WorldWideScience

Sample records for correlated interaction potentials

  1. Host-pathogen Interaction at the Intestinal Mucosa Correlates With Zoonotic Potential of Streptococcus suis

    DEFF Research Database (Denmark)

    Ferrando, Maria Laura; de Greeff, Astrid; van Rooijen, Willemien J. M.;

    2015-01-01

    of SS2 infection. Methods. We developed a noninvasive in vivo model to study oral SS2 infection in piglets. We compared in vitro interaction of S. suis with human and porcine intestinal epithelial cells (IEC). Results. Two out of 15 piglets showed clinical symptoms compatible with S. suis infection 24...... be considered a food-borne pathogen. S. suis interaction with human and pig IEC correlates with S. suis serotype and genotype, which can explain the zoonotic potential of SS2....

  2. Construction of Exchange-Correlation Potentials for Strongly Interacting One-Dimensional Systems

    Science.gov (United States)

    Silva, J. Wildon O.; Vieira, Daniel

    2017-08-01

    One-dimensional (1D) systems are useful laboratories aiming further improvement of electronic structure calculations. In order to simulate electron-electron interactions, two types of expressions are commonly considered: soft-Coulomb and exponential. For both cases, in the context of density-functional theory (DFT), 1D systems can be employed to gain insight into the ingredients accurate exchange-correlation (XC) density functionals must incorporate. A question of major interest is the treatment of strongly interacting situations, one of the main modern challenges for DFT. In this manuscript, we propose a generalization of preexisting XC potentials which can be applied to investigate the transition from weak to strong interactions. Specifically, we employ the intriguing behavior of electrons confined in one dimension: the spin-charge separation, for which spin and charge are decoupled to form two independent quasiparticles, spinons, and chargons. By means of Friedel oscillations, our results indicate it is possible to reproduce the weak-strong interaction transition by using a simple strategy we name, from previous works, spin-charge separation correction (SCSC). In addition, SCSC also yields good results in reproducing the constancy of the highest occupied Kohn-Sham eigenvalues upon fractional electron charges.

  3. Correlation energy and dispersion interaction in the ab initio potential energy curve of the neon dimer.

    Science.gov (United States)

    Bytautas, Laimutis; Ruedenberg, Klaus

    2008-06-01

    A close approximation to the empirical potential energy curve of the neon dimer is obtained by coupled-cluster singles plus doubles plus noniterative triples calculations by using nonaugmented correlation-consistent basis sets without counterpoise corrections and complementing them by three-term extrapolations to the complete basis set limit. The potential energy is resolved into a self-consistent-field Hartree-Fock contribution and a correlation contribution. The latter is shown to decay in the long-range region in accordance with the empirical dispersion expansion.

  4. Correlation in narrow nanorods: a variational potential-configuration interaction scheme

    Energy Technology Data Exchange (ETDEWEB)

    Planelles, J; Climente, J I; Royo, M; Movilla, J L [Departament de Quimica-Fisica i AnalItica, UJI, Box 224, E-12080 Castello (Spain)], E-mail: josep.planelles@qfa.uji.es

    2009-05-27

    Full configuration interaction calculations for two electrons in narrow semiconductor nanorods are carried out employing different orbital basis sets. It is shown that the usual configurations built from single-particle states cannot yield a correct singlet-triplet energetic order regardless of the basis size, as they miss the correlation energy. Mean-field optimized orbitals partially correct this drawback. A new approach is introduced, based on a simple variational procedure, which yields robust results.

  5. Correlations between the zeta potentials of silica hydride-based stationary phases, analyte retention behaviour and their ionic interaction descriptors.

    Science.gov (United States)

    Kulsing, Chadin; Yang, Yuanzhong; Munera, Caesar; Tse, Colby; Matyska, Maria T; Pesek, Joseph J; Boysen, Reinhard I; Hearn, Milton T W

    2014-03-19

    In this study, the zeta potentials of type-B silica, bare silica hydride, the so-called Diamond Hydride™ and phenyl substituted silica hydride stationary phases have been measured in aqueous-organic media and correction procedures developed to account for the more negative zeta potential values in media containing different acetonitrile contents. Retention studies of 16 basic, acidic and neutral compounds were also performed with these four stationary phases with mobile phases containing 0.1% (v/v) formic acid and various acetonitrile-water compositions ranging from 0-90% (v/v) acetonitrile. The retention properties of these analytes were correlated to the corrected stationary phase zeta potentials measured under these different mobile phase conditions with R(2) values ranging from 0.01 to 1.00, depending on the stationary phase and analyte type. Using linear solvation energy relationships, stationary phase descriptors for each stationary phase have been developed for the different mobile phase conditions. Very high correlations of the zeta potentials with the ionic interaction descriptors were obtained for the type-B silica and the Diamond Hydride™ phases and good correlation with bare silica hydride material whilst there was no correlation observed for the phenyl substituted silica hydride phase. The nature of the retention mechanisms which gives rise to these different observations is discussed. The described methods represent a useful new approach to characterize and assess the retention properties of silica-hydride based chromatographic stationary phases of varying bonded-phase coverage and chemistries, as would be broadly applicable to other types of stationary phase used in the separation sciences.

  6. One-Range Addition Theorems in Terms of ψα-ETOs for STOs and Coulomb-Yukawa Like Correlated Interaction Potentials of Integer and Noninteger Indices

    Institute of Scientific and Technical Information of China (English)

    I.I.Guseinov

    2008-01-01

    @@ The expansion formulas in terms of complete orthonormal sets of ψα-exponential type orbitals are established for the Slater type orbitals and Coulomb-Yukawa-like correlated interaction potentials of integer and noninteger indices. These relations are used in obtaining their unsymmetrical and symmetrical one-range addition theorems.The final results are especially useful in the calculations of multicentre multielectron integrals occurring when Hartree-Fock-Roothaan and explicitly correlated methods are employed.

  7. PEPSI-Dock: a detailed data-driven protein-protein interaction potential accelerated by polar Fourier correlation.

    Science.gov (United States)

    Neveu, Emilie; Ritchie, David W; Popov, Petr; Grudinin, Sergei

    2016-09-01

    Docking prediction algorithms aim to find the native conformation of a complex of proteins from knowledge of their unbound structures. They rely on a combination of sampling and scoring methods, adapted to different scales. Polynomial Expansion of Protein Structures and Interactions for Docking (PEPSI-Dock) improves the accuracy of the first stage of the docking pipeline, which will sharpen up the final predictions. Indeed, PEPSI-Dock benefits from the precision of a very detailed data-driven model of the binding free energy used with a global and exhaustive rigid-body search space. As well as being accurate, our computations are among the fastest by virtue of the sparse representation of the pre-computed potentials and FFT-accelerated sampling techniques. Overall, this is the first demonstration of a FFT-accelerated docking method coupled with an arbitrary-shaped distance-dependent interaction potential. First, we present a novel learning process to compute data-driven distant-dependent pairwise potentials, adapted from our previous method used for rescoring of putative protein-protein binding poses. The potential coefficients are learned by combining machine-learning techniques with physically interpretable descriptors. Then, we describe the integration of the deduced potentials into a FFT-accelerated spherical sampling provided by the Hex library. Overall, on a training set of 163 heterodimers, PEPSI-Dock achieves a success rate of 91% mid-quality predictions in the top-10 solutions. On a subset of the protein docking benchmark v5, it achieves 44.4% mid-quality predictions in the top-10 solutions when starting from bound structures and 20.5% when starting from unbound structures. The method runs in 5-15 min on a modern laptop and can easily be extended to other types of interactions. https://team.inria.fr/nano-d/software/PEPSI-Dock sergei.grudinin@inria.fr. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e

  8. Single-cell protein secretomic signatures as potential correlates to tumor cell lineage evolution and cell-cell interaction

    Directory of Open Access Journals (Sweden)

    Minsuk eKwak

    2013-02-01

    Full Text Available Secreted proteins including cytokines, chemokines and growth factors represent important functional regulators mediating a range of cellular behavior and cell-cell paracrine/autocrine signaling, e.g. in the immunological system, tumor microenvironment or stem cell niche. Detection of these proteins is of great value not only in basic cell biology but also for diagnosis and therapeutic monitoring of human diseases such as cancer. However, due to co-production of multiple effector proteins from a single cell, referred to as polyfunctionality, it is biologically informative to measure a panel of secreted proteins, or secretomic signature, at the level of single cells. Recent evidence further indicates that a genetically-identical cell population can give rise to diverse phenotypic differences. It is known that cytokines, for example, in the immune system define the effector functions and lineage differentiation of immune cells. In this Perspective Article, we hypothesize that protein secretion profile may represent a universal measure to identify the definitive correlate in the larger context of cellular functions to dissect cellular heterogeneity and evolutionary lineage relationship in human cancer.

  9. Correlation energy, correlated electron density, and exchange-correlation potential in some spherically confined atoms.

    Science.gov (United States)

    Vyboishchikov, Sergei F

    2016-12-05

    We report correlation energies, electron densities, and exchange-correlation potentials obtained from configuration interaction and density functional calculations on spherically confined He, Be, Be(2+) , and Ne atoms. The variation of the correlation energy with the confinement radius Rc is relatively small for the He, Be(2+) , and Ne systems. Curiously, the Lee-Yang-Parr (LYP) functional works well for weak confinements but fails completely for small Rc . However, in the neutral beryllium atom the CI correlation energy increases markedly with decreasing Rc . This effect is less pronounced at the density-functional theory level. The LYP functional performs very well for the unconfined Be atom, but fails badly for small Rc . The standard exchange-correlation potentials exhibit significant deviation from the "exact" potential obtained by inversion of Kohn-Sham equation. The LYP correlation potential behaves erratically at strong confinements. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. Correlations in multi-parton interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kasemets, Tomas

    2012-07-27

    In double parton interactions, the two hard proceses are correlated via double parton densities. We examine the double Drell-Yan process and the impact of such correlations on the differential cross section. In particular correlations between the spins of the interacting quarks can induce correlations between the decay planes of the vector bosons. We investigate upper limits on spin correlations following from positivity of the double parton densities.

  11. General correlation and partial correlation analysis in finding interactions: with Spearman rank correlation and proportion correlation as correlation measures

    OpenAIRE

    WenJun Zhang; Xin Li

    2015-01-01

    Between-taxon interactions can be detected by calculating the sampling data of taxon sample type. In present study, Spearman rank correlation and proportion correlation are chosen as the general correlation measures, and their partial correlations are calculated and compared. The results show that for Spearman rank correlation measure, in all predicted candidate direct interactions by partial correlation, about 16.77% (x, 0-45.4%) of them are not successfully detected by Spearman rank correla...

  12. Diatomic interaction potential theory applications

    CERN Document Server

    Goodisman, Jerry

    2013-01-01

    Diatomic Interaction Potential Theory, Volume 2: Applications discusses the variety of applicable theoretical material and approaches in the calculations for diatomic systems in their ground states. The volume covers the descriptions and illustrations of modern calculations. Chapter I discusses the calculation of the interaction potential for large and small values of the internuclear distance R (separated and united atom limits). Chapter II covers the methods used for intermediate values of R, which in principle means any values of R. The Hartree-Fock and configuration interaction schemes des

  13. Calculation of Rydberg interaction potentials

    Science.gov (United States)

    Weber, Sebastian; Tresp, Christoph; Menke, Henri; Urvoy, Alban; Firstenberg, Ofer; Büchler, Hans Peter; Hofferberth, Sebastian

    2017-07-01

    The strong interaction between individual Rydberg atoms provides a powerful tool exploited in an ever-growing range of applications in quantum information science, quantum simulation and ultracold chemistry. One hallmark of the Rydberg interaction is that both its strength and angular dependence can be fine-tuned with great flexibility by choosing appropriate Rydberg states and applying external electric and magnetic fields. More and more experiments are probing this interaction at short atomic distances or with such high precision that perturbative calculations as well as restrictions to the leading dipole-dipole interaction term are no longer sufficient. In this tutorial, we review all relevant aspects of the full calculation of Rydberg interaction potentials. We discuss the derivation of the interaction Hamiltonian from the electrostatic multipole expansion, numerical and analytical methods for calculating the required electric multipole moments and the inclusion of electromagnetic fields with arbitrary direction. We focus specifically on symmetry arguments and selection rules, which greatly reduce the size of the Hamiltonian matrix, enabling the direct diagonalization of the Hamiltonian up to higher multipole orders on a desktop computer. Finally, we present example calculations showing the relevance of the full interaction calculation to current experiments. Our software for calculating Rydberg potentials including all features discussed in this tutorial is available as open source.

  14. Determination of interaction potentials of colloidal monolayers from the inversion of pair correlation functions: a two-dimensional predictor-corrector method.

    Science.gov (United States)

    Law, A D; Buzza, D M A

    2009-09-07

    The structure and stability of colloidal monolayers depend crucially on the effective pair potential u(r) between colloidal particles. In this paper, we develop a two-dimensional (2D) predictor-corrector method for extracting u(r) from the pair correlation function g(r) of dense colloidal monolayers. The method is based on an extension of the three-dimensional scheme of Rajagopalan and Rao [Phys. Rev. E 55, 4423 (1997)] to 2D by replacing the unknown bridge function B(r) with the hard-disk bridge function B(d)(r); the unknown hard-disk diameter d is then determined using an iterative scheme. We compare the accuracy of our predictor-corrector method to the conventional one-step inversion schemes of hypernetted chain closure (HNC) and Percus-Yevick (PY) closure. Specifically we benchmark all three schemes against g(r) data generated from Monte Carlo simulation for a range of 2D potentials: exponential decay, Stillinger-Hurd, Lennard-Jones, and Derjaguin-Landau-Verwey-Overbeek. We find that for all these potentials, the predictor-corrector method is at least as good as the most accurate one-step method for any given potential, and in most cases it is significantly better. In contrast the accuracy of the HNC and PY methods relative to each other depends on the potential studied. The proposed predictor-corrector scheme is therefore a robust and more accurate alternative to these conventional one-step inversion schemes.

  15. Correlated interaction fluctuations in photosynthetic complexes

    CERN Document Server

    Vlaming, Sebastiaan M

    2011-01-01

    The functioning and efficiency of natural photosynthetic complexes is strongly influenced by their embedding in a noisy protein environment, which can even serve to enhance the transport efficiency. Interactions with the environment induce fluctuations of the transition energies of and interactions between the chlorophyll molecules, and due to the fact that different fluctuations will partially be caused by the same environmental factors, correlations between the various fluctuations will occur. We argue that fluctuations of the interactions should in general not be neglected, as these have a considerable impact on population transfer rates, decoherence rates and the efficiency of photosynthetic complexes. Furthermore, while correlations between transition energy fluctuations have been studied, we provide the first quantitative study of the effect of correlations between interaction fluctuations and transition energy fluctuations, and of correlations between the various interaction fluctuations. It is shown t...

  16. Better band gaps for wide-gap semiconductors from a locally corrected exchange-correlation potential that nearly eliminates self-interaction errors

    Science.gov (United States)

    Singh, Prashant; Harbola, Manoj K.; Johnson, Duane D.

    2017-10-01

    This work constitutes a comprehensive and improved account of electronic-structure and mechanical properties of silicon-nitride (Si3 N4 ) polymorphs via van Leeuwen and Baerends (LB) exchange-corrected local density approximation (LDA) that enforces the exact exchange potential asymptotic behavior. The calculated lattice constant, bulk modulus, and electronic band structure of Si3 N4 polymorphs are in good agreement with experimental results. We also show that, for a single electron in a hydrogen atom, spherical well, or harmonic oscillator, the LB-corrected LDA reduces the (self-interaction) error to exact total energy to  ∼10%, a factor of three to four lower than standard LDA, due to a dramatically improved representation of the exchange-potential.

  17. Electron correlation by polarization of interacting densities

    CERN Document Server

    Whitten, Jerry L

    2016-01-01

    Coulomb interactions that occur in electronic structure calculations are correlated by allowing basis function components of the interacting densities to polarize, thereby reducing the magnitude of the interaction. Exchange integrals of molecular orbitals are not correlated. The modified Coulomb interactions are used in single-determinant or configuration interaction calculations. The objective is to account for dynamical correlation effects without explicitly introducing higher spherical harmonic functions into the molecular orbital basis. Molecular orbital densities are decomposed into a distribution of spherical components that conserve the charge and each of the interacting components is considered as a two-electron wavefunction embedded in the system acted on by an average field Hamiltonian plus . A method of avoiding redundancy is described. Applications to atoms, negative ions and molecules representing different types of bonding and spin states are discussed.

  18. Energetics of correlations in interacting systems.

    Science.gov (United States)

    Friis, Nicolai; Huber, Marcus; Perarnau-Llobet, Martí

    2016-04-01

    A fundamental connection between thermodynamics and information theory arises from the fact that correlations exhibit an inherent work value. For noninteracting systems this translates to a work cost for establishing correlations. Here we investigate the relationship between work and correlations in the presence of interactions that cannot be controlled or removed. For such naturally coupled systems, which are correlated even in thermal equilibrium, we determine general strategies that can reduce the work cost of correlations, and illustrate these for a selection of exemplary physical systems.

  19. Higgs Potential from Derivative Interactions

    CERN Document Server

    Quadri, A

    2016-01-01

    A formulation of the linear $\\sigma$ model with derivative interactions is studied. The theory is on-shell equivalent to the model with a quartic Higgs potential. The mass of the scalar mode only appears in the quadratic part and not in the interaction vertices, unlike in the ordinary formulation of the theory. Renormalization of the model is discussed. A natural non power-counting renormalizable extension of the theory is presented. The model is physically equivalent to the inclusion of a dimension six effective operator $\\partial_\\mu (\\Phi^\\dagger \\Phi) \\partial^\\mu (\\Phi^\\dagger \\Phi)$. The resulting UV divergences are arranged in a perturbation series around the power-counting renormalizable theory. UV completion of the non-power-counting renormalizable model through a symmetric deformation of the propagator of the massive physical scalar is addressed.

  20. Correlation expansion of the optical potential

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, D.J.; Londergan, J.T.; Miller, G.A.; Thaler, R.M.

    1977-08-01

    The multiple scattering theory for the optical potential is examined. This series is arranged according to the number of target particles struck in forming the optical potential. The term which involves two target particles is summed as a three-body problem. Explicit formulas for calculating the optical potential in the fixed scatterer approximation are presented. Corrections to the fixed scatterer approximation, one a correction to closure, another a correction due to nonlocality in the two-body interaction, are presented. The relation between this work and other formal,rearrangements of the multiple scattering series is presented.

  1. Correlation of action potentials in adjacent neurons

    CERN Document Server

    Shneider, M N

    2015-01-01

    A possible mechanism for the synchronization of action potential propagation along a bundle of neurons (ephaptic coupling) is considered. It is shown that this mechanism is similar to the salutatory conduction of the action potential between the nodes of Ranvier in myelinated axons. The proposed model allows us to estimate the scale of the correlation, i.e., the distance between neurons in the nervous tissue, wherein their synchronization becomes possible. The possibility for experimental verification of the proposed model of synchronization is discussed.

  2. Efimov correlations in strongly interacting Bose gases

    Science.gov (United States)

    Hofmann, Johannes; Barth, Marcus

    A series of recent hallmark experiments have demonstrated that Bose gases can be created in the strongly interacting unitary limit in the non-degenerate high-temperature regime. These systems display the three-body Efimov effect, which poses a theoretical challenge to compute observables including these relevant three-body correlations. In this talk, I shall present our results for the virial coefficients, the contact parameters, and the momentum distribution of a strongly interacting three-dimensional Bose gas obtained by means of a virial expansion up to third order in the fugacity, which takes into account three-body correlations exactly. Our results characterize the non-degenerate regime of the interacting Bose gas, where the thermal wavelength is smaller than the interparticle spacing but the scattering length may be arbitrarily large. In addition, we provide a calculation of the momentum distribution at unitarity, which displays a universal high-momentum tail with a log-periodic momentum dependence - a direct signature of Efimov physics. In particular, we provide a quantitative description of the momentum distribution at high momentum as measured by the JILA group [Makotyn et al., Nat. Phys. 10, 116 (2014)]. Our results allow the spectroscopy of Efimov states at unitarity.

  3. Correlation of disorder between S. cerevisiae interacting proteins.

    Science.gov (United States)

    Rue-Albrecht, Kevin; Shields, Denis C; Khaldi, Nora

    2012-01-01

    Protein disorder has been frequently associated with protein-protein interaction. However, our knowledge of how protein disorder evolves within a network is limited. It is expected that physically interacting proteins evolve in a coordinated manner. This has so far been shown in their evolutionary rate, and in their gene expression levels. Here we examine the percentage of predicted disorder residues within binary and complex interacting proteins (physical and functional interactions respectively) to investigate how the disorder of a protein relates to that of its interacting partners. We show that the level of disorder of interacting proteins are correlated, with a greater correlation seen among proteins that are co-members of the same complex, and a lesser correlation between proteins that are documented as binary interactors of each other. There is a striking variation among complexes not only in their disorder, but in the extent to which the proteins within the complex differ in their levels of disorder, with RNA processes and protein binding complexes showing more variation in the disorder of their proteins, whilst other complexes show very little variation in the overall disorder of their constituent proteins. There is likely to be a stronger selection for complex subunits to have similar disorder, than is seen for proteins involved in binary interactions. Thus, binary interactions may be more resilient to changes in disorder than are complex interactions. These results add a new dimension to the role of disorder in protein networks, and highlight the potential importance of maintaining similar disorder in the members of a complex.

  4. Developing a general interaction potential for hydrophobic and hydrophilic interactions.

    Science.gov (United States)

    Donaldson, Stephen H; Røyne, Anja; Kristiansen, Kai; Rapp, Michael V; Das, Saurabh; Gebbie, Matthew A; Lee, Dong Woog; Stock, Philipp; Valtiner, Markus; Israelachvili, Jacob

    2015-02-24

    We review direct force measurements on a broad class of hydrophobic and hydrophilic surfaces. These measurements have enabled the development of a general interaction potential per unit area, W(D) = -2γ(i)Hy exp(-D/D(H)) in terms of a nondimensional Hydra parameter, Hy, that applies to both hydrophobic and hydrophilic interactions between extended surfaces. This potential allows one to quantitatively account for additional attractions and repulsions not included in the well-known combination of electrostatic double layer and van der Waals theories, the so-called Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The interaction energy is exponentially decaying with decay length D(H) ≈ 0.3-2 nm for both hydrophobic and hydrophilic interactions, with the exact value of D(H) depending on the precise system and conditions. The pre-exponential factor depends on the interfacial tension, γ(i), of the interacting surfaces and Hy. For Hy > 0, the interaction potential describes interactions between partially hydrophobic surfaces, with the maximum hydrophobic interaction (i.e., two fully hydrophobic surfaces) corresponding to Hy = 1. Hydrophobic interactions between hydrophobic monolayer surfaces measured with the surface forces apparatus (SFA) are shown to be well described by the proposed interaction potential. The potential becomes repulsive for Hy < 0, corresponding to partially hydrophilic (hydrated) interfaces. Hydrated surfaces such as mica, silica, and lipid bilayers are discussed and reviewed in the context of the values of Hy appropriate for each system.

  5. Electrophysiological correlates of reading the single- and interactive-mind

    Directory of Open Access Journals (Sweden)

    Yi-Wen eWang

    2011-07-01

    Full Text Available Understanding minds is the cognitive basis of successful social interaction. In everyday life, human mental activity often happens at the moment of social interaction among two or multiple persons instead of only one person. Understanding the interactive mind of two- or multi-person is more complex and higher than understanding the single-person mind in the hierarchical structure of theory-of-mind. Understanding the interactive mind maybe differentiate from understanding the single mind. In order to examine the dissociative electrophysiological correlates of reading the single mind and reading the interactive mind, the 64 channels event-related potentials (ERP were recorded while 16 normal adults were observing three kinds of Chinese idioms depicted physical scenes, one-person with mental activity and two- or multi-person with mental interaction. After the equivalent N400, in the 500- to 700-ms epoch, the mean amplitudes of late positive component (LPC over frontal for reading the single mind and reading the interactive mind were significantly more positive than for physical representation, while there was no difference between the former two. In the 700-to 800-ms epoch, the mean amplitudes of LPC over frontal-central for reading the interactive mind were more positive than for reading the single mind and physical representation, while there was no difference between the latter two. The present study provides electrophysiological signature of the dissociations between reading the single mind and reading the interactive mind.

  6. Electrophysiological Correlates of Reading the Single- and Interactive-Mind

    Science.gov (United States)

    Wang, Yi-Wen; Zheng, Yu-Wei; Lin, Chong-De; Wu, Jie; Shen, De-Li

    2011-01-01

    Understanding minds is the cognitive basis of successful social interaction. In everyday life, human mental activity often happens at the moment of social interaction among two or multiple persons instead of only one-person. Understanding the interactive mind of two- or multi-person is more complex and higher than understanding the single-person mind in the hierarchical structure of theory of mind. Understanding the interactive mind maybe differentiate from understanding the single mind. In order to examine the dissociative electrophysiological correlates of reading the single mind and reading the interactive mind, the 64 channels event-related potentials were recorded while 16 normal adults were observing three kinds of Chinese idioms depicted physical scenes, one-person with mental activity, and two- or multi-person with mental interaction. After the equivalent N400, in the 500- to 700-ms epoch, the mean amplitudes of late positive component (LPC) over frontal for reading the single mind and reading the interactive mind were significantly more positive than for physical representation, while there was no difference between the former two. In the 700- to 800-ms epoch, the mean amplitudes of LPC over frontal–central for reading the interactive mind were more positive than for reading the single mind and physical representation, while there was no difference between the latter two. The present study provides electrophysiological signature of the dissociations between reading the single mind and reading the interactive mind. PMID:21845178

  7. Potential interactions between alternative therapies and warfarin.

    Science.gov (United States)

    Heck, A M; DeWitt, B A; Lukes, A L

    2000-07-01

    Potential and documented interactions between alternative therapy agents and warfarin are discussed. An estimated one third of adults in the United States use alternative therapies, including herbs. A major safety concern is potential interactions of alternative medicine products with prescription medications. This issue is especially important with respect to drugs with narrow therapeutic indexes, such as warfarin. Herbal products that may potentially increase the risk of bleeding or potentiate the effects of warfarin therapy include angelica root, arnica flower, anise, asafoetida, bogbean, borage seed oil, bromelain, capsicum, celery, chamomile, clove, fenugreek, feverfew, garlic, ginger ginkgo, horse chestnut, licorice root, lovage root, meadowsweet, onion, parsley, passionflower herb, poplar, quassia, red clover, rue, sweet clover, turmeric, and willow bark. Products that have been associated with documented reports of potential interactions with warfarin include coenzyme Q10, danshen, devil's claw, dong quai, ginseng, green tea, papain, and vitamin E. Interpretation of the available information on herb-warfarin interactions is difficult because nearly all of it is based on in vitro data, animal studies, or individual case reports. More study is needed to confirm and assess the clinical significance of these potential interactions. There is evidence that a wide range of alternative therapy products have the potential to interact with warfarin. Pharmacists and other health care professionals should question all patients about use of alternative therapies and report documented interactions to FDA's MedWatch program.

  8. Correlation between family interaction and adolescents’ attitudes

    Directory of Open Access Journals (Sweden)

    Rozana Petani

    2011-10-01

    Full Text Available The impact of the family on the individual is very powerful and life-long. The family differs from other factors because the individual spends the most time in the family environment. In his family the child makes his first steps, utters the first words, starts gaining knowledge, learns his first value, forms attitudes and forms the foundation for the later development as a complete personality. Parents are the first and most responsible educators of their child, and upbringing is the most important and probably the hardest task of every parent. The period of adolescence is very important in every person’s life, especially because of the process of separation and individuation. This is a transitional period from childhood to maturity with the greatest dynamics in the development of the individual. In this period adolescents change and mature. They are able to make independent decisions. Relationships with their parents play an important role in shaping their behavior. The paper observes the family through family interaction, which consists of the following dimensions: satisfaction with their own families, acceptance and rejection by the mother and father. The aim of this study was to examine whether dimensions of parental behavior and satisfaction with their own families, perceived by adolescents, are associated with adolescents’ attitudes to some aspects of family life. The study was conducted on 862 students of the final year of high school, of whom 385 were male and 477 female. The results showed a statistically significant correlation between the assessed family interaction dimensions and adolescents’ attitudes to family life, with the exception of the attitude to work. The results obtained can be used in organizing programs focusing on preparation of young people for parental and marital roles and strengthening the skills required later in their family lives for constructive solving of the problems they will encounter.

  9. Phase-Space Position-Momentum Correlation and Potentials

    Directory of Open Access Journals (Sweden)

    Robin P. Sagar

    2013-04-01

    Full Text Available Solutions to the radial Schr¨odinger equation of a particle in a quantum corral are used to probe how the statistical correlation between the position, and The momentum of the particle depends on the effective potential. The analysis is done via the Wigner function and its Shannon entropy. We show by comparison to the particle-in-a-box model that the attractive potential increases the magnitude of the correlation, while a repulsive potential decreases the magnitude of this correlation. Varying the magnitude of the repulsive potential yields that the correlation decreases with a stronger repulsive potential.

  10. Construction of exchange-correlation functionals through interpolation between the non-interacting and the strong-correlation limit

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yongxi; Ernzerhof, Matthias, E-mail: Matthias.Ernzerhof@UMontreal.ca [Département de Chimie, Université de Montréal, C.P. 6128, Succursale A, Montréal, Québec H3C 3J7 (Canada); Bahmann, Hilke [Department of Chemistry, Technische Universität Berlin, Strasse des 17 Juni, Berlin (Germany)

    2015-09-28

    Drawing on the adiabatic connection of density functional theory, exchange-correlation functionals of Kohn-Sham density functional theory are constructed which interpolate between the extreme limits of the electron-electron interaction strength. The first limit is the non-interacting one, where there is only exchange. The second limit is the strong correlated one, characterized as the minimum of the electron-electron repulsion energy. The exchange-correlation energy in the strong-correlation limit is approximated through a model for the exchange-correlation hole that is referred to as nonlocal-radius model [L. O. Wagner and P. Gori-Giorgi, Phys. Rev. A 90, 052512 (2014)]. Using the non-interacting and strong-correlated extremes, various interpolation schemes are presented that yield new approximations to the adiabatic connection and thus to the exchange-correlation energy. Some of them rely on empiricism while others do not. Several of the proposed approximations yield the exact exchange-correlation energy for one-electron systems where local and semi-local approximations often fail badly. Other proposed approximations generalize existing global hybrids by using a fraction of the exchange-correlation energy in the strong-correlation limit to replace an equal fraction of the semi-local approximation to the exchange-correlation energy in the strong-correlation limit. The performance of the proposed approximations is evaluated for molecular atomization energies, total atomic energies, and ionization potentials.

