WorldWideScience

Sample records for dependent variables include

  1. Including Children Dependent on Ventilators in School.

    Science.gov (United States)

    Levine, Jack M.

    1996-01-01

    Guidelines for including ventilator-dependent children in school are offered, based on experience with six such students at a New York State school. Guidelines stress adherence to the medical management plan, the school-family partnership, roles of the social worker and psychologist, orientation, transportation, classroom issues, and steps toward…

  2. Reward-dependent modulation of movement variability.

    Science.gov (United States)

    Pekny, Sarah E; Izawa, Jun; Shadmehr, Reza

    2015-03-04

    Movement variability is often considered an unwanted byproduct of a noisy nervous system. However, variability can signal a form of implicit exploration, indicating that the nervous system is intentionally varying the motor commands in search of actions that yield the greatest success. Here, we investigated the role of the human basal ganglia in controlling reward-dependent motor variability as measured by trial-to-trial changes in performance during a reaching task. We designed an experiment in which the only performance feedback was success or failure and quantified how reach variability was modulated as a function of the probability of reward. In healthy controls, reach variability increased as the probability of reward decreased. Control of variability depended on the history of past rewards, with the largest trial-to-trial changes occurring immediately after an unrewarded trial. In contrast, in participants with Parkinson's disease, a known example of basal ganglia dysfunction, reward was a poor modulator of variability; that is, the patients showed an impaired ability to increase variability in response to decreases in the probability of reward. This was despite the fact that, after rewarded trials, reach variability in the patients was comparable to healthy controls. In summary, we found that movement variability is partially a form of exploration driven by the recent history of rewards. When the function of the human basal ganglia is compromised, the reward-dependent control of movement variability is impaired, particularly affecting the ability to increase variability after unsuccessful outcomes. Copyright © 2015 the authors 0270-6474/15/354015-10$15.00/0.

  3. Problems Identifying Independent and Dependent Variables

    Science.gov (United States)

    Leatham, Keith R.

    2012-01-01

    This paper discusses one step from the scientific method--that of identifying independent and dependent variables--from both scientific and mathematical perspectives. It begins by analyzing an episode from a middle school mathematics classroom that illustrates the need for students and teachers alike to develop a robust understanding of…

  4. Benford's law and continuous dependent random variables

    Science.gov (United States)

    Becker, Thealexa; Burt, David; Corcoran, Taylor C.; Greaves-Tunnell, Alec; Iafrate, Joseph R.; Jing, Joy; Miller, Steven J.; Porfilio, Jaclyn D.; Ronan, Ryan; Samranvedhya, Jirapat; Strauch, Frederick W.; Talbut, Blaine

    2018-01-01

    Many mathematical, man-made and natural systems exhibit a leading-digit bias, where a first digit (base 10) of 1 occurs not 11% of the time, as one would expect if all digits were equally likely, but rather 30%. This phenomenon is known as Benford's Law. Analyzing which datasets adhere to Benford's Law and how quickly Benford behavior sets in are the two most important problems in the field. Most previous work studied systems of independent random variables, and relied on the independence in their analyses. Inspired by natural processes such as particle decay, we study the dependent random variables that emerge from models of decomposition of conserved quantities. We prove that in many instances the distribution of lengths of the resulting pieces converges to Benford behavior as the number of divisions grow, and give several conjectures for other fragmentation processes. The main difficulty is that the resulting random variables are dependent. We handle this by using tools from Fourier analysis and irrationality exponents to obtain quantified convergence rates as well as introducing and developing techniques to measure and control the dependencies. The construction of these tools is one of the major motivations of this work, as our approach can be applied to many other dependent systems. As an example, we show that the n ! entries in the determinant expansions of n × n matrices with entries independently drawn from nice random variables converges to Benford's Law.

  5. Age dependant somatometric and cephalometric variables among ...

    African Journals Online (AJOL)

    Background: The process of growth passes through stages of developmental processes. This stage is the age. Age is known to affect many parameters in the body and this includes somatometric and cephalometric variables. Methods: The study was conducted with a total number of 409 students of university of Jos, ...

  6. XFEL OSCILLATOR SIMULATION INCLUDING ANGLE-DEPENDENT CRYSTAL REFLECTIVITY

    International Nuclear Information System (INIS)

    Fawley, William; Lindberg, Ryan; Kim, K.-J.; Shvyd'ko, Yuri

    2010-01-01

    The oscillator package within the GINGER FEL simulation code has now been extended to include angle-dependent reflectivity properties of Bragg crystals. Previously, the package was modified to include frequencydependent reflectivity in order to model x-ray FEL oscillators from start-up from shot noise through to saturation. We present a summary of the algorithms used for modeling the crystal reflectivity and radiation propagation outside the undulator, discussing various numerical issues relevant to the domain of high Fresnel number and efficient Hankel transforms. We give some sample XFEL-O simulation results obtained with the angle-dependent reflectivity model, with particular attention directed to the longitudinal and transverse coherence of the radiation output.

  7. Impact of including surface currents on simulation of Indian Ocean variability with the POAMA coupled model

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Mei; Wang, Guomin; Hendon, Harry H.; Alves, Oscar [Bureau of Meteorology, Centre for Australian Weather and Climate Research, Melbourne (Australia)

    2011-04-15

    Impacts on the coupled variability of the Indo-Pacific by including the effects of surface currents on surface stress are explored in four extended integrations of an experimental version of the Bureau of Meteorology's coupled seasonal forecast model POAMA. The first pair of simulations differs only in their treatment of momentum coupling: one version includes the effects of surface currents on the surface stress computation and the other does not. The version that includes the effect of surface currents has less mean-state bias in the equatorial Pacific cold tongue but produces relatively weak coupled variability in the Tropics, especially that related to the Indian Ocean dipole (IOD) and El Nino/Southern Oscillation (ENSO). The version without the effects of surface currents has greater bias in the Pacific cold tongue but stronger IOD and ENSO variability. In order to diagnose the role of changes in local coupling from changes in remote forcing by ENSO for causing changes in IOD variability, a second set of simulations is conducted where effects of surface currents are included only in the Indian Ocean and only in the Pacific Ocean. IOD variability is found to be equally reduced by inclusion of the local effects of surface currents in the Indian Ocean and by the reduction of ENSO variability as a result of including effects of surface currents in the Pacific. Some implications of these results for predictability of the IOD and its dependence on ENSO, and for ocean subsurface data assimilation are discussed. (orig.)

  8. Maximal Inequalities for Dependent Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jorgensen, Jorgen

    2016-01-01

    Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X-k. Then a......Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X......-k. Then a maximal inequality gives conditions ensuring that the maximal partial sum M-n = max(1) (...

  9. Future-dependent Flow Policies with Prophetic Variables

    DEFF Research Database (Denmark)

    Li, Ximeng; Nielson, Flemming; Nielson, Hanne Riis

    2016-01-01

    future-dependent flow policies- policies that can depend on not only the current values of variables, but also their final values. The final values are referred to using what we call prophetic variables, just as the initial values can be referenced using logical variables in Hoare logic. We develop...... and enforce a notion of future-dependent security for open systems, in the spirit of "non-deducibility on strategies". We also illustrate our approach in scenarios where future-dependency has advantages over present-dependency and avoids mixtures of upgradings and downgradings....

  10. Validity of a Residualized Dependent Variable after Pretest Covariance Adjustments: Still the Same Variable?

    Science.gov (United States)

    Nimon, Kim; Henson, Robin K.

    2015-01-01

    The authors empirically examined whether the validity of a residualized dependent variable after covariance adjustment is comparable to that of the original variable of interest. When variance of a dependent variable is removed as a result of one or more covariates, the residual variance may not reflect the same meaning. Using the pretest-posttest…

  11. A Case for Including Atmospheric Thermodynamic Variables in Wind Turbine Fatigue Loading Parameter Identification

    International Nuclear Information System (INIS)

    Kelley, Neil D.

    1999-01-01

    This paper makes the case for establishing efficient predictor variables for atmospheric thermodynamics that can be used to statistically correlate the fatigue accumulation seen on wind turbines. Recently, two approaches to this issue have been reported. One uses multiple linear-regression analysis to establish the relative causality between a number of predictors related to the turbulent inflow and turbine loads. The other approach, using many of the same predictors, applies the technique of principal component analysis. An examination of the ensemble of predictor variables revealed that they were all kinematic in nature; i.e., they were only related to the description of the velocity field. Boundary-layer turbulence dynamics depends upon a description of the thermal field and its interaction with the velocity distribution. We used a series of measurements taken within a multi-row wind farm to demonstrate the need to include atmospheric thermodynamic variables as well as velocity-related ones in the search for efficient turbulence loading predictors in various turbine-operating environments. Our results show that a combination of vertical stability and hub-height mean shearing stress variables meet this need over a period of 10 minutes

  12. Fixed transaction costs and modelling limited dependent variables

    NARCIS (Netherlands)

    Hempenius, A.L.

    1994-01-01

    As an alternative to the Tobit model, for vectors of limited dependent variables, I suggest a model, which follows from explicitly using fixed costs, if appropriate of course, in the utility function of the decision-maker.

  13. Hoeffding’s Inequality for Sums of Dependent Random Variables

    Czech Academy of Sciences Publication Activity Database

    Pelekis, Christos; Ramon, J.

    2017-01-01

    Roč. 14, č. 6 (2017), č. článku 243. ISSN 1660-5446 Institutional support: RVO:67985807 Keywords : dependent random variables * Hoeffding’s inequality * k-wise independent random variables * martingale differences Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.868, year: 2016

  14. Statistical Dependence of Pipe Breaks on Explanatory Variables

    Directory of Open Access Journals (Sweden)

    Patricia Gómez-Martínez

    2017-02-01

    Full Text Available Aging infrastructure is the main challenge currently faced by water suppliers. Estimation of assets lifetime requires reliable criteria to plan assets repair and renewal strategies. To do so, pipe break prediction is one of the most important inputs. This paper analyzes the statistical dependence of pipe breaks on explanatory variables, determining their optimal combination and quantifying their influence on failure prediction accuracy. A large set of registered data from Madrid water supply network, managed by Canal de Isabel II, has been filtered, classified and studied. Several statistical Bayesian models have been built and validated from the available information with a technique that combines reference periods of time as well as geographical location. Statistical models of increasing complexity are built from zero up to five explanatory variables following two approaches: a set of independent variables or a combination of two joint variables plus an additional number of independent variables. With the aim of finding the variable combination that provides the most accurate prediction, models are compared following an objective validation procedure based on the model skill to predict the number of pipe breaks in a large set of geographical locations. As expected, model performance improves as the number of explanatory variables increases. However, the rate of improvement is not constant. Performance metrics improve significantly up to three variables, but the tendency is softened for higher order models, especially in trunk mains where performance is reduced. Slight differences are found between trunk mains and distribution lines when selecting the most influent variables and models.

  15. How a dependent's variable non-randomness affects taper equation ...

    African Journals Online (AJOL)

    In order to apply the least squares method in regression analysis, the values of the dependent variable Y should be random. In an example of regression analysis linear and nonlinear taper equations, which estimate the diameter of the tree dhi at any height of the tree hi, were compared. For each tree the diameter at the ...

  16. The discovery of timescale-dependent color variability of quasars

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yu-Han; Wang, Jun-Xian; Chen, Xiao-Yang [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zheng, Zhen-Ya, E-mail: sunyh92@mail.ustc.edu.cn, E-mail: jxw@ustc.edu.cn [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)

    2014-09-01

    Quasars are variable on timescales from days to years in UV/optical and generally appear bluer while they brighten. The physics behind the variations in fluxes and colors remains unclear. Using Sloan Digital Sky Survey g- and r-band photometric monitoring data for quasars in Stripe 82, we find that although the flux variation amplitude increases with timescale, the color variability exhibits the opposite behavior. The color variability of quasars is prominent at timescales as short as ∼10 days, but gradually reduces toward timescales up to years. In other words, the variable emission at shorter timescales is bluer than that at longer timescales. This timescale dependence is clearly and consistently detected at all redshifts from z = 0 to 3.5; thus, it cannot be due to contamination to broadband photometry from emission lines that do not respond to fast continuum variations. The discovery directly rules out the possibility that simply attributes the color variability to contamination from a non-variable redder component such as the host galaxy. It cannot be interpreted as changes in global accretion rate either. The thermal accretion disk fluctuation model is favored in the sense that fluctuations in the inner, hotter region of the disk are responsible for short-term variations, while longer-term and stronger variations are expected from the larger and cooler disk region. An interesting implication is that one can use quasar variations at different timescales to probe disk emission at different radii.

  17. Quadratic time dependent Hamiltonians and separation of variables

    International Nuclear Information System (INIS)

    Anzaldo-Meneses, A.

    2017-01-01

    Time dependent quantum problems defined by quadratic Hamiltonians are solved using canonical transformations. The Green’s function is obtained and a comparison with the classical Hamilton–Jacobi method leads to important geometrical insights like exterior differential systems, Monge cones and time dependent Gaussian metrics. The Wei–Norman approach is applied using unitary transformations defined in terms of generators of the associated Lie groups, here the semi-direct product of the Heisenberg group and the symplectic group. A new explicit relation for the unitary transformations is given in terms of a finite product of elementary transformations. The sequential application of adequate sets of unitary transformations leads naturally to a new separation of variables method for time dependent Hamiltonians, which is shown to be related to the Inönü–Wigner contraction of Lie groups. The new method allows also a better understanding of interacting particles or coupled modes and opens an alternative way to analyze topological phases in driven systems. - Highlights: • Exact unitary transformation reducing time dependent quadratic quantum Hamiltonian to zero. • New separation of variables method and simultaneous uncoupling of modes. • Explicit examples of transformations for one to four dimensional problems. • New general evolution equation for quadratic form in the action, respectively Green’s function.

  18. Quadratic time dependent Hamiltonians and separation of variables

    Science.gov (United States)

    Anzaldo-Meneses, A.

    2017-06-01

    Time dependent quantum problems defined by quadratic Hamiltonians are solved using canonical transformations. The Green's function is obtained and a comparison with the classical Hamilton-Jacobi method leads to important geometrical insights like exterior differential systems, Monge cones and time dependent Gaussian metrics. The Wei-Norman approach is applied using unitary transformations defined in terms of generators of the associated Lie groups, here the semi-direct product of the Heisenberg group and the symplectic group. A new explicit relation for the unitary transformations is given in terms of a finite product of elementary transformations. The sequential application of adequate sets of unitary transformations leads naturally to a new separation of variables method for time dependent Hamiltonians, which is shown to be related to the Inönü-Wigner contraction of Lie groups. The new method allows also a better understanding of interacting particles or coupled modes and opens an alternative way to analyze topological phases in driven systems.

  19. Taylor Series Trajectory Calculations Including Oblateness Effects and Variable Atmospheric Density

    Science.gov (United States)

    Scott, James R.

    2011-01-01

    Taylor series integration is implemented in NASA Glenn's Spacecraft N-body Analysis Program, and compared head-to-head with the code's existing 8th- order Runge-Kutta Fehlberg time integration scheme. This paper focuses on trajectory problems that include oblateness and/or variable atmospheric density. Taylor series is shown to be significantly faster and more accurate for oblateness problems up through a 4x4 field, with speedups ranging from a factor of 2 to 13. For problems with variable atmospheric density, speedups average 24 for atmospheric density alone, and average 1.6 to 8.2 when density and oblateness are combined.

  20. Exercise training improves heart rate variability after methamphetamine dependency.

    Science.gov (United States)

    Dolezal, Brett Andrew; Chudzynski, Joy; Dickerson, Daniel; Mooney, Larissa; Rawson, Richard A; Garfinkel, Alan; Cooper, Christopher B

    2014-06-01

    Heart rate variability (HRV) reflects a healthy autonomic nervous system and is increased with physical training. Methamphetamine dependence (MD) causes autonomic dysfunction and diminished HRV. We compared recently abstinent methamphetamine-dependent participants with age-matched, drug-free controls (DF) and also investigated whether HRV can be improved with exercise training in the methamphetamine-dependent participants. In 50 participants (MD = 28; DF = 22), resting heart rate (HR; R-R intervals) was recorded over 5 min while seated using a monitor affixed to a chest strap. Previously reported time domain (SDNN, RMSSD, pNN50) and frequency domain (LFnu, HFnu, LF/HF) parameters of HRV were calculated with customized software. MD were randomized to thrice-weekly exercise training (ME = 14) or equal attention without training (MC = 14) over 8 wk. Groups were compared using paired and unpaired t-tests. Statistical significance was set at P ≤ 0.05. Participant characteristics were matched between groups (mean ± SD): age = 33 ± 6 yr; body mass = 82.7 ± 12 kg, body mass index = 26.8 ± 4.1 kg·min. Compared with DF, the MD group had significantly higher resting HR (P HRV indices were similar between ME and MC groups. However, after training, the ME group significantly (all P HRV, based on several conventional indices, was diminished in recently abstinent, methamphetamine-dependent individuals. Moreover, physical training yielded a marked increase in HRV, representing increased vagal modulation or improved autonomic balance.

  1. Value of Construction Company and its Dependence on Significant Variables

    Science.gov (United States)

    Vítková, E.; Hromádka, V.; Ondrušková, E.

    2017-10-01

    The paper deals with the value of the construction company assessment respecting usable approaches and determinable variables. The reasons of the value of the construction company assessment are different, but the most important reasons are the sale or the purchase of the company, the liquidation of the company, the fusion of the company with another subject or the others. According the reason of the value assessment it is possible to determine theoretically different approaches for valuation, mainly it concerns about the yield method of valuation and the proprietary method of valuation. Both approaches are dependant of detailed input variables, which quality will influence the final assessment of the company´s value. The main objective of the paper is to suggest, according to the analysis, possible ways of input variables, mainly in the form of expected cash-flows or the profit, determination. The paper is focused mainly on methods of time series analysis, regression analysis and mathematical simulation utilization. As the output, the results of the analysis on the case study will be demonstrated.

  2. Direct-phase-variable model of a synchronous reluctance motor including all slot and winding harmonics

    International Nuclear Information System (INIS)

    Obe, Emeka S.; Binder, A.

    2011-01-01

    A detailed model in direct-phase variables of a synchronous reluctance motor operating at mains voltage and frequency is presented. The model includes the stator and rotor slot openings, the actual winding layout and the reluctance rotor geometry. Hence, all mmf and permeance harmonics are taken into account. It is seen that non-negligible harmonics introduced by slots are present in the inductances computed by the winding function procedure. These harmonics are usually ignored in d-q models. The machine performance is simulated in the stator reference frame to depict the difference between this new direct-phase model including all harmonics and the conventional rotor reference frame d-q model. Saturation is included by using a polynomial fitting the variation of d-axis inductance with stator current obtained by finite-element software FEMAG DC (registered) . The detailed phase-variable model can yield torque pulsations comparable to those obtained from finite elements while the d-q model cannot.

  3. How to include the variability of TMS responses in simulations: a speech mapping case study

    Science.gov (United States)

    De Geeter, N.; Lioumis, P.; Laakso, A.; Crevecoeur, G.; Dupré, L.

    2016-11-01

    When delivered over a specific cortical site, TMS can temporarily disrupt the ongoing process in that area. This allows mapping of speech-related areas for preoperative evaluation purposes. We numerically explore the observed variability of TMS responses during a speech mapping experiment performed with a neuronavigation system. We selected four cases with very small perturbations in coil position and orientation. In one case (E) a naming error occurred, while in the other cases (NEA, B, C) the subject appointed the images as smoothly as without TMS. A realistic anisotropic head model was constructed of the subject from T1-weighted and diffusion-weighted MRI. The induced electric field distributions were computed, associated to the coil parameters retrieved from the neuronavigation system. Finally, the membrane potentials along relevant white matter fibre tracts, extracted from DTI-based tractography, were computed using a compartmental cable equation. While only minor differences could be noticed between the induced electric field distributions of the four cases, computing the corresponding membrane potentials revealed different subsets of tracts were activated. A single tract was activated for all coil positions. Another tract was only triggered for case E. NEA induced action potentials in 13 tracts, while NEB stimulated 11 tracts and NEC one. The calculated results are certainly sensitive to the coil specifications, demonstrating the observed variability in this study. However, even though a tract connecting Broca’s with Wernicke’s area is only triggered for the error case, further research is needed on other study cases and on refining the neural model with synapses and network connections. Case- and subject-specific modelling that includes both electromagnetic fields and neuronal activity enables demonstration of the variability in TMS experiments and can capture the interaction with complex neural networks.

  4. Human phoneme recognition depending on speech-intrinsic variability.

    Science.gov (United States)

    Meyer, Bernd T; Jürgens, Tim; Wesker, Thorsten; Brand, Thomas; Kollmeier, Birger

    2010-11-01

    The influence of different sources of speech-intrinsic variation (speaking rate, effort, style and dialect or accent) on human speech perception was investigated. In listening experiments with 16 listeners, confusions of consonant-vowel-consonant (CVC) and vowel-consonant-vowel (VCV) sounds in speech-weighted noise were analyzed. Experiments were based on the OLLO logatome speech database, which was designed for a man-machine comparison. It contains utterances spoken by 50 speakers from five dialect/accent regions and covers several intrinsic variations. By comparing results depending on intrinsic and extrinsic variations (i.e., different levels of masking noise), the degradation induced by variabilities can be expressed in terms of the SNR. The spectral level distance between the respective speech segment and the long-term spectrum of the masking noise was found to be a good predictor for recognition rates, while phoneme confusions were influenced by the distance to spectrally close phonemes. An analysis based on transmitted information of articulatory features showed that voicing and manner of articulation are comparatively robust cues in the presence of intrinsic variations, whereas the coding of place is more degraded. The database and detailed results have been made available for comparisons between human speech recognition (HSR) and automatic speech recognizers (ASR).

  5. Motivation as an independent and a dependent variable in medical education: a review of the literature.

    Science.gov (United States)

    Kusurkar, R A; Ten Cate, Th J; van Asperen, M; Croiset, G

    2011-01-01

    Motivation in learning behaviour and education is well-researched in general education, but less in medical education. To answer two research questions, 'How has the literature studied motivation as either an independent or dependent variable? How is motivation useful in predicting and understanding processes and outcomes in medical education?' in the light of the Self-determination Theory (SDT) of motivation. A literature search performed using the PubMed, PsycINFO and ERIC databases resulted in 460 articles. The inclusion criteria were empirical research, specific measurement of motivation and qualitative research studies which had well-designed methodology. Only studies related to medical students/school were included. Findings of 56 articles were included in the review. Motivation as an independent variable appears to affect learning and study behaviour, academic performance, choice of medicine and specialty within medicine and intention to continue medical study. Motivation as a dependent variable appears to be affected by age, gender, ethnicity, socioeconomic status, personality, year of medical curriculum and teacher and peer support, all of which cannot be manipulated by medical educators. Motivation is also affected by factors that can be influenced, among which are, autonomy, competence and relatedness, which have been described as the basic psychological needs important for intrinsic motivation according to SDT. Motivation is an independent variable in medical education influencing important outcomes and is also a dependent variable influenced by autonomy, competence and relatedness. This review finds some evidence in support of the validity of SDT in medical education.

  6. Time-dependent shock acceleration of energetic electrons including synchrotron losses

    International Nuclear Information System (INIS)

    Fritz, K.; Webb, G.M.

    1990-01-01

    The present investigation of the time-dependent particle acceleration problem in strong shocks, including synchrotron radiation losses, solves the transport equation analytically by means of Laplace transforms. The particle distribution thus obtained is then transformed numerically into real space for the cases of continuous and impulsive injections of particles at the shock. While in the continuous case the steady-state spectrum undergoes evolution, impulsive injection is noted to yield such unpredicted features as a pile-up of high-energy particles or a steep power-law with time-dependent spectral index. The time-dependent calculations reveal varying spectral shapes and more complex features for the higher energies which may be useful in the interpretation of outburst spectra. 33 refs

  7. Variability of interconnected wind plants: correlation length and its dependence on variability time scale

    Science.gov (United States)

    St. Martin, Clara M.; Lundquist, Julie K.; Handschy, Mark A.

    2015-04-01

    The variability in wind-generated electricity complicates the integration of this electricity into the electrical grid. This challenge steepens as the percentage of renewably-generated electricity on the grid grows, but variability can be reduced by exploiting geographic diversity: correlations between wind farms decrease as the separation between wind farms increases. But how far is far enough to reduce variability? Grid management requires balancing production on various timescales, and so consideration of correlations reflective of those timescales can guide the appropriate spatial scales of geographic diversity grid integration. To answer ‘how far is far enough,’ we investigate the universal behavior of geographic diversity by exploring wind-speed correlations using three extensive datasets spanning continents, durations and time resolution. First, one year of five-minute wind power generation data from 29 wind farms span 1270 km across Southeastern Australia (Australian Energy Market Operator). Second, 45 years of hourly 10 m wind-speeds from 117 stations span 5000 km across Canada (National Climate Data Archive of Environment Canada). Finally, four years of five-minute wind-speeds from 14 meteorological towers span 350 km of the Northwestern US (Bonneville Power Administration). After removing diurnal cycles and seasonal trends from all datasets, we investigate dependence of correlation length on time scale by digitally high-pass filtering the data on 0.25-2000 h timescales and calculating correlations between sites for each high-pass filter cut-off. Correlations fall to zero with increasing station separation distance, but the characteristic correlation length varies with the high-pass filter applied: the higher the cut-off frequency, the smaller the station separation required to achieve de-correlation. Remarkable similarities between these three datasets reveal behavior that, if universal, could be particularly useful for grid management. For high

  8. How to include frequency dependent complex permeability Into SPICE models to improve EMI filters design?

    Science.gov (United States)

    Sixdenier, Fabien; Yade, Ousseynou; Martin, Christian; Bréard, Arnaud; Vollaire, Christian

    2018-05-01

    Electromagnetic interference (EMI) filters design is a rather difficult task where engineers have to choose adequate magnetic materials, design the magnetic circuit and choose the size and number of turns. The final design must achieve the attenuation requirements (constraints) and has to be as compact as possible (goal). Alternating current (AC) analysis is a powerful tool to predict global impedance or attenuation of any filter. However, AC analysis are generally performed without taking into account the frequency-dependent complex permeability behaviour of soft magnetic materials. That's why, we developed two frequency-dependent complex permeability models able to be included into SPICE models. After an identification process, the performances of each model are compared to measurements made on a realistic EMI filter prototype in common mode (CM) and differential mode (DM) to see the benefit of the approach. Simulation results are in good agreement with the measured ones especially in the middle frequency range.

  9. A thermal conductivity model for nanofluids including effect of the temperature-dependent interfacial layer

    International Nuclear Information System (INIS)

    Sitprasert, Chatcharin; Dechaumphai, Pramote; Juntasaro, Varangrat

    2009-01-01

    The interfacial layer of nanoparticles has been recently shown to have an effect on the thermal conductivity of nanofluids. There is, however, still no thermal conductivity model that includes the effects of temperature and nanoparticle size variations on the thickness and consequently on the thermal conductivity of the interfacial layer. In the present work, the stationary model developed by Leong et al. (J Nanopart Res 8:245-254, 2006) is initially modified to include the thermal dispersion effect due to the Brownian motion of nanoparticles. This model is called the 'Leong et al.'s dynamic model'. However, the Leong et al.'s dynamic model over-predicts the thermal conductivity of nanofluids in the case of the flowing fluid. This suggests that the enhancement in the thermal conductivity of the flowing nanofluids due to the increase in temperature does not come from the thermal dispersion effect. It is more likely that the enhancement in heat transfer of the flowing nanofluids comes from the temperature-dependent interfacial layer effect. Therefore, the Leong et al.'s stationary model is again modified to include the effect of temperature variation on the thermal conductivity of the interfacial layer for different sizes of nanoparticles. This present model is then evaluated and compared with the other thermal conductivity models for the turbulent convective heat transfer in nanofluids along a uniformly heated tube. The results show that the present model is more general than the other models in the sense that it can predict both the temperature and the volume fraction dependence of the thermal conductivity of nanofluids for both non-flowing and flowing fluids. Also, it is found to be more accurate than the other models due to the inclusion of the effect of the temperature-dependent interfacial layer. In conclusion, the present model can accurately predict the changes in thermal conductivity of nanofluids due to the changes in volume fraction and temperature for

  10. Solute transport modelling with the variable temporally dependent ...

    Indian Academy of Sciences (India)

    Pintu Das

    2018-02-07

    Feb 7, 2018 ... in a finite domain with time-dependent sources and dis- tance-dependent dispersivities. Also, existing ... solute transport in multi-layered porous media using gen- eralized integral transform technique with .... methods for solving the fractional reaction-–sub-diffusion equation. To solve numerically the Eqs.

  11. Modeling of Temperature-Dependent Noise in Silicon Nanowire FETs including Self-Heating Effects

    Directory of Open Access Journals (Sweden)

    P. Anandan

    2014-01-01

    Full Text Available Silicon nanowires are leading the CMOS era towards the downsizing limit and its nature will be effectively suppress the short channel effects. Accurate modeling of thermal noise in nanowires is crucial for RF applications of nano-CMOS emerging technologies. In this work, a perfect temperature-dependent model for silicon nanowires including the self-heating effects has been derived and its effects on device parameters have been observed. The power spectral density as a function of thermal resistance shows significant improvement as the channel length decreases. The effects of thermal noise including self-heating of the device are explored. Moreover, significant reduction in noise with respect to channel thermal resistance, gate length, and biasing is analyzed.

  12. Refitting density dependent relativistic model parameters including Center-of-Mass corrections

    International Nuclear Information System (INIS)

    Avancini, Sidney S.; Marinelli, Jose R.; Carlson, Brett Vern

    2011-01-01

    Full text: Relativistic mean field models have become a standard approach for precise nuclear structure calculations. After the seminal work of Serot and Walecka, which introduced a model Lagrangian density where the nucleons interact through the exchange of scalar and vector mesons, several models were obtained through its generalization, including other meson degrees of freedom, non-linear meson interactions, meson-meson interactions, etc. More recently density dependent coupling constants were incorporated into the Walecka-like models, which are then extensively used. In particular, for these models a connection with the density functional theory can be established. Due to the inherent difficulties presented by field theoretical models, only the mean field approximation is used for the solution of these models. In order to calculate finite nuclei properties in the mean field approximation, a reference set has to be fixed and therefore the translational symmetry is violated. It is well known that in such case spurious effects due to the center-of-mass (COM) motion are present, which are more pronounced for light nuclei. In a previous work we have proposed a technique based on the Pierls-Yoccoz projection operator applied to the mean-field relativistic solution, in order to project out spurious COM contributions. In this work we obtain a new fitting for the density dependent parameters of a density dependent hadronic model, taking into account the COM corrections. Our fitting is obtained taking into account the charge radii and binding energies for He 4 , O 16 , Ca 40 , Ca 48 , Ni 56 , Ni 68 , Sn 100 , Sn 132 and Pb 208 . We show that the nuclear observables calculated using our fit are of a quality comparable to others that can be found in the literature, with the advantage that now a translational invariant many-body wave function is at our disposal. (author)

  13. A temperature dependent cyclic plasticity model for hot work tool steel including particle coarsening

    Science.gov (United States)

    Jilg, Andreas; Seifert, Thomas

    2018-05-01

    Hot work tools are subjected to complex thermal and mechanical loads during hot forming processes. Locally, the stresses can exceed the material's yield strength in highly loaded areas as e.g. in small radii in die cavities. To sustain the high loads, the hot forming tools are typically made of martensitic hot work steels. While temperatures for annealing of the tool steels usually lie in the range between 400 and 600 °C, the steels may experience even higher temperatures during hot forming, resulting in softening of the material due to coarsening of strengthening particles. In this paper, a temperature dependent cyclic plasticity model for the martensitic hot work tool steel 1.2367 (X38CrMoV5-3) is presented that includes softening due to particle coarsening and that can be applied in finite-element calculations to assess the effect of softening on the thermomechanical fatigue life of hot work tools. To this end, a kinetic model for the evolution of the mean size of secondary carbides based on Ostwald ripening is coupled with a cyclic plasticity model with kinematic hardening. Mechanism-based relations are developed to describe the dependency of the mechanical properties on carbide size and temperature. The material properties of the mechanical and kinetic model are determined on the basis of tempering hardness curves as well as monotonic and cyclic tests.

  14. On Direction of Dependence in Latent Variable Contexts

    Science.gov (United States)

    von Eye, Alexander; Wiedermann, Wolfgang

    2014-01-01

    Approaches to determining direction of dependence in nonexperimental data are based on the relation between higher-than second-order moments on one side and correlation and regression models on the other. These approaches have experienced rapid development and are being applied in contexts such as research on partner violence, attention deficit…

  15. Inlet-engine matching for SCAR including application of a bicone variable geometry inlet

    Science.gov (United States)

    Wasserbauer, J. F.; Gerstenmaier, W. H.

    1978-01-01

    Airflow characteristics of variable cycle engines (VCE) designed for Mach 2.32 can have transonic airflow requirements as high as 1.6 times the cruise airflow. This is a formidable requirement for conventional, high performance, axisymmetric, translating centerbody mixed compression inlets. An alternate inlet is defined, where the second cone of a two cone center body collapses to the initial cone angle to provide a large off-design airflow capability, and incorporates modest centerbody translation to minimize spillage drag. Estimates of transonic spillage drag are competitive with those of conventional translating centerbody inlets. The inlet's cruise performance exhibits very low bleed requirements with good recovery and high angle of attack capability.

  16. Spatial modelling of marine organisms in Forsmark and Oskarshamn. Including calculation of physical predictor variables

    Energy Technology Data Exchange (ETDEWEB)

    Carlen, Ida; Nikolopoulos, Anna; Isaeus, Martin (AquaBiota Water Research, Stockholm (SE))

    2007-06-15

    GIS grids (maps) of marine parameters were created using point data from previous site investigations in the Forsmark and Oskarshamn areas. The proportion of global radiation reaching the sea bottom in Forsmark and Oskarshamn was calculated in ArcView, using Secchi depth measurements and the digital elevation models for the respective area. The number of days per year when the incoming light exceeds 5 MJ/m2 at the bottom was then calculated using the result of the previous calculations together with measured global radiation. Existing modelled grid-point data on bottom and pelagic temperature for Forsmark were interpolated to create surface covering grids. Bottom and pelagic temperature grids for Oskarshamn were calculated using point measurements to achieve yearly averages for a few points and then using regressions with existing grids to create new maps. Phytoplankton primary production in Forsmark was calculated using point measurements of chlorophyll and irradiance, and a regression with a modelled grid of Secchi depth. Distribution of biomass of macrophyte communities in Forsmark and Oskarshamn was calculated using spatial modelling in GRASP, based on field data from previous surveys. Physical parameters such as those described above were used as predictor variables. Distribution of biomass of different functional groups of fish in Forsmark was calculated using spatial modelling based on previous surveys and with predictor variables such as physical parameters and results from macrophyte modelling. All results are presented as maps in the report. The quality of the modelled predictions varies as a consequence of the quality and amount of the input data, the ecology and knowledge of the predicted phenomena, and by the modelling technique used. A substantial part of the variation is not described by the models, which should be expected for biological modelling. Therefore, the resulting grids should be used with caution and with this uncertainty kept in mind. All

  17. Spatial modelling of marine organisms in Forsmark and Oskarshamn. Including calculation of physical predictor variables

    International Nuclear Information System (INIS)

    Carlen, Ida; Nikolopoulos, Anna; Isaeus, Martin

    2007-06-01

    GIS grids (maps) of marine parameters were created using point data from previous site investigations in the Forsmark and Oskarshamn areas. The proportion of global radiation reaching the sea bottom in Forsmark and Oskarshamn was calculated in ArcView, using Secchi depth measurements and the digital elevation models for the respective area. The number of days per year when the incoming light exceeds 5 MJ/m2 at the bottom was then calculated using the result of the previous calculations together with measured global radiation. Existing modelled grid-point data on bottom and pelagic temperature for Forsmark were interpolated to create surface covering grids. Bottom and pelagic temperature grids for Oskarshamn were calculated using point measurements to achieve yearly averages for a few points and then using regressions with existing grids to create new maps. Phytoplankton primary production in Forsmark was calculated using point measurements of chlorophyll and irradiance, and a regression with a modelled grid of Secchi depth. Distribution of biomass of macrophyte communities in Forsmark and Oskarshamn was calculated using spatial modelling in GRASP, based on field data from previous surveys. Physical parameters such as those described above were used as predictor variables. Distribution of biomass of different functional groups of fish in Forsmark was calculated using spatial modelling based on previous surveys and with predictor variables such as physical parameters and results from macrophyte modelling. All results are presented as maps in the report. The quality of the modelled predictions varies as a consequence of the quality and amount of the input data, the ecology and knowledge of the predicted phenomena, and by the modelling technique used. A substantial part of the variation is not described by the models, which should be expected for biological modelling. Therefore, the resulting grids should be used with caution and with this uncertainty kept in mind. All

  18. [Correlation coefficient-based classification method of hydrological dependence variability: With auto-regression model as example].

    Science.gov (United States)

    Zhao, Yu Xi; Xie, Ping; Sang, Yan Fang; Wu, Zi Yi

    2018-04-01

    Hydrological process evaluation is temporal dependent. Hydrological time series including dependence components do not meet the data consistency assumption for hydrological computation. Both of those factors cause great difficulty for water researches. Given the existence of hydrological dependence variability, we proposed a correlationcoefficient-based method for significance evaluation of hydrological dependence based on auto-regression model. By calculating the correlation coefficient between the original series and its dependence component and selecting reasonable thresholds of correlation coefficient, this method divided significance degree of dependence into no variability, weak variability, mid variability, strong variability, and drastic variability. By deducing the relationship between correlation coefficient and auto-correlation coefficient in each order of series, we found that the correlation coefficient was mainly determined by the magnitude of auto-correlation coefficient from the 1 order to p order, which clarified the theoretical basis of this method. With the first-order and second-order auto-regression models as examples, the reasonability of the deduced formula was verified through Monte-Carlo experiments to classify the relationship between correlation coefficient and auto-correlation coefficient. This method was used to analyze three observed hydrological time series. The results indicated the coexistence of stochastic and dependence characteristics in hydrological process.

  19. Fatigue Behavior under Multiaxial Stress States Including Notch Effects and Variable Amplitude Loading

    Science.gov (United States)

    Gates, Nicholas R.

    The central objective of the research performed in this study was to be able to better understand and predict fatigue crack initiation and growth from stress concentrations subjected to complex service loading histories. As such, major areas of focus were related to the understanding and modeling of material deformation behavior, fatigue damage quantification, notch effects, cycle counting, damage accumulation, and crack growth behavior under multiaxial nominal loading conditions. To support the analytical work, a wide variety of deformation and fatigue tests were also performed using tubular and plate specimens made from 2024-T3 aluminum alloy, with and without the inclusion of a circular through-thickness hole. However, the analysis procedures implemented were meant to be general in nature, and applicable to a wide variety of materials and component geometries. As a result, experimental data from literature were also used, when appropriate, to supplement the findings of various analyses. Popular approaches currently used for multiaxial fatigue life analysis are based on the idea of computing an equivalent stress/strain quantity through the extension of static yield criteria. This equivalent stress/strain is then considered to be equal, in terms of fatigue damage, to a uniaxial loading of the same magnitude. However, it has often been shown, and was shown again in this study, that although equivalent stress- and strain-based analysis approaches may work well in certain situations, they lack a general robustness and offer little room for improvement. More advanced analysis techniques, on the other hand, provide an opportunity to more accurately account for various aspects of the fatigue failure process under both constant and variable amplitude loading conditions. As a result, such techniques were of primary interest in the investigations performed. By implementing more advanced life prediction methodologies, both the overall accuracy and the correlation of fatigue

  20. Degree of multicollinearity and variables involved in linear dependence in additive-dominant models

    Directory of Open Access Journals (Sweden)

    Juliana Petrini

    2012-12-01

    Full Text Available The objective of this work was to assess the degree of multicollinearity and to identify the variables involved in linear dependence relations in additive-dominant models. Data of birth weight (n=141,567, yearling weight (n=58,124, and scrotal circumference (n=20,371 of Montana Tropical composite cattle were used. Diagnosis of multicollinearity was based on the variance inflation factor (VIF and on the evaluation of the condition indexes and eigenvalues from the correlation matrix among explanatory variables. The first model studied (RM included the fixed effect of dam age class at calving and the covariates associated to the direct and maternal additive and non-additive effects. The second model (R included all the effects of the RM model except the maternal additive effects. Multicollinearity was detected in both models for all traits considered, with VIF values of 1.03 - 70.20 for RM and 1.03 - 60.70 for R. Collinearity increased with the increase of variables in the model and the decrease in the number of observations, and it was classified as weak, with condition index values between 10.00 and 26.77. In general, the variables associated with additive and non-additive effects were involved in multicollinearity, partially due to the natural connection between these covariables as fractions of the biological types in breed composition.

  1. Microscopic age determination of human skeletons including an unknown but calculable variable

    DEFF Research Database (Denmark)

    Wallin, Johan Albert; Tkocz, Izabella; Kristensen, Gustav

    1994-01-01

    estimation, which includes the covariance matrix of four single equation residuals, improves the accuracy of age determination. The standard deviation, however, of age prediction remains 12.58 years. An experimental split of the data was made in order to demonstrate that the use of subgroups gives a false...

  2. Distance and Azimuthal Dependence of Ground‐Motion Variability for Unilateral Strike‐Slip Ruptures

    KAUST Repository

    Vyas, Jagdish Chandra

    2016-06-21

    We investigate near‐field ground‐motion variability by computing the seismic wavefield for five kinematic unilateral‐rupture models of the 1992 Mw 7.3 Landers earthquake, eight simplified unilateral‐rupture models based on the Landers event, and a large Mw 7.8 ShakeOut scenario. We include the geometrical fault complexity and consider different 1D velocity–density profiles for the Landers simulations and a 3D heterogeneous Earth structure for the ShakeOut scenario. For the Landers earthquake, the computed waveforms are validated using strong‐motion recordings. We analyze the simulated ground‐motion data set in terms of distance and azimuth dependence of peak ground velocity (PGV). Our simulations reveal that intraevent ground‐motion variability Graphic is higher in close distances to the fault (<20  km) and decreases with increasing distance following a power law. This finding is in stark contrast to constant sigma‐values used in empirical ground‐motion prediction equations. The physical explanation of a large near‐field Graphic is the presence of strong directivity and rupture complexity. High values of Graphic occur in the rupture‐propagation direction, but small values occur in the direction perpendicular to it. We observe that the power‐law decay of Graphic is primarily controlled by slip heterogeneity. In addition, Graphic, as function of azimuth, is sensitive to variations in both rupture speed and slip heterogeneity. The azimuth dependence of the ground‐motion mean μln(PGV) is well described by a Cauchy–Lorentz function that provides a novel empirical quantification to model the spatial dependency of ground motion. Online Material: Figures of slip distributions, residuals to ground‐motion prediction equations (GMPEs), distance and azimuthal dependence, and directivity predictor of ground‐motion variability for different source models.

  3. Energy decay of a variable-coefficient wave equation with nonlinear time-dependent localized damping

    Directory of Open Access Journals (Sweden)

    Jieqiong Wu

    2015-09-01

    Full Text Available We study the energy decay for the Cauchy problem of the wave equation with nonlinear time-dependent and space-dependent damping. The damping is localized in a bounded domain and near infinity, and the principal part of the wave equation has a variable-coefficient. We apply the multiplier method for variable-coefficient equations, and obtain an energy decay that depends on the property of the coefficient of the damping term.

  4. Using Copulas in the Estimation of the Economic Project Value in the Mining Industry, Including Geological Variability

    Science.gov (United States)

    Krysa, Zbigniew; Pactwa, Katarzyna; Wozniak, Justyna; Dudek, Michal

    2017-12-01

    Geological variability is one of the main factors that has an influence on the viability of mining investment projects and on the technical risk of geology projects. In the current scenario, analyses of economic viability of new extraction fields have been performed for the KGHM Polska Miedź S.A. underground copper mine at Fore Sudetic Monocline with the assumption of constant averaged content of useful elements. Research presented in this article is aimed at verifying the value of production from copper and silver ore for the same economic background with the use of variable cash flows resulting from the local variability of useful elements. Furthermore, the ore economic model is investigated for a significant difference in model value estimated with the use of linear correlation between useful elements content and the height of mine face, and the approach in which model parameters correlation is based upon the copula best matched information capacity criterion. The use of copula allows the simulation to take into account the multi variable dependencies at the same time, thereby giving a better reflection of the dependency structure, which linear correlation does not take into account. Calculation results of the economic model used for deposit value estimation indicate that the correlation between copper and silver estimated with the use of copula generates higher variation of possible project value, as compared to modelling correlation based upon linear correlation. Average deposit value remains unchanged.

  5. Statistical methodology for discrete fracture model - including fracture size, orientation uncertainty together with intensity uncertainty and variability

    Energy Technology Data Exchange (ETDEWEB)

    Darcel, C. (Itasca Consultants SAS (France)); Davy, P.; Le Goc, R.; Dreuzy, J.R. de; Bour, O. (Geosciences Rennes, UMR 6118 CNRS, Univ. def Rennes, Rennes (France))

    2009-11-15

    the lineament scale (k{sub t} = 2) on the other, addresses the issue of the nature of the transition. We develop a new 'mechanistic' model that could help in modeling why and where this transition can occur. The transition between both regimes would occur for a fracture length of 1-10 m and even at a smaller scale for the few outcrops that follow the self-similar density model. A consequence for the disposal issue is that the model that is likely to apply in the 'blind' scale window between 10-100 m is the self-similar model as it is defined for large-scale lineaments. The self-similar model, as it is measured for some outcrops and most lineament maps, is definitely worth being investigated as a reference for scales above 1-10 m. In the rest of the report, we develop a methodology for incorporating uncertainty and variability into the DFN modeling. Fracturing properties arise from complex processes which produce an intrinsic variability; characterizing this variability as an admissible variation of model parameter or as the division of the site into subdomains with distinct DFN models is a critical point of the modeling effort. Moreover, the DFN model encompasses a part of uncertainty, due to data inherent uncertainties and sampling limits. Both effects must be quantified and incorporated into the DFN site model definition process. In that context, all available borehole data including recording of fracture intercept positions, pole orientation and relative uncertainties are used as the basis for the methodological development and further site model assessment. An elementary dataset contains a set of discrete fracture intercepts from which a parent orientation/density distribution can be computed. The elementary bricks of the site, from which these initial parent density distributions are computed, rely on the former Single Hole Interpretation division of the boreholes into sections whose local boundaries are expected to reflect - locally - geology

  6. Statistical methodology for discrete fracture model - including fracture size, orientation uncertainty together with intensity uncertainty and variability

    International Nuclear Information System (INIS)

    Darcel, C.; Davy, P.; Le Goc, R.; Dreuzy, J.R. de; Bour, O.

    2009-11-01

    the other, addresses the issue of the nature of the transition. We develop a new 'mechanistic' model that could help in modeling why and where this transition can occur. The transition between both regimes would occur for a fracture length of 1-10 m and even at a smaller scale for the few outcrops that follow the self-similar density model. A consequence for the disposal issue is that the model that is likely to apply in the 'blind' scale window between 10-100 m is the self-similar model as it is defined for large-scale lineaments. The self-similar model, as it is measured for some outcrops and most lineament maps, is definitely worth being investigated as a reference for scales above 1-10 m. In the rest of the report, we develop a methodology for incorporating uncertainty and variability into the DFN modeling. Fracturing properties arise from complex processes which produce an intrinsic variability; characterizing this variability as an admissible variation of model parameter or as the division of the site into subdomains with distinct DFN models is a critical point of the modeling effort. Moreover, the DFN model encompasses a part of uncertainty, due to data inherent uncertainties and sampling limits. Both effects must be quantified and incorporated into the DFN site model definition process. In that context, all available borehole data including recording of fracture intercept positions, pole orientation and relative uncertainties are used as the basis for the methodological development and further site model assessment. An elementary dataset contains a set of discrete fracture intercepts from which a parent orientation/density distribution can be computed. The elementary bricks of the site, from which these initial parent density distributions are computed, rely on the former Single Hole Interpretation division of the boreholes into sections whose local boundaries are expected to reflect - locally - geology and fracturing properties main characteristics. From that

  7. A void ratio dependent water retention curve model including hydraulic hysteresis

    Directory of Open Access Journals (Sweden)

    Pasha Amin Y.

    2016-01-01

    Full Text Available Past experimental evidence has shown that Water Retention Curve (WRC evolves with mechanical stress and structural changes in soil matrix. Models currently available in the literature for capturing the volume change dependency of WRC are mainly empirical in nature requiring an extensive experimental programme for parameter identification which renders them unsuitable for practical applications. In this paper, an analytical model for the evaluation of the void ratio dependency of WRC in deformable porous media is presented. The approach proposed enables quantification of the dependency of WRC on void ratio solely based on the form of WRC at the reference void ratio and requires no additional parameters. The effect of hydraulic hysteresis on the evolution process is also incorporated in the model, an aspect rarely addressed in the literature. Expressions are presented for the evolution of main and scanning curves due to loading and change in the hydraulic path from scanning to main wetting/drying and vice versa as well as the WRC parameters such as air entry value, air expulsion value, pore size distribution index and slope of the scanning curve. The model is validated using experimental data on compacted and reconstituted soils subjected to various hydro-mechanical paths. Good agreement is obtained between model predictions and experimental data in all the cases considered.

  8. Chromospheric activity of periodic variable stars (including eclipsing binaries) observed in DR2 LAMOST stellar spectral survey

    Science.gov (United States)

    Zhang, Liyun; Lu, Hongpeng; Han, Xianming L.; Jiang, Linyan; Li, Zhongmu; Zhang, Yong; Hou, Yonghui; Wang, Yuefei; Cao, Zihuang

    2018-05-01

    The LAMOST spectral survey provides a rich databases for studying stellar spectroscopic properties and chromospheric activity. We cross-matched a total of 105,287 periodic variable stars from several photometric surveys and databases (CSS, LINEAR, Kepler, a recently updated eclipsing star catalogue, ASAS, NSVS, some part of SuperWASP survey, variable stars from the Tsinghua University-NAOC Transient Survey, and other objects from some new references) with four million stellar spectra published in the LAMOST data release 2 (DR2). We found 15,955 spectra for 11,469 stars (including 5398 eclipsing binaries). We calculated their equivalent widths (EWs) of their Hα, Hβ, Hγ, Hδ and Caii H lines. Using the Hα line EW, we found 447 spectra with emission above continuum for a total of 316 stars (178 eclipsing binaries). We identified 86 active stars (including 44 eclipsing binaries) with repeated LAMOST spectra. A total of 68 stars (including 34 eclipsing binaries) show chromospheric activity variability. We also found LAMOST spectra of 12 cataclysmic variables, five of which show chromospheric activity variability. We also made photometric follow-up studies of three short period targets (DY CVn, HAT-192-0001481, and LAMOST J164933.24+141255.0) using the Xinglong 60-cm telescope and the SARA 90-cm and 1-m telescopes, and obtained new BVRI CCD light curves. We analyzed these light curves and obtained orbital and starspot parameters. We detected the first flare event with a huge brightness increase of more than about 1.5 magnitudes in R filter in LAMOST J164933.24+141255.0.

  9. Non-uniform approximations for sums of discrete m-dependent random variables

    OpenAIRE

    Vellaisamy, P.; Cekanavicius, V.

    2013-01-01

    Non-uniform estimates are obtained for Poisson, compound Poisson, translated Poisson, negative binomial and binomial approximations to sums of of m-dependent integer-valued random variables. Estimates for Wasserstein metric also follow easily from our results. The results are then exemplified by the approximation of Poisson binomial distribution, 2-runs and $m$-dependent $(k_1,k_2)$-events.

  10. Using k-dependence causal forest to mine the most significant dependency relationships among clinical variables for thyroid disease diagnosis.

    Directory of Open Access Journals (Sweden)

    LiMin Wang

    Full Text Available Numerous data mining models have been proposed to construct computer-aided medical expert systems. Bayesian network classifiers (BNCs are more distinct and understandable than other models. To graphically describe the dependency relationships among clinical variables for thyroid disease diagnosis and ensure the rationality of the diagnosis results, the proposed k-dependence causal forest (KCF model generates a series of submodels in the framework of maximum spanning tree (MST and demonstrates stronger dependence representation. Friedman test on 12 UCI datasets shows that KCF has classification accuracy advantage over the other state-of-the-art BNCs, such as Naive Bayes, tree augmented Naive Bayes, and k-dependence Bayesian classifier. Our extensive experimental comparison on 4 medical datasets also proves the feasibility and effectiveness of KCF in terms of sensitivity and specificity.

  11. How novice, skilled and advanced clinical researchers include variables in a case report form for clinical research: a qualitative study.

    Science.gov (United States)

    Chu, Hongling; Zeng, Lin; Fetters, Micheal D; Li, Nan; Tao, Liyuan; Shi, Yanyan; Zhang, Hua; Wang, Xiaoxiao; Li, Fengwei; Zhao, Yiming

    2017-09-18

    Despite varying degrees in research training, most academic clinicians are expected to conduct clinical research. The objective of this research was to understand how clinical researchers of different skill levels include variables in a case report form for their clinical research. The setting for this research was a major academic institution in Beijing, China. The target population was clinical researchers with three levels of experience, namely, limited clinical research experience, clinicians with rich clinical research experience and clinical research experts. Using a qualitative approach, we conducted 13 individual interviews (face to face) and one group interview (n=4) with clinical researchers from June to September 2016. Based on maximum variation sampling to identify researchers with three levels of research experience: eight clinicians with limited clinical research experience, five clinicians with rich clinical research experience and four clinical research experts. These 17 researchers had diverse hospital-based medical specialties and or specialisation in clinical research. Our analysis yields a typology of three processes developing a case report form that varies according to research experience level. Novice clinician researchers often have an incomplete protocol or none at all, and conduct data collection and publication based on a general framework. Experienced clinician researchers include variables in the case report form based on previous experience with attention to including domains or items at risk for omission and by eliminating unnecessary variables. Expert researchers consider comprehensively in advance data collection and implementation needs and plan accordingly. These results illustrate increasing levels of sophistication in research planning that increase sophistication in selection for variables in the case report form. These findings suggest that novice and intermediate-level researchers could benefit by emulating the comprehensive

  12. Dislocation concepts applied to fatigue properties of austenitic stainless steels including time-dependent modes

    Energy Technology Data Exchange (ETDEWEB)

    Tavassoli, A.A.

    1986-10-01

    Dislocation substructures formed in austenitic stainless steel 304L and 316L, fatigued at 673 K, 823 K and 873 K under total imposed strain ranges of 0.7 to 2.25%, and their correlation with mechanical properties have been investigated. In addition substructures formed at lower strain ranges have been examined using foils prepared from parts of the specimens with larger cross-sections. Investigation has also been extended to include the effect of intermittent hold-times up to 1.8 x 10/sup 4/s and sequential creep-fatigue and fatigue-creep. The experimental results obtained are analysed and their implications for current dislocation concepts and mechanical properties are discussed.

  13. Punishment induced behavioural and neurophysiological variability reveals dopamine-dependent selection of kinematic movement parameters

    Science.gov (United States)

    Galea, Joseph M.; Ruge, Diane; Buijink, Arthur; Bestmann, Sven; Rothwell, John C.

    2013-01-01

    Action selection describes the high-level process which selects between competing movements. In animals, behavioural variability is critical for the motor exploration required to select the action which optimizes reward and minimizes cost/punishment, and is guided by dopamine (DA). The aim of this study was to test in humans whether low-level movement parameters are affected by punishment and reward in ways similar to high-level action selection. Moreover, we addressed the proposed dependence of behavioural and neurophysiological variability on DA, and whether this may underpin the exploration of kinematic parameters. Participants performed an out-and-back index finger movement and were instructed that monetary reward and punishment were based on its maximal acceleration (MA). In fact, the feedback was not contingent on the participant’s behaviour but pre-determined. Blocks highly-biased towards punishment were associated with increased MA variability relative to blocks with either reward or without feedback. This increase in behavioural variability was positively correlated with neurophysiological variability, as measured by changes in cortico-spinal excitability with transcranial magnetic stimulation over the primary motor cortex. Following the administration of a DA-antagonist, the variability associated with punishment diminished and the correlation between behavioural and neurophysiological variability no longer existed. Similar changes in variability were not observed when participants executed a pre-determined MA, nor did DA influence resting neurophysiological variability. Thus, under conditions of punishment, DA-dependent processes influence the selection of low-level movement parameters. We propose that the enhanced behavioural variability reflects the exploration of kinematic parameters for less punishing, or conversely more rewarding, outcomes. PMID:23447607

  14. Equivalent conditions of complete moment convergence for extended negatively dependent random variables

    Directory of Open Access Journals (Sweden)

    Qunying Wu

    2017-05-01

    Full Text Available Abstract In this paper, we study the equivalent conditions of complete moment convergence for sequences of identically distributed extended negatively dependent random variables. As a result, we extend and generalize some results of complete moment convergence obtained by Chow (Bull. Inst. Math. Acad. Sin. 16:177-201, 1988 and Li and Spătaru (J. Theor. Probab. 18:933-947, 2005 from the i.i.d. case to extended negatively dependent sequences.

  15. Construction of adjoint operators for coupled equations depending on different variables

    International Nuclear Information System (INIS)

    Hoogenboom, J.E.

    1986-01-01

    A procedure is described for the construction of the adjoint operator matrix in case of coupled equations defining quantities that depend on different sets of variables. This case is not properly treated in the literature. From this procedure a simple rule can be deduced for the construction of such adjoint operator matrices

  16. Panel data models extended to spatial error autocorrelation or a spatially lagged dependent variable

    NARCIS (Netherlands)

    Elhorst, J. Paul

    2001-01-01

    This paper surveys panel data models extended to spatial error autocorrelation or a spatially lagged dependent variable. In particular, it focuses on the specification and estimation of four panel data models commonly used in applied research: the fixed effects model, the random effects model, the

  17. Human Performance Technology (HPT): An Examination of Definitions through Dependent and Independent Variables.

    Science.gov (United States)

    Irlbeck, Sonja A.

    2002-01-01

    Provides a chronological perspective of human performance technology (HPT) definitions and an evaluation of them in terms of independent and dependent variables. Discusses human competence and performance technology and compares the definitions with the goals that have been articulated for HPT. (Author/LRW)

  18. Central limit theorem for the Banach-valued weakly dependent random variables

    International Nuclear Information System (INIS)

    Dmitrovskij, V.A.; Ermakov, S.V.; Ostrovskij, E.I.

    1983-01-01

    The central limit theorem (CLT) for the Banach-valued weakly dependent random variables is proved. In proving CLT convergence of finite-measured (i.e. cylindrical) distributions is established. A weak compactness of the family of measures generated by a certain sequence is confirmed. The continuity of the limiting field is checked

  19. Understanding morphological variability in a taxonomic context in Chilean diplomystids (Teleostei: Siluriformes, including the description of a new species

    Directory of Open Access Journals (Sweden)

    Gloria Arratia

    2017-02-01

    Full Text Available Following study of the external morphology and its unmatched variability throughout ontogeny and a re-examination of selected morphological characters based on many specimens of diplomystids from Central and South Chile, we revised and emended previous specific diagnoses and consider Diplomystes chilensis, D. nahuelbutaensis, D. camposensis, and Olivaichthys viedmensis (Baker River to be valid species. Another group, previously identified as Diplomystes sp., D. spec., D. aff. chilensis, and D. cf. chilensis inhabiting rivers between Rapel and Itata Basins is given a new specific name (Diplomystes incognitus and is diagnosed. An identification key to the Chilean species, including the new species, is presented. All specific diagnoses are based on external morphological characters, such as aspects of the skin, neuromast lines, and main lateral line, and position of the anus and urogenital pore, as well as certain osteological characters to facilitate the identification of these species that previously was based on many internal characters. Diplomystids below 150 mm standard length (SL share a similar external morphology and body proportions that make identification difficult; however, specimens over 150 mm SL can be diagnosed by the position of the urogenital pore and anus, and a combination of external and internal morphological characters. According to current knowledge, diplomystid species have an allopatric distribution with each species apparently endemic to particular basins in continental Chile and one species (O. viedmensis known only from one river in the Chilean Patagonia, but distributed extensively in southern Argentina.

  20. Method of nuclear reactor control using a variable temperature load dependent set point

    International Nuclear Information System (INIS)

    Kelly, J.J.; Rambo, G.E.

    1982-01-01

    A method and apparatus for controlling a nuclear reactor in response to a variable average reactor coolant temperature set point is disclosed. The set point is dependent upon percent of full power load demand. A manually-actuated ''droop mode'' of control is provided whereby the reactor coolant temperature is allowed to drop below the set point temperature a predetermined amount wherein the control is switched from reactor control rods exclusively to feedwater flow

  1. TWO MEASURES OF THE DEPENDENCE OF PREFERENTIAL RANKINGS ON CATEGORICAL VARIABLES

    Directory of Open Access Journals (Sweden)

    Lissowski Grzegorz

    2017-06-01

    Full Text Available The aim of this paper is to apply a general methodology for constructing statistical methods, which is based on decision theory, to give a statistical description of preferential rankings, with a focus on the rankings’ dependence on categorical variables. In the paper, I use functions of description errors that are based on the Kemeny and Hamming distances between preferential orderings, but the proposed methodology can also be applied to other methods of estimating description errors.

  2. An edgeworth expansion for a sum of M-Dependent random variables

    Directory of Open Access Journals (Sweden)

    Wan Soo Rhee

    1985-01-01

    Full Text Available Given a sequence X1,X2,…,Xn of m-dependent random variables with moments of order 3+α (0<α≦1, we give an Edgeworth expansion of the distribution of Sσ−1(S=X1+X2+…+Xn, σ2=ES2 under the assumption that E[exp(it Sσ1] is small away from the origin. The result is of the best possible order.

  3. ABCB1 genetic variability and methadone dosage requirements in opioid-dependent individuals.

    Science.gov (United States)

    Coller, Janet K; Barratt, Daniel T; Dahlen, Karianne; Loennechen, Morten H; Somogyi, Andrew A

    2006-12-01

    The most common treatment for opioid dependence is substitution therapy with another opioid such as methadone. The methadone dosage is individualized but highly variable, and program retention rates are low due in part to nonoptimal dosing resulting in withdrawal symptoms and further heroin craving and use. Methadone is a substrate for the P-glycoprotein transporter, encoded by the ABCB1 gene, which regulates central nervous system exposure. This retrospective study aimed to investigate the influence of ABCB1 genetic variability on methadone dose requirements. Genomic deoxyribonucleic acid was isolated from opioid-dependent subjects (n = 60) and non-opioid-dependent control subjects (n = 60), and polymerase chain reaction-restriction fragment length polymorphism and allele-specific polymerase chain reaction were used to determine the presence of single nucleotide polymorphisms at positions 61, 1199, 1236, 2677, and 3435. ABCB1 haplotypes were inferred with PHASE software (version 2.1). There were no significant differences in the allele or genotype frequencies of the individual single nucleotide polymorphisms or haplotypes between the 2 populations. ABCB1 genetic variability influenced daily methadone dose requirements, such that subjects carrying 2 copies of the wild-type haplotype required higher doses compared with those with 1 copy and those with no copies (98.3 +/- 10.4, 58.6 +/- 20.9, and 55.4 +/- 26.1 mg/d, respectively; P = .029). In addition, carriers of the AGCTT haplotype required significantly lower doses than noncarriers (38.0 +/- 16.8 and 61.3 +/- 24.6 mg/d, respectively; P = .04). Although ABCB1 genetic variability is not related to the development of opioid dependence, identification of variant haplotypes may, after larger prospective studies have been performed, provide clinicians with a tool for methadone dosage individualization.

