land cover, physico-chemistry, and diatoms was shown to increase with the spatial scale, from the local to the basin scale, emphasizing the importance of continuous processes of accumulation throughout the river gradient. Unexpectedly, we established that the influence of land cover on the diatom metric was of primary importance both at the basin and local scale, as a result of discontinuous but not necessarily antagonist processes. The most detailed spatial grain of the Corine land cover classification appeared as the most relevant spatial grain to relate land cover to water chemistry and diatoms. Our findings provide suitable information to improve the implementation of effective diatom-based monitoring programs, especially within the scope of the European Water Framework Directive. PMID:23892023

  11. A universal metric for ferroic energy materials

    PubMed Central

    Yibole, Hargen; Zhang, Lian

    2016-01-01

    After almost 20 years of intensive research on magnetocaloric effects near room temperature, magnetic refrigeration with first-order magnetocaloric materials has come close to real-life applications. Many materials have been discussed as potential candidates to be used in multicaloric devices. However, phase transitions in ferroic materials are often hysteretic and a metric is needed to estimate the detrimental effects of this hysteresis. We propose the coefficient of refrigerant performance, which compares the net work in a reversible cycle with the positive work on the refrigerant, as a universal metric for ferroic materials. Here, we concentrate on examples from magnetocaloric materials and only consider one barocaloric experiment. This is mainly due to lack of data on electrocaloric materials. It appears that adjusting the field-induced transitions and the hysteresis effects can minimize the losses in first-order materials. This article is part of the themed issue ‘Taking the temperature of phase transitions in cool materials’. PMID:27402924

  12. A universal metric for ferroic energy materials.

    PubMed

    Brück, Ekkes; Yibole, Hargen; Zhang, Lian

    2016-08-13

    After almost 20 years of intensive research on magnetocaloric effects near room temperature, magnetic refrigeration with first-order magnetocaloric materials has come close to real-life applications. Many materials have been discussed as potential candidates to be used in multicaloric devices. However, phase transitions in ferroic materials are often hysteretic and a metric is needed to estimate the detrimental effects of this hysteresis. We propose the coefficient of refrigerant performance, which compares the net work in a reversible cycle with the positive work on the refrigerant, as a universal metric for ferroic materials. Here, we concentrate on examples from magnetocaloric materials and only consider one barocaloric experiment. This is mainly due to lack of data on electrocaloric materials. It appears that adjusting the field-induced transitions and the hysteresis effects can minimize the losses in first-order materials.This article is part of the themed issue 'Taking the temperature of phase transitions in cool materials'. PMID:27402924

  13. Using TRACI for Sustainability Metrics

    EPA Science Inventory

    TRACI, the Tool for the Reduction and Assessment of Chemical and other environmental Impacts, has been developed for sustainability metrics, life cycle impact assessment, and product and process design impact assessment for developing increasingly sustainable products, processes,...

  14. Let's Make Metric Ice Cream

    ERIC Educational Resources Information Center

    Zimmerman, Marianna

    1975-01-01

    Describes a classroom activity which involved sixth grade students in a learning situation including making ice cream, safety procedures in a science laboratory, calibrating a thermometer, using metric units of volume and mass. (EB)

  15. Spacetime metric from linear electrodynamics

    NASA Astrophysics Data System (ADS)

    Obukhov, Yuri N.; Hehl, Friedrich W.

    1999-07-01

    The Maxwell equations are formulated on an arbitrary (1+3)-dimensional manifold. Then, imposing a (constrained) linear constitutive relation between electromagnetic field (E,B) and excitation (D,ℌ), we derive the metric of spacetime therefrom.

  16. Coverage Metrics for Model Checking

    NASA Technical Reports Server (NTRS)

    Penix, John; Visser, Willem; Norvig, Peter (Technical Monitor)

    2001-01-01

    When using model checking to verify programs in practice, it is not usually possible to achieve complete coverage of the system. In this position paper we describe ongoing research within the Automated Software Engineering group at NASA Ames on the use of test coverage metrics to measure partial coverage and provide heuristic guidance for program model checking. We are specifically interested in applying and developing coverage metrics for concurrent programs that might be used to support certification of next generation avionics software.

  17. The Effects of Bowel Preparation on Microbiota-Related Metrics Differ in Health and in Inflammatory Bowel Disease and for the Mucosal and Luminal Microbiota Compartments

    PubMed Central

    Shobar, Rima M; Velineni, Suresh; Keshavarzian, Ali; Swanson, Garth; DeMeo, Mark T; Melson, Joshua E; Losurdo, John; Engen, Philip A; Sun, Yan; Koenig, Lars; Mutlu, Ece A

    2016-01-01

    OBJECTIVES: Bowel preparations (BPs) taken before colonoscopy may introduce a confounding effect on the results of gastrointestinal microbiota studies. This study aimed to determine the effect of bowel preparation on the mucosa-associated and luminal colonic microbiota in healthy subjects (HC) and inflammatory bowel disease (IBD) patients. METHODS: Biopsy samples (n=36) and fecal samples (n=30) were collected from 10 HC and 8 IBD subjects pre- and post-BP. 16S rRNA gene was pyrosequenced using 454 Titanium protocols. We compared the differences between the pre- and post-BP samples (i.e., comparisons-across-bowel-prep); we examined the effect of BP on the expected separation of the mucosal vs. the luminal compartments (i.e., comparisons-across-compartments). Last, we compared the baseline differences between the HC vs. IBD groups (a secondary analysis), and examined whether the differences between the HC vs. IBD changed after BP. RESULTS: In comparisons-across-bowel-prep, the Shannon's index (SI) decreased only in the biopsy samples of IBD subjects post-BP (P=0.025) and phylogenetic diversity-whole tree (PD-WT) metric decreased in biopsy samples of HC subjects post-BP (P=0.021). In secondary comparisons, the subtle differences between the fecal samples of the HC vs. IBD groups, in terms of evenness and the SI, were not apparent post-BP. In terms of β-diversity, in comparisons-across-bowel-prep, the proportion of shared operational taxonomic units (OTUs) in pre- and post-BP samples was low (~30%) and unweighted Unifrac distances between pre- and post-BP specimens ranged from 0.52 to 0.66. HC biopsies were affected more than IBD biopsies with BP (P=0.004). In comparisons-across-compartments, the proportion of shared OTUs between biopsy and fecal samples increased and Unifrac distances decreased post-BP in IBD subjects, reducing the differences between the mucosal and luminal compartments of the gut microbiota. Interindividual differences in Unifrac distances were

  18. Degraded visual environment image/video quality metrics

    NASA Astrophysics Data System (ADS)

    Baumgartner, Dustin D.; Brown, Jeremy B.; Jacobs, Eddie L.; Schachter, Bruce J.

    2014-06-01

    A number of image quality metrics (IQMs) and video quality metrics (VQMs) have been proposed in the literature for evaluating techniques and systems for mitigating degraded visual environments. Some require both pristine and corrupted imagery. Others require patterned target boards in the scene. None of these metrics relates well to the task of landing a helicopter in conditions such as a brownout dust cloud. We have developed and used a variety of IQMs and VQMs related to the pilot's ability to detect hazards in the scene and to maintain situational awareness. Some of these metrics can be made agnostic to sensor type. Not only are the metrics suitable for evaluating algorithm and sensor variation, they are also suitable for choosing the most cost effective solution to improve operating conditions in degraded visual environments.

  19. Metrics with Galilean conformal isometry

    SciTech Connect

    Bagchi, Arjun; Kundu, Arnab

    2011-03-15

    The Galilean conformal algebra (GCA) arises in taking the nonrelativistic limit of the symmetries of a relativistic conformal field theory in any dimensions. It is known to be infinite dimensional in all spacetime dimensions. In particular, the 2d GCA emerges out of a scaling limit of linear combinations of two copies of the Virasoro algebra. In this paper, we find metrics in dimensions greater than 2 which realize the finite 2d GCA (the global part of the infinite algebra) as their isometry by systematically looking at a construction in terms of cosets of this finite algebra. We list all possible subalgebras consistent with some physical considerations motivated by earlier work in this direction and construct all possible higher-dimensional nondegenerate metrics. We briefly study the properties of the metrics obtained. In the standard one higher-dimensional ''holographic'' setting, we find that the only nondegenerate metric is Minkowskian. In four and five dimensions, we find families of nontrivial metrics with a rather exotic signature. A curious feature of these metrics is that all but one of them are Ricci-scalar flat.

  20. Resistivity and thickness effects in dendritic web silicon solar cells

    NASA Astrophysics Data System (ADS)

    Meier, D. L.; Hwang, J. M.; Greggi, J.; Campbell, R. B.

    The decrease of minority carrier lifetime as resistivity decreases in dendritic-web silicon solar cells is addressed. This variation is shown to be consistent with the presence of defect levels in the bandgap which arise from extended defects in the web material. The extended defects are oxide precipitates (SiOx) and the dislocation cores they decorate. Sensitivity to this background distribution of defect levels increases with doping because the Fermi level moves closer to the majority carrier band edge. For high-resistivity dendritic-web silicon, which has a low concentration of these extended defects, cell efficiencies as high as 16.6 percent (4 sq cm, 40 ohm-cm boron-doped base, AM1.5 global, 100 mW/sq cm, 25 C JPL LAPSS1 measurement) and a corresponding electron lifetime of 38 microsec have been obtained. Thickness effects occur in bifacial cell designs and in designs which use light trapping. In some cases, the dislocation/precipitate defect can be passivated through the full thickness of web cells by hydrogen ion implantation.

  1. Resistivity and thickness effects in dendritic web silicon solar cells

    NASA Technical Reports Server (NTRS)

    Meier, D. L.; Hwang, J. M.; Greggi, J.; Campbell, R. B.

    1987-01-01

    The decrease of minority carrier lifetime as resistivity decreases in dendritic-web silicon solar cells is addressed. This variation is shown to be consistent with the presence of defect levels in the bandgap which arise from extended defects in the web material. The extended defects are oxide precipitates (SiOx) and the dislocation cores they decorate. Sensitivity to this background distribution of defect levels increases with doping because the Fermi level moves closer to the majority carrier band edge. For high-resistivity dendritic-web silicon, which has a low concentration of these extended defects, cell efficiencies as high as 16.6 percent (4 sq cm, 40 ohm-cm boron-doped base, AM1.5 global, 100 mW/sq cm, 25 C JPL LAPSS1 measurement) and a corresponding electron lifetime of 38 microsec have been obtained. Thickness effects occur in bifacial cell designs and in designs which use light trapping. In some cases, the dislocation/precipitate defect can be passivated through the full thickness of web cells by hydrogen ion implantation.

  2. Effects of cementation surface modifications on fracture resistance of zirconia

    PubMed Central

    Srikanth, Ramanathan; Kosmac, Tomaz; Bona, Alvaro Della; Yin, Ling; Zhang, Yu

    2015-01-01

    Objectives To examine the effects of glass infiltration (GI) and alumina coating (AC) on the indentation flexural load and four-point bending strength of monolithic zirconia. Methods Plate-shaped (12 mm × 12 mm × 1.0 mm or 1.5 mm or 2.0 mm) and bar-shaped (4 mm × 3 mm × 25 mm) monolithic zirconia specimens were fabricated. In addition to monolithic zirconia (group Z), zirconia monoliths were glass-infiltrated or alumina-coated on their tensile surfaces to form groups ZGI and ZAC, respectively. They were also glass-infiltrated on their upper surfaces, and glass-infiltrated or alumina-coated on their lower (tensile) surfaces to make groups ZGI2 and ZAC2, respectively. For comparison, porcelain-veneered zirconia (group PVZ) and monolithic lithium disilicate glass-ceramic (group LiDi) specimens were also fabricated. The plate-shaped specimens were cemented onto a restorative composite base for Hertzian indentation using a tungsten carbide spherical indenter with a radius of 3.2 mm. Critical loads for indentation flexural fracture at the zirconia cementation surface were measured. Strengths of bar-shaped specimens were evaluated in four-point bending. Results Glass infiltration on zirconia tensile surfaces increased indentation flexural loads by 32% in Hertzian contact and flexural strength by 24% in four-point bending. Alumina coating showed no significant effect on resistance to flexural damage of zirconia. Monolithic zirconia outperformed porcelain-veneered zirconia and monolithic lithium disilicate glass-ceramics in terms of both indentation flexural load and flexural strength. Significance While both alumina coating and glass infiltration can be used to effectively modify the cementation surface of zirconia, glass infiltration can further increase the flexural fracture resistance of zirconia. PMID:25687628

  3. Effects of pharmacological agents on subcortical resistance shifts

    NASA Technical Reports Server (NTRS)

    Klivington, K. A.

    1975-01-01

    Microliter quantities of tetrodotoxin, tetraethylammonium chloride, and picrotoxin injected into the inferior colliculus and superior olive of unanesthetized cats differentially affect the amplitude and waveform of click-evoked potentials and evoked resistance shifts. Tetrodotoxin simultaneously reduces the negative phase of the evoked potential and eliminates the evoked resistance shift. Tetraethylammonium enhances the negative evoked potential component, presumably of postsynaptic origin, without significantly altering evoked resistance shift amplitude. Picrotoxin also enhances the negative evoked potential wave but increases evoked resistance shift amplitude. These findings implicate events associated with postsynaptic membrane depolarization in the production of the evoked resistance shift.

  4. The effect of filter cakes on filter medium resistance

    SciTech Connect

    Chase, G.G.; Arconti, J.; Kanel, J.

    1994-10-01

    The high resistance of a filter medium to fluid flow is a universal problem affecting many industries. The small thickness of the filter media makes local pressure and porosity measurements impractical. Analysis of the continuum equations and boundary conditions provide a basis for defining a relative medium resistance. Experiments are conducted on three particulate materials and on three different high flow rate filter media. The results show that the increase in medium resistance varies up to about four times the resistance of a clean filter medium with no cake present. The results also show that in most cases the relative resistance is dependent upon cake height.

  5. A wavelet contrast metric for the targeting task performance metric

    NASA Astrophysics Data System (ADS)

    Preece, Bradley L.; Flug, Eric A.

    2016-05-01

    Target acquisition performance depends strongly on the contrast of the target. The Targeting Task Performance (TTP) metric, within the Night Vision Integrated Performance Model (NV-IPM), uses a combination of resolution, signal-to-noise ratio (SNR), and contrast to predict and model system performance. While the dependence on resolution and SNR are well defined and understood, defining a robust and versatile contrast metric for a wide variety of acquisition tasks is more difficult. In this correspondence, a wavelet contrast metric (WCM) is developed under the assumption that the human eye processes spatial differences in a manner similar to a wavelet transform. The amount of perceivable information, or useful wavelet coefficients, is used to predict the total viewable contrast to the human eye. The WCM is intended to better match the measured performance of the human vision system for high-contrast, low-contrast, and low-observable targets. After further validation, the new contrast metric can be incorporated using a modified TTP metric into the latest Army target acquisition software suite, the NV-IPM.

  6. Effective nonlocal spin injection through low-resistance oxide junctions

    NASA Astrophysics Data System (ADS)

    Cai, Yunjiao; Luo, Yongming; Qin, Chuan; Chen, Shuhan; Wu, Yizheng; Ji, Yi

    2016-05-01

    Many (>40) nonlocal spin valves on the same substrate have been characterized at 6 K and 295 K by using a probe station. Low-resistance oxide junctions (0.2-0.8 Ω) are used to inject spin current into mesoscopic Cu channels. Spin signals exceeding 10 mΩ at 6 K have been consistently observed, indicating efficient spin injection and detection. However, complex switching behavior and possible variations between devices pose a challenge to using a standard fitting method to quantify the spin signals. Two methods are used for quantitative analysis. The range of the effective spin polarizations can be estimated by assuming a reasonable range for the Cu spin diffusion lengths. A nonlocal spin polarization is introduced to evaluate the spin current in the Cu channels.

  7. Resistance of platelet proteins to effects of ionizing radiation

    SciTech Connect

    Prodouz, K.N.; Habraken, J.W.; Moroff, G. )

    1990-12-01

    Gamma irradiation of blood components prevents lymphocyte-induced graft-versus-host disease after transfusion in immunocompromised individuals. In this report we demonstrate the resistance of blood platelet proteins to gamma radiation-induced protein cleavage and aggregate formation when platelet concentrates were treated with a dose of 5000 rad. Results of one- and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total platelet protein and cytoskeletal protein preparations indicate that platelet proteins are neither cleaved nor cross-linked under these conditions of irradiation. These results support those of a previous study that documented the lack of any adverse effect of 5000 rad gamma radiation on in vitro platelet properties.

  8. Effects produced by iodine irradiation on high resistivity silicon

    SciTech Connect

    Lazanu, S.; Slav, A.; Lepadatu, A.-M.; Stavarache, I.; Palade, C.; Iordache, G.; Ciurea, M. L.

    2012-12-10

    The effects of 5 Multiplication-Sign 10{sup 11} cm{sup -26+}I{sup 127} ions of 28 MeV kinetic energy on high resistivity (100) Si were studied. The profile of primary defects was simulated. The defects produced by irradiation which act as traps were investigated. Thermally stimulated current measurements without externally applied bias were used, and for this the traps were charged by illuminating samples with 1000, 800, and 400 nm wavelengths. The discharge currents were recorded and modeled, and therefore the parameters of the traps were determined. The presence of I ions, heavier than Si, stopped into the target was modeled as a temperature independent electric field.

  9. Metric conversion: Future progress depends upon private sector and public support. Report to Congressional requesters

    NASA Astrophysics Data System (ADS)

    1994-01-01

    In reviewing federal metric conversion (metrication) activities, the General Accounting Office (GAO) evaluated federal agency activities in (1) establishing metric guidelines and preparing reports on the transition, (2) using the metric system in procurements, (3) using the metric system in grants and other business activities, and (4) dealing with private sector and public attitudes toward conversion. Since 1990, federal preparations for metric conversion have advanced dramatically, with more than 30 agencies having developed some combination of guidelines, transition plans, and progress reports that indicate a substantially greater commitment to metrication. However, they are still facing serious difficulties in putting their plans into practice. These difficulties include a procurement environment in which most products are nonmetric and in which federal agencies represent too small a share of the total market to stimulate private sector conversion. Mixed progress has been made toward metric conversion in the areas of federal grants and other business activities. Grants for research require the use of the metric system, but such a commitment has not been made for grants in other areas, such as housing and education. Agencies that undertake other business-related activities, such as federal programs involving farmers or highway signs, are concerned about private sector and public resistance to conversion. Now that most agencies have made significant progress in preparing for metric conversion, a broader national dialogue between the government, the private sector, and the public is needed to discuss the next steps in decision-making about metric conversion.

  10. Effects of pink bollworm resistance to Bt on phenoloxidase activity and susceptibility to entomopathogenic nematodes.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Widespread planting of crops genetically engineered to produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) imposes selection on many key agricultural pests to evolve resistance to Bt. Fitness costs of Bt resistance can slow the evolution of Bt resistance. We examined effects...

  11. Testing the Effectiveness of Intervention Programs on Children's Compliance-Resisting Behaviors.

    ERIC Educational Resources Information Center

    McQuillen, Jeffrey S.; And Others

    A study examined the effectiveness of a resistance-based prevention program to increase subjects' ability to comprehend and apply resistance skills. Subjects were 30 participants in kindergarten through third grade. Fifteen subjects received resistance-based prevention training from the We Help Ourselves (WHO) program. The remaining 15 subjects…

  12. The correlation of metrics in complex networks with applications in functional brain networks

    NASA Astrophysics Data System (ADS)

    Li, C.; Wang, H.; de Haan, W.; Stam, C. J.; Van Mieghem, P.

    2011-11-01

    An increasing number of network metrics have been applied in network analysis. If metric relations were known better, we could more effectively characterize networks by a small set of metrics to discover the association between network properties/metrics and network functioning. In this paper, we investigate the linear correlation coefficients between widely studied network metrics in three network models (Bárabasi-Albert graphs, Erdös-Rényi random graphs and Watts-Strogatz small-world graphs) as well as in functional brain networks of healthy subjects. The metric correlations, which we have observed and theoretically explained, motivate us to propose a small representative set of metrics by including only one metric from each subset of mutually strongly dependent metrics. The following contributions are considered important. (a) A network with a given degree distribution can indeed be characterized by a small representative set of metrics. (b) Unweighted networks, which are obtained from weighted functional brain networks with a fixed threshold, and Erdös-Rényi random graphs follow a similar degree distribution. Moreover, their metric correlations and the resultant representative metrics are similar as well. This verifies the influence of degree distribution on metric correlations. (c) Most metric correlations can be explained analytically. (d) Interestingly, the most studied metrics so far, the average shortest path length and the clustering coefficient, are strongly correlated and, thus, redundant. Whereas spectral metrics, though only studied recently in the context of complex networks, seem to be essential in network characterizations. This representative set of metrics tends to both sufficiently and effectively characterize networks with a given degree distribution. In the study of a specific network, however, we have to at least consider the representative set so that important network properties will not be neglected.

  13. Kinetic Effects of Energetic Particles on Resistive MHD Stability

    SciTech Connect

    Takahashi, R.; Brennan, D. P.; Kim, C. C.

    2009-04-03

    We show that the kinetic effects of energetic particles can play a crucial role in the stability of the m/n=2/1 tearing mode in tokamaks (e.g., JET, JT-60U, and DIII-D), where the fraction of energetic particle {beta}{sub frac} is high. Using model equilibria based on DIII-D experimental reconstructions, the nonideal MHD linear stability of cases unstable to the 2/1 mode is investigated including a {delta}f particle-in-cell model for the energetic particles coupled to the nonlinear 3D resistive MHD code NIMROD[C. C. Kim et al., Phys. Plasmas 15, 072507 (2008)]. It is observed that energetic particles have significant damping and stabilizing effects at experimentally relevant {beta}, {beta}{sub frac}, and S, and excite a real frequency of the 2/1 mode. Extrapolation of the results is discussed for implications to JET and ITER, where the effects are projected to be significant.

  14. Symbolic planning with metric time

    NASA Astrophysics Data System (ADS)

    MacMillan, T. R.

    1992-03-01

    Most AI planning systems have considered time in a qualitative way only. For example, a plan may require one action to come 'before' another. Metric time enables AI planners to represent action durations and reason over quantitative temporal constraints such as windows of opportunity. This paper presents preliminary results observed while developing a theory of multi-agent adversarial planning for battle management research. Quantitative temporal reasoning seems essential in this domain. For example, Orange may plan to block Blue's attack by seizing a river ford which Blue must cross, but only if Orange can get there during the window of opportunity while Blue is approaching the ford but has not yet arrived. In nonadversarial multi-agent planning, metric time enables planners to detect windows of opportunity for agents to help or hinder each other. In single-agent planning, metric time enables planners to reason about deadlines, temporally constrained resource availability, and asynchronous processes which the agent can initiate and monitor. Perhaps surprisingly, metric time increases the computational complexity of planning less than might be expected, because it reduces the computational complexity of modal truth criteria. To make this observation precise, we review Chapman's analysis to modal truth criteria and describe a tractable heuristic criterion, 'worst case necessarily true.' Deciding if a proposition is worst case necessarily true, in a single-agent plan with n steps, requires O(n) computations only if qualitative temporal information is used. We show how it can be decided in O(log n) using metric time.

  15. Zingiber officinale (ginger) compounds have tetracycline-resistance modifying effects against clinical extensively drug-resistant Acinetobacter baumannii.

    PubMed

    Wang, Hui-Min; Chen, Chung-Yi; Chen, Hsi-An; Huang, Wan-Chun; Lin, Wei-Ru; Chen, Tun-Chieh; Lin, Chun-Yu; Chien, Hsin-Ju; Lu, Po-Liang; Lin, Chiu-Mei; Chen, Yen-Hsu

    2010-12-01

    Extensively drug-resistant Acinetobacter baumannii (XDRAB) is a growing and serious nosocomial infection worldwide, such that developing new agents against it is critical. The antimicrobial activities of the rhizomes from Zingiber officinale, known as ginger, have not been proven in clinical bacterial isolates with extensive drug-resistance. This study aimed to investigate the effects of four known components of ginger, [6]-dehydrogingerdione, [10]-gingerol, [6]-shogaol and [6]-gingerol, against clinical XDRAB. All these compounds showed antibacterial effects against XDRAB. Combined with tetracycline, they showed good resistance modifying effects to modulate tetracycline resistance. Using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method, these four ginger compounds demonstrated antioxidant properties, which were inhibited by MnO₂, an oxidant without antibacterial effects. After the antioxidant property was blocked, their antimicrobial effects were abolished significantly. These results indicate that ginger compounds have antioxidant effects that partially contribute to their antimicrobial activity and are candidates for use in the treatment of infections with XDRAB. PMID:20564496

  16. Kinetic and resistive effects on interchange instabilities for a cylindrical model spheromak

    SciTech Connect

    Hammett, G.W.; Tang, W.M.

    1983-04-01

    The stabilizing influence of diamagnetic drift effects on ideal and resistive interchange modes is investigated. A resistive-ballooning-mode equation is derived using a kinetic theory approach and is applied to a cylindrical model spheromak equilibrium. It is found that these kinetic effects can significantly improve the ..beta.. limits for collisionless interchange stability. For the resistive modes, the diamagnetic drift terms lead to growth rates which scale linearly with resistivity and are considerably reduced in magnitude. However, the resistive interchange growth rates estimated for near-term spheromak parameters remain significant.

  17. How Soon Will We Measure in Metric?

    ERIC Educational Resources Information Center

    Weaver, Kenneth F.

    1977-01-01

    A brief history of measurement systems beginning with the Egyptians and Babylonians is given, ending with a discussion of the metric system and its adoption by the United States. Tables of metric prefixes, metric units, and common metric conversions are included. (MN)

  18. Metrics for Occupations. Information Series No. 118.

    ERIC Educational Resources Information Center

    Peterson, John C.

    The metric system is discussed in this information analysis paper with regard to its history, a rationale for the United States' adoption of the metric system, a brief overview of the basic units of the metric system, examples of how the metric system will be used in different occupations, and recommendations for research and development. The…

  19. Effect of resistance training on muscle use during exercise

    NASA Technical Reports Server (NTRS)

    Ploutz, Lori L.; Tesch, Per A.; Biro, Ronald L.; Dudley, Gary A.

    1994-01-01

    This study examined the effect of resistance training on exercise-induced contrast shift in magnetic resonance (MR) images. It was hypothesized that a given load could be lifted after training with less muscle showing contrast shift, thereby suggesting less muscle was used to perform the exercise. Nine males trained the left quadriceps femoris (QF) muscle 2 days/wk for 9 wk using 3-6 sets of 12 knee extensions each day. The right QF served as a control. Exercise-induced contrast shifts in MR images evoked by each of three bouts of exercise (5 sets of 10 knee extensions with a load equal to 50, 75, and 100% of the maximum pretraining load that could be lifted for 5 sets of 10 repetitions) were quantified pre- and posttraining. MR image contrast shift was quantified by determining QF cross-sectional area (CSA) showing increased spin-spin relaxation time. One repetition maximum increased 14% in the left trained QF and 7% in the right untrained QF. Left QF CSA increased 5%, with no change in right QSF CSA. Left QF CSA showing contrast shift was less after each bout of the exercise test posttraining. This was also true, to a lesser extent, for the right QF at the higher two loads. The results suggest that short-term resistance training reduces MR image contrast shift evoked by a given effort, thereby reflecting the use of less muscle to lift the load. Because this response was evident in both trained and contralateral untrained muscle, neural factors are suggested to be responsible. The consequence of this adaptation could be to increase 'stress' per unit area of active muscle during the course of training and thereby evoke hypertrophy.

  20. Application of resistivity monitoring to evaluate cement grouting effect in earth filled dam

    SciTech Connect

    Kim, Jin-Mo; Yoon, Wang-Jung

    2015-03-10

    In this paper, we applied electrical resistivity monitoring method to evaluate the cement grouting effect. There are a lot of ways to evaluate cement grouting effect. In order to do this evaluation in a great safety, high efficiency, and lower cost, resistivity monitoring is found to be the most appropriate technique. In this paper we have selected a dam site from Korea to acquire resistivity monitoring data and compare the results of inversion to estimate the cement grouting effect.

  1. A parallel variable metric optimization algorithm

    NASA Technical Reports Server (NTRS)

    Straeter, T. A.

    1973-01-01

    An algorithm, designed to exploit the parallel computing or vector streaming (pipeline) capabilities of computers is presented. When p is the degree of parallelism, then one cycle of the parallel variable metric algorithm is defined as follows: first, the function and its gradient are computed in parallel at p different values of the independent variable; then the metric is modified by p rank-one corrections; and finally, a single univariant minimization is carried out in the Newton-like direction. Several properties of this algorithm are established. The convergence of the iterates to the solution is proved for a quadratic functional on a real separable Hilbert space. For a finite-dimensional space the convergence is in one cycle when p equals the dimension of the space. Results of numerical experiments indicate that the new algorithm will exploit parallel or pipeline computing capabilities to effect faster convergence than serial techniques.

  2. EFFECT OF PYRAZINAMIDASE ACTIVITY ON PYRAZINAMIDE RESISTANCE IN MYCOBACTERIUM TUBERCULOSIS

    PubMed Central

    Sheen, Patricia; Ferrer, Patricia; Gilman, Robert H.; López-Llano, Jon; Fuentes, Patricia; Valencia, Eddy; Zimic, Mirko J.

