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Sample records for strongly delays pre-rrna

  1. Strongly asymmetric square waves in a time-delayed system.

    PubMed

    Weicker, Lionel; Erneux, Thomas; D'Huys, Otti; Danckaert, Jan; Jacquot, Maxime; Chembo, Yanne; Larger, Laurent

    2012-11-01

    Time-delayed systems are known to exhibit symmetric square waves oscillating with a period close to twice the delay. Here, we show that strongly asymmetric square waves of a period close to one delay are possible. The plateau lengths can be tuned by changing a control parameter. The problem is investigated experimentally and numerically using a simple bandpass optoelectronic delay oscillator modeled by nonlinear delay integrodifferential equations. An asymptotic approximation of the square-wave periodic solution valid in the large delay limit allows an analytical description of its main properties (extrema and square pulse durations). A detailed numerical study of the bifurcation diagram indicates that the asymmetric square waves emerge from a Hopf bifurcation.

  2. STRONG LENS TIME DELAY CHALLENGE. I. EXPERIMENTAL DESIGN

    SciTech Connect

    Dobler, Gregory; Fassnacht, Christopher D.; Rumbaugh, Nicholas; Treu, Tommaso; Liao, Kai; Marshall, Phil; Hojjati, Alireza; Linder, Eric

    2015-02-01

    The time delays between point-like images in gravitational lens systems can be used to measure cosmological parameters. The number of lenses with measured time delays is growing rapidly; the upcoming Large Synoptic Survey Telescope (LSST) will monitor ∼10{sup 3} strongly lensed quasars. In an effort to assess the present capabilities of the community, to accurately measure the time delays, and to provide input to dedicated monitoring campaigns and future LSST cosmology feasibility studies, we have invited the community to take part in a ''Time Delay Challenge'' (TDC). The challenge is organized as a set of ''ladders'', each containing a group of simulated data sets to be analyzed blindly by participating teams. Each rung on a ladder consists of a set of realistic mock observed lensed quasar light curves, with the rungs' data sets increasing in complexity and realism. The initial challenge described here has two ladders, TDC0 and TDC1. TDC0 has a small number of data sets, and is designed to be used as a practice set by the participating teams. The (non-mandatory) deadline for completion of TDC0 was the TDC1 launch date, 2013 December 1. The TDC1 deadline was 2014 July 1. Here we give an overview of the challenge, we introduce a set of metrics that will be used to quantify the goodness of fit, efficiency, precision, and accuracy of the algorithms, and we present the results of TDC0. Thirteen teams participated in TDC0 using 47 different methods. Seven of those teams qualified for TDC1, which is described in the companion paper.

  3. Dynamics of strongly coupled spatially distributed logistic equations with delay

    NASA Astrophysics Data System (ADS)

    Kashchenko, I. S.; Kashchenko, S. A.

    2015-04-01

    The dynamics of a system of two logistic delay equations with spatially distributed coupling is studied. The coupling coefficient is assumed to be sufficiently large. Special nonlinear systems of parabolic equations are constructed such that the behavior of their solutions is determined in the first approximation by the dynamical properties of the original system.

  4. The time delay in strong gravitational lensing with Gauss-Bonnet correction

    SciTech Connect

    Man, Jingyun; Cheng, Hongbo E-mail: hbcheng@ecust.edu.cn

    2014-11-01

    The time delay between two relativistic images in the strong gravitational lensing governed by Gauss-Bonnet gravity is studied. We make a complete analytical derivation of the expression of time delay in presence of Gauss-Bonnet coupling. With respect to Schwarzschild, the time delay decreases as a consequence of the shrinking of the photon sphere. As the coupling increases, the second term in the time delay expansion becomes more relevant. Thus time delay in strong limit encodes some new information about geometry in five-dimensional spacetime with Gauss-Bonnet correction.

  5. Time delay in strong-field photoionization of a hydrogen atom

    SciTech Connect

    Ivanov, I. A.

    2011-02-15

    We study time delay for the process of photoionization of a hydrogen atom in a strong electromagnetic field. We compute this quantity by solving the time-dependent Schroedinger equation. We show that even a moderately strong field can have quite a considerable effect on the time delay. Analysis of the wave-packet motion performed by means of the Gabor transform shows that a simple semiclassical model can explain this phenomenon.

  6. Strongly Lensed Jets, Time Delays, and the Value of H 0

    NASA Astrophysics Data System (ADS)

    Barnacka, Anna; Geller, Margaret J.; Dell'Antonio, Ian P.; Benbow, Wystan

    2015-01-01

    In principle, the most straightforward method of estimating the Hubble constant relies on time delays between mirage images of strongly lensed sources. It is a puzzle, then, that the values of H 0 obtained with this method span a range from ~50-100 km s-1Mpc-1. Quasars monitored to measure these time delays are multi-component objects. The variability may arise from different components of the quasar or may even originate from a jet. Misidentifying a variable-emitting region in a jet with emission from the core region may introduce an error in the Hubble constant derived from a time delay. Here, we investigate the complex structure of the sources as the underlying physical explanation of the wide spread in values of the Hubble constant based on gravitational lensing. Our Monte Carlo simulations demonstrate that the derived value of the Hubble constant is very sensitive to the offset between the center of the emission and the center of the variable emitting region. Therefore, we propose using the value of H 0 known from other techniques to spatially resolve the origin of the variable emission once the time delay is measured. We particularly advocate this method for gamma-ray astronomy, where the angular resolution of detectors reaches approximately 0.°1 lensed blazars offer the only route for identify the origin of gamma-ray flares. Large future samples of gravitationally lensed sources identified with Euclid, SKA, and LSST will enable a statistical determination of H 0.

  7. Strong Delayed Interactive Effects of Metal Exposure and Warming: Latitude-Dependent Synergisms Persist Across Metamorphosis.

    PubMed

    Debecker, Sara; Dinh, Khuong V; Stoks, Robby

    2017-02-21

    As contaminants are often more toxic at higher temperatures, predicting their impact under global warming remains a key challenge for ecological risk assessment. Ignoring delayed effects, synergistic interactions between contaminants and warming, and differences in sensitivity across species' ranges could lead to an important underestimation of the risks. We addressed all three mechanisms by studying effects of larval exposure to zinc and warming before, during, and after metamorphosis in Ischnura elegans damselflies from high- and low-latitude populations. By integrating these mechanisms into a single study, we could identify two novel patterns. First, during exposure zinc did not affect survival, whereas it induced mild to moderate postexposure mortality in the larval stage and at metamorphosis, and very strongly reduced adult lifespan. This severe delayed effect across metamorphosis was especially remarkable in high-latitude animals, as they appeared almost insensitive to zinc during the larval stage. Second, the well-known synergism between metals and warming was manifested not only during the larval stage but also after metamorphosis, yet notably only in low-latitude damselflies. These results highlight that a more complete life-cycle approach that incorporates the possibility of delayed interactions between contaminants and warming in a geographical context is crucial for a more realistic risk assessment in a warming world.

  8. STRONGLY LENSED JETS, TIME DELAYS, AND THE VALUE OF H {sub 0}

    SciTech Connect

    Barnacka, Anna; Geller, Margaret J.; Benbow, Wystan; Dell'Antonio, Ian P.

    2015-01-20

    In principle, the most straightforward method of estimating the Hubble constant relies on time delays between mirage images of strongly lensed sources. It is a puzzle, then, that the values of H {sub 0} obtained with this method span a range from ∼50-100 km s{sup –1}Mpc{sup –1}. Quasars monitored to measure these time delays are multi-component objects. The variability may arise from different components of the quasar or may even originate from a jet. Misidentifying a variable-emitting region in a jet with emission from the core region may introduce an error in the Hubble constant derived from a time delay. Here, we investigate the complex structure of the sources as the underlying physical explanation of the wide spread in values of the Hubble constant based on gravitational lensing. Our Monte Carlo simulations demonstrate that the derived value of the Hubble constant is very sensitive to the offset between the center of the emission and the center of the variable emitting region. Therefore, we propose using the value of H {sub 0} known from other techniques to spatially resolve the origin of the variable emission once the time delay is measured. We particularly advocate this method for gamma-ray astronomy, where the angular resolution of detectors reaches approximately 0.°1; lensed blazars offer the only route for identify the origin of gamma-ray flares. Large future samples of gravitationally lensed sources identified with Euclid, SKA, and LSST will enable a statistical determination of H {sub 0}.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  10. Test of the FLRW Metric and Curvature with Strong Lens Time Delays

    NASA Astrophysics Data System (ADS)

    Liao, Kai; Li, Zhengxiang; Wang, Guo-Jian; Fan, Xi-Long

    2017-04-01

    We present a new model-independent strategy for testing the Friedmann-Lemaître-Robertson-Walker (FLRW) metric and constraining cosmic curvature, based on future time-delay measurements of strongly lensed quasar-elliptical galaxy systems from the Large Synoptic Survey Telescope and supernova observations from the Dark Energy Survey. The test only relies on geometric optics. It is independent of the energy contents of the universe and the validity of the Einstein equation on cosmological scales. The study comprises two levels: testing the FLRW metric through the distance sum rule (DSR) and determining/constraining cosmic curvature. We propose an effective and efficient (redshift) evolution model for performing the former test, which allows us to concretely specify the violation criterion for the FLRW DSR. If the FLRW metric is consistent with the observations, then on the second level the cosmic curvature parameter will be constrained to ˜0.057 or ˜0.041 (1σ), depending on the availability of high-redshift supernovae, which is much more stringent than current model-independent techniques. We also show that the bias in the time-delay method might be well controlled, leading to robust results. The proposed method is a new independent tool for both testing the fundamental assumptions of homogeneity and isotropy in cosmology and for determining cosmic curvature. It is complementary to cosmic microwave background plus baryon acoustic oscillation analyses, which normally assume a cosmological model with dark energy domination in the late-time universe.

  11. Polarisation response of delay dependent absorption modulation in strong field dressed helium atoms probed near threshold

    NASA Astrophysics Data System (ADS)

    Simpson, E. R.; Sanchez-Gonzalez, A.; Austin, D. R.; Diveki, Z.; Hutchinson, S. E. E.; Siegel, T.; Ruberti, M.; Averbukh, V.; Miseikis, L.; Strüber, C. S.; Chipperfield, L.; Marangos, J. P.

    2016-08-01

    We present the first measurement of the vectorial response of strongly dressed helium atoms probed by an attosecond pulse train (APT) polarised either parallel or perpendicular to the dressing field polarisation. The transient absorption is probed as a function of delay between the APT and the linearly polarised 800 nm field of peak intensity 1.3× {10}14 {{W}} {{cm}}-2. The APT spans the photon energy range 16-42 eV, covering the first ionisation energy of helium (24.59 eV). With parallel polarised dressing and probing fields, we observe modulations with periods of one half and one quarter of the dressing field period. When the polarisation of the dressing field is altered from parallel to perpendicular with respect to the APT polarisation we observe a large suppression in the modulation depth of the above ionisation threshold absorption. In addition to this we present the intensity dependence of the harmonic modulation depth as a function of delay between the dressing and probe fields, with dressing field peak intensities ranging from 2 × 1012 to 2 × 1014 {{W}} {{cm}}-2. We compare our experimental results with a full-dimensional solution of the single-atom time-dependent (TD) Schrödinger equation obtained using the recently developed abinitio TD B-spline ADC method and find good qualitative agreement for the above threshold harmonics.

  12. The contribution of the delayed ionization in strong-field nonsequential double ionization

    SciTech Connect

    Chen, Yinbo; Zhou, Yueming Li, Yang; Li, Min; Lan, Pengfei; Lu, Peixiang

    2016-01-14

    With the classical ensemble model, we have investigated the pulse-duration dependence of nonsequential double ionization (NSDI) over a wide range of laser intensity. The correlated electron momentum distributions are distinctly different for the few-cycle and multiple cycle pulses, which agree well with the previous experiments. Based on this agreement, we analyzed the underlying process for the pulse-duration dependence of the electron correlation by tracing the classical trajectories. Counterintuitively, our analysis shows that the recollision-induced excited states of NSDI could resist ionization in the strong laser field for a time much longer than one optical cycle even at very high intensities. For the multiple-cycle pulses, NSDI events with such a long time delay have significant contribution to the total NSDI yields, which is responsible for the pulse-duration dependence of the observed correlated patterns in the electron momentum distributions.

  13. Observational selection biases in time-delay strong lensing and their impact on cosmography

    NASA Astrophysics Data System (ADS)

    Collett, Thomas E.; Cunnington, Steven D.

    2016-11-01

    Inferring cosmological parameters from time-delay strong lenses requires a significant investment of telescope time; it is therefore tempting to focus on the systems with the brightest sources, the highest image multiplicities and the widest image separations. We investigate if this selection bias can influence the properties of the lenses studied and the cosmological parameters inferred. Using an ellipsoidal power-law deflector population, we build a sample of double- and quadruple-image systems. Assuming reasonable thresholds on image separation and flux, based on current lens monitoring campaigns, we find that the typical density profile slopes of monitorable lenses are significantly shallower than the input ensemble. From a sample of quads, we find that this selection function can introduce a 3.5 per cent bias on the inferred time-delay distances if the properties of the input ensemble are (incorrectly) used as priors on the lens model. This bias remains at the 2.4 per cent level when high-resolution imaging of the quasar host is used to precisely infer the properties of individual lenses. We also investigate if the lines of sight for monitorable strong lenses are biased. The expectation value for the line-of-sight convergence is increased by 0.009 (0.004) for quads (doubles) implying a 0.9 per cent (0.4 per cent) bias on H0. We therefore conclude that whilst the properties of typical quasar lenses and their lines of sight do deviate from the global population, the total magnitude of this effect is likely to be a subdominant effect for current analyses, but has the potential to be a major systematic for samples of ˜25 or more lenses.

  14. Strong-field Breit-Wheeler pair production in two consecutive laser pulses with variable time delay

    NASA Astrophysics Data System (ADS)

    Jansen, Martin J. A.; Müller, Carsten

    2017-03-01

    Photoproduction of electron-positron pairs by the strong-field Breit-Wheeler process in an intense laser field is studied. The laser field is assumed to consist of two consecutive short pulses, with a variable time delay in between. By numerical calculations within the framework of scalar quantum electrodynamics, we demonstrate that the time delay exerts a strong impact on the pair-creation probability. For the case when both pulses are identical, the effect is traced back to the relative quantum phase of the interfering S-matrix amplitudes and explained within a simplified analytical model. Conversely, when the two laser pulses differ from each other, the pair-creation probability depends not only on the time delay but, in general, also on the temporal order of the pulses.

  15. From inverse to delayed magnetic catalysis in a strong magnetic field

    NASA Astrophysics Data System (ADS)

    Mao, Shijun

    2016-08-01

    We study the magnetic field effect on chiral phase transition in a Nambu-Jona-Lasinio model. In comparison with a mean-field approximation containing only quarks, including mesons as quantum fluctuations in the model leads to a transition from inverse to delayed magnetic catalysis at finite temperature and delays the transition at finite baryon chemical potential. The location of the critical end point depends nonmonotonically on the magnetic field.

  16. Global exponential stability of recurrent neural networks with time-varying delays in the presence of strong external stimuli.

    PubMed

    Zeng, Zhigang; Wang, Jun

    2006-12-01

    This paper presents new theoretical results on the global exponential stability of recurrent neural networks with bounded activation functions and bounded time-varying delays in the presence of strong external stimuli. It is shown that the Cohen-Grossberg neural network is globally exponentially stable, if the absolute value of the input vector exceeds a criterion. As special cases, the Hopfield neural network and the cellular neural network are examined in detail. In addition, it is shown that criteria herein, if partially satisfied, can still be used in combination with existing stability conditions. Simulation results are also discussed in two illustrative examples.

  17. Subcutaneous fat accumulation in early infancy is more strongly associated with motor development and delay than muscle growth.

    PubMed

    Kanazawa, H; Kawai, M; Niwa, F; Hasegawa, T; Iwanaga, K; Ohata, K; Tamaki, A; Heike, T

    2014-06-01

    Physical growth in neurologically healthy preterm infants affects motor development. This study investigated the separate relationships between muscle and fat in infancy and later motor development and physical growth. Muscle thickness and subcutaneous fat thickness of the anterior thigh were measured using ultrasound images obtained from neurologically healthy preterm infants at birth, 3, 6, 12 and 18 months' corrected age. We also obtained the Pediatric Evaluation of Disability Inventory and Alberta Infant Motor Scale scores at 18 months' corrected age to assess motor ability and motor delay. Thirty preterm infants completed the study protocol. There was a significant positive correlation between motor ability and increments in subcutaneous fat thickness during the first 3 and 6 months' corrected age (r = 0.48 and 0.40, p < 0.05, respectively), but not between motor ability and muscle thickness growth in any of the periods. A secondary, logistic regression analysis showed that increments in subcutaneous fat thickness during the first 3 months were a protective factor for motor delay. Subcutaneous fat accumulation in early infancy is more strongly associated with motor development and delay than muscle growth. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  18. The mass-sheet degeneracy and time-delay cosmography: analysis of the strong lens RXJ1131-1231

    NASA Astrophysics Data System (ADS)

    Birrer, Simon; Amara, Adam; Refregier, Alexandre

    2016-08-01

    We present extended modelling of the strong lens system RXJ1131-1231 with archival data in two HST bands in combination with existing line-of-sight contribution and velocity dispersion estimates. Our focus is on source size and its influence on time-delay cosmography. We therefore examine the impact of mass-sheet degeneracy and especially the degeneracy pointed out by Schneider & Sluse (2013) [1] using the source reconstruction scale. We also extend on previous work by further exploring the effects of priors on the kinematics of the lens and the external convergence in the environment of the lensing system. Our results coming from RXJ1131-1231 are given in a simple analytic form so that they can be easily combined with constraints coming from other cosmological probes. We find that the choice of priors on lens model parameters and source size are subdominant for the statistical errors for H0 measurements of this systems. The choice of prior for the source is sub-dominant at present (2% uncertainty on H0) but may be relevant for future studies. More importantly, we find that the priors on the kinematic anisotropy of the lens galaxy have a significant impact on our cosmological inference. When incorporating all the above modeling uncertainties, we find H0 = 86.6+6.8-6.9 km s-1 Mpc-1, when using kinematic priors similar to other studies. When we use a different kinematic prior motivated by Barnabè et al. (2012) [2] but covering the same anisotropic range, we find H0 = 74.5+8.0-7.8 km s-1 Mpc-1. This means that the choice of kinematic modeling and priors have a significant impact on cosmographic inferences. The way forward is either to get better velocity dispersion measures which would down weight the impact of the priors or to construct physically motivated priors for the velocity dispersion model.

  19. Correction: A strongly greenish-blue-emitting Cu4Cl4 cluster with an efficient spin-orbit coupling (SOC): fast phosphorescence versus thermally activated delayed fluorescence.

    PubMed

    Chen, Xu-Lin; Yu, Rongmin; Wu, Xiao-Yuan; Liang, Dong; Jia, Ji-Hui; Lu, Can-Zhong

    2016-06-21

    Correction for 'A strongly greenish-blue-emitting Cu4Cl4 cluster with an efficient spin-orbit coupling (SOC): fast phosphorescence versus thermally activated delayed fluorescence' by Xu-Lin Chen et al., Chem. Commun., 2016, 52, 6288-6291.

  20. Interpreting the Strongly Lensed Supernova iPTF16geu: Time Delay Predictions, Microlensing, and Lensing Rates

    NASA Astrophysics Data System (ADS)

    More, Anupreeta; Suyu, Sherry H.; Oguri, Masamune; More, Surhud; Lee, Chien-Hsiu

    2017-02-01

    We present predictions for time delays between multiple images of the gravitationally lensed supernova, iPTF16geu, which was recently discovered from the intermediate Palomar Transient Factory (iPTF). As the supernova is of Type Ia where the intrinsic luminosity is usually well known, accurately measured time delays of the multiple images could provide tight constraints on the Hubble constant. According to our lens mass models constrained by the Hubble Space Telescope F814W image, we expect the maximum relative time delay to be less than a day, which is consistent with the maximum of 100 hr reported by Goobar et al. but places a stringent upper limit. Furthermore, the fluxes of most of the supernova images depart from expected values suggesting that they are affected by microlensing. The microlensing timescales are small enough that they may pose significant problems to measure the time delays reliably. Our lensing rate calculation indicates that the occurrence of a lensed SN in iPTF is likely. However, the observed total magnification of iPTF16geu is larger than expected, given its redshift. This may be a further indication of ongoing microlensing in this system.

  1. Delayed electron emission in strong-field driven tunnelling from a metallic nanotip in the multi-electron regime

    PubMed Central

    Yanagisawa, Hirofumi; Schnepp, Sascha; Hafner, Christian; Hengsberger, Matthias; Kim, Dong Eon; Kling, Matthias F.; Landsman, Alexandra; Gallmann, Lukas; Osterwalder, Jürg

    2016-01-01

    Illuminating a nano-sized metallic tip with ultrashort laser pulses leads to the emission of electrons due to multiphoton excitations. As optical fields become stronger, tunnelling emission directly from the Fermi level becomes prevalent. This can generate coherent electron waves in vacuum leading to a variety of attosecond phenomena. Working at high emission currents where multi-electron effects are significant, we were able to characterize the transition from one regime to the other. Specifically, we found that the onset of laser-driven tunnelling emission is heralded by the appearance of a peculiar delayed emission channel. In this channel, the electrons emitted via laser-driven tunnelling emission are driven back into the metal, and some of the electrons reappear in the vacuum with some delay time after undergoing inelastic scattering and cascading processes inside the metal. Our understanding of these processes gives insights on attosecond tunnelling emission from solids and should prove useful in designing new types of pulsed electron sources. PMID:27786287

  2. Delayed electron emission in strong-field driven tunnelling from a metallic nanotip in the multi-electron regime

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Hirofumi; Schnepp, Sascha; Hafner, Christian; Hengsberger, Matthias; Kim, Dong Eon; Kling, Matthias F.; Landsman, Alexandra; Gallmann, Lukas; Osterwalder, Jürg

    2016-10-01

    Illuminating a nano-sized metallic tip with ultrashort laser pulses leads to the emission of electrons due to multiphoton excitations. As optical fields become stronger, tunnelling emission directly from the Fermi level becomes prevalent. This can generate coherent electron waves in vacuum leading to a variety of attosecond phenomena. Working at high emission currents where multi-electron effects are significant, we were able to characterize the transition from one regime to the other. Specifically, we found that the onset of laser-driven tunnelling emission is heralded by the appearance of a peculiar delayed emission channel. In this channel, the electrons emitted via laser-driven tunnelling emission are driven back into the metal, and some of the electrons reappear in the vacuum with some delay time after undergoing inelastic scattering and cascading processes inside the metal. Our understanding of these processes gives insights on attosecond tunnelling emission from solids and should prove useful in designing new types of pulsed electron sources.

  3. Marginal zone B cell enrichment and strong follicular B cell reduction correlate with a delayed IgG response in a light chain diversity restricted mouse model.

    PubMed

    Amrani, Yacine M; Voegtlé, Danielle; Barbier, Eliane; Six, Adrien; Cazenave, Pierre-André

    2004-10-01

    Recently developed B6.kappa(-)lambda(SEG) mice (by crossing kappa(-) and C57BL/6 mice congenic for the wild Mus spretus SEG strain lambda locus lacking genes coding for lambda1 and lambda3) have a very reduced light chain diversity. B6.kappa(-)lambda(SEG) mice produce only lambda2 and lambdax light chains. Regardless of their Igh haplotype, B6.kappa(-)lambda(SEG) mice show a restricted B cell distribution by light chain subtype with lambdax dominance in all peripheral compartments except peritoneal cavity where lambda2 is dominant. This distribution suggests that selection mechanisms act differently in different B cell compartments on lambda2 and lambdax bearing B cells. Sequence analysis before or following immunization did not reveal unusual mechanisms of diversification. B6.kappa(-)lambda(SEG) mice still respond to various challenging antigens using new Ab patterns. In particular, regardless of Igh(a) or Igh(b) haplotypes, the anti-2,4-dinitrophenyl response is characterized by a restricted diversity for both heavy and light chains and a delayed IgG response when compared to B6 and B6.kappa(-) mice. We suggest that the delayed IgG response is due to the expansion of marginal zone B cells whereas follicular B cells are strongly reduced.

  4. Cloning of a Mycobacterium tuberculosis gene encoding a purifed protein derivative protein that elicits strong tuberculosis-specific delayed-type hypersensitivity.

    PubMed

    Coler, R N; Skeiky, Y A; Ovendale, P J; Vedvick, T S; Gervassi, L; Guderian, J; Jen, S; Reed, S G; Campos-Neto, A

    2000-07-01

    The purified protein derivative (PPD) skin test has been used for the diagnosis of tuberculosis for more than 75 years. However, the test lacks specificity because all mycobacteria share antigens present in PPD. Therefore, sensitization with nontuberculous pathogenic or with environmental nonpathogenic mycobacteria can lead to positive skin tests. This communication describes a novel PPD protein present only in tuberculous complex mycobacteria. A recombinant protein was obtained and named DPPD on the basis of the first 4 amino acids of its N-terminus sequence. DPPD elicited delayed-type hypersensitivity (DTH) in 100% of Mycobacterium tuberculosis-infected guinea pigs but in no animals sensitized with several organisms representative of all members of the Mycobacterium genus. Preliminary results indicate that DPPD induces strong and specific DTH in humans. This work points to the definition of a single recombinant M. tuberculosis protein that may be an alternative to the PPD test.

  5. Equivalent Stimuli Are More Strongly Related after Training with Delayed Matching than after Simultaneous Matching: A Study Using the Implicit Relational Assessment Procedure (IRAP)

    ERIC Educational Resources Information Center

    Bortoloti, Renato; de Rose, Julio C.

    2012-01-01

    Bortoloti and de Rose (2009) found evidence that the level of functional transfer is higher in equivalence classes generated by delayed matching to sample (DMTS) than in classes generated by simultaneous matching (SMTS). We attempted to replicate these findings with the Implicit Relational Assessment Procedure (IRAP). Two experimental groups…

  6. Equivalent Stimuli Are More Strongly Related after Training with Delayed Matching than after Simultaneous Matching: A Study Using the Implicit Relational Assessment Procedure (IRAP)

    ERIC Educational Resources Information Center

    Bortoloti, Renato; de Rose, Julio C.

    2012-01-01

    Bortoloti and de Rose (2009) found evidence that the level of functional transfer is higher in equivalence classes generated by delayed matching to sample (DMTS) than in classes generated by simultaneous matching (SMTS). We attempted to replicate these findings with the Implicit Relational Assessment Procedure (IRAP). Two experimental groups…

  7. 5-Aminolevulinic acid strongly enhances delayed intracellular production of reactive oxygen species (ROS) generated by ionizing irradiation: quantitative analyses and visualization of intracellular ROS production in glioma cells in vitro.

    PubMed

    Kitagawa, Takehiro; Yamamoto, Junkoh; Tanaka, Tohru; Nakano, Yoshiteru; Akiba, Daisuke; Ueta, Kunihiro; Nishizawa, Shigeru

    2015-02-01

    Postoperative adjuvant radiotherapy has important roles in multimodal treatment for highly aggressive malignant gliomas. Previously, we demonstrated that multi-dose ionizing irradiation with repetitive administration of 5-aminolevulinic acid (5-ALA) enhanced the host antitumor response and strongly inhibited tumor growth in experimental glioma. However, the mechanism of the radiosensitizing effect of 5-ALA is not known. Ionizing irradiation not only causes reactive oxygen species (ROS) formation initially by water radiolysis but also induces delayed production of mitochondrial ROS for mediating the long-lasting effects of ionizing irradiation on tumor cells. 5-ALA leads to high accumulation of protoporphyrin IX (PpIX) in the mitochondria of tumor cells, yet can also improve dysfunction of the mitochondrial respiratory chain in tumor cells. Here, we assessed the effect of 5-ALA-induced PpIX synthesis and delayed production of intracellular ROS after ionizing irradiation with 5-ALA in glioma cells in vitro. Temporal changes in intracellular 5-ALA-induced PpIX synthesis after ionizing irradiation in glioma cell lines were evaluated using flow cytometry (FCM). Then, the effect of 5-ALA on delayed production of intracellular ROS 12 h after ionizing irradiation in glioma cells was evaluated by FCM and confocal laser scanning microscopy. Ionizing irradiation had no effect on 5-ALA-induced PpIX synthesis in glioma cells. Delayed intracellular production of ROS was significantly higher than that just after ionizing irradiation, but 5-ALA pretreatment strongly enhanced the delayed intracellular production of ROS, mainly in the cytoplasm of glioma cells. This 5-ALA-induced increase in the delayed production of ROS tended to be higher in the case of 5-ALA treatment before rather than after ionizing irradiation. These results suggest that 5-ALA can affect tumor cells under ionizing irradiation, and greatly increase secondary intracellular production of ROS long after ionizing

  8. A strongly greenish-blue-emitting Cu4Cl4 cluster with an efficient spin-orbit coupling (SOC): fast phosphorescence versus thermally activated delayed fluorescence.

    PubMed

    Chen, Xu-Lin; Yu, Rongmin; Wu, Xiao-Yuan; Liang, Dong; Jia, Ji-Hui; Lu, Can-Zhong

    2016-05-07

    In this communication, we report a new greenish-blue-emitting Cu(i) complex, Cu4Cl4(NP)2, a with high photoluminescence quantum yield of 90% and a short decay time of 9.9 μs. Due to the strong SOC combined with the small activation energy ΔEST, the emission at room temperature consists of approximately equivalent fast phosphorescence and TADF.

  9. H0LiCOW - V. New COSMOGRAIL time delays of HE 0435-1223: H0 to 3.8 per cent precision from strong lensing in a flat ΛCDM model

    NASA Astrophysics Data System (ADS)

    Bonvin, V.; Courbin, F.; Suyu, S. H.; Marshall, P. J.; Rusu, C. E.; Sluse, D.; Tewes, M.; Wong, K. C.; Collett, T.; Fassnacht, C. D.; Treu, T.; Auger, M. W.; Hilbert, S.; Koopmans, L. V. E.; Meylan, G.; Rumbaugh, N.; Sonnenfeld, A.; Spiniello, C.

    2017-03-01

    We present a new measurement of the Hubble Constant H0 and other cosmological parameters based on the joint analysis of three multiply imaged quasar systems with measured gravitational time delays. First, we measure the time delay of HE 0435-1223 from 13-yr light curves obtained as part of the COSMOGRAIL project. Companion papers detail the modelling of the main deflectors and line-of-sight effects, and how these data are combined to determine the time-delay distance of HE 0435-1223. Crucially, the measurements are carried out blindly with respect to cosmological parameters in order to avoid confirmation bias. We then combine the time-delay distance of HE 0435-1223 with previous measurements from systems B1608+656 and RXJ1131-1231 to create a Time Delay Strong Lensing probe (TDSL). In flat Λ cold dark matter (ΛCDM) with free matter and energy density, we find H0 =71.9^{+2.4}_{-3.0} {km s^{-1} Mpc^{-1}} and Ω _{Λ }=0.62^{+0.24}_{-0.35}. This measurement is completely independent of, and in agreement with, the local distance ladder measurements of H0. We explore more general cosmological models combining TDSL with other probes, illustrating its power to break degeneracies inherent to other methods. The joint constraints from TDSL and Planck are H0 = 69.2_{-2.2}^{+1.4} {km s^{-1} Mpc^{-1}}, Ω _{Λ }=0.70_{-0.01}^{+0.01} and Ω _k=0.003_{-0.006}^{+0.004} in open ΛCDM and H0 =79.0_{-4.2}^{+4.4} {km s^{-1} Mpc^{-1}}, Ω _de=0.77_{-0.03}^{+0.02} and w=-1.38_{-0.16}^{+0.14} in flat wCDM. In combination with Planck and baryon acoustic oscillation data, when relaxing the constraints on the numbers of relativistic species we find Neff = 3.34_{-0.21}^{+0.21} in NeffΛCDM and when relaxing the total mass of neutrinos we find Σmν ≤ 0.182 eV in mνΛCDM. Finally, in an open wCDM in combination with Planck and cosmic microwave background lensing, we find H0 =77.9_{-4.2}^{+5.0} {km s^{-1} Mpc^{-1}}, Ω _de=0.77_{-0.03}^{+0.03}, Ω _k=-0.003_{-0.004}^{+0.004} and w=-1.37_{-0.23}^{+0.18}.

  10. Delayed ejaculation

    MedlinePlus

    Ejaculatory incompetence; Sex - delayed ejaculation; Retarded ejaculation; Anejaculation; Infertility - delayed ejaculation ... include: Religious background that makes the person view sex as sinful Lack of attraction for a partner ...

  11. Viva Delay.

    PubMed

    Yahaghi, Hossein; Sorooshian, Shahryar; Yahaghi, Javad

    2016-06-28

    The time delay between submission of a thesis and Viva Voce is intolerable for students. This letter tries to draw the readers' attention to the effect of choosing the right examiner, in order to reduce the Viva Voce delay.

  12. [Delayed puberty].

    PubMed

    Edouard, T; Tauber, M

    2010-02-01

    Delayed puberty is defined in girls by the absence of breast development beyond 13 years old and in boys by the absence of testicular enlargement (< 4 ml) beyond 14 years old. Simple investigations lead to the diagnosis of central or peripheral hypogonadism and constitutional delay of puberty. In girls, delayed puberty is rare and often organic, and then Turner syndrome should be systematically suspected. In boys, delayed puberty is often constitutional and functional. Treatment is etiologic when possible, hormonal replacement therapy (oestrogen in girls and testosterone in boys) and psychological management.

  13. Delayed puberty.

    PubMed

    Traggiai, Cristina; Stanhope, Richard

    2002-03-01

    Puberty is the acquisition of secondary sexual characteristics associated with a growth spurt and resulting in the attainment of reproductive function. Delayed puberty is diagnosed when there is no breast development by 13.4 years of age in a girl and no testicular enlargement by 14.0 years in a boy. The aetiologies are: (i) pubertal delay, either with constitutional delay of growth and puberty or secondary to chronic illness, and (ii) pubertal failure, with hypogonadotrophic (defect in the hypothalamo-pituitary region) or hypergonadotrophic (secondary to gonadal failure) hypogonadism, or both (secondary to radio/chemotherapy). The investigation includes: history, auxological data and pubertal development examination. Boys usually require treatment and, if they do not respond, investigation. In girls it is appropriate to measure the thyroid function and karyotype first and, if necessary, to offer treatment. If they present with dysmorphic features, or positive familial history, an assessment is required before treatment.

  14. Delayed puberty.

    PubMed

    Fenichel, Patrick

    2012-01-01

    Since puberty is a long ongoing developmental process with significant individual and population differences in timing, the definition of delayed puberty for a given individual needs to rest on simple, though arbitrary criteria based on epidemiological data. Although several genes involved in the hypothalamic-pituitary-gonadal maturation cascade have been characterized recently from familial or sporadic cases of primitive isolated hypogonadotropic hypogonadism, many genes regulating puberty onset remain undetermined. In case of delayed puberty and/or primary amenorrhea, a complete clinical examination including a detailed past history will evaluate the development of secondary sex characteristics, verify the association with a growth delay and look for specific indicative features pertaining to the etiological diagnosis. This clinical check-up completed if necessary with biological, ultrasonographic, radiological and genetic investigations will try to determine which girls will have a permanent sexual infantilism of gonadal, hypophyseal or hypothalamic origin, which girls will undergo spontaneous but delayed puberty and which girls have primary amenorrhea with developed secondary sex characteristics. Therapeutic attitude will have to integrate etiological factors, statural prognosis, bone mass preservation and psychological factors.

  15. Delayed puberty.

    PubMed

    Reiter, Edward O; Lee, Peter A

    2002-02-01

    Normal puberty is a time of life and a process of development that results in full adult maturity of growth, sexual development, and psychosocial achievement. Delayed puberty describes the clinical condition in which the pubertal events start late (usually > +2.5 SD later than the mean) or are attenuated in progression. The differential diagnosis includes syndromes of low gonadotropin production, usually constitutional delay of growth and maturation associated with chronic disease, but also an array of gene-mediated disorders, and syndromes of primary gonadal dysfunction with hypergonadotropic hypogonadism, including Turner and Klinefelter syndromes, and a group of acquired and genetic abnormalities. Diagnostic assessment and varied therapeutic modalities are discussed. The issues of androgen or estrogen therapy are important to assess, and growth hormone treatment remains a difficult dilemma.

  16. On Strong Anticipation

    PubMed Central

    Stepp, N.; Turvey, M. T.

    2009-01-01

    We examine Dubois's (2003) distinction between weak anticipation and strong anticipation. Anticipation is weak if it arises from a model of the system via internal simulations. Anticipation is strong if it arises from the system itself via lawful regularities embedded in the system's ordinary mode of functioning. The assumption of weak anticipation dominates cognitive science and neuroscience and in particular the study of perception and action. The assumption of strong anticipation, however, seems to be required by anticipation's ubiquity. It is, for example, characteristic of homeostatic processes at the level of the organism, organs, and cells. We develop the formal distinction between strong and weak anticipation by elaboration of anticipating synchronization, a phenomenon arising from time delays in appropriately coupled dynamical systems. The elaboration is conducted in respect to (a) strictly physical systems, (b) the defining features of circadian rhythms, often viewed as paradigmatic of biological behavior based in internal models, (c) Pavlovian learning, and (d) forward models in motor control. We identify the common thread of strongly anticipatory systems and argue for its significance in furthering understanding of notions such as “internal”, “model” and “prediction”. PMID:20191086

  17. Delaying obsolescence.

    PubMed

    Lawlor, Rob

    2015-04-01

    This paper argues that those who emphasise that designers and engineers need to plan for obsolescence are too conservative. Rather, in addition to planning for obsolescence, designers and engineers should also think carefully about what they could do in order delay obsolescence. They should so this by thinking about the design itself, thinking of ways in which products could be useful and appealing for longer before becoming obsolete, as well thinking about the wider context in terms of the marketing of products, and also the social and legal. The paper also considers objections that these suggestions are unrealistically idealistic, failing to recognise the economic realities. I respond to these objections appealing to research in advertising, psychology, cognitive linguistics, philosophy, history, and economics, as well as drawing on the Statement of Ethical Principles developed by the Royal Academy of Engineering and the Engineering Council.

  18. Hamlet's delay.

    PubMed

    Dendy, E B

    2001-01-01

    This paper raises a question about Freud's understanding of Hamlet and offers a fresh psychoanalytic perspective on the play, emphasizing the psychological use made of Hamlet by the audience. It suggests Hamlet and Claudius both serve as sacrificial objects, scapegoats, for the audience, embodying, through a mechanism of both identification and disidentification, the fulfillment, punishment, and renunciation of the audience's forbidden (i.e. Oedipal) wishes. The play is thus seen to represent unconsciously a rite of sacrifice in which both Claudius and Hamlet, both the father and the son, are led, albeit circuitously, to the slaughter. The need for delay on the part of Hamlet is thus seen to arise not merely from Hamlet's psychology, whatever the audience may project onto it, but ultimately from the function (both sadistic and defensive) that the sacrificial spectacle, the play as a whole, serves for the audience. The paper also speculates somewhat on the role of tragic heroes and heroines in general, and points to the unconscious collusion that permits author and audience to make use of them. Finally, in an addendum, the paper discusses the work of René Girard, a nonpsychoanalytic thinker whose ideas nonetheless are somewhat similar to those presented here.

  19. UAVs and Control Delays

    DTIC Science & Technology

    2005-09-01

    Transport Delay itI tl2 s2+(tl +t2tI2)s+ 1 Delay Figure 17 A Matlab Simulink model used to compare a simple delayed system , in this case an integrator...23 3 Control of tim e-delay system s...discuss the various sources of delays, leading to an assessment of typical delays to be expected in a few example systems . Sources of delay that will

  20. Delayed childbearing.

    PubMed

    Francis, H H

    1985-06-01

    In many Western nations, including England and Wales, Sweden, and the US, there is a current trend towards delayed childbearing because of women's pursuit of a career, later marriage, a longer interval between marriage and the 1st birth, and the increasing number of divorcees having children in a 2nd marriage. Wives of men in social classes I and II in England and Wales are, on average, having their 1st child at 27.9 years, 1.6 years later than in 1973, and in social classes IV and V, 1.0 years later than in 1973, at a mean age of 23.7 years. Consequently, the total period fertility rate for British women aged 30-34 years, 35-39 years, and 40 and over increased by 4%, 2%, and 4%, respectively, between 1982-83, in contrast to reductions of 2% and 3%, respectively, in the 15-19 year and 20-24 year age groups, with the 25-29-year-olds remaining static. The average maternal mortality for all parties in England and Wales during 1976-78 was 106/million for adolescents, 70.4/million for 20-24 year-olds, and 1162/million for those aged 40 years and older. The specific obstetric and allied conditions which increase with age are the hypertensive diseases of pregnancy, hemorrhage, pulmonary embolism, abortion, cardiac disease, caesarean section, ruptured uterus, and amniotic fluid embolism. The Swedish Medical Birth Registry of all live births and perinatal deaths since 1973 has shown that the risk of late fetal death is significantly greater in women aged 30-39 years than in those of the same parity and gravidity aged 20-24 years. The risk of giving birth to low birth weight babies preterm and at term and of premature labor are similarly increased. The early neonatal death rate also was increased for primigravidas and nulliparas in the 30-39 year age group but not in parous women. This is, in part, due to the rise in incidence of fetal abnormalities with advancing maternal age because of chromosomal and nonchromosomal anomalies. These also appear to be the cause of the

  1. Behavioral effects of delayed timeouts from reinforcement.

    PubMed

    Byrne, Tom; Poling, Alan

    2017-02-14

    Timeouts are sometimes used in applied settings to reduce target responses, and in some circumstances delays are unavoidably imposed between the onset of a timeout and the offset of the response that produces it. The present study examined the effects of signaled and unsignaled timeouts in rats exposed to concurrent fixed-ratio 1 fixed-ratio 1 schedules of food delivery, where each response on one lever, the location of which changed across conditions, produced both food and a delayed 10-s timeout. Delays of 0 to 38 s were examined. Delayed timeouts often, but not always, substantially reduced the number of responses emitted on the lever that produced timeouts relative to the number emitted on the lever that did not produce timeouts. In general, greater sensitivity was observed to delayed timeouts when they were signaled. These results demonstrate that delayed timeouts, like other delayed consequences, can affect behavior, albeit less strongly than immediate consequences.

  2. Early identification of motor delay

    PubMed Central

    Harris, Susan R.

    2016-01-01

    Objective To describe the Harris Infant Neuromotor Test (HINT), an infant neuromotor test using Canadian norms published in 2010 that could be used to screen for motor delay during the first year of life. Quality of evidence Extensive research has been published on the intrarater, interrater, and test-retest reliability and the content, concurrent, predictive, and known-groups validity of the HINT, as well as on the sensitivity, specificity, and positive and negative predictive values of parental concerns, as assessed by the HINT. Most evidence is level II. Main message Diagnosing motor delays during the first year of life is important because these often indicate more generalized developmental delays or specific disabilities, such as cerebral palsy. Parental concerns about their children’s motor development are strongly predictive of subsequent diagnoses involving motor delay. Conclusion Only through early identification of developmental motor delays, initially with screening tools such as the HINT, is it possible to provide referrals for early intervention that could benefit both the infant and the family. PMID:27521388

  3. Relativistic calculations of angle-dependent photoemission time delay

    NASA Astrophysics Data System (ADS)

    Kheifets, Anatoli; Mandal, Ankur; Deshmukh, Pranawa C.; Dolmatov, Valeriy K.; Keating, David A.; Manson, Steven T.

    2016-07-01

    Angular dependence of photoemission time delay for the valence n p3 /2 and n p1 /2 subshells of Ar, Kr, and Xe is studied in the dipole relativistic random phase approximation. Strong angular anisotropy of the time delay is reproduced near respective Cooper minima while the spin-orbit splitting affects the time delay near threshold.

  4. Delayed Geodynamo in Hadean

    NASA Astrophysics Data System (ADS)

    Arkani-Hamed, J.

    2014-12-01

    Paleointensity measurements of Archean rocks reveal a strong geodynamo at ~3.45 Ga, while excess nitrogen content of lunar soil samples implies no geodynamo at ~3.9 Ga. Here I propose that initiation of a strong geodynamo is delayed due to accretion style of Earth, involving collision and merging of a few dozen Moon to Mars size planetary embryos. Two accretion scenarios consisting of 25 and 50 embryos are investigated. The collision of an embryo heats the proto-Earth's core differentially and the rotating low-viscosity core stably stratifies, creating a spherically symmetric and radially increasing temperature distribution. Convection starts in the outer core after each impact but is destroyed by the next impact. The iron core of an impacting embryo descends in the mantle and merges to the proto-Earth's core. Both adiabatic and non-adiabatic merging cases are studied. A major part of the gravitational energy released due to core merging is used to lift up the upper portion of the core to emplace the impactor core material at the neutrally buoyant level in the proto-Earth's core. The remaining energy is converted to heat. In the adiabatic case the merging embryo's core retains all of the remaining energy, while in the non-adiabatic merging 50% of the remaining energy is shared with the outer part of the proto-Earth's core where the embryo's core descends. The two merging models result in significantly different temperature distributions in the core at the end of accretion. After the accretion, the convecting shell in the outer core grows monotonically and generates geodynamo gradually. It takes about 50-100 Myr for the convecting shell to generate a strong dipole field at the surface, 50,000 to 100,000 nT, in the presence of a large stably stratified liquid inner core when the convecting outer core thickness exceeds about one half the radius of the Earth's core.

  5. Delayed puberty in girls

    MedlinePlus

    ... hormones. These changes normally begin to appear in girls between ages 8 to 14 years old. With delayed puberty, these changes either don't occur, or if they do, they don't progress normally. Delayed puberty is more common in boys than in girls. Causes In most cases of delayed puberty, growth ...

  6. Adaptive global synchronization of a general complex dynamical network with non-delayed and delayed coupling

    NASA Astrophysics Data System (ADS)

    Wen, Sun; Chen, Shihua; Guo, Wanli

    2008-10-01

    This Letter investigates the global synchronization of a general complex dynamical network with non-delayed and delayed coupling. Based on Lasalle's invariance principle, adaptive global synchronization criteria is obtained. Analytical result shows that under the designed adaptive controllers, a general complex dynamical network with non-delayed and delayed coupling can globally asymptotically synchronize to a given trajectory. What is more, the node dynamic need not satisfy the very strong and conservative uniformly Lipschitz condition and the coupling matrix is not assumed to be symmetric or irreducible. Finally, numerical simulations are presented to verify the effectiveness of the proposed synchronization criteria.

  7. Angular dependence of Wigner time delay: Relativistic Effects

    NASA Astrophysics Data System (ADS)

    Mandal, A.; Deshmukh, P. C.; Manson, S. T.; Kkeifets, A. S.

    2016-05-01

    Laser assisted photoionization time delay mainly consists of two parts: Wigner time delay, and time delay in continuum-continuum transition. Wigner time delay results from the energy derivative of the phase of the photoionization amplitude (matrix element). In general, the photoionization time delay is not the same in all directions relative to the incident photon polarization, although when a single transition dominates the amplitude, the resultant time delay is essentially isotropic. The relativistic-random-phase approximation is employed to determine the Wigner time delay in photoionization from the outer np subshells of the noble gas atoms, Ne through Xe. The time delay is found to significantly depend on angle, as well as energy. The angular dependence of the time delay is found to be quite sensitive to atomic dynamics and relativistic effects, and exhibit strong energy and angular variation in the neighborhood of Cooper minima. Work supported by DOE, Office of Chemical Sciences and DST (India).

  8. Phase derivatives and simulation of strong ground motions

    USGS Publications Warehouse

    Boore, D.M.

    2003-01-01

    Phase derivatives can be used to compute instantaneous frequency and envelope delay (also known as group delay). Envelope delay, in the guise of phase differences, has been used by engineers in the simulation of strong ground motion, particularly as a way of controlling the duration of motion. Simulations using the stochastic method, in which duration is a simple function of source duration and a path-dependent duration, possess envelope delay properties similar to those from simulations based on phase differences. Envelope delay provides a way of extending the standard stochastic method to produce nonstationary frequency content, as produced by ground motions containing surface waves.

  9. CGI delay compensation

    NASA Technical Reports Server (NTRS)

    Mcfarland, Richard E.

    1986-01-01

    Computer-generated graphics in real-time helicopter simulation produces objectionable scene-presentation time delays. In the flight simulation laboratory at Ames Research Center, it has been determined that these delays have an adverse influence on pilot performance during aggressive tasks such as nap-of-the-earth (NOE) maneuvers. Using contemporary equipment, computer-generated image (CGI) time delays are an unavoidable consequence of the operations required for scene generation. However, providing that magnitide distortions at higher frequencies are tolerable, delay compensation is possible over a restricted frequency range. This range, assumed to have an upper limit of perhaps 10 or 15 rad/sec, conforms approximately to the bandwidth associated with helicopter handling qualities research. A compensation algorithm is introduced here and evaluated in terms of tradeoffs in frequency responses. The algorithm has a discrete basis and accommodates both a large, constant transport delay interval and a periodic delay interval, as associated with asynchronous operations.

  10. Environmentally Benign Pyrotechnic Delays

    DTIC Science & Technology

    2012-06-01

    jay.poret@us.army.mil † School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA ABSTRACT Pyrotechnic delays are used in...benign formulations are described. The delay time of the new system is easily tunable. These compositions will consistently function in aluminum ...tunable. These compositions will consistently function in aluminum housings which is generally difficult for delay compositions due to extreme thermal

  11. Delayed puberty and amenorrhea.

    PubMed

    Hoffman, Barbara; Bradshaw, Karen D

    2003-11-01

    The ability to diagnose and manage disorders that cause delayed puberty requires a thorough understanding of the physical and hormonal events of puberty. Wide variation exists within normal pubertal maturation, but most adolescent girls in the United States have begun to mature by the age of 13. Delayed puberty, a rare condition in girls, occurs in only approximately 2.5% of the population. Constitutional delay, genetic defects, or hypothalamic-pituitary disorders are common causes. Amenorrhea, often found as a symptom of delayed puberty, may be due to congenital genital tract anomalies, ovarian failure, or chronic anovulation with estrogen presence or with estrogen absence.

  12. Delayed Orgasm and Anorgasmia

    PubMed Central

    Jenkins, Lawrence C.; Mulhall, John P.

    2016-01-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies; which include: medications, penile sensation loss, endocrinopathies, penile hyperstimulation and psychological etiologies, amongst others. Unfortunately, there are no excellent pharmacotherapies for delayed orgasm/anorgasmia, and treatment revolves largely around addressing potential causative factors and psychotherapy. PMID:26439762

  13. Delayed orgasm and anorgasmia.

    PubMed

    Jenkins, Lawrence C; Mulhall, John P

    2015-11-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies, which include medications, penile sensation loss, endocrinopathies, penile hyperstimulation, and psychological etiologies. Unfortunately, there are no excellent pharmacotherapies for delayed orgasm/anorgasmia, and treatment revolves largely around addressing potential causative factors and psychotherapy. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  14. Delayed emergence after anesthesia.

    PubMed

    Tzabazis, Alexander; Miller, Christopher; Dobrow, Marc F; Zheng, Karl; Brock-Utne, John G

    2015-06-01

    In most instances, delayed emergence from anesthesia is attributed to residual anesthetic or analgesic medications. However, delayed emergence can be secondary to unusual causes and present diagnostic dilemmas. Data from clinical studies is scarce and most available published material is comprised of case reports. In this review, we summarize and discuss less common and difficult to diagnose reasons for delayed emergence and present cases from our own experience or reference published case reports/case series. The goal is to draw attention to less common reasons for delayed emergence, identify patient populations that are potentially at risk and to help anesthesiologists identifying a possible cause why their patient is slow to wake up.

  15. VARIABLE TIME DELAY MEANS

    DOEpatents

    Clemensen, R.E.

    1959-11-01

    An electrically variable time delay line is described which may be readily controlled simuitaneously with variable impedance matching means coupied thereto such that reflections are prevented. Broadly, the delay line includes a signal winding about a magnetic core whose permeability is electrically variable. Inasmuch as the inductance of the line varies directly with the permeability, the time delay and characteristic impedance of the line both vary as the square root of the permeability. Consequently, impedance matching means may be varied similariy and simultaneously w:th the electrically variable permeability to match the line impedance over the entire range of time delay whereby reflections are prevented.

  16. Digital time delay

    DOEpatents

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.

  17. Time Delay Estimation

    DTIC Science & Technology

    2006-01-01

    investigate the possibility of exploiting the properties of a detected Low Probability of Intercept (LPI) signal waveform to estimate time delay, and by...ratios, namely 10 dB and less. We also examine the minimum time –delay estimate error – the Cramer–Rao bound. The results indicate that the method

  18. IDENTIFYING ANOMALIES IN GRAVITATIONAL LENS TIME DELAYS

    SciTech Connect

    Congdon, Arthur B.; Keeton, Charles R.; Nordgren, C. Erik E-mail: keeton@physics.rutgers.ed

    2010-02-01

    We examine the ability of gravitational lens time delays to reveal complex structure in lens potentials. In a previous paper, we predicted how the time delay between the bright pair of images in a 'fold' lens scales with the image separation, for smooth lens potentials. Here we show that the proportionality constant increases with the quadrupole moment of the lens potential, and depends only weakly on the position of the source along the caustic. We use Monte Carlo simulations to determine the range of time delays that can be produced by realistic smooth lens models consisting of isothermal ellipsoid galaxies with tidal shear. We can then identify outliers as 'time delay anomalies'. We find evidence for anomalies in close image pairs in the cusp lenses RX J1131 - 1231 and B1422+231. The anomalies in RX J1131 - 1231 provide strong evidence for substructure in the lens potential, while at this point the apparent anomalies in B1422+231 mainly indicate that the time delay measurements need to be improved. We also find evidence for time delay anomalies in larger-separation image pairs in the fold lenses, B1608+656 and WFI 2033 - 4723, and the cusp lens RX J0911+0551. We suggest that these anomalies are caused by some combination of substructure and a complex lens environment. Finally, to assist future monitoring campaigns we use our smooth models with shear to predict the time delays for all known four-image lenses.

  19. Simple method of measuring delay time in manufacturing delay lines

    NASA Astrophysics Data System (ADS)

    Kasahara, Yukio; Mikoda, Masanari

    1982-07-01

    A simple method for measuring delay time in an operational frequency range is required in manufacturing delay lines used for video tape recorders and television receiver sets. This paper describes a simple method of measuring and adjusting the delay time of such delay lines. The delay time is obtained by measuring a phase difference ϑ between the signals at the input and output transducers of the delay line with frequencies under test. The delay time is more precisely obtained by measuring the ϑ at a constant frequency within the bandwidth of the delay line. A delay-time tolerance of a polished glass medium at 3.58 MHz was found to be within 100 ns. The delay time was found to be shortened by 30 ns by attaching the medium on polishing powder and oil. Also shown is a simple method for adjusting the delay time by polishing a delay medium while measuring the phase difference.

  20. Delayed neutrons in fission of polonium isotopes

    SciTech Connect

    Ramazanov, R.; Urikbaev, Z.S.; Maksyutenko, B.P.; Ignat'ev, S.V.

    1988-06-01

    A strong difference is found in the relative yields of delayed neutrons in the production of compound nuclei of polonium isotopes in reactions in which bismuth and lead are bombarded by various charged particles. The effect can be partially explained by the different lengths of the ..beta..-decay chains of the light and heavy fission products.

  1. Partially strong WW scattering

    SciTech Connect

    Cheung Kingman; Chiang Chengwei; Yuan Tzuchiang

    2008-09-01

    What if only a light Higgs boson is discovered at the CERN LHC? Conventional wisdom tells us that the scattering of longitudinal weak gauge bosons would not grow strong at high energies. However, this is generally not true. In some composite models or general two-Higgs-doublet models, the presence of a light Higgs boson does not guarantee complete unitarization of the WW scattering. After partial unitarization by the light Higgs boson, the WW scattering becomes strongly interacting until it hits one or more heavier Higgs bosons or other strong dynamics. We analyze how LHC experiments can reveal this interesting possibility of partially strong WW scattering.

  2. Speech and Language Delay

    MedlinePlus

    ... adults)Being a twinAutism (a developmental disorder)Elective mutism (the child just doesn’t want to talk) ... palsy, developmental disability, Early Language Milestone Scale, elective mutism, expressive language disorder, hearing loss, language delay, psychosocial ...

  3. Choice and reinforcement delay

    SciTech Connect

    Gentry, G.D.; Marr, M.J.

    1980-01-01

    Previous studies of choice between two delayed reinforcers have indicated that the relative immediacy of the reinforcer is a major determinant of the relative frequency of responding. Parallel studies of choice between two interresponse times have found exceptions to this generality. The present study looked at the choice by pigeons between two delays, one of which was always four times longer than the other, but whose absolute durations were varied across conditions. The results indicated that choice is not uniquely determined by the relative immediacy of reinforcement, but that absolute delays are also involved. Models for concurrent chained schedules appear to be more applicable to the present data than the matching relation; however, these too failed to predict choice for long delays.

  4. Delayed puberty in boys

    MedlinePlus

    ... Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 139. Curry SA, Biancuzzo RM. ... FF, ed. Ferri's Clinical Advisor 2017 . Philadelphia, PA: Elsevier; 2017:348-350. Haddad NG, Eugster EA. Delayed ...

  5. Time delay spectrum conditioner

    DOEpatents

    Greiner, Norman R.