  11. A single particle effective potential for interacting positron and positronium

    CERN Document Server

    Zubiaga, A; Puska, M

    2013-01-01

    We have studied small systems composed by an atom and a positron or a positronium atom. We have used many-body quantum mechanical calculations to describe the correlation effects of light particles. Explicitly correlated gaussian for the basis functions and a stochastical variational optimization method has allowed to obtain accurate wavefunctions and energies. We have discussed the chemistry of positrons in those systems by means of analyzing the densities of the light particles (electrons and positrons). During the discussion, we propose an effective potential that describes the properties of the positron in those systems, valid also when it forms a Ps cluster. The effective potential is a mean field description of the interaction of the positron that can be used to calculate the distribution of the positron and its interaction energy. This potential can be a step forward for an accurate single particle description of the positron in cases when it forms positronium, specially molecular soft matter.

  12. A new interaction potential for swarming models

    CERN Document Server

    Carrillo, J A; Panferov, V

    2012-01-01

    We consider a self-propelled particle system which has been used to describe certain types of collective motion of animals, such as fish schools and bird flocks. Interactions between particles are specified by means of a pairwise potential, repulsive at short ranges and attractive at longer ranges. The exponentially decaying Morse potential is a typical choice, and is known to reproduce certain types of collective motion observed in nature, particularly aligned flocks and rotating mills. We introduce a class of interaction potentials, that we call Quasi-Morse, for which flock and rotating mills states are also observed numerically, however in that case the corresponding macroscopic equations allow for explicit solutions in terms of special functions, with coefficients that can be obtained numerically without solving the particle evolution. We compare thus obtained solutions with long-time dynamics of the particle systems and find a close agreement for several types of flock and mill solutions.

  13. A new interaction potential for swarming models

    Science.gov (United States)

    Carrillo, J. A.; Martin, S.; Panferov, V.

    2013-10-01

    We consider a self-propelled particle system which has been used to describe certain types of collective motion of animals, such as fish schools and bird flocks. Interactions between particles are specified by means of a pairwise potential, repulsive at short ranges and attractive at longer ranges. The exponentially decaying Morse potential is a typical choice, and is known to reproduce certain types of collective motion observed in nature, particularly aligned flocks and rotating mills. We introduce a class of interaction potentials, that we call Quasi-Morse, for which flock and rotating mills states are also observed numerically, however in that case the corresponding macroscopic equations allow for explicit solutions in terms of special functions, with coefficients that can be obtained numerically without solving the particle evolution. We compare the obtained solutions with long-time dynamics of the particle systems and find a close agreement for several types of flock and mill solutions.

  14. Potential interaction between pomegranate juice and warfarin.

    Science.gov (United States)

    Komperda, Kathy E

    2009-08-01

    To my knowledge, no published reports have described an interaction between pomegranate juice and warfarin. Investigators from previous animal and in vitro studies have reported a potential for pomegranate juice to inhibit metabolism involving the cytochrome P450 system, an effect that could translate into a clinical drug-diet interaction with warfarin. This case report describes a 64-year-old Caucasian woman who was treated with warfarin for recurrent deep vein thrombosis. She had been receiving a relatively stable dosage of warfarin 4 mg/day for several months, with stable international normalized ratios (INRs). During that time, the patient was consuming pomegranate juice 2-3 times/week. She stopped drinking the juice, and her INRs became subtherapeutic. Her dosage of warfarin was increased to maintain therapeutic anticoagulation. No rechallenge with pomegranate juice was performed. Use of the Drug Interaction Probability Scale indicated a possible relationship between the patient's subtherapeutic INR and the pomegranate juice. Although this potential interaction needs to be explored further, clinicians should be aware of the interaction and thoroughly interview and closely monitor their patients who are receiving warfarin.

  15. Fluctuating Potential Barrier System with Correlated Spatial Noises

    Institute of Scientific and Technical Information of China (English)

    LI Jing-Hui

    2004-01-01

    In this paper, we study a fluctuating potential barrier system with correlated spatial noises. Study shows that for this system, there is the resonant activation over the fluctuating potential barrier, and that the correlation between the different spatial noises can enhance (or weaken) the resonant activation.

  16. Kinetic and potential components of the exact time-dependent correlation potential

    CERN Document Server

    Luo, Kai; Sandoval, Ernesto D; Elliott, Peter; Maitra, Neepa T

    2013-01-01

    The exact exchange-correlation (xc) potential of time-dependent density functional theory has been shown to have striking features. For example, step and peak features are generically found when the system is far from its ground-state, and these depend nonlocally on the density in space and time. We analyze the xc potential by decomposing it into kinetic and interaction potential components, and comparing each with their exact-adiabatic counterparts, for a range of dynamical situations in model one-dimensional (1D) two-electron systems. We find that often, but not always, the kinetic contri- bution is mostly responsible for these features, that are missed by the adiabatic approximation. The adiabatic approximation often makes a smaller error for the potential contribution, which we write in two parts, one being the Coulomb potential due to the time-dependent xc hole. These observations also held in non-equilibrium cases we studied where there are large features in the correlation po- tential although no step ...

  17. Potential intravenous drug interactions in intensive care

    Directory of Open Access Journals (Sweden)

    Maiara Benevides Moreira

    Full Text Available Abstract OBJECTIVE To analyze potential intravenous drug interactions, and their level of severity associated with the administration of these drugs based on the prescriptions of an intensive care unit. METHOD Quantitative study, with aretrospective exploratory design, and descriptive statistical analysis of the ICU prescriptions of a teaching hospital from March to June 2014. RESULTS The sample consisted of 319 prescriptions and subsamples of 50 prescriptions. The mean number of drugs per patient was 9.3 records, and a higher probability of drug interaction inherent to polypharmacy was evidenced. The study identified severe drug interactions, such as concomitant administration of Tramadol with selective serotonin reuptake inhibitor drugs (e.g., Metoclopramide and Fluconazole, increasing the risk of seizures due to their epileptogenic actions, as well as the simultaneous use of Ranitidine-Fentanyl®, which can lead to respiratory depression. CONCLUSION A previous mapping of prescriptions enables the characterization of the drug therapy, contributing to prevent potential drug interactions and their clinical consequences.

  18. Sudden Transition between Quantum Correlation and Classical Correlation: the Effect of Interaction between Subsystems

    Institute of Scientific and Technical Information of China (English)

    YAN Jun-Yan; WANG Lin-Cheng; YI Xue-Xi

    2011-01-01

    We study the quantum discord dynamics of a bipartite composite system in the presence of a dissipative environment and investigate the effect of the interaction between the two subsystems. The results show that the interaction can influence the sudden transition between the quantum correlation and the classical correlation and for the maximally mixed marginals initial states, the sudden transition regime will always exist. The entanglements are also discussed in comparison to the quantum discord in describing the quantum correlations.%@@ We study the quantum discord dynamics of a bipartite composite system in the presence of a dissipative envi- ronment and investigate the effect of the interaction between the two subsystems.The results show that the interaction can influence the sudden transition between the quantum correlation and the classical correlation and for the maximally mixed marginals initial states, the sudden transition regime will always exist.The entangle- ments are also discussed in comparison to the quantum discord in describing the quantum correlations.

  19. Factors Correlated with the Interactional Diversity of Community College Students

    Science.gov (United States)

    Jones, Willis A.

    2016-01-01

    This study used data from the Community College Survey of Student Engagement (CCSSE) to examine how student background characteristics, student engagement, and institutional characteristics correlate with the frequency of interactional diversity among community college students. Given the current lack of research on interactional diversity among…

  20. A correlation method of detecting and estimating interactions of QTLs

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    More and more studies demonstrate that a great deal of interactions among the quantitative trait loci (QTLs) are far more than those detected by single markers. A correlation method was proposed for estimating the interactions of multiple QTLs detected by multi-markers in several mapping populations. Genetic implication of this method and usage were discussed.

  1. Optimizing Interacting Potentials to Form Targeted Materials Structures

    Energy Technology Data Exchange (ETDEWEB)

    Torquato, Salvatore [Princeton Univ., NJ (United States)

    2015-09-28

    Conventional applications of the principles of statistical mechanics (the "forward" problems), start with particle interaction potentials, and proceed to deduce local structure and macroscopic properties. Other applications (that may be classified as "inverse" problems), begin with targeted configurational information, such as low-order correlation functions that characterize local particle order, and attempt to back out full-system configurations and/or interaction potentials. To supplement these successful experimental and numerical "forward" approaches, we have focused on inverse approaches that make use of analytical and computational tools to optimize interactions for targeted self-assembly of nanosystems. The most original aspect of our work is its inherently inverse approach: instead of predicting structures that result from given interaction potentials among particles, we determine the optimal potential that most robustly stabilizes a given target structure subject to certain constraints. Our inverse approach could revolutionize the manner in which materials are designed and fabricated. There are a number of very tangible properties (e.g. zero thermal expansion behavior), elastic constants, optical properties for photonic applications, and transport properties.

  2. Dynamics of Nonclassical Correlation in Interacting Qubits under Correlated Dissipative Environments

    Institute of Scientific and Technical Information of China (English)

    QIU Liang

    2011-01-01

    The dynamical evolution of nonclassical correlation in interacting qubits is investigated under the correlated dissipative environments for two classes of initial states.If the correlated decay rate equals the independent decay rate,there will be stationary nonclassical correlation between the qubits prepared initially in some separable states.When the correlated decay rate is different from the independent decay rate,the nonclassical correlation between the qubits eventually decays to zero for a certain class of initial states.Quantum entanglement is one of the most remarkable features of quantum mechanics and it plays a central role in quantum information and communication theory.There exists,however,nonclassical correlation,which is more general and more fundamental than entanglement in the sense that separable mixed states can have nonclassical correlation.Moreover,nonclassical correlation other than entanglement can be responsible for the quantum computational efficiency of deterministic quantum computation with one pure qubit.[1,2] Nonclassical correlation has also been used in other physical contexts,such as improving the efficiency of quantum Carnot engines,[3] quantum phase transition and Grover search processes.[4-6]In these contexts,nonclassical correlation could be a new resource for quantum computation.Quantum discord,the most popular measure of such correlations,was introduced by Olliver and Zurek.[7]%The dynamical evolution of nonclassical correlation in interacting qubits is investigated under the correlated dissipative environments for two classes of initial states. If the correlated decay rate equals the independent decay rate, there will be stationary nonclassical correlation between the qubits prepared initially in some separable states. When the correlated decay rate is different from the independent decay rate, the nonclassical correlation between the qubits eventually decays to zero for a certain class of initial states.

  3. Photodisintegration of light nuclei for testing a correlated realistic interaction in the continuum

    CERN Document Server

    Bacca, S

    2006-01-01

    An exact calculation of the photodisintegration cross section of 3H, 3He and 4He is performed using as interaction the correlated Argonne V18 potential, constructed within the Unitary Correlation Operator Method (VUCOM). Calculations are carried out using the Lorentz Integral Transform method in conjunction with an hyperspherical harmonics basis expansion. A comparison with other realistic potentials and with available experimental data is discussed. The VUCOM potential leads to a very similar description of the cross section as the Argonne V18 interaction with the inclusion of the Urbana IX three-body force for photon energies 45< w < 120 MeV, while larger differences are found close to threshold.

  4. Identified Particle Correlations at RHIC: Medium Interactions & Modified Fragmentation

    CERN Document Server

    Sickles, Anne

    2007-01-01

    Azimuthal angle two particle correlations have been shown to be a powerful probe for extracting novel features of jet induced correlations produced in Au+Au collisions at RHIC. At intermediate $p_T$, 2-5GeV/c, the jets have been shown to be significantly modified in both their particle composition and their angular distribution compared to p+p collisions. Two-particle angular correlations with identified particles provide sensitive probes of both the interactions between hard scattered partons and the medium. The systematics of these correlations are essential to understanding the physics of intermediate $p_T$ in heavy ion collisions.

  5. Asymptotic Near Nucleus Structure of the Electron-Interaction Potential in Local Effective Potential Theories

    Science.gov (United States)

    Sahni, Viraht; Qian, Zhixin

    2007-03-01

    In previous work, it has been shown that for spherically symmetric or sphericalized systems, the asymptotic near nucleus structure of the electron-interaction potential is vee(r) = vee(0) + βr + γr^2. In this paper we prove via time-independent Quantal Density Functional Theory[1](Q-DFT): (i) correlations due to the Pauli exclusion principle and Coulomb repulsion do not contribute to the linear structure;(ii) these Pauli and Coulomb correlations contribute quadratically; (iii) the linear structure is solely due to Correlation-Kinetic effects, the coefficient β being determined analytically. By application of adiabatic coupling constant perturbation theory via QDFT we further prove: (iv) the Kohn-Sham (KS-DFT) `exchange' potential vx(r) approaches the nucleus linearly, this structure being due solely to lowest- order Correlation-Kinetic effects: (v) the KS-DFT `correlation' potential vc(r) also approaches the nucleus linearly, being solely due to higher-order Correlation-Kinetic contributions. The above conclusions are equally valid for system of arbitrary symmetry, provided spherical averages of the properties are employed. 1 Quantal Density Functional Theory, V. Sahni (Springer-Verlag 2004)

  6. PRESENTATION POTENTIAL USING IN PEDAGOGICAL INTERACTION PROCESS

    Directory of Open Access Journals (Sweden)

    Olga V. Ershova

    2016-01-01

    Full Text Available The given article is aimed at considering multimedia presentation potential and its influence on strengthening classroom teacher-student interaction. In the article the importance of using this kind of activity in the study process is pointed in connection with educational state policy on the one hand. On the other hand, gained students’ skills as a final result of work with presentations met employers’ demand for both parent and world labour-markets and bring competitive benefit to the candidates. Scientific novelty and results. Multimedia presentation is considered as a specific complex of classroom activities. The students are oriented on the self analysis and presentation assessment. It is shown that well-organized process of peer students’ assessment allows to simultaneously helping in solving the didactic and methodical problems. To this purpose the system of assessment criteria should be developed. It has to be clear for students for making assessment feasible and time-saving. The example of a possible variant of criteria system is described; quality of the presentations prepared by students can be defined based on such system criteria. The author also analyzed software products of the three main platforms (Windows, Linux, MacOs which have different tools and allow to follow users’ needs for creating presentations. In the article there is a comparative table of the two most popular software development: the program Microsoft PowerPoint and the web-service Prezi for realizing the relevance of their use in the study process. Practical significance of the present article concludes in author’s suggestions of some recommendations for presentation potential use as a tool of improving pedagogical interaction process with contemporary students. 

  7. Measuring spin correlations in optical lattices using superlattice potentials

    DEFF Research Database (Denmark)

    Pedersen, Kim Georg Lind; Andersen, Brian Møller; Bruun, Georg Morten;

    2011-01-01

    We suggest two experimental methods for probing both short- and long-range spin correlations of atoms in optical lattices using superlattice potentials. The first method involves an adiabatic doubling of the periodicity of the underlying lattice to probe neighboring singlet (triplet) correlations...... for fermions (bosons) by the occupation of the resulting vibrational ground state. The second method utilizes a time-dependent superlattice potential to generate spin-dependent transport by any number of prescribed lattice sites, and probes correlations by the resulting number of doubly occupied sites....... For experimentally relevant parameters, we demonstrate how both methods yield large signatures of antiferromagnetic correlations of strongly repulsive fermionic atoms in a single shot of the experiment. Lastly, we show how this method may also be applied to probe d-wave pairing, a possible ground-state candidate...

  8. Space-time combined correlation integral and earthquake interactions

    Directory of Open Access Journals (Sweden)

    L. Pietronero

    2004-06-01

    Full Text Available Scale invariant properties of seismicity argue for the presence of complex triggering mechanisms. We propose a new method, based on the space-time combined generalization of the correlation integral, that leads to a self-consistent visualization and analysis of both spatial and temporal correlations. The analysis has been applied on global medium-high seismicity. Results show that earthquakes do interact even on long distances and are correlated in time within defined spatial ranges varying over elapsed time. On that base we redefine the aftershock concept.

  9. Correlation between electric potential and peristaltic behavior in Physarum polycephalum.

    Science.gov (United States)

    Zheng, Yutong; Jia, Ruonan; Qian, Yiqing; Ye, Yang; Liu, Changhong

    2015-06-01

    Plasmodium of Physarum polycephalum is a model species of eukaryotic microorganisms for studying amoeboid movement. Plasmodium's natural movements are characterized by the rhythmic back-and-forth streaming of cytoplasm peristalsis, which results in the directed locomotion of plasmodium, and the periodic change of the electric potential on the surface of plasmodium. Although it was suggested the causal connection between the cytoplasmic streaming and the electric potential in P. polycephalum, the relationship between its plasmodium peristaltic behavior and the surface electric potential had not been statistically proven. In this study, based on the modern microscopic observation and the new electric potential measurement, we proved the consistence between the frequency spectrums of the electric potential wave and the peristaltic wave during the growth of plasmodium and the synchronization of their waveforms through cross-correlational analysis. And we concluded that the correlation exists between the peristaltic wave and the electric potential wave. This study added new evidence to the hypothesis of the sharing inner biological mechanism between plasmodium's peristaltic behavior and electric potential as previous studies indicated, and brought a new perspective towards the future research on amoeboid movement. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Personal Well-Being and Family Interactions of Working Couples With Preschool Children: A Correlational Study

    Directory of Open Access Journals (Sweden)

    Danila Secolim Coser

    2013-09-01

    Full Text Available This study’s objective was to verify potential relationships among personal well-being, parental practices, and interactions between parents and preschool children reported by working fathers and mothers ( n = 120, 60 couples from a city in the interior of São Paulo, Brazil. Data were collected using the Questionnaire on family and professional lives. Three scales were selected for data analysis: well-being; interaction between parents and children; and family life. Statistical tests (One-Way ANOVA and Pearson’s correlation coefficient showed negative correlations between child-rearing practices and health problems reported by parents. Positive correlations were also found between reported parental interactions and child-rearing practices. Parental practices and interactions between parents and children varied according to the number of children (one or two.

  11. Patching the Exchange-Correlation Potential in Density Functional Theory.

    Science.gov (United States)

    Huang, Chen

    2016-05-10

    A method for directly patching exchange-correlation (XC) potentials in materials is derived. The electron density of a system is partitioned into subsystem densities by dividing its Kohn-Sham (KS) potential among the subsystems. Inside each subsystem, its projected KS potential is required to become the total system's KS potential. This requirement, together with the nearsightedness principle of electronic matters, ensures that the electronic structures inside subsystems can be good approximations to the total system's electronic structure. The nearsightedness principle also ensures that subsystem densities could be well localized in their regions, making it possible to use high-level methods to invert the XC potentials for subsystem densities. Two XC patching methods are developed. In the local XC patching method, the total system's XC potential is improved in the cluster region. We show that the coupling between a cluster and its environment is important for achieving a fast convergence of the electronic structure in the cluster region. In the global XC patching method, we discuss how to patch the subsystem XC potentials to construct the XC potential in the total system, aiming to scale up high-level quantum mechanics simulations of materials. Proof-of-principle examples are given.

  12. University students' psychopathology: correlates and the examiner's potential bias effect

    Directory of Open Access Journals (Sweden)

    Helena Espirito Santo

    2015-02-01

    Aims: the main objective was to verify if there is a difference on psychopathological symptoms between two groups questioned by two different examiners, controlling for the potential role of social desirability, and other potential covariates. Additionally, we want to assess the level of psychopathology and its socio-demographic correlates.Methods: 185 Coimbra's university students completed the Brief Symptom Inventory/BSI and the Marlowe-Crowne Social Desirability Scale. In one group the examiner was of the same age and academic status as the students, while in the other group the examiner was older and a teacher. We studied the psychopathological correlates with Pearson, point-biserial correlations, and qui-square analyses, and we controlled the potential role of covariates through Quade non-parametric ANCOVAs. Results: The level of distress was lower in comparison with other investigations. Women had higher level of distress and more symptoms of somatization, anxiety, phobic anxiety, obsessive-compulsion, and depression. The students that live a higher distance from home had more anxiety and obsessive-compulsive symptoms. The group assessed by the younger examiner scored higher in distress and in some BSI factors, and had lower levels on social desirability. Conclusions: Sex and distance from home seem important factors for university students' mental health. However, the examiner does have an influence in the evaluation, probably because of social desirability, suggesting that the examiner's characteristics should be given in investigations involving university students.

  13. Neural correlate of human reciprocity in social interactions.

    Science.gov (United States)

    Sakaiya, Shiro; Shiraito, Yuki; Kato, Junko; Ide, Hiroko; Okada, Kensuke; Takano, Kouji; Kansaku, Kenji

    2013-01-01

    Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human) and strategy (random, tit-for-tat) in repeated prisoner's dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate) and theory of mind (ToM) regions [i.e., ventromedial prefrontal cortex (VMPFC) and precuneus]. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (de)activation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during social interactions.

  14. Neural correlate of human reciprocity in social interactions

    Directory of Open Access Journals (Sweden)

    Shiro eSakaiya

    2013-12-01

    Full Text Available Reciprocity plays a key role maintaining cooperation in society. However, little is known about the neural process that underpins human reciprocity during social interactions. Our neuroimaging study manipulated partner identity (computer, human and strategy (random, tit-for-tat in repeated prisoner’s dilemma games and investigated the neural correlate of reciprocal interaction with humans. Reciprocal cooperation with humans but exploitation of computers by defection was associated with activation in the left amygdala. Amygdala activation was also positively and negatively correlated with a preference change for human partners following tit-for-tat and random strategies, respectively. The correlated activation represented the intensity of positive feeling toward reciprocal and negative feeling toward non-reciprocal partners, and so reflected reciprocity in social interaction. Reciprocity in social interaction, however, might plausibly be misinterpreted and so we also examined the neural coding of insight into the reciprocity of partners. Those with and without insight revealed differential brain activation across the reward-related circuitry (i.e., the right middle dorsolateral prefrontal cortex and dorsal caudate and theory of mind (ToM regions (i.e., ventromedial prefrontal cortex [VMPFC] and precuneus. Among differential activations, activation in the precuneus, which accompanied deactivation of the VMPFC, was specific to those without insight into human partners who were engaged in a tit-for-tat strategy. This asymmetric (deactivation might involve specific contributions of ToM regions to the human search for reciprocity. Consequently, the intensity of emotion attached to human reciprocity was represented in the amygdala, whereas insight into the reciprocity of others was reflected in activation across the reward-related and ToM regions. This suggests the critical role of mentalizing, which was not equated with reward expectation during

  15. Hadron-hadron correlation and interaction from heavy-ion collisions

    Science.gov (United States)

    Ohnishi, Akira; Morita, Kenji; Miyahara, Kenta; Hyodo, Tetsuo

    2016-10-01

    We investigate the ΛΛ and K- p intensity correlations in high-energy heavy-ion collisions. First, we examine the dependence of the ΛΛ correlation on the ΛΛ interaction and the ΛΛ pair purity probability λ. For small λ, the correlation function needs to be suppressed by the ΛΛ interaction in order to explain the recently measured ΛΛ correlation data. By comparison, when we adopt the λ value evaluated from the experimentally measured Σ0 / Λ ratio, the correlation function needs to be enhanced by the interaction. We demonstrate that these two cases correspond to the two analyses which gave opposite signs of the ΛΛ scattering length. Next, we discuss the K- p correlation function. By using the local K bar N potential which reproduces the kaonic hydrogen data by SIDDHARTA, we obtain the K- p correlation function. We find that the K- p correlation can provide a complementary information to the K- p elastic scattering amplitude.

  16. Origin of the step structure of molecular exchange-correlation potentials.

    Science.gov (United States)

    Kohut, Sviataslau V; Polgar, Alexander M; Staroverov, Viktor N

    2016-08-21

    The exact exchange-correlation potential of a stretched heteronuclear diatomic molecule exhibits a localized upshift in the region around the more electronegative atom; by this device the Kohn-Sham scheme ensures that the molecule dissociates into neutral atoms. Baerends and co-workers showed earlier that the upshift originates in the response part of the exchange-correlation potential. We describe a reliable numerical method for constructing the response potential of a given many-electron system and report accurate plots of this quantity. We also demonstrate that the step feature itself can be obtained directly from the interacting wavefunction of the system by computing the so-called average local electron energy. These findings illustrate in previously unavailable detail the mechanism of the formation of the upshift and the role played by static correlation in this process.

  17. Interaction of elementary waves for equations of potential flow

    Institute of Scientific and Technical Information of China (English)

    陈恕行; 王辉

    1997-01-01

    Interaction of elementary waves for equations of unsteady potential flow in gas dynamics is considered . Under the assumptions on weakness of strength of the elementary waves the structure of solutions has been given in various cases of interaction of simple wave with shock, or interaction between simple waves or shocks. Hence the complete results on interaction of weak elementary waves for second-order equation of potential flow are obtained.

  18. Molecular Kohn-Sham exchange-correlation potential from the correlated ab initio electron density

    Science.gov (United States)

    Gritsenko, Oleg V.; van Leeuwen, Robert; Baerends, Evert Jan

    1995-09-01

    The molecular Kohn-Sham (KS) exchange-correlation potential vxc has been constructed for LiH from the correlated ab initio density ρ by means of the simple iterative procedure developed by van Leeuwen and Baerends [Phys. Rev. A 49, 2421 (1994)]. The corresponding KS energy characteristics, such as the kinetic energy of noninteracting particles Ts, kinetic part of the exchange-correlation energy Tc, and energy of the highest occupied molecular orbital ɛN, have been obtained with reasonable accuracy. A relation between the form of vxc and the electronic structure of LiH has been discussed. Test calculations for the two-electron H2 molecule have shown the efficiency of the procedure.

  19. Photodisintegration of light nuclei for testing a correlated realistic interaction in the continuum

    Science.gov (United States)

    Bacca, Sonia

    2007-04-01

    An exact calculation of the photodisintegration cross section of H3, He3, and He4 is performed by using as interaction the correlated Argonne V18 potential, constructed within the unitary correlation operator method (VUCOM). Calculations are carried out by using the Lorentz integral transform method in conjunction with a hyperspherical harmonics basis expansion. A comparison with other realistic potentials and with available experimental data is discussed. The VUCOM potential leads to a description of the cross section that is very similar to that of the Argonne V18 interaction with the inclusion of the Urbana IX three-body force for photon energies 45⩽ω⩽120 MeV, whereas larger differences are found close to threshold.

  20. A Partitioned Correlation Function Interaction approach for describing electron correlation in atoms

    CERN Document Server

    Verdebout, S; Jönsson, P; Gaigalas, G; Fischer, C Froese; Godefroid, M

    2013-01-01

    Traditional multiconfiguration Hartree-Fock (MCHF) and configuration interaction (CI) methods are based on a single orthonormal orbital basis (OB). For atoms with complicated shell structures, a large OB is needed to saturate all the electron correlation effects. The large OB leads to massive configuration state function (CSF) expansions that are difficult to handle. We show that it is possible to relax the orthonormality restriction on the OB and break down the originally large calculations to a set of smaller ones that can be run in parallel. Each calculation determines a partitioned correlation function (PCF) that accounts for a specific correlation effect. The PCFs are built on optimally localized orbital sets and are added to a zero-order multireference (MR) function to form a total wave function. The mixing coefficients of the PCFs are fixed from a small generalized eigenvalue problem. The required matrices are computed using a biorthonormal transformation technique. The new method, called partitioned c...

  1. Water-mediated correlations in DNA-enzyme interactions

    CERN Document Server

    Capolupo, A; Kurian, P; Vitiello, G

    2016-01-01

    In this paper we consider dipole-mediated correlations between DNA and enzymes in the context of their water environment. Such correlations emerge from electric dipole-dipole interactions between aromatic ring structures in DNA and in enzymes, and they are mediated by radiative fields that stimulate transitions between the $l=0$ and $l=1$ rotational levels of the molecular water electric dipoles. We show that there are matching collective modes between DNA and enzyme dipole fields, and that a dynamic time-averaged polarization vanishes in the water dipole field only if either DNA, enzyme, or both are absent from the sample. This persistent field may serve as the electromagnetic image that, in popular colloquialisms about DNA biochemistry, allows enzymes to "scan" or "read" the double helix. Topologically nontrivial configurations in the coherent ground state requiring clamplike enzyme behavior on the DNA may stem, ultimately, from spontaneously broken gauge symmetries.

  2. Screening for the drug-phospholipid interaction: correlation to phospholipidosis

    DEFF Research Database (Denmark)

    Alakoskela, Juha-Matti; Vitovic, Pavol; Kinnunen, Paavo K J

    2009-01-01

    Phospholipid bilayers represent a complex, anisotropic environment fundamentally different from bulk oil or octanol, for instance. Even "simple" drug association to phospholipid bilayers can only be fully understood if the slab-of-hydrocarbon approach is abandoned and the complex, anisotropic pro...... of these interactions in PLD in particular. We also focus on a potential causal connection between drug-induced PLD and steatohepatitis, which is induced by some cationic amphiphilic drugs....

  3. Ground State Correlations Using exp(S) Method for the Argonne-v18 Potential.

    Science.gov (United States)

    Heisenberg, Jochen; Mihaila, Bogdan

    1997-04-01

    We use the Argonne-v18 potential together with the phenomenological three-nucleon interaction to do the calculation of the mean-field single particle wave functions and the correlation operator S for ^16O. Our correlation operator includes the contributions from up to 4p4h terms. From the three-nucleon interaction we include only those terms that can be written as a density dependent two-body term. We present a breakdown of the contributions to the binding from the two- and the three-body interactions. The one- and the two-body densities for ^16O are presented. Effects of the center-of-mass correction on the charge density and form factor are also discussed.