  4. Auxiliary variables in multiple imputation in regression with missing X: a warning against including too many in small sample research

    Directory of Open Access Journals (Sweden)

    Hardt Jochen

    2012-12-01

    Full Text Available Abstract Background Multiple imputation is becoming increasingly popular. Theoretical considerations as well as simulation studies have shown that the inclusion of auxiliary variables is generally of benefit. Methods A simulation study of a linear regression with a response Y and two predictors X1 and X2 was performed on data with n = 50, 100 and 200 using complete cases or multiple imputation with 0, 10, 20, 40 and 80 auxiliary variables. Mechanisms of missingness were either 100% MCAR or 50% MAR + 50% MCAR. Auxiliary variables had low (r=.10 vs. moderate correlations (r=.50 with X’s and Y. Results The inclusion of auxiliary variables can improve a multiple imputation model. However, inclusion of too many variables leads to downward bias of regression coefficients and decreases precision. When the correlations are low, inclusion of auxiliary variables is not useful. Conclusion More research on auxiliary variables in multiple imputation should be performed. A preliminary rule of thumb could be that the ratio of variables to cases with complete data should not go below 1 : 3.

  5. Laser-induced electron dynamics including photoionization: A heuristic model within time-dependent configuration interaction theory.

    Science.gov (United States)

    Klinkusch, Stefan; Saalfrank, Peter; Klamroth, Tillmann

    2009-09-21

    We report simulations of laser-pulse driven many-electron dynamics by means of a simple, heuristic extension of the time-dependent configuration interaction singles (TD-CIS) approach. The extension allows for the treatment of ionizing states as nonstationary states with a finite, energy-dependent lifetime to account for above-threshold ionization losses in laser-driven many-electron dynamics. The extended TD-CIS method is applied to the following specific examples: (i) state-to-state transitions in the LiCN molecule which correspond to intramolecular charge transfer, (ii) creation of electronic wave packets in LiCN including wave packet analysis by pump-probe spectroscopy, and, finally, (iii) the effect of ionization on the dynamic polarizability of H(2) when calculated nonperturbatively by TD-CIS.

  6. BAYESIAN TECHNIQUES FOR COMPARING TIME-DEPENDENT GRMHD SIMULATIONS TO VARIABLE EVENT HORIZON TELESCOPE OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Junhan; Marrone, Daniel P.; Chan, Chi-Kwan; Medeiros, Lia; Özel, Feryal; Psaltis, Dimitrios, E-mail: junhankim@email.arizona.edu [Department of Astronomy and Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States)

    2016-12-01

    The Event Horizon Telescope (EHT) is a millimeter-wavelength, very-long-baseline interferometry (VLBI) experiment that is capable of observing black holes with horizon-scale resolution. Early observations have revealed variable horizon-scale emission in the Galactic Center black hole, Sagittarius A* (Sgr A*). Comparing such observations to time-dependent general relativistic magnetohydrodynamic (GRMHD) simulations requires statistical tools that explicitly consider the variability in both the data and the models. We develop here a Bayesian method to compare time-resolved simulation images to variable VLBI data, in order to infer model parameters and perform model comparisons. We use mock EHT data based on GRMHD simulations to explore the robustness of this Bayesian method and contrast it to approaches that do not consider the effects of variability. We find that time-independent models lead to offset values of the inferred parameters with artificially reduced uncertainties. Moreover, neglecting the variability in the data and the models often leads to erroneous model selections. We finally apply our method to the early EHT data on Sgr A*.

  7. ASSESSMENT OF THE CHANGES IN BLOOD PRESSURE CIRCADIAN PROFILE AND VARIABILITY IN PATIENTS WITH CHRONIC HEART FAILURE AND ARTERIAL HYPERTENSION DURING COMBINED THERAPY INCLUDING IVABRADINE

    Directory of Open Access Journals (Sweden)

    M. V. Surovtseva

    2012-01-01

    Full Text Available Aim. To assess the changes in blood pressure (BP circadian profile and variability in patients with chronic heart failure (CHF of ischemic etiology and arterial hypertension (HT due to the complex therapy including ivabradine. Material and methods. Patients (n=90 with CHF class II–III NYHA associated with stable angina II-III class and HT were examined. The patients were randomized into 3 groups depending on received drugs: perindopril and ivabradine - group 1; perindopril, bisoprolol and ivabradine - group 2; perindopril and bisoprolol - group 3. The duration of therapy was 6 months. Ambulatory BP monitoring (ABPM was assessed at baseline and after treatment. Results. More significant reduction in average 24-hours systolic BP was found in groups 1 and 2 compared to group 3 (Δ%: -19.4±0,4; -21.1±0.4 and -11.8±0.6, respectively as well as diastolic BP (Δ%: -10.6±0.6; -12.9±0.4 and -4,3±0.3, respectively and other ABPM indicators. Improvement of BP circadian rhythm was found due to increase in the number of «Dipper» patients (p=0.016. More significant reduction in average daily and night systolic and diastolic BP (p=0.001, as well as daily and night BP variability (p=0.001 was also found in patients of group 2 compared to these of group 1. Conclusion. Moderate antihypertensive effect (in respect of both diastolic and systolic BP was shown when ivabradine was included into the complex therapy of patients with ischemic CHF and HT. The effect was more pronounced when ivabradine was combined with perindopril and bisoprolol. This was accompanied by reduction in high BP daily variability and improvement of the BP circadian rhythm. 

  8. ASSESSMENT OF THE CHANGES IN BLOOD PRESSURE CIRCADIAN PROFILE AND VARIABILITY IN PATIENTS WITH CHRONIC HEART FAILURE AND ARTERIAL HYPERTENSION DURING COMBINED THERAPY INCLUDING IVABRADINE

    Directory of Open Access Journals (Sweden)

    M. V. Surovtseva

    2015-12-01

    Full Text Available Aim. To assess the changes in blood pressure (BP circadian profile and variability in patients with chronic heart failure (CHF of ischemic etiology and arterial hypertension (HT due to the complex therapy including ivabradine. Material and methods. Patients (n=90 with CHF class II–III NYHA associated with stable angina II-III class and HT were examined. The patients were randomized into 3 groups depending on received drugs: perindopril and ivabradine - group 1; perindopril, bisoprolol and ivabradine - group 2; perindopril and bisoprolol - group 3. The duration of therapy was 6 months. Ambulatory BP monitoring (ABPM was assessed at baseline and after treatment. Results. More significant reduction in average 24-hours systolic BP was found in groups 1 and 2 compared to group 3 (Δ%: -19.4±0,4; -21.1±0.4 and -11.8±0.6, respectively as well as diastolic BP (Δ%: -10.6±0.6; -12.9±0.4 and -4,3±0.3, respectively and other ABPM indicators. Improvement of BP circadian rhythm was found due to increase in the number of «Dipper» patients (p=0.016. More significant reduction in average daily and night systolic and diastolic BP (p=0.001, as well as daily and night BP variability (p=0.001 was also found in patients of group 2 compared to these of group 1. Conclusion. Moderate antihypertensive effect (in respect of both diastolic and systolic BP was shown when ivabradine was included into the complex therapy of patients with ischemic CHF and HT. The effect was more pronounced when ivabradine was combined with perindopril and bisoprolol. This was accompanied by reduction in high BP daily variability and improvement of the BP circadian rhythm. 

  9. Iwamoto-Harada coalescence/pickup model for cluster emission: state density approach including angular momentum variables

    Directory of Open Access Journals (Sweden)

    Běták Emil

    2014-04-01

    Full Text Available For low-energy nuclear reactions well above the resonance region, but still below the pion threshold, statistical pre-equilibrium models (e.g., the exciton and the hybrid ones are a frequent tool for analysis of energy spectra and the cross sections of cluster emission. For α’s, two essentially distinct approaches are popular, namely the preformed one and the different versions of coalescence approaches, whereas only the latter group of models can be used for other types of cluster ejectiles. The original Iwamoto-Harada model of pre-equilibrium cluster emission was formulated using the overlap of the cluster and its constituent nucleons in momentum space. Transforming it into level or state densities is not a straigthforward task; however, physically the same model was presented at a conference on reaction models five years earlier. At that time, only the densities without spin were used. The introduction of spin variables into the exciton model enabled detailed calculation of the γ emission and its competition with nucleon channels, and – at the same time – it stimulated further developments of the model. However – to the best of our knowledge – no spin formulation has been presented for cluster emission till recently, when the first attempts have been reported, but restricted to the first emission only. We have updated this effort now and we are able to handle (using the same simplifications as in our previous work pre-equilibrium cluster emission with spin including all nuclei in the reaction chain.

  10. MIRU-VNTR allelic variability depends on Mycobacterium bovis clonal group identity.

    Science.gov (United States)

    Hauer, Amandine; Michelet, Lorraine; De Cruz, Krystel; Cochard, Thierry; Branger, Maxime; Karoui, Claudine; Henault, Sylvie; Biet, Franck; Boschiroli, María Laura

    2016-11-01

    The description of the population of M. bovis strains circulating in France from 1978 to 2013 has highlighted the discriminating power of the MLVA among predominant spoligotype groups. In the present study we aimed to characterize clonal groups via MLVA and to better understand the strain's population structure. MLVA was performed with eight MIRU-VNTR loci, most of them defined by the Venomyc European consortium. The discriminatory index of each MLVA loci was calculated for SB0120, SB0134, SB0121 and the "F4-family", the main spoligotype groups in France. Differences in global DI per spoligotype, but also by locus within each spoligotype, were observed, which strongly suggest the clonal complex nature of these major groups. These MLVA results were compared to those of other European countries where strain collections had been characterized (Spain, Portugal, Italy, Northern Ireland and Belgium). Overall, QUB 3232 and ETR D are respectively the most and the least discriminative loci, regardless of the strains geographical origin. However, marked DI differences are observed in the rest of the MIRU-VNTR loci, again highlighting that strain genetic variability in a country depends on the dominant existing clonal complexes. A web application for M. bovis, including spoligotyping and MIRU-VNTR typing data, was developed to allow inter-laboratory comparison of field isolates. In conclusion, combination of typing methods is required for M. bovis optimum discrimination and differentiation of groups of strains. Thus, the loci employed for MLVA in a country should be those which are the most discriminative for the clonal complexes which characterize their M. bovis population. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Variations in Carabidae assemblages across the farmland habitats in relation to selected environmental variables including soil properties

    Directory of Open Access Journals (Sweden)

    Beáta Baranová

    2018-03-01

    Full Text Available The variations in ground beetles (Coleoptera: Carabidae assemblages across the three types of farmland habitats, arable land, meadows and woody vegetation were studied in relation to vegetation cover structure, intensity of agrotechnical interventions and selected soil properties. Material was pitfall trapped in 2010 and 2011 on twelve sites of the agricultural landscape in the Prešov town and its near vicinity, Eastern Slovakia. A total of 14,763 ground beetle individuals were entrapped. Material collection resulted into 92 Carabidae species, with the following six species dominating: Poecilus cupreus, Pterostichus melanarius, Pseudoophonus rufipes, Brachinus crepitans, Anchomenus dorsalis and Poecilus versicolor. Studied habitats differed significantly in the number of entrapped individuals, activity abundance as well as representation of the carabids according to their habitat preferences and ability to fly. However, no significant distinction was observed in the diversity, evenness neither dominance. The most significant environmental variables affecting Carabidae assemblages species variability were soil moisture and herb layer 0-20 cm. Another best variables selected by the forward selection were intensity of agrotechnical interventions, humus content and shrub vegetation. The other from selected soil properties seem to have just secondary meaning for the adult carabids. Environmental variables have the strongest effect on the habitat specialists, whereas ground beetles without special requirements to the habitat quality seem to be affected by the studied environmental variables just little.

  12. The dependence of J/ψ-nucleon inelastic cross section on the Feynman variable

    International Nuclear Information System (INIS)

    Duan Chungui; Liu Na; Miao Wendan

    2011-01-01

    By means of two typical sets of nuclear parton distribution functions, meanwhile taking account of the energy loss of the beam proton and the nuclear absorption of the charmonium states traversing the nuclear matter in the uniform framework of the Glauber model, a leading order phenomenological analysis is given in the color evaporation model of the E866 experimental data on J/ψ production differential cross section ratios R Fe/Be (x F ). It is shown that the energy loss effect of beam proton on R Fe/Be (x F ) is more important than the nuclear effects on parton distribution functions in the high Feynman variable x F region. It is found that the J/ψ-nucleon inelastic cross section depends on the Feynman variable x F and increases linearly with x F in the region x F > 0.2. (authors)

  13. Building the nodal nuclear data dependences in a many-dimensional state-variable space

    International Nuclear Information System (INIS)

    Dufek, Jan

    2011-01-01

    Highlights: → The Abstract and Introduction are revised to reflect reviewers' comments. → Section is revised and simplified. → The third paragraph in Section is revised. → All typos are fixed. - Abstract: We present new methods for building the polynomial-regression based nodal nuclear data models. The data models can reflect dependences on a large number of state variables, and they can consider various history effects. Suitable multivariate polynomials that approximate the nodal data dependences are identified efficiently in an iterative manner. The history effects are analysed using a new sampling scheme for lattice calculations where the traditional base burnup and branch calculations are replaced by a large number of diverse burnup histories. The total number of lattice calculations is controlled so that the data models are built to a required accuracy.

  14. Memory effects, two color percolation, and the temperature dependence of Mott variable-range hopping

    Science.gov (United States)

    Agam, Oded; Aleiner, Igor L.

    2014-06-01

    There are three basic processes that determine hopping transport: (a) hopping between normally empty sites (i.e., having exponentially small occupation numbers at equilibrium), (b) hopping between normally occupied sites, and (c) transitions between normally occupied and unoccupied sites. In conventional theories all these processes are considered Markovian and the correlations of occupation numbers of different sites are believed to be small (i.e., not exponential in temperature). We show that, contrary to this belief, memory effects suppress the processes of type (c) and manifest themselves in a subleading exponential temperature dependence of the variable-range hopping conductivity. This temperature dependence originates from the property that sites of type (a) and (b) form two independent resistor networks that are weakly coupled to each other by processes of type (c). This leads to a two-color percolation problem which we solve in the critical region.

  15. Population and prehistory III: food-dependent demography in variable environments.

    Science.gov (United States)

    Lee, Charlotte T; Puleston, Cedric O; Tuljapurkar, Shripad

    2009-11-01

    The population dynamics of preindustrial societies depend intimately on their surroundings, and food is a primary means through which environment influences population size and individual well-being. Food production requires labor; thus, dependence of survival and fertility on food involves dependence of a population's future on its current state. We use a perturbation approach to analyze the effects of random environmental variation on this nonlinear, age-structured system. We show that in expanding populations, direct environmental effects dominate induced population fluctuations, so environmental variability has little effect on mean hunger levels, although it does decrease population growth. The growth rate determines the time until population is limited by space. This limitation introduces a tradeoff between population density and well-being, so population effects become more important than the direct effects of the environment: environmental fluctuation increases mortality, releasing density dependence and raising average well-being for survivors. We discuss the social implications of these findings for the long-term fate of populations as they transition from expansion into limitation, given that conditions leading to high well-being during growth depress well-being during limitation.

  16. Numerical Solution of the Time-Dependent Navier–Stokes Equation for Variable Density–Variable Viscosity. Part I

    Czech Academy of Sciences Publication Activity Database

    Axelsson, Owe; Xin, H.; Neytcheva, M.

    2015-01-01

    Roč. 20, č. 2 (2015), s. 232-260 ISSN 1392-6292 Institutional support: RVO:68145535 Keywords : variable density * phase-field model * Navier-Stokes equations * preconditioning * variable viscosity Subject RIV: BA - General Mathematics Impact factor: 0.468, year: 2015 http://www.tandfonline.com/doi/abs/10.3846/13926292.2015.1021395

  17. Inlet-engine matching for SCAR including application of a bicone variable geometry inlet. [Supersonic Cruise Aircraft Research

    Science.gov (United States)

    Wasserbauer, J. F.; Gerstenmaier, W. H.

    1978-01-01

    Airflow characteristics of variable cycle engines (VCE) designed for Mach 2.32 can have transonic airflow requirements as high as 1.6 times the cruise airflow. This is a formidable requirement for conventional, high performance, axisymmetric, translating centerbody mixed compression inlets. An alternate inlet is defined where the second cone of a two cone centerbody collapses to the initial cone angle to provide a large off-design airflow capability, and incorporates modest centerbody translation to minimize spillage drag. Estimates of transonic spillage drag are competitive with those of conventional translating centerbody inlets. The inlet's cruise performance exhibits very low bleed requirements with good recovery and high angle of attack capability.

  18. Internal state variable plasticity-damage modeling of AISI 4140 steel including microstructure-property relations: temperature and strain rate effects

    Science.gov (United States)

    Nacif el Alaoui, Reda

    Mechanical structure-property relations have been quantified for AISI 4140 steel. under different strain rates and temperatures. The structure-property relations were used. to calibrate a microstructure-based internal state variable plasticity-damage model for. monotonic tension, compression and torsion plasticity, as well as damage evolution. Strong stress state and temperature dependences were observed for the AISI 4140 steel. Tension tests on three different notched Bridgman specimens were undertaken to study. the damage-triaxiality dependence for model validation purposes. Fracture surface. analysis was performed using Scanning Electron Microscopy (SEM) to quantify the void. nucleation and void sizes in the different specimens. The stress-strain behavior exhibited. a fairly large applied stress state (tension, compression dependence, and torsion), a. moderate temperature dependence, and a relatively small strain rate dependence.

  19. Uncovering state-dependent relationships in shallow lakes using Bayesian latent variable regression.

    Science.gov (United States)

    Vitense, Kelsey; Hanson, Mark A; Herwig, Brian R; Zimmer, Kyle D; Fieberg, John

    2018-03-01

    Ecosystems sometimes undergo dramatic shifts between contrasting regimes. Shallow lakes, for instance, can transition between two alternative stable states: a clear state dominated by submerged aquatic vegetation and a turbid state dominated by phytoplankton. Theoretical models suggest that critical nutrient thresholds differentiate three lake types: highly resilient clear lakes, lakes that may switch between clear and turbid states following perturbations, and highly resilient turbid lakes. For effective and efficient management of shallow lakes and other systems, managers need tools to identify critical thresholds and state-dependent relationships between driving variables and key system features. Using shallow lakes as a model system for which alternative stable states have been demonstrated, we developed an integrated framework using Bayesian latent variable regression (BLR) to classify lake states, identify critical total phosphorus (TP) thresholds, and estimate steady state relationships between TP and chlorophyll a (chl a) using cross-sectional data. We evaluated the method using data simulated from a stochastic differential equation model and compared its performance to k-means clustering with regression (KMR). We also applied the framework to data comprising 130 shallow lakes. For simulated data sets, BLR had high state classification rates (median/mean accuracy >97%) and accurately estimated TP thresholds and state-dependent TP-chl a relationships. Classification and estimation improved with increasing sample size and decreasing noise levels. Compared to KMR, BLR had higher classification rates and better approximated the TP-chl a steady state relationships and TP thresholds. We fit the BLR model to three different years of empirical shallow lake data, and managers can use the estimated bifurcation diagrams to prioritize lakes for management according to their proximity to thresholds and chance of successful rehabilitation. Our model improves upon

  20. Size-dependent nonlinear bending of micro/nano-beams made of nanoporous biomaterials including a refined truncated cube cell

    Science.gov (United States)

    Sahmani, S.; Aghdam, M. M.

    2017-12-01

    Morphology and pore size plays an essential role in the mechanical properties as well as the associated biological capability of a porous structure made of biomaterials. The objective of the current study is to predict the Young's modulus and Poisson's ratio of nanoporous biomaterials including refined truncated cube cells based on a hyperbolic shear deformable beam model. Analytical relationships for the mechanical properties of nanoporous biomaterials are given as a function of the refined cell's dimensions. After that, the size dependency in the nonlinear bending behavior of micro/nano-beams made of such nanoporous biomaterials is analyzed using the nonlocal strain gradient elasticity theory. It is assumed that the micro/nano-beam has one movable end under axial compression in conjunction with a uniform distributed lateral load. The Galerkin method together with an improved perturbation technique is employed to propose explicit analytical expression for nonlocal strain gradient load-deflection curves of the micro/nano-beams made of nanoporous biomaterials subjected to uniform transverse distributed load. It is found that through increment of the pore size, the micro/nano-beam will undergo much more deflection corresponding to a specific distributed load due to the reduction in the stiffness of nanoporous biomaterial. This pattern is more prominent for lower value of applied axial compressive load at the free end of micro/nano-beam.

  1. Major histocompatibility complex harbors widespread genotypic variability of non-additive risk of rheumatoid arthritis including epistasis.

    Science.gov (United States)

    Wei, Wen-Hua; Bowes, John; Plant, Darren; Viatte, Sebastien; Yarwood, Annie; Massey, Jonathan; Worthington, Jane; Eyre, Stephen

    2016-04-25

    Genotypic variability based genome-wide association studies (vGWASs) can identify potentially interacting loci without prior knowledge of the interacting factors. We report a two-stage approach to make vGWAS applicable to diseases: firstly using a mixed model approach to partition dichotomous phenotypes into additive risk and non-additive environmental residuals on the liability scale and secondly using the Levene's (Brown-Forsythe) test to assess equality of the residual variances across genotype groups per marker. We found widespread significant (P 5e-05) vGWAS signals within the major histocompatibility complex (MHC) across all three study cohorts of rheumatoid arthritis. We further identified 10 epistatic interactions between the vGWAS signals independent of the MHC additive effects, each with a weak effect but jointly explained 1.9% of phenotypic variance. PTPN22 was also identified in the discovery cohort but replicated in only one independent cohort. Combining the three cohorts boosted power of vGWAS and additionally identified TYK2 and ANKRD55. Both PTPN22 and TYK2 had evidence of interactions reported elsewhere. We conclude that vGWAS can help discover interacting loci for complex diseases but require large samples to find additional signals.

  2. Variability of Surface Reflection Amplitudes of GPR Horn Antenna Depending on Distance between Antenna and Surface

    Directory of Open Access Journals (Sweden)

    Komačka Jozef

    2016-05-01

    Full Text Available The study focused on variability of surface reflections amplitudes of GPR horn antenna in relation to distance between an antenna and a surface is presented in the paper. The air-coupled antenna with the central frequency of 1 GHz was used in the investigation. Four types of surfaces (dry pavement, wet pavement, metal plate and composite layer from gypsum and wood were tested. The distance of antenna above the surfaces was changed in the range from 37.5 cm to 53.5 cm. The amplitudes of negative and positive peaks and their variability were analysed in relation to the distance of antenna above the surfaces. Moreover, the influence of changes in the peaks of negative and positive amplitudes on the total amplitudes was assessed. It was found out the amplitudes of negative peaks for all investigated surfaces were relatively consistent in the range from 40.5 cm to 48.5 cm and the moderate decline was identified in the case of amplitudes of positive peaks in the range of distances from 37.5 cm to 51.5 cm. This decline influences the tendency of total amplitudes. Based on the results of analysis it can be stated the distance of air-coupled antenna above the surface can influence the value of total amplitude and the differences depend on the type of surface.

  3. Chemical Variability and Biological Activities of Brassica rapa var. rapifera Parts Essential Oils Depending on Geographic Variation and Extraction Technique.

    Science.gov (United States)

    Saka, Boualem; Djouahri, Abderrahmane; Djerrad, Zineb; Terfi, Souhila; Aberrane, Sihem; Sabaou, Nasserdine; Baaliouamer, Aoumeur; Boudarene, Lynda

    2017-06-01

    In the present work, the Brassica rapa var. rapifera parts essential oils and their antioxidant and antimicrobial activities were investigated for the first time depending on geographic origin and extraction technique. Gas-chromatography (GC) and GC/mass spectrometry (MS) analyses showed several constituents, including alcohols, aldehydes, esters, ketones, norisoprenoids, terpenic, nitrogen and sulphur compounds, totalizing 38 and 41 compounds in leaves and root essential oils, respectively. Nitrogen compounds were the main volatiles in leaves essential oils and sulphur compounds were the main volatiles in root essential oils. Qualitative and quantitative differences were found among B. rapa var. rapifera parts essential oils collected from different locations and extracted by hydrodistillation and microwave-assisted hydrodistillation techniques. Furthermore, our findings showed a high variability for both antioxidant and antimicrobial activities. The highlighted variability reflects the high impact of plant part, geographic variation and extraction technique on chemical composition and biological activities, which led to conclude that we should select essential oils to be investigated carefully depending on these factors, in order to isolate the bioactive components or to have the best quality of essential oil in terms of biological activities and preventive effects in food. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  4. Large Variability in the Diversity of Physiologically Complex Surgical Procedures Exists Nationwide Among All Hospitals Including Among Large Teaching Hospitals.

    Science.gov (United States)

    Dexter, Franklin; Epstein, Richard H; Thenuwara, Kokila; Lubarsky, David A

    2017-11-22

    Multiple previous studies have shown that having a large diversity of procedures has a substantial impact on quality management of hospital surgical suites. At hospitals with substantial diversity, unless sophisticated statistical methods suitable for rare events are used, anesthesiologists working in surgical suites will have inaccurate predictions of surgical blood usage, case durations, cost accounting and price transparency, times remaining in late running cases, and use of intraoperative equipment. What is unknown is whether large diversity is a feature of only a few very unique set of hospitals nationwide (eg, the largest hospitals in each state or province). The 2013 United States Nationwide Readmissions Database was used to study heterogeneity among 1981 hospitals in their diversities of physiologically complex surgical procedures (ie, the procedure codes). The diversity of surgical procedures performed at each hospital was quantified using a summary measure, the number of different physiologically complex surgical procedures commonly performed at the hospital (ie, 1/Herfindahl). A total of 53.9% of all hospitals commonly performed 3-fold larger diversity (ie, >30 commonly performed physiologically complex procedures). Larger hospitals had greater diversity than the small- and medium-sized hospitals (P 30 procedures (lower 99% CL, 71.9% of hospitals). However, there was considerable variability among the large teaching hospitals in their diversity (interquartile range of the numbers of commonly performed physiologically complex procedures = 19.3; lower 99% CL, 12.8 procedures). The diversity of procedures represents a substantive differentiator among hospitals. Thus, the usefulness of statistical methods for operating room management should be expected to be heterogeneous among hospitals. Our results also show that "large teaching hospital" alone is an insufficient description for accurate prediction of the extent to which a hospital sustains the

  5. The Attentional Dependence of Emotion Cognition is Variable with the Competing Task

    Directory of Open Access Journals (Sweden)

    Cheng Chen

    2016-11-01

    Full Text Available The relationship between emotion and attention has fascinated researchers for decades. Many previous studies have used eye-tracking, ERP, MEG and fMRI to explore this issue but have reached different conclusions: some researchers hold that emotion cognition is an automatic process and independent of attention, while some others believed that emotion cognition is modulated by attentional resources and is a type of controlled processing. The present research aimed to investigate this controversy, and we hypothesized that the attentional dependence of emotion cognition is variable with the competing task. Eye-tracking technology and a dual-task paradigm were adopted, and subjects’ attention was manipulated to fixate at the central task to investigate whether subjects could detect the emotional faces presented in the peripheral area with a decrease or near-absence of attention. The results revealed that when the peripheral task was emotional face discrimination but the central attention-demanding task was different, subjects performed well in the peripheral task, which means that emotional information can be processed in parallel with other stimuli, and there may be a specific channel in the human brain for processing emotional information. However, when the central and peripheral tasks were both emotional face discrimination, subjects could not perform well in the peripheral task, indicating that the processing of emotional information required attentional resources and that it is a type of controlled processing. Therefore, we concluded that the attentional dependence of emotion cognition varied with the competing task.

  6. Evaluating the Impact of Antibiotic Exposures as Time-Dependent Variables on the Acquisition of Carbapenem-Resistant Acinetobacter baumannii.

    Science.gov (United States)

    Munoz-Price, L Silvia; Rosa, Rossana; Castro, Jose G; Laowansiri, Panthipa; Latibeaudiere, Rachel; Namias, Nicholas; Tarima, Sergey

    2016-10-01

    To determine the time-dependent effect of antibiotics on the initial acquisition of carbapenem-resistant Acinetobacter baumannii. Retrospective cohort study. Forty-bed trauma ICU in Miami, FL. All consecutive patients admitted to the unit from November 1, 2010, to November 30, 2011. None. Patients underwent surveillance cultures at admission to the unit and weekly thereafter. The primary outcome was the acquisition of carbapenem-resistant A. baumannii on surveillance cultures. Daily antibiotic exposures during the time of observation were used to construct time-dependent variables, including cumulative exposures (in grams and daily observed doses [defined daily doses]). Among 360 patients, 45 (12.5%) became colonized with carbapenem-resistant A. baumannii. Adjusted Cox models showed that each additional point in the Acute Physiologic and Chronic Health Evaluation score increased the hazard by 4.8% (hazard ratio, 1.048; 95% CI, 1.010-1.087; p = 0.0124) and time-dependent exposure to carbapenems quadrupled the hazard (hazard ratio, 4.087; 95% CI, 1.873-8.920; p = 0.0004) of acquiring carbapenem-resistant A. baumannii. Additionally, adjusted Cox models determined that every additional carbapenem defined daily dose increased the hazard of acquiring carbapenem-resistant A. baumannii by 5.1% (hazard ratio, 1.051; 95% CI, 1.007-1.093; p = 0.0243). Carbapenem exposure quadrupled the hazards of acquiring A. baumannii even after controlling for severity of illness.

  7. Demographic models reveal the shape of density dependence for a specialist insect herbivore on variable host plants.

    Science.gov (United States)

    Miller, Tom E X

    2007-07-01

    1. It is widely accepted that density-dependent processes play an important role in most natural populations. However, persistent challenges in our understanding of density-dependent population dynamics include evaluating the shape of the relationship between density and demographic rates (linear, concave, convex), and identifying extrinsic factors that can mediate this relationship. 2. I studied the population dynamics of the cactus bug Narnia pallidicornis on host plants (Opuntia imbricata) that varied naturally in relative reproductive effort (RRE, the proportion of meristems allocated to reproduction), an important plant quality trait. I manipulated per-plant cactus bug densities, quantified subsequent dynamics, and fit stage-structured models to the experimental data to ask if and how density influences demographic parameters. 3. In the field experiment, I found that populations with variable starting densities quickly converged upon similar growth trajectories. In the model-fitting analyses, the data strongly supported a model that defined the juvenile cactus bug retention parameter (joint probability of surviving and not dispersing) as a nonlinear decreasing function of density. The estimated shape of this relationship shifted from concave to convex with increasing host-plant RRE. 4. The results demonstrate that host-plant traits are critical sources of variation in the strength and shape of density dependence in insects, and highlight the utility of integrated experimental-theoretical approaches for identifying processes underlying patterns of change in natural populations.

  8. Resistor capacitor, primitive variable solution of buoyant fluid flow within an enclosure with highly temperature dependent viscosity

    Energy Technology Data Exchange (ETDEWEB)

    Burns, S.P. [Texas Univ., Austin, TX (United States); Gianoulakis, S.E. [Sandia National Labs., Albuquerque, NM (United States)

    1995-07-01

    A numerical solution for buoyant natural convection within a square enclosure containing a fluid with highly temperature dependent viscosity is presented. Although the fluid properties employed do not represent any real fluid, the large variation in the fluid viscosity with temperature is characteristic of turbulent flow modeling with eddy-viscosity concepts. Results are obtained using a primitive variable formulation and the resistor method. The results presented include velocity, temperature and pressure distributions within the enclosure as well as shear stress and heat flux distributions along the enclosure walls. Three mesh refinements were employed and uncertainty values are suggested for the final mesh refinement. These solutions are part of a contributed benchmark solution set for the subject problem.

  9. Robust Variance Estimation with Dependent Effect Sizes: Practical Considerations Including a Software Tutorial in Stata and SPSS

    Science.gov (United States)

    Tanner-Smith, Emily E.; Tipton, Elizabeth

    2014-01-01

    Methodologists have recently proposed robust variance estimation as one way to handle dependent effect sizes in meta-analysis. Software macros for robust variance estimation in meta-analysis are currently available for Stata (StataCorp LP, College Station, TX, USA) and SPSS (IBM, Armonk, NY, USA), yet there is little guidance for authors regarding…

  10. The Dependence of Cloud Particle Size on Non-Aerosol-Loading Related Variables

    Energy Technology Data Exchange (ETDEWEB)

    Shao, H.; Liu, G.

    2005-03-18

    An enhanced concentration of aerosol may increase the number of cloud drops by providing more cloud condensation nuclei (CCN), which in turn results in a higher cloud albedo at a constant cloud liquid water path. This process is often referred to as the aerosol indirect effect (AIE). Many in situ and remote sensing observations support this hypothesis (Ramanathan et al. 2001). However, satellite observed relations between aerosol concentration and cloud drop size are not always in agreement with the AIE. Based on global analysis of cloud effective radius (r{sub e}) and aerosol number concentration (N{sub a}) derived from satellite data, Sekiguchi et al. (2003) found that the correlations between the two variables can be either negative, or positive, or none, depending on the location of the clouds. They discovered that significantly negative r{sub e} - N{sub a} correlation can only be identified along coastal regions of the continents where abundant continental aerosols inflow from land, whereas Feingold et al. (2001) found that the response of r{sub e} to aerosol loading is the greatest in the region where aerosol optical depth ({tau}{sub a}) is the smallest. The reason for the discrepancy is likely due to the variations in cloud macroscopic properties such as geometrical thickness (Brenguier et al. 2003). Since r{sub e} is modified not only by aerosol but also by cloud geometrical thickness (H), the correlation between re and {tau}{sub a} actually reflects both the aerosol indirect effect and dependence of H. Therefore, discussing AIE based on the r{sub e}-{tau}{sub a} correlation without taking into account variations in cloud geometrical thickness may be misleading. This paper is motivated to extract aerosols' effect from overall effects using the independent measurements of cloud geometrical thickness, {tau}{sub a} and r{sub e}.

  11. Time-dependence in relativistic collisionless shocks: theory of the variable

    Energy Technology Data Exchange (ETDEWEB)

    Spitkovsky, A

    2004-02-05

    We describe results from time-dependent numerical modeling of the collisionless reverse shock terminating the pulsar wind in the Crab Nebula. We treat the upstream relativistic wind as composed of ions and electron-positron plasma embedded in a toroidal magnetic field, flowing radially outward from the pulsar in a sector around the rotational equator. The relativistic cyclotron instability of the ion gyrational orbit downstream of the leading shock in the electron-positron pairs launches outward propagating magnetosonic waves. Because of the fresh supply of ions crossing the shock, this time-dependent process achieves a limit-cycle, in which the waves are launched with periodicity on the order of the ion Larmor time. Compressions in the magnetic field and pair density associated with these waves, as well as their propagation speed, semi-quantitatively reproduce the behavior of the wisp and ring features described in recent observations obtained using the Hubble Space Telescope and the Chandra X-Ray Observatory. By selecting the parameters of the ion orbits to fit the spatial separation of the wisps, we predict the period of time variability of the wisps that is consistent with the data. When coupled with a mechanism for non-thermal acceleration of the pairs, the compressions in the magnetic field and plasma density associated with the optical wisp structure naturally account for the location of X-ray features in the Crab. We also discuss the origin of the high energy ions and their acceleration in the equatorial current sheet of the pulsar wind.

  12. Nanostructures study of CNT nanofluids transport with temperature-dependent variable viscosity in a muscular tube

    Science.gov (United States)

    Akbar, Noreen Sher; Abid, Syed Ali; Tripathi, Dharmendra; Mir, Nazir Ahmed

    2017-03-01

    The transport of single-wall carbon nanotube (CNT) nanofluids with temperature-dependent variable viscosity is analyzed by peristaltically driven flow. The main flow problem has been modeled using cylindrical coordinates and flow equations are simplified to ordinary differential equations using long wavelength and low Reynolds' number approximation. Analytical solutions have been obtained for axial velocity, pressure gradient and temperature. Results acquired are discussed graphically for better understanding. It is observed that with an increment in the Grashof number the velocity of the governing fluids starts to decrease significantly and the pressure gradient is higher for pure water as compared to single-walled carbon nanotubes due to low density. As the specific heat is very high for pure water as compared to the multi-wall carbon nanotubes, it raises temperature of the muscles, in the case of pure water, as compared to the multi-walled carbon nanotubes. Furthermore, it is noticed that the trapped bolus starts decreasing in size as the buoyancy forces are dominant as compared to viscous forces. This model may be applicable in biomedical engineering and nanotechnology to design the biomedical devices.

  13. Alaskan soil carbon stocks: spatial variability and dependence on environmental factors

    Directory of Open Access Journals (Sweden)

    U. Mishra

    2012-09-01

    Full Text Available The direction and magnitude of soil organic carbon (SOC changes in response to climate change depend on the spatial and vertical distributions of SOC. We estimated spatially resolved SOC stocks from surface to C horizon, distinguishing active-layer and permafrost-layer stocks, based on geospatial analysis of 472 soil profiles and spatially referenced environmental variables for Alaska. Total Alaska state-wide SOC stock was estimated to be 77 Pg, with 61% in the active-layer, 27% in permafrost, and 12% in non-permafrost soils. Prediction accuracy was highest for the active-layer as demonstrated by highest ratio of performance to deviation (1.5. Large spatial variability was predicted, with whole-profile, active-layer, and permafrost-layer stocks ranging from 1–296 kg C m−2, 2–166 kg m−2, and 0–232 kg m−2, respectively. Temperature and soil wetness were found to be primary controllers of whole-profile, active-layer, and permafrost-layer SOC stocks. Secondary controllers, in order of importance, were found to be land cover type, topographic attributes, and bedrock geology. The observed importance of soil wetness rather than precipitation on SOC stocks implies that the poor representation of high-latitude soil wetness in Earth system models may lead to large uncertainty in predicted SOC stocks under future climate change scenarios. Under strict caveats described in the text and assuming temperature changes from the A1B Intergovernmental Panel on Climate Change emissions scenario, our geospatial model indicates that the equilibrium average 2100 Alaska active-layer depth could deepen by 11 cm, resulting in a thawing of 13 Pg C currently in permafrost. The equilibrium SOC loss associated with this warming would be highest under continuous permafrost (31%, followed by discontinuous (28%, isolated (24.3%, and sporadic (23.6% permafrost areas. Our high-resolution mapping of soil carbon stock reveals the

  14. Robust variance estimation with dependent effect sizes: practical considerations including a software tutorial in Stata and spss.

    Science.gov (United States)

    Tanner-Smith, Emily E; Tipton, Elizabeth

    2014-03-01

    Methodologists have recently proposed robust variance estimation as one way to handle dependent effect sizes in meta-analysis. Software macros for robust variance estimation in meta-analysis are currently available for Stata (StataCorp LP, College Station, TX, USA) and spss (IBM, Armonk, NY, USA), yet there is little guidance for authors regarding the practical application and implementation of those macros. This paper provides a brief tutorial on the implementation of the Stata and spss macros and discusses practical issues meta-analysts should consider when estimating meta-regression models with robust variance estimates. Two example databases are used in the tutorial to illustrate the use of meta-analysis with robust variance estimates. Copyright © 2013 John Wiley & Sons, Ltd.

  15. Characterization of SiO2/SiC interface states and channel mobility from MOSFET characteristics including variable-range hopping at cryogenic temperature

    Directory of Open Access Journals (Sweden)

    Hironori Yoshioka

    2018-04-01

    Full Text Available The characteristics of SiC MOSFETs (drain current vs. gate voltage were measured at 0.14−350 K and analyzed considering variable-range hopping conduction through interface states. The total interface state density was determined to be 5.4×1012 cm−2 from the additional shift in the threshold gate voltage with a temperature change. The wave-function size of interface states was determined from the temperature dependence of the measured hopping current and was comparable to the theoretical value. The channel mobility was approximately 100 cm2V−1s−1 and was almost independent of temperature.

  16. Characterization of SiO2/SiC interface states and channel mobility from MOSFET characteristics including variable-range hopping at cryogenic temperature

    Science.gov (United States)

    Yoshioka, Hironori; Hirata, Kazuto

    2018-04-01

    The characteristics of SiC MOSFETs (drain current vs. gate voltage) were measured at 0.14-350 K and analyzed considering variable-range hopping conduction through interface states. The total interface state density was determined to be 5.4×1012 cm-2 from the additional shift in the threshold gate voltage with a temperature change. The wave-function size of interface states was determined from the temperature dependence of the measured hopping current and was comparable to the theoretical value. The channel mobility was approximately 100 cm2V-1s-1 and was almost independent of temperature.

  17. Conductance of partially disordered graphene: crossover from temperature-dependent to field-dependent variable-range hopping

    International Nuclear Information System (INIS)

    Cheah, C Y; Jaurigue, L C; Kaiser, A B; Gómez-Navarro, C

    2013-01-01

    We report an analysis of low-temperature measurements of the conductance of partially disordered reduced graphene oxide, finding that the data follow a simple crossover scenario. At room temperature, the conductance is dominated by two-dimensional (2D) electric field-assisted, thermally driven (Pollak–Riess) variable-range hopping (VRH) through highly disordered regions. However, at lower temperatures T, we find a smooth crossover to follow the exp(−E 0 /E) 1/3 field-driven (Shklovskii) 2D VRH conductance behaviour when the electric field E exceeds a specific crossover value E C (T) 2D =(E a E 0 1/3 /3) 3/4 determined by the scale factors E 0 and E a for the high-field and intermediate-field regimes respectively. Our crossover scenario also accounts well for experimental data reported by other authors for three-dimensional disordered carbon networks, suggesting wide applicability. (paper)

  18. Outer membrane targeting of Pseudomonas aeruginosa proteins shows variable dependence on the components of Bam and Lol machineries.

    Science.gov (United States)

    Hoang, Hanh H; Nickerson, Nicholas N; Lee, Vincent T; Kazimirova, Anastasia; Chami, Mohamed; Pugsley, Anthony P; Lory, Stephen

    2011-01-01

    In Gram-negative bacteria, the Lol and Bam machineries direct the targeting of lipidated and nonlipidated proteins, respectively, to the outer membrane (OM). Using Pseudomonas aeruginosa strains with depleted levels of specific Bam and Lol proteins, we demonstrated a variable dependence of different OM proteins on these targeting pathways. Reduction in the level of BamA significantly affected the ability of the β-barrel membrane protein OprF to localize to the OM, while the targeting of three secretins that are functionally related OM proteins was less affected (PilQ and PscC) or not at all affected (XcpQ). Depletion of LolB affected all lipoproteins examined and had a variable effect on the nonlipidated proteins. While the levels of OprF, PilQ, and PscC were significantly reduced by LolB depletion, XcpQ was unaffected and was correctly localized to the OM. These results suggest that certain β-barrel proteins such as OprF primarily utilize the complete Bam machinery. The Lol machinery participates in the OM targeting of secretins to variable degrees, likely through its involvement in the assembly of lipidated Bam components. XcpQ, but not PilQ or PscC, was shown to assemble spontaneously into liposomes as multimers. This work raises the possibility that there is a gradient of utilization of Bam and Lol insertion and targeting machineries. Structural features of individual proteins, including their β-barrel content, may determine the propensity of these proteins for folding (or misfolding) during periplasmic transit and OM insertion, thereby influencing the extent of utilization of the Bam targeting machinery, respectively. Targeting of lipidated and nonlipidated proteins to the outer membrane (OM) compartment in Gram-negative bacteria involves the transfer across the periplasm utilizing the Lol and Bam machineries, respectively. We show that depletion of Bam and Lol components in Pseudomonas aeruginosa does not lead to a general OM protein translocation defect

  19. pH-dependent release of trace elements including platinum group elements (PGEs) from gasoline and diesel catalysts

    Science.gov (United States)

    Sucha, Veronika; Mihaljevic, Martin; Ettler, Vojtech; Strnad, Ladislav

    2014-05-01

    The release of trace metals and platinum group elements (PGEs) from automobile exhaust catalysts represents a remarkable source of higly dispersed environmental contamination. Especially, PGEs have shown increasing research interest due to their possible bioaccessibility. In our research, we focused on leaching behaviour of trace metals from gasoline and diesel automobile catalysts. While catalysts for gasoline engines contain a mixture of Pt-Pd-Rh or Pd-Rh, catalysts for diesel engines are composed only of Pt. We used dust from two crushed gasoline and two crushed diesel catalysts (new and aged). The dust of gasoline catalysts contains significant concentrations of Pt (700 mg.kg-1), Pd (11 000 mg.kg-1) and Rh (700 mg.kg-1). And the dust of diesel catalysts are composed of Pt (3 900 mg.kg-1) and they contains negligible amounts of Pd dan Rh (leaching of trace metals from dust we used pH-stat leaching test according to the European standard CEN/TS 14997. The concentrations of cations: PGEs (Pt, Pd a Rh), K, Na, Ca, Mg, Al, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, La and Ce were determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS), and anions: F-, Cl-, SO42- and NO3- by high-performance liquid chromatography. Although the dusts from catalysts were relatively stable to acid/base influence, the leaching of trace metals from catalysts showed a dependence on pH. Generally, the highest concentrations were released under acidic conditions. The leaching of PGEs was higher for Pt in diesel catalysts and for Pd and Rh in gasoline catalysts. The highest concentrations of Zn and Pb were observed in old catalysts. The rare earth metals were released more from gasoline catalysts. Catalysts particles represent health risk especially with respect to their PGEs contents.

  20. The HTLV-1 Tax protein binding domain of cyclin-dependent kinase 4 (CDK4 includes the regulatory PSTAIRE helix

    Directory of Open Access Journals (Sweden)

    Grassmann Ralph

    2005-09-01

    Full Text Available Abstract Background The Tax oncoprotein of human T-cell leukemia virus type 1 (HTLV-1 is leukemogenic in transgenic mice and induces permanent T-cell growth in vitro. It is found in active CDK holoenzyme complexes from adult T-cell leukemia-derived cultures and stimulates the G1- to-S phase transition by activating the cyclin-dependent kinase (CDK CDK4. The Tax protein directly and specifically interacts with CDK4 and cyclin D2 and binding is required for enhanced CDK4 kinase activity. The protein-protein contact between Tax and the components of the cyclin D/CDK complexes increases the association of CDK4 and its positive regulatory subunit cyclin D and renders the complex resistant to p21CIP inhibition. Tax mutants affecting the N-terminus cannot bind cyclin D and CDK4. Results To analyze, whether the N-terminus of Tax is capable of CDK4-binding, in vitro binding -, pull down -, and mammalian two-hybrid analyses were performed. These experiments revealed that a segment of 40 amino acids is sufficient to interact with CDK4 and cyclin D2. To define a Tax-binding domain and analyze how Tax influences the kinase activity, a series of CDK4 deletion mutants was tested. Different assays revealed two regions which upon deletion consistently result in reduced binding activity. These were isolated and subjected to mammalian two-hybrid analysis to test their potential to interact with the Tax N-terminus. These experiments concurrently revealed binding at the N- and C-terminus of CDK4. The N-terminal segment contains the PSTAIRE helix, which is known to control the access of substrate to the active cleft of CDK4 and thus the kinase activity. Conclusion Since the N- and C-terminus of CDK4 are neighboring in the predicted three-dimensional protein structure, it is conceivable that they comprise a single binding domain, which interacts with the Tax N-terminus.

  1. The Relationship of Field Dependent/Independent Cognitive Styles, Stimuli Variability and Time Factor on Student Achievement.

    Science.gov (United States)

    Atang, Christopher I.

    The effects of black and white and color illustrations on student achievement were studied to investigate the relationships between cognitive styles and instructional design. Field dependence (FD) and field independence (FI) were chosen as the cognitive style variables. Subjects were 85 freshman students in the Iowa State University Psychology…

  2. Time-Dependent Drug Administration in Hypertension and its Effect on Blood Pressure Variability

    Directory of Open Access Journals (Sweden)

    Magdás Annamária

    2017-06-01

    Full Text Available Background: Optimizing blood pressure variability seems to represent a new therapeutic target in the management of hypertension. It is emphasized that scheduling at least one antihypertensive agent at bedtime, has the ability to reduce blood pressure.

  3. Time-Dependent Drug Administration in Hypertension and its Effect on Blood Pressure Variability

    OpenAIRE

    Magdás Annamária; Podoleanu Cristian; Tusa Anna-Boróka; Găburoi Adina; Incze Alexandru

    2017-01-01

    Background: Optimizing blood pressure variability seems to represent a new therapeutic target in the management of hypertension. It is emphasized that scheduling at least one antihypertensive agent at bedtime, has the ability to reduce blood pressure.

  4. The Variability of Atmospheric Deuterium Brightness at Mars: Evidence for Seasonal Dependence

    Science.gov (United States)

    Mayyasi, Majd; Clarke, John; Bhattacharyya, Dolon; Deighan, Justin; Jain, Sonal; Chaffin, Michael; Thiemann, Edward; Schneider, Nick; Jakosky, Bruce

    2017-10-01

    The enhanced ratio of deuterium to hydrogen on Mars has been widely interpreted as indicating the loss of a large column of water into space, and the hydrogen content of the upper atmosphere is now known to be highly variable. The variation in the properties of both deuterium and hydrogen in the upper atmosphere of Mars is indicative of the dynamical processes that produce these species and propagate them to altitudes where they can escape the planet. Understanding the seasonal variability of D is key to understanding the variability of the escape rate of water from Mars. Data from a 15 month observing campaign, made by the Mars Atmosphere and Volatile Evolution Imaging Ultraviolet Spectrograph high-resolution echelle channel, are used to determine the brightness of deuterium as observed at the limb of Mars. The D emission is highly variable, with a peak in brightness just after southern summer solstice. The trends of D brightness are examined against extrinsic as well as intrinsic sources. It is found that the fluctuations in deuterium brightness in the upper atmosphere of Mars (up to 400 km), corrected for periodic solar variations, vary on timescales that are similar to those of water vapor fluctuations lower in the atmosphere (20-80 km). The observed variability in deuterium may be attributed to seasonal factors such as regional dust storm activity and subsequent circulation lower in the atmosphere.

  5. On history dependence of stress-strain diagrams and creep curves under variable repeated loading

    International Nuclear Information System (INIS)

    Gokhfeld, D.A.; Sadakov, O.S.; Martynenko, M.E.

    1979-01-01

    The ability of structural alloys to 'keep in memory' the loading prehistory becomes of special importance when inelastic variable repeated loading is considered. There are two main approaches to the development of the mathematical description of this phenomenon: the inclusion of hidden state variables in the incremental theory constitutive equations (a) and construction of proper hereditary functionals (b). In this respect the assumption that the 'memory' regarding the previous deformation history is due to structural nonhomogeneity of actual materials proves to be fruitful. (orig.)

  6. Distance and Azimuthal Dependence of Ground‐Motion Variability for Unilateral Strike‐Slip Ruptures

    KAUST Repository

    Vyas, Jagdish Chandra; Mai, Paul Martin; Galis, Martin

    2016-01-01

    We investigate near‐field ground‐motion variability by computing the seismic wavefield for five kinematic unilateral‐rupture models of the 1992 Mw 7.3 Landers earthquake, eight simplified unilateral‐rupture models based on the Landers event, and a

  7. Phase dependence of transport-aperture coordination variability reveals control strategy of reach-to-grasp movements.

    Science.gov (United States)

    Rand, Miya K; Shimansky, Y P; Hossain, Abul B M I; Stelmach, George E

    2010-11-01

    Based on an assumption of movement control optimality in reach-to-grasp movements, we have recently developed a mathematical model of transport-aperture coordination (TAC), according to which the hand-target distance is a function of hand velocity and acceleration, aperture magnitude, and aperture velocity and acceleration (Rand et al. in Exp Brain Res 188:263-274, 2008). Reach-to-grasp movements were performed by young adults under four different reaching speeds and two different transport distances. The residual error magnitude of fitting the above model to data across different trials and subjects was minimal for the aperture-closure phase, but relatively much greater for the aperture-opening phase, indicating considerable difference in TAC variability between those phases. This study's goal is to identify the main reasons for that difference and obtain insights into the control strategy of reach-to-grasp movements. TAC variability within the aperture-opening phase of a single trial was found minimal, indicating that TAC variability between trials was not due to execution noise, but rather a result of inter-trial and inter-subject variability of motor plan. At the same time, the dependence of the extent of trial-to-trial variability of TAC in that phase on the speed of hand transport was sharply inconsistent with the concept of speed-accuracy trade-off: the lower the speed, the larger the variability. Conversely, the dependence of the extent of TAC variability in the aperture-closure phase on hand transport speed was consistent with that concept. Taking into account recent evidence that the cost of neural information processing is substantial for movement planning, the dependence of TAC variability in the aperture-opening phase on task performance conditions suggests that it is not the movement time that the CNS saves in that phase, but the cost of neuro-computational resources and metabolic energy required for TAC regulation in that phase. Thus, the CNS

  8. Morphometric variability of mandible linear characteristics depending on level of teeth alveolus position

    Directory of Open Access Journals (Sweden)

    Olga Yu. Aleshkina

    2017-05-01

    Results and Conclusion ― The highest altitude was marked at levels of incisors and 3rd molar, the smallest one – at level of 1st and 2nd molars; maximum mandible thickness was defined at level of 2nd molar, minimum – at levels of canine and 1st – 2nd premolars on both sides of mandible; average thickness was revealed at levels of incisors, 1st and 2nd molars and had the same statistical values. Bilateral variability of thickness was significantly dominating on the right side and only at levels of 1st – 2nd premolars and 1st molar. Average values of altitude and thickness from both sides of mandible and at all levels had medium degree of variability.

  9. Scale-dependent spatial variability in peatland lead pollution in the southern Pennines, UK

    International Nuclear Information System (INIS)

    Rothwell, James J.; Evans, Martin G.; Lindsay, John B.; Allott, Timothy E.H.

    2007-01-01

    Increasingly, within-site and regional comparisons of peatland lead pollution have been undertaken using the inventory approach. The peatlands of the Peak District, southern Pennines, UK, have received significant atmospheric inputs of lead over the last few hundred years. A multi-core study at three peatland sites in the Peak District demonstrates significant within-site spatial variability in industrial lead pollution. Stochastic simulations reveal that 15 peat cores are required to calculate reliable lead inventories at the within-site and within-region scale for this highly polluted area of the southern Pennines. Within-site variability in lead pollution is dominant at the within-region scale. The study demonstrates that significant errors may be associated with peatland lead inventories at sites where only a single peat core has been used to calculate an inventory. Meaningful comparisons of lead inventories at the regional or global scale can only be made if the within-site variability of lead pollution has been quantified reliably. - Multiple peat cores are required for accurate peatland Pb inventories

  10. Scale-dependent spatial variability in peatland lead pollution in the southern Pennines, UK.

    Science.gov (United States)

    Rothwell, James J; Evans, Martin G; Lindsay, John B; Allott, Timothy E H

    2007-01-01

    Increasingly, within-site and regional comparisons of peatland lead pollution have been undertaken using the inventory approach. The peatlands of the Peak District, southern Pennines, UK, have received significant atmospheric inputs of lead over the last few hundred years. A multi-core study at three peatland sites in the Peak District demonstrates significant within-site spatial variability in industrial lead pollution. Stochastic simulations reveal that 15 peat cores are required to calculate reliable lead inventories at the within-site and within-region scale for this highly polluted area of the southern Pennines. Within-site variability in lead pollution is dominant at the within-region scale. The study demonstrates that significant errors may be associated with peatland lead inventories at sites where only a single peat core has been used to calculate an inventory. Meaningful comparisons of lead inventories at the regional or global scale can only be made if the within-site variability of lead pollution has been quantified reliably.

  11. Natural variability of biochemical biomarkers in the macro-zoobenthos: Dependence on life stage and environmental factors.

    Science.gov (United States)

    Scarduelli, Lucia; Giacchini, Roberto; Parenti, Paolo; Migliorati, Sonia; Di Brisco, Agnese Maria; Vighi, Marco

    2017-11-01

    Biomarkers are widely used in ecotoxicology as indicators of exposure to toxicants. However, their ability to provide ecologically relevant information remains controversial. One of the major problems is understanding whether the measured responses are determined by stress factors or lie within the natural variability range. In a previous work, the natural variability of enzymatic levels in invertebrates sampled in pristine rivers was proven to be relevant across both space and time. In the present study, the experimental design was improved by considering different life stages of the selected taxa and by measuring more environmental parameters. The experimental design considered sampling sites in 2 different rivers, 8 sampling dates covering the whole seasonal cycle, 4 species from 3 different taxonomic groups (Plecoptera, Perla grandis; Ephemeroptera, Baetis alpinus and Epeorus alpicula; Tricoptera, Hydropsyche pellucidula), different life stages for each species, and 4 enzymes (acetylcholinesterase, glutathione S-transferase, alkaline phosphatase, and catalase). Biomarker levels were related to environmental (physicochemical) parameters to verify any kind of dependence. Data were statistically elaborated using hierarchical multilevel Bayesian models. Natural variability was found to be relevant across both space and time. The results of the present study proved that care should be paid when interpreting biomarker results. Further research is needed to better understand the dependence of the natural variability on environmental parameters. Environ Toxicol Chem 2017;36:3158-3167. © 2017 SETAC. © 2017 SETAC.

  12. Assessment of variability in the hydrological cycle of the Loess Plateau, China: examining dependence structures of hydrological processes

    Science.gov (United States)

    Guo, A.; Wang, Y.

    2017-12-01

    Investigating variability in dependence structures of hydrological processes is of critical importance for developing an understanding of mechanisms of hydrological cycles in changing environments. In focusing on this topic, present work involves the following: (1) identifying and eliminating serial correlation and conditional heteroscedasticity in monthly streamflow (Q), precipitation (P) and potential evapotranspiration (PE) series using the ARMA-GARCH model (ARMA: autoregressive moving average; GARCH: generalized autoregressive conditional heteroscedasticity); (2) describing dependence structures of hydrological processes using partial copula coupled with the ARMA-GARCH model and identifying their variability via copula-based likelihood-ratio test method; and (3) determining conditional probability of annual Q under different climate scenarios on account of above results. This framework enables us to depict hydrological variables in the presence of conditional heteroscedasticity and to examine dependence structures of hydrological processes while excluding the influence of covariates by using partial copula-based ARMA-GARCH model. Eight major catchments across the Loess Plateau (LP) are used as study regions. Results indicate that (1) The occurrence of change points in dependence structures of Q and P (PE) varies across the LP. Change points of P-PE dependence structures in all regions almost fully correspond to the initiation of global warming, i.e., the early 1980s. (3) Conditional probabilities of annual Q under various P and PE scenarios are estimated from the 3-dimensional joint distribution of (Q, P and PE) based on the above change points. These findings shed light on mechanisms of the hydrological cycle and can guide water supply planning and management, particularly in changing environments.

  13. A SEARCH FOR L/T TRANSITION DWARFS WITH Pan-STARRS1 AND WISE: DISCOVERY OF SEVEN NEARBY OBJECTS INCLUDING TWO CANDIDATE SPECTROSCOPIC VARIABLES

    International Nuclear Information System (INIS)

    Best, William M. J.; Liu, Michael C.; Magnier, Eugene A.; Aller, Kimberly M.; Burgett, W. S.; Chambers, K. C.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J.; Deacon, Niall R.; Dupuy, Trent J.; Redstone, Joshua; Price, P. A.

    2013-01-01

    We present initial results from a wide-field (30,000 deg 2 ) search for L/T transition brown dwarfs within 25 pc using the Pan-STARRS1 and Wide-field Infrared Survey Explorer (WISE) surveys. Previous large-area searches have been incomplete for L/T transition dwarfs, because these objects are faint in optical bands and have near-infrared (near-IR) colors that are difficult to distinguish from background stars. To overcome these obstacles, we have cross-matched the Pan-STARRS1 (optical) and WISE (mid-IR) catalogs to produce a unique multi-wavelength database for finding ultracool dwarfs. As part of our initial discoveries, we have identified seven brown dwarfs in the L/T transition within 9-15 pc of the Sun. The L9.5 dwarf PSO J140.2308+45.6487 and the T1.5 dwarf PSO J307.6784+07.8263 (both independently discovered by Mace et al.) show possible spectroscopic variability at the Y and J bands. Two more objects in our sample show evidence of photometric J-band variability, and two others are candidate unresolved binaries based on their spectra. We expect our full search to yield a well-defined, volume-limited sample of L/T transition dwarfs that will include many new targets for study of this complex regime. PSO J307.6784+07.8263 in particular may be an excellent candidate for in-depth study of variability, given its brightness (J = 14.2 mag) and proximity (11 pc)

  14. A SEARCH FOR L/T TRANSITION DWARFS WITH Pan-STARRS1 AND WISE: DISCOVERY OF SEVEN NEARBY OBJECTS INCLUDING TWO CANDIDATE SPECTROSCOPIC VARIABLES

    Energy Technology Data Exchange (ETDEWEB)

    Best, William M. J.; Liu, Michael C.; Magnier, Eugene A.; Aller, Kimberly M.; Burgett, W. S.; Chambers, K. C.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Deacon, Niall R. [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Dupuy, Trent J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Redstone, Joshua [Facebook, 335 Madison Ave, New York, NY 10017-4677 (United States); Price, P. A., E-mail: wbest@ifa.hawaii.edu [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2013-11-10

    We present initial results from a wide-field (30,000 deg{sup 2}) search for L/T transition brown dwarfs within 25 pc using the Pan-STARRS1 and Wide-field Infrared Survey Explorer (WISE) surveys. Previous large-area searches have been incomplete for L/T transition dwarfs, because these objects are faint in optical bands and have near-infrared (near-IR) colors that are difficult to distinguish from background stars. To overcome these obstacles, we have cross-matched the Pan-STARRS1 (optical) and WISE (mid-IR) catalogs to produce a unique multi-wavelength database for finding ultracool dwarfs. As part of our initial discoveries, we have identified seven brown dwarfs in the L/T transition within 9-15 pc of the Sun. The L9.5 dwarf PSO J140.2308+45.6487 and the T1.5 dwarf PSO J307.6784+07.8263 (both independently discovered by Mace et al.) show possible spectroscopic variability at the Y and J bands. Two more objects in our sample show evidence of photometric J-band variability, and two others are candidate unresolved binaries based on their spectra. We expect our full search to yield a well-defined, volume-limited sample of L/T transition dwarfs that will include many new targets for study of this complex regime. PSO J307.6784+07.8263 in particular may be an excellent candidate for in-depth study of variability, given its brightness (J = 14.2 mag) and proximity (11 pc)

  15. Time-dependent inelastic analysis of metallic media using constitutive relations with state variables

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, V; Mukherjee, S [Cornell Univ., Ithaca, N.Y. (USA)

    1977-03-01

    A computational technique in terms of stress, strain and displacement rates is presented for the solution of boundary value problems for metallic structural elements at uniform elevated temperatures subjected to time varying loads. This method can accommodate any number of constitutive relations with state variables recently proposed by other researchers to model the inelastic deformation of metallic media at elevated temperatures. Numerical solutions are obtained for several structural elements subjected to steady loads. The constitutive relations used for these numerical solutions are due to Hart. The solutions are discussed in the context of the computational scheme and Hart's theory.

  16. SECOND ORDER LEAST SQUARE ESTIMATION ON ARCH(1 MODEL WITH BOX-COX TRANSFORMED DEPENDENT VARIABLE

    Directory of Open Access Journals (Sweden)

    Herni Utami

    2014-03-01

    Full Text Available Box-Cox transformation is often used to reduce heterogeneity and to achieve a symmetric distribution of response variable. In this paper, we estimate the parameters of Box-Cox transformed ARCH(1 model using second-order leastsquare method and then we study the consistency and asymptotic normality for second-order least square (SLS estimators. The SLS estimation was introduced byWang (2003, 2004 to estimate the parameters of nonlinear regression models with independent and identically distributed errors

  17. THE DIFFERENCES IN MORAL, GROUP IDENTITY AND THE PERCON’S VARIABILITY DEPENDING ON THE EDUCATION

    Directory of Open Access Journals (Sweden)

    Irina Aleksandrobna Kolinichenko

    2017-06-01

    Results. The results of the study have revealed the dominance of all specified assessment parameters in the group of test subjects with incomplete higher education: higher level of moral development in all dilemmas (the opposition of life values (compassion and following the law, self-interest – the interests of the city (law, business (benefit and law, personal interests (career and the freedom of another person, except for the dilemma of the opposition between the interests of a majority and a single person. The differences have also been revealed between the two groups of test subjects according to the group identity, group variability, the desirability of the common categories of identity.