    1980-01-01

    A device for delaying specified frequencies of a multiple frequency laser beam. The device separates the multiple frequency beam into a series of spatially separated single frequency beams. The propagation distance of the single frequency beam is subsequently altered to provide the desired delay for each specific frequency. Focusing reflectors can be utilized to provide a simple but nonadjustable system or, flat reflectors with collimating and focusing optics can be utilized to provide an adjustable system.

  6. Strong Navajo Marriages

    ERIC Educational Resources Information Center

    Skogrand, Linda; Mueller, Mary Lou; Arrington, Rachel; LeBlanc, Heidi; Spotted Elk, Davina; Dayzie, Irene; Rosenbrand, Reva

    2008-01-01

    The purpose of this qualitative study, conducted in two Navajo Nation chapters, was to learn what makes Navajo marriages strong because no research has been done on this topic. Twenty-one Navajo couples (42 individuals) who felt they had strong marriages volunteered to participate in the study. Couples identified the following marital strengths:…

  7. Delay of Transition Using Forced Damping

    NASA Technical Reports Server (NTRS)

    Exton, Reginald J.

    2014-01-01

    Several experiments which have reported a delay of transition are analyzed in terms of the frequencies of the induced disturbances generated by different flow control elements. Two of the experiments employed passive stabilizers in the boundary layer, one leading-edge bluntness, and one employed an active spark discharge in the boundary layer. It is found that the frequencies generated by the various elements lie in the damping region of the associated stability curve. It is concluded that the creation of strong disturbances in the damping region stabilizes the boundary-layer and delays the transition from laminar to turbulent flow.

  8. Living Bones, Strong Bones

    NASA Image and Video Library

    In this classroom activity, engineering, nutrition, and physical activity collide when students design and build a healthy bone model of a space explorer which is strong enough to withstand increas...

  9. Downhole delay assembly for blasting with series delay

    DOEpatents

    Ricketts, Thomas E.

    1982-01-01

    A downhole delay assembly is provided which can be placed into a blasthole for initiation of explosive in the blasthole. The downhole delay assembly includes at least two detonating time delay devices in series in order to effect a time delay of longer than about 200 milliseconds in a round of explosions. The downhole delay assembly provides a protective housing to prevent detonation of explosive in the blasthole in response to the detonation of the first detonating time delay device. There is further provided a connection between the first and second time delay devices. The connection is responsive to the detonation of the first detonating time delay device and initiates the second detonating time delay device. A plurality of such downhole delay assemblies are placed downhole in unfragmented formation and are initiated simultaneously for providing a round of explosive expansions. The explosive expansions can be used to form an in situ oil shale retort containing a fragmented permeable mass of formation particles.

  10. The Strong Nuclear Force

    SciTech Connect

    Lincoln, Don

    2016-05-24

    Scientists are aware of four fundamental forces- gravity, electromagnetism, and the strong and weak nuclear forces. Most people have at least some familiarity with gravity and electromagnetism, but not the other two. How is it that scientists are so certain that two additional forces exist? In this video, Fermilab’s Dr. Don Lincoln explains why scientists are so certain that the strong force exists.

  11. The Strong Nuclear Force

    ScienceCinema

    Lincoln, Don

    2016-07-12

    Scientists are aware of four fundamental forces- gravity, electromagnetism, and the strong and weak nuclear forces. Most people have at least some familiarity with gravity and electromagnetism, but not the other two. How is it that scientists are so certain that two additional forces exist? In this video, Fermilab’s Dr. Don Lincoln explains why scientists are so certain that the strong force exists.

  12. Strong Cosmic Censorship

    NASA Astrophysics Data System (ADS)

    Isenberg, James

    2017-01-01

    The Hawking-Penrose theorems tell us that solutions of Einstein's equations are generally singular, in the sense of the incompleteness of causal geodesics (the paths of physical observers). These singularities might be marked by the blowup of curvature and therefore crushing tidal forces, or by the breakdown of physical determinism. Penrose has conjectured (in his `Strong Cosmic Censorship Conjecture`) that it is generically unbounded curvature that causes singularities, rather than causal breakdown. The verification that ``AVTD behavior'' (marked by the domination of time derivatives over space derivatives) is generically present in a family of solutions has proven to be a useful tool for studying model versions of Strong Cosmic Censorship in that family. I discuss some of the history of Strong Cosmic Censorship, and then discuss what is known about AVTD behavior and Strong Cosmic Censorship in families of solutions defined by varying degrees of isometry, and discuss recent results which we believe will extend this knowledge and provide new support for Strong Cosmic Censorship. I also comment on some of the recent work on ``Weak Null Singularities'', and how this relates to Strong Cosmic Censorship.

  13. Prediction of delayed subsidence

    NASA Astrophysics Data System (ADS)

    Burns, K.

    A predictive model of delayed subsidence is discussed. A numerical implementation is tested on one of the best-described study areas, Allegheny County in Pennsylvania. In planning insurance of restitution measures, a predictive model is of value in estimating the magnitude of the problem and the size of long-term budgetary commitments. Contrary to active subsidence, which occurs concurrently with mining operations, or is completed within a few days following coal extraction, delayed subsidence may take many years to appear at the surface after coal mines are abandoned. There are two principal morphological types of delayed subsidence: troughs, which are shallow depressions, and sinks, which are steep-sided crown pits. Both types are damaging to surface structures, and a variety of methods were introduced to deal with the problem, ranging from subsidence insurance to site restitution.

  14. [Delayed post effort muscle soreness].

    PubMed

    Coudreuse, J M; Dupont, P; Nicol, C

    2004-08-01

    Muscle intolerance to exercise may result from different processes. Diagnosis involves confirming first the source of pain, then potential pathological myalgia. Delayed-onset muscle soreness (DOMS), commonly referred as tiredness, occurs frequently in sport. DOMS usually develops 12-48 h after intensive and/or unusual eccentric muscle action. Symptoms usually involve the quadriceps muscle group but may also affect the hamstring and triceps surae groups. The muscles are sensitive to palpation, contraction and passive stretch. Acidosis, muscle spasm and microlesions in both connective and muscle tissues may explain the symptoms. However, inflammation appears to be the most common explanation. Interestingly, there is strong evidence that the progression of the exercise-induced muscle injury proceeds no further in the absence of inflammation. Even though unpleasant, DOMS should not be considered as an indicator of muscle damage but, rather, a sign of the regenerative process, which is well known to contribute to the increased muscle mass. DOMS can be associated with decreased proprioception and range of motion, as well as maximal force and activation. DOMS disappears 2-10 days before complete functional recovery. This painless period is ripe for additional joint injuries. Similarly, if some treatments are well known to attenuate DOMS, none has been demonstrated to accelerate either structural or functional recovery. In terms of the role of the inflammatory process, these treatments might even delay overall recovery.

  15. Logistic map with a delayed feedback: Stability of a discrete time-delay control of chaos.

    PubMed

    Buchner, T; Zebrowski, J J

    2001-01-01

    The logistic map with a delayed feedback is studied as a generic model. The stability of the model and its bifurcation scheme is analyzed as a function of the feedback amplitude and of the delay. Stability analysis is performed semianalytically. A relation between the delay and the periodicity of the orbit, which explains why some terms used in chaos control are ineffective, was found. The consequences for chaos control are discussed. The structure of bifurcations is found to depend strongly on the parity and on the length of the delay. Boundary crisis, the tangent, the Neimark, as well as the period-doubling bifurcations occur in this system. The effective dimension of the model is also discussed.

  16. Yugoslav strong motion network

    NASA Astrophysics Data System (ADS)

    Mihailov, Vladimir

    1985-04-01

    Data concerning ground motion and the response of structures during strong earthquakes are necessary for seismic hazard evaluation and the definition of design criteria for structures to be constructed in seismically active zones. The only way to obtain such data is the installation of a strong-motion instrument network. The Yugoslav strong-motion programme was created in 1972 to recover strong-motion response data used by the structural engineering community in developing earthquake resistant design. Instruments, accelerographs SMA-1 and seismoscopes WM-1, were installed in free-field stations and on structures (high-rise buildings, dams, bridges, etc.). A total number of 176 accelerographs and 137 seismoscopes have been installed and are operating in Yugoslavia. The strong-motion programme in Yugoslavia consists of five subactivities: network design, network operation, data processing, network management and research as well as application. All these activities are under the responsibility of IZIIS in cooperation with the Yugoslav Association of Seismology. By 1975 in the realisation of this project participated the CALTECH as cooperative institution in the joint American-Yugoslav cooperative project. The results obtained which are presented in this paper, and their application in the aseismic design justify the necessity for the existence of such a network in Yugoslavia.

  17. 'No delays achiever'.

    PubMed

    2007-05-01

    The latest version of the NHS Institute for Innovation and Improvement's 'no delays achiever', a web based tool created to help NHS organisations achieve the 18-week target for GP referrals to first treatment, is available at www.nodelaysachiever.nhs.uk.

  18. Contingencies promote delay tolerance.

    PubMed

    Ghaemmaghami, Mahshid; Hanley, Gregory P; Jessel, Joshua

    2016-09-01

    The effectiveness of functional communication training as treatment for problem behavior depends on the extent to which treatment can be extended to typical environments that include unavoidable and unpredictable reinforcement delays. Time-based progressive delay (TBPD) often results in the loss of acquired communication responses and the resurgence of problem behavior, whereas contingency-based progressive delay (CBPD) appears to be effective for increasing tolerance for delayed reinforcement. No direct comparison of TBPD and CBPD has, however, been conducted. We used single-subject designs to compare the relative efficacy of TBPD and CBPD. Four individuals who engaged in problem behavior (e.g., aggression, vocal and motor disruptions, self-injury) participated. Results were consistent across all participants, and showed lower rates of problem behavior and collateral responses during CBPD than during TBPD. The generality of CBPD treatment effects, including optimal rates of communication and compliance with demands, was demonstrated across a small but heterogeneous group of participants, reinforcement contingencies, and contexts.

  19. Delayed traumatic diaphragmatic hernia

    PubMed Central

    Lu, Jing; Wang, Bo; Che, Xiangming; Li, Xuqi; Qiu, Guanglin; He, Shicai; Fan, Lin

    2016-01-01

    Abstract Background: Traumatic diaphragmatic hernias (TDHs) are sometimes difficult to identify at an early stage and can consequently result in diagnostic delays with life-threatening outcomes. It is the aim of this case study to highlight the difficulties encountered with the earlier detection of traumatic diaphragmatic hernias. Methods: Clinical data of patients who received treatment for delayed traumatic diaphragmatic hernias in registers of the First Affiliated Hospital of Xi’an Jiaotong University from 1998 to 2014 were analyzed retrospectively. Results: Six patients were included in this study. Left hemidiaphragm was affected in all of them. Most of the patients had a history of traffic accident and 1 a stab-penetrating injury. The interval from injury to developing symptoms ranged from 2 to 11 years (median 5 years). The hernial contents included the stomach, omentum, small intestine, and colon. Diaphragmatic injury was missed in all of them during the initial managements. All patients received operations once the diagnosis of delayed TDH was confirmed, and no postoperative mortality was detected. Conclusions: Delayed TDHs are not common, but can lead to serious consequences once occurred. Early detection of diaphragmatic injuries is crucial. Surgeons should maintain a high suspicion for injuries of the diaphragm in cases with abdominal or lower chest traumas, especially in the initial surgical explorations. We emphasize the need for radiographical follow-up to detect diaphragmatic injuries at an earlier stage. PMID:27512848

  20. Interferometric Propagation Delay

    NASA Technical Reports Server (NTRS)

    Goldstein, Richard

    1999-01-01

    Radar interferometry based on (near) exact repeat passes has lately been used by many groups of scientists, worldwide, to achieve state of the art measurements of topography, glacier and ice stream motion, earthquake displacements, oil field subsidence, lava flows, crop-induced surface decorrelation, and other effects. Variations of tropospheric and ionospheric propagation delays limit the accuracy of all such measurements. We are investigating the extent of this limitation, using data from the Shuttle radar flight, SIR-C, which is sensitive to the troposphere, and the Earth Resources Satellites, ERS-1/2, which are sensitive to both the troposphere and the ionosphere. We are presently gathering statistics of the delay variations over selected, diverse areas to determine the best accuracy possible for repeat track interferometry. The phases of an interferogram depend on both the topography of the scene and variations in propagation delay. The delay variations can be caused by movement of elements in the scene, by changes in tropospheric water vapor and by changes of the charge concentrations in the ionosphere. We plan to separate these causes by using the data from a third satellite visit (three-pass interferometry). The figure gives the geometry of the three-pass observations. The page of the figure is taken to be perpendicular to the spacecraft orbits. The three observational locations are marked on the figure, giving baselines B-12 and B-13, separated by the angle alpha. These parameters are almost constant over the whole scene. However, each pixel has an individual look angle, theta, which is related to the topography, rho is the slant range. A possible spurious time delay is shown. Additional information is contained in the original.

  1. Delayed fluorescence in photosynthesis.

    PubMed

    Goltsev, Vasilij; Zaharieva, Ivelina; Chernev, Petko; Strasser, Reto J

    2009-01-01

    Photosynthesis is a very efficient photochemical process. Nevertheless, plants emit some of the absorbed energy as light quanta. This luminescence is emitted, predominantly, by excited chlorophyll a molecules in the light-harvesting antenna, associated with Photosystem II (PS II) reaction centers. The emission that occurs before the utilization of the excitation energy in the primary photochemical reaction is called prompt fluorescence. Light emission can also be observed from repopulated excited chlorophylls as a result of recombination of the charge pairs. In this case, some time-dependent redox reactions occur before the excitation of the chlorophyll. This delays the light emission and provides the name for this phenomenon-delayed fluorescence (DF), or delayed light emission (DLE). The DF intensity is a decreasing polyphasic function of the time after illumination, which reflects the kinetics of electron transport reactions both on the (electron) donor and the (electron) acceptor sides of PS II. Two main experimental approaches are used for DF measurements: (a) recording of the DF decay in the dark after a single turnover flash or after continuous light excitation and (b) recording of the DF intensity during light adaptation of the photosynthesizing samples (induction curves), following a period of darkness. In this paper we review historical data on DF research and recent advances in the understanding of the relation between the delayed fluorescence and specific reactions in PS II. An experimental method for simultaneous recording of the induction transients of prompt and delayed chlorophyll fluorescence and decay curves of DF in the millisecond time domain is discussed.

  2. Interferometric Propagation Delay

    NASA Technical Reports Server (NTRS)

    Goldstein, Richard

    1999-01-01

    Radar interferometry based on (near) exact repeat passes has lately been used by many groups of scientists, worldwide, to achieve state of the art measurements of topography, glacier and ice stream motion, earthquake displacements, oil field subsidence, lava flows, crop-induced surface decorrelation, and other effects. Variations of tropospheric and ionospheric propagation delays limit the accuracy of all such measurements. We are investigating the extent of this limitation, using data from the Shuttle radar flight, SIR-C, which is sensitive to the troposphere, and the Earth Resources Satellites, ERS-1/2, which are sensitive to both the troposphere and the ionosphere. We are presently gathering statistics of the delay variations over selected, diverse areas to determine the best accuracy possible for repeat track interferometry. The phases of an interferogram depend on both the topography of the scene and variations in propagation delay. The delay variations can be caused by movement of elements in the scene, by changes in tropospheric water vapor and by changes of the charge concentrations in the ionosphere. We plan to separate these causes by using the data from a third satellite visit (three-pass interferometry). The figure gives the geometry of the three-pass observations. The page of the figure is taken to be perpendicular to the spacecraft orbits. The three observational locations are marked on the figure, giving baselines B-12 and B-13, separated by the angle alpha. These parameters are almost constant over the whole scene. However, each pixel has an individual look angle, theta, which is related to the topography, rho is the slant range. A possible spurious time delay is shown. Additional information is contained in the original.

  3. Strong Little Magnets

    ERIC Educational Resources Information Center

    Moloney, Michael J.

    2007-01-01

    Did you know that some strong little cylindrical magnets available in local hardware stores can have an effective circumferential current of 2500 A? This intriguing information can be obtained by hanging a pair of magnets at the center of a coil, as shown in Fig. 1, and measuring the oscillation frequency as a function of coil current.

  4. Partners: Forging Strong Relationships.

    ERIC Educational Resources Information Center

    Spears, Ellen, Ed.

    1999-01-01

    This newsletter issue asserts that sound, effective relationships in which diverse groups of people and organizations work together toward a common goal are the basis of the collaborative efforts in education that can accomplish change. The first article, "Partners: Forging Strong Relationships" (Sarah E. Torian), briefly describes the…

  5. Strong Little Magnets

    ERIC Educational Resources Information Center

    Moloney, Michael J.

    2007-01-01

    Did you know that some strong little cylindrical magnets available in local hardware stores can have an effective circumferential current of 2500 A? This intriguing information can be obtained by hanging a pair of magnets at the center of a coil, as shown in Fig. 1, and measuring the oscillation frequency as a function of coil current.

  6. Networks of strong ties

    NASA Astrophysics Data System (ADS)

    Shi, Xiaolin; Adamic, Lada A.; Strauss, Martin J.

    2007-05-01

    Social networks transmitting covert or sensitive information cannot use all ties for this purpose. Rather, they can only use a subset of ties that are strong enough to be “trusted”. This paper addresses whether it is still possible, under this restriction, for information to be transmitted widely and rapidly in social networks. We use transitivity as evidence of strong ties, requiring one or more shared contacts in order to count an edge as strong. We examine the effect of removing all non-transitive ties in two real social network data sets, imposing varying thresholds in the number of shared contacts. We observe that transitive ties occupy a large portion of the network and that removing all other ties, while causing some individuals to become disconnected, preserves the majority of the giant connected component. Furthermore, the average shortest path, important for the rapid diffusion of information, increases only slightly relative to the original network. We also evaluate the cost of forming transitive ties by modeling a random graph composed entirely of closed triads and comparing its connectivity and average shortest path with the equivalent Erdös-Renyi random graph. Both the empirical study and random model point to a robustness of strong ties with respect to the connectivity and small world property of social networks.

  7. Abortion: Strong's counterexamples fail.

    PubMed

    Di Nucci, E

    2009-05-01

    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally wrong even though that human being is not being deprived of a "valuable future". So Marquis would be wrong in thinking that what is essential about the wrongness of killing an adult human being is that they are being deprived of a valuable future. This paper shows that whichever way the concept of "valuable future" is interpreted, the proposed counterexamples fail: if it is interpreted as "future like ours", the proposed counterexamples have no bearing on Marquis's argument. If the concept is interpreted as referring to the patient's preferences, it must be either conceded that the patients in Strong's scenarios have some valuable future or admitted that killing them is not seriously morally wrong. Finally, if "valuable future" is interpreted as referring to objective standards, one ends up with implausible and unpalatable moral claims.

  8. [Diagnosis of delayed puberty].

    PubMed

    Busiah, K; Belien, V; Dallot, N; Fila, M; Guilbert, J; Harroche, A; Leger, J

    2007-09-01

    Puberty is the phenomenon that conducts once to reproductive maturation. Delayed puberty (DP) is defined by the absence of testicular development in boys beyond 14 years old (or a testicular volume lower than 4 ml) and by the absence of breast development in girls beyond 13 years old. DP occurs in approximatively 3% of cases. Most cases are functional DP, with a large amount of constitutional delay of puberty. Others etiologies are hypogonadotrophic hypogonadism like Kallmann syndrome, or hypergonadotrophic hypogonadism. Turner syndrome is a diagnostic one should not forget by its frequency. Treatment is hormonal replacement therapy and of the etiology. During the last decade, many genes have been identified and elucidated the etiological diagnosis of some hypogonadotrophic hypogonadism syndrome. Further studies are required in collaboration with molecular biologists to better understand the mechanism of hypothalamic pituitary gonadal axis abnormalities and of the neuroendocrine physiology of the onset of puberty.

  9. Theoretical Delay Time Distributions

    NASA Astrophysics Data System (ADS)

    Nelemans, Gijs; Toonen, Silvia; Bours, Madelon

    2013-01-01

    We briefly discuss the method of population synthesis to calculate theoretical delay time distributions of Type Ia supernova progenitors. We also compare the results of different research groups and conclude that, although one of the main differences in the results for single degenerate progenitors is the retention efficiency with which accreted hydrogen is added to the white dwarf core, this alone cannot explain all the differences.

  10. [Striated and delayed nephrography].

    PubMed

    Marlois, O; Padovani, J; Faure, F; Devred, P; Grangier, M L; Panuel, M

    1985-10-01

    About a case of striated and delayed nephrogram seen on a diabetic child, authors come back to the different etiologies. Among them, the tubular precipitation of Tamm-Horsfall protein seems to be given like on the right possibilities. Whatever is its etiology, the mechanism of striated appearance is always the same, being founded on the radiated disposal of the collecting ducts and on a tubular stasis beeing with iodine concentration.

  11. Delayed visual maturation.

    PubMed Central

    Cole, G F; Hungerford, J; Jones, R B

    1984-01-01

    Sixteen blind babies who were considered to be showing the characteristics of delayed visual maturation were studied prospectively. The diagnosis was made on clinical grounds, and the criteria for this are discussed. All of these infants developed visual responses between 4 and 6 months of age and had normal or near normal visual acuities by 1 year of age. Long term follow up, however, has shown neurological abnormalities in some of these children. PMID:6200080

  12. Delayed coking process

    SciTech Connect

    Shigley, J.K.; Roussel, K.M.; Harris, S.D.

    1991-07-02

    This patent describes improvement in a delayed premium coking process in which an aromatic mineral oil feedstock is heated to elevated temperature and introduced continuously to a coking drum under delayed coking conditions wherein the heated feedstock soaks in its contained heat to convert the feedstock to cracked vapors and premium coke at lower than normal coking temperatures in the range of about 780{degrees} F. to about 895{degrees} F. and in which the introduction of feedstock to the coking drum is discontinued after the coking drum is filled to a desired level. The improvement comprises: introducing additional aromatic mineral oil capable of forming coke admixed with a non-coking material to the coking drum under delayed coking conditions for a sufficient period of time to convert unconverted liquid material to coke wherein the concentration of aromatic mineral oil in the admixture is from 5 to 90 percent, and thereafter subjecting the contents of the coke drum to a heat soak at a temperature greater than the initial coking temperature whereby a premium coke having improved CTE and reduced fluff is obtained.

  13. Cosmological test using strong gravitational lensing systems

    NASA Astrophysics Data System (ADS)

    Yuan, C. C.; Wang, F. Y.

    2015-09-01

    As one of the probes of universe, strong gravitational lensing systems allow us to compare different cosmological models and constrain vital cosmological parameters. This purpose can be reached from the dynamic and geometry properties of strong gravitational lensing systems, for instance, time-delay Δτ of images, the velocity dispersion σ of the lensing galaxies and the combination of these two effects, Δτ/σ2. In this paper, in order to carry out one-on-one comparisons between ΛCDM universe and Rh = ct universe, we use a sample containing 36 strong lensing systems with the measurement of velocity dispersion from the Sloan Lens Advanced Camera for Surveys (SLACS) and Lens Structure and Dynamic survey (LSD) survey. Concerning the time-delay effect, 12 two-image lensing systems with Δτ are also used. In addition, Monte Carlo simulations are used to compare the efficiency of the three methods as mentioned above. From simulations, we estimate the number of lenses required to rule out one model at the 99.7 per cent confidence level. Comparing with constraints from Δτ and the velocity dispersion σ, we find that using Δτ/σ2 can improve the discrimination between cosmological models. Despite the independence tests of these methods reveal a correlation between Δτ/σ2 and σ, Δτ/σ2 could be considered as an improved method of σ if more data samples are available.

  14. Delay-correlation landscape reveals characteristic time delays of brain rhythms and heart interactions.

    PubMed

    Lin, Aijing; Liu, Kang K L; Bartsch, Ronny P; Ivanov, Plamen Ch

    2016-05-13

    Within the framework of 'Network Physiology', we ask a fundamental question of how modulations in cardiac dynamics emerge from networked brain-heart interactions. We propose a generalized time-delay approach to identify and quantify dynamical interactions between physiologically relevant brain rhythms and the heart rate. We perform empirical analysis of synchronized continuous EEG and ECG recordings from 34 healthy subjects during night-time sleep. For each pair of brain rhythm and heart interaction, we construct a delay-correlation landscape (DCL) that characterizes how individual brain rhythms are coupled to the heart rate, and how modulations in brain and cardiac dynamics are coordinated in time. We uncover characteristic time delays and an ensemble of specific profiles for the probability distribution of time delays that underly brain-heart interactions. These profiles are consistently observed in all subjects, indicating a universal pattern. Tracking the evolution of DCL across different sleep stages, we find that the ensemble of time-delay profiles changes from one physiologic state to another, indicating a strong association with physiologic state and function. The reported observations provide new insights on neurophysiological regulation of cardiac dynamics, with potential for broad clinical applications. The presented approach allows one to simultaneously capture key elements of dynamic interactions, including characteristic time delays and their time evolution, and can be applied to a range of coupled dynamical systems. © 2016 The Author(s).

  15. Delay-correlation landscape reveals characteristic time delays of brain rhythms and heart interactions

    NASA Astrophysics Data System (ADS)

    Lin, Aijing; Liu, Kang K. L.; Bartsch, Ronny P.; Ivanov, Plamen Ch.

    2016-05-01

    Within the framework of `Network Physiology', we ask a fundamental question of how modulations in cardiac dynamics emerge from networked brain-heart interactions. We propose a generalized time-delay approach to identify and quantify dynamical interactions between physiologically relevant brain rhythms and the heart rate. We perform empirical analysis of synchronized continuous EEG and ECG recordings from 34 healthy subjects during night-time sleep. For each pair of brain rhythm and heart interaction, we construct a delay-correlation landscape (DCL) that characterizes how individual brain rhythms are coupled to the heart rate, and how modulations in brain and cardiac dynamics are coordinated in time. We uncover characteristic time delays and an ensemble of specific profiles for the probability distribution of time delays that underly brain-heart interactions. These profiles are consistently observed in all subjects, indicating a universal pattern. Tracking the evolution of DCL across different sleep stages, we find that the ensemble of time-delay profiles changes from one physiologic state to another, indicating a strong association with physiologic state and function. The reported observations provide new insights on neurophysiological regulation of cardiac dynamics, with potential for broad clinical applications. The presented approach allows one to simultaneously capture key elements of dynamic interactions, including characteristic time delays and their time evolution, and can be applied to a range of coupled dynamical systems.

  16. Delay discounting by pathological gamblers.

    PubMed Central

    Dixon, Mark R; Marley, Janice; Jacobs, Eric A

    2003-01-01

    Discounting of delayed rewards by pathological gamblers was compared to discounting of delayed rewards by matched control nongambling participants. All participants completed a hypothetical choice task in which they made repeated choices between dollars 1,000 available after a delay and an equal or lesser amount of money available immediately. The delay to the large amount of money was varied from 1 week to 10 years across conditions. Indifference points between immediate money and delayed money were identified at each delay condition by varying the amount of immediate money across choice trials. For the majority of participants, indifference points decreased monotonically across delays. Overall, gamblers discounted the delayed rewards more steeply than did control participants. PMID:14768665

  17. Strongly Regular Graphs,

    DTIC Science & Technology

    1973-10-01

    The theory of strongly regular graphs was introduced by Bose r7 1 in 1963, in connection with partial geometries and 2 class association schemes. One...non adjacent vertices is constant and equal to ~. We shall denote by ~(p) (reap.r(p)) the set of vertices adjacent (resp.non adjacent) to a vertex p...is the complement of .2’ if the set of vertices of ~ is the set of vertices of .2’ and if two vertices in .2’ are adjacent if and only if they were

  18. Electromagnetic strong plasma turbulence

    SciTech Connect

    Melatos, A.; Jenet, F. A.; Robinson, P. A.

    2007-02-15

    The first large-scale simulations of continuously driven, two-dimensional electromagnetic strong plasma turbulence are performed, for electron thermal speeds 0.01c{<=}v{<=}0.57c, by integrating the Zakharov equations for coupled Langmuir and transverse (T) waves near the plasma frequency. Turbulence scalings and wave number spectra are calculated, a transition is found from a mix of trapped and free T eigenstates for v{>=}0.1c to just free eigenstates for v{<=}0.1c, and wave energy densities are observed to undergo slow quasiperiodic oscillations.

  19. Strongly correlated materials.

    PubMed

    Morosan, Emilia; Natelson, Douglas; Nevidomskyy, Andriy H; Si, Qimiao

    2012-09-18

    Strongly correlated materials are profoundly affected by the repulsive electron-electron interaction. This stands in contrast to many commonly used materials such as silicon and aluminum, whose properties are comparatively unaffected by the Coulomb repulsion. Correlated materials often have remarkable properties and transitions between distinct, competing phases with dramatically different electronic and magnetic orders. These rich phenomena are fascinating from the basic science perspective and offer possibilities for technological applications. This article looks at these materials through the lens of research performed at Rice University. Topics examined include: Quantum phase transitions and quantum criticality in "heavy fermion" materials and the iron pnictide high temperature superconductors; computational ab initio methods to examine strongly correlated materials and their interface with analytical theory techniques; layered dichalcogenides as example correlated materials with rich phases (charge density waves, superconductivity, hard ferromagnetism) that may be tuned by composition, pressure, and magnetic field; and nanostructure methods applied to the correlated oxides VO₂ and Fe₃O₄, where metal-insulator transitions can be manipulated by doping at the nanoscale or driving the system out of equilibrium. We conclude with a discussion of the exciting prospects for this class of materials.

  20. Programmable Differential Delay Circuit With Fine Delay Adjustment

    DOEpatents

    DeRyckere, John F.; Jenkins, Philip Nord; Cornett, Frank Nolan

    2002-07-09

    Circuitry that provides additional delay to early arriving signals such that all data signals arrive at a receiving latch with same path delay. The delay of a forwarded clock reference is also controlled such that the capturing clock edge will be optimally positioned near quadrature (depending on latch setup/hold requirements). The circuitry continuously adapts to data and clock path delay changes and digital filtering of phase measurements reduce errors brought on by jittering data edges. The circuitry utilizes only the minimum amount of delay necessary to achieve objective thereby limiting any unintended jitter. Particularly, this programmable differential delay circuit with fine delay adjustment is designed to allow the skew between ASICS to be minimized. This includes skew between data bits, between data bits and clocks as well as minimizing the overall skew in a channel between ASICS.

  1. In-flight evaluation of pure time delays in pitch and roll

    NASA Technical Reports Server (NTRS)

    Berry, D. T.

    1985-01-01

    An in-flight investigation of the effect of pure time delays in pitch and roll was undertaken. The evaluation tasks consisted of low lift-to-drag-ratio landings of various levels of difficulty and formation flying. The results indicate that the effect of time delay is strongly dependent on the task. In the pitch axis, in calm air, spot landings from a lateral offset were most strongly influenced by time delay. In the roll axis, in calm air, formation flying was most strongly influenced by time delay. However, when landings were made in turbulence, flying qualities in pitch were only slightly degraded, whereas in roll they were severely degraded.

  2. Delay Choice vs. Delay Maintenance: Different Measures of Delayed Gratification in Capuchin Monkeys (Cebus apella)

    PubMed Central

    Addessi, Elsa; Paglieri, Fabio; Beran, Michael J.; Evans, Theodore A.; Macchitella, Luigi; De Petrillo, Francesca; Focaroli, Valentina

    2013-01-01

    Delaying gratification involves two components: (i) delay choice (selecting a delayed reward over an immediate one), and (ii) delay maintenance (sustaining the decision to delay gratification even if the immediate reward is available during the delay). In primates, two tasks most commonly have explored these components, the Intertemporal choice task and the Accumulation task. It is unclear whether these tasks provide equivalent measures of delay of gratification. Here, we compared the performance of the same capuchin monkeys, belonging to two study populations, between these tasks. We found only limited evidence of a significant correlation in performance. Consequently, in contrast to what is often assumed, our data provide only partial support to the hypothesis that these tasks provide equivalent measures of delay of gratification. PMID:23544770

  3. Adaptive Phase Delay Generator

    NASA Technical Reports Server (NTRS)

    Greer, Lawrence

    2013-01-01

    There are several experimental setups involving rotating machinery that require some form of synchronization. The adaptive phase delay generator (APDG) the Bencic-1000 is a flexible instrument that allows the user to generate pulses synchronized to the rising edge of a tachometer signal from any piece of rotating machinery. These synchronized pulses can vary by the delay angle, pulse width, number of pulses per period, number of skipped pulses, and total number of pulses. Due to the design of the pulse generator, any and all of these parameters can be changed independently, yielding an unparalleled level of versatility. There are two user interfaces to the APDG. The first is a LabVIEW program that has the advantage of displaying all of the pulse parameters and input signal data within one neatly organized window on the PC monitor. Furthermore, the LabVIEW interface plots the rpm of the two input signal channels in real time. The second user interface is a handheld portable device that goes anywhere a computer is not accessible. It consists of a liquid-crystal display and keypad, which enable the user to control the unit by scrolling through a host of command menus and parameter listings. The APDG combines all of the desired synchronization control into one unit. The experimenter can adjust the delay, pulse width, pulse count, number of skipped pulses, and produce a specified number of pulses per revolution. Each of these parameters can be changed independently, providing an unparalleled level of versatility when synchronizing hardware to a host of rotating machinery. The APDG allows experimenters to set up quickly and generate a host of synchronizing configurations using a simple user interface, which hopefully leads to faster results.

  4. Strong, Lightweight, Porous Materials

    NASA Technical Reports Server (NTRS)

    Leventis, Nicholas; Meador, Mary Ann B.; Johnston, James C.; Fabrizio, Eve F.; Ilhan, Ulvi

    2007-01-01

    A new class of strong, lightweight, porous materials has been invented as an outgrowth of an effort to develop reinforced silica aerogels. The new material, called X-Aerogel is less hygroscopic, but no less porous and of similar density to the corresponding unmodified aerogels. However, the property that sets X-Aerogels apart is their mechanical strength, which can be as much as two and a half orders of magnitude stronger that the unmodified aerogels. X-Aerogels are envisioned to be useful for making extremely lightweight, thermally insulating, structural components, but they may also have applications as electrical insulators, components of laminates, catalyst supports, templates for electrode materials, fuel-cell components, and filter membranes.

  5. Quine's 'needlessly strong' holism.

    PubMed

    Verhaegh, Sander

    2017-02-01

    Quine is routinely perceived as having changed his mind about the scope of the Duhem-Quine thesis, shifting from what has been called an 'extreme holism' to a more moderate view. Where the Quine of 'Two Dogmas of Empiricism' argues that "the unit of empirical significance is the whole of science" (1951, 42), the later Quine seems to back away from this "needlessly strong statement of holism" (1991, 393). In this paper, I show that the received view is incorrect. I distinguish three ways in which Quine's early holism can be said to be wide-scoped and show that he has never changed his mind about any one of these aspects of his early view. Instead, I argue that Quine's apparent change of mind can be explained away as a mere shift of emphasis.

  6. Strongly correlated electronic materials

    SciTech Connect

    Bedell, K.; Albers, R.; Balatsky, A.; Bishop, A.; Bonca, J.; Gubernatis, J.; Gulasci, M.; Silver, R.; Trugman, S.

    1996-04-01

    This is the final report of a 3-year project. Novel electronic materials characterized by strong electronic correlations display a number of unexpected, often extraordinary, properties. These are likely to play a major role in purpose-specific high-technology electronic materials of the future developed for electronic, magnetic, and optical applications. This project sought to develop predictive control of the novel properties by formulating, solving and applying many-body models for the underlying microscopic physics. This predictive control required the development of new analytical and numerical many-body techniques and strategies for materials of varying strengths of interactions, dimensionality and geometry. Results are compared with experiment on classes of novel materials, and the robust techniques are used to predict additional properties and motivate key additional experiments.

  7. Vehicle barrier with access delay

    DOEpatents

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  8. Delayed reinforcement of operant behavior.

    PubMed

    Lattal, Kennon A

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement, but, also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between responses and reinforcers can be isolated from other features of the environment that often accompany delays, such as stimuli or changes in the temporal distribution or rate of reinforcement. The second question is that of the effects of delays on operant behavior. Beyond the common denominator of a temporal separation between reinforcers and the responses that produce them, delay of reinforcement procedures differ from one another along several dimensions, making delay effects circumstance dependent. The final question is one of interpreting delay of reinforcement effects. It centers on the role of the response-reinforcer temporal relation in the context of other, concurrently operating behavioral processes.

  9. DELAYED REINFORCEMENT OF OPERANT BEHAVIOR

    PubMed Central

    Lattal, Kennon A

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement, but, also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between responses and reinforcers can be isolated from other features of the environment that often accompany delays, such as stimuli or changes in the temporal distribution or rate of reinforcement. The second question is that of the effects of delays on operant behavior. Beyond the common denominator of a temporal separation between reinforcers and the responses that produce them, delay of reinforcement procedures differ from one another along several dimensions, making delay effects circumstance dependent. The final question is one of interpreting delay of reinforcement effects. It centers on the role of the response–reinforcer temporal relation in the context of other, concurrently operating behavioral processes. PMID:20676272

  10. Strong gravitational lensing and dark energy complementarity

    SciTech Connect

    Linder, Eric V.

    2004-01-21

    In the search for the nature of dark energy most cosmological probes measure simple functions of the expansion rate. While powerful, these all involve roughly the same dependence on the dark energy equation of state parameters, with anticorrelation between its present value w{sub 0} and time variation w{sub a}. Quantities that have instead positive correlation and so a sensitivity direction largely orthogonal to, e.g., distance probes offer the hope of achieving tight constraints through complementarity. Such quantities are found in strong gravitational lensing observations of image separations and time delays. While degeneracy between cosmological parameters prevents full complementarity, strong lensing measurements to 1 percent accuracy can improve equation of state characterization by 15-50 percent. Next generation surveys should provide data on roughly 105 lens systems, though systematic errors will remain challenging.

  11. Deterministic strong-field quantum control

    NASA Astrophysics Data System (ADS)

    Cavaletto, Stefano M.; Harman, Zoltán; Pfeifer, Thomas; Keitel, Christoph H.

    2017-04-01

    Strong-field quantum-state control is investigated, taking advantage of the full—amplitude and phase—characterization of the interaction between matter and intense ultrashort pulses via transient-absorption spectroscopy. As an example, we apply the method to a nondegenerate V -type three-level system modeling atomic Rb, and use a sequence of intense delayed pulses, whose parameters are tailored to steer the system into a desired quantum state. We show how to experimentally enable this optimization by retrieving all quantum features of the light-matter interaction from observable spectra. This provides a full characterization of the action of strong fields on the atomic system, including the dependence upon possibly unknown pulse properties and atomic structures. Precision and robustness of the scheme are tested, in the presence of surrounding atomic levels influencing the system's dynamics.

  12. Epidemiology of delayed ejaculation

    PubMed Central

    Di Sante, Stefania; Mollaioli, Daniele; Gravina, Giovanni Luca; Ciocca, Giacomo; Limoncin, Erika; Carosa, Eleonora; Lenzi, Andrea

    2016-01-01

    A large body of literature on diminished ejaculatory disorders has been generated without the use of a clear diagnostic definition. Many studies have not distinguished between the orgasm and ejaculation disorders leading to doubtful results. Delayed ejaculation (DE) is one of the diminished ejaculatory disorders, which range from varying delays in ejaculatory latency to a complete inability to ejaculate. The present review is aimed at providing a comprehensive overview of the current knowledge on the definition and epidemiology of diminished ejaculatory disorders. We focus on the acquired diseases, such as benign prostatic hyperplasia (BPH) and specific drug regimens that may cause an iatrogenic form of ejaculatory disorder. In addition, the impact of aging is discussed since the prevalence of DE appears to be moderately but positively related to age. Finally, we also focus on the importance of the hormonal milieu on male ejaculation. To date, evidence on the endocrine control of ejaculation is derived from small clinical trials, but the evidence suggests that hormones modulate the ejaculatory process by altering its overall latency. PMID:27652226

  13. Epidemiology of delayed ejaculation.

    PubMed

    Di Sante, Stefania; Mollaioli, Daniele; Gravina, Giovanni Luca; Ciocca, Giacomo; Limoncin, Erika; Carosa, Eleonora; Lenzi, Andrea; Jannini, Emmanuele A

    2016-08-01

    A large body of literature on diminished ejaculatory disorders has been generated without the use of a clear diagnostic definition. Many studies have not distinguished between the orgasm and ejaculation disorders leading to doubtful results. Delayed ejaculation (DE) is one of the diminished ejaculatory disorders, which range from varying delays in ejaculatory latency to a complete inability to ejaculate. The present review is aimed at providing a comprehensive overview of the current knowledge on the definition and epidemiology of diminished ejaculatory disorders. We focus on the acquired diseases, such as benign prostatic hyperplasia (BPH) and specific drug regimens that may cause an iatrogenic form of ejaculatory disorder. In addition, the impact of aging is discussed since the prevalence of DE appears to be moderately but positively related to age. Finally, we also focus on the importance of the hormonal milieu on male ejaculation. To date, evidence on the endocrine control of ejaculation is derived from small clinical trials, but the evidence suggests that hormones modulate the ejaculatory process by altering its overall latency.

  14. Strong-interaction nonuniversality

    SciTech Connect

    Volkas, R. R.; Foot, R.; He, X.; Joshi, G. C.

    1989-07-01

    The universal QCD color theory is extended to an SU(3)/sub 1//direct product/SU(3)/sub 2//direct product/SU(3)/sub 3/ gauge theory, where quarks of the /ital i/th generation transform as triplets under SU(3)/sub /ital i// and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements.

  15. Foreshocks of strong earthquakes

    NASA Astrophysics Data System (ADS)

    Guglielmi, A. V.; Sobisevich, L. E.; Sobisevich, A. L.; Lavrov, I. P.

    2014-07-01

    The specific enhancement of ultra-low-frequency (ULF) electromagnetic oscillations a few hours prior to the strong earthquakes, which was previously mentioned in the literature, motivated us to search for the distinctive features of the mechanical (foreshock) activity of the Earth's crust in the epicentral zones of the future earthquakes. Activation of the foreshocks three hours before the main shock is revealed, which is roughly similar to the enhancement of the specific electromagnetic ULF emission. It is hypothesized that the round-the-world seismic echo signals from the earthquakes, which form the peak of energy release 2 h 50 min before the main events, act as the triggers of the main shocks due to the cumulative action of the surface waves converging to the epicenter. It is established that the frequency of the fluctuations in the foreshock activity decreases at the final stages of the preparation of the main shocks, which probably testifies to the so-called mode softening at the approach of the failure point according to the catastrophe theory.

  16. Kinematics of Strong Discontinuities

    NASA Technical Reports Server (NTRS)

    Peterson, K.; Nguyen, G.; Sulsky, D.

    2006-01-01

    Synthetic Aperture Radar (SAR) provides a detailed view of the Arctic ice cover. When processed with the RADARSAT Geophysical Processor System (RGPS), it provides estimates of sea ice motion and deformation over large regions of the Arctic for extended periods of time. The deformation is dominated by the appearance of linear kinematic features that have been associated with the presence of leads. The RGPS deformation products are based on the assumption that the displacement and velocity are smooth functions of the spatial coordinates. However, if the dominant deformation of multiyear ice results from the opening, closing and shearing of leads, then the displacement and velocity can be discontinuous. This presentation discusses the kinematics associated with strong discontinuities that describe possible jumps in displacement or velocity. Ice motion from SAR data are analyzed using this framework. It is assumed that RGPS cells deform due to the presence of a lead. The lead orientation is calculated to optimally account for the observed deformation. It is shown that almost all observed deformation can be represented by lead opening and shearing. The procedure used to reprocess motion data to account for leads will be described and applied to regions of the Beaufort Sea. The procedure not only provides a new view of ice deformation, it can be used to obtain information about the presence of leads for initialization and/or validation of numerical simulations.

  17. Studies on Strong Interactions

    NASA Astrophysics Data System (ADS)

    Coriano, Claudio

    Five studies, four in Quantum field theory and one in fermionic molecular dynamics are presented. In the first study, introduced in chapter one and developed in chapter two of this dissertation, we formulate an extension of QCD sum rules to Compton scattering of the pion at intermediate energy. The chapter is based on the research paper Fixed angle pion Compton scattering and QCD sum rules by Prof. George Sterman and the author, which has been submitted for publication as a regular article. In chapter 3 we discuss the relation between traditional bosonic exchange models of nuclear strong interaction and soliton models, in the particular case of the sine-Gordon model. The chapter is based on the research paper "Scattering in soliton models and bosonic exchange descriptions", by R. R. Parwani, H. Yamagishi, I. Zahed and the author, and is published in Phys. Rev. D 45 (1992), 2542. A preprint of this paper (Preprint 1) has been included as an Appendix to the Chapter. In Chapter 4 we discuss aspects of the propagation of quantized fields in classical backgrounds, using the light-cone expansion of the propagator. The chapter is based on the research papers "Electrodynamics in the presence of an axion", published by the author in Modern Physics Letters A 7 (1992), 1253, and on the paper "Singularity of Green's function and the effective action in massive Yang Mills theories, by Prof. H. Yamagishi and the author. This last paper is published in Physical Review D 41 (1990), 3226 and its reprint appears in the final part of the Chapter (Reprint 1). In chapter 5, entitled "On the time dependent Rayleigh-Ritz equations", we discuss aspects of the variational approach to fermionic molecular dynamics. This investigation by R. Parwani, H. Yamagishi and the author has been published in Nucl. Physics A 522 (1991), 591. A preprint of this research paper has been inserted in the final part of the Chapter (Preprint 2).

  18. The pathophysiology of delayed ejaculation

    PubMed Central

    2016-01-01

    Delayed ejaculation (DE) is probably least studied, and least understood of male sexual dysfunctions, with an estimated prevalence of 1–4% of the male population. Pathophysiology of DE is multifactorial and including psychosexual-behavioral and cultural factors, disruption of ejaculatory apparatus, central and peripheral neurotransmitters, hormonal or neurochemical ejaculatory control and psychosocial factors. Although knowledge of the physiology of the DE has increased in the last two decade, our understanding of the different pathophysiological process of the causes of DE remains limited. To provide a systematic update on the pathophysiology of DE. A systematic review of Medline and PubMed for relevant publications on ejaculatory dysfunction (EjD), DE, retarded ejaculation, inhibited ejaculation, and climax was performed. The search was limited to the articles published between the January 1960 and December 2015 in English. Of 178 articles, 105 were selected for this review. Only those publications relevant to the pathophysiology, epidemiology and prevalence of DE were included. The pathophysiology of DE involves cerebral sensory areas, motor centers, and several spinal nuclei that are tightly interconnected. The biogenic, psychogenic and other factors strongly affect the pathophysiology of DE. Despite the many publications on this disorder, there still is a paucity of publications dedicated to the subject. PMID:27652227

  19. Small delay approximation of stochastic delay differential equations

    NASA Astrophysics Data System (ADS)

    Guillouzic, Steve; L'heureux, Ivan; Longtin, André

    1999-04-01

    Delay differential equations evolve in an infinite-dimensional phase space. In this paper, we consider the effect of external fluctuations (noise) on delay differential equations involving one variable, thus leading to univariate stochastic delay differential equations (SDDE's). For small delays, a univariate nondelayed stochastic differential equation approximating such a SDDE is presented. Another approximation, complementary to the first, is also obtained using an average of the SDDE's drift term over the delayed dynamical variable, which defines a conditional average drift. This second approximation is characterized by the fact that the diffusion term is identical to that of the original SDDE. For small delays, our approach yields a steady-state probability density and a conditional average drift which are in close agreement with numerical simulations of the original SDDE. We illustrate this scheme with the delayed linear Langevin equation and a stochastic version of the delayed logistic equation. The technique can be used with any type of noise, and is easily generalized to multiple delays.

  20. Multimessenger time delays from lensed gravitational waves

    NASA Astrophysics Data System (ADS)

    Baker, Tessa; Trodden, Mark

    2017-03-01

    We investigate the potential of high-energy astrophysical events, from which both massless and massive signals are detected, to probe fundamental physics. In particular, we consider how strong gravitational lensing can induce time delays in multimessenger signals from the same source. Obvious messenger examples are massless photons and gravitational waves, and massive neutrinos, although more exotic applications can also be imagined, such as to massive gravitons or axions. The different propagation times of the massive and massless particles can, in principle, place bounds on the total neutrino mass and probe cosmological parameters. Whilst measuring such an effect may pose a significant experimental challenge, we believe that the "massive time delay" represents an unexplored fundamental physics phenomenon.

  1. Probing electron delays in above-threshold ionization

    SciTech Connect

    Zipp, Lucas J.; Natan, Adi; Bucksbaum, Philip H.

    2014-11-21

    Recent experiments have revealed attosecond delays in the emission of electrons from atoms ionized by extreme UV light, offering a glimpse into the ultrafast nature of light-induced electron dynamics. In this work, we extend these measurements to the strong-field above-threshold ionization (ATI) regime, by measuring delays in the photoemission of electrons from argon in the presence of an intense laser field. We probe the ATI process with a weak coherent reference, at half the laser frequency. The interfering ionization signal reveals the relative spectral phase of adjacent ATI channels, with an equivalent resolution of a few attoseconds. These relative delays depend on the strong field, and approach zero at higher intensity. Our phase measurements of ATI electrons show how strong fields alter ionization dynamics in atoms.

  2. Delayed cure bismaleimide resins

    DOEpatents

    Adams, Johnnie E.; Jamieson, Donald R.

    1984-08-07

    Polybismaleimides prepared by delayed curing of bis-imides having the formula ##STR1## wherein R.sub.1 and R.sub.2 each independently is H, C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, Cl or Br, or R.sub.1 and R.sub.2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R.sub.1 and R.sub.2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the --(CH.sub.2).sub.n -- group, optionally, is substituted by 1-3 methyl groups or by fluorine.

  3. Soviet delays raise prices

    SciTech Connect

    Young, I.

    1992-01-15

    The breakup of the Soviet Union is causing massive disruptions to methanol exports. The changeover to a Commonwealth of independent States has created logistical problems which have led some shipments of Russian methanol to be cancelled and delayed other deliveries by up to two weeks. In recent years the Soviet Union has exported 700,000 m.t./year-900,000 m.t./year of methanol, mainly to Western Europe. The product is made at 750,000-m.t./year plants at Tomsk and Gubakha in Russia and transported by rail for shipment from the ports of Ventspils, Latvia, on the Baltic Sea and Yuzhnyy in Ukraine, on the Black Sea. The exports were handled by state export agency Soyuzagrochim, mainly under contract to West European traders and consumers in areas like Scandinavia and France.

  4. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    PubMed Central

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Bennett, Matthew R.; Josić, Krešimir; Ott, William

    2014-01-01

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay. PMID:24880267

  5. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    SciTech Connect

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William; Bennett, Matthew R.; Josić, Krešimir

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  6. PRECISION TIME-DELAY CIRCUIT

    DOEpatents

    Creveling, R.

    1959-03-17

    A tine-delay circuit which produces a delay time in d. The circuit a capacitor, an te back resistance, connected serially with the anode of the diode going to ground. At the start of the time delay a negative stepfunction is applied to the series circuit and initiates a half-cycle transient oscillatory voltage terminated by a transient oscillatory voltage of substantially higher frequency. The output of the delay circuit is taken at the junction of the inductor and diode where a sudden voltage rise appears after the initiation of the higher frequency transient oscillations.

  7. Time Delay of CGM Sensors

    PubMed Central

    Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

    2015-01-01

    Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

  8. When good pigeons make bad decisions: Choice with probabilistic delays and outcomes.

    PubMed

    Pisklak, Jeffrey M; McDevitt, Margaret A; Dunn, Roger M; Spetch, Marcia L

    2015-11-01

    Pigeons chose between an (optimal) alternative that sometimes provided food after a 10-s delay and other times after a 40-s delay and another (suboptimal) alternative that sometimes provided food after 10 s but other times no food after 40 s. When outcomes were not signaled during the delays, pigeons strongly preferred the optimal alternative. When outcomes were signaled, choices of the suboptimal alternative increased and most pigeons preferred the alternative that provided no food after the long delay despite the cost in terms of obtained food. The pattern of results was similar whether the short delays occurred on 25% or 50% of the trials. Shortening the 40-s delay to food sharply reduced suboptimal choices, but shortening the delay to no food had little effect. The results suggest that a signaled delay to no food does not punish responding in probabilistic choice procedures. The findings are discussed in terms of conditioned reinforcement by signals for good news.

  9. Delayed magnetic catalysis

    NASA Astrophysics Data System (ADS)

    Braun, Jens; Mian, Walid Ahmed; Rechenberger, Stefan

    2016-04-01

    We study the effect of an external magnetic field on the chiral phase transition in the theory of the strong interaction by means of a renormalization-group (RG) fixed-point analysis, relying on only one physical input parameter, the strong coupling at a given large momentum scale. To be specific, we consider the interplay of the RG flow of four-quark interactions and the running gauge coupling. Depending on the temperature and the strength of the magnetic field, the gauge coupling can drive the quark sector to criticality, resulting in chiral symmetry breaking. In accordance with lattice Monte-Carlo simulations, we find that the chiral phase transition temperature decreases for small values of the external magnetic field. For large magnetic field strengths, however, our fixed-point study predicts that the phase transition temperature increases monotonically.

  10. Passband ripple observed in MSFVW delay lines

    NASA Astrophysics Data System (ADS)

    Talisa, S. H.; Emtage, P. R.; Daniel, M. R.; Adam, J. D.

    1986-09-01

    It is suggested that the long-period (100-200 MHz) ripple noted in magnetostatic forward volume wave (MSFVW) delay lines comprising YIG samples a few millimeters wide by a few centimeters long is due to the nonuniformity in the DC demagnetizing field across the YIG sample width. The results indicate that even very small variations in the internal field near the center of the sample can cause the MSFVWs to focus at distances close to the input transducers, and that ray bending is stronger outside the central half of the sample. Experimental studies confirm the strong effects of sample width on the breadth and smoothness of the passband.

  11. Tunable optical delay via carrier induced exciton dephasing in semiconductor quantum wells.

    PubMed

    Sarkar, Susanta; Guo, Yan; Wang, Hailin

    2006-04-03

    We report the experimental realization of a tunable optical delay by exploiting unique incoherent nonlinear optical processes in semiconductors. The tunable optical delay takes advantage of the strong Coulomb interactions between excitons and free carriers and uses optical injection of free carriers to broaden and bleach an exciton absorption resonance. Fractional delay exceeding 200% has been obtained for an 8 ps optical pulse propagating near the heavy-hole excitonic transition in a GaAs quantum well structure. Tunable optical delay based on optical injection of free carriers avoids strong absorption of the pump beam and is also robust against variations in the frequency of the pump beam.

  12. Delay Adjusted Incidence

    Cancer.gov

    This Infographic shows the National Cancer Institute SEER Incidence Trends. The graphs show the Average Annual Percent Change (AAPC) 2002-2011. For Men, Thyroid: 5.3*,Liver & IBD: 3.6*, Melanoma: 2.3*, Kidney: 2.0*, Myeloma: 1.9*, Pancreas: 1.2*, Leukemia: 0.9*, Oral Cavity: 0.5, Non-Hodgkin Lymphoma: 0.3*, Esophagus: -0.1, Brain & ONS: -0.2*, Bladder: -0.6*, All Sites: -1.1*, Stomach: -1.7*, Larynx: -1.9*, Prostate: -2.1*, Lung & Bronchus: -2.4*, and Colon & Rectum: -3/0*. For Women, Thyroid: 5.8*, Liver & IBD: 2.9*, Myeloma: 1.8*, Kidney: 1.6*, Melanoma: 1.5, Corpus & Uterus: 1.3*, Pancreas: 1.1*, Leukemia: 0.6*, Brain & ONS: 0, Non-Hodgkin Lymphoma: -0.1, All Sites: -0.1, Breast: -0.3, Stomach: -0.7*, Oral Cavity: -0.7*, Bladder: -0.9*, Ovary: -0.9*, Lung & Bronchus: -1.0*, Cervix: -2.4*, and Colon & Rectum: -2.7*. * AAPC is significantly different from zero (p<.05). Rates were adjusted for reporting delay in the registry. www.cancer.gov Source: Special section of the Annual Report to the Nation on the Status of Cancer, 1975-2011.

  13. Delayed cerebral radiation necrosis.

    PubMed

    Morris, J G; Grattan-Smith, P; Panegyres, P K; O'Neill, P; Soo, Y S; Langlands, A O

    1994-02-01

    The clinical features and long-term outcome of seven patients with delayed cerebral radiation necrosis (DCRN) are described. Radiotherapy had been given for pituitary tumour (1), astrocytoma (2), pinealoma (2), craniopharyngioma (1) and parotid carcinoma (1). The mean latency to onset of the first neurological symptoms was 22 months (range 6-40 months), and mean duration of follow-up was 86 months (range 60-126). Three patients died at a mean of 84 months after radiotherapy (range 62-98). A fourth patient probably died from metastatic disease. Three patients remain alive, albeit severely disabled, after 5-10 years. The illness typically ran a stepwise course, with fits and stroke-like episodes occurring against a background of progressive dementia and somnolence. CT and MRI scans showed progressive ventricular dilatation associated with cerebral atrophy and diffuse or focal changes in the white matter. Four patients had had two or more neurosurgical procedures after the radiotherapy. In only one of the seven patients was the diagnosis made at presentation. DCRN produces a distinctive clinical picture, yet remains a poorly recognized complication of cranial irradiation.