  4. Potential Flow Interactions With Directional Solidification

    Science.gov (United States)

    Buddhavarapu, Sudhir S.; Meiburg, Eckart

    1999-01-01

    The effect of convective melt motion on the growth of morphological instabilities in crystal growth has been the focus of many studies in the past decade. While most of the efforts have been directed towards investigating the linear stability aspects, relatively little attention has been devoted to experimental and numerical studies. In a pure morphological case, when there is no flow, morphological changes in the solid-liquid interface are governed by heat conduction and solute distribution. Under the influence of a convective motion, both heat and solute are redistributed, thereby affecting the intrinsic morphological phenomenon. The overall effect of the convective motion could be either stabilizing or destabilizing. Recent investigations have predicted stabilization by a flow parallel to the interface. In the case of non-parallel flows, e.g., stagnation point flow, Brattkus and Davis have found a new flow-induced morphological instability that occurs at long wavelengths and also consists of waves propagating against the flow. Other studies have addressed the nonlinear aspects (Konstantinos and Brown, Wollkind and Segel)). In contrast to the earlier studies, our present investigation focuses on the effects of the potential flow fields typically encountered in Hele-Shaw cells. Such a Hele-Shaw cell can simulate a gravity-free environment in the sense that buoyancy-driven convection is largely suppressed, and hence negligible. Our interest lies both in analyzing the linear stability of the solidification process in the presence of potential flow fields, as well as in performing high-accuracy nonlinear simulations. Linear stability analysis can be performed for the flow configuration mentioned above. It is observed that a parallel potential flow is stabilizing and gives rise to waves traveling downstream. We have built a highly accurate numerical scheme which is validated at small amplitudes by comparing with the analytically predicted results for the pure

  5. Many-body correlations in Semiclassical Molecular Dynamics and Skyrme interaction

    CERN Document Server

    Papa, Massimo

    2012-01-01

    Constraint Molecular dynamics CoMD calculations have been performed for asymmetric nuclear matter (NM) by using a simple effective interactions of the Skyrme type. The set of parameter values reproducing common accepted saturation properties of nuclear matter have been obtained for different degree of stiffness characterizing the iso-vectorial potential density dependence. A comparison with results obtained in the limit of the Semi-Classical Mean Field approximation using the same kind of interaction put in evidence the role played by the many-body correlations in to explain the noticeable differences obtained in the parameter values in the two cases. Even if from a numerical point of view the obtained results are strictly valid for the CoMD model, some rather general feature of the discussed correlations can give a wider meaning to the obtained differences being strongly related to the spacial correlations generated in the semiclassical wave packets dynamics.

  6. Molecular spin on surface: From strong correlation to dispersion interactions

    Science.gov (United States)

    Zhang, Yachao

    2016-09-01

    A reliable prediction of magnetic properties of surface-supported molecules containing 3d/4f spin carriers has challenged the electronic structure theory for decades. Here we tackle this problem with Hubbard-U corrected van der Waals density functional (vdW-DF), incorporating strong correlation effects of the localized electrons and dispersion interactions involved in the molecule-surface binding. By fitting the spin state energetics of a series of Fe(ii) compounds with varying ligand field strength, we find that the optimal U value for vdW-DF is much smaller than that for the local density approximation (LDA) while quite similar to that for the generalized gradient approximation (GGA). We show that although vdW-DF+U overestimates largely the metal-ligand bond distance, the predicted adiabatic high-spin-low-spin energy splitting ΔEHL is only slightly changed with respect to that obtained using the LDA+U geometries consistent with experiment. Then we use Cu(111)-supported metallocene (M(C5H5)2, M = Fe, and Co) as a prototype example to explore the effects of the molecule-surface interactions. We show that the non-local dispersion interactions, poorly described by LDA and GGA while reasonably captured by vdW-DF, are critical for reproducing ΔEHL at large molecule-surface distances. Besides, we find that ΔEHL is decreased by the molecule-metal contact, which is shown to weaken the local ligand field around the magnetic center.

  7. Discrete Time Markovian Agents Interacting Through a Potential

    CERN Document Server

    Budhiraja, Amarjit; Rubenthaler, Sylvain

    2011-01-01

    A discrete time stochastic model for a multiagent system given in terms of a large collection of interacting Markov chains is studied. The evolution of the interacting particles is described through a time inhomogeneous transition probability kernel that depends on the 'gradient' of the potential field. The particles, in turn, dynamically modify the potential field through their cumulative input. Interacting Markov processes of the above form have been suggested as models for active biological transport in response to external stimulus such as a chemical gradient. One of the basic mathematical challenges is to develop a general theory of stability for such interacting Markovian systems and for the corresponding nonlinear Markov processes that arise in the large agent limit. Such a theory would be key to a mathematical understanding of the interactive structure formation that results from the complex feedback between the agents and the potential field. It will also be a crucial ingredient in developing simulat...

  8. Correlated Light-Matter Interactions in Cavity QED

    Science.gov (United States)

    Flick, Johannes; Pellegrini, Camilla; Ruggenthaler, Michael; Appel, Heiko; Tokatly, Ilya; Rubio, Angel

    2015-03-01

    In the last decade, time-dependent density functional theory (TDDFT) has been successfully applied to a large variety of problems, such as calculations of absorption spectra, excitation energies, or dynamics in strong laser fields. Recently, we have generalized TDDFT to also describe electron-photon systems (QED-TDDFT). Here, matter and light are treated on an equal quantized footing. In this work, we present the first numerical calculations in the framework of QED-TDDFT. We show exact solutions for fully quantized prototype systems consisting of atoms or molecules placed in optical high-Q cavities and coupled to quantized electromagnetic modes. We focus on the electron-photon exchange-correlation (xc) contribution by calculating exact Kohn-Sham potentials using fixed-point inversions and present the performance of the first approximated xc-potential based on an optimized effective potential (OEP) approach. Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, and Fritz-Haber-Institut der MPG, Berlin

  9. Helium-3 Microscopic Optical Model Potential Based on Skyrme Interaction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The helium-3 microscopic optical potential is obtained by Green function method through nuclear matter approximation and local density approximation based on the effective Skyrme interaction. The reaction cross

  10. Calculation of Interaction Potentials between Spherical and Deformed Nuclei

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gao-Long; XU Xin-Xing; BAI Chun-Lin; YU Ning; ZHANG Huan-Qiao; LIU Zu-Hua; ZHANG Chun-Lei; LIN Cheng-Jian; YANG Feng; AN Guang-Peng; JIA Hui-Ming; WU Zhen-Dong

    2007-01-01

    The interaction potential for spherical-deformed reaction partners is calculated. The shape, separation and orientation dependence of the interaction potential and fusion cross section of the system 32S+154Sm are investigated within the double-folding model of the deformed nuclei. The effective nucleon-nucleon interaction is taken to be the M3Y-Reid potential. The density is considered for three terms of the expansion using the truncated multipole expansion method, which is a deformed Fermi shape with quadrupole and hexadecapole for the density distribution of 154Sm. It is found for the interaction potential that the height and the position of barrier strongly depend on the deformations, the orientation angle of the deformed nucleus, and hence produce great effects on fusion cross section. The integrated fusion cross section is in good agreement with the experimental data.

  11. [Correlation of evoked potentials in the frontal cortex and hippocampus of cats in emotional stress].

    Science.gov (United States)

    Vanetsian, G L; Pavlova, I V

    2002-01-01

    Averaged auditory evoked potentials (AEPs) were recorded in symmetric points of the frontal cortex and dorsal hippocampus of cats performing acquired conditioned food-procuring reaction reinforced in 100% cases, urgent transition to 30%-reinforcement, and return to 100%-reinforcement. Emotional stress estimated by a heart rate rise developed during increased food motivation of a cat as well as during change in ordinary food-procuring stereotype. The emotional stress was accompanied by a high positive correlation of cortical and hippocampal AEPs. Decrease in the stress level led to a drop between AEP correlations and appearance of their negative values. In emotional stress, the interactions between the frontal cortex and dorsal hippocampus were asymmetric: right-side correlations were higher.

  12. Child abuse potential inventory and parenting behavior: relationships with high-risk correlates.

    Science.gov (United States)

    Haskett, M E; Scott, S S; Fann, K D

    1995-12-01

    The primary purpose of this research was to examine the construct validity of the Child Abuse Potential Inventory by comparing maltreating and high-risk parents' CAP Inventory abuse scores to their behavior during interactions with their children. A second purpose was to determine the degree to which CAP Inventory scores and parenting behavior were related to several known correlates of abuse, as measured by parent and teacher reports. Participants (n = 41) included abusive and high-risk parents and their children referred to a treatment group. Correlational analyses revealed that CAP Inventory scores and observed parenting style yielded highly related findings, supporting construct validity of the CAP Inventory. However, the CAP Inventory and observed behavior index showed a different pattern of relationships to the risk correlates. Implications for assessment of risk status are discussed and recommendations are provided for continued research.

  13. Potential drug interactions in patients given antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Wendel Mombaque dos Santos

    Full Text Available ABSTRACT Objective: to investigate potential drug-drug interactions (PDDI in patients with HIV infection on antiretroviral therapy. Methods: a cross-sectional study was conducted on 161 adults with HIV infection. Clinical, socio demographic, and antiretroviral treatment data were collected. To analyze the potential drug interactions, we used the software Micromedex(r. Statistical analysis was performed by binary logistic regression, with a p-value of ≤0.05 considered statistically significant. Results: of the participants, 52.2% were exposed to potential drug-drug interactions. In total, there were 218 potential drug-drug interactions, of which 79.8% occurred between drugs used for antiretroviral therapy. There was an association between the use of five or more medications and potential drug-drug interactions (p = 0.000 and between the time period of antiretroviral therapy being over six years and potential drug-drug interactions (p < 0.00. The clinical impact was prevalent sedation and cardiotoxicity. Conclusions: the PDDI identified in this study of moderate and higher severity are events that not only affect the therapeutic response leading to toxicity in the central nervous and cardiovascular systems, but also can interfere in tests used for detection of HIV resistance to antiretroviral drugs.

  14. Incidence of potential drug-drug interactions with antidiabetic drugs.

    Science.gov (United States)

    Samardzic, I; Bacic-Vrca, V

    2015-06-01

    In an effort to achieve normoglycemia more than one antidiabetic agent is usually needed. Diabetes is associated with several comorbidities and patients with diabetes are often treated with multiple medications. Therefore, patients with diabetes are especially exposed to drug-drug interactions (DDIs). The aim of this study was to analyse the incidence and type of potential DDIs of antidiabetic drugs in patients with diabetes. This retrospective study analyzed pharmacy record data of 225 patients with diabetes mellitus. Both type 1 and type 2 diabetic patients who were taking at least one antidiabetic agent during the period of six months were included. We investigated associated therapy in that period in order to identify potential DDIs with antidiabetic therapy. Potential interactions were identified by Lexicomp Lexi-Interat Online (Lexi-Comp, Inc., Hudson, USA) software which categorizes potential DDIs according to clinical significance in five types (A, B, C, D and X). Categories C, D and X are of clinical concern and always require medical attention (therapy monitoring, therapy modification or avoiding combination). We found that 80.9% of patients had at least one potential category C interaction while there were no D and X interactions. Most frequently encountered potential DDI (n = 176) included antidiabetic drugs and thiazide or thiazide like diuretics. Patients with diabetes are exposed to a large number of potential clinically significant DDIs that may require appropriate monitoring. Using databases of DDIs could be helpful in reducing the risk of potential clinically significant DDIs.

  15. Risk factors for potential drug interactions in general practice

    DEFF Research Database (Denmark)

    Bjerrum, Lars; Gonzalez Lopez-Valcarcel, Beatriz; Petersen, Gert

    2008-01-01

    Pharmacoepidemiologic Database, OPED) covering prescriptions to all inhabitants in the county of Funen, Denmark. All individuals exposed to concurrent use of two or more drugs (polypharmacy) were identified. Combinations of drugs with potential interactions were registered and classified as major, moderate, or minor......, depending on the severity of outcome and the quality of documentation. A two-level random coefficient logistic regression model was used to investigate factors related to potential drug interactions. Results: One-third of the population was exposed to polypharmacy, and 6% were exposed to potential drug...

  16. CRISPR Content Correlates with the Pathogenic Potential of Escherichia coli.

    Science.gov (United States)

    García-Gutiérrez, Enriqueta; Almendros, Cristóbal; Mojica, Francisco J M; Guzmán, Noemí M; García-Martínez, Jesús

    2015-01-01

    Guide RNA molecules (crRNA) produced from clustered regularly interspaced short palindromic repeat (CRISPR) arrays, altogether with effector proteins (Cas) encoded by cognate cas (CRISPR associated) genes, mount an interference mechanism (CRISPR-Cas) that limits acquisition of foreign DNA in Bacteria and Archaea. The specificity of this action is provided by the repeat intervening spacer carried in the crRNA, which upon hybridization with complementary sequences enables their degradation by a Cas endonuclease. Moreover, CRISPR arrays are dynamic landscapes that may gain new spacers from infecting elements or lose them for example during genome replication. Thus, the spacer content of a strain determines the diversity of sequences that can be targeted by the corresponding CRISPR-Cas system reflecting its functionality. Most Escherichia coli strains possess either type I-E or I-F CRISPR-Cas systems. To evaluate their impact on the pathogenicity of the species, we inferred the pathotype and pathogenic potential of 126 strains of this and other closely related species and analyzed their repeat content. Our results revealed a negative correlation between the number of I-E CRISPR units in this system and the presence of pathogenicity traits: the median number of repeats was 2.5-fold higher for commensal isolates (with 29.5 units, range 0-53) than for pathogenic ones (12.0, range 0-42). Moreover, the higher the number of virulence factors within a strain, the lower the repeat content. Additionally, pathogenic strains of distinct ecological niches (i.e., intestinal or extraintestinal) differ in repeat counts. Altogether, these findings support an evolutionary connection between CRISPR and pathogenicity in E. coli.

  17. CRISPR Content Correlates with the Pathogenic Potential of Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Enriqueta García-Gutiérrez

    Full Text Available Guide RNA molecules (crRNA produced from clustered regularly interspaced short palindromic repeat (CRISPR arrays, altogether with effector proteins (Cas encoded by cognate cas (CRISPR associated genes, mount an interference mechanism (CRISPR-Cas that limits acquisition of foreign DNA in Bacteria and Archaea. The specificity of this action is provided by the repeat intervening spacer carried in the crRNA, which upon hybridization with complementary sequences enables their degradation by a Cas endonuclease. Moreover, CRISPR arrays are dynamic landscapes that may gain new spacers from infecting elements or lose them for example during genome replication. Thus, the spacer content of a strain determines the diversity of sequences that can be targeted by the corresponding CRISPR-Cas system reflecting its functionality. Most Escherichia coli strains possess either type I-E or I-F CRISPR-Cas systems. To evaluate their impact on the pathogenicity of the species, we inferred the pathotype and pathogenic potential of 126 strains of this and other closely related species and analyzed their repeat content. Our results revealed a negative correlation between the number of I-E CRISPR units in this system and the presence of pathogenicity traits: the median number of repeats was 2.5-fold higher for commensal isolates (with 29.5 units, range 0-53 than for pathogenic ones (12.0, range 0-42. Moreover, the higher the number of virulence factors within a strain, the lower the repeat content. Additionally, pathogenic strains of distinct ecological niches (i.e., intestinal or extraintestinal differ in repeat counts. Altogether, these findings support an evolutionary connection between CRISPR and pathogenicity in E. coli.

  18. Communication: Configuration interaction combined with spin-projection for strongly correlated molecular electronic structures

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchimochi, Takashi, E-mail: tsuchimochi@gmail.com; Ten-no, Seiichiro, E-mail: tenno@garnet.kobe-u.ac.jp [Graduate School of System Informatics, Kobe University, Kobe 657-8501 (Japan)

    2016-01-07

    We present single and double particle-hole excitations in the recently revived spin-projected Hartree-Fock. Our motivation is to treat static correlation with spin-projection and recover the residual correlation, mostly dynamic in nature, with simple configuration interaction (CI). To this end, we introduce the Wick theorem for nonorthogonal determinants, which enables an efficient implementation in conjunction with the direct CI scheme. The proposed approach, termed spin-extended CI with singles and doubles, achieves a balanced treatment between dynamic and static correlations. To approximately account for the quadruple excitations, we also modify the well-known Davidson correction. We report that our approaches yield surprisingly accurate potential curves for HF, H{sub 2}O, N{sub 2}, and a hydrogen lattice, compared to traditional single reference wave function methods at the same computational scaling as regular CI.

  19. Configuration interaction combined with spin-projection for strongly correlated molecular electronic structures

    CERN Document Server

    Tsuchimochi, Takashi

    2015-01-01

    We introduce single and double particle-hole excitations in the recently revived spin-projected Hartree-Fock. Our motivation is to treat static correlation with spin-projection and recover the residual correlation, mostly dynamic in nature, with simple configuration interaction (CI). To this end, we introduce the Wick theorem for nonorhtogonal determinants, which enables an efficient implementation in conjunction with the direct CI scheme. The proposed approach, termed ECISD, achieves a balanced treatment between dynamic and static correlations. To approximately account for the quadruple excitations, we also modify the well-known Davidson correction. We report our approaches yield surprisingly accurate potential curves for HF, H2O, N2, and a hydrogen lattice, compared to traditional single reference wave function methods at the same computational scaling as regular CI.

  20. Linear correlation analysis in finding interactions: Half of predicted interactions are undeterministic and one-third of candidate direct interactions are missed

    OpenAIRE

    WenJun Zhang; Xin Li

    2015-01-01

    An ecological network can be constructed by calculating the sampling data of taxon by sample type. A statistically significant Pearson linear correlation means an indirect or direct linear interaction between two taxa, and a statistically significant partial correlation based on Pearson linear correlation, due to elimination of indirect effects of other taxa, means a candidate direct interaction between two taxa. People always use Pearson linear correlation to find interactions. However, some...

  1. Prevalence and Correlates of Drug-drug Interactions in the Regional Hospital of Gjilan, Kosovo.

    Science.gov (United States)

    Shabani, Driton; Tahiri, Zejdush; Bara, Petrit; Hudhra, Klejda; Malaj, Ledian; Jucja, Besnik; Bozalia, Adnan; Burazeri, Genc

    2014-08-01

    Our aim was to assess the prevalence and socioeconomic and clinical correlates of drug-drug interactions among the adult population of transitional Kosovo. A cross-sectional study was conducted including a representative sample of 1921 patients aged ≥18 years (mean age: 57.8±11.2 years; 50.3% women; overall response: 96%) from the regional hospital of Gjilan, Kosovo, during 2011-2013. Potential drug-drug-interactions were assessed and clinical data as well as demographic and socioeconomic information were collected. Binary logistic regression was used to assess the correlates of drug-drug interactions. Upon multivariable adjustment for all the demographic and socioeconomic factors as well as the clinical characteristics, drug-drug interactions were positively and significantly related to older age (OR=2.1, 95%CI=1.3-2.8), a lower educational attainment (OR=1.4, 95%CI=1.1-1.9), a longer hospitalization period (OR=2.7, 95%CI=2.1-3.6), presence of three groups of diseases [infectious diseases (OR=1.7, 95%CI=1.3-2.4), cardiovascular diseases (OR=1.8, 95%CI=1.4-2.6), respiratory diseases (OR=1.6, 95%CI=1.2-2.5)], presence of comorbid conditions (OR=3.2, 95%CI=2.3-4.4) and an intake of at least four drugs (OR=5.9, 95%CI=4.6-7.1). Our study provides important evidence on the prevalence and socioeconomic and clinical correlates of drug-drug interactions among the hospitalized patients in the regional hospital of Gjilan, Kosovo. Findings from our study should raise the awareness of decision-makers and policy makers about the prevalence and determinants of drug-drug interactions in the adult population of post-war Kosovo.

  2. Snapping Sharks, Maddening Mindreaders, and Interactive Images: Teaching Correlation.

    Science.gov (United States)

    Mitchell, Mark L.

    Understanding correlation coefficients is difficult for students. A free computer program that helps introductory psychology students distinguish between positive and negative correlation, and which also teaches them to understand the differences between correlation coefficients of different size is described in this paper. The program is…

  3. Predicting protein-protein interactions from sequence using correlation coefficient and high-quality interaction dataset.

    Science.gov (United States)

    Shi, Ming-Guang; Xia, Jun-Feng; Li, Xue-Ling; Huang, De-Shuang

    2010-03-01

    Identifying protein-protein interactions (PPIs) is critical for understanding the cellular function of the proteins and the machinery of a proteome. Data of PPIs derived from high-throughput technologies are often incomplete and noisy. Therefore, it is important to develop computational methods and high-quality interaction dataset for predicting PPIs. A sequence-based method is proposed by combining correlation coefficient (CC) transformation and support vector machine (SVM). CC transformation not only adequately considers the neighboring effect of protein sequence but describes the level of CC between two protein sequences. A gold standard positives (interacting) dataset MIPS Core and a gold standard negatives (non-interacting) dataset GO-NEG of yeast Saccharomyces cerevisiae were mined to objectively evaluate the above method and attenuate the bias. The SVM model combined with CC transformation yielded the best performance with a high accuracy of 87.94% using gold standard positives and gold standard negatives datasets. The source code of MATLAB and the datasets are available on request under smgsmg@mail.ustc.edu.cn.

  4. Electrostatic potential profile and nonlinear current in an interacting one-dimensional molecular wire

    Indian Academy of Sciences (India)

    S Lakshmi; Swapan K Pati

    2003-10-01

    We consider an interacting one-dimensional molecular wire attached to two metal electrodes on either side of it. The electrostatic potential profile across the wire-electrode interface has been deduced solving the Schrodinger and Poisson equations self-consistently. Since the Poisson distribution crucially depends on charge densities, we have considered different Hamiltonian parameters to model the nanoscale wire. We find that for very weak electron correlations, the potential gradient is almost zero in the middle of the wire but are large near the chain ends. However, for strong correlations, the potential is essentially a ramp function. The nonlinear current, obtained from the scattering formalism, is found to be less with the ramp potential than for weak correlations. Some of the interesting features in current-voltage characteristics have been explained using one-electron formalism and instabilities in the system.

  5. Effective polarization interaction potentials of the partially ionized dense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanov, T S [IETP, Al Farabi Kazakh National University, Tole Bi 96a, 050012 Almaty (Kazakhstan); Dzhumagulova, K N [IETP, Al Farabi Kazakh National University, Tole Bi 96a, 050012 Almaty (Kazakhstan); Omarbakiyeva, Yu A [IETP, Al Farabi Kazakh National University, Tole Bi 96a, 050012 Almaty (Kazakhstan); Roepke, G [Institute of Physics, University of Rostock, D-18051 Rostock (Germany)

    2006-04-28

    The effective polarization interaction potential between charged and neutral particles is considered for a partially ionized plasma. This pseudopotential is deduced taking into account quantum-mechanical effects at short distances as well as screening effects at large distances. Furthermore, a cutoff radius is obtained using a modified effective-range theory. Explicit results for parameters describing the interaction of the atom with charged particles are given.

  6. Generation of directional EOF by interactive oscillatory zeta potential.

    Science.gov (United States)

    Kuo, Chih-Yu; Wang, Chang-Yi; Chang, Chien-Cheng

    2008-11-01

    A steady directional EOF due to a nonlinear interaction between oscillatory axial electrical fields and oscillatory wall potentials (zeta potentials) is presented. This is a new mechanism to produce such a mean flow. It is found that the flow velocity depends not on the external driving frequency but on the phase angle difference between the electric fields and the zeta potentials. The formulation can also be reduced to the static EOF straightforwardly. For the purpose of theoretical demonstration, we use the Debye-Huckel approximation for the zeta potential. Results of planar and cylindrical capillaries are given.

  7. Electron interactions in graphene through an effective Coulomb potential

    Science.gov (United States)

    Rodrigues, Joao N. B.; Adam, Shaffique

    A recent numerical work [H.-K. Tang et al, PRL 115, 186602 (2015)] considering graphene's π-electrons interacting through an effective Coulomb potential that is finite at short-distances, stressed the importance of the sp2 -electrons in determining the semimetal to Mott insulator phase transition in graphene. Some years ago, I. F. Herbut [PRL 97, 146401 (2006)] studied such a transition by mapping graphene's π-electrons into a Gross-Neveu model. From a different perspective, D. T. Son [PRB 75, 235423 (2007)] put the emphasis on the long-range interactions by modelling graphene as Dirac fermions interacting through a bare Coulomb potential. Here we build on these works and explore the phase diagram of Dirac fermions interacting through an effective Coulomb-like potential screened at short-distances. The interaction potential used allows for analytic results that controllably switch between the two perspectives above. This work was supported by the Singapore National Research Foundation (NRF-NRFF2012-01 and CA2DM medium-sized centre program) and by the Singapore Ministry of Education and Yale-NUS College (R-607-265-01312).

  8. Observational evidences of the Yukawa Potential Interacting Dark Matter

    CERN Document Server

    Chan, Man Ho

    2013-01-01

    Recent observations in galaxies and clusters indicate dark matter density profiles exhibit core-like structures which contradict to the numerical simulation results of collisionless cold dark matter. On the other hand, it has been shown that cold dark matter particles interacting through a Yukawa potential could naturally explain the cores in dwarf galaxies. In this article, I use the Yukawa Potential interacting dark matter model to derive two simple scaling relations on the galactic and cluster scales respectively, which give excellent agreements with observations. Also, in our model, the masses of the force carrier and dark matter particle can be constrained by the observational data.

  9. An Interdisciplinary Meta-Analysis of the Potential Antecedents, Correlates, and Consequences of Protege Perceptions of Mentoring

    Science.gov (United States)

    Eby, Lillian Turner de Tormes; Allen, Tammy D.; Hoffman, Brian J.; Baranik, Lisa E.; Sauer, Julia B.; Baldwin, Sean; Morrison, M. Ashley; Kinkade, Katie M.; Maher, Charleen P.; Curtis, Sara; Evans, Sarah C.

    2013-01-01

    This meta-analysis summarized youth, academic, and workplace research on the potential antecedents (demographics, human capital, and relationship attributes), correlates (interaction frequency, relationship length, performance, motivation, and social capital), and consequences (attitudinal, behavioral, career-related, and health-related outcomes)…

  10. Study of interaction in silica glass via model potential approach

    Science.gov (United States)

    Mann, Sarita; Rani, Pooja

    2016-05-01

    Silica is one of the most commonly encountered substances in daily life and in electronics industry. Crystalline SiO2 (in several forms: quartz, cristobalite, tridymite) is an important constituent of many minerals and gemstones, both in pure form and mixed with related oxides. Cohesive energy of amorphous SiO2 has been investigated via intermolecular potentials i.e weak Van der Waals interaction and Morse type short-range interaction. We suggest a simple atom-atom based Van der Waals as well as Morse potential to find cohesive energy of glass. It has been found that the study of silica structure using two different model potentials is significantly different. Van der Waals potential is too weak (P.E =0.142eV/molecule) to describe the interaction between silica molecules. Morse potential is a strong potential, earlier given for intramolecular bonding, but if applied for intermolecular bonding, it gives a value of P.E (=-21.92eV/molecule) to appropriately describe the structure of silica.

  11. The electromyographic DC potential as a correlate of muscular activity.

    Science.gov (United States)

    Trimmel, M; Streicher, F; Groll-Knapp, E; Haider, M

    1989-01-01

    The present experiment was undertaken to demonstrate the effect of muscular force as well as duration of muscular work on the electromyographic (EMG) DC potential. Thirty subjects had to lift different weights by flexing the right forearm within a defined and constant setting for 20 s. The experimental variables were weight (0.5, 1, 2, and 3 kg) and time. The EMG was recorded from the belly of the right biceps brachii muscle in a quasi-unipolar manner and split into an integrated ac channel (IEMG) and a dc channel (DC-EMG). The average IEMG showed a ramp-like shape. Analysis showed a positive relationship for weight (p less than 0.0001) and time (p less than 0.0001) with the IEMG. The average shape of the DC-EMG showed a negative initiation potential, a monotonically increasing negative potential during contraction (contraction potential), a positively peaking off potential and a slow return to baseline (after potential). Analyses of variance demonstrated a significant (p less than 0.001) relationship of weight to the magnitude of the initiation and the termination potential. Regression analyses displayed an inverse relationship of time to the termination (p less than 0.01) and to the resolution potential (p less than 0.001). The DC-EMG showed higher peaks (initiation and termination potential) for heavier weights. For the termination and after potential less positive deflections were found with increasing time (fatigue). A control condition (isometric contraction) indicated that the initiation, contraction, and termination potential of the DC-EMG may also be related to aspects of the movement. Results suggest that the DC-EMG is a more complex measure of muscular activity than the IEMG.

  12. Interacting Bose gas confined in a Kronig-Penney potential

    Science.gov (United States)

    Rodríguez, O. A.; Solís, M. A.

    We analyze the effect of the 1D periodic Kronig-Penney potential, composed of barriers of width b and separated a distance a, over an interacting Bose gas. At T = 0 , the Gross-Pitaevskii equation is solved analytically in terms of the Jacobi elliptic functions for repulsive or attractive interaction between bosons. By applying the boundary conditions for periodic solutions as well as the normalization of the wave function, we arrive to a set of nonlinear equations from which we obtain the density profile and the chemical potential of the condensate as a function of the particle momentum. The profiles for attractive and repulsive interactions are compared with that of the non-interacting case. For attractive interaction we are able to observe a pronounced spatial localization in the middle of every two barriers. We reproduce the well known results when the Kronig-Penney potential becomes a Dirac Comb. We acknowledge partial support from Grants PAPIIT IN111613 and CONACyT 221030.

  13. Market potential for interactive audio-visual media

    NARCIS (Netherlands)

    Leurdijk, A.; Limonard, S.

    2005-01-01

    NM2 (New Media for a New Millennium) develops tools for interactive, personalised and non-linear audio-visual content that will be tested in seven pilot productions. This paper looks at the market potential for these productions from a technological, a business and a users' perspective. It shows tha

  14. Market potential for interactive audio-visual media

    NARCIS (Netherlands)

    Leurdijk, A.; Limonard, S.

    2005-01-01

    NM2 (New Media for a New Millennium) develops tools for interactive, personalised and non-linear audio-visual content that will be tested in seven pilot productions. This paper looks at the market potential for these productions from a technological, a business and a users' perspective. It shows tha

  15. Comparison of biomolecules on the basis of Molecular Interaction Potentials

    Directory of Open Access Journals (Sweden)

    Rodrigo Jordi

    2002-01-01

    Full Text Available Molecular Interaction Potentials (MIP are frequently used for the comparison of series of compounds displaying related biological behaviors. These potentials are interaction energies between the considered compounds and relevant probes. The interaction energies are computed in the nodes of grids defined around the compounds. There is a need of detailed and objective comparative analyses of MIP distributions in the framework of structure-activity studies. On the other hand, MIP-based studies do not have to be restricted to series of small ligands, since such studies present also interesting possibilities for the analysis and comparison of biological macromolecules. Such analyses can benefit from the application of new methods and computational approaches. The new software MIPSim (Molecular Interaction Potentials Similarity analysis has recently been introduced with the purpose of analyzing and comparing MIP distributions of series of biomolecules. This program is transparently integrated with other programs, like GAMESS or GRID, which can be used for the computation of the potentials to be analyzed or compared. MIPSim incorporates several definitions of similarity coefficients, and is capable of combining several similarity measures into a single one. On the other hand, MIPSim can perform automatic explorations of the maximum similarity alignments between pairs of molecules.