  18. Dependence of conductivity on thickness within the variable-range hopping regime for Coulomb glasses

    Directory of Open Access Journals (Sweden)

    M. Caravaca

    Full Text Available In this paper, we provide some computational evidence concerning the dependence of conductivity on the system thickness for Coulomb glasses. We also verify the Efros–Shklovskii law and deal with the calculation of its characteristic parameter as a function of the thickness. Our results strengthen the link between theoretical and experimental fields. Keywords: Coulomb glass, Conductivity, Density of states, Efros–Shklovskii law

  19. Temperature-dependent behaviours are genetically variable in the nematode Caenorhabditis briggsae.

    Science.gov (United States)

    Stegeman, Gregory W; de Mesquita, Matthew Bueno; Ryu, William S; Cutter, Asher D

    2013-03-01

    Temperature-dependent behaviours in Caenorhabditis elegans, such as thermotaxis and isothermal tracking, are complex behavioural responses that integrate sensation, foraging and learning, and have driven investigations to discover many essential genetic and neural pathways. The ease of manipulation of the Caenorhabditis model system also has encouraged its application to comparative analyses of phenotypic evolution, particularly contrasts of the classic model C. elegans with C. briggsae. And yet few studies have investigated natural genetic variation in behaviour in any nematode. Here we measure thermotaxis and isothermal tracking behaviour in genetically distinct strains of C. briggsae, further motivated by the latitudinal differentiation in C. briggsae that is associated with temperature-dependent fitness differences in this species. We demonstrate that C. briggsae performs thermotaxis and isothermal tracking largely similar to that of C. elegans, with a tendency to prefer its rearing temperature. Comparisons of these behaviours among strains reveal substantial heritable natural variation within each species that corresponds to three general patterns of behavioural response. However, intraspecific genetic differences in thermal behaviour often exceed interspecific differences. These patterns of temperature-dependent behaviour motivate further development of C. briggsae as a model system for dissecting the genetic underpinnings of complex behavioural traits.

  20. Performance prediction for silicon photonics integrated circuits with layout-dependent correlated manufacturing variability.

    Science.gov (United States)

    Lu, Zeqin; Jhoja, Jaspreet; Klein, Jackson; Wang, Xu; Liu, Amy; Flueckiger, Jonas; Pond, James; Chrostowski, Lukas

    2017-05-01

    This work develops an enhanced Monte Carlo (MC) simulation methodology to predict the impacts of layout-dependent correlated manufacturing variations on the performance of photonics integrated circuits (PICs). First, to enable such performance prediction, we demonstrate a simple method with sub-nanometer accuracy to characterize photonics manufacturing variations, where the width and height for a fabricated waveguide can be extracted from the spectral response of a racetrack resonator. By measuring the spectral responses for a large number of identical resonators spread over a wafer, statistical results for the variations of waveguide width and height can be obtained. Second, we develop models for the layout-dependent enhanced MC simulation. Our models use netlist extraction to transfer physical layouts into circuit simulators. Spatially correlated physical variations across the PICs are simulated on a discrete grid and are mapped to each circuit component, so that the performance for each component can be updated according to its obtained variations, and therefore, circuit simulations take the correlated variations between components into account. The simulation flow and theoretical models for our layout-dependent enhanced MC simulation are detailed in this paper. As examples, several ring-resonator filter circuits are studied using the developed enhanced MC simulation, and statistical results from the simulations can predict both common-mode and differential-mode variations of the circuit performance.

  1. Saddlepoint expansions for sums of Markov dependent variables on a continuous state space

    DEFF Research Database (Denmark)

    Jensen, J.L.

    1991-01-01

    Based on the conjugate kernel studied in Iscoe et al. (1985) we derive saddlepoint expansions for either the density or distribution function of a sum f(X1)+...+f(Xn), where the Xi's constitute a Markov chain. The chain is assumed to satisfy a strong recurrence condition which makes the results...... here very similar to the classical results for i.i.d. variables. In particular we establish also conditions under which the expansions hold uniformly over the range of the saddlepoint. Expansions are also derived for sums of the form f(X1, X0)+f(X2, X1)+...+f(Xn, Xn-1) although the uniformity result...

  2. Effects of Variable Production Rate and Time-Dependent Holding Cost for Complementary Products in Supply Chain Model

    Directory of Open Access Journals (Sweden)

    Mitali Sarkar

    2017-01-01

    Full Text Available Recently, a major trend is going to redesign a production system by controlling or making variable the production rate within some fixed interval to maintain the optimal level. This strategy is more effective when the holding cost is time-dependent as it is interrelated with holding duration of products and rate of production. An effort is made to make a supply chain model (SCM to show the joint effect of variable production rate and time-varying holding cost for specific type of complementary products, where those products are made by two different manufacturers and a common retailer makes them bundle and sells bundles to end customers. Demand of each product is specified by stochastic reservation prices with a known potential market size. Those players of the SCM are considered with unequal power. Stackelberg game approach is employed to obtain global optimum solution of the model. An illustrative numerical example, graphical representation, and managerial insights are given to illustrate the model. Results prove that variable production rate and time-dependent holding cost save more than existing literature.

  3. ENERGY-DEPENDENT POWER SPECTRAL STATES AND ORIGIN OF APERIODIC VARIABILITY IN BLACK HOLE BINARIES

    International Nuclear Information System (INIS)

    Yu Wenfei; Zhang Wenda

    2013-01-01

    We found that the black hole candidate MAXI J1659–152 showed distinct power spectra, i.e., power-law noise (PLN) versus band-limited noise (BLN) plus quasi-periodic oscillations (QPOs) below and above about 2 keV, respectively, in observations with Swift and the Rossi X-ray Timing Explorer during the 2010 outburst, indicating a high energy cutoff of the PLN and a low energy cutoff of the BLN and QPOs around 2 keV. The emergence of the PLN and the fading of the BLN and QPOs initially took place below 2 keV when the source entered the hard intermediate state and settled in the soft state three weeks later. The evolution was accompanied by the emergence of the disk spectral component and decreases in the amplitudes of variability in the soft and hard X-ray bands. Our results indicate that the PLN is associated with an optically thick disk in both hard and intermediate states, and the power spectral state is independent of the X-ray energy spectral state in a broadband view. We suggest that in the hard or intermediate state, the BLN and QPOs emerge from the innermost hot flow subjected to Comptonization, while the PLN originates from the optically thick disk farther out. The energy cutoffs of the PLN and the BLN or QPOs then follow the temperature of the seed photons from the inner edge of the optically thick disk, while the high frequency cutoff of the PLN follows the orbital frequency of the inner edge of the optically thick disk as well.

  4. Dark focus of accommodation as dependent and independent variables in visual display technology

    Science.gov (United States)

    Jones, Sherrie; Kennedy, Robert; Harm, Deborah

    1992-01-01

    When independent stimuli are available for accommodation, as in the dark or under low contrast conditions, the lens seeks its resting position. Individual differences in resting positions are reliable, under autonomic control, and can change with visual task demands. We hypothesized that motion sickness in a flight simulator might result in dark focus changes. Method: Subjects received training flights in three different Navy flight simulators. Two were helicopter simulators entailed CRT presentation using infinity optics, one involved a dome presentation of a computer graphic visual projection system. Results: In all three experiments there were significant differences between dark focus activity before and after simulator exposure when comparisons were made between sick and not-sick pilot subjects. In two of these experiments, the average shift in dark focus for the sick subjects was toward increased myopia when each subject was compared to his own baseline. In the third experiment, the group showed an average shift outward of small amount and the subjects who were sick showed significantly less outward movement than those who were symptom free. Conclusions: Although the relationship is not a simple one, dark focus changes in simulator sickness imply parasympathetic activity. Because changes can occur in relation to endogenous and exogenous events, such measurement may have useful applications as dependent measures in studies of visually coupled systems, virtual reality systems, and space adaptation syndrome.

  5. Modeling Time-Dependent Behavior of Concrete Affected by Alkali Silica Reaction in Variable Environmental Conditions.

    Science.gov (United States)

    Alnaggar, Mohammed; Di Luzio, Giovanni; Cusatis, Gianluca

    2017-04-28

    Alkali Silica Reaction (ASR) is known to be a serious problem for concrete worldwide, especially in high humidity and high temperature regions. ASR is a slow process that develops over years to decades and it is influenced by changes in environmental and loading conditions of the structure. The problem becomes even more complicated if one recognizes that other phenomena like creep and shrinkage are coupled with ASR. This results in synergistic mechanisms that can not be easily understood without a comprehensive computational model. In this paper, coupling between creep, shrinkage and ASR is modeled within the Lattice Discrete Particle Model (LDPM) framework. In order to achieve this, a multi-physics formulation is used to compute the evolution of temperature, humidity, cement hydration, and ASR in both space and time, which is then used within physics-based formulations of cracking, creep and shrinkage. The overall model is calibrated and validated on the basis of experimental data available in the literature. Results show that even during free expansions (zero macroscopic stress), a significant degree of coupling exists because ASR induced expansions are relaxed by meso-scale creep driven by self-equilibriated stresses at the meso-scale. This explains and highlights the importance of considering ASR and other time dependent aging and deterioration phenomena at an appropriate length scale in coupled modeling approaches.

  6. Single genome retrieval of context-dependent variability in mutation rates for human germline.

    Science.gov (United States)

    Sahakyan, Aleksandr B; Balasubramanian, Shankar

    2017-01-13

    Accurate knowledge of the core components of substitution rates is of vital importance to understand genome evolution and dynamics. By performing a single-genome and direct analysis of 39,894 retrotransposon remnants, we reveal sequence context-dependent germline nucleotide substitution rates for the human genome. The rates are characterised through rate constants in a time-domain, and are made available through a dedicated program (Trek) and a stand-alone database. Due to the nature of the method design and the imposed stringency criteria, we expect our rate constants to be good estimates for the rates of spontaneous mutations. Benefiting from such data, we study the short-range nucleotide (up to 7-mer) organisation and the germline basal substitution propensity (BSP) profile of the human genome; characterise novel, CpG-independent, substitution prone and resistant motifs; confirm a decreased tendency of moieties with low BSP to undergo somatic mutations in a number of cancer types; and, produce a Trek-based estimate of the overall mutation rate in human. The extended set of rate constants we report may enrich our resources and help advance our understanding of genome dynamics and evolution, with possible implications for the role of spontaneous mutations in the emergence of pathological genotypes and neutral evolution of proteomes.

  7. Spatio-temporal dependencies between hospital beds, physicians and health expenditure using visual variables and data classification in statistical table

    Science.gov (United States)

    Medyńska-Gulij, Beata; Cybulski, Paweł

    2016-06-01

    This paper analyses the use of table visual variables of statistical data of hospital beds as an important tool for revealing spatio-temporal dependencies. It is argued that some of conclusions from the data about public health and public expenditure on health have a spatio-temporal reference. Different from previous studies, this article adopts combination of cartographic pragmatics and spatial visualization with previous conclusions made in public health literature. While the significant conclusions about health care and economic factors has been highlighted in research papers, this article is the first to apply visual analysis to statistical table together with maps which is called previsualisation.

  8. Spatio-temporal dependencies between hospital beds, physicians and health expenditure using visual variables and data classification in statistical table

    Directory of Open Access Journals (Sweden)

    Medyńska-Gulij Beata

    2016-06-01

    Full Text Available This paper analyses the use of table visual variables of statistical data of hospital beds as an important tool for revealing spatio-temporal dependencies. It is argued that some of conclusions from the data about public health and public expenditure on health have a spatio-temporal reference. Different from previous studies, this article adopts combination of cartographic pragmatics and spatial visualization with previous conclusions made in public health literature. While the significant conclusions about health care and economic factors has been highlighted in research papers, this article is the first to apply visual analysis to statistical table together with maps which is called previsualisation.

  9. The Dependencies of Ecosystem Pattern, Structure, and Dynamics on Climate, Climate Variability, and Climate Change

    Science.gov (United States)

    Flanagan, S.; Hurtt, G. C.; Fisk, J. P.; Rourke, O.

    2012-12-01

    A robust understanding of the sensitivity of the pattern, structure, and dynamics of ecosystems to climate, climate variability, and climate change is needed to predict ecosystem responses to current and projected climate change. We present results of a study designed to first quantify the sensitivity of ecosystems to climate through the use of climate and ecosystem data, and then use the results to test the sensitivity of the climate data in a state-of the art ecosystem model. A database of available ecosystem characteristics such as mean canopy height, above ground biomass, and basal area was constructed from sources like the National Biomass and Carbon Dataset (NBCD). The ecosystem characteristics were then paired by latitude and longitude with the corresponding climate characteristics temperature, precipitation, photosynthetically active radiation (PAR) and dew point that were retrieved from the North American Regional Reanalysis (NARR). The average yearly and seasonal means of the climate data, and their associated maximum and minimum values, over the 1979-2010 time frame provided by NARR were constructed and paired with the ecosystem data. The compiled results provide natural patterns of vegetation structure and distribution with regard to climate data. An advanced ecosystem model, the Ecosystem Demography model (ED), was then modified to allow yearly alterations to its mechanistic climate lookup table and used to predict the sensitivities of ecosystem pattern, structure, and dynamics to climate data. The combined ecosystem structure and climate data results were compared to ED's output to check the validity of the model. After verification, climate change scenarios such as those used in the last IPCC were run and future forest structure changes due to climate sensitivities were identified. The results of this study can be used to both quantify and test key relationships for next generation models. The sensitivity of ecosystem characteristics to climate data

  10. Extracellular vesicles have variable dose-dependent effects on cultured draining cells in the eye.

    Science.gov (United States)

    Tabak, Saray; Schreiber-Avissar, Sofia; Beit-Yannai, Elie

    2018-03-01

    The role of extracellular vesicles (EVs) as signal mediators has been described in many biological fields. How many EVs are needed to deliver the desired physiological signal is yet unclear. Using a normal trabecular meshwork (NTM) cell culture exposed to non-pigmented ciliary epithelium (NPCE)-derived EVs, a relevant model for studying the human ocular drainage system, we addressed the EVs dose-response effects on the Wnt signaling. The objective of the study was to investigate the dosing effects of NPCE-derived EVs on TM Wnt signaling. EVs were isolated by PEG 8000 method from NPCE and RPE cells (used as controls) conditioned media. Concentrations were determined by Tunable Resistive Pulse Sensing method. Various exosomes concentration were incubated with TM cells, for the determination of mRNA (β-Catenin, Axin2 and LEF1) and protein (β-Catenin, GSK-3β) expression using real-time quantitative PCR and Western blot, respectively. Exposure of NTM cells for 8 hrs to low EVs concentrations was associated with a significant decreased expression of β-Catenin, GSK-3β, as opposed to exposure to high exosomal concentrations. Pro-MMP9 and MMP9 activities were significantly enhanced in NTM cells treated with high EV concentrations of (X10) as compared to low EV concentrations of either NPCE- or RPE-derived EVs and to untreated control. Our data support the concept that EVs biological effects are concentration-dependent at their target site. Specifically in the present study, we described a general dose-response at the gene and MMPs activity and a different dose-response regarding key canonical Wnt proteins expression. © 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  11. Insulin-dependent glucose metabolism in dairy cows with variable fat mobilization around calving.

    Science.gov (United States)

    Weber, C; Schäff, C T; Kautzsch, U; Börner, S; Erdmann, S; Görs, S; Röntgen, M; Sauerwein, H; Bruckmaier, R M; Metges, C C; Kuhla, B; Hammon, H M

    2016-08-01

    clamps, pp nonesterified fatty acid concentrations did not reach the ap levels. The study demonstrated a minor influence of different degrees of body fat mobilization on insulin metabolism in cows during the transition period. The distinct decrease in the glucose-dependent release of insulin pp is the most striking finding that explains the impaired insulin action after calving, but does not explain differences in body fat mobilization between HLFC and LLFC cows. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Variability in colonization of arbuscular mycorrhizal fungi and its effect on mycorrhizal dependency of improved and unimproved soybean cultivars.

    Science.gov (United States)

    Salloum, M S; Guzzo, M C; Velazquez, M S; Sagadin, M B; Luna, C M

    2016-12-01

    Breeding selection of germplasm under fertilized conditions may reduce the frequency of genes that promote mycorrhizal associations. This study was developed to compare variability in mycorrhizal colonization and its effect on mycorrhizal dependency (MD) in improved soybean genotypes (I-1 and I-2) with differential tolerance to drought stress, and in unimproved soybean genotypes (UI-3 and UI-4). As inoculum, a mixed native arbuscular mycorrhizal fungi (AMF) was isolated from soybean roots, showing spores mostly of the species Funneliformis mosseae. At 20 days, unimproved genotypes followed by I-2, showed an increase in arbuscule formation, but not in I-1. At 40 days, mycorrhizal plants showed an increase in nodulation, this effect being more evident in unimproved genotypes. Mycorrhizal dependency, evaluated as growth and biochemical parameters from oxidative stress was increased in unimproved and I-2 since 20 days, whereas in I-1, MD increased at 40 days. We cannot distinguish significant differences in AMF colonization and MD between unimproved and I-2. However, variability among improved genotypes was observed. Our results suggest that selection for improved soybean genotypes with good and rapid AMF colonization, particularly high arbuscule/hyphae ratio could be a useful strategy for the development of genotypes that optimize AMF contribution to cropping systems.

  13. Models of simulation and prediction of the behavior of dengue in four Colombian cities, including climate like modulating variable of the disease

    International Nuclear Information System (INIS)

    Garcia Giraldo, Jairo A; Boshell, Jose Francisco

    2004-01-01

    ARIMA-type models are proposed to simulate the behavior of dengue and to make apparent the relations with the climatic variability in four localities of Colombia. The climatic variable was introduced into the models as an index that modulates the behavior of the disease. It was obtained by means of a multivariate analysis of principal components. The investigation was carried out with information corresponding to the epidemiological weeks from January 1997 to December 2000, for both the number of disease cases and the data corresponding to the meteorological variables. The study shows that the variations of the climate between the previous 9 to 14 weeks have influence on the appearance of new cases of dengue. In particular, the precipitation in these weeks was seen to be greater when in later periods the disease presented epidemic characteristics than the precipitation in those weeks preceded the disease within endemic limits

  14. The IL--6 dependent effect of oral warfarin in heart valve replacement patients by measuring interacting clinical and demographic variables

    International Nuclear Information System (INIS)

    Shafiq, H.; Rashid, A.; Majeed, A.; Razah, S.; Asghar, I.

    2016-01-01

    Objective: To examine an inflammatory effect of warfarin and comparing with IL-6 levels along with different demographic and clinical variables. Study Design: Quasi experimental study. Place and Duration of Study: Center of Research in Experimental and Applied Medicine (CREAM), Army Medical College/National University of Sciences and Technology, Islamabad from Oct 2013 to Oct 2015. Material and Methods: The study design was Quasi Experimental study. Samples were collected by Non probability convenience sampling. Total 76 patients were included according to warfarin dose response in warfarin therapy patients, i.e. 32(42 percent) were taking 10mg/day of warfarin dose. Patient's demographic and clinical variables were noted i.e. age, gender, BMI, duration of therapy, INR history, hepatic, gastrointestinal and diabetic complications. Human IL-6 ELISA assay was performed. Results: The statistically significant difference was found between age groups (in years) and different levels of warfarin dose (p=0.046) along with IL-6 production. There is a negative correlation between warfarin dose and age group i.e. as age increases, the dose of warfarin decreases. Among the inter and intra-patient variability age and serum IL-6 levels were found to be statistically significant with warfarin dose response. BMI and warfarin dose were found to be weak positively correlated. Conclusion: A marked immunomodulatory response of warfarin was noted by measuring IL-6 levels. IL-6 levels retained a significant association with warfarin dose. (author)

  15. Variability and accuracy of coronary CT angiography including use of iterative reconstruction algorithms for plaque burden assessment as compared with intravascular ultrasound - an ex vivo study

    Energy Technology Data Exchange (ETDEWEB)

    Stolzmann, Paul [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Schlett, Christopher L.; Maurovich-Horvat, Pal; Scheffel, Hans; Engel, Leif-Christopher; Karolyi, Mihaly; Hoffmann, Udo [Massachusetts General Hospital and Harvard Medical School, Cardiac MR PET CT Program, Boston, MA (United States); Maehara, Akiko; Ma, Shixin; Mintz, Gary S. [Columbia University Medical Center, Cardiovascular Research Foundation, New York, NY (United States)

    2012-10-15

    To systematically assess inter-technique and inter-/intra-reader variability of coronary CT angiography (CTA) to measure plaque burden compared with intravascular ultrasound (IVUS) and to determine whether iterative reconstruction algorithms affect variability. IVUS and CTA data were acquired from nine human coronary arteries ex vivo. CT images were reconstructed using filtered back projection (FBPR) and iterative reconstruction algorithms: adaptive-statistical (ASIR) and model-based (MBIR). After co-registration of 284 cross-sections between IVUS and CTA, two readers manually delineated the cross-sectional plaque area in all images presented in random order. Average plaque burden by IVUS was 63.7 {+-} 10.7% and correlated significantly with all CTA measurements (r = 0.45-0.52; P < 0.001), while CTA overestimated the burden by 10 {+-} 10%. There were no significant differences among FBPR, ASIR and MBIR (P > 0.05). Increased overestimation was associated with smaller plaques, eccentricity and calcification (P < 0.001). Reproducibility of plaque burden by CTA and IVUS datasets was excellent with a low mean intra-/inter-reader variability of <1/<4% for CTA and <0.5/<1% for IVUS respectively (P < 0.05) with no significant difference between CT reconstruction algorithms (P > 0.05). In ex vivo coronary arteries, plaque burden by coronary CTA had extremely low inter-/intra-reader variability and correlated significantly with IVUS measurements. Accuracy as well as reader reliability were independent of CT image reconstruction algorithm. (orig.)

  16. 12 YEARS OF X-RAY VARIABILITY IN M31 GLOBULAR CLUSTERS, INCLUDING 8 BLACK HOLE CANDIDATES, AS SEEN BY CHANDRA

    International Nuclear Information System (INIS)

    Barnard, R.; Garcia, M.; Murray, S. S.

    2012-01-01

    We examined 134 Chandra observations of the population of X-ray sources associated with globular clusters (GCs) in the central region of M31. These are expected to be X-ray binary systems (XBs), consisting of a neutron star or black hole accreting material from a close companion. We created long-term light curves for these sources, correcting for background, interstellar absorption, and instrumental effects. We tested for variability by examining the goodness of fit for the best-fit constant intensity. We also created structure functions (SFs) for every object in our sample, the first time this technique has been applied to XBs. We found significant variability in 28 out of 34 GCs and GC candidates; the other 6 sources had 0.3-10 keV luminosities fainter than ∼2 × 10 36 erg s –1 , limiting our ability to detect similar variability. The SFs of XBs with 0.3-10 keV luminosities ∼2-50 × 10 36 erg s –1 generally showed considerably more variability than the published ensemble SF of active galactic nuclei (AGNs). Our brightest XBs were mostly consistent with the AGN SF; however, their 2-10 keV fluxes could be matched by <1 AGN per square degree. These encouraging results suggest that examining the long-term light curves of other X-ray sources in the field may provide an important distinction between X-ray binaries and background galaxies, as the X-ray emission spectra from these two classes of X-ray sources are similar. Additionally, we identify 3 new black hole candidates (BHCs) using additional XMM-Newton data, bringing the total number of M31 GC BHCs to 9, with 8 covered in this survey.

  17. Free energy of activation. Definition, properties, and dependent variables with special reference to linear free energy relations

    International Nuclear Information System (INIS)

    Levine, R.D.

    1979-01-01

    The reaction rate constant is expressed as Z exp(-G/sub a//RT). Z is the binary collision frequency. G/sub a/, the free energy of activation, is shown to be the difference between the free energy of the reactive reactants and the free energy of all reactants. The results are derived from both a statistical mechanical and a collision theoretic point of view. While the later is more suitable for an ab-initio computation of the reaction rate, it is the former that lends itself to the search of systematics and of correlations and to compaction of data. Different thermodynamic-like routes to the characterization of G/sub a/ are thus explored. The two most promising ones appear to be the use of thermodynamic type cycles and the changes of dependent variables using the Legendre transform technique. The dependence of G/sub a/ on ΔG 0 , the standard free energy change in the reaction, is examined from the later point of view. It is shown that one can rigorously express this dependence as G/sub a/ = αΔG 0 + G/sub a/ 0 M(α). Here α is the Bronsted slope, α = -par. delta ln k(T)/par. delta(ΔG 0 /RT), G/sub a/ 0 is independent of ΔG 0 and M(α), the Legendre transform of G/sub a/, is a function only of α. For small changes in ΔG 0 , the general result reduces to the familiar ''linear'' free energy relation delta G/sub a/ = α delta ΔG 0 . It is concluded from general considerations that M(α) is a symmetric, convex function of α and hence that α is a monotonically increasing function of ΔG 0 . Experimental data appear to conform well to the form α = 1/[1 + exp(-ΔG 0 /G/sub s/ 0 )]. A simple interpretation of the ΔG 0 dependence of G/sub a/, based on an interpolation of the free energy from that of the reagents to that of the products, is offered. 4 figures, 69 references

  18. Variability of Pinus halepensis Mill. Essential Oils and Their Antioxidant Activities Depending on the Stage of Growth During Vegetative Cycle.

    Science.gov (United States)

    Djerrad, Zineb; Djouahri, Abderrahmane; Kadik, Leila

    2017-04-01

    The impact of growth stages during vegetative cycle (B 0  - B 5 ) on chemical composition and antioxidant activities of Pinus halepensis Mill. needles essential oils was investigated for the first time. GC and GC/MS analyses pointed to a quantitative variability of components; terpene hydrocarbons derivatives, represented by α-pinene (8.5 - 12.9%), myrcene (17.5 - 21.6%), p-cymene (7.9 - 11.9%) and (Z)-β-caryophyllene (17.3 - 21.2%) as major components, decreased from 88.9% at B 0 growth stage to 66.9% at B 5 growth stage, whereas oxygenated derivatives, represented by caryophyllene oxide (5.4 - 12.6%) and terpinen-4-ol (0.4 - 3.3%) as major components, increased from 7% at B 0 growth stage to 28.4% at B 5 growth stage. Furthermore, our findings showed that essential oil of P. halepensis needles collected at B 5 growth stage possess higher antioxidant activities by four different testing systems than those collected at B 0  - B 4 growth stages. This highlighted variability led to conclude that we should select essential oils to be investigated carefully depending on growth stage, in order to have the highest effectiveness of essential oil in terms of biological activities for human health purposes. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  19. Development of eggs and larvae of Emmelichthys nitidus (Percoidei: Emmelichthyidae) in south-eastern Australia, including a temperature-dependent egg incubation model

    Science.gov (United States)

    Neira, Francisco J.; Keane, John P.; Lyle, Jeremy M.; Tracey, Sean R.

    2008-08-01

    Reared eggs and field-collected material were employed to describe the development of the pelagic eggs and larvae of Emmelichthys nitidus (Emmelichthyidae), a small (36 cm TL) mid-water schooling species common in shelf waters of temperate Australia. Hydrated oocytes from adults trawled from spawning grounds off eastern Tasmania were fertilized and reared to the yolk-sac larval stage, and the data employed to build a temperature-dependent egg incubation model. Embryogenesis lasted 96, 84 and 54 h at mean temperatures of 13.1, 14.4 and 16.5 °C respectively, and was divided into seven stages based on extent of epiboly until blastopore closure (stages I-III) and embryo growth (stages IV-VII). Eggs (1.00-1.05 mm diameter) are spherical with a smooth chorion, small perivitelline space and prominent, unsegmented yolk with a single, posteriorly-located oil globule (0.18-0.20 mm diameter) that becomes pigmented from stage III. Embryos have two distinct snout melanophores, and a paired melanophore row laterally along the trunk and tail. Morphological identification of eggs collected during surveys in October 2005 and 2006 was validated using quantitative PCR amplification of the mtDNA d-loop gene region unique to E. nitidus, producing an 80-100% agreement across all seven stages. Newly-emerged larvae (1.9-3.3 mm) possess a prominent yolk sac with the posteriorly-located, pigmented oil globule, mouth not yet functional and unpigmented eyes. Notochord flexion occurs between 5 and 8 mm while fins are formed by 12 mm. Larvae examined (3.3-17.4 mm) are lightly pigmented and possess percoid features such as an elongate to moderate body, coiled, triangular-shaped gut, preopercular spines and 24-25 myomeres; two prominent pigment patches opposite each other dorsally and ventrally along the tail are diagnostic. Variability of mean egg ages ( y) by temperature ( t) and stage ( i) was best described by the deterministic stage-to-age model y = 35.911exp[-(0.155 t + 0.262 i)] i2

  20. Influence of Flow Sequencing Attributed to Climate Change and Climate Variability on the Assessment of Water-dependent Ecosystem Outcomes

    Science.gov (United States)

    Wang, J.; Nathan, R.; Horne, A.

    2017-12-01

    Traditional approaches to characterize water-dependent ecosystem outcomes in response to flow have been based on time-averaged hydrological indicators, however there is increasing recognition for the need to characterize ecological processes that are highly dependent on the sequencing of flow conditions (i.e. floods and droughts). This study considers the representation of flow regimes when considering assessment of ecological outcomes, and in particular, the need to account for sequencing and variability of flow. We conducted two case studies - one in the largely unregulated Ovens River catchment and one in the highly regulated Murray River catchment (both located in south-eastern Australia) - to explore the importance of flow sequencing to the condition of a typical long-lived ecological asset in Australia, the River Red Gum forests. In the first, the Ovens River case study, the implications of representing climate change using different downscaling methods (annual scaling, monthly scaling, quantile mapping, and weather generator method) on the sequencing of flows and resulting ecological outcomes were considered. In the second, the Murray River catchment, sequencing within a historic drought period was considered by systematically making modest adjustments on an annual basis to the hydrological records. In both cases, the condition of River Red Gum forests was assessed using an ecological model that incorporates transitions between ecological conditions in response to sequences of required flow components. The results of both studies show the importance of considering how hydrological alterations are represented when assessing ecological outcomes. The Ovens case study showed that there is significant variation in the predicted ecological outcomes when different downscaling techniques are applied. Similarly, the analysis in the Murray case study showed that the drought as it historically occurred provided one of the best possible outcomes for River Red Gum

  1. Clinical variability of Waardenburg-Shah syndrome in patients with proximal 13q deletion syndrome including the endothelin-B receptor locus.

    Science.gov (United States)

    Tüysüz, Beyhan; Collin, Anna; Arapoğlu, Müjde; Suyugül, Nezir

    2009-10-01

    Waardenburg-Shah syndrome (Waardenburg syndrome type IV-WS4) is an auditory-pigmentary disorder that combines clinical features of pigmentary abnormalities of the skin, hair and irides, sensorineural hearing loss, and Hirschsprung disease (HSCR). Mutations in the endothelin-B receptor (EDNRB) gene on 13q22 have been found to cause this syndrome. Mutations in both alleles cause the full phenotype, while heterozygous mutations cause isolated HSCR or HSCR with minor pigmentary anomalies and/or sensorineural deafness. We investigated the status of the EDNRB gene, by FISH analysis, in three patients with de novo proximal 13q deletions detected at cytogenetic analysis and examined the clinical variability of WS4 among these patients. Chromosome 13q was screened with locus specific FISH probes and breakpoints were determined at 13q22.1q31.3 in Patients 1 and 3, and at 13q21.1q31.3 in Patient 2. An EDNRB specific FISH probe was deleted in all three patients. All patients had common facial features seen in proximal 13q deletion syndrome and mild mental retardation. However, findings related to WS4 were variable; Patient 1 had hypopigmentation of the irides and HSCR, Patient 2 had prominent bicolored irides and mild bilateral hearing loss, and Patient 3 had only mild unilateral hearing loss. These data contribute new insights into the pathogenesis of WS4.

  2. Kinetic and Mechanistic Study of the pH-Dependent Activation (Epoxidation) of Prodrug Treosulfan Including the Reaction Inhibition in a Borate Buffer.

    Science.gov (United States)

    Romański, Michał; Ratajczak, Whitney; Główka, Franciszek

    2017-07-01

    A prodrug treosulfan (T) undergoes a pH-dependent activation to epoxide derivatives. The process seems to involve an intramolecular Williamson reaction (IWR) but clear kinetic evidence is lacking. Moreover, a cis-diol system present in the T structure is expected to promote complexation with boric acid. As a result, the prodrug epoxidation would be inhibited; however, this phenomenon has not been investigated. In this article, the effect of pH on the kinetics of T conversion to its monoepoxide was studied from a mechanistic point of view. Also, the influence of boric acid on the reaction kinetics was examined. The rate constants observed for the activation of T (k obs ) in acetate, phosphate, and carbonate buffers satisfied the equation logk obs  = -7.48 + 0.96 pH. The reaction was inhibited in the excess of boric acid over T, and the k obs decreased with increasing borate buffer concentration. The experimental results were consistent with the inhibition model that included the formation of a tetrahedral, anionic T-boric acid monoester. To conclude, in nonborate buffers, the T activation to (2S,3S)-1,2-epoxybutane-3,4-diol 4-methanesulfonate follows IWR mechanism. A borate buffer changes the reaction kinetics and complicates kinetic analysis. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  3. Inference for binomial probability based on dependent Bernoulli random variables with applications to meta‐analysis and group level studies

    Science.gov (United States)

    Bakbergenuly, Ilyas; Morgenthaler, Stephan

    2016-01-01

    We study bias arising as a result of nonlinear transformations of random variables in random or mixed effects models and its effect on inference in group‐level studies or in meta‐analysis. The findings are illustrated on the example of overdispersed binomial distributions, where we demonstrate considerable biases arising from standard log‐odds and arcsine transformations of the estimated probability p^, both for single‐group studies and in combining results from several groups or studies in meta‐analysis. Our simulations confirm that these biases are linear in ρ, for small values of ρ, the intracluster correlation coefficient. These biases do not depend on the sample sizes or the number of studies K in a meta‐analysis and result in abysmal coverage of the combined effect for large K. We also propose bias‐correction for the arcsine transformation. Our simulations demonstrate that this bias‐correction works well for small values of the intraclass correlation. The methods are applied to two examples of meta‐analyses of prevalence. PMID:27192062

  4. HEART RATE VARIABILITY PARAMETERS IN PATIENTS WITH ARTERIAL HYPERTENSION IN DEPENDENCE ON THE TYPE OF DAILY BLOOD PRESSURE PROFILE

    Directory of Open Access Journals (Sweden)

    S. G. B. K. Gorantla

    2017-06-01

    Full Text Available Violation of functioning of the autonomic nervous system is an important factor in the formation and progression of arterial hypertension (AH. Abnormal nocturnal blood pressure (BP reduction is regarded as an independent prognostic factor for cardiovascular complications in patients with AH. One of the possible factors that determine the violation of BP circadian rhythm can be imbalance of different parts of autonomic nervous system. The aim of our study was to study heart rate variability (HRV in patients with AH, dependently of BP profile. 72 patients with AH were examined. Average age was 57 ± 11 years. All patients underwent ambulatory BP (ABPM and ECG monitoring. To define the daily profile the nocturnal BP dip was quantified and for HRV evaluation the frequency analysis method was used. HRV changes in patients with AH present with reduced total power and with a violation in the ratio of the powers of very low, low and high frequencies, enhanced sympathycotension and influence of humoral factors. Violations of systolic BP (SBP daily profile was mainly characterized by an increase in the power of low frequency waves, which indicates an intensification of sympathetic and decreased parasympathetic influences. Violations of diastolic BP (DBP daily profile were mainly characterized by a relative increase in the power of very low frequency waves. The obtained results showed that in the management of patients with AH it is important not only to control the circadian SBP and DBP profiles, but the evaluation of HRV also.

  5. Inference for binomial probability based on dependent Bernoulli random variables with applications to meta-analysis and group level studies.

    Science.gov (United States)

    Bakbergenuly, Ilyas; Kulinskaya, Elena; Morgenthaler, Stephan

    2016-07-01

    We study bias arising as a result of nonlinear transformations of random variables in random or mixed effects models and its effect on inference in group-level studies or in meta-analysis. The findings are illustrated on the example of overdispersed binomial distributions, where we demonstrate considerable biases arising from standard log-odds and arcsine transformations of the estimated probability p̂, both for single-group studies and in combining results from several groups or studies in meta-analysis. Our simulations confirm that these biases are linear in ρ, for small values of ρ, the intracluster correlation coefficient. These biases do not depend on the sample sizes or the number of studies K in a meta-analysis and result in abysmal coverage of the combined effect for large K. We also propose bias-correction for the arcsine transformation. Our simulations demonstrate that this bias-correction works well for small values of the intraclass correlation. The methods are applied to two examples of meta-analyses of prevalence. © 2016 The Authors. Biometrical Journal Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  6. A numerical model for density-and-viscosity-dependent flows in two-dimensional variably saturated porous media

    Science.gov (United States)

    Boufadel, Michel C.; Suidan, Makram T.; Venosa, Albert D.

    1999-04-01

    We present a formulation for water flow and solute transport in two-dimensional variably saturated media that accounts for the effects of the solute on water density and viscosity. The governing equations are cast in a dimensionless form that depends on six dimensionless groups of parameters. These equations are discretized in space using the Galerkin finite element formulation and integrated in time using the backward Euler scheme with mass lumping. The modified Picard method is used to linearize the water flow equation. The resulting numerical model, the MARUN model, is verified by comparison to published numerical results. It is then used to investigate beach hydraulics at seawater concentration (about 30 g l -1) in the context of nutrients delivery for bioremediation of oil spills on beaches. Numerical simulations that we conducted in a rectangular section of a hypothetical beach revealed that buoyancy in the unsaturated zone is significant in soils that are fine textured, with low anisotropy ratio, and/or exhibiting low physical dispersion. In such situations, application of dissolved nutrients to a contaminated beach in a freshwater solution is superior to their application in a seawater solution. Concentration-engendered viscosity effects were negligible with respect to concentration-engendered density effects for the cases that we considered.

  7. Including climate variability in determination of the optimum rate of N fertilizer application using a crop model: A case study for rainfed corn in eastern Canada

    Science.gov (United States)

    Mesbah, M.; Pattey, E.; Jégo, G.; Geng, X.; Tremblay, N.; Didier, A.

    2017-12-01

    Identifying optimum nitrogen (N) application rate is essential for increasing agricultural production while limiting potential environmental contaminations caused by release of reactive N, especially for high demand N crops such as corn. The central question of N management is then how the optimum N rate is affected by climate variability for given soil. The experimental determination of optimum N rates involve the analyses of variance on the mean value of crop yield response to various N application rates used by factorial plot based experiments for a few years in several regions. This traditional approach has limitations to capture 1) the non-linear response of yield to N application rates due to large incremental N rates (often more than 40 kg N ha-1) and 2) the ecophysiological response of the crop to climate variability because of limited numbers of growing seasons considered. Modeling on the other hand, does not have such limitations and hence we use a crop model and propose a model-based methodology called Finding NEMO (N Ecophysiologically Modelled Optimum) to identify the optimum N rates for variable agro-climatic conditions and given soil properties. The performance of the methodology is illustrated using the STICS crop model adapted for rainfed corn in the Mixedwood Plains ecozone of eastern Canada (42.3oN 83oW-46.8oN 71oW) where more than 90% of Canadian corn is produced. The simulations were performed using small increment of preplant N application rate (10 kg N ha -1), long time series of daily climatic data (48 to 61 years) for 5 regions along the ecozone, and three contrasting soils per region. The results show that N recommendations should be region and soil specific. Soils with lower available water capacity required more N compared to soil with higher available water capacity. When N rates were at their ecophysiologically optimum level, 10 to 17 kg increase in dry yield could be achieved by adding 1 kg N. Expected yield also affected the optimum

  8. Enhancement of Faraday effect in one-dimensional magneto-optical photonic crystal including a magnetic layer with wavelength dependent off-diagonal elements of dielectric constant tensor

    International Nuclear Information System (INIS)

    Inui, Chie; Ozaki, Shinsuke; Kura, Hiroaki; Sato, Tetsuya

    2011-01-01

    Optical and magneto-optical properties of one-dimensional magneto-optical photonic crystal (1-D MPC) prepared by the sol-gel dip-coating method, including a magnetic defect layer composed of mixture of CoFe 2 O 4 and SiO 2 , are investigated from both the experimental and theoretical standpoints. The resonant transmission of light was observed around 570 nm in the photonic band gap. The Faraday rotation angle θ F showed two maxima at 490 and 640 nm, and the wavelength dependence of θ F above 760 nm was similar to that of the CoFe 2 O 4 +SiO 2 single-layer film. The two maxima of θ F are attributed to the enhanced Faraday rotation of nonmagnetic TiO 2 layers in the cavity structure and that in magnetic CoFe 2 O 4 +SiO 2 layer through the light localization in MPC. The maximum value of θ F due to the magnetic CoFe 2 O 4 +SiO 2 layer in the MPC was 22-times larger than that in the single-layer film. The simulation study of MPC with CoFe 2 O 4 +SiO 2 magnetic defect layer, based on the matrix approach method, showed that the resonant light transmission was accompanied by the localization of electric field, and large enhancement of θ F appeared at different wavelengths so as to agree with the experimental features. This can be explained in terms of the wavelength dependent off-diagonal components of the dielectric constant tensor in addition to the large extinction coefficient in the CoFe 2 O 4 +SiO 2 magnetic defect layer. - Highlights: → 1-D magnetic photonic crystal (MPC) prepared by sol-gel method. → Enhancement of Faraday rotation due to the magnetic defect layer of CoFe 2 O 4 . → Shift of wavelength of Faraday rotation maximum from resonant light transmission.

  9. A 1D constitutive model for shape memory alloy using strain and temperature as control variables and including martensite reorientation and asymmetric behaviors

    International Nuclear Information System (INIS)

    Jaber, M Ben; Mehrez, S; Ghazouani, O

    2014-01-01

    In this paper, a new 1D constitutive model for shape memory alloy using strain and temperature as control variables is presented. The new formulation is restricted to the 1D stress case and takes into account the martensite reorientation and the asymmetry of the SMA behavior in tension and compression. Numerical implementation of the new model in a finite element code was conducted. The numerical results for superelastic behavior in tension and compression tests are presented and were compared to experimental data taken from the literature. Other numerical tests are presented, showing the model’s ability to reproduce the main aspects of SMA behavior such as the shape memory effect and the martensite reorientation under cyclic loading. Finally, to demonstrate the utility of the new constitutive model, a dynamic test of a bi-clamped SMA bending beam under forced oscillation is described. (paper)

  10. Oxygen-Dependent Cell-to-Cell Variability in the Output of the Escherichia coli Tor Phosphorelay.

    Science.gov (United States)

    Roggiani, Manuela; Goulian, Mark

    2015-06-15

    Escherichia coli senses and responds to trimethylamine-N-oxide (TMAO) in the environment through the TorT-TorS-TorR signal transduction system. The periplasmic protein TorT binds TMAO and stimulates the hybrid kinase TorS to phosphorylate the response regulator TorR through a phosphorelay. Phosphorylated TorR, in turn, activates transcription of the torCAD operon, which encodes the proteins required for anaerobic respiration via reduction of TMAO to trimethylamine. Interestingly, E. coli respires TMAO in both the presence and absence of oxygen, a behavior that is markedly different from the utilization of other alternative electron acceptors by this bacterium. Here we describe an unusual form of regulation by oxygen for this system. While the average level of torCAD transcription is the same for aerobic and anaerobic cultures containing TMAO, the behavior across the population of cells is strikingly different under the two growth conditions. Cellular levels of torCAD transcription in aerobic cultures are highly heterogeneous, in contrast to the relatively homogeneous distribution in anaerobic cultures. Thus, oxygen regulates the variance of the output but not the mean for the Tor system. We further show that this oxygen-dependent variability stems from the phosphorelay. Trimethylamine-N-oxide (TMAO) is utilized by numerous bacteria as an electron acceptor for anaerobic respiration. In E. coli, expression of the proteins required for TMAO respiration is tightly regulated by a signal transduction system that is activated by TMAO. Curiously, although oxygen is the energetically preferred electron acceptor, TMAO is respired even in the presence of oxygen. Here we describe an interesting and unexpected form of regulation for this system in which oxygen produces highly variable expression of the TMAO utilization proteins across a population of cells without affecting the mean expression of these proteins. To our knowledge, this is the first reported example of a stimulus

  11. Characterization of Genotoxic Response to 15 Multiwalled Carbon Nanotubes with Variable Physicochemical Properties Including Surface Functionalizations in the FE1-Muta(TM) Mouse Lung Epithelial Cell Line

    DEFF Research Database (Denmark)

    Jackson, Petra; Kling, Kirsten; Jensen, Keld Alstrup

    2015-01-01

    Carbon nanotubes vary greatly in physicochemical properties. We compared cytotoxic and genotoxic response to 15 multiwalled carbon nanotubes (MWCNT) with varying physicochemical properties to identify drivers of toxic responses. The studied MWCNT included OECD Working Party on Manufactured...... Nanomaterials (WPMN) (NM-401, NM-402, and NM-403), materials (NRCWE-026 and MWCNT-XNRI-7), and three sets of surface-modified MWCNT grouped by physical characteristics (thin, thick, and short I-III, respectively). Each Groups I-III included pristine, hydroxylated and carboxylated MWCNT. Group III also included...... an amino-functionalized MWCNT. The level of surface functionalization of the MWCNT was low. The level and type of elemental impurities of the MWCNT varied by...

  12. Diurnal and seasonal variability in size-dependent atmospheric deposition fluxes of polycyclic aromatic hydrocarbons in an urban center

    Science.gov (United States)

    Zhang, Kai; Zhang, Bao-Zhong; Li, Shao-Meng; Zhang, Lei-Ming; Staebler, Ralf; Zeng, Eddy Y.

    2012-09-01

    Atmospheric gaseous and size-segregated particle samples were collected from urban Guangzhou at the heights of 100 and 150 m above the ground in daytime and at night in August and December 2010, and were analyzed for polycyclic aromatic hydrocarbons (PAHs). Particulate PAHs were more abundant at night than in daytime, and significantly higher in winter than in summer. The observed vertical, diurnal, and seasonal variability in the occurrences of PAH were attributed to varying meteorological conditions and atmospheric boundary layers. More than 60% of the particulate PAHs were contained in particles in the accumulation mode with an aerodynamic diameter (Dp) in the range of 0.1-1.8 μm. Different mass transfer velocities by volatilization and condensation are considered the main causes for the different particle size distributions among individual PAHs, while combustion at different temperatures and atmospheric transport were probable causes of the observed seasonal variation in the size distribution of PAHs. Based on the modeled size-dependent dry deposition velocities, daily mean dry deposition fluxes of particulate PAHs ranged from 604 to 1190 ng m-2 d-1, with PAHs in coarse particles (Dp > 1.8 μm) accounting for 55-95% of the total fluxes. In addition, gaseous PAHs were estimated to contribute 0.6-3.1% to the total dry deposition fluxes if a conservative dry deposition velocity for gaseous species (2 × 10-4 m s-1) were used. Finally, disequilibrium phase partitioning, meteorological conditions and atmospheric transport were regarded as the main reasons for the variances in dry deposition velocities of individual PAHs.

  13. Temperature-dependent, behavioural, and transcriptional variability of a tritrophic interaction consisting of bean, herbivorous mite, and predator.

    Science.gov (United States)

    Ozawa, Rika; Nishimura, Osamu; Yazawa, Shigenobu; Muroi, Atsushi; Takabayashi, Junji; Arimura, Gen-ichiro

    2012-11-01

    Different organisms compensate for, and adapt to, environmental changes in different ways. In this way, environmental changes affect animal-plant interactions. In this study, we assessed the effect of temperature on a tritrophic system of the lima bean, the herbivorous spider mite Tetranychus urticae and the predatory mite Phytoseiulus persimilis. In this system, the plant defends itself against T. urticae by emitting volatiles that attract P. persimilis. Over 20-40 °C, the emission of volatiles by infested plants and the subsequent attraction of P. persimilis peaked at 30 °C, but the number of eggs laid by T. urticae adults and the number of eggs consumed by P. persimilis peaked at 35 °C. This indicates that the spider mites and predatory mites performed best at a higher temperature than that at which most volatile attractants were produced. Our data from transcriptome pyrosequencing of the mites found that P. persimilis up-regulated gene families for heat shock proteins (HSPs) and ubiquitin-associated proteins, whereas T. urticae did not. RNA interference-mediated gene suppression in P. persimilis revealed differences in temperature responses. Predation on T. urticae eggs by P. persimilis that had been fed PpHsp70-1 dsRNA was low at 35 °C but not at 25 °C when PpHsp70-1 expression was very high. Overall, our molecular and behavioural approaches revealed that the mode and tolerance of lima bean, T. urticae and P. persimilis are distinctly affected by temperature variability, thereby making their tritrophic interactions temperature dependent. © 2012 Blackwell Publishing Ltd.

  14. Mercury Concentrations in Fish and Sediment within Streams are Influenced by Watershed and Landscape Variables including Historical Gold Mining in the Sierra Nevada, California

    Science.gov (United States)

    Alpers, C. N.; Yee, J. L.; Ackerman, J. T.; Orlando, J. L.; Slotton, D. G.; Marvin-DiPasquale, M. C.

    2015-12-01

    We compiled available data on total mercury (THg) and methylmercury (MeHg) concentrations in fish tissue and streambed sediment from stream sites in the Sierra Nevada, California, to assess whether spatial data, including information on historical mining, can be used to make robust predictions of fish fillet tissue THg concentrations. A total of 1,271 fish from five species collected at 103 sites during 1980-2012 were used for the modeling effort: 210 brown trout, 710 rainbow trout, 79 Sacramento pikeminnow, 93 Sacramento sucker, and 179 smallmouth bass. Sediment data were used from 73 sites, including 106 analyses of THg and 77 analyses of MeHg. The dataset included 391 fish (mostly rainbow trout) and 28 sediment samples collected explicitly for this study during 2011-12. Spatial data on historical mining included the USGS Mineral Resources Data System and publicly available maps and satellite photos showing the areas of hydraulic mine pits and other placer mines. Modeling was done using multivariate linear regression and multi-model inference using Akaike Information Criteria. Results indicate that fish THg, accounting for species and length, can be predicted using geospatial data on mining history together with other landscape characteristics including land use/land cover. A model requiring only geospatial data, with an R2 value of 0.61, predicted fish THg correctly with respect to over-or-under 0.2 μg/g wet weight (a California regulatory threshold) for 108 of 121 (89 %) size-species combinations tested. Data for THg in streambed sediment did not improve the geospatial-only model. However, data for sediment MeHg, loss on ignition (organic content), and percent of sediment less than 0.063 mm resulted in a slightly improved model, with an R2 value of 0.63. It is anticipated that these models will be useful to the State of California and others to predict areas where mercury concentrations in fish are likely to exceed regulatory criteria.

  15. An Analysis of Some Variables Affecting the Internet Dependency Level of Turkish Adolescents by Using Decision Tree Methods

    Science.gov (United States)

    Kayri, Murat; Gunuc, Selim

    2010-01-01

    Internet dependency is going to expand into social life in wide area whereas it has been accepted as a pathological and psychological disease. Knowing the basic effects of internet dependency is an inevitable approach to use the internet technology healthy. In this study, internet dependency levels of 754 students were examined with the Internet…

  16. MYR1-Dependent Effectors Are the Major Drivers of a Host Cell’s Early Response to Toxoplasma, Including Counteracting MYR1-Independent Effects

    Directory of Open Access Journals (Sweden)

    Adit Naor

    2018-04-01

    Full Text Available The obligate intracellular parasite Toxoplasma gondii controls its host cell from within the parasitophorous vacuole (PV by using a number of diverse effector proteins, a subset of which require the aspartyl protease 5 enzyme (ASP5 and/or the recently discovered MYR1 protein to cross the PV membrane. To examine the impact these effectors have in the context of the entirety of the host response to Toxoplasma, we used RNA-Seq to analyze the transcriptome expression profiles of human foreskin fibroblasts infected with wild-type RH (RH-WT, RHΔmyr1, and RHΔasp5 tachyzoites. Interestingly, the majority of the differentially regulated genes responding to Toxoplasma infection are MYR1 dependent. A subset of MYR1 responses were ASP5 independent, and MYR1 function did not require ASP5 cleavage, suggesting the export of some effectors requires only MYR1. Gene set enrichment analysis of MYR1-dependent host responses suggests an upregulation of E2F transcription factors and the cell cycle and a downregulation related to interferon signaling, among numerous others. Most surprisingly, “hidden” responses arising in RHΔmyr1- but not RH-WT-infected host cells indicate counterbalancing actions of MYR1-dependent and -independent activities. The host genes and gene sets revealed here to be MYR1 dependent provide new insight into the parasite’s ability to co-opt host cell functions.

  17. Effect of short-term heart rate variability biofeedback on long-term abstinence in alcohol dependent patients - a one-year follow-up.

    Science.gov (United States)

    Penzlin, Ana Isabel; Barlinn, Kristian; Illigens, Ben Min-Woo; Weidner, Kerstin; Siepmann, Martin; Siepmann, Timo

    2017-09-06

    A randomized controlled study (RCT) recently showed that short-term heart rate variability (HRV) biofeedback in addition to standard rehabilitation care for alcohol dependence can reduce craving, anxiety and improve cardiovascular autonomic function. In this one-year follow-up study we aimed to explore whether completion of 2-week HRV-Biofeedback training is associated with long-term abstinence. Furthermore, we sought to identify potential predictors of post-treatment abstinence. We conducted a survey on abstinence in patients with alcohol dependence 1 year after completion of an RCT comparing HRV-biofeedback in addition to inpatient rehabilitation treatment alone (controls). Abstinence rates were compared and analysed for association with demographic data as well as psychometric and autonomic cardiac assessment before and after completion of the biofeedback training using bivariate and multivariate regression analyses. Out of 48 patients who participated in the RCT, 27 patients (9 females, ages 42.9 ± 8.6, mean ± SD) completed our one-year follow-up. When including in the analysis only patients who completed follow-up, the rate of abstinence tended to be higher in patients who underwent HRV-biofeedback 1 year earlier compared to those who received rehabilitative treatment alone (66.7% vs 50%, p = ns). This non-significant trend was also observed in the intention-to-treat analysis where patients who did not participate in the follow-up were assumed to have relapsed (46,7% biofeedback vs. 33.3% controls, p = ns). Neither cardiac autonomic function nor psychometric variables were associated with abstinence 1 year after HRV-biofeedback. Our follow-up study provide a first indication of possible increase in long-term abstinence after HRV-biofeedback for alcohol dependence in addition to rehabilitation. The original randomized controlled trial was registered in the German Clinical Trials Register ( DRKS00004618 ). This one-year follow-up survey has not been

  18. Signal or noise? Separating grain size-dependent Nd isotope variability from provenance shifts in Indus delta sediments, Pakistan

    Science.gov (United States)

    Jonell, T. N.; Li, Y.; Blusztajn, J.; Giosan, L.; Clift, P. D.

    2017-12-01

    Rare earth element (REE) radioisotope systems, such as neodymium (Nd), have been traditionally used as powerful tracers of source provenance, chemical weathering intensity, and sedimentary processes over geologic timescales. More recently, the effects of physical fractionation (hydraulic sorting) of sediments during transport have called into question the utility of Nd isotopes as a provenance tool. Is source terrane Nd provenance resolvable if sediment transport strongly induces noise? Can grain-size sorting effects be quantified? This study works to address such questions by utilizing grain size analysis, trace element geochemistry, and Nd isotope geochemistry of bulk and grain-size fractions (Pakistan. Here we evaluate how grain size effects drive Nd isotope variability and further resolve the total uncertainties associated with Nd isotope compositions of bulk sediments. Results from the Indus delta indicate bulk sediment ɛNd compositions are most similar to the <63 µm fraction as a result of strong mineralogical control on bulk compositions by silt- to clay-sized monazite and/or allanite. Replicate analyses determine that the best reproducibility (± 0.15 ɛNd points) is observed in the 125-250 µm fraction. The bulk and finest fractions display the worst reproducibility (±0.3 ɛNd points). Standard deviations (2σ) indicate that bulk sediment uncertainties are no more than ±1.0 ɛNd points. This argues that excursions of ≥1.0 ɛNd points in any bulk Indus delta sediments must in part reflect an external shift in provenance irrespective of sample composition, grain size, and grain size distribution. Sample standard deviations (2s) estimate that any terrigenous bulk sediment composition should vary no greater than ±1.1 ɛNd points if provenance remains constant. Findings from this study indicate that although there are grain-size dependent Nd isotope effects, they are minimal in the Indus delta such that resolvable provenance-driven trends can be

  19. MYR1-Dependent Effectors Are the Major Drivers of a Host Cell's Early Response to Toxoplasma, Including Counteracting MYR1-Independent Effects.

    Science.gov (United States)

    Naor, Adit; Panas, Michael W; Marino, Nicole; Coffey, Michael J; Tonkin, Christopher J; Boothroyd, John C

    2018-04-03

    The obligate intracellular parasite Toxoplasma gondii controls its host cell from within the parasitophorous vacuole (PV) by using a number of diverse effector proteins, a subset of which require the aspartyl protease 5 enzyme (ASP5) and/or the recently discovered MYR1 protein to cross the PV membrane. To examine the impact these effectors have in the context of the entirety of the host response to Toxoplasma , we used RNA-Seq to analyze the transcriptome expression profiles of human foreskin fibroblasts infected with wild-type RH (RH-WT), RHΔ myr1 , and RHΔ asp5 tachyzoites. Interestingly, the majority of the differentially regulated genes responding to Toxoplasma infection are MYR1 dependent. A subset of MYR1 responses were ASP5 independent, and MYR1 function did not require ASP5 cleavage, suggesting the export of some effectors requires only MYR1. Gene set enrichment analysis of MYR1-dependent host responses suggests an upregulation of E2F transcription factors and the cell cycle and a downregulation related to interferon signaling, among numerous others. Most surprisingly, "hidden" responses arising in RHΔ myr1 - but not RH-WT-infected host cells indicate counterbalancing actions of MYR1-dependent and -independent activities. The host genes and gene sets revealed here to be MYR1 dependent provide new insight into the parasite's ability to co-opt host cell functions. IMPORTANCE Toxoplasma gondii is unique in its ability to successfully invade and replicate in a broad range of host species and cells within those hosts. The complex interplay of effector proteins exported by Toxoplasma is key to its success in co-opting the host cell to create a favorable replicative niche. Here we show that a majority of the transcriptomic effects in tachyzoite-infected cells depend on the activity of a novel translocation system involving MYR1 and that the effectors delivered by this system are part of an intricate interplay of activators and suppressors. Removal of all MYR1

  20. Convergence Analysis of Semi-Implicit Euler Methods for Solving Stochastic Age-Dependent Capital System with Variable Delays and Random Jump Magnitudes

    Directory of Open Access Journals (Sweden)

    Qinghui Du

    2014-01-01

    Full Text Available We consider semi-implicit Euler methods for stochastic age-dependent capital system with variable delays and random jump magnitudes, and investigate the convergence of the numerical approximation. It is proved that the numerical approximate solutions converge to the analytical solutions in the mean-square sense under given conditions.

  1. Mycobacterial UvrD1 is a Ku-dependent DNA helicase that plays a role in multiple DNA repair events, including double-strand break repair.

    Science.gov (United States)

    Sinha, Krishna Murari; Stephanou, Nicolas C; Gao, Feng; Glickman, Michael S; Shuman, Stewart

    2007-05-18

    Mycobacterium tuberculosis and other bacterial pathogens have a Ku-dependent nonhomologous end joining pathway of DNA double-strand break repair. Here we identify mycobacterial UvrD1 as a novel interaction partner for Ku in a genome-wide yeast two-hybrid screen. UvrD1 per se is a vigorous DNA-dependent ATPase but a feeble DNA helicase. Ku stimulates UvrD1 to catalyze ATP-dependent unwinding of 3'-tailed DNAs. UvrD1, Ku, and DNA form a stable ternary complex in the absence of ATP. The Ku binding determinants are located in the distinctive C-terminal segment of UvrD1. A second mycobacterial paralog, UvrD2, is a vigorous Ku-independent DNA helicase. Ablation of UvrD1 sensitizes Mycobacterium smegmatis to killing by ultraviolet and ionizing radiation and to a single chromosomal break generated by I-SceI endonuclease. The physical and functional interactions of bacterial Ku and UvrD1 highlight the potential for cross-talk between components of nonhomologous end joining and nucleotide excision repair pathways.

  2. Degree of multicollinearity and variables involved in linear dependence in additive-dominant models Grau de multicolinearidade e variáveis envolvidas na dependência linear em modelos aditivo-dominantes

    Directory of Open Access Journals (Sweden)

    Juliana Petrini

    2012-12-01

    Full Text Available The objective of this work was to assess the degree of multicollinearity and to identify the variables involved in linear dependence relations in additive-dominant models. Data of birth weight (n=141,567, yearling weight (n=58,124, and scrotal circumference (n=20,371 of Montana Tropical composite cattle were used. Diagnosis of multicollinearity was based on the variance inflation factor (VIF and on the evaluation of the condition indexes and eigenvalues from the correlation matrix among explanatory variables. The first model studied (RM included the fixed effect of dam age class at calving and the covariates associated to the direct and maternal additive and non-additive effects. The second model (R included all the effects of the RM model except the maternal additive effects. Multicollinearity was detected in both models for all traits considered, with VIF values of 1.03 - 70.20 for RM and 1.03 - 60.70 for R. Collinearity increased with the increase of variables in the model and the decrease in the number of observations, and it was classified as weak, with condition index values between 10.00 and 26.77. In general, the variables associated with additive and non-additive effects were involved in multicollinearity, partially due to the natural connection between these covariables as fractions of the biological types in breed composition.O objetivo deste trabalho foi avaliar o grau de multicolinearidade e identificar as variáveis envolvidas na dependência linear em modelos aditivo-dominantes. Foram utilizados dados de peso ao nascimento (n=141.567, peso ao ano (n=58.124 e perímetro escrotal (n=20.371 de bovinos de corte compostos Montana Tropical. O diagnóstico de multicolinearidade foi baseado no fator de inflação de variância (VIF e no exame dos índices de condição e dos autovalores da matriz de correlações entre as variáveis explanatórias. O primeiro modelo estudado (RM incluiu o efeito fixo de classe de idade da mãe ao parto e

  3. Time dependent analysis of assay comparability: a novel approach to understand intra- and inter-site variability over time

    Science.gov (United States)

    Winiwarter, Susanne; Middleton, Brian; Jones, Barry; Courtney, Paul; Lindmark, Bo; Page, Ken M.; Clark, Alan; Landqvist, Claire

    2015-09-01

    We demonstrate here a novel use of statistical tools to study intra- and inter-site assay variability of five early drug metabolism and pharmacokinetics in vitro assays over time. Firstly, a tool for process control is presented. It shows the overall assay variability but allows also the following of changes due to assay adjustments and can additionally highlight other, potentially unexpected variations. Secondly, we define the minimum discriminatory difference/ratio to support projects to understand how experimental values measured at different sites at a given time can be compared. Such discriminatory values are calculated for 3 month periods and followed over time for each assay. Again assay modifications, especially assay harmonization efforts, can be noted. Both the process control tool and the variability estimates are based on the results of control compounds tested every time an assay is run. Variability estimates for a limited set of project compounds were computed as well and found to be comparable. This analysis reinforces the need to consider assay variability in decision making, compound ranking and in silico modeling.