  14. Delay Adjusted Incidence Infographic

    Cancer.gov

    This Infographic shows the National Cancer Institute SEER Incidence Trends. The graphs show the Average Annual Percent Change (AAPC) 2002-2011. For Men, Thyroid: 5.3*,Liver & IBD: 3.6*, Melanoma: 2.3*, Kidney: 2.0*, Myeloma: 1.9*, Pancreas: 1.2*, Leukemia: 0.9*, Oral Cavity: 0.5, Non-Hodgkin Lymphoma: 0.3*, Esophagus: -0.1, Brain & ONS: -0.2*, Bladder: -0.6*, All Sites: -1.1*, Stomach: -1.7*, Larynx: -1.9*, Prostate: -2.1*, Lung & Bronchus: -2.4*, and Colon & Rectum: -3/0*. For Women, Thyroid: 5.8*, Liver & IBD: 2.9*, Myeloma: 1.8*, Kidney: 1.6*, Melanoma: 1.5, Corpus & Uterus: 1.3*, Pancreas: 1.1*, Leukemia: 0.6*, Brain & ONS: 0, Non-Hodgkin Lymphoma: -0.1, All Sites: -0.1, Breast: -0.3, Stomach: -0.7*, Oral Cavity: -0.7*, Bladder: -0.9*, Ovary: -0.9*, Lung & Bronchus: -1.0*, Cervix: -2.4*, and Colon & Rectum: -2.7*. * AAPC is significantly different from zero (p<.05). Rates were adjusted for reporting delay in the registry. www.cancer.gov Source: Special section of the Annual Report to the Nation on the Status of Cancer, 1975-2011.

  15. Geometric time delay interferometry

    SciTech Connect

    Vallisneri, Michele

    2005-08-15

    The space-based gravitational-wave observatory LISA, a NASA-ESA mission to be launched after 2012, will achieve its optimal sensitivity using time delay interferometry (TDI), a LISA-specific technique needed to cancel the otherwise overwhelming laser noise in the interspacecraft phase measurements. The TDI observables of the Michelson and Sagnac types have been interpreted physically as the virtual measurements of a synthesized interferometer. In this paper, I present Geometric TDI, a new and intuitive approach to extend this interpretation to all TDI observables. Unlike the standard algebraic formalism, Geometric TDI provides a combinatorial algorithm to explore exhaustively the space of second-generation TDI observables (i.e., those that cancel laser noise in LISA-like interferometers with time-dependent arm lengths). Using this algorithm, I survey the space of second-generation TDI observables of length (i.e., number of component phase measurements) up to 24, and I identify alternative, improved forms of the standard second-generation TDI observables. The alternative forms have improved high-frequency gravitational-wave sensitivity in realistic noise conditions (because they have fewer nulls in the gravitational-wave and noise response functions), and are less susceptible to instrumental gaps and glitches (because their component phase measurements span shorter time periods)

  16. Delayed unlatching mechanism

    SciTech Connect

    Bzorgi, Fariborz M.

    2015-05-19

    In various embodiments an apparatus is presented for securing a structure such as a door, window, hatch, or gate that moves between an open and a closed position relative to a fixed structure to provide or deny access to a compartment, a room, an outdoor area, or a facility. Various embodiments provide a delay in opening the closure of sufficient duration to frustrate a rapid activation that might be desired by a person who is attempting to pass through the closure for some illicit purpose. Typically, hydraulics are used to activate the apparatus and no electrical energy or electronic signals are employed. In one embodiment, a plurality of actuations of a hand lever operates a hydraulic pump that moves a locking bolt from a first position in which a locking bolt is engaged with a recess in the fixed structure (preventing opening of a gate) to a second position in which the locking bolt is disengaged from the recess to permit opening of the gate.

  17. Calibrating for Ionospheric Phase Delays

    NASA Technical Reports Server (NTRS)

    Macdoran, P. F.

    1985-01-01

    Technique determines ionospheric phase delay on real-time universally applicable basis in terms of electrons per meter squared by coherently modulating two L-band carrier frequencies received from two Global Positioning System satelites. Two pseudorandom number sequences cross-correlated to derive delay time.

  18. Delayed Auditory Feedback and Movement

    ERIC Educational Resources Information Center

    Pfordresher, Peter Q.; Dalla Bella, Simone

    2011-01-01

    It is well known that timing of rhythm production is disrupted by delayed auditory feedback (DAF), and that disruption varies with delay length. We tested the hypothesis that disruption depends on the state of the movement trajectory at the onset of DAF. Participants tapped isochronous rhythms at a rate specified by a metronome while hearing DAF…

  19. High resolution digital delay timer

    DOEpatents

    Martin, Albert D.

    1988-01-01

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

  20. Imitation dynamics with time delay.

    PubMed

    Wang, Shi-Chang; Yu, Jie-Ru; Kurokawa, Shun; Tao, Yi

    2017-02-28

    Based on the classic imitation dynamics (Hofbauer and Sigmund, 1998, Evolutionary Games and Population Dynamics, Cambridge University Press), the imitation dynamics with time delay is investigated, where the probability that an individual will imitate its opponent's own strategy is assumed to depend on the comparison between the past expected payoff of this individual's own strategy and the past expected payoff of its opponent's own strategy, i.e. there is a time delay effect. For the two-phenotype model, we show that if the system has an interior equilibrium and this interior equilibrium is stable when there is no time delay, then there must be a critical value of time delay such that the system tends to a stable periodic solution when the time delay is larger than the critical value. On the other hand, for three-phenotype (rock-scissors-paper) model, the numerical analysis shows that for the stable periodic solution induced by the time delay, the amplitude and the period will increase with the increase of the time delay. These results should help to understand the evolution of behavior based on the imitation dynamics with time delay.

  1. Delayed Reinforcement of Operant Behavior

    ERIC Educational Resources Information Center

    Lattal, Kennon A.

    2010-01-01

    The experimental analysis of delay of reinforcement is considered from the perspective of three questions that seem basic not only to understanding delay of reinforcement but also, by implication, the contributions of temporal relations between events to operant behavior. The first question is whether effects of the temporal relation between…

  2. Registration Delay and Student Performance

    ERIC Educational Resources Information Center

    Siefken, Jason

    2017-01-01

    Tracking the difference between the time a first-year student is allowed to register for a course and the time he or she does register for a course (a student's registration delay), we notice a negative correlation between registration delay and final grade in a course. The difference between a student who registers within the first two minutes…

  3. Project delay analysis of HRSG

    NASA Astrophysics Data System (ADS)

    Silvianita; Novega, A. S.; Rosyid, D. M.; Suntoyo

    2017-08-01

    Completion of HRSG (Heat Recovery Steam Generator) fabrication project sometimes is not sufficient with the targeted time written on the contract. The delay on fabrication process can cause some disadvantages for fabricator, including forfeit payment, delay on HRSG construction process up until HRSG trials delay. In this paper, the author is using semi quantitative on HRSG pressure part fabrication delay with configuration plant 1 GT (Gas Turbine) + 1 HRSG + 1 STG (Steam Turbine Generator) using bow-tie analysis method. Bow-tie analysis method is a combination from FTA (Fault tree analysis) and ETA (Event tree analysis) to develop the risk matrix of HRSG. The result from FTA analysis is use as a threat for preventive measure. The result from ETA analysis is use as impact from fabrication delay.

  4. Discounting in Pigeons When the Choice is between Two Delayed Rewards: Implications for Species Comparisons

    PubMed Central

    Calvert, Amanda L.; Green, Leonard; Myerson, Joel

    2011-01-01

    Studies of delay discounting typically have involved choices between smaller, immediate outcomes and larger, delayed outcomes. In a study of delay discounting in humans, Green et al. (2005) added a period of time prior to both outcomes, creating a delay common to both. They found that the subjective value of the more delayed reward was well described by a hyperboloid discounting function and that the degree to which that outcome was discounted decreased as the common delay increased. In two experiments, we examined the effect of adding a common delay on the discounting of food rewards in pigeons. In Experiment 1, an adjusting-amount procedure was used to establish discounting functions when the common delay was 0, 3, 5, and 10 s, and different stimuli signaled time to the smaller, sooner and larger, later rewards. In contrast to humans, the pigeons showed increases in the degree of discounting when a common delay was added. In Experiment 2, the delay common to both rewards and the delay unique to the larger, later reward were each specifically signaled. With this procedure, the degree of discounting decreased as the common delay increased, a result consistent with that obtained with humans (Green et al., 2005). These findings reveal fundamental similarities between pigeons’ and humans’ choice behavior, and provide strong interspecies support for the hypothesis that choice between delayed outcomes is based on comparison of their hyperbolically discounted present subjective values. PMID:21887130

  5. Approximate controllability of a system of parabolic equations with delay

    NASA Astrophysics Data System (ADS)

    Carrasco, Alexander; Leiva, Hugo

    2008-09-01

    In this paper we give necessary and sufficient conditions for the approximate controllability of the following system of parabolic equations with delay: where [Omega] is a bounded domain in , D is an n×n nondiagonal matrix whose eigenvalues are semi-simple with nonnegative real part, the control and B[set membership, variant]L(U,Z) with , . The standard notation zt(x) defines a function from [-[tau],0] to (with x fixed) by zt(x)(s)=z(t+s,x), -[tau][less-than-or-equals, slant]s[less-than-or-equals, slant]0. Here [tau][greater-or-equal, slanted]0 is the maximum delay, which is supposed to be finite. We assume that the operator is linear and bounded, and [phi]0[set membership, variant]Z, [phi][set membership, variant]L2([-[tau],0];Z). To this end: First, we reformulate this system into a standard first-order delay equation. Secondly, the semigroup associated with the first-order delay equation on an appropriate product space is expressed as a series of strongly continuous semigroups and orthogonal projections related with the eigenvalues of the Laplacian operator (); this representation allows us to reduce the controllability of this partial differential equation with delay to a family of ordinary delay equations. Finally, we use the well-known result on the rank condition for the approximate controllability of delay system to derive our main result.

  6. Earth system commitments due to delayed mitigation

    NASA Astrophysics Data System (ADS)

    Pfister, Patrik L.; Stocker, Thomas F.

    2016-01-01

    As long as global CO2 emissions continue to increase annually, long-term committed Earth system changes grow much faster than current observations. A novel metric linking this future growth to policy decisions today is the mitigation delay sensitivity (MDS), but MDS estimates for Earth system variables other than peak temperature (ΔT max) are missing. Using an Earth System Model of Intermediate Complexity, we show that the current emission increase rate causes a ΔT max increase roughly 3-7.5 times as fast as observed warming, and a millenial steric sea level rise (SSLR) 7-25 times as fast as observed SSLR, depending on the achievable rate of emission reductions after the peak of emissions. These ranges are only slightly affected by the uncertainty range in equilibrium climate sensitivity, which is included in the above values. The extent of ocean acidification at the end of the century is also strongly dependent on the starting time and rate of emission reductions. The preservable surface ocean area with sufficient aragonite supersaturation for coral reef growth is diminished globally at an MDS of roughly 25%-80% per decade. A near-complete loss of this area becomes unavoidable if mitigation is delayed for a few years to decades. Also with respect to aragonite, 12%-18% of the Southern Ocean surface become undersaturated per decade, if emission reductions are delayed beyond 2015-2040. We conclude that the consequences of delaying global emission reductions are much better captured if the MDS of relevant Earth system variables is communicated in addition to current trends and total projected future changes.

  7. Local Effects of Delayed Food

    PubMed Central

    Davison, Michael; Baum, William M

    2007-01-01

    Five pigeons were trained on a procedure in which seven concurrent variable-interval schedules arranged seven different food–rate ratios in random sequence in each session. Each of these components lasted for 10 response-produced food deliveries, and components were separated by 10-s blackouts. We varied delays to food (signaled by blackout) between the two response alternatives in an experiment with three phases: In Phase 1, the delay on one alternative was 0 s, and the other was varied between 0 and 8 s; in Phase 2, both delays were equal and were varied from 0 to 4 s; in Phase 3, the two delays summed to 8 s, and each was varied from 1 to 7 s. The results showed that increasing delay affected local choice, measured by a pulse in preference, in the same way as decreasing magnitude, but we found also that increasing the delay at the other alternative increased local preference. This result casts doubt on the traditional view that a reinforcer strengthens a response depending only on the reinforcer's value discounted by any response–reinforcer delay. The results suggest that food guides, rather than strengthens, behavior. PMID:17465314

  8. Delayed and occult splenic rupture.

    PubMed

    Bundy, A L; Scott, M; Druckman, D; Siegal, T L; Verdi, T A

    1985-01-01

    Four patients with delayed splenic rupture were evaluated by CT or US and liver-spleen scan. The cases and radiographic findings and their significance are presented. The importance of this entity, in light of recent surgical trends, is discussed.

  9. 78 FR 59422 - Delayed Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-26

    ... Pipeline and Hazardous Materials Safety Administration Delayed Applications AGENCY: Office of Hazardous Materials Safety, Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: List of... Paquet, Director, Office of Hazardous Materials Special Permits and Approvals, Pipeline and...

  10. [Normal puberty and delayed puberty].

    PubMed

    Heinrichs, C

    2011-09-01

    Puberty includes important physical and growth changes, and takes place at a certain age range, leading to sexual maturation. Delayed puberty is defined clinically by the absence of breast development after the age of 13,5 in girls, or the absence of increase in testicular size after the age of 14 years in boys. Particularly in boys, delayed puberty, presented as short stature, is a frequent motivation for medical appointment. Constitutional delay of growth and puberty (CDGP) is the most frequent diagnosis ; however, the other etiologies have to be considered. Family history, physical examination including secondary sex characteristics, analysis of growth curve will help to clarify the diagnosis, and may permit avoidance of otherwise evaluations, Adequate work up is important, delayed puberty might lead to psychological difficulties in this context of peer's differences. Even in CDGP, symptomatic treatment with sex steroids might be considered.

  11. Delayed prescriptions: attitudes and experiences of general practitioners in the Midwest.

    PubMed

    Hayes, M; Faherty, A; Hannon, D

    2013-06-01

    141 questionnaires were posted to GPs randomly selected in the Mid-West. 103 responses were received. 32 GPs (31%) strongly agreed and 65 GPs (63%) agreed that antibiotics are over used in general practice. 35 GPs (34%) felt under pressure to prescribe an antibiotic at least once a day. 41 GPs (40%) agreed that delayed prescriptions are a safe prescribing strategy. 53 GPs (51%) agreed that delayed prescriptions have the potential to reduce antibiotic use. 33 GPs (32%) disagreed that giving delayed prescriptions increases the duration of the consultation. 49 GPs (47%) agreed that delayed prescriptions decrease the likelihood of return visit in the same illness. 55 GPs (53%) agreed that delayed prescriptions help to involve patients in managing their own illness. 46 GPs (45%) disagreed that patients find delayed prescriptions confusing. The majority of GPs (41/39.8%) use delayed prescriptions once a week or at least once a day (34/33%).

  12. Measuring Information-Transfer Delays

    PubMed Central

    Wibral, Michael; Pampu, Nicolae; Priesemann, Viola; Siebenhühner, Felix; Seiwert, Hannes; Lindner, Michael; Lizier, Joseph T.; Vicente, Raul

    2013-01-01

    In complex networks such as gene networks, traffic systems or brain circuits it is important to understand how long it takes for the different parts of the network to effectively influence one another. In the brain, for example, axonal delays between brain areas can amount to several tens of milliseconds, adding an intrinsic component to any timing-based processing of information. Inferring neural interaction delays is thus needed to interpret the information transfer revealed by any analysis of directed interactions across brain structures. However, a robust estimation of interaction delays from neural activity faces several challenges if modeling assumptions on interaction mechanisms are wrong or cannot be made. Here, we propose a robust estimator for neuronal interaction delays rooted in an information-theoretic framework, which allows a model-free exploration of interactions. In particular, we extend transfer entropy to account for delayed source-target interactions, while crucially retaining the conditioning on the embedded target state at the immediately previous time step. We prove that this particular extension is indeed guaranteed to identify interaction delays between two coupled systems and is the only relevant option in keeping with Wiener’s principle of causality. We demonstrate the performance of our approach in detecting interaction delays on finite data by numerical simulations of stochastic and deterministic processes, as well as on local field potential recordings. We also show the ability of the extended transfer entropy to detect the presence of multiple delays, as well as feedback loops. While evaluated on neuroscience data, we expect the estimator to be useful in other fields dealing with network dynamics. PMID:23468850

  13. Electrically Tunable Optical Delay Lines

    DTIC Science & Technology

    2003-04-01

    conjointly pursued for improved monolithic ODL device design was attempts to shed the simple DBR approach, and investigate other novel, perhaps aperiodic...tunable optical delay lines. Our approach focuses on monolithic semiconductor multilayer heterostructures (Distributed Bragg Reflector) to produce true...time delays for incident transmitted optical pulses. Quantum wells are grown in every other layer of the DBR stack. When a field is applied across

  14. Delay in cutaneous melanoma diagnosis

    PubMed Central

    Xavier, Marcus H.S.B.; Drummond-Lage, Ana P.; Baeta, Cyntia; Rocha, Lorena; Almeida, Alessandra M.; Wainstein, Alberto J.A.

    2016-01-01

    Abstract Advanced melanoma is an incurable disease with complex and expensive treatments. The best approach to prevent melanoma at advanced stages is an early diagnosis. A knowledge of factors associated with the process of detecting cutaneous melanomas and the reasons for delays in diagnosis is essential for the improvement of the secondary prevention of the disease. Identify sociodemographic, individual, and medical aspects related to cutaneous melanoma diagnosis delay. Interviews evaluated the knowledge of melanoma, signals, symptoms, persons who were suspected, delays in seeking medical attention, physician's deferrals, and related factors of 211 patients. Melanomas were self-discovered in 41.7% of the patients; healthcare providers detected 29.9% of patients and others detected 27%. The main component in delay was patient-related. Only 31.3% of the patients knew that melanoma was a serious skin cancer, and most thought that the pigmented lesion was not important, causing a delay in seeking medical assistance. Patients (36.4%) reported a wait interval of more than 6 months from the onset of an observed change in a pigmented lesion to the first visit to a physician. The delay interval from the first physician visit to a histopathological diagnosis was shorter (<1 month) in 55.5% of patients. Improper treatments without a histopathological confirmation occurred in 14.7% of patients. A professional delay was related to both inappropriate treatments performed without histopathological confirmation (P = 0.003) and long requirements for medical referrals (P < 0.001). A deficient knowledge in the population regarding melanoma and physicians’ misdiagnoses regarding suspicious lesions contributed to delays in diagnosis. PMID:27495055

  15. Conditioning with delayed vitamin injections.

    PubMed

    Garcia, J; Ervin, F R; Yorke, C H; Koelling, R A

    1967-02-10

    Rats deficient in thiamine were allowed to drink saccharin-fla vored water. They were then given an injection of thiamine which caused their intake of the nonnutritive fluid to increase. Delay of the intramuscular injection up to 30 minutes had no effect upon the acquisition of this condi tioning. Presumably, this delay reflects specialization in the central integrative mechanisms which serve these afferent modalities.

  16. Delayed puberty in chronic illness.

    PubMed

    Pozo, Jesús; Argente, Jesús

    2002-03-01

    Delayed puberty can be defined as the lack of pubertal development at an age of 2 SD above the mean, which corresponds to an age of approximately 14 years for males and 13 years for females, taking both sex and ethnic origin into consideration. Its incidence associated with chronic illnesses is unknown; however, its clinical importance is relevant due to the larger percentage of patients with chronic disorders surviving until the age of puberty. Virtually every child with any chronic disease could present with delayed puberty (due to recurrent infections, immunodeficiency, gastrointestinal disease, renal disturbances, respiratory illnesses, chronic anaemia, endocrine disease, eating disorders, exercise and a number of miscellaneous abnormalities). Pubertal delay associated with chronic illness is accompanied by a delay in growth and the pubertal growth spurt. The degree to which growth and pubertal development are affected in chronic illness depends upon the type of disease and individual factors, as well as on the age at illness onset, its duration and severity. The earlier its onset and the longer and more severe the illness, the greater the repercussions on growth and pubertal development. The mechanism that trigger the start of physiological puberty remain unknown. Although malnutrition is probably the most important mechanism responsible for delayed puberty, emotional deprivation, toxic substances, stress and the side effects of chronic therapy, among others, have been implicated in the pathophysiology of delayed puberty. Therefore, early diagnosis is essential and appropriate and specific therapy fundamental.

  17. Basin stability in delayed dynamics

    PubMed Central

    Leng, Siyang; Lin, Wei; Kurths, Jürgen

    2016-01-01

    Basin stability (BS) is a universal concept for complex systems studies, which focuses on the volume of the basin of attraction instead of the traditional linearization-based approach. It has a lot of applications in real-world systems especially in dynamical systems with a phenomenon of multi-stability, which is even more ubiquitous in delayed dynamics such as the firing neurons, the climatological processes, and the power grids. Due to the infinite dimensional property of the space for the initial values, how to properly define the basin’s volume for delayed dynamics remains a fundamental problem. We propose here a technique which projects the infinite dimensional initial state space to a finite-dimensional Euclidean space by expanding the initial function along with different orthogonal or nonorthogonal basis. A generalized concept of basin’s volume in delayed dynamics and a highly practicable calculating algorithm with a cross-validation procedure are provided to numerically estimate the basin of attraction in delayed dynamics. We show potential applicabilities of this approach by applying it to study several representative systems of biological or/and physical significance, including the delayed Hopfield neuronal model with multistability and delayed complex networks with synchronization dynamics. PMID:26907568

  18. Analytical applications for delayed neutrons

    SciTech Connect

    Eccleston, G.W.

    1983-01-01

    Analytical formulations that describe the time dependence of neutron populations in nuclear materials contain delayed-neutron dependent terms. These terms are important because the delayed neutrons, even though their yields in fission are small, permit control of the fission chain reaction process. Analytical applications that use delayed neutrons range from simple problems that can be solved with the point reactor kinetics equations to complex problems that can only be solved with large codes that couple fluid calculations with the neutron dynamics. Reactor safety codes, such as SIMMER, model transients of the entire reactor core using coupled space-time neutronics and comprehensive thermal-fluid dynamics. Nondestructive delayed-neutron assay instruments are designed and modeled using a three-dimensional continuous-energy Monte Carlo code. Calculations on high-burnup spent fuels and other materials that contain a mix of uranium and plutonium isotopes require accurate and complete information on the delayed-neutron periods, yields, and energy spectra. A continuing need exists for delayed-neutron parameters for all the fissioning isotopes.

  19. Prediction of Weather Related Center Delays

    NASA Technical Reports Server (NTRS)

    Deepak, Kulkarni; Banavar, Sridhar

    2008-01-01

    This paper presents results of an initial study of relations between national delay, center level delays and weather. The results presented in the paper indicate: (a) the methodology used for estimating the delay at the national level can be extended to estimate delays caused by a center and delays experienced by a center, (b)delays caused by a center can be predicted using that center's Weather Impacted Traffic Index (WITI) whereas delays experienced by a center are best predicted using WITI of that center and that of a few prominent centers (c) there is differential impact of weather of different centers on center delays.

  20. Delay Discounting in Adults Receiving Treatment for Marijuana Dependence

    PubMed Central

    Peters, Erica N.; Petry, Nancy M.; LaPaglia, Donna M.; Reynolds, Brady; Carroll, Kathleen M.

    2013-01-01

    Delay discounting is an index of impulsive decision-making and reflects an individual’s preference for smaller immediate rewards relative to larger delayed rewards. Multiple studies have indicated comparatively high rates of discounting among tobacco, alcohol, cocaine, and other types of drug users, but few studies have examined discounting among marijuana users. This report is a secondary analysis of data from a clinical trial that randomized adults with marijuana dependence to receive one of four treatments that involved contingency management (CM) and cognitive–behavioral therapy interventions. Delay discounting was assessed with the Experiential Discounting Task (Reynolds & Schiffbauer, 2004) at pretreatment in 93 participants and at 12 weeks posttreatment in 61 participants. Results indicated that higher pretreatment delay discounting (i.e., more impulsive decision-making) significantly correlated with lower readiness to change marijuana use (r = − 0.22, p = .03) and greater number of days of cigarette use (r = .21, p = .04). Pretreatment discounting was not associated with any marijuana treatment outcomes. CM treatment significantly interacted with time to predict change in delay discounting from pre- to posttreatment; participants who received CM did not change their discounting over time, whereas those who did not receive CM significantly increased their discounting from pre- to posttreatment. In this sample of court-referred young adults receiving treatment for marijuana dependence, delay discounting was not strongly related to treatment outcomes, but there was some evidence that CM may protect against time-related increases in discounting. PMID:23245197

  1. Delays induce novel stochastic effects in negative feedback gene circuits.

    PubMed

    Zavala, Eder; Marquez-Lago, Tatiana T

    2014-01-21

    Stochastic models of reaction networks are widely used to depict gene expression dynamics. However, stochastic does not necessarily imply accurate, as subtle assumptions can yield erroneous results, masking key discrete effects. For instance, transcription and translation are not instantaneous processes-explicit delays separate their initiation from the appearance of their functional products. However, delays are often ignored in stochastic, single-gene expression models. By consequence, effects such as delay-induced stochastic oscillations at the single-cell level have remained relatively unexplored. Here, we present a systematic study of periodicity and multimodality in a simple gene circuit with negative feedback, analyzing the influence of negative feedback strength and transcriptional/translational delays on expression dynamics. We demonstrate that an oscillatory regime emerges through a Hopf bifurcation in both deterministic and stochastic frameworks. Of importance, a shift in the stochastic Hopf bifurcation evidences inaccuracies of the deterministic bifurcation analysis. Furthermore, noise fluctuations within stochastic oscillations decrease alongside increasing values of transcriptional delays and within a specific range of negative feedback strengths, whereas a strong feedback is associated with oscillations triggered by bursts. Finally, we demonstrate that explicitly accounting for delays increases the number of accessible states in the multimodal regime, and also introduces features typical of excitable systems.

  2. Delays Induce Novel Stochastic Effects in Negative Feedback Gene Circuits

    PubMed Central

    Zavala, Eder; Marquez-Lago, Tatiana T.

    2014-01-01

    Stochastic models of reaction networks are widely used to depict gene expression dynamics. However, stochastic does not necessarily imply accurate, as subtle assumptions can yield erroneous results, masking key discrete effects. For instance, transcription and translation are not instantaneous processes—explicit delays separate their initiation from the appearance of their functional products. However, delays are often ignored in stochastic, single-gene expression models. By consequence, effects such as delay-induced stochastic oscillations at the single-cell level have remained relatively unexplored. Here, we present a systematic study of periodicity and multimodality in a simple gene circuit with negative feedback, analyzing the influence of negative feedback strength and transcriptional/translational delays on expression dynamics. We demonstrate that an oscillatory regime emerges through a Hopf bifurcation in both deterministic and stochastic frameworks. Of importance, a shift in the stochastic Hopf bifurcation evidences inaccuracies of the deterministic bifurcation analysis. Furthermore, noise fluctuations within stochastic oscillations decrease alongside increasing values of transcriptional delays and within a specific range of negative feedback strengths, whereas a strong feedback is associated with oscillations triggered by bursts. Finally, we demonstrate that explicitly accounting for delays increases the number of accessible states in the multimodal regime, and also introduces features typical of excitable systems. PMID:24461022

  3. Strong WW Interaction at LHC

    SciTech Connect

    Pelaez, Jose R

    1998-12-14

    We present a brief pedagogical introduction to the Effective Electroweak Chiral Lagrangians, which provide a model independent description of the WW interactions in the strong regime. When it is complemented with some unitarization or a dispersive approach, this formalism allows the study of the general strong scenario expected at the LHC, including resonances.

  4. Strong Beginnings: Learning To Live.

    ERIC Educational Resources Information Center

    Save the Children, Westport, CT.

    The Strong Beginnings program, initiated by the Save the Children Fund in 1991, supports community-based activities in 20 countries aimed at reconstructing educational systems in developing countries. This report presents the vision of the Strong Beginnings program, describes its components, and describes the continuing challenge to improve access…

  5. Probing electron delays in above-threshold ionization

    DOE PAGES

    Zipp, Lucas J.; Natan, Adi; Bucksbaum, Philip H.

    2014-11-21

    Recent experiments have revealed attosecond delays in the emission of electrons from atoms ionized by extreme UV light, offering a glimpse into the ultrafast nature of light-induced electron dynamics. In this work, we extend these measurements to the strong-field above-threshold ionization (ATI) regime, by measuring delays in the photoemission of electrons from argon in the presence of an intense laser field. We probe the ATI process with a weak coherent reference, at half the laser frequency. The interfering ionization signal reveals the relative spectral phase of adjacent ATI channels, with an equivalent resolution of a few attoseconds. These relative delaysmore » depend on the strong field, and approach zero at higher intensity. Our phase measurements of ATI electrons show how strong fields alter ionization dynamics in atoms.« less

  6. Delay Independent Criterion for Multiple Time-delay Systems

    NASA Astrophysics Data System (ADS)

    Chang, C. J.; Liu, K. F. R.; Yeh, K.; Chen, C. W.; Chung, P. Y.

    Based on the fuzzy Lyapunov method, this work addresses the stability conditions for nonlinear systems with multiple time delays to ensure the stability of building structure control systems. The delay independent conditions are derived via the traditional Lyapunov and fuzzy Lyapunov methods for multiple time-delay systems as approximated by the Tagagi-Sugeno (T-S) fuzzy model. The fuzzy Lyapunov function is defined as a fuzzy blending of quadratic Lyapunov functions. A parallel distributed compensation (PDC) scheme is utilized to construct a global fuzzy logic control (FLC) by blending all linear local state feedback controllers in the controller design procedure. Furthermore, the H infinity performance and robustness of the design for modeling errors also need to be considered in the stability conditions.

  7. Recent advances of strong-strong beam-beam simulation

    SciTech Connect

    Qiang, Ji; Furman, Miguel A.; Ryne, Robert D.; Fischer, Wolfram; Ohmi,Kazuhito

    2004-09-15

    In this paper, we report on recent advances in strong-strong beam-beam simulation. Numerical methods used in the calculation of the beam-beam forces are reviewed. A new computational method to solve the Poisson equation on nonuniform grid is presented. This method reduces the computational cost by a half compared with the standard FFT based method on uniform grid. It is also more accurate than the standard method for a colliding beam with low transverse aspect ratio. In applications, we present the study of coherent modes with multi-bunch, multi-collision beam-beam interactions at RHIC. We also present the strong-strong simulation of the luminosity evolution at KEKB with and without finite crossing angle.

  8. Nonequilibrium evolution of strong-field anisotropic ionized electrons towards a delayed plasma-state.

    PubMed

    Pasenow, B; Moloney, J V; Koch, S W; Chen, S H; Becker, A; Jaroń-Becker, A

    2012-01-30

    Rigorous quantum calculations of the femtosecond ionization of hydrogen atoms in air lead to highly anisotropic electron and ion angular (momentum) distributions. A quantum Monte-Carlo analysis of the subsequent many-body dynamics reveals two distinct relaxation steps, first to a nearly isotropic hot nonequilibrium and then to a quasi-equilibrium configuration. The collective isotropic plasma state is reached on a picosecond timescale well after the ultrashort ionizing pulse has passed.

  9. On the linearity of cross-correlation delay times

    NASA Astrophysics Data System (ADS)

    Mercerat, E. D.; Nolet, G.

    2012-12-01

    major contributor to deviation from linearity. The strong velocity contrast of 10% and the regularity of the anomalous structure generate strong reverberations. The test thus provides a worst-case scenario. The results scale up to regional (upper mantle) seismology if times and distances are multiplied by 10(4) . We conclude that in all but the most extreme cases, P-wave delay times depend quasi-linearly on the model perturbations.

  10. Effects of strong disorder in strongly correlated superconductors

    NASA Astrophysics Data System (ADS)

    Chakraborty, Debmalya; Sensarma, Rajdeep; Ghosal, Amit

    2017-01-01

    We investigate the effect of strong disorder on a system with strong electronic repulsion. In the absence of disorder, the system has a d-wave superconducting ground state with strong non-BCS features due to its proximity to a Mott insulator. We find that while strong correlations make superconductivity in this system immune to weak disorder, superconductivity is destroyed efficiently when disorder strength is comparable to the effective bandwidth. The suppression of charge motion in regions of strong potential fluctuation leads to the formation of Mott insulating patches, which anchor a larger nonsuperconducting region around them. The system thus breaks into islands of Mott insulating and superconducting regions, with Anderson insulating regions occurring along the boundary of these regions. Thus, electronic correlation and disorder, when both are strong, aid each other in destroying superconductivity, in contrast to their competition at weak disorder. Our results shed light on why zinc impurities are efficient in destroying superconductivity in cuprates, even though it is robust to weaker impurities.

  11. Titanium: light, strong, and white

    USGS Publications Warehouse

    Woodruff, Laurel; Bedinger, George

    2013-01-01

    Titanium (Ti) is a strong silver-gray metal that is highly resistant to corrosion and is chemically inert. It is as strong as steel but 45 percent lighter, and it is twice as strong as aluminum but only 60 percent heavier. Titanium dioxide (TiO2) has a very high refractive index, which means that it has high light-scattering ability. As a result, TiO2 imparts whiteness, opacity, and brightness to many products. ...Because of the unique physical properties of titanium metal and the whiteness provided by TiO2, titanium is now used widely in modern industrial societies.

  12. UWB delay and multiply receiver

    DOEpatents

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-09-10

    An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

  13. Adaptation to delayed auditory feedback

    NASA Technical Reports Server (NTRS)

    Katz, D. I.; Lackner, J. R.

    1977-01-01

    Delayed auditory feedback disrupts the production of speech, causing an increase in speech duration as well as many articulatory errors. To determine whether prolonged exposure to delayed auditory feedback (DAF) leads to adaptive compensations in speech production, 10 subjects were exposed in separate experimental sessions to both incremental and constant-delay exposure conditions. Significant adaptation occurred for syntactically structured stimuli in the form of increased speaking rates. After DAF was removed, aftereffects were apparent for all stimulus types in terms of increased speech rates. A carry-over effect from the first to the second experimental session was evident as long as 29 days after the first session. The use of strategies to overcome DAF and the differences between adaptation to DAF and adaptation to visual rearrangement are discussed.

  14. Dramatic robustness of a multiple delay dispersed interferometer to spectrograph errors: how mixing delays reduces or cancels wavelength drift

    NASA Astrophysics Data System (ADS)

    Erskine, David J.; Linder, E.; Wishnow, E.; Edelstein, J.; Sirk, M.; Muirhead, P.; Lloyd, J.; Kim, A.

    2016-08-01

    We describe demonstrations of remarkable robustness to instrumental noises by using a multiple delay externally dispersed interferometer (EDI) on stellar observations at the Hale telescope. Previous observatory EDI demonstrations used a single delay. The EDI (also called "TEDI") boosted the 2,700 resolution of the native TripleSpec NIR spectrograph (950-2450 nm) by as much as 10x to 27,000, using 7 overlapping delays up to 3 cm. We observed superb rejection of fixed pattern noises due to bad pixels, since the fringing signal responds only to changes in multiple exposures synchronous to the applied delay dithering. Remarkably, we observed a 20x reduction of reaction in the output spectrum to PSF shifts of the native spectrograph along the dispersion direction, using our standard processing. This allowed high resolution observations under conditions of severe and irregular PSF drift otherwise not possible without the interferometer. Furthermore, we recently discovered an improved method of weighting and mixing data between pairs of delays that can theoretically further reduce the net reaction to PSF drift to zero. We demonstrate a 350x reduction in reaction to a native PSF shift using a simple simulation. This technique could similarly reduce radial velocity noise for future EDI's that use two delays overlapped in delay space (or a single delay overlapping the native peak). Finally, we show an extremely high dynamic range EDI measurement of our ThAr lamp compared to a literature ThAr spectrum, observing weak features ( 0.001x height of nearest strong line) that occur between the major lines. Because of individuality of each reference lamp, accurate knowledge of its spectrum between the (unfortunately) sparse major lines is important for precision radial velocimetry.

  15. 49 CFR 236.563 - Delay time.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

  16. 49 CFR 236.563 - Delay time.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

  17. 49 CFR 236.563 - Delay time.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time. ...

  18. 49 CFR 236.563 - Delay time.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time....

  19. 49 CFR 236.563 - Delay time.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Delay time. 236.563 Section 236.563 Transportation... Cab Signal Systems Rules and Instructions; Locomotives § 236.563 Delay time. Delay time of automatic... requirements of § 236.24 shall take into consideration the delay time....

  20. Creating and Nurturing Strong Teams.

    ERIC Educational Resources Information Center

    Martin, Kaye M.

    1999-01-01

    Discusses ways to create and sustain strong teaching teams, including matching curriculum goals, complementary professional strengths, and exercise of autonomy. Elaborates the administrator's role in nurturing and supporting teamwork. (JPB)

  1. Cavity quantum electrodynamics: Beyond strong

    NASA Astrophysics Data System (ADS)

    Murch, Kater

    2017-01-01

    When light and matter are strongly coupled, they lose their distinct character and merge into a hybrid state. Three experiments explore this exotic regime using artificial atoms, with promise for quantum technologies.

  2. Fusion of Time Delayed Measurements With Uncertain Time Delays

    DTIC Science & Technology

    2005-06-01

    appear out of order. Nettleton derived an elegant implementation of this scheme using the inverse covariance (or information) form of the Kalman filter...measurement problems,” Informa- tion Fusion, vol. 4, pp. 185–199, 2003. [2] E. W. Nettleton and H. F. Durrant-Whyte, “Delayed and asequent data in

  3. Simulating strongly correlated electrons with a strongly interacting Fermi gas

    SciTech Connect

    Thomas, John E.

    2013-05-28

    The quantum many-body physics of strongly-correlated fermions is studied in a degenerate, strongly- interacting atomic Fermi gas, first realized by our group with DOE support in 2002. This system, which exhibits strong spin pairing, is now widely studied and provides an important paradigm for testing predictions based on state-of-the-art many-body theory in fields ranging from nuclear matter to high temperature superfluidity and superconductivity. As the system is strongly interacting, both the superfluid and the normal fluid are nontrivial and of great interest. A central part of our program on Fermi gases is the connection between the study of thermodynamics, supported by DOE and the study of hydrodynamic transport, supported by NSF. This connection is especially interesting in view of a recent conjecture from the string theory community on the concept of nearly perfect normal fluids, which exhibit a minimum ratio of shear viscosity to entropy density in strongly-interacting, scale-invariant systems.

  4. Variable Delay Testing Using ONE

    NASA Technical Reports Server (NTRS)

    Ishac, Joseph

    2002-01-01

    This paper investigates the effect of long and changing propagation delays on the performance of TCP file transfers. Tests are performed with machines that emulate communication from a low/medium-earth satellite to Earth by way of a geosynchronous satellite. As a result of these tests, we find that TCP is fairly robust to varying delays given a high enough TCP timer granularity. However, performance degrades noticeably for larger file transfers when a finer timer granularity is used. Such results have also been observed in previous simulations by other researchers, and thus, this work serves as an extension of those results.

  5. Spatio-temporal phenomena in complex systems with time delays

    NASA Astrophysics Data System (ADS)

    Yanchuk, Serhiy; Giacomelli, Giovanni

    2017-03-01

    Real-world systems can be strongly influenced by time delays occurring in self-coupling interactions, due to unavoidable finite signal propagation velocities. When the delays become significantly long, complicated high-dimensional phenomena appear and a simple extension of the methods employed in low-dimensional dynamical systems is not feasible. We review the general theory developed in this case, describing the main destabilization mechanisms, the use of visualization tools, and commenting on the most important and effective dynamical indicators as well as their properties in different regimes. We show how a suitable approach, based on a comparison with spatio-temporal systems, represents a powerful instrument for disclosing the very basic mechanism of long-delay systems. Various examples from different models and a series of recent experiments are reported.

  6. Recent Advances in Understanding Delayed Photoluminescence in Colloidal Semiconductor Nanocrystals.

    PubMed

    Marchioro, Arianna

    2017-02-22

    Colloidal semiconductor nanocrystals display remarkably bright, strongly size-dependent photoluminescence properties. Following photoexcitation of these materials, temporary charge carrier separation can occur where one or both charge carriers are trapped. Charge detrapping can reform the emissive state on long time scales up to seconds, causing delayed luminescence. This delayed luminescence has not yet been thoroughly explored, and appears to be closely associated with a phenomenon observed at the single particle level, i.e. photoluminescence intermittency (blinking). Here, some of our recent work on the delayed luminescence properties of nanocrystals of different chemical composition is reviewed. These results provide insight into the mechanism of carrier detrapping, and are discussed in the context of photoluminescence blinking.

  7. Can distributed delays perfectly stabilize dynamical networks?

    NASA Astrophysics Data System (ADS)

    Omi, Takahiro; Shinomoto, Shigeru

    2008-04-01

    Signal transmission delays tend to destabilize dynamical networks leading to oscillation, but their dispersion contributes oppositely toward stabilization. We analyze an integrodifferential equation that describes the collective dynamics of a neural network with distributed signal delays. With the Γ distributed delays less dispersed than exponential distribution, the system exhibits reentrant phenomena, in which the stability is once lost but then recovered as the mean delay is increased. With delays dispersed more highly than exponential, the system never destabilizes.

  8. Maturation delay for the predators can enhance stable coexistence for a class of prey-predator models.

    PubMed

    Banerjee, Malay; Takeuchi, Yasuhiro

    2017-01-07

    Maturation time delay for the predators is introduced in prey-predator models to implicitly model the stage-structure of predators. Most of the prey-predator models with maturation delay are known to exhibit destabilization of coexistence steady-state. Discrete time delay induced destabilization is a common finding, however, this is due to the introduction of time delay with lack of ecological justification. The main objective of the present work is to show the stabilizing role of maturation delay for a class of delayed prey-predator model. To be specific, we consider prey-predator models with strong and weak Allee effects in prey growth and Michaelis-Menten type functional response. We provide ecological justification for the introduction of maturation delay parameter in predator's growth equation. We obtain the conditions for stable and oscillatory coexistence of prey and their specialist predator in case of strong as well as weak Allee effect for non-delayed and delayed models. Apart from the analytical results for the models under consideration, we perform extensive numerical simulations to construct the relevant bifurcation diagrams. Our analytical and supportive numerical findings reveal that delay is not always a destabilizing factor rather the stable coexistence in the presence of time delay depends upon the formulation of the delayed model. The biological implications of the current investigation are provided in the conclusion section. We also explain the validity of obtained results for other types of prey-predator models with a specialist predator.

  9. The Trend toward Delayed Parenthood.

    ERIC Educational Resources Information Center

    Wilkie, Jane Riblett

    1981-01-01

    Studied the trend since the 1960s to delay parenthood. Proposes the decreased risk of unwanted conception and birth has made it easier. Suggests increased education and labor-force participation of women had an effect. Timing of first births affects fertility rates, family economics, and relations among generations. (Author)

  10. Local Effects of Delayed Food

    ERIC Educational Resources Information Center

    Davison, Michael; Baum, William M.

    2007-01-01

    Five pigeons were trained on a procedure in which seven concurrent variable-interval schedules arranged seven different food-rate ratios in random sequence in each session. Each of these components lasted for 10 response-produced food deliveries, and components were separated by 10-s blackouts. We varied delays to food (signaled by blackout)…

  11. Local Effects of Delayed Food

    ERIC Educational Resources Information Center

    Davison, Michael; Baum, William M.

    2007-01-01

    Five pigeons were trained on a procedure in which seven concurrent variable-interval schedules arranged seven different food-rate ratios in random sequence in each session. Each of these components lasted for 10 response-produced food deliveries, and components were separated by 10-s blackouts. We varied delays to food (signaled by blackout)…

  12. Measurement of Gravitational Lens Time Delays with LSST (SULI Paper)

    SciTech Connect

    Kirkby, Lowry Anna; /Oxford U. /SLAC

    2006-01-04

    The proposed Large Synoptic Survey Telescope will be the first to explore multiple dark energy probes simultaneously, including baryon acoustic oscillations, weak lensing, and strong gravitational lensing. The large data sample, covering the entire visible sky every few nights, will allow an unprecedented survey of deep supernova sources and their lensed images. The latter have not yet been observed. Notably, LSST will measure the time delays between different strong-lensed images of the same supernova. This will provide a unique probe of dark matter, dark energy, and the expansion rate of the Universe. By simulating LSST observations under realistic conditions, we determined the time delay precision of multiple images from a representative strong-lensed Type Ia supernova. The output of the simulation was a set of light curves according to field and filter, which were subsequently analyzed to determine the experimental time delays. We find that a time delay precision of better then 10% can be achieved under suitable conditions. Firstly, a minimum observed peak-magnitude of 22 is required for the lensed image, corresponding to an intrinsic source magnitude of about 24. The number of such supernova sources expected for LSST is under investigation, but it could amount to several thousand. Secondly, a minimum of about 50 visits per field is required, and, moreover, these visits must be evenly distributed over the duration of the event. The visit frequency should be approximately once per week, or better. Thirdly, the sky brightness should be below 21 magnitude arcsec{sup -2} to allow sufficient sensitivity to distance sources. Under the nominal LSST visiting schedule and field conditions, 15% of all fields satisfy these criteria, and allow time delay measurements of better than 10% precision. This performance can be further improved by fitting the predicted supernova light curves to the observations, rather than using the simple weighted mean as in the present study

  13. Strong fiber-reinforced hydrogel.

    PubMed

    Agrawal, Animesh; Rahbar, Nima; Calvert, Paul D

    2013-02-01

    In biological hydrogels, the gel matrix is usually reinforced with micro- or nanofibers, and the resulting composite is tough and strong. In contrast, synthetic hydrogels are weak and brittle, although they are highly elastic. The are many potential applications for strong synthetic hydrogels in medical devices, including as scaffolds for tissue growth. This work describes a new class of hydrogel composites reinforced with elastic fibers, giving them a cartilage-like structure. A three-dimensional rapid prototyping technique was used to form crossed "log-piles" of elastic fibers that are then impregnated with an epoxy-based hydrogel in order to form the fiber-reinforced gel. The fibrous construct improves the strength, modulus and toughness of the hydrogel, and also constrains the swelling. By altering the construct geometry and studying the effect on mechanical properties, we will develop the understanding needed to design strong hydrogels for biomedical devices and soft machines. Copyright © 2012. Published by Elsevier Ltd.

  14. Replication of Mu prophages lacking the central strong gyrase site.

    PubMed

    Pato, Martin L

    2004-09-01

    Replication of Mu prophages lacking the central strong gyrase site (SGS) is severely slowed. To study details of the replication of these prophages, an assay was developed for determining the rate and extent of introduction of nicks at the 3'-ends of a Mu prophage, an early step in Mu replicative transposition. The maximal level of end-nicking of a prophage with the SGS, about 70-90% depending upon the host strain, was achieved within about 15 min after induction, whereas at that time less than 5% nicking was observed with a prophage lacking the SGS. The amount of nicking at the end of the SGS(-) prophage increased with time, and approx. 30% nicking of the SGS(-) prophage was achieved by 60 min post-induction. Nicking kinetics were identical at each end of the prophages, and no nicking was observed at the 5'-ends of the prophages, verifying in vivo the earlier results with in vitro systems. To determine if prophage location affects the kinetics of replication, we examined prophages at numerous chromosomal locations. SGS(+) prophages at different chromosomal locations showed essentially identical replication kinetics. SGS(-) prophages showed a range of delays in replication and host lysis. A gradient of delays was apparent, with prophages further from the chromosomal origin of replication, oriC, showing longer delays than ones nearer to oriC. However, there were also exceptions to this overall gradient. Possible explanations for the differences in the delays observed with SGS(-) prophages are discussed.

  15. Strong Photoassociation in Ultracold Fermions

    NASA Astrophysics Data System (ADS)

    Jing, Li; Jamison, Alan; Rvachov, Timur; Ebadi, Sepher; Son, Hyungmok; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang

    2016-05-01

    Despite many studies there are still open questions about strong photoassociation in ultracold gases. Photoassociation occurs only at short range and thus can be used as a tool to probe and control the two-body correlation function in an interacting many-body system and to engineer Hamiltonians using dissipation. We propose the possibility to slow down decoherence by photoassociation through the quantum Zeno effect. This can realized by shining strong photoassociation light on the superposition of the lowest two hyperfine states of Lithium 6. NSF, ARO-MURI, Samsung, NSERC.

  16. Early identification of motor delay: Family-centred screening tool.

    PubMed

    Harris, Susan R

    2016-08-01

    To describe the Harris Infant Neuromotor Test (HINT), an infant neuromotor test using Canadian norms published in 2010 that could be used to screen for motor delay during the first year of life. Extensive research has been published on the intrarater, interrater, and test-retest reliability and the content, concurrent, predictive, and known-groups validity of the HINT, as well as on the sensitivity, specificity, and positive and negative predictive values of parental concerns, as assessed by the HINT. Most evidence is level II. Diagnosing motor delays during the first year of life is important because these often indicate more generalized developmental delays or specific disabilities, such as cerebral palsy. Parental concerns about their children's motor development are strongly predictive of subsequent diagnoses involving motor delay. Only through early identification of developmental motor delays, initially with screening tools such as the HINT, is it possible to provide referrals for early intervention that could benefit both the infant and the family. Copyright© the College of Family Physicians of Canada.

  17. β -delayed proton emission from 26P and 27S

    NASA Astrophysics Data System (ADS)

    Janiak, Ł.; Sokołowska, N.; Bezbakh, A. A.; Ciemny, A. A.; Czyrkowski, H.; Dąbrowski, R.; Dominik, W.; Fomichev, A. S.; Golovkov, M. S.; Gorshkov, A. V.; Janas, Z.; Kamiński, G.; Knyazev, A. G.; Krupko, S. A.; Kuich, M.; Mazzocchi, C.; Mentel, M.; Pfützner, M.; Pluciński, P.; Pomorski, M.; Slepniev, R. S.; Zalewski, B.

    2017-03-01

    Delayed emission of protons following β decay of neutron deficient nuclei 26P and 27S was investigated at the ACCULINNA separator in the Flerov Laboratory of Nuclear Reactions at Dubna. Ions of interest, identified in flight, were implanted into the active volume of the gaseous optical time projection chamber, which allowed us to record tracks of charged particles emitted in the decay. Total branching ratios for β -delayed proton emission and for β -delayed two-proton emission were determined. In addition, energy spectra for delayed protons below 2 MeV were established. Our findings for 26P agree with results of previous experiments. In the case of 27S, however, the observed probability of delayed proton emission is an order of magnitude larger than reported in literature. Two new strong proton transitions were identified representing decays of the first two excited states of 27P to the ground state of Si 26 . The probability ratio of γ -to-proton emission from these states is discussed.

  18. Tonal strength and melody recognition after long and short delays.

    PubMed

    Dowling, W J

    1991-10-01

    In a continuous-running-memory task, subjects heard novel seven-note melodies that were tested after delays of 11 sec (empty) or 39 sec (filled). Test items were transposed to new pitch levels (to moderately distant keys in the musical sense) and included exact transpositions (targets), same-contour lures with altered pitch intervals, and new-contour lures. Melodies differed in tonal strength (degree of conformity to a musical key) and were tonally strong, tonally weak, or atonal. False alarms to same-contour lures decreased over the longer delay period, but only for tonal stimuli. In agreement with previous studies, discrimination of detailed changes in pitch intervals improved with increased delay, whereas discrimination of more global contour information declined, again only for tonal stimuli. These results suggest that poor short-delay performance in rejecting same-contour lures arises from confusion that is based on the similarity of tonality between standard stimuli and lures. If a test item has the same contour and a similar tonality to a just-presented item, subjects tend to accept it. After a delay filled with melodies in other tonalities, the salience of key information recedes, and subjects base their judgments on more detailed pattern information (namely, exact pitch intervals). The fact that tonality affects judgments of melodic contour indicates that contour is not an entirely separable feature of melodies but rather that a melody with its contour constitutes an integrated perceptual whole.

  19. Continuous delay estimation with polynomial splines.

    PubMed

    Pinton, Gianmarco F; Trahey, Gregg E

    2006-11-01

    Delay estimation is used in ultrasonic imaging to estimate blood flow, determine phase aberration corrections, and to calculate elastographic images. Several algorithms have been developed to determine these delays. The accuracy of these methods depends in differing ways on noise, bandwidth, and delay range. In most cases relevant to delay estimation in ultrasonics, a subsample estimate of the delay is required. We introduce two new delay algorithms that use cubic polynomial splines to continuously represent the delay. These algorithms are compared to conventional delay estimators, such as normalized cross correlation and autocorrelation, and to another spline-based method. We present simulations that compare the algorithms' performance for varying amounts of noise, delay, and bandwidth. The proposed algorithms have better performance, in terms of bias and jitter, in a realistic ultrasonic imaging environment. The computational requirements of the new algorithms also are considered.

  20. PREFACE: Strongly Coupled Coulomb Systems Strongly Coupled Coulomb Systems

    NASA Astrophysics Data System (ADS)

    Neilson, David; Senatore, Gaetano

    2009-05-01

    This special issue contains papers presented at the International Conference on Strongly Coupled Coulomb Systems (SCCS), held from 29 July-2 August 2008 at the University of Camerino. Camerino is an ancient hill-top town located in the Apennine mountains of Italy, 200 kilometres northeast of Rome, with a university dating back to 1336. The Camerino conference was the 11th in a series which started in 1977: 1977: Orleans-la-Source, France, as a NATO Advanced Study Institute on Strongly Coupled Plasmas (hosted by Marc Feix and Gabor J Kalman) 1982: Les Houches, France (hosted by Marc Baus and Jean-Pierre Hansen) 1986: Santa Cruz, California, USA (hosted by Forrest J Rogers and Hugh E DeWitt) 1989: Tokyo, Japan (hosted by Setsuo Ichimaru) 1992: Rochester, New York, USA (hosted by Hugh M Van Horn and Setsuo Ichimaru) 1995: Binz, Germany (hosted by Wolf Dietrich Kraeft and Manfred Schlanges) 1997: Boston, Massachusetts, USA (hosted by Gabor J Kalman) 1999: St Malo, France (hosted by Claude Deutsch and Bernard Jancovici) 2002: Santa Fe, New Mexico, USA (hosted by John F Benage and Michael S Murillo) 2005: Moscow, Russia (hosted by Vladimir E Fortov and Vladimir Vorob'ev). The name of the series was changed in 1996 from Strongly Coupled Plasmas to Strongly Coupled Coulomb Systems to reflect a wider range of topics. 'Strongly Coupled Coulomb Systems' encompasses diverse many-body systems and physical conditions. The purpose of the conferences is to provide a regular international forum for the presentation and discussion of research achievements and ideas relating to a variety of plasma, liquid and condensed matter systems that are dominated by strong Coulomb interactions between their constituents. Each meeting has seen an evolution of topics and emphases that have followed new discoveries and new techniques. The field has continued to see new experimental tools and access to new strongly coupled conditions, most recently in the areas of warm matter, dusty plasmas

  1. Strong Ties and Job Information.

    ERIC Educational Resources Information Center

    Murray, Stephen O.; And Others

    1981-01-01

    This study of 299 social and physical scientists at universities reveals that strong personal contacts were more useful than reliance on weak ties (acquaintances) for job information. Using personal connections for employment information is thus an efficient job seeking method. (SK)

  2. Strong coupling electroweak symmetry breaking

    SciTech Connect

    Barklow, T.L.; Burdman, G.; Chivukula, R.S.

    1997-04-01

    The authors review models of electroweak symmetry breaking due to new strong interactions at the TeV energy scale and discuss the prospects for their experimental tests. They emphasize the direct observation of the new interactions through high-energy scattering of vector bosons. They also discuss indirect probes of the new interactions and exotic particles predicted by specific theoretical models.

  3. Strongly Coupled Nanotube Electromechanical Resonators.

    PubMed

    Deng, Guang-Wei; Zhu, Dong; Wang, Xin-He; Zou, Chang-Ling; Wang, Jiang-Tao; Li, Hai-Ou; Cao, Gang; Liu, Di; Li, Yan; Xiao, Ming; Guo, Guang-Can; Jiang, Kai-Li; Dai, Xing-Can; Guo, Guo-Ping

    2016-09-14

    Coupling an electromechanical resonator with carbon-nanotube quantum dots is a significant method to control both the electronic charge and the spin quantum states. By exploiting a novel microtransfer technique, we fabricate two separate strongly coupled and electrically tunable mechanical resonators for the first time. The frequency of the two resonators can be individually tuned by the bottom gates, and in each resonator, the electron transport through the quantum dot can be strongly affected by the phonon mode and vice versa. Furthermore, the conductance of either resonator can be nonlocally modulated by the other resonator through phonon-phonon interaction between the two resonators. Strong coupling is observed between the phonon modes of the two resonators, where the coupling strength larger than 200 kHz can be reached. This strongly coupled nanotube electromechanical resonator array provides an experimental platform for future studies of the coherent electron-phonon interaction, the phonon-mediated long-distance electron interaction, and entanglement state generation.

  4. Chokka-Chaffa' Kilimpi', Chikashshiyaakni' Kilimpi': strong family, strong nation.

    PubMed

    Deacon, Zermarie; Pendley, Joy; Hinson, Waymon R; Hinson, Joshua D

    2011-01-01

    To encourage the health and well-being of American Indian (AI) communities, it is first necessary to understand the meaning of health for particular tribes. As such, this investigation reports on the meaning of health and well-being for Chickasaw families. Findings from this investigation additionally highlight ways in which characteristics of strong Chickasaw families are both similar to and different from those of other AI tribes. Implications for science and practice are discussed.

  5. Galaxies with Strong Nitrogen Lines

    NASA Astrophysics Data System (ADS)

    Bergmann, T. S.; Pastoriza, M. G.