  16. Electronic properties and momentum densities of tin chalcogenides: Validation of PBEsol exchange-correlation potential

    Energy Technology Data Exchange (ETDEWEB)

    Ahuja, B.L., E-mail: blahuja@yahoo.ik [Department of Physics, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India); Raykar, Veera; Joshi, Ritu [Department of Physics, M.L. Sukhadia University, Udaipur 313001, Rajasthan (India); Tiwari, Shailja [Department of Physics, Govt. Women Engineering College, Ajmer 305001, Rajasthan (India); Talreja, Sonal [Department of Computer Science, M.L. Sukhadia University, Udaipur 313001 (India); Choudhary, Gopal [Department of Physics, Techno India NJR Institute of Technology, Udaipur 313001, Rajasthan (India)

    2015-05-15

    We report Compton profiles of SnS and SnTe at a momentum resolution of 0.34 a.u. using a 20 Ci {sup 137}Cs Compton spectrometer. To compare our experimental data, we have also computed the theoretical Compton profiles using density functional theory within linear combination of atomic orbitals (LCAO) method. To interpret the relative nature of bonding in these compounds, we have scaled the experimental and theoretical Compton profiles on equal-valence-electron-density (EVED). On the basis of EVED profiles, it is seen that SnTe shows more covalent character than SnS. To rectify the substantial disagreement between experimental and theoretical band gaps, we have also presented the energy bands and density of states of both the compounds using full-potential linearized augmented plane wave method (FP-LAPW) including spin–orbit interaction within the PBEsol exchange-correlation potential.

  17. Block renormalization group in a formalism with lattice wavelets: Correlation function formulas for interacting fermions

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, E. [Departamento Fisica-ICEx, UFMG, CP 702, Belo Horizonte MG 30.161-970 (Brazil); Procacci, A. [Departamento Matematica-ICEx, UFMG, CP 702, Belo Horizonte MG 30.161-970 (Brazil)

    1997-03-01

    Searching for a general and technically simple multiscale formalism to treat interacting fermions, we develop a (Wilson{endash}Kadanoff) block renormalization group mechanism, which, due to the property of {open_quotes}orthogonality between scales,{close_quotes} establishes a trivial link between the correlation functions and the effective potential flow, leading to simple expressions for the generating and correlation functions. Everything is based on the existence of {open_quotes}special configurations{close_quotes} (lattice wavelets) for multiscale problems: using a simple linear change of variables relating the initial fields to these configurations, we establish the formalism. The algebraic formulas show a perfect parallel with those obtained for bosonic problems, considered in previous works. {copyright} 1997 Academic Press, Inc.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. Potential disruption of protein-protein interactions by graphene oxide.

    Science.gov (United States)

    Feng, Mei; Kang, Hongsuk; Yang, Zaixing; Luan, Binquan; Zhou, Ruhong

    2016-06-14

    Graphene oxide (GO) is a promising novel nanomaterial with a wide range of potential biomedical applications due to its many intriguing properties. However, very little research has been conducted to study its possible adverse effects on protein-protein interactions (and thus subsequent toxicity to human). Here, the potential cytotoxicity of GO is investigated at molecular level using large-scale, all-atom molecular dynamics simulations to explore the interaction mechanism between a protein dimer and a GO nanosheet oxidized at different levels. Our theoretical results reveal that GO nanosheet could intercalate between the two monomers of HIV-1 integrase dimer, disrupting the protein-protein interactions and eventually lead to dimer disassociation as graphene does [B. Luan et al., ACS Nano 9(1), 663 (2015)], albeit its insertion process is slower when compared with graphene due to the additional steric and attractive interactions. This study helps to better understand the toxicity of GO to cell functions which could shed light on how to improve its biocompatibility and biosafety for its wide potential biomedical applications.

  1. Potential disruption of protein-protein interactions by graphene oxide

    Science.gov (United States)

    Feng, Mei; Kang, Hongsuk; Yang, Zaixing; Luan, Binquan; Zhou, Ruhong

    2016-06-01

    Graphene oxide (GO) is a promising novel nanomaterial with a wide range of potential biomedical applications due to its many intriguing properties. However, very little research has been conducted to study its possible adverse effects on protein-protein interactions (and thus subsequent toxicity to human). Here, the potential cytotoxicity of GO is investigated at molecular level using large-scale, all-atom molecular dynamics simulations to explore the interaction mechanism between a protein dimer and a GO nanosheet oxidized at different levels. Our theoretical results reveal that GO nanosheet could intercalate between the two monomers of HIV-1 integrase dimer, disrupting the protein-protein interactions and eventually lead to dimer disassociation as graphene does [B. Luan et al., ACS Nano 9(1), 663 (2015)], albeit its insertion process is slower when compared with graphene due to the additional steric and attractive interactions. This study helps to better understand the toxicity of GO to cell functions which could shed light on how to improve its biocompatibility and biosafety for its wide potential biomedical applications.

  2. Correlated wounded hot spots in proton-proton interactions

    Science.gov (United States)

    Albacete, Javier L.; Petersen, Hannah; Soto-Ontoso, Alba

    2017-06-01

    We investigate the effect of nontrivial spatial correlations between proton constituents, considered in this work to be gluonic hot spots, on the initial conditions of proton-proton collisions from ISR to Large Hadron Collider energies, i.e., √{s }=52.6 , 7000, and 13 000 GeV. The inclusion of these correlations is motivated by their fundamental role in the description of a recently observed new feature of p p scattering at √{s }=7 TeV, the hollowness effect. Our analysis relies on a Monte Carlo Glauber approach including fluctuations in the hot spot positions and their entropy deposition in the transverse plane. We explore both the energy dependence and the effect of spatial correlations on the number of wounded hot spots, their spatial distribution, and the eccentricities, ɛn, of the initial state geometry of the collision. In minimum bias collisions we find that the inclusion of short-range repulsive correlations between the hot spots reduces the value of the eccentricity (ɛ2) and the triangularity (ɛ3). In turn, upon considering only the events with the highest entropy deposition, i.e., the ultracentral ones, the probability of having larger ɛ2 ,3 increases significantly in the correlated scenario. Finally, the eccentricities show a quite mild energy dependence.

  3. The dependence of proton correlations on integral characteristics of eA interactions

    Energy Technology Data Exchange (ETDEWEB)

    Degtyarenko, P.V. (ITEP, Moscow (Russian Federation)); Doroshkevich, E.A. (ITEP, Moscow (Russian Federation)); Efremenko, Yu.V. (ITEP, Moscow (Russian Federation)); Gavrilov, V.B. (ITEP, Moscow (Russian Federation)); Kossov, M.V. (ITEP, Moscow (Russian Federation)); Leksin, G.A. (ITEP, Moscow (Russian Federation)); Stavinsky, A.V. (ITEP, Moscow (Russian Federation)); Vlassov, A.V. (ITEP, Moscow (Russian Federation))

    1994-12-01

    We report the results of analysis of correlations of the product protons from inelastic eA collisions at small Q[sup 2]. The experimental data were measured by the ARGUS detector. The correlation effect at small relative momenta q (interference and final state interaction) is closely associated with the angular correlations due to momentum conservation. The examined correlations in eA collisions also show features similar to correlations in hA collisions. (orig.)

  4. The dependence of proton correlations on integral characteristics of eA interactions

    Science.gov (United States)

    Degtyarenko, P. V.; Doroshkevich, E. A.; Efremenko, Yu. V.; Gavrilov, V. B.; Kossov, M. V.; Leksin, G. A.; Stavinsky, A. V.; Vlassov, A. V.

    1994-09-01

    We report the results of analysis of correlations of the product protons from inelastic eA collisions at small Q 2. The experimental data were measured by the ARGUS detector. The correlation effect at small relative momenta q (interference and final state interaction) is closely associated with the angular correlations due to momentum conservation. The examined correlations in eA collisions also show features similar to correlations in hA collisions.

  5. Interaction Potential between Parabolic Rotator and an Outside Particle

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2014-01-01

    Full Text Available At micro/nanoscale, the interaction potential between parabolic rotator and a particle located outside the rotator is studied on the basis of the negative exponential pair potential 1/Rn between particles. Similar to two-dimensional curved surfaces, we confirm that the potential of the three-dimensional parabolic rotator and outside particle can also be expressed as a unified form of curvatures; that is, it can be written as the function of curvatures. Furthermore, we verify that the driving forces acting on the particle may be induced by the highly curved micro/nano-parabolic rotator. Curvatures and the gradient of curvatures are the essential elements forming the driving forces. Through the idealized numerical experiments, the accuracy of the curvature-based potential is preliminarily proved.

  6. Neurophysiologic correlates of psychiatric disorders and potential applications in epilepsy.

    Science.gov (United States)

    Halford, J J

    2003-08-01

    There is increasing interest in psychiatric assessment using neurophysiologic tools such as electroencephalography (EEG), magnetoencephalography (MEG), and transcranial magnetic stimulation (TMS). This is because these technologies have good temporal resolution, are relatively noninvasive, and (with the exception of MEG) are economical. Many different experimental paradigms and analysis techniques for the assessment of psychiatric patients involving these technologies are reviewed including conventional quantitative electroencephalography (QEEG), EEG cordance, low-resolution electromagnetic tomography (LORETA), frontal midline theta, midlatency auditory evoked potentials (P50, N100, P300), loudness dependency of the auditory evoked potential (LDAEP), mismatch negativity (MMN), contingent negative variation (CNV), and transcranial magnetic stimulation (TMS). Many of these neurophysiologic stimulus paradigms hold the promise of improving psychiatric patient care by improving diagnostic precision, predicting treatment response, and providing new phenotypes for genetic studies. Large cooperative multisite studies need to be designed to test and validate a few of these paradigms so that they might find use in routine clinical practice.

  7. Multireference configuration interaction calculations of the first six ionization potentials of the uranium atom

    Energy Technology Data Exchange (ETDEWEB)

    Bross, David H.; Parmar, Payal; Peterson, Kirk A., E-mail: kipeters@wsu.edu [Department of Chemistry, Washington State University, Pullman, Washington 99164-4630 (United States)

    2015-11-14

    The first 6 ionization potentials (IPs) of the uranium atom have been calculated using multireference configuration interaction (MRCI+Q) with extrapolations to the complete basis set limit using new all-electron correlation consistent basis sets. The latter was carried out with the third-order Douglas-Kroll-Hess Hamiltonian. Correlation down through the 5s5p5d electrons has been taken into account, as well as contributions to the IPs due to the Lamb shift. Spin-orbit coupling contributions calculated at the 4-component Kramers restricted configuration interaction level, as well as the Gaunt term computed at the Dirac-Hartree-Fock level, were added to the best scalar relativistic results. The final ionization potentials are expected to be accurate to at least 5 kcal/mol (0.2 eV) and thus more reliable than the current experimental values of IP{sub 3} through IP{sub 6}.

  8. Multireference configuration interaction calculations of the first six ionization potentials of the uranium atom

    Science.gov (United States)

    Bross, David H.; Parmar, Payal; Peterson, Kirk A.

    2015-11-01

    The first 6 ionization potentials (IPs) of the uranium atom have been calculated using multireference configuration interaction (MRCI+Q) with extrapolations to the complete basis set limit using new all-electron correlation consistent basis sets. The latter was carried out with the third-order Douglas-Kroll-Hess Hamiltonian. Correlation down through the 5s5p5d electrons has been taken into account, as well as contributions to the IPs due to the Lamb shift. Spin-orbit coupling contributions calculated at the 4-component Kramers restricted configuration interaction level, as well as the Gaunt term computed at the Dirac-Hartree-Fock level, were added to the best scalar relativistic results. The final ionization potentials are expected to be accurate to at least 5 kcal/mol (0.2 eV) and thus more reliable than the current experimental values of IP3 through IP6.

  9. Interaction potentials and thermodynamic properties of two component semiclassical plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanov, T. S.; Moldabekov, Zh. A.; Ismagambetova, T. N. [Al-Farabi Kazakh National University, IETP, 71 al-Farabi Av., Almaty 050040 (Kazakhstan); Gabdullin, M. T. [Al-Farabi Kazakh National University, NNLOT, 71 al-Farabi Av., Almaty 050040 (Kazakhstan)

    2014-01-15

    In this paper, the effective interaction potential in two component semiclassical plasma, taking into account the long-range screening and the quantum-mechanical diffraction effects at short distances, is obtained on the basis of dielectric response function method. The structural properties of the semiclassical plasma are considered. The thermodynamic characteristics (the internal energy and the equation of state) are calculated using two methods: the method of effective potentials and the method of micropotentials with screening effect taken into account by the Ornstein-Zernike equation in the HNC approximation.

  10. Cosmological solutions in string theory with dilaton self interaction potential

    CERN Document Server

    Mora, C

    2003-01-01

    In this work we present homogeneous and isotropic cosmological solutions for the low energy limit of string theory with a self interacting potential for the scalar field. For a potential that is a linear combination of two exponential, a family of exact solutions are found for the different spatial curvatures. Among this family a non singular accelerating solution for positive curvature is singled out and the violation of the energy conditions for that solution is studied, and also its astrophysical consequences. The string coupling for this solution is finite. (Author)

  11. POTENTIALS OF INTERACTIVE TEACHING TECHNIQUES TO TRAIN EXPERTS IN PHARMACY

    Directory of Open Access Journals (Sweden)

    A. V. Krikova

    2016-01-01

    Full Text Available Various interactive teaching methods and techniques are extensively used in modern higher schools. Their implementation is considered to be one of the most significant and efficient ways to improve quality of pharmaceutical professional training. Efficiency of these interactive techniques applied at the Department of Economics and Management of Pharmaceutical Business of Smolensk State Medical University has been comprehensively investigated and assessed. Obtained results are presented in the paper, as well as students’ survey data as consumers of educational services. Fifth year full-time students were involved into the study. Students’ awareness on potentials and significance of applied interactive teaching methods, as well as their interest in innovative forms to gain professional knowledge comprised 93.3%. Potentials of interactive techniques to teach students to deal with a diversity of real life practical professional tasks and problems are particularly emphasized in the study (86.7% students.

  12. Comparing Extended System Interactions with Motions in Softened Potentials

    CERN Document Server

    Barnes, Eric I

    2015-01-01

    Using an $N$-body evolution code that does not rely on softened potentials, I have created a suite of interacting binary cluster simulations. The motions of the centers-of-mass of the clusters have been tracked and compared to the trajectories of point masses interacting via one of four different softened potential prescriptions. There is a robust, nearly linear relationship between the impact parameter of the cluster interaction and the point-mass softening length that best approximates the cluster centers-of-mass motion. In an $N$-body simulation that adopts a fixed softening length, such a relationship leads to regimes where two-body effects, like dynamical friction, can be either larger or smaller than the corresponding cluster situation. Further consideration of more specific $N$-body simulations leads to an estimate that roughly 10 per cent of point-mass interactions in an $N$-body simulation will experience two-body effects larger than those for equivalent clusters.

  13. Localization of interacting Fermi gases in quasiperiodic potentials

    Science.gov (United States)

    Pilati, Sebastiano; Varma, Vipin Kerala

    2017-01-01

    We investigate the zero-temperature metal-insulator transition in a one-dimensional two-component Fermi gas in the presence of a quasiperiodic potential resulting from the superposition of two optical lattices of equal intensity but incommensurate periods. A mobility edge separating (low-energy) Anderson localized and (high-energy) extended single-particle states appears in this continuous-space model beyond a critical intensity of the quasiperiodic potential. To discern the metallic phase from the insulating phase in the interacting many-fermion system, we employ unbiased quantum Monte Carlo (QMC) simulations combined with the many-particle localization length familiar from the modern theory of the insulating state. In the noninteracting limit, the critical optical-lattice intensity for the metal-insulator transition predicted by the QMC simulations coincides with the Anderson localization transition of the single-particle eigenstates. We show that weak repulsive interactions induce a shift of this critical point towards larger intensities, meaning that repulsion favors metallic behavior. This shift appears to be linear in the interaction parameter, suggesting that even infinitesimal interactions can affect the position of the critical point.

  14. [Identifying potential drug interactions in chronic kidney disease patients].

    Science.gov (United States)

    Marquito, Alessandra Batista; Fernandes, Natália Maria da Silva; Colugnati, Fernando Antonio Basile; de Paula, Rogério Baumgratz

    2014-01-01

    Drug interactions (DIs) are common in clinical practice and are directly related to factors such as polypharmacy, aging, hepatic metabolism and decreased renal function. Individuals with chronic kidney disease (CKD) often require multiple classes of drugs being at important risk for the development of DIs. Identify potential interactions among drugs prescribed to patients with CKD on conservative treatment, and factors associated with their occurrence. Observational cross-sectional study, with analysis of 558 prescriptions. Potential DIs were identified by the database MICROMEDEX®, software that provides an internationally known pharmacopoeia. There was a predominance of males (54.7%), seniors (69.4%), stage 3 CKD (47.5%), overweight and obese patients (66.7%). The most prevalent comorbidities were hypertension (68.5%) and diabetes mellitus (31.9%). Potential DIs were detected in 74.9% of prescriptions. Among the 1364 DIs diagnosed, 5 (0.4%) were contraindicated and 229 (16.8%) of greater severity, which need immediate intervention. Interactions of moderate and low severity were identified in 1049 (76.9%) and 81 (5.9%) prescriptions, respectively. The probability of one DI increased by 2.5 times for each additional drug (CI = 2.18 to 3.03). Obesity, hypertension, diabetes as well as advanced stage of CKD were risk factors strongly associated with DI occurrence. Drug associations in individuals with CKD were related to high prevalence of serious DIs, especially in the later stages of the disease.

  15. The neural correlates of theory of mind within interpersonal interactions

    NARCIS (Netherlands)

    Rilling, J.K.; Sanfey, A.G.; Aronson, J.A.; Nystrom, L.E.; Cohen, J.D.

    2004-01-01

    Tasks that engage a theory of mind seem to activate a consistent set of brain areas. In this study, we sought to determine whether two different interactive tasks, both of which involve receiving consequential feedback from social partners that can be used to infer intent, similarly engaged the puta

  16. Neural correlates of gene-environment interactions in ADHD

    NARCIS (Netherlands)

    van der Meer, Dennis

    2016-01-01

    The way we respond to our environment partly depends on our genes. So-called gene-environment interactions (GxE) may explain why some children develop attention-deficit/hyperactivity disorder (ADHD) when exposed to a stressful environment, whereas others do not. Knowledge of GxE may therefore not on

  17. Potential interaction and potential investigation of science center exhibits and visitors' interest

    Science.gov (United States)

    Busque, Laurier

    This research consisted of studying the characteristics of interaction and investigation potential present in museum or science center exhibits. Categories (strong and weak) for the characteristics of interaction potential and investigation potential were established. Fifteen exhibits were chosen from the Museum of Science (Ottawa) and from two science centers (Sudbury and Toronto); these were representative of the established characteristics and categories. A test was constructed that measured the interest in an exhibit in a museum or a science center. The final analysis of the test (20 items) reflects a coefficient of homogeneity (Cronbach alpha) of 0.97 (n = 278). In terms of the characteristics of interaction potential and investigation potential, a significant difference among the ranks of interest was not found once they were regrouped under the categories of strong and weak. The hypothesis of a relationship between the interaction potential and visitors' interest in an exhibit in a museum or science center and the hypothesis of a relationship between the investigation potential and the interest aroused were both rejected. In regards to the interaction potential, median ranks of interest in exhibits of 8.6 for the strong category and of 7.5 for the weak category were observed. In terms of the investigation potential, median ranks of interest of 7.0 for the strong category and of 9.1 for the weak category were observed. In the case of investigation potential, even if the difference is not significant, there is an indication that the strong investigation potential seems to have the effect of creating disinterest in the presentation of an exhibit in a museum or in a science center. In the context of new museum and science centers, the view of developing exhibits which are primarily objects which stimulate interest must be maintained. If this is done with exhibits that arc interactive and have an investigative approach, it is necessary for those in charge of

  18. Event-related potential correlates of emotional orthographic priming.

    Science.gov (United States)

    Faïta-Aïnseba, Frédérique; Gobin, Pamela; Bouaffre, Sarah; Mathey, Stéphanie

    2012-09-12

    Event-related potentials were used to explore the underlying mechanisms of masked orthographic priming and to determine whether the emotional valence of a word neighbor prime affects target processing in a lexical decision task. The results showed that the N200 and N400 amplitudes were modified by orthographic priming, which also varied with the emotional valence of the neighbors. These findings provide new evidence that the N400 component is sensitive to orthographic priming and further suggest that the affective content of the neighbor influences target word processing.

  19. Magnetic dipolar interaction between correlated triplets created by singlet fission in tetracene crystals

    CERN Document Server

    Wang, Rui; Zhang, Bo; Liu, Yunlong; Wang, Xiaoyong; Xiao, Min

    2015-01-01

    Singlet fission (SF) can potentially break the Shockley-Queisser efficiency limit in single-junction solar cells by splitting one photo-excited singlet exciton (S1) into two triplets (2T1) in organic semiconductors. A dark multi-exciton (ME) state has been proposed as the intermediate connecting S1 to 2T1. However, the exact nature of this ME state, especially how the doubly-excited triplets interact, remains elusive. Here, we report a quantitative study on the magnetic dipolar interaction between SF-induced correlated triplets in tetracene crystals by monitoring quantum beats relevant to the ME sublevels at room temperature. The resonances of ME sublevels approached by tuning an external magnetic field are observed to be avoided, which agrees well with the theoretical predictions considering a magnetic dipolar interaction of ~ 0.008 GHz. Our work paves a way to quantify the magnetic dipolar interaction in organic materials and marks an important step towards understanding the underlying physics of the ME sta...

  20. Behavioral and neural correlates of emotional intelligence: an event-related potentials (ERP) study.

    Science.gov (United States)

    Raz, Sivan; Dan, Orrie; Arad, Hen; Zysberg, Leehu

    2013-08-14

    The present study was aimed at identifying potential behavioral and neural correlates of emotional intelligence (EI) by using scalp-recorded Event-Related Potentials (ERPs). EI levels were defined according to both self-report questionnaire and a performance-based test. We identified ERP correlates of emotional processing by comparing ERPs elicited in trials using pleasant, neutral and unpleasant pictures. The effects of these emotion-inducing pictures were then compared across groups with low and high EI levels. Behavioral results revealed a significant valence×EI group interaction effect since valence ratings were lower for unpleasant pictures and higher for pleasant pictures in the high EI group compared with the low EI group. The groups did not differ with respect to neutral picture ratings. The ERP results indicate that participants with high EI exhibited significantly greater mean amplitudes of the P2 (200-300ms post-stimulus) and P3 (310-450ms post-stimulus) ERP components in response to emotional and neutral pictures, at posterior-parietal as well as at frontal scalp locations. This may suggest greater recruitment of resources to process all emotional and non-emotional stimuli at early and late processing stages among individuals with higher EI. The present study also underscores the usefulness of ERP methodology as a sensitive measure for the study of emotional stimuli processing in the research field of EI.

  1. Proton-pion and two-pion correlations in eA interactions

    Energy Technology Data Exchange (ETDEWEB)

    Degtyarenko, P.V. [ITEP, Moscow (Russian Federation); Doroshkevich, E.A. [ITEP, Moscow (Russian Federation); Kurzenkov, A.A. [ITEP, Moscow (Russian Federation); Leksin, G.A. [ITEP, Moscow (Russian Federation); Stavinsky, A.V. [ITEP, Moscow (Russian Federation); Vlassov, A.V. [ITEP, Moscow (Russian Federation)

    1997-05-01

    We report here the results on studying of proton-pion and two-pion correlations in eA interactions at 5 GeV. Kinematic correlations were studied as a function of the two-particle opening angle, their momenta and proton multiplicity. The universal properties of correlation functions were found with respect to different particle species. Interferometry method was used to determine the size of the interaction region. (orig.). With 2 figs.

  2. Correlated intermolecular interaction components from asymptotically corrected Kohn-Sham orbitals

    Institute of Scientific and Technical Information of China (English)

    SONG Huajie; XIAO Heming; DONG Haishan

    2004-01-01

    The symmetry-adapted perturbation theory (SAPT) that has the ability in decomposition of the total interaction energy into physically meaningful components is used to provide a more fundamental understanding of intermolecular forces. This work was motivated by the difficulty of standard SAPT in computing the intermolecular interactions for large energetic dimer systems. SAPT based on Kohn-Sham orbitals (SAPT(DFT)) proves computationally efficient for these large systems, but has been shown to perform poorly for interaction energy components. The deficiencies of SAPT(DFT) result from wrong asymptotical behaviors of commonly used exchange-correlation potentials. To remove the deficiencies, two asymptotic corrections by means of van Leeuwen and Baerends (LB) model potential and Fermi-Amaldi (FA) type potential were applied into three small test systems comprising He2, HF2 and (N2)2 and a set of larger nitramide dimers at several separations. The results showed that when utilizing newly developed frequency-dependent density susceptibilities (FDDS) technique for computing dispersion energy, the FA asymptotic correction is very effective to circumvent these deficiencies in SAPT(DFT) and yields a good accuracy over the LB correction. The FA corrected SAPT(DFT) approach is capable of correctly predicting all the quantitative trends in binding energies for all test cases and substantially reduces computational cost as compared with the standard SAPT calculations. The successful application of the approach to nitramide dimer demonstrates that it potentially provides a good means to calculate accurately intermolecular forces in larger system such as energetic systems.

  3. Neural correlates of mental state decoding in human adults: an event-related potential study.

    Science.gov (United States)

    Sabbagh, Mark A; Moulson, Margaret C; Harkness, Kate L

    2004-04-01

    Successful negotiation of human social interactions rests on having a theory of mind - an understanding of how others' behaviors can be understood in terms of internal mental states, such as beliefs, desires, intentions, and emotions. A core theory-of-mind skill is the ability to decode others' mental states on the basis of observable information, such as facial expressions. Although several recent studies have focused on the neural correlates of reasoning about mental states, no research has addressed the question of what neural systems underlie mental state decoding. We used dense-array event-related potentials (ERP) to show that decoding mental states from pictures of eyes is associated with an N270-400 component over inferior frontal and anterior temporal regions of the right hemisphere. Source estimation procedures suggest that orbitofrontal and medial temporal regions may underlie this ERP effect. These findings suggest that different components of everyday theory-of-mind skills may rely on dissociable neural mechanisms.

  4. Analytic, group-theoretic wave functions for confined, correlated N-body systems with general two-body interactions

    Science.gov (United States)

    Dunn, M.; Watson, D. K.; Loeser, J. G.

    2006-08-01

    In this paper, we develop an analytic N-body wave function for identical particles under quantum confinement with a general two-body interaction. A systematic approach to correlation is developed by combining three theoretical methods: dimensional perturbation theory, the FG method of Wilson et. al., and the group theory of the symmetric group. Analytic results are achieved for a completely general interaction potential. Unlike conventional perturbation methods which are applicable only for weakly interacting systems, this analytic approach is applicable to both weakly and strongly interacting systems. This method directly accounts for each two-body interaction, rather than an average interaction so even lowest-order results include beyond-mean-field effects. One major advantage is that N appears as a parameter in the analytical expressions for the energy so results for different N are easy to obtain.

  5. Examining Event-Related Potential (ERP correlates of decision bias in recognition memory judgments.

    Directory of Open Access Journals (Sweden)

    Holger Hill

    Full Text Available Memory judgments can be based on accurate memory information or on decision bias (the tendency to report that an event is part of episodic memory when one is in fact unsure. Event related potentials (ERP correlates are important research tools for elucidating the dynamics underlying memory judgments but so far have been established only for investigations of accurate old/new discrimination. To identify the ERP correlates of bias, and observe how these interact with ERP correlates of memory, we conducted three experiments that manipulated decision bias within participants via instructions during recognition memory tests while their ERPs were recorded. In Experiment 1, the bias manipulation was performed between blocks of trials (automatized bias and compared to trial-by-trial shifts of bias in accord with an external cue (flexibly controlled bias. In Experiment 2, the bias manipulation was performed at two different levels of accurate old/new discrimination as the memory strength of old (studied items was varied. In Experiment 3, the bias manipulation was added to another, bottom-up driven manipulation of bias induced via familiarity. In the first two Experiments, and in the low familiarity condition of Experiment 3, we found evidence of an early frontocentral ERP component at 320 ms poststimulus (the FN320 that was sensitive to the manipulation of bias via instruction, with more negative amplitudes indexing more liberal bias. By contrast, later during the trial (500-700 ms poststimulus, bias effects interacted with old/new effects across all three experiments. Results suggest that the decision criterion is typically activated early during recognition memory trials, and is integrated with retrieved memory signals and task-specific processing demands later during the trial. More generally, the findings demonstrate how ERPs can help to specify the dynamics of recognition memory processes under top-down and bottom-up controlled retrieval conditions.

  6. Examining Event-Related Potential (ERP) Correlates of Decision Bias in Recognition Memory Judgments

    Science.gov (United States)

    Hill, Holger; Windmann, Sabine

    2014-01-01

    Memory judgments can be based on accurate memory information or on decision bias (the tendency to report that an event is part of episodic memory when one is in fact unsure). Event related potentials (ERP) correlates are important research tools for elucidating the dynamics underlying memory judgments but so far have been established only for investigations of accurate old/new discrimination. To identify the ERP correlates of bias, and observe how these interact with ERP correlates of memory, we conducted three experiments that manipulated decision bias within participants via instructions during recognition memory tests while their ERPs were recorded. In Experiment 1, the bias manipulation was performed between blocks of trials (automatized bias) and compared to trial-by-trial shifts of bias in accord with an external cue (flexibly controlled bias). In Experiment 2, the bias manipulation was performed at two different levels of accurate old/new discrimination as the memory strength of old (studied) items was varied. In Experiment 3, the bias manipulation was added to another, bottom-up driven manipulation of bias induced via familiarity. In the first two Experiments, and in the low familiarity condition of Experiment 3, we found evidence of an early frontocentral ERP component at 320 ms poststimulus (the FN320) that was sensitive to the manipulation of bias via instruction, with more negative amplitudes indexing more liberal bias. By contrast, later during the trial (500–700 ms poststimulus), bias effects interacted with old/new effects across all three experiments. Results suggest that the decision criterion is typically activated early during recognition memory trials, and is integrated with retrieved memory signals and task-specific processing demands later during the trial. More generally, the findings demonstrate how ERPs can help to specify the dynamics of recognition memory processes under top-down and bottom-up controlled retrieval conditions. PMID

  7. Neurophysiological Correlates of Visual Dominance: A Lateralized Readiness Potential Investigation

    Science.gov (United States)

    Li, You; Liu, Mingxin; Zhang, Wei; Huang, Sai; Zhang, Bao; Liu, Xingzhou; Chen, Qi

    2017-01-01

    When multisensory information concurrently arrives at our receptors, visual information often receives preferential processing and eventually dominates awareness and behavior. Previous research suggested that the visual dominance effect implicated the prioritizing of visual information into the motor system. In order to further reveal the underpinning neurophysiological mechanism of how visual information is prioritized into the motor system when vision dominates audition, the present study examined the time course of a particular motor activation ERP component, the lateralized readiness potential (LRP), during multisensory competition. The onsets of both stimulus-locked LRP (S-LRP) and response-locked LRP (R-LRP) were measured. Results showed that, the R-LRP onset to the auditory target was delayed about 91 ms when it was paired with a simultaneous presented visual target, compared to that when it was presented by itself. For the visual target, however, the R-LRP onset was comparable irrespective of whether it was paired with an auditory target or not. No significant difference was obtained for the onset of S-LRP. Taken together, the time courses of LRPs indicated that visual information was preferentially processed within the motor system, which coincides with the previous finding that the dorsal visual stream prioritizes the flow of visual information into the motor system.