    2009-01-01

    Resistance of Mycobacterium tuberculosis to pyrazinamide is associated with mutations in the pncA gene, which codes for pyrazinamidase. The association between the enzymatic activity of mutated pyrazinamidases and the level of pyrazinamide resistance remains poorly understood. Twelve M. tuberculosis clinical isolates resistant to pyrazinamide were selected based on Wayne activity and localization of pyrazinamidase mutation. Recombinant pyrazinamidases were expressed and tested for their kinetic parameters (activity, kcat, Km, and efficiency). Pyrazinamide resistance level was measured by Bactec-460TB and 7H9 culture. The linear correlation between the resistance level and the kinetic parameters of the corresponding mutated pyrazinamidase was calculated. The enzymatic activity and efficiency of the mutated pyrazinamidases varied with the site of mutation and ranged widely from low to high levels close to the corresponding of the wild-type enzyme. The level of resistance was significantly associated with pyrazinamidase activity and efficiency, but only 27.3% of its statistical variability was explained. Although pyrazinamidase mutations are indeed associated with resistance, the loss of pyrazinamidase activity and efficiency as assessed in the recombinant mutated enzymes is not sufficient to explain a high variability of the level of pyrazinamide resistance, suggesting that complementary mechanisms for pyrazinamide resistance in M. tuberculosis with mutations in pncA are more important than currently thought. PMID:19249243

  3. Experimental validation of navigation workload metrics

    SciTech Connect

    Schryver, J.C.; Wachtel, J.A.

    1994-04-01

    Advanced digital computer display interfaces in the control room may increase operator workload. Workstation monitors provide limited display area, and information is represented in large-scale display networks. Display navigation may generate disorienting effects, require additional resources for window management, and increase memory and data integration requirements. Six ORNL employees participated in an experiment to validate proposed metrics of navigation workload in the advanced control room. The task environment was a display network consisting of 25 windows resembling a simplified Safety Parameter Display System for Pressurized Water Reactors. A repeated measures design with 3 within subjects factors was employed. The factors were task difficulty, navigation distance level, and a blocking factor. Participants were asked to monitor a single parameter or two parameters. Fourteen candidate metrics were tested. Analysis of variance of the modified task load index (MTLX) and rating subscales demonstrated substantial support for the claim that navigation of large-scale display networks can impose additional mental load. Primary and secondary task performance measures exhibited ceiling effects. Memory probes for these tasks were inadequate because they were recognition-based and coarse. Eye gaze measures were not validated, indicating a need for more refined data reduction algorithms. Strong positive correlations were found between MTLX and both navigation duration and standard deviation of pupil diameter. Further study and increased statistical power are required to validate objective navigation workload metrics.

  4. Requirement Metrics for Risk Identification

    NASA Technical Reports Server (NTRS)

    Hammer, Theodore; Huffman, Lenore; Wilson, William; Rosenberg, Linda; Hyatt, Lawrence

    1996-01-01

    The Software Assurance Technology Center (SATC) is part of the Office of Mission Assurance of the Goddard Space Flight Center (GSFC). The SATC's mission is to assist National Aeronautics and Space Administration (NASA) projects to improve the quality of software which they acquire or develop. The SATC's efforts are currently focused on the development and use of metric methodologies and tools that identify and assess risks associated with software performance and scheduled delivery. This starts at the requirements phase, where the SATC, in conjunction with software projects at GSFC and other NASA centers is working to identify tools and metric methodologies to assist project managers in identifying and mitigating risks. This paper discusses requirement metrics currently being used at NASA in a collaborative effort between the SATC and the Quality Assurance Office at GSFC to utilize the information available through the application of requirements management tools.

  5. Colonoscopy Quality: Metrics and Implementation

    PubMed Central

    Calderwood, Audrey H.; Jacobson, Brian C.

    2013-01-01

    Synopsis Colonoscopy is an excellent area for quality improvement 1 because it is high volume, has significant associated risk and expense, and there is evidence that variability in its performance affects outcomes. The best endpoint for validation of quality metrics in colonoscopy is colorectal cancer incidence and mortality, but because of feasibility issues, a more readily accessible metric is the adenoma detection rate (ADR). Fourteen quality metrics were proposed by the joint American Society of Gastrointestinal Endoscopy/American College of Gastroenterology Task Force on “Quality Indicators for Colonoscopy” in 2006, which are described in further detail below. Use of electronic health records and quality-oriented registries will facilitate quality measurement and reporting. Unlike traditional clinical research, implementation of quality improvement initiatives involves rapid assessments and changes on an iterative basis, and can be done at the individual, group, or facility level. PMID:23931862

  6. Distribution Metrics and Image Segmentation

    PubMed Central

    Georgiou, Tryphon; Michailovich, Oleg; Rathi, Yogesh; Malcolm, James; Tannenbaum, Allen

    2007-01-01

    The purpose of this paper is to describe certain alternative metrics for quantifying distances between distributions, and to explain their use and relevance in visual tracking. Besides the theoretical interest, such metrics may be used to design filters for image segmentation, that is for solving the key visual task of separating an object from the background in an image. The segmenting curve is represented as the zero level set of a signed distance function. Most existing methods in the geometric active contour framework perform segmentation by maximizing the separation of intensity moments between the interior and the exterior of an evolving contour. Here one can use the given distributional metric to determine a flow which minimizes changes in the distribution inside and outside the curve. PMID:18769529

  7. Rainbow metric from quantum gravity

    NASA Astrophysics Data System (ADS)

    Assanioussi, Mehdi; Dapor, Andrea; Lewandowski, Jerzy

    2015-12-01

    In this Letter, we describe a general mechanism for emergence of a rainbow metric from a quantum cosmological model. This idea is based on QFT on a quantum spacetime. Under general assumptions, we discover that the quantum spacetime on which the field propagates can be replaced by a classical spacetime, whose metric depends explicitly on the energy of the field: as shown by an analysis of dispersion relations, quanta of different energy propagate on different metrics, similar to photons in a refractive material (hence the name "rainbow" used in the literature). In deriving this result, we do not consider any specific theory of quantum gravity: the qualitative behaviour of high-energy particles on quantum spacetime relies only on the assumption that the quantum spacetime is described by a wave-function Ψo in a Hilbert space HG.

  8. The Rationality of Four Metrics of Network Robustness: A Viewpoint of Robust Growth of Generalized Meshes

    PubMed Central

    Yang, Xiaofan; Zhu, Yuanrui; Hong, Jing; Yang, Lu-Xing; Wu, Yingbo; Tang, Yuan Yan

    2016-01-01

    There are quite a number of different metrics of network robustness. This paper addresses the rationality of four metrics of network robustness (the algebraic connectivity, the effective resistance, the average edge betweenness, and the efficiency) by investigating the robust growth of generalized meshes (GMs). First, a heuristic growth algorithm (the Proximity-Growth algorithm) is proposed. The resulting proximity-optimal GMs are intuitively robust and hence are adopted as the benchmark. Then, a generalized mesh (GM) is grown up by stepwise optimizing a given measure of network robustness. The following findings are presented: (1) The algebraic connectivity-optimal GMs deviate quickly from the proximity-optimal GMs, yielding a number of less robust GMs. This hints that the rationality of the algebraic connectivity as a measure of network robustness is still in doubt. (2) The effective resistace-optimal GMs and the average edge betweenness-optimal GMs are in line with the proximity-optimal GMs. This partly justifies the two quantities as metrics of network robustness. (3) The efficiency-optimal GMs deviate gradually from the proximity-optimal GMs, yielding some less robust GMs. This suggests the limited utility of the efficiency as a measure of network robustness. PMID:27518448

  9. Reliability of in-stream retention metrics

    NASA Astrophysics Data System (ADS)

    Savickis, Jevgenijs; Zaramella, Mattia; Marion, Andrea

    2016-04-01

    The temporary solute retention within transient storage zones (TSZs) has been shown to have a large effect on the transport of solute. This retention can significantly increase the overall in-stream residence time and as consequence increase the contact time of solute with aquatic interfaces (biota, sediment) and living species. An important question that arises is whether the currently available metrics adequately represent retention mechanism. This work attempts to investigate the reliability of two existing measures, the hydrological retention factor (Rh) and the fraction of median travel time due to transient storage zone (Fmed200). For this purpose, five conservative tracer tests were conducted in four European streams with distinct morphological, sediment composition, vegetation and hydraulic characteristics. The obtained breakthrough curves (BTCs) were used to derive storage zone parameters (storage zone area, storage zone exchange coefficient and mean residence time), which then were used for comparison and in the metric expressions. The storage zone parameters were computed using a single TSZ model OTIS-P and a multiple TSZ model STIR. The STIR model was applied to BTCs as an additional tool to separate TSZs into short timescale (ST) and long timescale (LT). The study results reveal correlation between Fmed200 and LT residence time T2 values, where the streams with the lowest Fmed200 (0.01-0.96) have the smallest long timescale storage zones T2 values, ranging from 912 s to 1402 s. The findings also demonstrate an influence of discharge rate on both retention metrics. The greatest Fmed200 (6.19) and Rh (0.938) values are calculated for the streams with low discharge rates (0.08-0.10 m3s‑1) and a relatively high ST storage zone residence times T1 (159 s to 351 s). Results show that the Fmed200 and Rh metrics are strongly affected by the short timescale transient storage zones, whereas the LT storage zones (hyporheic) effects are not taken into account.

  10. The flexibility of optical metrics

    NASA Astrophysics Data System (ADS)

    Bittencourt, Eduardo; Pereira, Jonas P.; Smolyaninov, Igor I.; Smolyaninova, Vera N.

    2016-08-01

    We firstly revisit the importance, naturalness and limitations of the so-called optical metrics for describing the propagation of light rays in the limit of geometric optics. We then exemplify their flexibility and nontriviality in some nonlinear material media and in the context of nonlinear theories of the electromagnetism, both in the presence of curved backgrounds, where optical metrics could be flat and inaccessible regions for the propagation of photons could be conceived, respectively. Finally, we underline and discuss the relevance and potential applications of our analyses in a broad sense, ranging from material media to compact astrophysical systems.

  11. Thermodynamic Metrics and Optimal Paths

    SciTech Connect

    Sivak, David; Crooks, Gavin

    2012-05-08

    A fundamental problem in modern thermodynamics is how a molecular-scale machine performs useful work, while operating away from thermal equilibrium without excessive dissipation. To this end, we derive a friction tensor that induces a Riemannian manifold on the space of thermodynamic states. Within the linear-response regime, this metric structure controls the dissipation of finite-time transformations, and bestows optimal protocols with many useful properties. We discuss the connection to the existing thermodynamic length formalism, and demonstrate the utility of this metric by solving for optimal control parameter protocols in a simple nonequilibrium model.

  12. Effects of UV light disinfection on antibiotic-resistant coliforms in wastewater effluents

    SciTech Connect

    Meckes, M.C.

    1982-02-01

    Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation. Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher than the percentage of the total coliform population resistant to those antibiotics before UV irradiation. This finding was attributed to the mechanism of R-factor mediated resistance to tetracycline. No significant difference was noted for the percentage of the surviving total coliform population resistant to streptomycin before or after UV irradiation. Multiple drug resistant to patterns of 300 total coliform isolates revealed that 82% were resistant to two or more antibiotics. Furthermore, 46% of these isolates were capable of transferring antibiotic resistance to a sensitive strain of Escherichia coli.

  13. Effects of oxidation and roughness on Cu contact resistance from 4 to 290 K

    NASA Astrophysics Data System (ADS)

    Nilles, M. J.; van Sciver, S. W.

    Knowledge of the factors influencing contact resistance is important for optimizing system design in cryogenic applications. In space cryogenics, indirect cooling of infrared components is the primary concern. The presence of bolted joints results in contact resistances which can dominate all other contributions to the overall heat transfer rate. Here, thermal and electrical contact resistances measured between 4 K and 290 K for a series of bolted OFHC Cu contacts are reported. Surface roughness is found to have little effect on the overall contact resistance within the experimental limits, while oxidation can increase the contact resistance by as much as a factor of 100. Thermal and electrical contact resistances measured on the same contact show that the contact resistance temperature dependence does not follow the bulk dependence. For example, the residual resistance ratio (RRR) of the OFHC Cu is 110, but for contacts made from this material, the RRR is about two.

  14. Resistance and synergistic effects of insecticides in Bactrocera dorsalis (Diptera: Tephritidae) in Taiwan.

    PubMed

    Hsu, Ju-Chun; Feng, Hai-Tung; Wu, Wen-Jer

    2004-10-01

    Oriental fruit flies, Bactrocera dorsalis (Hendel), were treated with 10 insecticides, including six organophosphates (naled, trichlorfon, fenitrothion, fenthion, formothion, and malathion), one carbamate (methomyl), and three pyrethroids (cyfluthrin, cypermethrin, and fenvalerate), by a topical application assay under laboratory conditions. Subparental lines of each generation treated with the same insecticide were selected for 30 generations and were designated as x-r lines (x, insecticide; r, resistant). The parent colony was maintained as the susceptible colony. The line treated with naled exhibited the lowest increase in resistance (4.7-fold), whereas the line treated with formothion exhibited the highest increase in resistance (up to 594-fold) compared with the susceptible colony. Synergism bioassays also were carried out. Based on this, S,S,S-tributyl phosphorotrithioate displayed a synergistic effect for naled, trichlorfon, and malathion resistance, whereas piperonyl butoxide displayed a synergistic effect for pyrethroid resistance. All 10 resistant lines also exhibited some cross-resistance to other insecticides, not only to the same chemical class of insecticides but also to other classes. However, none of the organophosphate-resistant or the methomyl-resistant lines exhibited cross-resistance to two of the pyrethroids (cypermethrin and fenvalerate). Overall, the laboratory resistance and cross-resistance data developed here should provide useful tools and information for designing an insecticide management strategy for controlling this fruit fly in the field. PMID:15568360

  15. Soil spatial heterogeneity effect on soil electrical resistivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Electrical resistivity (ER) is growing in popularity due to its ease of use and because of its non-invasive techniques, which are used to reveal and map soil heterogeneity. The objective of this work was to evaluate how differing soil properties affect the electric resistivity and to observe these e...

  16. pH-metric chemical speciation modeling and studies of in vitro antidiabetic effects of bis[(imidazolyl)carboxylato]oxidovanadium(IV) complexes.

    PubMed

    Gundhla, Isaac Z; Walmsley, Ryan S; Ugirinema, Vital; Mnonopi, Nandipha O; Hosten, Eric; Betz, Richard; Frost, Carminita L; Tshentu, Zenixole R

    2015-04-01

    A range of bidentate N,O-donor ligands of the imidazolyl-carboxylate moiety, which partially mimic naturally occurring bioligands, were prepared and reacted with the oxidovanadium(IV) ion to form the corresponding bis-coordinated oxidovanadium(IV) complexes. The aqueous pH-metric chemical speciation was investigated using glass electrode potentiometry, which allowed for the determination of protonation and stability constants of the ligands and complexes, respectively. The species distribution diagrams generated from this information gave evidence that the bis[(imidazolyl)carboxylato]oxovanadium(IV) complexes possess a broad pH-metric stability. The complexes improved glucose uptake in cell cultures using 3T3-L1 adipocytes, C2C12 muscle cells and Chang liver cells. The PTP inhibition studies indicated that the mechanism underlying insulin-stimulated glucose uptake was possibly via the protein tyrosine phosphorylation through the inhibition of the protein tyrosine phosphatase 1B (PTP 1B). The vanadium compounds also demonstrated the inhibition of D-dimer formation, suggesting that these compounds could potentially relieve a hypercoagulative state in diabetic patients. PMID:25594947

  17. Effect of Contact Resistance on Bulk Resistivity of Dry Coke Beds

    NASA Astrophysics Data System (ADS)

    Eidem, P. A.; Runde, M.; Tangstad, M.; Bakken, J. A.; Zhou, Z. Y.; Yu, A. B.

    2009-06-01

    Measurements show that bulk resistivity of dry coke beds decreases with increasing particle size. A further development of a coke bed model is proposed to explain this correlation. By image analysis, it has been determined that the total porosity increases with increasing particle size. An increased total porosity of the particles decreases the mechanical strength of the particles. In the modeling work, the strength of the coke particles is introduced through Young’s modulus. By the use of discrete element method (DEM) modeling of a dry coke bed, the particle-to-particle contact area variation with varying particle size and particle strength has been introduced into a model of the dry coke bed. This was done by the introduction of the concept of the Holm’s radius, known from metal contact theory for describing how the contact resistance is affected by the material resistivity and the contact area. By assuming a decrease in the particle strength due to increased porosity of the coke particles with increasing particle size, the calculated bulk resistivity for 7.3-mm particles with a Young’s modulus of 1.0 GPa is 5.24·10-3 Ωm and 3.44·10-3 Ωm for the 20-mm particles with a Young’s modulus of 0.1 GPa. By comparison, the measured bulk resistivity of the Corus coke is 4.67 ± 0.30·10-3 Ωm for the 5- to 10-mm fraction and 3.71 ± 0.45·10-3 Ωm for the 15- to 20-mm fraction. The measured contact resistance of Swedish Steel AB (SSAB) coke decreases with increasing contact area size from a contact diameter of 5 mm to a contact diameter of 30 mm. This is probably due to an increasing number of electrical contact spots. When two spheres are in contact, the measured contact resistance is lower compared to the 5-mm-diameter contact, which indicates that the increased contact pressure has lowered the contact resistance. This supports the modeling results.

  18. Desiccation resistance in four Drosophila species: sex and population effects.

    PubMed

    Matzkin, Luciano M; Watts, Thomas D; Markow, Therese A

    2007-01-01

    Desiccation resistance and body mass were measured in multiple populations of each of four species of Drosophila: two desert endemic species (D. nigrospiracula and D. mojavensis), and two with more widespread distributions (D. melanogaster and D. pseudoobscura). While flies from the desert species were more desiccation tolerant, there was, in certain cases, significant variation in desiccation resistance among populations of the same species. A significant difference in desiccation resistance was observed between the sexes, females were more resistant than males, but this relationship was reversed when taking into account body mass differences between the sexes. The degree of observed within-species variability demonstrates that studies focusing upon differences between species can produce different conclusions if they rely on observations for only single populations of a given species. Our data also suggest the existence of multiple mechanisms for desiccation resistance. PMID:18836314

  19. Effect of Calcium Hydroxide on the Fracture Resistance of Dentin

    PubMed Central

    Whitbeck, Evan R.; Quinn, George D.; Quinn, Janet B.

    2011-01-01

    An increased incidence of fracture has been reported in teeth where root canals were treated with calcium hydroxide. Edge chipping is one test used to measure the resistance of brittle materials to fracture. Presently, no studies have reported on edge chipping in teeth. This study evaluated the fracture resistance of human dentin exposed to calcium hydroxide for up to 60 days using the edge chipping method. Twelve recently extracted teeth were divided into a control group and three experimental groups with varying calcium hydroxide exposures. All teeth underwent pulpectomy via standard protocol. It was expected that the edge chip resistance would decrease as a function of exposure, but the results showed the converse. Chip resistance may reflect both the fracture resistance and the hardness of dentin, a quasi brittle material. PMID:26989596

  20. Effects of temperature and antibiotics on persistence of antibiotic-resistant bacteria and antibiotic resistance genes in poultry litter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of low, residual concentrations of antibiotics in manure and other environmental matrices is not well understood. It has been hypothesized that antibiotic concentrations below clinical MIC (minimal inhibitory concentrations) are still capable of selecting for resistance. The objective of ...

  1. Masked target transform volume clutter metric applied to vehicle search

    NASA Astrophysics Data System (ADS)

    Moore, Richard K.; Camp, H. A.; Moyer, Steve; Halford, Carl E.

    2010-04-01

    The Night Vision and Electronic Sensors Directorate's current time-limited search model, which makes use of the targeting task performance (TTP) metric to describe imager quality, does not explicitly account for the effects of clutter on observer performance. The masked target transform volume (MTTV) clutter metric has been presented previously, but is first applied to the results of a vehicle search perception experiment with simulated thermal imagery here. NVESD's Electro-Optical Simulator program was used to generate hundreds of synthetic images of tracked vehicles hidden in a rural environment. 12 observers searched for the tracked vehicles and their performance is compared to the MTTV clutter level, signal-to-clutter ratios using several clutter metrics from open literature, and to the product of target size and contrast. The investigated clutter metrics included the Schmeider-Weathersby statistical variance, Silk's statistical variance, Aviram's probability of edge detection metric, and Chang's target structural similarity metric. The MTTV was shown to better model observer performance as measured by the perception experiment than any of the other compared metrics, including the product of target size and contrast.

  2. Comparison of objective metrics for image sensor crosstalk characterization

    NASA Astrophysics Data System (ADS)

    Li, Feng; Eliasson, Henrik; Dokoutchaev, Alexander

    2011-01-01

    Image sensor crosstalk can be divided into spectral crosstalk and pixel crosstalk. This paper focuses on the pixel crosstalk and its effect on signal to noise ratio (SNR). Pixel crosstalk occurs in the spatial domain and is due to the signal leakage between adjacent pixels either by imperfect optical isolation or diffusion of electrons. This will have a negative impact on image quality mainly in two ways: spatial blurring and decreased SNR due to more aggressive color correction required. A method for modeling the spectral broadening due to the pixel crosstalk is used where a matrix is calculated from crosstalk kernels representing the spatial leakage between neighboring pixels. In order to quantify the amount of crosstalk we present a method in which ratios of integrals of the same color channel but within different wavelength intervals are calculated. This provides a metric that is more robust with respect to color channel scaling. To study the impact on SNR due to pixel crosstalk, a number of SNR metrics are compared to results from a limited psychophysical study. The studied SNR metrics are the metric used for calculating the SNR10 value in mobile imaging, the ISO 12232 noise metric and a metric where the signal is transformed into orthogonal color opponent channels, thereby enabling the analysis of the luminance noise separate from the chrominance noises. The results indicate that the ISO total noise and SNR10 metric yield very similar results and that the green channel has the largest individual impact on the crosstalk.

  3. Economic Metrics for Commercial Reusable Space Transportation Systems

    NASA Technical Reports Server (NTRS)

    Shaw, Eric J.; Hamaker, Joseph (Technical Monitor)

    2000-01-01

    The success of any effort depends upon the effective initial definition of its purpose, in terms of the needs to be satisfied and the goals to be fulfilled. If the desired product is "A System" that is well-characterized, these high-level need and goal statements can be transformed into system requirements by traditional systems engineering techniques. The satisfaction of well-designed requirements can be tracked by fairly straightforward cost, schedule, and technical performance metrics. Unfortunately, some types of efforts, including those that NASA terms "Programs," tend to resist application of traditional systems engineering practices. In the NASA hierarchy of efforts, a "Program" is often an ongoing effort with broad, high-level goals and objectives. A NASA "project" is a finite effort, in terms of budget and schedule, that usually produces or involves one System. Programs usually contain more than one project and thus more than one System. Special care must be taken in the formulation of NASA Programs and their projects, to ensure that lower-level project requirements are traceable to top-level Program goals, feasible with the given cost and schedule constraints, and measurable against top-level goals. NASA Programs and projects are tasked to identify the advancement of technology as an explicit goal, which introduces more complicating factors. The justification for funding of technology development may be based on the technology's applicability to more than one System, Systems outside that Program or even external to NASA. Application of systems engineering to broad-based technology development, leading to effective measurement of the benefits, can be valid, but it requires that potential beneficiary Systems be organized into a hierarchical structure, creating a "system of Systems." In addition, these Systems evolve with the successful application of the technology, which creates the necessity for evolution of the benefit metrics to reflect the changing

  4. Hypoglycemic effects and mechanisms of electroacupuncture on insulin resistance

    PubMed Central

    Yin, Jieyun; Kuang, Jian; Chandalia, Manisha; Tuvdendorj, Demidmaa; Tumurbaatar, Batbayar; Abate, Nicola

    2014-01-01

    The aim of this study was to investigate effects and mechanisms of electroacupuncture (EA) on blood glucose and insulin sensitivity in mice fed a high-fat diet. Both wild-type (WT) and adipose ectonucleotide pyrophosphate phosphodiesterase (ENPP1) transgenic (TG) mice were fed a high-fat diet for 12 wk; for each mouse, an intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT) were performed with or without EA at abdomen or auricular areas. A high-fat diet-induced insulin resistance in both WT and TG mice. In the WT mice, EA at 3 Hz and 15 Hz, but not at 1 Hz or 100 Hz, via CV4+CV12 significantly reduced postprandial glucose levels; EA at 3 Hz was most potent. The glucose level was reduced by 61.7% at 60 min and 74.5% at 120 min with EA at 3 Hz (all P < 0.001 vs. control). Similar hypoglycemic effect was noted in the TG mice. On the contrary, EA at auricular points increased postprandial glucose level (P < 0.03). 4). EA at 3 Hz via CV4+CV12 significantly enhanced the decrease of blood glucose after insulin injection, suggesting improvement of insulin sensitivity. Plasma free fatty acid was significantly suppressed by 42.5% at 15 min and 50.8% at 30 min with EA (P < 0.01) in both WT and TG mice. EA improves glucose tolerance in both WT and TG mice fed a high-fat diet, and the effect is associated with stimulation parameters and acupoints and is probably attributed to the reduction of free fatty acid. PMID:24848362

  5. Effect of Phosphodiesterase Inhibition on Insulin Resistance in Obese Individuals

    PubMed Central

    Ho, Jennifer E.; Arora, Pankaj; Walford, Geoffrey A.; Ghorbani, Anahita; Guanaga, Derek P.; Dhakal, Bishnu P.; Nathan, Daniel I.; Buys, Emmanuel S.; Florez, Jose C.; Newton‐Cheh, Christopher; Lewis, Gregory D.; Wang, Thomas J.

    2014-01-01

    Background Obesity is associated with cardiometabolic disease, including insulin resistance (IR) and diabetes. Cyclic guanosine monophosphate (cGMP) signaling affects energy balance, IR, and glucose metabolism in experimental models. We sought to examine effects of phosphodiesterase‐5 inhibition with tadalafil on IR in a pilot study of obese nondiabetic individuals. Methods and Results We conducted a randomized, double‐blinded, placebo‐controlled trial of adults age 18 to 50 years with obesity and elevated fasting insulin levels (≥10 μU/mL). Participants were randomized to tadalafil 20 mg daily or placebo for 3 months. Oral glucose tolerance tests were performed, and the effect of tadalafil on IR was examined. A total of 53 participants (mean age, 33 years; body mass index [BMI], 38 kg/m2) were analyzed, 25 randomized to tadalafil and 28 to placebo. In the overall sample, measures of IR did not differ between tadalafil and placebo groups at 3 months. However, in individuals with severe obesity (BMI ≥36.2 kg/m2), tadalafil use was associated with improved IR (homeostatic model assessment for IR), compared to placebo (P=0.02, respectively). Furthermore, one measure of β‐cell compensation for IR (oral disposition index) improved with tadalafil in the overall sample (P=0.009) and in the subgroup with severe obesity (P=0.01). Conclusion Results of this pilot study did not show improvements in IR with tadalafil, compared to placebo. However, tadalafil may have favorable effects on β‐cell compensation, particularly in individuals with severe obesity. Future studies evaluating the potential metabolic benefits of cGMP modulation in obesity are warranted. Clinical Trial Registration URL: ClinicalTrials.gov. Unique Identifier: NCT01444651. PMID:25213566

  6. Effects of Oxidation on Oxidation-Resistant Graphite

    SciTech Connect

    Windes, William; Smith, Rebecca; Carroll, Mark

    2015-05-01

    The Advanced Reactor Technology (ART) Graphite Research and Development Program is investigating doped nuclear graphite grades that exhibit oxidation resistance through the formation of protective oxides on the surface of the graphite material. In the unlikely event of an oxygen ingress accident, graphite components within the VHTR core region are anticipated to oxidize so long as the oxygen continues to enter the hot core region and the core temperatures remain above 400°C. For the most serious air-ingress accident which persists over several hours or days the continued oxidation can result in significant structural damage to the core. Reducing the oxidation rate of the graphite core material during any air-ingress accident would mitigate the structural effects and keep the core intact. Previous air oxidation testing of nuclear-grade graphite doped with varying levels of boron-carbide (B4C) at a nominal 739°C was conducted for a limited number of doped specimens demonstrating a dramatic reduction in oxidation rate for the boronated graphite grade. This report summarizes the conclusions from this small scoping study by determining the effects of oxidation on the mechanical strength resulting from oxidation of boronated and unboronated graphite to a 10% mass loss level. While the B4C additive did reduce mechanical strength loss during oxidation, adding B4C dopants to a level of 3.5% or more reduced the as-fabricated compressive strength nearly 50%. This effectively minimized any benefits realized from the protective film formed on the boronated grades. Future work to infuse different graphite grades with silicon- and boron-doped material as a post-machining conditioning step for nuclear components is discussed as a potential solution for these challenges in this report.

  7. Hypoglycemic effects and mechanisms of electroacupuncture on insulin resistance.

    PubMed

    Yin, Jieyun; Kuang, Jian; Chandalia, Manisha; Tuvdendorj, Demidmaa; Tumurbaatar, Batbayar; Abate, Nicola; Chen, Jiande D Z

    2014-08-01

    The aim of this study was to investigate effects and mechanisms of electroacupuncture (EA) on blood glucose and insulin sensitivity in mice fed a high-fat diet. Both wild-type (WT) and adipose ectonucleotide pyrophosphate phosphodiesterase (ENPP1) transgenic (TG) mice were fed a high-fat diet for 12 wk; for each mouse, an intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT) were performed with or without EA at abdomen or auricular areas. A high-fat diet-induced insulin resistance in both WT and TG mice. In the WT mice, EA at 3 Hz and 15 Hz, but not at 1 Hz or 100 Hz, via CV4+CV12 significantly reduced postprandial glucose levels; EA at 3 Hz was most potent. The glucose level was reduced by 61.7% at 60 min and 74.5% at 120 min with EA at 3 Hz (all P < 0.001 vs. control). Similar hypoglycemic effect was noted in the TG mice. On the contrary, EA at auricular points increased postprandial glucose level (P < 0.03). 4). EA at 3 Hz via CV4+CV12 significantly enhanced the decrease of blood glucose after insulin injection, suggesting improvement of insulin sensitivity. Plasma free fatty acid was significantly suppressed by 42.5% at 15 min and 50.8% at 30 min with EA (P < 0.01) in both WT and TG mice. EA improves glucose tolerance in both WT and TG mice fed a high-fat diet, and the effect is associated with stimulation parameters and acupoints and is probably attributed to the reduction of free fatty acid. PMID:24848362

  8. Limiting the Spread of Resistant Pneumococci: Biological and Epidemiologic Evidence for the Effectiveness of Alternative Interventions

    PubMed Central

    Schrag, Stephanie J.; Beall, Bernard; Dowell, Scott F.