    1987-05-01

    ABSTRACT. From a qualitative spectroscopic survey of southern galaxies made by Pastoriza, a group with different morphological types whose nuclear region showed particular strong emission [N II]A6548-6584 lines when compared to Hn, was selected in order to investigate why [N II] is so strong. This work presents the results of a first analysis of the spectra of some of the galaxies above obtained with the 1-m telescope plus 2DFRUTTI detector of the Cerro Tololo Inter-American Observatory. The spectra are all very similar showing strong stellar continuum and absorption lines, and all the emission spectra show [0111] >[OII], [NIl] > H . None of the spectra show H in emission. Using the relative intensities of the H and K Call lines (Talent 1982, PLtb. A.S.P., 94,36), the obtained integrated spectra for all the observed galaxies is later than GO, which means that the H absorption lines should not be strong. From the relative intensities of the emission lines, we conclude that these galaxies cannot be classified as Starburst or LINERS. They are similar to Seyfert 2 (Osterbrock 1986, Act#va QSO4, preprint), but the FWHM of the lines is less than 300 km s . Also Ol X6300 is not clearly seen, and the absorption spectrum is strong relative to the emission spectrum. The preliminary conclusion is an activity similar but milder than that present in Seyfert 2 galaxies, as sug gested by Rose and Searle (1982, Ap. 5., 253, 556) and Rose and Cecil (1983, Ap. 5., 266, 531) for the nucleus of M51, maybe affected by an anomalous nitrogen abundance. K o : GALAXIES-ACTIVE - SPECTROSCOPY

  6. Quality control by <strong>HyperS>pectral <strong>I>maging (HSI) in solid waste recycling: logics, algorithms and procedures

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Serranti, Silvia

    2014-03-01

    In secondary raw materials and recycling sectors, the products quality represents, more and more, the key issue to pursuit in order to be competitive in a more and more demanding market, where quality standards and products certification play a preheminent role. These goals assume particular importance when recycling actions are applied. Recovered products, resulting from waste materials, and/or dismissed products processing, are, in fact, always seen with a certain suspect. An adequate response of the industry to the market can only be given through the utilization of equipment and procedures ensuring pure, high-quality production, and efficient work and cost. All these goals can be reached adopting not only more efficient equipment and layouts, but also introducing new processing logics able to realize a full control of the handled material flow streams fulfilling, at the same time, i) an easy management of the procedures, ii) an efficient use of the energy, iii) the definition and set up of reliable and robust procedures, iv) the possibility to implement network connectivity capabilities finalized to a remote monitoring and control of the processes and v) a full data storage, analysis and retrieving. Furthermore the ongoing legislation and regulation require the implementation of recycling infrastructure characterised by high resources efficiency and low environmental impacts, both aspects being strongly linked to the waste materials and/or dismissed products original characteristics. For these reasons an optimal recycling infrastructure design primarily requires a full knowledge of the characteristics of the input waste. What previously outlined requires the introduction of a new important concept to apply in solid waste recycling, the recycling-oriented characterization, that is the set of actions addressed to strategically determine selected attributes, in order to get goaloriented data on waste for the development, implementation or improvement of recycling

  7. PREFACE: Strongly correlated electron systems Strongly correlated electron systems

    NASA Astrophysics Data System (ADS)

    Saxena, Siddharth S.; Littlewood, P. B.

    2012-07-01

    This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which

  8. Strong localization of photonics in symmetric Fibonacci superlattices

    NASA Astrophysics Data System (ADS)

    Cheng, Y. H.; Tsao, C. W.; Chen, C. H.; Hsueh, W. J.

    2015-07-01

    Strong localization from the Fabry-Pérot-like resonances that occur in symmetric Fibonacci superlattices is presented in this study. When compared with traditional Fabry-Pérot resonators, in symmetric Fibonacci superlattices, the middle space is a variant rather than an invariant half-wavelength thickness for each resonance with different orders. In addition, the electric fields of the resonances may be located on both sides of the space layer in the superlattice, which is in contrast to those in a traditional Fabry-Pérot resonator. The electric field of the resonances is strongly localized as the generation order increases. Moreover, the group delays of these peaks increase with generation order. More strongly localized modes can be found from the symmetric Fibonacci superlattices than from the traditional Fabry-Pérot resonators, which makes the proposed structure an attractive alternative to a wide variety of optoelectronic devices.

  9. Baryogenesis from strong CP violation and the QCD axion.

    PubMed

    Servant, Géraldine

    2014-10-24

    We show that strong CP violation from the QCD axion can be responsible for the matter antimatter asymmetry of the Universe in the context of cold electroweak baryogenesis if the electroweak phase transition is delayed below the GeV scale. This can occur naturally if the Higgs couples to a O(100)  GeV dilaton, as expected in some models where the Higgs is a pseudo-Nambu-Goldstone boson of a new strongly interacting sector at the TeV scale. The existence of such a second scalar resonance with a mass and properties similar to the Higgs boson will soon be tested at the LHC. In this context, the QCD axion would not only solve the strong CP problem, but also the matter antimatter asymmetry and dark matter.

  10. Delay locked loop integrated circuit.

    SciTech Connect

    Brocato, Robert Wesley

    2007-10-01

    This report gives a description of the development of a Delay Locked Loop (DLL) integrated circuit (IC). The DLL was developed and tested as a stand-alone IC test chip to be integrated into a larger application specific integrated circuit (ASIC), the Quadrature Digital Waveform Synthesizer (QDWS). The purpose of the DLL is to provide a digitally programmable delay to enable synchronization between an internal system clock and external peripherals with unknown clock skew. The DLL was designed and fabricated in the IBM 8RF process, a 0.13 {micro}m CMOS process. It was designed to operate with a 300MHz clock and has been tested up to 500MHz.

  11. Response acquisition with delayed reinforcement.

    PubMed

    Lattal, K A; Gleeson, S

    1990-01-01

    Discrete responses of experimentally naive, food-deprived White Carneaux pigeons (key pecks) or Sprague-Dawley rats (bar or omnidirectional lever presses) initiated unsignaled delay periods that terminated with food delivery. Each subject first was trained to eat from the food source, but no attempt was made to shape or to otherwise train the response. In both species, the response developed and was maintained. Control procedures excluded the simple passage of time, response elicitation or induction by food presentation, type of operandum, food delivery device location, and adventitious immediate reinforcement of responding as the basis for the effects. Results revealed that neither training nor immediate reinforcement is necessary to establish new behavior. The conditions that give rise to both the first and second response are discussed, and the results are related to other studies of the delay of reinforcement and to explanations of behavior based on contingency or correlation and contiguity.

  12. Time delay and distance measurement

    NASA Technical Reports Server (NTRS)

    Abshire, James B. (Inventor); Sun, Xiaoli (Inventor)

    2011-01-01

    A method for measuring time delay and distance may include providing an electromagnetic radiation carrier frequency and modulating one or more of amplitude, phase, frequency, polarization, and pointing angle of the carrier frequency with a return to zero (RZ) pseudo random noise (PN) code. The RZ PN code may have a constant bit period and a pulse duration that is less than the bit period. A receiver may detect the electromagnetic radiation and calculate the scattering profile versus time (or range) by computing a cross correlation function between the recorded received signal and a three-state RZ PN code kernel in the receiver. The method also may be used for pulse delay time (i.e., PPM) communications.

  13. Delay of gratification in children.

    PubMed

    Mischel, W; Shoda, Y; Rodriguez, M I

    1989-05-26

    To function effectively, individuals must voluntarily postpone immediate gratification and persist in goal-directed behavior for the sake of later outcomes. The present research program analyzed the nature of this type of future-oriented self-control and the psychological processes that underlie it. Enduring individual differences in self-control were found as early as the preschool years. Those 4-year-old children who delayed gratification longer in certain laboratory situations developed into more cognitively and socially competent adolescents, achieving higher scholastic performance and coping better with frustration and stress. Experiments in the same research program also identified specific cognitive and attentional processes that allow effective self-regulation early in the course of development. The experimental results, in turn, specified the particular types of preschool delay situations diagnostic for predicting aspects of cognitive and social competence later in life.

  14. Delayed treatment of hemoglobin neurotoxicity.

    PubMed

    Regan, Raymond F; Rogers, Bret

    2003-01-01

    Hemoglobin is an oxidative neurotoxin that may contribute to cell injury after CNS trauma and hemorrhagic stroke. Prior studies have demonstrated that concomitant treatment with iron-chelating antioxidants prevents its neurotoxicity. However, the efficacy of these agents when applied hours after hemoglobin has not been determined, and is the subject of the present investigation. Consistent with prior observations, an increase in reactive oxygen species generation, detected by 2',7'-dichlorofluorescin oxidation, was observed when mixed neuronal/astrocyte cultures prepared from mouse cortex were exposed to hemoglobin alone. However, this oxidative stress developed slowly. A significant increase in the dichlorofluorescein signal compared with control, untreated cultures was not observed until four hours after addition of hemoglobin, and was followed by loss of membrane integrity and propidium iodide staining. Treating cultures with the 21-aminosteroid U74500A or the ferric iron chelator deferoxamine four hours after initiating hemoglobin treatment markedly attenuated reactive oxygen species production within 2 h. Continuous exposure to 5 micro M hemoglobin for 24 h resulted in death of about three-quarters of neurons, without injuring astrocytes. Most neuronal loss was prevented by concomitant treatment with U74500A; its effect was not significantly attenuated if treatment was delayed for 2-4 h, and it still prevented over half of neuronal death if treatment was delayed for 8 h. Similar neuroprotection was produced by delayed treatment with deferoxamine or the lipid-soluble iron chelator phenanthroline. None of these agents had any effect on neuronal death when added to cultures 12 h after hemoglobin. These results suggest that hemoglobin is a potent but slowly-acting neurotoxin. The delayed onset of hemoglobin neurotoxicity may make it an attractive target for therapeutic intervention.

  15. Method for calcining delayed coke

    SciTech Connect

    Smith, J.H.

    1981-02-17

    Delayed petroleum coke is calcined in an internally-fired vertical shaft kiln. A downwardly-moving bed of green coke is preheated in the top of the kiln by rising combustion gases, then heat soaked at calcining temperatures in the intermediate section of the kiln, and finally cooled by recycle gas moving upwardly from the lower part of the kiln. Partially cooled calcined coke is recovered from the bottom of the kiln.

  16. Josephson junctions with delayed feedback

    NASA Astrophysics Data System (ADS)

    Grønbech-Jensen, Niels; Blackburn, James A.; Huberman, Bernardo A.; Smith, H. J. T.

    1992-12-01

    We study a simple model of an overdamped Josephson junction coupled to a transmission line, which is regarded as a delayed feedback to the junction. It is demonstrated analytically how the nonlocal time dependence can give rise to hysteresis and steps in the current-voltage characteristics of the junction and the fundamental difference between positive and negative feedback is discussed. Excellent agreement between the analytical results and the results of numerical simulations is found.

  17. Delayed recombination and standard rulers

    SciTech Connect

    De Bernardis, Francesco; Melchiorri, Alessandro; Bean, Rachel; Galli, Silvia; Silk, Joseph I.; Verde, Licia

    2009-02-15

    Measurements of baryonic acoustic oscillations (BAOs) in galaxy surveys have been recognized as a powerful tool for constraining dark energy. However, this method relies on the knowledge of the size of the acoustic horizon at recombination derived from cosmic microwave background (CMB) anisotropy measurements. This estimate is typically derived assuming a standard recombination scheme; additional radiation sources can delay recombination altering the cosmic ionization history and the cosmological inferences drawn from CMB and BAO data. In this paper we quantify the effect of delayed recombination on the determination of dark energy parameters from future BAO surveys such as the Baryon Oscillation Spectroscopic Survey and the Wide-Field Multi-Object Spectrograph. We find the impact to be small but still not negligible. In particular, if recombination is nonstandard (to a level still allowed by CMB data), but this is ignored, future surveys may incorrectly suggest the presence of a redshift-dependent dark energy component. On the other hand, in the case of delayed recombination, adding to the analysis one extra parameter describing deviations from standard recombination does not significantly degrade the error bars on dark energy parameters and yields unbiased estimates. This is due to the CMB-BAO complementarity.

  18. Dynamics of strongly dissipative systems

    NASA Astrophysics Data System (ADS)

    Fang, H. P.

    1994-06-01

    The attractors in two-dimensional (2D) phase space of the strongly dissipative Hénon map are reduced to those of an effectively 1D map. From the grammar for this effectively 1D map we can generate all of the unstable periodic orbits, which are exactly consistent with those from the 2D map obtained directly both with a Newton procedure and the techniques of Biham and Wenzel [Phys. Rev. Lett. 63, 819 (1989)]. This idea provides a method to give a very precise and not too cumbersome estimate of the characteristic quantities of strange attractors of strongly dissipative systems. It is also helpful to understand many observations on high-dimensional systems both experimentally and numerically.

  19. Strongly Coupled Quantum Heat Machines

    SciTech Connect

    Gelbwaser-Klimovsky, David; Aspuru-Guzik, Alán

    2015-09-03

    Energy conversion of heat into work at the quantum level is modeled by quantum heat machines (QHMs) generally assumed to operate at weak coupling to the baths. This supposition is grounded in the separability principle between systems and allows the derivation of the evolution equation. In the weak coupling regime, the machine’s output is limited by the coupling strength, restricting their application. Seeking to overcome this limitation, we analyze QHMs in the virtually unexplored strong coupling regime here, where separability, as well as other standard thermodynamic assumptions, may no longer hold. We show that strongly coupled QHMs may be as efficient as their weakly coupled counterparts. In addition, we find a novel turnover behavior where their output saturates and disappears in the limit of ultrastrong coupling.

  20. Kinetic mixing at strong coupling

    NASA Astrophysics Data System (ADS)

    Del Zotto, Michele; Heckman, Jonathan J.; Kumar, Piyush; Malekian, Arada; Wecht, Brian

    2017-01-01

    A common feature of many string-motivated particle physics models is additional strongly coupled U (1 )'s. In such sectors, electric and magnetic states have comparable mass, and integrating out modes also charged under U (1 ) hypercharge generically yields C P preserving electric kinetic mixing and C P violating magnetic kinetic mixing terms. Even though these extra sectors are strongly coupled, we show that in the limit where the extra sector has approximate N =2 supersymmetry, we can use formal methods from Seiberg-Witten theory to compute these couplings. We also calculate various quantities of phenomenological interest such as the cross section for scattering between visible sector states and heavy extra sector states as well as the effects of supersymmetry breaking induced from coupling to the minimal supersymmetric Standard Model.

  1. Tilts in strong ground motion

    USGS Publications Warehouse

    Graizer, V.

    2006-01-01

    Most instruments used in seismological practice to record ground motion are pendulum seismographs, velocigraphs, or accelerographs. In most cases it is assumed that seismic instruments are only sensitive to the translational motion of the instrument's base. In this study the full equation of pendulum motion, including the inputs of rotations and tilts, is considered. It is shown that tilting the accelerograph's base can severely impact its response to the ground motion. The method of tilt evaluation using uncorrected strong-motion accelerograms was first suggested by Graizer (1989), and later tested in several laboratory experiments with different strong-motion instruments. The method is based on the difference in the tilt sensitivity of the horizontal and vertical pendulums. The method was applied to many of the strongest records of the Mw 6.7 Northridge earthquake of 1994. Examples are shown when relatively large tilts of up to a few degrees occurred during strong earthquake ground motion. Residual tilt extracted from the strong-motion record at the Pacoima Dam-Upper Left Abutment reached 3.1?? in N45??E direction, and was a result of local earthquake-induced tilting due to high-amplitude shaking. This value is in agreement with the residual tilt measured by using electronic level a few days after the earthquake. The method was applied to the building records from the Northridge earthquake. According to the estimates, residual tilt reached 2.6?? on the ground floor of the 12-story Hotel in Ventura. Processing of most of the strongest records of the Northridge earthquake shows that tilts, if happened, were within the error of the method, or less than about 0.5??.

  2. Strongly interacting parton matter equilibration

    SciTech Connect

    Ozvenchuk, V.; Linnyk, O.; Bratkovskaya, E.; Gorenstein, M.; Cassing, W.

    2012-07-15

    We study the kinetic and chemical equilibration in 'infinite' parton matter within the Parton-Hadron-String Dynamics transport approach. The 'infinite' matter is simulated within a cubic box with periodic boundary conditions initialized at different energy densities. Particle abundances, kinetic energy distributions, and the detailed balance of the off-shell quarks and gluons in the strongly-interacting quarkgluon plasma are addressed and discussed.

  3. Strong sphalerons and electroweak baryogenesis

    NASA Astrophysics Data System (ADS)

    Giudice, G. F.; Shaposhnikov, M.

    1994-04-01

    We analyze the spontaneous baryogenesis and charge transform mechanisms suggested by Cohen, Kaplan and Nelson for baryon asymmetry generation in extended versions of electroweak theory. We find that accounting for non-perturbative chirality-breaking transitions due to strong sphalerons reduces the baryonic asymmetry by the factor (mt/πT)2 or αW, provided those processes are in thermal equilibrium. On leave of absence from the Institute for Nuclear Research of the Russian Academy of Sciences, Moscow 117312, Russia.

  4. Flavour democracy in strong unification

    NASA Astrophysics Data System (ADS)

    Abel, S. A.; King, S. F.

    1998-09-01

    We show that the fermion mass spectrum may naturally be understood in terms of flavour democratic fixed points in supersymmetric theories which have a large domain of attraction in the presence of ``strong unification''. Our approach provides an alternative to the approximate Yukawa texture zeroes of the Froggatt-Nielsen mechanism. We discuss a particular model based on a broken gauged SU(3)LxSU(3)R family symmetry which illustrates our approach.

  5. Strong subadditivity and emergent surface

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Long, Jiang

    2014-09-01

    In this paper, we introduce two bounds which we call the upper differential entropy and the lower differential entropy for an infinite family of intervals (strips) in quantum field theory. The two bounds are equal provided that the theory is translational invariant and the entanglement entropy varies smoothly with respect to the interval. When the theory has a holographic dual, strong subadditivity of entanglement entropy indicates that there is always an emergent surface whose gravitational entropy is exactly given by the bound.

  6. Topics in strong Langmuir turbulence

    NASA Technical Reports Server (NTRS)

    Nicholson, D. R.

    1983-01-01

    Progress in two approaches to the study of strong Langmuir turbulence is reported. In two spatial dimensions, numerical solution of the Zakharov equations yields a steady state involving linear growth, linear damping, and a collection of coherent, long-lived entities which might loosely be called solitons. In one spatial dimension, a statistical theory is applied to the cubically nonlinear Schroedinger equation and is solved analytically in a special case.

  7. Topics in strong Langmuir turbulence

    NASA Technical Reports Server (NTRS)

    Nicholson, D. R.

    1982-01-01

    Progress in two approaches to the study of strong Langmuir turbulence is reported. In two spatial dimensions, numerical solution of the Zakharov equations yields a steady state involving linear growth, linear damping, and a collection of coherent, long-lived entities which might loosely be called solitons. In one spatial dimension, a statistical theory is applied to the cubically nonlinear Schroedinger equation and is solved analytically in a special case.

  8. Strongly magnetized classical plasma models

    NASA Technical Reports Server (NTRS)

    Montgomery, D.; Peyraud, J.; Dewitt, C.

    1974-01-01

    Discrete particle processes in the presence of a strong external magnetic field were investigated. These processes include equations of state and other equilibrium thermodynamic relations, thermal relaxation phenomena, transport properties, and microscopic statistical fluctuations in such quantities as the electric field and the charge density. Results from the equilibrium statistical mechanics of two-dimensional plasmas are discussed, along with nonequilibrium statistical mechanics of the electrostatic guiding-center plasma (a two-dimensional plasma model).

  9. Language Delays in Toddlers: Information for Parents

    MedlinePlus

    ... the time. When milestones are delayed If your child's development seems delayed or shows any of the behaviors ... do additional evaluations and reassure you that your child's development is normal or tell you that your child ...

  10. Delayed dispersal: youth costs carry lifetime gains.

    PubMed

    Ekman, Jan

    2007-06-05

    An analysis of reproductive success in the green woodhoopoe Phoeniculus purpures challenges the view that delayed dispersal is costly. Females delaying dispersal for longer had more reproductive events in life and higher lifetime production of offspring.

  11. Strong interactive massive particles from a strong coupled theory

    SciTech Connect

    Khlopov, Maxim Yu.; Kouvaris, Chris

    2008-03-15

    Minimal walking technicolor models can provide a nontrivial solution for cosmological dark matter, if the lightest technibaryon is doubly charged. Technibaryon asymmetry generated in the early Universe is related to baryon asymmetry, and it is possible to create an excess of techniparticles with charge (-2). These excessive techniparticles are all captured by {sup 4}He, creating techni-O-helium tOHe atoms, as soon as {sup 4}He is formed in big bang nucleosynthesis. The interaction of techni-O-helium with nuclei opens new paths to the creation of heavy nuclei in big bang nucleosynthesis. Because of the large mass of technibaryons, the tOHe ''atomic'' gas decouples from the baryonic matter and plays the role of dark matter in large scale structure formation, while structures in small scales are suppressed. Nuclear interactions with matter slow down cosmic techni-O-helium in the Earth below the threshold of underground dark matter detectors, thus escaping severe cryogenic dark matter search constraints. On the other hand, these nuclear interactions are not sufficiently strong to exclude this form of strongly interactive massive particles by constraints from the XQC experiment. Experimental tests of this hypothesis are possible in the search for tOHe in balloon-borne experiments (or on the ground) and for its charged techniparticle constituents in cosmic rays and accelerators. The tOHe atoms can cause cold nuclear transformations in matter and might form anomalous isotopes, offering possible ways to exclude (or prove?) their existence.

  12. Strongly interacting phases of metallic wires in strong magnetic field

    NASA Astrophysics Data System (ADS)

    Bulmash, Daniel; Jian, Chao-Ming; Qi, Xiao-Liang

    2017-07-01

    We investigate theoretically an interacting metallic wire with a strong magnetic field directed along its length and show that it is a highly tunable one-dimensional system. By considering a suitable change in spatial geometry, we build an analogy between the problem in the zeroth Landau level with Landau level degeneracy N to one-dimensional fermions with an N -component pseudospin degree of freedom and S U (2 ) -symmetric interactions. This analogy allows us to establish the phase diagram as a function of the interactions for small N (and make conjectures for large N ) using renormalization group and bosonization techniques. We find pseudospin-charge separation with a gapless U (1 ) charge sector and several possible strong-coupling phases in the pseudospin sector. For odd N , we find a fluctuating pseudospin-singlet charge density wave phase and a fluctuating pseudospin-singlet superconducting phase which are topologically distinct. For even N >2 , similar phases exist, although they are not topologically distinct, and an additional novel pseudospin-gapless phase appears. We discuss experimental conditions for observing our proposals.

  13. Disordered strongly correlated electronic systems

    NASA Astrophysics Data System (ADS)

    Javan Mard, Hossein

    Disorder can have a vast variety of consequences for the physics of phase transitions. Some transitions remain unchanged in the presence of disorder while others are completely destroyed. In this dissertation we study the effects of quenched disorder on electronic systmens at zero temperature. First, we perform variational studies of the interaction-localization problem to describe the interaction-induced renormalizations of the effective (screened) random potential seen by quasiparticles. Here we present results of careful finite-size scaling studies for the conductance of disordered Hubbard chains at half-filling and zero temperature. While our results indicate that quasiparticle wave functions remain exponentially localized even in the presence of moderate to strong repulsive interactions, we show that interactions produce a strong decrease of the characteristic conductance scale g* signaling the crossover to strong localization. This effect, which cannot be captured by a simple renormalization of the disorder strength, instead reflects a peculiar non-Gaussian form of the spatial correlations of the screened disordered potential, a hitherto neglected mechanism to dramatically reduce the impact of Anderson localization (interference) effects. Second, we formulate a strong-disorder renormalization-group (SDRG) approach to study the beta function of the tight-binding model in one dimension with both diagonal and off-diagonal disorder for states at the band center. We show that the SDRG method, when used to compute transport properties, yields exact results since it is identical to the transfer matrix method. The beta function is shown to be universal when only off-diagonal disorder is present even though single-parameter scaling is known to be violated. A different single-parameter scaling theory is formulated for this particular (particle-hole symmetric) case. Upon breaking particle-hole symmetry (by adding diagonal disorder), the beta function is shown to

  14. Wada property in systems with delay

    NASA Astrophysics Data System (ADS)

    Daza, Alvar; Wagemakers, Alexandre; Sanjuán, Miguel A. F.

    2017-02-01

    Delay differential equations take into account the transmission time of the information. These delayed signals may turn a predictable system into chaotic, with the usual fractalization of the phase space. In this work, we study the connection between delay and unpredictability, in particular we focus on the Wada property in systems with delay. This topological property gives rise to dramatic changes in the final state for small changes in the history functions.

  15. Direct-reading group-delay measurement

    NASA Technical Reports Server (NTRS)

    Trowbridge, D. L.

    1978-01-01

    Technique for measuring modulation signal retardation in microwave components gives direct plot of dependence of delay time on carrier frequency. Recorder sensitivity can be adjusted to give convenient scale factor for group delay. From family of such recordings, it is possible to observe changes in group delay due to temperature, mechanical stress, and other factors.

  16. Delayed reinforcement and fixed-ratio performance.

    PubMed

    Jarmolowicz, David P; Lattal, Kennon A

    2013-11-01

    Effects of delayed reinforcement on fixed-ratio (FR) maintained responding of pigeons were investigated. In Experiments 1-3, the delay of reinforcement was increased across successive sessions until pigeons paused for 300 s. Both signaled and unsignaled delays were studied across different conditions. Overall response rates and run rates (timed from the first to last response of a ratio) decreased and postreinforcement pauses increased as delays increased in each experiment. As delays increased, the likelihood of pausing during a ratio run also increased. When these measures were plotted as a function of obtained delays, signaled delays had less of an effect on the above measures than did unsignaled ones. In Experiment 2, delays had a greater effect on the above measures than did a control condition arranging equivalent interreinforcer intervals to those accompanying the delays. Experiments 3 and 4 examined the generality of the effects obtained in the first two experiments. In Experiment 3, delays imposed on FR or yoked-interval schedules had similar behavioral effects. In Experiment 4, effects similar to those found in Experiments 1-3 for 1, 10, and 20-s delays imposed on FR 50 schedules were found when the FR requirement increased across sessions. Despite the different contingencies relating response rate and reinforcement rates on interval and ratio schedules, delays of reinforcement generally affect performance on these schedules similarly.

  17. Articulatory Preparation in the Delayed Naming Task

    ERIC Educational Resources Information Center

    Kawamoto, Alan H.; Liu, Qiang; Mura, Keith; Sanchez, Adrianna

    2008-01-01

    The assumptions that acoustic onset must follow articulatory onset by a fixed delay and that response execution level processes are always effectively isolated in the delayed naming task were investigated with respect to the issue of articulatory preparation in three experiments. The results of these experiments showed that for the delayed naming…

  18. Contingency Tracking during Unsignaled Delayed Reinforcement

    ERIC Educational Resources Information Center

    Keely, Josue; Feola, Tyler; Lattal, Kennon A.

    2007-01-01

    Three experiments were conducted with rats in which responses on one lever (labeled the functional lever) produced reinforcers after an unsignaled delay period that reset with each response during the delay. Responses on a second, nonfunctional, lever did not initiate delays, but, in the first and third experiments, such responses during the last…

  19. Children's Delay of Gratification and Preschool Performance.

    ERIC Educational Resources Information Center

    Scoville, Satsuki; Chambliss, Catherine

    This study investigated the relationship between delay of gratification and preschool performance in 20 students aged 4 and 5 years old, and enrolled in a Head Start program. Gratification delay was measured through an experiment that allowed the students to choose between a smaller immediate reward or a larger delayed reward. Preschool…

  20. Contingency Tracking during Unsignaled Delayed Reinforcement

    ERIC Educational Resources Information Center

    Keely, Josue; Feola, Tyler; Lattal, Kennon A.

    2007-01-01

    Three experiments were conducted with rats in which responses on one lever (labeled the functional lever) produced reinforcers after an unsignaled delay period that reset with each response during the delay. Responses on a second, nonfunctional, lever did not initiate delays, but, in the first and third experiments, such responses during the last…

  1. Mathematical modeling of delayed pertussis vaccination in infants.

    PubMed

    Pesco, P; Bergero, P; Fabricius, G; Hozbor, D

    2015-10-05

    Pertussis is an acute vaccine-preventable respiratory disease that remains a public health problem. In an attempt to improve the control of the disease, many countries have incorporated new boosters in their vaccination schedule. Since the incorporation of these boosters is relatively recent, there are not enough data about their impact to support and/or universalize their use. Alternative strategies such as the improvement in vaccine coverage and reduction in vaccination delays, in addition to the incorporation of boosters, could be implemented. Though these strategies are not new, they have not been adequately evaluated in order to be implemented and/or prioritized. To evaluate the potential impact of these alternative strategies on pertussis incidence, we developed a methodology that involves the use of data collected from vaccination centers and an age-structured deterministic mathematical model for pertussis transmission. The results obtained show that strategies that avoid delays in vaccination have a strong impact on incidence reduction in the most vulnerable population (infants less than 1 y). In regions with high vaccination coverage (95%) the elimination of delays in the three primary doses decreases pertussis incidence in infants by approximately 20%. In regions where delays in the administration of vaccines are higher, the combined action to reduce delays and improve coverage leads to a significant improvement in disease control in infants. By repeating the calculations using different sets of parameters that describe different possible epidemiologic scenarios, we determined the robustness of our results. All the results presented highlight the importance of having high vaccine coverage and shorter delays in vaccine administration in order to reduce the impact of the disease in infants.

  2. PREFACE: Strongly Coupled Coulomb Systems

    NASA Astrophysics Data System (ADS)

    Fortov, Vladimir E.; Golden, Kenneth I.; Norman, Genri E.

    2006-04-01

    This special issue contains papers presented at the International Conference on Strongly Coupled Coulomb Systems (SCCS) which was held during the week of 20 24 June 2005 in Moscow, Russia. The Moscow conference was the tenth in a series of conferences. The previous conferences were organized as follows. 1977: Orleans-la-Source, France, as a NATO Advanced Study Institute on Strongly Coupled Plasmas (organized by Marc Feix and Gabor J Kalman) 1982: Les Houches, France (organized by Marc Baus and Jean-Pierre Hansen) 1986: Santa Cruz, California, USA (hosted by Forrest J Rogers and Hugh E DeWitt) 1989: Tokyo, Japan (hosted by Setsuo Ichimaru) 1992: Rochester, NY, USA (hosted by Hugh M Van Horn and Setsuo Ichimaru) 1995: Binz, Germany (hosted by Wolf Dietrich Kraeft and Manfred Schlanges) 1997: Boston, Massachusetts, USA (hosted by Gabor J Kalman) 1999: St Malo, France (hosted by Claude Deutsch and Bernard Jancovici) 2002: Santa Fe, New Mexico, USA (hosted by John F Benage and Michael S Murillo) After 1995 the name of the series was changed from `Strongly Coupled Plasmas' to the present name in order to extend the topics of the conferences. The planned frequency for the future is once every three years. The purpose of these conferences is to provide an international forum for the presentation and discussion of research accomplishments and ideas relating to a variety of plasma liquid and condensed matter systems, dominated by strong Coulomb interactions between their constituents. Strongly coupled Coulomb systems encompass diverse many-body systems and physical conditions. Each meeting has seen an evolution of topics and emphasis as new discoveries and new methods appear. This year, sessions were organized for invited presentations and posters on dense plasmas and warm matter, astrophysics and dense hydrogen, non-neutral and ultracold plasmas, dusty plasmas, condensed matter 2D and layered charged-particle systems, Coulomb liquids, and statistical theory of SCCS. Within

  3. Space Shuttle Propulsion Finishing Strong

    NASA Technical Reports Server (NTRS)

    Owen, James W.; Singer, Jody

    2011-01-01

    Numerous lessons have been documented from the Space Shuttle Propulsion elements. Major events include loss of the SRB's on STS-4 and shutdown of an SSME during ascent on STS- 51F. On STS-112 only half the pyrotechnics fired to release the vehicle from the launch pad, a testament for redundancy. STS-91 exhibited freezing of a main combustion chamber pressure measurement and on STS-93 nozzle tube ruptures necessitated a low liquid level oxygen cut off of the main engines. A number of on pad aborts were experienced during the early program resulting in delays. And the two accidents, STS-51L and STS-107, had unique heritage in history from early Program decisions and vehicle configuration. Following STS-51L significant resources were invested in developing fundamental physical understanding of solid rocket motor environments and material system behavior. Human rating of solid rocket motors was truly achieved. And following STS-107, the risk of ascent debris was better characterized and controlled. Situational awareness during all mission phases improved, and the management team instituted effective risk assessment practices. These major events and lessons for the future are discussed. The last 22 flights of the Space Shuttle, following the Columbia accident, were characterized by remarkable improvement in safety and reliability. Numerous problems were solved in addition to reduction of the ascent debris hazard. The propulsion system elements evolved to high reliability and heavy lift capability. The Shuttle system, though not a operable as envisioned in the 1970's, successfully assembled the International Space Station (ISS) and provided significant logistics and down mass for ISS operations. By the end of the Program, the remarkable Space Shuttle Propulsion system achieved very high performance, was largely reusable, exhibited high reliability, and is a heavy lift earth to orbit propulsion system. The story of this amazing system is discussed in detail in the paper.

  4. Strong turbulence of plasma waves

    NASA Technical Reports Server (NTRS)

    Goldman, M. V.

    1984-01-01

    This paper reviews recent work related to modulational instability and wave envelope self-focusing in dynamical and statistical systems. After introductory remarks pertinent to nonlinear optics realizations of these effects, the author summarizes the status of the subject in plasma physics, where it has come to be called 'strong Langmuir turbulence'. The paper treats the historical development of pertinent concepts, analytical theory, numerical simulations, laboratory experiments, and spacecraft observations. The role of self-similar self-focusing Langmuir envelope wave packets is emphasized, both in the Zakharov equation model for the wave dynamics and in a statistical theory based on this dynamical model.

  5. Strong Plate, Weak Slab Dichotomy

    NASA Astrophysics Data System (ADS)

    Petersen, R. I.; Stegman, D. R.; Tackley, P.

    2015-12-01

    Models of mantle convection on Earth produce styles of convection that are not observed on Earth.Moreover non-Earth-like modes, such as two-sided downwellings, are the de facto mode of convection in such models.To recreate Earth style subduction, i.e. one-sided asymmetric recycling of the lithosphere, proper treatment of the plates and plate interface are required. Previous work has identified several model features that promote subduction. A free surface or pseudo-free surface and a layer of material with a relatively low strength material (weak crust) allow downgoing plates to bend and slide past overriding without creating undue stress at the plate interface. (Crameri, et al. 2012, GRL)A low viscosity mantle wedge, possibly a result of slab dehydration, decouples the plates in the system. (Gerya et al. 2007, Geo)Plates must be composed of material which, in the case of the overriding plate, are is strong enough to resist bending stresses imposed by the subducting plate and yet, as in the case of the subducting plate, be weak enough to bend and subduct when pulled by the already subducted slab. (Petersen et al. 2015, PEPI) Though strong surface plates are required for subduction such plates may present a problem when they encounter the lower mantle.As the subducting slab approaches the higher viscosity, lower mantle stresses are imposed on the tip.Strong slabs transmit this stress to the surface.There the stress field at the plate interface is modified and potentially modifies the style of convection. In addition to modifying the stress at the plate interface, the strength of the slab affects the morphology of the slab at the base of the upper mantle. (Stegman, et al 2010, Tectonophysics)Slabs that maintain a sufficient portion of their strength after being bent require high stresses to unbend or otherwise change their shape.On the other hand slabs that are weakened though the bending process are more amenable to changes in morphology. We present the results of

  6. Dynamics of strongly correlated and strongly inhomogeneous plasmas.

    PubMed

    Kählert, Hanno; Kalman, Gabor J; Bonitz, Michael

    2014-07-01

    Kinetic and fluid equations are derived for the dynamics of classical inhomogeneous trapped plasmas in the strong coupling regime. The starting point is an extended Singwi-Tosi-Land-Sjölander (STLS) ansatz for the dynamic correlation function, which is allowed to depend on time and both particle coordinates separately. The time evolution of the correlation function is determined from the second equation of the Bogolyubov-Born-Green-Kirkwood-Yvon hierarchy. We study the equations in the linear limit and derive a nonlocal equation for the fluid displacement field. Comparisons to first-principles molecular dynamics simulations reveal an excellent quality of our approach thereby overcoming the limitations of the broadly used STLS scheme.

  7. BOLD delay times using group delay in sickle cell disease

    NASA Astrophysics Data System (ADS)

    Coloigner, Julie; Vu, Chau; Bush, Adam; Borzage, Matt; Rajagopalan, Vidya; Lepore, Natasha; Wood, John

    2016-03-01

    Sickle cell disease (SCD) is an inherited blood disorder that effects red blood cells, which can lead to vasoocclusion, ischemia and infarct. This disease often results in neurological damage and strokes, leading to morbidity and mortality. Functional Magnetic Resonance Imaging (fMRI) is a non-invasive technique for measuring and mapping the brain activity. Blood Oxygenation Level-Dependent (BOLD) signals contain also information about the neurovascular coupling, vascular reactivity, oxygenation and blood propagation. Temporal relationship between BOLD fluctuations in different parts of the brain provides also a mean to investigate the blood delay information. We used the induced desaturation as a label to profile transit times through different brain areas, reflecting oxygen utilization of tissue. In this study, we aimed to compare blood flow propagation delay times between these patients and healthy subjects in areas vascularized by anterior, middle and posterior cerebral arteries. In a group comparison analysis with control subjects, BOLD changes in these areas were found to be almost simultaneous and shorter in the SCD patients, because of their increased brain blood flow. Secondly, the analysis of a patient with a stenosis on the anterior cerebral artery indicated that signal of the area vascularized by this artery lagged the MCA signal. These findings suggest that sickle cell disease causes blood propagation modifications, and that these changes could be used as a biomarker of vascular damage.

  8. Strong-Coupling Superconductivity. I

    NASA Astrophysics Data System (ADS)

    Scalapino, D. J.; Schrieffer, J. R.; Wilkins, J. W.

    The pairing theory of superconductivity is extended to treat systems having strong electron-phonon coupling. In this regime the Landau quasiparticle approximation is invalid. In the theory we treat phonon and Coulomb interactions on the same basis and carry out the analysis using the nonzero-temperature Green's functions of the Nambu formalism. The generalized energy-gap equation thus obtained is solved (at T = 0°K) for a model which closely represents lead and the complex energy-gap parameter Δ(ω)) is plotted as a function of energy for several choices of phonon and Coulomb interaction strengths. An expression for the single-particle tunneling density of states is derived, which, when combined with Δ(ω), gives excellent agreement with experiment, if the phonon interaction strength is chosen to give the observed energy gap Δ0 at zero temperature. The tunneling experiments therefore give a detailed justification of the phonon mechanism of superconductivity and of the validity of the strong-coupling theory. In addition, by combining theory and the tunneling experiments, much can be learned about the electron-phon interaction and the phonon density of states. The theory is accurate to terms of order the square root of the electron-ion mass ratio, 10-2-10-3.

  9. Strong dynamics at the LHC

    NASA Astrophysics Data System (ADS)

    Ittisamai, Pawin

    The limitations of the Standard Model of particle physics, despite its being a well-established theory, have prompted various proposals for new physics capable of addressing its shortcomings. The particular issue to be explored here is the mechanism of electroweak symmetry breaking, the probing of which lies within the TeV-scale physics accessible to the Large Hadron Collider (LHC). This thesis focuses on the phenomenology of a class of models featuring a dynamical breaking of the electroweak symmetry via strong dynamics. Consequences of recent experiments and aspects of near-future experiments are presented. We study the implications of the LHC Higgs searches available at the time the related journal article was written for technicolor models that feature colored technifermions. Then we discuss the properties of a technicolor model featuring strong-top dynamics that is viable for explaining the recently discovered boson of mass 126 GeV. We introduce a novel method of characterizing the color structure of a new massive vector boson, often predicted in various new physics models, using information that will be promptly available if it is discovered in the near-future experiments at the LHC. We generalize the idea for more realistic models where a vector boson has flavor non-universal couplings to quarks. Finally, we discuss the possibilities of probing the chiral structure of a new color-octet vector boson.

  10. Numerical micromagnetism of strong inhomogeneities

    NASA Astrophysics Data System (ADS)

    Andreas, Christian; Gliga, Sebastian; Hertel, Riccardo

    2014-08-01

    The size of micromagnetic structures, such as domain walls or vortices, is comparable to the exchange length of the ferromagnet. Both, the exchange length of the stray field ls and the magnetocrystalline exchange length lk, are material-dependent quantities that usually lie in the nanometer range. This emphasizes the theoretical challenges associated with the mesoscopic nature of micromagnetism: the magnetic structures are much larger than the atomic lattice constant, but at the same time much smaller than the sample size. In computer simulations, the smallest exchange length serves as an estimate for the largest cell size admissible to prevent appreciable discretization errors. This general rule is not valid in special situations where the magnetization becomes particularly inhomogeneous. When such strongly inhomogeneous structures develop, micromagnetic simulations inevitably contain systematic and numerical errors. It is suggested to combine micromagnetic theory with a Heisenberg model to resolve such problems. We analyze cases where strongly inhomogeneous structures pose limits to standard micromagnetic simulations, arising from fundamental aspects as well as from numerical drawbacks.

  11. ADHD and Delay Aversion: The Influence of Non-Temporal Stimulation on Choice for Delayed Rewards

    ERIC Educational Resources Information Center

    Antrop, Inge; Stock, Pieter; Verte, Sylvie; Wiersema, Jan Roelt; Baeyens, Dieter; Roeyers, Herbert

    2006-01-01

    Background: Delay aversion, the motivation to escape or avoid delay, results in preference for small immediate over large delayed rewards. Delay aversion has been proposed as one distinctive psychological process that may underlie the behavioural symptoms and cognitive deficits of attention deficit/hyperactivity disorder (ADHD). Furthermore, the…

  12. ADHD and Delay Aversion: The Influence of Non-Temporal Stimulation on Choice for Delayed Rewards

    ERIC Educational Resources Information Center

    Antrop, Inge; Stock, Pieter; Verte, Sylvie; Wiersema, Jan Roelt; Baeyens, Dieter; Roeyers, Herbert

    2006-01-01

    Background: Delay aversion, the motivation to escape or avoid delay, results in preference for small immediate over large delayed rewards. Delay aversion has been proposed as one distinctive psychological process that may underlie the behavioural symptoms and cognitive deficits of attention deficit/hyperactivity disorder (ADHD). Furthermore, the…

  13. EDITORIAL: Strongly correlated electron systems Strongly correlated electron systems

    NASA Astrophysics Data System (ADS)

    Ronning, Filip; Batista, Cristian

    2011-03-01

    Strongly correlated electrons is an exciting and diverse field in condensed matter physics. This special issue aims to capture some of that excitement and recent developments in the field. Given that this issue was inspired by the 2010 International Conference on Strongly Correlated Electron Systems (SCES 2010), we briefly give some history in order to place this issue in context. The 2010 International Conference on Strongly Correlated Electron Systems was held in Santa Fe, New Mexico, a reunion of sorts from the 1989 International Conference on the Physics of Highly Correlated Electron Systems that also convened in Santa Fe. SCES 2010—co-chaired by John Sarrao and Joe Thompson—followed the tradition of earlier conferences, in this century, hosted by Buzios (2008), Houston (2007), Vienna (2005), Karlsruhe (2004), Krakow (2002) and Ann Arbor (2001). Every three years since 1997, SCES has joined the International Conference on Magnetism (ICM), held in Recife (2000), Rome (2003), Kyoto (2006) and Karlsruhe (2009). Like its predecessors, SCES 2010 topics included strongly correlated f- and d-electron systems, heavy-fermion behaviors, quantum-phase transitions, non-Fermi liquid phenomena, unconventional superconductivity, and emergent states that arise from electronic correlations. Recent developments from studies of quantum magnetism and cold atoms complemented the traditional subjects and were included in SCES 2010. 2010 celebrated the 400th anniversary of Santa Fe as well as the birth of astronomy. So what's the connection to SCES? The Dutch invention of the first practical telescope and its use by Galileo in 1610 and subsequent years overturned dogma that the sun revolved about the earth. This revolutionary, and at the time heretical, conclusion required innovative combinations of new instrumentation, observation and mathematics. These same combinations are just as important 400 years later and are the foundation of scientific discoveries that were discussed

  14. Modeling of SAW Delay Lines

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Atkinson, Gary M.

    2007-01-01

    Integrated Vehicle Health Monitoring (IVHM) of aerospace vehicles requires rugged sensors having reduced volume, mass, and power that can be used to measure a variety of phenomena. Wireless systems are preferred when retro-fitting sensors onto existing vehicles. Surface Acoustic Wave (SAW) devices are capable of sensing: temperature, pressure, strain, chemical species, mass loading, acceleration, and shear stress. SAW technology is low cost, rugged, lightweight, and extremely low power. To aid in the development of SAW sensors for IVHM applications, a first order model of a SAW Delay line has been created.

  15. Reactor shutdown delays medical procedures

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2008-01-01

    A longer-than-expected maintenance shutdown of the Canadian nuclear reactor that produces North America's entire supply of molybdenum-99 - from which the radioactive isotopes technetium-99 and iodine-131 are made - caused delays to the diagnosis and treatment of thousands of seriously ill patients last month. Technetium-99 is a key component of nuclear-medicine scans, while iodine-131 is used to treat cancer and other diseases of the thyroid. Production eventually resumed, but only after the Canadian government had overruled the Canadian Nuclear Safety Commission (CNSC), which was still concerned about the reactor's safety.

  16. Controllability of Nonlinear Fractional Delay Dynamical Systems

    NASA Astrophysics Data System (ADS)

    Nirmala, R. Joice; Balachandran, K.; Rodríguez-Germa, L.; Trujillo, J. J.

    2016-02-01

    This paper is concerned with controllability of nonlinear fractional delay dynamical systems with delay in state variables. The solution representations of fractional delay differential equations have been established by using the Laplace transform technique and the Mittag-Leffler function. Necessary and sufficient conditions for the controllability criteria of linear fractional delay systems are established. Further sufficient condition for the controllability of nonlinear fractional delay dynamical system are obtained by using the fixed point argument. Examples and numerical simulation are presented to illustrate the results.

  17. Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities

    SciTech Connect

    Virbhadra, K. S.; Keeton, C. R.

    2008-06-15

    We model the massive dark object at the center of the Galaxy as a Schwarzschild black hole as well as Janis-Newman-Winicour naked singularities, characterized by the mass and scalar charge parameters, and study gravitational lensing (particularly time delay, magnification centroid, and total magnification) by them. We find that the lensing features are qualitatively similar (though quantitatively different) for Schwarzschild black holes, weakly naked, and marginally strongly naked singularities. However, the lensing characteristics of strongly naked singularities are qualitatively very different from those due to Schwarzschild black holes. The images produced by Schwarzschild black hole lenses and weakly naked and marginally strongly naked singularity lenses always have positive time delays. On the other hand, strongly naked singularity lenses can give rise to images with positive, zero, or negative time delays. In particular, for a large angular source position the direct image (the outermost image on the same side as the source) due to strongly naked singularity lensing always has a negative time delay. We also found that the scalar field decreases the time delay and increases the total magnification of images; this result could have important implications for cosmology. As the Janis-Newman-Winicour metric also describes the exterior gravitational field of a scalar star, naked singularities as well as scalar star lenses, if these exist in nature, will serve as more efficient cosmic telescopes than regular gravitational lenses.

  18. The influences of delay time on the stability of a market model with stochastic volatility

    NASA Astrophysics Data System (ADS)

    Li, Jiang-Cheng; Mei, Dong-Cheng

    2013-02-01

    The effects of the delay time on the stability of a market model are investigated, by using a modified Heston model with a cubic nonlinearity and cross-correlated noise sources. These results indicate that: (i) There is an optimal delay time τo which maximally enhances the stability of the stock price under strong demand elasticity of stock price, and maximally reduces the stability of the stock price under weak demand elasticity of stock price; (ii) The cross correlation coefficient of noises and the delay time play an opposite role on the stability for the case of the delay time <τo and the same role for the case of the delay time >τo. Moreover, the probability density function of the escape time of stock price returns, the probability density function of the returns and the correlation function of the returns are compared with other literatures.

  19. Estimation of time delay by coherence analysis

    NASA Astrophysics Data System (ADS)

    Govindan, R. B.; Raethjen, J.; Kopper, F.; Claussen, J. C.; Deuschl, G.

    2005-05-01

    Using coherence analysis (which is an extensively used method to study the correlations in frequency domain, between two simultaneously measured signals) we estimate the time delay between two signals. This method is suitable for time delay estimation of narrow band coherence signals for which the conventional methods cannot be reliably applied. We show, by analysing coupled Rössler attractors with a known delay, that the method yields satisfactory results. Then, we apply this method to human pathologic tremor. The delay between simultaneously measured traces of electroencephalogram (EEG) and electromyogram (EMG) data of subjects with essential hand tremor is calculated. We find that there is a delay of 11-27 milli-seconds (ms) between the tremor correlated parts (cortex) of the brain (EEG) and the trembling hand (EMG) which is in agreement with the experimentally observed delay value of 15 ms for the cortico-muscular conduction time. By surrogate analysis we calculate error bars of the estimated delay.

  20. Precise delay measurement through combinatorial logic

    NASA Technical Reports Server (NTRS)

    Burke, Gary R. (Inventor); Chen, Yuan (Inventor); Sheldon, Douglas J. (Inventor)

    2010-01-01

    A high resolution circuit and method for facilitating precise measurement of on-chip delays for FPGAs for reliability studies. The circuit embeds a pulse generator on an FPGA chip having one or more groups of LUTS (the "LUT delay chain"), also on-chip. The circuit also embeds a pulse width measurement circuit on-chip, and measures the duration of the generated pulse through the delay chain. The pulse width of the output pulse represents the delay through the delay chain without any I/O delay. The pulse width measurement circuit uses an additional asynchronous clock autonomous from the main clock and the FPGA propagation delay can be displayed on a hex display continuously for testing purposes.

  1. Imitation of contrastive lexical stress in children with speech delay

    NASA Astrophysics Data System (ADS)

    Vick, Jennell C.; Moore, Christopher A.

    2005-09-01

    This study examined the relationship between acoustic correlates of stress in trochaic (strong-weak), spondaic (strong-strong), and iambic (weak-strong) nonword bisyllables produced by children (30-50) with normal speech acquisition and children with speech delay. Ratios comparing the acoustic measures (vowel duration, rms, and f0) of the first syllable to the second syllable were calculated to evaluate the extent to which each phonetic parameter was used to mark stress. In addition, a calculation of the variability of jaw movement in each bisyllable was made. Finally, perceptual judgments of accuracy of stress production were made. Analysis of perceptual judgments indicated a robust difference between groups: While both groups of children produced errors in imitating the contrastive lexical stress models (~40%), the children with normal speech acquisition tended to produce trochaic forms in substitution for other stress types, whereas children with speech delay showed no preference for trochees. The relationship between segmental acoustic parameters, kinematic variability, and the ratings of stress by trained listeners will be presented.

  2. Electrophoresis in strong electric fields.

    PubMed

    Barany, Sandor

    2009-01-01

    Two kinds of non-linear electrophoresis (ef) that can be detected in strong electric fields (several hundred V/cm) are considered. The first ("classical" non-linear ef) is due to the interaction of the outer field with field-induced ionic charges in the electric double layer (EDL) under conditions, when field-induced variations of electrolyte concentration remain to be small comparatively to its equilibrium value. According to the Shilov theory, the non-linear component of the electrophoretic velocity for dielectric particles is proportional to the cubic power of the applied field strength (cubic electrophoresis) and to the second power of the particles radius; it is independent of the zeta-potential but is determined by the surface conductivity of particles. The second one, the so-called "superfast electrophoresis" is connected with the interaction of a strong outer field with a secondary diffuse layer of counterions (space charge) that is induced outside the primary (classical) diffuse EDL by the external field itself because of concentration polarization. The Dukhin-Mishchuk theory of "superfast electrophoresis" predicts quadratic dependence of the electrophoretic velocity of unipolar (ionically or electronically) conducting particles on the external field gradient and linear dependence on the particle's size in strong electric fields. These are in sharp contrast to the laws of classical electrophoresis (no dependence of V(ef) on the particle's size and linear dependence on the electric field gradient). A new method to measure the ef velocity of particles in strong electric fields is developed that is based on separation of the effects of sedimentation and electrophoresis using videoimaging and a new flowcell and use of short electric pulses. To test the "classical" non-linear electrophoresis, we have measured the ef velocity of non-conducting polystyrene, aluminium-oxide and (semiconductor) graphite particles as well as Saccharomice cerevisiae yeast cells as a

  3. Delayed coker fractionator advanced control

    SciTech Connect

    Jaisinghani, R.; Minter, B. ); Tica, A.; Puglesi, A.; Ojeda, R. )

    1993-08-01

    In a delayed coking process, as coke drum switches are made, rapid changes occur in both the fractionator feed rate and composition. With conventional control, it is not unusual to see long transient behavior of large swings in both quality and flowrates of coker gas oils. This can extract a heavy economic toll, not only in coker operation, but in the operation of downstream units as the upset is propagated. An advanced process control application (APC) was recently implemented on the coker fractionator at the Yacimentos Petroliferos Fiscales (YPF), Lujan de Cuyo Refinery, in Mendoza, Argentina. This coker fractionator control design was unique as it handled two different operating objectives: control of product qualities via tower temperature profile during normal operation and control of gas oil product flow ratio during drum switch. This combination of control objectives in one multivariable predictive control program was achieved by including special logic to decouple the individual tuning requirements. Also, additional logic was included to unambiguously detect and identify drum switch and drum steam out as discrete events within 30 seconds of their actual occurrence. These discrete events were then used as disturbance variables to minimize fractionator transient behavior. As a performance measure, the overhead temperature was controlled within 2 C to 2.5 C of its target, gas oil flows were stabilized during drum switches and steam generation via pump around was maximized. Overall, implementing advanced control for the delayed coker fractionator resulted in substantial benefits from product quality control, product flow control and minimized energy consumption.

  4. Elite athletes and pubertal delay.

    PubMed

    Kapczuk, Karina

    2017-10-01

    Intensive physical training and participation in competitive sports during childhood and early adolescence may affect athletes' pubertal development. On the other hand, pubertal timing, early or late, may impact on an athlete selection for a particular sport. Genetic predisposition, training load, nutritional status and psychological stress determine athletes' pubertal timing. Athletes that practice esthetic sports, especially gymnasts, are predisposed to a delay in pubertal development. The growing evidence indicates that energy deficiency, not a systemic training per se, plays a crucial role in the pathogenesis of functional hypothalamic hypogonadism in female athletes. Metabolic and psychologic stress activate hypothalamic-pituitary-adrenal axis and suppress hypothalamic-pituitary-ovarian axis. Female athletes who do not begin secondary sexual development by the age of 14 or menstruation by the age of 16 warrant a comprehensive evaluation and a targeted treatment. Somatic growth and sexual maturation of elite female athletes are largely sport-specific since each sport favors a particular somatotype and requires a specific training. Chronic negative energy balance resulting from a systemic physical training and inadequate energy intake may delay pubertal development in elite athletes. Youth athletes, especially those engaged in competitive sports that emphasize prepubertal or lean appearance, are at risk of developing relative energy deficiency in sport associated with disordered eating or eating disorders. Management strategies should address the complex conditions underlying functional hypothalamic hypogonadism.

  5. PRECISION TIME-DELAY GENERATOR

    DOEpatents

    Carr, B.J.; Peckham, V.D.

    1959-06-16

    A precision time-delay generator circuit with low jitter is described. The first thyratron has a series resonant circuit and a diode which is connected to the second thyratron. The first thyratron is triggered at the begin-ning of a time delay and a capacitor is discharged through the first thyratron and the diode, thereby, triggering the second thyratron. (T.R.H.) l6l9O The instrument described can measure pressures between sea level and 300,000 ft. The pressure- sensing transducer of the instrument is a small cylindrical tube with a thin foil of titanium-tritium fastened around the inside of the tube. Output is a digital signal which can be used for storage or telemetering more conveniently than an analog signal. (W.D.M.) l6l9l An experimental study was made on rolling contacts in the temperature range of 550 to 1000 deg F. Variables such as material composition, hardness, and operating conditions were investigated in a rolling test stand. Ball bearing tests were run to determine the effect of design parameters, bearing materials, lubricants, and operating conditions. (auth)

  6. Delayed recombination and cosmic parameters

    SciTech Connect

    Galli, Silvia; Melchiorri, Alessandro; Bean, Rachel; Silk, Joseph

    2008-09-15

    Current cosmological constraints from cosmic microwave background anisotropies are typically derived assuming a standard recombination scheme, however additional resonance and ionizing radiation sources can delay recombination, altering the cosmic ionization history and the cosmological inferences drawn from the cosmic microwave background data. We show that for recent observations of the cosmic microwave background anisotropy, from the Wilkinson microwave anisotropy probe satellite mission (WMAP) 5-year survey and from the arcminute cosmology bolometer array receiver experiment, additional resonance radiation is nearly degenerate with variations in the spectral index, n{sub s}, and has a marked effect on uncertainties in constraints on the Hubble constant, age of the universe, curvature and the upper bound on the neutrino mass. When a modified recombination scheme is considered, the redshift of recombination is constrained to z{sub *}=1078{+-}11, with uncertainties in the measurement weaker by 1 order of magnitude than those obtained under the assumption of standard recombination while constraints on the shift parameter are shifted by 1{sigma} to R=1.734{+-}0.028. From the WMAP5 data we obtain the following constraints on the resonance and ionization sources parameters: {epsilon}{sub {alpha}}<0.39 and {epsilon}{sub i}<0.058 at 95% c.l.. Although delayed recombination limits the precision of parameter estimation from the WMAP satellite, we demonstrate that this should not be the case for future, smaller angular scales measurements, such as those by the Planck satellite mission.