  8. Neurophysiological Correlates of Visual Dominance: A Lateralized Readiness Potential Investigation.

    Science.gov (United States)

    Li, You; Liu, Mingxin; Zhang, Wei; Huang, Sai; Zhang, Bao; Liu, Xingzhou; Chen, Qi

    2017-01-01

    When multisensory information concurrently arrives at our receptors, visual information often receives preferential processing and eventually dominates awareness and behavior. Previous research suggested that the visual dominance effect implicated the prioritizing of visual information into the motor system. In order to further reveal the underpinning neurophysiological mechanism of how visual information is prioritized into the motor system when vision dominates audition, the present study examined the time course of a particular motor activation ERP component, the lateralized readiness potential (LRP), during multisensory competition. The onsets of both stimulus-locked LRP (S-LRP) and response-locked LRP (R-LRP) were measured. Results showed that, the R-LRP onset to the auditory target was delayed about 91 ms when it was paired with a simultaneous presented visual target, compared to that when it was presented by itself. For the visual target, however, the R-LRP onset was comparable irrespective of whether it was paired with an auditory target or not. No significant difference was obtained for the onset of S-LRP. Taken together, the time courses of LRPs indicated that visual information was preferentially processed within the motor system, which coincides with the previous finding that the dorsal visual stream prioritizes the flow of visual information into the motor system.

  9. Potential interaction between warfarin and high dietary protein intake.

    Science.gov (United States)

    Hornsby, Lori B; Hester, E Kelly; Donaldson, Amy R

    2008-04-01

    A 55-year-old Caucasian man was receiving warfarin therapy after undergoing aortic valve replacement. His international normalized ratio (INR) was stabilized with warfarin 95 mg/week for 5 weeks. Commencement of a low-carbohydrate, high-protein diet resulted in a series of subtherapeutic INRs that led to a 16% increase in the dosage requirement to maintain therapeutic INRs. After the patient discontinued the diet, his INR increased, and several dosage reductions were required until his INR stabilized with his original dosage of 95 mg/week. Two additional case reports have described a possible interaction between warfarin and a high-protein diet. The potential for increased dietary protein intake to raise serum albumin levels and/or cytochrome P450 activity has been postulated as mechanisms for the resulting decrease in INRs. Given the available animal and human data that demonstrate alterations in drug metabolism in the presence of altered dietary protein intake, an increase in warfarin metabolism due to cytochrome P450 activation appears to be the most likely cause. In addition to the previously reported cases, this case indicates a potential interaction between warfarin and a high-protein diet. Because of the popularity of high-protein diets and because of the risks associated with inadequate or excessive warfarin anticoagulation, patients and health care providers should be aware of this interaction to ensure appropriate monitoring when warranted.

  10. Diquark correlations in baryons: the Interacting Quark Diquark Model

    CERN Document Server

    Santopinto, E

    2015-01-01

    A review of the underlying ideas of the Interacting Quark Diquark Model (IQDM) that asses the baryon spectroscopy in terms of quark diquark degrees of freedom is given, together with a discussion of the missing resonances problem. Some ideas about its generalization the heavy baryon spectroscopy is given.s of freedom is given, together with a discussion of the missing resonances problem. Some ideas about its generalization the heavy baryon spectroscopy is given.The results are compared to the existing experimental data.

  11. Influence of degree correlations on network structure and stability in protein-protein interaction networks

    Directory of Open Access Journals (Sweden)

    Zimmer Ralf

    2007-08-01

    Full Text Available Abstract Background The existence of negative correlations between degrees of interacting proteins is being discussed since such negative degree correlations were found for the large-scale yeast protein-protein interaction (PPI network of Ito et al. More recent studies observed no such negative correlations for high-confidence interaction sets. In this article, we analyzed a range of experimentally derived interaction networks to understand the role and prevalence of degree correlations in PPI networks. We investigated how degree correlations influence the structure of networks and their tolerance against perturbations such as the targeted deletion of hubs. Results For each PPI network, we simulated uncorrelated, positively and negatively correlated reference networks. Here, a simple model was developed which can create different types of degree correlations in a network without changing the degree distribution. Differences in static properties associated with degree correlations were compared by analyzing the network characteristics of the original PPI and reference networks. Dynamics were compared by simulating the effect of a selective deletion of hubs in all networks. Conclusion Considerable differences between the network types were found for the number of components in the original networks. Negatively correlated networks are fragmented into significantly less components than observed for positively correlated networks. On the other hand, the selective deletion of hubs showed an increased structural tolerance to these deletions for the positively correlated networks. This results in a lower rate of interaction loss in these networks compared to the negatively correlated networks and a decreased disintegration rate. Interestingly, real PPI networks are most similar to the randomly correlated references with respect to all properties analyzed. Thus, although structural properties of networks can be modified considerably by degree

  12. Spatial coincidence modulates interaction between visual and somatosensory evoked potentials.

    Science.gov (United States)

    Schürmann, Martin; Kolev, Vasil; Menzel, Kristina; Yordanova, Juliana

    2002-05-07

    The time course of interaction between concurrently applied visual and somatosensory stimulation with respect to evoked potentials (EPs) was studied. Visual stimuli, either in the left or right hemifield, and electric stimuli to the left wrist were delivered either alone or simultaneously. Visual and somatosensory EPs were summed and compared to bimodal EPs (BiEP, response to actual combination of both modalities). Temporal coincidence of stimuli lead to sub-additive or over-additive amplitudes in BiEPs in several time windows between 75 and 275 ms. Additional effects of spatial coincidence (left wrist with left hemifield) were found between 75 and 300 ms and beyond 450 ms. These interaction effects hint at a temporo-spatial pattern of multiple brain areas participating in the process of multimodal integration.

  13. Quantum Monte Carlo study of strange correlator in interacting topological insulators

    Science.gov (United States)

    Wu, Han-Qing; He, Yuan-Yao; You, Yi-Zhuang; Xu, Cenke; Meng, Zi Yang; Lu, Zhong-Yi

    Distinguishing the nontrivial symmetry-protected topological (SPT) phase from the trivial insulator phase in the presence of electron-electron interaction is an urgent question to the study of topological insulators. In this work, we demonstrate that the strange correlator is a sensitive diagnosis to detect SPT states in interacting systems. Employing large-scale quantum Monte Carlo (QMC) simulations, we investigate the interaction-driven quantum phase transition in the Kane-Mele-Hubbard model. The transition from the quantum spin Hall insulator at weak interaction to an antiferromagnetic Mott insulator at strong interaction can be readily detected by the momentum space behavior of the strange correlator in single-particle, spin, and pairing sectors. The interaction e?ects on the symmetry-protected edge states in various sectors are well captured in the QMC measurements of strange correlators. Moreover, we demonstrate that the strange correlator is technically easier to implement in QMC and more robust in performance than other proposed numerical diagnoses for interacting topological states, as only static correlations are needed. The attempt in this work paves the way for using the strange correlator to study interaction-driven topological phase transitions.

  14. Potential drug interactions in patients given antiretroviral therapy.

    Science.gov (United States)

    Santos, Wendel Mombaque Dos; Secoli, Silvia Regina; Padoin, Stela Maris de Mello

    2016-11-21

    to investigate potential drug-drug interactions (PDDI) in patients with HIV infection on antiretroviral therapy. a cross-sectional study was conducted on 161 adults with HIV infection. Clinical, socio demographic, and antiretroviral treatment data were collected. To analyze the potential drug interactions, we used the software Micromedex(r). Statistical analysis was performed by binary logistic regression, with a p-value of ≤0.05 considered statistically significant. of the participants, 52.2% were exposed to potential drug-drug interactions. In total, there were 218 potential drug-drug interactions, of which 79.8% occurred between drugs used for antiretroviral therapy. There was an association between the use of five or more medications and potential drug-drug interactions (p = 0.000) and between the time period of antiretroviral therapy being over six years and potential drug-drug interactions (p antirretroviral. um estudo de corte transversal foi conduzido em 161 pessoas infectadas com o HIV. Dados de tratamentos clínicos, sociodemográficos e antirretrovirais foram coletados. Para analisar a possível interação medicamentosa, nós usamos o software Micromedex(r). A análise estatística foi feita por regressão logística binária, com um valor P de ≤0.05, considerado estatisticamente significativo. dos participantes, 52.2% foram expostos a potenciais interações droga-droga. No total, houve 218 interações droga-droga, das quais 79.8% ocorreram entre drogas usadas para a terapia antirretroviral. Houve uma associação entre o uso de cinco ou mais medicamentos e possíveis interações droga-droga (p = 0.000), e entre o período de tempo de terapia antirretroviral acima de seis anos e possíveis interações droga-droga (p VIH que reciben terapia antirretroviral. un estudio transversal se llevó a cabo en 161 adultos con infección por VIH. Se recogieron datos clínicos, socio demográficos, y de tratamiento antirretroviral. Para analizar las posibles

  15. Types of college student-to-student learning: correlated interactions.

    Science.gov (United States)

    Miley, William M; Gonsalves, Sonia V; Arcuri, Alan

    2004-02-01

    209 college men and 327 college women took a 20-item Likert survey to assess the types of education-related information students may learn from other students during their informal interactions. Students were very likely to ask other students low level questions such as which professors were good and which classes to take. They were less likely to ask other students about concepts discussed in class and how to solve problems generated in class. If students asked about test taking, these students were also likely to ask about study skills and writing skills for the class. Other research suggests these higher level help-seeking behaviors seem to be related to classroom mastery and achievement.

  16. Correlations and Symmetry of Interactions Influence Collective Dynamics of Molecular Motors

    CERN Document Server

    Celis-Garza, Daniel; Kolomeisky, Anatoly B

    2015-01-01

    Enzymatic molecules that actively support many cellular processes, including transport, cell division and cell motility, are known as motor proteins or molecular motors. Experimental studies indicate that they interact with each other and they frequently work together in large groups. To understand the mechanisms of collective behavior of motor proteins we study the effect of interactions in the transport of molecular motors along linear filaments. It is done by analyzing a recently introduced class of totally asymmetric exclusion processes that takes into account the intermolecular interactions via thermodynamically consistent approach. We develop a new theoretical method that allows us to compute analytically all dynamic properties of the system. Our analysis shows that correlations play important role in dynamics of interacting molecular motors. Surprisingly, we find that the correlations for repulsive interactions are weaker and more short-range than the correlations for the attractive interactions. In ad...

  17. Correlated and cooperative motions in segmental relaxation: Influence of constitutive unit weight and intermolecular interactions

    Science.gov (United States)

    Rijal, Bidur; Soto Puente, Jorge Arturo; Atawa, Bienvenu; Delbreilh, Laurent; Fatyeyeva, Kateryna; Saiter, Allisson; Dargent, Eric

    2016-12-01

    This work clarifies the notion of correlated and cooperative motions appearing during the α-relaxation process through the role of the molecular weight of the constitutive units and of the interchain dipolar interactions. By studying amorphous copolymers of poly(ethylene-co-vinyl acetate) with different vinyl acetate contents, we show that the correlated motions are not sensitive to the interchain dipolar interactions, in contrast to the cooperative motions, which increase with a strengthening of the intermolecular interactions for this sample family. Concerning the influence of the molecular weight m0, the notion of "correlated motions" seems to be equivalent to the notion of "cooperative motions" only for low m0 systems.

  18. Gender differences, polypharmacy, and potential pharmacological interactions in the elderly

    Directory of Open Access Journals (Sweden)

    Carina Duarte Venturini

    2011-01-01

    Full Text Available OBJECTIVE: This study aims to analyze pharmacological interactions among drugs taken by elderly patients and their age and gender differences in a population from Porto Alegre, Brazil. METHODS: We retrospectively analyzed the database provided by the Institute of Geriatric and Gerontology, Porto Alegre, Brazil. The database was composed of 438 elderly and includes information about the patients' disease, therapy regimens, utilized drugs. All drugs reported by the elderly patients were classified using the Anatomical Therapeutic and Chemical Classification System. The drug-drug interactions and their severity were assessed using the Micromedex® Healthcare Series. RESULTS: Of the 438 elderly patients in the data base, 376 (85.8% used pharmacotherapy, 274 were female, and 90.4% of females used drugs. The average number of drugs used by each individual younger than 80 years was 3.2±2.6. Women younger than 80 years old used more drugs than men in the same age group whereas men older than 80 years increased their use of drugs in relation to other age groups. Therefore, 32.6% of men and 49.2% of women described at least one interaction, and 8.1% of men and 10.6% of women described four or more potential drug-drug interactions. Two-thirds of drug-drug interactions were moderate in both genders, and most of them involved angiotensin-converting enzyme inhibitor, non-steroidal anti-inflammatory, loop and thiazide diuretics, and β-blockers. CONCLUSION: Elderly patients should be closely monitored, based on drug class, gender, age group and nutritional status.

  19. Anxiety symptoms and quality of interaction among oncology nurses: a correlational, cross-sectional study.

    Science.gov (United States)

    Karanikola, Maria Nk; Giannakopoulou, Margarita; Kalafati, Maria; Kaite, Charis P; Patiraki, Elisabeth; Mpouzika, Meropi; Papathanassoglou, Elisabeth E D; Middleton, Nicos

    2016-01-01

    To explore the severity of Anxiety Symptoms (AS) among Greek oncology nursing personnel, the degree of satisfaction from professional relationships, and potential association between them. A descriptive cross-sectional correlational study was performed in 2 Greek Oncology Hospitals, in 72 members of nursing personnel. Hamilton Anxiety Scale was used for the assessment of AS severity and the Index of Work Satisfaction subscale "Satisfaction from Interaction" for the degree of satisfaction from professional relationships among nursing personnel (NN) and between nursing personnel and physicians (NP). 11% of the sample reported clinical AS [≥26, scale range (SR): 0-52]. Satisfaction from NN [5.10 (SD: 1.04), SR: 1-7], and NP [4.21 (SD: 0.77), SR: 1-7] professional interaction were both moderate. Statistically significantly associations were observed between clinical AS and satisfaction from NN (p=0.014) and NP (p=0.013) professional interaction. Anxiety reduction interventions and improvement of professional relationships are essentials in order to reduce oncology nurses' psychological distress.

  20. Interactive Correlation Analysis and Visualization of Climate Data

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Kwan-Liu [Univ. of California, Davis, CA (United States)

    2016-09-21

    The relationship between our ability to analyze and extract insights from visualization of climate model output and the capability of the available resources to make those visualizations has reached a crisis point. The large volume of data currently produced by climate models is overwhelming the current, decades-old visualization workflow. The traditional methods for visualizing climate output also have not kept pace with changes in the types of grids used, the number of variables involved, and the number of different simulations performed with a climate model or the feature-richness of high-resolution simulations. This project has developed new and faster methods for visualization in order to get the most knowledge out of the new generation of high-resolution climate models. While traditional climate images will continue to be useful, there is need for new approaches to visualization and analysis of climate data if we are to gain all the insights available in ultra-large data sets produced by high-resolution model output and ensemble integrations of climate models such as those produced for the Coupled Model Intercomparison Project. Towards that end, we have developed new visualization techniques for performing correlation analysis. We have also introduced highly scalable, parallel rendering methods for visualizing large-scale 3D data. This project was done jointly with climate scientists and visualization researchers at Argonne National Laboratory and NCAR.

  1. Collective multipole excitations based on correlated realistic nucleon-nucleon interactions

    Energy Technology Data Exchange (ETDEWEB)

    Paar, N. [Zagreb Univ. (Croatia). Fac. of Science, Physics Dept.; Papakonstantinou, P.; Hergert, H.; Roth, R. [Technische Univ. Darmstadt (Germany). Inst. fuer Kernphysik

    2006-05-24

    We investigate collective multipole excitations for closed shell nuclei from {sup 16}O to {sup 208}Pb using correlated realistic nucleon-nucleon interactions in the framework of the random phase approximation (RPA). The dominant short-range central and tensor correlations a re treated explicitly within the Unitary Correlation Operator Method (UCOM), which provides a phase-shift equivalent correlated interaction VUCOM adapted to simple uncorrelated Hilbert spaces. The same unitary transformation that defines the correlated interaction is used to derive correlated transition operators. Using VUCOM we solve the Hartree-Fock problem and employ the single-particle states as starting point for the RPA. By construction, the UCOM-RPA is fully self-consistent, i.e. the same correlated nucleon-nucleon interact ion is used in calculations of the HF ground state and in the residual RPA interaction. Consequently, the spurious state associated with the center-of-mass motion is properly removed and the sum-rules are exhausted within {+-}3%. The UCOM-RPA scheme results in a collective character of giant monopole, dipole, and quadrupole resonances in closed-shell nuclei across the nuclear chart. For the isoscalar giant monopole resonance, the resonance energies are in agreement with experiment hinting at a reasonable compressibility. However, in the 1{sup -} and 2{sup +} channels the resonance energies are overestimated due to missing long-range correlations and three-body contributions. (orig.)

  2. [St. John's wort: a pharmaceutical with potentially dangerous interactions].

    Science.gov (United States)

    Rätz, A E; von Moos, M; Drewe, J

    2001-05-10

    Over-the-counter preparations of St. John's wort are widely used as 'natural' herbal medicine alternative to traditional antidepressants. The antidepressant effect has been shown in numerous placebo controlled studies. The mechanism of action is assumed to be at least in part, similar to conventional antidepressants, due to presynaptic serotonin reuptake inhibition as well as GABA-modulation and inhibition of monoaminoxidases. Because of its favorable safety profile compared to conventional antidepressants, the use of St. John's wort preparations has gained high acceptance with doctors and patients. However, any biologically active compound contains a certain risk of untoward effects and/or interactions which often are neither known nor recognised with the use of herbal remedies. Thus, doctors, pharmacists, and patients might feel themselves in false safety. Recently, a variety of case reports of potentially hazardous interactions due to drug combinations with St. John's wort have been published (e.g. cellular rejection of pancreas-, kidney- as well as heart transplants with ciclosporin therapy, rise of INR with oral anticoagulants, bleeding with oral contraceptives, reduction of plasma concentration of digoxin, indinavir, amitriptyline, and theophylline). We report a case of irregular bleeding with oral contraception and discuss these drug interactions and the mechanisms.

  3. Potential interaction between proton pump inhibitor and clopidogrel

    Directory of Open Access Journals (Sweden)

    Indra Kurniawan

    2013-02-01

    Full Text Available Clopidogrel is an anti-platelet agent commonly used in patients with atherosclerotic cardiovascular (CV disease. Although formerly considered safe, several studies reported that the use of clopidogrel may cause a significant increase in the rate of gastrointestinal (GI bleeding. This adverse effect could be minimized by coadministration of proton pump inhibitor (PPI. However, since PPI and clopidogrel share the same metabolic pathway, it has been hypothesized that the administration of PPI following clopidogrel therapy may cause a reduction in its anti-platelet effect, thereby increasing the risk of CV events. Recent studies found no significant inhibition in the activation of clopidogrel by CYP2C19 with administration of PPI in vitro. Pharmacokinetic and pharmacodynamic studies, as well as clinical studies, reported conflicting results regarding the potential interaction between PPI and clopidogrel. Until now, the available study investigated the PPI-clopidogrel interaction are primarily observational. The COGENT study is the only prospective, placebo-controlled trial examined the PPI-clopidogrel interaction. This study revealed no significant increase in CV events in patients receiving PPI following clopidogrel therapy, compared to the control group. Though remains controversial, current expert consensus recommended the administration of PPI in patients receiving clopidogrel, particularly in high-risk patients. (Med J Indones. 2013;22:57-62Keywords: Cardiovascular, clopidogrel, gastrointestinal, proton pump inhibitor

  4. Use of Two-Body Correlated Basis Functions with van der Waals Interaction to Study the Shape-Independent Approximation for a Large Number of Trapped Interacting Bosons

    Science.gov (United States)

    Lekala, M. L.; Chakrabarti, B.; Das, T. K.; Rampho, G. J.; Sofianos, S. A.; Adam, R. M.; Haldar, S. K.

    2017-01-01

    We study the ground-state and the low-lying excitations of a trapped Bose gas in an isotropic harmonic potential for very small (˜ 3) to very large (˜ 10^7 ) particle numbers. We use the two-body correlated basis functions and the shape-dependent van der Waals interaction in our many-body calculations. We present an exhaustive study of the effect of inter-atomic correlations and the accuracy of the mean-field equations considering a wide range of particle numbers. We calculate the ground-state energy and the one-body density for different values of the van der Waals parameter C6 . We compare our results with those of the modified Gross-Pitaevskii results, the correlated Hartree hypernetted-chain equations (which also utilize the two-body correlated basis functions), as well as of the diffusion Monte Carlo for hard sphere interactions. We observe the effect of the attractive tail of the van der Waals potential in the calculations of the one-body density over the truly repulsive zero-range potential as used in the Gross-Pitaevskii equation and discuss the finite-size effects. We also present the low-lying collective excitations which are well described by a hydrodynamic model in the large particle limit.

  5. The impact of highly correlated potential energy surfaces on the anharmonically corrected IR spectrum of acetonitrile

    Science.gov (United States)

    Lutz, Oliver M. D.; Rode, Bernd M.; Bonn, Günther K.; Huck, Christian W.

    2014-10-01

    This paper discusses the quality and feasibility of highly correlated ab initio techniques in a vibrational self-consistent field (VSCF) approach using acetonitrile as a model system. The topical renormalized coupled-cluster technique exploiting the similarity-transformed Hamiltonian's left eigenstates (i.e. CR-CC(2,3)) is investigated alongside the well-known Hartree-Fock (HF), Møller-Plesset second-order perturbation theory (MP2) and coupled cluster (CCSD(T)) methods. The inclusion of mode triple interactions is discussed and it is found that the use of an effective core potential (ECP) serves as a viable compromise during the highly demanding task of computing such contributions, thus enabling a grid-based evaluation of three mode interaction terms with coupled cluster techniques also for larger molecules. In this context, a previously proposed reduced coupling scheme [1] is investigated, confirming the applicability of this technique to a system exhibiting a rather complex electronic structure. A combination of Ahlrichs' triple-ζ valence polarized (TZVP) basis set with Dunning's set of core-valence correlation functions is found to deliver results in good agreement with experiment while being computationally very feasible. Since CH3CN exhibits four degenerate vibrational degrees of freedom, it serves as an ideal model system for critically assessing the qualities of the degenerate second-order perturbation theory corrected (DPT2) VSCF technique. Besides fundamental vibrations, a thorough investigation of overtone transitions and combination bands is conducted by means of comparing the results to both available and newly recorded experimental data.

  6. Implementation of $ab$ $initio$ perturbed angular correlation observables for analysis of fluctuating quadrupole interactions

    CERN Document Server

    Barbosa, Marcelo

    A review about the nuclear properties, namely the nuclear moments (magnetic dipole moment and electric quadrupole moment) and their interaction with electromagnetic fields external to the nucleus (hyperfine interactions), as well as the angular distribution of radiation produced by $\\gamma$-decay, is presented. A detailed description about the theory of Perturbed Angular Correlations was done, including the comparison between $\\gamma-\\gamma$- correlations and $e^{-}- \\gamma$ correlations. For dynamic nuclear interactions, an introduction to the theory of stochastic states in PAC was performed. We focused on ab-initio implementation of observables for analyzing fluctuating quadrupole hyperfine interactions on time dependent perturbed angular correlations experiments. The development of computacional codes solving the full problem, adapted to fit data obtained on single crystals or polycrystals for two-state transient fields with any axial symmetry and orientation was the main purpose of this work. The final pa...

  7. Constructing ecological interaction networks by correlation analysis: hints from community sampling

    Directory of Open Access Journals (Sweden)

    WenJun Zhang

    2011-09-01

    Full Text Available A set of methodology for constructing ecological interaction networks by correlation analysis of community sampling data was presented in this study. Nearly 30 data sets at different levels of taxa for different sampling seasons and locations were used to construct networks and find network properties. I defined the network constructed by Pearson linear correlation is the linear network, and the network constructed by quasi-linear correlation measure (e.g., Spearman correlation is the quasi-linear network. Two taxa with statistically significant linear or quasi-linear correlation are determined to interact. The quasi-linear network is more general than linear network.The results reveled that correlation distributions of Pearson linear correlation and partial linear correlation constructed networks are unimodal functions and most of them are short-head (mostly negative correlations and long-tailed (mostly positive correlations. Spearman correlation distributions are either long-head and short-tailed unimodal functions or monotonically increasing functions. It was found that both mean partial linear correlation and mean Pearson linear correlation were approximately 0. The proportion of positive (partial linear correlations declined significantly with the increase in taxa. The mean (partial linear correlation declined significantly with the increase of taxa. More than 90% of network interactions are positive interactions. The average connectance was 9.8% (9.3% for (partial linear correlation constructed network. The parameter λ in power low distribution (L(x=x-λ increased as the decline of taxon level (from functional group to species for the partial linear correlation constructed network. λ is in average 0.8 to 0.9. The number of (positive interactions increased with the number of taxa for both linear and partial linear correlations constructed networks. The addition of a taxon would result in an increase of 0.4 (0.3 interactions (positive

  8. Interaction of baseline synaptic noise and Ia EPSPs: evidence for appreciable negative correlation under physiological conditions.

    Science.gov (United States)

    Solodkin, M; Jiménez, I; Collins, W F; Mendell, L M; Rudomin, P

    1991-04-01

    1. In the anesthetized cat, simultaneous intracellular recordings from pairs of spinal motoneurons were undertaken to see whether the amplitude of single-fiber excitatory postsynaptic potentials (EPSPs) in both cells fluctuated in a coordinated manner that would indicate correlative mechanisms at either pre- or post-synaptic level. Although these recordings revealed correlated fluctuations in the baseline, the single-fiber Ia/EPSPs recorded with the spike-triggered averaging technique exhibited no correlated fluctuations and, unexpectedly, virtually no increase in baseline variance associated with the EPSP. However, the fact that these experiments were carried out under conditions of high baseline synaptic noise (i.e., with muscle stretch) may have influenced the outcome because of interaction between EPSP and synaptic noise, and this possibility was evaluated explicitly. 2. A given connection was studied under low noise by electrically stimulating a single Ia fiber in the absence of muscle stretch. The same connection was analyzed under conditions of high noise by activating the fiber and all other stretch receptor afferents with muscle stretch and by using spike-triggered averaging to extract the EPSP. The differences in mean EPSP amplitude at a given connection under conditions of low noise and high noise were minimal. 3. Fluctuations in EPSP amplitude were then determined to see whether these were influenced by presence of baseline synaptic noise and whether the interaction was nonlinear. Two methods were used to measure EPSP fluctuations: measurement of the variance associated with the EPSP, and determination by the use of deconvolution methods of the discrete amplitude components associated with the EPSP. 4. An increase in baseline variance was observed during the EPSP evoked under low noise conditions at all six connections studied in this way. This increase disappeared at two of these connections when examined under high noise. This may help to explain the

  9. Effective homogeneity of the exchange-correlation and non-interacting kinetic energy functionals under density scaling.

    Science.gov (United States)

    Borgoo, Alex; Teale, Andrew M; Tozer, David J

    2012-01-21

    Correlated electron densities, experimental ionisation potentials, and experimental electron affinities are used to investigate the homogeneity of the exchange-correlation and non-interacting kinetic energy functionals of Kohn-Sham density functional theory under density scaling. Results are presented for atoms and small molecules, paying attention to the influence of the integer discontinuity and the choice of the electron affinity. For the exchange-correlation functional, effective homogeneities are highly system-dependent on either side of the integer discontinuity. By contrast, the average homogeneity-associated with the potential that averages over the discontinuity-is generally close to 4/3 when the discontinuity is computed using positive affinities for systems that do bind an excess electron and negative affinities for those that do not. The proximity to 4/3 becomes increasingly pronounced with increasing atomic number. Evaluating the discontinuity using a zero affinity in systems that do not bind an excess electron instead leads to effective homogeneities on the electron abundant side that are close to 4/3. For the non-interacting kinetic energy functional, the effective homogeneities are less system-dependent and the effect of the integer discontinuity is less pronounced. Average values are uniformly below 5/3. The study provides information that may aid the development of improved exchange-correlation and non-interacting kinetic energy functionals. © 2012 American Institute of Physics

  10. Potential of Root Exudates from Wetland Plants and Their Potential Role for Denitrification and Allelopathic Interactions

    DEFF Research Database (Denmark)

    Zhai, Xu

    vary among different Phragmites haplotypes and consequently affect their invasion potential. The studies presented in this dissertation aimed at investigating the quantity and composition of the organic carbon released in root exudates from three common wetland species as affected by temperature...... wetlands. Furthermore, environmental factors such as temperature and light-regime affect the photosynthetic carbon fixation, which continuously influence the compositions and quantity of root exudates released into rhizosphere. Conversely, root exudates from invasive species might contain some phytotoxic...... and light-regime and how the root exudates potentially affect the nitrogen removal by denitrification in constructed wetlands. Also, the studies aimed at further elucidating the potential allelopathic interaction between the plants. The findings of the research suggest that the root exudates from wetland...