  4. Time dependence of the UV resonance lines in the cataclysmic variables SU UMa, RX And and 0623+71

    International Nuclear Information System (INIS)

    Woods, J.A.; Drew, J.E.; Verbunt, Frank

    1990-01-01

    We present IUE observations of the dwarf novae SU UMa and RX And, and of the nova-like variable 0623 + 71. At the time of observation, SU UMa and RX And were in outburst. All three systems show variability in the wind-formed UV resonance lines of N v λ 1240, Si IV λ 1397 and C IV λ 1549 on timescale of hours. The amplitude of variation is smallest in RX And and largest in 0623 + 71. There is evidence that the variations observed in SU UMa's UV spectrum repeat on the orbital period. Our observations of SU UMa also reveal variability in the continuum flux during the decline from outburst maximum that is much more marked in the UV than at optical wavelengths. (author)

  5. Illicit drug use and abuse/dependence: modeling of two-stage variables using the CCC approach.

    Science.gov (United States)

    Agrawal, A; Neale, M C; Jacobson, K C; Prescott, C A; Kendler, K S

    2005-06-01

    Drug use and abuse/dependence are stages of a complex drug habit. Most genetically informative models that are fit to twin data examine drug use and abuse/dependence independent of each other. This poses an interesting question: for a multistage process, how can we partition the factors influencing each stage specifically from the factors that are common to both stages? We used a causal-common-contingent (CCC) model to partition the common and specific influences on drug use and abuse/dependence. Data on use and abuse/dependence of cannabis, cocaine, sedatives, stimulants and any illicit drug was obtained from male and female twin pairs. CCC models were tested individually for each sex and in a sex-equal model. Our results suggest that there is evidence for additive genetic, shared environmental and unique environmental influences that are common to illicit drug use and abuse/dependence. Furthermore, we found substantial evidence for factors that were specific to abuse/dependence. Finally, sexes could be equated for all illicit drugs. The findings of this study emphasize the need for models that can partition the sources of individual differences into common and stage-specific influences.

  6. An Analysis of the Effectiveness of Supplemental Instruction: The Problem of Selection Bias and Limited Dependent Variables

    Science.gov (United States)

    Bowles, Tyler J.; Jones, Jason

    2004-01-01

    Single equation regression models have been used rather extensively to test the effectiveness of Supplemental Instruction (SI). This approach, however, fails to account for the possibility that SI attendance and the outcome of SI attendance are jointly determined endogenous variables. Moreover, the standard approach fails to account for the fact…

  7. High-Rate Pacing Reduces Variability of Repolarization and Prevents Repolarization-Dependent Arrhythmias in Dogs With Chronic AV Block

    DEFF Research Database (Denmark)

    Oosterhoff, Peter; Thomsen, Morten Bækgaard; Maas, Joep N

    2010-01-01

    -term variability of repolarization (STV) as a feedback parameter of arrhythmic risk. Methods and Results: The minimal signal sampling frequency required for measuring STV was determined through computer simulation. Arrhythmogenic response to dofetilide (25 µg/kg/5minutes) was tested at two different paced heart...

  8. Enteric bacterial metabolites propionic and butyric acid modulate gene expression, including CREB-dependent catecholaminergic neurotransmission, in PC12 cells--possible relevance to autism spectrum disorders.

    Directory of Open Access Journals (Sweden)

    Bistra B Nankova

    Full Text Available Alterations in gut microbiome composition have an emerging role in health and disease including brain function and behavior. Short chain fatty acids (SCFA like propionic (PPA, and butyric acid (BA, which are present in diet and are fermentation products of many gastrointestinal bacteria, are showing increasing importance in host health, but also may be environmental contributors in neurodevelopmental disorders including autism spectrum disorders (ASD. Further to this we have shown SCFA administration to rodents over a variety of routes (intracerebroventricular, subcutaneous, intraperitoneal or developmental time periods can elicit behavioral, electrophysiological, neuropathological and biochemical effects consistent with findings in ASD patients. SCFA are capable of altering host gene expression, partly due to their histone deacetylase inhibitor activity. We have previously shown BA can regulate tyrosine hydroxylase (TH mRNA levels in a PC12 cell model. Since monoamine concentration is known to be elevated in the brain and blood of ASD patients and in many ASD animal models, we hypothesized that SCFA may directly influence brain monoaminergic pathways. When PC12 cells were transiently transfected with plasmids having a luciferase reporter gene under the control of the TH promoter, PPA was found to induce reporter gene activity over a wide concentration range. CREB transcription factor(s was necessary for the transcriptional activation of TH gene by PPA. At lower concentrations PPA also caused accumulation of TH mRNA and protein, indicative of increased cell capacity to produce catecholamines. PPA and BA induced broad alterations in gene expression including neurotransmitter systems, neuronal cell adhesion molecules, inflammation, oxidative stress, lipid metabolism and mitochondrial function, all of which have been implicated in ASD. In conclusion, our data are consistent with a molecular mechanism through which gut related environmental signals

  9. A composite model including visfatin, tissue polypeptide-specific antigen, hyaluronic acid, and hematological variables for the diagnosis of moderate-to-severe fibrosis in nonalcoholic fatty liver disease: a preliminary study.

    Science.gov (United States)

    Chwist, Alina; Hartleb, Marek; Lekstan, Andrzej; Kukla, Michał; Gutkowski, Krzysztof; Kajor, Maciej

    2014-01-01

    Histopathological risk factors for end-stage liver failure in patients with nonalcoholic fatty liver disease (NAFLD) include nonalcoholic steatohepatitis (NASH) and advanced liver fibrosis. There is a need for noninvasive diagnostic methods for these 2 conditions. The aim of this study was to investigate new laboratory variables with a predictive potential to detect advanced fibrosis (stages 2 and 3) in NAFLD. The study involved 70 patients with histologically proven NAFLD of varied severity. Additional laboratory variables included zonulin, haptoglobin, visfatin, adiponectin, leptin, tissue polypeptide-specific antigen (TPSA), hyaluronic acid, and interleukin 6. Patients with NASH (NAFLD activity score of ≥5) had significantly higher HOMA-IR values and serum levels of visfatin, haptoglobin, and zonulin as compared with those without NASH on histological examination. Advanced fibrosis was found in 16 patients (22.9%) and the risk factors associated with its prevalence were age, the ratio of erythrocyte count to red blood cell distribution width, platelet count, and serum levels of visfatin and TPSA. Based on these variables, we constructed a scoring system that differentiated between NAFLD patients with and without advanced fibrosis with a sensitivity of 75% and specificity of 100% (area under the receiver operating characteristic curve, 0.93). The scoring system based on the above variables allows to predict advanced fibrosis with high sensitivity and specificity. However, its clinical utility should be verified in further studies involving a larger number of patients.

  10. Defining an EPOR- regulated transcriptome for primary progenitors, including Tnfr-sf13c as a novel mediator of EPO- dependent erythroblast formation.

    Directory of Open Access Journals (Sweden)

    Seema Singh

    Full Text Available Certain concepts concerning EPO/EPOR action modes have been challenged by in vivo studies: Bcl-x levels are elevated in maturing erythroblasts, but not in their progenitors; truncated EPOR alleles that lack a major p85/PI3K recruitment site nonetheless promote polycythemia; and Erk1 disruption unexpectedly bolsters erythropoiesis. To discover novel EPO/EPOR action routes, global transcriptome analyses presently are applied to interrogate EPO/EPOR effects on primary bone marrow-derived CFUe-like progenitors. Overall, 160 EPO/EPOR target transcripts were significantly modulated 2-to 21.8-fold. A unique set of EPO-regulated survival factors included Lyl1, Gas5, Pim3, Pim1, Bim, Trib3 and Serpina 3g. EPO/EPOR-modulated cell cycle mediators included Cdc25a, Btg3, Cyclin-d2, p27-kip1, Cyclin-g2 and CyclinB1-IP-1. EPO regulation of signal transduction factors was also interestingly complex. For example, not only Socs3 plus Socs2 but also Spred2, Spred1 and Eaf1 were EPO-induced as negative-feedback components. Socs2, plus five additional targets, further proved to comprise new EPOR/Jak2/Stat5 response genes (which are important for erythropoiesis during anemia. Among receptors, an atypical TNF-receptor Tnfr-sf13c was up-modulated >5-fold by EPO. Functionally, Tnfr-sf13c ligation proved to both promote proerythroblast survival, and substantially enhance erythroblast formation. The EPOR therefore engages a sophisticated set of transcriptome response circuits, with Tnfr-sf13c deployed as one novel positive regulator of proerythroblast formation.

  11. Upper and lower solutions for BVPs on the half-line with variable coefficient and derivative depending nonlinearity

    Directory of Open Access Journals (Sweden)

    S. Djebali

    2011-02-01

    Full Text Available This paper is concerned with a second-order nonlinear boundary value problem with a derivative depending nonlinearity and posed on the positive half-line. The derivative operator is time dependent. Upon a priori estimates and under a Nagumo growth condition, the Schauder's fixed point theorem combined with the method of upper and lower solutions on unbounded domains are used to prove existence of solutions. A uniqueness theorem is also obtained and some examples of application illustrate the obtained results.

  12. A similarity solution of time dependent MHD liquid film flow over stretching sheet with variable physical properties

    Directory of Open Access Journals (Sweden)

    M. Idrees

    2018-03-01

    Full Text Available An analysis is performed for the fluid dynamics incorporating the variation of viscosity and thermal conductivity on an unsteady two-dimensional free surface flow of a viscous incompressible conducting fluid taking into account the effect of a magnetic field. Surface tension quadratically vary with temperature while fluid viscosity and thermal conductivity are assumed to vary as a linear function of temperature. The boundary layer partial differential equations in cartesian coordinates are transformed into a system of nonlinear ordinary differential equations (ODEs by similarity transformation. The developed nonlinear equations are solved analytically by Homotopy Analysis Method (HAM while numerically by using the shooting method. The Effects of natural parameters such as the variable viscosity parameter A, variable thermal conductivity parameter N, Hartmann number Ma, film Thickness, unsteadiness parameter S, Thermocapillary number M and Prandtl number Pr on the velocity and temperature profiles are investigated. The results for the surface skin friction coefficient f″(0, Nusselt number (heat flux -θ′(0 and free surface temperature θ(1 are presented graphically and in tabular form. Keywords: Variable viscosity and thermal conductivity, Thermocapillary number, Magnetic field, Thin film, Unsteady stretching surface

  13. The Association of Selected Conative Variables to Field-Dependence with Inferences for Reasoning Characteristics in Marketing Education.

    Science.gov (United States)

    Fritz, Robert L.

    A study examined the association between field-dependence and its related information processing characteristics, and educational cognitive style as a model of conative influence. Data were collected from 145 secondary marketing education students in nothern Georgia during spring 1991. Descriptive statistics, Pearson product moment correlations,…

  14. [Reconsideration of nicotine and other substance dependence: a clue from dependence-related mentation including reward, motivation, learning, delusion and hallucination toward understanding the concept of non-substance-related addiction].

    Science.gov (United States)

    Miyata, Hisatsugu

    2013-11-01

    Nicotine produces core symptoms of substance dependence (craving and withdrawal) without any psychotic symptoms. The psychopharmacological structure of craving is hypothesized to be constituted by three components: the primary reinforcing property of a substance, the secondary reinforcing property of that substance (conditioned aspects of the environment, such as contextual or specific cues associated with substance taking), and the negative affective motivational property during withdrawal (i.e. the desire to avoid the dysphoric withdrawal symptoms elicits craving). Among the three components, the primary reinforcing property of a substance forms the most fundamental factor for establishing substance dependence. Sensitization or reverse tolerance observed in locomotor activity of animals, which had been believed to be a methamphetamine psychosis model, is demonstrated to reflect the establishment of conditioned reinforcement. Finally, non-substance-related addiction such as gambling, internet, and sex is discussed. From the aspect of the above hypothetical psychopharmacological structure of craving, the most significant difference between substance dependence and non-substance-related addiction is that the primary reinforcing property of non-substance reward is relatively intangible in comparison with that of a substance of abuse.

  15. The TAL effector PthA4 interacts with nuclear factors involved in RNA-dependent processes including a HMG protein that selectively binds poly(U RNA.

    Directory of Open Access Journals (Sweden)

    Tiago Antonio de Souza

    Full Text Available Plant pathogenic bacteria utilize an array of effector proteins to cause disease. Among them, transcriptional activator-like (TAL effectors are unusual in the sense that they modulate transcription in the host. Although target genes and DNA specificity of TAL effectors have been elucidated, how TAL proteins control host transcription is poorly understood. Previously, we showed that the Xanthomonas citri TAL effectors, PthAs 2 and 3, preferentially targeted a citrus protein complex associated with transcription control and DNA repair. To extend our knowledge on the mode of action of PthAs, we have identified new protein targets of the PthA4 variant, required to elicit canker on citrus. Here we show that all the PthA4-interacting proteins are DNA and/or RNA-binding factors implicated in chromatin remodeling and repair, gene regulation and mRNA stabilization/modification. The majority of these proteins, including a structural maintenance of chromosomes protein (CsSMC, a translin-associated factor X (CsTRAX, a VirE2-interacting protein (CsVIP2, a high mobility group (CsHMG and two poly(A-binding proteins (CsPABP1 and 2, interacted with each other, suggesting that they assemble into a multiprotein complex. CsHMG was shown to bind DNA and to interact with the invariable leucine-rich repeat region of PthAs. Surprisingly, both CsHMG and PthA4 interacted with PABP1 and 2 and showed selective binding to poly(U RNA, a property that is novel among HMGs and TAL effectors. Given that homologs of CsHMG, CsPABP1, CsPABP2, CsSMC and CsTRAX in other organisms assemble into protein complexes to regulate mRNA stability and translation, we suggest a novel role of TAL effectors in mRNA processing and translational control.

  16. Variability of photovoltaic panels efficiency depending on the value of the angle of their inclination relative to the horizon

    Directory of Open Access Journals (Sweden)

    Majdak Marek

    2017-01-01

    Full Text Available The objective of this paper was to determine the relationship between the efficiency of photovoltaic panels and the value of the angle of their inclination relative to the horizon. For the purpose of experimental research have been done tests on the photovoltaic modules made of monocrystalline, polycrystalline and amorphous silicon. The experiment consisted of measurement of the voltage and current generated by photovoltaic panels at a known value of solar radiation and a specified resistance value determined by using resistor with variable value of resistance and known value of the angle of their inclination relative to the horizon.

  17. SU-F-T-113: Inherent Functional Dependence of Spinal Cord Doses of Variable Irradiated Volumes in Spine SBRT

    Energy Technology Data Exchange (ETDEWEB)

    Ma, L; Braunstein, S; Chiu, J [University of California San Francisco, San Francisco, CA (United States); Sahgal, A [Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario (Canada)

    2016-06-15

    Purpose: Spinal cord tolerance for SBRT has been recommended for the maximum point dose level or at irradiated volumes such as 0.35 mL or 10% of contoured volumes. In this study, we investigated an inherent functional relationship that associates these dose surrogates for irradiated spinal cord volumes of up to 3.0 mL. Methods: A hidden variable termed as Effective Dose Radius (EDR) was formulated based on a dose fall-off model to correlate dose at irradiated spinal cord volumes ranging from 0 mL (point maximum) to 3.0 mL. A cohort of 15 spine SBRT cases was randomly selected to derive an EDR-parameterized formula. The mean prescription dose for the studied cases was 21.0±8.0 Gy (range, 10–40Gy) delivered in 3±1 fractions with target volumes of 39.1 ± 70.6 mL. Linear regression and variance analysis were performed for the fitting parameters of variable EDR values. Results: No direct correlation was found between the dose at maximum point and doses at variable spinal cord volumes. For example, Pearson R{sup 2} = 0.643 and R{sup 2}= 0.491 were obtained when correlating the point maximum dose with the spinal cord dose at 1 mL and 3 mL, respectively. However, near perfect correlation (R{sup 2} ≥0.99) was obtained when corresponding parameterized EDRs. Specifically, Pearson R{sup 2}= 0.996 and R{sup 2} = 0.990 were obtained when correlating EDR (maximum point dose) with EDR (dose at 1 mL) and EDR(dose at 3 mL), respectively. As a result, high confidence level look-up tables were established to correlate spinal cord doses at the maximum point to any finite irradiated volumes. Conclusion: An inherent functional relationship was demonstrated for spine SBRT. Such a relationship unifies dose surrogates at variable cord volumes and proves that a single dose surrogate (e.g. point maximum dose) is mathematically sufficient in constraining the overall spinal cord dose tolerance for SBRT.

  18. A similarity solution of time dependent MHD liquid film flow over stretching sheet with variable physical properties

    Science.gov (United States)

    Idrees, M.; Rehman, Sajid; Shah, Rehan Ali; Ullah, M.; Abbas, Tariq

    2018-03-01

    An analysis is performed for the fluid dynamics incorporating the variation of viscosity and thermal conductivity on an unsteady two-dimensional free surface flow of a viscous incompressible conducting fluid taking into account the effect of a magnetic field. Surface tension quadratically vary with temperature while fluid viscosity and thermal conductivity are assumed to vary as a linear function of temperature. The boundary layer partial differential equations in cartesian coordinates are transformed into a system of nonlinear ordinary differential equations (ODEs) by similarity transformation. The developed nonlinear equations are solved analytically by Homotopy Analysis Method (HAM) while numerically by using the shooting method. The Effects of natural parameters such as the variable viscosity parameter A, variable thermal conductivity parameter N, Hartmann number Ma, film Thickness, unsteadiness parameter S, Thermocapillary number M and Prandtl number Pr on the velocity and temperature profiles are investigated. The results for the surface skin friction coefficient f″ (0) , Nusselt number (heat flux) -θ‧ (0) and free surface temperature θ (1) are presented graphically and in tabular form.

  19. The dynamic relationship between current and previous severe hypoglycemic events: a lagged dependent variable analysis among patients with type 2 diabetes who have initiated basal insulin.

    Science.gov (United States)

    Ganz, Michael L; Li, Qian; Wintfeld, Neil S; Lee, Yuan-Chi; Sorli, Christopher; Huang, Joanna C

    2015-01-01

    Past studies have found episodes of severe hypoglycemia (SH) to be serially dependent. Those studies, however, only considered the impact of a single (index) event on future risk; few have analyzed SH risk as it evolves over time in the presence (or absence) of continuing events. The objective of this study was to determine the dynamic risks of SH events conditional on preceding SH events among patients with type 2 diabetes (T2D) who have initiated basal insulin. We used an electronic health records database from the United States that included encounter and laboratory data and clinical notes on T2D patients who initiated basal insulin therapy between 2008 and 2011 and to identify SH events. We used a repeated-measures lagged dependent variable logistic regression model to estimate the impact of SH in one quarter on the risk of SH in the next quarter. We identified 7235 patients with T2D who initiated basal insulin. Patients who experienced ≥1 SH event during any quarter were more likely to have ≥1 SH event during the subsequent quarter than those who did not (predicted probabilities of 7.4% and 1.0%, respectively; p history of SH before starting basal insulin (predicted probabilities of 1.0% and 3.2%, respectively; p history of SH during the titration period (predicted probabilities of 1.1% and 2.8%, respectively; p history of SH events and therefore the value of preventing one SH event may be substantial. These results can inform patient care by providing clinicians with dynamic data on a patient's risk of SH, which in turn can facilitate appropriate adjustment of the risk-benefit ratio for individualized patient care. These results should, however, be interpreted in light of the key limitations of our study: not all SH events may have been captured or coded in the database, data on filled prescriptions were not available, we were unable to adjust for basal insulin dose, and the post-titration follow-up period could have divided into time units other

  20. Increased Variability and Asymmetric Expansion of the Hippocampal Spatial Representation in a Distal Cue-Dependent Memory Task.

    Science.gov (United States)

    Park, Seong-Beom; Lee, Inah

    2016-08-01

    Place cells in the hippocampus fire at specific positions in space, and distal cues in the environment play critical roles in determining the spatial firing patterns of place cells. Many studies have shown that place fields are influenced by distal cues in foraging animals. However, it is largely unknown whether distal-cue-dependent changes in place fields appear in different ways in a memory task if distal cues bear direct significance to achieving goals. We investigated this possibility in this study. Rats were trained to choose different spatial positions in a radial arm in association with distal cue configurations formed by visual cue sets attached to movable curtains around the apparatus. The animals were initially trained to associate readily discernible distal cue configurations (0° vs. 80° angular separation between distal cue sets) with different food-well positions and then later experienced ambiguous cue configurations (14° and 66°) intermixed with the original cue configurations. Rats showed no difficulty in transferring the associated memory formed for the original cue configurations when similar cue configurations were presented. Place field positions remained at the same locations across different cue configurations, whereas stability and coherence of spatial firing patterns were significantly disrupted when ambiguous cue configurations were introduced. Furthermore, the spatial representation was extended backward and skewed more negatively at the population level when processing ambiguous cue configurations, compared with when processing the original cue configurations only. This effect was more salient for large cue-separation conditions than for small cue-separation conditions. No significant rate remapping was observed across distal cue configurations. These findings suggest that place cells in the hippocampus dynamically change their detailed firing characteristics in response to a modified cue environment and that some of the firing

  1. Optimization of the Method of Active Ingredients Adding to the Base of Medicinal Films Depending on Certain Variables

    Directory of Open Access Journals (Sweden)

    L. L. Davtian

    2018-03-01

    Full Text Available The influence of variables of pharmaceutical factors on the technological processes of drugs manufacturing is incredibly important. Thus, in the development of a new drug in the form of medicinal films, the relevance and necessity of determining the effect of the methods of active substances adding on the effectiveness of the drug was determined. The aim is rationalization of the method of the active pharmaceutical ingredients adding into the composition of the developed drug. Materials and methods. As experimental samples we used medicinal films, which were made using various methods of active ingredients adding. The quality of the samples was evaluated by the antimicrobial activity against Clostridium sporogenes and Staphylococcus aureus, which was determined by the diffusion method in agar. Results. The study of the antimicrobial activity of medicinal films with various methods of active ingredients adding showed that the adding of metronidazole as an aqueous solution increases the antimicrobial activity of the films by 21.23%, 16.89%, 28.59%, respectively, compared with films of similar composition, in which metronidazole was added as a suspension, and the remaining ingredients were added by the same way. The introduction of chlorhexidine bigluconate and glucosamine hydrochloride in the film-forming solution lastly together with the solution of metronidazole increases the antimicrobial activity by 24.67%, which is probably due to the absence of contact between thermolabile ingredients and solutions of film-forming substances having a high dissolution temperature. Conclusions. The most rational is adding of metronidazole to the medicinal films in the form of a 0.01% aqueous solution in a mixture with the chlorhexidine bigluconate and glucosamine hydrochloride solution to the final film-forming solution.

  2. Intraspecies Variability Affects Heterotypic Biofilms of Porphyromonas gingivalis and Prevotella intermedia: Evidences of Strain-Dependence Biofilm Modulation by Physical Contact and by Released Soluble Factors.

    Directory of Open Access Journals (Sweden)

    Graziela Murta Barbosa

    Full Text Available It is well known that strain and virulence diversity exist within the population structure of Porphyromonas gingivalis. In the present study we investigate intra- and inter-species variability in biofilm formation of Porphyromonas gingivalis and partners Prevotella intermedia and Prevotella nigrescens. All strains tested showed similar hydrophobicity, except for P. gingivalis W83 which has roughly half of the hydrophobicity of P. gingivalis ATCC33277. An intraspecies variability in coaggregation of P. gingivalis with P. intermedia was also found. The association P. gingivalis W83/P. intermedia 17 produced the thickest biofilm and strain 17 was prevalent. In a two-compartment system P. gingivalis W83 stimulates an increase in biomass of strain 17 and the latter did not stimulate the growth of P. gingivalis W83. In addition, P. gingivalis W83 also stimulates the growth of P. intermedia ATCC25611 although strain W83 was prevalent in the association with P. intermedia ATCC25611. P. gingivalis ATCC33277 was prevalent in both associations with P. intermedia and both strains of P. intermedia stimulate the growth of P. gingivalis ATCC33277. FISH images also showed variability in biofilm structure. Thus, the outcome of the association P. gingivalis/P. intermedia seems to be strain-dependent, and both soluble factors and physical contact are relevant. The association P. gingivalis-P. nigrescens ATCC33563 produced larger biomass than each monotypic biofilm, and P. gingivalis was favored in consortia, while no differences were found in the two-compartment system. Therefore, in consortia P. gingivalis-P. nigrescens physical contact seems to favor P. gingivalis growth. The intraspecies variability found in our study suggests strain-dependence in ability of microorganisms to recognize molecules in other bacteria which may further elucidate the dysbiosis event during periodontitis development giving additional explanation for periodontal bacteria, such as P

  3. Intraspecies Variability Affects Heterotypic Biofilms of Porphyromonas gingivalis and Prevotella intermedia: Evidences of Strain-Dependence Biofilm Modulation by Physical Contact and by Released Soluble Factors.

    Science.gov (United States)

    Barbosa, Graziela Murta; Colombo, Andrea Vieira; Rodrigues, Paulo Henrique; Simionato, Maria Regina Lorenzetti

    2015-01-01

    It is well known that strain and virulence diversity exist within the population structure of Porphyromonas gingivalis. In the present study we investigate intra- and inter-species variability in biofilm formation of Porphyromonas gingivalis and partners Prevotella intermedia and Prevotella nigrescens. All strains tested showed similar hydrophobicity, except for P. gingivalis W83 which has roughly half of the hydrophobicity of P. gingivalis ATCC33277. An intraspecies variability in coaggregation of P. gingivalis with P. intermedia was also found. The association P. gingivalis W83/P. intermedia 17 produced the thickest biofilm and strain 17 was prevalent. In a two-compartment system P. gingivalis W83 stimulates an increase in biomass of strain 17 and the latter did not stimulate the growth of P. gingivalis W83. In addition, P. gingivalis W83 also stimulates the growth of P. intermedia ATCC25611 although strain W83 was prevalent in the association with P. intermedia ATCC25611. P. gingivalis ATCC33277 was prevalent in both associations with P. intermedia and both strains of P. intermedia stimulate the growth of P. gingivalis ATCC33277. FISH images also showed variability in biofilm structure. Thus, the outcome of the association P. gingivalis/P. intermedia seems to be strain-dependent, and both soluble factors and physical contact are relevant. The association P. gingivalis-P. nigrescens ATCC33563 produced larger biomass than each monotypic biofilm, and P. gingivalis was favored in consortia, while no differences were found in the two-compartment system. Therefore, in consortia P. gingivalis-P. nigrescens physical contact seems to favor P. gingivalis growth. The intraspecies variability found in our study suggests strain-dependence in ability of microorganisms to recognize molecules in other bacteria which may further elucidate the dysbiosis event during periodontitis development giving additional explanation for periodontal bacteria, such as P. gingivalis and P

  4. Systematic spatial bias in DNA microarray hybridization is caused by probe spot position-dependent variability in lateral diffusion.

    Science.gov (United States)

    Steger, Doris; Berry, David; Haider, Susanne; Horn, Matthias; Wagner, Michael; Stocker, Roman; Loy, Alexander

    2011-01-01

    The hybridization of nucleic acid targets with surface-immobilized probes is a widely used assay for the parallel detection of multiple targets in medical and biological research. Despite its widespread application, DNA microarray technology still suffers from several biases and lack of reproducibility, stemming in part from an incomplete understanding of the processes governing surface hybridization. In particular, non-random spatial variations within individual microarray hybridizations are often observed, but the mechanisms underpinning this positional bias remain incompletely explained. This study identifies and rationalizes a systematic spatial bias in the intensity of surface hybridization, characterized by markedly increased signal intensity of spots located at the boundaries of the spotted areas of the microarray slide. Combining observations from a simplified single-probe block array format with predictions from a mathematical model, the mechanism responsible for this bias is found to be a position-dependent variation in lateral diffusion of target molecules. Numerical simulations reveal a strong influence of microarray well geometry on the spatial bias. Reciprocal adjustment of the size of the microarray hybridization chamber to the area of surface-bound probes is a simple and effective measure to minimize or eliminate the diffusion-based bias, resulting in increased uniformity and accuracy of quantitative DNA microarray hybridization.

  5. Variability of the 2014-present inflation source at Mauna Loa volcano revealed using time-dependent modeling

    Science.gov (United States)

    Johanson, I. A.; Miklius, A.; Okubo, P.; Montgomery-Brown, E. K.

    2017-12-01

    Mauna Loa volcano is the largest active volcano on earth and in the 20thcentury produced roughly one eruption every seven years. The 33-year quiescence since its last eruption 1984 has been punctuated by three inflation episodes where magma likely entered the shallow plumbing system, but was not erupted. The most recent began in 2014 and is ongoing. Unlike prior inflation episodes, the current one is accompanied by a significant increase in shallow seismicity, a pattern that is similar to earlier pre-eruptive periods. We apply the Kalman filter based Network Inversion Filter (NIF) to the 2014-present inflation episode using data from a 27 station continuous GPS network on Mauna Loa. The model geometry consists of a point volume source and tabular, dike-like body, which have previously been shown to provide a good fit to deformation data from a 2004-2009 inflation episode. The tabular body is discretized into 1km x 1km segments. For each day, the NIF solves for the rates of opening on the tabular body segments (subject to smoothing and positivity constraints), volume change rate in the point source, and slip rate on a deep décollement fault surface, which is constrained to a constant (no transient slip allowed). The Kalman filter in the NIF provides for smoothing both forwards and backwards in time. The model shows that the 2014-present inflation episode occurred as several sub-events, rather than steady inflation. It shows some spatial variability in the location of the inflation sub-events. In the model, opening in the tabular body is initially concentrated below the volcano's summit, in an area roughly outlined by shallow seismicity. In October, 2015 opening in the tabular body shifts to be centered beneath the southwest portion of the summit and seismicity becomes concentrated in this area. By late 2016, the opening rate on the tabular body decreases and is once again under the central part of summit. This modeling approach has allowed us to track these

  6. A variable-order time-dependent neutron transport method for nuclear reactor kinetics using analytically-integrated space-time characteristics

    International Nuclear Information System (INIS)

    Hoffman, A. J.; Lee, J. C.

    2013-01-01

    A new time-dependent neutron transport method based on the method of characteristics (MOC) has been developed. Whereas most spatial kinetics methods treat time dependence through temporal discretization, this new method treats time dependence by defining the characteristics to span space and time. In this implementation regions are defined in space-time where the thickness of the region in time fulfills an analogous role to the time step in discretized methods. The time dependence of the local source is approximated using a truncated Taylor series expansion with high order derivatives approximated using backward differences, permitting the solution of the resulting space-time characteristic equation. To avoid a drastic increase in computational expense and memory requirements due to solving many discrete characteristics in the space-time planes, the temporal variation of the boundary source is similarly approximated. This allows the characteristics in the space-time plane to be represented analytically rather than discretely, resulting in an algorithm comparable in implementation and expense to one that arises from conventional time integration techniques. Furthermore, by defining the boundary flux time derivative in terms of the preceding local source time derivative and boundary flux time derivative, the need to store angularly-dependent data is avoided without approximating the angular dependence of the angular flux time derivative. The accuracy of this method is assessed through implementation in the neutron transport code DeCART. The method is employed with variable-order local source representation to model a TWIGL transient. The results demonstrate that this method is accurate and more efficient than the discretized method. (authors)

  7. Analysis of arterial pressure variability in patients with acute cerebral stroke depending on the time of occurrence

    Directory of Open Access Journals (Sweden)

    Volosovets A.O.

    2017-12-01

    Full Text Available Arterial hypertension can cause a pronounced negative influence on the state of the cerebral vascular system and lead to significant microtraumatization of the walls of the vessels and disruption of vascular autoregulation. This predictor has the greatest influence on the onset of ischemic stroke of atherothrombotic and lacunar subtypes, however, hypertension occurs almost in all patients with acute cerebral ischemia. Interesting and not at all presented in modern scientific literature is the question of the relationship of oscillation of blood pressure with the period of the onset of the focus of ischemia, which predetermined the purpose of our work. The purpose of our study was to determine the relationship between deformation of the profile of fluctuations in blood pressure of patients in the acute period of ischemic stroke, depending on the time of the occurrence of cerebrovascular accident. We examined 300 patients who suffered acute ischemic stroke (men - 196, women - 104 aged 42 to 84 years (average age - 65.2 ± 8.7 years. All patients were divided into 3 groups according to the period of the day when an ischemic stroke occurred: 1 group (n=146, patients suffering from cerebral ischemia during the day (8.00-14.59; In group 2 (n=107, patients stroke was observed in the evening (15.00-21.59; Group 3 (n=47, patients had an ischemic stroke at night (22.00-7.59. For the 1st group of patients who have had ischemic stroke during the day and as a rule with an increase in blood pressure, a marked increase in blood pressure was at 12.00 and 15.00 and a tendency towards compensatory parasympathetic effect in the form of blood pressure decrease at night (over-dipper was typical. At the same time, in the 2nd group of patients with stroke in the evening, elevated blood pressure at 18.00 and 21.00 and parasympathetic activity disorders with prevalence of insufficient reduction of blood pressure in the evening and during sleep (non-dipper was observed

  8. Soil variability in mountain areas

    OpenAIRE

    Zanini, E.; Freppaz, M.; Stanchi, S.; Bonifacio, E.; Egli, M.

    2015-01-01

    The high spatial variability of soils is a relevant issue at local and global scales, and determines the complexity of soil ecosystem functions and services. This variability derives from strong dependencies of soil ecosystems on parent materials, climate, relief and biosphere, including human impact. Although present in all environments, the interactions of soils with these forming factors are particularly striking in mountain areas.

  9. Unbiased proteomics analysis demonstrates significant variability in mucosal immune factor expression depending on the site and method of collection.

    Directory of Open Access Journals (Sweden)

    Kenzie M Birse

    Full Text Available Female genital tract secretions are commonly sampled by lavage of the ectocervix and vaginal vault or via a sponge inserted into the endocervix for evaluating inflammation status and immune factors critical for HIV microbicide and vaccine studies. This study uses a proteomics approach to comprehensively compare the efficacy of these methods, which sample from different compartments of the female genital tract, for the collection of immune factors. Matching sponge and lavage samples were collected from 10 healthy women and were analyzed by tandem mass spectrometry. Data was analyzed by a combination of differential protein expression analysis, hierarchical clustering and pathway analysis. Of the 385 proteins identified, endocervical sponge samples collected nearly twice as many unique proteins as cervicovaginal lavage (111 vs. 61 with 55% of proteins common to both (213. Each method/site identified 73 unique proteins that have roles in host immunity according to their gene ontology. Sponge samples enriched for specific inflammation pathways including acute phase response proteins (p = 3.37×10(-24 and LXR/RXR immune activation pathways (p = 8.82×10(-22 while the role IL-17A in psoriasis pathway (p = 5.98×10(-4 and the complement system pathway (p = 3.91×10(-3 were enriched in lavage samples. Many host defense factors were differentially enriched (p<0.05 between sites including known/potential antimicrobial factors (n = 21, S100 proteins (n = 9, and immune regulatory factors such as serpins (n = 7. Immunoglobulins (n = 6 were collected at comparable levels in abundance in each site although 25% of those identified were unique to sponge samples. This study demonstrates significant differences in types and quantities of immune factors and inflammation pathways collected by each sampling technique. Therefore, clinical studies that measure mucosal immune activation or factors assessing HIV transmission should utilize

  10. Meteorological variables affect fertility rate after intrauterine artificial insemination in sheep in a seasonal-dependent manner: a 7-year study

    Science.gov (United States)

    Palacios, C.; Abecia, J. A.

    2015-05-01

    A total number of 48,088 artificial inseminations (AIs) have been controlled during seven consecutive years in 79 dairy sheep Spanish farms (41° N). Mean, maximum and minimum ambient temperatures ( Ts), temperature amplitude (TA), mean relative humidity (RH), mean solar radiation (SR) and total rainfall of each insemination day and 15 days later were recorded. Temperature-humidity index (THI) and effective temperature (ET) have been calculated. A binary logistic regression model to estimate the risk of not getting pregnant compared to getting pregnant, through the odds ratio (OR), was performed. Successful winter inseminations were carried out under higher SR ( P 1 (maximum T, ET and rainfall on AI day, and ET and rainfall on day 15), and two variables presented OR AI day and maximum T on day 15). However, the effect of meteorological factors affected fertility in opposite ways, so T becomes a protective or risk factor on fertility depending on season. In conclusion, the percentage of pregnancy after AI in sheep is significantly affected by meteorological variables in a seasonal-dependent manner, so the parameters such as temperature reverse their effects in the hot or cold seasons. A forecast of the meteorological conditions could be a useful tool when AI dates are being scheduled.

  11. Variable H13CO+ Emission in the IM Lup Disk: X-Ray Driven Time-dependent Chemistry?

    Science.gov (United States)

    Cleeves, L. Ilsedore; Bergin, Edwin A.; Öberg, Karin I.; Andrews, Sean; Wilner, David; Loomis, Ryan

    2017-07-01

    We report the first detection of a substantial brightening event in an isotopologue of a key molecular ion, HCO+, within a protoplanetary disk of a T Tauri star. The H13CO+ J=3-2 rotational transition was observed three times toward IM Lup between 2014 July and 2015 May with the Atacama Large Millimeter/submillimeter Array. The first two observations show similar spectrally integrated line and continuum fluxes, while the third observation shows a doubling in the disk-integrated J=3-2 line flux compared to the continuum, which does not change between the three epochs. We explore models of an X-ray active star irradiating the disk via stellar flares, and find that the optically thin H13CO+ emission variation can potentially be explained via X-ray-driven chemistry temporarily enhancing the HCO+ abundance in the upper layers of the disk atmosphere during large or prolonged flaring events. If the HCO+ enhancement is indeed caused by an X-ray flare, future observations should be able to spatially resolve these events and potentially enable us to watch the chemical aftermath of the high-energy stellar radiation propagating across the face of protoplanetary disks, providing a new pathway to explore ionization physics and chemistry, including electron density, in disks.

  12. Variability in a three-generation family with Pierre Robin sequence, acampomelic campomelic dysplasia, and intellectual disability due to a novel ∼1 Mb deletion upstream of SOX9, and including KCNJ2 and KCNJ16.

    Science.gov (United States)

    Castori, Marco; Bottillo, Irene; Morlino, Silvia; Barone, Chiara; Cascone, Piero; Grammatico, Paola; Laino, Luigi

    2016-01-01

    Campomelic dysplasia and acampomelic campomelic dysplasia (ACD) are allelic disorders due to heterozygous mutations in or around SOX9. Translocations and deletions involving the SOX9 5' regulatory region are rare causes of these disorders, as well as Pierre Robin sequence (PRS) and 46,XY gonadal dysgenesis. Genotype-phenotype correlations are not straightforward due to the complex epigenetic regulation of SOX9 expression during development. We report a three-generation pedigree with a novel ∼1 Mb deletion upstream of SOX9 and including KCNJ2 and KCNJ16, and ascertained for dominant transmission of PRS. Further characterization of the family identified subtle appendicular anomalies and a variable constellation of axial skeletal features evocative of ACD in several members. Affected males showed learning disability. The identified deletion was smaller than all other chromosome rearrangements associated with ACD. Comparison with other reported translocations and deletions involving this region allowed further refining of genotype-phenotype correlations and an update of the smallest regions of overlap associated with the different phenotypes. Intrafamilial variability in this pedigree suggests a phenotypic continuity between ACD and PRS in patients carrying mutations in the SOX9 5' regulatory region. © 2015 Wiley Periodicals, Inc.

  13. Phase variable expression of a single phage receptor in Campylobacter jejuni NCTC12662 influences sensitivity toward several diverse CPS-dependent phages

    DEFF Research Database (Denmark)

    Gencay, Yilmaz Emre; Sørensen, Martine C.H.; Wenzel, Cory Q.

    2018-01-01

    Campylobacter jejuni NCTC12662 is sensitive to infection by many Campylobacter bacteriophages. Here we used this strain to investigate the molecular mechanism behind phage resistance development when exposed to a single phage and demonstrate how phase variable expression of one surface component...... influences phage sensitivity against many diverse C. jejuni phages. When C. jejuni NCTC12662 was exposed to phage F207 overnight, 25% of the bacterial cells were able to grow on a lawn of phage F207, suggesting that resistance develops at a high frequency. One resistant variant, 12662R, was further...... characterized and shown to be an adsorption mutant. Plaque assays using our large phage collection showed that seven out of 36 diverse capsular polysaccharide (CPS)-dependent phages could not infect 12662R, whereas the remaining phages formed plaques on 12662R with reduced efficiencies. Analysis of the CPS...

  14. An alternative approach to exact wave functions for time-dependent coupled oscillator model of charged particle in variable magnetic field

    International Nuclear Information System (INIS)

    Menouar, Salah; Maamache, Mustapha; Choi, Jeong Ryeol

    2010-01-01

    The quantum states of time-dependent coupled oscillator model for charged particles subjected to variable magnetic field are investigated using the invariant operator methods. To do this, we have taken advantage of an alternative method, so-called unitary transformation approach, available in the framework of quantum mechanics, as well as a generalized canonical transformation method in the classical regime. The transformed quantum Hamiltonian is obtained using suitable unitary operators and is represented in terms of two independent harmonic oscillators which have the same frequencies as that of the classically transformed one. Starting from the wave functions in the transformed system, we have derived the full wave functions in the original system with the help of the unitary operators. One can easily take a complete description of how the charged particle behaves under the given Hamiltonian by taking advantage of these analytical wave functions.

  15. Origins of intersubject variability of blood oxygenation level dependent and arterial spin labeling fMRI: implications for quantification of brain activity.

    Science.gov (United States)

    Gaxiola-Valdez, Ismael; Goodyear, Bradley G

    2012-12-01

    Accurate localization of brain activity using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) has been challenged because of the large BOLD signal within distal veins. Arterial spin labeling (ASL) techniques offer greater sensitivity to the microvasculature but possess low temporal resolution and limited brain coverage. In this study, we show that the physiological origins of BOLD and ASL depend on whether percent change or statistical significance is being considered. For BOLD and ASL fMRI data collected during a simple unilateral hand movement task, we found that in the area of the contralateral motor cortex the centre of gravity (CoG) of the intersubject coefficient of variation (CV) of BOLD fMRI was near the brain surface for percent change in signal, whereas the CoG of the intersubject CV for Z-score was in close proximity of sites of brain activity for both BOLD and ASL. These findings suggest that intersubject variability of BOLD percent change is vascular in origin, whereas the origin of inter-subject variability of Z-score is neuronal for both BOLD and ASL. For longer duration tasks (12 s or greater), however, there was a significant correlation between BOLD and ASL percent change, which was not evident for short duration tasks (6 s). These findings suggest that analyses directly comparing percent change in BOLD signal between pre-defined regions of interest using short duration stimuli, as for example in event-related designs, may be heavily weighted by large-vessel responses rather than neuronal responses. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Sensitivity of Photosynthetic Gas Exchange and Growth of Lodgepole Pine to Climate Variability Depends on the Age of Pleistocene Glacial Surfaces

    Science.gov (United States)

    Osborn, B.; Chapple, W.; Ewers, B. E.; Williams, D. G.

    2014-12-01

    The interaction between soil conditions and climate variability plays a central role in the ecohydrological functions of montane conifer forests. Although soil moisture availability to trees is largely dependent on climate, the depth and texture of soil exerts a key secondary influence. Multiple Pleistocene glacial events have shaped the landscape of the central Rocky Mountains creating a patchwork of soils differing in age and textural classification. This mosaic of soil conditions impacts hydrological properties, and montane conifer forests potentially respond to climate variability quite differently depending on the age of glacial till and soil development. We hypothesized that the age of glacial till and associated soil textural changes exert strong control on growth and photosynthetic gas exchange of lodgepole pine. We examined physiological and growth responses of lodgepole pine to interannual variation in maximum annual snow water equivalence (SWEmax) of montane snowpack and growing season air temperature (Tair) and vapor pressure deficit (VPD) across a chronosequence of Pleistocene glacial tills ranging in age from 700k to 12k years. Soil textural differences across the glacial tills illustrate the varying degrees of weathering with the most well developed soils with highest clay content on the oldest till surfaces. We show that sensitivity of growth and carbon isotope discrimination, an integrated measure of canopy gas exchange properties, to interannual variation SWEmax , Tair and VPD is greatest on young till surfaces, whereas trees on old glacial tills with well-developed soils are mostly insensitive to these interannual climate fluctuations. Tree-ring widths were most sensitive to changes in SWEmax on young glacial tills (p < 0.01), and less sensitive on the oldest till (p < 0.05). Tair correlates strongly with δ13C values on the oldest and youngest tills sites, but shows no significant relationship on the middle aged glacial till. It is clear that

  17. Intra- and inter-individual variability of Aspergillus fumigatus reactive T-cell frequencies in healthy volunteers in dependency of mould exposure in residential and working environment.

    Science.gov (United States)

    Wurster, Sebastian; Weis, Philipp; Page, Lukas; Helm, Johanna; Lazariotou, Maria; Einsele, Hermann; Ullmann, Andrew J

    2017-10-01

    Invasive aspergillosis remains a deadly disease in immunocompromised patients, whereas the combination of an exaggerated immune response and continuous exposure lead to various hyperinflammatory diseases. This pilot study aimed to gain an overview of the intra- and inter-individual variability in Aspergillus fumigatus reactive T-helper cells in healthy adults and the correlation with environmental mould exposure. In this flow cytometric study, the frequencies of CD154 + A. fumigatus reactive T cells were evaluated in 70 healthy volunteers. All subjects completed a standardised questionnaire addressing their mould exposure. Subjects with intensive mould exposure in their professional or residential surrounding demonstrated considerably higher mean frequencies of A. fumigatus reactive T-helper and T-memory cells. Comparative evaluation of multiple measurements over time demonstrated relatively conserved reactive T-cell frequencies in the absence of major changes to the exposure profile, whereas those frequently exposed in professional environment or with changes to their risk score demonstrated a marked dependency of antigen reactive T-cell frequencies on recent mould exposure. This pilot study was the first to provide data on the intra-individual variability in A. fumigatus reactive T-cell frequencies and its linkage to mould encounter. Fungus reactive T cells are to be considered a valued tool for the assessment of environmental mould exposure. © 2017 Blackwell Verlag GmbH.

  18. Self-produced Time Intervals Are Perceived as More Variable and/or Shorter Depending on Temporal Context in Subsecond and Suprasecond Ranges

    Directory of Open Access Journals (Sweden)

    Keita eMitani

    2016-06-01

    Full Text Available The processing of time intervals is fundamental for sensorimotor and cognitive functions. Perceptual and motor timing are often performed concurrently (e.g., playing a musical instrument. Although previous studies have shown the influence of body movements on time perception, how we perceive self-produced time intervals has remained unclear. Furthermore, it has been suggested that the timing mechanisms are distinct for the sub- and suprasecond ranges. Here, we compared perceptual performances for self-produced and passively presented time intervals in random contexts (i.e., multiple target intervals presented in a session across the sub- and suprasecond ranges (Experiment 1 and within the sub- (Experiment 2 and suprasecond (Experiment 3 ranges, and in a constant context (i.e., a single target interval presented in a session in the sub- and suprasecond ranges (Experiment 4. We show that self-produced time intervals were perceived as shorter and more variable across the sub- and suprasecond ranges and within the suprasecond range but not within the subsecond range in a random context. In a constant context, the self-produced time intervals were perceived as more variable in the suprasecond range but not in the subsecond range. The impairing effects indicate that motor timing interferes with perceptual timing. The dependence of impairment on temporal contexts suggests multiple timing mechanisms for the subsecond and suprasecond ranges. In addition, violation of the scalar property (i.e., a constant variability to target interval ratio was observed between the sub- and suprasecond ranges. The violation was clearer for motor timing than for perceptual timing. This suggests that the multiple timing mechanisms for the sub- and suprasecond ranges overlap more for perception than for motor. Moreover, the central tendency effect (i.e., where shorter base intervals are overestimated and longer base intervals are underestimated disappeared with subsecond

  19. A new method to detect transitory signatures and local time/space variability structures in the climate system: the scale-dependent correlation analysis

    Science.gov (United States)

    Rodó, Xavier; Rodríguez-Arias, Miquel-Àngel

    2006-10-01

    The study of transitory signals and local variability structures in both/either time and space and their role as sources of climatic memory, is an important but often neglected topic in climate research despite its obvious importance and extensive coverage in the literature. Transitory signals arise either from non-linearities, in the climate system, transitory atmosphere-ocean couplings, and other processes in the climate system evolving after a critical threshold is crossed. These temporary interactions that, though intense, may not last long, can be responsible for a large amount of unexplained variability but are normally considered of limited relevance and often, discarded. With most of the current techniques at hand these typology of signatures are difficult to isolate because the low signal-to-noise ratio in midlatitudes, the limited recurrence of the transitory signals during a customary interval of data considered. Also, there is often a serious problem arising from the smoothing of local or transitory processes if statistical techniques are applied, that consider all the length of data available, rather than taking into account the size of the specific variability structure under investigation. Scale-dependent correlation (SDC) analysis is a new statistical method capable of highlighting the presence of transitory processes, these former being understood as temporary significant lag-dependent autocovariance in a single series, or covariance structures between two series. This approach, therefore, complements other approaches such as those resulting from the families of wavelet analysis, singular-spectrum analysis and recurrence plots. A main feature of SDC is its high-performance for short time series, its ability to characterize phase-relationships and thresholds in the bivariate domain. Ultimately, SDC helps tracking short-lagged relationships among processes that locally or temporarily couple and uncouple. The use of SDC is illustrated in the present

  20. Reminiscence therapy using odor in alcohol-dependent patients--psychophysiological evaluation and psychological evaluation; power spectral analysis of heart rate variability.

    Science.gov (United States)

    Arizono, H; Morita, N; Iizuka, S; Satoh, S; Nakatani, Y

    2000-12-01

    This research was based on the hypothesis that when alcohol-dependent patients describe themselves, awakening of emotion by affirmative odor stimulation may facilitate memory reframing focusing on more affirmative emotion and memories. To prove the hypothesis, physiological changes accompanied by emotional awakening were evaluated by measuring the autonomic activity. In addition, subjective evaluation by a self-report manner was examined to investigate the effectiveness of Reminiscence Therapy (RT) using odor in alcohol-dependent patients. Thirty-four patients who met the DSM-IV criteria of alcohol-related disorders and were hospitalized in a ward specialized to alcohol dependence therapy. Each patient underwent a one-to-one interview twice. For counterbalance, one interview was performed with odor stimulation using an odor with a relaxing effect that recall pleasant emotion, and the other was without odor stimulation. As the evaluation indices of physiological changes accompanied by emotional awakening, index of autonomic function (HRV; Heart rate variability) for objective evaluation and psychological indices (STAI; State-Trait Anxiety Inventory VAS; Visual Analog Scale) for subjective evaluation were measured. 1) Objective evaluation: Regarding the evaluation index of the autonomic function, the sympathetic nervous system activity (LF/HF; low frequency component/high frequency component ratio) was significantly inhibited by odor stimulation (p Subjective evaluation: Compared to the state prior to interview, state anxiety judged by STAI was significantly decreased after interview (p subjective evaluation, but the objective evaluation suggested that the odor inhibited the sympathetic nervous system. Thus, it was suggested that odor can be used in RT, that is, emotional changes due to stimulation of odor may be applicable in RT.

  1. Threshold-dependent variability of coronary artery calcification measurements - implications for contrast-enhanced multi-detector row-computed tomography

    International Nuclear Information System (INIS)

    Moselewski, Fabian; Ferencik, Maros; Achenbach, Stephan; Abbara, Suhny; Cury, Ricardo C.; Booth, Sarah L.; Jang, Ik-Kyung; Brady, Thomas J.; Hoffmann, Udo

    2006-01-01

    Introduction: The present study investigated the threshold-dependent variability of coronary artery calcification (CAC) measurements and the potential to quantify CAC in contrast-enhanced multi-detector row-computed tomography (MDCT). Methods: We compared the mean CT attenuation of CAC to luminal contrast enhancement of the coronary arteries in 30 patients (n = 30) undergoing standard coronary contrast-enhanced spiral MDCT. The modified Agatston score [AS], calcified plaque volume [CV], and mineral mass [MM]) at four different thresholds (130, 200, 300, and 400 HU) were measured in 50 patients who underwent non-contrast-enhanced MDCT. Results: Mean CT attenuation of CAC was similar to the attenuation of the contrast-enhanced coronary lumen (CAC 297.1 ± 68.7 HU versus 295 ± 65 HU (p < 0.0001), respectively). Above a threshold of 300 HU CAC measurements significantly varied to standard measurements obtained at a threshold of 130 HU (p < 0.0001). The threshold-dependent variation of MM measurements was significantly smaller than for AS and CV (130 HU versus 400 HU: 63, 75, and 81, respectively; p < 0.001). These differences resulted in a change of age and gender based percentile category for AS in 78% of subjects. Discussion: We demonstrated that CAC measurements are threshold dependent with MM measurements having significantly less variation than AS or CV. Due to the similarity of mean CT attenuation of CAC and the contrast-enhanced coronary lumen accurate quantification of CAC may be difficult in standard coronary contrast-enhanced spiral MDCT

  2. Threshold-dependent variability of coronary artery calcification measurements - implications for contrast-enhanced multi-detector row-computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Moselewski, Fabian [Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Ferencik, Maros [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Achenbach, Stephan [Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Department of Internal Medicine II (Cardiology), University of Erlangen (Germany); Abbara, Suhny [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Cury, Ricardo C. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Booth, Sarah L. [Jean Mayer USDA Human Nutrition Research Center on Aging, 711 Washington St., Boston, MA 02114 (United States); Jang, Ik-Kyung [Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Brady, Thomas J. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)]. E-mail: uhoffman@partners.org

    2006-03-15

    Introduction: The present study investigated the threshold-dependent variability of coronary artery calcification (CAC) measurements and the potential to quantify CAC in contrast-enhanced multi-detector row-computed tomography (MDCT). Methods: We compared the mean CT attenuation of CAC to luminal contrast enhancement of the coronary arteries in 30 patients (n = 30) undergoing standard coronary contrast-enhanced spiral MDCT. The modified Agatston score [AS], calcified plaque volume [CV], and mineral mass [MM] at four different thresholds (130, 200, 300, and 400 HU) were measured in 50 patients who underwent non-contrast-enhanced MDCT. Results: Mean CT attenuation of CAC was similar to the attenuation of the contrast-enhanced coronary lumen (CAC 297.1 {+-} 68.7 HU versus 295 {+-} 65 HU (p < 0.0001), respectively). Above a threshold of 300 HU CAC measurements significantly varied to standard measurements obtained at a threshold of 130 HU (p < 0.0001). The threshold-dependent variation of MM measurements was significantly smaller than for AS and CV (130 HU versus 400 HU: 63, 75, and 81, respectively; p < 0.001). These differences resulted in a change of age and gender based percentile category for AS in 78% of subjects. Discussion: We demonstrated that CAC measurements are threshold dependent with MM measurements having significantly less variation than AS or CV. Due to the similarity of mean CT attenuation of CAC and the contrast-enhanced coronary lumen accurate quantification of CAC may be difficult in standard coronary contrast-enhanced spiral MDCT.

  3. Density dependence and climate effects in Rocky Mountain elk: an application of regression with instrumental variables for population time series with sampling error.

    Science.gov (United States)

    Creel, Scott; Creel, Michael

    2009-11-01

    1. Sampling error in annual estimates of population size creates two widely recognized problems for the analysis of population growth. First, if sampling error is mistakenly treated as process error, one obtains inflated estimates of the variation in true population trajectories (Staples, Taper & Dennis 2004). Second, treating sampling error as process error is thought to overestimate the importance of density dependence in population growth (Viljugrein et al. 2005; Dennis et al. 2006). 2. In ecology, state-space models are used to account for sampling error when estimating the effects of density and other variables on population growth (Staples et al. 2004; Dennis et al. 2006). In econometrics, regression with instrumental variables is a well-established method that addresses the problem of correlation between regressors and the error term, but requires fewer assumptions than state-space models (Davidson & MacKinnon 1993; Cameron & Trivedi 2005). 3. We used instrumental variables to account for sampling error and fit a generalized linear model to 472 annual observations of population size for 35 Elk Management Units in Montana, from 1928 to 2004. We compared this model with state-space models fit with the likelihood function of Dennis et al. (2006). We discuss the general advantages and disadvantages of each method. Briefly, regression with instrumental variables is valid with fewer distributional assumptions, but state-space models are more efficient when their distributional assumptions are met. 4. Both methods found that population growth was negatively related to population density and winter snow accumulation. Summer rainfall and wolf (Canis lupus) presence had much weaker effects on elk (Cervus elaphus) dynamics [though limitation by wolves is strong in some elk populations with well-established wolf populations (Creel et al. 2007; Creel & Christianson 2008)]. 5. Coupled with predictions for Montana from global and regional climate models, our results

  4. Time-dependent density functional theory (TD-DFT) coupled with reference interaction site model self-consistent field explicitly including spatial electron density distribution (RISM-SCF-SEDD)

    Energy Technology Data Exchange (ETDEWEB)

    Yokogawa, D., E-mail: d.yokogawa@chem.nagoya-u.ac.jp [Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602 (Japan)

    2016-09-07

    Theoretical approach to design bright bio-imaging molecules is one of the most progressing ones. However, because of the system size and computational accuracy, the number of theoretical studies is limited to our knowledge. To overcome the difficulties, we developed a new method based on reference interaction site model self-consistent field explicitly including spatial electron density distribution and time-dependent density functional theory. We applied it to the calculation of indole and 5-cyanoindole at ground and excited states in gas and solution phases. The changes in the optimized geometries were clearly explained with resonance structures and the Stokes shift was correctly reproduced.

  5. A Pareto-Based Adaptive Variable Neighborhood Search for Biobjective Hybrid Flow Shop Scheduling Problem with Sequence-Dependent Setup Time

    Directory of Open Access Journals (Sweden)

    Huixin Tian

    2016-01-01

    Full Text Available Different from most researches focused on the single objective hybrid flowshop scheduling (HFS problem, this paper investigates a biobjective HFS problem with sequence dependent setup time. The two objectives are the minimization of total weighted tardiness and the total setup time. To efficiently solve this problem, a Pareto-based adaptive biobjective variable neighborhood search (PABOVNS is developed. In the proposed PABOVNS, a solution is denoted as a sequence of all jobs and a decoding procedure is presented to obtain the corresponding complete schedule. In addition, the proposed PABOVNS has three major features that can guarantee a good balance of exploration and exploitation. First, an adaptive selection strategy of neighborhoods is proposed to automatically select the most promising neighborhood instead of the sequential selection strategy of canonical VNS. Second, a two phase multiobjective local search based on neighborhood search and path relinking is designed for each selected neighborhood. Third, an external archive with diversity maintenance is adopted to store the nondominated solutions and at the same time provide initial solutions for the local search. Computational results based on randomly generated instances show that the PABOVNS is efficient and even superior to some other powerful multiobjective algorithms in the literature.

  6. Variable temperature ion trap studies of CH4+ + H2, HD and D2: negative temperature dependence and significant isotope effect

    International Nuclear Information System (INIS)

    Asvany, O.; Savic, I.; Schlemmer, S.; Gerlich, D.

    2004-01-01

    Reactions of methane cations, CH 4 + , with H 2 , HD and D 2 have been studied in a variable temperature 22-pole ion trap from room temperature down to 15 K. The formation of CH 5 + in collisions with H 2 is slow at 300 K, but it becomes faster by at least one order of magnitude when the temperature is lowered to 15 K. This behavior is tentatively explained with a longer complex lifetime at low temperatures. However, since tunneling is most probably not responsible for product formation, other dynamical or statistical restrictions must be responsible for the negative temperature dependence. In collisions of CH 4 + with HD, the CH 5 + product ion (68% at 15 K) prevails over CH 4 D + (32%). Reaction of CH 4 + with D 2 is found to be much slower than with H 2 or HD. The rate coefficient for converting CH 4 + into CH 3 D + by H-D exchange has been determined to be smaller than 10 -12 cm 3 /s, indicating that scrambling in the CH 6 + complex is very unlikely

  7. Variable temperature ion trap studies of CH{sub 4}{sup +} + H{sub 2}, HD and D{sub 2}: negative temperature dependence and significant isotope effect

    Energy Technology Data Exchange (ETDEWEB)

    Asvany, O.; Savic, I.; Schlemmer, S.; Gerlich, D

    2004-03-08

    Reactions of methane cations, CH{sub 4}{sup +}, with H{sub 2}, HD and D{sub 2} have been studied in a variable temperature 22-pole ion trap from room temperature down to 15 K. The formation of CH{sub 5}{sup +} in collisions with H{sub 2} is slow at 300 K, but it becomes faster by at least one order of magnitude when the temperature is lowered to 15 K. This behavior is tentatively explained with a longer complex lifetime at low temperatures. However, since tunneling is most probably not responsible for product formation, other dynamical or statistical restrictions must be responsible for the negative temperature dependence. In collisions of CH{sub 4}{sup +} with HD, the CH{sub 5}{sup +} product ion (68% at 15 K) prevails over CH{sub 4}D{sup +} (32%). Reaction of CH{sub 4}{sup +} with D{sub 2} is found to be much slower than with H{sub 2} or HD. The rate coefficient for converting CH{sub 4}{sup +} into CH{sub 3}D{sup +} by H-D exchange has been determined to be smaller than 10{sup -12} cm{sup 3}/s, indicating that scrambling in the CH{sub 6}{sup +} complex is very unlikely.

  8. Vaccine induced antibodies to the first variable loop of human immunodeficiency virus type 1 gp120, mediate antibody-dependent virus inhibition in macaques.

    Science.gov (United States)

    Bialuk, Izabela; Whitney, Stephen; Andresen, Vibeke; Florese, Ruth H; Nacsa, Janos; Cecchinato, Valentina; Valeri, Valerio W; Heraud, Jean-Michel; Gordon, Shari; Parks, Robyn Washington; Montefiori, David C; Venzon, David; Demberg, Thorsten; Guroff, Marjorie Robert-; Landucci, Gary; Forthal, Donald N; Franchini, Genoveffa

    2011-12-09

    The role of antibodies directed against the hyper variable envelope region V1 of human immunodeficiency virus type 1 (HIV-1), has not been thoroughly studied. We show that a vaccine able to elicit strain-specific non-neutralizing antibodies to this region of gp120 is associated with control of highly pathogenic chimeric SHIV(89.6P) replication in rhesus macaques. The vaccinated animal that had the highest titers of antibodies to the amino terminus portion of V1, prior to challenge, had secondary antibody responses that mediated cell killing by antibody-dependent cellular cytotoxicity (ADCC), as early as 2 weeks after infection and inhibited viral replication by antibody-dependent cell-mediated virus inhibition (ADCVI), by 4 weeks after infection. There was a significant inverse correlation between virus level and binding antibody titers to the envelope protein, (R=-0.83, p=0.015), and ADCVI (R=-0.84 p=0.044). Genotyping of plasma virus demonstrated in vivo selection of three SHIV(89.6P) variants with changes in potential N-linked glycosylation sites in V1. We found a significant inverse correlation between virus levels and titers of antibodies that mediated ADCVI against all the identified V1 virus variants. A significant inverse correlation was also found between neutralizing antibody titers to SHIV(89.6) and virus levels (R=-0.72 p=0.0050). However, passive inoculation of purified immunoglobulin from animal M316, the macaque that best controlled virus, to a naïve macaque, resulted in a low serum neutralizing antibodies and low ADCVI activity that failed to protect from SHIV(89.6P) challenge. Collectively, while our data suggest that anti-envelope antibodies with neutralizing and non-neutralizing Fc(R-dependent activities may be important in the control of SHIV replication, they also demonstrate that low levels of these antibodies alone are not sufficient to protect from infection. Published by Elsevier Ltd.

  9. Can a soda-lime glass be used to demonstrate how patterns of strength dependence are influenced by pre-cementation and resin-cementation variables?

    LENUS (Irish Health Repository)

    Hooi, Paul

    2013-01-01

    To determine how the variability in biaxial flexure strength of a soda-lime glass analogue for a PLV and DBC material was influenced by precementation operative variables and following resin-cement coating.