  7. Cross delay line sensor characterization

    SciTech Connect

    Owens, Israel J; Remelius, Dennis K; Tiee, Joe J; Buck, Steven E; Whittemore, Stephen R; Thompson, David C; Shirey, Robert

    2010-01-01

    There exists a wealth of information in the scientific literature on the physical properties and device characterization procedures for complementary metal oxide semiconductor (CMOS), charge coupled device (CCD) and avalanche photodiode (APD) format detectors. Numerous papers and books have also treated photocathode operation in the context of photomultiplier tube (PMT) operation for either non imaging applications or limited night vision capability. However, much less information has been reported in the literature about the characterization procedures and properties of photocathode detectors with novel cross delay line (XDL) anode structures. These allow one to detect single photons and create images by recording space and time coordinate (X, Y & T) information. In this paper, we report on the physical characteristics and performance of a cross delay line anode sensor with an enhanced near infrared wavelength response photocathode and high dynamic range micro channel plate (MCP) gain (> 10{sup 6}) multiplier stage. Measurement procedures and results including the device dark event rate (DER), pulse height distribution, quantum and electronic device efficiency (QE & DQE) and spatial resolution per effective pixel region in a 25 mm sensor array are presented. The overall knowledge and information obtained from XDL sensor characterization allow us to optimize device performance and assess capability. These device performance properties and capabilities make XDL detectors ideal for remote sensing field applications that require single photon detection, imaging, sub nano-second timing response, high spatial resolution (10's of microns) and large effective image format.

  8. Cross delay line sensor characterization

    NASA Astrophysics Data System (ADS)

    Owens, Israel J.; Remelius, Dennis K.; Tiee, Joe J.; Buck, Steven E.; Whittemore, Stephen R.; Thompson, David C.; Shirey, Robert

    2010-04-01

    There exists a wealth of information in the scientific literature on the physical properties and device characterization procedures for complementary metal oxide semiconductor (CMOS), charge coupled device (CCD) and avalanche photodiode (APD) format detectors. Numerous papers and books have also treated photocathode operation in the context of photomultiplier tube (PMT) operation for either non imaging applications or limited night vision capability. However, much less information has been reported in the literature about the characterization procedures and properties of photocathode detectors with novel cross delay line (XDL) anode structures. These allow one to detect single photons and create images by recording space and time coordinate (X, Y & T) information. In this paper, we report on the physical characteristics and performance of a cross delay line anode sensor with an enhanced near infrared wavelength response photocathode and high dynamic range micro channel plate (MCP) gain (> 106 ) multiplier stage. Measurement procedures and results including the device dark event rate (DER), pulse height distribution, quantum and electronic device efficiency (QE & DQE) and spatial resolution per effective pixel region in a 25 mm sensor array are presented. The overall knowledge and information obtained from XDL sensor characterization allow us to optimize device performance and assess capability. These device performance properties and capabilities make XDL detectors ideal for remote sensing field applications that require single photon detection, imaging, sub nano-second timing response, high spatial resolution (10's of microns) and large effective image format.ÿ

  9. Eikonal Scattering at Strong Coupling

    NASA Astrophysics Data System (ADS)

    Irizarry-Gelpi, Melvin Eloy

    The scattering of subatomic particles is a source of important physical phenomena. Decades of work have yielded many techniques for the computation of scattering amplitudes. Most of these techniques involve perturbative quantum field theory and thus apply only at weak coupling. Complementary to scattering is the formation of bound states, which are intrinsically nonperturbative. Regge theory arose in the late 1950s as an attempt to describe, with a single framework, both scattering and the formation of bound states. In Regge theory one obtains an amplitude with bound state poles after analytic continuation of a nonperturbative scattering amplitude, corresponding to a sum of an infinite number of Feynman diagrams at large energy and fixed momentum transfer (but with crossed kinematics). Thus, in order to obtain bound states at fixed energy, one computes an amplitude at large momentum transfer. In this dissertation we calculate amplitudes with bound states in the regime of fixed energy and small momentum transfer. We formulate the elastic scattering problem in terms of many-body path integrals, familiar from quantum mechanics. Then we invoke the semiclassical JWKB approximation, where the path integral is dominated by classical paths. The dynamics in the semiclassical regime are strongly coupled, as found by Halpern and Siegel. When the momentum transfer is small, the classical paths are simple straight lines and the resulting semiclassical amplitudes display a spectrum of bound states that agrees with the spectrum found by solving wave equations with potentials. In this work we study the bound states of matter particles with various types of interactions, including electromagnetic and gravitational interactions. Our work has many analogies with the work started by Alday and Maldacena, who computed scattering amplitudes of gluons at strong coupling with semiclassical quantum mechanics of strings in anti de-Sitter spacetime. We hope that in the future we can apply our

  10. Flexible pulse delay control up to picosecond for high-intensity twin electron bunches

    DOE PAGES

    Zhang, Zhen; Ding, Yuantao; Emma, Paul; ...

    2015-09-10

    Two closely spaced electron bunches have attracted strong interest due to their applications in two color X-ray free-electron lasers as well as witness bunch acceleration in plasmas and dielectric structures. In this paper, we propose a new scheme of delay system to vary the time delay up to several picoseconds while not affecting the bunch compression. Numerical simulations based on the Linac Coherent Light Source are performed to demonstrate the feasibility of this method.

  11. Non-autonomous lattice systems with switching effects and delayed recovery

    NASA Astrophysics Data System (ADS)

    Han, Xiaoying; Kloeden, Peter E.

    2016-09-01

    The long term behavior of a type of non-autonomous lattice dynamical systems is investigated, where these have a diffusive nearest neighborhood interaction and discontinuous reaction terms with recoverable delays. This problem is of both biological and mathematical interests, due to its application in systems of excitable cells as well as general biological systems involving delayed recovery. The problem is formulated as an evolution inclusion with delays and the existence of weak and strong solutions is established. It is then shown that the solutions generate a set-valued non-autonomous dynamical system and that this non-autonomous dynamical system possesses a non-autonomous global pullback attractor.

  12. Delayed Visual Feedback of One’s Own Action Promotes Sense of Control for Auditory Events

    PubMed Central

    Kawabe, Takahiro

    2015-01-01

    Sense of control refers to one’s feelings to control environmental events through one’s own action. A prevailing view is that the sense of control is strong (or is not diminished) when predicted sensory signals, which are generated in motor control mechanisms, are consistent with afferent sensory signals. Such intact sense of control often leads to the misjudgment of temporal relation between timings of one’s action and its effect (so-called, intentional binding). The present study showed that the intentional binding could be enhanced by the delayed visual feedback of an agent’s action. We asked participants to press a button to produce a tone as action outcome. In some conditions, they were given the delayed visual feedback of their button press. Participants judged whether the onset of the auditory outcome was delayed from the timing of their button press. Consequently, delay detection thresholds were significantly higher when the feedback was given 0.2 and 0.4 s delays than when no feedback was displayed to the participants. The results indicate that action agents misjudge the timing of their action (button press) in the presence of the delayed visual feedback of their action. Interestingly, delay detection thresholds were strongly correlated with the subjective magnitude of the sense of control. Thus, the sense of control is possibly determined by cross-modal processing for action-related and outcome-related sensory signals. PMID:26635552

  13. Strong Winds over the Keel

    NASA Astrophysics Data System (ADS)

    2009-02-01

    The latest ESO image reveals amazing detail in the intricate structures of one of the largest and brightest nebulae in the sky, the Carina Nebula (NGC 3372), where strong winds and powerful radiation from an armada of massive stars are creating havoc in the large cloud of dust and gas from which the stars were born. ESO PR Photo 05a/09 The Carina Nebula ESO PR Video 05a/09 Pan over the Carina Nebula ESO PR Video 05b/09 Carina Nebula Zoom-in The large and beautiful image displays the full variety of this impressive skyscape, spattered with clusters of young stars, large nebulae of dust and gas, dust pillars, globules, and adorned by one of the Universe's most impressive binary stars. It was produced by combining exposures through six different filters from the Wide Field Imager (WFI), attached to the 2.2 m ESO/MPG telescope at ESO's La Silla Observatory, in Chile. The Carina Nebula is located about 7500 light-years away in the constellation of the same name (Carina; the Keel). Spanning about 100 light-years, it is four times larger than the famous Orion Nebula and far brighter. It is an intensive star-forming region with dark lanes of cool dust splitting up the glowing nebula gas that surrounds its many clusters of stars. The glow of the Carina Nebula comes mainly from hot hydrogen basking in the strong radiation of monster baby stars. The interaction between the hydrogen and the ultraviolet light results in its characteristic red and purple colour. The immense nebula contains over a dozen stars with at least 50 to 100 times the mass of our Sun. Such stars have a very short lifespan, a few million years at most, the blink of an eye compared with the Sun's expected lifetime of ten billion years. One of the Universe's most impressive stars, Eta Carinae, is found in the nebula. It is one of the most massive stars in our Milky Way, over 100 times the mass of the Sun and about four million times brighter, making it the most luminous star known. Eta Carinae is highly

  14. Attosecond Electron Wave Packet Dynamics in Strong Laser Fields

    SciTech Connect

    Johnsson, P.; Remetter, T.; Varju, K.; L'Huillier, A.; Lopez-Martens, R.; Valentin, C.; Balcou, Ph.; Kazamias, S.; Mauritsson, J.; Gaarde, M. B.; Schafer, K. J.; Mairesse, Y.; Wabnitz, H.; Salieres, P.

    2005-07-01

    We use a train of sub-200 attosecond extreme ultraviolet (XUV) pulses with energies just above the ionization threshold in argon to create a train of temporally localized electron wave packets. We study the energy transfer from a strong infrared (IR) laser field to the ionized electrons as a function of the delay between the XUV and IR fields. When the wave packets are born at the zero crossings of the IR field, a significant amount of energy ({approx}20 eV) is transferred from the field to the electrons. This results in dramatically enhanced above-threshold ionization in conditions where the IR field alone does not induce any significant ionization. Because both the energy and duration of the wave packets can be varied independently of the IR laser, they are valuable tools for studying and controlling strong-field processes.

  15. Psychological interventions for delayed ejaculation/orgasm.

    PubMed

    Althof, S E

    2012-01-01

    Of all the male sexual dysfunctions, delayed ejaculation (DE) is the least understood, least common and least studied. This paper aims to review and integrate the diverse psychological theories and proposed psychological interventions for DE. Clinicians will then be able to more clearly discern the relevant psychological/interpersonal issues of the patient/couple and implement systematically based effective interventions. After reviewing the literature, it is clear that no one theory accounts for all the varied presentations of DE, and no theory by itself has strong empirical support. However, awareness of the diverse points of view helps clinicians conduct better assessments and broaden their understanding of the patient's ejaculatory dysfunction. Similarly, no one psychological intervention works for all patients, nor will unsystematic random selection of interventions. This paper stresses on the need to clearly identify the source of the dysfunction and select treatments based upon the precipitating and maintaining factors. Much work remains to be done with regard to our understanding and treatment of DE. Specifically, we need to craft an evidence-based definition, assess the true prevalence of the dysfunction, demonstrate the efficacy of psychological interventions and design validated outcome measures.

  16. Delayed signatures of underground nuclear explosions

    PubMed Central

    Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; Ruddle, David G.; Wagoner, Jeffrey L.; Myers, Katherine B. L.; Emer, Dudley F.; Drellack, Sigmund L.; Chipman, Veraun D.

    2016-01-01

    Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. We observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be an indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). Our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates. PMID:26979288

  17. Delayed signatures of underground nuclear explosions

    DOE PAGES

    Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; ...

    2016-03-16

    Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. Here, we observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be anmore » indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). In conclusion, our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates.« less

  18. Delayed signatures of underground nuclear explosions

    SciTech Connect

    Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; Ruddle, David G.; Wagoner, Jeffrey L.; Myers, Katherine B. L.; Emer, Dudley F.; Drellack, Sigmund L.; Chipman, Veraun D.

    2016-03-16

    Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. Here, we observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be an indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). In conclusion, our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates.

  19. Strongly correlated perovskite fuel cells.

    PubMed

    Zhou, You; Guan, Xiaofei; Zhou, Hua; Ramadoss, Koushik; Adam, Suhare; Liu, Huajun; Lee, Sungsik; Shi, Jian; Tsuchiya, Masaru; Fong, Dillon D; Ramanathan, Shriram

    2016-06-09

    Fuel cells convert chemical energy directly into electrical energy with high efficiencies and environmental benefits, as compared with traditional heat engines. Yttria-stabilized zirconia is perhaps the material with the most potential as an electrolyte in solid oxide fuel cells (SOFCs), owing to its stability and near-unity ionic transference number. Although there exist materials with superior ionic conductivity, they are often limited by their ability to suppress electronic leakage when exposed to the reducing environment at the fuel interface. Such electronic leakage reduces fuel cell power output and the associated chemo-mechanical stresses can also lead to catastrophic fracture of electrolyte membranes. Here we depart from traditional electrolyte design that relies on cation substitution to sustain ionic conduction. Instead, we use a perovskite nickelate as an electrolyte with high initial ionic and electronic conductivity. Since many such oxides are also correlated electron systems, we can suppress the electronic conduction through a filling-controlled Mott transition induced by spontaneous hydrogen incorporation. Using such a nickelate as the electrolyte in free-standing membrane geometry, we demonstrate a low-temperature micro-fabricated SOFC with high performance. The ionic conductivity of the nickelate perovskite is comparable to the best-performing solid electrolytes in the same temperature range, with a very low activation energy. The results present a design strategy for high-performance materials exhibiting emergent properties arising from strong electron correlations.

  20. Strongly correlated perovskite fuel cells

    NASA Astrophysics Data System (ADS)

    Zhou, You; Guan, Xiaofei; Zhou, Hua; Ramadoss, Koushik; Adam, Suhare; Liu, Huajun; Lee, Sungsik; Shi, Jian; Tsuchiya, Masaru; Fong, Dillon D.; Ramanathan, Shriram

    2016-06-01

    Fuel cells convert chemical energy directly into electrical energy with high efficiencies and environmental benefits, as compared with traditional heat engines. Yttria-stabilized zirconia is perhaps the material with the most potential as an electrolyte in solid oxide fuel cells (SOFCs), owing to its stability and near-unity ionic transference number. Although there exist materials with superior ionic conductivity, they are often limited by their ability to suppress electronic leakage when exposed to the reducing environment at the fuel interface. Such electronic leakage reduces fuel cell power output and the associated chemo-mechanical stresses can also lead to catastrophic fracture of electrolyte membranes. Here we depart from traditional electrolyte design that relies on cation substitution to sustain ionic conduction. Instead, we use a perovskite nickelate as an electrolyte with high initial ionic and electronic conductivity. Since many such oxides are also correlated electron systems, we can suppress the electronic conduction through a filling-controlled Mott transition induced by spontaneous hydrogen incorporation. Using such a nickelate as the electrolyte in free-standing membrane geometry, we demonstrate a low-temperature micro-fabricated SOFC with high performance. The ionic conductivity of the nickelate perovskite is comparable to the best-performing solid electrolytes in the same temperature range, with a very low activation energy. The results present a design strategy for high-performance materials exhibiting emergent properties arising from strong electron correlations.

  1. Strongly correlated perovskite fuel cells

    SciTech Connect

    Zhou, You; Guan, Xiaofei; Zhou, Hua; Ramadoss, Koushik; Adam, Suhare; Liu, Huajun; Lee, Sungsik; Shi, Jian; Tsuchiya, Masaru; Fong, Dillon D.; Ramanathan, Shriram

    2016-05-16

    Fuel cells convert chemical energy directly into electrical energy with high efficiencies and environmental benefits, as compared with traditional heat engines1, 2, 3, 4. Yttria-stabilized zirconia is perhaps the material with the most potential as an electrolyte in solid oxide fuel cells (SOFCs), owing to its stability and near-unity ionic transference number5. Although there exist materials with superior ionic conductivity, they are often limited by their ability to suppress electronic leakage when exposed to the reducing environment at the fuel interface. Such electronic leakage reduces fuel cell power output and the associated chemo-mechanical stresses can also lead to catastrophic fracture of electrolyte membranes6. Here we depart from traditional electrolyte design that relies on cation substitution to sustain ionic conduction. Instead, we use a perovskite nickelate as an electrolyte with high initial ionic and electronic conductivity. Since many such oxides are also correlated electron systems, we can suppress the electronic conduction through a filling-controlled Mott transition induced by spontaneous hydrogen incorporation. Using such a nickelate as the electrolyte in free-standing membrane geometry, we demonstrate a low-temperature micro-fabricated SOFC with high performance. The ionic conductivity of the nickelate perovskite is comparable to the best-performing solid electrolytes in the same temperature range, with a very low activation energy. The results present a design strategy for high-performance materials exhibiting emergent properties arising from strong electron correlations.

  2. THE PENETRATION OF STRONG ELECTROLYTES

    PubMed Central

    Cooper, W. C.; Dorcas, M. J.; Osterhout, W. J. V.

    1929-01-01

    The entrance of strong electrolytes into Valonia is very slow unless the cells are injured. This, together with the very high electrical resistance of the protoplasm, suggests that they may penetrate largely as undissociated molecules formed at the surface of the protoplasm by the collision of ions. Under favorable circumstances KCl may be absorbed to the extent of 3 x 10–8 mols per hour per sq. cm. of surface together with about 0.17 as much NaCl. Other substances which seem to penetrate to some extent are Li, Rb, Br, BrO3, I, IO3, and selenite. Little or no penetration is shown by SCN, ferricyanide, ferrocyanide, formate, salicylate, tungstate, seleniate, NO2, SO3, Sb, glycerophosphate, and many heavy metals and the alkaline earths. In sea water whose specific gravity had been increased by CsCl cells of Valonia floated for over a year and there was little or no penetration of Cs except as the result of injury. The penetration of NH4Cl decreases the specific gravity of the sap and causes the cells to float: under these circumstances they live indefinitely. It is probable that NH3 or NH4OH penetrates and is subsequently changed to NH4Cl. It would seem that if the sea contained a little more ammonia this would be a floating organism. PMID:19872471

  3. Strongly correlated perovskite fuel cells

    DOE PAGES

    Zhou, You; Guan, Xiaofei; Zhou, Hua; ...

    2016-05-16

    Fuel cells convert chemical energy directly into electrical energy with high efficiencies and environmental benefits, as compared with traditional heat engines. Yttria-stabilized zirconia is perhaps the material with the most potential as an electrolyte in solid oxide fuel cells (SOFCs), owing to its stability and near-unity ionic transference number. Although there exist materials with superior ionic conductivity, they are often limited by their ability to suppress electronic leakage when exposed to the reducing environment at the fuel interface. Such electronic leakage reduces fuel cell power output and the associated chemo-mechanical stresses can also lead to catastrophic fracture of electrolyte membranes.more » Here we depart from traditional electrolyte design that relies on cation substitution to sustain ionic conduction. Instead, we use a perovskite nickelate as an electrolyte with high initial ionic and electronic conductivity. Since many such oxides are also correlated electron systems, we can suppress the electronic conduction through a filling-controlled Mott transition induced by spontaneous hydrogen incorporation. Using such a nickelate as the electrolyte in free-standing membrane geometry, we demonstrate a low-temperature micro-fabricated SOFC with high performance. The ionic conductivity of the nickelate perovskite is comparable to the best-performing solid electrolytes in the same temperature range, with a very low activation energy. The results present a design strategy for high-performance materials exhibiting emergent properties arising from strong electron correlations.« less

  4. Strongly correlated perovskite fuel cells

    SciTech Connect

    Zhou, You; Guan, Xiaofei; Zhou, Hua; Ramadoss, Koushik; Adam, Suhare; Liu, Huajun; Lee, Sungsik; Shi, Jian; Tsuchiya, Masaru; Fong, Dillon D.; Ramanathan, Shriram

    2016-05-16

    Fuel cells convert chemical energy directly into electrical energy with high efficiencies and environmental benefits, as compared with traditional heat engines. Yttria-stabilized zirconia is perhaps the material with the most potential as an electrolyte in solid oxide fuel cells (SOFCs), owing to its stability and near-unity ionic transference number. Although there exist materials with superior ionic conductivity, they are often limited by their ability to suppress electronic leakage when exposed to the reducing environment at the fuel interface. Such electronic leakage reduces fuel cell power output and the associated chemo-mechanical stresses can also lead to catastrophic fracture of electrolyte membranes. Here we depart from traditional electrolyte design that relies on cation substitution to sustain ionic conduction. Instead, we use a perovskite nickelate as an electrolyte with high initial ionic and electronic conductivity. Since many such oxides are also correlated electron systems, we can suppress the electronic conduction through a filling-controlled Mott transition induced by spontaneous hydrogen incorporation. Using such a nickelate as the electrolyte in free-standing membrane geometry, we demonstrate a low-temperature micro-fabricated SOFC with high performance. The ionic conductivity of the nickelate perovskite is comparable to the best-performing solid electrolytes in the same temperature range, with a very low activation energy. The results present a design strategy for high-performance materials exhibiting emergent properties arising from strong electron correlations.

  5. Extreme fluctuations in stochastic network coordination with time delays

    NASA Astrophysics Data System (ADS)

    Hunt, D.; Molnár, F.; Szymanski, B. K.; Korniss, G.

    2015-12-01

    We study the effects of uniform time delays on the extreme fluctuations in stochastic synchronization and coordination problems with linear couplings in complex networks. We obtain the average size of the fluctuations at the nodes from the behavior of the underlying modes of the network. We then obtain the scaling behavior of the extreme fluctuations with system size, as well as the distribution of the extremes on complex networks, and compare them to those on regular one-dimensional lattices. For large complex networks, when the delay is not too close to the critical one, fluctuations at the nodes effectively decouple, and the limit distributions converge to the Fisher-Tippett-Gumbel density. In contrast, fluctuations in low-dimensional spatial graphs are strongly correlated, and the limit distribution of the extremes is the Airy density. Finally, we also explore the effects of nonlinear couplings on the stability and on the extremes of the synchronization landscapes.

  6. Vibrational resonance in a time-delayed genetic toggle switch

    NASA Astrophysics Data System (ADS)

    Daza, Alvar; Wagemakers, Alexandre; Rajasekar, Shanmuganathan; Sanjuán, Miguel A. F.

    2013-02-01

    Biological oscillators can respond in a surprising way when they are perturbed by two external periodic forcing signals of very different frequencies. The response of the system to a low-frequency signal can be enhanced or depressed when a high-frequency signal is acting. This is what is known as vibrational resonance (VR). Here we study this phenomenon in a simple time-delayed genetic toggle switch, which is a synthetic gene-regulatory network. We have found out how the low-frequency signal changes the range of the response, while the high-frequency signal influences the amplitude at which the resonance occurs. The delay of the toggle switch has also a strong effect on the resonance since it can also induce autonomous oscillations.

  7. Delay-dependent global exponential robust stability for delayed cellular neural networks with time-varying delay.

    PubMed

    Liu, Pin-Lin

    2013-11-01

    This paper investigates a class of delayed cellular neural networks (DCNN) with time-varying delay. Based on the Lyapunov-Krasovski functional and integral inequality approach (IIA), a uniformly asymptotic stability criterion in terms of only one simple linear matrix inequality (LMI) is addressed, which guarantees stability for such time-varying delay systems. This LMI can be easily solved by convex optimization techniques. Unlike previous methods, the upper bound of the delay derivative is taken into consideration, even if larger than or equal to 1. It is proven that results obtained are less conservative than existing ones. Four numerical examples illustrate efficacy of the proposed methods.

  8. Transition delay using control theory.

    PubMed

    Bagheri, S; Henningson, D S

    2011-04-13

    This review gives an account of recent research efforts to use feedback control for the delay of laminar-turbulent transition in wall-bounded shear flows. The emphasis is on reducing the growth of small-amplitude disturbances in the boundary layer using numerical simulations and a linear control approach. Starting with the application of classical control theory to two-dimensional perturbations developing in spatially invariant flows, flow control based on control theory has progressed towards more realistic three-dimensional, spatially inhomogeneous flow configurations with localized sensing/actuation. The development of low-dimensional models of the Navier-Stokes equations has played a key role in this progress. Moreover, shortcomings and future challenges, as well as recent experimental advances in this multi-disciplinary field, are discussed.

  9. Delayed feedback control of chaos.

    PubMed

    Pyragas, Kestutis

    2006-09-15

    Time-delayed feedback control is well known as a practical method for stabilizing unstable periodic orbits embedded in chaotic attractors. The method is based on applying feedback perturbation proportional to the deviation of the current state of the system from its state one period in the past, so that the control signal vanishes when the stabilization of the target orbit is attained. A brief review on experimental implementations, applications for theoretical models and most important modifications of the method is presented. Recent advancements in the theory, as well as an idea of using an unstable degree of freedom in a feedback loop to avoid a well-known topological limitation of the method, are described in detail.

  10. Cell probing by delayed luminescence

    NASA Astrophysics Data System (ADS)

    Musumeci, Francesco; Ballerini, Monica; Baroni, Giuliana; Costato, Michele; Ferraro, Lorenzo; Milani, Marziale; Scordino, Agata; Triglia, Antonio

    1999-05-01

    Delayed luminescence (D.L.) is a measure that provides important information on biological systems fields, structures and activities, by counting impinging and emitted photons. Many recent experimental works have shown the existence of a close connection, sometimes analytically expressed between the biological state of the system and D.L. parameters. Our investigations aim to show that D.L. is a workable analytical technique covering a large number of disciplinary fields, from agriculture to pollution control and from medical diagnostics to food quality control. The authors have conducted systematic research about D.L. from unicellular alga Acetabularia acetabulum to Saccharomyces cerevisiae yeast cultures and about more complex systems such as Soya seed (Glycine max, L.) and its dependence on sample preparation, history, intracellular signaling, metabolism and pollutant presence. We will discuss the most relevant results together with theoretical considerations on the basic interaction at work between biological systems and electromagnetic fields.

  11. Strong field gravitational lensing by a charged Galileon black hole

    NASA Astrophysics Data System (ADS)

    Zhao, Shan-Shan; Xie, Yi

    2016-07-01

    Strong field gravitational lensings are dramatically disparate from those in the weak field by representing relativistic images due to light winds one to infinity loops around a lens before escaping. We study such a lensing caused by a charged Galileon black hole, which is expected to have possibility to evade no-hair theorem. We calculate the angular separations and time delays between different relativistic images of the charged Galileon black hole. All these observables can potentially be used to discriminate a charged Galileon black hole from others. We estimate the magnitudes of these observables for the closest supermassive black hole Sgr A*. The strong field lensing observables of the charged Galileon black hole can be close to those of a tidal Reissner-Nordström black hole or those of a Reissner-Nordström black hole. It will be helpful to distinguish these black holes if we can separate the outermost relativistic images and determine their angular separation, brightness difference and time delay, although it requires techniques beyond the current limit.

  12. Measuring angular diameter distances of strong gravitational lenses

    NASA Astrophysics Data System (ADS)

    Jee, Inh; Komatsu, Eiichiro; Suyu, Sherry H.

    2014-10-01

    The distance-redshift relation plays a fundamental role in constraining cosmological models. In this paper, we show that measurements of positions and time delays of strongly lensed images of a background galaxy, as well as those of the velocity dispersion and mass profile of a lens galaxy, can be combined to extract the angular diameter distance of the lens galaxy. Physically, as the velocity dispersion and the time delay give a gravitational potential ($GM/r$) and a mass ($GM$) of the lens, respectively, dividing them gives a physical size ($r$) of the lens. Comparing the physical size with the image positions of a lensed galaxy gives the angular diameter distance to the lens. A mismatch between the exact locations at which these measurements are made can be corrected by measuring a local slope of the mass profile. We expand on the original idea put forward by Paraficz and Hjorth, who analyzed singular isothermal lenses, by allowing for an arbitrary slope of a power-law spherical mass density profile, an external convergence, and an anisotropic velocity dispersion. We find that the effect of external convergence cancels out when dividing the time delays and velocity dispersion measurements. We derive a formula for the uncertainty in the angular diameter distance in terms of the uncertainties in the observables. As an application, we use two existing strong lens systems, B1608+656 ($z_{\\rm L}=0.6304$) and RXJ1131$-$1231 ($z_{\\rm L}=0.295$), to show that the uncertainty in the inferred angular diameter distances is dominated by that in the velocity dispersion, $\\sigma^2$, and its anisotropy. We find that the current data on these systems should yield about 16% uncertainty in $D_A$ per object. This improves to 13% when we measure $\\sigma^2$ at the so-called sweet-spot radius. Achieving 7% is possible if we can determine $\\sigma^2$ with 5% precision.

  13. Measuring angular diameter distances of strong gravitational lenses

    NASA Astrophysics Data System (ADS)

    Jee, I.; Komatsu, E.; Suyu, S. H.

    2015-11-01

    The distance-redshift relation plays a fundamental role in constraining cosmological models. In this paper, we show that measurements of positions and time delays of strongly lensed images of a background galaxy, as well as those of the velocity dispersion and mass profile of a lens galaxy, can be combined to extract the angular diameter distance of the lens galaxy. Physically, as the velocity dispersion and the time delay give a gravitational potential (GM/r) and a mass (GM) of the lens, respectively, dividing them gives a physical size (r) of the lens. Comparing the physical size with the image positions of a lensed galaxy gives the angular diameter distance to the lens. A mismatch between the exact locations at which these measurements are made can be corrected by measuring a local slope of the mass profile. We expand on the original idea put forward by Paraficz and Hjorth, who analyzed singular isothermal lenses, by allowing for an arbitrary slope of a power-law spherical mass density profile, an external convergence, and an anisotropic velocity dispersion. We find that the effect of external convergence cancels out when dividing the time delays and velocity dispersion measurements. We derive a formula for the uncertainty in the angular diameter distance in terms of the uncertainties in the observables. As an application, we use two existing strong lens systems, B1608+656 (zL=0.6304) and RXJ1131-1231 (zL=0.295), to show that the uncertainty in the inferred angular diameter distances is dominated by that in the velocity dispersion, σ2, and its anisotropy. We find that the current data on these systems should yield about 16% uncertainty in DA per object. This improves to 13% when we measure σ2 at the so-called sweet-spot radius. Achieving 7% is possible if we can determine σ2 with 5% precision.

  14. Measuring angular diameter distances of strong gravitational lenses

    SciTech Connect

    Jee, I.; Komatsu, E.; Suyu, S.H. E-mail: komatsu@mpa-garching.mpg.de

    2015-11-01

    The distance-redshift relation plays a fundamental role in constraining cosmological models. In this paper, we show that measurements of positions and time delays of strongly lensed images of a background galaxy, as well as those of the velocity dispersion and mass profile of a lens galaxy, can be combined to extract the angular diameter distance of the lens galaxy. Physically, as the velocity dispersion and the time delay give a gravitational potential (GM/r) and a mass (GM) of the lens, respectively, dividing them gives a physical size (r) of the lens. Comparing the physical size with the image positions of a lensed galaxy gives the angular diameter distance to the lens. A mismatch between the exact locations at which these measurements are made can be corrected by measuring a local slope of the mass profile. We expand on the original idea put forward by Paraficz and Hjorth, who analyzed singular isothermal lenses, by allowing for an arbitrary slope of a power-law spherical mass density profile, an external convergence, and an anisotropic velocity dispersion. We find that the effect of external convergence cancels out when dividing the time delays and velocity dispersion measurements. We derive a formula for the uncertainty in the angular diameter distance in terms of the uncertainties in the observables. As an application, we use two existing strong lens systems, B1608+656 (z{sub L}=0.6304) and RXJ1131−1231 (z{sub L}=0.295), to show that the uncertainty in the inferred angular diameter distances is dominated by that in the velocity dispersion, σ{sup 2}, and its anisotropy. We find that the current data on these systems should yield about 16% uncertainty in D{sub A} per object. This improves to 13% when we measure σ{sup 2} at the so-called sweet-spot radius. Achieving 7% is possible if we can determine σ{sup 2} with 5% precision.

  15. Diagnostic delay in oral squamous cell carcinoma: the role of cognitive and psychological variables.

    PubMed

    Panzarella, Vera; Pizzo, Giuseppe; Calvino, Francesco; Compilato, Domenico; Colella, Giuseppe; Campisi, Giuseppina

    2014-03-01

    This retrospective study investigated, in two cohorts of subjects living in Southern Italy and awaiting treatment for oral squamous cell carcinoma (OSCC), the variables related to diagnostic delay ascribable to the patient, with particular reference to the cognitive and psychological ones. A total of 156 patients with OSCC (mean age: 62 years, M/F: 2.39∶1) were recruited at the Universities of Palermo and Naples. Risk factors related to patient delay included: sociodemographic, health-related, cognitive and psychological variables. The analysis was conducted by considering two different delay ranges: dichotomous (≤1 month vs. >1 month) and polytomous (<1 month, 1-3 months, >3 months) delay. Data were investigated by univariate and multivariate analyses and a P value ≤0.05 was considered statistically significant. For both delay measurements, the most relevant variables were: 'Personal experience of cancer' (dichotomous delay: P=0.05, odds ratio (OR)=0.33, 95% confidence interval (CI)=0.11-0.99; polytomous delay: P=0.006, Chi-square=10.224) and 'Unawareness' (dichotomous delay: P<0.01, OR=4.96, 95% CI=2.16-11.37; polytomous delay: P=0.087, Chi-square=4.77). Also 'Denial' (P<0.01, OR=6.84, 95% CI=2.31-20.24) and 'Knowledge of cancer' (P=0.079, Chi-square=8.359) were found to be statistically significant both for dichotomous and for polytomous categorization of delay, respectively. The findings of this study indicated that, in the investigated cohorts, the knowledge about cancer issues is strongly linked to the patient delay. Educational interventions on the Mediterranean population are necessary in order to increase the patient awareness and to emphasize his/her key role in early diagnosis of OSCC.

  16. The Effects of Pitch Shifts on Delay-Induced Changes in Vocal Sequencing in a Songbird.

    PubMed

    Wyatt, MacKenzie; Berthiaume, Emily A; Kelly, Conor W; Sober, Samuel J

    2017-01-01

    Like human speech, vocal behavior in songbirds depends critically on auditory feedback. In both humans and songbirds, vocal skills are acquired by a process of imitation whereby current vocal production is compared to an acoustic target. Similarly, performance in adulthood relies strongly on auditory feedback, and online manipulations of auditory signals can dramatically alter acoustic production even after vocalizations have been well learned. Artificially delaying auditory feedback can disrupt both speech and birdsong, and internal delays in auditory feedback have been hypothesized as a cause of vocal dysfluency in persons who stutter. Furthermore, in both song and speech, online shifts of the pitch (fundamental frequency) of auditory feedback lead to compensatory changes in vocal pitch for small perturbations, but larger pitch shifts produce smaller changes in vocal output. Intriguingly, large pitch shifts can partially restore normal speech in some dysfluent speakers, suggesting that the effects of auditory feedback delays might be ameliorated by online pitch manipulations. Although birdsong provides a promising model system for understanding speech production, the interactions between sensory feedback delays and pitch shifts have not yet been assessed in songbirds. To investigate this, we asked whether the addition of a pitch shift modulates delay-induced changes in Bengalese finch song, hypothesizing that pitch shifts would reduce the effects of feedback delays. Compared with the effects of delays alone, combined delays and pitch shifts resulted in a significant reduction in behavioral changes in one type of sequencing (branch points) but not another (distribution of repeated syllables).

  17. The Effects of Pitch Shifts on Delay-Induced Changes in Vocal Sequencing in a Songbird

    PubMed Central

    Kelly, Conor W.

    2017-01-01

    Abstract Like human speech, vocal behavior in songbirds depends critically on auditory feedback. In both humans and songbirds, vocal skills are acquired by a process of imitation whereby current vocal production is compared to an acoustic target. Similarly, performance in adulthood relies strongly on auditory feedback, and online manipulations of auditory signals can dramatically alter acoustic production even after vocalizations have been well learned. Artificially delaying auditory feedback can disrupt both speech and birdsong, and internal delays in auditory feedback have been hypothesized as a cause of vocal dysfluency in persons who stutter. Furthermore, in both song and speech, online shifts of the pitch (fundamental frequency) of auditory feedback lead to compensatory changes in vocal pitch for small perturbations, but larger pitch shifts produce smaller changes in vocal output. Intriguingly, large pitch shifts can partially restore normal speech in some dysfluent speakers, suggesting that the effects of auditory feedback delays might be ameliorated by online pitch manipulations. Although birdsong provides a promising model system for understanding speech production, the interactions between sensory feedback delays and pitch shifts have not yet been assessed in songbirds. To investigate this, we asked whether the addition of a pitch shift modulates delay-induced changes in Bengalese finch song, hypothesizing that pitch shifts would reduce the effects of feedback delays. Compared with the effects of delays alone, combined delays and pitch shifts resulted in a significant reduction in behavioral changes in one type of sequencing (branch points) but not another (distribution of repeated syllables). PMID:28144622

  18. Does it pay to delay? Flesh flies show adaptive plasticity in reproductive timing.

    PubMed

    Wessels, Frank J; Kristal, Ross; Netter, Fleta; Hatle, John D; Hahn, Daniel A

    2011-02-01

    Life-history plasticity is widespread among organisms. However, an important question is whether it is adaptive. Most models for plasticity in life-history timing predict that animals, once they have reached the minimal nutritional threshold under poor conditions, will accelerate development or time to reproduction. Adaptive delays in reproduction are not common, especially in short-lived species. Examples of adaptive reproductive delays exist in mammalian populations experiencing strong interspecific (e.g., predation) and intraspecific (e.g., infanticide) competition. But are there other environmental factors that may trigger an adaptive delay in reproductive timing? We show that the short-lived flesh fly Sarcophaga crassipalpis will delay reproduction under nutrient-poor conditions, even though it has already met the minimal nutritional threshold for reproduction. We test whether this delay strategy is an adaptive response allowing the scavenger time to locate more resources by experimentally providing supplemental protein pulses (early, mid and late) throughout the reproductive delay period. Flies receiving additional protein produced more and larger eggs, demonstrating a benefit of the delay. In addition, by tracking the allocation of carbon from the pulses using stable isotopes, we show that flies receiving earlier pulses incorporated more carbon into eggs and somatic tissue than those given a later pulse. These results indicate that the reproductive delay in S. crassipalpis is consistent with adaptive post-threshold plasticity, a nutritionally linked reproductive strategy that has not been reported previously in an invertebrate species.

  19. Strong-field ionization via a high-order Coulomb-corrected strong-field approximation

    NASA Astrophysics Data System (ADS)

    Klaiber, Michael; Daněk, Jiří; Yakaboylu, Enderalp; Hatsagortsyan, Karen Z.; Keitel, Christoph H.

    2017-02-01

    Signatures of the Coulomb corrections in the photoelectron momentum distribution during laser-induced ionization of atoms or ions in tunneling and multiphoton regimes are investigated analytically in the case of a one-dimensional problem. A high-order Coulomb-corrected strong-field approximation is applied, where the exact continuum state in the S matrix is approximated by the eikonal Coulomb-Volkov state including the second-order corrections to the eikonal. Although without high-order corrections our theory coincides with the known analytical R -matrix (ARM) theory, we propose a simplified procedure for the matrix element derivation. Rather than matching the eikonal Coulomb-Volkov wave function with the bound state as in the ARM theory to remove the Coulomb singularity, we calculate the matrix element via the saddle-point integration method by time as well as by coordinate, and in this way avoiding the Coulomb singularity. The momentum shift in the photoelectron momentum distribution with respect to the ARM theory due to high-order corrections is analyzed for tunneling and multiphoton regimes. The relation of the quantum corrections to the tunneling delay time is discussed.

  20. Delayed puberty associated with inflammatory bowel disease.

    PubMed

    Ballinger, Anne B; Savage, Martin O; Sanderson, Ian R

    2003-02-01

    Delayed puberty frequently complicates the clinical course of young patients with inflammatory bowel disease, more often in Crohn's disease than ulcerative colitis. Undernutrition has been thought to be the main reason for delayed puberty in these patients. However, puberty may be delayed despite a normal nutritional status. Observations in patients with inflammatory bowel disease and in rats with experimental colitis suggest that inflammatory mediators may have a direct adverse influence, independent of undernutrition, on the onset and progression of puberty. Serum androgens are consistently reported to be reduced in patients with delayed puberty and inflammatory bowel disease. This reduction is not necessarily secondary to a reduction in gonadotrophins as serum concentrations of gonadotrophins have been reported to be normal or even increased in some studies. Management of delayed puberty involves calorie supplements to correct undernutrition and treatment of inflammation. Observations in boys with delayed puberty and controlled studies in experimental models of intestinal inflammation suggest that testosterone therapy can accelerate puberty.

  1. RESPONSE ACQUISITION BY HUMANS WITH DELAYED REINFORCEMENT

    PubMed Central

    Okouchi, Hiroto

    2009-01-01

    The present experiment examined whether a response class was acquired by humans with delayed reinforcement. Eight white circles were presented on a computer touch screen. If the undergraduates touched two of the eight circles in a specified sequence (i.e., touching first the upper-left circle then the bottom-left circle), then the touches initiated an unsignaled resetting delay culminating in point delivery. Participants experienced one of three different delays (0 s, 10 s, or 30 s). Rates of the target two-response sequence were higher with delayed reinforcement than with no reinforcement. Terminal rates of the target sequence decreased and postreinforcement pauses increased as a function of delay duration. Other undergraduates exposed to yoked schedules of response-independent point deliveries failed to acquire the sequence. The results demonstrate that a response class was acquired with delayed reinforcement, extending the generality of this phenomenon found with nonhuman animals to humans. PMID:19949494

  2. Delay banking for air traffic management

    NASA Technical Reports Server (NTRS)

    Green, Steven M. (Inventor)

    2007-01-01

    A method and associated system for time delay banking for aircraft arrival time, aircraft departure time and/or en route flight position. The delay credit value for a given flight may decrease with passage of time and may be transferred to or traded with other flights having the same or a different user (airline owner or operator). The delay credit value for a given aircraft flight depends upon an initial delay credit value, which is determined by a central system and depends upon one or more other flight characteristics. Optionally, the delay credit value decreases with passage of time. Optionally, a transaction cost is assessed against a delay credit value that is used on behalf of another flight with the same user or is traded with a different user.

  3. Promoting Strong Written Communication Skills

    NASA Astrophysics Data System (ADS)

    Narayanan, M.

    2015-12-01

    The reason that an improvement in the quality of technical writing is still needed in the classroom is due to the fact that universities are facing challenging problems not only on the technological front but also on the socio-economic front. The universities are actively responding to the changes that are taking place in the global consumer marketplace. Obviously, there are numerous benefits of promoting strong written communication skills. They can be summarized into the following six categories. First, and perhaps the most important: The University achieves learner satisfaction. The learner has documented verbally, that the necessary knowledge has been successfully acquired. This results in learner loyalty that in turn will attract more qualified learners.Second, quality communication lowers the cost per pupil, consequently resulting in increased productivity backed by a stronger economic structure and forecast. Third, quality communications help to improve the cash flow and cash reserves of the university. Fourth, having high quality communication enables the university to justify the need for high costs of tuition and fees. Fifth, better quality in written communication skills result in attracting top-quality learners. This will lead to happier and satisfied learners, not to mention greater prosperity for the university as a whole. Sixth, quality written communication skills result in reduced complaints, thus meaning fewer hours spent on answering or correcting the situation. The University faculty and staff are thus able to devote more time on scholarly activities, meaningful research and productive community service. References Boyer, Ernest L. (1990). Scholarship reconsidered: Priorities of the Professorate.Princeton, NJ: Carnegie Foundation for the Advancement of Teaching. Hawkins, P., & Winter, J. (1997). Mastering change: Learning the lessons of the enterprise.London: Department for Education and Employment. Buzzel, Robert D., and Bradley T. Gale. (1987

  4. The strong maximum principle revisited

    NASA Astrophysics Data System (ADS)

    Pucci, Patrizia; Serrin, James

    In this paper we first present the classical maximum principle due to E. Hopf, together with an extended commentary and discussion of Hopf's paper. We emphasize the comparison technique invented by Hopf to prove this principle, which has since become a main mathematical tool for the study of second order elliptic partial differential equations and has generated an enormous number of important applications. While Hopf's principle is generally understood to apply to linear equations, it is in fact also crucial in nonlinear theories, such as those under consideration here. In particular, we shall treat and discuss recent generalizations of the strong maximum principle, and also the compact support principle, for the case of singular quasilinear elliptic differential inequalities, under generally weak assumptions on the quasilinear operators and the nonlinearities involved. Our principal interest is in necessary and sufficient conditions for the validity of both principles; in exposing and simplifying earlier proofs of corresponding results; and in extending the conclusions to wider classes of singular operators than previously considered. The results have unexpected ramifications for other problems, as will develop from the exposition, e.g. two point boundary value problems for singular quasilinear ordinary differential equations (Sections 3 and 4); the exterior Dirichlet boundary value problem (Section 5); the existence of dead cores and compact support solutions, i.e. dead cores at infinity (Section 7); Euler-Lagrange inequalities on a Riemannian manifold (Section 9); comparison and uniqueness theorems for solutions of singular quasilinear differential inequalities (Section 10). The case of p-regular elliptic inequalities is briefly considered in Section 11.

  5. Compact programmable photonic variable delay devices

    NASA Technical Reports Server (NTRS)

    Yao, X. Steve (Inventor)

    1999-01-01

    Optical variable delay devices for providing variable true time delay to multiple optical beams simultaneously. A ladder-structured variable delay device comprises multiple basic building blocks stacked on top of each other resembling a ladder. Each basic building block has two polarization beamsplitters and a polarization rotator array arranged to form a trihedron; Controlling an array element of the polarization rotator array causes a beam passing through the array element either going up to a basic building block above it or reflect back towards a block below it. The beams going higher on the ladder experience longer optical path delay. An index-switched optical variable delay device comprises of many birefringent crystal segments connected with one another, with a polarization rotator array sandwiched between any two adjacent crystal segments. An array element in the polarization rotator array controls the polarization state of a beam passing through the element, causing the beam experience different refractive indices or path delays in the following crystal segment. By independently control each element in each polarization rotator array, variable optical path delays of each beam can be achieved. Finally, an index-switched variable delay device and a ladder-structured variable device are cascaded to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. The device is inherently two dimensional and has a packing density exceeding 25 lines/cm.sup.2. The delay resolution of the device is on the order of a femtosecond (one micron in space) and the total delay exceeds 10 nanosecond. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

  6. Delays in the human heartbeat dynamics.

    PubMed

    Alvarez-Ramirez, Jose; Rodriguez, Eduardo; Echeverría, Juan Carlos

    2009-06-01

    This paper explores the possibility of applying statistical nonlinear physics methods to elucidate the underlying mechanisms controlling the heart rate. In particular, the presence of delays in RR interval dynamics is studied by using a lagged detrended fluctuation analysis. The results indicate that patients with congestive heart failure (CHF) have a prolonged time delay in the baroreflex response. Some implications of large delays for the functioning of autonomic control in subjects with CHF are discussed.

  7. DUI offenders delay license reinstatement: a problem?

    PubMed

    Voas, Robert B; Tippetts, A Scott; McKnight, A Scott

    2010-07-01

    We examined the extent to which driving under the influence (DUI) offenders delay reinstatement, the reasons for that delay, and the relationship of the delay to recidivism. Analyzed were the driving records of 40 million drivers (3 million convicted of DUI) from 7 of the largest states spanning 7 to 14 years. License suspension effectively reduces, but does not eliminate, impaired driving. Apparently, many feel they can avoid apprehension for unlicensed driving; the limited research to date suggests that up to 75% of convicted offenders continue to drive and up to 84% delay reinstatement for 3 or more years. ANOVA and regression procedures were used to determine the relationship of prior driving record and sentence length to the DUI offender's delay in reinstatement. Meta-analysis was used to summarize results across the 7 states and survival analysis to determine the effect of the delay on recidivism. Forty-two percent of first offenders and 55% of multiple offenders convicted for DUI delay reinstatement for more than a year. For a third of the offenders, there were no records of their having reinstated within 5 years of becoming eligible. Both factors-more than one prior offense and the length of suspension imposed-were related to delay in reinstatement. Offenders who delayed reinstatement were more likely to recidivate both while they delayed before reinstating and after they reinstated. DUI offenders who delay reinstatement after they become eligible are high-risk drivers. Offenders who reinstate, however, have lower recidivism rates than those who do not. This suggests that encouraging reinstatement but with continued controls, as some states have provided through laws requiring interlocks as a condition of reinstatement, may be effective if they do not motivate extended delays.

  8. Delays in the human heartbeat dynamics

    NASA Astrophysics Data System (ADS)

    Alvarez-Ramirez, Jose; Rodriguez, Eduardo; Echeverría, Juan Carlos

    2009-06-01

    This paper explores the possibility of applying statistical nonlinear physics methods to elucidate the underlying mechanisms controlling the heart rate. In particular, the presence of delays in RR interval dynamics is studied by using a lagged detrended fluctuation analysis. The results indicate that patients with congestive heart failure (CHF) have a prolonged time delay in the baroreflex response. Some implications of large delays for the functioning of autonomic control in subjects with CHF are discussed.

  9. Terrestrial Planet Finder cryogenic delay line development

    NASA Technical Reports Server (NTRS)

    Smythe, Robert F.; Swain, Mark R.; Alvarez-Salazar, Oscar; Moore, James D.

    2004-01-01

    Delay lines provide the path-length compensation that makes the measurement of interference fringes possible. When used for nulling interferometry, the delay line must control path-lengths so that the null is stable and controlled throughout the measurement. We report on a low noise, low disturbance, and high bandwidth optical delay line capable of meeting the TPF interferometer optical path length control requirements at cryogenic temperatures.

  10. Computation of signal delays in RC networks

    NASA Technical Reports Server (NTRS)

    Hidalgo, Juan Carlos; Narendran, Paliath; Chaiken, Seth

    1993-01-01

    A model for signal delay computation in RC networks is presented. The strength of the paradigm is its generality and simplicity. The definition of delay is applicable to RC meshes with potential resistive attenuating paths to ground. The algorithms can also be applied to undriven circuits (static charge sharing) and circuits with initial charge. To compute the delays, each node in the network is explored locally to derive a system of sparse linear equations. The solutions of the system are delay values based on the Elmore time constant at each point in the circuit.

  11. Oscillation onset in neural delayed feedback

    SciTech Connect

    Longtin, A.

    1990-01-01

    This paper studies dynamical aspects of neural systems with delayed negative feedback modelled by nonlinear delay-differential equations. These systems undergo a Hopf bifurcation from a stable fixed point to a limit cycle oscillation as certain parameters are varied. We show that their frequency of oscillation is robust to parameter variations and noisy fluctuations, a property that makes these systems good candidates for pacemakers. The onset of oscillation is postponed by both additive and parametric noise in the sense that the state variable spends more time near the fixed point. Finally, we show that a distributed delay (rather than a fixed delay) also stabilizes the fixed point solution. 40 refs., 2 figs.

  12. Intron Delays and Transcriptional Timing during Development

    PubMed Central

    Swinburne, Ian A.; Silver, Pamela A.

    2010-01-01

    The time taken to transcribe most metazoan genes is significant because of the substantial length of introns. Developmentally regulated gene networks, where timing and dynamic patterns of expression are critical, may be particularly sensitive to intron delays. We revisit and comment on a perspective last presented by Thummel 16 years ago: transcriptional delays may contribute to timing mechanisms during development. We discuss the presence of intron delays in genetic networks. We consider how delays can impact particular moments during development, which mechanistic attributes of transcription can influence them, how they can be modeled, and how they can be studied using recent technological advances as well as classical genetics. PMID:18331713

  13. Literacy Activities for Developmentally Delayed Adults.

    ERIC Educational Resources Information Center

    Giordano, Gerard; D'Alonzo, Bruno J.

    1993-01-01

    Reviews six models of prereading programs for developmentally delayed adults: readinglike behavior, picture reading, global features of books, print in the environment, labeling, and rebus symbols. (SK)

  14. Semigroup Properties and the Crandall Liggett Approximation for a Class of Differential Equations with State-Dependent Delays

    NASA Astrophysics Data System (ADS)

    Louihi, M.; Hbid, M. L.; Arino, O.

    2002-05-01

    We present an approach for the resolution of a class of differential equations with state-dependent delays by the theory of strongly continuous nonlinear semigroups. We show that this class determines a strongly continuous semigroup in a closed subset of C0, 1. We characterize the infinitesimal generator of this semigroup through its domain. Finally, an approximation of the Crandall-Liggett type for the semigroup is obtained in a dense subset of (C, ‖·‖∞). As far as we know this approach is new in the context of state-dependent delay equations while it is classical in the case of constant delay differential equations.

  15. Constraints on interacting dark energy from time delay lenses

    NASA Astrophysics Data System (ADS)

    Pan, Yu; Cao, Shuo; Li, Li

    2016-10-01

    We use the time delay measurements between multiple images of lensed sources in 18 strongly gravitationally lensed (SGL) systems to put additional constraints on three phenomenological interaction models for dark energy (DE) and dark matter (DM). The compatibility among the fits on the three models seems to imply that the coupling between DE and DM is a small value close to zero, which is compatible with the previous results for constraining interacting DE parameters. We find that, among the three interacting DE models, the γmIDE model with the interaction term Q proportional to the energy density of DM provides relatively better fits to recent observations. However, the coincidence problem is still very severe in the framework of three interacting DE models, since the fitting results do not show any preference for a nonzero coupling between DE and DM. More importantly, we have studied the significance of the current strong lensing data in deriving the interacting information between dark sectors, which highlights the importance of strong lensing time delay measurements to provide additional observational fits on alternative cosmological models.

  16. Delay-range-dependent chaos synchronization approach under varying time-lags and delayed nonlinear coupling.

    PubMed

    Zaheer, Muhammad Hamad; Rehan, Muhammad; Mustafa, Ghulam; Ashraf, Muhammad

    2014-11-01

    This paper proposes a novel state feedback delay-range-dependent control approach for chaos synchronization in coupled nonlinear time-delay systems. The coupling between two systems is esteemed to be nonlinear subject to time-lags. Time-varying nature of both the intrinsic and the coupling delays is incorporated to broad scope of the present study for a better-quality synchronization controller synthesis. Lyapunov-Krasovskii (LK) functional is employed to derive delay-range-dependent conditions that can be solved by means of the conventional linear matrix inequality (LMI)-tools. The resultant control approach for chaos synchronization of the master-slave time-delay systems considers non-zero lower bound of the intrinsic as well as the coupling time-delays. Further, the delay-dependent synchronization condition has been established as a special case of the proposed LK functional treatment. Furthermore, a delay-range-dependent condition, independent of the delay-rate, has been provided to address the situation when upper bound of the delay-derivative is unknown. A robust state feedback control methodology is formulated for synchronization of the time-delay chaotic networks against the L2 norm bounded perturbations by minimizing the L2 gain from the disturbance to the synchronization error. Numerical simulation results are provided for the time-delay chaotic networks to show effectiveness of the proposed delay-range-dependent chaos synchronization methodologies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Neuronal model with distributed delay: analysis and simulation study for gamma distribution memory kernel.

    PubMed

    Karmeshu; Gupta, Varun; Kadambari, K V

    2011-06-01

    A single neuronal model incorporating distributed delay (memory)is proposed. The stochastic model has been formulated as a Stochastic Integro-Differential Equation (SIDE) which results in the underlying process being non-Markovian. A detailed analysis of the model when the distributed delay kernel has exponential form (weak delay) has been carried out. The selection of exponential kernel has enabled the transformation of the non-Markovian model to a Markovian model in an extended state space. For the study of First Passage Time (FPT) with exponential delay kernel, the model has been transformed to a system of coupled Stochastic Differential Equations (SDEs) in two-dimensional state space. Simulation studies of the SDEs provide insight into the effect of weak delay kernel on the Inter-Spike Interval(ISI) distribution. A measure based on Jensen-Shannon divergence is proposed which can be used to make a choice between two competing models viz. distributed delay model vis-á-vis LIF model. An interesting feature of the model is that the behavior of (CV(t))((ISI)) (Coefficient of Variation) of the ISI distribution with respect to memory kernel time constant parameter η reveals that neuron can switch from a bursting state to non-bursting state as the noise intensity parameter changes. The membrane potential exhibits decaying auto-correlation structure with or without damped oscillatory behavior depending on the choice of parameters. This behavior is in agreement with empirically observed pattern of spike count in a fixed time window. The power spectral density derived from the auto-correlation function is found to exhibit single and double peaks. The model is also examined for the case of strong delay with memory kernel having the form of Gamma distribution. In contrast to fast decay of damped oscillations of the ISI distribution for the model with weak delay kernel, the decay of damped oscillations is found to be slower for the model with strong delay kernel.

  18. Strong expectations cancel locality effects: evidence from Hindi.

    PubMed

    Husain, Samar; Vasishth, Shravan; Srinivasan, Narayanan

    2014-01-01

    Expectation-driven facilitation (Hale, 2001; Levy, 2008) and locality-driven retrieval difficulty (Gibson, 1998, 2000; Lewis & Vasishth, 2005) are widely recognized to be two critical factors in incremental sentence processing; there is accumulating evidence that both can influence processing difficulty. However, it is unclear whether and how expectations and memory interact. We first confirm a key prediction of the expectation account: a Hindi self-paced reading study shows that when an expectation for an upcoming part of speech is dashed, building a rarer structure consumes more processing time than building a less rare structure. This is a strong validation of the expectation-based account. In a second study, we show that when expectation is strong, i.e., when a particular verb is predicted, strong facilitation effects are seen when the appearance of the verb is delayed; however, when expectation is weak, i.e., when only the part of speech "verb" is predicted but a particular verb is not predicted, the facilitation disappears and a tendency towards a locality effect is seen. The interaction seen between expectation strength and distance shows that strong expectations cancel locality effects, and that weak expectations allow locality effects to emerge.