  11. Effect of Inter-particle Interactions on Pair Correlations of One-Dimensional Anyon Gases

    Science.gov (United States)

    Li, Yan; He, Zhi

    2015-10-01

    The pair correlation function of the one-dimensional interacting anyonic system in its ground state is investigated based on the exact Bethe ansatz solution for arbitrary coupling constant () and statistics parameter (). We discuss the effects of the inter-particle interactions and the fractional statistics on the pair correlations in both position and momentum spaces. The pair correlations of anyons with coupling constant c and statistical parameter in position space are identical to that of the Lieb-Liniger Bose model with effective coupling constant . Besides the effect of renormalized coupling, the correlations in momentum space reveal more effects induced by the statistics parameter. The anyonic statistics results in the nonsymmetric correlation when the statistics parameter deviates from 0 (Bose statistics) and (Fermi statistics) for any coupling constant c. The correlations display peaks and dips, representing the bunching and antibunching of atoms, respectively. The correlations show crossover from bunching behavior of bosons to antibunching behavior of fermions as varies from 0 to for arbitrary coupling constant. Besides the fractional effect, we also observe the effects induced by the inter-particle interactions in the momentum correlations. With the increase of the coupling constant, the bunching effect between particles weakens and the antibunching points in the correlations shift.

  12. Schematic potential energy for interaction between isobutene and zeolite mordenite

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Serrano, L A [Programa de Crudo Maya, IMP, AP 15-805, DF 07730 (Mexico); Flores-Sandoval, C A [Programa de Crudo Maya, IMP, AP 15-805, DF 07730 (Mexico); Zaragoza, I P [Programa de Ingenieria Molecular, IMP, AP 15-805, DF 07730 (Mexico)

    2004-06-09

    A schematic representation of the potential energy for the interaction between isobutene and H mordenite was presented by using eight different positions (P1-P8) of C{sub 1} or C{sub 2} atoms located in front of the acid hydrogen (H{sup +}). In all cases a {pi} complex was formed yielding different values of the adsorption energy. In some cases of the adsorption point in P1-P8 the frontier orbitals are shown. The P8 position exhibits the highest value obtained for the adsorption energy, where the C{sub 1} atom is in front of the H{sup +}. Calculations were of all electron type employing HF/6-31G**.

  13. Strongly Interacting Matter at Finite Chemical Potential: Hybrid Model Approach

    Science.gov (United States)

    Srivastava, P. K.; Singh, C. P.

    2013-06-01

    Search for a proper and realistic equation of state (EOS) for strongly interacting matter used in the study of the QCD phase diagram still appears as a challenging problem. Recently, we constructed a hybrid model description for the quark-gluon plasma (QGP) as well as hadron gas (HG) phases where we used an excluded volume model for HG and a thermodynamically consistent quasiparticle model for the QGP phase. The hybrid model suitably describes the recent lattice results of various thermodynamical as well as transport properties of the QCD matter at zero baryon chemical potential (μB). In this paper, we extend our investigations further in obtaining the properties of QCD matter at finite value of μB and compare our results with the most recent results of lattice QCD calculation.

  14. Biotechnological potential of aquatic plant-microbe interactions.

    Science.gov (United States)

    Stout, L; Nüsslein, K

    2010-06-01

    The rhizosphere in terrestrial systems is the region of soil surrounding plant roots where there is increased microbial activity; in aquatic plants, this definition may be less clear because of diffusion of nutrients in water, but there is still a zone of influence by plant roots in this environment [1]. Within that zone chemical conditions differ from those of the surrounding environment as a consequence of a range of processes that were induced either directly by the activity of plant roots or by the activity of rhizosphere microflora. Recently, there are a number of new studies related to rhizospheres of aquatic plants and specifically their increased potential for remediation of contaminants, especially remediation of metals through aquatic plant-microbial interaction.

  15. Interactions among endophytic bacteria and fungi: effects and potentials

    Indian Academy of Sciences (India)

    W M M S Bandara; Gamini Seneviratne; S A Kulasooriya

    2006-12-01

    Plants benefit extensively by harbouring endophytic microbes. They promote plant growth and confer enhanced resistance to various pathogens. However, the way the interactions among endophytes influence the plant productivity has not been explained. Present study experimentally showed that endophytes isolated from rice (Oryza sativa) used as the test plant produced two types of interactions; biofilms (bacteria attached to mycelia) and mixed cultures with no such attachments. Acidity, as measured by pH in cultures with biofilms was higher than that of fungi alone, bacteria alone or the mixed cultures. Production of indoleacetic acid like substances (IAAS) of biofilms was higher than that of mixed cultures, fungi or bacteria. Bacteria and fungi produced higher quantities of IAAS than mixed cultures. In mixed cultures, the potential of IAAS production of resident microbes was reduced considerably. There was a negative relationship between IAAS and pH of the biofilms, indicating that IAAS was the main contributor to the acidity. However, such a relationship was not observed in mixed cultures. Microbial acid production is important for suppressing plant pathogens. Thus the biofilm formation in endophytic environment seems to be very important for healthy and improved plant growth. However, it is unlikely that an interaction among endophytes takes place naturally in the endophytic environment, due to physical barriers of plant tissues. Further, critical cell density dependant quorum sensing that leads to biofilm formation may not occur in the endophytic environment as there is a limited space. As such in vitro production and application of beneficial biofilmed inocula of endophytes are important for improved plant production in any agro-ecosystem. The conventional practice of plant inoculation with monocultures or mixed cultures of effective microbes may not give the highest microbial effect, which may only be achieved by biofilm formation.

  16. Ciprofloxacin and Clozapine: A Potentially Fatal but Underappreciated Interaction

    Directory of Open Access Journals (Sweden)

    Jonathan M. Meyer

    2016-01-01

    Full Text Available Objective. Clozapine provides a 50%–60% response rate in refractory schizophrenia but has a narrow therapeutic index and is susceptible to pharmacokinetic interactions, particularly with strong inhibitors or inducers of cytochrome P450 (CYP 1A2. Case Report. We report the case of a 28-year-old nonsmoking female with intellectual disability who was maintained for 3 years on clozapine 100 mg orally twice daily. The patient was treated for presumptive urinary tract infection with ciprofloxacin 500 mg orally twice daily and two days later collapsed and died despite resuscitation efforts. The postmortem femoral clozapine plasma level was dramatically elevated at 2900 ng/mL, and the cause of death was listed as acute clozapine toxicity. Conclusion. Given the potentially fatal pharmacokinetic interaction between clozapine and ciprofloxacin, clinicians are advised to monitor baseline clozapine levels prior to adding strong CYP450 1A2 inhibitors, reduce the clozapine dose by at least two-thirds if adding a 1A2 inhibitor such as ciprofloxacin, check subsequent steady state clozapine levels, and adjust the clozapine dose to maintain levels close to those obtained at baseline.

  17. Two-site fluctuations and multipolar intersite exchange interactions in strongly correlated systems

    Science.gov (United States)

    Pourovskii, L. V.

    2016-09-01

    An approach is proposed for evaluating dipolar and multipolar intersite interactions in strongly correlated materials. This approach is based on the single-site dynamical mean-field theory (DMFT) in conjunction with the atomic approximation for the local self-energy. Starting from the local-moment paramagnetic state described by DMFT, we derive intersite interactions by considering the response of the DMFT grand potential to small fluctuations of atomic configurations on two neighboring sites. The present method is validated by applying it to one-band and two-band eg Hubbard models on the simple-cubic 3 d lattice. It is also applied to study the spin-orbital order in the parent cubic structure of ternary chromium fluoride KCrF3. We obtain the onset of a G-type antiferro-orbital order at a significantly lower temperature compared to that in real distorted KCrF3. In contrast, its layered A-type antiferromagnetic order and Néel temperature are rather well reproduced. The calculated full Kugel-Khomskii Hamiltonian contains spin-orbital coupling terms inducing a misalignment in the antiferro-orbital order upon the onset of antiferromagnetism.

  18. Nonexponential decay of velocity correlations in surface diffusion: The role of interactions and ordering

    DEFF Research Database (Denmark)

    Vattulainen, Ilpo Tapio; Hjelt, T.; Ala-Nissila, T.

    2000-01-01

    We study the diffusive dynamics of adparticles in two model systems with strong interactions by considering the decay of the single-particle velocity correlation function phi (t). In accordance with previous studies, we find phi (t) to decay nonexponentially and follow a power-law phi (t)similar ......We study the diffusive dynamics of adparticles in two model systems with strong interactions by considering the decay of the single-particle velocity correlation function phi (t). In accordance with previous studies, we find phi (t) to decay nonexponentially and follow a power-law phi (t...... be rationalized in terms of interaction effects. Namely, x is typically larger than two in cases where repulsive adparticle-adparticle interactions dominate, while attractive interactions lead to x...

  19. A study on the correlation between soil radon potential and average indoor radon potential in Canadian cities.

    Science.gov (United States)

    Chen, Jing; Ford, Ken L

    2017-01-01

    Exposure to indoor radon is identified as the main source of natural radiation exposure to the population. Since radon in homes originates mainly from soil gas radon, it is of public interest to study the correlation between radon in soil and radon indoors in different geographic locations. From 2007 to 2010, a total of 1070 sites were surveyed for soil gas radon and soil permeability. Among the sites surveyed, 430 sites were in 14 cities where indoor radon information is available from residential radon and thoron surveys conducted in recent years. It is observed that indoor radon potential (percentage of homes above 200 Bq m(-3); range from 1.5% to 42%) correlates reasonably well with soil radon potential (SRP: an index proportional to soil gas radon concentration and soil permeability; average SRP ranged from 8 to 26). In five cities where in-situ soil permeability was measured at more than 20 sites, a strong correlation (R(2) = 0.68 for linear regression and R(2) = 0.81 for non-linear regression) was observed between indoor radon potential and soil radon potential. This summary report shows that soil gas radon measurement is a practical and useful predictor of indoor radon potential in a geographic area, and may be useful for making decisions around prioritizing activities to manage population exposure and future land-use planning. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  20. Tracking the processes behind conscious perception: a review of event-related potential correlates of visual consciousness.

    Science.gov (United States)

    Railo, Henry; Koivisto, Mika; Revonsuo, Antti

    2011-09-01

    Event-related potential (ERP) studies have attempted to discover the processes that underlie conscious visual perception by contrasting ERPs produced by stimuli that are consciously perceived with those that are not. Variability of the proposed ERP correlates of consciousness is considerable: the earliest proposed ERP correlate of consciousness (P1) coincides with sensory processes and the last one (P3) marks postperceptual processes. A negative difference wave called visual awareness negativity (VAN), typically observed around 200 ms after stimulus onset in occipitotemporal sites, gains strong support for reflecting the processes that correlate with, and possibly enable, aware visual perception. Research suggests that the early parts of conscious processing can proceed independently of top-down attention, although top-down attention may modulate visual processing even before consciousness. Evidence implies that the contents of consciousness are provided by interactions in the ventral stream, but indispensable contributions from dorsal regions influence already low-level visual responses.

  1. Immunologic correlates of protection and potential role for adjuvants to improve influenza vaccines in older adults.

    Science.gov (United States)

    McElhaney, Janet E; Coler, Rhea N; Baldwin, Susan L

    2013-07-01

    The decrease in influenza vaccine efficacy in the elderly is associated with a decline in the stimulation of cell-mediated and cytotoxic T-lymphocyte responses required for clinical protection against influenza, and may be particularly problematic when this population is administered split-virus vaccines that lack conserved viral proteins. Adjuvants, which act through innate immune mechanisms, are known to enhance both humoral and T-cell-mediated responses to influenza vaccines in this population. Adjuvant effects including enhanced antigen presentation, activation and maturation of dendritic cells and production of inflammatory cytokines can drive the desired cell-mediated immune responses. Toll-like receptor ligands comprise one class of adjuvants, which interact with external and internal receptors associated with dendritic cells and other APCs, leading to the regulation and production of important inflammatory cytokines. Potential advances in the production of more effective influenza vaccines for older people include the addition of adjuvants to standard split-virus vaccines and the use of alternate routes of vaccine delivery to augment the response to influenza infection. In this review, the authors discuss the impact of immune senescence on the response to influenza vaccination, the correlates of protection against influenza disease and the progress being made in the design of better influenza vaccines for the population aged 65 years and older.

  2. Long-range correlation of the membrane potential in neocortical neurons during slow oscillation

    Science.gov (United States)

    Volgushev, Maxim; Chauvette, Sylvain; Timofeev, Igor

    2012-01-01

    Large amplitude slow waves are characteristic for the summary brain activity, recorded as electroencephalogram (EEG) or local field potentials (LFP), during deep stages of sleep and some types of anesthesia. Slow rhythm of the synchronized EEG reflects an alternation of active (depolarized, UP) and silent (hyperpolarized, DOWN) states of neocortical neurons. In neurons, involvement in the generalized slow oscillation results in a long-range synchronization of changes of their membrane potential as well as their firing. Here, we aimed at intracellular analysis of details of this synchronization. We asked which components of neuronal activity exhibit long-range correlations during the synchronized EEG? To answer this question, we made simultaneous intracellular recordings from two to four neocortical neurons in cat neocortex. We studied how correlated is the occurrence of active and silent states, and how correlated are fluctuations of the membrane potential in pairs of neurons located close one to the other or separated by up to 13 mm. We show that strong long-range correlation of the membrane potential was observed only (i) during the slow oscillation but not during periods without the oscillation, (ii) during periods which included transitions between the states but not during within-the-state periods, and (iii) for the low-frequency (10 Hz). In contrast to the neurons located several millimeters one from the other, membrane potential fluctuations in neighboring neurons remain strongly correlated during periods without slow oscillation. We conclude that membrane potential correlation in distant neurons is brought about by synchronous transitions between the states, while activity within the states is largely uncorrelated. The lack of the generalized fine-scale synchronization of membrane potential changes in neurons during the active states of slow oscillation may allow individual neurons to selectively engage in short living episodes of correlated activity

  3. Antiparkinsonian potential of interaction of LEK-8829 with bromocriptine.

    Science.gov (United States)

    Zivin, M; Sprah, L; Sket, D

    1998-05-22

    The ergoline derivative, LEK-8829 (9,10-didehydro-N-methyl-(2-propynyl)-6-methyl-8-aminomethylerg oline), has been proposed as a potential atypical antipsychotic drug with antagonistic actions at dopamine D2 and serotonin 5-HT2 and 5-HT1A receptors (Krisch et al., 1994, 1996). LEK-8829 also induces contralateral turning in rats with 6-hydroxydopamine-induced unilateral lesion of dopamine nigrostriatal neurons. Turning is blocked by SCH-23390 (R(+)-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzaze pine), a dopamine D1 receptor antagonist. It has been suggested that LEK-8829 could have beneficial effects in parkinsonian patients suffering from psychotic episodes induced as a side-effect of antiparkinsonian treatment with dopamine D2 receptor agonists. Therefore, we now investigated the interaction of LEK-8829 with the dopamine D2 receptor agonist bromocriptine (2-bromo-alpha-ergokryptine) in 6-hydroxydopamine-lesioned rats. Treatment with either LEK-8829 (3 mg kg(-1)) or bromocriptine (3 mg kg(-1)) induced a vigorous contralateral turning response. The cumulated number of turns induced by the treatment with both drugs combined was not significantly different from the cumulated number of turns induced by single-drug treatment. The pretreatment with SCH-23390 (1 mg kg(-1)) did not have a significant effect on the bromocriptine-induced turning but significantly decreased the turning observed after the combined LEK-8829/bromocriptine treatment. We conclude that in the 6-hydroxydopamine model, the turning behaviour mediated by the LEK-8829/bromocriptine combination may be the result of opposing activity of both drugs at dopamine D2 receptors with concomitant stimulation of dopamine D1 receptors by LEK-8829. Therefore, LEK-8829 may have a potential for the therapy of parkinsonism complicated by dopamine D2 receptor agonist drug-induced psychosis.

  4. Myocardial fibroblast-matrix interactions and potential therapeutic targets.

    Science.gov (United States)

    Goldsmith, Edie C; Bradshaw, Amy D; Zile, Michael R; Spinale, Francis G

    2014-05-01

    The cardiac extracellular matrix (ECM) is a dynamic structure, adapting to physiological and pathological stresses placed on the myocardium. Deposition and organization of the matrix fall under the purview of cardiac fibroblasts. While often overlooked compared to myocytes, fibroblasts play a critical role in maintaining ECM homeostasis under normal conditions and in response to pathological stimuli assume an activated, myofibroblast phenotype associated with excessive collagen accumulation contributing to impaired cardiac function. Complete appreciation of fibroblast function is hampered by the lack of fibroblast-specific reagents and the heterogeneity of fibroblast precursors. This is further complicated by our ability to dissect the role of myofibroblasts versus fibroblasts in myocardial in remodeling. This review highlights critical points in the regulation of collagen deposition by fibroblasts, the current panel of molecular tools used to identify fibroblasts and the role of fibroblast-matrix interactions in fibroblast function and differentiation into the myofibroblast phenotype. The clinical potential of exploiting differences between fibroblasts and myofibroblasts and using them to target specific fibroblast populations is also discussed. This article is part of a Special Issue entitled "Myocyte-Fibroblast Signalling in Myocardium." Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Probiotics: Interaction with gut microbiome and antiobesity potential.

    Science.gov (United States)

    Arora, Tulika; Singh, Satvinder; Sharma, Raj Kumar

    2013-04-01

    Obesity is a metabolic disorder afflicting people globally. There has been a pivotal advancement in the understanding of the intestinal microbiota composition and its implication in extraintestinal (metabolic) diseases. Therefore, any agent modulating gut microbiota may produce an influential effect in preventing the pathogenesis of disease. Probiotics are live microbes that, when administered in adequate amounts, have been shown to confer health benefits to the host. Over the years, probiotics have been a part of the human diet in the form of different fermented foods consumed around the world. Their influence on different physiologic functions in the host is increasingly being documented. The antiobesity potential of probiotics is also gaining wide attention because of increasing evidence of the role of gut microbiota in energy homeostasis and fat accumulation. Probiotics have also been shown to interact with the resident bacterial members already present in the gut by altering their properties, which may also affect the metabolic pathways involved in the regulation of fat metabolism. The underlying pathways governing the antiobesity effects of probiotics remain unclear. However, it is hoped that the evidence presented and discussed in this review will encourage and thus drive more extensive research in this field.

  6. Improved Interaction Potentials for Charged Residues in Proteins

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2008-01-01

    -consistent, experimental set of hydration free energies for acetate (Asp), propionate (Glu), 4-methylimidazolium (Hip), n-butylammonium (Lys), and n-propylguanidinium (Arg), all resembling charged residue side chains, including -carbons. It is shown that OPLS-AA free energies depend critically on the type of water model......, TIP4P or TIP3P; i.e., each water model requires specific water-charged molecule interaction potentials. New models (models 1 and 3) are thus described for both water models. Uncertainties in relative free energies of charged residues are ~2 kcal/mol with the new parameters, due to variations in system...... setup (MAEs of ca. 1 kcal/mol) and noise from simulations (ca. 1 kcal/mol). The latter error of ~1 kcal/mol contrasts MAEs from standard OPLS-AA of up to 13 kcal/mol for the entire series of charged residues or up to 5 kcal/mol for the cationic series Lys, Arg, and Hip. The new parameters can be used...

  7. Commercially available interactive video games in burn rehabilitation: therapeutic potential.

    Science.gov (United States)

    Parry, Ingrid S; Bagley, Anita; Kawada, Jason; Sen, Soman; Greenhalgh, David G; Palmieri, Tina L

    2012-06-01

    Commercially available interactive video games (IVG) like the Nintendo Wii™ (NW) and PlayStation™II Eye Toy (PE) are increasingly used in the rehabilitation of patients with burn. Such games have gained popularity in burn rehabilitation because they encourage range of motion (ROM) while distracting from pain. However, IVGs were not originally designed for rehabilitation purposes but rather for entertainment and may lack specificity for achieving rehabilitative goals. Objectively evaluating the specific demands of IVGs in relation to common burn therapy goals will determine their true therapeutic benefit and guide their use in burn rehabilitation. Upper extremity (UE) motion of 24 normal children was measured using 3D motion analysis during play with the two types of IVGs most commonly described for use after burn: NW and PE. Data was analyzed using t-tests and One-way Analysis of Variance. Active range of motion for shoulder flexion and abduction during play with both PE and NW was within functional range, thus supporting the idea that IVGs offer activities with therapeutic potential to improve ROM. PE resulted in higher demands and longer duration of UE motion than NW, and therefore may be the preferred tool when UE ROM or muscular endurance are the goals of rehabilitation. When choosing a suitable IVG for application in rehabilitation, the user's impairment together with the therapeutic attributes of the IVG should be considered to optimize outcome.

  8. Induced gravity with Higgs potential. Elementary interactions and quantum processes

    Energy Technology Data Exchange (ETDEWEB)

    Bezares Roder, Nils Manuel

    2010-07-01

    This work is intended to first serve as introduction in fundamental subjects of physics in order to be then able to review the mechanism of symmetry breakdown and its essential character in physics. It introduces the concept of scalar-tensor theories of gravity based on Bergmann-Wagoner models with a Higgs potential. The main physical context aimed is the problem of Dark Matter and Dark Energy. On the one hand, there is gravitation. Within this context, we have Dark Matter as an especially relevant concept. This work entails the following main contributions: - General features of Einstein's theory are introduced together with generalities of the different elementary interactions of physics from which the concepts of dark sectors and Higgs Mechanism are derived. - The concept of symmetry breaking and especially the Higgs Mechanism of mass generation are discussed in their relevance for the most different subjects of physics, especially in relation to the Standard Model of elementary particle physics with elementary Higgs fields. - Scalar-Tensor Theories are introduced in order to build in them the process of Higgs Mechanism. This is then fulfilled with a theory of induced gravity with a Higgs potential which seems renormalizable according to deWitt's power counting criterion, and with mass-generating Higgs fields which only couple gravitationally as well as with Higgs fields which act analogously to cosmon fields. - Further, the energy density of the gravitational field is derived for the specific model of induced gravity from an analogy to electrodynamics. It is shown that a nonvanishing value of pressure related to the scalar field is necessary in order to reproduce standard linear solar-relativistic dynamics. Within astrophysical considerations for flat rotation curves of galaxies, a possible dark-matter behavior is concluded within spherical symmetry. The scalar field and the dark-matter profile of total energy density are derived. An analogous

  9. Long-range rapidity correlations in soft interactions at high energies

    Science.gov (United States)

    Gotsman, E.; Levin, E.; Maor, U.

    2013-12-01

    In this paper we take the next step (following the successful description of inclusive hadron production) in describing the structure of the bias events without the aid of Monte Carlo codes. Two new results are presented: (i) a method for calculating the two particle correlation functions in the BFKL pomeron calculus in zero transverse dimension; and (ii) an estimation of the values of these correlations in a model of soft interactions. Comparison with the multiplicity data at the LHC is given.

  10. Employing an interaction picture to remove artificial correlations in multilayer multiconfiguration time-dependent Hartree simulations

    Science.gov (United States)

    Wang, Haobin; Thoss, Michael

    2016-10-01

    The multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method is implemented in the interaction picture to allow a more effective description of correlation effects. It is shown that the artificial correlation present in the original Schrödinger picture can be removed with an appropriate choice of the zeroth-order Hamiltonian. Thereby, operators in the interaction picture are obtained through time-dependent unitary transformations, which have negligible computational cost compared with other parts of the ML-MCTDH algorithm. The efficiency of the method is demonstrated by application to a model of vibrationally coupled charge transport in molecular junctions.

  11. Potential-of-mean-force description of ionic interactions and structural hydration in biomolecular systems

    Energy Technology Data Exchange (ETDEWEB)

    Hummer, G.; Garcia, A.E. [Los Alamos National Lab., NM (United States). Theoretical Biology and Biophysics Group; Soumpasis, D.M. [Max-Planck-Inst for Biophysical Chemistry, Goettingen (Germany). Biocomputation Group

    1994-10-01

    To understand the functioning of living organisms on a molecular level, it is crucial to dissect the intricate interplay of the immense number of biological molecules. Most of the biochemical processes in cells occur in a liquid environment formed mainly by water and ions. This solvent environment plays an important role in biological systems. The potential-of-mean-force (PMF) formalism attempts to describe quantitatively the interactions of the solvent with biological macromolecules on the basis of an approximate statistical-mechanical representation. At its current status of development, it deals with ionic effects on the biomolecular structure and with the structural hydration of biomolecules. The underlying idea of the PMF formalism is to identify the dominant sources of interactions and incorporate these interactions into the theoretical formalism using PMF`s (or particle correlation functions) extracted from bulk-liquid systems. In the following, the authors shall briefly outline the statistical-mechanical foundation of the PMF formalism and introduce the PMF expansion formalism, which is intimately linked to superposition approximations for higher-order particle correlation functions. The authors shall then sketch applications, which describe the effects of the ionic environment on nucleic-acid structure. Finally, the authors shall present the more recent extension of the PMF idea to describe quantitatively the structural hydration of biomolecules. Results for the interface of ice and water and for the hydration of deoxyribonucleic acid (DNA) will be discussed.

  12. Semi-Empirical Effective Interactions for Inelastic Scattering Derived from the Reid Potential

    Science.gov (United States)

    Fiase, J. O.; Sharma, L. K.; Winkoun, D. P.; Hosaka, A.

    2001-09-01

    An effective local interaction suitable for inelastic scattering is constructed from the Reid soft - core potential. We proceed in two stages: We first calculated a set of relative two - body matrix elements in a variational approach using the Reid soft-core potential folded with two-body correlation functions. In the second stage we constructed a potential for inelastic scattering by fitting the matrix elements to a sum of Yukawa central, tensor and spin-orbit terms to the set of relative two - body matrix elements obtained in the first stage by a least squares fitting procedure. The ranges of the new potential were selected to ensure the OPEP tails in the relevant channels as well as the short - range part of the interaction. It is found that the results of our variational techniques are very similar to the G - matrix calculations of Bertsch and co - workers in the singlet - even, triplet - even, tensor - even and spin-orbit odd channels thus putting our calculations of two - body matrix elements of nuclear forces in these channels on a sound footing. However, there exist major differences in the singlet - odd, triplet - odd, tensor - odd and spin - orbit even channels which casts some doubt on our understanding of nuclear forces in these channels.

  13. Spin-orbit interaction in quantum dots and quantum wires of correlated electrons - a way to spintronics?

    Energy Technology Data Exchange (ETDEWEB)

    Birkholz, Jens Eiko

    2008-10-06

    We study the influence of the spin-orbit interaction on the electronic transport through quantum dots and quantum wires of correlated electrons. Starting with a one-dimensional infinite continuum model without Coulomb interaction, we analyze the interplay of the spin-orbit interaction, an external magnetic field, and an external potential leading to currents with significant spin-polarization in appropriate parameter regimes. Since lattice models are known to often be superior to continuum models in describing the experimental situation of low-dimensional mesoscopic systems, we construct a lattice model which exhibits the same low-energy physics in terms of energy dispersion and spin expectation values. Confining the lattice to finite length and connecting it to two semi-infinite noninteracting Fermi liquid leads, we calculate the zero temperature linear conductance using the Landauer-Bttiker formalism and show that spin-polarization effects also evolve for the lattice model by adding an adequate potential structure and can be controlled by tuning the overall chemical potential of the system (quantum wire and leads). Next, we allow for a finite Coulomb interaction and use the functional renormalization group (fRG) method to capture correlation effects induced by the Coulomb interaction. The interacting system is thereby transformed into a noninteracting system with renormalized system parameters. For short wires ({proportional_to}100 lattice sites), we show that the energy regime in which spin polarization is found is strongly affected by the Coulomb interaction. For long wires (>1000 lattice sites), we find the power-law suppression of the total linear conductance on low energy scales typical for inhomogeneous Luttinger liquids while the degree of spin polarization stays constant. Considering quantum dots which consist of two lattice sites, we observe the well-known Kondo effect and analyze, how the Kondo temperature is affected by the spin-orbit interaction

  14. EPR statistical mixture of correlated states with fractional brownian process induced by third party interaction

    CERN Document Server

    Tamburini, F; Bianchini, A

    1999-01-01

    A time-correlated EPR pairs protocol is analized, based on detection of fractal correlated signals into a statistical mixture of EPR correlated pairs: an approximated alpha-Fractional Brownian Motion (FBM) is induced on the group of EPR pairs (e.g. by sender-third party eavesdropper-like interactions as in Ekert quantum cryptography), to be detected by the receiver using a non - orthogonal wavelet filter, able to characterize the FBM from a noisy enviroment by formalizing a nonlinear optimization problem for the FBM alpha-characteristic parameter extimation.

  15. Subsystem-DFT potential-energy curves for weakly interacting systems.

    Science.gov (United States)

    Schlüns, Danny; Klahr, Kevin; Mück-Lichtenfeld, Christian; Visscher, Lucas; Neugebauer, Johannes

    2015-06-14

    Kohn-Sham density-functional theory (DFT) within the local-density approximation (LDA) or the generalized-gradient approximation (GGA) is known to fail for the correct description of London dispersion interactions. Often, not even bound potential-energy surfaces are obtained for van der Waals complexes, unless special correction schemes are employed. In contrast to that, there has been some evidence for the fact that subsystem-based density functional theory produces interaction energies for weakly bound systems which are superior to Kohn-Sham DFT results without dispersion corrections. This is usually attributed to an error cancellation between the approximate exchange-correlation and non-additive kinetic-energy functionals employed in subsystem DFT. Here, we investigate the accuracy of subsystem DFT for weakly interacting systems in detail, paying special attention to the shape of the potential-energy surfaces (PESs). Our test sets include the extensive S22x5 and S66x8 data sets. Our results indicate that subsystem DFT PESs strongly vary depending on the functional. LDA results are usually quite good, but behave differently from their KS counterparts. GGA results from the popular Perdew-Wang (PW91) set of functionals produce PESs that are often, but not in general overbinding. Results from Becke-Perdew (BP86) GGAs, by contrast, show the typical problems known from the corresponding KS results. We provide some preliminary results for empirical corrections for both PW91 and BP86 in subsystem DFT.

  16. Interaction Effects between Maternal Lifetime Depressive/Anxiety Disorders and Correlates of Children's Externalizing Symptoms

    Science.gov (United States)

    Piche, Genevieve; Bergeron, Lise; Cyr, Mireille; Berthiaume, Claude

    2011-01-01

    We investigated the interaction effects between mother's lifetime depressive/anxiety disorders and psychosocial correlates of 6 to 11 year-old children's self-reported externalizing symptoms in the Quebec Child Mental Health Survey. A representative subsample of 1,490 Quebec children aged 6 to 11 years was selected from the original sample. We…

  17. Prevalence and Correlates of Drug-drug Interactions in the Regional Hospital of Gjilan, Kosovo

    NARCIS (Netherlands)

    Shabani, D.; Tahiri, Z.; Bara, P.; Hudhra, K.; Malaj, L.; Jucja, B.; Bozalia, A.; Burazeri, G.