  10. Genetic Variability of the Glucose-Dependent Insulinotropic Peptide Gene Is Involved in the Premature Coronary Artery Disease in a Chinese Population with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Xiaowei Ma

    2018-01-01

    Full Text Available Background. Glucose-dependent insulinotropic polypeptide (GIP is closely related to diabetes and obesity, both of which are confirmed to increase the risk of coronary artery disease (CAD. Our study aimed to investigate whether the polymorphisms in GIP genes could affect the risk of cardiovascular disease in type 2 diabetic patients in the Chinese Han population. Methods. We selected and genotyped two haplotype-tagging single nucleotide polymorphisms (tag-SNPs (rs2291725 C>T, rs8078510 G>A of GIP gene based on CHB data in HapMap Phase II database (r2<0.8. The case-control study of Chinese Han population involved 390 diabetic patients with CAD as positive group and 276 diabetic patients without CAD as control group. Allele and genotype frequencies were compared between the two groups. Results. In dominant inheritance model, the carriers of T/T or T/C had a lower risk of CAD (OR = 0.635, 95% CI = 0.463–0.872, p=0.005, even after adjustment other CAD risk factors (gender, age, BMI, smoking status, dyslipidemia, hypertension history, and diabetic duration (OR′ = 0.769, 95% CI′ = 0.626–0.945, p′=0.013. The allele A at rs8078510 was associated with decreased risk of CAD (OR = 0.732, p=0.039. p=0.018 in subgroup analysis, individuals with higher BMI (≥24 kg/m2 had increased risk for CAD when carrying C/C at rs2291725 (OR′ = 1.291, 95% CI′ = 1.017–1.639, p′=0.036. In age < 55 men and age < 65 women, the carriers of allele C at rs2291725 had a higher risk of CAD than noncarriers (OR = 1.627, p=0.015. Carriers of allele G in rs8078510 had higher susceptibility to CAD (OR = 2.049, 95% = CI 1.213–3.463, p=0.007. p=0.004; in addition, allele G in rs8078510 would bring higher CAD risk to the carriers who ever smoked (OR = 1.695, 95% CI = 1.080–2.660, p=0.021. Conclusion. The genetic variability of GIP gene is associated with CAD and it may play a role in the premature CAD in the

  11. Variability of the Cyclin-Dependent Kinase 2 Flexibility Without Significant Change in the Initial Conformation of the Protein or Its Environment; a Computational Study.

    Science.gov (United States)

    Taghizadeh, Mohammad; Goliaei, Bahram; Madadkar-Sobhani, Armin

    2016-06-01

    Protein flexibility, which has been referred as a dynamic behavior has various roles in proteins' functions. Furthermore, for some developed tools in bioinformatics, such as protein-protein docking software, considering the protein flexibility, causes a higher degree of accuracy. Through undertaking the present work, we have accomplished the quantification plus analysis of the variations in the human Cyclin Dependent Kinase 2 (hCDK2) protein flexibility without affecting a significant change in its initial environment or the protein per se. The main goal of the present research was to calculate variations in the flexibility for each residue of the hCDK2, analysis of their flexibility variations through clustering, and to investigate the functional aspects of the residues with high flexibility variations. Using Gromacs package (version 4.5.4), three independent molecular dynamics (MD) simulations of the hCDK2 protein (PDB ID: 1HCL) was accomplished with no significant changes in their initial environments, structures, or conformations, followed by Root Mean Square Fluctuations (RMSF) calculation of these MD trajectories. The amount of variations in these three curves of RMSF was calculated using two formulas. More than 50% of the variation in the flexibility (the distance between the maximum and the minimum amount of the RMSF) was found at the region of Val-154. As well, there are other major flexibility fluctuations in other residues. These residues were mostly positioned in the vicinity of the functional residues. The subsequent works were done, as followed by clustering all hCDK2 residues into four groups considering the amount of their variability with respect to flexibility and their position in the RMSF curves. This work has introduced a new class of flexibility aspect of the proteins' residues. It could also help designing and engineering proteins, with introducing a new dynamic aspect of hCDK2, and accordingly, for the other similar globular proteins. In

  12. The morphological signs of plants of white cabbage (Brassica oleraceae L. convar. capitata (L. Alef. var. alba DC and their variability depending on type of sort

    Directory of Open Access Journals (Sweden)

    О. Я. Жук

    2008-04-01

    Full Text Available Indicators of the morphological signs of type of sort on white cabbage plants Dutch flat, Belarus, Amager, Langendijker winter and their variability are the presented. It is established low and average factor of a variation at the majority of the morphological signs. Strong high-quality and ecological variability of signs “height external rake” and “its size leafy parts” at type of sort Dutch flat is defined.

  13. Diagnostic screening identifies a wide range of mutations involving the SHOX gene, including a common 47.5 kb deletion 160 kb downstream with a variable phenotypic effect.

    Science.gov (United States)

    Bunyan, David J; Baker, Kevin R; Harvey, John F; Thomas, N Simon

    2013-06-01

    Léri-Weill dyschondrosteosis (LWD) results from heterozygous mutations of the SHOX gene, with homozygosity or compound heterozygosity resulting in the more severe form, Langer mesomelic dysplasia (LMD). These mutations typically take the form of whole or partial gene deletions, point mutations within the coding sequence, or large (>100 kb) 3' deletions of downstream regulatory elements. We have analyzed the coding sequence of the SHOX gene and its downstream regulatory regions in a cohort of 377 individuals referred with symptoms of LWD, LMD or short stature. A causative mutation was identified in 68% of the probands with LWD or LMD (91/134). In addition, a 47.5 kb deletion was found 160 kb downstream of the SHOX gene in 17 of the 377 patients (12% of the LWD referrals, 4.5% of all referrals). In 14 of these 17 patients, this was the only potentially causative abnormality detected (13 had symptoms consistent with LWD and one had short stature only), but the other three 47.5 kb deletions were found in patients with an additional causative SHOX mutation (with symptoms of LWD rather than LMD). Parental samples were available on 14/17 of these families, and analysis of these showed a more variable phenotype ranging from apparently unaffected to LWD. Breakpoint sequence analysis has shown that the 47.5 kb deletion is identical in all 17 patients, most likely due to an ancient founder mutation rather than recurrence. This deletion was not seen in 471 normal controls (P<0.0001), providing further evidence for a phenotypic effect, albeit one with variable penetration. Copyright © 2013 Wiley Periodicals, Inc.

  14. Clinical-dosimetric analysis of measures of dysphagia including gastrostomy-tube dependence among head and neck cancer patients treated definitively by intensity-modulated radiotherapy with concurrent chemotherapy

    International Nuclear Information System (INIS)

    Li, Baoqing; Chen, Allen M; Li, Dan; Lau, Derick H; Farwell, D Gregory; Luu, Quang; Rocke, David M; Newman, Kathleen; Courquin, Jean; Purdy, James A

    2009-01-01

    To investigate the association between dose to various anatomical structures and dysphagia among patients with head and neck cancer treated by definitive intensity-modulated radiotherapy (IMRT) and concurrent chemotherapy. Thirty-nine patients with squamous cancer of the head and neck were treated by definitive concurrent chemotherapy and IMRT to a median dose of 70 Gy (range, 68 to 72). In each patient, a gastrostomy tube (GT) was prophylacticly placed prior to starting treatment. Prolonged GT dependence was defined as exceeding the median GT duration of 192 days. Dysphagia was scored using standardized quality-of-life instruments. Dose-volume histogram (DVH) data incorporating the superior/middle pharyngeal constrictors (SMPC), inferior pharyngeal constrictor (IPC), cricoid pharyngeal inlet (CPI), and cervical esophagus (CE) were analyzed in relation to prolonged GT dependence, dysphagia, and weight loss. At 3 months and 6 months after treatment, 87% and 44% of patients, respectively, were GT dependent. Spearman's ρ analysis identified statistical correlations (p < 0.05) between prolonged GT dependence or high grade dysphagia with IPC V65, IPC V60, IPC Dmean, and CPI Dmax. Logistic regression model showed that IPC V65 > 30%, IPC V60 > 60%, IPC Dmean > 60 Gy, and CPI Dmax > 62 Gy predicted for greater than 50% probability of prolonged GT dependence. Our analysis suggests that adhering to the following parameters may decrease the risk of prolonged GT dependence and dysphagia: IPC V65 < 15%, IPC V60 < 40%, IPC Dmean < 55 Gy, and CPI Dmax < 60 Gy

  15. High-resolution delineation of chlorinated volatile organic compounds in a dipping, fractured mudstone: depth- and strata-dependent spatial variability from rock-core sampling

    Science.gov (United States)

    Goode, Daniel J.; Imbrigiotta, Thomas E.; Lacombe, Pierre J.

    2014-01-01

    Synthesis of rock-core sampling and chlorinated volatile organic compound (CVOC) analysis at five coreholes, with hydraulic and water-quality monitoring and a detailed hydrogeologic framework, was used to characterize the fine-scale distribution of CVOCs in dipping, fractured mudstones of the Lockatong Formation of Triassic age, of the Newark Basin in West Trenton, New Jersey. From these results, a refined conceptual model for more than 55 years of migration of CVOCs and depth- and strata-dependent rock-matrix contamination was developed. Industrial use of trichloroethene (TCE) at the former Naval Air Warfare Center (NAWC) from 1953 to 1995 resulted in dense non-aqueous phase liquid (DNAPL) TCE and dissolved TCE and related breakdown products, including other CVOCs, in underlying mudstones. Shallow highly weathered and fractured strata overlie unweathered, gently dipping, fractured strata that become progressively less fractured with depth. The unweathered lithology includes black highly fractured (fissile) carbon-rich strata, gray mildly fractured thinly layered (laminated) strata, and light-gray weakly fractured massive strata. CVOC concentrations in water samples pumped from the shallow weathered and highly fractured strata remain elevated near residual DNAPL TCE, but dilution by uncontaminated recharge, and other natural and engineered attenuation processes, have substantially reduced concentrations along flow paths removed from sources and residual DNAPL. CVOCs also were detected in most rock-core samples in source areas in shallow wells. In many locations, lower aqueous concentrations, compared to rock core concentrations, suggest that CVOCs are presently back-diffusing from the rock matrix. Below the weathered and highly fractured strata, and to depths of at least 50 meters (m), groundwater flow and contaminant transport is primarily in bedding-plane-oriented fractures in thin fissile high-carbon strata, and in fractured, laminated strata of the gently

  16. Correlation between perception of quality of life and social/demographic/medical variables as well as anti-health behaviours among alcohol-dependent individuals

    Directory of Open Access Journals (Sweden)

    Marta Makara-Studzińska

    2013-10-01

    Full Text Available Introduction: The level of life quality of people with alcohol dependence is significantly influenced by socio-demographic factors such as: gender, marital status and having a family. Additionally promoting anti-health behaviors such as smoking or using psychoactive substances among those with alcohol dependence also reduces the quality of life in this population. Aim of the research: The purpose of this project was to determine the impact of selected psycho-social and medical factors on the quality of life in alcohol-dependent patients in relation to the duration of abstinence. Study data served to determine whether there is a correlation between the presence of selected psycho-social and medical factors and a patient’s subjective perception of his/her quality of life. Material and methods: The study involved alcohol-dependent patients undergoing treatment in the Residential Alcohol Addiction Therapy Department of the Neuropsychiatric Hospital in Lublin. In the first stage of the study, the severity of the alcohol problem was assessed with the MAST and CAGE tests and quality of life was assessed with the SF-36 questionnaire. An Original Socio-Demographic Questionnaire was also used. In the second stage of the study, the SF-36 scale was used to evaluate the quality of life. The Original Socio-Demographic Questionnaire was also used. Results : The socio-economic factors that had a statistically significant impact on the quality of life of the alcohol-dependent individuals comprised sex, marital status and having a family. Marital status was shown to be one of the most important family-related factors significantly influencing the quality of life. Having a family was not a factor associated with subjective improvement of the quality of life during abstinence for alcohol-dependent individuals. Awareness of socio-economic and medical factors influencing quality of life in individuals addicted to alcohol and gambling is an important

  17. Applying the Transactional Stress and Coping Model to Sickle Cell Disorder and Insulin-Dependent Diabetes Mellitus: Identifying Psychosocial Variables Related to Adjustment and Intervention

    Science.gov (United States)

    Hocking, Matthew C.; Lochman, John E.

    2005-01-01

    This review paper examines the literature on psychosocial factors associated with adjustment to sickle cell disease and insulin-dependent diabetes mellitus in children through the framework of the transactional stress and coping (TSC) model. The transactional stress and coping model views adaptation to a childhood chronic illness as mediated by…

  18. Menstrual Cycle Dependent Variability for Serum Tumor Markers CEA, AFP, CA 19-9, CA 125 and CA 15-3 in Healthy Women

    Directory of Open Access Journals (Sweden)

    Ayşe Binnur Erbağci

    1999-01-01

    Full Text Available Information on menstrual cycle dependent variation of tumor markers in healthy women is a subject of diagnostic efficiency and has an impact in elucidating the normal function of these markers. In this study midfollicular and midluteal concentrations of serum CEA, AFP, CA 19-9, CA 125, CA 15-3 and their relations with LH, FSH, prolactin, estradiol and progesterone were evaluated during ovulatory cycles in a group of 23 healthy female individuals. Samples were collected on the 7th and 21st day of the same menstrual cycle. Tumor marker and hormone concentrations were determined with chemiluminescence or electrochemiluminescence EIA methods. A significant phase-dependent difference was observed for CA 15-3, midluteal concentrations (mean ± SEM; 26.33 ± 1.56 U/ml higher than the midfollicular (mean ± SEM; 19.27 ± 1.49 U/ml concentrations (p < 0.001. But an obvious difference for other tumor markers investigated did not exist. Significant correlations of follicular and luteal CA 125 levels with body mass index of the subjects were observed (r:0.52, p < 0.05 and r:0.57, p < 0.005, respectively.

  19. Determining Directional Dependency in Causal Associations

    Science.gov (United States)

    Pornprasertmanit, Sunthud; Little, Todd D.

    2012-01-01

    Directional dependency is a method to determine the likely causal direction of effect between two variables. This article aims to critique and improve upon the use of directional dependency as a technique to infer causal associations. We comment on several issues raised by von Eye and DeShon (2012), including: encouraging the use of the signs of…

  20. Thermo-Mechanical Calculations of Hybrid Rotary Friction Welding at Equal Diameter Copper Bars and Effects of Essential Parameters on Dependent Special Variables

    International Nuclear Information System (INIS)

    Parsa, M. H.; Davari, H.; Hadian, A. M.; Ahmadabadi, M. Nili

    2007-01-01

    Hybrid Rotary Friction Welding is a modified type of common rotary friction welding processes. In this welding method parameters such as pressure, angular velocity and time of welding control temperature, stress, strain and their variations. These dependent factors play an important rule in defining optimum process parameters combinations in order to improve the design and manufacturing of welding machines and quality of welded parts. Thermo-mechanical simulation of friction welding has been carried out and it has been shown that, simulation is an important tool for prediction of generated heat and strain at the weld interface and can be used for prediction of microstructure and evaluation of quality of welds. For simulation of Hybrid Rotary Friction Welding, a commercial finite element program has been used and the effects of pressure and rotary velocity of rotary part on temperature and strain variations have been investigated

  1. Thermo-Mechanical Calculations of Hybrid Rotary Friction Welding at Equal Diameter Copper Bars and Effects of Essential Parameters on Dependent Special Variables

    Science.gov (United States)

    Parsa, M. H.; Davari, H.; Hadian, A. M.; Ahmadabadi, M. Nili

    2007-05-01

    Hybrid Rotary Friction Welding is a modified type of common rotary friction welding processes. In this welding method parameters such as pressure, angular velocity and time of welding control temperature, stress, strain and their variations. These dependent factors play an important rule in defining optimum process parameters combinations in order to improve the design and manufacturing of welding machines and quality of welded parts. Thermo-mechanical simulation of friction welding has been carried out and it has been shown that, simulation is an important tool for prediction of generated heat and strain at the weld interface and can be used for prediction of microstructure and evaluation of quality of welds. For simulation of Hybrid Rotary Friction Welding, a commercial finite element program has been used and the effects of pressure and rotary velocity of rotary part on temperature and strain variations have been investigated.

  2. A comparative study of night-time enhancement of TEC at a low latitude station on storm and quiet nights including the local time, seasonal and solar activity dependence

    Directory of Open Access Journals (Sweden)

    K. Unnikrishnan

    Full Text Available The main characteristics of night-time enhancements in TEC during magnetic storms are compared with those during quiet nights for different seasons and solar activity conditions at Palehua, a low latitude station during the period 1980–1989. We find that the mean amplitude has both a seasonal and solar activity dependence: in winter, the values are higher for weak storms as compared to those during quiet nights and increase with an increase in solar activity. In summer, the mean amplitude values during weak storms and quiet nights are almost equal. But during equinox, the mean amplitude values for quiet nights are greater than those during weak storms. The mean half-amplitude duration is higher during weak storms as compared to that during quiet nights in summer. However, during winter and equinox, the durations are almost equal for both quiet and weak storm nights. For the mean half-amplitude duration, the quiet night values for all the seasons and equinoctial weak storm values increase with an increase in solar activity. The occurrence frequency (in percent of TEC enhancement during weak storms is greater than during quiet nights for all seasons. The mean amplitude, the mean half-amplitude duration and the occurrence frequency (in percent of TEC enhancement values are higher during major storms as compared to those during quiet nights. The above parameters have their highest values during pre-midnight hours. From the data analysed, this behaviour is true in the case of major storms also.

    Key words. Ionosphere (ionospheric disturbances; plasma convection Magnetospheric physics (storms and substorms

  3. Thermal- and pH-Dependent Size Variable Radical Nanoparticles and Its Water Proton Relaxivity for Metal-Free MRI Functional Contrast Agents.

    Science.gov (United States)

    Morishita, Kosuke; Murayama, Shuhei; Araki, Takeru; Aoki, Ichio; Karasawa, Satoru

    2016-09-16

    For development of the metal-free MRI contrast agents, we prepared the supra-molecular organic radical, TEMPO-UBD, carrying TEMPO radical, as well as the urea, alkyl group, and phenyl ring, which demonstrate self-assembly behaviors using noncovalent bonds in an aqueous solution. In addition, TEMPO-UBD has the tertiary amine and the oligoethylene glycol chains (OEGs) for the function of pH and thermal responsiveness. By dynamic light scattering and transmission electron microscopy imaging, the resulting self-assembly was seen to form the spherical nanoparticles 10-150 nm in size. On heating, interestingly, the nanoparticles showed a lower critical solution temperature (LCST) behavior having two-step variation. This double-LCST behavior is the first such example among the supra-molecules. To evaluate of the ability as MRI contrast agents, the values of proton ((1)H) longitudinal relaxivity (r1) were determined using MRI apparatus. In conditions below and above CAC at pH 7.0, the distinguishable r1 values were estimated to be 0.17 and 0.21 mM(-1) s(1), indicating the suppression of fast tumbling motion of TEMPO moiety in a nanoparticle. Furthermore, r1 values became larger in the order of pH 7.0 > 9.0 > 5.0. Those thermal and pH dependencies indicated the possibility of metal-fee MRI functional contrast agents in the future.

  4. StralSV: assessment of sequence variability within similar 3D structures and application to polio RNA-dependent RNA polymerase

    Energy Technology Data Exchange (ETDEWEB)

    Zemla, A; Lang, D; Kostova, T; Andino, R; Zhou, C

    2010-11-29

    Most of the currently used methods for protein function prediction rely on sequence-based comparisons between a query protein and those for which a functional annotation is provided. A serious limitation of sequence similarity-based approaches for identifying residue conservation among proteins is the low confidence in assigning residue-residue correspondences among proteins when the level of sequence identity between the compared proteins is poor. Multiple sequence alignment methods are more satisfactory - still, they cannot provide reliable results at low levels of sequence identity. Our goal in the current work was to develop an algorithm that could overcome these difficulties and facilitate the identification of structurally (and possibly functionally) relevant residue-residue correspondences between compared protein structures. Here we present StralSV, a new algorithm for detecting closely related structure fragments and quantifying residue frequency from tight local structure alignments. We apply StralSV in a study of the RNA-dependent RNA polymerase of poliovirus and demonstrate that the algorithm can be used to determine regions of the protein that are relatively unique or that shared structural similarity with structures that are distantly related. By quantifying residue frequencies among many residue-residue pairs extracted from local alignments, one can infer potential structural or functional importance of specific residues that are determined to be highly conserved or that deviate from a consensus. We further demonstrate that considerable detailed structural and phylogenetic information can be derived from StralSV analyses. StralSV is a new structure-based algorithm for identifying and aligning structure fragments that have similarity to a reference protein. StralSV analysis can be used to quantify residue-residue correspondences and identify residues that may be of particular structural or functional importance, as well as unusual or unexpected

  5. VARIABILITY IN LEVELS OF LOW-DENSITY LIPOPROTEINS CHOLESTEROL IN PATIENTS WITH FAMILIAL HYPERCHOLESTEROLEMIA DEPENDING ON AGE AND SEX AND ITS IMPORTANCE IN THE DIAGNOSIS OF THIS DISEASE

    Directory of Open Access Journals (Sweden)

    V. А. Korneva

    2017-01-01

    Full Text Available Aim. To study the ranges of low density lipoprotein (LDL cholesterol depending on the age and gender of patients with familial hypercholesterolemia (FHC by an example of a sample of patients living in the Republic of Karelia.Material and methods. Parameters of lipid spectrum of 219 patients (aged 52.5±1.7 years; males 38.3% with heterozygous FHC were studied before the start of statin therapy. Definite FHC was diagnosed in 102 patients. Lipid profile was estimated by enzymatic calorimetric method. The diagnosis of FHC was established according to the criteria of The Dutch Lipid Clinic Network.  Genetic analysis was performed in 102 patients (46.6%; pathogenic mutation in the LDL receptor was identified in 21 patients. The control group consisted of 539 people with the excluded diagnosis of FHC (aged 46.8±0.8 years; males 53.8%.Results. We determined the level of LDL cholesterol (LDLC associated with increased frequency of mutations of the LDL receptor in patients with definite FHC; mutation frequency was 3 times higher when LDLC level was more than 6.5 mmol/L. We revealed the following characteristic intervals of the LDLC levels in patients with a definite FHC: up to 20 years old – 4.8-6.2 mmol/l; in patients of 20-29 years old – 5.9-8.2 mmol/l; in the age range of 30-39 years the upper value of the LDLC levels reached 9.6 mmol/l; in individuals of 40-49 years old a stabilization, "plateau", was observed – LDLC level did not differ significantly compared to the previous decade, and was 5.4-9.0 mmol/l. In the age range  of 50-59 years the upper LDLC level was up to 11.4 mmol/l. Similar indicators were identified in patients aged 60-69 years. Patients older than 70 years with a definite FHC an upper level of LDLC was higher and reached 12.5 mmol/l. Tendency to increase in the characteristic values of LDLC with age was observed both in men and in women. Specific age-related trends  for men (an increase from a plateau by the age of 50

  6. Statistical Modeling of Stochastic Dependences between Variables that Characterize Labor Market in Romania for Taking Relevant Management Decisions for a Competitive and Sustainable Development of Labor Force

    Directory of Open Access Journals (Sweden)

    Barbu Bogdan POPESCU

    2013-12-01

    Full Text Available The labor market is an important component of the entire economic system and for social-economic development. However, the labor market is known as the most inflexible of markets, the existence of the phenomenon of permanent labor mobility. After 1990, the Romanian society has experienced a series of economic and social transformation, new reforms covering all areas of activity. Increasing labor resources was accompanied by a continued reduction in employment and increase in unemployment. The government tried to initiate programs, including external funding to create jobs, but compared to the massive layoffs that occurred following the restructuring of sectors, the number of new jobs created has proved insufficient. The paper presents a multiple regression model for employment and prognosis for this until 2020.

  7. Properties of the surface snow in Princess Elizabeth Land, East Antarctica - climate and non-climate dependent variability of the surface mass balance and stable water isotopic composition

    Science.gov (United States)

    Vladimirova, D.; Ekaykin, A.; Lipenkov, V.; Popov, S. V.; Petit, J. R.; Masson-Delmotte, V.

    2017-12-01

    Glaciological and meteorological observations conducted during the past four decades in Princess Elizabeth Land, East Antarctica, are compiled. The database is used to investigate spatial patterns of surface snow isotopic composition and surface mass balance, including detailed information near subglacial lake Vostok. We show diverse relationships between snow isotopic composition and surface temperature. In the most inland part (elevation 3200-3400 m a.s.l.), surface snow isotopic composition varies independently from surface temperature, and is closely related to the distance to the open water source (with a slope of 0.98±0.17 ‰ per 100 km). Surface mass balance values are higher along the ice sheet slope, and relatively evenly distributed inland. The minimum values of snow isotopic composition and surface mass balance are identified in an area XX km southwestward from Vostok station. The spatial distribution of deuterium excess delineates regions influenced by the Indian Ocean and Pacific Ocean air masses, with Vostok area being situated close to their boundary. Anomalously high deuterium excess values are observed near Dome A, suggesting high kinetic fractionation for its moisture source, or specifically high post-deposition artifacts. The dataset is available for further studies such as the assessment of skills of general circulation or regional atmospheric models, and the search for the oldest ice.

  8. Propositional Logics of Dependence

    NARCIS (Netherlands)

    Yang, F.; Väänänen, J.

    2016-01-01

    In this paper, we study logics of dependence on the propositional level. We prove that several interesting propositional logics of dependence, including propositional dependence logic, propositional intuitionistic dependence logic as well as propositional inquisitive logic, are expressively complete

  9. Reduction in camera-specific variability in [{sup 123}I]FP-CIT SPECT outcome measures by image reconstruction optimized for multisite settings: impact on age-dependence of the specific binding ratio in the ENC-DAT database of healthy controls

    Energy Technology Data Exchange (ETDEWEB)

    Buchert, Ralph; Lange, Catharina [Charite - Universitaetsmedizin Berlin, Department of Nuclear Medicine, Berlin (Germany); Kluge, Andreas; Bronzel, Marcus [ABX-CRO advanced pharmaceutical services Forschungsgesellschaft m.b.H., Dresden (Germany); Tossici-Bolt, Livia [University Hospital Southampton NHS Foundation Trust, Department of Medical Physics, Southampton (United Kingdom); Dickson, John [University College London Hospital NHS Foundation Trust, Institute of Nuclear Medicine, London (United Kingdom); Asenbaum, Susanne [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); Booij, Jan [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Centre, Amsterdam (Netherlands); Kapucu, L. Oezlem Atay [Gazi University, Department of Nuclear Medicine, Faculty of Medicine, Ankara (Turkey); Svarer, Claus [Rigshospitalet and University of Copenhagen, Neurobiology Research Unit, Copenhagen (Denmark); Koulibaly, Pierre-Malick [University of Nice-Sophia Antipolis, Nuclear Medicine Department, Centre Antoine Lacassagne, Nice (France); Nobili, Flavio [University of Genoa, Department of Neuroscience (DINOGMI), Clinical Neurology Unit, Genoa (Italy); Pagani, Marco [CNR, Institute of Cognitive Sciences and Technologies, Rome (Italy); Karolinska Hospital, Department of Nuclear Medicine, Stockholm (Sweden); Sabri, Osama [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Sera, Terez [University of Szeged, Department of Nuclear Medicine and Euromedic Szeged, Szeged (Hungary); Tatsch, Klaus [Municipal Hospital of Karlsruhe Inc, Department of Nuclear Medicine, Karlsruhe (Germany); Borght, Thierry vander [CHU Namur, IREC, Nuclear Medicine Division, Universite catholique de Louvain, Yvoir (Belgium); Laere, Koen van [University Hospital and K.U. Leuven, Nuclear Medicine, Leuven (Belgium); Varrone, Andrea [Karolinska University Hospital, Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm (Sweden); Iida, Hidehiro [National Cerebral and Cardiovascular Center - Research Institute, Osaka (Japan)

    2016-07-15

    Quantitative estimates of dopamine transporter availability, determined with [{sup 123}I]FP-CIT SPECT, depend on the SPECT equipment, including both hardware and (reconstruction) software, which limits their use in multicentre research and clinical routine. This study tested a dedicated reconstruction algorithm for its ability to reduce camera-specific intersubject variability in [{sup 123}I]FP-CIT SPECT. The secondary aim was to evaluate binding in whole brain (excluding striatum) as a reference for quantitative analysis. Of 73 healthy subjects from the European Normal Control Database of [{sup 123}I]FP-CIT recruited at six centres, 70 aged between 20 and 82 years were included. SPECT images were reconstructed using the QSPECT software package which provides fully automated detection of the outer contour of the head, camera-specific correction for scatter and septal penetration by transmission-dependent convolution subtraction, iterative OSEM reconstruction including attenuation correction, and camera-specific ''to kBq/ml'' calibration. LINK and HERMES reconstruction were used for head-to-head comparison. The specific striatal [{sup 123}I]FP-CIT binding ratio (SBR) was computed using the Southampton method with binding in the whole brain, occipital cortex or cerebellum as the reference. The correlation between SBR and age was used as the primary quality measure. The fraction of SBR variability explained by age was highest (1) with QSPECT, independently of the reference region, and (2) with whole brain as the reference, independently of the reconstruction algorithm. QSPECT reconstruction appears to be useful for reduction of camera-specific intersubject variability of [{sup 123}I]FP-CIT SPECT in multisite and single-site multicamera settings. Whole brain excluding striatal binding as the reference provides more stable quantitative estimates than occipital or cerebellar binding. (orig.)

  10. New seismograph includes filters

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-02

    The new Nimbus ES-1210 multichannel signal enhancement seismograph from EG and G geometrics has recently been redesigned to include multimode signal fillers on each amplifier. The ES-1210F is a shallow exploration seismograph for near subsurface exploration such as in depth-to-bedrock, geological hazard location, mineral exploration, and landslide investigations.

  11. Motivational and psychological correlates of bodybuilding dependence.

    Science.gov (United States)

    Emini, Neim N; Bond, Malcolm J

    2014-09-01

    Exercise may become physically and psychologically maladaptive if taken to extremes. One example is the dependence reported by some individuals who engage in weight training. The current study explored potential psychological, motivational, emotional and behavioural concomitants of bodybuilding dependence, with a particular focus on motives for weight training. Using a path analysis paradigm, putative causal models sought to explain associations among key study variables. A convenience sample of 101 men aged between 18 and 67 years was assembled from gymnasia in Adelaide, South Australia. Active weight trainers voluntarily completed a questionnaire that included measures of bodybuilding dependence (social dependency, training dependency, and mastery), anger, hostility and aggression, stress and motivations for weight training. Three motives for weight training were identified: mood control, physique anxiety and personal challenge. Of these, personal challenge and mood control were the most directly salient to dependence. Social dependency was particularly relevant to personal challenge, whereas training dependency was associated with both personal challenge and mood control. Mastery demonstrated a direct link with physique anxiety, thus reflecting a unique component of exercise dependence. While it was not possible to determine causality with the available data, the joint roles of variables that influence, or are influenced by, bodybuilding dependence are identified. RESULTS highlight unique motivations for bodybuilding and suggest that dependence could be a result of, and way of coping with, stress manifesting as aggression. A potential framework for future research is provided through the demonstration of plausible causal linkages among these variables.

  12. Variability Bugs:

    DEFF Research Database (Denmark)

    Melo, Jean

    . Although many researchers suggest that preprocessor-based variability amplifies maintenance problems, there is little to no hard evidence on how actually variability affects programs and programmers. Specifically, how does variability affect programmers during maintenance tasks (bug finding in particular......)? How much harder is it to debug a program as variability increases? How do developers debug programs with variability? In what ways does variability affect bugs? In this Ph.D. thesis, I set off to address such issues through different perspectives using empirical research (based on controlled...... experiments) in order to understand quantitatively and qualitatively the impact of variability on programmers at bug finding and on buggy programs. From the program (and bug) perspective, the results show that variability is ubiquitous. There appears to be no specific nature of variability bugs that could...

  13. Analytic device including nanostructures

    KAUST Repository

    Di Fabrizio, Enzo M.; Fratalocchi, Andrea; Totero Gongora, Juan Sebastian; Coluccio, Maria Laura; Candeloro, Patrizio; Cuda, Gianni

    2015-01-01

    A device for detecting an analyte in a sample comprising: an array including a plurality of pixels, each pixel including a nanochain comprising: a first nanostructure, a second nanostructure, and a third nanostructure, wherein size of the first nanostructure is larger than that of the second nanostructure, and size of the second nanostructure is larger than that of the third nanostructure, and wherein the first nanostructure, the second nanostructure, and the third nanostructure are positioned on a substrate such that when the nanochain is excited by an energy, an optical field between the second nanostructure and the third nanostructure is stronger than an optical field between the first nanostructure and the second nanostructure, wherein the array is configured to receive a sample; and a detector arranged to collect spectral data from a plurality of pixels of the array.

  14. Saskatchewan resources. [including uranium

    Energy Technology Data Exchange (ETDEWEB)

    1979-09-01

    The production of chemicals and minerals for the chemical industry in Saskatchewan are featured, with some discussion of resource taxation. The commodities mentioned include potash, fatty amines, uranium, heavy oil, sodium sulfate, chlorine, sodium hydroxide, sodium chlorate and bentonite. Following the successful outcome of the Cluff Lake inquiry, the uranium industry is booming. Some developments and production figures for Gulf Minerals, Amok, Cenex and Eldorado are mentioned.

  15. Being Included and Excluded

    DEFF Research Database (Denmark)

    Korzenevica, Marina

    2016-01-01

    Following the civil war of 1996–2006, there was a dramatic increase in the labor mobility of young men and the inclusion of young women in formal education, which led to the transformation of the political landscape of rural Nepal. Mobility and schooling represent a level of prestige that rural...... politics. It analyzes how formal education and mobility either challenge or reinforce traditional gendered norms which dictate a lowly position for young married women in the household and their absence from community politics. The article concludes that women are simultaneously excluded and included from...... community politics. On the one hand, their mobility and decision-making powers decrease with the increase in the labor mobility of men and their newly gained education is politically devalued when compared to the informal education that men gain through mobility, but on the other hand, schooling strengthens...

  16. Influência das características sociodemográficas e clínicas e do nível de dependência na qualidade de vida de pacientes com DPOC em oxigenoterapia domiciliar prolongada Influence that sociodemographic variables, clinical characteristics, and level of dependence have on quality of life in COPD patients on long-term home oxygen therapy

    Directory of Open Access Journals (Sweden)

    Simone Cedano

    2012-06-01

    of dependence. METHODS: This was a cross-sectional analytical study involving COPD patients on LTOT followed at the Oxygen Therapy Outpatient Clinic of the Federal University of São Paulo Hospital São Paulo, in the city of São Paulo, Brazil. Sociodemographic, clinical, and biochemical data were collected. We assessed QoL and level of dependence using the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36 and the Katz index, respectively. Multiple linear regression models were constructed in order to determine the influence of these variables on QoL. RESULTS: We included 80 patients in the study. The mean age was 69.6 ± 9.1 years, and 51.3% were female. The lowest SF-36 scores were for the physical functioning and role-physical domains. All sociodemographic characteristics (except gender were found to correlate significantly with the SF-36 domains mental health, vitality, role-physical, and social functioning. We also found that body mass index, PaO2, post-bronchodilator FEV1, hemoglobin, and Katz index correlated significantly with the physical functioning, mental health, role-physical, and bodily pain domains. In addition, oxygen flows were found to correlate negatively with the physical functioning, mental health, vitality, and role-emotional domains. CONCLUSIONS: Low scores for SF-36 domains, as well as the variables that negatively influence them, should be considered and analyzed during the development and implementation of strategies for improving the QoL of COPD patients on LTOT.

  17. [Caffeine dependence].

    Science.gov (United States)

    Ogawa, Naoshi; Ueki, Hirofumi

    2010-08-01

    Caffeine is the most widely consumed psychoactive substance in the world and is a legal stimulant that is readily available to children. The potential for dependence on caffeine has been debated. Presently, due to a paucity of clinical evidence on caffeine dependence, no such diagnosis is included in the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision (DSM-IV-TR). Although in recent studies, a subset of the general population was found to demonstrate caffeine dependence. It is valuable for psychiatrists and primary care physicians to recognize caffeine dependence as a clinical syndrome, since some people are distressed by their caffeine use and feel they can not control or stop their problematic use.

  18. Variable screening and ranking using sampling-based sensitivity measures

    International Nuclear Information System (INIS)

    Wu, Y-T.; Mohanty, Sitakanta

    2006-01-01

    This paper presents a methodology for screening insignificant random variables and ranking significant important random variables using sensitivity measures including two cumulative distribution function (CDF)-based and two mean-response based measures. The methodology features (1) using random samples to compute sensitivities and (2) using acceptance limits, derived from the test-of-hypothesis, to classify significant and insignificant random variables. Because no approximation is needed in either the form of the performance functions or the type of continuous distribution functions representing input variables, the sampling-based approach can handle highly nonlinear functions with non-normal variables. The main characteristics and effectiveness of the sampling-based sensitivity measures are investigated using both simple and complex examples. Because the number of samples needed does not depend on the number of variables, the methodology appears to be particularly suitable for problems with large, complex models that have large numbers of random variables but relatively few numbers of significant random variables

  19. Pulsating variables

    International Nuclear Information System (INIS)

    1989-01-01

    The study of stellar pulsations is a major route to the understanding of stellar structure and evolution. At the South African Astronomical Observatory (SAAO) the following stellar pulsation studies were undertaken: rapidly oscillating Ap stars; solar-like oscillations in stars; 8-Scuti type variability in a classical Am star; Beta Cephei variables; a pulsating white dwarf and its companion; RR Lyrae variables and galactic Cepheids. 4 figs

  20. Variable mechanical ventilation.

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini, Luiz Alberto; Friedman, Gilberto

    2017-01-01

    To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation.

  1. Cognitive Variability

    Science.gov (United States)

    Siegler, Robert S.

    2007-01-01

    Children's thinking is highly variable at every level of analysis, from neural and associative levels to the level of strategies, theories, and other aspects of high-level cognition. This variability exists within people as well as between them; individual children often rely on different strategies or representations on closely related problems…

  2. Rapidly variable relatvistic absorption

    Science.gov (United States)

    Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

    2017-10-01

    I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

  3. Variability in large-scale wind power generation: Variability in large-scale wind power generation

    Energy Technology Data Exchange (ETDEWEB)

    Kiviluoma, Juha [VTT Technical Research Centre of Finland, Espoo Finland; Holttinen, Hannele [VTT Technical Research Centre of Finland, Espoo Finland; Weir, David [Energy Department, Norwegian Water Resources and Energy Directorate, Oslo Norway; Scharff, Richard [KTH Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Söder, Lennart [Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Menemenlis, Nickie [Institut de recherche Hydro-Québec, Montreal Canada; Cutululis, Nicolaos A. [DTU, Wind Energy, Roskilde Denmark; Danti Lopez, Irene [Electricity Research Centre, University College Dublin, Dublin Ireland; Lannoye, Eamonn [Electric Power Research Institute, Palo Alto California USA; Estanqueiro, Ana [LNEG, Laboratorio Nacional de Energia e Geologia, UESEO, Lisbon Spain; Gomez-Lazaro, Emilio [Renewable Energy Research Institute and DIEEAC/EDII-AB, Castilla-La Mancha University, Albacete Spain; Zhang, Qin [State Grid Corporation of China, Beijing China; Bai, Jianhua [State Grid Energy Research Institute Beijing, Beijing China; Wan, Yih-Huei [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA; Milligan, Michael [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA

    2015-10-25

    The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net load events. The comparison shows regions with low variability (Sweden, Spain and Germany), medium variability (Portugal, Ireland, Finland and Denmark) and regions with higher variability (Quebec, Bonneville Power Administration and Electric Reliability Council of Texas in North America; Gansu, Jilin and Liaoning in China; and Norway and offshore wind power in Denmark). For regions with low variability, the maximum 1 h wind ramps are below 10% of nominal capacity, and for regions with high variability, they may be close to 30%. Wind power variability is mainly explained by the extent of geographical spread, but also higher capacity factor causes higher variability. It was also shown how wind power ramps are autocorrelated and dependent on the operating output level. When wind power was concentrated in smaller area, there were outliers with high changes in wind output, which were not present in large areas with well-dispersed wind power.

  4. Variable volume combustor

    Science.gov (United States)

    Ostebee, Heath Michael; Ziminsky, Willy Steve; Johnson, Thomas Edward; Keener, Christopher Paul

    2017-01-17

    The present application provides a variable volume combustor for use with a gas turbine engine. The variable volume combustor may include a liner, a number of micro-mixer fuel nozzles positioned within the liner, and a linear actuator so as to maneuver the micro-mixer fuel nozzles axially along the liner.

  5. Dependence of nuclear moments of inertia on the triaxial parameter

    International Nuclear Information System (INIS)

    Helgesson, J.; Hamamoto, Ikuko

    1989-01-01

    The dependence of nuclear moments of inertia on the triaxial parameter (γ-variable) is investigated including both the Belyaev term and the Migdal term. The obtained dependence is compared with that of hydrodynamical moments of inertia and other moments of inertia used conventionally. (orig.)

  6. The nebular variables

    CERN Document Server

    Glasby, John S

    1974-01-01

    The Nebular Variables focuses on the nebular variables and their characteristics. Discussions are organized by type of nebular variable, namely, RW Aurigae stars, T Orionis stars, T Tauri stars, and peculiar nebular objects. Topics range from light variations of the stars to their spectroscopic and physical characteristics, spatial distribution, interaction with nebulosity, and evolutionary features. This volume is divided into four sections and consists of 25 chapters, the first of which provides general information on nebular variables, including their stellar associations and their classifi

  7. Several complex variables

    International Nuclear Information System (INIS)

    Field, M.J.

    1976-01-01

    Topics discussed include the elementary of holomorphic functions of several complex variables; the Weierstrass preparation theorem; meromorphic functions, holomorphic line bundles and divisors; elliptic operators on compact manifolds; hermitian connections; the Hodge decomposition theorem. ( author)

  8. Complex variables

    CERN Document Server

    Fisher, Stephen D

    1999-01-01

    The most important topics in the theory and application of complex variables receive a thorough, coherent treatment in this introductory text. Intended for undergraduates or graduate students in science, mathematics, and engineering, this volume features hundreds of solved examples, exercises, and applications designed to foster a complete understanding of complex variables as well as an appreciation of their mathematical beauty and elegance. Prerequisites are minimal; a three-semester course in calculus will suffice to prepare students for discussions of these topics: the complex plane, basic

  9. Variable stars

    International Nuclear Information System (INIS)

    Feast, M.W.; Wenzel, W.; Fernie, J.D.; Percy, J.R.; Smak, J.; Gascoigne, S.C.B.; Grindley, J.E.; Lovell, B.; Sawyer Hogg, H.B.; Baker, N.; Fitch, W.S.; Rosino, L.; Gursky, H.

    1976-01-01

    A critical review of variable stars is presented. A fairly complete summary of major developments and discoveries during the period 1973-1975 is given. The broad developments and new trends are outlined. Essential problems for future research are identified. (B.R.H. )

  10. Compound Poisson Approximations for Sums of Random Variables

    OpenAIRE

    Serfozo, Richard F.

    1986-01-01

    We show that a sum of dependent random variables is approximately compound Poisson when the variables are rarely nonzero and, given they are nonzero, their conditional distributions are nearly identical. We give several upper bounds on the total-variation distance between the distribution of such a sum and a compound Poisson distribution. Included is an example for Markovian occurrences of a rare event. Our bounds are consistent with those that are known for Poisson approximations for sums of...

  11. Emissions of metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs) from Portland cement manufacturing plants: inter-kiln variability and dependence on fuel-types.

    Science.gov (United States)

    Zemba, Stephen; Ames, Michael; Green, Laura; Botelho, Maria João; Gossman, David; Linkov, Igor; Palma-Oliveira, José

    2011-09-15

    Emissions from Portland cement manufacturing facilities may increase health risks in nearby populations and are thus subject to stringent regulations. Direct testing of pollutant concentrations in exhaust gases provides the best basis for assessing the extent of these risks. However, these tests (i) are often conducted under stressed, rather than typical, operating conditions, (ii) may be limited in number and duration, and (iii) may be influenced by specific fuel-types and attributes of individual kilns. We report here on the results of more than 150 emissions-tests conducted of two kilns at a Portland cement manufacturing plant in Portugal. The tests measured various regulated metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs). Stack-gas concentrations of pollutants were found to be highly variable, with standard deviations on the order of mean values. Emission rates of many pollutants were higher when coal was used as the main kiln fuel (instead of petroleum coke). Use of various supplemental fuels, however, had little effect on stack emissions, and few statistically significant differences were observed when hazardous waste was included in the fuel mix. Significant differences in emissions for some pollutants were observed between the two kilns despite their similar designs and uses of similar fuels. All measured values were found to be within applicable regulatory limits. Published by Elsevier B.V.

  12. Variables associated with active spondylolysis.

    Science.gov (United States)

    Gregg, Chris D; Dean, Sarah; Schneiders, Anthony G

    2009-11-01

    Retrospective non-experimental study. To investigate variables associated with active spondylolysis. A retrospective study audited clinical data over a two year period from patients with suspected spondylolysis that were referred for a SPECT bone scan. Six exploratory variables were identified and analysed using uni- and multi-variate regression from 82 patient records to determine the association between symptomatic, physical and demographic characteristics, and the presence of an active spondylolysis. Tertiary level multidisciplinary private practice sports medicine clinic. All patients with low back pain that required a SPECT bone scan to confirm suspected spondylolysis. 82 subjects were included in the final sample group. The six exploratory variables included Age, Gender, Injury duration, Injury onset, Sports participation and the result of the Single Leg Hyperextension Test. The dependent outcome variable was the result of the SPECT bone scan (scan-positive or scan-negative). Adolescent males had a higher incidence of spondylolysis detected by SPECT bone scan compared to other patients and a statistically significant association was demonstrated for both age (p=0.01) and gender (p=0.01). Subjects with an active spondylolysis were nearly five times more likely to be male and aged less than 20 years. Furthermore, the likelihood ratio indicated that adolescent males with suspected spondylolysis were three and a half times more likely to have a positive bone scan result. The Single Leg Hyperextension Test did not demonstrate a statistically significant association with spondylolysis (p=0.47). Clinicians assessing for a predisposition to the development of spondylolysis should consider the gender and age of the patient and not rely on the predictive ability of the Single Leg Hyperextension Test.

  13. Calculus of one variable

    CERN Document Server

    Grossman, Stanley I

    1986-01-01

    Calculus of One Variable, Second Edition presents the essential topics in the study of the techniques and theorems of calculus.The book provides a comprehensive introduction to calculus. It contains examples, exercises, the history and development of calculus, and various applications. Some of the topics discussed in the text include the concept of limits, one-variable theory, the derivatives of all six trigonometric functions, exponential and logarithmic functions, and infinite series.This textbook is intended for use by college students.

  14. Statistical variability of hydro-meteorological variables as indicators ...

    African Journals Online (AJOL)

    Statistical variability of hydro-meteorological variables as indicators of climate change in north-east Sokoto-Rima basin, Nigeria. ... water resources development including water supply project, agriculture and tourism in the study area. Key word: Climate change, Climatic variability, Actual evapotranspiration, Global warming ...

  15. TEC variability over Havana

    International Nuclear Information System (INIS)

    Lazo, B.; Alazo, K.; Rodriguez, M.; Calzadilla, A.

    2003-01-01

    The variability of total electron content (TEC) measured over Havana using ATS-6, SMS-1 and GOES-3 geosynchronous satellite signals has been investigated for low, middle and high solar activity periods from 1974 to 1982. The obtained results show that standard deviation is smooth during nighttime hours and maximum at noon or postnoon hours. Strong solar activity dependence of standard deviation with a maximum values during HSA has been found. (author)

  16. Complex variables

    CERN Document Server

    Flanigan, Francis J

    2010-01-01

    A caution to mathematics professors: Complex Variables does not follow conventional outlines of course material. One reviewer noting its originality wrote: ""A standard text is often preferred [to a superior text like this] because the professor knows the order of topics and the problems, and doesn't really have to pay attention to the text. He can go to class without preparation."" Not so here-Dr. Flanigan treats this most important field of contemporary mathematics in a most unusual way. While all the material for an advanced undergraduate or first-year graduate course is covered, discussion

  17. Surfing wave climate variability

    Science.gov (United States)

    Espejo, Antonio; Losada, Iñigo J.; Méndez, Fernando J.

    2014-10-01

    International surfing destinations are highly dependent on specific combinations of wind-wave formation, thermal conditions and local bathymetry. Surf quality depends on a vast number of geophysical variables, and analyses of surf quality require the consideration of the seasonal, interannual and long-term variability of surf conditions on a global scale. A multivariable standardized index based on expert judgment is proposed for this purpose. This index makes it possible to analyze surf conditions objectively over a global domain. A summary of global surf resources based on a new index integrating existing wave, wind, tides and sea surface temperature databases is presented. According to general atmospheric circulation and swell propagation patterns, results show that west-facing low to middle-latitude coasts are more suitable for surfing, especially those in the Southern Hemisphere. Month-to-month analysis reveals strong seasonal variations in the occurrence of surfable events, enhancing the frequency of such events in the North Atlantic and the North Pacific. Interannual variability was investigated by comparing occurrence values with global and regional modes of low-frequency climate variability such as El Niño and the North Atlantic Oscillation, revealing their strong influence at both the global and the regional scale. Results of the long-term trends demonstrate an increase in the probability of surfable events on west-facing coasts around the world in recent years. The resulting maps provide useful information for surfers, the surf tourism industry and surf-related coastal planners and stakeholders.

  18. Predator persistence through variability of resource productivity in Tritrophic systems

    DEFF Research Database (Denmark)

    Soudijn, Floor Helena; de Roos, Andre M.

    2017-01-01

    The trophic structure of species communities depends on the energy transfer between trophic levels. Primary productivity varies strongly through time, challenging the persistence of species at higher trophic levels. Yet resource variability has mostly been studied in systems with only one or two...... trophic levels. We test the effect of variability in resource productivity in a tritrophic model system including a resource, a size-structured consumer, and a size-specific predator. The model complies with fundamental principles of mass conservation and the body-size dependence of individual......-level energetics and predator-prey interactions. Surprisingly, we find that resource variability may promote predator persistence. The positive effect of variability on the predator arises through periods with starvation mortality of juvenile prey, which reduces the intraspecific competition in the prey population...

  19. Path Dependency

    OpenAIRE

    Mark Setterfield

    2015-01-01

    Path dependency is defined, and three different specific concepts of path dependency – cumulative causation, lock in, and hysteresis – are analyzed. The relationships between path dependency and equilibrium, and path dependency and fundamental uncertainty are also discussed. Finally, a typology of dynamical systems is developed to clarify these relationships.

  20. Systems dependability assessment

    CERN Document Server

    Aubry, Jean-François

    2015-01-01

    Presents recent developments of probabilistic assessment of systems dependability based on stochastic models, including graph theory, finite state automaton and language theory, for both dynamic and hybrid contexts.

  1. How to get rid of W: a latent variables approach to modelling spatially lagged variables

    NARCIS (Netherlands)

    Folmer, H.; Oud, J.

    2008-01-01

    In this paper we propose a structural equation model (SEM) with latent variables to model spatial dependence. Rather than using the spatial weights matrix W, we propose to use latent variables to represent spatial dependence and spillover effects, of which the observed spatially lagged variables are

  2. How to get rid of W : a latent variables approach to modelling spatially lagged variables

    NARCIS (Netherlands)

    Folmer, Henk; Oud, Johan

    2008-01-01

    In this paper we propose a structural equation model (SEM) with latent variables to model spatial dependence. Rather than using the spatial weights matrix W, we propose to use latent variables to represent spatial dependence and spillover effects, of which the observed spatially lagged variables are

  3. Variable collimator

    International Nuclear Information System (INIS)

    Richey, J.B.; McBride, T.R.; Covic, J.

    1979-01-01

    This invention describes an automatic variable collimator which controls the width and thickness of X-ray beams in X-ray diagnostic medical equipment, and which is particularly adapted for use with computerized axial tomographic scanners. A two-part collimator is provided which shapes an X-ray beam both prior to its entering an object subject to radiographic analysis and after the attenuated beam has passed through the object. Interposed between a source of radiation and the object subject to radiographic analysis is a first or source collimator. The source collimator causes the X-ray beam emitted by the source of radiation to be split into a plurality of generally rectangular shaped beams. Disposed within the source collimator is a movable aperture plate which may be used to selectively vary the thickness of the plurality of generally rectangular shaped beams transmitted through the source collimator. A second or receiver collimator is interposed between the object subject to radiographic analysis and a series of radiation detectors. The receiver collimator is disposed to receive the attenuated X-ray beams passing through the object subject to radiographic analysis. Located within the receiver collimator are a plurality of movable aperture plates adapted to be displaced relative to a plurality of fixed aperture plates for the purpose of varying the width and thickness of the attenuated X-ray beams transmitted through the object subject to radiographic analysis. The movable aperture plates of the source and receiver collimators are automatically controlled by circuitry which is provided to allow remote operation of the movable aperture plates

  4. Dependent Classes

    DEFF Research Database (Denmark)

    Gasiunas, Vaidas; Mezini, Mira; Ostermann, Klaus

    2007-01-01

    of dependent classes and a machine-checked type soundness proof in Isabelle/HOL [29], the first of this kind for a language with virtual classes and path-dependent types. [29] T.Nipkow, L.C. Poulson, and M. Wenzel. Isabelle/HOL -- A Proof Assistant for Higher-Order Logic, volume 2283 of LNCS, Springer, 2002......Virtual classes allow nested classes to be refined in subclasses. In this way nested classes can be seen as dependent abstractions of the objects of the enclosing classes. Expressing dependency via nesting, however, has two limitations: Abstractions that depend on more than one object cannot...... be modeled and a class must know all classes that depend on its objects. This paper presents dependent classes, a generalization of virtual classes that expresses similar semantics by parameterization rather than by nesting. This increases expressivity of class variations as well as the flexibility...

  5. Exercise Dependence

    Directory of Open Access Journals (Sweden)

    Erdal Vardar

    2012-06-01

    Full Text Available Exercise dependence define a condition in which a person performs excessive exercise resulting in deterioration of his or her physical and mental health wellness. Despite many clinical research studies on exercise dependence, exact diagnostic criteria has not been developed yet. Clinical evidences concerning etiology, epidemiology, underlying mechanisms and treatment of exercise dependence are still not sufficient. Moreover, evaluation of this clinical disorder within dependency perspective is a fairly new concept. Recent studies have shown that exercise dependence has similar features like chemical substance dependence with regards to withdrawal and tolerance symptoms. The aim of this review was to briefly evaluate diagnostic and clinical features of exercise dependence. [Archives Medical Review Journal 2012; 21(3.000: 163-173

  6. Internal variables in thermoelasticity

    CERN Document Server

    Berezovski, Arkadi

    2017-01-01

    This book describes an effective method for modeling advanced materials like polymers, composite materials and biomaterials, which are, as a rule, inhomogeneous. The thermoelastic theory with internal variables presented here provides a general framework for predicting a material’s reaction to external loading. The basic physical principles provide the primary theoretical information, including the evolution equations of the internal variables. The cornerstones of this framework are the material representation of continuum mechanics, a weak nonlocality, a non-zero extra entropy flux, and a consecutive employment of the dissipation inequality. Examples of thermoelastic phenomena are provided, accompanied by detailed procedures demonstrating how to simulate them.

  7. Technological Capability's Predictor Variables

    Directory of Open Access Journals (Sweden)

    Fernanda Maciel Reichert

    2011-03-01

    Full Text Available The aim of this study was to identify the factors that influence in configuration of the technological capability of companies in sectors with medium-low technological intensity. To achieve the goal proposed in this article a survey was carried out. Based on the framework developed by Lall (1992 which classifies firms in basic, intermediate and advanced level of technological capability; it was found that the predominant technological capability is intermediate, with 83.7% of respondent companies (plastics companies in Brazil. It is believed that the main contribution of this study is the finding that the dependent variable named “Technological Capability” can be explained at a rate of 65% by six variables: development of new processes; selection of the best equipment supplier; sales of internally developed new technology to third parties; design and manufacture of equipment; study of the work methods and perform inventory control; and improvement of product quality.

  8. Behaviors Predicting Foot Lesions in Patients with Non-Insulin-Dependent Diabetes Mellitus

    OpenAIRE

    Suico, Jeffrey G; Marriott, Deanna J; Vinicor, Frank; Litzelman, Debra K

    1998-01-01

    Associations between specific foot-care behaviors and foot lesions in patients with non-insulin-dependent diabetes mellitus were prospectively investigated. Data from a randomized controlled trial for preventing diabetic foot lesions were analyzed as a prospective cohort using logistic regression. Independent variables included foot-care behaviors, patient self-foot examination, going barefoot, availability of foot-care assistance, and visits to health-care providers. The dependent variable w...

  9. Effects of nanoscale size dependent parameters on lattice thermal ...

    Indian Academy of Sciences (India)

    diameter dependence also indicates a strong control of surface effect in surface to bulk ratio for the 22 nm wire diameter. ... dimensional systems of variable transverse dimension using a large scale numerical transverse .... include unharmonic interaction (three-phonon Umklapp scattering,τU ), mass difference scat-.

  10. Dependency Parsing

    CERN Document Server

    Kubler, Sandra; Nivre, Joakim

    2009-01-01

    Dependency-based methods for syntactic parsing have become increasingly popular in natural language processing in recent years. This book gives a thorough introduction to the methods that are most widely used today. After an introduction to dependency grammar and dependency parsing, followed by a formal characterization of the dependency parsing problem, the book surveys the three major classes of parsing models that are in current use: transition-based, graph-based, and grammar-based models. It continues with a chapter on evaluation and one on the comparison of different methods, and it close

  11. (including travel dates) Proposed itinerary

    Indian Academy of Sciences (India)

    Ashok

    31 July to 22 August 2012 (including travel dates). Proposed itinerary: Arrival in Bangalore on 1 August. 1-5 August: Bangalore, Karnataka. Suggested institutions: Indian Institute of Science, Bangalore. St Johns Medical College & Hospital, Bangalore. Jawaharlal Nehru Centre, Bangalore. 6-8 August: Chennai, TN.

  12. AUTOMATIC CLASSIFICATION OF VARIABLE STARS IN CATALOGS WITH MISSING DATA

    International Nuclear Information System (INIS)

    Pichara, Karim; Protopapas, Pavlos

    2013-01-01

    We present an automatic classification method for astronomical catalogs with missing data. We use Bayesian networks and a probabilistic graphical model that allows us to perform inference to predict missing values given observed data and dependency relationships between variables. To learn a Bayesian network from incomplete data, we use an iterative algorithm that utilizes sampling methods and expectation maximization to estimate the distributions and probabilistic dependencies of variables from data with missing values. To test our model, we use three catalogs with missing data (SAGE, Two Micron All Sky Survey, and UBVI) and one complete catalog (MACHO). We examine how classification accuracy changes when information from missing data catalogs is included, how our method compares to traditional missing data approaches, and at what computational cost. Integrating these catalogs with missing data, we find that classification of variable objects improves by a few percent and by 15% for quasar detection while keeping the computational cost the same

  13. AUTOMATIC CLASSIFICATION OF VARIABLE STARS IN CATALOGS WITH MISSING DATA

    Energy Technology Data Exchange (ETDEWEB)

    Pichara, Karim [Computer Science Department, Pontificia Universidad Católica de Chile, Santiago (Chile); Protopapas, Pavlos [Institute for Applied Computational Science, Harvard University, Cambridge, MA (United States)

    2013-11-10

    We present an automatic classification method for astronomical catalogs with missing data. We use Bayesian networks and a probabilistic graphical model that allows us to perform inference to predict missing values given observed data and dependency relationships between variables. To learn a Bayesian network from incomplete data, we use an iterative algorithm that utilizes sampling methods and expectation maximization to estimate the distributions and probabilistic dependencies of variables from data with missing values. To test our model, we use three catalogs with missing data (SAGE, Two Micron All Sky Survey, and UBVI) and one complete catalog (MACHO). We examine how classification accuracy changes when information from missing data catalogs is included, how our method compares to traditional missing data approaches, and at what computational cost. Integrating these catalogs with missing data, we find that classification of variable objects improves by a few percent and by 15% for quasar detection while keeping the computational cost the same.

  14. [Affective dependency].

    Science.gov (United States)

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy.

  15. Theory including future not excluded

    DEFF Research Database (Denmark)

    Nagao, K.; Nielsen, H.B.

    2013-01-01

    We study a complex action theory (CAT) whose path runs over not only past but also future. We show that, if we regard a matrix element defined in terms of the future state at time T and the past state at time TA as an expectation value in the CAT, then we are allowed to have the Heisenberg equation......, Ehrenfest's theorem, and the conserved probability current density. In addition,we showthat the expectation value at the present time t of a future-included theory for large T - t and large t - T corresponds to that of a future-not-included theory with a proper inner product for large t - T. Hence, the CAT...

  16. Directional Dependence in Developmental Research

    Science.gov (United States)

    von Eye, Alexander; DeShon, Richard P.

    2012-01-01

    In this article, we discuss and propose methods that may be of use to determine direction of dependence in non-normally distributed variables. First, it is shown that standard regression analysis is unable to distinguish between explanatory and response variables. Then, skewness and kurtosis are discussed as tools to assess deviation from…

  17. Variability in human body size

    Science.gov (United States)

    Annis, J. F.

    1978-01-01

    The range of variability found among homogeneous groups is described and illustrated. Those trends that show significantly marked differences between sexes and among a number of racial/ethnic groups are also presented. Causes of human-body size variability discussed include genetic endowment, aging, nutrition, protective garments, and occupation. The information is presented to aid design engineers of space flight hardware and equipment.

  18. EVIDENCE FOR DYNAMICAL CHANGES IN A TRANSITIONAL PROTOPLANETARY DISK WITH MID-INFRARED VARIABILITY

    International Nuclear Information System (INIS)

    Muzerolle, James; Flaherty, Kevin; Balog, Zoltan; Smith, Paul S.; Rieke, George H.; Furlan, Elise; Allen, Lori; Muench, August; Calvet, Nuria; D'Alessio, Paola; Megeath, S. Thomas; Sherry, William H.

    2009-01-01

    We present multi-epoch Spitzer Space Telescope observations of the transitional disk LRLL 31 in the 2-3 Myr old star-forming region IC 348. Our measurements show remarkable mid-infrared variability on timescales as short as one week. The infrared continuum emission exhibits systematic wavelength-dependent changes that suggest corresponding dynamical changes in the inner disk structure and variable shadowing of outer disk material. We propose several possible sources for the structural changes, including a variable accretion rate or a stellar or planetary companion embedded in the disk. Our results indicate that variability studies in the infrared can provide important new constraints on protoplanetary disk behavior.

  19. An evaluation of FIA's stand age variable

    Science.gov (United States)

    John D. Shaw

    2015-01-01

    The Forest Inventory and Analysis Database (FIADB) includes a large number of measured and computed variables. The definitions of measured variables are usually well-documented in FIA field and database manuals. Some computed variables, such as live basal area of the condition, are equally straightforward. Other computed variables, such as individual tree volume,...

  20. Device including a contact detector

    DEFF Research Database (Denmark)

    2011-01-01

    arms (12) may extend from the supporting body in co-planar relationship with the first surface. The plurality of cantilever arms (12) may extend substantially parallel to each other and each of the plurality of cantilever arms (12) may include an electrical conductive tip for contacting the area......The present invention relates to a probe for determining an electrical property of an area of a surface of a test sample, the probe is intended to be in a specific orientation relative to the test sample. The probe may comprise a supporting body defining a first surface. A plurality of cantilever...... of the test sample by movement of the probe relative to the surface of the test sample into the specific orientation.; The probe may further comprise a contact detector (14) extending from the supporting body arranged so as to contact the surface of the test sample prior to any one of the plurality...

  1. Neoclassical transport including collisional nonlinearity.

    Science.gov (United States)

    Candy, J; Belli, E A

    2011-06-10

    In the standard δf theory of neoclassical transport, the zeroth-order (Maxwellian) solution is obtained analytically via the solution of a nonlinear equation. The first-order correction δf is subsequently computed as the solution of a linear, inhomogeneous equation that includes the linearized Fokker-Planck collision operator. This equation admits analytic solutions only in extreme asymptotic limits (banana, plateau, Pfirsch-Schlüter), and so must be solved numerically for realistic plasma parameters. Recently, numerical codes have appeared which attempt to compute the total distribution f more accurately than in the standard ordering by retaining some nonlinear terms related to finite-orbit width, while simultaneously reusing some form of the linearized collision operator. In this work we show that higher-order corrections to the distribution function may be unphysical if collisional nonlinearities are ignored.