  19. RHESSI Timing Studies: Multithermal Delays

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.

    2007-06-01

    We investigate the energy-dependent timing of thermal emission in solar flares using high-resolution spectra and demodulated time profiles from the RHESSI instrument. We model for the first time the spectral-temporal hard X-ray flux f(ɛ,t) in terms of a multitemperature plasma governed by thermal conduction cooling. In this quantitative model we characterize the multitemperature differential emission measure distribution (DEM) and nonthermal spectra with power-law functions. We fit this model to the spectra and energy-dependent time delays of a representative data set of 89 solar flares observed with RHESSI during 2002-2005. Eliminating weak flares, we find 65 events suitable for fitting and obtain in 44 events (68%) a satisfactory fit that is consistent with the theoretical model. The best-fit results yield a thermal-nonthermal crossover energy of ɛth=18.0+/-3.4 keV, nonthermal spectral indices of γnth=3.5+/-1.1 (at ~30-50 keV), thermal multispectral indices of γth=6.9+/-0.9 (at ~10-20 keV), and thermal conduction cooling times of τc0=101.6+/-0.6 s at ɛth=1 keV (or T0=11.6 MK), which scale with temperature as τc(T)~T-β with β=2.7+/-1.2, consistent with the theoretically expected scaling of τc(T)~T-5/2 for thermal conduction cooling. The (empirical) Neupert effect is consistent with this theoretical model in the asymptotic limit of long cooling times. This study provides clear evidence that all analyzed flares are consistent with the model of a multitemperature plasma distribution and with thermal conduction as dominant cooling mechanism (at flare temperatures of T>~10 MK). Our modeling of energy-dependent time delays provides an alternative method for separating multithermal from nonthermal spectral components based on information in the time domain, in contrast to previous spectral fitting methods.

  20. Delayed umbilical cord clamping in premature neonates.

    PubMed

    Kaempf, Joseph W; Tomlinson, Mark W; Kaempf, Andrew J; Wu, YingXing; Wang, Lian; Tipping, Nicole; Grunkemeier, Gary

    2012-08-01

    Delayed umbilical cord clamping is reported to increase neonatal blood volume. We estimated the clinical outcomes in premature neonates who had delayed umbilical cord clamping compared with a similar group who had early umbilical cord clamping. This was a before-after investigation comparing early umbilical cord clamping with delayed umbilical cord clamping (45 seconds) in two groups of singleton neonates, very low birth weight (VLBW) (401-1,500 g) and low birth weight (LBW) (greater than 1,500 g but less than 35 weeks gestation). Neonates were excluded from delayed umbilical cord clamping if they needed immediate major resuscitation. Primary outcomes were provision of delivery room resuscitation, hematocrit, red cell transfusions, and the principle Vermont Oxford Network outcomes. In VLBW neonates (77 delayed umbilical cord clamping, birth weight [mean±standard deviation] 1,099±266 g; 77 early umbilical cord clamping 1,058±289 g), delayed umbilical cord clamping was associated with less delivery room resuscitation, higher Apgar scores at 1 minute, and higher hematocrit. Delayed umbilical cord clamping was not associated with significant differences in the overall transfusion rate, peak bilirubin, any of the principle Vermont Oxford Network outcomes, or mortality. In LBW neonates (172 delayed umbilical cord clamping, birth weight [mean±standard deviation] 2,159±384 g; 172 early umbilical cord clamping 2,203±447 g), delayed umbilical cord clamping was associated with higher hematocrit and was not associated with a change in delivery room resuscitation or Apgar scores or with changes in the transfusion rate or peak bilirubin. Regression analysis showed increasing gestational age and birth weight and delayed umbilical cord clamping were the best predictors of higher hematocrit and less delivery room resuscitation. Delayed umbilical cord clamping can safely be performed in singleton premature neonates and is associated with a higher hematocrit, less delivery room

  1. Spike phase synchronization in delayed-coupled neural networks: Uniform vs. non-uniform transmission delay

    NASA Astrophysics Data System (ADS)

    Jalili, Mahdi

    2013-03-01

    In this paper, we investigated phase synchronization in delayed dynamical networks. Non-identical spiking Hindmarsh-Rose neurons were considered as individual dynamical systems and coupled through a number of network structures such as scale-free, Erdős-Rényi, and modular. The individual neurons were coupled through excitatory chemical synapses with uniform or distributed time delays. The profile of spike phase synchrony was different when the delay was uniform across the edges as compared to the case when it was distributed, i.e., different delays for the edges. When an identical transmission delay was considered, a quasi-periodic pattern was observed in the spike phase synchrony. There were specific values of delay where the phase synchronization reached to its peaks. The behavior of the phase synchronization in the networks with non-uniform delays was different with the former case, where the phase synchrony decreased as distributed delays introduced to the networks.

  2. Decoherence delays false vacuum decay

    NASA Astrophysics Data System (ADS)

    Bachlechner, Thomas C.

    2013-05-01

    We show that gravitational interactions between massless thermal modes and a nucleating Coleman-de Luccia bubble may lead to efficient decoherence and strongly suppress metastable vacuum decay for bubbles that are small compared to the Hubble radius. The vacuum decay rate including gravity and thermal photon interactions has the exponential scaling \\Gamma \\sim \\Gamma _{CDL}^{2}, where ΓCDL is the Coleman-de Luccia decay rate neglecting photon interactions. For the lowest metastable initial state an efficient quantum Zeno effect occurs due to thermal radiation of temperatures as low as the de Sitter temperature. This strong decoherence effect is a consequence of gravitational interactions with light external mode. We argue that efficient decoherence does not occur for the case of Hawking-Moss decay. This observation is consistent with requirements set by Poincaré recurrence in de Sitter space.

  3. Adaptive synchronization of asymmetric coupled networks with multiple coupling delays

    NASA Astrophysics Data System (ADS)

    Sun, Weiwei; Hao, Fei; Chen, Xia

    2012-05-01

    The synchronization problem of asymmetric networks with multiple coupled delays is investigated in this paper. By using Lyapunov stability theory and Lasalle's invariance principle, several synchronization criteria are deduced for both asymmetric networks with and without norm uncertainties. Furthermore, the synchronization problem of a special complex network with each node being a Lurie system is studied. The main results show that the states of all nodes of networks globally asymptotically synchronize to a desired synchronization state by designing suitable adaptive controllers, and these controllers have strong robustness against the uncertain coupling matrixes. Finally, several illustrative examples with numerical simulations are given to show the feasibility and efficiency of theoretical results.

  4. Delay Banking for Managing Air Traffic

    NASA Technical Reports Server (NTRS)

    Green, Steve

    2008-01-01

    Delay banking has been invented to enhance air-traffic management in a way that would increase the degree of fairness in assigning arrival, departure, and en-route delays and trajectory deviations to aircraft impacted by congestion in the national airspace system. In delay banking, an aircraft operator (airline, military, general aviation, etc.) would be assigned a numerical credit when any of their flights are delayed because of an air-traffic flow restriction. The operator could subsequently bid against other operators competing for access to congested airspace to utilize part or all of its accumulated credit. Operators utilize credits to obtain higher priority for the same flight, or other flights operating at the same time, or later, in the same airspace, or elsewhere. Operators could also trade delay credits, according to market rules that would be determined by stakeholders in the national airspace system. Delay banking would be administered by an independent third party who would use delay banking automation to continually monitor flights, allocate delay credits, maintain accounts of delay credits for participating airlines, mediate bidding and the consumption of credits of winning bidders, analyze potential transfers of credits within and between operators, implement accepted transfers, and ensure fair treatment of all participating operators. A flow restriction can manifest itself in the form of a delay in assigned takeoff time, a reduction in assigned airspeed, a change in the position for the aircraft in a queue of all aircraft in a common stream of traffic (e.g., similar route), a change in the planned altitude profile for an aircraft, or change in the planned route for the aircraft. Flow restrictions are typically imposed to mitigate traffic congestion at an airport or in a region of airspace, particularly congestion due to inclement weather, or the unavailability of a runway or region of airspace. A delay credit would be allocated to an operator of a

  5. Telepresence, time delay, and adaptation

    NASA Technical Reports Server (NTRS)

    Held, Richard; Durlach, Nathaniel

    1989-01-01

    Displays are now being used extensively throughout the society. More and more time is spent watching television, movies, computer screens, etc. Furthermore, in an increasing number of cases, the observer interacts with the display and plays the role of operator as well as observer. To a large extent, the normal behavior in the normal environment can also be thought of in these same terms. Taking liberties with Shakespeare, it might be said, all the world's a display and all the individuals in it are operators in and on the display. Within this general context of interactive display systems, a discussion is began with a conceptual overview of a particular class of such systems, namely, teleoperator systems. The notion is considered of telepresence and the factors that limit telepresence, including decorrelation between the: (1) motor output of the teleoperator as sensed directly via the kinesthetic/tactual system, and (2) the motor output of the teleoperator as sensed indirectly via feedback from the slave robot, i.e., via a visual display of the motor actions of the slave robot. Finally, the deleterious effect of time delay (a particular decorrelation) on sensory-motor adaptation (an important phenomenon related to telepresence) is examined.

  6. Hard X-ray delays

    NASA Technical Reports Server (NTRS)

    Schwartz, Richard A.

    1986-01-01

    High time resolution hard X-ray rates with good counting statistics over 5 energy intervals were obtained using a large area balloon-borne scintillation detector during the 27 June 1980 solar flare. The impulsive phase of the flare was comprised of a series of major bursts of several to several tens of seconds long. Superimposed on these longer bursts are numerous smaller approximately 0.5 to 1.0 second spikes. The time profiles for different energies were cross-correlated for the major bursts. The rapid burst decay rates and the simultaneous peaks below 120 keV both indicate a rapid electron energy loss process. Thus, the flux profiles reflect the electron acceleration/injection process. The fast rate data was obtained by a burst memory in 8 and 32 msec resolution over the entire main impulsive phase. These rates will be cross-correlated to look for short time delays and to find rapid fluctuations. However, a cursory examination shows that almost all fluctuations, down to the 5% level, were resolved with 256 msec bins.

  7. Factors in delayed muscle soreness.

    PubMed

    Abraham, W M

    1977-01-01

    The possible causes of delayed muscle soreness which occur 24 to 48 hr after exercise were examined from three different approaches, each designed to test an existing hypothesis. Surface electromyograms were used to evaluate the muscle spasm theory; the possibility of actual muscle cell damage was monitored by the presence of myoglobinuria, while the ratio of hydroxyproline/creatinine (OHP/Cr) in 24 hr urine collection was used as a marker for connective tissue involvement. In the first study, although all volunteers developed muscle soreness 24 and 48 hr after exercise, no change in the EMG activity of the sore muscles was observed. Myoglobin excretion was found in 88% of the subjects who developed soreness. However, in a second study, 92% of the subject who performed both moderate and heavy exercise but did not develop muscle soreness had myoglobinuria. In contrast, during a third experiment subjects on gelatin-free diets showed an increase (P less than .1) in the OHP/Cr between control (.020+/-.001) and 48 hr post-exercise (.002+/-.001, X+/-SE). Soreness resulted in all cases. When the OHP/Cr value is taken for the day of maximal soreness, the post-exercise mean increases to .024+/-.001 and the level of significance rises (P less than .005). These observations support the concept that exercise induced soreness may be related to disruption of the connective tissue elements in the muscle and/or their attachments.

  8. High performance microring resonator (MRR)-based optical filter with reduced group delay and simplified center-wavelength control

    NASA Astrophysics Data System (ADS)

    Dingel, Benjamin; Ye, Bo; Cui, Weili; Madamopoulos, Nicholas

    2013-06-01

    We present a new microring resonator (MRR)-based optical filter that takes advantage of the improvements that can be gained from cascading two (or more) MRR elements while physically using only one MRR element due to its unique looped-back configuration. This approach avoids the costly problem associated with dynamic control of matching (or aligning) the center-wavelengths coming from the two MRR elements. This new optical filter is a generalization of our previously reported filter (called <strong>LOBOUR>) based on the <strong>C>ascaded <strong>O>ver- and <strong>U>nder-coupling <strong>R>esonator (<strong>COUR>) architecture. Here, we compare the performance of our filter to four different configurations under the following criteria: (1) lower group delay (GD), and (2) simplified solution to wavelength-drift problem, (3) lower power consumption, (4) narrower linewidth, and (5) better extinction ratio (ER).

  9. Application of digital pulse delay device in range-gated control for range-gated imaging lidar

    NASA Astrophysics Data System (ADS)

    Yuan, Chaokai; Chen, Siying; Zhang, Yinchao; Qiu, Zongjia; Ni, Guoqiang

    2009-11-01

    Digital pulse delay device is one of the key techniques of range-gated imaging lidar. At present, Digital method and analog method are the two main implementations of pulse delay device. Digital method is mainly achieved by counter or FIFO memory. With the development of Complex Programmable Logic Device (CPLD), the digital delay device can be achieved with a single chip of CPLD. With this method, the digital delay device enjoys the advantages of high integration, high reliability and strong ability of anti-electromagnetic interference. However, since the maximum clock frequency of CPLD is limited, the improvement of temporal resolution is restricted. Analog method is mainly realized by the delay-line, which is one of the dedicated integrated circuit. Using this method, a higher time resolution can be arrived. In this paper, the timing characteristics of the delay signal are analyzed. Three design options are presented and the advantages and deficiencies are discussed. Based on the theoretical analysis and numerical simulation, the digital delay device combined with the delay chip AD9501 and Field Programmable Gate Array (FPGA) is chosen because of its large dynamic range and high accuracy. Besides, the output pulse width can be adjusted conveniently. The digital delay device is simulated and the result shows that the delay control for range-gated imaging lidar is feasible.

  10. Delay to reperfusion in patients with acute myocardial infarction presenting to acute care hospitals: an international perspective

    PubMed Central

    Spencer, Frederick A.; Montalescot, Gilles; Fox, Keith A.A.; Goodman, Shaun G.; Granger, Christopher B.; Goldberg, Robert J.; Oliveira, Gustavo B.F.; Anderson, Frederick A.; Eagle, Kim A.; Fitzgerald, Gordon; Gore, Joel M.

    2010-01-01

    Aims To examine the extent of delay from initial hospital presentation to fibrinolytic therapy or primary percutaneous coronary intervention (PCI), characteristics associated with prolonged delay, and changes in delay patterns over time in patients with ST-segment elevation myocardial infarction (STEMI). Methods and results We analysed data from 5170 patients with STEMI enrolled in the Global Registry of Acute Coronary Events from 2003 to 2007. The median elapsed time from first hospital presentation to initiation of fibrinolysis was 30 min (interquartile range 18–60) and to primary PCI was 86 min (interquartile range 53–135). Over the years under study, there were no significant changes in delay times to treatment with either strategy. Geographic region was the strongest predictor of delay to initiation of fibrinolysis >30 min. Patient's transfer status and geographic location were strongly associated with delay to primary PCI. Patients treated in Europe were least likely to experience delay to fibrinolysis or primary PCI. Conclusion These data suggest no improvements in delay times from hospital presentation to initiation of fibrinolysis or primary PCI during our study period. Geographic location and patient transfer were the strongest predictors of prolonged delay time, suggesting that improvements in modifiable healthcare system factors can shorten delay to reperfusion therapy even further. PMID:20231154

  11. Real time simulation of transport delay

    NASA Astrophysics Data System (ADS)

    Veigend, Petr; Necasova, Gabriela; Kocina, Filip; Chaloupka, Jan; Satek, Vaclav; Kunovsky, Jiri

    2017-07-01

    The paper presents the approach to modelling of the transport delay using several approximation formulas. The selected approximation of the transport delay is then used in the simple control system model to demonstrate its operation. The aim of the approach is to create the homogeneous system, therefore, hardware representation is discussed.

  12. On Delay and Security in Network Coding

    ERIC Educational Resources Information Center

    Dikaliotis, Theodoros K.

    2013-01-01

    In this thesis, delay and security issues in network coding are considered. First, we study the delay incurred in the transmission of a fixed number of packets through acyclic networks comprised of erasure links. The two transmission schemes studied are routing with hop-by-hop retransmissions, where every node in the network simply stores and…

  13. Clinical implications of delayed orthostatic hypotension

    PubMed Central

    Freeman, Roy

    2015-01-01

    Objective: To define the long-term outcome of delayed orthostatic hypotension (OH). Hypothesis: Delayed OH is an early and milder form of OH that progresses over time. Methods: We reviewed the medical records of 230 previously reported patients who completed autonomic testing at our center from January 1, 2002, through December 31, 2003. All available information on clinical diagnosis, mortality, medication use, and autonomic testing were extracted and included in the reported outcomes. Standard criteria were used to define OH and delayed OH. Results: Forty-eight individuals with delayed OH, 42 individuals with OH, and 75 controls had complete follow-up data. Fifty-four percent of individuals with delayed OH progressed to OH. Thirty-one percent of individuals with delayed OH developed an α-synucleinopathy. The 10-year mortality rate in individuals with delayed OH was 29%, in individuals with baseline OH was 64%, and in controls was 9%. The 10-year mortality of individuals who progressed to OH was 50%. Progression to OH was associated with developing an α-synucleinopathy, baseline diabetes, and abnormal baseline autonomic test results. Conclusion: Delayed OH frequently progresses to OH with a high associated mortality. PMID:26400576

  14. Space object tracking with delayed measurements

    NASA Astrophysics Data System (ADS)

    Chen, Huimin; Shen, Dan; Chen, Genshe; Blasch, Erik; Pham, Khanh

    2010-04-01

    This paper is concerned with the nonlinear filtering problem for tracking a space object with possibly delayed measurements. In a distributed dynamic sensing environment, due to limited communication bandwidth and long distances between the earth and the satellites, it is possible for sensor reports to be delayed when the tracking filter receives them. Such delays can be complete (the full observation vector is delayed) or partial (part of the observation vector is delayed), and with deterministic or random time lag. We propose an approximate approach to incorporate delayed measurements without reprocessing the old measurements at the tracking filter. We describe the optimal and suboptimal algorithms for filter update with delayed measurements in an orbital trajectory estimation problem without clutter. Then we extend the work to a single object tracking under clutter where probabilistic data association filter (PDAF) is used to replace the recursive linear minimum means square error (LMMSE) filter and delayed measurements with arbitrary lags are be handled without reprocessing the old measurements. Finally, we demonstrate the proposed algorithms in realistic space object tracking scenarios using the NASA General Mission Analysis Tool (GMAT).

  15. Delayed biodiversity change: no time to waste.

    PubMed

    Essl, Franz; Dullinger, Stefan; Rabitsch, Wolfgang; Hulme, Philip E; Pyšek, Petr; Wilson, John R U; Richardson, David M

    2015-07-01

    Delayed biodiversity responses to environmental forcing mean that rates of contemporary biodiversity changes are underestimated, yet these delays are rarely addressed in conservation policies. Here, we identify mechanisms that lead to such time lags, discuss shifting human perceptions, and propose how these phenomena should be addressed in biodiversity management and science.

  16. 78 FR 51819 - List of Applications Delayed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-21

    ... Pipeline and Hazardous Materials Safety Administration List of Applications Delayed AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: List of applications delayed more than 180... following list of special permit applications that have been in process for 180 days or more. The reason(s...

  17. 78 FR 43270 - List of Applications Delayed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-19

    ... Pipeline and Hazardous Materials Safety Administration List of Applications Delayed AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: List of applications delayed more than 180... following list of special permit applications that have been in process for 180 days or more. The reason(s...

  18. 78 FR 36820 - List of Applications Delayed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-19

    ... Pipeline and Hazardous Materials Safety Administration List of Applications Delayed AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: List of applications delayed more than 180... following list of special permit applications that have been in process for 180 days or more. The reason(s...

  19. Discounting of Delayed Rewards Is Not Hyperbolic

    ERIC Educational Resources Information Center

    Luhmann, Christian C.

    2013-01-01

    Delay discounting refers to decision-makers' tendency to value immediately available goods more than identical goods available only after some delay. In violation of standard economic theory, decision-makers frequently exhibit dynamic inconsistency; their preferences change simply due to the passage of time. The standard explanation for this…

  20. Analyzing delay causes in Egyptian construction projects.

    PubMed

    Marzouk, Mohamed M; El-Rasas, Tarek I

    2014-01-01

    Construction delays are common problems in civil engineering projects in Egypt. These problems occur frequently during project life-time leading to disputes and litigation. Therefore, it is essential to study and analyze causes of construction delays. This research presents a list of construction delay causes retrieved from literature. The feedback of construction experts was obtained through interviews. Subsequently, a questionnaire survey was prepared. The questionnaire survey was distributed to thirty-three construction experts who represent owners, consultants, and contractor's organizations. Frequency Index, Severity Index, and Importance Index are calculated and according to the highest values of them the top ten delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the research. Statistical analysis is carried out using analysis of variance ANOVA method to test delay causes, obtained from the survey. The test results reveal good correlation between groups while there is significant difference between them for some delay causes and finally roadmap for prioritizing delay causes groups is presented.

  1. Analyzing delay causes in Egyptian construction projects

    PubMed Central

    Marzouk, Mohamed M.; El-Rasas, Tarek I.

    2013-01-01

    Construction delays are common problems in civil engineering projects in Egypt. These problems occur frequently during project life-time leading to disputes and litigation. Therefore, it is essential to study and analyze causes of construction delays. This research presents a list of construction delay causes retrieved from literature. The feedback of construction experts was obtained through interviews. Subsequently, a questionnaire survey was prepared. The questionnaire survey was distributed to thirty-three construction experts who represent owners, consultants, and contractor’s organizations. Frequency Index, Severity Index, and Importance Index are calculated and according to the highest values of them the top ten delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the research. Statistical analysis is carried out using analysis of variance ANOVA method to test delay causes, obtained from the survey. The test results reveal good correlation between groups while there is significant difference between them for some delay causes and finally roadmap for prioritizing delay causes groups is presented. PMID:25685471

  2. 48 CFR 3442.7003 - Delays clause.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Delays clause. 3442.7003 Section 3442.7003 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION ACQUISITION REGULATION CONTRACT MANAGEMENT CONTRACT ADMINISTRATION Contract Monitoring 3442.7003 Delays clause. The...

  3. On Delay and Security in Network Coding

    ERIC Educational Resources Information Center

    Dikaliotis, Theodoros K.

    2013-01-01

    In this thesis, delay and security issues in network coding are considered. First, we study the delay incurred in the transmission of a fixed number of packets through acyclic networks comprised of erasure links. The two transmission schemes studied are routing with hop-by-hop retransmissions, where every node in the network simply stores and…

  4. Minimizing the Delay at Traffic Lights

    ERIC Educational Resources Information Center

    Van Hecke, Tanja

    2009-01-01

    Vehicles holding at traffic lights is a typical queuing problem. At crossings the vehicles experience delay in both directions. Longer periods with green lights in one direction are disadvantageous for the vehicles coming from the other direction. The total delay for getting through the traffic point is what counts. This article presents an…

  5. 49 CFR 236.831 - Time, delay.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Time, delay. 236.831 Section 236.831 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Time, delay. As applied to an automatic train stop or train control system, the time which elapses...

  6. Discounting of Delayed Rewards Is Not Hyperbolic

    ERIC Educational Resources Information Center

    Luhmann, Christian C.

    2013-01-01

    Delay discounting refers to decision-makers' tendency to value immediately available goods more than identical goods available only after some delay. In violation of standard economic theory, decision-makers frequently exhibit dynamic inconsistency; their preferences change simply due to the passage of time. The standard explanation for this…

  7. 49 CFR 236.831 - Time, delay.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Time, delay. 236.831 Section 236.831 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Time, delay. As applied to an automatic train stop or train control system, the time which elapses...

  8. 49 CFR 236.831 - Time, delay.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Time, delay. 236.831 Section 236.831 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Time, delay. As applied to an automatic train stop or train control system, the time which elapses...

  9. Motivational Determinants of Academic Delay of Gratification.

    ERIC Educational Resources Information Center

    Karabenick, Stuart A.; Bembenutty, Hefer

    This study examined motivational determinants of academic delay of gratification (ADOG) with 196 undergraduate college students at a large midwestern university. Students completed the academic delay of gratification scale, in which students are presented with 10 hypothetical situations and they indicate their preference among options offering…

  10. Test Anxiety and Academic Delay of Gratification

    ERIC Educational Resources Information Center

    Bembenutty, Hefer

    2009-01-01

    The present study examined the relationship between college students' willingness to delay gratification, motivation, self-regulation of learning, and their level of test anxiety (N = 364). Academic delay of gratification refers to students' postponement of immediately available opportunities to satisfy impulses in favor of pursuing academic…

  11. Minimizing the Delay at Traffic Lights

    ERIC Educational Resources Information Center

    Van Hecke, Tanja

    2009-01-01

    Vehicles holding at traffic lights is a typical queuing problem. At crossings the vehicles experience delay in both directions. Longer periods with green lights in one direction are disadvantageous for the vehicles coming from the other direction. The total delay for getting through the traffic point is what counts. This article presents an…

  12. Delay synchronization of temporal Boolean networks

    NASA Astrophysics Data System (ADS)

    Wei, Qiang; Xie, Cheng-jun; Liang, Yi; Niu, Yu-jun; Lin, Da

    2016-01-01

    This paper investigates the delay synchronization between two temporal Boolean networks base on semi-tensor product method, which improve complete synchronization. Necessary and sufficient conditions for delay synchronization are drawn base on algebraic expression of temporal Boolean networks. A example is presented to show the effectiveness of theoretical analysis.

  13. 49 CFR 236.831 - Time, delay.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Time, delay. 236.831 Section 236.831 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Time, delay. As applied to an automatic train stop or train control system, the time which...

  14. Delaying gratification depends on social trust

    PubMed Central

    Michaelson, Laura; de la Vega, Alejandro; Chatham, Christopher H.; Munakata, Yuko

    2013-01-01

    Delaying gratification is hard, yet predictive of important life outcomes, such as academic achievement and physical health. Prominent theories focus on the role of self-control, hypersensitivity to immediate rewards, and the cost of time spent waiting. However, delaying gratification may also require trust in people delivering future rewards as promised. To test the role of social trust, participants were presented with character vignettes and faces that varied in trustworthiness, and then choose between hypothetical smaller immediate or larger delayed rewards from those characters. Across two experiments, participants were less willing to wait for delayed rewards from less trustworthy characters, and perceived trustworthiness predicted willingness to delay gratification. These findings provide the first demonstration of a causal role for social trust in willingness to delay gratification, independent of other relevant factors, such as self-control or reward history. Thus, delaying gratification requires choosing not only a later reward, but a reward that is potentially less likely to be delivered, when there is doubt about the person promising it. Implications of this work include the need to revise prominent theories of delay of gratification, and new directions for interventions with populations characterized by impulsivity. PMID:23801977

  15. Delay of Gratification in Children: A Function of Magnitude of Reward and the Delay Cue

    ERIC Educational Resources Information Center

    Montgomery, Gary T.

    1976-01-01

    The delay and magnitude of reward cues were independently varied to investigate whether children's delay of gratification choices were attributable to (1) the magnitude of reward cue, and/or (2) discriminative stimulus properties of the delay cue. (Author/SB)

  16. Comparison of delayed female mating on reproductive biology of codling moth and obliquebanded leafroller.

    PubMed

    Jones, Vincent P; Wiman, Nik G; Brunner, Jay F

    2008-06-01

    Delay of mating was examined as a possible mechanism for population decreases associated with mating disruption for codling moth, Cydia pomonella L., and obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). We examined the effect of delaying female mating 0, 2, 4, or 6 d while holding male age constant on life table parameters of both species. We found that increasing delays in mating were accompanied by two responses: (1) an increase in the percentage of sterile pairs and (2) a reduction in net reproductive rate and population growth unrelated to sterility. On a percentage basis, obliquebanded leafroller population growth was more strongly affected than codling moth. However, the net fertility rate of obliquebanded leafroller was nearly eight-fold higher than that of codling moth, so that obliquebanded leafroller females that experienced a 4-d delay in mating had nearly the same reproductive rate as codling moth females that experienced no delay. Leslie matrix simulations using life tables with field-based adult longevity estimates showed that codling moth females experiencing >2-d delay in mating resulted in decreases in population density or extinction within two generations. In contrast, obliquebanded leafroller females delayed <6 d showed rapid population growth that decreased as female age at mating increased; only the 6-d delay treatment resulted in decreased population levels. Our results indicate that obliquebanded leafroller females must on average experience a much longer delay in mating to significantly reduce population growth compared with codling moth females, suggesting that delay of mating likely plays a greater role in codling moth mating disruption than for obliquebanded leafroller.

  17. Experimental study of high-energy fractures delayed operation in promote bone healing

    PubMed Central

    Pan, Zhi-Jun; Li, Zhong; Li, Jing

    2015-01-01

    To investigate role of delayed operation to stimulate growth of strong external callus in high-energy fractures, and explore a new way for bone healing. Twenty adult dogs were employed, and randomly divided into four groups, including group A-D. The dogs underwent osteotomy by wire saw in middle of femur, electric coagulation damaged surrounding periosteum, forming a 1 cm defect. Group A were internal fixed 14 days after osteotomy (higher-energy fractures delayed operation), Group B and C were internal fixed immediately (no delayed operation), Group D were internal fixed 14 days after osteotomy (delayed operation, but resected granulations around extremities). The results showed that groups of early fixed have no external callus growth and almost no growth in internal callus, these conditions leads to atrophy nonunion. On contrary, the porosis was strong and callus union was steady in group A and D, which have a delayed operation. In conclusion, early surgical fixation of high-energy fracture restrains external callus growth, easily lead to poor callus healing phenomenon of low-quality. Delayed surgical fixation can begin to repair soft tissues injury, stimulate external callus growth and improve fracture healing, so a small incision open reduction produce more robust growth effect than closed reduction. PMID:26379852

  18. 77 FR 53212 - Notice of Proposed Information Collection: Comment Request Strong Cities Strong Communities...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-31

    ... Communities National Resource Network AGENCY: Office of the Assistant Secretary for Policy Development and... Proposal: Strong Cities Strong Communities National Resource Network. OMB Control Number, if applicable... Transformation Initiative (TI) account. Through the Strong Cities Strong Communities National Resource Network...

  19. Future altruism: Social discounting of delayed rewards.

    PubMed

    Yi, Richard; Charlton, Shawn; Porter, Caitlin; Carter, Anne E; Bickel, Warren K

    2011-01-01

    Social discounting assesses an individual's willingness to forgo an outcome for the self in lieu of a larger outcome for someone else. The purpose of the present research was to examine the effect of adding a common delay to outcomes in a binary choice, social discounting procedure. Based on the premise that both social and temporal distances are dimensions of psychological distance, we hypothesized that social discounting should decrease as a function of delay to the outcomes. Across two within-subject experiments, participants indicated preference between a hypothetical money reward for the self or for someone else. The outcomes were associated with no, short, and long delays. Both studies confirmed our hypothesis that adding any delay to the receipt of outcomes decreases social discounting, though no significant differences were observed between short and long delays. These results are discussed in the context of some existing literature on altruism. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Improving profitability of the delayed coking process

    SciTech Connect

    Weisenborn, W.J.B.; Jansen, H.R.; Hanke, T.D.

    1986-01-01

    The delayed coking process is the predominant process used in the refining industry to upgrade low value vacuum resid to higher valued liquid products. The petroleum coke produced is almost always an unwanted by-product which has a significantly lower value. In the delayed coking process, ''Conoco Delayed Coking Technology'' can play an important role in maximizing the profitability of the coking unit. The authors briefly discuss the basic sections of the delayed coking process. In the typical delayed coking process, resid feed is combined with recycle and rapidly heated in a furnace. It is then transferred to a coke drum where the coking reactions continue to completion. As coke is formed in the drum, the cracked products leave and are cooled and separated in the fractionator.

  1. Digital tanlock loop architecture with no delay

    NASA Astrophysics Data System (ADS)

    Al-Kharji AL-Ali, Omar; Anani, Nader; Al-Araji, Saleh; Al-Qutayri, Mahmoud; Ponnapalli, Prasad

    2012-02-01

    This article proposes a new architecture for a digital tanlock loop which eliminates the time-delay block. The ? (rad) phase shift relationship between the two channels, which is generated by the delay block in the conventional time-delay digital tanlock loop (TDTL), is preserved using two quadrature sampling signals for the loop channels. The proposed system outperformed the original TDTL architecture, when both systems were tested with frequency shift keying input signal. The new system demonstrated better linearity and acquisition speed as well as improved noise performance compared with the original TDTL architecture. Furthermore, the removal of the time-delay block enables all processing to be digitally performed, which reduces the implementation complexity. Both the original TDTL and the new architecture without the delay block were modelled and simulated using MATLAB/Simulink. Implementation issues, including complexity and relation to simulation of both architectures, are also addressed.

  2. Determinants of delayed diagnosis in Parkinson's disease.

    PubMed

    Breen, David P; Evans, Jonathan R; Farrell, Krista; Brayne, Carol; Barker, Roger A

    2013-08-01

    The early and accurate diagnosis of Parkinson's disease (PD) is the first step towards optimal patient management. The aim of this study was to investigate the major determinants of delayed diagnosis in PD. We recruited a population-representative cohort of 239 newly-diagnosed PD patients who underwent clinical and neuropsychological evaluation. Non-parametric methods were used to define the factors associated with diagnostic delay. The median time from motor symptom onset to primary care physician (PCP) presentation was considerably longer than the time from PCP presentation to PD diagnosis (11 vs. 1 months). Male sex and presenting motor phenotype were independently associated with delayed PCP presentation on Cox regression analysis. Patients presenting with gait disturbance experienced the longest delay, whilst those presenting with tremor had the shortest. In summary, male sex and presenting motor phenotype are key determinants of delayed diagnosis in PD.

  3. Effects of elongation delay in transcription dynamics.

    PubMed

    Zhang, Xuan; Jin, Huiqin; Yang, Zhuoqin; Lei, Jinzhi

    2014-12-01

    In the transcription process, elongation delay is induced by the movement of RNA polymerases (RNAP) along the DNA sequence, and can result in changes in the transcription dynamics. This paper studies the transcription dynamics that involved the elongation delay and effects of cell division and DNA replication. The stochastic process of gene expression is modeled with delay chemical master equation with periodic coefficients, and is studied numerically through the stochastic simulation algorithm with delay. We show that the average transcription level approaches to a periodic dynamics over cell cycles at homeostasis, and the elongation delay can reduce the transcription level and increase the transcription noise. Moreover, the transcription elongation can induce bimodal distribution of mRNA levels that can be measured by the techniques of flow cytometry.

  4. Delayed splenic rupture: real or imaginary?

    PubMed

    Farhat, G A; Abdu, R A; Vanek, V W

    1992-06-01

    Although splenic injury is the most frequent abdominal injury resulting from blunt trauma, delayed splenic rupture is a rare event. From 1981 to 1990, 75 patients treated at St. Elizabeth Hospital Medical Center (Youngstown, OH) had blunt splenic injury. Splenic rupture was delayed in six of these patients (8%). More severe trauma, such as occurs with motor vehicle accidents, is more likely to lead to immediate rupture. Lesser trauma resulting from minor falls or fights is more likely to lead to delayed rupture. Subcapsular hematoma is the most common etiology for delayed splenic rupture. Although there is no reliable symptom or sign during the latent period, abdominal pain occurs almost uniformly and Kehr's sign is quite common. Peritoneal lavage and abdominal computerized axial tomography scan are accurate in diagnosing splenic rupture. Unfortunately, they are not always reliable in predicting delayed rupture.

  5. Stochastic thermodynamics for delayed Langevin systems.

    PubMed

    Jiang, Huijun; Xiao, Tiejun; Hou, Zhonghuai

    2011-06-01

    We discuss stochastic thermodynamics (ST) for delayed Langevin systems in this paper. By using the general principles of ST, the first-law-like energy balance and trajectory-dependent entropy s(t) can be well defined in a way that is similar to that in a system without delay. Because the presence of time delay brings an additional entropy flux into the system, the conventional second law (Δs(tot))≥0 no longer holds true, where Δs(tot) denotes the total entropy change along a stochastic path and (·) stands for the average over the path ensemble. With the help of a Fokker-Planck description, we introduce a delay-averaged trajectory-dependent dissipation functional η[χ(t)] which involves the work done by a delay-averaged force F(x,t) along the path χ(t) and equals the medium entropy change Δs(m)[x(t)] in the absence of delay. We show that the total dissipation functional R=Δs+η, where Δs denotes the system entropy change along a path, obeys (R)≥0, which could be viewed as the second law in the delayed system. In addition, the integral fluctuation theorem (e(-R))=1 also holds true. We apply these concepts to a linear Langevin system with time delay and periodic external force. Numerical results demonstrate that the total entropy change (Δs(tot)) could indeed be negative when the delay feedback is positive. By using an inversing-mapping approach, we are able to obtain the delay-averaged force F(x,t) from the stationary distribution and then calculate the functional R as well as its distribution. The second law (R)≥0 and the fluctuation theorem are successfully validated.

  6. Mitochondrial respiratory complex I probed by delayed luminescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Baran, Irina; Ionescu, Diana; Privitera, Simona; Scordino, Agata; Mocanu, Maria Magdalena; Musumeci, Francesco; Grasso, Rosaria; Gulino, Marisa; Iftime, Adrian; Tofolean, Ioana Teodora; Garaiman, Alexandru; Goicea, Alexandru; Irimia, Ruxandra; Dimancea, Alexandru; Ganea, Constanta

    2013-12-01

    The role of mitochondrial complex I in ultraweak photon-induced delayed photon emission [delayed luminescence (DL)] of human leukemia Jurkat T cells was probed by using complex I targeting agents like rotenone, menadione, and quercetin. Rotenone, a complex I-specific inhibitor, dose-dependently increased the mitochondrial level of reduced nicotinamide adenine dinucleotide (NADH), decreased clonogenic survival, and induced apoptosis. A strong correlation was found between the mitochondrial levels of NADH and oxidized flavin mononucleotide (FMNox) in rotenone-, menadione- and quercetin-treated cells. Rotenone enhanced DL dose-dependently, whereas quercetin and menadione inhibited DL as well as NADH or FMNox. Collectively, the data suggest that DL of Jurkat cells originates mainly from mitochondrial complex I, which functions predominantly as a dimer and less frequently as a tetramer. In individual monomers, both pairs of pyridine nucleotide (NADH/reduced nicotinamide adenine dinucleotide phosphate) sites and flavin (FMN-a/FMN-b) sites appear to bind cooperatively their specific ligands. Enhancement of delayed red-light emission by rotenone suggests that the mean time for one-electron reduction of ubiquinone or FMN-a by the terminal Fe/S center (N2) is 20 or 284 μs, respectively. All these findings suggest that DL spectroscopy could be used as a reliable, sensitive, and robust technique to probe electron flow within complex I in situ.

  7. Detection of coupling delay: A problem not yet solved

    NASA Astrophysics Data System (ADS)

    Coufal, David; Jakubík, Jozef; Jajcay, Nikola; Hlinka, Jaroslav; Krakovská, Anna; Paluš, Milan

    2017-08-01

    Nonparametric detection of coupling delay in unidirectionally and bidirectionally coupled nonlinear dynamical systems is examined. Both continuous and discrete-time systems are considered. Two methods of detection are assessed—the method based on conditional mutual information—the CMI method (also known as the transfer entropy method) and the method of convergent cross mapping—the CCM method. Computer simulations show that neither method is generally reliable in the detection of coupling delays. For continuous-time chaotic systems, the CMI method appears to be more sensitive and applicable in a broader range of coupling parameters than the CCM method. In the case of tested discrete-time dynamical systems, the CCM method has been found to be more sensitive, while the CMI method required much stronger coupling strength in order to bring correct results. However, when studied systems contain a strong oscillatory component in their dynamics, results of both methods become ambiguous. The presented study suggests that results of the tested algorithms should be interpreted with utmost care and the nonparametric detection of coupling delay, in general, is a problem not yet solved.

  8. Suspended animation for delayed resuscitation.

    PubMed

    Bellamy, R; Safar, P; Tisherman, S A; Basford, R; Bruttig, S P; Capone, A; Dubick, M A; Ernster, L; Hattler, B G; Hochachka, P; Klain, M; Kochanek, P M; Kofke, W A; Lancaster, J R; McGowan, F X; Oeltgen, P R; Severinghaus, J W; Taylor, M J; Zar, H

    1996-02-01

    Suspended animation is defined as the therapeutic induction of a state of tolerance to temporary complete systemic ischemia, i.w., protection-preservation of the whole organism during prolonged circulatory arrest ( > or = 1 hr), followed by resuscitation to survival without brain damage. The objectives of suspended animation include: a) helping to save victims of temporarily uncontrollable (internal) traumatic (e.g., combat casualties) or nontraumatic (e.g., ruptured aortic aneurysm) exsanguination, without severe brain trauma, by enabling evacuation and resuscitative surgery during circulatory arrest, followed by delayed resuscitation; b) helping to save some nontraumatic cases of sudden death, seemingly unresuscitable before definite repair; and c) enabling selected (elective) surgical procedures to be performed which are only feasible during a state of no blood flow. In the discussion session, investigators with suspended animation-relevant research interests brainstorm on present knowledge, future research potentials, and the advisability of a major research effort concerning this subject. The following topics are addressed: the epidemiologic facts of sudden death in combat casualties, which require a totally new resuscitative approach; the limits and potentials of reanimation research; complete reversibility of circulatory arrest of 1 hr in dogs under profound hypothermia ( < 10 degrees C), induced and reversed by portable cardiopulmonary bypass; the need for a still elusive pharmacologic or chemical induction of suspended animation in the field; asanguinous profound hypothermic low-flow with cardiopulmonary bypass; electric anesthesia; opiate therapy; lessons learned by hypoxia tolerant vertebrate animals, hibernators, and freeze-tolerant animals (cryobiology); myocardial preservation during open-heart surgery; organ preservation for transplantation; and reperfusion-reoxygenation injury in vital organs, including the roles of nitric oxide and free radicals

  9. Delaying Treatment of Ocular Hypertension

    PubMed Central

    Kass, Michael A.; Gordon, Mae O.; Gao, Feng; Heuer, Dale K.; Higginbotham, Eve J.; Johnson, Chris A.; Keltner, John K.; Miller, J. Philip; Parrish, Richard K.; Wilson, M. Roy

    2014-01-01

    Objective To compare the safety and efficacy of earlier vs later treatment in preventing primary open-angle glaucoma (POAG) in individuals with ocular hypertension. Methods One thousand six hundred thirty-six individuals with intraocular pressure (IOP) from 24 to 32 mm Hg in 1 eye and 21 to 32 mm Hg in the fellow eye were randomized to observation or to topical ocular hypotensive medication. Median time of treatment in the medication group was 13.0 years. After a median of 7.5 years without treatment, the observation group received medication for a median of 5.5 years. To determine if there is a penalty for delaying treatment, we compared the cumulative proportions of participants who developed POAG at a median follow-up of 13 years in the original observation group and in the original medication group. Main Outcome Measures Cumulative proportion of participants who developed POAG. Results The cumulative proportion of participants in the original observation group who developed POAG at 13 years was 0.22 (95% confidence interval [CI], 0.19–0.25), vs 0.16 (95% CI, 0.13–0.19) in the original medication group (P=.009). Among participants at the highest third of baseline risk of developing POAG, the cumulative proportion who developed POAG was 0.40 (95% CI, 0.33–0.46) in the original observation group and 0.28 (95% CI, 0.22–0.34) in the original medication group. There was little evidence of increased adverse events associated with medication. Application to Clinical Practice Absolute reduction was greatest among participants at the highest baseline risk of developing POAG. Individuals at high risk of developing POAG may benefit from more frequent examinations and early preventive treatment. Trial Registration clinicaltrials.gov Identifier: NCT00000125 PMID:20212196

  10. Persistent Language Delay Versus Late Language Emergence in Children With Early Cochlear Implantation

    PubMed Central

    Nicholas, Johanna; Tobey, Emily; Davidson, Lisa

    2016-01-01

    Purpose The purpose of the present investigation is to differentiate children using cochlear implants (CIs) who did or did not achieve age-appropriate language scores by midelementary grades and to identify risk factors for persistent language delay following early cochlear implantation. Materials and Method Children receiving unilateral CIs at young ages (12–38 months) were tested longitudinally and classified with normal language emergence (n = 19), late language emergence (n = 22), or persistent language delay (n = 19) on the basis of their test scores at 4.5 and 10.5 years of age. Relative effects of demographic, audiological, linguistic, and academic characteristics on language emergence were determined. Results Age at CI was associated with normal language emergence but did not differentiate late emergence from persistent delay. Children with persistent delay were more likely to use left-ear implants and older speech processor technology. They experienced higher aided thresholds and lower speech perception scores. Persistent delay was foreshadowed by low morphosyntactic and phonological diversity in preschool. Logistic regression analysis predicted normal language emergence with 84% accuracy and persistent language delay with 74% accuracy. Conclusion CI characteristics had a strong effect on persistent versus resolving language delay, suggesting that right-ear (or bilateral) devices, technology upgrades, and improved audibility may positively influence long-term language outcomes. PMID:26501740

  11. Species differences between rats and pigeons in choices with probabilistic and delayed reinforcers.

    PubMed

    Mazur, James E

    2007-06-01

    An adjusting-delay procedure was used to study rats' choices with probabilistic and delayed reinforcers, and to compare them with previous results from pigeons. A left lever press led to a 5-s delay signaled by a light and a tone, followed by a food pellet on 50% of the trials. A right lever press led to an adjusting delay signaled by a light followed by a food pellet on 100% of the trials. In some conditions, the light and tone for the probabilistic reinforcer were present only on trials that delivered food. In other conditions, the light and tone were present on all trials that the left lever was chosen. Similar studies with pigeons [Mazur, J.E., 1989. Theories of probabilistic reinforcement. J. Exp. Anal. Behav. 51, 87-99; Mazur, J.E., 1991. Conditioned reinforcement and choice with delayed and uncertain primary reinforcers. J. Exp. Anal. Behav. 63, 139-150] found that choice of the probabilistic reinforcer increased dramatically when the delay-interval stimuli were omitted on no-food trials, but this study found no such effect with the rats. In other conditions, the probability of food was varied, and comparisons to previous studies with pigeons indicated that rats showed greater sensitivity to decreasing reinforcer probabilities. The results support the hypothesis that rats' choices in these situations depend on the total time between a choice response and a reinforcer, whereas pigeons' choices are strongly influenced by the presence of delay-interval stimuli.

  12. Trading Later Rewards for Current Pleasure: Pornography Consumption and Delay Discounting.

    PubMed

    Negash, Sesen; Sheppard, Nicole Van Ness; Lambert, Nathaniel M; Fincham, Frank D

    2016-01-01

    Internet pornography is a multi-billion-dollar industry that has grown increasingly accessible. Delay discounting involves devaluing larger, later rewards in favor of smaller, more immediate rewards. The constant novelty and primacy of sexual stimuli as particularly strong natural rewards make Internet pornography a unique activator of the brain's reward system, thereby having implications for decision-making processes. Based on theoretical studies of evolutionary psychology and neuroeconomics, two studies tested the hypothesis that consuming Internet pornography would relate to higher rates of delay discounting. Study 1 used a longitudinal design. Participants completed a pornography use questionnaire and a delay discounting task at Time 1 and then again four weeks later. Participants reporting higher initial pornography use demonstrated a higher delay discounting rate at Time 2, controlling for initial delay discounting. Study 2 tested for causality with an experimental design. Participants were randomly assigned to abstain from either their favorite food or pornography for three weeks. Participants who abstained from pornography use demonstrated lower delay discounting than participants who abstained from their favorite food. The finding suggests that Internet pornography is a sexual reward that contributes to delay discounting differently than other natural rewards. Theoretical and clinical implications of these studies are highlighted.

  13. Complexity in electro-optic delay dynamics: modelling, design and applications.

    PubMed

    Larger, Laurent

    2013-09-28

    Nonlinear delay dynamics have found during the last 30 years a particularly prolific exploration area in the field of photonic systems. Besides the popular external cavity laser diode set-ups, we focus in this article on another experimental realization involving electro-optic (EO) feedback loops, with delay. This approach has strongly evolved with the important technological progress made on broadband photonic and optoelectronic devices dedicated to high-speed optical telecommunications. The complex dynamical systems performed by nonlinear delayed EO feedback loop architectures were designed and explored within a huge range of operating parameters. Thanks to the availability of high-performance photonic devices, these EO delay dynamics led also to many successful, efficient and diverse applications, beyond the many fundamental questions raised from the observation of experimental behaviours. Their chaotic motion allowed for a physical layer encryption method to secure optical data, with a demonstrated capability to operate at the typical speed of modern optical telecommunications. Microwave limit cycles generated in similar EO delay oscillators showed significantly improved spectral purity thanks to the use of a very long fibre delay line. Last but not least, a novel brain inspired computational principle has been recently implemented physically in photonics for the first time, again on the basis of an EO delay dynamical system. In this latter emerging application, the computed result is obtained by a proper 'read-out' of the complex nonlinear transients emerging from a fixed point, the transient being issued by the injection of the information signal to be processed.

  14. Dynamics of Time Delay-Induced Multiple Synchronous Behaviors in Inhibitory Coupled Neurons

    PubMed Central

    Gu, Huaguang; Zhao, Zhiguo

    2015-01-01

    The inhibitory synapse can induce synchronous behaviors different from the anti-phase synchronous behaviors, which have been reported in recent studies. In the present paper, synchronous behaviors are investigated in the motif model composed of reciprocal inhibitory coupled neurons with endogenous bursting and time delay. When coupling strength is weak, synchronous behavior appears at a single interval of time delay within a bursting period. When coupling strength is strong, multiple synchronous behaviors appear at different intervals of time delay within a bursting period. The different bursting patterns of synchronous behaviors, and time delays and coupling strengths that can induce the synchronous bursting patterns can be well interpreted by the dynamics of the endogenous bursting pattern of isolated neuron, which is acquired by the fast-slow dissection method, combined with the inhibitory coupling current. For an isolated neuron, when a negative impulsive current with suitable strength is applied at different phases of the bursting, multiple different bursting patterns can be induced. For a neuron in the motif, the inhibitory coupling current, of which the application time and strength is modulated by time delay and coupling strength, can cause single or multiple synchronous firing patterns like the negative impulsive current when time delay and coupling strength is suitable. The difference compared to the previously reported multiple synchronous behaviors that appear at time delays wider than a period of the endogenous firing is discussed. The results present novel examples of synchronous behaviors in the neuronal network with inhibitory synapses and provide a reasonable explanation. PMID:26394224

  15. Influence of the circadian rhythm in cell division on radiation-induced mitotic delay in vivo

    SciTech Connect

    Rubin, N.H.

    1982-01-01

    Mitotic delay is described as a classical response to radiation; however, circadian rhythmicity in cell division in vivo has not been considered by many authors. The present study investigated the relation between fluctuations reported as mitotic delay and recovery in vivo and circadian oscillations in mitotic index in mouse corneal epithelium. One aspect involved single doses (approximately 600 rad) given to mice at different circadian stages. The normal circadian rhythm in cell division was never obliterated. Inhibition of mitosis was evident but unpredictable, ranging from 6 to 15 hr after irradiation. Recovery was evident only during the daily increase in mitotic index of controls. The classical interpretation of recovery from mitotic delay may be in an in vitro phenomenon not reflecting in vivo responses, which are apparently strongly circadian stage dependent. The second portion of the study demonstrated a dose-response effect on length of mitotic delay and, to a lesser extent, degree of recovery.

  16. Two-dimensional dissipative rogue waves due to time-delayed feedback in cavity nonlinear optics

    NASA Astrophysics Data System (ADS)

    Tlidi, Mustapha; Panajotov, Krassimir

    2017-01-01

    We demonstrate a way to generate two-dimensional rogue waves in two types of broad area nonlinear optical systems subject to time-delayed feedback: in the generic Lugiato-Lefever model and in the model of a broad-area surface-emitting laser with saturable absorber. The delayed feedback is found to induce a spontaneous formation of rogue waves. In the absence of delayed feedback, spatial pulses are stationary. The rogue waves are exited and controlled by the delay feedback. We characterize their formation by computing the probability distribution of the pulse height. The long-tailed statistical contribution, which is often considered as a signature of the presence of rogue waves, appears for sufficiently strong feedback. The generality of our analysis suggests that the feedback induced instability leading to the spontaneous formation of two-dimensional rogue waves is a universal phenomenon.

  17. Delayed extinction fails to reduce skin conductance reactivity to fear-conditioned stimuli.

    PubMed

    Fricchione, Jon; Greenberg, Mark S; Spring, Justin; Wood, Nellie; Mueller-Pfeiffer, Christoph; Milad, Mohammed R; Pitman, Roger K; Orr, Scott P

    2016-09-01

    A brief 10-min time delay between an initial and subsequent exposure to extinction trials has been found to impair memory reconsolidation in fear-conditioned rodents and humans, providing a potential means to reduce fearfulness in anxiety disorders and posttraumatic stress disorder (PTSD). The present study used videos of biologically prepared, conditioned stimuli (tarantulas) to test the efficacy of delayed extinction in blocking reconsolidation of conditioned fear in healthy young adults. Strong differential conditioning, measured by skin conductance, was observed among a screened subset of participants during acquisition. However, the delayed-extinction intervention failed to reduce reactivity to the conditioned stimulus paired with the extinction delay. These results are partially consistent with other recent, mixed findings and point to a need for testing other candidate interventions designed to interfere with the reconsolidation process. © 2016 Society for Psychophysiological Research.

  18. Anomalous delayed loss of trapped D-D fusion products in TFTR

    SciTech Connect

    Zweben, S.J.; Darrow, D.S.; Fredrickson, E.D.; Mynick, H.E.

    1993-02-01

    A new anomalous delayed loss of D-D fusion products has been measured at the bottom of the TFRR vessel. This loss is delayed by [approximately] 0.2 sec with respect to the usual prompt first-orbit loss, and has a correspondingly lower energy, i.e. about half the fusion product birth energy. This loss process dominates the total fusion product loss measured 90[degrees] below the midplane for plasma currents. I[ge] 1.8 MA and major radii near R=2.45 m, e.g. for recent TFTR supershots. This delayed feature can occur without large coherent MED activity, although it can be strongly modulated by such activity. Several possible causes for this phenomenon are discussed, but no clear explanation for this delayed loss has yet been found.

  19. Anomalous delayed loss of trapped D-D fusion products in TFTR

    SciTech Connect

    Zweben, S.J.; Darrow, D.S.; Fredrickson, E.D.; Mynick, H.E.

    1993-02-01

    A new anomalous delayed loss of D-D fusion products has been measured at the bottom of the TFRR vessel. This loss is delayed by {approximately} 0.2 sec with respect to the usual prompt first-orbit loss, and has a correspondingly lower energy, i.e. about half the fusion product birth energy. This loss process dominates the total fusion product loss measured 90{degrees} below the midplane for plasma currents. I{ge} 1.8 MA and major radii near R=2.45 m, e.g. for recent TFTR supershots. This delayed feature can occur without large coherent MED activity, although it can be strongly modulated by such activity. Several possible causes for this phenomenon are discussed, but no clear explanation for this delayed loss has yet been found.

  20. Testing the bed-blocking hypothesis: does nursing and care home supply reduce delayed hospital discharges?

    PubMed

    Gaughan, James; Gravelle, Hugh; Siciliani, Luigi

    2015-03-01

    Hospital bed-blocking occurs when hospital patients are ready to be discharged to a nursing home, but no place is available, so that hospital care acts as a more costly substitute for long-term care. We investigate the extent to which greater supply of nursing home beds or lower prices can reduce hospital bed-blocking using a new Local Authority (LA) level administrative data from England on hospital delayed discharges in 2009-2013. The results suggest that delayed discharges respond to the availability of care home beds, but the effect is modest: an increase in care home beds by 10% (250 additional beds per LA) would reduce social care delayed discharges by about 6-9%. We also find strong evidence of spillover effects across LAs: more care home beds or fewer patients aged over 65 years in nearby LAs are associated with fewer delayed discharges.