    2000-01-01

    Streptococcus pneumoniae infections are a leading cause of respiratory illness in young children, the elderly, and persons with chronic medical conditions. The emergence of multidrug-resistant pneumococci has compromised the effectiveness of antibiotic therapy for pneumococcal infections. As antibiotic-resistant strains increase in prevalence, there is a need for interventions that minimize the spread of resistant pneumococci. In this review we provide a framework for understanding the spread of pneumococcal resistance and evaluate proposed interventions to reduce this spread. Pneumococci differ from many drug-resistant pathogens because asymptomatic carriers play a key role in transmission of resistant strains and the genes encoding resistance are spread primarily by transformation and conjugative transposons. Evidence suggests that modifications of treatment regimens that have proved effective at limiting resistance in other pathogens may not prevent the spread of pneumococcal resistance. In contrast, programs encouraging more judicious antibiotic use have been shown to be effective. Additionally, a newly developed conjugate pneumococcal vaccine holds great potential as an “antiresistance vaccine” that simultaneously reduces the burden of invasive disease and the prevalence of resistant strains. Several areas of future epidemiologic and laboratory research hold promise to contribute to the reduced spread of pneumococcal resistance. PMID:11023959

  9. Metric optimized gating for fetal cardiac MRI.

    PubMed

    Jansz, Michael S; Seed, Mike; van Amerom, Joshua F P; Wong, Derek; Grosse-Wortmann, Lars; Yoo, Shi-Joon; Macgowan, Christopher K

    2010-11-01

    Phase-contrast magnetic resonance imaging can be used to complement echocardiography for the evaluation of the fetal heart. Cardiac imaging typically requires gating with peripheral hardware; however, a gating signal is not readily available in utero. No successful application of existing technologies to human fetal phase-contrast magnetic resonance imaging has been reported to date in the literature. The purpose of this work is to develop a technique for phase-contrast magnetic resonance imaging of the fetal heart that does not require measurement of a gating signal. Metric optimized gating involves acquiring data without gating and retrospectively determining the proper reconstruction by optimizing an image metric. The effects of incorrect gating on phase contrast images were investigated, and the time-entropy of the series of images was found to provide a good measure of the level of corruption. The technique was validated with a pulsatile flow phantom, experiments with adult volunteers, and in vivo application in the fetal population. Images and flow curves from these measurements are presented. Additionally, numerical simulations were used to investigate the degree to which heart rate variability affects the reconstruction process. Metric optimized gating enables imaging with conventional phase-contrast magnetic resonance imaging sequences in the absence of a gating signal, permitting flow measurements in the great vessels in utero. PMID:20632406

  10. Unipolar resistive switching effect in YMn1-δO3 thin films

    NASA Astrophysics Data System (ADS)

    Yan, Z. B.; Li, S. Z.; Wang, K. F.; Liu, J.-M.

    2010-01-01

    Steady unipolar resistive switching of Pt/YMn1-δO3/Pt MIM structure is investigated. High resistance ratio (>104) of high resistance state (HRS) over low resistance state (LRS) and long retention (>105 s) are achieved. It is suggested that the Joule heating and Poole-Frenkel effect dominate respectively the conduction of the LRS and HRS in high electric field region. The resistive switching is explained by the rupture and formation of conductive filaments in association with the local Joule-heat-induced redox inside YMn1-δO3.

  11. Resistive Switching and Memory effects in Silicon Oxide Based Nanostructures

    NASA Astrophysics Data System (ADS)

    Yao, Jun

    Silicon oxide (SiOx 1 < x ≦2) has long been used and considered as a passive and insulating component in the construction of electronic devices. In contrast, here the active role of SiOx in constructing a type of resistive switching memory is studied. From electrode-independent electrical behaviors to the visualization of the conducting filament inside the SiOx matrix, the intrinsic switching picture in SiOx is gradually revealed. The thesis starts with the introduction of some similar phenomenological switching behaviors in different electronic structures (Chapter 1), and then generalizes the electrode-material-independent electrical behaviors on SiOx substrates, providing indirect evidence to the intrinsic SiOx switching (Chapter 2). From planar nanogap systems to vertical sandwiched structures, Chapter 3 further discusses the switching behaviors and properties in SiOx. By localization of the switching site, the conducting filament in SiOx is visualized under transmission electron microscope using both static and in situ imaging methods (Chapter 4). With the intrinsic conduction and switching in SiO x largely revealed, Chapter 5 discusses its impact and implications to the molecular electronics and nanoelectronics where SiOx is constantly used. As comparison, another type of memory effect in semiconductors (carbon nanotubes) based on charge trapping at the semiconductor/SiO x interface is discussed (Chapter 6).

  12. Standardization of resistance exercise training: effects in diabetic ovariectomized rats.

    PubMed

    Sanches, I C; Conti, F F; Sartori, M; Irigoyen, M C; De Angelis, K

    2014-04-01

    This study was carried out with a 3-fold aim: 1) to standardize a maximal load test (MLT) on ladders for prescription of resistance exercise training (RET) in rats, 2) to prescribe moderate-intensity RET based on this MLT and 3) to test the effect of this RET in diabetic ovariectomized rats. Female Wistar rats were divided into control (C), diabetic ovariectomized sedentary (DOS) and trained (DOT) groups. The MLT was standardized with increased load applied to the rat tail for each climb, and blood lactate was measured to identify lactate threshold in C rats. MLT was applied in the 1st, 4th and 8th week of the protocol. After 8 weeks of RET, the arterial pressure was directly recorded. DOS group reduced performance in MLT, body weight, left ventricular, plantar and soleus muscles mass (vs. C). DOT rats showed an improvement in MLT associated with plantar muscle mass increased (vs. C and DOS), with attenuation of hypotension and bradycardia (vs. DOS). In conclusion, the results provide a useful method for determining the maximal load and applying RET in rats. Moreover, this study showed that moderate intensity RET improves hemodynamic status in diabetic ovariectomized rats, thereby reinforcing the role of RET in diabetes management. PMID:24022577

  13. Effects of bacteriocins on methicillin-resistant Staphylococcus aureus biofilm.

    PubMed

    Okuda, Ken-ichi; Zendo, Takeshi; Sugimoto, Shinya; Iwase, Tadayuki; Tajima, Akiko; Yamada, Satomi; Sonomoto, Kenji; Mizunoe, Yoshimitsu

    2013-11-01

    Control of biofilms formed by microbial pathogens is an important subject for medical researchers, since the development of biofilms on foreign-body surfaces often causes biofilm-associated infections in patients with indwelling medical devices. The present study examined the effects of different kinds of bacteriocins, which are ribosomally synthesized antimicrobial peptides produced by certain bacteria, on biofilms formed by a clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA). The activities and modes of action of three bacteriocins with different structures (nisin A, lacticin Q, and nukacin ISK-1) were evaluated. Vancomycin, a glycopeptide antibiotic used in the treatment of MRSA infections, showed bactericidal activity against planktonic cells but not against biofilm cells. Among the tested bacteriocins, nisin A showed the highest bactericidal activity against both planktonic cells and biofilm cells. Lacticin Q also showed bactericidal activity against both planktonic cells and biofilm cells, but its activity against biofilm cells was significantly lower than that of nisin A. Nukacin ISK-1 showed bacteriostatic activity against planktonic cells and did not show bactericidal activity against biofilm cells. Mode-of-action studies indicated that pore formation leading to ATP efflux is important for the bactericidal activity against biofilm cells. Our results suggest that bacteriocins that form stable pores on biofilm cells are highly potent for the treatment of MRSA biofilm infections. PMID:23979748

  14. Effects of Bacteriocins on Methicillin-Resistant Staphylococcus aureus Biofilm

    PubMed Central

    Zendo, Takeshi; Sugimoto, Shinya; Iwase, Tadayuki; Tajima, Akiko; Yamada, Satomi; Sonomoto, Kenji

    2013-01-01

    Control of biofilms formed by microbial pathogens is an important subject for medical researchers, since the development of biofilms on foreign-body surfaces often causes biofilm-associated infections in patients with indwelling medical devices. The present study examined the effects of different kinds of bacteriocins, which are ribosomally synthesized antimicrobial peptides produced by certain bacteria, on biofilms formed by a clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA). The activities and modes of action of three bacteriocins with different structures (nisin A, lacticin Q, and nukacin ISK-1) were evaluated. Vancomycin, a glycopeptide antibiotic used in the treatment of MRSA infections, showed bactericidal activity against planktonic cells but not against biofilm cells. Among the tested bacteriocins, nisin A showed the highest bactericidal activity against both planktonic cells and biofilm cells. Lacticin Q also showed bactericidal activity against both planktonic cells and biofilm cells, but its activity against biofilm cells was significantly lower than that of nisin A. Nukacin ISK-1 showed bacteriostatic activity against planktonic cells and did not show bactericidal activity against biofilm cells. Mode-of-action studies indicated that pore formation leading to ATP efflux is important for the bactericidal activity against biofilm cells. Our results suggest that bacteriocins that form stable pores on biofilm cells are highly potent for the treatment of MRSA biofilm infections. PMID:23979748

  15. Gatifloxacin for short, effective treatment of multidrug-resistant tuberculosis.

    PubMed

    Chiang, C-Y; Van Deun, A; Rieder, H L

    2016-09-01

    The 9-month regimen for the treatment of multidrug-resistant tuberculosis (MDR-TB) piloted in Bangladesh and used, with modifications, in Cameroon and Niger, has achieved treatment success in a very large proportion of patients; gatifloxacin (GFX) is likely to have played a critical role in this success. Two months after the publication of a study reporting that GFX and not moxifloxacin (MFX) was associated with dysglycaemia, the manufacturer announced the withdrawal of GFX from the market. The findings of that study may have less significance for the majority of MDR-TB patients living in high-incidence countries who are much younger, have a lower risk of dysglycaemia and suffer from a highly fatal condition. The problem of dysglycaemia is not limited to GFX use and may occur with other fluoroquinolones; furthermore, GFX-associated dysglycemia was manageable among those MDR-TB patients in Bangladesh and Niger in whom it occurred. GFX has now become unavailable in Bangladesh, Cameroon, Niger and other countries piloting the shorter MDR-TB regimens, depriving resource-poor countries of an efficacious, effective and inexpensive drug with a demonstrated good safety profile for the given indication. There is little reason not to make GFX available for MDR-TB treatment as long as the superiority of non-GFX-based MDR-TB regimens is not demonstrated. PMID:27510237

  16. In Vitro Antibacterial and Antibiotic Resistance Modifying Effect of Bioactive Plant Extracts on Methicillin-Resistant Staphylococcus epidermidis

    PubMed Central

    Chovanová, Romana; Vaverková, Štefánia

    2013-01-01

    The crude extracts of plants from Asteraceae and Lamiaceae family and essential oils from Salvia officinalis and Salvia sclarea were studied for their antibacterial as well as antibiotic resistance modifying activity. Using disc diffusion and broth microdilution assays we determined higher antibacterial effect of three Salvia spp. and by evaluating the leakage of 260 nm absorbing material we detected effect of extracts and, namely, of essential oils on the disruption of cytoplasmic membrane. The evaluation of in vitro interactions between plant extracts and oxacillin described in terms of fractional inhibitory concentration (FIC) indices revealed synergistic or additive effects of plant extracts and clearly synergistic effects of essential oil from Salvia officinalis with oxacillin in methicillin-resistant Staphylococcus epidermidis. PMID:24222768

  17. Guidelines for Teaching Metric Concepts.

    ERIC Educational Resources Information Center

    Wisconsin State Dept. of Public Instruction, Madison.

    The primary purpose of these guidelines is to provide teachers and other decision-makers with a suggested framework within which sound planning for metric education can be done. Student behavioral objectives are listed by topic. Each objective is coded to indicate grade level, topic, and objective number. A chart is provided to show a kindergarten…

  18. Metrics in Education - Resource Materials.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Div. of Curriculum Development.

    This publication contains materials suitable for reproduction as transparencies or as classroom handouts. These metric materials may be used in a variety of occupational and practical arts courses. The format of the materials is in large print, some with humorous drawing; details of drawings and charts are easy to read. Introductory pages deal…

  19. Metrication and the Technical Teacher

    ERIC Educational Resources Information Center

    Irving, Michael

    1975-01-01

    The conclusion of the two-part feature on the S1 metric (International System of Units) reviews the basics and some of the rules technical teachers need to know in order to prepare their students for the changing world. (Author)

  20. Improving an Imperfect Metric System

    ERIC Educational Resources Information Center

    Frasier, E. Lewis

    1974-01-01

    Suggests some improvements and additional units necessary for the International Metric System to expand its use to all measureable entities and defined quantities, especially in the measurement of time and angles. Included are tables of proposed unit systems in contrast with the presently available systems. (CC)

  1. Metric Units in Primary Schools.

    ERIC Educational Resources Information Center

    Lighthill, M. J.; And Others

    Although this pamphlet is intended as background material for teachers in English primary schools changing to the System International d'Unites (SI units), the form of the metric system being adopted by the United Kingdom, the educational implications of the change and the lists of apparatus suitable for use with children up to 14 years of age are…

  2. Resources available for applying metrics in security and safety programming.

    PubMed

    Luizzo, Anthony

    2016-01-01

    Incorporating metrics into security surveys has been championed as a better way of substantiating program-related effectiveness and expenditures. Although security surveys have been aroundfor well over 40 years, rarely, if ever, have metric-related strategies been part of the equation, the author says. In this article, he cites several published articles and research findings available to security professionals and their surveyors that may give them the expertise and confidence they need to make use of this valuable tool. PMID:26978954

  3. Effects of antibiotic resistance alleles on bacterial evolutionary responses to viral parasites

    PubMed Central

    Hall, Alex R.

    2016-01-01

    Antibiotic resistance has wide-ranging effects on bacterial phenotypes and evolution. However, the influence of antibiotic resistance on bacterial responses to parasitic viruses remains unclear, despite the ubiquity of such viruses in nature and current interest in therapeutic applications. We experimentally investigated this by exposing various Escherichia coli genotypes, including eight antibiotic-resistant genotypes and a mutator, to different viruses (lytic bacteriophages). Across 960 populations, we measured changes in population density and sensitivity to viruses, and tested whether variation among bacterial genotypes was explained by their relative growth in the absence of parasites, or mutation rate towards phage resistance measured by fluctuation tests for each phage. We found that antibiotic resistance had relatively weak effects on adaptation to phages, although some antibiotic-resistance alleles impeded the evolution of resistance to phages via growth costs. By contrast, a mutator allele, often found in antibiotic-resistant lineages in pathogenic populations, had a relatively large positive effect on phage-resistance evolution and population density under parasitism. This suggests costs of antibiotic resistance may modify the outcome of phage therapy against pathogenic populations previously exposed to antibiotics, but the effects of any co-occurring mutator alleles are likely to be stronger. PMID:27194288

  4. Effects of antibiotic resistance alleles on bacterial evolutionary responses to viral parasites.

    PubMed

    Arias-Sánchez, Flor I; Hall, Alex R

    2016-05-01

    Antibiotic resistance has wide-ranging effects on bacterial phenotypes and evolution. However, the influence of antibiotic resistance on bacterial responses to parasitic viruses remains unclear, despite the ubiquity of such viruses in nature and current interest in therapeutic applications. We experimentally investigated this by exposing various Escherichia coli genotypes, including eight antibiotic-resistant genotypes and a mutator, to different viruses (lytic bacteriophages). Across 960 populations, we measured changes in population density and sensitivity to viruses, and tested whether variation among bacterial genotypes was explained by their relative growth in the absence of parasites, or mutation rate towards phage resistance measured by fluctuation tests for each phage. We found that antibiotic resistance had relatively weak effects on adaptation to phages, although some antibiotic-resistance alleles impeded the evolution of resistance to phages via growth costs. By contrast, a mutator allele, often found in antibiotic-resistant lineages in pathogenic populations, had a relatively large positive effect on phage-resistance evolution and population density under parasitism. This suggests costs of antibiotic resistance may modify the outcome of phage therapy against pathogenic populations previously exposed to antibiotics, but the effects of any co-occurring mutator alleles are likely to be stronger. PMID:27194288

  5. Effectiveness of Genes for Hessian Fly (Diptera: Cecidomyiidae) Resistance in the Southeastern United States.

    PubMed

    Shukle, Richard H; Cambron, Sue E; Moniem, Hossam Abdel; Schemerhorn, Brandon J; Redding, Julie; David Buntin, G; Flanders, Kathy L; Reisig, Dominic D; Mohammadi, Mohsen

    2016-02-01

    The Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae), is the most important insect pest of wheat (Triticum aestivum L. subsp. aestivum) in the southeastern United States, and the deployment of genetically resistant wheat is the most effective control. However, the use of resistant wheat results in the selection of pest genotypes that can overcome formerly resistant wheat. We have evaluated the effectiveness of 16 resistance genes for protection of wheat from Hessian fly infestation in the southeastern United States. Results documented that while 10 of the genes evaluated could provide protection of wheat, the most highly effective genes were H12, H18, H24, H25, H26, and H33. However, H12 and H18 have been reported to be only partially effective in field evaluations, and H24, H25, and H26 may be associated with undesirable effects on agronomic traits when introgressed into elite wheat lines. Thus, the most promising new gene for Hessian fly resistance appears to be H33. These results indicate that identified highly effective resistance in wheat to the Hessian fly is a limited resource and emphasize the need to identify novel sources of resistance. Also, we recommend that the deployment of resistance in gene pyramids and the development of novel strategies for engineered resistance be considered. PMID:26468515

  6. Anticancer effects of the organosilicon multidrug resistance modulator SILA 421.

    PubMed

    Olszewski, Ulrike; Zeillinger, Robert; Kars, Meltem Demirel; Zalatnai, Attila; Molnar, Jozsef; Hamilton, Gerhard

    2012-07-01

    1,3-dimethyl-1,3-bis(4-fluorophenyl)-1,3-bis{3-[1(4-butylpiperazinyl)]-propyl}-disiloxan-tetrahydrochlorid (SILA 421) is a compound that was developed as modulator of the ABC cassette transporter P-glycoprotein. Furthermore, it exerted antimicrobial toxicity, vascular effects, downregulation of chaperone induction and plasmid curing in bacterial cells. Here, this drug was found to possess cytotoxic activity against a panel of human cancer cell lines that do not overexpress P-gp, with 50% inhibitory concentrations ranging between 1.75±0.38 μM for GLC14 small cell lung cancer and 34.00±4.75 μM for PC-3 prostate cancer cells. HL-60 leukemia and MDA-MB-435 breast cancer cells exhibited cell cycle arrest and apoptotic cell death in response to SILA 421. Assessment of global gene expression of SILA 421-treated HL-60 cells was employed to identify cellular pathways affected by the compound and revealed disturbance of DNA replication, transcription and production of apparently misfolded proteins. Endoplasmatic reticulum stress and downregulation of cell cycle, cellular repair mechanisms and growth factor-related signaling cascades eventually resulted in induction of apoptosis in this cell line. In addition to the well established P-gp inhibitory effect of SILA compounds, reversal of resistance to taxanes, which had been reported for SILA 421 and the related molecule SILA 409, may be linked to downregulation of gene expression of kinesins. Interference with DNA replication and transcription seems to be the common denominator of antimicrobial activity and plasmid curing, as well as anticancer toxicity in human cell lines. Thus, in consideration of the full range of putative cellular targets found in the present work, the application of these SILA compounds for treatment of tumors should be further evaluated. PMID:22263791

  7. Banana resistant starch and its effects on constipation model mice.

    PubMed

    Wang, Juan; Huang, Ji Hong; Cheng, Yan Feng; Yang, Gong Ming

    2014-08-01

    Banana resistant starch (BRS) was extracted to investigate the structural properties of BRS, its effects on the gastrointestinal transit, and dejecta of normal and experimentally constipated mice. The mouse constipation model was induced by diphenoxylate administration. The BRS administered mice were divided into three groups and gavaged with 1.0, 2.0, or 4.0 g/kg body weight BRS per day. The small intestinal movement, time of the first black dejecta, dejecta granules, weight and their moisture content, body weight, and food intake of mice were studied. Results showed that the BRS particles were oval and spindly and some light cracks and pits were in the surface. The degree of crystallinity of BRS was 23.13%; the main diffraction peaks were at 2(θ) 15.14, 17.38, 20.08, and 22.51. The degree of polymerization of BRS was 81.16 and the number-average molecular weight was 13147.92 Da, as determined by the reducing terminal method. In animal experiments, BRS at the dose of 4.0 g/kg body weight per day was able to increase the gastrointestinal propulsive rate, and BRS at the doses of 2.0 and 4.0 g/kg body weight per day was found to shorten the start time of defecation by observing the first black dejecta exhaust. However, there were no influences of BRS on the dejecta moisture content, the dejecta granules and their weight, body weight, or daily food intake in mice. BRS was effective in accelerating the movement of the small intestine and in shortening the start time of defecation, but did not impact body weight and food intake. Therefore, BRS had the potential to be useful for improving intestinal motility during constipation. PMID:25046686

  8. Metric redefinitions in Einstein-Aether theory

    SciTech Connect

    Foster, Brendan Z.

    2005-08-15

    'Einstein-Aether' theory, in which gravity couples to a dynamical, timelike, unit-norm vector field, provides a means for studying Lorentz violation in a generally covariant setting. Demonstrated here is the effect of a redefinition of the metric and 'aether' fields in terms of the original fields and two free parameters. The net effect is a change of the coupling constants appearing in the action. Using such a redefinition, one of the coupling constants can be set to zero, simplifying studies of solutions of the theory.

  9. The effects of immunity and resistance on the development of AIDS

    NASA Astrophysics Data System (ADS)

    Abell, Martha; Braselton, James; Braselton, Lorraine

    2007-09-01

    We incorporate basic genetics into an AIDS model. We illustrate that if a homozygote is immune to the disease or is resistant to the effects of the disease, the corresponding allele goes to fixation. On the other hand, if the heterozygote is immune to the disease or is resistant to the effects of the disease, polymorphism usually occurs.

  10. Resistive-wall wake effect in the beam delivery system

    SciTech Connect

    J.R. Delayen; Juhao Wu; T.O. Raubenheimer; Jiunn-Ming Wang

    2004-08-16

    General formulae for resistive-wall induced beam dilution are presented and then applied to the final beam delivery system of linear colliders. Criteria for the design of final beam delivery systems are discussed.

  11. Effects of deprotected species on chemically amplified resist systems

    NASA Astrophysics Data System (ADS)

    Ota, Toshiyuki; Ikezaki, Yoji; Kajita, Toru; Kobayashi, Eiichi; Tsuji, Akira

    1994-05-01

    We studied the deprotecting chemistry of poly(4-hydroxystyrene) based positive-working CA resist systems by using model reactions. Detailed analyses of acid-catalyzed deprotecting reactions of TMS-, THP-, and t-BOC-protected p-cresols were carried out, and it was found that alkylated derivatives of p- cresol were formed as major products for THP- and t-BOC-protected p-cresol, while no alkylated products were obtained for TMS derivatives after deprotection treatment (90 degree(s)C, 2 min). In the THP- and t-BOC-protected PHS systems were also observed such alkylations, which decreased the alkaline dissolution rate of the polymer film. The alkylations are considered to lower the alkaline dissolution contrast between an exposed area and an unexposed area in a resist film, and to deteriorate the resist performance. Therefore, we propose to introduce an alkylation inhibitor to the resist components so as to improve the performance.

  12. The effect of inhalation resistance on facepiece leakage.

    PubMed

    Nelson, T J; Colton, C E

    2000-01-01

    Air purifying respirators use filters to remove particulate air contaminants. Resistance to airflow generally increases as the filter loads and a "filter cake" is formed. It has been recommended by ANSI and the Occupational Safety and Health Administration that filters should be replaced when the wearer notices they are hard to breathe through. Repeated faceseal leak rate measurements were made during respiratory wear over a range of simulated breathing resistances from 5.6 to 19.6 mm (0.22 to 0.77 inches) of water. The measured faceseal leak rates increased as the breathing resistance increased and varied depending on the initial leak rate at the 5.6 mm pressure. The increase in faceseal leak rate from 5.6 to 19.6 mm breathing resistance was as high as a factor of 4. Theoretically, a person with an initial respirator penetration of 2.5% could have that value increase to 10% as filter loading increased breathing resistance by 14 mm. Some research has shown that breathing resistances between 60 and 140 mm of water would be "noticeable but well tolerated." It is not known if workers would be able to detect an increase in breathing resistance that would lead to a significant increase in faceseal leakage. These data suggest a need to establish a replacement schedule for all filters used in the workplace. How often a filter should be replaced is difficult to determine. Breathing resistance would vary depending on the individual filter and aerosol loading characteristics, the concentration of the aerosol in the workplace, and breathing rates. PMID:10772622

  13. An improved virtual aberration model to simulate mask 3D and resist effects

    NASA Astrophysics Data System (ADS)

    Kanaya, Reiji; Fujii, Koichi; Imai, Motokatsu; Matsuyama, Tomoyuki; Tsuzuki, Takao; Lin, Qun Ying

    2015-03-01

    As shrinkage of design features progresses, the difference in best focus positions among different patterns is becoming a fatal issue, especially when many patterns co-exist in a layer. The problem arises from three major factors: aberrations of projection optics, mask 3D topography effects, and resist thickness effects. Aberrations in projection optics have already been thoroughly investigated, but mask 3D topography effects and resist thickness effects are still under study. It is well known that mask 3D topography effects can be simulated by various Electro-magnetic Field (EMF) analysis methods. However, it is almost impossible to use them for full chip modeling because all of these methods are extremely computationally intensive. Consequently, they usually apply only to a limited range of mask patterns which are about tens of square micro meters in area. Resist thickness effects on best focus positions are rarely treated as a topic of lithography investigations. Resist 3D effects are treated mostly for resist profile prediction, which also requires an intensive EMF analysis when one needs to predict it accurately. In this paper, we present a simplified Virtual Aberration (VA) model to simulate both mask 3D induced effects and resist thickness effects. A conventional simulator, when applied with this simplified method, can factor in both mask 3D topography effects and resist thickness effects. Thus it can be used to model inter-pattern Best Focus Difference (BFD) issues with the least amount of rigorous EMF analysis.

  14. [Effects of application resistive and flex resistance to breath in training sportsmen].

    PubMed

    Gorbaneva, E P; Solopov, A I; Vlasov, A A; Voskresenskiĭ, S A

    2010-01-01

    Research on studying influence of a rate of muscular training in conditions of additional aerodynamic and flex resistance to breath on a level of physical working capacity, aerobic productivity and a functional condition of system of breath is executed. It is shown, that regular muscular training on a background of use of the dosed out breath with increased aerodynamic and flex resistance to respiratory stream and respiratory movements, first of all. provides essential growth of functionalities of the respiratory muscles expressed in authentic increase of power and speed-power parameters, shortening of time of impellent reaction of respiratory muscles. Improvement of a functional condition of respiratory system, and, in particular, respiratory muscles, caused significant growth of physical working capacity and physical readiness of young sportsmen. PMID:20432701

  15. Charged C -metric in conformal gravity

    NASA Astrophysics Data System (ADS)

    Lim, Yen-Kheng

    2016-04-01

    Using a C -metric-type ansatz, we obtain an exact solution to conformal gravity coupled to a Maxwell electromagnetic field. The solution resembles a C -metric spacetime carrying an electromagnetic charge. The metric is cast in a factorized form which allows us to study the domain structure of its static coordinate regions. This metric reduces to the well-known Mannheim-Kazanas metric under an appropriate limiting procedure, and also reduces to the (anti)de Sitter C -metric of Einstein gravity for a particular choice of parameters.

  16. Semantic Metrics for Analysis of Software

    NASA Technical Reports Server (NTRS)

    Etzkorn, Letha H.; Cox, Glenn W.; Farrington, Phil; Utley, Dawn R.; Ghalston, Sampson; Stein, Cara

    2005-01-01

    A recently conceived suite of object-oriented software metrics focus is on semantic aspects of software, in contradistinction to traditional software metrics, which focus on syntactic aspects of software. Semantic metrics represent a more human-oriented view of software than do syntactic metrics. The semantic metrics of a given computer program are calculated by use of the output of a knowledge-based analysis of the program, and are substantially more representative of software quality and more readily comprehensible from a human perspective than are the syntactic metrics.

  17. A study of a proposed modified torsional agility metric

    NASA Technical Reports Server (NTRS)

    Valasek, John; Eggold, David P.; Downing, David R.