  2. Seasonal Variability in European Radon Measurements

    Science.gov (United States)

    Groves-Kirkby, C. J.; Denman, A. R.; Phillips, P. S.; Crockett, R. G. M.; Sinclair, J. M.

    2009-04-01

    In temperate climates, domestic radon concentration levels are generally seasonally dependent, the level in the home reflecting the convolution of two time-dependent functions. These are the source soil-gas radon concentration itself, and the principal force driving radon into the building from the soil, namely the pressure-difference between interior and exterior environment. While the meteorological influence can be regarded as relatively uniform on a European scale, its variability being defined largely by the influence of North-Atlantic weather systems, soil-gas radon is generally more variable as it is essentially geologically dependent. Seasonal variability of domestic radon concentration can therefore be expected to exhibit geographical variability, as is indeed the case. To compensate for the variability of domestic radon levels when assessing the long term radon health risks, the results of individual short-term measurements are generally converted to equivalent mean annual levels by application of a Seasonal Correction Factor (SCF). This is a multiplying factor, typically derived from measurements of a large number of homes, applied to the measured short-term radon concentration to provide a meaningful annual mean concentration for dose-estimation purposes. Following concern as to the universal applicability of a single SCF set, detailed studies in both the UK and France have reported location-specific SCF sets for different regions of each country. Further results indicate that SCFs applicable to the UK differ significantly from those applicable elsewhere in Europe and North America in both amplitude and phase, supporting the thesis that seasonal variability in indoor radon concentration cannot realistically be compensated for by a single national or international SCF scheme. Published data characterising the seasonal variability of European national domestic radon concentrations, has been collated and analysed, with the objective of identifying

  3. Several real variables

    CERN Document Server

    Kantorovitz, Shmuel

    2016-01-01

    This undergraduate textbook is based on lectures given by the author on the differential and integral calculus of functions of several real variables. The book has a modern approach and includes topics such as: •The p-norms on vector space and their equivalence •The Weierstrass and Stone-Weierstrass approximation theorems •The differential as a linear functional; Jacobians, Hessians, and Taylor's theorem in several variables •The Implicit Function Theorem for a system of equations, proved via Banach’s Fixed Point Theorem •Applications to Ordinary Differential Equations •Line integrals and an introduction to surface integrals This book features numerous examples, detailed proofs, as well as exercises at the end of sections. Many of the exercises have detailed solutions, making the book suitable for self-study. Several Real Variables will be useful for undergraduate students in mathematics who have completed first courses in linear algebra and analysis of one real variable.

  4. Possible impact of fixed point sources of SO2 in NSW to the secondary sulphate measurements at Richmond and the dependence of the background secondary sulphate on meteorological variables

    International Nuclear Information System (INIS)

    Crawford, C.; Cohen, D.D.; Stelcer, E.

    2010-01-01

    The contribution to secondary sulfate measurements at Richmond, Australia, from known point sources of SOz is investigated using air mass back trajectories. The conditional probability function (CPF) shows that contribution for days of high sulfur is from areas north east of the site. This is an area where known point sources of SOz, such as coal fired power stations, are located. The meteorological conditions associated with high sulfur days are examined and an artificial neural network is employed to determine the relationship between meteorological variables and sulfur measurements after the influence of known point sources was removed. It is shown that temperature and humidity have a nonlinear positive correlation with sulphate measurements, while wind speed, mixing layer depth and rainfall have a negative nonlinear correlation. In addition, the time of day at which air masses reach Richmond from the eastern and western power stations varies, and so thus the altitude at which the power stations are crossed. The time of day, as well as the altitude at which an SOz point source was passed, show an impact to the measured sulfate at Richmond, although the extent of this remains to be fully investigated

  5. Manipulating continuous variable photonic entanglement

    International Nuclear Information System (INIS)

    Plenio, M.B.

    2005-01-01

    I will review our work on photonic entanglement in the continuous variable regime including both Gaussian and non-Gaussian states. The feasibility and efficiency of various entanglement purification protocols are discussed this context. (author)

  6. Quantification of variables that affect energy consumption

    International Nuclear Information System (INIS)

    Warren, C.S.

    1993-01-01

    Facility energy consumption is the summation of a number of contributory factors, caused by equipment that uses energy in response to demands placed by the user and according to its particular design. While energy efficiency improvements usually concentrate on individual parts or systems, overall energy consumption is analyzed by examining the use of specific fuels. Because independent variables effect the consumption of these fuels, accurate comparisons of a facility's energy consumption for time-measured periods must include these effects. In many cases, it is possible to determine and quantify the effects of one or more of the independent variables through a statistically valid regression analysis of the data. The regression model can be linear, or be dependent on other functions such as powers, time lead or lag, or exponential. The most common model is linear, but other dependencies are often encountered. Regression analyses are not difficult to accomplish, and are included as one of the tools in most spreadsheet software. The analyses provide the energy manager with a means to better understand the energy consumption of his/her facility

  7. Modeling dependencies in product families with COVAMOF

    NARCIS (Netherlands)

    Sinnema, Marco; Deelstra, Sybren; Nijhuis, Jos; Bosch, Jan; Riebisch, M; Tabeling, P; Zorn, W

    2006-01-01

    Many variability modeling approaches consider only formalized dependencies, i.e. in- or exclude relations between variants. However, in real industrial product families, dependencies are often much more complicated. In this paper, we discuss the product derivation problems associated with

  8. Glycoengineered Monoclonal Antibodies with Homogeneous Glycan (M3, G0, G2, and A2 Using a Chemoenzymatic Approach Have Different Affinities for FcγRIIIa and Variable Antibody-Dependent Cellular Cytotoxicity Activities.

    Directory of Open Access Journals (Sweden)

    Masaki Kurogochi

    Full Text Available Many therapeutic antibodies have been developed, and IgG antibodies have been extensively generated in various cell expression systems. IgG antibodies contain N-glycans at the constant region of the heavy chain (Fc domain, and their N-glycosylation patterns differ during various processes or among cell expression systems. The Fc N-glycan can modulate the effector functions of IgG antibodies, such as antibody-dependent cellular cytotoxicity (ADCC and complement dependent cytotoxicity (CDC. To control Fc N-glycans, we performed a rearrangement of Fc N-glycans from a heterogeneous N-glycosylation pattern to homogeneous N-glycans using chemoenzymatic approaches with two types of endo-β-N-acetyl glucosaminidases (ENG'ases, one that works as a hydrolase to cleave all heterogeneous N-glycans, another that is used as a glycosynthase to generate homogeneous N-glycans. As starting materials, we used an anti-Her2 antibody produced in transgenic silkworm cocoon, which consists of non-fucosylated pauci-mannose type (Man2-3GlcNAc2, high-mannose type (Man4-9GlcNAc2, and complex type (Man3GlcNAc3-4 N-glycans. As a result of the cleavage of several ENG'ases (endoS, endoM, endoD, endoH, and endoLL, the heterogeneous glycans on antibodies were fully transformed into homogeneous-GlcNAc by a combination of endoS, endoD, and endoLL. Next, the desired N-glycans (M3; Man3GlcNAc1, G0; GlcNAc2Man3GlcNAc1, G2; Gal2GlcNAc2Man3GlcNAc1, A2; NeuAc2Gal2GlcNAc2Man3GlcNAc1 were transferred from the corresponding oxazolines to the GlcNAc residue on the intact anti-Her2 antibody with an ENG'ase mutant (endoS-D233Q, and the glycoengineered anti-Her2 antibody was obtained. The binding assay of anti-Her2 antibody with homogenous N-glycans with FcγRIIIa-V158 showed that the glycoform influenced the affinity for FcγRIIIa-V158. In addition, the ADCC assay for the glycoengineered anti-Her2 antibody (mAb-M3, mAb-G0, mAb-G2, and mAb-A2 was performed using SKBR-3 and BT-474 as target

  9. Glycoengineered Monoclonal Antibodies with Homogeneous Glycan (M3, G0, G2, and A2) Using a Chemoenzymatic Approach Have Different Affinities for FcγRIIIa and Variable Antibody-Dependent Cellular Cytotoxicity Activities.

    Science.gov (United States)

    Kurogochi, Masaki; Mori, Masako; Osumi, Kenji; Tojino, Mami; Sugawara, Shu-Ichi; Takashima, Shou; Hirose, Yuriko; Tsukimura, Wataru; Mizuno, Mamoru; Amano, Junko; Matsuda, Akio; Tomita, Masahiro; Takayanagi, Atsushi; Shoda, Shin-Ichiro; Shirai, Takashi

    2015-01-01

    Many therapeutic antibodies have been developed, and IgG antibodies have been extensively generated in various cell expression systems. IgG antibodies contain N-glycans at the constant region of the heavy chain (Fc domain), and their N-glycosylation patterns differ during various processes or among cell expression systems. The Fc N-glycan can modulate the effector functions of IgG antibodies, such as antibody-dependent cellular cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC). To control Fc N-glycans, we performed a rearrangement of Fc N-glycans from a heterogeneous N-glycosylation pattern to homogeneous N-glycans using chemoenzymatic approaches with two types of endo-β-N-acetyl glucosaminidases (ENG'ases), one that works as a hydrolase to cleave all heterogeneous N-glycans, another that is used as a glycosynthase to generate homogeneous N-glycans. As starting materials, we used an anti-Her2 antibody produced in transgenic silkworm cocoon, which consists of non-fucosylated pauci-mannose type (Man2-3GlcNAc2), high-mannose type (Man4-9GlcNAc2), and complex type (Man3GlcNAc3-4) N-glycans. As a result of the cleavage of several ENG'ases (endoS, endoM, endoD, endoH, and endoLL), the heterogeneous glycans on antibodies were fully transformed into homogeneous-GlcNAc by a combination of endoS, endoD, and endoLL. Next, the desired N-glycans (M3; Man3GlcNAc1, G0; GlcNAc2Man3GlcNAc1, G2; Gal2GlcNAc2Man3GlcNAc1, A2; NeuAc2Gal2GlcNAc2Man3GlcNAc1) were transferred from the corresponding oxazolines to the GlcNAc residue on the intact anti-Her2 antibody with an ENG'ase mutant (endoS-D233Q), and the glycoengineered anti-Her2 antibody was obtained. The binding assay of anti-Her2 antibody with homogenous N-glycans with FcγRIIIa-V158 showed that the glycoform influenced the affinity for FcγRIIIa-V158. In addition, the ADCC assay for the glycoengineered anti-Her2 antibody (mAb-M3, mAb-G0, mAb-G2, and mAb-A2) was performed using SKBR-3 and BT-474 as target cells, and

  10. Biological Sampling Variability Study

    Energy Technology Data Exchange (ETDEWEB)

    Amidan, Brett G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hutchison, Janine R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-11-08

    There are many sources of variability that exist in the sample collection and analysis process. This paper addresses many, but not all, sources of variability. The main focus of this paper was to better understand and estimate variability due to differences between samplers. Variability between days was also studied, as well as random variability within each sampler. Experiments were performed using multiple surface materials (ceramic and stainless steel), multiple contaminant concentrations (10 spores and 100 spores), and with and without the presence of interfering material. All testing was done with sponge sticks using 10-inch by 10-inch coupons. Bacillus atrophaeus was used as the BA surrogate. Spores were deposited using wet deposition. Grime was coated on the coupons which were planned to include the interfering material (Section 3.3). Samples were prepared and analyzed at PNNL using CDC protocol (Section 3.4) and then cultured and counted. Five samplers were trained so that samples were taken using the same protocol. Each sampler randomly sampled eight coupons each day, four coupons with 10 spores deposited and four coupons with 100 spores deposited. Each day consisted of one material being tested. The clean samples (no interfering materials) were run first, followed by the dirty samples (coated with interfering material). There was a significant difference in recovery efficiency between the coupons with 10 spores deposited (mean of 48.9%) and those with 100 spores deposited (mean of 59.8%). There was no general significant difference between the clean and dirty (containing interfering material) coupons or between the two surface materials; however, there was a significant interaction between concentration amount and presence of interfering material. The recovery efficiency was close to the same for coupons with 10 spores deposited, but for the coupons with 100 spores deposited, the recovery efficiency for the dirty samples was significantly larger (65

  11. Spectroscopic and computational studies of cobalamin species with variable lower axial ligation: implications for the mechanism of Co-C bond activation by class I cobalamin-dependent isomerases.

    Science.gov (United States)

    Conrad, Karen S; Jordan, Christopher D; Brown, Kenneth L; Brunold, Thomas C

    2015-04-20

    5'-deoxyadenosylcobalamin (coenzyme B12, AdoCbl) serves as the cofactor for several enzymes that play important roles in fermentation and catabolism. All of these enzymes initiate catalysis by promoting homolytic cleavage of the cofactor's Co-C bond in response to substrate binding to their active sites. Despite considerable research efforts, the role of the lower axial ligand in facilitating Co-C bond homolysis remains incompletely understood. In the present study, we characterized several derivatives of AdoCbl and its one-electron reduced form, Co(II)Cbl, by using electronic absorption and magnetic circular dichroism spectroscopies. To complement our experimental data, we performed computations on these species, as well as additional Co(II)Cbl analogues. The geometries of all species investigated were optimized using a quantum mechanics/molecular mechanics method, and the optimized geometries were used to compute absorption spectra with time-dependent density functional theory. Collectively, our results indicate that a reduction in the basicity of the lower axial ligand causes changes to the cofactor's electronic structure in the Co(II) state that replicate the effects seen upon binding of Co(II)Cbl to Class I isomerases, which replace the lower axial dimethylbenzimidazole ligand of AdoCbl with a protein-derived histidine (His) residue. Such a reduction of the basicity of the His ligand in the enzyme active site may be achieved through proton uptake by the catalytic triad of conserved residues, DXHXGXK, during Co-C bond homolysis.

  12. Path Dependence

    DEFF Research Database (Denmark)

    Madsen, Mogens Ove

    Begrebet Path Dependence blev oprindelig udviklet inden for New Institutionel Economics af bl.a. David, Arthur og North. Begrebet har spredt sig vidt i samfundsvidenskaberne og undergået en udvikling. Dette paper propagerer for at der er sket så en så omfattende udvikling af begrebet, at man nu kan...... tale om 1. og 2. generation af Path Dependence begrebet. Den nyeste udvikling af begrebet har relevans for metodologi-diskusionerne i relation til Keynes...

  13. Caffeine dependence in teenagers.

    Science.gov (United States)

    Bernstein, Gail A; Carroll, Marilyn E; Thuras, Paul D; Cosgrove, Kelly P; Roth, Megan E

    2002-03-01

    This study identifies and characterizes symptoms of caffeine dependence in adolescents. Thirty-six adolescents who consumed caffeine daily and had some features of caffeine dependence on telephone screen were scheduled for outpatient evaluation. Evaluation included the Diagnostic Interview Schedule for Children-IV-Youth Version (DISC-IV) and modified DISC-IV questions that assessed caffeine dependence based on DSM-IV substance dependence criteria. Of 36 subjects, 41.7% (n=15) reported tolerance to caffeine, 77.8% (n=28) described withdrawal symptoms after cessation or reduction of caffeine intake, 38.9% (n=14) reported desire or unsuccessful attempts to control use, and 16.7% (n=6) endorsed use despite knowledge of physical or psychological problems associated with caffeine. There was no significant difference in the amount of caffeine consumed daily by caffeine dependent versus non-dependent teenagers. These findings are important due to the vast number of adolescents who drink caffeinated beverages.

  14. Broad-Band Variability in Accreting Compact Objects

    Directory of Open Access Journals (Sweden)

    S. Scaringi

    2015-02-01

    Full Text Available Cataclysmic variable stars are in many ways similar to X-ray binaries. Both types of systems possess an accretion disk, which in most cases can reach the surface (or event horizon of the central compact object. The main difference is that the embedded gravitational potential well in X-ray binaries is much deeper than those found in cataclysmic variables. As a result, X-ray binaries emit most of their radiation at X-ray wavelengths, as opposed to cataclysmic variables which emit mostly at optical/ultraviolet wavelengths. Both types of systems display aperiodic broad-band variability which can be associated to the accretion disk. Here, the properties of the observed X-ray variability in XRBs are compared to those observed at optical wavelengths in CVs. In most cases the variability properties of both types of systems are qualitatively similar once the relevant timescales associated with the inner accretion disk regions have been taken into account. The similarities include the observed power spectral density shapes, the rms-flux relation as well as Fourier-dependant time lags. Here a brief overview on these similarities is given, placing them in the context of the fluctuating accretion disk model which seeks to reproduce the observed variability.

  15. CLIMATE CHANGE, VARIABILITY AND SUSTAINABLE AGRICULTURE IN ZIMBABWE'S RURAL COMMUNITIES

    Directory of Open Access Journals (Sweden)

    Gukurume Simbarashe

    2013-02-01

    Full Text Available This article explores the impact of climate change and variability on agricultural productivity in the communal area of Bikita. The article further examines the adaptation and mitigation strategies devised by farmers to deal with the vagaries of climate change and variability. The sustainability of these is also interrogated in this article. This study juxtaposed qualitative and quantitative methodologies albeit with more bias on the former. A total of 40 farmers were sampled for unstructured interviews and focus group discussions. This article argues that the adverse impacts of climate change and variability are felt heavily by the poor communal farmers who are directly dependent on agriculture for livelihood. From the study, some of the widely reported signs of climate variability in Bikita included late and unpredictable rains, high temperatures (heat waves, successive drought, shortening rainfall seasons and seasonal changes in the timing of rainfall. The paper argues that climate change has compounded the vulnerability of peasant farmers in the drought - prone district of Bikita plunging them into food insecurity and abject poverty. It emerged in the study that some of effects of climate variability felt by communal farmers in Bikita included failure of crops, death of livestock and low crop yields, all of which have led to declining agricultural productivity. Findings in this study however established that communal farmers have not been passive victims of the vagaries of climate change and variability. They have rationally responded to it through various adaptation and mitigation strategies both individually and collectively.

  16. Imaging Variable Stars with HST

    Science.gov (United States)

    Karovska, M.

    2012-06-01

    (Abstract only) The Hubble Space Telescope (HST) observations of astronomical sources, ranging from objects in our solar system to objects in the early Universe, have revolutionized our knowledge of the Universe its origins and contents. I highlight results from HST observations of variable stars obtained during the past twenty or so years. Multiwavelength observations of numerous variable stars and stellar systems were obtained using the superb HST imaging capabilities and its unprecedented angular resolution, especially in the UV and optical. The HST provided the first detailed images probing the structure of variable stars including their atmospheres and circumstellar environments. AAVSO observations and light curves have been critical for scheduling of many of these observations and provided important information and context for understanding of the imaging results of many variable sources. I describe the scientific results from the imaging observations of variable stars including AGBs, Miras, Cepheids, semiregular variables (including supergiants and giants), YSOs and interacting stellar systems with a variable stellar components. These results have led to an unprecedented understanding of the spatial and temporal characteristics of these objects and their place in the stellar evolutionary chains, and in the larger context of the dynamic evolving Universe.

  17. Evaluation of and quality assurance in HER2 analysis in breast carcinomas from patients registered in Danish Breast Cancer Group (DBCG) in the period of 2002-2006. A nationwide study including correlation between HER-2 status and other prognostic variables.

    Science.gov (United States)

    Rasmussen, Birgitte Bruun; Andersson, Michael; Christensen, Ib J; Møller, Susanne

    2008-01-01

    In Denmark, analysis for HER2 is situated in the pathology laboratories dealing with breast pathology. The analysis was introduced during the late 1990's, and was gradually intensified in the following years up to now. The present study deals with the experience with the analysis during the last 5 years, from 2002 - 2006. All patients, registered in DBCG (Danish Breast Cancer Group) and with a HER2-test were included. The analysis followed international recommendations, with an initial immunohistochemical (IHC) analysis with a semiquantitative grading of the reaction in four grades, 0 and 1+, defined as HER2-negative, 2+, equivocal and 3+, HER2-positive. In the 2+ group, a FISH-test was applied to identify the presence of gene amplification, defined as a ratio >/=2. We investigated the number of analyses performed, the number of positive cases and the relation between the result of IHC and the result of FISH. Furthermore we looked at the relation to other prognostic factors. The number of analyses gradually increased during the years of investigation, from 30% of patients in 2002 to 71% in 2006. The increase was seen in all laboratories resulting in all laboratories but one having a substantial number of analyses. Sixty-two percent of all cases were HER2-negative, 18% were equivocal and 21% positive in the IHC-analysis. Of the 2+, equivocal cases, 23% had gene-amplification. Thus, 23% of patients were defined as HER2-positive and eligible for treatment with trastuzumab. There was a significant correlation to other prognostic factors. The results are in accordance with what is found elsewhere. The quality of the test is further assured by all laboratories participating in external quality assurance schemes.

  18. Harvesting Atlantic Cod under Climate Variability

    Science.gov (United States)

    Oremus, K. L.

    2016-12-01

    Previous literature links the growth of a fishery to climate variability. This study uses an age-structured bioeconomic model to compare optimal harvest in the Gulf of Maine Atlantic cod fishery under a variable climate versus a static climate. The optimal harvest path depends on the relationship between fishery growth and the interest rate, with higher interest rates dictating greater harvests now at the cost of long-term stock sustainability. Given the time horizon of a single generation of fishermen under assumptions of a static climate, the model finds that the economically optimal management strategy is to harvest the entire stock in the short term and allow the fishery to collapse. However, if the biological growth of the fishery is assumed to vary with climate conditions, such as the North Atlantic Oscillation, there will always be pulses of high growth in the stock. During some of these high-growth years, the growth of the stock and its economic yield can exceed the growth rate of the economy even under high interest rates. This implies that it is not economically optimal to exhaust the New England cod fishery if NAO is included in the biological growth function. This finding may have theoretical implications for the management of other renewable yet exhaustible resources whose growth rates are subject to climate variability.

  19. Classification of decays involving variable decay chains with convolutional architectures

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Vidyo contribution We present a technique to perform classification of decays that exhibit decay chains involving a variable number of particles, which include a broad class of $B$ meson decays sensitive to new physics. The utility of such decays as a probe of the Standard Model is dependent upon accurate determination of the decay rate, which is challenged by the combinatorial background arising in high-multiplicity decay modes. In our model, each particle in the decay event is represented as a fixed-dimensional vector of feature attributes, forming an $n \\times k$ representation of the event, where $n$ is the number of particles in the event and $k$ is the dimensionality of the feature vector. A convolutional architecture is used to capture dependencies between the embedded particle representations and perform the final classification. The proposed model performs outperforms standard machine learning approaches based on Monte Carlo studies across a range of variable final-state decays with the Belle II det...

  20. Slovak Dependency Treebank in Universal Dependencies

    Directory of Open Access Journals (Sweden)

    Zeman Daniel

    2017-12-01

    Full Text Available We describe a conversion of the syntactically annotated part of the Slovak National Corpus into the annotation scheme known as Universal Dependencies. Only a small subset of the data has been converted so far; yet it is the first Slovak treebank that is publicly available for research. We list a number of research projects in which the dataset has been used so far, including the first parsing results.

  1. Variable importance in latent variable regression models

    NARCIS (Netherlands)

    Kvalheim, O.M.; Arneberg, R.; Bleie, O.; Rajalahti, T.; Smilde, A.K.; Westerhuis, J.A.

    2014-01-01

    The quality and practical usefulness of a regression model are a function of both interpretability and prediction performance. This work presents some new graphical tools for improved interpretation of latent variable regression models that can also assist in improved algorithms for variable

  2. Period--luminosity--color relations and pulsation modes of pulsating variable stars

    International Nuclear Information System (INIS)

    Breger, M.; Bregman, J.N.

    1975-01-01

    The periods of delta Scuti, RR Lyrae, dwarf Cepheid, and W Virginis variables have been investigated for their dependence on luminosity, color, mass, and pulsation modes. A maximum-likelihood method, which includes consideration of the observational errors in each coordinate, has been applied to obtain observational period-luminosity-color (P-L-C) relations

  3. PSA methodology including new design, operational and safety factors, 'Level of recognition of phenomena with a presumed dominant influence upon operational safety' (failures of conventional as well as non-conventional passive components, dependent failures, influence of operator, fires and external threats, digital control, organizational factors)

    International Nuclear Information System (INIS)

    Jirsa, P.

    2001-10-01

    The document represents a specific type of discussion of existing methodologies for the creation and application of probabilistic safety assessment (PSA) in light of the EUR document summarizing requirements placed by Western European NPP operators on the future design of nuclear power plants. A partial goal of this discussion consists in mapping, from the PSA point of view, those selected design, operational and/or safety factors of future NPPs that may be entirely new or, at least, newly addressed. Therefore, the terms of reference for this stage were formulated as follows: Assess current level of knowledge and procedures in the analysis of factors and phenomena with a dominant influence upon operational safety of new generation reactors, especially in the following areas: (1) Phenomenology of failure types and mechanisms and reliability of conventional passive safety system components; (2) Phenomenology of failure types and mechanisms and reliability of non-conventional passive components of newly designed safety systems; (3) Phenomenology of types and mechanisms of dependent failures; (4) Human factor role in new generation reactors and its effect upon safety; (5) Fire safety and other external threats to new nuclear installations; (6) Reliability of the digital systems of the I and C system and their effect upon safety; and (7) Organizational factors in new nuclear installations. (P.A.)

  4. All varieties of encoding variability are not created equal: Separating variable processing from variable tasks

    Science.gov (United States)

    Huff, Mark J.; Bodner, Glen E.

    2014-01-01

    Whether encoding variability facilitates memory is shown to depend on whether item-specific and relational processing are both performed across study blocks, and whether study items are weakly versus strongly related. Variable-processing groups studied a word list once using an item-specific task and once using a relational task. Variable-task groups’ two different study tasks recruited the same type of processing each block. Repeated-task groups performed the same study task each block. Recall and recognition were greatest in the variable-processing group, but only with weakly related lists. A variable-processing benefit was also found when task-based processing and list-type processing were complementary (e.g., item-specific processing of a related list) rather than redundant (e.g., relational processing of a related list). That performing both item-specific and relational processing across trials, or within a trial, yields encoding-variability benefits may help reconcile decades of contradictory findings in this area. PMID:25018583

  5. Groundwater level responses to precipitation variability in Mediterranean insular aquifers

    Science.gov (United States)

    Lorenzo-Lacruz, Jorge; Garcia, Celso; Morán-Tejeda, Enrique

    2017-09-01

    Groundwater is one of the largest and most important sources of fresh water on many regions under Mediterranean climate conditions, which are exposed to large precipitation variability that includes frequent meteorological drought episodes, and present high evapotranspiration rates and water demand during the dry season. The dependence on groundwater increases in those areas with predominant permeable lithologies, contributing to aquifer recharge and the abundance of ephemeral streams. The increasing pressure of tourism on water resources in many Mediterranean coastal areas, and uncertainty related to future precipitation and water availability, make it urgent to understand the spatio-temporal response of groundwater bodies to precipitation variability, if sustainable use of the resource is to be achieved. We present an assessment of the response of aquifers to precipitation variability based on correlations between the Standardized Precipitation Index (SPI) at various time scales and the Standardized Groundwater Index (SGI) across a Mediterranean island. We detected three main responses of aquifers to accumulated precipitation anomalies: (i) at short time scales of the SPI (24 months). The differing responses were mainly explained by differences in lithology and the percentage of highly permeable rock strata in the aquifer recharge areas. We also identified differences in the months and seasons when aquifer storages are more dependent on precipitation; these were related to climate seasonality and the degree of aquifer exploitation or underground water extraction. The recharge of some aquifers, especially in mountainous areas, is related to precipitation variability within a limited spatial extent, whereas for aquifers located in the plains, precipitation variability influence much larger areas; the topography and geological structure of the island explain these differences. Results indicate large spatial variability in the response of aquifers to precipitation in

  6. An Efficient Method for Synthesis of Planar Multibody Systems including Shape of Bodies as Design Variables

    DEFF Research Database (Denmark)

    Hansen, Michael R.; Hansen, John Michael

    1998-01-01

    A point contact joint has been developed and implemented in a joint coordinate based planar multibody dynamics analysis program that also supports revolute and translational joints. Further, a segment library for the definition of the contours of the point contact joints has been integrated...

  7. Scale-Dependent Solute Dispersion in Variably Saturated Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Rockhold, Mark L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Z. F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bott, Yi-Ju [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-29

    This work was performed to support performance assessment (PA) calculations for the Integrated Disposal Facility (IDF) at the Hanford Site. PA calculations require defensible estimates of physical, hydraulic, and transport parameters to simulate subsurface water flow and contaminant transport in both the near- and far-field environments. Dispersivity is one of the required transport parameters.

  8. Stable limits for sums of dependent infinite variance random variables

    DEFF Research Database (Denmark)

    Bartkiewicz, Katarzyna; Jakubowski, Adam; Mikosch, Thomas

    2011-01-01

    The aim of this paper is to provide conditions which ensure that the affinely transformed partial sums of a strictly stationary process converge in distribution to an infinite variance stable distribution. Conditions for this convergence to hold are known in the literature. However, most of these...

  9. Handling Time-dependent Variables : Antibiotics and Antibiotic Resistance

    NARCIS (Netherlands)

    Munoz-Price, L. Silvia; Frencken, Jos F.; Tarima, Sergey; Bonten, Marc

    2016-01-01

    Elucidating quantitative associations between antibiotic exposure and antibiotic resistance development is important. In the absence of randomized trials, observational studies are the next best alternative to derive such estimates. Yet, as antibiotics are prescribed for varying time periods,

  10. Electric power prices: variable tendency depending on the country

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    The deregulation of the electric power sector is very much in the news in most countries and at different stages. A study carried out by the national utility service (NUS) in 17 countries worldwide takes stock of the influence of deregulation on electric power prices. According to this study, the most important price increases are found in 4 non-European countries (Norway, South Africa, USA, New Zealand) while the most important decreases are found within Europe (Sweden 20%, Denmark 15.6%, Italy 12% and Germany 8%). In France the decrease of tariffs reaches only 3%. This short paper analyzes the evolution of prices in the different countries selected in the study, but no real tendency is outlined as the stage of competition is different in each country. (J.S.)

  11. Assessing carbon source-dependent phenotypic variability in Pseudomonas putida

    DEFF Research Database (Denmark)

    Nikel, Pablo Ivan; de Lorenzo, Victor

    2018-01-01

    capacity of single bacteria by means of fluorescence microscopy and flow cytometry, in combination with the analysis of the temporal takeoff of growth in single-cell cultures, is a simple and easy-to-implement approach. It can help to understand the link between macroscopic phenotypes (e.g., microbial......The soil bacterium Pseudomonas putida is rapidly becoming a platform of choice for applications that require a microbial host highly resistant to different types of stresses and elevated rates of reducing power regeneration. P. putida is capable of growing in a wide variety of carbon sources...

  12. Identifying Midshipmen for Academic Assistance Using Entry Variables

    National Research Council Canada - National Science Library

    Watson, Arthur

    2001-01-01

    .... Categorical values from the Learning and Study Strategies Inventory (LASSI), SAT scores and high school rank were incorporated as independent variables in a linear regression model with dependent variable Cumulative Quality Point Rating (CQPR...

  13. Rowing, the ultimate challenge to the human body - implications for physiological variables

    DEFF Research Database (Denmark)

    Volianitis, S.; Secher, Niels H.

    2009-01-01

    Clinical diagnoses depend on a variety of physiological variables but the full range of these variables is seldom known. With the load placed on the human body during competitive rowing, the physiological range for several variables is illustrated. The extreme work produced during rowing...... is explained by the seated position and the associated ability to increase venous return and, thus, cardiac output. This review highlights experimental work on Olympic rowing that presents a unique challenge to the human capacities, including cerebral metabolism, to unprecedented limits, and provides a unique...

  14. A Core Language for Separate Variability Modeling

    DEFF Research Database (Denmark)

    Iosif-Lazăr, Alexandru Florin; Wasowski, Andrzej; Schaefer, Ina

    2014-01-01

    Separate variability modeling adds variability to a modeling language without requiring modifications of the language or the supporting tools. We define a core language for separate variability modeling using a single kind of variation point to define transformations of software artifacts in object...... hierarchical dependencies between variation points via copying and flattening. Thus, we reduce a model with intricate dependencies to a flat executable model transformation consisting of simple unconditional local variation points. The core semantics is extremely concise: it boils down to two operational rules...

  15. Classification and prediction of port variables

    Energy Technology Data Exchange (ETDEWEB)

    Molina Serrano, B.

    2016-07-01

    Many variables are included in planning and management of port terminals. They can beeconomic, social, environmental and institutional. Agent needs to know relationshipbetween these variables to modify planning conditions. Use of Bayesian Networks allowsfor classifying, predicting and diagnosing these variables. Bayesian Networks allow forestimating subsequent probability of unknown variables, basing on know variables.In planning level, it means that it is not necessary to know all variables because theirrelationships are known. Agent can know interesting information about how port variablesare connected. It can be interpreted as cause-effect relationship. Bayesian Networks can beused to make optimal decisions by introduction of possible actions and utility of theirresults.In proposed methodology, a data base has been generated with more than 40 port variables.They have been classified in economic, social, environmental and institutional variables, inthe same way that smart port studies in Spanish Port System make. From this data base, anetwork has been generated using a non-cyclic conducted grafo which allows for knowingport variable relationships - parents-children relationships-. Obtained network exhibits thateconomic variables are – in cause-effect terms- cause of rest of variable typologies.Economic variables represent parent role in the most of cases. Moreover, whenenvironmental variables are known, obtained network allows for estimating subsequentprobability of social variables.It has been concluded that Bayesian Networks allow for modeling uncertainty in aprobabilistic way, even when number of variables is high as occurs in planning andmanagement of port terminals. (Author)

  16. Understanding Solar Cycle Variability

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, R. H.; Schüssler, M., E-mail: cameron@mps.mpg.de [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

    2017-07-10

    The level of solar magnetic activity, as exemplified by the number of sunspots and by energetic events in the corona, varies on a wide range of timescales. Most prominent is the 11-year solar cycle, which is significantly modulated on longer timescales. Drawing from dynamo theory, together with the empirical results of past solar activity and similar phenomena for solar-like stars, we show that the variability of the solar cycle can be essentially understood in terms of a weakly nonlinear limit cycle affected by random noise. In contrast to ad hoc “toy models” for the solar cycle, this leads to a generic normal-form model, whose parameters are all constrained by observations. The model reproduces the characteristics of the variable solar activity on timescales between decades and millennia, including the occurrence and statistics of extended periods of very low activity (grand minima). Comparison with results obtained with a Babcock–Leighton-type dynamo model confirm the validity of the normal-mode approach.

  17. Dynamic Dependence and Diversification in Corporate Credit

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Jin, Xisong

    2018-01-01

    We characterize dependence in corporate credit and equity returns for 215 firms using a new class of large-scale dynamic copula models. Copula dependence and especially tail dependence are highly variable and persistent, increase significantly in the financial crisis, and have remained high since...

  18. Variable cycle engine

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, A.P.; Sprunger, E.V.

    1980-09-16

    A variable cycle turboshaft engine includes a remote fan system and respective high and low pressure systems for selectively driving the fan system in such a manner as to provide VTOL takeoff capability and minimum specific fuel consumption (SFC) at cruise and loiter conditions. For takeoff the fan system is primarily driven by the relatively large low pressure system whose combustor receives the motive fluid from a core bypass duct and, for cruise and loiter conditions, the fan system is driven by both a relatively small high pressure core and the low pressure system with its combustor inoperative. A mixer is disposed downstream of the high pressure system for mixing the relatively cold air from the bypass duct and the relatively hot air from the core prior to its flow to the low pressure turbine.

  19. Statistical methods and regression analysis of stratospheric ozone and meteorological variables in Isfahan

    Science.gov (United States)

    Hassanzadeh, S.; Hosseinibalam, F.; Omidvari, M.

    2008-04-01

    Data of seven meteorological variables (relative humidity, wet temperature, dry temperature, maximum temperature, minimum temperature, ground temperature and sun radiation time) and ozone values have been used for statistical analysis. Meteorological variables and ozone values were analyzed using both multiple linear regression and principal component methods. Data for the period 1999-2004 are analyzed jointly using both methods. For all periods, temperature dependent variables were highly correlated, but were all negatively correlated with relative humidity. Multiple regression analysis was used to fit the meteorological variables using the meteorological variables as predictors. A variable selection method based on high loading of varimax rotated principal components was used to obtain subsets of the predictor variables to be included in the linear regression model of the meteorological variables. In 1999, 2001 and 2002 one of the meteorological variables was weakly influenced predominantly by the ozone concentrations. However, the model did not predict that the meteorological variables for the year 2000 were not influenced predominantly by the ozone concentrations that point to variation in sun radiation. This could be due to other factors that were not explicitly considered in this study.

  20. Pressure dependence of conductivity

    International Nuclear Information System (INIS)

    Bracewell, B.L.; Hochheimer, H.D.

    1993-01-01

    The overall objectives of this work were to attempt the following: (1) Measure the pressure dependence of the electrical conductivity of several quasi-one-dimensional, charge-density-wave solids, including measurements along various crystal directions. (2) Measure photocurrents in selected MX solids at ambient and elevated pressures. (3) Measure the resonance Raman spectra for selected MX solids as a function of pressure

  1. SEEPAGE MODEL FOR PA INCLUDING DRIFT COLLAPSE

    International Nuclear Information System (INIS)

    C. Tsang

    2004-01-01

    The purpose of this report is to document the predictions and analyses performed using the seepage model for performance assessment (SMPA) for both the Topopah Spring middle nonlithophysal (Tptpmn) and lower lithophysal (Tptpll) lithostratigraphic units at Yucca Mountain, Nevada. Look-up tables of seepage flow rates into a drift (and their uncertainty) are generated by performing numerical simulations with the seepage model for many combinations of the three most important seepage-relevant parameters: the fracture permeability, the capillary-strength parameter 1/a, and the percolation flux. The percolation flux values chosen take into account flow focusing effects, which are evaluated based on a flow-focusing model. Moreover, multiple realizations of the underlying stochastic permeability field are conducted. Selected sensitivity studies are performed, including the effects of an alternative drift geometry representing a partially collapsed drift from an independent drift-degradation analysis (BSC 2004 [DIRS 166107]). The intended purpose of the seepage model is to provide results of drift-scale seepage rates under a series of parameters and scenarios in support of the Total System Performance Assessment for License Application (TSPA-LA). The SMPA is intended for the evaluation of drift-scale seepage rates under the full range of parameter values for three parameters found to be key (fracture permeability, the van Genuchten 1/a parameter, and percolation flux) and drift degradation shape scenarios in support of the TSPA-LA during the period of compliance for postclosure performance [Technical Work Plan for: Performance Assessment Unsaturated Zone (BSC 2002 [DIRS 160819], Section I-4-2-1)]. The flow-focusing model in the Topopah Spring welded (TSw) unit is intended to provide an estimate of flow focusing factors (FFFs) that (1) bridge the gap between the mountain-scale and drift-scale models, and (2) account for variability in local percolation flux due to

  2. Delay-slope-dependent stability results of recurrent neural networks.

    Science.gov (United States)

    Li, Tao; Zheng, Wei Xing; Lin, Chong

    2011-12-01

    By using the fact that the neuron activation functions are sector bounded and nondecreasing, this brief presents a new method, named the delay-slope-dependent method, for stability analysis of a class of recurrent neural networks with time-varying delays. This method includes more information on the slope of neuron activation functions and fewer matrix variables in the constructed Lyapunov-Krasovskii functional. Then some improved delay-dependent stability criteria with less computational burden and conservatism are obtained. Numerical examples are given to illustrate the effectiveness and the benefits of the proposed method.

  3. Continuous-variable quantum teleportation with non-Gaussian resources

    International Nuclear Information System (INIS)

    Dell'Anno, F.; De Siena, S.; Albano, L.; Illuminati, F.

    2007-01-01

    We investigate continuous variable quantum teleportation using non-Gaussian states of the radiation field as entangled resources. We compare the performance of different classes of degaussified resources, including two-mode photon-added and two-mode photon-subtracted squeezed states. We then introduce a class of two-mode squeezed Bell-like states with one-parameter dependence for optimization. These states interpolate between and include as subcases different classes of degaussified resources. We show that optimized squeezed Bell-like resources yield a remarkable improvement in the fidelity of teleportation both for coherent and nonclassical input states. The investigation reveals that the optimal non-Gaussian resources for continuous variable teleportation are those that most closely realize the simultaneous maximization of the content of entanglement, the degree of affinity with the two-mode squeezed vacuum, and the, suitably measured, amount of non-Gaussianity

  4. An Integrated Biochemistry Laboratory, Including Molecular Modeling

    Science.gov (United States)

    Hall, Adele J. Wolfson Mona L.; Branham, Thomas R.

    1996-11-01

    for lysozyme activity and a colorimetric one for protein concentration. Familiarity with the assays is reinforced by an independently designed project to modify a variable in one of these assays. The assay for lysozyme activity is that of Shugar (6), based on hydrolysis of a cell-wall suspension from the bacterium Micrococcus lysodeikticus, a substrate that is particularly sensitive to lysozyme. As the cell walls are broken down by the enzyme, the turbidity of the sample decreases. This decrease can be conveniently measured by following the decrease in absorbance at a wavelength of 450 nm, using a spectrophotometer or other device for measuring light scattering. The Bradford method (7), a standard assay, is used to determine protein concentration. Using the data from both lysozyme activity assays and protein concentration assays, students can calculate the specific activity for commercial lysozyme and an egg- white solution. These calculations clearly demonstrate the increase in specific activity with increasing purity, since the purified (commercial) preparation has a specific activity approximately 20-fold higher than that of the crude egg-white solution. Lysozyme Purification by Ion-Exchange Chromatography (5 weeks) As suggested by Strang (8), students can design a rational purification of lysozyme using ion-exchange chromatography when presented with information on the isoelectric point of the enzyme and the properties of ion- exchange resins. One week is spent discussing protein purification and the relative advantages and disadvantages of different resins. Each group has a choice of anion-exchange (DEAE) or cation-exchange (CM) resins. Because lysozyme is positively charged below a pH of 11, it will not be adsorbed to an anion-exchange resin, but will be adsorbed to the cation-exchange resin. Therefore, for the cation-exchange protocols, there are further options for methods of collecting and eluting the desired protein. A purification table, including

  5. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ; SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and

  6. Amplification factor variable amplifier

    NARCIS (Netherlands)

    Akitsugu, Oshita; Nauta, Bram

    2010-01-01

    PROBLEM TO BE SOLVED: To provide an amplification factor variable amplifier capable of achieving temperature compensation of an amplification factor over a wide variable amplification factor range. ;SOLUTION: A Gilbert type amplification factor variable amplifier 11 amplifies an input signal and can

  7. Canonical basis for type A4 (II) - Polynomial elements in one variable

    International Nuclear Information System (INIS)

    Hu Yuwang; Ye Jiachen

    2003-12-01

    All the 62 monomial elements in the canonical basis B of the quantized enveloping algebra for type A 4 have been determined. According to Lusztig's idea, the elements in the canonical basis B consist of monomials and linear combinations of monomials (for convenience, we call them polynomials). In this note, we compute all the 144 polynomial elements in one variable in the canonical basis B of the quantized enveloping algebra for type A 4 based on our joint note. We conjecture that there are other polynomial elements in two or three variables in the canonical basis B, which include independent variables and dependent variables. Moreover, it is conjectured that there are no polynomial elements in the canonical basis B with four or more variables. (author)

  8. Efficiency of a new internal combustion engine concept with variable piston motion

    Directory of Open Access Journals (Sweden)

    Dorić Jovan Ž.

    2014-01-01

    Full Text Available This paper presents simulation of working process in a new IC engine concept. The main feature of this new IC engine concept is the realization of variable movement of the piston. With this unconventional piston movement it is easy to provide variable compression ratio, variable displacement and combustion during constant volume. These advantages over standard piston mechanism are achieved through synthesis of the two pairs of non-circular gears. Presented mechanism is designed to obtain a specific motion law which provides better fuel consumption of IC engines. For this paper Ricardo/WAVE software was used, which provides a fully integrated treatment of time-dependent fluid dynamics and thermodynamics by means of onedimensional formulation. The results obtained herein include the efficiency characteristic of this new heat engine concept. The results show that combustion during constant volume, variable compression ratio and variable displacement have significant impact on improvement of fuel consumption.

  9. Impact of Psychological Variables on Playing Ability of University Level Soccer Players

    Directory of Open Access Journals (Sweden)

    Ertan Tufekcioglu

    2014-10-01

    Full Text Available The purpose of the study was to find out the relationship between psychological variables and soccer playing ability among the university level male players. 42 soccer players representing different universities who participated in inter university competitions were selected as the subjects of the study. The dependent variable was soccer playing ability and independent variables were the selected psychological variables. Soccer playing ability was determined through a 10 point scale at the time of competitions. Psychological variables included achievement motivation, anxiety, self-concept and aggression. The data was statistically analyzed using Karl Pearson’s correlation coefficient and multiple regression analysis using SPSS. It was concluded that soccer playing ability has a positive correlation with achievement motivation and self-concept whereas anxiety and aggression have a negative correlation with soccer playing ability.

  10. Establishment of regression dependences. Linear and nonlinear dependences

    International Nuclear Information System (INIS)

    Onishchenko, A.M.

    1994-01-01

    The main problems of determination of linear and 19 types of nonlinear regression dependences are completely discussed. It is taken into consideration that total dispersions are the sum of measurement dispersions and parameter variation dispersions themselves. Approaches to all dispersions determination are described. It is shown that the least square fit gives inconsistent estimation for industrial objects and processes. The correction methods by taking into account comparable measurement errors for both variable give an opportunity to obtain consistent estimation for the regression equation parameters. The condition of the correction technique application expediency is given. The technique for determination of nonlinear regression dependences taking into account the dependence form and comparable errors of both variables is described. 6 refs., 1 tab

  11. Variable Selection via Partial Correlation.

    Science.gov (United States)

    Li, Runze; Liu, Jingyuan; Lou, Lejia

    2017-07-01

    Partial correlation based variable selection method was proposed for normal linear regression models by Bühlmann, Kalisch and Maathuis (2010) as a comparable alternative method to regularization methods for variable selection. This paper addresses two important issues related to partial correlation based variable selection method: (a) whether this method is sensitive to normality assumption, and (b) whether this method is valid when the dimension of predictor increases in an exponential rate of the sample size. To address issue (a), we systematically study this method for elliptical linear regression models. Our finding indicates that the original proposal may lead to inferior performance when the marginal kurtosis of predictor is not close to that of normal distribution. Our simulation results further confirm this finding. To ensure the superior performance of partial correlation based variable selection procedure, we propose a thresholded partial correlation (TPC) approach to select significant variables in linear regression models. We establish the selection consistency of the TPC in the presence of ultrahigh dimensional predictors. Since the TPC procedure includes the original proposal as a special case, our theoretical results address the issue (b) directly. As a by-product, the sure screening property of the first step of TPC was obtained. The numerical examples also illustrate that the TPC is competitively comparable to the commonly-used regularization methods for variable selection.

  12. Mechanics of deformations in terms of scalar variables

    Science.gov (United States)

    Ryabov, Valeriy A.

    2017-05-01

    Theory of particle and continuous mechanics is developed which allows a treatment of pure deformation in terms of the set of variables "coordinate-momentum-force" instead of the standard treatment in terms of tensor-valued variables "strain-stress." This approach is quite natural for a microscopic description of atomic system, according to which only pointwise forces caused by the stress act to atoms making a body deform. The new concept starts from affine transformation of spatial to material coordinates in terms of the stretch tensor or its analogs. Thus, three principal stretches and three angles related to their orientation form a set of six scalar variables to describe deformation. Instead of volume-dependent potential used in the standard theory, which requires conditions of equilibrium for surface and body forces acting to a volume element, a potential dependent on scalar variables is introduced. A consistent introduction of generalized force associated with this potential becomes possible if a deformed body is considered to be confined on the surface of torus having six genuine dimensions. Strain, constitutive equations and other fundamental laws of the continuum and particle mechanics may be neatly rewritten in terms of scalar variables. Giving a new presentation for finite deformation new approach provides a full treatment of hyperelasticity including anisotropic case. Derived equations of motion generate a new kind of thermodynamical ensemble in terms of constant tension forces. In this ensemble, six internal deformation forces proportional to the components of Irving-Kirkwood stress are controlled by applied external forces. In thermodynamical limit, instead of the pressure and volume as state variables, this ensemble employs deformation force measured in kelvin unit and stretch ratio.

  13. Decomposing global crop yield variability

    Science.gov (United States)

    Ben-Ari, Tamara; Makowski, David

    2014-11-01

    Recent food crises have highlighted the need to better understand the between-year variability of agricultural production. Although increasing future production seems necessary, the globalization of commodity markets suggests that the food system would also benefit from enhanced supplies stability through a reduction in the year-to-year variability. Here, we develop an analytical expression decomposing global crop yield interannual variability into three informative components that quantify how evenly are croplands distributed in the world, the proportion of cultivated areas allocated to regions of above or below average variability and the covariation between yields in distinct world regions. This decomposition is used to identify drivers of interannual yield variations for four major crops (i.e., maize, rice, soybean and wheat) over the period 1961-2012. We show that maize production is fairly spread but marked by one prominent region with high levels of crop yield interannual variability (which encompasses the North American corn belt in the USA, and Canada). In contrast, global rice yields have a small variability because, although spatially concentrated, much of the production is located in regions of below-average variability (i.e., South, Eastern and South Eastern Asia). Because of these contrasted land use allocations, an even cultivated land distribution across regions would reduce global maize yield variance, but increase the variance of global yield rice. Intermediate results are obtained for soybean and wheat for which croplands are mainly located in regions with close-to-average variability. At the scale of large world regions, we find that covariances of regional yields have a negligible contribution to global yield variance. The proposed decomposition could be applied at any spatial and time scales, including the yearly time step. By addressing global crop production stability (or lack thereof) our results contribute to the understanding of a key

  14. Evidence for a time-invariant phase variable in human ankle control.

    Directory of Open Access Journals (Sweden)

    Robert D Gregg

    Full Text Available Human locomotion is a rhythmic task in which patterns of muscle activity are modulated by state-dependent feedback to accommodate perturbations. Two popular theories have been proposed for the underlying embodiment of phase in the human pattern generator: a time-dependent internal representation or a time-invariant feedback representation (i.e., reflex mechanisms. In either case the neuromuscular system must update or represent the phase of locomotor patterns based on the system state, which can include measurements of hundreds of variables. However, a much simpler representation of phase has emerged in recent designs for legged robots, which control joint patterns as functions of a single monotonic mechanical variable, termed a phase variable. We propose that human joint patterns may similarly depend on a physical phase variable, specifically the heel-to-toe movement of the Center of Pressure under the foot. We found that when the ankle is unexpectedly rotated to a position it would have encountered later in the step, the Center of Pressure also shifts forward to the corresponding later position, and the remaining portion of the gait pattern ensues. This phase shift suggests that the progression of the stance ankle is controlled by a biomechanical phase variable, motivating future investigations of phase variables in human locomotor control.

  15. About the relationships among variables observed in the real world

    Science.gov (United States)

    Petkov, Boyan H.

    2018-06-01

    Since a stationary chaotic system is determined by nonlinear equations connecting its components, the appurtenance of two variables to such a system has been considered a sign of nontrivial relationships between them including also other quantities. These relationships could remain hidden for the approach usually employed in the research analyses, which is based on the extent of the correlation that characterises the dependence of one variable on the other. The appurtenance to the same system can be hypothesized if the topological features of the attractors reconstructed from two time series representing the evolution of the corresponding variables are close to each other. However, the possibility that both attractors represent different systems with similar behaviour cannot be excluded. For that reason, an approach allowing the reconstruction of the attractor by using jointly two time series was proposed and the conclusion about the common origin of the variables under study can be made if this attractor is topologically similar to those built separately from the two time series. In the present study, the features of the attractors were presented by the correlation dimension and the largest Lyapunov exponent and the proposed algorithm has been tested on numerically generated sequences obtained from various maps. It is believed that this approach could be used to reveal connections among the variables observed in experiments or field measurements.

  16. Influence of attrition variables on iron ore flotation

    Directory of Open Access Journals (Sweden)

    Fabiana Fonseca Fortes

    Full Text Available Abstract The presence of slimes is harmful to the flotation process: the performance and consumption of reagents are negatively affected. Traditionally, the desliming stage has been responsible for removing slimes. However, depending on the porosity of the mineral particles, desliming may not be sufficient to maximize the concentration results. An attrition process before the desliming operation can improve the removal of slime, especially when slimes cover the surface and/or are confined to the cavities/pores of the mineral particles. Attrition is present in the flowcharts of the beneficiation process of phosphate and industrial sand (silica sand. Research has been undertaken for its application to produce pre-concentrates of zircon and iron ore. However, there is still little knowledge of the influence of the attrition variables on the beneficiation process of iron ore. This study presents a factorial design and analysis of the effects of these variables on the reverse flotation of iron ore. The standard of the experimental procedures for all tests included the attrition of pulp, under the conditions of dispersion, desliming and flotation. The parameter analysed (variable response was the metallurgical recovery in reverse flotation tests. The planning and analysis of the full factorial experiment indicated that with 95% reliability, the rotation speed of the attrition cell impeller was the main variable in the attrition process of the iron ore. The percentage of solid variables in the pulp and the time of the attrition, as well as their interactions, were not indicated to be significant.

  17. Photometric variability in earthshine observations.

    Science.gov (United States)

    Langford, Sally V; Wyithe, J Stuart B; Turner, Edwin L

    2009-04-01

    The identification of an extrasolar planet as Earth-like will depend on the detection of atmospheric signatures or surface non-uniformities. In this paper we present spatially unresolved flux light curves of Earth for the purpose of studying a prototype extrasolar terrestrial planet. Our monitoring of the photometric variability of earthshine revealed changes of up to 23% per hour in the brightness of Earth's scattered light at around 600 nm, due to the removal of specular reflection from the view of the Moon. This variability is accompanied by reddening of the spectrum and results from a change in surface properties across the continental boundary between the Indian Ocean and Africa's east coast. Our results based on earthshine monitoring indicate that specular reflection should provide a useful tool in determining the presence of liquid water on extrasolar planets via photometric observations.

  18. Evolution of α-particle distribution in burning plasmas including energy dependent α-transport effects

    International Nuclear Information System (INIS)

    Kamelander, G.; Sigmar, D.; Woloch, F.

    1991-09-01

    This report resumes the essential results of a common OEFZS/MIT (Plasma Fusion Center) project to investigate fusion alpha transport. A computer code has been developed going beyond standard FOKKER-PLANCK-codes assuming that the fusion products give their energy to the plasma on the place of their birth. The present transport code admits the calculation of the α-distribution function. By means of the distribution function the energy deposition rates are calculated. The time-evolution of the α-distribution function has been evaluated for an ignited plasma. A description of the transport code, of the subroutines and of the input data as well as a listing is enclosed to this report. (Authors)

  19. Multilevel Cross-Dependent Binary Longitudinal Data

    KAUST Repository

    Serban, Nicoleta; Staicu, Ana-Maria; Carroll, Raymond J.

    2013-01-01

    processes describing the within- and between-variability, and describing the cross-dependence of the repeated longitudinal measurements. We estimate the model components without employing mixed-effects modeling but assuming an approximation to the logistic

  20. Cataclysmic Variable Stars

    Science.gov (United States)

    Hellier, Coel

    2001-01-01

    Cataclysmic variable stars are the most variable stars in the night sky, fluctuating in brightness continually on timescales from seconds to hours to weeks to years. The changes can be recorded using amateur telescopes, yet are also the subject of intensive study by professional astronomers. That study has led to an understanding of cataclysmic variables as binary stars, orbiting so closely that material transfers from one star to the other. The resulting process of accretion is one of the most important in astrophysics. This book presents the first account of cataclysmic variables at an introductory level. Assuming no previous knowledge of the field, it explains the basic principles underlying the variability, while providing an extensive compilation of cataclysmic variable light curves. Aimed at amateur astronomers, undergraduates, and researchers, the main text is accessible to those with no mathematical background, while supplementary boxes present technical details and equations.

  1. Understanding Brown Dwarf Variability

    Science.gov (United States)

    Marley, Mark S.

    2013-01-01

    Surveys of brown dwarf variability continue to find that roughly half of all brown dwarfs are variable. While variability is observed amongst all types of brown dwarfs, amplitudes are typically greatest for L-T transition objects. In my talk I will discuss the possible physical mechanisms that are responsible for the observed variability. I will particularly focus on comparing and contrasting the effects of changes in atmospheric thermal profile and cloud opacity. The two different mechanisms will produce different variability signatures and I will discuss the extent to which the current datasets constrain both mechanisms. By combining constraints from studies of variability with existing spectral and photometric datasets we can begin to construct and test self-consistent models of brown dwarf atmospheres. These models not only aid in the interpretation of existing objects but also inform studies of directly imaged giant planets.

  2. Size-dependent thermoelasticity

    Directory of Open Access Journals (Sweden)

    Ali R. Hadjesfandiari

    Full Text Available In this paper a consistent theory is developed for size-dependent thermoelasticity in heterogeneous anisotropic solids. This theory shows that the temperature change can create not only thermal strains, but also thermal mean curvatures in the solids. This formulation is based on the consistent size-dependent continuum mechanics in which the couple-stress tensor is skew-symmetric. Here by including scale-dependent measures in the energy and entropy equations, the general expressions for force- and couple-stresses, as well as entropy density, are obtained. Next, for the linear material the constitutive relations and governing coupled size-dependent thermoelasticity equations are developed. For linear material, one can see that the thermal properties are characterized by the classical symmetric thermal expansion tensor and the new size-dependent skew-symmetric thermal flexion tensor. Thus, for the most general anisotropic case, there are nine independent thermoelastic constants. Interestingly, for isotropic and cubic materials the thermal flexion tensor vanishes, which shows there is no thermal mean curvature

  3. Hydroclimate variability: comparing dendroclimatic records and future GCM scenarios

    International Nuclear Information System (INIS)

    Lapp, S.

    2008-01-01

    Drought events of the 20th Century in western North America have been linked to teleconnections that influence climate variability on inter-annual and decadal to multi-decadal time scales. These teleconnections represent the changes sea surface temperatures (SSTs) in the tropical and extra-tropical regions of the Pacific Ocean, ENSO (El-Nino Southern Oscillation) and PDO (Pacific Decadal Oscillation), respectively, and the Atlantic Ocean, AMO (Atlantic Multidecadal Oscillation), and also to atmospheric circulation patterns (PNA: Pacific-North American). A network of precipitation sensitive tree-ring chronologies from Montana, Alberta, Saskatchewan and NWT highly correlate to the climate moisture index (CMI) of precipitation potential evapotranspiration (P-PET), thus, capturing the long-term hydroclimatic variability of the region. Reconstructions of annual and seasonal CMI identify drought events in previous centuries that are more extreme in magnitude, frequency and duration than recorded during the instrumental period. Variability in the future climate will include these natural climate cycles as well as modulations of these cycles affected by human induced global warming. The proxy hydroclimate records derived from tree-rings present information on decadal and multi-decadal hydroclimatic variability for the past millennium; therefore, providing a unique opportunity to validate the climate variability simulated by GCMs (Global Climate Models) on longer time scales otherwise constrained by the shorter observation records. Developing scenarios of future variability depends: 1) on our understanding of the interaction of these teleconnection; and, 2) to identify climate models that are able to accurately simulate the hydroclimatic variability as detected in the instrumental and proxy records. (author)

  4. Ultrasonic variables affecting inspection

    International Nuclear Information System (INIS)

    Lautzenheiser, C.E.; Whiting, A.R.; McElroy, J.T.

    1977-01-01

    There are many variables which affect the detection of the effects and reproducibility of results when utilizing ultrasonic techniques. The most important variable is the procedure, as this document specifies, to a great extent, the controls that are exercised over the other variables. The most important variable is personnel with regards to training, qualification, integrity, data recording, and data analysis. Although the data is very limited, these data indicate that, if the procedure is carefully controlled, reliability of defect detection and reproducibility of results are both approximately 90 percent for reliability of detection, this applies to relatively small defects as reliability increases substantially as defect size increases above the recording limit. (author)

  5. Different definitions in childhood asthma: how dependable is the dependent variable?

    NARCIS (Netherlands)

    van Wonderen, K. E.; van der Mark, L. B.; Mohrs, J.; Bindels, P. J. E.; van Aalderen, W. M. C.; ter Riet, G.

    2010-01-01

    There is abundant literature on how to select and statistically deal with predictors in prediction models. Less attention has been paid to the choice of the outcome. We assessed the impact of different asthma definitions on prevalence estimates and on the prediction model's performances. We searched

  6. How Robust Is Linear Regression with Dummy Variables?

    Science.gov (United States)

    Blankmeyer, Eric

    2006-01-01

    Researchers in education and the social sciences make extensive use of linear regression models in which the dependent variable is continuous-valued while the explanatory variables are a combination of continuous-valued regressors and dummy variables. The dummies partition the sample into groups, some of which may contain only a few observations.…

  7. Collective variables and dissipation

    International Nuclear Information System (INIS)

    Balian, R.

    1984-09-01

    This is an introduction to some basic concepts of non-equilibrium statistical mechanics. We emphasize in particular the relevant entropy relative to a given set of collective variables, the meaning of the projection method in the Liouville space, its use to establish the generalized transport equations for these variables, and the interpretation of dissipation in the framework of information theory

  8. Variability: A Pernicious Hypothesis.

    Science.gov (United States)

    Noddings, Nel

    1992-01-01

    The hypothesis of greater male variability in test results is discussed in its historical context, and reasons feminists have objected to the hypothesis are considered. The hypothesis acquires political importance if it is considered that variability results from biological, rather than cultural, differences. (SLD)

  9. Reinforcing Saccadic Amplitude Variability

    Science.gov (United States)

    Paeye, Celine; Madelain, Laurent

    2011-01-01

    Saccadic endpoint variability is often viewed as the outcome of neural noise occurring during sensorimotor processing. However, part of this variability might result from operant learning. We tested this hypothesis by reinforcing dispersions of saccadic amplitude distributions, while maintaining constant their medians. In a first experiment we…

  10. POVMs and hidden variables

    International Nuclear Information System (INIS)

    Stairs, Allen

    2007-01-01

    Recent results by Paul Busch and Adan Cabello claim to show that by appealing to POVMs, non-contextual hidden variables can be ruled out in two dimensions. While the results of Busch and Cabello are mathematically correct, interpretive problems render them problematic as no hidden variable proofs

  11. Interdependence Among Organizational Variables

    Science.gov (United States)

    Knowles, M. C.

    1975-01-01

    The interrelationship between a set of organizational variables was investigated at 14 work organizations within a company. The variables were production, quality, costs, job satisfaction of operatives, job satisfaction of supervisors, work anxiety, accidents, absence, labor turnover, and industrial unrest. (Author)

  12. Variable gearing in a biologically inspired pneumatic actuator array

    International Nuclear Information System (INIS)

    Azizi, Emanuel; Roberts, Thomas J

    2013-01-01

    A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle's gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system's gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions. (paper)

  13. Variable gearing in a biologically inspired pneumatic actuator array.

    Science.gov (United States)

    Azizi, Emanuel; Roberts, Thomas J

    2013-06-01

    A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle's gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system's gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions.

  14. VARIABLE GEARING IN A BIOLOGICALLY-INSPIRED PNEUMATIC ACTUATOR ARRAY

    Science.gov (United States)

    Azizi, Emanuel; Roberts, Thomas J.