  1. Risk Factors for Delayed Enteral Nutrition in Critically Ill Children.

    PubMed

    Canarie, Michael F; Barry, Suzanne; Carroll, Christopher L; Hassinger, Amanda; Kandil, Sarah; Li, Simon; Pinto, Matthew; Valentine, Stacey L; Faustino, E Vincent S

    2015-10-01

    Delayed enteral nutrition, defined as enteral nutrition started 48 hours or more after admission to the PICU, is associated with an inability to achieve full enteral nutrition and worse outcomes in critically ill children. We reviewed nutritional practices in six medical-surgical PICUs and determined risk factors associated with delayed enteral nutrition in critically ill children. Retrospective cross-sectional study using medical records as source of data. Six medical-surgical PICUs in northeastern United States. Children less than 21 years old admitted to the PICU for 72 hours or more excluding those awaiting or recovering from abdominal surgery. A total of 444 children with a median age of 4.0 years were included in the study. Enteral nutrition was started at a median time of 20 hours after admission to the PICU. There was no significant difference in time to start enteral nutrition among the PICUs. Of those included, 88 children (19.8%) had delayed enteral nutrition. Risk factors associated with delayed enteral nutrition were noninvasive (odds ratio, 3.37; 95% CI, 1.69-6.72) and invasive positive-pressure ventilation (odds ratio, 2.06; 95% CI, 1.15-3.69), severity of illness (odds ratio for every 0.1 increase in pediatric index of mortality 2 score, 1.39; 95% CI, 1.14-1.71), procedures (odds ratio, 3.33; 95% CI, 1.67-6.64), and gastrointestinal disturbances (odds ratio, 2.05; 95% CI, 1.14-3.68) within 48 hours after admission to the PICU. Delayed enteral nutrition was associated with failure to reach full enteral nutrition while in the PICU (odds ratio, 4.09; 95% CI, 1.97-8.53). Nutrition consults were obtained in less than half of the cases, and none of the PICUs used tools to assure the adequacy of energy and protein nutrition. Institutions in this study initiated enteral nutrition for a high percentage of patients by 48 hours of admission. Noninvasive positive-pressure ventilation was most strongly associated with delay enteral nutrition. A better

  2. Spatiotemporal Control of Light Transmission through a Multimode Fiber with Strong Mode Coupling

    NASA Astrophysics Data System (ADS)

    Xiong, Wen; Ambichl, Philipp; Bromberg, Yaron; Redding, Brandon; Rotter, Stefan; Cao, Hui

    2016-07-01

    We experimentally generate and characterize eigenstates of the Wigner-Smith time-delay matrix, called principal modes, in a multimode fiber with strong mode coupling. The unique spectral and temporal properties of principal modes enable global control of temporal dynamics of optical pulses transmitted through the fiber, despite random mode mixing. Our analysis reveals that well-defined delay times of the eigenstates are formed by multipath interference, which can be effectively manipulated by spatial degrees of freedom of input wave fronts. This study is essential to controlling dynamics of wave scattering, paving the way for coherent control of pulse propagation through complex media.

  3. Development and validation of the Delaying Gratification Inventory.

    PubMed

    Hoerger, Michael; Quirk, Stuart W; Weed, Nathan C

    2011-09-01

    Deficits in gratification delay are associated with a broad range of public health problems, such as obesity, risky sexual behavior, and substance abuse. However, 6 decades of research on the construct has progressed less quickly than might be hoped, largely because of measurement issues. Although past research has implicated 5 domains of delay behavior, involving food, physical pleasures, social interactions, money, and achievement, no published measure to date has tapped all 5 components of the content domain. Existing measures have been criticized for limitations related to efficiency, reliability, and construct validity. Using an innovative Internet-mediated approach to survey construction, we developed the 35-item 5-factor Delaying Gratification Inventory (DGI). Evidence from 4 studies and a large, diverse sample of respondents (N = 10,741) provided support for the psychometric properties of the measure. Specifically, scores on the DGI demonstrated strong internal consistency and test-retest reliability for the 35-item composite, each of the 5 domains, and a 10-item short form. The 5-factor structure fit the data well and had good measurement invariance across subgroups. Construct validity was supported by correlations with scores on closely related self-control measures, behavioral ratings, Big Five personality trait measures, and measures of adjustment and psychopathology, including those on the Minnesota Multiphasic Personality Inventory-2-Restructured Form. DGI scores also showed incremental validity in accounting for well-being and health-related variables. The present investigation holds implications for improving public health, accelerating future research on gratification delay, and facilitating survey construction research more generally by demonstrating the suitability of an Internet-mediated strategy.

  4. Development and validation of the Delaying Gratification Inventory

    PubMed Central

    Hoerger, Michael; Quirk, Stuart W.; Weed, Nathan C.

    2011-01-01

    Deficits in gratification delay are associated with a broad range of public health problems, such as obesity, risky sexual behavior, and substance abuse. However, six decades of research on the construct has progressed less quickly than might be hoped, largely due to measurement issues. Although past research implicates five domains of delay behavior, involving food, physical pleasures, social interactions, money, and achievement, no published measure to date has tapped all five components of the content domain. Existing measures have been criticized for limitations related to efficiency, reliability, and construct validity. Using an innovative Internet-mediated approach to survey construction, we developed the 35-item five-factor Delaying Gratification Inventory (DGI). Evidence from four studies and a large, diverse sample of respondents (N = 10,741) provided support for the psychometric properties of the measure. Specifically, scores on the DGI demonstrated strong internal consistency and test-retest reliability for the 35-item composite, each of the five domains, and a 10-item short-form. The five-factor structure fit the data well and had good measurement invariance across subgroups. Construct validity was supported by correlations with scores on closely-related self-control measures, behavioral ratings, Big Five personality trait measures, and measures of adjustment and psychopathology, including those on the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF). DGI scores also showed incremental validity in accounting for well-being and health-related variables. The present investigation holds implications for improving public health, accelerating future research on gratification delay, and facilitating survey construction research more generally by demonstrating the suitability of an Internet-mediated strategy. PMID:21480721

  5. Spin-orbit delays in photoemission

    NASA Astrophysics Data System (ADS)

    Jordan, I.; Huppert, M.; Pabst, S.; Kheifets, A. S.; Baykusheva, D.; Wörner, H. J.

    2017-01-01

    Attosecond delays between photoelectron wave packets emitted from different electronic shells are now well established. Is there any delay between electrons originating from the same electronic shell but leaving the cation in different fine-structure states? This question is relevant for all attosecond photoemission studies involving heavy elements, be it atoms, molecules or solids. We answer this fundamental question by measuring energy-dependent delays between photoelectron wave packets associated with the 3/2 2P and 1/2 2P components of the electronic ground states of Xe+ and Kr+. We observe delays reaching up to 33 ±6 as in the case of Xe. Our results are compared with two state-of-the-art theories. Whereas both theories quantitatively agree with the results obtained for Kr, neither of them fully reproduces the experimental results in Xe. Performing delay measurements very close to the ionization thresholds, we compare the agreement of several analytical formulas for the continuum-continuum delays with experimental data. Our results show an important influence of spin-orbit coupling on attosecond photoionization delays, highlight the requirement for additional theory development, and offer a precision benchmark for such work.

  6. Ascertainment and treatment of delayed puberty.

    PubMed

    Pozo, Jesús; Argente, Jesús

    2003-01-01

    The majority of patients with pubertal delay, can be classified as having primary pubertal delay (constitutional delay of growth and puberty, CDGP), although any child with a chronic disease could present with delayed puberty. In contrast, children with hypogonadism, either hyper- or hypogonadotropic, exhibit a total absence of pubertal development. Hence, early evaluation of these patients should be performed. Delay of puberty leads to psychological problems, secondary to short stature and/or delay in the acquisition of secondary sex characteristics and the reduction of bone mass. Although the final height in patients with CDGP is usually normal, some of these patients do not reach the third percentile or remain in the lowest part of the growth chart according to familial height. The most common reason for treating CDGP patients, usually with sex steroids, is for psychological difficulties and for loss of bone mineralization. Treatment must be individualized. Therapeutic options and new drugs will be discussed. Appropriate treatment and adequate nutritional intake are indicated in patients with delayed puberty due to chronic illness. In patients with hypo- or hypergonadotropic hypogonadism, puberty must be induced or completed. Different treatments (GnRH analogues, gonadotropins and sex steroids), and the main objectives are discussed.

  7. Delayed feedback applied to breathing in humans

    NASA Astrophysics Data System (ADS)

    Janson, N. B.; Pototsky, A.; Parkes, C.

    2013-10-01

    We studied the response of healthy volunteers to the delayed feedback generated from the breathing signals. Namely, in the freely-breathing volunteers the breathing signal was recorded, delayed by τ seconds and fed back to the same volunteer in real time in the form of a visual and auditory stimulus of low intensity, i.e. the stimulus was crucially non-intrusive. In each case volunteers were instructed to breathe in the way which was most comfortable for them, and no explanation about the kind of applied stimulus was provided to them. Each volunteer experienced 10 different delay times ranging between 10% and 100% of the average breathing period without external stimulus. It was observed that in a significant proportion of subjects (11 out of 24) breathing was slowed down in the presence of delayed feedback with moderate delay. Also, in 6 objects out of 24 the delayed feedback was able to induce transition from nearly periodic to irregular breathing. These observations are consistent with the phenomena observed in numerical simulation of the models of periodic and chaotic self-oscillations with delays, and also in experiments with simpler self-oscillating systems.

  8. Delayed diagnosis of narcolepsy: characterization and impact.

    PubMed

    Thorpy, Michael J; Krieger, Ana C

    2014-05-01

    Narcolepsy, a chronic neurologic condition resulting from dysregulation of the sleep-wake cycle, usually has an onset at an early age. However, a long delay until diagnosis has been consistently reported in the literature across countries and several publications have focused on characterizing this delay. Most studies report a mean delay to diagnosis of up to 15 years, with individual cases of >60 years, although a trend over time toward a shorter diagnostic delay has been suggested. While variables associated with this delay have been identified, a lack of symptom recognition resulting in misdiagnosis prior to reaching the narcolepsy diagnosis is the likely underlying reason. This lack of symptom recognition is especially relevant considering the high comorbidity burden that has been shown in patients with narcolepsy as some disorders manifest with symptoms that overlap with narcolepsy. A consequence of delayed diagnosis is delayed treatment, which affects the burden of disease. Substantial detrimental effects on health-care resource utilization, employment, and quality of life have been described after narcolepsy onset and prior to the diagnosis of narcolepsy. This review highlights the importance of closing the diagnostic gap by expanding awareness of narcolepsy and its symptoms.

  9. Strong-Field Control of Laser Filamentation Mechanisms

    NASA Astrophysics Data System (ADS)

    Levis, Robert; Romanov, Dmitri; Filin, Aleskey; Compton, Ryan

    2008-05-01

    The propagation of short strong-file laser pulses in gas and solution phases often result in formation of filaments. This phenomenon involves many nonlinear processes including Kerr lensing, group velocity dispersion, multi-photon ionization, plasma defocusing, intensity clamping, and self-steepening. Of these, formation and dynamics of pencil-shape plasma areas plays a crucial role. The fundamental understanding of these laser-induced plasmas requires additional effort, because the process is highly nonlinear and complex. We studied the ultrafast laser-generated plasma dynamics both experimentally and theoretically. Ultrafast plasma dynamics was probed using Coherent Anti-Stokes Raman Scattering. The measurements were made in a room temperature gas maintained at 1 atm in a flowing cell. The time dependent scattering was measured by delaying the CARS probe with respect to the intense laser excitation pulse. A general trend is observed between the spacing of the ground state and the first allowed excited state with the rise time for the noble gas series and the molecular gases. This trend is consistent with our theoretical model, which considers the ultrafast dynamics of the strong field generated plasma as a three-step process; (i) strong-field ionization followed by the electron gaining considerable kinetic energy during the pulse; (ii) immediate post-pulse dynamics: fast thermalization, impact-ionization-driven electron multiplication and cooling; (iii) ensuing relaxation: evolution to electron-ion equilibrium and eventual recombination.

  10. Organophosphate-induced delayed polyneuropathy.

    PubMed

    Lotti, Marcello; Moretto, Angelo

    2005-01-01

    Organophosphate-induced delayed polyneuropathy (OPIDP) is a rare toxicity resulting from exposure to certain organophosphorus (OP) esters. It is characterised by distal degeneration of some axons of both the peripheral and central nervous systems occurring 1-4 weeks after single or short-term exposures. Cramping muscle pain in the lower limbs, distal numbness and paraesthesiae occur, followed by progressive weakness, depression of deep tendon reflexes in the lower limbs and, in severe cases, in the upper limbs. Signs include high-stepping gait associated with bilateral foot drop and, in severe cases, quadriplegia with foot and wrist drop as well as pyramidal signs. In time, there might be significant recovery of the peripheral nerve function but, depending on the degree of pyramidal involvement, spastic ataxia may be a permanent outcome of severe OPIDP. Human and experimental data indicate that recovery is usually complete in the young. At onset, the electrophysiological changes include reduced amplitude of the compound muscle potential, increased distal latencies and normal or slightly reduced nerve conduction velocities. The progression of the disease, usually over a few days, may lead to non-excitability of the nerve with electromyographical signs of denervation. Nerve biopsies have been performed in a few cases and showed axonal degeneration with secondary demyelination. Neuropathy target esterase (NTE) is thought to be the target of OPIDP initiation. The ratio of inhibitory powers for acetylcholinesterase and NTE represents the crucial guideline for the aetiological attribution of OP-induced peripheral neuropathy. In fact, pre-marketing toxicity testing in animals selects OP insecticides with cholinergic toxicity potential much higher than that to result in OPIDP. Therefore, OPIDP may develop only after very large exposures to insecticides, causing severe cholinergic toxicity. However, this was not the case with certain triaryl phosphates that were not used as

  11. Delayed visual maturation and lead pollution.

    PubMed

    Gulson, B L; Yui, L A; Howarth, D

    1998-12-11

    Three children were born in the Broken Hill Australia lead mining community with delayed visual maturation of the optic nerve (blindness) within a period of 19 months. Because of the association with the lead pollution, the delayed visual maturation was attributed to lead exposure of the fetus during pregnancy. Lead isotopic analyses of the shed deciduous teeth from the three children demonstrate that they were not exposed to increased levels of lead from a mining or any other source during pregnancy and the etiology of the delayed visual maturation must be sought elsewhere.

  12. Delayed lead perforation: a disturbing trend.

    PubMed

    Khan, Mohammed N; Joseph, George; Khaykin, Yaariv; Ziada, Khaled M; Wilkoff, Bruce L

    2005-03-01

    Delayed lead perforation (occurring more than 1 month after implantation) is a rare complication. Its pathophysiology and optimal management are currently unclear. Three cases of delayed lead perforation (6-10 month) were identified in patients with low-profile active fixation leads. All cases presented in a subacute fashion with pleuritic chest pain with confirmatory chest x-ray and device interrogation. Given the potential complications of a perforated lead, all cases had the lead extracted under TEE observation with cardiac surgery backup in the operating room. All patients tolerated extraction without complication. Based on these cases, we recommend a management scheme for patients who present with delayed lead perforation.

  13. Finite time stabilization of delayed neural networks.

    PubMed

    Wang, Leimin; Shen, Yi; Ding, Zhixia

    2015-10-01

    In this paper, the problem of finite time stabilization for a class of delayed neural networks (DNNs) is investigated. The general conditions on the feedback control law are provided to ensure the finite time stabilization of DNNs. Then some specific conditions are derived by designing two different controllers which include the delay-dependent and delay-independent ones. In addition, the upper bound of the settling time for stabilization is estimated. Under fixed control strength, discussions of the extremum of settling time functional are made and a switched controller is designed to optimize the settling time. Finally, numerical simulations are carried out to demonstrate the effectiveness of the obtained results.

  14. Strong curvature singularities and causal simplicity

    SciTech Connect

    Krolak, A. )

    1992-02-01

    Techniques of differential topology in Lorentzian manifolds developed by Geroch, Hawking, and Penrose are used to rule out a class of locally naked strong curvature singularities in strongly causal space-times. This result yields some support to the validity of Penrose's strong cosmic censorship hypothesis.

  15. Strong gravitation and models of particles

    SciTech Connect

    Panov, V.F.

    1987-01-01

    The problem of determining the most realistic model of particles in strong gravitation is considered. The relation between the hypothesis of strong gravitation and the structure of the proton is analyzed. The thermodynamics of a hadron as a black hole in strong gravitation is studied.

  16. [Delay in diagnosis of common variable immunodeficiency: a paradigmatic case report].

    PubMed

    Iebba, Filippo; Di Sora, Fiorella; Leti, Wilma; Montella, Tatiana; Corea, Francesco; Montella, Francesco

    2015-11-01

    This case report highlights the frequent delay in diagnosis of common variable immunodeficiency. The patient, 84 years old, had over 30 years of recurrent infections. At the first visit serum IgG were less than 134 mg/dl. From the review of previous examinations strong hypogammaglobulinemia was present for over 14 years.

  17. A maximum a posteriori probability time-delay estimation for seismic signals

    NASA Astrophysics Data System (ADS)

    Carrier, A.; Got, J.-L.

    2014-09-01

    Cross-correlation and cross-spectral time delays often exhibit strong outliers due to ambiguities or cycle jumps in the correlation function. Their number increases when signal-to-noise, signal similarity or spectral bandwidth decreases. Such outliers heavily determine the time-delay probability density function and the results of further computations (e.g. double-difference location and tomography) using these time delays. In the present research we expressed cross-correlation as a function of the squared difference between signal amplitudes and show that they are closely related. We used this difference as a cost function whose minimum is reached when signals are aligned. Ambiguities may be removed in this function by using a priori information. We propose using the traveltime difference as a priori time-delay information. By modelling the probability density function of the traveltime difference by a Cauchy distribution and the probability density function of the data (differences of seismic signal amplitudes) by a Laplace distribution we were able to find explicitly the time-delay a posteriori probability density function. The location of the maximum of this a posteriori probability density function is the maximum a posteriori time-delay estimation for earthquake signals. Using this estimation to calculate time delays for earthquakes on the south flank of Kilauea statistically improved the cross-correlation time-delay estimation for these data and resulted in successful double-difference relocation for an increased number of earthquakes. This robust time-delay estimation improves the spatiotemporal resolution of seismicity rates in the south flank of Kilauea.

  18. Effect of phase response curve skew on synchronization with and without conduction delays

    PubMed Central

    Canavier, Carmen C.; Wang, Shuoguo; Chandrasekaran, Lakshmi

    2013-01-01

    A central problem in cortical processing including sensory binding and attentional gating is how neurons can synchronize their responses with zero or near-zero time lag. For a spontaneously firing neuron, an input from another neuron can delay or advance the next spike by different amounts depending upon the timing of the input relative to the previous spike. This information constitutes the phase response curve (PRC). We present a simple graphical method for determining the effect of PRC shape on synchronization tendencies and illustrate it using type 1 PRCs, which consist entirely of advances (delays) in response to excitation (inhibition). We obtained the following generic solutions for type 1 PRCs, which include the pulse-coupled leaky integrate and fire model. For pairs with mutual excitation, exact synchrony can be stable for strong coupling because of the stabilizing effect of the causal limit region of the PRC in which an input triggers a spike immediately upon arrival. However, synchrony is unstable for short delays, because delayed inputs arrive during a refractory period and cannot trigger an immediate spike. Right skew destabilizes antiphase and enables modes with time lags that grow as the conduction delay is increased. Therefore, right skew favors near synchrony at short conduction delays and a gradual transition between synchrony and antiphase for pairs coupled by mutual excitation. For pairs with mutual inhibition, zero time lag synchrony is stable for conduction delays ranging from zero to a substantial fraction of the period for pairs. However, for right skew there is a preferred antiphase mode at short delays. In contrast to mutual excitation, left skew destabilizes antiphase for mutual inhibition so that synchrony dominates at short delays as well. These pairwise synchronization tendencies constrain the synchronization properties of neurons embedded in larger networks. PMID:24376399

  19. A single dose of melatonin prevents the phase delay associated with a delayed weekend sleep pattern.

    PubMed

    Yang, C M; Spielman, A J; D'Ambrosio, P; Serizawa, S; Nunes, J; Birnbaum, J

    2001-05-01

    This study was designed to test the hypotheses that a delayed weekend sleep pattern may lead to a phase delay of the endogenous circadian rhythm, and that melatonin administration can counteract the phase delay and prevent the sleep and functional impairments associated with this sleep pattern. A within-subject, counterbalanced design was used in which each subject participated in both placebo and melatonin conditions. Subjects' sleep-wake schedules were delayed by two hours on Friday and Saturday to simulate the delayed weekend sleep pattern. Six mg of melatonin or a placebo pill was administered double blind on Sunday late afternoon. N/A. Ten healthy volunteers (mean age = 22.1 years old). Salivary dim-light melatonin onset (DLMO) was measured on Friday and Monday nights. Subject's sleep was recorded with polysomnography on Sunday night and their levels of sleepiness, cognitive functioning and mood were assessed on Sunday night and Monday morning. Results show that the delayed weekend sleep pattern caused a 31.6 min delay of the endogenous melatonin rhythm. Melatonin administration counteracted the phase delay of endogenous melatonin onset. On Sunday, melatonin administration increased the sleepiness throughout the evening and reduced sleep onset latency at bedtime. On Monday morning, subjective sleepiness was decreased in the melatonin condition. A delayed weekend sleep pattern did show a mild phase-delay effect on the endogenous circadian rhythm. A single dose of melatonin can acutely reverse the weekend drift.

  20. Piloted simulator study of allowable time delay in pitch flight control system of a transport airplane with negative static stability

    NASA Technical Reports Server (NTRS)

    Grantham, William D.; Smith, Paul M.; Person, Lee H., Jr.; Meyer, Robert T.; Tingas, Stephen A.

    1987-01-01

    A piloted simulation study was conducted to determine the permissible time delay in the flight control system of a 10-percent statically unstable transport airplane during cruise flight conditions. The math model used for the simulation was a derivative Lockheed L-1011 wide-body jet transport. Data were collected and analyzed from a total of 137 cruising flights in both calm- and turbulent-air conditions. Results of this piloted simulation study verify previous findings that show present military specifications for allowable control-system time delay may be too stringent when applied to transport-size airplanes. Also, the degree of handling-qualities degradation due to time delay is shown to be strongly dependent on the source of the time delay in an advanced flight control system. Maximum allowable time delay for each source of time delay in the control system, in addition to a less stringent overall maximum level of time delay, should be considered for large aircraft. Preliminary results also suggest that adverse effects of control-system time delay may be at least partially offset by variations in control gearing. It is recommended that the data base include different airplane baselines, control systems, and piloting tasks with many pilots participating, so that a reasonable set of limits for control-system time delay can be established to replace the military specification limits currently being used.

  1. Delayed feedback control of cavity solitons in a broad area vertical cavity surface emitting laser with saturable absorbtion

    NASA Astrophysics Data System (ADS)

    Gurevich, S. V.; Schelte, C.; Tlidi, M.; Panajotov, K.

    2016-04-01

    We are interested in spatio-temporal dynamics of cavity solitons (CSs) in a transverse section of a broad area vertical cavity surface emitting laser (VCSEL) with saturable absorbtion subjected to time-delayed optical feedback. In the absence of delayed feedback, a single branch of localized solutions appears in the parameter space. However, in the presence of the delayed feedback, multistability of CS solutions emerges; The branches of CSs fill the surface of the "solution tube" in the parameter space, which is filled densely with increasing delay time. Further, our study reveals that the multistability of stationary solutions is caused by a delayed-induced phase bifurcation of CSs. Furthermore, it was shown that stability properties of CSs strongly depend on the delayed feedback parameters. In particular, the thresholds of the drift and phase bifurcations as well as corresponding bifurcation diagrams are obtained by a combination of analytical and numerical continuation methods. It turns out that both thresholds tend to zero in the limit of large delay times. In addition, we demonstrate that the presence of the delayed optical feedback can induce Andronov-Hopf bifurcation and a period doubling route to chaos. Moreover, a coupling between this bifurcation scenario with aforementioned delay-induced multistability leads to a complex spatio-temporal behavior of the system in question. The results of analytical bifurcation analysis are in agreement with those obtained by direct numerical integration of the model equation.

  2. Framework to Delay Corn Rootworm Resistance

    EPA Pesticide Factsheets

    This proposed framework is intended to delay the corn rootworm pest becoming resistant to corn genetically engineered to produce Bt proteins, which kill corn rootworms but do not affect people or wildlife. It includes requirements on Bt corn manufacturers.

  3. Isolation Effect in Immediate and Delayed Recall

    ERIC Educational Resources Information Center

    Bellezza, Francis S.; Cheney, Terry L.

    1973-01-01

    If the hypothesis of selective rehearsal is used to account for the isolation effect, then the recall of isolated items will depend both on the serial position of the isolated item and on whether recall is immediate or delayed. (Author)

  4. SBASI: Actuated pyrotechnic time delay initiator

    NASA Technical Reports Server (NTRS)

    Salter, S. J.; Lundberg, R. E.; Mcdougal, G. L.

    1975-01-01

    A precision pyrotechnic time delay initiator for missile staging was developed and tested. Incorporated in the assembly is a single bridgewire Apollo standard initiator (SBASI) for initiation, a through-bulkhead-initiator to provide isolation of the SBASI output from the delay, the pyrotechnic delay, and an output charge. An attempt was made to control both primary and secondary variables affecting functional performance of the delay initiator. Design and functional limit exploration was performed to establish tolerance levels on manufacturing and assembling operations. The test results demonstrate a 2% coefficient of variation at any one temperature and an overall 2.7% coefficient of variation throughout the temperature range of 30 to 120 F. Tests were conducted at simulated operational altitude from sea level to 200,000 feet.

  5. Resonance Effects in Photoemission Time Delays.

    PubMed

    Sabbar, M; Heuser, S; Boge, R; Lucchini, M; Carette, T; Lindroth, E; Gallmann, L; Cirelli, C; Keller, U

    2015-09-25

    We present measurements of single-photon ionization time delays between the outermost valence electrons of argon and neon using a coincidence detection technique that allows for the simultaneous measurement of both species under identical conditions. The analysis of the measured traces reveals energy-dependent time delays of a few tens of attoseconds with high energy resolution. In contrast to photoelectrons ejected through tunneling, single-photon ionization can be well described in the framework of Wigner time delays. Accordingly, the overall trend of our data is reproduced by recent Wigner time delay calculations. However, besides the general trend we observe resonance features occurring at specific photon energies. These features have been qualitatively reproduced and identified by a calculation using the multiconfigurational Hartree-Fock method, including the influence of doubly excited states and ionization thresholds.

  6. Delaying Your Period with Birth Control Pills

    MedlinePlus

    ... side effects sometimes associated with a hormone-free interval. Quartette. With this 91-day regimen, you take ... year. There are no breaks for hormone-free intervals, which means no periods. It's possible to delay ...

  7. 48 CFR 1252.217-79 - Delays.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... at (TAR) 48 CFR 1217.7001(b) and (c), insert the following clause: Delays (OCT 1994) When during the... incurring additional costs on account thereof, an equitable adjustment shall be made in the price of...

  8. Time to implement delayed cord clamping.

    PubMed

    McAdams, Ryan M

    2014-03-01

    Immediate umbilical cord clamping after delivery is routine in the United States despite little evidence to support this practice. Numerous trials in both term and preterm neonates have demonstrated the safety and benefit of delayed cord clamping. In premature neonates, delayed cord clamping has been shown to stabilize transitional circulation, lessening needs for inotropic medications and reducing blood transfusions, necrotizing enterocolitis, and intraventricular hemorrhage. In term neonates, delayed cord clamping has been associated with decreased iron-deficient anemia and increased iron stores with potential valuable effects that extend beyond the newborn period, including improvements in long-term neurodevelopment. The failure to more broadly implement delayed cord clamping in neonates ignores published benefits of increased placental blood transfusion at birth and may represent an unnecessary harm for vulnerable neonates.

  9. Delay in diagnosis: the experience in Denmark

    PubMed Central

    Olesen, F; Hansen, R P; Vedsted, P

    2009-01-01

    Background: Denmark has poorer 5-year survival rates than many other Western European countries, and cancer patients tend to have more advanced stages at diagnosis than those in other Scandinavian countries. Part of this may be due to delay in diagnosis. The aim of this paper is to give an overview of the initiatives currently underway to reduce delays. Methods: Description of Danish actions to reduce delay. Results: Results of surveys of patient-, doctor- and system-related delays are presented and so are the political initiatives to ensure that cancer is seen as an acute disease. Conclusion: In future, fast-track diagnosis and treatment will be provided for suspected cancers and access to general diagnostic investigations will be improved. A large national experiment with cancer seen as an acute disease is currently being implemented, and as yet the results are unknown. PMID:19956163

  10. The SAS-3 delayed command system

    NASA Technical Reports Server (NTRS)

    Hoffman, E. J.

    1975-01-01

    To meet the requirements arising from the increased complexity of the power, attitude control and telemetry systems, a full redundant high-performance control section with delayed command capability was designed for the Small Astronomy Satellite-3 (SAS-3). The relay command system of SAS-3 is characterized by 56 bystate relay commands, with capability for handling up to 64 commands in future versions. The 'short' data command service of SAS-1 and SAS-2 consisting of shifting 24-bit words to two users was expanded to five users and augmented with a 'long load' data command service (up to 4080 bits) used to program the telemetry system and the delayed command subsystem. The inclusion of a delayed command service ensures a program of up to 30 relay or short data commands to be loaded for execution at designated times. The design and system operation of the SAS-3 command section are analyzed, with special attention given to the delayed command subsystem.

  11. Isolation Effect in Immediate and Delayed Recall

    ERIC Educational Resources Information Center

    Bellezza, Francis S.; Cheney, Terry L.

    1973-01-01

    If the hypothesis of selective rehearsal is used to account for the isolation effect, then the recall of isolated items will depend both on the serial position of the isolated item and on whether recall is immediate or delayed. (Author)

  12. Constant-Delay Broadband Microwave Phase Modulator

    NASA Technical Reports Server (NTRS)

    Francisco, Mark; Praba, Krishna

    1994-01-01

    Varactor diodes and transformer waveguide sections used instead of tuned circuits. Microwave phase modulator exhibits approximately flat delay-vs.-frequency response in frequency band of interest, according to design computations.

  13. Anticipation in manual tracking with multiple delays.

    PubMed

    Stepp, Nigel; Turvey, Michael T

    2017-05-01

    Two experiments are reported showing that behavior exhibited in manual tracking is consistent with behavior predicted by a dynamical systems phenomenon known as anticipating synchronization (Voss, 2000). They extend a prior investigation of the effect of delay on anticipatory manual tracking (Stepp, 2009) by also manipulating coupling strength. The coupling scheme in Experiment 1 and that in Experiment 2 go beyond the single delayed feedback coupling used in previous research and articulations of anticipating synchronization. These advanced coupling arrangements are addressed using an extended formulation which allows for multiple feedback delays, a continuous range of delay, or even coupling to real future values. The latter case is specifically investigated in Experiment 2, which utilizes a navigation task that provides a natural way to speak about coupling to future values. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  14. Suprasellar arachnoid cyst with delayed puberty.

    PubMed

    Kumar, Raj; Singhal, Namit

    2007-11-01

    A 15-year-old female presented with primary amenorrhea and delayed onset of secondary sexual characteristics. Earlier she was operated for endoscopic third ventriculostomy (ETV) for a tense suprasellar arachnoid cyst with obstructive hydrocephalus. MRI revealed recurrence of hydrocephalus. Hormonal levels were suggestive of hypogonadism and deficiency of growth hormone. She was operated for fenestration of cyst. In this case, suprasellar arachnoid cyst presented with delayed puberty, which is unusual.

  15. CT densities in delayed iodine hepatic scanning

    SciTech Connect

    Perkerson, R.B. Jr.; Erwin, B.C.; Baumgartner, B.R.; Phillips, V.M.; Torres, W.E.; Clements, J.L. Jr.; Gedgaudas-McClees, K.; Bernardino, M.E.

    1985-05-01

    Sixty patients underwent CT scanning of the liver prior to, immediately after, and four hours after intravenous administration of 60% meglumine diatrizoate. Twenty patients received a 50 ml bolus of contrast material, 20 received 100 ml, and 20 received 200 ml. In each group, delayed CT scanning safely raised the inherent density of the liver significantly. Thus, delayed scanning with doses presently used in abdominal and neurological CT examinations may be helpful in detecting hepatic lesions.

  16. Optical Fiber Delay Line Signal Processing.

    NASA Astrophysics Data System (ADS)

    Newton, Steven Arthur

    The delay line transversal filter is a basic component in analog signal processing systems. Unfortunately, conventional delay line devices, such as those that use surface acoustic waves, are largely limited to operation at frequencies of several hundred megahertz and below. In this work, single-mode optical fiber has been used as a delay medium to make transversal filters that extend this kind of signal processing to frequencies of one gigahertz and above. Single-mode optical fiber is an excellent delay medium because it exhibits extremely low loss and dispersion. By efficiently collecting, weighting, and combining signals extracted from a fiber delay line, single-mode fiber can be used, not only to transmit broadband signals, but to process them as well. The goals of the work have been to study efficient tapping mechanisms, and to construct fiber transversal filters capable of performing some basic signal processing functions. Several different tapped and recirculating delay line prototypes have been fabricated using a variety of tapping techniques, including macrobending and evanescent field coupling. These devices have been used to demonstrate basic signal processing functions, such as code generation, convolution, correlation, and frequency filtering, at frequencies that exceed those possible using conventional delay line technologies. Fiber recirculating delay line loops have also been demonstrated as transient memories for the temporary storage of signals and as a means of time division multiplexing via data rate transformation. These devices are the building blocks that are necessary to make systems capable of performing complex signal processing functions. With the recent development of high speed optical sources and detectors to interface with fiber systems of this kind, the real time processing of signals having bandwidths of tens of gigahertz is envisioned.

  17. MSW Variable Time-Delay Techniques.

    DTIC Science & Technology

    1982-07-01

    Phase Measurements Delay Dispersion Angle YIG Epitaxy Microwaves Films 20. ABSTRACT (Coninv. an r..eves side it nocesomr and identUify by Nocak ne...Work performed during the first year of a program to investigate magneto- static wave device techniques for phased arrays and microwave signal...device techniques for phased antenna arrays and microwave signal processing. At the start of this " program, initial experiments on variable delay(1

  18. Time delay control of hysteretic composite plate

    NASA Astrophysics Data System (ADS)

    Chen, Long-Xiang; Li, Shi-Hong; Liu, Kun; Cai, Guo-Ping; Li, Hong-Guang

    2015-04-01

    Due to boosting usage of flexible and damping materials, it is of great significance for both science and engineering to explore active control methods for vibration within time-delayed hysteretic structures. This paper conducts theoretical and experimental research on a time-delayed controller for a flexible plate with a single-layer rubber glued on its back. First of all, the dynamic equation for a composite plate is given on the base of the Kirchhoff-Love assumption, where damping-restoring force is described by the Bouc-Wen hysteresis model. Then, the influence of time delay is taken into account and the state equation of the plate with time delay is obtained. Next, a standard state equation, with implicit time delay, is derived using one specific form of integral transformation and vector augmentation. Finally, an instantaneous optimal control method is used to design an active controller. This controller does not only involve state feedback of the current step, but also a linear addition of former state feedbacks within several steps. In order to verify this method, experimental work is conducted. Problems encountered like differential computation and lifting of displacement signal are also handled. According to a comparison between simulations and experiments, the control method given in this paper is feasible and valid, and it is available for both small and large time delay.

  19. Operant variability when reinforcement is delayed.

    PubMed

    Wagner, Katie; Neuringer, Allen

    2006-05-01

    Operant responses are often weakened when delays are imposed between the responses and reinforcers. We examined what happens when delayed reinforcers were contingent upon operant response variability. Three groups of rats were rewardedfor varying their response sequences, with onegroup rewarded for high variability, another for middle, and the third for low levels. Consistent with many reports in the literature, responding slowed significantly in all groups as delays were lengthened. Consistent with other reports, large differences in variability were maintained across the three groups despite the delays. Reinforced variability appears to be relatively immune to disruption by such things as delays, response slowing, prefeeding, and noncontingent reinforcement. Furthermore, the small effects on variability depended on baseline levels: As delays lengthened, variability increased in the low group, was statistically unchanged in the middle group, and decreased in the high group, an interaction similar to that reported previously when reinforcement frequencies were lowered. Thus, variable operant responding is controlled by reinforcement contingencies, but sometimes differently than more commonly studied repetitive responding.

  20. Estimating ionospheric delay using kriging: 1. Methodology

    NASA Astrophysics Data System (ADS)

    Sparks, Lawrence; Blanch, Juan; Pandya, Nitin

    2011-12-01

    The Wide Area Augmentation System (WAAS) is an augmentation of the Global Positioning System (GPS) that provides safe and reliable use of GPS signals for airline navigation over much of North America. Ever since WAAS was first commissioned in July of 2003, the vertical delay estimate at each node in the WAAS ionospheric grid has been determined from a planar fit of slant delay measurements, projected to vertical using an obliquity factor specified by the standard thin shell model of the ionosphere. In a future WAAS upgrade (WAAS Follow-On Release 3), however, the vertical delay will be estimated by an established, geo-statistical technique known as kriging. When compared to the planar fit model, the kriging model is generally found to match better the observed random structure of the vertical delay. This paper presents the kriging methodology to be used to estimate the vertical delay and its uncertainty at each ionospheric grid point. In addition, it provides examples of the improvement in delay accuracy achieved. Under disturbed conditions, the implementation of kriging reduces the magnitude of the root mean square fit residual by up to 15%.

  1. Ladder-structured photonic variable delay device

    NASA Technical Reports Server (NTRS)

    Yao, X. Steve (Inventor)

    1998-01-01

    An ladder-structured variable delay device for providing variable true time delay to multiple optical beams simultaneously. The device comprises multiple basic units stacked on top of each other resembling a ladder. Each basic unit comprises a polarization sensitive corner reflector formed by two polarization beamsplitters and a polarization rotator array placed parallel to the hypotenuse of the corner reflector. Controlling an array element of the polarization rotator array causes an optical beam passing through the array element to either go up to a basic unit above it or reflect back towards output. The beams going higher on the ladder experience longer optical path delay. Finally, the ladder-structured variable device can be cascaded with another multi-channel delay device to form a new device which combines the advantages of the two individual devices. This programmable optic device has the properties of high packing density, low loss, easy fabrication, and virtually infinite bandwidth. In addition, the delay is reversible so that the same delay device can be used for both antenna transmitting and receiving.

  2. Short conduction delays cause inhibition rather than excitation to favor synchrony in hybrid neuronal networks of the entorhinal cortex.

    PubMed

    Wang, Shuoguo; Chandrasekaran, Lakshmi; Fernandez, Fernando R; White, John A; Canavier, Carmen C

    2012-01-01

    How stable synchrony in neuronal networks is sustained in the presence of conduction delays is an open question. The Dynamic Clamp was used to measure phase resetting curves (PRCs) for entorhinal cortical cells, and then to construct networks of two such neurons. PRCs were in general Type I (all advances or all delays) or weakly type II with a small region at early phases with the opposite type of resetting. We used previously developed theoretical methods based on PRCs under the assumption of pulsatile coupling to predict the delays that synchronize these hybrid circuits. For excitatory coupling, synchrony was predicted and observed only with no delay and for delays greater than half a network period that cause each neuron to receive an input late in its firing cycle and almost immediately fire an action potential. Synchronization for these long delays was surprisingly tight and robust to the noise and heterogeneity inherent in a biological system. In contrast to excitatory coupling, inhibitory coupling led to antiphase for no delay, very short delays and delays close to a network period, but to near-synchrony for a wide range of relatively short delays. PRC-based methods show that conduction delays can stabilize synchrony in several ways, including neutralizing a discontinuity introduced by strong inhibition, favoring synchrony in the case of noisy bistability, and avoiding an initial destabilizing region of a weakly type II PRC. PRCs can identify optimal conduction delays favoring synchronization at a given frequency, and also predict robustness to noise and heterogeneity. © 2012 Wang et al.

  3. A negative group delay model for feedback-delayed manual tracking performance.

    PubMed

    Voss, Henning U; Stepp, Nigel

    2016-12-01

    We propose that feedback-delayed manual tracking performance is limited by fundamental constraints imposed by the physics of negative group delay. To test this hypothesis, the results of an experiment in which subjects demonstrate both reactive and predictive dynamics are modeled by a linear system with delay-induced negative group delay. Although one of the simplest real-time predictors conceivable, this model explains key components of experimental observations. Most notably, it explains the observation that prediction time linearly increases with feedback delay, up to a certain point when tracking performance deteriorates. It also explains the transition from reactive to predictive behavior with increasing feedback delay. The model contains only one free parameter, the feedback gain, which has been fixed by comparison with one set of experimental observations for the reactive case. Our model provides quantitative predictions that can be tested in further experiments.

  4. Allowable delay bound for consensus of linear multi-agent systems with communication delay

    NASA Astrophysics Data System (ADS)

    Zhang, Ya; Tian, Yu-Ping

    2014-10-01

    This paper studies the consensus of a group of linear dynamic agents with a uniform communication delay and focuses on searching an allowable delay bound. As long as the delay is less than this bound, there exist linear feedback consensus protocols driving the multi-agent system to achieve consensus. Both fixed and switching topology cases are investigated. In both cases, the consensus problem is converted to the robust stability problem of corresponding uncertain state-delayed systems. By using Lyapunov-Krasovskii functional analysis, consensus conditions which contain the feedback gain conditions and delay conditions are proposed for systems over fixed and switching topologies, respectively. Furthermore, allowable delay bounds are obtained for both systems by solving the optimal robust stabilisation problems. Numerical examples are given to illustrate the results.

  5. Delayed antibiotic prescriptions for respiratory infections.

    PubMed

    Spurling, Geoffrey Kp; Del Mar, Chris B; Dooley, Liz; Foxlee, Ruth; Farley, Rebecca

    2017-09-07

    Concerns exist regarding antibiotic prescribing for respiratory tract infections (RTIs) owing to adverse reactions, cost, and antibacterial resistance. One proposed strategy to reduce antibiotic prescribing is to provide prescriptions, but to advise delay in antibiotic use with the expectation that symptoms will resolve first. This is an update of a Cochrane Review originally published in 2007, and updated in 2010 and 2013. To evaluate the effects on clinical outcomes, antibiotic use, antibiotic resistance, and patient satisfaction of advising a delayed prescription of antibiotics in respiratory tract infections. For this 2017 update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 4, 2017), which includes the Cochrane Acute Respiratory Infection Group's Specialised Register; Ovid MEDLINE (2013 to 25 May 2017); Ovid Embase (2013 to 2017 Week 21); EBSCO CINAHL Plus (1984 to 25 May 2017); Web of Science (2013 to 25 May 2017); WHO International Clinical Trials Registry Platform (1 September 2017); and ClinicalTrials.gov (1 September 2017). Randomised controlled trials involving participants of all ages defined as having an RTI, where delayed antibiotics were compared to immediate antibiotics or no antibiotics. We defined a delayed antibiotic as advice to delay the filling of an antibiotic prescription by at least 48 hours. We considered all RTIs regardless of whether antibiotics were recommended or not. We used standard Cochrane methodological procedures. Three review authors independently extracted and collated data. We assessed the risk of bias of all included trials. We contacted trial authors to obtain missing information. For this 2017 update we added one new trial involving 405 participants with uncomplicated acute respiratory infection. Overall, this review included 11 studies with a total of 3555 participants. These 11 studies involved acute respiratory infections including acute otitis media (three studies

  6. Enhancing the modulation bandwidth of VCSELs to the millimeter-waveband using strong transverse slow-light feedback.

    PubMed

    Ahmed, Moustafa; Bakry, Ahmed; Alghamdi, Mohamed S; Dalir, Hamed; Koyama, Fumio

    2015-06-15

    We present modeling on the millimeter (mm)-wave modulation of vertical-cavity surface-emitting laser (VCSEL) with a transverse coupled cavity (TCC). We show that strong slow-light feedback can induce 300% boosting of the modulation bandwidth of the TCC-VCSEL. Also, the strong lateral feedback can induce resonance modulation over passbands centered on frequencies as high as 3.8 times the VCSEL bandwidth. The slow-light feedback is modeled by a time-delay rate equation model that takes into account the multiple round trips as well as the optical loss and phase delay in each round trip in the feedback cavity.

  7. Apparatus and Method for Compensating for Process, Voltage, and Temperature Variation of the Time Delay of a Digital Delay Line

    NASA Technical Reports Server (NTRS)

    Seefeldt, James (Inventor); Feng, Xiaoxin (Inventor); Roper, Weston (Inventor)

    2013-01-01

    A process, voltage, and temperature (PVT) compensation circuit and a method of continuously generating a delay measure are provided. The compensation circuit includes two delay lines, each delay line providing a delay output. The two delay lines may each include a number of delay elements, which in turn may include one or more current-starved inverters. The number of delay lines may differ between the two delay lines. The delay outputs are provided to a combining circuit that determines an offset pulse based on the two delay outputs and then averages the voltage of the offset pulse to determine a delay measure. The delay measure may be one or more currents or voltages indicating an amount of PVT compensation to apply to input or output signals of an application circuit, such as a memory-bus driver, dynamic random access memory (DRAM), a synchronous DRAM, a processor or other clocked circuit.

  8. Chaotic optical communications using delayed feedback systems

    NASA Astrophysics Data System (ADS)

    Locquet, Alexandre

    Chaotic dynamics produced by optical delay systems have interesting applications in telecommunications. Optical chaos can be used to transmit secretly, in real-time, a message between an emitter and a receiver. The noise-like appearance of chaos is used to conceal the message, and the synchronization of the receiver with the chaotic emitter is used to decode the message. This work focuses on the study of two crucial topics in the field of chaotic optical communications. The first topic is the synchronization of chaotic external-cavity laser diodes, which are among the most promising chaotic emitters for secure communications. It is shown that, for edge-emitting lasers, two drastically different synchronization regimes are possible. The regimes differ in terms of the delay time in the synchronization and in terms of the robustness of the synchronization with respect to parameter mismatches between the emitter and the receiver. In vertical-cavity surface-emitting lasers, the two linearly-polarized components of the electric field also exhibit isochronous and anticipating synchronization when the coupling between the lasers is isotropic. When the coupling is polarized, the linearly-polarized component that is parallel to the injected polarization tends to synchronize isochronously with the injected optical field, while the other component tends to be suppressed, but it can also be antisynchronized. The second topic is the analysis of time series produced by optical chaotic emitters subjected to a delayed feedback. First, we verify with experimental data that chaos produced by optical delay systems is highly complex. This high complexity is demonstrated by estimating chaos dimension and entropy from experimental time series and from models of optical delay systems. Second, by analyzing chaotic time series, it is shown that the value of the delay of a single-delay system can always be identified, independently of the type of system used and of its complexity

  9. Multivariate Markov processes for stochastic systems with delays: application to the stochastic Gompertz model with delay.

    PubMed

    Frank, T D

    2002-07-01

    Using the method of steps, we describe stochastic processes with delays in terms of Markov diffusion processes. Thus, multivariate Langevin equations and Fokker-Planck equations are derived for stochastic delay differential equations. Natural, periodic, and reflective boundary conditions are discussed. Both Ito and Stratonovich calculus are used. In particular, our Fokker-Planck approach recovers the generalized delay Fokker-Planck equation proposed by Guillouzic et al. The results obtained are applied to a model for population growth: the Gompertz model with delay and multiplicative white noise.

  10. Derivation and computation of discrete-delay and continuous-delay SDEs in mathematical biology.

    PubMed

    Allen, Edward J

    2014-06-01

    Stochastic versions of several discrete-delay and continuous-delay differential equations, useful in mathematical biology, are derived from basic principles carefully taking into account the demographic, environmental, or physiological randomness in the dynamic processes. In particular, stochastic delay differential equation (SDDE) models are derived and studied for Nicholson's blowflies equation, Hutchinson's equation, an SIS epidemic model with delay, bacteria/phage dynamics, and glucose/insulin levels. Computational methods for approximating the SDDE models are described. Comparisons between computational solutions of the SDDEs and independently formulated Monte Carlo calculations support the accuracy of the derivations and of the computational methods.

  11. Delayed feedback control of time-delayed chaotic systems: Analytical approach at Hopf bifurcation

    NASA Astrophysics Data System (ADS)

    Vasegh, Nastaran; Sedigh, Ali Khaki

    2008-07-01

    This Letter is concerned with bifurcation and chaos control in scalar delayed differential equations with delay parameter τ. By linear stability analysis, the conditions under which a sequence of Hopf bifurcation occurs at the equilibrium points are obtained. The delayed feedback controller is used to stabilize unstable periodic orbits. To find the controller delay, it is chosen such that the Hopf bifurcation remains unchanged. Also, the controller feedback gain is determined such that the corresponding unstable periodic orbit becomes stable. Numerical simulations are used to verify the analytical results.

  12. Advanced X-Ray Astrophysics Facility Delivery Delayed

    NASA Astrophysics Data System (ADS)

    1997-12-01

    TRW Space and Electronics Group, Redondo Beach, CA, has notified NASA that it will be unable to deliver the Advanced X-ray Astrophysics Facility (AXAF) to NASA's Kennedy Space Center, FL, on June 1, 1998, as required by contract, because it has experienced delays in assembly and testing of the facility. TRW is NASA's prime contractor for the observatory. NASA and contractor officials met at NASA Headquarters in Washington, DC, this week to discuss the issue. While no new delivery date was agreed upon, the agency has directed TRW to develop a plan of action that would show how the contractor can minimize impact to the June 1 delivery. Although a delay in delivery could delay the launch, currently scheduled for August 1998 aboard Space Shuttle Columbia's STS-93 mission, and could result in additional program costs, the exact impact is not yet known. "The delay in delivery of the observatory is unfortunate," said Fred Wojtalik, NASA Marshall Space Flight Center observatory projects office manager in Huntsville, AL. "However, our first priority is to launch a world-class observatory which has been thoroughly tested and meets all requirements. We will work closely with TRW to ensure that happens." The delay is primarily due to TRW's difficulty in configuring and programming its Integrated Spacecraft Automated Test System to test the observatory before it is delivered to NASA. The Advanced X-ray Astrophysics Facility is expected to play a vital role in answering fundamental questions about the universe, including its age and size, and will probe the nature and amounts of so-called "dark matter," providing unique insight into one of nature's great puzzles. The observatory also will allow scientists to see and measure the details of hot gas clouds in clusters of galaxies; observe X-rays generated when stars are torn apart by the incredibly strong gravity around massive black holes in the centers of galaxies; and provide images that will help understand how exploding stars

  13. Rates and Delay Times of Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Ruiter, Ashley J.; Belczynski, Krzysztof; Fryer, Chris

    2009-07-01

    We analyze the evolution of binary stars to calculate synthetic rates and delay times of the most promising Type Ia Supernovae (SNe Ia) progenitors. We present and discuss evolutionary scenarios in which a white dwarf (WD) reaches the Chandrasekhar mass and potentially explodes in a SNe Ia. We consider Double Degenerate (DDS; merger of two WDs), Single Degenerate (SDS; WD accreting from H-rich companion), and AM Canum Venaticorum (AM CVn; WD accreting from He-rich companion) scenarios. The results are presented for two different star formation histories: burst (elliptical-like galaxies) and continuous (spiral-like galaxies). It is found that delay times for the DDS in our standard model (with common envelope efficiency αCE = 1) follow a power-law distribution. For the SDS we note a wide range of delay times, while AM CVn progenitors produce a short burst of SNe Ia at early times. The DDS median delay time falls between ~0.5 and 1 Gyr the SDS between ~2 and 3 Gyr and the AM CVn between ~0.8 and 0.6 Gyr depending on the assumed αCE. For a Milky-Way-like (MW-like) galaxy, we estimate the rates of SNe Ia arising from different progenitors as: ~10-4 yr-1 for the SDS and AM CVn, and ~10-3 yr-1 for the DDS. We point out that only the rates for two merging carbon-oxygen WDs, the only systems found in the DDS, are consistent with the observed rates for typical MW-like spirals. We also note that DDS progenitors are the dominant population in elliptical galaxies. The fact that the delay time distribution for the DDS follows a power law implies more SNe Ia (per unit mass) in young rather than in aged populations. Our results do not exclude other scenarios, but strongly indicate that the DDS is the dominant channel generating SNe Ia in spiral galaxies, at least in the framework of our adopted evolutionary models. Since it is believed that WD mergers cannot produce a thermonuclear explosion given the current understanding of accreting WDs, either the evolutionary calculations

  14. Strongly Magnetized Accretion Disks Around Black Holes

    NASA Astrophysics Data System (ADS)

    Salvesen, Greg; Armitage, Philip J.; Simon, Jacob B.; Begelman, Mitchell C.

    2017-01-01

    Recent observations are suggestive of strongly magnetized accretion disks around black holes. Performing local (shearing box) simulations of accretion disks, we investigate how a strong magnetization state can develop and persist. We demonstrate that poloidal flux is a necessary prerequisite for the sustainability of strongly magnetized accretion disks. We also show that black hole spin measurements can become unconstrained if magnetic fields provide a significant contribution to the vertical pressure support of the accretion disk atmosphere.

  15. Effects of delay and noise in a negative feedback regulatory motif

    NASA Astrophysics Data System (ADS)

    Palassini, Matteo; Dies, Marta

    2009-03-01

    The small copy number of the molecules involved in gene regulation can induce nontrivial stochastic phenomena such as noise-induced oscillations. An often neglected aspect of regulation dynamics are the delays involved in transcription and translation. Delays introduce analytical and computational complications because the dynamics is non-Markovian. We study the interplay of noise and delays in a negative feedback model of the p53 core regulatory network. Recent experiments have found pronounced oscillations in the concentrations of proteins p53 and Mdm2 in individual cells subjected to DNA damage. Similar oscillations occur in the Hes-1 and NK-kB systems, and in circadian rhythms. Several mechanisms have been proposed to explain this oscillatory behaviour, such as deterministic limit cycles, with and without delay, or noise-induced excursions in excitable models. We consider a generic delayed Master Equation incorporating the activation of Mdm2 by p53 and the Mdm2-promoted degradation of p53. In the deterministic limit and for large delays, the model shows a Hopf bifurcation. Via exact stochastic simulations, we find strong noise-induced oscillations well outside the limit-cycle region. We propose that this may be a generic mechanism for oscillations in gene regulatory systems.

  16. Delay Discounting of Monetary Rewards over a Wide Range of Amounts

    PubMed Central

    Green, Leonard; Myerson, Joel; Oliveira, Luís; Chang, Seo Eun

    2013-01-01

    The present study examined delay discounting of hypothetical monetary rewards over a wide range of amounts (from $20 to $10 million) in order to determine how reward amount affects the parameters of the hyperboloid discounting function and to compare fits of the hyperboloid model with fits of two discounting models used in neuroeconomics: the quasi-hyperbolic and the double-exponential. Of the three models assessed, the hyperboloid provided the best fit to the delay discounting data. The present delay discounting results may be compared to those of a previous study on probability discounting (Myerson, Green, & Morris, 2011) that used the same extended range of amounts. The hyperboloid function accurately described both types of discounting, but reward amount had opposite effects on the degree of discounting. Importantly, the amount of delayed reward affected the rate parameter of the hyperboloid discounting function but not its exponent, whereas the opposite was true for the amount of probabilistic reward. The finding that the exponent of the hyperboloid discounting function remains relatively constant across a wide range of delayed amounts provides strong support for a psychophysical scaling interpretation, and stands in stark contrast to the finding that the exponent of the hyperboloid function increases with the amount of probabilistic reward. Taken together, these findings argue that delay and probability discounting involve fundamentally different decision-making mechanisms. PMID:24037826

  17. Undervaluing delayed rewards explains adolescents’ impulsivity in inter-temporal choice: an ERP study

    PubMed Central

    Huang, Yunyun; Hu, Ping; Li, Xueting

    2017-01-01

    Adolescence has frequently been characterized as a period of choice impulsivity relative to adulthood. According to the control-integrated valuation model of inter-temporal choice, this choice impulsivity may be driven partly by an age-related difference in reward processing. We hypothesized that, compared to adults, adolescents would undervalue delayed rewards during reward processing and would thus be more impulsive in inter-temporal choice. To test this hypothesis at the behavioural and neural levels, we first measured the choice impulsivity of 18 adolescents and 19 adults using a delay discounting task (DDT). Then, we recorded event-related potentials (ERPs) from the participants while they were performing the valuation task, in which monetary gains and losses were either immediate or delayed. The behavioural results showed that adolescents were more impulsive than adults in the DDT. The ERP results showed that, whilst both groups valued immediate rewards, implied by a similarly strong feedback-related negativity (FRN) effect associated with immediate outcomes, adolescents devalued delayed rewards more than adults did, as they produced a significantly smaller FRN effect associated with delayed outcomes. As predicted, the mediation analysis revealed that the adolescents’ lower FRN effect of delayed outcomes underpinned their stronger impulsive decision making in the DDT. PMID:28198452

  18. Preferences for fixed and variable food sources: variability in amount and delay.

    PubMed Central

    Bateson, M; Kacelnik, A

    1995-01-01

    Much research has focused on the effects of environmental variability on foraging decisions. However, the general pattern of preference for variability in delay to reward and aversion to variability in amount of reward remains unexplained a either a mechanistic or a functional level. Starlings' preferences between a fixed and a variable option were studied in two treatments, A and D. The fixed option was the same in both treatments (20-s fixed-interval delay, five units food). In Treatment A the variable option gave two equiprobable amounts of food (20-s delay, three or seven units) and in D it gave two equiprobable delays to food (2.5-s or 60.5-s delays, five units). In both treatments the programmed ratio [amount/(intertrial interval+latency+delay)] in the fixed option equaled the arithmetic mean of the two possible ratios in the variable option (ITI = 40 s, latency = 1 s). The variable option was strongly preferred in Treatment D and was weakly avoided in Treatment A. These results are discussed in the light of two theoretical models, a form of constrained rate maximization and a version of scalar expectancy theory. The latter accommodates more of the data and is based on independently verifiable assumptions, including Weber's law. PMID:7751835

  19. Undervaluing delayed rewards explains adolescents' impulsivity in inter-temporal choice: an ERP study.

    PubMed

    Huang, Yunyun; Hu, Ping; Li, Xueting

    2017-02-15

    Adolescence has frequently been characterized as a period of choice impulsivity relative to adulthood. According to the control-integrated valuation model of inter-temporal choice, this choice impulsivity may be driven partly by an age-related difference in reward processing. We hypothesized that, compared to adults, adolescents would undervalue delayed rewards during reward processing and would thus be more impulsive in inter-temporal choice. To test this hypothesis at the behavioural and neural levels, we first measured the choice impulsivity of 18 adolescents and 19 adults using a delay discounting task (DDT). Then, we recorded event-related potentials (ERPs) from the participants while they were performing the valuation task, in which monetary gains and losses were either immediate or delayed. The behavioural results showed that adolescents were more impulsive than adults in the DDT. The ERP results showed that, whilst both groups valued immediate rewards, implied by a similarly strong feedback-related negativity (FRN) effect associated with immediate outcomes, adolescents devalued delayed rewards more than adults did, as they produced a significantly smaller FRN effect associated with delayed outcomes. As predicted, the mediation analysis revealed that the adolescents' lower FRN effect of delayed outcomes underpinned their stronger impulsive decision making in the DDT.