    1991-01-01

    A new candidate lateral agility metric, the modified torsional agility parameter, is proposed and tested through generic, nonlinear, non-real-time flight simulation programs of the F-18 and F-5A. The metric is aimed at quantifying high subsonic loaded roll capabilities which might be useful in modern air combat. The metric is considered to be straightforward for testing and measuring based on nonreal-time unmanned flight simulation. The metric is found to be sensitive to pilot input errors of less than full lateral stick to capture bank angle, when tested using unmanned flight simulations. It is suggested that, for redesigned configurations of both aircraft with improved lateral agility, the major benefit would be provided by fast and highly effective rudders, and a high level of pitch, roll, and yaw damping at moderate to high normal load factor levels.

  18. Conformal Gravity and the Alcubierre Warp Drive Metric

    NASA Astrophysics Data System (ADS)

    Varieschi, Gabriele; Burstein, Zily

    2013-04-01

    We present an analysis of the classic Alcubierre metric based on conformal gravity, rather than standard general relativity. The main characteristics of the resulting warp drive remain the same as in the original study by Alcubierre, namely that effective super-luminal motion is a viable outcome of the metric. We show that for particular choices of the shaping function, the Alcubierre metric in the context of conformal gravity does not violate the weak energy condition, as was the case of the original solution. In particular, the resulting warp drive does not require the use of exotic matter. Therefore, if conformal gravity is a correct extension of general relativity, super-luminal motion via an Alcubierre metric might be a realistic solution, thus allowing faster-than-light interstellar travel.

  19. Bipolar and unipolar resistive switching effects in an Al/DLC/W structure

    NASA Astrophysics Data System (ADS)

    Peng, Pinggang; Xie, Dan; Yang, Yi; Zhou, Changjian; Ma, Shuo; Feng, Tingting; Tian, He; Ren, Tianling

    2012-09-01

    In this paper, nonvolatile bipolar resistive switching (BRS) as well as unipolar resistive switching (URS) effects are observed in diamond-like carbon (DLC) thin films prepared by the filtered cathodic vacuum arc technique. By controlling the current compliance, either bipolar or unipolar switching is obtained. The fabricated Al/DLC/W structure showing BRS exhibits good performance with a low operation voltage (<1.0 V) and a data retention time of >105 s. The mechanism of BRS is fitted by ohmic and SCLC laws in the low resistance state and high resistance state scenarios. Fuse and antifuse effects are proposed to be the principle for the URS behaviour.

  20. Light-Induced Resistance Effect Observed in Nano Au Films Covered Two-Dimensional Colloidal Crystals.

    PubMed

    Liu, Shuai; Huang, Meizhen; Yao, Yanjie; Wang, Hui; Jin, Kui-juan; Zhan, Peng; Wang, Zhenlin

    2015-09-01

    Tailoring resistance response using periodic nanostructures is one of the key issues in the current research. Two-dimensional colloidal crystals (CCs) structure is one of popular periodic nanospheres' structures and most of reports are focused on anomalous transmission of light or biomedical applications. In this work, a light-induced resistance effect is observed on silicon-based Au films covered CCs, featuring a remarkable resistance change as much as 56% and resistance switching characteristic. The diffusion and recombination of photocarriers is the crucial factor for this effect. This finding will expand photoelectricity functionality and be useful for future development of CC-based photoelectric devices. PMID:26314930

  1. Effects of Streptococcus pneumoniae Strain Background on Complement Resistance

    PubMed Central

    Hyams, Catherine; Opel, Sophia; Hanage, William; Yuste, Jose; Bax, Katie; Henriques-Normark, Birgitta; Spratt, Brian G.; Brown, Jeremy S.

    2011-01-01

    Background Immunity to infections caused by Streptococcus pneumoniae is dependent on complement. There are wide variations in sensitivity to complement between S. pneumoniae strains that could affect their ability to cause invasive infections. Although capsular serotype is one important factor causing differences in complement resistance between strains, there is also considerable other genetic variation between S. pneumoniae strains that may affect complement-mediated immunity. We have therefore investigated whether genetically distinct S. pneumoniae strains with the same capsular serotype vary in their sensitivity to complement mediated immunity. Methodology and Principal Findings C3b/iC3b deposition and neutrophil association were measured using flow cytometry assays for S. pneumoniae strains with different genetic backgrounds for each of eight capsular serotypes. For some capsular serotypes there was marked variation in C3b/iC3b deposition between different strains that was independent of capsule thickness and correlated closely to susceptibility to neutrophil association. C3b/iC3b deposition results also correlated weakly with the degree of IgG binding to each strain. However, the binding of C1q (the first component of the classical pathway) correlated more closely with C3b/iC3b deposition, and large differences remained in complement sensitivity between strains with the same capsular serotype in sera in which IgG had been cleaved with IdeS. Conclusions These data demonstrate that bacterial factors independent of the capsule and recognition by IgG have strong effects on the susceptibility of S. pneumoniae to complement, and could therefore potentially account for some of the differences in virulence between strains. PMID:22022358

  2. Cyclic resistive switching effect in plasma electrolytically oxidized mesoporous Pt/TiO2 structures

    NASA Astrophysics Data System (ADS)

    Fullam, S.; Ray, N. J.; Karpov, E. G.

    2015-06-01

    Understanding the resistive switching phenomenon in metal oxide semiconductors is necessary in producing reliable resistive random access memory and other variable resistance devices. An alternative technique for fabricating resistive switching elements is presented. Using plasma electrolytic oxidation, 10-11 μ m thick oxide layers were galvanostatically grown on Ti substrates in a 3 M H2SO4 electrolyte. Analysis of the TiO2 layer by SEM, AFM, and XRD found the mesoporous titania surface to have a high ratio of rutile to anatase phases. The samples demonstrated pinched I-V hysteresis attributed to the resistive switching effect, when subjected to cyclic loading (±2.5, 1.6, 0.7 V; 23-736 μ Hz) at room temperature. Ratio with magnitude of 6 is reported for the resistance switching effect during 1.6 V 368 μ Hz loads.

  3. Evaluating the relationship between biotic and sediment metrics using mesocosms and field studies.

    PubMed

    Conroy, E; Turner, J N; Rymszewicz, A; Bruen, M; O'Sullivan, J J; Lawler, D M; Lally, H; Kelly-Quinn, M

    2016-10-15

    An ongoing research challenge is the detection of biological responses to elevated sediment and the identification of sediment-specific bioassessment metrics to evaluate these biological responses. Laboratory mesocosms and field observations in rivers in Ireland were used to evaluate the relationship between a range of biological and sediment metrics and to assess which biological metrics were best at discerning the effects of excess sediment on macroinvertebrates. Results from the mesocosm study indicated a marked decrease in the abundance of sensitive taxa with increasing sediment surface cover. % EPT (Ephemeroptera, Plecoptera, Trichoptera) and % E abundances exhibited the strongest negative correlation with sediment surface cover in the mesocosm study. The field study revealed that % EPT abundance was most closely correlated with % sediment surface cover, explaining 13% of the variance in the biological metric. Both studies revealed weaker relationships with a number of other taxonomy-based metrics including total taxon abundance, total taxon richness and moderate relationships with the Proportion of Sediment-sensitive Invertebrates metric (PSI). All trait-based metrics were poorly correlated with sediment surface cover in the field study. In terms of sediment metrics, % surface cover was more closely related to biological metrics than either re-suspendable sediment or turbidity. These results indicate that % sediment surface cover and % EPT abundance may be useful metrics for assessing the effect of excessive sediment on macroinvertebrates. However, EPT metrics may not be specific to sediment impact and therefore when applied to rivers with multiple pressures should be combined with observations on sediment cover. PMID:27373379

  4. Persuasive communication: A theoretical model for changing the attitude of preservice elementary teachers toward metric conversion

    NASA Astrophysics Data System (ADS)

    Shrigley, Robert L.

    This study was based on Hovland's four-part statement, Who says what to whom with what effect, the rationale for persuasive communication, a theoretical model for modifying attitudes. Part I was a survey of 139 perservice elementary teachers from which were generated the more credible characteristics of metric instructors, a central element in the who component of Hovland's model. They were: (1) background in mathematics and science, (2) fluency in metrics, (3) capability of thinking metrically, (4) a record of excellent teaching, (5) previous teaching of metric measurement to children, (6) responsibility for teaching metric content in methods courses and (7) an open enthusiasm for metric conversion. Part II was a survey of 45 mathematics educators where belief statements were synthesized for the what component of Hovland's model. It found that math educators support metric measurement because: (1) it is consistent with our monetary system; (2) the conversion of units is easier into metric than English; (3) it is easier to teach and easier to learn than English measurement; there is less need for common fractions; (4) most nations use metric measurement; scientists have used it for decades; (5) American industry has begun to use it; (6) metric measurement will facilitate world trade and communication; and (7) American children will need it as adults; educational agencies are mandating it. With the who and what of Hovland's four-part statement defined, educational researchers now have baseline data to use in testing experimentally the effect of persuasive communication on the attitude of preservice teachers toward metrication.

  5. Metrics for Labeled Markov Systems

    NASA Technical Reports Server (NTRS)

    Desharnais, Josee; Jagadeesan, Radha; Gupta, Vineet; Panangaden, Prakash

    1999-01-01

    Partial Labeled Markov Chains are simultaneously generalizations of process algebra and of traditional Markov chains. They provide a foundation for interacting discrete probabilistic systems, the interaction being synchronization on labels as in process algebra. Existing notions of process equivalence are too sensitive to the exact probabilities of various transitions. This paper addresses contextual reasoning principles for reasoning about more robust notions of "approximate" equivalence between concurrent interacting probabilistic systems. The present results indicate that:We develop a family of metrics between partial labeled Markov chains to formalize the notion of distance between processes. We show that processes at distance zero are bisimilar. We describe a decision procedure to compute the distance between two processes. We show that reasoning about approximate equivalence can be done compositionally by showing that process combinators do not increase distance. We introduce an asymptotic metric to capture asymptotic properties of Markov chains; and show that parallel composition does not increase asymptotic distance.

  6. Object-oriented productivity metrics

    NASA Technical Reports Server (NTRS)

    Connell, John L.; Eller, Nancy

    1992-01-01

    Software productivity metrics are useful for sizing and costing proposed software and for measuring development productivity. Estimating and measuring source lines of code (SLOC) has proven to be a bad idea because it encourages writing more lines of code and using lower level languages. Function Point Analysis is an improved software metric system, but it is not compatible with newer rapid prototyping and object-oriented approaches to software development. A process is presented here for counting object-oriented effort points, based on a preliminary object-oriented analysis. It is proposed that this approach is compatible with object-oriented analysis, design, programming, and rapid prototyping. Statistics gathered on actual projects are presented to validate the approach.

  7. Weighted contrast metric for imaging system performance

    NASA Astrophysics Data System (ADS)

    Teaney, Brian P.

    2012-06-01

    There have been significant improvements in the image quality metrics used in the NVESD model suite in recent years. The introduction of the Targeting Task Performance (TTP) metric to replace the Johnson criteria yielded significantly more accurate predictions for under-sampled imaging systems in particular. However, there are certain cases which cause the TTP metric to predict optimistic performance. In this paper a new metric for predicting performance of imaging systems is described. This new weighted contrast metric is characterized as a hybrid of the TTP metric and Johnson criteria. Results from a number of historical perception studies are presented to compare the performance of the TTP metric and Johnson criteria to the newly proposed metric.

  8. Do Your Students Measure Up Metrically?

    ERIC Educational Resources Information Center

    Taylor, P. Mark; Simms, Ken; Kim, Ok-Kyeong; Reys, Robert E.

    2001-01-01

    Examines released metric items from the Third International Mathematics and Science Study (TIMSS) and the 3rd and 4th grade results. Recommends refocusing instruction on the metric system to improve student performance in measurement. (KHR)

  9. Hands-On Activities with Metrics

    ERIC Educational Resources Information Center

    McFee, Evan

    1978-01-01

    Suggestions for familiarizing elementary teachers with the use of the metric system are given. These include a "stair-steps" method of converting units within the metric system and estimation and measurement activities using familiar everyday objects. (MN)

  10. Measure Metric: A Multi-State Consortium

    ERIC Educational Resources Information Center

    Dowling, Kenneth W.

    1977-01-01

    Describes the "Measure Metric" series of twelve fifteen-minute programs and related classroom materials for grades 5 and 6 for teaching the metric system and the International System of Units (SI). (SL)

  11. Measuring Sustainability: Deriving Metrics From Objectives (Presentation)

    EPA Science Inventory

    The definition of 'sustain', to keep in existence, provides some insight into the metrics that are required to measure sustainability and adequately respond to assure sustainability. Keeping something in existence implies temporal and spatial contexts and requires metrics that g...

  12. Sustainability Metrics: The San Luis Basin Project

    EPA Science Inventory

    Sustainability is about promoting humanly desirable dynamic regimes of the environment. Metrics: ecological footprint, net regional product, exergy, emergy, and Fisher Information. Adaptive management: (1) metrics assess problem, (2) specific problem identified, and (3) managemen...

  13. Effect of resin monomer composition on toothbrush wear resistance.

    PubMed

    Kawai, K; Iwami, Y; Ebisu, S

    1998-04-01

    The purpose of this study was to compare the toothbrush abrasion resistance of seven different experimental resins which were made by changing the composition of resin monomers. The experimental resins were made by mixing four kinds of dental resin monomers (Bis-GMA, UDMA, TMPT and TEGDMA), camphorquinone (1 wt%), dimethylaminoethyl methacrylate (2 wt%) and 2,6-di-tert-butyl-p-cresol (0.05 wt%). The resin specimens were stored in air for 2 weeks, and then put on a toothbrush abrasion testing machine. After 100000 strokes, the wear loss of each specimen was determined by weight change during the wear test. TMPT-TEGDMA resin showed the most wear resistance, while Bis-GMA- and UDMA-based resins showed increased wear resistance with an increased content of TEGDMA. Also, a inverse relationship between the microhardness number and the amount of wear of the respective resins was confirmed. PMID:9610853

  14. Nickel-cadmium Battery Cell Reversal from Resistive Network Effects

    NASA Technical Reports Server (NTRS)

    Zimmerman, A. H.

    1985-01-01

    During the individual cell short-down procedures often used for storing or reconditioning nickel-cadmium (Ni-Cd) batteries, it is possible for significant reversal of the lowest capacity cells to occur. The reversal is caused by the finite resistance of the common current-carrying leads in the resistive network that is generally used during short-down. A model is developed to evaluate the extent of such a reversal in any specific battery, and the model is verified by means of data from the short-down of a f-cell, 3.5-Ah battery. Computer simulations of short-down on a variety of battery configurations indicate the desirability of controlling capacity imbalances arising from cell configuration and battery management, limiting variability in the short-down resistors, minimizing lead resistances, and optimizing lead configurations.

  15. Metric reconstruction from Weyl scalars

    NASA Astrophysics Data System (ADS)

    Whiting, Bernard F.; Price, Larry R.

    2005-08-01

    The Kerr geometry has remained an elusive world in which to explore physics and delve into the more esoteric implications of general relativity. Following the discovery, by Kerr in 1963, of the metric for a rotating black hole, the most major advance has been an understanding of its Weyl curvature perturbations based on Teukolsky's discovery of separable wave equations some ten years later. In the current research climate, where experiments across the globe are preparing for the first detection of gravitational waves, a more complete understanding than concerns just the Weyl curvature is now called for. To understand precisely how comparatively small masses move in response to the gravitational waves they emit, a formalism has been developed based on a description of the whole spacetime metric perturbation in the neighbourhood of the emission region. Presently, such a description is not available for the Kerr geometry. While there does exist a prescription for obtaining metric perturbations once curvature perturbations are known, it has become apparent that there are gaps in that formalism which are still waiting to be filled. The most serious gaps include gauge inflexibility, the inability to include sources—which are essential when the emitting masses are considered—and the failure to describe the ell = 0 and 1 perturbation properties. Among these latter properties of the perturbed spacetime, arising from a point mass in orbit, are the perturbed mass and axial component of angular momentum, as well as the very elusive Carter constant for non-axial angular momentum. A status report is given on recent work which begins to repair these deficiencies in our current incomplete description of Kerr metric perturbations.

  16. Multi-Metric Sustainability Analysis

    SciTech Connect

    Cowlin, S.; Heimiller, D.; Macknick, J.; Mann, M.; Pless, J.; Munoz, D.

    2014-12-01

    A readily accessible framework that allows for evaluating impacts and comparing tradeoffs among factors in energy policy, expansion planning, and investment decision making is lacking. Recognizing this, the Joint Institute for Strategic Energy Analysis (JISEA) funded an exploration of multi-metric sustainability analysis (MMSA) to provide energy decision makers with a means to make more comprehensive comparisons of energy technologies. The resulting MMSA tool lets decision makers simultaneously compare technologies and potential deployment locations.

  17. The Effect of Oxygen on Bile Resistance in Listeria monocytogenes

    PubMed Central

    Wright, Morgan L; Pendarvis, Ken; Nanduri, Bindu; Edelmann, Mariola J; Jenkins, Haley N; Reddy, Joseph S; Wilson, Jessica G; Ding, Xuan; Broadway, Paul R; Ammari, Mais G; Paul, Oindrila; Roberts, Brandy; Donaldson, Janet R

    2016-01-01

    Listeria monocytogenes is a Gram-positive facultative anaerobe that is the causative agent of the disease listeriosis. The infectious ability of this bacterium is dependent upon resistance to stressors encountered within the gastrointestinal tract, including bile. Previous studies have indicated bile salt hydrolase activity increases under anaerobic conditions, suggesting anaerobic conditions influence stress responses. Therefore, the goal of this study was to determine if reduced oxygen availability increased bile resistance of L. monocytogenes. Four strains representing three serovars were evaluated for changes in viability and proteome expression following exposure to bile in aerobic or anaerobic conditions. Viability for F2365 (serovar 4b), EGD-e (serovar 1/2a), and 10403S (serovar 1/2a) increased following exposure to 10% porcine bile under anaerobic conditions (P < 0.05). However, HCC23 (serovar 4a) exhibited no difference (P > 0.05) in bile resistance between aerobic and anaerobic conditions, indicating that oxygen availability does not influence resistance in this strain. The proteomic analysis indicated F2365 and EGD-e had an increased expression of proteins associated with cell envelope and membrane bioenergetics under anaerobic conditions, including thioredoxin-disulfide reductase and cell division proteins. Interestingly, HCC23 had an increase in several dehydrogenases following exposure to bile under aerobic conditions, suggesting that the NADH:NAD+ is altered and may impact bile resistance. Variations were observed in the expression of the cell shape proteins between strains, which corresponded to morphological differences observed by scanning electron microscopy. These data indicate that oxygen availability influences bile resistance. Further research is needed to decipher how these changes in metabolism impact pathogenicity in vivo and also the impact that this has on susceptibility of a host to listeriosis. PMID:27274623

  18. Pressure effects on the resistivity of TmS

    NASA Astrophysics Data System (ADS)

    Lapierre, F.; Haen, P.; Coqblin, B.; Ribault, M.; Holtzberg, F.

    1981-08-01

    Quasi hydrostatic pressure measurements of the resistivity of a single crystal of TmS are reported. The resistivity σ is reduced by pressure P over the full range studied (up to 28 kbar and down to liquid He). It goes through a maximum near 10K and decreases logarithmically for higher temperatures. Both this behavior and the reduction of the InT slope by P can be explained in a model of resonant scattering as previously done for Ce compounds. The Néel temperature T N, marked by a small anomaly in σ, increases with P in accordance with previous susceptibility results.

  19. Pleiotropic effects of herbicide-resistance genes on crop yield: a review.

    PubMed

    Darmency, Henri

    2013-08-01

    The rapid adoption of genetically engineered herbicide-resistant crop varieties (HRCVs)-encompassing 83% of all GM crops and nearly 8% of the worldwide arable area-is due to technical efficiency and higher returns. Other herbicide-resistant varieties obtained from genetic resources and mutagenesis have also been successfully released. Although the benefit for weed control is the main criteria for choosing HRCVs, the pleiotropic costs of genes endowing resistance have rarely been investigated in crops. Here the available data of comparisons between isogenic resistant and susceptible varieties are reviewed. Pleiotropic harmful effects on yield are reported in half of the cases, mostly with resistance mechanisms that originate from genetic resources and mutagenesis (atrazine in oilseed rape and millet, trifluralin in millet, imazamox in cotton) rather than genetic engineering (chlorsulfuron and glufosinate in some oilseed rape varieties, glyphosate in soybean). No effect was found for sethoxydim and bromoxynil resistance. Variable minor effects were found for imazamox, chlorsulfuron, glufosinate and glyphosate resistance. The importance of the breeding plan and the genetic background on the emergence of these effects is pointed out. Breeders' efforts to produce better varieties could compensate for the yield loss, which eliminates any possibility of formulating generic conclusions on pleiotropic effects that can be applied to all resistant crops. PMID:23457026

  20. The effects of Myxobolus cerebralis on the physiological performance of whirling disease resistant and susceptible strains of rainbow trout.

    PubMed

    Fetherman, Eric R; Winkelman, Dana L; Schisler, George J; Myrick, Christopher A

    2011-12-01

    The development of rainbow trout Oncorhynchus mykiss strains that are resistant to whirling disease has shown promise as a management tool for populations in areas where Myxobolus cerebralis is present. However, the physiological effects of the disease on characteristics necessary for fish survival in natural river conditions have not been tested in many of these strains. Five rainbow trout strains were evaluated for their swimming ability and growth characteristics in relation to M. cerebralis exposure: the resistant German rainbow trout (GR) strain (Hofer strain), the susceptible Colorado River rainbow trout (CRR) strain, and three intermediate (hybrid) strains (F1 = GR x CRR; F2 = F1 x F1; B2 = backcross of F1 x CRR). Three broad response patterns among strain and exposure were evident in our study. First, exposure metrics, growth performance, and swimming ability differed among strains. Second, exposure to the parasite did not necessarily produce differences in growth or swimming ability. Exposure to M. cerebralis did not affect batch weight for any strain, and critical swimming velocity did not differ between exposed and unexposed families. Third, although exposure did not necessarily affect growth or swimming ability, individuals that exhibited clinical deformities did show reduced growth and swimming performance; fish with clinical deformities were significantly smaller and had lower critical swimming velocities than exposed fish without clinical deformities. Research and management have focused on GR x CRR hybrid strains; however, given the performance of the GR strain in our study, it should not be discounted as a potential broodstock. Additional field trials comparing the GR and F1 strains should be conducted before wholesale adoption of the GR strain to reestablish rainbow trout populations in Colorado. PMID:22372244

  1. Hidden Node Problem Aware Routing Metrics for WLAN Mesh Networks

    NASA Astrophysics Data System (ADS)

    Sangiamwong, Jaturong; Yagyu, Kengo; Suzuki, Toshihiro

    This paper proposes two novel hidden node problem aware routing metrics for wireless local area network (WLAN) mesh networks. To select the path that is least affected by the serious hidden node problem, we propose two routing metrics, MNn and MPCP, that take into account the number of neighboring nodes (Nn) and the packet collision probability (PCP), respectively. The PCP is estimated from neighbor information that is periodically gathered as state announcement packets, which include the transmission time ratio and the neighbor list. Simulation results show that the first proposed MNn routing metric tends to be less effective as the number of WLAN nodes increases, i. e., the mesh network becomes denser. On the other hand, with an acceptable increased in the control overhead in the mesh network due to the neighbor information, the second proposed MPCP routing metric improves the number of allowable concurrent voice over Internet Protocol (VoIP) calls and the user datagram protocol (UDP) data throughput compared to the MNn metric. The MPCP also provides better performance than the other conventional routing metrics, the hop count, and the Airtime proposed in IEEE 802.11s.

  2. Measures of agreement between computation and experiment : validation metrics.

    SciTech Connect

    Barone, Matthew Franklin; Oberkampf, William Louis

    2004-06-01

    With the increasing role of computational modeling in engineering design, performance estimation, and safety assessment, improved methods are needed for comparing computational results and experimental measurements. Traditional methods of graphically comparing computational and experimental results, though valuable, are essentially qualitative. Computable measures are needed that can quantitatively compare computational and experimental results over a range of input, or control, variables to sharpen assessment of computational accuracy. This type of measure has been recently referred to as a validation metric. We discuss various features that we believe should be incorporated in a validation metric, as well as features that we believe should be excluded. We develop a new validation metric that is based on the statistical concept of confidence intervals. Using this fundamental concept, we construct two specific metrics: one that requires interpolation of experimental data and one that requires regression (curve fitting) of experimental data. We apply the metrics to three example problems: thermal decomposition of a polyurethane foam, a turbulent buoyant plume of helium, and compressibility effects on the growth rate of a turbulent free-shear layer. We discuss how the present metrics are easily interpretable for assessing computational model accuracy, as well as the impact of experimental measurement uncertainty on the accuracy assessment.

  3. Measures of agreement between computation and experiment: Validation metrics

    SciTech Connect

    Oberkampf, William L. . E-mail: wloberk@sandia.gov; Barone, Matthew F. . E-mail: mbarone@sandia.gov

    2006-09-01

    With the increasing role of computational modeling in engineering design, performance estimation, and safety assessment, improved methods are needed for comparing computational results and experimental measurements. Traditional methods of graphically comparing computational and experimental results, though valuable, are essentially qualitative. Computable measures are needed that can quantitatively compare computational and experimental results over a range of input, or control, variables to sharpen assessment of computational accuracy. This type of measure has been recently referred to as a validation metric. We discuss various features that we believe should be incorporated in a validation metric, as well as features that we believe should be excluded. We develop a new validation metric that is based on the statistical concept of confidence intervals. Using this fundamental concept, we construct two specific metrics: one that requires interpolation of experimental data and one that requires regression (curve fitting) of experimental data. We apply the metrics to three example problems: thermal decomposition of a polyurethane foam, a turbulent buoyant plume of helium, and compressibility effects on the growth rate of a turbulent free-shear layer. We discuss how the present metrics are easily interpretable for assessing computational model accuracy, as well as the impact of experimental measurement uncertainty on the accuracy assessment.

  4. Electrofishing in boatable rivers: does sampling design affect bioassessment metrics?

    PubMed

    Flotemersch, Joseph E; Blocksom, Karen A

    2005-03-01

    Data were collected from 60 boatable sites using an electrofishing design that permitted comparisons of the effects of designs and distances on fish assemblage metrics. Sites were classified a priori as Run-of-the-River (ROR) or Restricted Flow (RF). Data representing four different design options (i.e., 1000 and 2000 m for both single and paired banks) were extracted from the dataset and analyzed. Friedman tests comparing metric values among the designs detected significant differences for all richness metrics at both types of sites and for catch per unit effort and percent tolerant species at ROR sites. Richness metrics were generally higher for the two 2000-m designs than for the two 1000-m designs. When plotted against cumulative electrofishing distance, the percent change in metrics declined sharply within approximately 1000 m, after which metrics usually varied by less than 10%. These data demonstrate that designs electrofishing 1000 m of shoreline are sufficient for bioassessments on boatable rivers similar to those in this study, regardless of whether the shoreline is along a single bank or distributed equally among paired banks. However, at sites with depths greater than 4 m, it may be advisable to employ nighttime electrofishing or increase day electrofishing designs to 2000 m. PMID:15869190

  5. Public reporting of patient safety metrics: ready or not?

    PubMed

    Podolsky, Daniel K; Nagarkar, Purushottam A; Reed, W Gary; Rohrich, Rod J

    2014-12-01

    In its 1999 report, the Institute of Medicine estimated that medical error leads to between 44,000 and 98,000 deaths per year. Given that statistic, public reporting of quality and safety metrics is a welcome response that may serve to reduce the rate of adverse events and restore patients' trust in the health care system. To ensure that any public reporting system fulfills its potential, several questions must be addressed: Are we measuring the right metrics? Are the metrics accurate, valid, and is their public reporting effecting change? Based on a review of the literature, it is clear that current metrics suffer from low reliability, low validity, and possibly minimal relevance to the intended consumer. To improve data collection and analysis, both physicians and health care consumers need to be involved in the design and collection of metrics. Until we have a valid, reliable, and actionable data set at our fingertips, it would behoove patients, providers, and institutions to look at outcome and safety metrics with a skeptical and discerning eye. PMID:25415121

  6. Towards a Visual Quality Metric for Digital Video

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.

    1998-01-01

    The advent of widespread distribution of digital video creates a need for automated methods for evaluating visual quality of digital video. This is particularly so since most digital video is compressed using lossy methods, which involve the controlled introduction of potentially visible artifacts. Compounding the problem is the bursty nature of digital video, which requires adaptive bit allocation based on visual quality metrics. In previous work, we have developed visual quality metrics for evaluating, controlling, and optimizing the quality of compressed still images. These metrics incorporate simplified models of human visual sensitivity to spatial and chromatic visual signals. The challenge of video quality metrics is to extend these simplified models to temporal signals as well. In this presentation I will discuss a number of the issues that must be resolved in the design of effective video quality metrics. Among these are spatial, temporal, and chromatic sensitivity and their interactions, visual masking, and implementation complexity. I will also touch on the question of how to evaluate the performance of these metrics.

  7. Measures of agreement between computation and experiment:validation metrics.

    SciTech Connect

    Barone, Matthew Franklin; Oberkampf, William Louis

    2005-08-01

    With the increasing role of computational modeling in engineering design, performance estimation, and safety assessment, improved methods are needed for comparing computational results and experimental measurements. Traditional methods of graphically comparing computational and experimental results, though valuable, are essentially qualitative. Computable measures are needed that can quantitatively compare computational and experimental results over a range of input, or control, variables and sharpen assessment of computational accuracy. This type of measure has been recently referred to as a validation metric. We discuss various features that we believe should be incorporated in a validation metric and also features that should be excluded. We develop a new validation metric that is based on the statistical concept of confidence intervals. Using this fundamental concept, we construct two specific metrics: one that requires interpolation of experimental data and one that requires regression (curve fitting) of experimental data. We apply the metrics to three example problems: thermal decomposition of a polyurethane foam, a turbulent buoyant plume of helium, and compressibility effects on the growth rate of a turbulent free-shear layer. We discuss how the present metrics are easily interpretable for assessing computational model accuracy, as well as the impact of experimental measurement uncertainty on the accuracy assessment.