    2013-01-01

    A fundamental feature of pennate muscles is that muscle fibers are oriented at an angle to the line of action and rotate as they shorten, becoming more oblique throughout a contraction. This change in fiber orientation (pennation angle) can amplify the shortening velocity of a fiber and increase output velocity of the muscle. The velocity advantage resulting from dynamic changes in pennation angle can be characterized as a gear ratio (muscle velocity/fiber velocity). A recent study has shown that a pennate muscle’s gear ratio varies automatically depending on the load such that a muscle operates with a high gear during rapid contractions and low gear during forceful contractions. We examined whether this variable gearing behavior can be replicated in a pennate array of artificial muscles. We used McKibben type pneumatic actuators, which shorten in tension when filled with compressed gas. Similar to muscle fibers, the actuators expand radially during shortening, a feature thought to be a critical part of the variable gearing mechanism in pennate muscles. We arranged McKibben actuators in an array oriented to mimic a pennate muscle, and quantified the system’s gear ratio during contraction against a range of loads. Video was used to measure the gear ratio during each contraction. We find that similar to pennate muscles, the gear ratio decreases significantly with increasing load and that variable gearing results from load-dependent variation in the amount of actuator rotation. These results support the idea that variable gearing in pennate muscles is mediated by difference is fiber rotation and the direction of muscle bulging. The behavior of our artificial muscle array also highlights the potential benefits of bio-inspired architectures in artificial muscle arrays, including the ability to vary force and speed automatically in response to variable loading conditions. PMID:23462288

  15. A variable thickness window: Thermal and structural analyses

    International Nuclear Information System (INIS)

    Wang, Zhibi; Kuzay, T.M.

    1994-01-01

    In this paper, the finite difference formulations for variable thickness thermal analysis and variable thickness plane stress analysis are presented. In heat transfer analysis, radiation effects and temperature-dependent thermal conductivity are taken into account. While in thermal stress analysis, the thermal expansion coefficient is considered as temperature dependent. An application of the variable thickness window to an Advanced Photon Source beamline is presented

  16. Dependent seniors garment design

    Science.gov (United States)

    Caldas, A. L.; Carvalho, M. A.; Lopes, H. P.

    2017-10-01

    This paper is part of a PhD research in Textile Engineering at University of Minho and aims to establish an ergonomic pattern design methodology to be used in the construction of garments for elderly women, aged 65 and over, dependent of care. The research was developed with a close contact with four institutions involved in supporting this aged population, located in the cities of Guimarães (Portugal) and Teresina (Brazil). These clothes should be adequate to their anthropometrics and their special needs, in accordance with important functional factors for the dependency of their caregiver, such as: care for the caregiver and comfort for the user. Questions regarding the functional properties of the materials, the pattern design process, trimmings and the assembling process of the garments are specially considered in the desired comfort levels, in order to provide an adequate handling by facilitating the dressing and undressing tasks, but also to assure the user the needed comfort in all its variables.

  17. IDENTIFICATION OF THOSE VARIABLES THAT HAVE A SIGNIFICANT INFLUENCE ON THE EXPECTED NUMBER OF DAYS OF STAYING IN THE CENTRE DEVELOPMENT REGION OF ROMANIA

    Directory of Open Access Journals (Sweden)

    Erika KULCSÁR

    2010-06-01

    Full Text Available I started from the assumption that there are more variables that have a significant influence on the expected number of days of staying in the Centre Development Region. To identify those variables this paper includes the analysis of variance with two variables that are not interacting, in this case the dependent variable is the question "How many days did you plan to stay in Centre Development Region?" and the independent variables are: "What is the purpose of your stay?" "What is the highest level of education?". Given that there are cases when interactions occur between variables, I also analyzed the interaction effects between the two independent variables. The paper also includes an ANOVA analysis with three variables between which interactions relationships occur. After identifying the dependency relations between the variables I found that the inclusion of the third variable, namely the "Marital status" of respondents, adds value to the model. Following the results obtained by ANOVA analysis, I identified those socio-demographic characteristics that, in my opinion, companies that operate on tourist market in the Center Development Region should consider when fundamenting marketing strategies in tourism.

  18. Variability in Measured Space Temperatures in 60 Homes

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, D.; Lay, K.

    2013-03-01

    This report discusses the observed variability in indoor space temperature in a set of 60 homes located in Florida, New York, Oregon, and Washington. Temperature data were collected at 15-minute intervals for an entire year, including living room, master bedroom, and outdoor air temperature (Arena, et. al). The data were examined to establish the average living room temperature for the set of homes for the heating and cooling seasons, the variability of living room temperature depending on climate, and the variability of indoor space temperature within the homes. The accuracy of software-based energy analysis depends on the accuracy of input values. Thermostat set point is one of the most influential inputs for building energy simulation. Several industry standards exist that recommend differing default thermostat settings for heating and cooling seasons. These standards were compared to the values calculated for this analysis. The data examined for this report show that there is a definite difference between the climates and that the data do not agree well with any particular standard.

  19. Chemical dependence - resources

    Science.gov (United States)

    Substance use - resources, Drug abuse - resources; Resources - chemical dependence ... are a good resource for information on drug dependence: National Council on Alcoholism and Drug Dependence -- ncadd. ...

  20. Discriminant Profile of Young Internet Dependents: The Role of Family Relationships

    Directory of Open Access Journals (Sweden)

    Michele Terres-Trindade

    2015-12-01

    Full Text Available AbstractInternational studies have shown effects of family relations on Internet addiction in young people. This research aimed to outline a discriminant profile of young people classified as dependent and not dependent on the Internet regarding to socio-biodemographic variables to parenting practices, parent-child conflict and interparental conflict. The sample consisted of 200 students (152 girls and 48 boys, between 15 and 24 years of age, 85.5% reside in Rio Grande do Sul and 14.5% in other Brazilian states. Participants responded individually to the protocol available online. The results showed that interparental conflict, parent-child conflict and the educational practice of supervision of paternal behavior discriminate dependents on Internet. The educational practice of maternal emotional support was the only discriminating variable for non-dependents. These national findings corroborate the international context studies and reinforce the importance of including the family in promotion and prevention of mental health of young people.

  1. Hardness variability in commercial technologies

    International Nuclear Information System (INIS)

    Shaneyfelt, M.R.; Winokur, P.S.; Meisenheimer, T.L.; Sexton, F.W.; Roeske, S.B.; Knoll, M.G.

    1994-01-01

    The radiation hardness of commercial Floating Gate 256K E 2 PROMs from a single diffusion lot was observed to vary between 5 to 25 krad(Si) when irradiated at a low dose rate of 64 mrad(Si)/s. Additional variations in E 2 PROM hardness were found to depend on bias condition and failure mode (i.e., inability to read or write the memory), as well as the foundry at which the part was manufactured. This variability is related to system requirements, and it is shown that hardness level and variability affect the allowable mode of operation for E 2 PROMs in space applications. The radiation hardness of commercial 1-Mbit CMOS SRAMs from Micron, Hitachi, and Sony irradiated at 147 rad(Si)/s was approximately 12, 13, and 19 krad(Si), respectively. These failure levels appear to be related to increases in leakage current during irradiation. Hardness of SRAMs from each manufacturer varied by less than 20%, but differences between manufacturers are significant. The Qualified Manufacturer's List approach to radiation hardness assurance is suggested as a way to reduce variability and to improve the hardness level of commercial technologies

  2. A cross-sectional study on tobacco use and dependence among women: Does menthol matter?

    Science.gov (United States)

    Rosenbloom, Judith; Rees, Vaughan W; Reid, Kathleen; Wong, Jeannie; Kinnunen, Taru

    2012-11-27

    The question of whether mentholation of cigarettes enhances tobacco dependence has generated conflicting findings. Potential mediating factors in a putative relationship between menthol use and tobacco dependence may include race and gender. While an association between menthol use and dependence is mixed, research on the role of race solely among women smokers is scarce. This study examined whether women menthol smokers have higher tobacco use and dependence than non-menthol smokers. Further, the study investigated differences between White and African American smokers. A cross-sectional study was conducted among 928 women seeking tobacco dependence treatment in Boston, Massachusetts. Measures obtained included preferred brand and menthol content, dependence markers (cigarettes per day (CPD); time to first cigarette in the morning; number of and longest previous quit attempts) and smoking history (age of initiation; years smoking; menthol or non-menthol cigarette preference). Analysis of variance (ANOVA) was used to detect interactions between menthol preference by race for continuous variables, and Pearson's chi-squared test was used for analyses with dichotomous variables. A greater proportion of menthol smokers smoked their first cigarette within five minutes of waking (p preferences. However, African American smokers smoked fewer CPD (pbrand for longer (p= .04). Women menthol smokers showed signs of greater tobacco dependence than non-menthol smokers. African Americans smoked fewer CPD but nevertheless had evidence of greater dependence.

  3. Short-timescale variability in cataclysmic binaries

    International Nuclear Information System (INIS)

    Cordova, F.A.; Mason, K.O.

    1982-01-01

    Rapid variability, including flickering and pulsations, has been detected in cataclysmic binaries at optical and x-ray frequencies. In the case of the novalike variable TT Arietis, simultaneous observations reveal that the x-ray and optical flickering activity is strongly correlated, while short period pulsations are observed that occur at the same frequencies in both wavelength bands

  4. The MEXSAS2 Sample and the Ensemble X-ray Variability of Quasars

    Energy Technology Data Exchange (ETDEWEB)

    Serafinelli, Roberto [Dipartimento di Fisica, Università di Roma Tor Vergata, Rome (Italy); Dipartimento di Fisica, Università di Roma Sapienza, Rome (Italy); Vagnetti, Fausto; Chiaraluce, Elia [Dipartimento di Fisica, Università di Roma Tor Vergata, Rome (Italy); Middei, Riccardo, E-mail: roberto.serafinelli@roma2.infn.it [Dipartimento di Matematica e Fisica, Università Roma Tre, Rome (Italy)

    2017-10-11

    We present the second Multi-Epoch X-ray Serendipitous AGN Sample (MEXSAS2), extracted from the 6th release of the XMM Serendipitous Source Catalog (XMMSSC-DR6), cross-matched with Sloan Digital Sky Survey quasar Catalogs DR7Q and DR12Q. Our sample also includes the available measurements for masses, bolometric luminosities, and Eddington ratios. Analyses of the ensemble structure function and spectral variability are presented, together with their dependences on such parameters. We confirm a decrease of the structure function with the X-ray luminosity, and find a weak dependence on the black hole mass. We introduce a new spectral variability estimator, taking errors on both fluxes and spectral indices into account. We confirm an ensemble softer when brighter trend, with no dependence of such estimator on black hole mass, Eddington ratio, redshift, X-ray and bolometric luminosity.

  5. The MEXSAS2 Sample and the Ensemble X-ray Variability of Quasars

    Directory of Open Access Journals (Sweden)

    Roberto Serafinelli

    2017-10-01

    Full Text Available We present the second Multi-Epoch X-ray Serendipitous AGN Sample (MEXSAS2, extracted from the 6th release of the XMM Serendipitous Source Catalog (XMMSSC-DR6, cross-matched with Sloan Digital Sky Survey quasar Catalogs DR7Q and DR12Q. Our sample also includes the available measurements for masses, bolometric luminosities, and Eddington ratios. Analyses of the ensemble structure function and spectral variability are presented, together with their dependences on such parameters. We confirm a decrease of the structure function with the X-ray luminosity, and find a weak dependence on the black hole mass. We introduce a new spectral variability estimator, taking errors on both fluxes and spectral indices into account. We confirm an ensemble softer when brighter trend, with no dependence of such estimator on black hole mass, Eddington ratio, redshift, X-ray and bolometric luminosity.

  6. [Hydrologic variability and sensitivity based on Hurst coefficient and Bartels statistic].

    Science.gov (United States)

    Lei, Xu; Xie, Ping; Wu, Zi Yi; Sang, Yan Fang; Zhao, Jiang Yan; Li, Bin Bin

    2018-04-01

    Due to the global climate change and frequent human activities in recent years, the pure stochastic components of hydrological sequence is mixed with one or several of the variation ingredients, including jump, trend, period and dependency. It is urgently needed to clarify which indices should be used to quantify the degree of their variability. In this study, we defined the hydrological variability based on Hurst coefficient and Bartels statistic, and used Monte Carlo statistical tests to test and analyze their sensitivity to different variants. When the hydrological sequence had jump or trend variation, both Hurst coefficient and Bartels statistic could reflect the variation, with the Hurst coefficient being more sensitive to weak jump or trend variation. When the sequence had period, only the Bartels statistic could detect the mutation of the sequence. When the sequence had a dependency, both the Hurst coefficient and the Bartels statistics could reflect the variation, with the latter could detect weaker dependent variations. For the four variations, both the Hurst variability and Bartels variability increased with the increases of variation range. Thus, they could be used to measure the variation intensity of the hydrological sequence. We analyzed the temperature series of different weather stations in the Lancang River basin. Results showed that the temperature of all stations showed the upward trend or jump, indicating that the entire basin had experienced warming in recent years and the temperature variability in the upper and lower reaches was much higher. This case study showed the practicability of the proposed method.

  7. Soil-structure interaction including nonlinear soil

    OpenAIRE

    Gicev, Vlado

    2008-01-01

    There are two types of models of soil-structure system depending upon the rigidity of foundation: models with rigid and models with flexible foundation. Main features of the soil-structure interaction phenomenon: -wave scattering, -radiation damping, -reduction of the system frequencies. In this presentation, the influence of interaction on the development of nonlinear zones in the soil is studied.

  8. Topology Optimization including Inequality Buoyancy Constraints

    NARCIS (Netherlands)

    Picelli, R.; Van Dijk, R.; Vicente, W.M.; Pavanello, R.; Langelaar, M.; Van Keuen, A.

    2014-01-01

    This paper presents an evolutionary topology optimization method for applications in design of completely submerged buoyant devices with design-dependent fluid pressure loading. This type of structures aid rig installations and pipeline transportation in all water depths in offshore structural

  9. Anticonvulsants for cocaine dependence.

    Science.gov (United States)

    Minozzi, Silvia; Cinquini, Michela; Amato, Laura; Davoli, Marina; Farrell, Michael F; Pani, Pier Paolo; Vecchi, Simona

    2015-04-17

    Cocaine dependence is a major public health problem that is characterised by recidivism and a host of medical and psychosocial complications. Although effective pharmacotherapy is available for alcohol and heroin dependence, none is currently available for cocaine dependence, despite two decades of clinical trials primarily involving antidepressant, anticonvulsivant and dopaminergic medications. Extensive consideration has been given to optimal pharmacological approaches to the treatment of individuals with cocaine dependence, and both dopamine antagonists and agonists have been considered. Anticonvulsants have been candidates for use in the treatment of addiction based on the hypothesis that seizure kindling-like mechanisms contribute to addiction. To evaluate the efficacy and safety of anticonvulsants for individuals with cocaine dependence. We searched the Cochrane Drugs and Alcohol Group Trials Register (June 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 6), MEDLINE (1966 to June 2014), EMBASE (1988 to June 2014), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to June 2014), Web of Science (1991 to June 2014) and the reference lists of eligible articles. All randomised controlled trials and controlled clinical trials that focus on the use of anticonvulsant medications to treat individuals with cocaine dependence. We used the standard methodological procedures expected by The Cochrane Collaboration. We included a total of 20 studies with 2068 participants. We studied the anticonvulsant drugs carbamazepine, gabapentin, lamotrigine, phenytoin, tiagabine, topiramate and vigabatrin. All studies compared anticonvulsants versus placebo. Only one study had one arm by which the anticonvulsant was compared with the antidepressant desipramine. Upon comparison of anticonvulsant versus placebo, we found no significant differences for any of the efficacy and safety measures. Dropouts: risk ratio (RR) 0.95, 95

  10. Exactly solvable position dependent mass schroedinger equation

    International Nuclear Information System (INIS)

    Koc, R.; Tuetuencueler, H.; Koercuek, E.

    2002-01-01

    Exact solution of the Schrodinger equation with a variable mass is presented. We have derived general expressions for the eigenstates and eigenvalues of the position dependent mass systems. We provide supersymmetric and Lie algebraic methods to discuss the position dependent mass systems

  11. 42 CFR 410.100 - Included services.

    Science.gov (United States)

    2010-10-01

    ... service; however, maintenance therapy itself is not covered as part of these services. (c) Occupational... increase respiratory function, such as graded activity services; these services include physiologic... rehabilitation plan of treatment, including physical therapy services, occupational therapy services, speech...

  12. Reconstructing time-dependent dynamics

    OpenAIRE

    Clemson, Philip; Lancaster, Gemma; Stefanovska, Aneta

    2016-01-01

    The usefulness of the information extracted from biomedical data relies heavily on the underlying theory of the methods used in its extraction. The assumptions of stationarity and autonomicity traditionally applied to dynamical systems break down when considering living systems, due to their inherent time-variability. Living systems are thermodynamically open, and thus constantly interacting with their environment. This results in highly nonlinear, time-dependent dynamics. The aim of signal a...

  13. Probability densities and the radon variable transformation theorem

    International Nuclear Information System (INIS)

    Ramshaw, J.D.

    1985-01-01

    D. T. Gillespie recently derived a random variable transformation theorem relating to the joint probability densities of functionally dependent sets of random variables. The present author points out that the theorem can be derived as an immediate corollary of a simpler and more fundamental relation. In this relation the probability density is represented as a delta function averaged over an unspecified distribution of unspecified internal random variables. The random variable transformation is derived from this relation

  14. Static, Lightweight Includes Resolution for PHP

    NARCIS (Netherlands)

    M.A. Hills (Mark); P. Klint (Paul); J.J. Vinju (Jurgen)

    2014-01-01

    htmlabstractDynamic languages include a number of features that are challenging to model properly in static analysis tools. In PHP, one of these features is the include expression, where an arbitrary expression provides the path of the file to include at runtime. In this paper we present two

  15. Article Including Environmental Barrier Coating System

    Science.gov (United States)

    Lee, Kang N. (Inventor)

    2015-01-01

    An enhanced environmental barrier coating for a silicon containing substrate. The enhanced barrier coating may include a bond coat doped with at least one of an alkali metal oxide and an alkali earth metal oxide. The enhanced barrier coating may include a composite mullite bond coat including BSAS and another distinct second phase oxide applied over said surface.

  16. Rare thoracic cancers, including peritoneum mesothelioma

    NARCIS (Netherlands)

    Siesling, Sabine; van der Zwan, Jan Maarten; Izarzugaza, Isabel; Jaal, Jana; Treasure, Tom; Foschi, Roberto; Ricardi, Umberto; Groen, Harry; Tavilla, Andrea; Ardanaz, Eva

    Rare thoracic cancers include those of the trachea, thymus and mesothelioma (including peritoneum mesothelioma). The aim of this study was to describe the incidence, prevalence and survival of rare thoracic tumours using a large database, which includes cancer patients diagnosed from 1978 to 2002,

  17. Rare thoracic cancers, including peritoneum mesothelioma

    NARCIS (Netherlands)

    Siesling, Sabine; Zwan, J.M.V.D.; Izarzugaza, I.; Jaal, J.; Treasure, T.; Foschi, R.; Ricardi, U.; Groen, H.; Tavilla, A.; Ardanaz, E.

    2012-01-01

    Rare thoracic cancers include those of the trachea, thymus and mesothelioma (including peritoneum mesothelioma). The aim of this study was to describe the incidence, prevalence and survival of rare thoracic tumours using a large database, which includes cancer patients diagnosed from 1978 to 2002,

  18. Oracle Efficient Variable Selection in Random and Fixed Effects Panel Data Models

    DEFF Research Database (Denmark)

    Kock, Anders Bredahl

    This paper generalizes the results for the Bridge estimator of Huang et al. (2008) to linear random and fixed effects panel data models which are allowed to grow in both dimensions. In particular we show that the Bridge estimator is oracle efficient. It can correctly distinguish between relevant...... and irrelevant variables and the asymptotic distribution of the estimators of the coefficients of the relevant variables is the same as if only these had been included in the model, i.e. as if an oracle had revealed the true model prior to estimation. In the case of more explanatory variables than observations......, we prove that the Marginal Bridge estimator can asymptotically correctly distinguish between relevant and irrelevant explanatory variables. We do this without restricting the dependence between covariates and without assuming sub Gaussianity of the error terms thereby generalizing the results...

  19. Eternity Variables to Simulate Specifications

    NARCIS (Netherlands)

    Hesselink, WH; Boiten, EA; Moller, B

    2002-01-01

    Simulation of specifications is introduced as a unification and generalization of refinement mappings, history variables, forward simulations, prophecy variables, and backward simulations. Eternity variables are introduced as a more powerful alternative for prophecy variables and backward

  20. Intraspecific chromosome variability

    Directory of Open Access Journals (Sweden)

    N Dubinin

    2010-12-01

    Full Text Available (Editorial preface. The publication is presented in order to remind us of one of dramatic pages of the history of genetics. It re-opens for the contemporary reader a comprehensive work marking the priority change from plant cytogenetics to animal cytogenetics led by wide population studies which were conducted on Drosophila polytene chromosomes. The year of the publication (1937 became the point of irretrievable branching between the directions of Old World and New World genetics connected with the problems of chromosome variability and its significance for the evolution of the species. The famous book of T. Dobzhansky (1937 was published by Columbia University in the US under the title “Genetics and the origin of species”, and in the shadow of this American ‘skybuilding’ all other works grew dim. It is remarkable that both Dobzhansky and Dubinin come to similar conclusions about the role of chromosomes in speciation. This is not surprising given that they both might be considered as representatives of the Russian genetic school, by their birth and education. Interestingly, Dobzhansky had never referred to the full paper of Dubinin et al. (1937, though a previous short communication in Nature (1936 was included together with all former papers on the related subject. In full, the volume of the original publication printed in the Biological Journal in Moscow comprised 47 pages, in that number 41 pages of the Russian text accompanied by 16 Figs, a table and reference list, and, above all, 6 pages of the English summary. This final part in English is now reproduced in the authors’ version with the only addition being the reference list in the originally printed form.

  1. Collective variables method in relativistic theory

    International Nuclear Information System (INIS)

    Shurgaya, A.V.

    1983-01-01

    Classical theory of N-component field is considered. The method of collective variables accurately accounting for conservation laws proceeding from invariance theory under homogeneous Lorentz group is developed within the frames of generalized hamiltonian dynamics. Hyperboloids are invariant surfaces Under the homogeneous Lorentz group. Proceeding from this, field transformation is introduced, and the surface is parametrized so that generators of the homogeneous Lorentz group do not include components dependent on interaction and their effect on the field function is reduced to geometrical. The interaction is completely included in the expression for the energy-momentum vector of the system which is a dynamical value. Gauge is chosen where parameters of four-dimensional translations and their canonically-conjugated pulses are non-physical and thus phase space is determined by parameters of the homogeneous Lorentz group, field function and their canonically-conjugated pulses. So it is managed to accurately account for conservation laws proceeding from the requirement of lorentz-invariance

  2. Quantifying the increasing sensitivity of power systems to climate variability

    Science.gov (United States)

    Bloomfield, H. C.; Brayshaw, D. J.; Shaffrey, L. C.; Coker, P. J.; Thornton, H. E.

    2016-12-01

    Large quantities of weather-dependent renewable energy generation are expected in power systems under climate change mitigation policies, yet little attention has been given to the impact of long term climate variability. By combining state-of-the-art multi-decadal meteorological records with a parsimonious representation of a power system, this study characterises the impact of year-to-year climate variability on multiple aspects of the power system of Great Britain (including coal, gas and nuclear generation), demonstrating why multi-decadal approaches are necessary. All aspects of the example system are impacted by inter-annual climate variability, with the impacts being most pronounced for baseload generation. The impacts of inter-annual climate variability increase in a 2025 wind-power scenario, with a 4-fold increase in the inter-annual range of operating hours for baseload such as nuclear. The impacts on peak load and peaking-plant are comparably small. Less than 10 years of power supply and demand data are shown to be insufficient for providing robust power system planning guidance. This suggests renewable integration studies—widely used in policy, investment and system design—should adopt a more robust approach to climate characterisation.

  3. State-dependent neutral delay equations from population dynamics.

    Science.gov (United States)

    Barbarossa, M V; Hadeler, K P; Kuttler, C

    2014-10-01

    A novel class of state-dependent delay equations is derived from the balance laws of age-structured population dynamics, assuming that birth rates and death rates, as functions of age, are piece-wise constant and that the length of the juvenile phase depends on the total adult population size. The resulting class of equations includes also neutral delay equations. All these equations are very different from the standard delay equations with state-dependent delay since the balance laws require non-linear correction factors. These equations can be written as systems for two variables consisting of an ordinary differential equation (ODE) and a generalized shift, a form suitable for numerical calculations. It is shown that the neutral equation (and the corresponding ODE--shift system) is a limiting case of a system of two standard delay equations.

  4. Modelling comonotonic group-life under dependent decrement causes

    OpenAIRE

    Wang, Dabuxilatu

    2011-01-01

    Comonotonicity had been a extreme case of dependency between random variables. This article consider an extension of single life model under multiple dependent decrement causes to the case of comonotonic group-life.

  5. Variable-Period Undulators for Synchrotron Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

    2005-02-22

    A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

  6. Variable-Period Undulators For Synchrotron Radiation

    Science.gov (United States)

    Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

    2005-02-22

    A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

  7. Effects of variable transformations on errors in FORM results

    International Nuclear Information System (INIS)

    Qin Quan; Lin Daojin; Mei Gang; Chen Hao

    2006-01-01

    On the basis of studies on second partial derivatives of the variable transformation functions for nine different non-normal variables the paper comprehensively discusses the effects of the transformation on FORM results and shows that senses and values of the errors in FORM results depend on distributions of the basic variables, whether resistances or actions basic variables represent, and the design point locations in the standard normal space. The transformations of the exponential or Gamma resistance variables can generate +24% errors in the FORM failure probability, and the transformation of Frechet action variables could generate -31% errors

  8. Variable Attitude Test Stand

    Data.gov (United States)

    Federal Laboratory Consortium — The Variable Attitude Test Stand designed and built for testing of the V-22 tilt rotor aircraft propulsion system, is used to evaluate the effect of aircraft flight...

  9. Variable-Rate Premiums

    Data.gov (United States)

    Pension Benefit Guaranty Corporation — These interest rates are used to value vested benefits for variable rate premium purposes as described in PBGC's regulation on Premium Rates (29 CFR Part 4006) and...

  10. Variable Pricing Feasibility Assessment

    National Research Council Canada - National Science Library

    2004-01-01

    ...) and Willard Bishop Consulting (Barrington, IL) to evaluate the practicality of using a variable pricing system within DeCA to maintain an average of 30 percent customer savings and lower appropriated fund costs...

  11. Evolution of variable stars

    International Nuclear Information System (INIS)

    Becker, S.A.

    1986-08-01

    Throughout the domain of the H R diagram lie groupings of stars whose luminosity varies with time. These variable stars can be classified based on their observed properties into distinct types such as β Cephei stars, δ Cephei stars, and Miras, as well as many other categories. The underlying mechanism for the variability is generally felt to be due to four different causes: geometric effects, rotation, eruptive processes, and pulsation. In this review the focus will be on pulsation variables and how the theory of stellar evolution can be used to explain how the various regions of variability on the H R diagram are populated. To this end a generalized discussion of the evolutionary behavior of a massive star, an intermediate mass star, and a low mass star will be presented. 19 refs., 1 fig., 1 tab

  12. Software Testing Requires Variability

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2003-01-01

    Software variability is the ability of a software system or artefact to be changed, customized or configured for use in a particular context. Variability in software systems is important from a number of perspectives. Some perspectives rightly receive much attention due to their direct economic...... impact in software production. As is also apparent from the call for papers these perspectives focus on qualities such as reuse, adaptability, and maintainability....

  13. Suspended graphene variable capacitor

    OpenAIRE

    AbdelGhany, M.; Mahvash, F.; Mukhopadhyay, M.; Favron, A.; Martel, R.; Siaj, M.; Szkopek, T.

    2016-01-01

    The tuning of electrical circuit resonance with a variable capacitor, or varactor, finds wide application with the most important being wireless telecommunication. We demonstrate an electromechanical graphene varactor, a variable capacitor wherein the capacitance is tuned by voltage controlled deflection of a dense array of suspended graphene membranes. The low flexural rigidity of graphene monolayers is exploited to achieve low actuation voltage in an ultra-thin structure. Large arrays compr...

  14. Cosmologies with a time dependent vacuum

    International Nuclear Information System (INIS)

    Sola, Joan

    2011-01-01

    The idea that the cosmological term Λ should be a time dependent quantity in cosmology is a most natural one. It is difficult to conceive an expanding universe with a strictly constant vacuum energy density, ρ Λ = Λ/(8π G), namely one that has remained immutable since the origin of time. A smoothly evolving vacuum energy density ρ Λ = ρ Λ (ξ(t)) that inherits its time-dependence from cosmological functions ξ = ξ(t), such as the Hubble rate H(t) or the scale factor a(t), is not only a qualitatively more plausible and intuitive idea, but is also suggested by fundamental physics, in particular by quantum field theory (QFT) in curved space-time. To implement this notion, is not strictly necessary to resort to ad hoc scalar fields, as usually done in the literature (e.g. in quintessence formulations and the like). A 'running' Λ term can be expected on very similar grounds as one expects (and observes) the running of couplings and masses with a physical energy scale in QFT. Furthermore, the experimental evidence that the equation of state (EOS) of the dark energy (DE) could be evolving with time/redshift (including the possibility that it might currently behave phantom-like) suggests that a time-variable Λ = Λ(t) term (possibly accompanied by a variable Newton's gravitational coupling too, G = G(t)) could account in a natural way for all these features. Remarkably enough, a class of these models (the 'new cosmon') could even be the clue for solving the old cosmological constant problem, including the coincidence problem.

  15. Evidence for a climate signal in trends of global crop yield variability over the past 50 years

    International Nuclear Information System (INIS)

    Osborne, T M; Wheeler, T R

    2013-01-01

    Low variability of crop production from year to year is desirable for many reasons, including reduced income risk and stability of supplies. Therefore, it is important to understand the nature of yield variability, whether it is changing through time, and how it varies between crops and regions. Previous studies have shown that national crop yield variability has changed in the past, with the direction and magnitude dependent on crop type and location. Whilst such studies acknowledge the importance of climate variability in determining yield variability, it has been assumed that its magnitude and its effect on crop production have not changed through time and, hence, that changes to yield variability have been due to non-climatic factors. We address this assumption by jointly examining yield and climate variability for three major crops (rice, wheat and maize) over the past 50 years. National yield time series and growing season temperature and precipitation were de-trended and related using multiple linear regression. Yield variability changed significantly in half of the crop–country combinations examined. For several crop–country combinations, changes in yield variability were related to changes in climate variability. (letter)

  16. Predictors of functional dependency after stroke in Nigeria.

    Science.gov (United States)

    Ojagbemi, Akin; Owolabi, Mayowa

    2013-11-01

    The factors impacting poststroke functional dependency have not been adequately explored in sub-Saharan Africa. This study examined the risk factors for functional dependency in a group of Nigerian African stroke survivors. One hundred twenty-eight stroke survivors attending a tertiary general hospital in southwestern Nigeria were consecutively recruited and assessed for functional dependency using the modified Rankin Scale (mRS). Stroke was diagnosed according to the World Health Organization criteria. Candidate independent variables assessed included the demographic and clinical characteristics of survivors, cognitive dysfunction, and a diagnosis of major depressive disorder. Variables with significant relationship to functional dependency were entered into a logistic regression model to identify factors that were predictive of functional dependency among the stroke survivors. In all, 60.9% of the stroke survivors were functionally dependent (mRS scores≥3), with mean±SD mRS scores of 2.71±1.01. Female sex (P=.003; odds ratio [OR] 3.08; 95% confidence interval [CI] 1.47-6.44), global cognitive dysfunction (P=.002; OR 5.04; 95% CI 1.79-14.16), and major depressive disorder (Pdependency in univariate analysis. Major depressive disorder was an independent predictor of functional dependency in multivariate analysis (P<.0001; OR 6.89; 95% CI 2.55-18.6; R2=0.19). Depression, female sex, and cognitive dysfunction were strongly associated with poorer functioning after stroke. Interventions aimed at depression and cognitive dysfunction after stroke may improve functional independence in stroke survivors. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  17. Risk assessment of groundwater level variability using variable Kriging methods

    Science.gov (United States)

    Spanoudaki, Katerina; Kampanis, Nikolaos A.

    2015-04-01

    Assessment of the water table level spatial variability in aquifers provides useful information regarding optimal groundwater management. This information becomes more important in basins where the water table level has fallen significantly. The spatial variability of the water table level in this work is estimated based on hydraulic head measured during the wet period of the hydrological year 2007-2008, in a sparsely monitored basin in Crete, Greece, which is of high socioeconomic and agricultural interest. Three Kriging-based methodologies are elaborated in Matlab environment to estimate the spatial variability of the water table level in the basin. The first methodology is based on the Ordinary Kriging approach, the second involves auxiliary information from a Digital Elevation Model in terms of Residual Kriging and the third methodology calculates the probability of the groundwater level to fall below a predefined minimum value that could cause significant problems in groundwater resources availability, by means of Indicator Kriging. The Box-Cox methodology is applied to normalize both the data and the residuals for improved prediction results. In addition, various classical variogram models are applied to determine the spatial dependence of the measurements. The Matérn model proves to be the optimal, which in combination with Kriging methodologies provides the most accurate cross validation estimations. Groundwater level and probability maps are constructed to examine the spatial variability of the groundwater level in the basin and the associated risk that certain locations exhibit regarding a predefined minimum value that has been set for the sustainability of the basin's groundwater resources. Acknowledgement The work presented in this paper has been funded by the Greek State Scholarships Foundation (IKY), Fellowships of Excellence for Postdoctoral Studies (Siemens Program), 'A simulation-optimization model for assessing the best practices for the

  18. Comparison of Maladaptive Meta Cognition Beliefs among Substance Dependents and Non-Dependents

    Directory of Open Access Journals (Sweden)

    Omid Saed

    2011-05-01

    Full Text Available Introduction: The aim of present research was the comparison of maladaptive meta cognition beliefs among substance abusers and non abusers. Methods: For this purpose 70 substance abusers and 70 individuals from the general population by purposive sampling participated in this research and responded to meta cognition questionnaire. For analysis data multiple analysis of variance (MANOVA and discriminant analysis were run. Results: MANOVA revealed that there was significant difference in linier combination of dependent variables (meta cognitive beliefs among two groups also, analysis of dependent variables lonely showed that two groups were significantly different in Positive meta cognitive beliefs, "Negative meta cognitive beliefs", "lack of cognitive confidence", "need to control of thoughts", and "cognitive self-consciousness". Also, the discriminant analysis indicated that three meta-cognitive factors included “negative meta cognitive beliefs", "need to control of thoughts" and "cognitive self-consciousness" were significant predictors to discriminate substance abusers. Conclusion: With consideration of the results it can be concluded that substance abusers have more maladaptive beliefs and these maladaptive beliefs can lead to susceptibility toward substance abuse and staying in this disorder. It is hoped that psychotherapists can be more useful in treating and staying in this research.

  19. Dependent Human Error Probability Assessment

    International Nuclear Information System (INIS)

    Simic, Z.; Mikulicic, V.; Vukovic, I.

    2006-01-01

    This paper presents an assessment of the dependence between dynamic operator actions modeled in a Nuclear Power Plant (NPP) PRA and estimate the associated impact on Core damage frequency (CDF). This assessment was done improve HEP dependencies implementation inside existing PRA. All of the dynamic operator actions modeled in the NPP PRA are included in this assessment. Determining the level of HEP dependence and the associated influence on CDF are the major steps of this assessment. A decision on how to apply the results, i.e., should permanent HEP model changes be made, is based on the resulting relative CDF increase. Some CDF increase was selected as a threshold based on the NPP base CDF value and acceptance guidelines from the Regulatory Guide 1.174. HEP dependence resulting in a CDF increase of > 5E-07 would be considered potential candidates for specific incorporation into the baseline model. The approach used to judge the level of dependence between operator actions is based on dependency level categories and conditional probabilities developed in the Handbook of Human Reliability Analysis with Emphasis on Nuclear Power Plant Applications NUREG/CR-1278. To simplify the process, NUREG/CR-1278 identifies five levels of dependence: ZD (zero dependence), LD (low dependence), MD (moderate dependence), HD (high dependence), and CD (complete dependence). NUREG/CR-1278 also identifies several qualitative factors that could be involved in determining the level of dependence. Based on the NUREG/CR-1278 information, Time, Function, and Spatial attributes were judged to be the most important considerations when determining the level of dependence between operator actions within an accident sequence. These attributes were used to develop qualitative criteria (rules) that were used to judge the level of dependence (CD, HD, MD, LD, ZD) between the operator actions. After the level of dependence between the various HEPs is judged, quantitative values associated with the

  20. Variable frequency microwave heating apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Bible, D.W.; Lauf, R.J.; Johnson, A.C.; Thigpen, L.T.

    1999-10-05

    A variable frequency microwave heating apparatus (10) designed to allow modulation of the frequency of the microwaves introduced into a multi-mode microwave cavity (34) for testing or other selected applications. The variable frequency microwave heating apparatus (10) includes a microwave signal generator (12) and a high-power microwave amplifier (20) or a high-power microwave oscillator (14). A power supply (22) is provided for operation of the high-power microwave oscillator (14) or microwave amplifier (20). A directional coupler (24) is provided for detecting the direction and amplitude of signals incident upon and reflected from the microwave cavity (34). A first power meter (30) is provided for measuring the power delivered to the microwave furnace (32). A second power meter (26) detects the magnitude of reflected power. Reflected power is dissipated in the reflected power load (28).

  1. Truck Drivers And Risk Of STDs Including HIV

    Directory of Open Access Journals (Sweden)

    Bansal R.K

    1995-01-01

    Full Text Available Research Question: Whether long distance truck drivers are at a higher risk of contracting and transmitting STDs including HIV? Objectives: i To study the degree of knowledge of HIV and AIDS among long- distance truck drivers. ii Assess their sexual behaviour including condom use. iii Explore their prevailing social influences and substance abuse patterns. iv Explore their treatment seeking bahaviour as regards STDs. v Deduce their risk of contracting and transmitting STDs including HIV. Study Design: Cross- sectional interview. Setting: Transport Nagar, Indore (M.P Participants: 210 senior drivers (First drivers and 210 junior drivers (Second drivers. Study Variables: Extra-Marital sexual intercourse, condom usage, past and present history of STDs, treatment and counseling, substance abuse, social â€" cultural milieu. Outcome Variables: Risk of contraction of STDs. Statistical Analysis: Univariate analysis. Results: 94% of the drivers were totally ignorant about AIDS. 82.9% and 43.8 % of the senior and junior drivers had a history of extra- marital sex and of these only 2 regularly used condoms. 13.8% and 3.3 % of the senior and junior drivers had a past or present history suggestive of STD infection. Alcohol and Opium were regularly used by them. Conclusion: The studied drivers are at a high risk of contracting and transmitting STDs including HIV.

  2. Medicare Program; Hospital Inpatient Prospective Payment Systems for Acute Care Hospitals and the Long-Term Care Hospital Prospective Payment System Policy Changes and Fiscal Year 2016 Rates; Revisions of Quality Reporting Requirements for Specific Providers, Including Changes Related to the Electronic Health Record Incentive Program; Extensions of the Medicare-Dependent, Small Rural Hospital Program and the Low-Volume Payment Adjustment for Hospitals. Final rule; interim final rule with comment period.

    Science.gov (United States)

    2015-08-17

    We are revising the Medicare hospital inpatient prospective payment systems (IPPS) for operating and capital related costs of acute care hospitals to implement changes arising from our continuing experience with these systems for FY 2016. Some of these changes implement certain statutory provisions contained in the Patient Protection and Affordable Care Act and the Health Care and Education Reconciliation Act of 2010 (collectively known as the Affordable Care Act), the Pathway for Sustainable Growth Reform(SGR) Act of 2013, the Protecting Access to Medicare Act of 2014, the Improving Medicare Post-Acute Care Transformation Act of 2014, the Medicare Access and CHIP Reauthorization Act of 2015, and other legislation. We also are addressing the update of the rate-of-increase limits for certain hospitals excluded from the IPPS that are paid on a reasonable cost basis subject to these limits for FY 2016.As an interim final rule with comment period, we are implementing the statutory extensions of the Medicare dependent,small rural hospital (MDH)Program and changes to the payment adjustment for low-volume hospitals under the IPPS.We also are updating the payment policies and the annual payment rates for the Medicare prospective payment system (PPS) for inpatient hospital services provided by long-term care hospitals (LTCHs) for FY 2016 and implementing certain statutory changes to the LTCH PPS under the Affordable Care Act and the Pathway for Sustainable Growth Rate (SGR) Reform Act of 2013 and the Protecting Access to Medicare Act of 2014.In addition, we are establishing new requirements or revising existing requirements for quality reporting by specific providers (acute care hospitals,PPS-exempt cancer hospitals, and LTCHs) that are participating in Medicare, including related provisions for eligible hospitals and critical access hospitals participating in the Medicare Electronic Health Record (EHR)Incentive Program. We also are updating policies relating to the

  3. MEASURING PATH DEPENDENCY

    Directory of Open Access Journals (Sweden)

    Peter Juhasz

    2017-03-01

    Full Text Available While risk management gained popularity during the last decades even some of the basic risk types are still far out of focus. One of these is path dependency that refers to the uncertainty of how we reach a certain level of total performance over time. While decision makers are careful in accessing how their position will look like the end of certain periods, little attention is given how they will get there through the period. The uncertainty of how a process will develop across a shorter period of time is often “eliminated” by simply choosing a longer planning time interval, what makes path dependency is one of the most often overlooked business risk types. After reviewing the origin of the problem we propose and compare seven risk measures to access path. Traditional risk measures like standard deviation of sub period cash flows fail to capture this risk type. We conclude that in most cases considering the distribution of the expected cash flow effect caused by the path dependency may offer the best method, but we may need to use several measures at the same time to include all the optimisation limits of the given firm

  4. Spatial and temporal variability in urban fine particulate matter concentrations

    International Nuclear Information System (INIS)

    Levy, Jonathan I.; Hanna, Steven R.

    2011-01-01

    Identification of hot spots for urban fine particulate matter (PM 2.5 ) concentrations is complicated by the significant contributions from regional atmospheric transport and the dependence of spatial and temporal variability on averaging time. We focus on PM 2.5 patterns in New York City, which includes significant local sources, street canyons, and upwind contributions to concentrations. A literature synthesis demonstrates that long-term (e.g., one-year) average PM 2.5 concentrations at a small number of widely-distributed monitoring sites would not show substantial variability, whereas short-term (e.g., 1-h) average measurements with high spatial density would show significant variability. Statistical analyses of ambient monitoring data as a function of wind speed and direction reinforce the significance of regional transport but show evidence of local contributions. We conclude that current monitor siting may not adequately capture PM 2.5 variability in an urban area, especially in a mega-city, reinforcing the necessity of dispersion modeling and methods for analyzing high-resolution monitoring observations. - Highlights: →Fine particulate matter (PM 2.5 ) hot spots are hard to identify in urban areas. → Literature conclusions about PM 2.5 hot spots depend on study design and methods. → Hot spots are more likely for short-term concentrations at high spatial density. → Statistical methods illustrate local source impacts beyond regional transport. → Dispersion models and high-resolution monitors are both needed to find hot spots. - Fine particulate matter can vary spatially within large urban areas, in spite of the significant contribution from regional atmospheric transport.

  5. Pulsating red variables

    International Nuclear Information System (INIS)

    Whitelock, P.A.

    1990-01-01

    The observational characteristics of pulsating red variables are reviewed with particular emphasis on the Miras. These variables represent the last stage in the evolution of stars on the Asymptotic Giant Branch (AGB). A large fraction of the IRAS sources in the Bulge are Mira variables and a subset of these are also OH/IR sources. Their periods range up to 720 days, though most are between 360 and 560 days. At a given period those stars with the highest pulsation amplitudes have the highest mass-loss rates; this is interpreted as evidence for a causal connection between mass-loss and pulsation. It is suggested that once an AGB star has become a Mira it will evolve with increasing pulsation amplitude and mass-loss, but with very little change of luminosity or logarithmic period. 26 refs

  6. Variable stator radial turbine

    Science.gov (United States)

    Rogo, C.; Hajek, T.; Chen, A. G.

    1984-01-01

    A radial turbine stage with a variable area nozzle was investigated. A high work capacity turbine design with a known high performance base was modified to accept a fixed vane stagger angle moveable sidewall nozzle. The nozzle area was varied by moving the forward and rearward sidewalls. Diffusing and accelerating rotor inlet ramps were evaluated in combinations with hub and shroud rotor exit rings. Performance of contoured sidewalls and the location of the sidewall split line with respect to the rotor inlet was compared to the baseline. Performance and rotor exit survey data are presented for 31 different geometries. Detail survey data at the nozzle exit are given in contour plot format for five configurations. A data base is provided for a variable geometry concept that is a viable alternative to the more common pivoted vane variable geometry radial turbine.

  7. Inter-dependence not Over-dependence: Reducing Urban Transport Energy Dependence

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, Michael James; Rodrigues da Silva, Antonio Nelson

    2007-07-01

    A major issue of concern in today's world is urban transport energy dependence and energy supply security. In an energy inter-dependent world, energy over-dependence brings risks to urban transport systems. Many urban areas are over-dependent on finite petroleum resources for transport. New technology and the development and integration of renewable resources into transport energy systems may reduce some of the current transport energy dependence of urban areas. However, the most effective means of reducing energy dependence is to first design urban areas for this condition. An urban policy framework is proposed that requires transport energy dependence to be measured and controlled in the urban development process. A new tool has been created for this purpose, the Transport Energy Specification (TES), which measures transport energy dependence of urban areas. This creates the possibility for cities to regulate urban development with respect to energy dependence. Trial assessments were performed in Germany, New Zealand and Brazil; initial analysis by transport and government professionals shows promise of this tool being included into urban policy. The TES combined with a regulatory framework has the potential to significantly reduce transport energy consumption and dependence in urban areas in the future. (auth)

  8. Births and deaths including fetal deaths

    Data.gov (United States)

    U.S. Department of Health & Human Services — Access to a variety of United States birth and death files including fetal deaths: Birth Files, 1968-2009; 1995-2005; Fetal death file, 1982-2005; Mortality files,...

  9. Including Indigenous Minorities in Decision-Making

    DEFF Research Database (Denmark)

    Pristed Nielsen, Helene

    Based on theories of public sphere participation and deliberative democracy, this book presents empirical results from a study of experiences with including Aboriginal and Maori groups in political decision-making in respectively Western Australia and New Zealand......Based on theories of public sphere participation and deliberative democracy, this book presents empirical results from a study of experiences with including Aboriginal and Maori groups in political decision-making in respectively Western Australia and New Zealand...

  10. Gas storage materials, including hydrogen storage materials

    Science.gov (United States)

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2013-02-19

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

  11. Resiliencia y variables sociodemograficas

    OpenAIRE

    Calero Martinez, Edgar David

    2015-01-01

    En el presente trabajo se aborda la definición de una de las variables dentro de lo que se denomina Capital psicológico positivo, la Resiliencia, sus principales características y algunas de las variables socio demográficas que en el estudio pretenden ver el nivel de relación existente entre cada una de ellas (indirecta o directamente) en el proceso resiliente de una persona para posteriores discusiones y su implicación dentro de la gestión empresarial y sus direcciones futuras.

  12. Winds in cataclysmic variable stars

    International Nuclear Information System (INIS)

    Cordova, F.A.; Ladd, E.F.; Mason, K.O.

    1984-01-01

    Ultraviolet spectrophotometry of two dwarf novae, CN Ori and RX And, at various phases of their outburst cycles confirms that the far uv flux increases dramatically about 1-2 days after the optical outburst begins. At this time the uv spectral line profiles indicate the presence of a high velocity wind. The detectability of the wind depends more on the steepness of the spectrum, and thus on the flux in the extreme ultraviolet, than on the absolute value of the far uv luminosity. The uv continuum during outburst consists of (at least) two components, the most luminous of which is located behind the wind and is completely absorbed by the wind at the line frequencies. Several pieces of evidence suggest that the uv emission lines that are observed in many cataclysmic variables during quiescence have a different location in the binary than the wind, and are affected very little by the outburst

  13. A surplus production model including environmental effects: Application to the Senegalese white shrimp stocks

    Science.gov (United States)

    Thiaw, Modou; Gascuel, Didier; Jouffre, Didier; Thiaw, Omar Thiom

    2009-12-01

    In Senegal, two stocks of white shrimp ( Penaeusnotialis) are intensively exploited, one in the north and another in the south. We used surplus production models including environmental effects to analyse their changes in abundance over the past 10 years and to estimate their Maximum Sustainable Yield (MSY) and the related fishing effort ( EMSY). First, yearly abundance indices were estimated from commercial statistics using GLM techniques. Then, two environmental indices were alternatively tested in the model: the coastal upwelling intensity from wind speeds provided by the SeaWifs database and the primary production derived from satellite infrared images of chlorophyll a. Models were fitted, with or without the environmental effect, to the 1996-2005 time series. They express stock abundance and catches as functions of the fishing effort and the environmental index (when considered). For the northern stock, fishing effort and abundance fluctuate over the period without any clear trends. The model based on the upwelling index explains 64.9% of the year-to-year variability. It shows that the stock was slightly overexploited in 2002-2003 and is now close to full exploitation. Stock abundance strongly depends on environmental conditions; consequently, the MSY estimate varies from 300 to 900 tons according to the upwelling intensity. For the southern stock, fishing effort has strongly increased over the past 10 years, while abundance has been reduced 4-fold. The environment has a significant effect on abundance but only explains a small part of the year-to-year variability. The best fit is obtained using the primary production index ( R2 = 0.75), and the stock is now significantly overfished regardless of environmental conditions. MSY varies from 1200 to 1800 tons according to environmental conditions. Finally, in northern Senegal, the upwelling is highly variable from year to year and constitutes the major factor determining productivity. In the south, hydrodynamic

  14. Contextuality is about identity of random variables

    International Nuclear Information System (INIS)

    Dzhafarov, Ehtibar N; Kujala, Janne V

    2014-01-01

    Contextual situations are those in which seemingly ‘the same’ random variable changes its identity depending on the conditions under which it is recorded. Such a change of identity is observed whenever the assumption that the variable is one and the same under different conditions leads to contradictions when one considers its joint distribution with other random variables (this is the essence of all Bell-type theorems). In our Contextuality-by-Default approach, instead of asking why or how the conditions force ‘one and the same’ random variable to change ‘its’ identity, any two random variables recorded under different conditions are considered different ‘automatically.’ They are never the same, nor are they jointly distributed, but one can always impose on them a joint distribution (probabilistic coupling). The special situations when there is a coupling in which these random variables are equal with probability 1 are considered noncontextual. Contextuality means that such couplings do not exist. We argue that the determination of the identity of random variables by conditions under which they are recorded is not a causal relationship and cannot violate laws of physics. (paper)

  15. Time dependent emission line profiles in the radially streaming particle model of Seyfert galaxy nuclei and quasi-stellar objects

    Science.gov (United States)

    Hubbard, R.

    1974-01-01

    The radially-streaming particle model for broad quasar and Seyfert galaxy emission features is modified to include sources of time dependence. The results are suggestive of reported observations of multiple components, variability, and transient features in the wings of Seyfert and quasi-stellar emission lines.

  16. Aggregated Demand Modelling Including Distributed Generation, Storage and Demand Response

    OpenAIRE

    Marzooghi, Hesamoddin; Hill, David J.; Verbic, Gregor

    2014-01-01

    It is anticipated that penetration of renewable energy sources (RESs) in power systems will increase further in the next decades mainly due to environmental issues. In the long term of several decades, which we refer to in terms of the future grid (FG), balancing between supply and demand will become dependent on demand actions including demand response (DR) and energy storage. So far, FG feasibility studies have not considered these new demand-side developments for modelling future demand. I...

  17. PaCAL: A Python Package for Arithmetic Computations with Random Variables

    Directory of Open Access Journals (Sweden)

    Marcin Korze?

    2014-05-01

    Full Text Available In this paper we present PaCAL, a Python package for arithmetical computations on random variables. The package is capable of performing the four arithmetic operations: addition, subtraction, multiplication and division, as well as computing many standard functions of random variables. Summary statistics, random number generation, plots, and histograms of the resulting distributions can easily be obtained and distribution parameter ?tting is also available. The operations are performed numerically and their results interpolated allowing for arbitrary arithmetic operations on random variables following practically any probability distribution encountered in practice. The package is easy to use, as operations on random variables are performed just as they are on standard Python variables. Independence of random variables is, by default, assumed on each step but some computations on dependent random variables are also possible. We demonstrate on several examples that the results are very accurate, often close to machine precision. Practical applications include statistics, physical measurements or estimation of error distributions in scienti?c computations.

  18. A stochastic Galerkin method for the Euler equations with Roe variable transformation

    KAUST Repository

    Pettersson, Per; Iaccarino, Gianluca; Nordströ m, Jan

    2014-01-01

    The Euler equations subject to uncertainty in the initial and boundary conditions are investigated via the stochastic Galerkin approach. We present a new fully intrusive method based on a variable transformation of the continuous equations. Roe variables are employed to get quadratic dependence in the flux function and a well-defined Roe average matrix that can be determined without matrix inversion.In previous formulations based on generalized polynomial chaos expansion of the physical variables, the need to introduce stochastic expansions of inverse quantities, or square roots of stochastic quantities of interest, adds to the number of possible different ways to approximate the original stochastic problem. We present a method where the square roots occur in the choice of variables, resulting in an unambiguous problem formulation.The Roe formulation saves computational cost compared to the formulation based on expansion of conservative variables. Moreover, the Roe formulation is more robust and can handle cases of supersonic flow, for which the conservative variable formulation fails to produce a bounded solution. For certain stochastic basis functions, the proposed method can be made more effective and well-conditioned. This leads to increased robustness for both choices of variables. We use a multi-wavelet basis that can be chosen to include a large number of resolution levels to handle more extreme cases (e.g. strong discontinuities) in a robust way. For smooth cases, the order of the polynomial representation can be increased for increased accuracy. © 2013 Elsevier Inc.

  19. Fire-regime variability impacts forest carbon dynamics for centuries to millennia

    Science.gov (United States)

    Hudiburg, Tara W.; Higuera, Philip E.; Hicke, Jeffrey A.

    2017-08-01

    Wildfire is a dominant disturbance agent in forest ecosystems, shaping important biogeochemical processes including net carbon (C) balance. Long-term monitoring and chronosequence studies highlight a resilience of biogeochemical properties to large, stand-replacing, high-severity fire events. In contrast, the consequences of repeated fires or temporal variability in a fire regime (e.g., the characteristic timing or severity of fire) are largely unknown, yet theory suggests that such variability could strongly influence forest C trajectories (i.e., future states or directions) for millennia. Here we combine a 4500-year paleoecological record of fire activity with ecosystem modeling to investigate how fire-regime variability impacts soil C and net ecosystem carbon balance. We found that C trajectories in a paleo-informed scenario differed significantly from an equilibrium scenario (with a constant fire return interval), largely due to variability in the timing and severity of past fires. Paleo-informed scenarios contained multi-century periods of positive and negative net ecosystem C balance, with magnitudes significantly larger than observed under the equilibrium scenario. Further, this variability created legacies in soil C trajectories that lasted for millennia. Our results imply that fire-regime variability is a major driver of C trajectories in stand-replacing fire regimes. Predicting carbon balance in these systems, therefore, will depend strongly on the ability of ecosystem models to represent a realistic range of fire-regime variability over the past several centuries to millennia.

  20. Modeling of carbon sequestration in coal-beds: A variable saturated simulation

    International Nuclear Information System (INIS)

    Liu Guoxiang; Smirnov, Andrei V.

    2008-01-01

    Storage of carbon dioxide in deep coal seams is a profitable method to reduce the concentration of green house gases in the atmosphere while the methane as a byproduct can be extracted during carbon dioxide injection into the coal seam. In this procedure, the key element is to keep carbon dioxide in the coal seam without escaping for a long term. It is depended on many factors such as properties of coal basin, fracture state, phase equilibrium, etc., especially the porosity, permeability and saturation of the coal seam. In this paper, a variable saturation model was developed to predict the capacity of carbon dioxide sequestration and coal-bed methane recovery. This variable saturation model can be used to track the saturation variability with the partial pressures change caused by carbon dioxide injection. Saturation variability is a key factor to predict the capacity of carbon dioxide storage and methane recovery. Based on this variable saturation model, a set of related variables including capillary pressure, relative permeability, porosity, coupled adsorption model, concentration and temperature equations were solved. From results of the simulation, historical data agree with the variable saturation model as well as the adsorption model constructed by Langmuir equations. The Appalachian basin, as an example, modeled the carbon dioxide sequestration in this paper. The results of the study and the developed models can provide the projections for the CO 2 sequestration and methane recovery in coal-beds within different regional specifics

  1. Heat Diffusion in Gases, Including Effects of Chemical Reaction

    Science.gov (United States)

    Hansen, C. Frederick

    1960-01-01

    The diffusion of heat through gases is treated where the coefficients of thermal conductivity and diffusivity are functions of temperature. The diffusivity is taken proportional to the integral of thermal conductivity, where the gas is ideal, and is considered constant over the temperature interval in which a chemical reaction occurs. The heat diffusion equation is then solved numerically for a semi-infinite gas medium with constant initial and boundary conditions. These solutions are in a dimensionless form applicable to gases in general, and they are used, along with measured shock velocity and heat flux through a shock reflecting surface, to evaluate the integral of thermal conductivity for air up to 5000 degrees Kelvin. This integral has the properties of a heat flux potential and replaces temperature as the dependent variable for problems of heat diffusion in media with variable coefficients. Examples are given in which the heat flux at the stagnation region of blunt hypersonic bodies is expressed in terms of this potential.

  2. Graphical models for inference under outcome-dependent sampling

    DEFF Research Database (Denmark)

    Didelez, V; Kreiner, S; Keiding, N

    2010-01-01

    a node for the sampling indicator, assumptions about sampling processes can be made explicit. We demonstrate how to read off such graphs whether consistent estimation of the association between exposure and outcome is possible. Moreover, we give sufficient graphical conditions for testing and estimating......We consider situations where data have been collected such that the sampling depends on the outcome of interest and possibly further covariates, as for instance in case-control studies. Graphical models represent assumptions about the conditional independencies among the variables. By including...

  3. INTER-EXAMINER VARIABILITY

    African Journals Online (AJOL)

    Objective: To establish whether inter-examiner variability is still a significant factor for the undergraduate orthopaedic clinical ... D. The scores for each student were tabulated and the range, mean, and pass rate determined for each of the examiners. ... has not the heart to reject the man”, consistently gave higher scores (1).

  4. Variability in GPS sources

    NARCIS (Netherlands)

    Jauncey, DL; King, EA; Bignall, HE; Lovell, JEJ; Kedziora-Chudczer, L; Tzioumis, AK; Tingay, SJ; Macquart, JP; McCulloch, PM

    2003-01-01

    Flux density monitoring data at 2.3 and 8.4 GHz is presented for a sample of 33 southern hemisphere GPS sources, drawn from the 2.7 GHz Parkes survey. This monitoring data, together with VLBI monitoring data, shows that a small fraction of these sources, similar to10%, vary. Their variability falls

  5. All Those Independent Variables.

    Science.gov (United States)

    Meacham, Merle L.

    This paper presents a case study of a sixth grade remedial math class which illustrates the thesis that only the "experimental attitude," not the "experimental method," is appropriate in the classroom. The thesis is based on the fact that too many independent variables exist in a classroom situation to allow precise measurement. The case study…

  6. Variable speed generators

    CERN Document Server

    Boldea, Ion

    2005-01-01

    With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc

  7. Visual hydrogen detector with variable reversibility

    Science.gov (United States)

    Muradov, Nazim (Inventor)

    2011-01-01

    Methods, processes and compositions are provided for a visual or chemochromic hydrogen-detector with variable or tunable reversible color change. The working temperature range for the hydrogen detector is from minus 100.degree. C. to plus 500.degree. C. A hydrogen-sensitive pigment, including, but not limited to, oxides, hydroxides and polyoxo-compounds of tungsten, molybdenum, vanadium, chromium and combinations thereof, is combined with nano-sized metal activator particles and preferably, coated on a porous or woven substrate. In the presence of hydrogen, the composition rapidly changes its color from white or light-gray or light-tan to dark gray, navy-blue or black depending on the exposure time and hydrogen concentration in the medium. After hydrogen exposure ceases, the original color of the hydrogen-sensitive pigment is restored, and the visual hydrogen detector can be used repeatedly. By changing the composition of the hydrogen-sensitive pigment, the time required for its complete regeneration is varied from a few seconds to several days.

  8. Visual hydrogen detector with variable reversibilty

    Science.gov (United States)

    Muradov, Nazim Z. (Inventor)

    2012-01-01

    Methods, processes and compositions are provided for a visual or chemochromic hydrogen-detector with variable or tunable reversible color change. The working temperature range for the hydrogen detector is from minus 100.degree. C. to plus 500.degree. C. A hydrogen-sensitive pigment, including, but not limited to, oxides, hydroxides and polyoxo-compounds of tungsten, molybdenum, vanadium, chromium and combinations thereof, is combined with nano-sized metal activator particles and preferably, coated on a porous or woven substrate. In the presence of hydrogen, the composition rapidly changes its color from white or light-gray or light-tan to dark gray, navy-blue or black depending on the exposure time and hydrogen concentration in the medium. After hydrogen exposure ceases, the original color of the hydrogen-sensitive pigment is restored, and the visual hydrogen detector can be used repeatedly. By changing the composition of the hydrogen-sensitive pigment, the time required for its complete regeneration is varied from a few seconds to several days.

  9. Electric Power Monthly, August 1990. [Glossary included

    Energy Technology Data Exchange (ETDEWEB)

    1990-11-29

    The Electric Power Monthly (EPM) presents monthly summaries of electric utility statistics at the national, Census division, and State level. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead. Data includes generation by energy source (coal, oil, gas, hydroelectric, and nuclear); generation by region; consumption of fossil fuels for power generation; sales of electric power, cost data; and unusual occurrences. A glossary is included.

  10. Electrochemical cell structure including an ionomeric barrier

    Science.gov (United States)

    Lambert, Timothy N.; Hibbs, Michael

    2017-06-20

    An apparatus includes an electrochemical half-cell comprising: an electrolyte, an anode; and an ionomeric barrier positioned between the electrolyte and the anode. The anode may comprise a multi-electron vanadium phosphorous alloy, such as VP.sub.x, wherein x is 1-5. The electrochemical half-cell is configured to oxidize the vanadium and phosphorous alloy to release electrons. A method of mitigating corrosion in an electrochemical cell includes disposing an ionomeric barrier in a path of electrolyte or ion flow to an anode and mitigating anion accumulation on the surface of the anode.

  11. Isolators Including Main Spring Linear Guide Systems

    Science.gov (United States)

    Goold, Ryan (Inventor); Buchele, Paul (Inventor); Hindle, Timothy (Inventor); Ruebsamen, Dale Thomas (Inventor)

    2017-01-01

    Embodiments of isolators, such as three parameter isolators, including a main spring linear guide system are provided. In one embodiment, the isolator includes first and second opposing end portions, a main spring mechanically coupled between the first and second end portions, and a linear guide system extending from the first end portion, across the main spring, and toward the second end portion. The linear guide system expands and contracts in conjunction with deflection of the main spring along the working axis, while restricting displacement and rotation of the main spring along first and second axes orthogonal to the working axis.

  12. Tides and Decadal Variability

    Science.gov (United States)

    Ray, Richard D.

    2003-01-01

    This paper reviews the mechanisms by which oceanic tides and decadal variability in the oceans are connected. We distinguish between variability caused by tides and variability observed in the tides themselves. Both effects have been detected at some level. The most obvious connection with decadal timescales is through the 18.6-year precession of the moon's orbit plane. This precession gives rise to a small tide of the same period and to 18.6-year modulations in the phase and amplitudes of short-period tides. The 18.6-year "node tide" is very small, no more than 2 cm anywhere, and in sea level data it is dominated by the ocean's natural Variability. Some authors have naively attributed climate variations with periods near 19 years directly to the node tide, but the amplitude of the tide is too small for this mechanism to be operative. The more likely explanation (Loder and Garrett, JGR, 83, 1967-70, 1978) is that the 18.6-y modulations in short-period tides, especially h e principal tide M2, cause variations in ocean mixing, which is then observed in temperature and other climatic indicators. Tidally forced variability has also been proposed by some authors, either in response to occasional (and highly predictable) tidal extremes or as a nonlinear low-frequency oscillation caused by interactions between short-period tides. The former mechanism can produce only short-duration events hardly more significant than normal tidal ranges, but the latter mechanism can in principle induce low-frequency oscillations. The most recent proposal of this type is by Keeling and Whorf, who highlight the 1800-year spectral peak discovered by Bond et al. (1997). But the proposal appears contrived and should be considered, in the words of Munk et al. (2002), "as the most likely among unlikely candidates."