    2014-01-01

    AIM: Our aim was to assess the prevalence and socioeconomic and clinical correlates of drug-drug interactions among the adult population of transitional Kosovo. METHODS: A cross-sectional study was conducted including a representative sample of 1921 patients aged >/=18 years (mean age: 57.8+/-11.2 y

  18. Prevalence and Correlates of Drug-drug Interactions in the Regional Hospital of Gjilan, Kosovo

    NARCIS (Netherlands)

    Shabani, D.; Tahiri, Z.; Bara, P.; Hudhra, K.; Malaj, L.; Jucja, B.; Bozalia, A.; Burazeri, G.

    2014-01-01

    AIM: Our aim was to assess the prevalence and socioeconomic and clinical correlates of drug-drug interactions among the adult population of transitional Kosovo. METHODS: A cross-sectional study was conducted including a representative sample of 1921 patients aged >/=18 years (mean age: 57.8+/-11.2

  19. Non-Local Propagation of Correlations in Quantum Systems with Long-Range Interactions

    Science.gov (United States)

    2014-07-10

    LETTER doi:10.1038/nature13450 Non-local propagation of correlations in quantum systems with long-range interactions Philip Richerme1, Zhe -Xuan Gong1...2013). 29. James, D. F. V. Quantum dynamics of cold trapped ions with application to quantum computation. Appl. Phys. B 66, 181–190 (1998). 30. Wang

  20. Spreading of correlations in exactly solvable quantum models with long-range interactions in arbitrary dimensions

    Science.gov (United States)

    Cevolani, Lorenzo; Carleo, Giuseppe; Sanchez-Palencia, Laurent

    2016-09-01

    We study the out-of-equilibrium dynamics induced by quantum quenches in quadratic Hamiltonians featuring both short- and long-range interactions. The spreading of correlations in the presence of algebraic decaying interactions, 1/R α , is studied for lattice Bose models in arbitrary dimension D. These models are exactly solvable and provide useful insight in the universal description of more complex systems as well as comparisons to the known universal upper bounds for the spreading of correlations. Using analytical calculations of the dominant terms and full numerical integration of all quasi-particle contributions, we identify three distinct dynamical regimes. For strong decay of interactions, α \\gt D+1, we find a causal regime, qualitatively similar to what previously found for short-range interactions. This regime is characterized by ballistic (linear cone) spreading of the correlations with a cone velocity equal to twice the maximum group velocity of the quasi-particles. For weak decay of interactions, α molecular, and optical systems, and pave the way to the observation of causality and its breaking in diverse experimental realization.

  1. The power of a handshake: neural correlates of evaluative judgments in observed social interactions.

    Science.gov (United States)

    Dolcos, Sanda; Sung, Keen; Argo, Jennifer J; Flor-Henry, Sophie; Dolcos, Florin

    2012-12-01

    Effective social interactions require the ability to evaluate other people's actions and intentions, sometimes only on the basis of such subtle factors as body language, and these evaluative judgments may lead to powerful impressions. However, little is known about the impact of affective body language on evaluative responses in social settings and the associated neural correlates. This study investigated the neural correlates of observing social interactions in a business setting, in which whole-body dynamic stimuli displayed approach and avoidance behaviors that were preceded or not by a handshake and were followed by participants' ratings of these behaviors. First, approach was associated with more positive evaluations than avoidance behaviors, and a handshake preceding social interaction enhanced the positive impact of approach and diminished the negative impact of avoidance behavior on the evaluation of social interaction. Second, increased sensitivity to approach than to avoidance behavior in the amygdala and STS was linked to a positive evaluation of approach behavior and a positive impact of handshake. Third, linked to the positive effect of handshake on social evaluation, nucleus accumbens showed greater activity for Handshake than for No-handshake conditions. These findings shed light on the neural correlates of observing and evaluating nonverbal social interactions and on the role of handshake as a way of formal greeting.

  2. Influence of Solvent-Solvent and Solute-Solvent Interaction Properties on Solvent-Mediated Potential

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Qi

    2005-01-01

    A recently proposed universal calculational recipe for solvent-mediated potential is applied to calculate excess potential of mean force between two large Lennard-Jones (LJ) or hard core attractive Yukawa particles immersed in small LJ solvent bath at supercritical state. Comparison between the present prediction with a hypernetted chain approximation adopted for solute-solute correlation at infinitely dilute limit and existing simulation data shows high accuracy for the region with large separation, and qualitative reliability for the solute particle contact region. The calculational simplicity of the present recipe allows for a detailed investigation on the effect of the solute-solvent and solvent-solvent interaction details on the excess potential of mean force. The resultant conclusion is that gathering of solvent particles near a solute particle leads to repulsive excess PMF, while depletion of solvent particles away from the solute particle leads to attractive excess PMF, and minor change of the solvent-solvent interaction range has large influence on the excess PMF.

  3. Correlation effects on the energy spectra of quantum dot electrons with harmonic model interactions

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The low-lying excitation energy spectra of two, three and five quantum dot electrons with harmonic model interactions in a large magnetic field are calculated by the Hartree-Fock(HF) methods. Correlation effects on the energy level structures are investigated by comparing the HF results with the exact ones. It is found that the pure collective excitations(center-of-mass mode quanta) existing in the exact energy spectra do not appear in the HF energy spectra. The degeneracies of energy levels are also related to the correlation interactions, especially in the energy spectrum of two electrons. In the cases of more than two electrons, as the electron-electron interaction strength is increased the HF energy levels exhibit more complex crossings than the exact ones.

  4. Interaction potentials for water from accurate cluster calculations

    Energy Technology Data Exchange (ETDEWEB)

    Xantheas, Sotiris S.

    2006-03-15

    The abundance of water in nature, its function as a universal solvent and its role in many chemical and biological processes that are responsible for sustaining life on earth is the driving force behind the need for understanding its behavior under different conditions, and in various environments. The availability of models that describe the properties of either pure water/ice or its mixtures with a variety of solutes ranging from simple chemical species to complex biological molecules and environmental interfaces is therefore crucial in order to be able to develop predictive paradigms that attempt to model solvation and reaction and transport in aqueous environments. In attempting to develop these models the question naturally arises 'is water different/more complex than other hydrogen bonded liquids'. This proposition has been suggested based on the 'anomalous' behavior of its macroscopic properties such as the density maximum at 4 C, the non-monotonic behavior of its compressibility with temperature, the anomalous behavior of its relaxation time below typical temperatures of the human body, the large value and non-monotonic dependence below 35 C of the specific heat of constant pressure, the smaller than expected value of the coefficient of thermal expansion. This suggestion infers that simple models used to describe the relevant inter- and intra-molecular interactions will not suffice in order to reproduce the behavior of these properties under a wide temperature range. To this end, explicit microscopic level detailed information needs to be incorporated into the models in order to capture the appropriate physics at the molecular level. From the simple model of Bernal and Fowler, which was the first attempt to develop an empirical model for water back in 1933, this process has yielded ca. 50 different models to date. A recent review provides a nearly complete account of this effort coupled to the milestones in the area of molecular

  5. Partition and Correlation Functions of a Freely Crossed Network Using Ising Model-Type Interactions

    CERN Document Server

    Saito, Akira

    2016-01-01

    We set out to determine the partition and correlation functions of a network under the assumption that its elements are freely connected, with an Ising model-type interaction energy associated with each connection. The partition function is obtained from all combinations of loops on the free network, while the correlation function between two elements is obtained based on all combinations of routes between these points, as well as all loops on the network. These functions allow measurement of the dynamics over the whole of any network, regardless of its form. Furthermore, even as parts are added to the network, the partition and correlation functions can still be obtained. As an example, we obtain the partition and correlation functions in a crystal system under the repeated addition of fixed parts.

  6. Analysis of correlations between protein complex and protein-protein interaction and mRNA expression

    Institute of Scientific and Technical Information of China (English)

    CAI Lun; XUE Hong; LU Hongchao; ZHAO Yi; ZHU Xiaopeng; BU Dongbo; LING Lunjiang; CHEN Runsheng

    2003-01-01

    Protein-protein interaction is a physical interaction of two proteins in living cells. In budding yeast Saccharomyces cerevisiae, large-scale protein-protein interaction data have been obtained through high-throughput yeast two-hybrid systems (Y2H) and protein complex purification techniques based on mass-spectrometry. Here, we collect 11855 interactions between total 2617 proteins. Through seriate genome-wide mRNA expression data, similarity between two genes could be measured. Protein complex data can also be obtained publicly and can be translated to pair relationship that any two proteins can only exist in the same complex or not. Analysis of protein complex data, protein-protein interaction data and mRNA expression data can elucidate correlations between them. The results show that proteins that have interactions or similar expression patterns have a higher possibility to be in the same protein complex than randomized selected proteins, and proteins which have interactions and similar expression patterns are even more possible to exist in the same protein complex. The work indicates that comprehensive integration and analysis of public large-scale bioinformatical data, such as protein complex data, protein-protein interaction data and mRNA expression data, may help to uncover their relationships and common biological information underlying these data. The strategies described here may help to integrate and analyze other functional genomic and proteomic data, such as gene expression profiling, protein-localization mapping and large-scale phenotypic data, both in yeast and in other organisms.

  7. Correlation between safety assessments in the driver-car interaction design process.

    Science.gov (United States)

    Broström, Robert; Bengtsson, Peter; Axelsson, Jakob

    2011-05-01

    With the functional revolution in modern cars, evaluation methods to be used in all phases of driver-car interaction design have gained importance. It is crucial for car manufacturers to discover and solve safety issues early in the interaction design process. A current problem is thus to find a correlation between the formative methods that are used during development and the summative methods that are used when the product has reached the customer. This paper investigates the correlation between efficiency metrics from summative and formative evaluations, where the results of two studies on sound and navigation system tasks are compared. The first, an analysis of the J.D. Power and Associates APEAL survey, consists of answers given by about two thousand customers. The second, an expert evaluation study, was done by six evaluators who assessed the layouts by task completion time, TLX and Nielsen heuristics. The results show a high degree of correlation between the studies in terms of task efficiency, i.e. between customer ratings and task completion time, and customer ratings and TLX. However, no correlation was observed between Nielsen heuristics and customer ratings, task completion time or TLX. The results of the studies introduce a possibility to develop a usability evaluation framework that includes both formative and summative approaches, as the results show a high degree of consistency between the different methodologies. Hence, combining a quantitative approach with the expert evaluation method, such as task completion time, should be more useful for driver-car interaction design.

  8. Dynamics of local symmetry correlators for interacting many-particle systems

    Science.gov (United States)

    Schmelcher, P.; Krönke, S.; Diakonos, F. K.

    2017-01-01

    Recently [P. A. Kalozoumis et al. Phys. Rev. Lett. 113, 050403 (2014)] the concept of local symmetries in one-dimensional stationary wave propagation has been shown to lead to a class of invariant two-point currents that allow to generalize the parity and Bloch theorem. In the present work, we establish the theoretical framework of local symmetries for higher-dimensional interacting many-body systems. Based on the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy, we derive the equations of motion of local symmetry correlators which are off-diagonal elements of the reduced one-body density matrix at symmetry related positions. The natural orbital representation yields equations of motion for the convex sum of the local symmetry correlators of the natural orbitals as well as for the local symmetry correlators of the individual orbitals themselves. An alternative integral representation with a unique interpretation is provided. We discuss special cases, such as the bosonic and fermionic mean field theory, and show in particular that the invariance of two-point currents is recovered in the case of the non-interacting one-dimensional stationary wave propagation. Finally we derive the equations of motion for anomalous local symmetry correlators which indicate the breaking of a global into a local symmetry in the stationary non-interacting case.

  9. Quantum correlation dynamics subjected to critical spin environment with short-range anisotropic interaction

    Science.gov (United States)

    Guo, J. L.; Zhang, X. Z.

    2016-01-01

    Short-range interaction among the spins can not only results in the rich phase diagram but also brings about fascinating phenomenon both in the contexts of quantum computing and information. In this paper, we investigate the quantum correlation of the system coupled to a surrounding environment with short-range anisotropic interaction. It is shown that the decay of quantum correlation of the central spins measured by pairwise entanglement and quantum discord can serve as a signature of quantum phase transition. In addition, we study the decoherence factor of the system when the environment is in the vicinity of the phase transition point. In the strong coupling regime, the decay of the decoherence factor exhibits Gaussian envelop in the time domain. However, in weak coupling limit, the quantum correlation of the system is robust against the disturbance of the magnetic field through optimal control of the anisotropic short-range interaction strength. Based on this, the effects of the short-range anisotropic interaction on the sudden transition from classical to quantum decoherence are also presented. PMID:27596050

  10. Lambda-Lambda interaction from two-particle intensity correlation in relativistic heavy-ion collisions

    CERN Document Server

    Ohnishi, Akira; Furumoto, Takenori

    2015-01-01

    We investigate $\\Lambda\\Lambda$ interaction dependence of the $\\Lambda\\Lambda$ intensity correlation in high-energy heavy-ion collisions. By analyzing the correlation data recently obtained by the STAR collaboration based on theoretically proposed $\\Lambda\\Lambda$ interactions, we give a constraint on the $\\Lambda\\Lambda$ scattering length, $-1.25~\\text{fm} < a_0 < 0$, suggesting that $\\Lambda\\Lambda$ interaction is weakly attractive and there is no loosely bound state. In addition to the fermionic quantum statistics and the $\\Lambda\\Lambda$ interaction, effects of collective flow, feed-down from $\\Sigma^0$, and the residual source are also found to be important to understand the data. We demonstrate that the correlation data favor negative $\\Lambda\\Lambda$ scattering length with the pair purity parameter $\\lambda=(0.67)^2$ evaluated by using experimental data on the $\\Sigma^0/\\Lambda$ ratio, while the positive scattering length could be favored when we regard $\\lambda$ as a free fitting parameter.

  11. Effects of interactions on dynamic correlations of hard-core bosons at finite temperatures

    Science.gov (United States)

    Fauseweh, Benedikt; Uhrig, Götz S.

    2017-09-01

    We investigate how dynamic correlations of hard-core bosonic excitation at finite temperature are affected by additional interactions besides the hard-core repulsion which prevents them from occupying the same site. We focus especially on dimerized spin systems, where these additional interactions between the elementary excitations, triplons, lead to the formation of bound states, relevant for the correct description of scattering processes. In order to include these effects quantitatively, we extend the previously developed Brückner approach to include also nearest-neighbor (NN) and next-nearest neighbor (NNN) interactions correctly in a low-temperature expansion. This leads to the extension of the scalar Bethe-Salpeter equation to a matrix-valued equation. As an example, we consider the Heisenberg spin ladder to illustrate the significance of the additional interactions on the spectral functions at finite temperature, which are proportional to inelastic neutron scattering rates.

  12. Effective potentials for atom-atom interaction at low temperatures

    OpenAIRE

    Gao, Bo

    2002-01-01

    We discuss the concept and design of effective atom-atom potentials that accurately describe any physical processes involving only states around the threshold. The existence of such potentials gives hope to a quantitative, and systematic, understanding of quantum few-atom and quantum many-atom systems at relatively low temperatures.

  13. Host-Microbiome Interaction and Cancer: Potential Application in Precision Medicine

    Science.gov (United States)

    Contreras, Alejandra V.; Cocom-Chan, Benjamin; Hernandez-Montes, Georgina; Portillo-Bobadilla, Tobias; Resendis-Antonio, Osbaldo

    2016-01-01

    It has been experimentally shown that host-microbial interaction plays a major role in shaping the wellness or disease of the human body. Microorganisms coexisting in human tissues provide a variety of benefits that contribute to proper functional activity in the host through the modulation of fundamental processes such as signal transduction, immunity and metabolism. The unbalance of this microbial profile, or dysbiosis, has been correlated with the genesis and evolution of complex diseases such as cancer. Although this latter disease has been thoroughly studied using different high-throughput (HT) technologies, its heterogeneous nature makes its understanding and proper treatment in patients a remaining challenge in clinical settings. Notably, given the outstanding role of host-microbiome interactions, the ecological interactions with microorganisms have become a new significant aspect in the systems that can contribute to the diagnosis and potential treatment of solid cancers. As a part of expanding precision medicine in the area of cancer research, efforts aimed at effective treatments for various kinds of cancer based on the knowledge of genetics, biology of the disease and host-microbiome interactions might improve the prediction of disease risk and implement potential microbiota-directed therapeutics. In this review, we present the state of the art of sequencing and metabolome technologies, computational methods and schemes in systems biology that have addressed recent breakthroughs of uncovering relationships or associations between microorganisms and cancer. Together, microbiome studies extend the horizon of new personalized treatments against cancer from the perspective of precision medicine through a synergistic strategy integrating clinical knowledge, HT data, bioinformatics, and systems biology. PMID:28018236

  14. Host-microbiome interaction and cancer: potential application in precision medicine

    Directory of Open Access Journals (Sweden)

    Alejandra V Contreras

    2016-12-01

    Full Text Available It has been experimentally shown that host-microbial interaction plays a major role in shaping the wellness or disease of the human body. Microorganisms coexisting in human tissues provide a variety of benefits that contribute to proper functional activity in the host through the modulation of fundamental processes such as signal transduction, immunity and metabolism. The unbalance of this microbial profile, or dysbiosis, has been correlated with the genesis and evolution of complex diseases such as cancer. Although this latter disease has been thoroughly studied using different high-throughput technologies, its heterogeneous nature makes its understanding and proper treatment in patients a remaining challenge in clinical settings. Notably, given the outstanding role of host-microbiome interactions, the ecological interactions with microorganisms have become a new significant aspect in the systems that can contribute to the diagnosis and potential treatment of solid cancers. As a part of expanding precision medicine in the area of cancer research, efforts aimed at effective treatments for various kinds of cancer based on the knowledge of genetics, biology of the disease and host-microbiome interactions might improve the prediction of disease risk and implement potential microbiota-directed therapeutics. In this review, we present the state of the art of sequencing and metabolome technologies, computational methods and schemes in systems biology that have addressed recent breakthroughs of uncovering relationships or associations between microorganisms and cancer. Together, microbiome studies extend the horizon of new personalized treatments against cancer from the perspective of precision medicine through a synergistic strategy integrating clinical knowledge, high-throughput data, bioinformatics and systems biology.

  15. The Cross Correlation between the Gravitational Potential and the Large Scale Matter Distribution

    CERN Document Server

    Madsen, S; Gottlöber, S; Müller, V; Madsen, Soeren; Doroshkevich, Andrei G.; Gottloeber, Stefan; Müller, Volker

    1997-01-01

    The large scale gravitational potential distribution and its influence on the large-scale matter clustering is considered on the basis of six simulations. It is found that the mean separation between zero levels of the potential along random straight lines coincides with the theoretical expectations, but it scatters largely. A strong link of the initial potential and the structure evolution is shown. It is found that the under-dense and over-dense regions correlate with regions of positive and negative gravitational potential at large redshifts. The over-dense regions arise due to a slow matter flow into the negative potential regions, where more pronounced non-linear structures appear. Such regions are related to the formation of huge super-large scale structures seen in the galaxy distribution.

  16. Quantum Entanglement and Correlation of Two Qubit Atoms Interacting with the Coherent State Optical Field

    Science.gov (United States)

    Liu, Tang-Kun; Tao, Yu; Shan, Chuan-Jia; Liu, Ji-bing

    2017-10-01

    Using the three criterions of the concurrence, the negative eigenvalue and the geometric quantum discord, we investigate the quantum entanglement and quantum correlation dynamics of two two-level atoms interacting with the coherent state optical field. We discuss the influence of different photon number of the mean square fluctuations on the temporal evolution of the concurrence, the negative eigenvalue and the geometric quantum discord between two atoms when the two atoms are initially in specific three states. The results show that different photon number of the mean square fluctuations can lead to different effects of quantum entanglement and quantum correlation dynamics.

  17. Quantum Entanglement and Correlation of Two Qubit Atoms Interacting with the Coherent State Optical Field

    Science.gov (United States)

    Liu, Tang-Kun; Tao, Yu; Shan, Chuan-Jia; Liu, Ji-bing

    2017-08-01

    Using the three criterions of the concurrence, the negative eigenvalue and the geometric quantum discord, we investigate the quantum entanglement and quantum correlation dynamics of two two-level atoms interacting with the coherent state optical field. We discuss the influence of different photon number of the mean square fluctuations on the temporal evolution of the concurrence, the negative eigenvalue and the geometric quantum discord between two atoms when the two atoms are initially in specific three states. The results show that different photon number of the mean square fluctuations can lead to different effects of quantum entanglement and quantum correlation dynamics.

  18. A correlated basis-function description of 16O with realistic interactions

    Science.gov (United States)

    Boscá, M. C.

    1994-01-01

    The correlated basis-function theory is applied at the lowest order to analyze the ground state and low-energy spectrum of the 16O nucleus. Results are quoted for both the Urbana and the Argonne υ 14 nucleon-nucleon interactions. The work includes state-dependent correlations and their radial components are determined by solving a set of Euler-Lagrange equations. The matrix elements are computed by using a cluster expansion and the sequential condition is imposed in order to insure convergence. The results clearly disagree with the experimental values.

  19. Dynamics of Non- interacting System with Long-Range Correlated Quenched Impurities

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuan

    2003-01-01

    The theoretic renormalization group approach is applied to the study of the critical behavior of non-interacting system with long-range correlated quenched impurities, which has a power-like correlations r-(d-ρ). Totwo-loop order, the asymptotic scaling laws and the critical exponents are studied in the frame of a double (ε, ρ)expansion with ρ of order ε = 4 - d. In d < 4, it is argued that the initial slip exponent θ = 0 together with the dynamicexponent z < 2 is exact in this kind of random system.

  20. Correlating Nitrile IR Frequencies to Local Electrostatics Quantifies Noncovalent Interactions of Peptides and Proteins.

    Science.gov (United States)

    Deb, Pranab; Haldar, Tapas; Kashid, Somnath M; Banerjee, Subhrashis; Chakrabarty, Suman; Bagchi, Sayan

    2016-05-05

    Noncovalent interactions, in particular the hydrogen bonds and nonspecific long-range electrostatic interactions are fundamental to biomolecular functions. A molecular understanding of the local electrostatic environment, consistently for both specific (hydrogen-bonding) and nonspecific electrostatic (local polarity) interactions, is essential for a detailed understanding of these processes. Vibrational Stark Effect (VSE) has proven to be an extremely useful method to measure the local electric field using infrared spectroscopy of carbonyl and nitrile based probes. The nitrile chemical group would be an ideal choice because of its absorption in an infrared spectral window transparent to biomolecules, ease of site-specific incorporation into proteins, and common occurrence as a substituent in various drug molecules. However, the inability of VSE to describe the dependence of IR frequency on electric field for hydrogen-bonded nitriles to date has severely limited nitrile's utility to probe the noncovalent interactions. In this work, using infrared spectroscopy and atomistic molecular dynamics simulations, we have reported for the first time a linear correlation between nitrile frequencies and electric fields in a wide range of hydrogen-bonding environments that may bridge the existing gap between VSE and H-bonding interactions. We have demonstrated the robustness of this field-frequency correlation for both aromatic nitriles and sulfur-based nitriles in a wide range of molecules of varying size and compactness, including small molecules in complex solvation environments, an amino acid, disordered peptides, and structured proteins. This correlation, when coupled to VSE, can be used to quantify noncovalent interactions, specific or nonspecific, in a consistent manner.

  1. In vitro and in vivo evaluation of CYP1a interaction potential of terminalia arjuna bark

    Directory of Open Access Journals (Sweden)

    Alice Varghese

    2014-01-01

    Full Text Available Terminalia arjuna Wight and Arn. (Combretaceae is a tree having an extensive medicinal potential in cardiovascular disorders. Triterpenoids are mainly responsible for cardiovascular properties. Aqueous, hydroalcoholic and alcoholic extract of T. arjuna, arjunic acid and arjungenin were examined for their potential to inhibit CYP1A enzyme in rat and human liver microsomes. IC 50 values of aqueous, hydroalcoholic and alcoholic extract of T. arjuna was found to be 11.4, 28.9 and 44.6 μg/ml in rat liver microsomes while 30.0, 29.7 and 39.0 μg/ml in human liver microsomes, respectively for CYP1A. However IC 50 values of arjunic acid and arjungenin for both rat liver microsomes and human liver microsomes were found to be >50 μM. Arjunic acid and arjungenin did not show inhibition of CYP1A enzyme up to concentrations of 50 μM. These in vitro data indicate that Terminalia arjuna extracts contain constituents that can potently inhibit the activity of CYP1A, which could in turn lead to undesirable pharmacokinetic drug-herb interactions in vivo. Based on the in vitro data, interaction potential of the aqueous extract of Terminalia arjuna orally in rats was investigated. A probe substrate, phenacetin, was used to index the activity of CYP1A. In vivo pharmacokinetic study of coadministration of aqueous extract of Terminalia arjuna and phenacetin, revealed that the aqueous extract did not lead to any significant change in the pharmacokinetic parameters of phenacetin as compared with control group. Though there was no in vivo-in vitro correlation, drug interactions could arise with drugs having a narrow therapeutic range and extensively cleared by CYP1A enzyme, which could lead to undesirable side effects.

  2. MODELLING THE INTERACTION IN GAME SPORTS - RELATIVE PHASE AND MOVING CORRELATIONS

    Directory of Open Access Journals (Sweden)

    Martin Lames

    2006-12-01

    Full Text Available Model building in game sports should maintain the constitutive feature of this group of sports, the dynamic interaction process between the two parties. For single net/wall games relative phase is suggested to describe the positional interaction between the two players. 30 baseline rallies in tennis were examined and relative phase was calculated by Hilbert transform from the two time-series of lateral displacement and trajectory in the court respectively. Results showed that relative phase indicates some aspects of the tactical interaction in tennis. At a more abstract level the interaction between two teams in handball was studied by examining the relationship of the two scoring processes. Each process can be conceived as a random walk. Moving averages of the scoring probabilities indicate something like a momentary strength. A moving correlation (length = 20 ball possessions describes the momentary relationship between the teams' strength. Evidence was found that this correlation is heavily time-dependent, in almost every single game among the 40 examined ones we found phases with a significant positive as well as significant negative relationship. This underlines the importance of a dynamic view on the interaction in these games.

  3. Interaction of Shock Waves in Cement Mortar Plate Investigated by the Digital Speckle Correlation Method

    Institute of Scientific and Technical Information of China (English)

    LI Xu-Dong; LIU Kai-Xin; ZHANG Guang-Sheng; WEN Shang-Gang; TAN Fu-Li

    2008-01-01

    @@ Interaction of shock waves in cement mortar plate is studied by digital speckle correlation method and digital high-speed photography technique. When the plates were destroyed by two detonators exploding at the same time, variation of shock wave field is obtained. Experimental results show that the interaction of shock waves will result in a nonlinear huge increase of local normal strain, leading to large deformation and serious destruction. However, the occurrence of this strongly nonlinear phenomenon sensitively depends on the interval between detonators, and it will only appear when the interval is smaller than the diameter of the region where shock waves exist.

  4. Kohn-Sham potential for a strongly correlated finite system with fractional occupancy

    CERN Document Server

    Benitez, A

    2016-01-01

    Using a simplified one-dimensional model of a diatomic molecule, the associated interacting density and corresponding Kohn-Sham potential have been obtained analytically for all fractional molecule occupancies $N$ between 0 and 2. For the homonuclear case, and in the dissociation limit, the exact Kohn-Sham potential builds a barrier at the midpoint between the two atoms, whose strength increases linearly with $N$, with $1 < N \\leq 2$. In the heteronuclear case, the disociating KS potential besides the barrier also exhibits a plateau around the atom with the higher ionization potential, whose size (but not its strength) depends on $N$. An anomalous zero-order scaling of the Kohn-Sham potential with regards to the strength of the electron-electron repulsion is clearly displayed by our model; without this property both the unusual barrier and plateau features will be absent.

  5. The Stability of Icosahedral Cluster and the Range of Interaction Potential

    Institute of Scientific and Technical Information of China (English)

    DING Feng; WANG Jin-Lan; SHEN Wei-Feng; WANG Bao-Lin; LI Hui; WANG Guang-Hou

    2001-01-01

    The relation between the stability of icosahedral clusters and the range of interaction potential is discussed.We found that the stability of icosahedral clusters nay decrease with decreasing range of interaction potential. A simple formula about the critical number of icosahedral clusters and the range of interaction potential (M1/3c = A1 + A2r2eff)was proposed. The calculation of the stability of icosahedral fullerence molecular clusters shows that our idea is right.``

  6. Exact out-of-time-ordered correlation functions for an interacting lattice fermion model

    Science.gov (United States)

    Tsuji, Naoto; Werner, Philipp; Ueda, Masahito

    2017-01-01

    Exact solutions for local equilibrium and nonequilibrium out-of-time-ordered correlation (OTOC) functions are obtained for a lattice fermion model with on-site interactions, namely, the Falicov-Kimball (FK) model, in the large dimensional and thermodynamic limit. Our approach is based on the nonequilibrium dynamical mean-field theory generalized to an extended Kadanoff-Baym contour. We find that the density-density OTOC is most enhanced at intermediate coupling around the metal-insulator phase transition. In the high-temperature limit, the OTOC remains nontrivially finite and interaction dependent, even though dynamical charge correlations probed by an ordinary response function are completely suppressed. We propose an experiment to measure OTOCs of fermionic lattice systems including the FK and Hubbard models in ultracold atomic systems.

  7. Quantum Correlation of Two Entangled Atoms Interacting with the Binomial Optical Field

    Science.gov (United States)

    Liu, Tang-Kun; Tao, Yu; Shan, Chuan-Jia; Liu, Ji-bing

    2016-10-01

    Quantum correlations of two atoms in a system of two entangled atoms interacting with the binomial optical field are investigated. In eight different initial states of the two atoms, the influence of the strength of the dipole-dipole interaction, probabilities of a the Bernoulli trial and particle number of the binomial optical field on the temporal evolution of the geometrical quantum discord between two atoms are discussed. The result shows that two atoms always exist the correlation for different parameters. In addition, when and only when the two atoms are initially in the maximally entangled state, the temporal evolution of geometrical quantum discord is not affected by the parameters, and always keep in the degree of geometrical quantum discord that is a fixed value.