  8. Time transfer functions in Schwarzschild-like metrics in the weak-field limit: A unified description of Shapiro and lensing effects

    NASA Astrophysics Data System (ADS)

    Linet, B.; Teyssandier, P.

    2016-02-01

    We present a complete analysis of the light rays within the linearized, weak-field approximation of a Schwarzschild-like metric describing the gravitational field of an isolated, spherically symmetric body. We prove in this context the existence of two time transfer functions and we obtain these functions in an exact closed-form. We are led to distinguish two regimes. In the first regime, the two time transfer functions correspond to rays which are confined in regions of spacetime where the weak-field approximation is valid. Such a regime occurs in gravitational lensing configurations with double images of a given source. We find the general expressions of the angular separation and the difference in light travel time between the two images. In the second regime, there exists only one time transfer function corresponding to a light ray remaining in a region of weak field. Performing a Taylor expansion of this function with respect to the gravitational constant, we obtain the Shapiro time delay completed by a series of so-called "enhanced terms." The enhanced terms beyond the third order are new.

  9. A Look at Metrics in Distributive Education.

    ERIC Educational Resources Information Center

    Canei, Robert A.

    The United States will convert to the metric system of measurement in the near future, and the distributive education programs in high school and at the adult level will have to train the needed personnel for business. The manual gives the basic conversion methods and instruction in teaching metrics. Metric programs conducted for business…

  10. Metric Measurement: A Resource for Teachers.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin. Div. of Curriculum Development.

    This document is designed to help teachers deal with the changeover from the United States customary system to the metric system. This publication contains a brief introduction to the historical development of the metric system, tables of the International System of Units, and descriptions of everyday use of the metric system. Basic information…

  11. Materials for Metric Instruction. Mathematics Education Reports.

    ERIC Educational Resources Information Center

    Bitter, Gary G.; Geer, Charles

    This compilation lists available metric kits (41 listings), task cards (8 listings), films (24 listings), filmstrips (36 listings), slides (4 listings), and other miscellaneous metric materials (13 listings). The bibliography is intended as a quick reference or source of information for supplementary metric materials. For each entry the source,…

  12. Metrics, Lumber, and the Shop Teacher

    ERIC Educational Resources Information Center

    Craemer, Peter J.

    1978-01-01

    As producers of lumber are preparing to convert their output to the metric system, wood shop and building construction teachers must become familiar with the metric measurement language and methods. Manufacturers prefer the "soft conversion" process of changing English to metric units rather than hard conversion, or redimensioning of lumber. Some…

  13. Sensitivity and Strength: Effects of Instructions on Resistance to Change

    ERIC Educational Resources Information Center

    Podlesnik, Christopher A.; Chase, Philip N.

    2006-01-01

    Several research laboratories have found that instructed behavior can be less sensitive to changes in contingencies than shaped behavior. The current experiment examined whether these differences in sensitivity could be related to resistance to change. Two groups of subjects, who were matched on the basis of an initial disruption assessment, were…

  14. The Effect of Resistance on Rocket Injector Acoustics

    NASA Technical Reports Server (NTRS)

    Morgan, C. J.

    2015-01-01

    Combustion instability, where unsteady heat release couples with acoustic modes, has long been an area of concern in liquid rocket engines. Accurate modeling of the acoustic normal modes of the combustion chamber is important to understanding and preventing combustion instability. The injector resistance can have a significant influence on the chamber normal mode shape, and hence on the system stability.

  15. Effects of Behavioral History on Resistance to Change

    ERIC Educational Resources Information Center

    Doughty, Adam H.; Cirino, Sergio; Mayfield, Kristin H.; da Silva, Stephanie P.; Okouchi, Hiroto; Lattal, Kennon A.

    2005-01-01

    Two experiments examined whether differential resistance to change would occur under identical variable-interval schedules as a function of a differential behavioral history. In Experiment 1, each of 3 pigeons first pecked at different rates under a multiple variable-ratio differential-reinforcement-of-low-rate schedule. In a subsequent condition,…

  16. Effects of nonlinear resistance and aerobic interval training on cytokines and insulin resistance in sedentary men who are obese.

    PubMed

    Nikseresht, Mahmoud; Agha-Alinejad, Hamid; Azarbayjani, Mohammad A; Ebrahim, Khosrow

    2014-09-01

    Regular exercise training has been shown to reduce systemic inflammation, but there is limited research directly comparing different types of training. The purpose of this study was to compare the effects of nonlinear resistance training (NRT) and aerobic interval training (AIT) on serum interleukin-10 (IL-10), IL-20, and tumor necrosis factor-α (TNF-α) levels, insulin resistance index (homeostasis model assessment of insulin resistance), and aerobic capacity in middle-aged men who are obese. Sedentary volunteers were assigned to NRT (n = 12), AIT (n = 12), and (CON, n = 10) control groups. The experimental groups performed 3 weekly sessions for 12 weeks, whereas the CON grouped maintained a sedentary lifestyle. Nonlinear resistance training consisted of 40-65 minutes of weight training at different intensities with flexible periodization. Aerobic interval training consisted of running on a treadmill (4 sets of 4 minutes at 80-90% of maximal heart rate, with 3-minute recovery intervals). Serum IL-10, IL-20, and TNF-α levels did not change significantly in response to training (all p > 0.05), but IL-10:TNF-α ratio increased significantly with AIT compared with CON (2.95 ± 0.84 vs. 2.52 ± 0.65; p = 0.02). After the training period, maximal oxygen uptake increased significantly in AIT and NRT compared with CON (both p < 0.001; 46.7 ± 5.9, 45.1 ± 3.2, and 41.1 ± 4.7 ml·kg·min, respectively) and in AIT than in NRT (p = 0.001). The 2 exercise programs were equally effective at reducing insulin resistance (homeostasis model assessment for insulin resistance) (both p ≤ 0.05; AIT: 0.84 ± 0.34, NRT: 0.84 ± 0.27, and CON: 1.62 ± 0.56) and fasting insulin levels (both p ≤ 0.05; AIT: 3.61 ± 1.48, NRT: 3.66 ± 0.92, and CON: 6.20 ± 2.64 μU·ml), but the AIT seems to have better anti-inflammatory effects (as indicated by the IL-10:TNF-α ratio) compared with NRT. PMID:24662224

  17. Effect of three-dimensional current distribution on characterizing parasitic resistance of FinFETs

    NASA Astrophysics Data System (ADS)

    Meng, Fan-Hsuan; Lin, Po-Yen; Chiu, Yu-Lun; Huang, Bo-Rong; Lin, Chrong Jung; King, Ya-Chin

    2016-04-01

    A thorough analysis of the FinFET resistance and current distribution is presented. By combining multiple conventional and novel measurement techniques, the key components that contribute to the parasitic resistance of FinFETs can be quantified. Through a three-dimensional (3D) FinFET resistance network model, the impact of the FinFET 3D structure on the current distribution and parasitic resistance is analyzed. The heterogeneous current distribution, known as the current crowding effect, is also discussed with possible alleviation methods through 3D simulation.

  18. Effect of bacterial growth stage on resistance to chlorine disinfection.

    PubMed

    Cherchi, C; Gu, A Z

    2011-01-01

    The mechanisms and factors that affect microbial resistance to chlorine disinfection have not been fully elucidated. In this study, we investigated the impact of the cell growth stage on chlorine disinfection efficiency. Specifically, we evaluated the impact of the growth stage on chlorination resistance by comparing the inactivation efficiencies of two indicator bacterial strains (Escherichia coli K12 and Escherichia coli O157:H7) obtained from various growth phases, using Chick-Watson kinetic parameters. For both E. coli strains (K12 and O157:H7), the inactivation rate constants are the lowest at stationary phase (0.19 and 0.32) compared to those at initial lag (0.54 and 0.76) and exponential growth phase (0.63 and 0.69), respectively. These results suggested that the abundance of resistant subpopulations increases at stressed stationary conditions and E. coli cells obtained from the stationary growth phase exhibited more resistance and lower inactivation efficiency compared to those from the lag and exponential phases. This implies that microbes in wastewater treatment process with varying solids retention times (SRTs, which indicate growth rates) may show different extents of chlorine resistance. Comparison of the coefficient of dilution (n) values in both E. coli strains for the various growth phases suggest that cells seem to be more sensitive to disinfectant concentration at the stationary-lag phase than that at the exponential stage. Comparing the two E. coli strains, higher inactivation rates were observed for the pathogenic O157:H7 than for K12 at different stages of growth. The strain-to-strain variability in survivability to chlorine exposure has to be considered when selecting indicator microorganisms for water quality monitoring. PMID:22053451

  19. Effects of three novel resistant black raspberry selections on Amphorophora agathonica feeding behavior and performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host plant resistance is a practical and cost-effective approach for growers to manage insect pests. Recently, three new sources of resistance in black raspberry (selections ORUS 3778-1, ORUS 3817-1, and ORUS 4109-1) against the large raspberry aphid, Amphorophora agathonica, were identified. We stu...

  20. The multi-year effects of repeatedly growing cotton with moderate resistance to Meloidogyne incognita

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study documents the cumulative effect of moderate resistance on Meloidogyne incognita population density, root galling, and yield suppression in the southern United States when a moderately resistant cotton genotype was grown continuously for three years. Cotton genotypes were Phytogen PH98-31...

  1. Effectiveness of genes for Hessian fly (Diptera: Cecidomyiidae) resistance in the southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae), is the most important insect pest of wheat (Triticum aestivum L. subsp. aestivum) in the southeastern United States, and the deployment of genetically resistant wheat is the most effective control. However, the use of resistant w...

  2. QTL and Additive and Epistatic Effects for SCN Resistance in PI 437654

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is a major problem in soybean production in the USA. Planting SCN-resistant soybean cultivars is the most cost effective control method. PI 437654 is a unique accession because of its resistance to nearly all SCN HG types (races). The ...

  3. AHAS herbicide resistance endowing mutations: effect on AHAS functionality and plant growth

    PubMed Central

    Yu, Qin; Han, Heping; Vila-Aiub, Martin M.; Powles, Stephen B.

    2010-01-01

    Twenty-two amino acid substitutions at seven conserved amino acid residues in the acetohydroxyacid synthase (AHAS) gene have been identified to date that confer target-site resistance to AHAS-inhibiting herbicides in biotypes of field-evolved resistant weed species. However, the effect of resistance mutations on AHAS functionality and plant growth has been investigated for only a very few mutations. This research investigates the effect of various AHAS resistance mutations in Lolium rigidum on AHAS functionality and plant growth. The enzyme kinetics of AHAS from five purified L. rigidum populations, each homozygous for the resistance mutations Pro-197-Ala, Pro-197-Arg, Pro-197-Gln, Pro-197-Ser or Trp-574-Leu, were characterized and the pleiotropic effect of three mutations on plant growth was assessed via relative growth rate analysis. All these resistance mutations endowed a herbicide-resistant AHAS and most resulted in higher extractable AHAS activity, with no-to-minor changes in AHAS kinetics. The Pro-197-Arg mutation slightly (but significantly) increased the Km for pyruvate and remarkably increased sensitivity to feedback inhibition by branched chain amino acids. Whereas the Pro-197-Ser and Trp-574-Leu mutations exhibited no significant effects on plant growth, the Pro-197-Arg mutation resulted in lower growth rates. It is clear that, at least in L. rigidum, these five AHAS resistance mutations have no major impact on AHAS functionality and hence probably no plant resistance costs. These results, in part, explain why so many Pro-197 AHAS resistance mutations in AHAS have evolved and why the Pro-197-Ser and the Trp-574-Leu AHAS resistance mutations are frequently found in many weed species. PMID:20627897

  4. Temperature and mixing effects on electrical resistivity of carbon fiber enhanced concrete

    NASA Astrophysics Data System (ADS)

    Chang, Christiana; Song, Gangbing; Gao, Di; Mo, Y. L.

    2013-03-01

    In this paper, the effect of temperature and mixing procedure on the electrical resistivity of carbon fiber enhanced concrete is investigated. Different compositions of concrete containing varying concentrations of carbon fiber into normal and self-consolidating concrete (SCC) were tested under DC electrical loading over the temperature range -10 to 20 °C. The electrical resistivity of the bulk samples was calculated and compared against temperature. It was observed that there is an inverse exponential relationship between resistivity and temperature which follows the Arrhenius relationship. The bulk resistivity decreased with increasing fiber concentration, though data from SCC indicates a saturation limit beyond which electrical resistivity begins to drop. The activation energy of the bulk electrically conductive concrete was calculated and compared. While SCC exhibited the lowest observed electrical resistance, the activation energy was similar amongst SCC and surfactant enhanced concrete, both of which were lower than fiber dispersed in normal concrete.

  5. Effect of carrier materials on the resistance of spores of Bacillus stearothermophilus to gaseous hydrogen peroxide.

    PubMed

    Sigwarth, Volker; Stärk, Alexandra

    2003-01-01

    The testing of the H2O2 decontamination process using spores of Bacillus stearothermophilus has gained widespread acceptance. Usually, commercially available Biological Indicators (BIs) with a specified resistance to H2O2 are challenged to qualify the process. The question arises whether the resistance of test spores is dependant on the type of carrier material and whether the resistance is representative for the system under test. The objective of the study is to quantify the effect of different carrier materials on the resistance of spores of Bacillus stearothermophilus to H2O2. Materials from which isolators were built, as well as those used in disposables during daily work were investigated. These materials were inoculated with 106 spores of Bacillus stearothermophilus (ATCC 7953). The spore resistance was tested to a well defined H2O2 decontamination cycle by determining the D-value using the "Fractional Negative" method. This paper reports on the effect of different carrier materials to the resistance of the test organism against H2O2. Various materials have significantly increased resistance of the spores and should be avoided in isolator systems. If commercially available BIs are used for process qualification, the resistance of the BI used, the fluctuation in resistance caused by isolator materials, the required log reduction, and at least the bioload of isolator surfaces need to be known. PMID:12643502

  6. Effects of electron acceptors on removal of antibiotic resistant Escherichia coli, resistance genes and class 1 integrons under anaerobic conditions.

    PubMed

    Yuan, Heyang; Miller, Jennifer H; Abu-Reesh, Ibrahim M; Pruden, Amy; He, Zhen

    2016-11-01

    Anaerobic biotechnologies can effectively remove antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), but there is a need to better understand the mechanisms. Here we employ bioelectrochemical systems (BES) as a platform to investigate the fate of a native tetracycline and sulfonamide-resistant Escherichia coli strain and its ARGs. The E. coli strain carrying intI1, sulI and tet(E) was isolated from domestic wastewater and dosed into a tubular BES. The BES was first operated as a microbial fuel cell (MFC), with aeration in the cathode, which resulted in enhanced removal of E. coli and ARGs by ~2 log (i.e., order of magnitude) when switched from high current to open circuit operation mode. The BES was then operated as a microbial electrolysis cell (MEC) to exclude the effects of oxygen diffusion, and the removal of E. coli and ARGs during the open circuit configuration was again 1-2 log higher than that at high current mode. Significant correlations of E. coli vs. current (R(2)=0.73) and ARGs vs. E. coli (R(2) ranged from 0.54 to 0.87), and the fact that the BES substrate contained no electron acceptors, implied that the persistence of the E. coli and its ARGs was determined by the availability of indigenous electron acceptors in the BES, i.e., the anode electrode or the electron shuttles generated by the exoelectrogens. Subsequent experiments with pure-culture tetracycline and sulfonamide-resistant E. coli being incubated in a two-chamber MEC and serum bottles demonstrated that the E. coli could survive by respiring anode electrode and/or electron shuttles released by exoelectrogens, and ARGs persisted with their host E. coli. PMID:27450245

  7. Hybrid metric-Palatini brane system

    NASA Astrophysics Data System (ADS)

    Fu, Qi-Ming; Zhao, Li; Gu, Bao-Min; Yang, Ke; Liu, Yu-Xiao

    2016-07-01

    It is known that the metric and Palatini formalisms of gravity theories have their own interesting features but also suffer from some different drawbacks. Recently, a novel gravity theory called hybrid metric-Palatini gravity was put forward to cure or improve their individual deficiencies. The action of this gravity theory is a hybrid combination of the usual Einstein-Hilbert action and a f (R ) term constructed by the Palatini formalism. Interestingly, it seems that the existence of a light and long-range scalar field in this gravity may modify the cosmological and galactic dynamics without conflicting with the laboratory and Solar System tests. In this paper, we focus on the tensor and scalar perturbations of the thick branes in this novel gravity theory. We consider two models as examples, namely, the thick branes constructed by a background scalar field and by pure gravity. The thick branes in both models have no inner structure. However, affected by the hybrid combination of the metric and Palatini formalisms, the graviton zero mode in the first model has inner structure when the parameter in this model is larger than its critical value, which is different from the cases of general relativity and Palatini f (R ) gravity. We find that the effective four-dimensional gravity can be reproduced on the brane for both models and the scalar zero mode in the model without a background scalar field cannot be localized on the brane, which avoids a fifth force. Moreover, the stability of both brane systems against the linear perturbations can also be ensured.

  8. Effects of Diet and Exercise on Insulin Resistance during Pregnancy.

    PubMed

    Clapp, James F

    2006-01-01

    Current evidence suggests that both diet and exercise can alter the usual increase in insulin resistance seen in Western societies during mid and late pregnancy. A low-glycemic diet combined with a low-volume exercise regimen during pregnancy decreases the glucose and insulin response to both mixed caloric intake and exercise, and probably lowers both 24-h blood glucose concentrations and the maternal substrate utilization ratio of carbohydrate/fat. The end result is a marked decrease in both maternal weight gain and size at birth. Regular weight-bearing exercise alone lowers markers of insulin resistance and lowers blood glucose concentration during and immediately after exercise during pregnancy. Changes in diet and/or physical activity appear to prevent the onset of gestational diabetes mellitus in at-risk women and may be of value in the treatment of those who develop gestational diabetes. PMID:18370754

  9. Effect of bonded gold inlays on fracture resistance of teeth.

    PubMed

    Eakle, W S; Staninec, M

    1992-06-01

    The purpose of this study was to determine if bonding gold inlays to tooth structure with an adhesive resin cement would increase the fracture resistance of restored teeth. Extracted paired maxillary premolars were prepared for mesio-occlusodistal inlays, and the inlays were cast in type II gold. In one tooth of each pair, the inlay was sandblasted with aluminium oxide, tin plated, and cemented with an adhesive resin into the etched preparation. For the other (control) tooth in each pair, the inlay was sandblasted and then cemented into the preparation with zinc phosphate cement. The teeth were thermocycled and loaded until fracture. The teeth in the bonded group had a statistically significantly higher fracture resistance than did the teeth in the control group. Scanning electron microscopic examination revealed that failure in the bonded group occurred predominantly within the resin. PMID:1502322

  10. Fanpage metrics analysis. "Study on content engagement"

    NASA Astrophysics Data System (ADS)

    Rahman, Zoha; Suberamanian, Kumaran; Zanuddin, Hasmah Binti; Moghavvemi, Sedigheh; Nasir, Mohd Hairul Nizam Bin Md

    2016-08-01

    Social Media is now determined as an excellent communicative tool to connect directly with consumers. One of the most significant ways to connect with the consumers through these Social Networking Sites (SNS) is to create a facebook fanpage with brand contents and to place different posts periodically on these fanpages. In measuring social networking sites' effectiveness, corporate houses are now analyzing metrics in terms of calculating engagement rate, number of comments/share and likings in fanpages. So now, it is very important for the marketers to know the effectiveness of different contents or posts of fanpages in order to increase the fan responsiveness and engagement rate in the fan pages. In the study the authors have analyzed total 1834 brand posts from 17 international brands of Electronics companies. Data of 9 months (From December 2014 to August 2015) have been collected for analyses, which were available online in the Brand' fan pages. An econometrics analysis is conducted using Eviews 9, to determine the impact of different contents on fanpage engagement. The study picked the four most frequently posted content to determine their impact on PTA (people Talking About) metrics and Fanpage engagement activities.

  11. Effects of silicon on plant resistance to environmental stresses: review

    NASA Astrophysics Data System (ADS)

    Balakhnina, T.; Borkowska, A.

    2013-03-01

    The role of exogenous silicon in enhancing plant resistance to various abiotic stressors: salinity, drought, metal toxicities and ultraviolet radiation are presented. The data on possible involvement of silicon in reducing the reactive oxygen species generation, intensity of lipid peroxidation, and in some cases, increasing the activity of enzymes of the reactive oxygen species detoxificators: superoxide dismutase, ascorbate peroxidase, glutathione reductase, guaiacol peroxidase and catalase are analyzed.

  12. Reversal effect of vitamin D on different multidrug-resistant cells.

    PubMed

    Yan, M; Nuriding, H

    2014-01-01

    We investigated the reversal effect of vitamin D on the multidrug-resistant leukemic Jurkat/ADR and K562/ADR cell lines and conducted a preliminary investigation of its reversal mechanism. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was used to detect the reversal effect of vitamin D on multidrug-resistant cells. Real-time polymerase chain reaction was used to determine the effect of vitamin D on intracellular expression of mRNA of the multidrug-resistant gene (MDRI) and the multidrug-resistance-related gene (MRP1). A protein quantitative analysis method was used to determine the effect of vitamin D on intracellular glutathione content. After treatment of Jurkat/ADR and K562/ADR cells with vitamin D, multidrug resistance was reversed in a dose-dependent manner, which may have reduced mRNA expression of the MDR1 and MRP1 genes, the P-glycoprotein content on the cell surface, and the intracellular glutathione level. Different concentrations of vitamin D showed varying reversal effects on different multidrug-resistant cells. The resistance mechanism may be related to the inhibition of the expression of MDR1 and MRP1 genes. PMID:25158250

  13. The effect of interconnection resistance on the performance enhancement of liquid-nitrogen-cooled CMOS circuits

    SciTech Connect

    Watt, J.T. ); Plummer, J.D. . Center for Integrated Systems)

    1989-08-01

    The effect of interconnection resistance on CMOS circuit performance is examined at room temperature and liquid-nitrogen temperature. The interconnection is modeled as a distributed RLC line driven by an optimal configuration of cascaded inverters. The thin-film resistivity of pure aluminum has been measured to allow accurate prediction of the effect of interconnection resistance on performance. A critical interconnect length is defined as the point at which interconnect resistance begins to dominate propagation delay time. The critical interconnect length is computed at room temperature and liquid-nitrogen temperature for present-day and scaled CMOS technologies and compared to the maximum interconnect length expected in state-of-the-art VLSI circuits. Conclusions are drawn concerning the importance of interconnection resistance in determining the enhancement in performance achieved through reduced-temperature operation of CMOS integrated circuits.

  14. The effect of mechanical surface and heat treatments on the erosion resistance of 6061 aluminum alloy

    NASA Technical Reports Server (NTRS)

    Salik, J.; Buckley, D.; Brainard, W. A.

    1981-01-01

    The effects of both mechanical surface treatments and heat treatments on the erosion resistance of 6061 aluminum alloy were studied in order to gain a better understanding of material properties which affect erosion behavior. It was found that mechanical surface treatments have little or no effect on the erosion resistance. This is due to the formation by particle impact of a work-hardened surface layer, independent of the initial surface condition. The erosion resistance of aluminum single crystals was found to be independent of orientation, which is due to destruction of the surface microstructure and formation of a polycrystalline surface layer by the particle impact as observed by X-ray diffraction. Although on solution treatment of annealed aluminum 6061 the increase in hardness is accompanied by an increase in erosion resistance, precipitation treatment (which causes a further increase in hardness) results in a slightly lower erosion resistance.

  15. Texture metric that predicts target detection performance

    NASA Astrophysics Data System (ADS)

    Culpepper, Joanne B.

    2015-12-01

    Two texture metrics based on gray level co-occurrence error (GLCE) are used to predict probability of detection and mean search time. The two texture metrics are local clutter metrics and are based on the statistics of GLCE probability distributions. The degree of correlation between various clutter metrics and the target detection performance of the nine military vehicles in complex natural scenes found in the Search_2 dataset are presented. Comparison is also made between four other common clutter metrics found in the literature: root sum of squares, Doyle, statistical variance, and target structure similarity. The experimental results show that the GLCE energy metric is a better predictor of target detection performance when searching for targets in natural scenes than the other clutter metrics studied.

  16. Metric Ranking of Invariant Networks with Belief Propagation

    SciTech Connect

    Tao, Changxia; Ge, Yong; Song, Qinbao; Ge, Yuan; Omitaomu, Olufemi A

    2014-01-01

    The management of large-scale distributed information systems relies on the effective use and modeling of monitoring data collected at various points in the distributed information systems. A promising approach is to discover invariant relationships among the monitoring data and generate invariant networks, where a node is a monitoring data source (metric) and a link indicates an invariant relationship between two monitoring data. Such an invariant network representation can help system experts to localize and diagnose the system faults by examining those broken invariant relationships and their related metrics, because system faults usually propagate among the monitoring data and eventually lead to some broken invariant relationships. However, at one time, there are usually a lot of broken links (invariant relationships) within an invariant network. Without proper guidance, it is difficult for system experts to manually inspect this large number of broken links. Thus, a critical challenge is how to effectively and efficiently rank metrics (nodes) of invariant networks according to the anomaly levels of metrics. The ranked list of metrics will provide system experts with useful guidance for them to localize and diagnose the system faults. To this end, we propose to model the nodes and the broken links as a Markov Random Field (MRF), and develop an iteration algorithm to infer the anomaly of each node based on belief propagation (BP). Finally, we validate the proposed algorithm on both realworld and synthetic data sets to illustrate its effectiveness.

  17. Prioritizing Urban Habitats for Connectivity Conservation: Integrating Centrality and Ecological Metrics.

    PubMed

    Poodat, Fatemeh; Arrowsmith, Colin; Fraser, David; Gordon, Ascelin

    2015-09-01

    Connectivity among fragmented areas of habitat has long been acknowledged as important for the viability of biological conservation, especially within highly modified landscapes. Identifying important habitat patches in ecological connectivity is a priority for many conservation strategies, and the application of 'graph theory' has been shown to provide useful information on connectivity. Despite the large number of metrics for connectivity derived from graph theory, only a small number have been compared in terms of the importance they assign to nodes in a network. This paper presents a study that aims to define a new set of metrics and compares these with traditional graph-based metrics, used in the prioritization of habitat patches for ecological connectivity. The metrics measured consist of "topological" metrics, "ecological metrics," and "integrated metrics," Integrated metrics are a combination of topological and ecological metrics. Eight metrics were applied to the habitat network for the fat-tailed dunnart within Greater Melbourne, Australia. A non-directional network was developed in which nodes were linked to adjacent nodes. These links were then weighted by the effective distance between patches. By applying each of the eight metrics for the study network, nodes were ranked according to their contribution to the overall network connectivity. The structured comparison revealed the similarity and differences in the way the habitat for the fat-tailed dunnart was ranked based on different classes of metrics. Due to the differences in the way the metrics operate, a suitable metric should be chosen that best meets the objectives established by the decision maker. PMID:25924790

  18. Human Performance Optimization Metrics: Consensus Findings, Gaps, and Recommendations for Future Research.

    PubMed

    Nindl, Bradley C; Jaffin, Dianna P; Dretsch, Michael N; Cheuvront, Samuel N; Wesensten, Nancy J; Kent, Michael L; Grunberg, Neil E; Pierce, Joseph R; Barry, Erin S; Scott, Jonathan M; Young, Andrew J; OʼConnor, Francis G; Deuster, Patricia A

    2015-11-01

    Human performance optimization (HPO) is defined as "the process of applying knowledge, skills and emerging technologies to improve and preserve the capabilities of military members, and organizations to execute essential tasks." The lack of consensus for operationally relevant and standardized metrics that meet joint military requirements has been identified as the single most important gap for research and application of HPO. In 2013, the Consortium for Health and Military Performance hosted a meeting to develop a toolkit of standardized HPO metrics for use in military and civilian research, and potentially for field applications by commanders, units, and organizations. Performance was considered from a holistic perspective as being influenced by various behaviors and barriers. To accomplish the goal of developing a standardized toolkit, key metrics were identified and evaluated across a spectrum of domains that contribute to HPO: physical performance, nutritional status, psychological status, cognitive performance, environmental challenges, sleep, and pain. These domains were chosen based on relevant data with regard to performance enhancers and degraders. The specific objectives at this meeting were to (a) identify and evaluate current metrics for assessing human performance within selected domains; (b) prioritize metrics within each domain to establish a human performance assessment toolkit; and (c) identify scientific gaps and the needed research to more effectively assess human performance across domains. This article provides of a summary of 150 total HPO metrics across multiple domains that can be used as a starting point-the beginning of an HPO toolkit: physical fitness (29 metrics), nutrition (24 metrics), psychological status (36 metrics), cognitive performance (35 metrics), environment (12 metrics), sleep (9 metrics), and pain (5 metrics). These metrics can be particularly valuable as the military emphasizes a renewed interest in Human Dimension efforts

  19. Comparing Resource Adequacy Metrics: Preprint

    SciTech Connect

    Ibanez, E.; Milligan, M.