  20. Delay differential analysis of time series.

    PubMed

    Lainscsek, Claudia; Sejnowski, Terrence J

    2015-03-01

    Nonlinear dynamical system analysis based on embedding theory has been used for modeling and prediction, but it also has applications to signal detection and classification of time series. An embedding creates a multidimensional geometrical object from a single time series. Traditionally either delay or derivative embeddings have been used. The delay embedding is composed of delayed versions of the signal, and the derivative embedding is composed of successive derivatives of the signal. The delay embedding has been extended to nonuniform embeddings to take multiple timescales into account. Both embeddings provide information on the underlying dynamical system without having direct access to all the system variables. Delay differential analysis is based on functional embeddings, a combination of the derivative embedding with nonuniform delay embeddings. Small delay differential equation (DDE) models that best represent relevant dynamic features of time series data are selected from a pool of candidate models for detection or classification. We show that the properties of DDEs support spectral analysis in the time domain where nonlinear correlation functions are used to detect frequencies, frequency and phase couplings, and bispectra. These can be efficiently computed with short time windows and are robust to noise. For frequency analysis, this framework is a multivariate extension of discrete Fourier transform (DFT), and for higher-order spectra, it is a linear and multivariate alternative to multidimensional fast Fourier transform of multidimensional correlations. This method can be applied to short or sparse time series and can be extended to cross-trial and cross-channel spectra if multiple short data segments of the same experiment are available. Together, this time-domain toolbox provides higher temporal resolution, increased frequency and phase coupling information, and it allows an easy and straightforward implementation of higher-order spectra across time

  1. Delaying an appendectomy: is it safe?

    PubMed

    Nagpal, Kamal; Udgiri, Navalkishor; Sharma, Niraj; Curras, Ernesto; Cosgrove, John Morgan; Farkas, Daniel T

    2012-08-01

    Appendicitis has always been an indication for an urgent operation, as delay is thought to lead to disease progression and therefore worse outcomes. Recent studies suggest that appendectomy can be delayed slightly without worse outcomes, however the literature is contradictory. The goal of our study was to examine the relationship between this delay to surgery and patient outcomes. We reviewed all patients that underwent an appendectomy in our institution from January 2009 to December 2010. We recorded the time of surgical diagnosis from when both the surgical consult and the CT scan (if done) were completed. The delay from surgical diagnosis to incision was measured, and patients were divided into two groups: early (≤6 hours delay) and late (>6 hours delay). Outcome measures were 30-day complication rate, length of stay, perforation rate, and laparoscopic to open conversion rate. Three hundred and seventy-seven patients had appendectomies in the study period, and 35 patients were excluded as per the exclusion criteria leaving 342 in the study: 269 (78.7%) in the early group and 73 (21.3%) in the late group. Complications occurred in 21 patients (6.1%) with no difference between the groups: 16/253 (5.9%) in the early group and 5/73 (6.8%) in the late group (P = 0.93, χ(2)). The mean (± standard deviation) length of stay was 86.1 ± 67.1 hours in the early group, and 95.9 ± 73.0 hours in the late group. This difference was not significant (P = 0.22). Delaying an appendectomy more than 6 hours, but less than 24 hours from diagnosis is safe and does not lead to worse outcomes. This can help limit the disruption to the schedules of both the surgeon and the operating room.

  2. Transfer delays in a SIMA network

    NASA Astrophysics Data System (ADS)

    Ruutu, Jussi P. O.; Kilkki, Kalevi; Strandberg, Ove

    1998-12-01

    Differentiated Services approach has been recently proposed for providing Quality of Service in Internet. Simple Integrated Media Access is a network service concept that use this approach by utilizing priority bits in packet headers. Three drop preference bits are used for making the decision about packets to be discarded when congestion arises in a core network node. A single delay indication bit marks the packet either as belonging to a realtime or non real time flow. The acceptance of packets is not directly connected with real time properties of a packet. The real time support of SIMA is based on two features. First, real time packets are placed to a short real time buffer inside a core network node. Secondly, the real time buffer is always emptied before the longer, non real time buffer. This means a shorter queuing delay for real time packets. For the successful operation of the network it is crucial to have small enough transfer delay for real time packets. On the other hand, the difference in transfer delay must be significant enough between real time and non real time service in order to justify their existence. Finally, there is also the question, whether real time packets can block non real time flows since the real time packets are always transmitted first in a SIMA node. To answer these questions this paper addresses the issues related with transfer delay of packets over a SIMA network. We present extensive simulation results about the transfer delay distributions in order to provide insight into SIMA and transfer delays.

  3. Delay Differential Analysis of Time Series

    PubMed Central

    Lainscsek, Claudia; Sejnowski, Terrence J.

    2015-01-01

    Nonlinear dynamical system analysis based on embedding theory has been used for modeling and prediction, but it also has applications to signal detection and classification of time series. An embedding creates a multidimensional geometrical object from a single time series. Traditionally either delay or derivative embeddings have been used. The delay embedding is composed of delayed versions of the signal, and the derivative embedding is composed of successive derivatives of the signal. The delay embedding has been extended to nonuniform embeddings to take multiple timescales into account. Both embeddings provide information on the underlying dynamical system without having direct access to all the system variables. Delay differential analysis is based on functional embeddings, a combination of the derivative embedding with nonuniform delay embeddings. Small delay differential equation (DDE) models that best represent relevant dynamic features of time series data are selected from a pool of candidate models for detection or classification. We show that the properties of DDEs support spectral analysis in the time domain where nonlinear correlation functions are used to detect frequencies, frequency and phase couplings, and bispectra. These can be efficiently computed with short time windows and are robust to noise. For frequency analysis, this framework is a multivariate extension of discrete Fourier transform (DFT), and for higher-order spectra, it is a linear and multivariate alternative to multidimensional fast Fourier transform of multidimensional correlations. This method can be applied to short or sparse time series and can be extended to cross-trial and cross-channel spectra if multiple short data segments of the same experiment are available. Together, this time-domain toolbox provides higher temporal resolution, increased frequency and phase coupling information, and it allows an easy and straightforward implementation of higher-order spectra across time

  4. Facilitating tolerance of delayed reinforcement during functional communication training.

    PubMed

    Fisher, W W; Thompson, R H; Hagopian, L P; Bowman, L G; Krug, A

    2000-01-01

    Few clinical investigations have addressed the problem of delayed reinforcement. In this investigation, three individuals whose destructive behavior was maintained by positive reinforcement were treated using functional communication training (FCT) with extinction (EXT). Next, procedures used in the basic literature on delayed reinforcement and self-control (reinforcer delay fading, punishment of impulsive responding, and provision of an alternative activity during reinforcer delay) were used to teach participants to tolerate delayed reinforcement. With the first case, reinforcer delay fading alone was effective at maintaining low rates of destructive behavior while introducing delayed reinforcement. In the second case, the addition of a punishment component reduced destructive behavior to near-zero levels and facilitated reinforcer delay fading. With the third case, reinforcer delay fading was associated with increases in masturbation and head rolling, but prompting and praising the individual for completing work during the delay interval reduced all problem behaviors and facilitated reinforcer delay fading.

  5. Delay-dependent decentralised control for a class of uncertain similar interconnected systems with state delay and input delay

    NASA Astrophysics Data System (ADS)

    Ma, Yuechao; Jin, Shujie; Gu, Nannan

    2015-12-01

    In this paper, the problem of delay-dependent decentralised control for a class of uncertain similar interconnected systems is investigated, where not only the state vectors but also the input vectors involve time delay. The new similar structure is presented via state feedback, based on which, by exploiting the structure of interconnected systems, the new integral inequalities, constrained Lyapunov equations and LMI method, the decentralised stabilization controllers are designed, which is dependent on time delays, to stabilise the interconnected systems uniformly asymptotically. The results show that the design is easy to calculate and the controllers have the similar structure, so it is easy to realise project. Finally, a numerical example is given to demonstrate the effectiveness of the results obtained in this paper.

  6. Stochastic functional differential equations with infinite delay: Existence and uniqueness of solutions, solution maps, Markov properties, and ergodicity

    NASA Astrophysics Data System (ADS)

    Wu, Fuke; Yin, George; Mei, Hongwei

    2017-02-01

    This work is devoted to stochastic functional differential equations (SFDEs) with infinite delay. First, existence and uniqueness of the solutions of such equations are examined. Because the solutions of the delay equations are not Markov, a viable alternative for studying further asymptotic properties is to use solution maps or segment processes. By examining solution maps, this work investigates the Markov properties as well as the strong Markov properties. Also obtained are adaptivity and continuity, mean-square boundedness, and convergence of solution maps from different initial data. This paper then examines the ergodicity of underlying processes and establishes existence of the invariant measure for SFDEs with infinite delay under suitable conditions.

  7. Tunneling Time and Weak Measurement in Strong Field Ionization

    NASA Astrophysics Data System (ADS)

    Zimmermann, Tomáš; Mishra, Siddhartha; Doran, Brent R.; Gordon, Daniel F.; Landsman, Alexandra S.

    2016-06-01

    Tunneling delays represent a hotly debated topic, with many conflicting definitions and little consensus on when and if such definitions accurately describe the physical observables. Here, we relate these different definitions to distinct experimental observables in strong field ionization, finding that two definitions, Larmor time and Bohmian time, are compatible with the attoclock observable and the resonance lifetime of a bound state, respectively. Both of these definitions are closely connected to the theory of weak measurement, with Larmor time being the weak measurement value of tunneling time and Bohmian trajectory corresponding to the average particle trajectory, which has been recently reconstructed using weak measurement in a two-slit experiment [S. Kocsis, B. Braverman, S. Ravets, M. J. Stevens, R. P. Mirin, L. K. Shalm, and A. M. Steinberg, Science 332, 1170 (2011)]. We demonstrate a big discrepancy in strong field ionization between the Bohmian and weak measurement values of tunneling time, and we suggest this arises because the tunneling time is calculated for a small probability postselected ensemble of electrons. Our results have important implications for the interpretation of experiments in attosecond science, suggesting that tunneling is unlikely to be an instantaneous process.

  8. Scalable service architecture for providing strong service guarantees

    NASA Astrophysics Data System (ADS)

    Christin, Nicolas; Liebeherr, Joerg

    2002-07-01

    For the past decade, a lot of Internet research has been devoted to providing different levels of service to applications. Initial proposals for service differentiation provided strong service guarantees, with strict bounds on delays, loss rates, and throughput, but required high overhead in terms of computational complexity and memory, both of which raise scalability concerns. Recently, the interest has shifted to service architectures with low overhead. However, these newer service architectures only provide weak service guarantees, which do not always address the needs of applications. In this paper, we describe a service architecture that supports strong service guarantees, can be implemented with low computational complexity, and only requires to maintain little state information. A key mechanism of the proposed service architecture is that it addresses scheduling and buffer management in a single algorithm. The presented architecture offers no solution for controlling the amount of traffic that enters the network. Instead, we plan on exploiting feedback mechanisms of TCP congestion control algorithms for the purpose of regulating the traffic entering the network.

  9. Tunneling Time and Weak Measurement in Strong Field Ionization.

    PubMed

    Zimmermann, Tomáš; Mishra, Siddhartha; Doran, Brent R; Gordon, Daniel F; Landsman, Alexandra S

    2016-06-10

    Tunneling delays represent a hotly debated topic, with many conflicting definitions and little consensus on when and if such definitions accurately describe the physical observables. Here, we relate these different definitions to distinct experimental observables in strong field ionization, finding that two definitions, Larmor time and Bohmian time, are compatible with the attoclock observable and the resonance lifetime of a bound state, respectively. Both of these definitions are closely connected to the theory of weak measurement, with Larmor time being the weak measurement value of tunneling time and Bohmian trajectory corresponding to the average particle trajectory, which has been recently reconstructed using weak measurement in a two-slit experiment [S. Kocsis, B. Braverman, S. Ravets, M. J. Stevens, R. P. Mirin, L. K. Shalm, and A. M. Steinberg, Science 332, 1170 (2011)]. We demonstrate a big discrepancy in strong field ionization between the Bohmian and weak measurement values of tunneling time, and we suggest this arises because the tunneling time is calculated for a small probability postselected ensemble of electrons. Our results have important implications for the interpretation of experiments in attosecond science, suggesting that tunneling is unlikely to be an instantaneous process.

  10. Strong reflector-based beamforming in ultrasound medical imaging.

    PubMed

    Szasz, Teodora; Basarab, Adrian; Kouamé, Denis

    2016-03-01

    This paper investigates the use of sparse priors in creating original two-dimensional beamforming methods for ultrasound imaging. The proposed approaches detect the strong reflectors from the scanned medium based on the well known Bayesian Information Criteria used in statistical modeling. Moreover, they allow a parametric selection of the level of speckle in the final beamformed image. These methods are applied on simulated data and on recorded experimental data. Their performance is evaluated considering the standard image quality metrics: contrast ratio (CR), contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR). A comparison is made with the classical delay-and-sum and minimum variance beamforming methods to confirm the ability of the proposed methods to precisely detect the number and the position of the strong reflectors in a sparse medium and to accurately reduce the speckle and highly enhance the contrast in a non-sparse medium. We confirm that our methods improve the contrast of the final image for both simulated and experimental data. In all experiments, the proposed approaches tend to preserve the speckle, which can be of major interest in clinical examinations, as it can contain useful information. In sparse mediums we achieve a highly improvement in contrast compared with the classical methods.

  11. Coherent Dynamics Following Strong Field Ionization of Polyatomic Molecules

    NASA Astrophysics Data System (ADS)

    Konar, Arkaprabha; Shu, Yinan; Lozovoy, Vadim; Jackson, James; Levine, Benjamin; Dantus, Marcos

    2015-03-01

    Molecules, as opposed to atoms, present confounding possibilities of nuclear and electronic motion upon strong field ionization. The dynamics and fragmentation patterns in response to the laser field are structure sensitive; therefore, a molecule cannot simply be treated as a ``bag of atoms'' during field induced ionization. We consider here to what extent molecules retain their molecular identity and properties under strong laser fields. Using time-of-flight mass spectrometry in conjunction with pump-probe techniques we study the dynamical behavior of these molecules, monitoring ion yield modulation caused by intramolecular motions post ionization. The delay scans show that among positional isomers the variations in relative energies, amounting to only a few hundred meVs, influence the dynamical behavior of the molecules despite their having experienced such high fields (V/Å). Ab initio calculations were performed to predict dynamics along with single and multiphoton resonances in the neutral and ionic states. We propose that single electron ionization occurs within an optical cycle with the electron carrying away essentially all of the energy, leaving behind little internal energy in the cation. Evidence for this observation comes from coherent vibrational motion governed by the potential energy surface of the ground state of the cation. Subsequent fragmentation of the cation takes place as a result of further photon absorption modulated by one- and two-photon resonances, which provide sufficient energy to overcome the dissociation energy.

  12. Single photon delayed feedback: a way to stabilize intrinsic quantum cavity electrodynamics.

    PubMed

    Carmele, Alexander; Kabuss, Julia; Schulze, Franz; Reitzenstein, Stephan; Knorr, Andreas

    2013-01-04

    We propose a scheme to control cavity quantum electrodynamics in the single photon limit by delayed feedback. In our approach a single emitter-cavity system, operating in the weak coupling limit, can be driven into the strong coupling-type regime by an external mirror: The external loop produces Rabi oscillations directly connected to the electron-photon coupling strength. As an expansion of typical cavity quantum electrodynamics, we treat the quantum correlation of external and internal light modes dynamically and demonstrate a possible way to implement a fully quantum mechanical time-delayed feedback. Our theoretical approach proposes a way to experimentally feedback control quantum correlations in the single photon limit.

  13. Test structures for propagation delay measurements on high-speed integrated circuits

    NASA Technical Reports Server (NTRS)

    Long, S. I.

    1984-01-01

    The accuracy of high-speed wafer-level measurements on digital IC's is limited by the probe interface. This limitation strongly encourages the use of built-in on-chip test hardware to reduce the number of critical off-chip high-speed interfaces. A novel synchronous propagation delay test structure is described which will provide accurate parametric data under typical automatic test conditions. Built-in test features added to complex combinational circuits are shown which are useful for delay measurement and which reduce the total number of high-speed I/O connections while still providing acceptable fault coverage in many cases.

  14. Does it Pay to Delay? Flesh Flies Show Adaptive Plasticity in Reproductive Timing

    PubMed Central

    Kristal, Ross; Netter, Fleta; Hatle, John D.; Hahn, Daniel A.

    2013-01-01

    Life-history plasticity is widespread among organisms. However, an important question is whether this plasticity is adaptive, enhancing the organism’s fitness. Most models for plasticity in life-history timing predict that once they have reached the minimal nutritional threshold animals under poor conditions will accelerate timing to development or reproduction. Adaptive delays in reproductive timing are not common, especially in short-lived species. Examples of adaptive reproductive delays exist in mammalian populations experiencing strong interspecific (e.g. predation) and intraspecific (e.g. infanticide) competition. But are there other environmental factors that may trigger an adaptive delay in reproductive timing? We show that the short-lived flesh fly Sarcophaga crassipalpis will delay reproductive timing under nutrient poor conditions, even though it has already met the minimal nutritional threshold for reproduction. We test if this delay strategy is consistent with an adaptive response allowing the scavenger time to locate more resources by providing additional protein pulses (early, mid and late) throughout the reproductive delay period. Flies receiving additional protein produced more eggs and larger eggs, demonstrating a benefit of the delay. In addition, by tracking the allocation of carbon from the pulses using stable isotopes, we show that flies receiving earlier pulses incorporated more carbon into eggs and somatic tissue than those provided a later pulse. These results indicate that the reproductive delay in S. crassipalpis is consistent with adaptive post-threshold plasticity, a nutritionally-linked reproductive strategy that has not been previously reported in an invertebrate species. PMID:20953961

  15. Screening for language delay after life-saving therapies in term-born infants.

    PubMed

    Clark, Brenda G; Acton, Bryan V; Alton, Gwen Y; Joffe, Ari R; Dinu, Irina A; Robertson, Charlene M T

    2016-10-01

    Strong recommendations have been made for the periodic developmental surveillance, screening, and evaluation of children with CHD. This supports similar calls for all at-risk children in order to provide timely, structured early developmental intervention that may improve outcomes. The aim of this study was to determine the accuracy of screening for language delay after life-saving therapies using the parent-completed vocabulary screen of the language Development Survey, by comparing screening with the individually administered language scores of the Bayley Scales of Infant and Toddler Development, Third edition. In total, 310 (92.5%) of 335 eligible term-born children, born between 2004 and 2011, receiving complex cardiac surgery, heart or liver transplantation, or extracorporeal membrane oxygenation in infancy, were assessed at 21.5 (2.8) months of age (lost, 25 (7.5%)), through developmental/rehabilitation centres at six sites as part of the Western Canadian Complex Pediatric Therapies Follow-up Group. Vocabulary screening delay was defined as scores ⩽15th percentile. Language delay defined as scores >1 SD below the mean was calculated for language composite score, receptive and expressive communication scores of the Bayley-III. Delayed scores for the 310 children were as follows: vocabulary, 144 (46.5%); language composite, 125 (40.3%); receptive communication, 98 (31.6%); and expressive communication, 124 (40%). Sensitivity, specificity, positive predictive values, and negative predictive values of screened vocabulary delay for tested language composite delay were 79.2, 75.7, 68.8, and 84.3%, respectively. High rates of language delay after life-saving therapies are concerning. Although the screening test appears to over-identify language delay relative to the tested Bayley-III, it may be a useful screening tool for early language development leading to earlier referral for intervention.

  16. Queues with Choice via Delay Differential Equations

    NASA Astrophysics Data System (ADS)

    Pender, Jamol; Rand, Richard H.; Wesson, Elizabeth

    Delay or queue length information has the potential to influence the decision of a customer to join a queue. Thus, it is imperative for managers of queueing systems to understand how the information that they provide will affect the performance of the system. To this end, we construct and analyze two two-dimensional deterministic fluid models that incorporate customer choice behavior based on delayed queue length information. In the first fluid model, customers join each queue according to a Multinomial Logit Model, however, the queue length information the customer receives is delayed by a constant Δ. We show that the delay can cause oscillations or asynchronous behavior in the model based on the value of Δ. In the second model, customers receive information about the queue length through a moving average of the queue length. Although it has been shown empirically that giving patients moving average information causes oscillations and asynchronous behavior to occur in U.S. hospitals, we analytically and mathematically show for the first time that the moving average fluid model can exhibit oscillations and determine their dependence on the moving average window. Thus, our analysis provides new insight on how operators of service systems should report queue length information to customers and how delayed information can produce unwanted system dynamics.

  17. [Diagnosis delay of pleural and pulmonary tuberculosis].

    PubMed

    Cherif, J; Mjid, M; Ladhar, A; Toujani, S; Mokadem, S; Louzir, B; Mehiri, N; Béji, M

    2014-08-01

    Tuberculosis (TB) is still being endemic in our country. Time until management determines both evolution and prognosis of this condition. The aim of this work is to evaluate the delay in diagnosis of TB in a respiratory unit from a university hospital series. The authors conducted a cross-sectional study including patients with pulmonary TBC and/or pleural. An evaluation of time management was conducted from the beginning of symptoms and various consultations with reference to the date of hospitalization and treatment set up. One hundred patients were included (pulmonary TB: 68 cases, pleural TB 23 cases, miliary pulmonary TB: 4 cases, pulmonary TB associated with other extrathoracic locations: 5 cases). The mean time of patient delay and total delay institution were respectively 43.6, 25.7 and 69.3 days. Variables responsible for long delays were: number of consultations more than 3 before hospitalization, empirical antibiotic therapy, of a regional hospital first consultation and the presence of extra-respiratory impairment. The patient delay was considered long. A reorganization of the TB control program, in particular by partial decentralization of care and health education is imperative in order to improve the quality of tuberculosis management in our country.

  18. Intrinsic delay of permeable base transistor

    SciTech Connect

    Chen, Wenchao; Guo, Jing; So, Franky

    2014-07-28

    Permeable base transistors (PBTs) fabricated by vacuum deposition or solution process have the advantages of easy fabrication and low power operation and are a promising device structure for flexible electronics. Intrinsic delay of PBT, which characterizes the speed of the transistor, is investigated by solving the three-dimensional Poisson equation and drift-diffusion equation self-consistently using finite element method. Decreasing the emitter thickness lowers the intrinsic delay by improving on-current, and a thinner base is also preferred for low intrinsic delay because of fewer carriers in the base region at off-state. The intrinsic delay exponentially decreases as the emitter contact Schottky barrier height decreases, and it linearly depends on the carrier mobility. With an optimized emitter contact barrier height and device geometry, a sub-nano-second intrinsic delay can be achieved with a carrier mobility of ∼10 cm{sup 2}/V/s obtainable in solution processed indium gallium zinc oxide, which indicates the potential of solution processed PBTs for GHz operations.

  19. Data Assimilation by delay-coordinate nudging

    NASA Astrophysics Data System (ADS)

    Pazo, Diego; Lopez, Juan Manuel; Carrassi, Alberto

    2016-04-01

    A new nudging method for data assimilation, delay-coordinate nudging, is presented. Delay-coordinate nudging makes explicit use of present and past observations in the formulation of the forcing driving the model evolution at each time-step. Numerical experiments with a low order chaotic system show that the new method systematically outperforms standard nudging in different model and observational scenarios, also when using an un-optimized formulation of the delay-nudging coefficients. A connection between the optimal delay and the dominant Lyapunov exponent of the dynamics is found based on heuristic arguments and is confirmed by the numerical results, providing a guideline for the practical implementation of the algorithm. Delay-coordinate nudging preserves the easiness of implementation, the intuitive functioning and the reduced computational cost of the standard nudging, making it a potential alternative especially in the field of seasonal-to-decadal predictions with large Earth system models that limit the use of more sophisticated data assimilation procedures.

  20. Ataxia telangiectasia: presentation and diagnostic delay.

    PubMed

    Devaney, Rebecca; Pasalodos, Sara; Suri, Mohnish; Bush, Andy; Bhatt, Jayesh M

    2017-04-01

    Ataxia telangiectasia (A-T) is a rare progressive, multisystem genetic disease. Families of children with ultra-rare diseases often experience significant diagnostic delays. We reviewed the diagnostic process for A-T in order to identify causes of delay in an attempt to facilitate earlier identification of A-T in the future. A retrospective case note review of 79 children at the National Paediatric A-T clinic seen since May 2009. Data were collected on the nature and age of initial symptoms, the age at first presentation, measurement of alpha feto-protein (AFP) and age of genetic diagnostic confirmation. At presentation, 71 children (90%) had ataxia. The median presentation delay (from first parental concern to presentation) was 8 months (range 0-118 months), and the median diagnostic delay (genetic confirmation of diagnosis) was 12 months (range 1-109 months). There are significant delays in presentation and diagnostic confirmation of A-T. A greater awareness of A-T and early measurement of AFP may help to improve this. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  1. Theory of attosecond delays in molecular photoionization

    NASA Astrophysics Data System (ADS)

    Baykusheva, Denitsa; Wörner, Hans Jakob

    2017-03-01

    We present a theoretical formalism for the calculation of attosecond delays in molecular photoionization. It is shown how delays relevant to one-photon-ionization, also known as Eisenbud-Wigner-Smith delays, can be obtained from the complex dipole matrix elements provided by molecular quantum scattering theory. These results are used to derive formulae for the delays measured by two-photon attosecond interferometry based on an attosecond pulse train and a dressing femtosecond infrared pulse. These effective delays are first expressed in the molecular frame where maximal information about the molecular photoionization dynamics is available. The effects of averaging over the emission direction of the electron and the molecular orientation are introduced analytically. We illustrate this general formalism for the case of two polyatomic molecules. N2O serves as an example of a polar linear molecule characterized by complex photoionization dynamics resulting from the presence of molecular shape resonances. H2O illustrates the case of a non-linear molecule with comparably simple photoionization dynamics resulting from a flat continuum. Our theory establishes the foundation for interpreting measurements of the photoionization dynamics of all molecules by attosecond metrology.

  2. Keeping Marriages Strong in Challenging Times

    ERIC Educational Resources Information Center

    Ober, Marci Wolff

    2009-01-01

    What makes a strong marriage anyway...? There are definite qualities that exist in healthy marriages, that is, a marriage that is defined by both partners to be "mostly" or "usually" very satisfying. This article explores these qualities and looks at what really works to make and keep marriages strong, healthy, and satisfying…

  3. Keeping Marriages Strong in Challenging Times

    ERIC Educational Resources Information Center

    Ober, Marci Wolff

    2009-01-01

    What makes a strong marriage anyway...? There are definite qualities that exist in healthy marriages, that is, a marriage that is defined by both partners to be "mostly" or "usually" very satisfying. This article explores these qualities and looks at what really works to make and keep marriages strong, healthy, and satisfying…

  4. 78 FR 15710 - Strong Sensitizer Guidance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ... supplemental definition of ``strong sensitizer'' due to advancements in the science of sensitization that have... sensitization and made recommendations for proposed changes to the current definition, which eliminate... sensitization characteristics of substances, rank the criteria for classification of strong sensitizers in order...

  5. On the Strong Direct Summand Conjecture

    ERIC Educational Resources Information Center

    McCullough, Jason

    2009-01-01

    In this thesis, our aim is the study the Vanishing of Maps of Tor Conjecture of Hochster and Huneke. We mainly focus on an equivalent characterization called the Strong Direct Summand Conjecture, due to N. Ranganathan. Our results are separated into three chapters. In Chapter 3, we prove special cases of the Strong Direct Summand Conjecture in…

  6. Holographic equilibration at strong and intermediate coupling

    SciTech Connect

    Vuorinen, Aleksi

    2016-01-22

    In these conference proceedings, I will descibe recent developments in the study of thermalization dynamics in strongly, but not infinitely strongly coupled field theories using holography. After reviewing the main tools required in these calculations, I will introduce a set of central results, discuss their physical implications, and finally outline a number of challenges to be tackled in the future.

  7. Strong diamagnetism of normal metals and superconductivity

    NASA Astrophysics Data System (ADS)

    Abramov, O. V.; Gradov, O. M.; Kyrie, A. Yu

    1992-07-01

    The theory of strong diamagnetism of metals caused by the formation of a superlattice with the period being much larger than the crystal cell size has been developed. Strong diamagnetism has been shown to be the cause of the superconductivity of metals.

  8. On the Strong Direct Summand Conjecture

    ERIC Educational Resources Information Center

    McCullough, Jason

    2009-01-01

    In this thesis, our aim is the study the Vanishing of Maps of Tor Conjecture of Hochster and Huneke. We mainly focus on an equivalent characterization called the Strong Direct Summand Conjecture, due to N. Ranganathan. Our results are separated into three chapters. In Chapter 3, we prove special cases of the Strong Direct Summand Conjecture in…

  9. Seismic switch for strong motion measurement

    DOEpatents

    Harben, P.E.; Rodgers, P.W.; Ewert, D.W.

    1995-05-30

    A seismic switching device is described that has an input signal from an existing microseismic station seismometer and a signal from a strong motion measuring instrument. The seismic switch monitors the signal level of the strong motion instrument and passes the seismometer signal to the station data telemetry and recording systems. When the strong motion instrument signal level exceeds a user set threshold level, the seismometer signal is switched out and the strong motion signal is passed to the telemetry system. The amount of time the strong motion signal is passed before switching back to the seismometer signal is user controlled between 1 and 15 seconds. If the threshold level is exceeded during a switch time period, the length of time is extended from that instant by one user set time period. 11 figs.

  10. Seismic switch for strong motion measurement

    DOEpatents

    Harben, Philip E.; Rodgers, Peter W.; Ewert, Daniel W.

    1995-01-01

    A seismic switching device that has an input signal from an existing microseismic station seismometer and a signal from a strong motion measuring instrument. The seismic switch monitors the signal level of the strong motion instrument and passes the seismometer signal to the station data telemetry and recording systems. When the strong motion instrument signal level exceeds a user set threshold level, the seismometer signal is switched out and the strong motion signal is passed to the telemetry system. The amount of time the strong motion signal is passed before switching back to the seismometer signal is user controlled between 1 and 15 seconds. If the threshold level is exceeded during a switch time period, the length of time is extended from that instant by one user set time period.

  11. Runoff delay exerts a strong control on the field-scale removal of manure-borne fecal bacteria with runoff

    USDA-ARS?s Scientific Manuscript database

    The microbial safety of surface waters is an ongoing issue which is threatened by the transport of manure-borne bacteria to water sources used for irrigation or recreation. Predictive modeling has become an effective tool to forecast the microbial quality of water during precipitation events, howeve...

  12. Runoff delay exerts a strong control on the field-scale removal of manure-borne fecal bacteria with runoff

    USDA-ARS?s Scientific Manuscript database

    The microbial safety of surface waters is an ongoing issue which is threatened by the transport of manure-borne bacteria to water sources used for irrigation or recreation. Predictive modeling has become an effective tool to forecast the microbial quality of water duringprecipitation events, however...

  13. Adaptive synchronization of neural networks with time-varying delay and distributed delay

    NASA Astrophysics Data System (ADS)

    Wang, Kai; Teng, Zhidong; Jiang, Haijun

    2008-01-01

    In this paper, the adaptive synchronization of neural networks with time-varying delay and distributed delay is discussed. Based on the LaSalle invariant principle of functional differential equations and the adaptive feedback control technique, some sufficient conditions for adaptive synchronization of such a system are obtained. Finally, a numerical example is given to show the effectiveness of the proposed synchronization method.

  14. Advanced Transport Delay Compensation Algorithms: Results of Delay Measurement and Piloted Performance Tests

    NASA Technical Reports Server (NTRS)

    Guo, Liwen; Cardullo, Frank M.; Kelly, Lon C.

    2007-01-01

    This report summarizes the results of delay measurement and piloted performance tests that were conducted to assess the effectiveness of the adaptive compensator and the state space compensator for alleviating the phase distortion of transport delay in the visual system in the VMS at the NASA Langley Research Center. Piloted simulation tests were conducted to assess the effectiveness of two novel compensators in comparison to the McFarland predictor and the baseline system with no compensation. Thirteen pilots with heterogeneous flight experience executed straight-in and offset approaches, at various delay configurations, on a flight simulator where different predictors were applied to compensate for transport delay. The glideslope and touchdown errors, power spectral density of the pilot control inputs, NASA Task Load Index, and Cooper-Harper rating of the handling qualities were employed for the analyses. The overall analyses show that the adaptive predictor results in slightly poorer compensation for short added delay (up to 48 ms) and better compensation for long added delay (up to 192 ms) than the McFarland compensator. The analyses also show that the state space predictor is fairly superior for short delay and significantly superior for long delay than the McFarland compensator.

  15. The Effects of Delay of Feedback on a Delayed Concept Formation Transfer Task.

    ERIC Educational Resources Information Center

    Schroth, Marvin L.

    1992-01-01

    Delay and completeness of verbal information feedback were investigated within a transfer of learning paradigm involving concept formation. An experiment with 192 undergraduates indicates that, although delay of feedback (up to 30 seconds) slows speed of learning on the initial task, it has positive effects on the transfer task. (SLD)

  16. Delayed switching applied to memristor neural networks

    SciTech Connect

    Wang, Frank Z.; Yang Xiao; Lim Guan; Helian Na; Wu Sining; Guo Yike; Rashid, Md Mamunur

    2012-04-01

    Magnetic flux and electric charge are linked in a memristor. We reported recently that a memristor has a peculiar effect in which the switching takes place with a time delay because a memristor possesses a certain inertia. This effect was named the ''delayed switching effect.'' In this work, we elaborate on the importance of delayed switching in a brain-like computer using memristor neural networks. The effect is used to control the switching of a memristor synapse between two neurons that fire together (the Hebbian rule). A theoretical formula is found, and the design is verified by a simulation. We have also built an experimental setup consisting of electronic memristive synapses and electronic neurons.

  17. Cola beverage and delayed elimination of methotrexate

    PubMed Central

    Santucci, Raoul; Levêque, Dominique; Herbrecht, Raoul

    2010-01-01

    AIMS To report a case of severe delayed methotrexate elimination attributable to consumption of a cola beverage. METHODS To investigate unexplained low urinary pH in a lymphoma patient treated with high-dose methotrexate. RESULTS Unexpected urinary acidity, despite administration of large amounts of sodium bicarbonate, could be attributed to repeated consumption of a cola beverage. It resulted in a delayed elimination of methotrexate and acute renal failure. Discontinuation of cola drinks, increase in calcium folinate rescue and in sodium bicarbonate allowed satisfactory elimination of methotrexate on day 12 after infusion and recovery from renal impairment without other severe toxicity. No other cause of delay in methotrexate elimination could be identified. CONCLUSIONS Cola beverages have a low pH due to their phosphoric acid content that is excreted by renal route. We recommend patients receiving high dose methotrexate abstain from any cola drink within 24 h before and during methotrexate administration and until complete elimination of the drug. PMID:21545633

  18. Parallel acoustic delay lines for photoacoustic tomography

    PubMed Central

    Yapici, Murat Kaya; Kim, Chulhong; Chang, Cheng-Chung; Jeon, Mansik; Guo, Zijian; Cai, Xin

    2012-01-01

    Abstract. Achieving real-time photoacoustic (PA) tomography typically requires multi-element ultrasound transducer arrays and their associated multiple data acquisition (DAQ) electronics to receive PA waves simultaneously. We report the first demonstration of a photoacoustic tomography (PAT) system using optical fiber-based parallel acoustic delay lines (PADLs). By employing PADLs to introduce specific time delays, the PA signals (on the order of a few micro seconds) can be forced to arrive at the ultrasonic transducers at different times. As a result, time-delayed PA signals in multiple channels can be ultimately received and processed in a serial manner with a single-element transducer, followed by single-channel DAQ electronics. Our results show that an optically absorbing target in an optically scattering medium can be photoacoustically imaged using the newly developed PADL-based PAT system. Potentially, this approach could be adopted to significantly reduce the complexity and cost of ultrasonic array receiver systems. PMID:23139043

  19. Why do delayed summaries improve metacomprehension accuracy?

    PubMed

    Anderson, Mary C M; Thiede, Keith W

    2008-05-01

    We showed that metacomprehension accuracy improved when participants (N=87 college students) wrote summaries of texts prior to judging their comprehension; however, accuracy only improved when summaries were written after a delay, not when written immediately after reading. We evaluated two hypotheses proposed to account for this delayed-summarization effect (the accessibility hypothesis and the situation model hypothesis). The data suggest that participants based metacomprehension judgments more on the gist of texts when they generated summaries after a delay; whereas, they based judgments more on details when they generated summaries immediately after reading. Focusing on information relevant to the situation model of a text (the gist of a text) produced higher levels of metacomprehension accuracy, which is consistent with situation model hypothesis.

  20. Delayed feedback control in quantum transport.

    PubMed

    Emary, Clive

    2013-09-28

    Feedback control in quantum transport has been predicted to give rise to several interesting effects, among them quantum state stabilization and the realization of a mesoscopic Maxwell's daemon. These results were derived under the assumption that control operations on the system are affected instantaneously after the measurement of electronic jumps through it. In this contribution, I describe how to include a delay between detection and control operation in the master equation theory of feedback-controlled quantum transport. I investigate the consequences of delay for the state stabilization and Maxwell's daemon schemes. Furthermore, I describe how delay can be used as a tool to probe coherent oscillations of electrons within a transport system and how this formalism can be used to model finite detector bandwidth.

  1. Discounting of delayed rewards is not hyperbolic.

    PubMed

    Luhmann, Christian C

    2013-07-01

    Delay discounting refers to decision-makers' tendency to value immediately available goods more than identical goods available only after some delay. In violation of standard economic theory, decision-makers frequently exhibit dynamic inconsistency; their preferences change simply due to the passage of time. The standard explanation for this behavior has appealed to the nature of decision-makers' discount functions, specifically positing a hyperbolic discount function. Though this explanation has been largely accepted, there has been surprisingly little work examining whether preference reversals are actually consistent with hyperbolic discounting. The current study holds hyperbolic discounting to the same empirical standard that exponential discounting has been held to and finds that choice behavior is not consistent with hyperbolic discounting. Despite the overwhelming focus placed on hyperbolic discounting, the current findings cast doubt on hyperbolic discounting as an explanation of decision-makers' undesirable preference reversals and as an explanation of delay discounting behavior in general.

  2. Delayed switching applied to memristor neural networks

    NASA Astrophysics Data System (ADS)

    Wang, Frank Z.; Helian, Na; Wu, Sining; Yang, Xiao; Guo, Yike; Lim, Guan; Rashid, Md Mamunur

    2012-04-01

    Magnetic flux and electric charge are linked in a memristor. We reported recently that a memristor has a peculiar effect in which the switching takes place with a time delay because a memristor possesses a certain inertia. This effect was named the "delayed switching effect." In this work, we elaborate on the importance of delayed switching in a brain-like computer using memristor neural networks. The effect is used to control the switching of a memristor synapse between two neurons that fire together (the Hebbian rule). A theoretical formula is found, and the design is verified by a simulation. We have also built an experimental setup consisting of electronic memristive synapses and electronic neurons.

  3. HLA and Delayed Drug-Induced Hypersensitivity.

    PubMed

    Sousa-Pinto, Bernardo; Correia, Cláudia; Gomes, Lídia; Gil-Mata, Sara; Araújo, Luís; Correia, Osvaldo; Delgado, Luís

    2016-01-01

    Delayed drug allergy reactions (DDAR) are potentially fatal. Certain human leukocyte antigen (HLA) alleles have been associated with delayed allergy reactions following the administration of particular drugs. Examples are HLA-B*57:01 (abacavir), HLA-B*15:02/HLA-A*31:01 (carbamazepine), and HLA-B*58:01 (allopurinol). Based on the identification of these associations, it may now be possible to prevent certain allergy reactions that were, until recently, considered unpredictable. In this review, we will focus on the pharmacogenetics of the best-studied associations between specific HLA alleles and delayed allergy reactions and describe the pathogenesis models proposed so far. Finally, we will evaluate the genetic screening strategies available and discuss the clinical relevance of a better understanding of the immunogenetics and mechanisms involved in DDAR.

  4. Time-Delayed Quantum Feedback Control.

    PubMed

    Grimsmo, Arne L

    2015-08-07

    A theory of time-delayed coherent quantum feedback is developed. More specifically, we consider a quantum system coupled to a bosonic reservoir creating a unidirectional feedback loop. It is shown that the dynamics can be mapped onto a fictitious series of cascaded quantum systems, where the system is driven by past versions of itself. The derivation of this model relies on a tensor network representation of the system-reservoir time propagator. For concreteness, this general theory is applied to a driven two-level atom scattering into a coherent feedback loop. We demonstrate how delay effects can qualitatively change the dynamics of the atom and how quantum control can be implemented in the presence of time delays.

  5. A consensus dynamics with delay-induced instability can self-regulate for stability via agent regrouping

    NASA Astrophysics Data System (ADS)

    Hyong Koh, M.; Sipahi, Rifat

    2016-11-01

    Dynamics of many multi-agent systems is influenced by communication/activation delays τ. In the presence of delays, there exists a certain margin called the delay margin τ* , less than which system stability holds. This margin depends strongly on agents' dynamics and the agent network. In this article, three key elements, namely, the delay margin, network graph, and a distance threshold conditioning two agents' connectivity are considered in a multi-agent consensus dynamics under delay τ. We report that when the dynamics is unstable under this delay, its states can be naturally bounded, even for arbitrarily large threshold values, preventing agents to disperse indefinitely. This mechanism can also make the system recover stability in a self-regulating manner, mainly induced by network separation and enhanced delay margin. Under certain conditions, unstable consensus dynamics can keep separating into smaller stable subnetwork dynamics until all agents stabilize in their respective subnetworks. Results are then demonstrated on a previously validated robot coordination model, where specifically robustness of τ* is studied against the delay τinh inherently present in the orientation measurements of the robots. To this end, a mathematical framework to compute τ* with respect to τinh in quasi-state is developed, demonstrating that τ* can be sensitive to τinh, yet robot regrouping and stabilization of subnetworks is still possible.

  6. A consensus dynamics with delay-induced instability can self-regulate for stability via agent regrouping.

    PubMed

    Hyong Koh, M; Sipahi, Rifat

    2016-11-01

    Dynamics of many multi-agent systems is influenced by communication/activation delays τ. In the presence of delays, there exists a certain margin called the delay margin τ(*), less than which system stability holds. This margin depends strongly on agents' dynamics and the agent network. In this article, three key elements, namely, the delay margin, network graph, and a distance threshold conditioning two agents' connectivity are considered in a multi-agent consensus dynamics under delay τ. We report that when the dynamics is unstable under this delay, its states can be naturally bounded, even for arbitrarily large threshold values, preventing agents to disperse indefinitely. This mechanism can also make the system recover stability in a self-regulating manner, mainly induced by network separation and enhanced delay margin. Under certain conditions, unstable consensus dynamics can keep separating into smaller stable subnetwork dynamics until all agents stabilize in their respective subnetworks. Results are then demonstrated on a previously validated robot coordination model, where specifically robustness of τ(*) is studied against the delay τinh inherently present in the orientation measurements of the robots. To this end, a mathematical framework to compute τ(*) with respect to τinh in quasi-state is developed, demonstrating that τ(*) can be sensitive to τinh, yet robot regrouping and stabilization of subnetworks is still possible.

  7. Improved delay-leaping simulation algorithm for biochemical reaction systems with delays

    NASA Astrophysics Data System (ADS)

    Yi, Na; Zhuang, Gang; Da, Liang; Wang, Yifei

    2012-04-01

    In biochemical reaction systems dominated by delays, the simulation speed of the stochastic simulation algorithm depends on the size of the wait queue. As a result, it is important to control the size of the wait queue to improve the efficiency of the simulation. An improved accelerated delay stochastic simulation algorithm for biochemical reaction systems with delays, termed the improved delay-leaping algorithm, is proposed in this paper. The update method for the wait queue is effective in reducing the size of the queue as well as shortening the storage and access time, thereby accelerating the simulation speed. Numerical simulation on two examples indicates that this method not only obtains a more significant efficiency compared with the existing methods, but also can be widely applied in biochemical reaction systems with delays.

  8. Relation between delayed feedback and delay-coupled systems and its application to chaotic lasers

    SciTech Connect

    Soriano, Miguel C. Flunkert, Valentin; Fischer, Ingo

    2013-12-15

    We present a systematic approach to identify the similarities and differences between a chaotic system with delayed feedback and two mutually delay-coupled systems. We consider the general case in which the coupled systems are either unsynchronized or in a generally synchronized state, in contrast to the mostly studied case of identical synchronization. We construct a new time-series for each of the two coupling schemes, respectively, and present analytic evidence and numerical confirmation that these two constructed time-series are statistically equivalent. From the construction, it then follows that the distribution of time-series segments that are small compared to the overall delay in the system is independent of the value of the delay and of the coupling scheme. By focusing on numerical simulations of delay-coupled chaotic lasers, we present a practical example of our findings.

  9. Modeling of delays in PKPD: classical approaches and a tutorial for delay differential equations.

    PubMed

    Koch, Gilbert; Krzyzanski, Wojciech; Pérez-Ruixo, Juan Jose; Schropp, Johannes

    2014-08-01

    In pharmacokinetics/pharmacodynamics (PKPD) the measured response is often delayed relative to drug administration, individuals in a population have a certain lifespan until they maturate or the change of biomarkers does not immediately affects the primary endpoint. The classical approach in PKPD is to apply transit compartment models (TCM) based on ordinary differential equations to handle such delays. However, an alternative approach to deal with delays are delay differential equations (DDE). DDEs feature additional flexibility and properties, realize more complex dynamics and can complementary be used together with TCMs. We introduce several delay based PKPD models and investigate mathematical properties of general DDE based models, which serve as subunits in order to build larger PKPD models. Finally, we review current PKPD software with respect to the implementation of DDEs for PKPD analysis.

  10. Relation between delayed feedback and delay-coupled systems and its application to chaotic lasers

    SciTech Connect

    Soriano, Miguel C. Flunkert, Valentin; Fischer, Ingo

    2013-12-15

    We present a systematic approach to identify the similarities and differences between a chaotic system with delayed feedback and two mutually delay-coupled systems. We consider the general case in which the coupled systems are either unsynchronized or in a generally synchronized state, in contrast to the mostly studied case of identical synchronization. We construct a new time-series for each of the two coupling schemes, respectively, and present analytic evidence and numerical confirmation that these two constructed time-series are statistically equivalent. From the construction, it then follows that the distribution of time-series segments that are small compared to the overall delay in the system is independent of the value of the delay and of the coupling scheme. By focusing on numerical simulations of delay-coupled chaotic lasers, we present a practical example of our findings.

  11. Delayed Recompression for Decompression Sickness: Retrospective Analysis

    PubMed Central

    Hadanny, Amir; Fishlev, Gregori; Bechor, Yair; Bergan, Jacob; Friedman, Mony; Maliar, Amit; Efrati, Shai

    2015-01-01

    Introduction Most cases of decompression sickness (DCS) occur soon after surfacing, with 98% within 24 hours. Recompression using hyperbaric chamber should be administrated as soon as feasible in order to decrease bubble size and avoid further tissue injury. Unfortunately, there may be a significant time delay from surfacing to recompression. The time beyond which hyperbaric treatment is non effective is unclear. The aims of the study were first to evaluate the effect of delayed hyperbaric treatment, initiated more than 48h after surfacing for DCS and second, to evaluate the different treatment protocols. Methods From January 2000 to February 2014, 76 divers had delayed hyperbaric treatment (≥48h) for DCS in the Sagol center for Hyperbaric medicine and Research, Assaf-Harofeh Medical Center, Israel. Data were collected from their medical records and compared to data of 128 patients treated earlier than 48h after surfacing at the same hyperbaric institute. Results There was no significant difference, as to any of the baseline characteristics, between the delayed and early treatment groups. With respect to treatment results, at the delayed treatment divers, complete recovery was achieved in 76% of the divers, partial recovery in 17.1% and no improvement in 6.6%. Similar results were achieved when treatment started early, where 78% of the divers had complete recovery, 15.6% partial recovery and 6.2% no recovery. Delayed hyperbaric treatment using US Navy Table 6 protocol trended toward a better clinical outcome yet not statistically significant (OR=2.786, CI95%[0.896-8.66], p=0.07) compared to standard hyperbaric oxygen therapy of 90 minutes at 2 ATA, irrespective of the symptoms severity at presentation. Conclusions Late recompression for DCS, 48 hours or more after surfacing, has clinical value and when applied can achieve complete recovery in 76% of the divers. It seems that the preferred hyperbaric treatment protocol should be based on US Navy Table 6. PMID

  12. Fractional delay waveguide modeling of acoustic tubes

    NASA Astrophysics Data System (ADS)

    Vaelimaeki, V.

    The theme of this work is computational modeling of acoustic tubes. The models are intended to be used in a sound synthesizer based on physical modeling. Such a synthesizer could be used producing realistic sounds of, e.g., woodwind instruments or the human voice. This work deals with digital waveguide modeling of acoustic tubes, such as bores of musical woodwind instruments or the human vocal tract. The acoustic tube systems considered in this work are those consisting of a straight cylindrical or conical tube or of concatenated cylindrical or conical tube sections. Also, the joint of three tube sections is studied. Of special interest for our application is a junction where a side branch is connected to a cylindrical tube as it is needed in the simulation of finger holes of wood-wind instruments. All of the cylindrical tube models are described for both pressure and volume velocity. In the case of conical bores, only pressure waves are considered as models for volume velocity waves are more complicated. The basic waveguide models are extended by employing the concept of fractional delay, which means a delay smaller than a unit delay. The fractional delays are implemented using bandlimited interpolation. Applying fractional delay filtering techniques, a spatially discretized waveguide model is turned into a spatially continuous one. This implies that the length of the digital waveguide can be adjusted as accurately as required, and a change of the impedance of a waveguide may occur at any desired point between sampling points. The authors call this kind of system a fractional delay waveguide filter (FDWF). It is a discrete-time structure but a spatially continuous model of a physical system.

  13. 48 CFR 42.1304 - Government delay of work.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Government delay of work... CONTRACT MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Suspension of Work, Stop-Work Orders, and Government Delay of Work 42.1304 Government delay of work. (a) The clause at 52.242-17, Government Delay of...

  14. 48 CFR 42.1304 - Government delay of work.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Government delay of work... CONTRACT MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Suspension of Work, Stop-Work Orders, and Government Delay of Work 42.1304 Government delay of work. (a) The clause at 52.242-17, Government Delay of...

  15. 48 CFR 42.1304 - Government delay of work.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Government delay of work... CONTRACT MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Suspension of Work, Stop-Work Orders, and Government Delay of Work 42.1304 Government delay of work. (a) The clause at 52.242-17, Government Delay...

  16. Anomalous decay of photon echo in a quantum dot ensemble in the strong excitation regime

    SciTech Connect

    Suemori, Ryosuke; Ishi-Hayase, Junko; Akahane, Kouichi; Yamamoto, Naokatsu

    2013-12-04

    We investigated the coherent dynamics of exciton ground-state transitions in an 150-layer-stacked strain-compensated InAs quantum dot ensemble using photon echo (PE) technique in the strong excitation regime. The time delay dependence of PE signal intensity shows a drastic change depending on the excitation intensity and the aperture position placed in front of a detector. Our results suggest that the excitation-intensity-dependent spatial distribution of PE signal intensity plays an important role in observing PE signal decay in the strong excitation regime.

  17. Relating hippocampus to relational memory processing across domains and delays.

    PubMed

    Monti, Jim M; Cooke, Gillian E; Watson, Patrick D; Voss, Michelle W; Kramer, Arthur F; Cohen, Neal J

    2015-02-01

    The hippocampus has been implicated in a diverse set of cognitive domains and paradigms, including cognitive mapping, long-term memory, and relational memory, at long or short study-test intervals. Despite the diversity of these areas, their association with the hippocampus may rely on an underlying commonality of relational memory processing shared among them. Most studies assess hippocampal memory within just one of these domains, making it difficult to know whether these paradigms all assess a similar underlying cognitive construct tied to the hippocampus. Here we directly tested the commonality among disparate tasks linked to the hippocampus by using PCA on performance from a battery of 12 cognitive tasks that included two traditional, long-delay neuropsychological tests of memory and two laboratory tests of relational memory (one of spatial and one of visual object associations) that imposed only short delays between study and test. Also included were different tests of memory, executive function, and processing speed. Structural MRI scans from a subset of participants were used to quantify the volume of the hippocampus and other subcortical regions. Results revealed that the 12 tasks clustered into four components; critically, the two neuropsychological tasks of long-term verbal memory and the two laboratory tests of relational memory loaded onto one component. Moreover, bilateral hippocampal volume was strongly tied to performance on this component. Taken together, these data emphasize the important contribution the hippocampus makes to relational memory processing across a broad range of tasks that span multiple domains.

  18. Relating Hippocampus to Relational Memory Processing across Domains and Delays

    PubMed Central

    Monti, Jim M.; Cooke, Gillian E.; Watson, Patrick D.; Voss, Michelle W.; Kramer, Arthur F.; Cohen, Neal J.

    2015-01-01

    The hippocampus has been implicated in a diverse set of cognitive domains and paradigms, including cognitive mapping, long-term memory, and relational memory, at long or short study–test intervals. Despite the diversity of these areas, their association with the hippocampus may rely on an underlying commonality of relational memory processing shared among them. Most studies assess hippocampal memory within just one of these domains, making it difficult to know whether these paradigms all assess a similar underlying cognitive construct tied to the hippocampus. Here we directly tested the commonality among disparate tasks linked to the hippocampus by using PCA on performance from a battery of 12 cognitive tasks that included two traditional, long-delay neuropsychological tests of memory and two laboratory tests of relational memory (one of spatial and one of visual object associations) that imposed only short delays between study and test. Also included were different tests of memory, executive function, and processing speed. Structural MRI scans from a subset of participants were used to quantify the volume of the hippocampus and other subcortical regions. Results revealed that the 12 tasks clustered into four components; critically, the two neuropsychological tasks of long-term verbal memory and the two laboratory tests of relational memory loaded onto one component. Moreover, bilateral hippocampal volume was strongly tied to performance on this component. Taken together, these data emphasize the important contribution the hippocampus makes to relational memory processing across a broad range of tasks that span multiple domains. PMID:25203273

  19. Delayed plasticity of inhibitory neurons in developing visual cortex.

    PubMed

    Gandhi, Sunil P; Yanagawa, Yuchio; Stryker, Michael P

    2008-10-28

    During postnatal development, altered sensory experience triggers the rapid reorganization of neuronal responses and connections in sensory neocortex. This experience-dependent plasticity is disrupted by reductions of intracortical inhibition. Little is known about how the responses of inhibitory cells themselves change during plasticity. We investigated the time course of inhibitory cell plasticity in mouse primary visual cortex by using functional two-photon microscopy with single-cell resolution and genetic identification of cell type. Initially, local inhibitory and excitatory cells had similar binocular visual response properties, both favoring the contralateral eye. After 2 days of monocular visual deprivation, excitatory cell responses shifted to favor the open eye, whereas inhibitory cells continued to respond more strongly to the deprived eye. By 4 days of deprivation, inhibitory cell responses shifted to match the faster changes in their excitatory counterparts. These findings reveal a dramatic delay in inhibitory cell plasticity. A minimal linear model reveals that the delay in inhibitory cell plasticity potently accelerates Hebbian plasticity in neighboring excitatory neurons. These findings offer a network-level explanation as to how inhibition regulates the experience-dependent plasticity of neocortex.

  20. Puerto Rico Strong Motion Seismic Network

    NASA Astrophysics Data System (ADS)

    Huerta-Lopez, C. I.; Martínez-Cruzado, J. A.; Martínez-Pagan, J.; Santana-Torres, E. X.; Torres-O, D. M.

    2014-12-01

    The Puerto Rico Strong Motion Seismic Network is currently in charge of the operation of: (i) free-field (ff) strong motion stations, (ii) instrumented structures (STR) (Dams, Bridges, Buildings), and (iii) the data acquisition/monitoring and analysis of earthquakes considered strong from the point of view of their intensity and magnitude. All these instruments are deployed in the Puerto Rico Island (PRI), US-, and British-Virgin Islands (BVI), and Dominican Republic (DR). The Puerto Rico Island and the Caribbean region have high potential to be affected by earthquakes that could be catastrophic for the area. The Puerto Rico Strong Motion Seismic Network (actually Puerto Rico Strong Motion Program, PRSMP) has grown since 1970's from 7 ff strong motion stations and one instrumented building with analog accelerographs to 111 ff strong motion stations and 16 instrumented buildings with digital accelerographs: PRI: 88 ff, 16 STR., DR: 13 ff, BVI: 5 ff, 2 STR collecting data via IP (internet), DU (telephone), and stand alone stations The current stage of the PRSMP seismic network, the analysis of moderate earthquakes that were recorded and/or occurred on the island, results of the intensity distribution of selected earthquakes, as well as results of dynamic parameter identification of some of the instrumented structures are here presented.