  13. Dynamics of Variable Mass Systems

    Science.gov (United States)

    Eke, Fidelis O.

    1998-01-01

    This report presents the results of an investigation of the effects of mass loss on the attitude behavior of spinning bodies in flight. The principal goal is to determine whether there are circumstances under which the motion of variable mass systems can become unstable in the sense that their transverse angular velocities become unbounded. Obviously, results from a study of this kind would find immediate application in the aerospace field. The first part of this study features a complete and mathematically rigorous derivation of a set of equations that govern both the translational and rotational motions of general variable mass systems. The remainder of the study is then devoted to the application of the equations obtained to a systematic investigation of the effect of various mass loss scenarios on the dynamics of increasingly complex models of variable mass systems. It is found that mass loss can have a major impact on the dynamics of mechanical systems, including a possible change in the systems stability picture. Factors such as nozzle geometry, combustion chamber geometry, propellant's initial shape, size and relative mass, and propellant location can all have important influences on the system's dynamic behavior. The relative importance of these parameters on-system motion are quantified in a way that is useful for design purposes.

  14. Asymptotics of Multivariate Regression with Consecutively Added Dependent Varibles

    NARCIS (Netherlands)

    Raats, V.M.; van der Genugten, B.B.; Moors, J.J.A.

    2004-01-01

    We consider multivariate regression where new dependent variables are consecutively added during the experiment (or in time).So, viewed at the end of the experiment, the number of observations decreases with each added variable. The explanatory variables are observed throughout.In a previous paper

  15. THE CHANDRA VARIABLE GUIDE STAR CATALOG

    International Nuclear Information System (INIS)

    Nichols, Joy S.; Lauer, Jennifer L.; Morgan, Douglas L.; Sundheim, Beth A.; Henden, Arne A.; Huenemoerder, David P.; Martin, Eric

    2010-01-01

    Variable stars have been identified among the optical-wavelength light curves of guide stars used for pointing control of the Chandra X-ray Observatory. We present a catalog of these variable stars along with their light curves and ancillary data. Variability was detected to a lower limit of 0.02 mag amplitude in the 4000-10000 A range using the photometrically stable Aspect Camera on board the Chandra spacecraft. The Chandra Variable Guide Star Catalog (VGUIDE) contains 827 stars, of which 586 are classified as definitely variable and 241 are identified as possibly variable. Of the 586 definite variable stars, we believe 319 are new variable star identifications. Types of variables in the catalog include eclipsing binaries, pulsating stars, and rotating stars. The variability was detected during the course of normal verification of each Chandra pointing and results from analysis of over 75,000 guide star light curves from the Chandra mission. The VGUIDE catalog represents data from only about 9 years of the Chandra mission. Future releases of VGUIDE will include newly identified variable guide stars as the mission proceeds. An important advantage of the use of space data to identify and analyze variable stars is the relatively long observations that are available. The Chandra orbit allows for observations up to 2 days in length. Also, guide stars were often used multiple times for Chandra observations, so many of the stars in the VGUIDE catalog have multiple light curves available from various times in the mission. The catalog is presented as both online data associated with this paper and as a public Web interface. Light curves with data at the instrumental time resolution of about 2 s, overplotted with the data binned at 1 ks, can be viewed on the public Web interface and downloaded for further analysis. VGUIDE is a unique project using data collected during the mission that would otherwise be ignored. The stars available for use as Chandra guide stars are

  16. 28 CFR 20.32 - Includable offenses.

    Science.gov (United States)

    2010-07-01

    ... Exchange of Criminal History Record Information § 20.32 Includable offenses. (a) Criminal history record... vehicular manslaughter, driving under the influence of drugs or liquor, and hit and run), when unaccompanied by a § 20.32(a) offense. These exclusions may not be applicable to criminal history records...

  17. Including Students with Visual Impairments: Softball

    Science.gov (United States)

    Brian, Ali; Haegele, Justin A.

    2014-01-01

    Research has shown that while students with visual impairments are likely to be included in general physical education programs, they may not be as active as their typically developing peers. This article provides ideas for equipment modifications and game-like progressions for one popular physical education unit, softball. The purpose of these…

  18. Extending flood damage assessment methodology to include ...

    African Journals Online (AJOL)

    Optimal and sustainable flood plain management, including flood control, can only be achieved when the impacts of flood control measures are considered for both the man-made and natural environments, and the sociological aspects are fully considered. Until now, methods/models developed to determine the influences ...

  19. BIOLOGIC AND ECONOMIC EFFECTS OF INCLUDING DIFFERENT ...

    African Journals Online (AJOL)

    The biologic and economic effects of including three agro-industrial by-products as ingredients in turkey poult diets were investigated using 48 turkey poults in a completely randomised design experiment. Diets were formulated to contain the three by-products – wheat offal, rice husk and palm kernel meal, each at 20% level ...

  20. An assessment of the impact of demographic, cognitive, and non-cognitive variables on student success in a community college science course

    Science.gov (United States)

    Mackey, Audrey Leroy

    The impact of demographic, cognitive, and non-cognitive variables on academic success among community college science students was studied. Demographic variables included gender, employment status, and ethnicity. Cognitive variables included college grade point average, assessment status, course prerequisites, college course success ratios, final course grade, withdrawal patterns, and curriculum format. Non-cognitive variables included enrollment status, educational objectives, academic expectations, and career goals. The sample population included students enrolled in human anatomy courses (N = 191) at a large metropolitan community college located in central Texas. Variables that potentially influence attrition and achievement in college level science courses were examined. Final course grade and withdrawal phenomena were treated as dependent variables, while all other variables were treated as independent variables. No significant differences were found to exist between any of the demographic variables studied and the numbers of students who withdrew passing or failing. A difference was shown to be associated with the ethnicity variable and achievement levels. Educational objectives and career goals were shown to have an impact on the number of students who withdrew failing. The career goals variable and the academic expectations variable were shown to have an impact on achievement among daytime and evening students. College grade point average and course success ratios were shown to make a difference among students who withdrew passing. None of the other cognitive variables studied were shown to influence the numbers of students who withdrew passing or failing. College grade point average and course prerequisites, however, were shown to make a difference in achievement. The collaborative learning instructional format was found to have no impact on attrition or achievement, however, mean scores earned by students experiencing the collaborative learning format

  1. Transition Achievement among Young Adults with Deafness: What Variables Relate to Success?

    Science.gov (United States)

    Bullis, Michael; And Others

    1995-01-01

    Examines the transition achievement of deaf persons 3 or 4 years out of high school (n=308). Ten independent variables were used to predict 2 dichotomous dependent variables: engagement with community (56%), and residential status (52% living independently). Results are presented for each dependent variable. (JPS)

  2. Additive measures of travel time variability

    DEFF Research Database (Denmark)

    Engelson, Leonid; Fosgerau, Mogens

    2011-01-01

    This paper derives a measure of travel time variability for travellers equipped with scheduling preferences defined in terms of time-varying utility rates, and who choose departure time optimally. The corresponding value of travel time variability is a constant that depends only on preference...... parameters. The measure is unique in being additive with respect to independent parts of a trip. It has the variance of travel time as a special case. Extension is provided to the case of travellers who use a scheduled service with fixed headway....

  3. The WFCAM multiwavelength Variable Star Catalog

    Science.gov (United States)

    Ferreira Lopes, C. E.; Dékány, I.; Catelan, M.; Cross, N. J. G.; Angeloni, R.; Leão, I. C.; De Medeiros, J. R.

    2015-01-01

    Context. Stellar variability in the near-infrared (NIR) remains largely unexplored. The exploitation of public science archives with data-mining methods offers a perspective for a time-domain exploration of the NIR sky. Aims: We perform a comprehensive search for stellar variability using the optical-NIR multiband photometric data in the public Calibration Database of the WFCAM Science Archive (WSA), with the aim of contributing to the general census of variable stars and of extending the current scarce inventory of accurate NIR light curves for a number of variable star classes. Methods: Standard data-mining methods were applied to extract and fine-tune time-series data from the WSA. We introduced new variability indices designed for multiband data with correlated sampling, and applied them for preselecting variable star candidates, i.e., light curves that are dominated by correlated variations, from noise-dominated ones. Preselection criteria were established by robust numerical tests for evaluating the response of variability indices to the colored noise characteristic of the data. We performed a period search using the string-length minimization method on an initial catalog of 6551 variable star candidates preselected by variability indices. Further frequency analysis was performed on positive candidates using three additional methods in combination, in order to cope with aliasing. Results: We find 275 periodic variable stars and an additional 44 objects with suspected variability with uncertain periods or apparently aperiodic variation. Only 44 of these objects had been previously known, including 11 RR Lyrae stars on the outskirts of the globular cluster M 3 (NGC 5272). We provide a preliminary classification of the new variable stars that have well-measured light curves, but the variability types of a large number of objects remain ambiguous. We classify most of the new variables as contact binary stars, but we also find several pulsating stars, among which

  4. Photoactive devices including porphyrinoids with coordinating additives

    Science.gov (United States)

    Forrest, Stephen R; Zimmerman, Jeramy; Yu, Eric K; Thompson, Mark E; Trinh, Cong; Whited, Matthew; Diev, Vlacheslav

    2015-05-12

    Coordinating additives are included in porphyrinoid-based materials to promote intermolecular organization and improve one or more photoelectric characteristics of the materials. The coordinating additives are selected from fullerene compounds and organic compounds having free electron pairs. Combinations of different coordinating additives can be used to tailor the characteristic properties of such porphyrinoid-based materials, including porphyrin oligomers. Bidentate ligands are one type of coordinating additive that can form coordination bonds with a central metal ion of two different porphyrinoid compounds to promote porphyrinoid alignment and/or pi-stacking. The coordinating additives can shift the absorption spectrum of a photoactive material toward higher wavelengths, increase the external quantum efficiency of the material, or both.

  5. Electric power monthly, September 1990. [Glossary included

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-17

    The purpose of this report is to provide energy decision makers with accurate and timely information that may be used in forming various perspectives on electric issues. The power plants considered include coal, petroleum, natural gas, hydroelectric, and nuclear power plants. Data are presented for power generation, fuel consumption, fuel receipts and cost, sales of electricity, and unusual occurrences at power plants. Data are compared at the national, Census division, and state levels. 4 figs., 52 tabs. (CK)

  6. Nuclear reactor shield including magnesium oxide

    International Nuclear Information System (INIS)

    Rouse, C.A.; Simnad, M.T.

    1981-01-01

    An improvement is described for nuclear reactor shielding of a type used in reactor applications involving significant amounts of fast neutron flux. The reactor shielding includes means providing structural support, neutron moderator material, neutron absorber material and other components, wherein at least a portion of the neutron moderator material is magnesium in the form of magnesium oxide either alone or in combination with other moderator materials such as graphite and iron

  7. Model for safety reports including descriptive examples

    International Nuclear Information System (INIS)

    1995-12-01

    Several safety reports will be produced in the process of planning and constructing the system for disposal of high-level radioactive waste in Sweden. The present report gives a model, with detailed examples, of how these reports should be organized and what steps they should include. In the near future safety reports will deal with the encapsulation plant and the repository. Later reports will treat operation of the handling systems and the repository

  8. Jet-calculus approach including coherence effects

    International Nuclear Information System (INIS)

    Jones, L.M.; Migneron, R.; Narayanan, K.S.S.

    1987-01-01

    We show how integrodifferential equations typical of jet calculus can be combined with an averaging procedure to obtain jet-calculus-based results including the Mueller interference graphs. Results in longitudinal-momentum fraction x for physical quantities are higher at intermediate x and lower at large x than with the conventional ''incoherent'' jet calculus. These results resemble those of Marchesini and Webber, who used a Monte Carlo approach based on the same dynamics

  9. Variable Permanent Magnet Quadrupole

    International Nuclear Information System (INIS)

    Mihara, T.; Iwashita, Y.; Kyoto U.; Kumada, M.; NIRS, Chiba; Spencer, C.M.; SLAC

    2007-01-01

    A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments

  10. On Complex Random Variables

    Directory of Open Access Journals (Sweden)

    Anwer Khurshid

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In this paper, it is shown that a complex multivariate random variable  is a complex multivariate normal random variable of dimensionality if and only if all nondegenerate complex linear combinations of  have a complex univariate normal distribution. The characteristic function of  has been derived, and simpler forms of some theorems have been given using this characterization theorem without assuming that the variance-covariance matrix of the vector  is Hermitian positive definite. Marginal distributions of  have been given. In addition, a complex multivariate t-distribution has been defined and the density derived. A characterization of the complex multivariate t-distribution is given. A few possible uses of this distribution have been suggested.

  11. Variable Kernel Density Estimation

    OpenAIRE

    Terrell, George R.; Scott, David W.

    1992-01-01

    We investigate some of the possibilities for improvement of univariate and multivariate kernel density estimates by varying the window over the domain of estimation, pointwise and globally. Two general approaches are to vary the window width by the point of estimation and by point of the sample observation. The first possibility is shown to be of little efficacy in one variable. In particular, nearest-neighbor estimators in all versions perform poorly in one and two dimensions, but begin to b...

  12. Internet interventions for chronic pain including headache: A systematic review

    Directory of Open Access Journals (Sweden)

    Monica Buhrman

    2016-05-01

    Full Text Available Chronic pain is a major health problem and behavioral based treatments have been shown to be effective. However, the availability of these kinds of treatments is scarce and internet-based treatments have been shown to be promising in this area. The objective of the present systematic review is to evaluate internet-based interventions for persons with chronic pain. The specific aims are to do an updated review with a broad inclusion of different chronic pain diagnoses and to assess disability and pain and also measures of catastrophizing, depression and anxiety. A systematic search identified 891 studies and 22 trials were selected as eligible for review. Two of the selected trials included children/youth and five included individuals with chronic headache and/or migraine. The most frequently measured domain reflected in the primary outcomes was interference/disability, followed by catastrophizing. Result across the studies showed a number of beneficial effects. Twelve trials reported significant effects on disability/interference outcomes and pain intensity. Positive effects were also found on psychological variable such as catastrophizing, depression and anxiety. Several studies (n = 12 were assessed to have an unclear level of risk bias. The attrition levels ranged from 4% to 54% where the headache trials had the highest drop-out levels. However, findings suggest that internet-based treatments based on cognitive behavioural therapy (CBT are efficacious measured with different outcome variables. Results are in line with trials in clinical settings. Meta-analytic statistics were calculated for interference/disability, pain intensity, catastrophizing and mood ratings. Results showed that the effect size for interference/disability was Hedge's g = −0.39, for pain intensity Hedge's g = −0.33, for catastrophizing Hedge's g = −0.49 and for mood variables (depression Hedge's g = −0.26.

  13. Short timescale variability in the faint sky variability survey

    NARCIS (Netherlands)

    Morales-Rueda, L.; Groot, P.J.; Augusteijn, T.; Nelemans, G.A.; Vreeswijk, P.M.; Besselaar, E.J.M. van den

    2006-01-01

    We present the V-band variability analysis of the Faint Sky Variability Survey (FSVS). The FSVS combines colour and time variability information, from timescales of 24 minutes to tens of days, down to V = 24. We find that �1% of all point sources are variable along the main sequence reaching �3.5%

  14. Spatial Variability of Wet Troposphere Delays Over Inland Water Bodies

    Science.gov (United States)

    Mehran, Ali; Clark, Elizabeth A.; Lettenmaier, Dennis P.

    2017-11-01

    Satellite radar altimetry has enabled the study of water levels in large lakes and reservoirs at a global scale. The upcoming Surface Water and Ocean Topography (SWOT) satellite mission (scheduled launch 2020) will simultaneously measure water surface extent and elevation at an unprecedented accuracy and resolution. However, SWOT retrieval accuracy will be affected by a number of factors, including wet tropospheric delay—the delay in the signal's passage through the atmosphere due to atmospheric water content. In past applications, the wet tropospheric delay over large inland water bodies has been corrected using atmospheric moisture profiles based on atmospheric reanalysis data at relatively coarse (tens to hundreds of kilometers) spatial resolution. These products cannot resolve subgrid variations in wet tropospheric delays at the spatial resolutions (of 1 km and finer) that SWOT is intended to resolve. We calculate zenith wet tropospheric delays (ZWDs) and their spatial variability from Weather Research and Forecasting (WRF) numerical weather prediction model simulations at 2.33 km spatial resolution over the southwestern U.S., with attention in particular to Sam Rayburn, Ray Hubbard, and Elephant Butte Reservoirs which have width and length dimensions that are of order or larger than the WRF spatial resolution. We find that spatiotemporal variability of ZWD over the inland reservoirs depends on climatic conditions at the reservoir location, as well as distance from ocean, elevation, and surface area of the reservoir, but that the magnitude of subgrid variability (relative to analysis and reanalysis products) is generally less than 10 mm.

  15. Articulatory variability in cluttering.

    Science.gov (United States)

    Hartinger, Mariam; Mooshammer, Christine

    2008-01-01

    In order to investigate the articulatory processes of the hasty and mumbled speech in cluttering, the kinematic variability was analysed by means of electromagnetic midsagittal articulography. In contrast to persons with stuttering, those with cluttering improve their intelligibility by concentrating on their speech task. Variability has always been an important criterion in comparable studies of stuttering and is discussed in terms of the stability of the speech motor system. The aim of the current study was to analyse the spatial and temporal variability in the speech of three persons with cluttering (PWC) and three control speakers. All participants were native speakers of German. The speech material consisted of repetitive CV syllables and loan words such as 'emotionalisieren', because PWC have the severest problems with long words with a complex syllable structure. The results showed a significantly higher coefficient of variation for PWC in loan word production, both in the temporal and in the spatial domain, whereas the means of displacements and durations did not differ between groups. These findings were discussed in terms of the effects of the linguistic complexity, since for the syllable repetition task, no significant differences between PWC and controls were found. Copyright 2008 S. Karger AG, Basel.

  16. Climatological variability in regional air pollution

    International Nuclear Information System (INIS)

    Shannon, J.D.; Trexler, E.C. Jr.

    1995-01-01

    Although some air pollution modeling studies examine events that have already occurred (e.g., the Chernobyl plume) with relevant meteorological conditions largely known, most pollution modeling studies address expected or potential scenarios for the future. Future meteorological conditions, the major pollutant forcing function other than emissions, are inherently uncertain although much relevant information is contained in past observational data. For convenience in our discussions of regional pollutant variability unrelated to emission changes, we define meteorological variability as short-term (within-season) pollutant variability and climatological variability as year-to-year changes in seasonal averages and accumulations of pollutant variables. In observations and in some of our simulations the effects are confounded because for seasons of two different years both the mean and the within-season character of a pollutant variable may change. Effects of climatological and meteorological variability on means and distributions of air pollution parameters, particularly those related to regional visibility, are illustrated. Over periods of up to a decade climatological variability may mask or overstate improvements resulting from emission controls. The importance of including climatological uncertainties in assessing potential policies, particularly when based partly on calculated source-receptor relationships, is highlighted

  17. Construction of Database for Pulsating Variable Stars

    Science.gov (United States)

    Chen, B. Q.; Yang, M.; Jiang, B. W.

    2011-07-01

    A database for the pulsating variable stars is constructed for Chinese astronomers to study the variable stars conveniently. The database includes about 230000 variable stars in the Galactic bulge, LMC and SMC observed by the MACHO (MAssive Compact Halo Objects) and OGLE (Optical Gravitational Lensing Experiment) projects at present. The software used for the construction is LAMP, i.e., Linux+Apache+MySQL+PHP. A web page is provided to search the photometric data and the light curve in the database through the right ascension and declination of the object. More data will be incorporated into the database.

  18. A novel large deletion of the ICR1 region including H19 and putative enhancer elements.

    Science.gov (United States)

    Fryssira, Helen; Amenta, Stella; Kanber, Deniz; Sofocleous, Christalena; Lykopoulou, Evangelia; Kanaka-Gantenbein, Christina; Cerrato, Flavia; Lüdecke, Hermann-Josef; Bens, Susanne; Riccio, Andrea; Buiting, Karin

    2015-05-06

    Beckwith-Wiedemann syndrome (BWS) is a rare pediatric overgrowth disorder with a variable clinical phenotype caused by deregulation affecting imprinted genes in the chromosomal region 11p15. Alterations of the imprinting control region 1 (ICR1) at the IGF2/H19 locus resulting in biallelic expression of IGF2 and biallelic silencing of H19 account for approximately 10% of patients with BWS. The majority of these patients have epimutations of the ICR1 without detectable DNA sequence changes. Only a few patients were found to have deletions. Most of these deletions are small affecting different parts of the ICR1 differentially methylated region (ICR1-DMR) removing target sequences for CTCF. Only a very few deletions reported so far include the H19 gene in addition to the CTCF binding sites. None of these deletions include IGF2. A male patient was born with hypotonia, facial dysmorphisms and hypoglycemia suggestive of Beckwith-Wiedemann syndrome. Using methylation-specific (MS)-MLPA (Multiplex ligation-dependent probe amplification) we have identified a maternally inherited large deletion of the ICR1 region in a patient and his mother. The deletion results in a variable clinical expression with a classical BWS in the mother and a more severe presentation of BWS in her son. By genome-wide SNP array analysis the deletion was found to span ~100 kb genomic DNA including the ICR1DMR, H19, two adjacent non-imprinted genes and two of three predicted enhancer elements downstream to H19. Methylation analysis by deep bisulfite next generation sequencing revealed hypermethylation of the maternal allele at the IGF2 locus in both, mother and child, although IGF2 is not affected by the deletion. We here report on a novel large familial deletion of the ICR1 region in a BWS family. Due to the deletion of the ICR1-DMR CTCF binding cannot take place and the residual enhancer elements have access to the IGF2 promoters. The aberrant methylation (hypermethylation) of the maternal IGF2

  19. Including investment risk in large-scale power market models

    DEFF Research Database (Denmark)

    Lemming, Jørgen Kjærgaard; Meibom, P.

    2003-01-01

    Long-term energy market models can be used to examine investments in production technologies, however, with market liberalisation it is crucial that such models include investment risks and investor behaviour. This paper analyses how the effect of investment risk on production technology selection...... can be included in large-scale partial equilibrium models of the power market. The analyses are divided into a part about risk measures appropriate for power market investors and a more technical part about the combination of a risk-adjustment model and a partial-equilibrium model. To illustrate...... the analyses quantitatively, a framework based on an iterative interaction between the equilibrium model and a separate risk-adjustment module was constructed. To illustrate the features of the proposed modelling approach we examined how uncertainty in demand and variable costs affects the optimal choice...

  20. PLUTINO DETECTION BIASES, INCLUDING THE KOZAI RESONANCE

    International Nuclear Information System (INIS)

    Lawler, S. M.; Gladman, B.

    2013-01-01

    Because of their relative proximity within the trans-Neptunian region, the plutinos (objects in the 3:2 mean-motion resonance with Neptune) are numerous in flux-limited catalogs, and well-studied theoretically. We perform detailed modeling of the on-sky detection biases for plutinos, with special attention to those that are simultaneously in the Kozai resonance. In addition to the normal 3:2 resonant argument libration, Kozai plutinos also show periodic oscillations in eccentricity and inclination, coupled to the argument of perihelion (ω) oscillation. Due to the mean-motion resonance, plutinos avoid coming to pericenter near Neptune's current position in the ecliptic plane. Because Kozai plutinos are restricted to certain values of ω, perihelion always occurs out of the ecliptic plane, biasing ecliptic surveys against finding these objects. The observed Kozai plutino fraction f koz obs has been measured by several surveys, finding values between 8% and 25%, while the true Kozai plutino fraction f koz true has been predicted to be between 10% and 30% by different giant planet migration simulations. We show that f koz obs varies widely depending on the ecliptic latitude and longitude of the survey, so debiasing to find the true ratio is complex. Even a survey that covers most or all of the sky will detect an apparent Kozai fraction that is different from f koz true . We present a map of the on-sky plutino Kozai fraction that would be detected by all-sky flux-limited surveys. This will be especially important for the Panoramic Survey Telescope and Rapid Response System and Large Synoptic Survey Telescope projects, which may detect large numbers of plutinos as they sweep the sky. f koz true and the distribution of the orbital elements of Kozai plutinos may be a diagnostic of giant planet migration; future migration simulations should provide details on their resonant Kozai populations.

  1. Variable Cycle Intake for Reverse Core Engine

    Science.gov (United States)

    Suciu, Gabriel L (Inventor); Chandler, Jesse M (Inventor); Staubach, Joseph B (Inventor)

    2016-01-01

    A gas generator for a reverse core engine propulsion system has a variable cycle intake for the gas generator, which variable cycle intake includes a duct system. The duct system is configured for being selectively disposed in a first position and a second position, wherein free stream air is fed to the gas generator when in the first position, and fan stream air is fed to the gas generator when in the second position.

  2. Handbook of latent variable and related models

    CERN Document Server

    Lee, Sik-Yum

    2011-01-01

    This Handbook covers latent variable models, which are a flexible class of models for modeling multivariate data to explore relationships among observed and latent variables.- Covers a wide class of important models- Models and statistical methods described provide tools for analyzing a wide spectrum of complicated data- Includes illustrative examples with real data sets from business, education, medicine, public health and sociology.- Demonstrates the use of a wide variety of statistical, computational, and mathematical techniques.

  3. [Renal patient's diet: Can fish be included?].

    Science.gov (United States)

    Castro González, M I; Maafs Rodríguez, A G; Galindo Gómez, C

    2012-01-01

    Medical and nutritional treatment for renal disease, now a major public health issue, is highly complicated. Nutritional therapy must seek to retard renal dysfunction, maintain an optimal nutritional status and prevent the development of underlying pathologies. To analyze ten fish species to identify those that, because of their low phosphorus content, high biological value protein and elevated n-3 fatty acids EPA and DHA, could be included in renal patient's diet. The following fish species (Litte tunny, Red drum, Spotted eagleray, Escolar, Swordfish, Big-scale pomfret, Cortez flounder, Largemouth blackbass, Periche mojarra, Florida Pompano) were analyzed according to the AOAC and Keller techniques to determine their protein, phosphorus, sodium, potassium, cholesterol, vitamins D(3) and E, and n-3 EPA+DHA content. These results were used to calculate relations between nutrients. The protein in the analyzed species ranged from 16.5 g/100 g of fillet (Largemouth black bass) to 27.2 g/100 g (Red drum); the lowest phosphorus value was 28.6 mg/100 g (Periche mojarra) and the highest 216.3 mg/100 g (Spotted eagle ray). 80% of the fish presented > 100 mg EPA + DHA in 100 g of fillet. By its Phosphorus/gProtein ratio, Escolar and Swordfish could not be included in the renal diet; Little tunny, Escolar, Big-scale pomfret, Largemouth black-bass, Periche mojarra and Florida Pompano presented a lower Phosphorus/EPA + DHA ratio. Florida pompano is the most recommended specie for renal patients, due to its optimal nutrient relations. However, all analyzed species, except Escolar and Swordfish, could be included in renal diets.

  4. Risk variables in evaluation of transport projects

    Science.gov (United States)

    Vařbuchta, Petr; Kovářová, Hana; Hromádka, Vít; Vítková, Eva

    2017-09-01

    Depending on the constantly increasing demands on assessment of investment projects, especially assessment of large-scale projects in transport and important European projects with wide impacts, there is constantly increasing focus on risk management, whether to find mitigations, creating corrective measures or their implementation in assessment, especially in the context of Cost-Benefit analysis. To project assessment is often used implementation of certain risk variables, which can generate negative impacts of project outputs in framework of assess. Especially in case of transportation infrastructure projects is taken much emphasis on the influence of risk variables. However, currently in case of assessment of transportation projects is in Czech Republic used a few risk variables, which occur in the most projects. This leads to certain limitation in framework of impact assessment of risk variables. This papers aims to specify a new risk variables and process of applying them to already executed project assessment. Based on changes generated by new risk variables will be evaluated differences between original and adapted assessment.

  5. MOS modeling hierarchy including radiation effects

    International Nuclear Information System (INIS)

    Alexander, D.R.; Turfler, R.M.

    1975-01-01

    A hierarchy of modeling procedures has been developed for MOS transistors, circuit blocks, and integrated circuits which include the effects of total dose radiation and photocurrent response. The models were developed for use with the SCEPTRE circuit analysis program, but the techniques are suitable for other modern computer aided analysis programs. The modeling hierarchy permits the designer or analyst to select the level of modeling complexity consistent with circuit size, parametric information, and accuracy requirements. Improvements have been made in the implementation of important second order effects in the transistor MOS model, in the definition of MOS building block models, and in the development of composite terminal models for MOS integrated circuits

  6. Drug delivery device including electrolytic pump

    KAUST Repository

    Foulds, Ian G.; Buttner, Ulrich; Yi, Ying

    2016-01-01

    Systems and methods are provided for a drug delivery device and use of the device for drug delivery. In various aspects, the drug delivery device combines a “solid drug in reservoir” (SDR) system with an electrolytic pump. In various aspects an improved electrolytic pump is provided including, in particular, an improved electrolytic pump for use with a drug delivery device, for example an implantable drug delivery device. A catalytic reformer can be incorporated in a periodically pulsed electrolytic pump to provide stable pumping performance and reduced actuation cycle.

  7. Drug delivery device including electrolytic pump

    KAUST Repository

    Foulds, Ian G.

    2016-03-31

    Systems and methods are provided for a drug delivery device and use of the device for drug delivery. In various aspects, the drug delivery device combines a “solid drug in reservoir” (SDR) system with an electrolytic pump. In various aspects an improved electrolytic pump is provided including, in particular, an improved electrolytic pump for use with a drug delivery device, for example an implantable drug delivery device. A catalytic reformer can be incorporated in a periodically pulsed electrolytic pump to provide stable pumping performance and reduced actuation cycle.

  8. Discovery of Paradigm Dependencies

    OpenAIRE

    Sun, Jizhou; Li, Jianzhong; Gao, Hong

    2017-01-01

    Missing and incorrect values often cause serious consequences. To deal with these data quality problems, a class of common employed tools are dependency rules, such as Functional Dependencies (FDs), Conditional Functional Dependencies (CFDs) and Edition Rules (ERs), etc. The stronger expressing ability a dependency has, data with the better quality can be obtained. To the best of our knowledge, all previous dependencies treat each attribute value as a non-splittable whole. Actually however, i...

  9. About hidden influence of predictor variables: Suppressor and mediator variables

    Directory of Open Access Journals (Sweden)

    Milovanović Boško

    2013-01-01

    Full Text Available In this paper procedure for researching hidden influence of predictor variables in regression models and depicting suppressor variables and mediator variables is shown. It is also shown that detection of suppressor variables and mediator variables could provide refined information about the research problem. As an example for applying this procedure, relation between Atlantic atmospheric centers and air temperature and precipitation amount in Serbia is chosen. [Projekat Ministarstva nauke Republike Srbije, br. 47007

  10. [Dependent patient and interpersonal dependency: psychotherapeutic strategies].

    Science.gov (United States)

    Versaevel, C

    2012-04-01

    This article is a review of psychotherapies for patients suffering from dependent personality and interpersonal dependency. We synthesized articles making reference to this question, notably those written by Bornstein, author who refers to the dependent personality. We highlighted the psychotherapies that have been the object of an evaluation. The research on the subject is sparse: only eight studies permitting assessment of psychotherapies in this indication in 2005. Besides these psychotherapies, we detailed other approaches which are used by practitioners in these indications. The therapy does not aim at autonomy "at all costs", but that the patient finds a dependence "adapted" to his/her environment. Before starting a therapy, an evaluation is useful to specify the type of dependence. First of all, is there a "pathological" dependence? Is the suffering of the patient secondary to his personality or not supportive enough? Does insight exist? What is the reaction of the patient if we suggest the hypothesis of a dependence on his/her part? Does he/she consider this idea or reject it? Finally, is the dependence primary or secondary? For that purpose, it is necessary to study the biography of the patient and the appearance of the comorbidity over time. The primary dependence is seen in childhood and precedes the other psychological disorders. The secondary dependence follows after the comorbidity and events of life that alter self-esteem (depression, for example). Various therapeutic strategies arise from various currents. The therapies of analytical inspiration recommend replaying the relationship of object and explicitly evoking the transfer. The behavioural and cognitive psychotherapies aim at making the patient identify the cognitions which underlie the dependence, then leading the patient to modify his/her cognition and to behave in a more autonomous way, using the theory of learning. The humanist therapies aim at a therapeutic relationship of acceptance and

  11. Variables That Can Affect Student Ratings of Their Professors

    Science.gov (United States)

    Gotlieb, Jerry

    2013-01-01

    Attribution theory was applied to help predict the results of an experiment that examined the effects of three independent variables on students' ratings of their professors. The dependent variables were students' perceptions of whether the professor caused the students' grades and student satisfaction with their professor. The results suggest…

  12. A geometric model for magnetizable bodies with internal variables

    Directory of Open Access Journals (Sweden)

    Restuccia, L

    2005-11-01

    Full Text Available In a geometrical framework for thermo-elasticity of continua with internal variables we consider a model of magnetizable media previously discussed and investigated by Maugin. We assume as state variables the magnetization together with its space gradient, subjected to evolution equations depending on both internal and external magnetic fields. We calculate the entropy function and necessary conditions for its existence.

  13. Genetic variability and heritability studies of some reproductive traits ...

    African Journals Online (AJOL)

    GRACE

    2006-07-03

    Jul 3, 2006 ... The success of most crop improvement programs largely depends upon the genetic variability and the heritability of desirable traits. The magnitude and type of genetic variability help the breeder to determine the selection criteria and breeding schemes to be used for improvement purposes. A screen.

  14. Frequency dependent changes in NMDAR-dependent synaptic plasticity

    Directory of Open Access Journals (Sweden)

    Arvind eKumar

    2011-09-01

    Full Text Available The NMDAR-dependent synaptic plasticity is thought to mediate several forms of learning, and can be induced by spike trains containing a small number of spikes occurring with varying rates and timing, as well as with oscillations. We computed the influence of these variables on the plasticity induced at a single NMDAR containing synapse using a reduced model that was analytically tractable, and these findings were confirmed using detailed, multi-compartment model. In addition to explaining diverse experimental results about the rate and timing dependence of synaptic plasticity, the model made several novel and testable predictions. We found that there was a preferred frequency for inducing long-term potentiation (LTP such that higher frequency stimuli induced lesser LTP, decreasing as 1/f when the number of spikes in the stimulus was kept fixed. Among other things, the preferred frequency for inducing LTP varied as a function of the distance of the synapse from the soma. In fact, same stimulation frequencies could induce LTP or LTD depending on the dendritic location of the synapse. Next, we found that rhythmic stimuli induced greater plasticity then irregular stimuli. Furthermore, brief bursts of spikes significantly expanded the timing dependence of plasticity. Finally, we found that in the ~5-15Hz frequency range both rate- and timing-dependent plasticity mechanisms work synergistically to render the synaptic plasticity most sensitive to spike-timing. These findings provide computational evidence that oscillations can have a profound influence on the plasticity of an NMDAR-dependent synapse, and show a novel role for the dendritic morphology in this process.

  15. Energy principle with included boundary conditions

    International Nuclear Information System (INIS)

    Lehnert, B.

    1994-01-01

    Earlier comments by the author on the limitations of the classical form of the extended energy principle are supported by a complementary analysis on the potential energy change arising from free-boundary displacements of a magnetically confined plasma. In the final formulation of the extended principle, restricted displacements, satisfying pressure continuity by means of plasma volume currents in a thin boundary layer, are replaced by unrestricted (arbitrary) displacements which can give rise to induced surface currents. It is found that these currents contribute to the change in potential energy, and that their contribution is not taken into account by such a formulation. A general expression is further given for surface currents induced by arbitrary displacements. The expression is used to reformulate the energy principle for the class of displacements which satisfy all necessary boundary conditions, including that of the pressure balance. This makes a minimization procedure of the potential energy possible, for the class of all physically relevant test functions which include the constraints imposed by the boundary conditions. Such a procedure is also consistent with a corresponding variational calculus. (Author)

  16. Aerosol simulation including chemical and nuclear reactions

    International Nuclear Information System (INIS)

    Marwil, E.S.; Lemmon, E.C.

    1985-01-01

    The numerical simulation of aerosol transport, including the effects of chemical and nuclear reactions presents a challenging dynamic accounting problem. Particles of different sizes agglomerate and settle out due to various mechanisms, such as diffusion, diffusiophoresis, thermophoresis, gravitational settling, turbulent acceleration, and centrifugal acceleration. Particles also change size, due to the condensation and evaporation of materials on the particle. Heterogeneous chemical reactions occur at the interface between a particle and the suspending medium, or a surface and the gas in the aerosol. Homogeneous chemical reactions occur within the aersol suspending medium, within a particle, and on a surface. These reactions may include a phase change. Nuclear reactions occur in all locations. These spontaneous transmutations from one element form to another occur at greatly varying rates and may result in phase or chemical changes which complicate the accounting process. This paper presents an approach for inclusion of these effects on the transport of aerosols. The accounting system is very complex and results in a large set of stiff ordinary differential equations (ODEs). The techniques for numerical solution of these ODEs require special attention to achieve their solution in an efficient and affordable manner. 4 refs

  17. Addressing Stillbirth in India Must Include Men.

    Science.gov (United States)

    Roberts, Lisa; Montgomery, Susanne; Ganesh, Gayatri; Kaur, Harinder Pal; Singh, Ratan

    2017-07-01

    Millennium Development Goal 4, to reduce child mortality, can only be achieved by reducing stillbirths globally. A confluence of medical and sociocultural factors contribute to the high stillbirth rates in India. The psychosocial aftermath of stillbirth is a well-documented public health problem, though less is known of the experience for men, particularly outside of the Western context. Therefore, men's perceptions and knowledge regarding reproductive health, as well as maternal-child health are important. Key informant interviews (n = 5) were analyzed and 28 structured interviews were conducted using a survey based on qualitative themes. Qualitative themes included men's dual burden and right to medical and reproductive decision making power. Wives were discouraged from expressing grief and pushed to conceive again. If not successful, particularly if a son was not conceived, a second wife was considered a solution. Quantitative data revealed that men with a history of stillbirths had greater anxiety and depression, perceived less social support, but had more egalitarian views towards women than men without stillbirth experience. At the same time fathers of stillbirths were more likely to be emotionally or physically abusive. Predictors of mental health, attitudes towards women, and perceived support are discussed. Patriarchal societal values, son preference, deficient women's autonomy, and sex-selective abortion perpetuate the risk for future poor infant outcomes, including stillbirth, and compounds the already higher risk of stillbirth for males. Grief interventions should explore and take into account men's perceptions, attitudes, and behaviors towards reproductive decision making.

  18. Analysis of Critical Infrastructure Dependencies and Interdependencies

    Energy Technology Data Exchange (ETDEWEB)

    Petit, Frederic [Argonne National Lab. (ANL), Argonne, IL (United States); Verner, Duane [Argonne National Lab. (ANL), Argonne, IL (United States); Brannegan, David [Argonne National Lab. (ANL), Argonne, IL (United States); Buehring, William [Argonne National Lab. (ANL), Argonne, IL (United States); Dickinson, David [Argonne National Lab. (ANL), Argonne, IL (United States); Guziel, Karen [Argonne National Lab. (ANL), Argonne, IL (United States); Haffenden, Rebecca [Argonne National Lab. (ANL), Argonne, IL (United States); Phillips, Julia [Argonne National Lab. (ANL), Argonne, IL (United States); Peerenboom, James [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-06-01

    The report begins by defining dependencies and interdependencies and exploring basic concepts of dependencies in order to facilitate a common understanding and consistent analytical approaches. Key concepts covered include; Characteristics of dependencies: upstream dependencies, internal dependencies, and downstream dependencies; Classes of dependencies: physical, cyber, geographic, and logical; and Dimensions of dependencies: operating environment, coupling and response behavior, type of failure, infrastructure characteristics, and state of operations From there, the report proposes a multi-phase roadmap to support dependency and interdependency assessment activities nationwide, identifying a range of data inputs, analysis activities, and potential products for each phase, as well as key steps needed to progress from one phase to the next. The report concludes by outlining a comprehensive, iterative, and scalable framework for analyzing dependencies and interdependencies that stakeholders can integrate into existing risk and resilience assessment efforts.

  19. PLUTINO DETECTION BIASES, INCLUDING THE KOZAI RESONANCE

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, S. M.; Gladman, B. [Department of Physics and Astronomy, 6224 Agricultural Road, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada)

    2013-07-01

    Because of their relative proximity within the trans-Neptunian region, the plutinos (objects in the 3:2 mean-motion resonance with Neptune) are numerous in flux-limited catalogs, and well-studied theoretically. We perform detailed modeling of the on-sky detection biases for plutinos, with special attention to those that are simultaneously in the Kozai resonance. In addition to the normal 3:2 resonant argument libration, Kozai plutinos also show periodic oscillations in eccentricity and inclination, coupled to the argument of perihelion ({omega}) oscillation. Due to the mean-motion resonance, plutinos avoid coming to pericenter near Neptune's current position in the ecliptic plane. Because Kozai plutinos are restricted to certain values of {omega}, perihelion always occurs out of the ecliptic plane, biasing ecliptic surveys against finding these objects. The observed Kozai plutino fraction f{sub koz}{sup obs} has been measured by several surveys, finding values between 8% and 25%, while the true Kozai plutino fraction f{sub koz}{sup true} has been predicted to be between 10% and 30% by different giant planet migration simulations. We show that f{sub koz}{sup obs} varies widely depending on the ecliptic latitude and longitude of the survey, so debiasing to find the true ratio is complex. Even a survey that covers most or all of the sky will detect an apparent Kozai fraction that is different from f{sub koz}{sup true}. We present a map of the on-sky plutino Kozai fraction that would be detected by all-sky flux-limited surveys. This will be especially important for the Panoramic Survey Telescope and Rapid Response System and Large Synoptic Survey Telescope projects, which may detect large numbers of plutinos as they sweep the sky. f{sub koz}{sup true} and the distribution of the orbital elements of Kozai plutinos may be a diagnostic of giant planet migration; future migration simulations should provide details on their resonant Kozai populations.

  20. Including gauge corrections to thermal leptogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Huetig, Janine

    2013-05-17

    This thesis provides the first approach of a systematic inclusion of gauge corrections to leading order to the ansatz of thermal leptogenesis. We have derived a complete expression for the integrated lepton number matrix including all resummations needed. For this purpose, a new class of diagram has been invented, namely the cylindrical diagram, which allows diverse investigations into the topic of leptogenesis such as the case of resonant leptogenesis. After a brief introduction of the topic of the baryon asymmetry in the universe and a discussion of its most promising solutions as well as their advantages and disadvantages, we have presented our framework of thermal leptogenesis. An effective model was described as well as the associated Feynman rules. The basis for using nonequilibrium quantum field theory has been built in chapter 3. At first, the main definitions have been presented for equilibrium thermal field theory, afterwards we have discussed the Kadanoff-Baym equations for systems out of equilibrium using the example of the Majorana neutrino. The equations have also been solved in the context of leptogenesis in chapter 4. Since gauge corrections play a crucial role throughout this thesis, we have also repeated the naive ansatz by replacing the free equilibrium propagator by propagators including thermal damping rates due to the Standard Model damping widths for lepton and Higgs fields. It is shown that this leads to a comparable result to the solutions of the Boltzmann equations for thermal leptogenesis. Thus it becomes obvious that Standard Model corrections are not negligible for thermal leptogenesis and therefore need to be included systematically from first principles. In order to achieve this we have started discussing the calculation of ladder rung diagrams for Majorana neutrinos using the HTL and the CTL approach in chapter 5. All gauge corrections are included in this framework and thus it has become the basis for the following considerations

  1. Including gauge corrections to thermal leptogenesis

    International Nuclear Information System (INIS)

    Huetig, Janine

    2013-01-01

    This thesis provides the first approach of a systematic inclusion of gauge corrections to leading order to the ansatz of thermal leptogenesis. We have derived a complete expression for the integrated lepton number matrix including all resummations needed. For this purpose, a new class of diagram has been invented, namely the cylindrical diagram, which allows diverse investigations into the topic of leptogenesis such as the case of resonant leptogenesis. After a brief introduction of the topic of the baryon asymmetry in the universe and a discussion of its most promising solutions as well as their advantages and disadvantages, we have presented our framework of thermal leptogenesis. An effective model was described as well as the associated Feynman rules. The basis for using nonequilibrium quantum field theory has been built in chapter 3. At first, the main definitions have been presented for equilibrium thermal field theory, afterwards we have discussed the Kadanoff-Baym equations for systems out of equilibrium using the example of the Majorana neutrino. The equations have also been solved in the context of leptogenesis in chapter 4. Since gauge corrections play a crucial role throughout this thesis, we have also repeated the naive ansatz by replacing the free equilibrium propagator by propagators including thermal damping rates due to the Standard Model damping widths for lepton and Higgs fields. It is shown that this leads to a comparable result to the solutions of the Boltzmann equations for thermal leptogenesis. Thus it becomes obvious that Standard Model corrections are not negligible for thermal leptogenesis and therefore need to be included systematically from first principles. In order to achieve this we have started discussing the calculation of ladder rung diagrams for Majorana neutrinos using the HTL and the CTL approach in chapter 5. All gauge corrections are included in this framework and thus it has become the basis for the following considerations

  2. The surgery of peripheral nerves (including tumors)

    DEFF Research Database (Denmark)

    Fugleholm, Kåre

    2013-01-01

    Surgical pathology of the peripheral nervous system includes traumatic injury, entrapment syndromes, and tumors. The recent significant advances in the understanding of the pathophysiology and cellular biology of peripheral nerve degeneration and regeneration has yet to be translated into improved...... surgical techniques and better outcome after peripheral nerve injury. Decision making in peripheral nerve surgery continues to be a complex challenge, where the mechanism of injury, repeated clinical evaluation, neuroradiological and neurophysiological examination, and detailed knowledge of the peripheral...... nervous system response to injury are prerequisite to obtain the best possible outcome. Surgery continues to be the primary treatment modality for peripheral nerve tumors and advances in adjuvant oncological treatment has improved outcome after malignant peripheral nerve tumors. The present chapter...

  3. AMS at the ANU including biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L K; Allan, G L; Cresswell, R G; Ophel, T R [Australian National Univ., Canberra, ACT (Australia); King, S J; Day, J P [Manchester Univ. (United Kingdom). Dept. of Chemistry

    1994-12-31

    An extensive accelerator mass spectrometry program has been conducted on the 14UD accelerator at the Australian National University since 1986. In the two years since the previous conference, the research program has expanded significantly to include biomedical applications of {sup 26}Al and studies of landform evolution using isotopes produced in situ in surface rocks by cosmic ray bombardment. The system is now used for the measurement of {sup 10}Be, {sup 14}C, {sup 26}Al, {sup 36}Cl, {sup 59}Ni and {sup 129}I, and research is being undertaken in hydrology, environmental geochemistry, archaeology and biomedicine. On the technical side, a new test system has permitted the successful off-line development of a high-intensity ion source. A new injection line to the 14UD has been established and the new source is now in position and providing beams to the accelerator. 4 refs.

  4. AMS at the ANU including biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L.K.; Allan, G.L.; Cresswell, R.G.; Ophel, T.R. [Australian National Univ., Canberra, ACT (Australia); King, S.J.; Day, J.P. [Manchester Univ. (United Kingdom). Dept. of Chemistry

    1993-12-31

    An extensive accelerator mass spectrometry program has been conducted on the 14UD accelerator at the Australian National University since 1986. In the two years since the previous conference, the research program has expanded significantly to include biomedical applications of {sup 26}Al and studies of landform evolution using isotopes produced in situ in surface rocks by cosmic ray bombardment. The system is now used for the measurement of {sup 10}Be, {sup 14}C, {sup 26}Al, {sup 36}Cl, {sup 59}Ni and {sup 129}I, and research is being undertaken in hydrology, environmental geochemistry, archaeology and biomedicine. On the technical side, a new test system has permitted the successful off-line development of a high-intensity ion source. A new injection line to the 14UD has been established and the new source is now in position and providing beams to the accelerator. 4 refs.

  5. CERN Technical Training: LABVIEW courses include RADE

    CERN Multimedia

    HR Department

    2009-01-01

    The contents of the "LabView Basic I" and "LabView Intermediate II" courses have recently been changed to include, respectively, an introduction to and expert training in the Rapid Application Development Environment (RADE). RADE is a LabView-based application developed at CERN to integrate LabView in the accelerator and experiment control infrastructure. It is a suitable solution to developing expert tools, machine development analysis and independent test facilities. The course names have also been changed to "LabVIEW Basics I with RADE Introduction" and "LabVIEW Intermediate II with Advanced RADE Application". " LabVIEW Basics I with RADE Introduction" is designed for: Users preparing to develop applications using LabVIEW, or NI Developer Suite; users and technical managers evaluating LabVIEW or NI Developer Suite in purchasing decisions; users pursuing the Certified LabVIEW Developer certification. The course pr...

  6. CERN Technical Training: LABVIEW courses include RADE

    CERN Multimedia

    HR Department

    2009-01-01

    The contents of the "LabView Basic I" and "LabView Intermediate II" courses have recently been changed to include, respectively, an introduction to and expert training in the Rapid Application Development Environment (RADE). RADE is a LabView-based application developed at CERN to integrate LabView in the accelerator and experiment control infrastructure. It is a suitable solution to developing expert tools, machine development analysis and independent test facilities. The course names have also been changed to "LabVIEW Basics I with RADE Introduction" and "LabVIEW Intermediate II with Advanced RADE Application". " LabVIEW Basics I with RADE Introduction" is designed for: Users preparing to develop applications using LabVIEW, or NI Developer Suite; users and technical managers evaluating LabVIEW or NI Developer Suite in purchasing decisions; users pursuing the Certified LabVIEW Developer certification. The course prepares participants to develop test and measurement, da...

  7. CERN Technical Training: LABVIEW courses include RADE

    CERN Multimedia

    HR Department

    2009-01-01

    The contents of "LabView Basic I" and "LabView Intermediate II" trainings have been recently changed to include, respectively, an introduction and an expert training on the Rapid Application Development Environment (RADE). RADE is a LabView-based application developed at CERN to integrate LabView in the accelerator and experiment control infrastructure. It is a suitable solution to develop expert tools, machine development analysis and independent test facilities. The course names have also been changed to "LabVIEW Basics I with RADE Introduction" and "LabVIEW Intermediate II with Advanced RADE Application". " LabVIEW Basics I with RADE Introduction" is designed for: Users preparing to develop applications using LabVIEW, or NI Developer Suite; users and technical managers evaluating LabVIEW or NI Developer Suite in purchasing decisions; users pursuing the Certified LabVIEW Developer certification. The course prepare...

  8. Critical point anomalies include expansion shock waves

    Energy Technology Data Exchange (ETDEWEB)

    Nannan, N. R., E-mail: ryan.nannan@uvs.edu [Mechanical Engineering Discipline, Anton de Kom University of Suriname, Leysweg 86, PO Box 9212, Paramaribo, Suriname and Process and Energy Department, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft (Netherlands); Guardone, A., E-mail: alberto.guardone@polimi.it [Department of Aerospace Science and Technology, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Colonna, P., E-mail: p.colonna@tudelft.nl [Propulsion and Power, Delft University of Technology, Kluyverweg 1, 2629 HS Delft (Netherlands)

    2014-02-15

    From first-principle fluid dynamics, complemented by a rigorous state equation accounting for critical anomalies, we discovered that expansion shock waves may occur in the vicinity of the liquid-vapor critical point in the two-phase region. Due to universality of near-critical thermodynamics, the result is valid for any common pure fluid in which molecular interactions are only short-range, namely, for so-called 3-dimensional Ising-like systems, and under the assumption of thermodynamic equilibrium. In addition to rarefaction shock waves, diverse non-classical effects are admissible, including composite compressive shock-fan-shock waves, due to the change of sign of the fundamental derivative of gasdynamics.

  9. CLIC expands to include the Southern Hemisphere

    CERN Multimedia

    Roberto Cantoni

    2010-01-01

    Australia has recently joined the CLIC collaboration: the enlargement will bring new expertise and resources to the project, and is especially welcome in the wake of CERN budget redistributions following the recent adoption of the Medium Term Plan.   The countries involved in CLIC collaboration With the signing of a Memorandum of Understanding on 26 August 2010, the ACAS network (Australian Collaboration for Accelerator Science) became the 40th member of in the multilateral CLIC collaboration making Australia the 22nd country to join the collaboration. “The new MoU was signed by the ACAS network, which includes the Australian Synchrotron and the University of Melbourne”, explains Jean-Pierre Delahaye, CLIC Study Leader. “Thanks to their expertise, the Australian institutes will contribute greatly to the CLIC damping rings and the two-beam test modules." Institutes from any country wishing to join the CLIC collaboration are invited to assume responsibility o...

  10. Should Broca's area include Brodmann area 47?

    Science.gov (United States)

    Ardila, Alfredo; Bernal, Byron; Rosselli, Monica

    2017-02-01

    Understanding brain organization of speech production has been a principal goal of neuroscience. Historically, brain speech production has been associated with so-called Broca’s area (Brodmann area –BA- 44 and 45), however, modern neuroimaging developments suggest speech production is associated with networks rather than with areas. The purpose of this paper was to analyze the connectivity of BA47 ( pars orbitalis) in relation to language . A meta-analysis was conducted to assess the language network in which BA47 is involved. The Brainmap database was used. Twenty papers corresponding to 29 experimental conditions with a total of 373 subjects were included. Our results suggest that BA47 participates in a “frontal language production system” (or extended Broca’s system). The BA47  connectivity found is also concordant with a minor role in language semantics. BA47 plays a central role in the language production system.

  11. Musculoskeletal ultrasound including definitions for ultrasonographic pathology

    DEFF Research Database (Denmark)

    Wakefield, RJ; Balint, PV; Szkudlarek, Marcin

    2005-01-01

    Ultrasound (US) has great potential as an outcome in rheumatoid arthritis trials for detecting bone erosions, synovitis, tendon disease, and enthesopathy. It has a number of distinct advantages over magnetic resonance imaging, including good patient tolerability and ability to scan multiple joints...... in a short period of time. However, there are scarce data regarding its validity, reproducibility, and responsiveness to change, making interpretation and comparison of studies difficult. In particular, there are limited data describing standardized scanning methodology and standardized definitions of US...... pathologies. This article presents the first report from the OMERACT ultrasound special interest group, which has compared US against the criteria of the OMERACT filter. Also proposed for the first time are consensus US definitions for common pathological lesions seen in patients with inflammatory arthritis....

  12. Grand unified models including extra Z bosons

    International Nuclear Information System (INIS)

    Li Tiezhong

    1989-01-01

    The grand unified theories (GUT) of the simple Lie groups including extra Z bosons are discussed. Under authors's hypothesis there are only SU 5+m SO 6+4n and E 6 groups. The general discussion of SU 5+m is given, then the SU 6 and SU 7 are considered. In SU 6 the 15+6 * +6 * fermion representations are used, which are not same as others in fermion content, Yukawa coupling and broken scales. A conception of clans of particles, which are not families, is suggested. These clans consist of extra Z bosons and the corresponding fermions of the scale. The all of fermions in the clans are down quarks except for the standard model which consists of Z bosons and 15 fermions, therefore, the spectrum of the hadrons which are composed of these down quarks are different from hadrons at present

  13. Including climate change in energy investment decisions

    International Nuclear Information System (INIS)

    Ybema, J.R.; Boonekamp, P.G.M.; Smit, J.T.J.

    1995-08-01

    To properly take climate change into account in the analysis of energy investment decisions, it is required to apply decision analysis methods that are capable of considering the specific characteristics of climate change (large uncertainties, long term horizon). Such decision analysis methods do exist. They can explicitly include evolving uncertainties, multi-stage decisions, cumulative effects and risk averse attitudes. Various methods are considered in this report and two of these methods have been selected: hedging calculations and sensitivity analysis. These methods are applied to illustrative examples, and its limitations are discussed. The examples are (1a) space heating and hot water for new houses from a private investor perspective and (1b) as example (1a) but from a government perspective, (2) electricity production with an integrated coal gasification combined cycle (ICGCC) with or without CO 2 removal, and (3) national energy strategy to hedge for climate change. 9 figs., 21 tabs., 42 refs., 1 appendix

  14. Education Program on Fossil Resources Including Coal

    Science.gov (United States)

    Usami, Masahiro

    Fossil fuels including coal play a key role as crucial energies in contributing to economic development in Asia. On the other hand, its limited quantity and the environmental problems causing from its usage have become a serious global issue and a countermeasure to solve such problems is very much demanded. Along with the pursuit of sustainable development, environmentally-friendly use of highly efficient fossil resources should be therefore, accompanied. Kyushu-university‧s sophisticated research through long years of accumulated experience on the fossil resources and environmental sectors together with the advanced large-scale commercial and empirical equipments will enable us to foster cooperative research and provide internship program for the future researchers. Then, this program is executed as a consignment business from the Ministry of Economy, Trade and Industry from 2007 fiscal year to 2009 fiscal year. The lecture that uses the textbooks developed by this program is scheduled to be started a course in fiscal year 2010.

  15. Individual Movement Variability Magnitudes Are Explained by Cortical Neural Variability.

    Science.gov (United States)

    Haar, Shlomi; Donchin, Opher; Dinstein, Ilan

    2017-09-13

    Humans exhibit considerable motor variability even across trivial reaching movements. This variability can be separated into specific kinematic components such as extent and direction that are thought to be governed by distinct neural processes. Here, we report that individual subjects (males and females) exhibit different magnitudes of kinematic variability, which are consistent (within individual) across movements to different targets and regardless of which arm (right or left) was used to perform the movements. Simultaneous fMRI recordings revealed that the same subjects also exhibited different magnitudes of fMRI variability across movements in a variety of motor system areas. These fMRI variability magnitudes were also consistent across movements to different targets when performed with either arm. Cortical fMRI variability in the posterior-parietal cortex of individual subjects explained their movement-extent variability. This relationship was apparent only in posterior-parietal cortex and not in other motor system areas, thereby suggesting that individuals with more variable movement preparation exhibit larger kinematic variability. We therefore propose that neural and kinematic variability are reliable and interrelated individual characteristics that may predispose individual subjects to exhibit distinct motor capabilities. SIGNIFICANCE STATEMENT Neural activity and movement kinematics are remarkably variable. Although intertrial variability is rarely studied, here, we demonstrate that individual human subjects exhibit distinct magnitudes of neural and kinematic variability that are reproducible across movements to different targets and when performing these movements with either arm. Furthermore, when examining the relationship between cortical variability and movement variability, we find that cortical fMRI variability in parietal cortex of individual subjects explained their movement extent variability. This enabled us to explain why some subjects

  16. Search for rapid variability of 53 Cam

    International Nuclear Information System (INIS)

    Zverko, J.

    1982-01-01

    Photoelectric observations of magnetic Ap star 53 Cam made at the Skalnate Pleso Observatory in 1978 and 1979 are analyzed from the point of view of rapid variability. The observations were made with an intermediate passband filter, effective wavelength 526 nm. Besides the differences msub(53Cam)-msub(Comp), the behaviour was also investigated of the deflections for the comparison star during the observation runs. A strong correlation between the behaviour of the comparison and variable star light curve was found and the appearance differs from night to night depending on atmospheric conditions. Each observation run is analyzed in detail and it was concluded that all observed variations are only apparent and due to the variability of atmospheric extinction above the observation site. (author)

  17. Dynamics of mechanical systems with variable mass

    CERN Document Server

    Belyaev, Alexander

    2014-01-01

    The book presents up-to-date and unifying formulations for treating dynamics of different types of mechanical systems with variable mass. The starting point is overview of the continuum mechanics relations of balance and jump for open systems from which extended Lagrange and Hamiltonian formulations are derived. Corresponding approaches are stated at the level of analytical mechanics with emphasis on systems with a position-dependent mass and at the level of structural mechanics. Special emphasis is laid upon axially moving structures like belts and chains, and on pipes with an axial flow of fluid. Constitutive relations in the dynamics of systems with variable mass are studied with particular reference to modeling of multi-component mixtures. The dynamics of machines with a variable mass are treated in detail and conservation laws and the stability of motion will be analyzed. Novel finite element formulations for open systems in coupled fluid and structural dynamics are presented.

  18. Within-otolith variability in chemical fingerprints: implications for sampling designs and possible environmental interpretation.

    Science.gov (United States)

    Di Franco, Antonio; Bulleri, Fabio; Pennetta, Antonio; De Benedetto, Giuseppe; Clarke, K Robert; Guidetti, Paolo

    2014-01-01

    Largely used as a natural biological tag in studies of dispersal/connectivity of fish, otolith elemental fingerprinting is usually analyzed by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). LA-ICP-MS produces an elemental fingerprint at a discrete time-point in the life of a fish and can generate data on within-otolith variability of that fingerprint. The presence of within-otolith variability has been previously acknowledged but not incorporated into experimental designs on the presumed, but untested, grounds of both its negligibility compared to among-otolith variability and of spatial autocorrelation among multiple ablations within an otolith. Here, using a hierarchical sampling design of spatial variation at multiple scales in otolith chemical fingerprints for two Mediterranean coastal fishes, we explore: 1) whether multiple ablations within an otolith can be used as independent replicates for significance tests among otoliths, and 2) the implications of incorporating within-otolith variability when assessing spatial variability in otolith chemistry at a hierarchy of spatial scales (different fish, from different sites, at different locations on the Apulian Adriatic coast). We find that multiple ablations along the same daily rings do not necessarily exhibit spatial dependency within the otolith and can be used to estimate residual variability in a hierarchical sampling design. Inclusion of within-otolith measurements reveals that individuals at the same site can show significant variability in elemental uptake. Within-otolith variability examined across the spatial hierarchy identifies differences between the two fish species investigated, and this finding leads to discussion of the potential for within-otolith variability to be used as a marker for fish exposure to stressful conditions. We also demonstrate that a 'cost'-optimal allocation of sampling effort should typically include some level of within-otolith replication in the

  19. Dynamical invariants for variable quadratic Hamiltonians

    International Nuclear Information System (INIS)

    Suslov, Sergei K

    2010-01-01

    We consider linear and quadratic integrals of motion for general variable quadratic Hamiltonians. Fundamental relations between the eigenvalue problem for linear dynamical invariants and solutions of the corresponding Cauchy initial value problem for the time-dependent Schroedinger equation are emphasized. An eigenfunction expansion of the solution of the initial value problem is also found. A nonlinear superposition principle for generalized Ermakov systems is established as a result of decomposition of the general quadratic invariant in terms of the linear ones.

  20. Internally generated natural variability of global-mean temperatures

    International Nuclear Information System (INIS)

    Wigley, T.M.L.; Raper, S.C.B.

    1990-01-01

    Quantitative frequency-domain and time-domain estimates are made of an important aspect of natural variability of global-mean temperatures, namely, passive internal variability resulting from the modulation of atmospheric variability by the ocean. The results are derived using an upwelling-diffusion, energy-balance climate model. In the frequency domain, analytical spectral results show a transition from a high-frequency region in which the response is determined by the mixed-layer heat capacity and is independent of the climate sensitivity (time scales less than around 10 years), to a low-frequency region in which the response depends only on the climate sensitivity. In the former region the spectral power is proportional to f -2 , where f is the frequency, while in the latter the power is independent of frequency. The range of validity of these results depends on the components of the climate system that are included in the model. In this case these restrict the low-frequency results to time scales less than about 1,000 years. A qualitative extrapolation is presented in an attempt to explain the observed low-frequency power spectra from deep-sea-core δ 18 O time series. The spectral results are also used to estimate the effective heat capacity of the ocean as a function of frequency. At low frequencies, this can range up to 50 times greater than the heat capacity of the mixed layer. Results in the time domain are obtained by solving the model equations numerically