    2014-09-01

    As the penetration of variable generation (wind and solar) increases around the world, there is an accompanying growing interest and importance in accurately assessing the contribution that these resources can make toward planning reserve. This contribution, also known as the capacity credit or capacity value of the resource, is best quantified by using a probabilistic measure of overall resource adequacy. In recognizing the variable nature of these renewable resources, there has been interest in exploring the use of reliability metrics other than loss of load expectation. In this paper, we undertake some comparisons using data from the Western Electricity Coordinating Council in the western United States.

  20. A class of integrable metrics

    NASA Astrophysics Data System (ADS)

    Anabalón, Andrés; Batista, Carlos

    2016-03-01

    In four dimensions, the most general metric admitting two commuting Killing vectors and a rank-two Killing tensor can be parametrized by ten arbitrary functions of a single variable. We show that picking a special vierbein, reducing the system to eight functions, implies the existence of two geodesic and share-free, null congruences, generated by two principal null directions of the Weyl tensor. Thus, if the spacetime is an Einstein manifold, the Goldberg-Sachs theorem implies it is Petrov type D, and by explicit construction, is in the Carter class. Hence, our analysis provides a straightforward connection between the most general integrable structure and the Carter family of spacetimes.

  1. Thoracic injury metrics with side airbag: Stationary and dynamic occupants

    PubMed Central

    Hallman, Jason J; Yoganandan, N; Pintar, Frank A

    2010-01-01

    Objective Injury risk from side airbag deployment has been assessed using stationary out-of-position occupant test protocols. However, stationary conditions may not always represent real world environments. Therefore, the objective of the present study was to evaluate the effects of torso side airbag deployment on close-proximity occupants, comparing a stationary test protocol with dynamic sled conditions. Methods Chest compression and viscous metrics were quantified from sled tests utilizing post-mortem human specimens and computational simulations with three boundary conditions: rigid wall, ideal airbag interaction, and close-proximity airbag deployment. PMHS metrics were quantified from chestband contour reconstructions. The parametric effect of ΔV on close-proximity occupant was examined with the computational model. Results PMHS injuries suggested close-proximity occupants may sustain visceral trauma, which was not observed in occupants subjected to rigid wall or ideal airbag boundary conditions. Peak injury metrics were also elevated with close-proximity occupant relative to other boundary conditions. The computational model indicated decreasing influence of airbag on compression metrics with increasing ΔV. Airbag influence on viscous metric was greatest with close-proximity occupant at ΔV = 7.0 m/s, at which the response magnitude was greater than linear summation of metrics resulting from rigid impact and stationary close-proximity interaction. Conclusions These results suggest that stationary close-proximity occupants may not represent the only scenario of side airbag deployment harmful to the thoracoabdominal region. The sensitivity of the viscous metric and implications for visceral trauma are also discussed. PMID:20730691

  2. Residual stress effects on the impact resistance and strength of fiber composites

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1973-01-01

    Equations have been derived to predict degradation effects of microresidual stresses on impact resistance of unidirectional fiber composites. Equations also predict lamination residual stresses in multilayered angle ply composites.

  3. Effect of Electromagnetic Treatment on Fatigue Resistance of 2011 Aluminum Alloy

    NASA Astrophysics Data System (ADS)

    Mohin, M. A.; Toofany, H.; Babutskyi, A.; Lewis, A.; Xu, Y. G.

    2016-08-01

    Beneficial effects of the electromagnetic treatment on fatigue resistance were reported on several engineering alloys. These could be linked to the dislocation activity and the rearrangement of the crystal structure of the material under the electromagnetic field (EMF), resulting in delayed crack initiation. This paper presents an experimental study on the effect of pulsed electromagnetic treatment on the fatigue resistance of 2011 aluminum alloy. Circular cantilever specimens with loads at their ends were tested on rotating fatigue machine SM1090. Fatigue lives of treated and untreated specimens were analyzed and compared systematically. It has been found that the effect of the pulsed electromagnetic treatment on the fatigue resistance is dependent on the intensity of the pulsed EMF and the number of the treatment applied. Clear beneficial effect of the pulsed electromagnetic treatment on the fatigue resistance of the aluminum alloys has been observed, demonstrating a potential new technique to industries for fatigue life extension.

  4. Stochastic effects in 11 nm imaging of extreme ultraviolet lithography with chemically amplified resists

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

    2014-03-01

    The resolution of extreme ultraviolet (EUV) lithography with chemically amplified resist processes has reached 16 nm (half-pitch). The development of chemically amplified resists is ongoing toward the 11 nm node. However, the stochastic effects are increasingly becoming a significant concern with the continuing shrinkage of features. In this study, the fluctuation of protected unit distribution caused by the stochastic effects during image formation was investigated assuming line-and-space patterns with 11 nm half-pitch. Contrary to expectations, the standard deviation of the number of protected units connected to a polymer after postexposure baking (PEB) did not differ from that for 16 nm half-pitch. The standard deviation after PEB increased with the effective reaction radius for deprotection and the initial standard deviation before PEB. Because of the severe requirements for resist processes, the stochastic effects in chemical reactions should be taken into account in the design of next-generation resists.

  5. Reversal effect of Dioscin on multidrug resistance in human hepatoma HepG2/adriamycin cells.

    PubMed

    Sun, Bu Tong; Zheng, Li Hua; Bao, Yong Li; Yu, Chun Lei; Wu, Yin; Meng, Xiang Ying; Li, Yu Xin

    2011-03-01

    Multidrug resistance is a serious obstacle encountered in cancer treatment. Since drug resistance in human cancer is mainly associated with overexpression of the multidrug resistance gene 1 (MDR1), the promoter of the human MDR1 gene may be a target for multidrug resistance reversion drug screening. In the present study, HEK293T cells were transfected with pGL3 reporter plasmids containing the 2kb of MDR1 promoter, and the transfected cells were used as models to screen for candidate multidrug resistance inhibitors from over 300 purified naturally occurring compounds extracted from plants and animals. Dioscin was found to have an inhibiting effect on MDR1 promoter activity. The resistant HepG2 cell line (HepG2/adriamycin) was used to validate the activity of multidrug resistance reversal by Dioscin. Results showed that Dioscin could decrease the resistance degree of HepG2/adriamycin cells, and significantly inhibit P-glycoprotein expression, as well as increase the accumulation of adriamycin in HepG2/adriamycin cells as measured by Flow Cytometric analysis. These results suggest that Dioscin is a potent multidrug resistance reversal agent and may be a potential adjunctive agent for tumor chemotherapy. PMID:21195709

  6. Magnetic isotope effect of magnesium (25)Mg on E. coli resistance to antibiotics.

    PubMed

    Letuta, U G; Vekker, A S; Kornilova, T A; Gryaznov, A A; Cheplakov, I A

    2016-07-01

    Effects of synergism and antagonism of antibacterial drugs and magnetic isotope of magnesium (25)Mg on antibiotic resistance of bacteria E. coli were discovered. Fourteen antibiotics from seven different groups were tested. The increase in antibiotic resistance in the presence of the ion (25)Mg(2+) was discovered in E. coli cells incubated with quinolones/fluoroquinolones, indicating the inhibiting effect of the magnetic moments of nuclei (25)Mg on DNA synthesis. The change in antibiotic resistance was also detected in bacteria affected by magnesium (25)Mg and certain antibiotics from aminoglycoside and lincosamide groups. PMID:27599512

  7. Research status on aerodynamic interference effects of wind-resistant performance of pylon

    NASA Astrophysics Data System (ADS)

    LI, Shengli; Lu, Yu; Wang, Dongwei; Chen, Huai

    2011-04-01

    The aerodynamic interference effects of wind-resistant performance for pylon is one of very important problems in numerical simulation studies of wind resistant of bridges. On the basis of looking through a great deal of related literatures at home and abroad, research history, contents, method and achievements of the aerodynamic interference effects are summarized, and the existing problem for galloping, buffeting and vortex-induced vibration of pylon and directions for the next research are pointed out.

  8. The Equivalence of Precession Phenomena in Metric Theories of Gravity

    NASA Technical Reports Server (NTRS)

    Krisher, Timothy P.

    1996-01-01

    The requirement of general covariance imparts to metric theories of gravity, such as general relativity, important structural features. A precise mathematical form results, ensuring that computation of observable physical effects in the theory gives the same answers independently of the chosen system of coordinates. This coordinate independence property, in turn, can lead to an equivalence of apparently different physical effects.

  9. Short-Term Effects of Different Loading Schemes in Fitness-Related Resistance Training.

    PubMed

    Eifler, Christoph

    2016-07-01

    Eifler, C. Short-term effects of different loading schemes in fitness-related resistance training. J Strength Cond Res 30(7): 1880-1889, 2016-The purpose of this investigation was to analyze the short-term effects of different loading schemes in fitness-related resistance training and to identify the most effective loading method for advanced recreational athletes. The investigation was designed as a longitudinal field-test study. Two hundred healthy mature subjects with at least 12 months' experience in resistance training were randomized in 4 samples of 50 subjects each. Gender distribution was homogenous in all samples. Training effects were quantified by 10 repetition maximum (10RM) and 1 repetition maximum (1RM) testing (pre-post-test design). Over a period of 6 weeks, a standardized resistance training protocol with 3 training sessions per week was realized. Testing and training included 8 resistance training exercises in a standardized order. The following loading schemes were randomly matched to each sample: constant load (CL) with constant volume of repetitions, increasing load (IL) with decreasing volume of repetitions, decreasing load (DL) with increasing volume of repetitions, daily changing load (DCL), and volume of repetitions. For all loading schemes, significant strength gains (p < 0.001) could be noted for all resistance training exercises and both dependent variables (10RM, 1RM). In all cases, DCL obtained significantly higher strength gains (p < 0.001) than CL, IL, and DL. There were no significant differences in strength gains between CL, IL, and DL. The present data indicate that resistance training following DCL is more effective for advanced recreational athletes than CL, IL, or DL. Considering that DCL is widely unknown in fitness-related resistance training, the present data indicate, there is potential for improving resistance training in commercial fitness clubs. PMID:26670986

  10. Set Configuration in Resistance Exercise: Muscle Fatigue and Cardiovascular Effects

    PubMed Central

    Río-Rodríguez, Dan; Iglesias-Soler, Eliseo; Fernández del Olmo, Miguel

    2016-01-01

    Purpose Cardiovascular responses of traditional resistance (TS) training have been extensively explored. However, the fatigue mechanisms associated with an intra-set rest configuration (ISR) have not been investigated. This study compares two modalities of set configurations for resistance exercise that equates work to rest ratios and measures the central and peripheral fatigue in combination with cortical, hemodynamic and cardiovascular measures. Methods 11 subjects performed two isometric knee extension training sessions using TS and ISR configurations. Voluntary activation (VA), single twitch amplitude, low frequency fatigue (LFF), Mwave, motor evoked potential (MEP), short intracortical inhibition (SICI), intracortical facilitation (ICF) and heart rate variability were evaluated before and after each training session. During each session beat to beat heart rate, blood pressure and rate pressure product (RPP) were also evaluated. Results After exercise VA decreased significantly for TS but not for ISR (P < 0.001), single twitch amplitude and LFF values were lower for TS than ISR (P < 0.004), and SICI was reduced only for the TS configuration (P = 0.049). During exercise RPP values were significantly higher for the TS than for ISR (P = 0.001). RPP correlated with VA for TS (r = -.85 P < 0.001) suggesting a relationship between central fatigue and cardiovascular stress. Conclusions We conclude that ISR induced lower central and peripheral fatigue as well as lower cardiovascular stress in comparison with TS configuration. Our study suggests that set configuration is a key factor in the regulation of the neuromuscular and cardiovascular responses of resistance training. PMID:26982500

  11. Metrics for building performance assurance

    SciTech Connect

    Koles, G.; Hitchcock, R.; Sherman, M.

    1996-07-01

    This report documents part of the work performed in phase I of a Laboratory Directors Research and Development (LDRD) funded project entitled Building Performance Assurances (BPA). The focus of the BPA effort is to transform the way buildings are built and operated in order to improve building performance by facilitating or providing tools, infrastructure, and information. The efforts described herein focus on the development of metrics with which to evaluate building performance and for which information and optimization tools need to be developed. The classes of building performance metrics reviewed are (1) Building Services (2) First Costs, (3) Operating Costs, (4) Maintenance Costs, and (5) Energy and Environmental Factors. The first category defines the direct benefits associated with buildings; the next three are different kinds of costs associated with providing those benefits; the last category includes concerns that are broader than direct costs and benefits to the building owner and building occupants. The level of detail of the various issues reflect the current state of knowledge in those scientific areas and the ability of the to determine that state of knowledge, rather than directly reflecting the importance of these issues; it intentionally does not specifically focus on energy issues. The report describes work in progress and is intended as a resource and can be used to indicate the areas needing more investigation. Other reports on BPA activities are also available.

  12. A family of heavenly metrics

    NASA Astrophysics Data System (ADS)

    Nutku, Y.; Sheftel, M. B.

    2014-02-01

    This is a corrected and essentially extended version of the unpublished manuscript by Y Nutku and M Sheftel which contains new results. It is proposed to be published in honour of Y Nutku’s memory. All corrections and new results in sections 1, 2 and 4 are due to M Sheftel. We present new anti-self-dual exact solutions of the Einstein field equations with Euclidean and neutral (ultra-hyperbolic) signatures that admit only one rotational Killing vector. Such solutions of the Einstein field equations are determined by non-invariant solutions of Boyer-Finley (BF) equation. For the case of Euclidean signature such a solution of the BF equation was first constructed by Calderbank and Tod. Two years later, Martina, Sheftel and Winternitz applied the method of group foliation to the BF equation and reproduced the Calderbank-Tod solution together with new solutions for the neutral signature. In the case of Euclidean signature we obtain new metrics which asymptotically locally look like a flat space and have a non-removable singular point at the origin. In the case of ultra-hyperbolic signature there exist three inequivalent forms of metric. Only one of these can be obtained by analytic continuation from the Calderbank-Tod solution whereas the other two are new.

  13. Determining GPS average performance metrics

    NASA Technical Reports Server (NTRS)

    Moore, G. V.

    1995-01-01

    Analytic and semi-analytic methods are used to show that users of the GPS constellation can expect performance variations based on their location. Specifically, performance is shown to be a function of both altitude and latitude. These results stem from the fact that the GPS constellation is itself non-uniform. For example, GPS satellites are over four times as likely to be directly over Tierra del Fuego than over Hawaii or Singapore. Inevitable performance variations due to user location occur for ground, sea, air and space GPS users. These performance variations can be studied in an average relative sense. A semi-analytic tool which symmetrically allocates GPS satellite latitude belt dwell times among longitude points is used to compute average performance metrics. These metrics include average number of GPS vehicles visible, relative average accuracies in the radial, intrack and crosstrack (or radial, north/south, east/west) directions, and relative average PDOP or GDOP. The tool can be quickly changed to incorporate various user antenna obscuration models and various GPS constellation designs. Among other applications, tool results can be used in studies to: predict locations and geometries of best/worst case performance, design GPS constellations, determine optimal user antenna location and understand performance trends among various users.

  14. A high-throughput contact-hole resolution metric for photoresists:Full-process sensitivity study

    SciTech Connect

    Anderson, Christopher N.; Naulleau, Patrick P.

    2008-01-22

    The ability to accurately quantify the intrinsic resolution of chemically amplified photoresists is critical for the optimization of resists for extreme ultraviolet (EUV) Iithography. We have recently reported on two resolution metrics that have been shown to extract resolution numbers consistent with direct observation. In this paper we examine the previously reported contact-hole resolution metric and explore the sensitivity of the metric to potential error sources associated with the experimental side of the resolution extraction process. For EUV exposures at the SEMATECH Berkeley microfield exposure tool, we report a full-process error-bar in extracted resolution of 1.75 nm RMS and verify this result experimentally.

  15. The effect of oxytetracycline on insulin resistance in obese mice

    PubMed Central

    Bégin-Heick, Nicole; Bourassa, Michel; Heick, H. M. C.

    1974-01-01

    1. Chronic oxytetracycline treatment was found to improve the insulin resistance of the obese–hyperglycaemic mouse. 2. The improved response to insulin was accompanied by decreased concentrations of circulating insulin and glucose, by a decrease in the lipid content of the liver and by an increase in the insulin-receptor sites of the liver and adipose tissue. 3. The increase in insulin-receptor sites preceded the fall in blood glucose. 4. Comparable studies done on food-restricted animals indicated that although chronic food restriction corrected the hyperinsulinaemia it did not restore the insulin-receptor sites or the hyperglycaemia. PMID:4464837

  16. Test patterns and quality metrics for digital video compression

    NASA Astrophysics Data System (ADS)

    Fenimore, Charles P.; Field, Bruce F.; Van Degrift, Craig

    1997-06-01

    Lossy video compression systems such as MPEG2 introduce picture impairments such as image blocking, color distortion and persistent color fragments, 'mosquito noise,' and blurring in their outputs. While there are video test clips which exhibit one or more of these distortions upon coding, there is need of a set of well-characterized test patterns and video quality metrics. Digital test patterns can deliver calibrated stresses to specific features of the encoder, much as the test patterns for analog video stress critical characteristics of that system. Metrics quantify the error effects of compression by a computation. NIST is developing such test patterns and metrics for compression rates that typically introduce perceptually negligible artifacts, i.e. for high quality video. The test patterns are designed for subjective and objective evaluation. The test patterns include a family of computer-generated spinning wheels to stress luminance-based macro-block motion estimation algorithms and images with strongly directional high-frequency content to stress quantization algorithms. In this paper we discuss the spinning wheel test pattern. It has been encoded at a variety of bit rates near the threshold for the perception of impairments. We have observed that impairment perceptibility depends on the local contrast. For the spinning wheel we report the contrast at the threshold for perception of impairments as a function of the bit rate. To quantify perceptual image blocking we have developed a metric which detects 'flats:' image blocks of constant (or near constant) luminance. The effectiveness of this metric is appraised.

  17. Experimental and numerical study of the effective thermal conductivity of silica nanocomposites with thermal boundary resistance

    SciTech Connect

    Kothari, Rushabh M; Dinwiddie, Ralph Barton; Wang, Hsin

    2013-01-01

    The thermal interface resistance at the macro scale is mainly described by the physical gap between two interfaces and constriction resistance due to this gap. The small gaps between the two material faces makes up the majority of thermal interface resistance at the macro scale. So, most of the studies have been focused on characterizing effect of surface geometry and material properties to thermal interface resistance. This resistance is more widely known as thermal contact resistance, represented with Rc. There are various models to predict thermal contact resistance at macro scale. These models predict thermal resistance Rc for given two materials by utilizing their bulk thermomechanical properties. Although, Rc represents thermal resistance accurately for macro size contacts between two metals, it is not suitable to describe interface resistance of particles in modern TIMs, aka particulate composites. The particles inside recently available TIMs are micron size and with effort to further increase surface area this particle size is approaching nano scale. At this small scale, Rc does not accurately predict thermal interface, as it is very difficult to characterize the surface topography. The thermal discontinuity at perfectly bonded interface of two dissimilar materials is termed as thermal boundary resistance (Rb) or Kapitza resistance. The macroscopic assumptions that thermal discontinuity only exists due to gaps and surface geometry leads to substantial error in determining interface thermal properties at micron and nano scale. The phenomenon of thermal boundary resistance is an inherent material property and arises due to fundamental mechanism of thermal transport. For metal-matrix particulate composites, Rb plays more important role than Rc. The free flowing nature of the polymer would eliminate most of the gaps between the two materials at their interface. This means almost all of the thermal resistance at particle/matrix interface would occur due to Rb

  18. Mesoscale spatial variability of selected aquatic invertebrate community metrics from a minimally impaired stream segment

    USGS Publications Warehouse

    Gebler, J.B.

    2004-01-01

    The related topics of spatial variability of aquatic invertebrate community metrics, implications of spatial patterns of metric values to distributions of aquatic invertebrate communities, and ramifications of natural variability to the detection of human perturbations were investigated. Four metrics commonly used for stream assessment were computed for 9 stream reaches within a fairly homogeneous, minimally impaired stream segment of the San Pedro River, Arizona. Metric variability was assessed for differing sampling scenarios using simple permutation procedures. Spatial patterns of metric values suggest that aquatic invertebrate communities are patchily distributed on subsegment and segment scales, which causes metric variability. Wide ranges of metric values resulted in wide ranges of metric coefficients of variation (CVs) and minimum detectable differences (MDDs), and both CVs and MDDs often increased as sample size (number of reaches) increased, suggesting that any particular set of sampling reaches could yield misleading estimates of population parameters and effects that can be detected. Mean metric variabilities were substantial, with the result that only fairly large differences in metrics would be declared significant at ?? = 0.05 and ?? = 0.20. The number of reaches required to obtain MDDs of 10% and 20% varied with significance level and power, and differed for different metrics, but were generally large, ranging into tens and hundreds of reaches. Study results suggest that metric values from one or a small number of stream reach(es) may not be adequate to represent a stream segment, depending on effect sizes of interest, and that larger sample sizes are necessary to obtain reasonable estimates of metrics and sample statistics. For bioassessment to progress, spatial variability may need to be investigated in many systems and should be considered when designing studies and interpreting data.

  19. Plant resistance reduces the strength of consumptive and non-consumptive effects of predators on aphids.

    PubMed

    Kersch-Becker, Mônica F; Thaler, Jennifer S

    2015-09-01

    1. The impact of predators on prey has traditionally been attributed to the act of consumption. Prey responses to the presence of the predator (non-consumptive effects), however, can be as important as predation itself. While plant defences are known to influence predator-prey interactions, their relative effects on consumptive vs. non-consumptive effects are not well understood. 2. We evaluated the consequences of plant resistance and predators (Hippodamia convergens) on the mass, number of nymphs, population growth, density and dispersal of aphids (Macrosiphum euphorbiae). We tested for the effects of plant resistance on non-consumptive and consumptive effects of predators on aphid performance and dispersal using a combination of path analysis and experimental manipulation of predation risk. 3. We manipulated plant resistance using genetically modified lines of tomato (Solanum lycopersicum) that vary incrementally in the expression of the jasmonate pathway, which mediates induced resistance to insects and manipulated aphid exposure to lethal and risk predators. Predation risk predators had mandibles impaired to prevent killing. 4. Plant resistance reduced predation rate (consumptive effect) on high resistance plants. As a consequence, predators had no impact on the number of nymphs, aphid density or population growth on high resistance plants, whereas on low resistance plants, predators reduced aphid density by 35% and population growth by 86%. Path analysis and direct manipulation of predation risk showed that predation risk rather than predation rate promoted aphid dispersal and varied with host plant resistance. Aphid dispersal in response to predation risk was greater on low compared to high resistance plants. The predation risk experiment also showed that the number of aphid nymphs increased in the presence of risk predators but did not translate into increased population growth. 5. In conclusion, the consumptive and non-consumptive components of predators

  20. Effect of displacement on resistance and capacitance of polyaniline film

    NASA Astrophysics Data System (ADS)

    Khasan Sanginovich, Karimov; Muhammad Tariq, Saeed; Fazal, Ahmad Khalid; Syed, Abdul Moiz

    2011-04-01

    This paper investigates the properties of displacement sensors based on polyaniline (PANI) films. About 1 wt% of PANI micropowder is mixed and stirred in a solution of 90 wt% water and 10 wt% alcohol at room temperature. The films of PANI are deposited from solution by drop-casting on Ag electrodes, which are preliminary deposited on glass substrates. The thicknesses of the PANI films are in the range of 20 μm-80 μm. A displacement sensor with polyaniline film as an active material is designed and fabricated. The investigations showed that, on average, the AC resistance of the sensor decreases by 2 times and the capacitance accordingly increases by 1.6 times as the displacement changes in the range of 0 mm-0.5 mm. The polyaniline is the only active material of the displacement sensor. The resistance and capacitance of the PANI changes under the pressure of spring and elastic rubber, and this pressure is created by the downward movement of the micrometer.

  1. Effects of Mefloquine Use on Plasmodium vivax Multidrug Resistance

    PubMed Central

    Khim, Nimol; Andrianaranjaka, Voahangy; Popovici, Jean; Kim, Saorin; Ratsimbasoa, Arsene; Benedet, Christophe; Barnadas, Celine; Durand, Remy; Thellier, Marc; Legrand, Eric; Musset, Lise; Menegon, Michela; Severini, Carlo; Nour, Bakri Y.M.; Tichit, Magali; Bouchier, Christiane; Mercereau-Puijalon, Odile

    2014-01-01

    Numerous studies have indicated a strong association between amplification of the multidrug resistance-1 gene and in vivo and in vitro mefloquine resistance of Plasmodium falciparum. Although falciparum infection usually is not treated with mefloquine, incorrect diagnosis, high frequency of undetected mixed infections, or relapses of P. vivax infection triggered by P. falciparum infections expose non–P. falciparum parasites to mefloquine. To assess the consequences of such unintentional treatments on P. vivax, we studied variations in number of Pvmdr-1 (PlasmoDB accession no. PVX_080100, NCBI reference sequence NC_009915.1) copies worldwide in 607 samples collected in areas with different histories of mefloquine use from residents and from travelers returning to France. Number of Pvmdr-1 copies correlated with drug use history. Treatment against P. falciparum exerts substantial collateral pressure against sympatric P. vivax, jeopardizing future use of mefloquine against P. vivax. A drug policy is needed that takes into consideration all co-endemic species of malaria parasites. PMID:25272023

  2. Effect of chlorfenapyr on cypermethrin-resistant Culex pipiens pallens Coq mosquitoes.

    PubMed

    Yuan, J Z; Li, Q F; Huang, J B; Gao, J F

    2015-03-01

    Chlorfenapyr is a promising pyrrole insecticide with a unique mechanism of action that does not confer cross-resistance to neurotoxic insecticides. The effect of chlorfenapyr on pyrethorid-resistant Culex pipiens pallens Coq (Diptera: Culicidae) has not been fully investigated under laboratory conditions. In this study, cypermethrin-resistant C. p. pallens exhibited 376.79-fold and 395.40-fold increase in resistance to cypermethrin compared with susceptible strains after exposure for 24 and 48h, respectively. Larvae and adults were tested for susceptibility using dipping, topical, and impregnated paper methods as recommended by the WHO. No cross-resistance to chlorfenapyr was found. Increased mortality was apparent between 48 and 72h, indicating a slow rate of toxic activity. Synergism experiments with piperonyl butoxide (PBO) showed an antagonistic effect on chlorfenapyr toxicity. Mixtures of chlorfenapyr and cypermethrin could therefore provide additional benefits over either insecticide used alone. Mixtures of 5ng/ml chlorfenapyr and 500ng/ml cypermethrin exhibited a slight synergistic effect on cypermethrin-resistant mosquitoes (3.33, 6.84 and 2.34% after 24, 48 and 72h exposure, respectively. This activity was lost when the chlorfenapyr concentration was increased to 10 or 20ng/ml. Chlorfenapyr showed quite good results for pyrethroid-resistant C. p. pallens, and could improve public health by reducing the occurrence of mosquito bites and subsequently protecting against transmission of lymphatic filariasis and Japanese encephalitis. PMID:25497774

  3. Substitution for chromium in 304 stainless steel. [effects on oxidation and corrosion resistance

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.; Barrett, C. A.

    1978-01-01

    An investigation was conducted to determine the effects of substituting less strategic elements for Cr on oxidation and corrosion resistance of AISI 304 stainless steel. Cyclic oxidation resistance was evaluated at 870 C. Corrosion resistance was determined by exposure of specimens to a boiling copper-rich solution of copper sulfate and sulfuric acid. Alloy substitutes for Cr included Al, Mn, Mo, Si, Ti, V, Y, and misch metal. A level of about 12% Cr was the minimum amount of Cr required for adequate oxidation and corrosion resistance in the modified composition 304 stainless steels. This represents a Cr saving of 33 percent. Two alloys containing 12% Cr plus 2% Al plus 2% Mo and 12% Cr plus 2.65% Si were identified which exhibited oxidation and corrosion resistance comparable to AISI 304 stainless steel.

  4. Predicting date rape perceptions: the effects of gender, gender role attitudes, and victim resistance.

    PubMed

    Black, Katherine A; McCloskey, Kathy A

    2013-08-01

    The effects of participant gender and victim resistance on date rape perceptions have been inconsistent. Participant gender role attitudes may contribute to these inconsistencies. We found women with traditional gender role attitudes were least likely to agree that the perpetrator was guilty of rape. Participants were less convinced of the perpetrator's guilt when the victim resisted verbally than when she resisted verbally and physically, and participants with traditional gender role attitudes were less convinced of the negative impact on the victim when she resisted verbally than when she resisted verbally and physically. Perhaps previous inconsistencies resulted from varying proportions of men and women with traditional versus liberal gender role attitudes in the samples. PMID:24048185

  5. Second post-Minkowskian order harmonic metric for a moving Kerr-Newman black hole

    NASA Astrophysics Data System (ADS)

    He, Guan-Sheng; Lin, Wen-Bin

    2015-05-01

    We apply the Lorentz boosting method to the Kerr-Newman metric in harmonic coordinates, and obtain the second post-Minkowskian order harmonic metric for a moving Kerr-Newman black hole with an arbitrary constant speed. This metric may be useful for investigating observable relativistic effects due to the motion of the moving source. As an application, the post-Newtonian equations of motion for a particle and a photon in the far field of this black hole are calculated.

  6. Two-Basket Approach and Emission Metrics

    NASA Astrophysics Data System (ADS)

    Tanaka, K.; Schmale, J.; von Schneidemesser, E.

    2013-12-01

    Cutting the emissions of Short-Lived Climate-Forcing Air Pollutants (SLCPs) gains increasing global attention as a mitigation policy option because of direct benefits for climate and co-benefits such as improvements in air quality. Including SLCPs as target components to abate within a single basket (e.g. the Kyoto Protocol) would, however, face issues with regard to: i) additional assumptions that are required to compare SLCP emissions and CO2 emissions within a basket in terms of climatic effects, especially because of the difference in lifetimes, ii) the accountability of non-climatic effects in the emission trading between SLCPs and CO2. The idea of a two-basket approach was originally proposed as a climatic analogue to the Montreal Protocol dealing with ozone depleting substances (Jackson 2009; Daniel et al. 2012; Smith et al. 2013). In a two-basket approach, emissions are allowed to be traded within a basket but not across the baskets. While this approach potentially ensures scientifically supported emission trading (e.g. (Smith et al. 2013)), this approach leaves open the important issue of how to determine the relative weight between two baskets. Determining the weight cannot be answered by science alone, as the question involves a value judgment as stressed in metric studies (e.g. (Tanaka et al. 2010; Tanaka et al. 2013)). We discuss emission metrics in the context of a two-basket approach and present policy implications of such an approach. In a two-basket approach, the weight between two baskets needs to be determined a priori or exogenously. Here, an opportunity arises to present synergetic policy options targeted at mitigating climate change and air pollution simultaneously. In other words, this could be a strategy to encourage policymakers to consider cross-cutting issues. Under a two-basket climate policy, policymakers would be exposed to questions such as: - What type of damages caused by climate change does one choose to avoid? - To what extent

  7. Effect of length of chopped pristine and intercalated graphite fibers on the resistivity of fiber networks

    NASA Technical Reports Server (NTRS)

    Gaier, James R.; Stahl, Mark

    1988-01-01

    Samples of Amoco P-100 fibers were chopped to lengths of 3.14, 2.53, 1.90, 1.27, 0.66 mm, or milled for 2 hours. The two-point resistivity of compacts of these fibers were measured as a function of pressure from 34 kPa to 143 MPa. Samples of each fiber length were intercalated with bromine at room temperature and similarly measured. The low pressure resistivity of the compacts decreased with increasing fiber length. Intercalation lowered the resistivity of each of the chopped length compacts, but raised the resistivity of the milled fiber compacts. Bulk resistivity of all samples decreased with increasing pressure at similar rates. Even though fiber volumes were as low as 5 percent, all measurements exhibited measurable resistivity. A greater change with pressure in the resistance was observed for shorter fibers than for longer, probably an indication of tighter fiber packing. Intercalation appeared to have no effect on the fiber to fiber contact resistance.

  8. Effects of durum wheat background on the expression of hexaploid wheat-derived Fusarium head blight resistance genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple Fusarium head blight (FHB) resistance sources have been identified in common wheat, but an effective source of resistance to FHB has not found in durum wheat. Here we report preliminary results on the effects of durum background on the expression of hexaploid wheat-derived FHB resistance g...

  9. Fighter agility metrics, research, and test

    NASA Technical Reports Server (NTRS)

    Liefer, Randall K.; Valasek, John; Eggold, David P.

    1990-01-01

    Proposed new metrics to assess fighter aircraft agility are collected and analyzed. A framework for classification of these new agility metrics is developed and applied. A completed set of transient agility metrics is evaluated with a high fidelity, nonlinear F-18 simulation provided by the NASA Dryden Flight Research Center. Test techniques and data reduction methods are proposed. A method of providing cuing information to the pilot during flight test is discussed. The sensitivity of longitudinal and lateral agility metrics to deviations from the pilot cues is studied in detail. The metrics are shown to be largely insensitive to reasonable deviations from the nominal test pilot commands. Instrumentation required to quantify agility via flight test is also considered. With one exception, each of the proposed new metrics may be measured with instrumentation currently available. Simulation documentation and user instructions are provided in an appendix.

  10. New Self-Dual Einstein Metrics

    NASA Astrophysics Data System (ADS)

    Casteill, P. Y.; Valent, G.

    A new family of euclidean Einstein metrics with self-dual Weyl tensor have been obtained using ideas from extended supersymmetries1,2. The basic supersymmetric formalism3, known as harmonic superspace, was adapted to the computation of self-dual Einstein metrics in 4. The resulting metric depends on 4 parameters besides the Einstein constant and has for isometry group U(1) × U(1), with hypersurface generating Killing vectors. In the limit of vanishing Einstein constant we recover a family of hyperkähler metrics within the Multicentre family 5 (in fact the most general one with two centres). Our results include the metrics of Plebanski and Demianski6 when these ones are restricted to be self-dual Weyl. From Flaherty's equivalence 7 these metrics can also be interpreted as a solution of the coupled Einstein-Maxwell field equations, for which we have given the Maxwell field strength forms2.

  11. Effect of contrast magnitude and resolution metric on noise-resolution tradeoffs in x-ray CT imaging: a comparison of non-quadratic penalized alternating minimization and filtered backprojection algorithms

    NASA Astrophysics Data System (ADS)

    Evans, Joshua D.; Politte, David G.; Whiting, Bruce R.; O'Sullivan, Joseph A.; Williamson, Jeffrey F.

    2011-03-01

    Purpose: To assess the impact of contrast magnitude and spatial resolution metric choices on the noise-resolution tradeoff of a non-quadratic penalized statistical iterative algorithm, Alternating Minimization (AM), in x-ray transmission CT. Methods: Monoenergetic Poisson-counting CT data were simulated for a water phantom containing circular inserts of varying contrast (7% to 238%). The data was reconstructed with conventional filtered backprojection (FBP) and two non-quadratic penalty parameterizations of AM. A range of smoothing strengths is reconstructed for each algorithm to quantify the noise-resolution tradeoff curve. Modulation transfer functions (MTFs) were estimated from the circular contrast-insert edges and then integrated up to a cutoff frequency as a single-parameter measure of local spatial resolution. Two cutoff frequencies and two resolution comparison values are investigated for their effect on reported tradeoff advantage. Results: The noise-resolution tradeoff curve was always more favorable for AM than FBP. For strongly edge-preserving penalty functions, this advantage was found to be dependent upon the contrast for which resolution is quantified for comparison. The magnitude of the reported dose reduction potential of the AM algorithm was shown to be dependent on the resolution metric choices, though the general contrast-dependence was always evident. Conclusions: The penalized AM algorithm shows the potential to reconstruct images of comparable quality using a fraction of the dose required by FBP. The contrast-dependence on the tradeoff advantage implies that statistical algorithms using non-quadratic penalty functions should be assessed using contrasts relevant to the intended clinical task.

  12. Delayed mortality effects cut the malaria transmission potential of insecticide-resistant mosquitoes.

    PubMed

    Viana, Mafalda; Hughes, Angela; Matthiopoulos, Jason; Ranson, Hilary; Ferguson, Heather M

    2016-08-01

    Malaria transmission has been substantially reduced across Africa through the distribution of long-lasting insecticidal nets (LLINs). However, the emergence of insecticide resistance within mosquito vectors risks jeopardizing the future efficacy of this control strategy. The severity of this threat is uncertain because the consequences of resistance for mosquito fitness are poorly understood: while resistant mosquitoes are no longer immediately killed upon contact with LLINs, their transmission potential may be curtailed because of longer-term fitness costs that persist beyond the first 24 h after exposure. Here, we used a Bayesian state-space model to quantify the immediate (within 24 h of exposure) and delayed (>24 h after exposure) impact of insecticides on daily survival and malaria transmission potential of moderately and highly resistant laboratory populations of the major African malaria vector Anopheles gambiae Contact with LLINs reduced the immediate survival of moderately and highly resistant An. gambiae strains by 60-100% and 3-61%, respectively, and delayed mortality impacts occurring beyond the first 24 h after exposure further reduced their overall life spans by nearly one-half. In total, insecticide exposure was predicted to reduce the lifetime malaria transmission potential of insecticide-resistant vectors by two-thirds, with delayed effects accounting for at least one-half of this reduction. The existence of substantial, previously unreported, delayed mortality effects within highly resistant malaria vectors following exposure to insecticides does not diminish the threat of growing resistance, but posits an explanation for the apparent paradox of continued LLIN effectiveness in the presence of high insecticide resistance. PMID:27402740

  13. Measurement of perceived stereoscopic sensation through disparity metrics and compositions

    NASA Astrophysics Data System (ADS)

    Toyosawa, Satoshi; Kawai, Takashi

    2014-03-01

    Literatures use disparity as a principle measure evaluating discomfort, various artifacts, or movie production styles associated to stereoscopy, yet, statistics used to represent image or frame are often different. The current study examines 20 disparity statistics to find metrics that would best represent subjective stereoscopic sensation. Additionally, effect of disparity distribution pattern within an image is considered: Here, the patterns are categorised either single-peak or multiple-peak from the shape of disparity histogram. In the experiment, 14 stereoscopic images were presented to 15 subjects. Each subject evaluated perceived sense of distance and volume (3D space) through 7 points Likert scale. The result shows that the statistics that correlated significantly to the subjective sensation differed by the disparity compositions, hence, the metrics should be chosen accordingly. For the sense of distance, maximum, range, and the difference between 95th and 5th percentiles were found to be appropriate metrics under the single-peak, and minimum, contrast, and 5th percentile were representative under the multiple-peak. Similarly, for the sense of volume, range was found to be appropriate under the single-peak, but no metrics was found under the multiple-peak. The discrepancy is assumed due to different observation styles under differently composed images. We believe that the current study provides optimal disparity metrics for stereoscopic sensation measurements.

  14. Skill metrics for evaluation and comparison of sea ice models

    NASA Astrophysics Data System (ADS)

    Dukhovskoy, Dmitry S.; Ubnoske, Jonathan; Blanchard-Wrigglesworth, Edward; Hiester, Hannah R.; Proshutinsky, Andrey

    2015-09-01

    Five quantitative methodologies (metrics) that may be used to assess the skill of sea ice models against a control field are analyzed. The methodologies are Absolute Deviation, Root-Mean-Square Deviation, Mean Displacement, Hausdorff Distance, and Modified Hausdorff Distance. The methodologies are employed to quantify similarity between spatial distribution of the simulated and control scalar fields providing measures of model performance. To analyze their response to dissimilarities in two-dimensional fields (contours), the metrics undergo sensitivity tests (scale, rotation, translation, and noise). Furthermore, in order to assess their ability to quantify resemblance of three-dimensional fields, the metrics are subjected to sensitivity tests where tested fields have continuous random spatial patterns inside the contours. The Modified Hausdorff Distance approach demonstrates the best response to tested differences, with the other methods limited by weak responses to scale and translation. Both Hausdorff Distance and Modified Hausdorff Distance metrics are robust to noise, as opposed to the other methods. The metrics are then employed in realistic cases that validate sea ice concentration fields from numerical models and sea ice mean outlook against control data and observations. The Modified Hausdorff Distance method again exhibits high skill in quantifying similarity between both two-dimensional (ice contour) and three-dimensional (ice concentration) sea ice fields. The study demonstrates that the Modified Hausdorff Distance is a mathematically tractable and efficient method for model skill assessment and comparison providing effective and objective evaluation of both two-dimensional and three-dimensional sea ice characteristics across data sets.

  15. a New Centrality Metric Based on Clustering Coefficient

    NASA Astrophysics Data System (ADS)

    Li, Chong; Guo, Shi-Ze; Lu, Zhe-Ming; Qiao, Yu-Long; Song, Guang-Hua

    2013-07-01

    Many centrality metrics have been proposed over the years to compute the centrality of nodes, which has been a key issue in complex network analysis. The most important node can be estimated through a variety of metrics, such as degree, closeness, eigenvector, betweenness, flow betweenness, cumulated nominations and subgraph. Simulated flow is a common method adopted by many centrality metrics, such as flow betweenness centrality, which assumes that the information spreads freely in the entire network. Generally speaking, the farther the information travels, the more times the information passes the geometric center. Thus, it is easy to determine which node is more likely to be the center of the geometry network. However, during information transmission, different nodes do not share the same vitality, and some nodes are more active than others. Therefore, the product of one node's degree and its clustering coefficient can be viewed as a good factor to show how active this node is. In this paper, a new centrality metric called vitality centrality is introduced, which is only based on this product and the simulated flow. Simulation experiments based on six test networks have been carried out to demonstrate the effectiveness of our new metric.

  16. Resistivity Lows Near Paeroa Fault (TVZ, NZ) Caused by Topographic Effects

    SciTech Connect

    Risk, G.F.; Bibby, H.M.

    1995-01-01

    Modeling of two-dimensional resistivity structures has been undertaken using a finite elements scheme that allows for accurate matching of the elevation of the ground surface. With this modeling program, interpretations were made of apparent resistivities measured with the multiple-source bipole-dipole array along several lines crossing the northern part of the Paeroa Fault. On a line crossing the Paeroa Scarp near its highest point, where the throw is 425 m, the topographic effect is inferred to cause the apparent resistivities to be lowered by about 40%, which accounts for the measured resistivity anomaly at the fault scarp. At the north-west of the Waikite-Puakohurea thermal region on another line, the topographic effect of a 100 m high ridge on Mt Waikorapa causes the apparent resistivities to be reduced by about 15%. This is insufficient to explain the measured low-resistivity anomaly. Thus, low-resistivity rock is inferred to underlie the site, suggesting that the thermal region extends about 1 km further to the north-westward than previously thought.

  17. Common Metrics for Human-Robot Interaction

    NASA Technical Reports Server (NTRS)

    Steinfeld, Aaron; Lewis, Michael; Fong, Terrence; Scholtz, Jean; Schultz, Alan; Kaber, David; Goodrich, Michael

    2006-01-01

    This paper describes an effort to identify common metrics for task-oriented human-robot interaction (HRI). We begin by discussing the need for a toolkit of HRI metrics. We then describe the framework of our work and identify important biasing factors that must be taken into consideration. Finally, we present suggested common metrics for standardization and a case study. Preparation of a larger, more detailed toolkit is in progress.

  18. Metrics for Business Process Models

    NASA Astrophysics Data System (ADS)

    Mendling, Jan

    Up until now, there has been little research on why people introduce errors in real-world business process models. In a more general context, Simon [404] points to the limitations of cognitive capabilities and concludes that humans act rationally only to a certain extent. Concerning modeling errors, this argument would imply that human modelers lose track of the interrelations of large and complex models due to their limited cognitive capabilities and introduce errors that they would not insert in a small model. A recent study by Mendling et al. [275] explores in how far certain complexity metrics of business process models have the potential to serve as error determinants. The authors conclude that complexity indeed appears to have an impact on error probability. Before we can test such a hypothesis in a more general setting, we have to establish an understanding of how we can define determinants that drive error probability and how we can measure them.

  19. Metrics for antibody therapeutics development.

    PubMed

    Reichert, Janice M

    2010-01-01

    A wide variety of full-size monoclonal antibodies (mAbs) and therapeutics derived from alternative antibody formats can be produced through genetic and biological engineering techniques. These molecules are now filling the preclinical and clinical pipelines of every major pharmaceutical company and many biotechnology firms. Metrics for the development of antibody therapeutics, including averages for the number of candidates entering clinical study and development phase lengths for mAbs approved in the United States, were derived from analysis of a dataset of over 600 therapeutic mAbs that entered clinical study sponsored, at least in part, by commercial firms. The results presented provide an overview of the field and context for the evaluation of on-going and prospective mAb development programs. The expansion of therapeutic antibody use through supplemental marketing approvals and the increase in the study of therapeutics derived from alternative antibody formats are discussed. PMID:20930555

  20. [Effect of biologically active compounds on the resistance of bacteria to antibiotics].

    PubMed

    Levchenko, A B; Belousova, I I; El'gart, R E; Chistiakova, A M; Tereshin, I M

    1975-11-01

    A number of biologically active substances, i. e. main protamine proteins and histones, EDTA, lysozyme, methacyl and pentoxyl was studied with respect to their effect on the levels of the minimum inhibitory concentrations of antibiotics against E. coli and Staph. aureus and transfer of resistence to chloramphenicol in E. coli on conjugation. It was shown that the above substances lowered the minimum inhibitory concentrations of the antibiotics 2--10 times when added to the culture simultaneously with the latter. The results varied depending on the strain and the resistance nature. Marked inhibition of transfer of resistance to chloramphenicol in the presence of the main proteins and EDTA was found. PMID:817644

  1. Resistive memory effects in BiFeO3 single crystals controlled by transverse electric fields

    NASA Astrophysics Data System (ADS)

    Kawachi, S.; Kuroe, H.; Ito, T.; Miyake, A.; Tokunaga, M.

    2016-04-01

    The effects of electric fields perpendicular to the c-axis of the trigonal cell in single crystals of BiFeO3 are investigated through magnetization and resistance measurements. Magnetization and resistance exhibit hysteretic changes under applied electric fields, which can be ascribed to the reorientation of the magnetoelectric domains. Samples are repetitively switched between high- and low-resistance states by changing the polarity of the applied electric fields over 20 000 cycles at room temperature. These results demonstrate the potential of BiFeO3 for use in non-volatile memory devices.

  2. Effect of electron-phonon interaction on resistivity of some heavy fermion (HF) systems

    SciTech Connect

    Sahoo, J.; Shadangi, N.; Nayak, P.

    2014-04-24

    Here, we have analyzed the electron-phonon interaction in the Periodic Anderson Model (PAM) to describe the temperature dependence of resistivity in some heavy fermion (HF) systems for finite wave vector (q) and for finite temperature (T). Since the resistivity is related to the imaginary part of the electron self energy, the expression for the same is evaluated through double time temperature dependant Green function technique of the Zubarev type. The effect of different system parameters namely the position of 4f level, E{sub 0} and the electron - phonon coupling strengths on resistivity have been studied. The results obtained give satisfactory explanations to the experimental observations.

  3. Effects of air resistance on AT-cut quartz thickness-shear resonators.

    PubMed

    Chen, Yangyang; Wang, Ji; Du, Jianke; Zhang, Weiping; Yang, Jiashi

    2013-02-01

    We study theoretically the effects of air resistance on an AT-cut quartz plate thickness-shear mode resonator. Mindlin's two-dimensional equations for coupled thickness-shear and flexural motions of piezoelectric plates are employed for the crystal resonator. The equations of a Newtonian fluid and the equations of linear acoustics are used for the shear and compressive waves in the air surrounding the resonator, respectively. Solutions for free and electrically forced vibrations are obtained. The impedance of the resonator is calculated. The effects of air resistance are examined. It is found that air viscosity causes a relative frequency shift of the order of ppm. When the material quality factor of quartz Q = 10(5), the air viscosity and compressibility both have significant effects on resonator impedance. For resonators with larger aspect ratios the effects of air resistance are weaker, and the effect of air compressibility is weaker than air viscosity. PMID:23357914

  4. The effect of muscle stimulation during resistive training on performance parameters.

    PubMed

    Wolf, S L; Ariel, G B; Saar, D; Penny, M A; Railey, P

    1986-01-01

    This study compared changes in movement velocity, force, and work from bilateral quadriceps muscle stimulation during resistive squatting exercise to identical exercise without stimulation. Both the group undergoing resistive training over 24 sessions (N = 9) and the group receiving the same treatment in conjunction with stimulation during the last 12 sessions (N = 9) showed significant improvements in measures of movement velocity, force, total work, power, sprint time, and vertical jump distance when compared to a control group receiving no treatment (N = 9). All subjects were baseline tested and tested at 3, 6, and 7 week intervals. Both experimental groups improved significantly for all measures, but the electrical stimulation group did not produce more significant changes overall than those with resistive training alone. However, when compared to control measures, the effect of electrical stimulation-augmented responses among some measures was more pronounced than the effect of resistive training alone. PMID:3752341

  5. Semantic Metrics for Object Oriented Design

    NASA Technical Reports Server (NTRS)

    Etzkorn, Lethe

    2003-01-01

    The purpose of this proposal is to research a new suite of object-oriented (OO) software metrics, called semantic metrics, that have the potential to help software engineers identify fragile, low quality code sections much earlier in the development cycle than is possible with traditional OO metrics. With earlier and better Fault detection, software maintenance will be less time consuming and expensive, and software reusability will be improved. Because it is less costly to correct faults found earlier than to correct faults found later in the software lifecycle, the overall cost of software development will be reduced. Semantic metrics can be derived from the knowledge base of a program understanding system. A program understanding system is designed to understand a software module. Once understanding is complete, the knowledge-base contains digested information about the software module. Various semantic metrics can be collected on the knowledge base. This new kind of metric measures domain complexity, or the relationship of the software to its application domain, rather than implementation complexity, which is what traditional software metrics measure. A semantic metric will thus map much more closely to qualities humans are interested in, such as cohesion and maintainability, than is possible using traditional metrics, that are calculated using only syntactic aspects of software.

  6. Fusion metrics for dynamic situation analysis

    NASA Astrophysics Data System (ADS)

    Blasch, Erik P.; Pribilski, Mike; Daughtery, Bryan; Roscoe, Brian; Gunsett, Josh

    2004-08-01

    To design information fusion systems, it is important to develop metrics as part of a test and evaluation strategy. In many cases, fusion systems are designed to (1) meet a specific set of user information needs (IN), (2) continuously validate information pedigree and updates, and (3) maintain this performance under changing conditions. A fusion system"s performance is evaluated in many ways. However, developing a consistent set of metrics is important for standardization. For example, many track and identification metrics have been proposed for fusion analysis. To evaluate a complete fusion system performance, level 4 sensor management and level 5 user refinement metrics need to be developed simultaneously to determine whether or not the fusion system is meeting information needs. To describe fusion performance, the fusion community needs to agree on a minimum set of metrics for user assessment and algorithm comparison. We suggest that such a minimum set should include feasible metrics of accuracy, confidence, throughput, timeliness, and cost. These metrics can be computed as confidence (probability), accuracy (error), timeliness (delay), throughput (amount) and cost (dollars). In this paper, we explore an aggregate set of metrics for fusion evaluation and demonstrate with information need metrics for dynamic situation analysis.

  7. Metrics for measuring net-centric data strategy implementation

    NASA Astrophysics Data System (ADS)

    Kroculick, Joseph B.

    2010-04-01

    An enterprise data strategy outlines an organization's vision and objectives for improved collection and use of data. We propose generic metrics and quantifiable measures for each of the DoD Net-Centric Data Strategy (NCDS) data goals. Data strategy metrics can be adapted to the business processes of an enterprise and the needs of stakeholders in leveraging the organization's data assets to provide for more effective decision making. Generic metrics are applied to a specific application where logistics supply and transportation data is integrated across multiple functional groups. A dashboard presents a multidimensional view of the current progress to a state where logistics data shared in a timely and seamless manner among users, applications, and systems.

  8. Comparing Prices for Food and Diet Research: The Metric Matters

    PubMed Central

    Jones, N. R. V.; Monsivais, P.

    2016-01-01

    ABSTRACT An important issue in research into access to healthy food is how best to compare the price of foods. The appropriate metric for comparison has been debated at length, with proponents variously stating that food prices should be compared in terms of their energy content, their edible mass, or their typical portion size. In this article we assessed the impact of using different food price metrics on the observed difference in price between food groups and categories of healthiness, using United Kingdom consumer price index data for 148 foods and beverages in 2012. We found that the choice of metric had a marked effect on the findings and conclude that this must be decided in advance to suit the reason for comparing food prices.

  9. Value-based metrics and Internet-based enterprises

    NASA Astrophysics Data System (ADS)

    Gupta, Krishan M.

    2001-10-01

    Within the last few years, a host of value-based metrics like EVA, MVA, TBR, CFORI, and TSR have evolved. This paper attempts to analyze the validity and applicability of EVA and Balanced Scorecard for Internet based organizations. Despite the collapse of the dot-com model, the firms engaged in e- commerce continue to struggle to find new ways to account for customer-base, technology, employees, knowledge, etc, as part of the value of the firm. While some metrics, like the Balance Scorecard are geared towards internal use, others like EVA are for external use. Value-based metrics are used for performing internal audits as well as comparing firms against one another; and can also be effectively utilized by individuals outside the firm looking to determine if the firm is creating value for its stakeholders.

  10. Non-minimal derivative couplings of the composite metric

    SciTech Connect

    Heisenberg, Lavinia

    2015-11-04

    In the context of massive gravity, bi-gravity and multi-gravity non-minimal matter couplings via a specific composite effective metric were investigated recently. Even if these couplings generically reintroduce the Boulware-Deser ghost, this composite metric is unique in the sense that the ghost reemerges only beyond the decoupling limit and the matter quantum loop corrections do not detune the potential interactions. We consider non-minimal derivative couplings of the composite metric to matter fields for a specific subclass of Horndeski scalar-tensor interactions. We first explore these couplings in the mini-superspace and investigate in which scenario the ghost remains absent. We further study these non-minimal derivative couplings in the decoupling-limit of the theory and show that the equation of motion for the helicity-0 mode remains second order in derivatives. Finally, we discuss preliminary implications for cosmology.

  11. Eye Tracking Metrics for Workload Estimation in Flight Deck Operation

    NASA Technical Reports Server (NTRS)

    Ellis, Kyle; Schnell, Thomas

    2010-01-01

    Flight decks of the future are being enhanced through improved avionics that adapt to both aircraft and operator state. Eye tracking allows for non-invasive analysis of pilot eye movements, from which a set of metrics can be derived to effectively and reliably characterize workload. This research identifies eye tracking metrics that correlate to aircraft automation conditions, and identifies the correlation of pilot workload to the same automation conditions. Saccade length was used as an indirect index of pilot workload: Pilots in the fully automated condition were observed to have on average, larger saccadic movements in contrast to the guidance and manual flight conditions. The data set itself also provides a general model of human eye movement behavior and so ostensibly visual attention distribution in the cockpit for approach to land tasks with various levels of automation, by means of the same metrics used for workload algorithm development.

  12. Effect of chemical heat treatment on the fatigue resistance of titanium alloys

    SciTech Connect

    Matokhnyuk, L.E.; Nochovnaya, N.A.; Voinalovich, A.V.; Yakovleva, T.Y.

    1985-11-01

    In order to improve the wear resistance of titanium alloy articles, chemical heat treatment, in particular, oxidation and nitriding diffusion impregnation of the article is performed. As a result of this treatment there is a marked increase in surface layer hardness. The change in structure and properties of surface layers have a marked effect on material resistance in fatigue failure as well as on sensitivity to stress concentration. This is the subject of the research discussed here.

  13. Effect of ultrasonic waves on the heat resistance of Bacillus cereus and Bacillus licheniformis spores.

    PubMed

    Burgos, J; Ordóñez, J A; Sala, F

    1972-09-01

    Heat resistance of Bacillus cereus and Bacillus licheniformis spores in quarter-strength Ringer solution decreases markedly after ultrasonic treatments which are unable to kill a significant proportion of the spore population. This effect does not seem to be caused by a loss of Ca(2+) or dipicolinic acid. The use of ultrasonics to eliminate vegetative cells or to break aggregates in Bacillus spore suspensions to be used subsequently in heat resistance experiments appears to be unadvisable. PMID:4627969

  14. Exploratory study into the effect of abdominal mass loading on airways resistance and ventilatory failure

    PubMed Central

    Dattani, Raj S; Swerner, Casey B; Stradling, John R; Manuel, Ari RG

    2016-01-01

    Objective We hypothesised that the airway resistance during tidal breathing would correlate with a particular pattern of increasing obesity, particularly when supine, and would differ between participants with and without ventilatory failure. Methods In our cross-sectional cohort study, 72 morbidly obese patients (40 males, 32 females, mean body mass index (BMI) 47.2) had measurements of both airways resistance (by impulse oscillometry (IOS)) and adiposity (by dual-energy X-ray absorptiometry (DXA)). Results All measures of airways resistance increased in the supine position: total airways resistance (R5) +37% (p<0.0005); large airways resistance (R20) +29% (p<0.0005); and small airways resistance (R5–R20) +52% (p<0.0005). BMI was correlated with seated R5, seated R5–R20, supine R5 and supine R5–R20 (r=0.33 p<0.006, r=0.32 p<0.004, r=0.30 p<0.02 and r=0.36 p<0.04, respectively). Visceral adipose tissue mass was correlated with supine R5–20 (r=0.46 p<0.05). Supine measures of total airways resistance (R5) and large airways resistance (R20) differed between those with and without ventilatory failure, as did mean weight and BMI. Conclusions Our study identifies a potentially detrimental effect of the supine posture on tidal breathing airways resistance in obese patients. This change is correlated most with visceral adipose tissue mass and the small airways. We were able to demonstrate that supine increases in airways resistance during tidal breathing, within obese patients, are different between those with and without ventilatory failure. Trial registration number NCT01380418; pre-results. PMID:27335651

  15. Effects of dipeptidyl peptidase-4 inhibitor in insulin-resistant rats with myocardial infarction.

    PubMed

    Apaijai, Nattayaporn; Inthachai, Tharnwimol; Lekawanvijit, Suree; Chattipakorn, Siriporn C; Chattipakorn, Nipon

    2016-06-01

    Adverse cardiac remodeling after myocardial infarction (MI) leads to progressive heart failure. Obese-insulin resistance increases risks of MI and heart failure. Although dipeptidyl peptidase-4 (DPP4) inhibitor is known to exert cardioprotection, its effects on adverse remodeling after MI in obese-insulin-resistant rats are unclear. We hypothesized that DPP4 inhibitor reduces adverse left ventricular (LV) remodeling and LV dysfunction in obese-insulin-resistant rats with MI. Rats were fed either normal diet (ND) or high-fat diet (HFD) for 12 weeks to induce obese-insulin resistance, followed by left anterior descending coronary artery ligation to induce MI. Then, rats in each dietary group were divided into five subgroups to receive vehicle, enalapril (10mg/kg/day), metformin (30mg/kg/day), DPP4 inhibitor vildagliptin (3mg/kg/day), or combined metformin and vildagliptin for 8 weeks. Heart rate variability (HRV), LV function, pathological and biochemical studies for LV remodeling, and cardiomyocyte apoptosis were determined. Obese-insulin-resistant rats had severe insulin resistance and LV dysfunction. HFD rats had a higher mortality rate than ND rats, and all treatments reduced the mortality rate in obese-insulin-resistant rats. Although all drugs improved insulin resistance, HRV, LV function as well as reduced cardiac hypertrophy and fibrosis, vildagliptin effectively reduced cardiomyocyte cross-sectional areas more than enalapril and was related to markedly decreased ERK1/2 phosphorylation. In ND rats with MI, metformin neither improved LV ejection fraction nor reduced cardiac fibrosis. The infarct size and transforming growth factor-β expression were not different among groups. In obese-insulin-resistant rats with chronic MI, DPP4 inhibitor vildagliptin exerts better cardioprotection than enalapril in attenuating adverse LV remodeling. PMID:27044778

  16. Acute and training effects of resistance exercise on heart rate variability.

    PubMed

    Kingsley, J Derek; Figueroa, Arturo

    2016-05-01

    Heart rate variability (HRV) has been used as a non-invasive method to evaluate heart rate (HR) regulation by the parasympathetic and sympathetic divisions of the autonomic nervous system. In this review, we discuss the effect of resistance exercise both acutely and after training on HRV in healthy individuals and in those with diseases characterized by autonomic dysfunction, such as hypertension and fibromyalgia. HR recovery after exercise is influenced by parasympathetic reactivation and sympathetic recovery to resting levels. Therefore, examination of HRV in response to acute exercise yields valuable insight into autonomic cardiovascular modulation and possible underlying risk for disease. Acute resistance exercise has shown to decrease cardiac parasympathetic modulation more than aerobic exercise in young healthy adults suggesting an increased risk for cardiovascular dysfunction after resistance exercise. Resistance exercise training appears to have no effect on resting HRV in healthy young adults, while it may improve parasympathetic modulation in middle-aged adults with autonomic dysfunction. Acute resistance exercise appears to decrease parasympathetic activity regardless of age. This review examines the acute and chronic effects of resistance exercise on HRV in young and older adults. PMID:25524332

  17. Regularities in temperature, magnetic field and pressure effect on the resistive properties of magnetic semiconductors

    NASA Astrophysics Data System (ADS)

    Polyakov, P. I.; Kucherenko, S. S.

    2002-08-01

    The influence of hydrostatic pressure, magnetic field and temperature on resistivity behaviour of bulk and film samples La 0.9Mn 1.1O 3 and La 0.56Ca 0.24Mn 1.2O 3 at action of magnetic field and temperature has been analysed. It is established that the maximum of magnetoresistive and the revealed baroresistive, magnetobaroresistive effects coincide at the same temperature Tpp. This temperature is equal to the "metal-semiconductor" phase transition temperature Tms. "Cooling" and "heating" effects of pressure and magnetic field have been revealed. A mutual correspondence of T- P- H (6.2 K, 1 kbar, 2.7 kOe) influence on polycrystalline sample La 0.9Mn 1.1O 3 resistivity has been determined. The linear change of Tms( P) and Tms( H) in La 0.9Mn 1.1O 3, La 0.56Ca 0.24Mn 1.2O 3 resistivity have been found. An importance of the regularities of elastic-deforming correspondence of T- H- P influence on magnetic, resistivity properties, phase transitions and effects was elucidated and explained. An alternating influence of T- H- P and its role in resistivity has been pointed. A correlation between structural, elastic and resistive properties is specified.

  18. Effects of resistance training on cardiovascular health in non-obese active adolescents

    PubMed Central

    Yu, Clare Chung-Wah; McManus, Alison Mary; So, Hung-Kwan; Chook, Ping; Au, Chun-Ting; Li, Albert Martin; Kam, Jack Tat-Chi; So, Raymond Chi-Hung; Lam, Christopher Wai-Kei; Chan, Iris Hiu-Shuen; Sung, Rita Yn-Tz

    2016-01-01

    AIM To determine the benefits of a 10-wk resistance training programme on cardiovascular health in non-obese and active adolescents. METHODS This is a pragmatic randomised controlled intervention. The study was carried out in a Hong Kong Government secondary school. Thirty-eight lean and active boys and girls were randomised to either the resistance training group or the control group. Students in the resistance training group received in-school 10-wk supervised resistance training twice per week, with each session lasting 70 min. Main outcome measures taken before and after training included brachial endothelial dependent flow-mediated dilation, body composition, fasting serum lipids, fasting glucose and insulin, high sensitive C-reactive protein, 24-h ambulatory blood pressure and aerobic fitness. RESULTS The only training related change was in endothelial dependent flow-mediated dilation which increased from 8.5% to 9.8%. A main effect of time and an interaction (P < 0.005) indicated that this improvement was a result of the 10-wk resistance training. Main effects for time (P < 0.05) in a number of anthropometric, metabolic and vascular variables were noted; however, there were no significant interactions indicating the change was more likely an outcome of normal growth and development as opposed to a training effect. CONCLUSION Ten weeks of resistance training in school appears to have some vascular benefit in active, lean children PMID:27610345

  19. Metric Learning to Enhance Hyperspectral Image Segmentation

    NASA Technical Reports Server (NTRS)

    Thompson, David R.; Castano, Rebecca; Bue, Brian; Gilmore, Martha S.

    2013-01-01

    Unsupervised hyperspectral image segmentation can reveal spatial trends that show the physical structure of the scene to an analyst. They highlight borders and reveal areas of homogeneity and change. Segmentations are independently helpful for object recognition, and assist with automated production of symbolic maps. Additionally, a good segmentation can dramatically reduce the number of effective spectra in an image, enabling analyses that would otherwise be computationally prohibitive. Specifically, using an over-segmentation of the image instead of individual pixels can reduce noise and potentially improve the results of statistical post-analysis. In this innovation, a metric learning approach is presented to improve the performance of unsupervised hyperspectral image segmentation. The prototype demonstrations attempt a superpixel segmentation in which the image is conservatively over-segmented; that is, the single surface features may be split into multiple segments, but each individual segment, or superpixel, is ensured to have homogenous mineralogy.

  20. Metric projection for dynamic multiplex networks.

    PubMed

    Jurman, Giuseppe

    2016-08-01

    Evolving multiplex networks are a powerful model for representing the dynamics along time of different phenomena, such as social networks, power grids, biological pathways. However, exploring the structure of the multiplex network time series is still an open problem. Here we propose a two-step strategy to tackle this problem based on the concept of distance (metric) between networks. Given a multiplex graph, first a network of networks is built for each time step, and then a real valued time series is obtained by the sequence of (simple) networks by evaluating the distance from the first element of the series. The effectiveness of this approach in detecting the occurring changes along the original time series is shown on a synthetic example first, and then on the Gulf dataset of political events. PMID:27626089

  1. A Metric Encoding for Bounded Model Checking

    NASA Astrophysics Data System (ADS)

    Pradella, Matteo; Morzenti, Angelo; San Pietro, Pierluigi

    In Bounded Model Checking, both the system model and the checked property are translated into a Boolean formula to be analyzed by a SAT-solver. We introduce a new encoding technique which is particularly optimized for managing quantitative future and past metric temporal operators, typically found in properties of hard real time systems. The encoding is simple and intuitive in principle, but it is made more complex by the presence, typical of the Bounded Model Checking technique, of backward and forward loops used to represent an ultimately periodic infinite domain by a finite structure. We report and comment on the new encoding technique and on an extensive set of experiments carried out to assess its feasibility and effectiveness.

  2. Effects of pefloxacin in multi drug resistant typhoid Fever.

    PubMed

    Ullah, Zakir; Ahmed, Wilayat; Khan, Abdul Matin; Khan, M Farid; Qureshi, Ayaz Hussain; Khan, Ahmed

    2005-10-01

    In 28 children, with bacteriologically and/or serologically diagnosed typhoid fever treated at CMH, Rawalpindi in 2003, first one of the three recommended drugs (viz. chloramphenicol, amoxycillin or co-trimoxazole) was given for 7 days for defervescence to occur. In those who failed to respond a second trial of therapy with one of the other two drugs was initiated, after excluding the first drug. A second failure of therapy was taken as an indication to use pefloxacin singly. Finally, 18 (64.3%) cases responded to chloramphenicol or amoxycillin or co-trimoxazole. Pefloxacin was used in 10 (35.7%) cases. The failure rate of treatment with chloramphenicol was 50%, with amoxycillin 71.4% with co-trimoxazole 75% and 0% with pefloxacin. An analysis of the 28 cases revealed that apart from fever (in 100%), splenomegaly (in 82.1%) was the most important clinical indicator to diagnosis. along with absolute eosinopenia (in 71.4%). There were no major complications, except 2 cases with typhoid hepatitis that responded to choramphenicol and co-trimoxazole, respectively. Blood culture grew Salmonella typhi in 7 cases of which 5 (72%) were multi drug resistant S. typhi. PMID:16380360

  3. The effectiveness of resistive force theory in granular locomotiona)

    NASA Astrophysics Data System (ADS)

    Zhang, Tingnan; Goldman, Daniel I.

    2014-10-01

    Resistive force theory (RFT) is often used to analyze the movement of microscopic organisms swimming in fluids. In RFT, a body is partitioned into infinitesimal segments, each of which generates thrust and experiences drag. Linear superposition of forces from elements over the body allows prediction of swimming velocities and efficiencies. We show that RFT quantitatively describes the movement of animals and robots that move on and within dry granular media (GM), collections of particles that display solid, fluid, and gas-like features. RFT works well when the GM is slightly polydisperse, and in the "frictional fluid" regime such that frictional forces dominate material inertial forces, and when locomotion can be approximated as confined to a plane. Within a given plane (horizontal or vertical) relationships that govern the force versus orientation of an elemental intruder are functionally independent of the granular medium. We use the RFT to explain features of locomotion on and within granular media including kinematic and muscle activation patterns during sand-swimming by a sandfish lizard and a shovel-nosed snake, optimal movement patterns of a Purcell 3-link sand-swimming robot revealed by a geometric mechanics approach, and legged locomotion of small robots on the surface of GM. We close by discussing situations to which granular RFT has not yet been applied (such as inclined granular surfaces), and the advances in the physics of granular media needed to apply RFT in such situations.

  4. Effect of bonded amalgam on the fracture resistance of teeth.

    PubMed

    Eakle, W S; Staninec, M; Lacy, A M

    1992-08-01

    The purpose of this study was to determine whether amalgam bonded to tooth structure with an adhesive resin cement can increase the fracture resistance of restored teeth. Extracted paired upper premolars were prepared for G.V. Black type mesioocclusodistal amalgam restorations. In one tooth of each pair (the experimental group), the enamel walls were etched with phosphoric acid and were painted with an adhesive resin (Panavia), and amalgam was condensed and carved. For the other tooth in each pair (the control group), amalgam was placed in the same manner but was not etched and lined with resin. The teeth were thermocycled and mounted for testing and then were loaded until fracture. A significant difference (p less than 0.05, the paired Student's t-test) was found in the force needed to fracture the bonded amalgam group (70.5 +/- 21.6 kg) compared with that needed to fracture the conventional amalgam group (60.3 +/- 16.8 kg). SEM examination of fractures at the interface occurred predominantly within the resin. PMID:1501170

  5. Distorting the metric fabric of the cognitive map.

    PubMed

    Jeffery, Kate J

    2015-06-01

    Grid cells are neurons whose regularly spaced firing fields form apparently symmetric arrays, or grids, that are thought to collectively provide an environment-independent metric framework for the brain's cognitive map of space. However, two recent studies show that grids are naturally distorted, revealing greater local environment-specific effects than previously recognized. PMID:25882915

  6. ELECTROFISHING IN BOATABLE RIVERS: DOES SAMPLING DESIGN AFFECT BIOASSESSMENT METRICS?

    EPA Science Inventory

    Data were collected from 60 boatable sites using an electrofishing design that permitted comparisons of the effects of designs and distances on fish assemblage metrics. Sites were classified a priori as Run-of-the-River (ROR) or Restricted Flow (RF). Data representing four diff...

  7. Operational Plan for SI (Metric) Transition in Engineering Education.

    ERIC Educational Resources Information Center

    Engineering Education, 1984

    1984-01-01

    Presents guidelines by which all engineering schools under the American Society for Engineering Education umbrella can work together with the American enterprise, through the American National Metric Council, to achieve transition to the International System of Units in a purposeful, cost-effective, and well-coordinated manner. (JN)

  8. In Transit...Making the Change to Metrics.

    ERIC Educational Resources Information Center

    Farnsworth, Briant J.; And Others

    1980-01-01

    Granite School District (Utah) developed a systematic, effective, and cost-efficient teacher inservice program which provides a basic understanding of metrics, materials and methods for direct classroom use, and evaluation of the learning process, through the use of self-contained, three-phase modules for home or school use. (Author/SB)

  9. Metric approach for sound propagation in nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Pereira, E.; Fumeron, S.; Moraes, F.

    2013-02-01

    In the eikonal approach, we describe sound propagation near topological defects of nematic liquid crystals as geodesics of a non-Euclidian manifold endowed with an effective metric tensor. The relation between the acoustics of the medium and this geometrical description is given by Fermat's principle. We calculate the ray trajectories and propose a diffraction experiment to retrieve information about the elastic constants.

  10. Differential resistance of GaN-based laser diodes with and without polarization effect.

    PubMed

    Li, X; Liu, Z S; Zhao, D G; Jiang, D S; Chen, P; Zhu, J J; Yang, J; Le, L C; Liu, W; He, X G; Li, X J; Liang, F; Zhang, L Q; Liu, J Q; Yang, H

    2015-10-10

    In this paper, we used numerical calculation and simulation to investigate the differential resistance of GaN-based laser diodes (LDs) with and without polarization effect. We confirmed the existence of a kink at the vicinity of threshold current in the differential resistance curve of GaN-based LDs and found that the kink polarity can be reversed dependent on the polarization effect. The serial parasitic diodes should be included in the theoretical analysis of the equivalent circuit of the LD devices. We determined that the superposition effects of the n-side, active, and p-side regions of the LDs caused the kink and its polarity. We also found that the differential resistance before and after the threshold was dominated by the p-side region and its gradual reduction is related to an electron overflow into p-side. Finally, we studied the effects of cavity facet reflectivity on the kink. PMID:26479807

  11. Effects of astaxanthin and emodin on the growth, stress resistance and disease resistance of yellow catfish (Pelteobagrus fulvidraco).

    PubMed

    Liu, Fei; Shi, Hong-zhuan; Guo, Qiao-sheng; Yu, Ye-bing; Wang, Ai-ming; Lv, Fu; Shen, Wen-biao

    2016-04-01

    Yellow catfish (Pelteobagrus fulvidraco) has become a commercially important fish species in China and eastern Asia. High-density aquaculture has led to congestion and excessive stress and contributed to bacterial infection outbreaks that have caused high mortality. We investigated the effects of dietary supplementation with astaxanthin and emodin alone and in combination on the growth and stress resistance of yellow catfish. After 60 days of feeding, each group of fish (control, astaxanthin, emodin, and astaxanthin plus emodin (combination) groups) was exposed to acute crowding stress for 24 h, and a subsample of fish from the four groups was challenged with the bacterial septicemia pathogen Proteus mirabilis after the end of the crowding stress experiment. Compared with the control, the astaxanthin and emodin groups showed increases in serum total protein (TP), hepatic superoxide dismutase (SOD) activity and hepatic heat shock proteins 70 (HSP70) mRNA levels at 12 and 24 h after the initiation of crowding stress. The combination group exhibited increases in alanine aminotransferase (ALT) activity, aspartate aminotransferase (AST) activity, serum TP, hepatic SOD activity and hepatic HSP70 mRNA levels within 24 h after the initiation of crowding stress. However, decreases relative to the control were observed in the serum cortisol and glucose contents in the three treatment groups at 12 and 24 h after the initiation of crowding stress, in ALT and AST activity in the astaxanthin and emodin group at 24 h after the initiation of crowding stress, and in the serum lysozyme activity, serum alkaline phosphatase (ALP) activity, and hepatic catalase (CAT) and malondialdehyde (MDA) activity in the combination group at 24 h after the initiation of crowding stress. Additionally, the cumulative mortality after P. mirabilis infection was lower in all three treatment groups (57.00%-70.33%) than in the control (77.67%). Dietary supplementation with astaxanthin and emodin decreased

  12. The synthesis and synergistic antifungal effects of chalcones against drug resistant Candida albicans.

    PubMed

    Wang, Yuan-Hua; Dong, Huai-Huai; Zhao, Fei; Wang, Jie; Yan, Fang; Jiang, Yuan-Ying; Jin, Yong-Sheng

    2016-07-01

    To identify effective and low toxicity synergistic antifungal compounds, 24 derivatives of chalcone were synthesized to restore the effectiveness of fluconazole against fluconazole-resistant Candida albicans. The minimal inhibitory concentration (MIC80) and the fractional inhibitory concentration index (FICI) of the antifungal synergist fluconazole were measured against fluconazole-resistant Candida albicans. This was done via methods established by the clinical and laboratory standards institute (CLSI). Of the synthesized compounds, 2'-hydroxy-4'-methoxychalcone (8) exhibited the most potent in vitro (FICI=0.007) effects. The structure activity relationship of the compounds are then discussed. PMID:27210436

  13. Origin of Self-preservation Effect for Hydrate Decomposition: Coupling of Mass and Heat Transfer Resistances.

    PubMed

    Bai, Dongsheng; Zhang, Diwei; Zhang, Xianren; Chen, Guangjin

    2015-01-01

    Gas hydrates could show an unexpected high stability at conditions out of thermodynamic equilibrium, which is called the self-preservation effect. The mechanism of the effect for methane hydrates is here investigated via molecular dynamics simulations, in which an NVT/E method is introduced to represent different levels of heat transfer resistance. Our simulations suggest a coupling between the mass transfer resistance and heat transfer resistance as the driving mechanism for self-preservation effect. We found that the hydrate is initially melted from the interface, and then a solid-like water layer with temperature-dependent structures is formed next to the hydrate interface that exhibits fractal feature, followed by an increase of mass transfer resistance for the diffusion of methane from hydrate region. Furthermore, our results indicate that heat transfer resistance is a more fundamental factor, since it facilitates the formation of the solid-like layer and hence inhibits the further dissociation of the hydrates. The self-preservation effect is found to be enhanced with the increase of pressure and particularly the decrease of temperature. Kinetic equations based on heat balance calculations is also developed to describe the self-preservation effect, which reproduces our simulation results well and provides an association between microscopic and macroscopic properties. PMID:26423519

  14. Origin of Self-preservation Effect for Hydrate Decomposition: Coupling of Mass and Heat Transfer Resistances

    PubMed Central

    Bai, Dongsheng; Zhang, Diwei; Zhang, Xianren; Chen, Guangjin

    2015-01-01

    Gas hydrates could show an unexpected high stability at conditions out of thermodynamic equilibrium, which is called the self-preservation effect. The mechanism of the effect for methane hydrates is here investigated via molecular dynamics simulations, in which an NVT/E method is introduced to represent different levels of heat transfer resistance. Our simulations suggest a coupling between the mass transfer resistance and heat transfer resistance as the driving mechanism for self-preservation effect. We found that the hydrate is initially melted from the interface, and then a solid-like water layer with temperature-dependent structures is formed next to the hydrate interface that exhibits fractal feature, followed by an increase of mass transfer resistance for the diffusion of methane from hydrate region. Furthermore, our results indicate that heat transfer resistance is a more fundamental factor, since it facilitates the formation of the solid-like layer and hence inhibits the further dissociation of the hydrates. The self-preservation effect is found to be enhanced with the increase of pressure and particularly the decrease of temperature. Kinetic equations based on heat balance calculations is also developed to describe the self-preservation effect, which reproduces our simulation results well and provides an association between microscopic and macroscopic properties. PMID:26423519

  15. Effects of V addition on recrystallization resistance of 7150 aluminum alloy after simulative hot deformation

    SciTech Connect

    Lai, Jing; Shi, Cangji; Chen, X.-Grant

    2014-10-15

    The effects of different V contents (0.01 to 0.19 wt.%) on the recrystallization resistance of 7150 aluminum alloys during post-deformation heat treatment were investigated. The microstructural evolutions at as-cast, as-homogenized conditions and after post-deformation annealing were studied using optical, scanning electron and transmission electron microscopes and using the electron backscattered diffraction technique. The precipitation of Al{sub 21}V{sub 2} dispersoids was observed in alloys containing 0.11 to 0.19 wt.% V after homogenization. The dispersoids were mainly distributed in the dendrite cells, and the precipitate-free zones occurred in the interdendritic regions and near grain boundaries. V addition could significantly enhance the recrystallization resistance during post-deformation annealing, particularly in the presence of a great number of Al{sub 21}V{sub 2} dispersoids. Recrystallized grain growth was effectively restricted because of the dispersoid pinning effect. The alloy containing 0.15 wt.% V exhibited the highest recrystallization resistance amongst all V-containing alloys studied. - Highlights: • Investigated the effect of V level on microstructure and flow stress of 7150 alloys • Characterized microstructures using optical microscopy, SEM, TEM and EBSD • Described the precipitation behavior of V-dispersoids in the dendritic structure • Studied the V effect on recrystallization resistance during post heat treatment • V addition greatly enhanced the recrystallization resistance during annealing.

  16. Antiplatelet Effect of Sequential Administration of Cilostazol in Patients with Acetylsalycilic Acid Resistance

    PubMed Central

    Cakmak, Muzaffer; Demircelik, Bora; Cetin, Mustafa; Cetin, Zehra; Isık, Serhat; Cıcekcıoglu, Hulya; Ulusoy, Feridun Vasfi; Eryonucu, Beyhan

    2016-01-01

    Background Acetylsalicylic acid (ASA) resistance in patients with coronary artery disease is an important medical problem that can affect treatment decision-making and outcomes. Cilostazol has been investigated to determine its effectiveness in patients with acetylsalicylic acid resistance. The aim of this study was to evaluate the antiplatelet efficacy of sequential administration of CLZ in patients with ASA resistance. Methods A total of 180 patients were enrolled in our study. Patients with stable coronary artery disease were first given orally ASA 100 for 10 days, followed by collagen/epinephrine induced closure time (CTCEPI) measurements. Those who were found to be resistant to orally 100 mg of ASA were given orally 300 mg of ASA for an additional 10 days after which we repeated CTCEPI measurements. Those patients with resistance to orally 300 mg ASA were then given CLZ at a daily dose of orally 200 mg for 10 days followed by a final CTCEPI measurement. Results The rate of resistance to 100 mg ASA was 81/180 (45%) compared to a rate of 35/81 (43.2%) with 300 mg ASA. Of the 35 patients found to be resistant to 300 mg ASA, 22 (62.9%) also failed to respond to CLZ treatment. Overall, sequential administration of 300 mg ASA and 200 mg CLZ resulted in a reduction in the number of non-responders from 45% to 12.2%. Conclusions Initiation of CLZ could be of benefit in some patients with ASA-resistance for whom an effective anti-aggregant effect is of clinical importance. PMID:27274173

  17. Structural remodeling of coronary resistance arteries: effects of age and exercise training

    PubMed Central

    Hanna, Mina A.; Taylor, Curtis R.; Chen, Bei; La, Hae-Sun; Maraj, Joshua J.; Kilar, Cody R.; Behnke, Bradley J.; Delp, Michael D.

    2014-01-01

    Age is known to induce remodeling and stiffening of large-conduit arteries; however, little is known of the effects of age on remodeling and mechanical properties of coronary resistance arteries. We employed a rat model of aging to investigate whether 1) age increases wall thickness and stiffness of coronary resistance arteries, and 2) exercise training reverses putative age-induced increases in wall thickness and stiffness of coronary resistance arteries. Young (4 mo) and old (21 mo) Fischer 344 rats remained sedentary or underwent 10 wk of treadmill exercise training. Coronary resistance arteries were isolated for determination of wall-to-lumen ratio, effective elastic modulus, and active and passive responses to changes in intraluminal pressure. Elastin and collagen content of the vascular wall were assessed histologically. Wall-to-lumen ratio increased with age, but this increase was reversed by exercise training. In contrast, age reduced stiffness, and exercise training increased stiffness in coronary resistance arteries from old rats. Myogenic responsiveness was reduced with age and restored by exercise training. Collagen-to-elastin ratio (C/E) of the wall did not change with age and was reduced with exercise training in arteries from old rats. Thus age induces hypertrophic remodeling of the vessel wall and reduces the stiffness and myogenic function of coronary resistance arteries. Exercise training reduces wall-to-lumen ratio, increases wall stiffness, and restores myogenic function in aged coronary resistance arteries. The restorative effect of exercise training on myogenic function of coronary resistance arteries may be due to both changes in vascular smooth muscle phenotype and expression of extracellular matrix proteins. PMID:25059239

  18. Synergistic Effects of Simvastatin and Irinotecan against Colon Cancer Cells with or without Irinotecan Resistance.

    PubMed

    Jang, Hyun Joo; Hong, Eun Mi; Jang, Juah; Choi, Jung Eun; Park, Se Woo; Byun, Hyun Woo; Koh, Dong Hee; Choi, Min Ho; Kae, Sea Hyub; Lee, Jin

    2016-01-01

    Aims. We here investigated whether the combination of simvastatin and irinotecan could induce the synergistic effect on colon cancer cells with or without resistance to irinotecan. Methods. We investigated cell proliferation assay and assessed cell death detection ELISA and caspase-3 activity assay of various concentrations of simvastatin and irinotecan to evaluate the efficacy of drug combination on colon cancer cells with or without irinotecan resistance. Results. The IC50 values of simvastatin alone and irinotecan alone were 115.4 ± 0.14 μM (r = 0.98) and 62.5 ± 0.18 μM (r = 0.98) in HT-29 cells without resistance to irinotecan. The IC50 values of these two drugs were 221.9 ± 0.22 μM (r = 0.98) and 195.9 ± 0.16 μM (r = 0.99), respectively, in HT-29 cell with resistance to irinotecan. The results of combinations of the various concentrations of two drugs showed that combined treatment with irinotecan and simvastatin more efficiently suppressed cell proliferation of HT-29 cells even with resistance to irinotecan as well as without resistance. Furthermore, the combination of simvastatin and irinotecan at 2 : 1 molar ratio showed the best synergistic interaction. Conclusion. Simvastatin could act synergistically with irinotecan to overcome irinotecan resistance of colon cancer. PMID:26966430

  19. Synergistic Effects of Simvastatin and Irinotecan against Colon Cancer Cells with or without Irinotecan Resistance

    PubMed Central

    Jang, Hyun Joo; Hong, Eun Mi; Jang, Juah; Choi, Jung Eun; Park, Se Woo; Byun, Hyun Woo; Koh, Dong Hee; Choi, Min Ho; Kae, Sea Hyub; Lee, Jin

    2016-01-01

    Aims. We here investigated whether the combination of simvastatin and irinotecan could induce the synergistic effect on colon cancer cells with or without resistance to irinotecan. Methods. We investigated cell proliferation assay and assessed cell death detection ELISA and caspase-3 activity assay of various concentrations of simvastatin and irinotecan to evaluate the efficacy of drug combination on colon cancer cells with or without irinotecan resistance. Results. The IC50 values of simvastatin alone and irinotecan alone were 115.4 ± 0.14 μM (r = 0.98) and 62.5 ± 0.18 μM (r = 0.98) in HT-29 cells without resistance to irinotecan. The IC50 values of these two drugs were 221.9 ± 0.22 μM (r = 0.98) and 195.9 ± 0.16 μM (r = 0.99), respectively, in HT-29 cell with resistance to irinotecan. The results of combinations of the various concentrations of two drugs showed that combined treatment with irinotecan and simvastatin more efficiently suppressed cell proliferation of HT-29 cells even with resistance to irinotecan as well as without resistance. Furthermore, the combination of simvastatin and irinotecan at 2 : 1 molar ratio showed the best synergistic interaction. Conclusion. Simvastatin could act synergistically with irinotecan to overcome irinotecan resistance of colon cancer. PMID:26966430

  20. Effects of bronchoconstriction and external resistive loading on the sensation of dyspnea.

    PubMed

    Taguchi, O; Kikuchi, Y; Hida, W; Iwase, N; Satoh, M; Chonan, T; Takishima, T

    1991-12-01

    To determine whether the intensity of dyspnea at a given level of respiratory motor output differs between bronchoconstriction and the presence of an external resistance, we compared the sensation of difficulty in breathing during isocapnic voluntary hyperventilation in six normal subjects. An external resistance of 1.9 cmH2O.1-1.s was applied during both inspiration and expiration. To induce bronchoconstriction, histamine aerosol (5 mg/ml) was inhaled until airway resistance (Raw) increased to a level approximately equal to the subject's control Raw plus the added external resistance. To clarify the role of vagal afferents on the genesis of dyspnea during both forms of obstruction to airflow, the effect of airway anesthesia by lidocaine aerosol inhalation was also examined after histamine and during external resistive loading. The sensation of difficulty in breathing was rated at 30-s intervals on a visual analog scale during isocapnic voluntary hyperpnea, in which the subjects were asked to copy an oscilloscope volume trace obtained previously during progressive hypercapnia. Histamine inhalation significantly increased the intensity of the dyspneic sensation over the equivalent external resistive load at the same levels of ventilation and occlusion pressure during voluntary hyperpnea. Inhaled lidocaine decreased the sensation of dyspnea during bronchoconstriction with no change in Raw, but it did not significantly change the sensation during external resistive loading. These results suggest that afferent vagal activity plays a role in the genesis of dyspnea during bronchoconstriction. PMID:1778911