  8. Peri-event cross-correlation over time for analysis of interactions in neuronal firing.

    Science.gov (United States)

    Paiva, António R C; Park, Il; Sanchez, Justin C; Príncipe, José C

    2008-01-01

    Several methods have been described in the literature to verify the presence of couplings between neurons in the brain. In this paper we introduce the peri-event cross-correlation over time (PECCOT) to describe the interaction among the two neurons as a function of the event onset. Instead of averaging over time, the PECCOT averages the cross-correlation over instances of the event. As a consequence, the PECCOT is able to characterize with high temporal resolution the interactions over time among neurons. To illustrate the method, the PECCOT is applied to a simulated dataset and for analysis of synchrony in recordings of a rat performing a go/no go behavioral lever press task. We verify the presence of synchrony before the lever press time and its suppression afterwards.

  9. Spin-orbit interaction in final state as possible reason for T-odd correlation in ternary fission

    CERN Document Server

    Barabanov, A L

    2001-01-01

    The work was presented at the ISINN-9 (2001, Dubna, Russia) after a T odd triple correlation had been found in ternary fission. Now the model proposed in this work is of additional interest because it provides a possibility to describe a smooth angular dependence of triple correlation recently observed (see F. Goennenwein et al. PLB, 2007, V.652, P.13.) A model for ternary fission is discussed in which a third particle (alpha-particle) is emitted due to non-adiabatic change of the nuclear potential at neck rapture. An expression for energy and angular distribution of alpha-particles is proposed. It is shown that an interaction between spin of fissioning system and orbital momentum of alpha-particle (spin-orbit interaction in the final state) results in recently observed asymmetry of alpha-particle emission, which can be formally related to T-odd correlation. No strong dependence of the asymmetry on the angle of alpha-particle emission with respect to the fission axis is predicted by the model in accordance wi...

  10. Two-Way Gene Interaction From Microarray Data Based on Correlation Methods

    OpenAIRE

    Alavi Majd, Hamid; Talebi, Atefeh; Gilany, Kambiz; Khayyer, Nasibeh

    2016-01-01

    Background Gene networks have generated a massive explosion in the development of high-throughput techniques for monitoring various aspects of gene activity. Networks offer a natural way to model interactions between genes, and extracting gene network information from high-throughput genomic data is an important and difficult task. Objectives The purpose of this study is to construct a two-way gene network based on parametric and nonparametric correlation coefficients. The first step in const...

  11. Explicitly correlated intermolecular distances and interaction energies of hydrogen bonded complexes

    DEFF Research Database (Denmark)

    Lane, Joseph R; Kjærgaard, Henrik G

    2009-01-01

    We have optimized the lowest energy structures and calculated interaction energies for the H(2)O-H(2)O, H(2)O-H(2)S, H(2)O-NH(3), and H(2)O-PH(3) dimers with the recently developed explicitly correlated CCSD(T)-F12 methods and the associated VXZ-F12 (where X = D,T,Q) basis sets. For a given...

  12. Van Hove correlation functions in an interacting electron gas: Equation-of-motion approach

    Science.gov (United States)

    Schinner, Andreas; Bachlechner, Martina E.

    1992-10-01

    An extension of the classical van Hove correlation functions to a three-dimensional system of identical fermions is investigated, taking into account interaction effects. This is done within the framework of a Singwi-Tosi-Land-Sjölander-like static local-field approximation, combined with second-order effects of plasmon damping. As a main result the relaxation of the Fermi hole around an instantaneously removed electron is presented.

  13. Bose-Einstein Correlations in charged current muon-neutrino interactions in NOMAD

    CERN Document Server

    Zei, R

    2004-01-01

    Bose-Einstein Correlations in one and two dimensions have been studied in charged current muon-neutrino interaction events collected with NOMAD. In one dimension the Bose-Einstein effect has been analyzed with the Goldhaber and the Kopylov parametrizations. The two-dimensional shape of the source has been investigated in the longitudinal co-moving frame. A significant difference between the transverse and the longitudinal sizes is observed.

  14. MicroRNAs and potential target interactions in psoriasis

    DEFF Research Database (Denmark)

    Zibert, John Robert; Løvendorf, Marianne B.; Litman, Thomas

    2010-01-01

    BACKGROUND: Psoriasis is a chronic inflammatory skin disease often seen in patients with a genetic susceptibility. MicroRNAs (miRNA) are endogenous, short RNA molecules that can bind to parts of mRNA target genes, thus inhibiting their translation and causing accelerated turnover or transcript...... degradation. MicroRNAs are important in the pathogenesis of human diseases such as immunological disorders, as they regulate a broad range of biological processes. OBJECTIVE: We investigated miRNA-mRNA interactions in involved (PP) and non-involved (PN) psoriatic skin compared with healthy skin (NN). METHODS......: Biopsies were obtained from PP, PN and NN, the miRNA and mRNA expression was analyzed by microarray techniques and a subset of miRNAs and mRNAs were validated by q-RT-PCR. Novel target interactions in psoriasis were found using PubMed, miRBase and RNAhybrid. In addition, TIMP3 protein expression...

  15. Bubble-bubble interaction: A potential source of cavitation noise

    CERN Document Server

    Ida, Masato

    2009-01-01

    The interaction between microbubbles through pressure pulses has been studied to show that it can be a source of cavitation noise. A recent report demonstrated that the acoustic noise generated by a shrimp originates from the collapse of a cavitation bubble produced when the shrimp closes its snapper claw. The recorded acoustic signal contains a broadband noise that consists of positive and negative pulses, but a theoretical model for single bubbles fails to reproduce the negative ones. Using a nonlinear multibubble model we have shown here that the negative pulses can be explained by considering the interaction of microbubbles formed after the cavitation bubble has collapsed and fragmented: Positive pulses produced at the collapse of the microbubbles hit and impulsively compress neighboring microbubbles to generate reflected pulses whose amplitudes are negative. Discussing the details of the noise generation process, we have found that no negative pulses are generated if the internal pressure of the reflecti...

  16. Thermomagnetic correlation lengths of strongly interacting matter in the Nambu-Jona-Lasinio model

    Science.gov (United States)

    Ayala, Alejandro; Hernández, L. A.; Loewe, M.; Raya, Alfredo; Rojas, J. C.; Zamora, R.

    2017-08-01

    We study the correlation length between test quarks with the same electric and color charges in the Nambu-Jona-Lasinio model, considering thermal and magnetic effects. We extract the correlation length from the quark correlation function. The latter is constructed from the probability amplitude to bring a given quark into the plasma once a previous one with the same quantum numbers is placed at a given distance apart. For temperatures below the transition temperature, the correlation length starts growing as the field strength increases to then decrease for large magnetic fields. For temperatures above the pseudocritical temperature, the correlation length continues increasing as the field strength increases. We found that such behavior can be understood as a competition between the tightening induced by the classical magnetic force versus the random thermal motion. For large enough temperatures, the increase of the occupation number contributes to the screening of the interaction between the test particles. The growth of the correlation distance with the magnetic field can be understood as due to the closer proximity between one of the test quarks and the ones popped up from the vacuum, which in turn appear due to the increase of the occupation number with the temperature.

  17. Improved Interaction Potentials for Charged Residues in Proteins

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2008-01-01

    Electrostatic interactions dominate the structure and free energy of biomolecules. To obtain accurate free energies involving charged groups from molecular simulations, OPLS-AA parameters have been reoptimized using Monte Carlo free energy perturbation. New parameters fit a self-consistent, exper...... directly in molecular simulations with no modification of neutral residues needed and are envisioned to be particular important in simulations where charged residues change environment....

  18. In vitro interactions between Armillaria species and potential biocontrol fungi

    Directory of Open Access Journals (Sweden)

    Keča Nenad

    2009-01-01

    Full Text Available Interaction between Armillaria species and seven other fungi were tested in vitro. Tree antagonistic (Trichoderma viride, Trichotecium roseum and Penicillium sp. and four decaying (Hypholoma fasciculare¸ Hypholoma capnoides, Phlebiopsis gigantea, and Pleurotus ostreatus fungi were chosen for this study. The best results were noted for Trichoderma viride, because fungus was able to kill both mycelia and rhizomorphs of Armillaria species, while Hypholoma spp. inhibited both growth of Armillaria colonies and rhizomorph production.

  19. The index of ideality of correlation: A criterion of predictive potential of QSPR/QSAR models?

    Science.gov (United States)

    Toropov, Andrey A; Toropova, Alla P

    2017-07-01

    The index of ideality of correlation (IIC) is a new criterion of the predictive potential of quantitative structure-property/activity relationships (QSPRs/QSARs). This IIC is calculated with using of the correlation coefficient between experimental and calculated values of endpoint for the calibration set, with taking into account the positive and negative dispersions between experimental and calculated values. The mutagenicity is well-known important characteristic of substances from ecological point of view. Consequently, the estimation of the IIC for mutagenicity is well motivated. It is confirmed that the utilization of this criterion significantly improves the predictive potential of QSAR models of mutagenicity. The new criterion can be used for other endpoints. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Connections among residual strong interaction, the EMC effect and short range correlations

    CERN Document Server

    Wang, Rong

    2015-01-01

    A linear correlation is shown quantitatively between the magnitude of the EMC effect measured in electron deep inelastic scattering (DIS) and the nuclear residual strong interaction energy (RSIE) obtained from the nuclear binding energy subtracting the Coulomb energy part. The observed correlation supports the recent speculation that the nuclear dependence of quark distributions depend on the local nuclear density. This phenomenological relationship can be used to extract the size of in-medium correction (IMC) effect on deuteron. Most importantly, the EMC slopes $dR_{EMC}/dx$ of nuclei can be predicted with the nuclear binding energy data. The relationship between nucleon-nucleon (N-N) short range correlation (SRC) and RSIE is also presented.

  1. Assessment of Multireference Approaches to Explicitly Correlated Full Configuration Interaction Quantum Monte Carlo

    CERN Document Server

    Kersten, Jennifer; Alavi, Ali

    2016-01-01

    The Full Configuration Interaction Quantum Monte Carlo (FCIQMC) method has proved able to provide near-exact solutions to the electronic Schr\\"odinger equation within a finite orbital basis set, without relying on an expansion about a reference state. However, a drawback to the approach is that being based on an expansion of Slater determinants, the FCIQMC method suffers from a basis set incompleteness error that decays very slowly with the size of the employed single particle basis. The FCIQMC results obtained in a small basis set can be improved significantly with explicitly correlated techniques. Here, we present a study that assesses and compares two contrasting `universal' explicitly correlated approaches that fit into the FCIQMC framework; the $[2]_{R12}$ method of Valeev {\\em et al.}, and the explicitly correlated canonical transcorrelation approach of Yanai {\\em et al}. The former is an {\\em a posteriori} internally-contracted perturbative approach, while the latter transforms the Hamiltonian prior to...

  2. CGC/saturation approach for soft interactions at high energy: long range rapidity correlations

    Energy Technology Data Exchange (ETDEWEB)

    Gotsman, E.; Maor, U. [Tel Aviv University, Department of Particle Physics, School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Science, Tel Aviv (Israel); Levin, E. [Tel Aviv University, Department of Particle Physics, School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Science, Tel Aviv (Israel); Universidad Tecnica Federico Santa Maria and Centro Cientifico- Tecnologico de Valparaiso, Departemento de Fisica, Valparaiso (Chile)

    2015-11-15

    In this paper we continue our program to construct a model for high energy soft interactions that is based on the CGC/saturation approach. The main result of this paper is that we have discovered a mechanism that leads to large long range rapidity correlations and results in large values of the correlation function R(y{sub 1}, y{sub 2}) ≥ 1, which is independent of y{sub 1} and y{sub 2}. Such a behavior of the correlation function provides strong support for the idea that at high energies the system of partons that is produced is not only dense but also has strong attractive forces acting between the partons. (orig.)

  3. Cross-correlation measurement techniques for cavity-based axion and weakly interacting slim particle searches

    CERN Document Server

    Parker, Stephen R; Ivanov, Eugene N; Tobar, Michael E

    2015-01-01

    Weakly Interacting Slim Particles (WISPs), such as axions, are highly motivated dark matter candidates. The most sensitive experimental searches for these particles exploit WISP-to-photon conversion mechanisms and use resonant cavity structures to enhance the resulting power signal. For WISPs to constitute Cold Dark Matter their required masses correspond to photons in the microwave spectrum. As such, searches for these types of WISPs are primarily limited by the thermal cavity noise and the broadband first-stage amplifier noise. In this work we propose and then verify two cross-correlation measurement techniques for cavity-based WISP searches. These are two channel measurement schemes where the cross-spectrum is computed, rejecting uncorrelated noise sources while still retaining correlated signals such as those generated by WISPs. The first technique allows for the cavity thermal spectrum to be observed with an enhanced resolution. The second technique cross-correlates two individual cavity/amplifier system...

  4. Generation of spatiotemporally correlated spike trains and local field potentials using a multivariate autoregressive process.

    Science.gov (United States)

    Gutnisky, Diego A; Josić, Kresimir

    2010-05-01

    Experimental advances allowing for the simultaneous recording of activity at multiple sites have significantly increased our understanding of the spatiotemporal patterns in neural activity. The impact of such patterns on neural coding is a fundamental question in neuroscience. The simulation of spike trains with predetermined activity patterns is therefore an important ingredient in the study of potential neural codes. Such artificially generated spike trains could also be used to manipulate cortical neurons in vitro and in vivo. Here, we propose a method to generate spike trains with given mean firing rates and cross-correlations. To capture this statistical structure we generate a point process by thresholding a stochastic process that is continuous in space and discrete in time. This stochastic process is obtained by filtering Gaussian noise through a multivariate autoregressive (AR) model. The parameters of the AR model are obtained by a nonlinear transformation of the point-process correlations to the continuous-process correlations. The proposed method is very efficient and allows for the simulation of large neural populations. It can be optimized to the structure of spatiotemporal correlations and generalized to nonstationary processes and spatiotemporal patterns of local field potentials and spike trains.

  5. Modeling and mapping potential distribution of Crimean juniper (Juniperus excelsa Bieb.) using correlative approaches.

    Science.gov (United States)

    Özkan, Kürşad; Şentürk, Özdemir; Mert, Ahmet; Negiz, Mehmet Güvenç

    2015-01-01

    Modeling and mapping potential distribution of living organisms has become an important component of conservation planning and ecosystem management in recent years. Various correlative and mechanistic methods can be applied to build predictive distributions of living organisms in terrestrial and marine ecosystems. Correlative methods used to predict species' potential distribution have been described as either group discrimination techniques or profile techniques. We attempted to determine whether group discrimination techniques could perform as well as profile techniques for predicting species potential distributions, using elevation (ELVN), parent material (ROCK), slope (SLOP), radiation index (RI) and topographic position index (TPI)) as explanatory variables. We compared potential distribution predictions made for Crimean juniper (Juniperus excelsa Bieb.) in the Yukan Gokdere forest district of the Mediterranean region, Turkey, applying four group discrimination techniques (discriminate analysis (DA), logistic regression analysis (LR), generalized addictive model (GAM) and classification tree technique (CT)) and two profile techniques (a maximum entropy approach to species distribution modeling (MAXENT), the genetic algorithm for rule-set prediction (GARP)). Visual assessments of the potential distribution probability of the applied models for Crimean juniper were performed by using geographical information systems (GIS). Receiver-operating characteristic (ROC) curves were used to objectively assess model performance. The results suggested that group discrimination techniques are better than profile techniques and, among the group discrimination techniques, GAM indicated the best performance.

  6. Role of Structure and Entropy in Determining Differences in Dynamics for Glass Formers with Different Interaction Potentials

    Science.gov (United States)

    Banerjee, Atreyee; Sengupta, Shiladitya; Sastry, Srikanth; Bhattacharyya, Sarika Maitra

    2014-11-01

    We present a study of two model liquids with different interaction potentials, exhibiting similar structure but significantly different dynamics at low temperatures. By evaluating the configurational entropy, we show that the differences in the dynamics of these systems can be understood in terms of their thermodynamic differences. Analyzing their structure, we demonstrate that differences in pair correlation functions between the two systems, through their contribution to the entropy, dominate the differences in their dynamics, and indeed overestimate the differences. Including the contribution of higher order structural correlations to the entropy leads to smaller estimates for the relaxation times, as well as smaller differences between the two studied systems.

  7. Heat shock-induced interactions among nuclear HSFs detected by fluorescence cross-correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pack, Chan-Gi, E-mail: changipack@amc.seoul.kr [Asan Institute for Life Sciences, University of Ulsan, College of Medicine, Asan Medical Center, Seoul 138-736 (Korea, Republic of); Ahn, Sang-Gun [Dept. of Pathology, College of Dentistry, Chosun University, Seosuk-dong, Dong-gu, Gwangju 501-759 (Korea, Republic of)

    2015-07-31

    The cellular response to stress is primarily controlled in cells via transcriptional activation by heat shock factor 1 (HSF1). HSF1 is well-known to form homotrimers for activation upon heat shock and subsequently bind to target DNAs, such as heat-shock elements, by forming stress granules. A previous study demonstrated that nuclear HSF1 and HSF2 molecules in live cells interacted with target DNAs on the stress granules. However, the process underlying the binding interactions of HSF family in cells upon heat shock remains unclear. This study demonstrate for the first time that the interaction kinetics among nuclear HSF1, HSF2, and HSF4 upon heat shock can be detected directly in live cells using dual color fluorescence cross-correlation spectroscopy (FCCS). FCCS analyses indicated that the binding between HSFs was dramatically changed by heat shock. Interestingly, the recovery kinetics of interaction between HSF1 molecules after heat shock could be represented by changes in the relative interaction amplitude and mobility. - Highlights: • The binding interactions among nuclear HSFs were successfully detected. • The binding kinetics between HSF1s during recovery was quantified. • HSF2 and HSF4 strongly formed hetero-complex, even before heat shock. • Nuclear HSF2 and HSF4 bound to HSF1 only after heat shock.

  8. [Specific interaction study in collagen/hyaluronic acid blends by two-dimensional infrared correlation spectroscopy].

    Science.gov (United States)

    Tan, Qing-Tian; Tian, Zhen-Hua; Li, Guo-Ying

    2011-04-01

    Conformational changes and specific interactions in the collagen/hyaluronic acid blends were studied by two-dimensional infrared correlation spectroscopy with the interruption of the component of hyaluronic acid in collagen/ hyaluronic acid blends. It was found that the synchronous cross-peaks, derived from stretching vibrations of C=O at 1 694 cm(-1), wagging of N-H at 1 524 cm(-1) and in-plane deformation of N-H at 1 241 cm(-1) of collagen, were indicative of local conformational changes of collagen. The synchronous negative cross-peak between stretching vibrations of C-OH of hyaluronic acid at 1 045 cm(-1) and streching vibrations of C=O of collagen at 1 694 cm(-1) suggested that the interaction of hydrogen bonding existing between O-H of HA and C=O of collagen with the content of HA varied from 0% to 50%. With the content of HA more than 50%, the cross-peak at 1 045 cm(-1) disappeared in synchronous correlation spectra while the intensity of cross-peak at (1 694, 1 524), (1 694, 1 241), (1 524, 1 241) increased, which indicated that no interaction was found between O-H of HA and collagen, however, the interactions of hydrogen bonding existed between C=O of HA and N-H of collagen, resulting in the conformational changes of collagen.

  9. Concepts relating magnetic interactions, intertwined electronic orders, and strongly correlated superconductivity.

    Science.gov (United States)

    Davis, J C Séamus; Lee, Dung-Hai

    2013-10-29

    Unconventional superconductivity (SC) is said to occur when Cooper pair formation is dominated by repulsive electron-electron interactions, so that the symmetry of the pair wave function is other than an isotropic s-wave. The strong, on-site, repulsive electron-electron interactions that are the proximate cause of such SC are more typically drivers of commensurate magnetism. Indeed, it is the suppression of commensurate antiferromagnetism (AF) that usually allows this type of unconventional superconductivity to emerge. Importantly, however, intervening between these AF and SC phases, intertwined electronic ordered phases (IP) of an unexpected nature are frequently discovered. For this reason, it has been extremely difficult to distinguish the microscopic essence of the correlated superconductivity from the often spectacular phenomenology of the IPs. Here we introduce a model conceptual framework within which to understand the relationship between AF electron-electron interactions, IPs, and correlated SC. We demonstrate its effectiveness in simultaneously explaining the consequences of AF interactions for the copper-based, iron-based, and heavy-fermion superconductors, as well as for their quite distinct IPs.

  10. Numerical integration of exchange-correlation energies and potentials using transformed sparse grids.

    Science.gov (United States)

    Rodríguez, Juan I; Thompson, David C; Ayers, Paul W; Köster, Andreas M

    2008-06-14

    A new numerical integration procedure for exchange-correlation energies and potentials is proposed and "proof of principle" results are presented. The numerical integration grids are built from sparse-tensor product grids (constructed according to Smolyak's prescription [Dokl. Akad. Nauk. 4, 240 (1963)] ) on the unit cube. The grid on the unit cube is then transformed to a grid over real space with respect to a weight function, which we choose to be the promolecular density. This produces a "whole molecule" grid, in contrast to conventional integration methods in density-functional theory, which use atom-in-molecule grids. The integration scheme was implemented in a modified version of the DEMON2K density-functional theory program, where it is used to evaluate integrals of the exchange-correlation energy density and the exchange-correlation potential. Ground-state energies and molecular geometries are accurately computed. The biggest advantages of the grid are its flexibility (it is easy to change the number and distribution of grid points) and its whole molecule nature. The latter feature is potentially helpful for basis-set-free computational algorithms.

  11. arXiv Two particle correlations from the energy scan with p+p interactions

    CERN Document Server

    Maksiak, Bartosz

    2015-05-12

    The NA61/Shine experiment aims to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. These goals are to be achieved by performing a two dimensional phase diagram T-mu_B scan by measurements of hadron production properties in proton-proton, proton-nucleus and nucleus-nucleus interactions as a function of collision energy and system size. Close to the phase transition and/or close to the critical point large fluctuations are predicted. In this contribution preliminary results on two-particle correlations in pseudorapidity and azimuthal angle will be presented for p+p interactions at beam momenta: 20, 31, 40, 80 and 158 GeV/c. The NA61/Shine results will be compared with the corresponding data of other experiments and model predictions. A striking evolution with collision energy is observed.

  12. Fluid-Structure Interaction Using Retarded Potential and ABAQUS

    Science.gov (United States)

    1992-08-19

    but require the formuation and factoring of a global stiffness matrix. This is very costly and even prohibitive especially for Manuacript approved...Dimensional Retarded Potential Fluid - Finite Element Structural Analysis, NRL Memorandum, Report 5903, May 1987. 20. Tamm. M. A., A Parametric Patch

  13. Problems in the links between scattering data and interaction potentials

    Energy Technology Data Exchange (ETDEWEB)

    Amos, K.

    1995-10-01

    The scattering function is of paramount importance in any approaches by which quantitative information on the interaction between colliding quantal systems of nuclear, atomic or molecular type, may be sought from measured, elastic scattering data. Therein there are two possible spectral parameters, the energy and the angular momentum. Most experimental results suggest use of fixed energy and variable angular momentum schemes. Such fixed energy data and their analyses are the subject of this report, with particular emphasis placed upon the problems of the link between data and the scattering function. 18 figs.

  14. The evaluation of statins as potential inhibitors of the LEDGF/p75-HIV-1 integrase interaction.

    Science.gov (United States)

    Harrison, Angela T; Kriel, Frederik H; Papathanasopoulos, Maria A; Mosebi, Salerwe; Abrahams, Shaakira; Hewer, Raymond

    2015-03-01

    Lovastatin was identified through virtual screening as a potential inhibitor of the LEDGF/p75-HIV-1 integrase interaction. In an AlphaScreen assay, lovastatin inhibited the purified recombinant protein-protein interaction (IC50 = 1.97 ± 0.45 μm) more effectively than seven other tested statins. None of the eight statins, however, yielded antiviral activity in vitro, while only pravastatin lactone yielded detectable inhibition of HIV-1 integrase strand transfer activity (31.65% at 100 μm). A correlation between lipophilicity and increased cellular toxicity of the statins was observed.

  15. Gene expression correlations in human cancer cell lines define molecular interaction networks for epithelial phenotype.

    Directory of Open Access Journals (Sweden)

    Kurt W Kohn

    Full Text Available Using gene expression data to enhance our knowledge of control networks relevant to cancer biology and therapy is a challenging but urgent task. Based on the premise that genes that are expressed together in a variety of cell types are likely to functions together, we derived mutually correlated genes that function together in various processes in epithelial-like tumor cells. Expression-correlated genes were derived from data for the NCI-60 human tumor cell lines, as well as data from the Broad Institute's CCLE cell lines. NCI-60 cell lines that selectively expressed a mutually correlated subset of tight junction genes served as a signature for epithelial-like cancer cells. Those signature cell lines served as a seed to derive other correlated genes, many of which had various other epithelial-related functions. Literature survey yielded molecular interaction and function information about those genes, from which molecular interaction maps were assembled. Many of the genes had epithelial functions unrelated to tight junctions, demonstrating that new function categories were elicited. The most highly correlated genes were implicated in the following epithelial functions: interactions at tight junctions (CLDN7, CLDN4, CLDN3, MARVELD3, MARVELD2, TJP3, CGN, CRB3, LLGL2, EPCAM, LNX1; interactions at adherens junctions (CDH1, ADAP1, CAMSAP3; interactions at desmosomes (PPL, PKP3, JUP; transcription regulation of cell-cell junction complexes (GRHL1 and 2; epithelial RNA splicing regulators (ESRP1 and 2; epithelial vesicle traffic (RAB25, EPN3, GRHL2, EHF, ADAP1, MYO5B; epithelial Ca(+2 signaling (ATP2C2, S100A14, BSPRY; terminal differentiation of epithelial cells (OVOL1 and 2, ST14, PRSS8, SPINT1 and 2; maintenance of apico-basal polarity (RAB25, LLGL2, EPN3. The findings provide a foundation for future studies to elucidate the functions of regulatory networks specific to epithelial-like cancer cells and to probe for anti-cancer drug targets.

  16. A constructive model potential method for atomic interactions

    Science.gov (United States)

    Bottcher, C.; Dalgarno, A.

    1974-01-01

    A model potential method is presented that can be applied to many electron single centre and two centre systems. The development leads to a Hamiltonian with terms arising from core polarization that depend parametrically upon the positions of the valence electrons. Some of the terms have been introduced empirically in previous studies. Their significance is clarified by an analysis of a similar model in classical electrostatics. The explicit forms of the expectation values of operators at large separations of two atoms given by the model potential method are shown to be equivalent to the exact forms when the assumption is made that the energy level differences of one atom are negligible compared to those of the other.

  17. Exchange-Correlation Effects for Noncovalent Interactions in Density Functional Theory.

    Science.gov (United States)

    Otero-de-la-Roza, A; DiLabio, Gino A; Johnson, Erin R

    2016-07-12

    In this article, we develop an understanding of how errors from exchange-correlation functionals affect the modeling of noncovalent interactions in dispersion-corrected density-functional theory. Computed CCSD(T) reference binding energies for a collection of small-molecule clusters are decomposed via a molecular many-body expansion and are used to benchmark density-functional approximations, including the effect of semilocal approximation, exact-exchange admixture, and range separation. Three sources of error are identified. Repulsion error arises from the choice of semilocal functional approximation. This error affects intermolecular repulsions and is present in all n-body exchange-repulsion energies with a sign that alternates with the order n of the interaction. Delocalization error is independent of the choice of semilocal functional but does depend on the exact exchange fraction. Delocalization error misrepresents the induction energies, leading to overbinding in all induction n-body terms, and underestimates the electrostatic contribution to the 2-body energies. Deformation error affects only monomer relaxation (deformation) energies and behaves similarly to bond-dissociation energy errors. Delocalization and deformation errors affect systems with significant intermolecular orbital interactions (e.g., hydrogen- and halogen-bonded systems), whereas repulsion error is ubiquitous. Many-body errors from the underlying exchange-correlation functional greatly exceed in general the magnitude of the many-body dispersion energy term. A functional built to accurately model noncovalent interactions must contain a dispersion correction, semilocal exchange, and correlation components that minimize the repulsion error independently and must also incorporate exact exchange in such a way that delocalization error is absent.

  18. The Statics Dielectric Function and Interaction Potential In Strong Coupling With AdS/CFT

    CERN Document Server

    Liu, Lian; Liu, Hui

    2013-01-01

    In this paper, we studied the static dielectric function and interaction potential in strong coupling limit with AdS/CFT correspondence. The dielectric function is depressed compared with that in weak coupling. The interaction potential then presents a weaker screening characteristics in strong coupling, which indicates a smaller Debye mass compared with weak coupling.

  19. On critical stability of three quantum charges interacting through delta potentials

    DEFF Research Database (Denmark)

    Cornean, Horia; Duclos, Pierre; Ricaud, Benjamin

    We consider three one dimensional quantum, charged and spinless particles interacting through delta potentials. We derive sufficient conditions which guarantee the existence of at least one bound state.......We consider three one dimensional quantum, charged and spinless particles interacting through delta potentials. We derive sufficient conditions which guarantee the existence of at least one bound state....

  20. Technological Dangers and the Potential of Human-Robot Interaction

    DEFF Research Database (Denmark)

    2016-01-01

    watching a soccer game in which our child is one of the players. The question of which team we should cheer for never occurs to the parent. By changing the vantage point to a radical phenomenological perspective, informed by Eastern as well as Western thought, this chapter tests the basis for this type...... technological dangers and opportunities. Finally, aiming for the very limits of the theory, I discuss the contours of a praxis facilitating being-with-robots beyond conceptualization. Basically, this mode of being, pertaining to non-technological HRI, bypasses Heidegger’s warnings, and potentially facilitates...

  1. Effects of exchange-correlation potentials on the density-functional description of C60 versus C240 photoionization

    Science.gov (United States)

    Choi, Jinwoo; Chang, EonHo; Anstine, Dylan M.; Madjet, Mohamed El-Amine; Chakraborty, Himadri S.

    2017-02-01

    We study the photoionization properties of the C60 versus C240 molecule in a spherical jellium frame of the density-functional method. Two prototypical approximations of the exchange-correlation (xc) functional are used: (i) the Gunnarsson-Lundqvist parametrization [Gunnarsson and Lundqvist, Phys. Rev. B 13, 4274 (1976), 10.1103/PhysRevB.13.4274] with a correction for the electron self-interaction (SIC) introduced artificially from the outset and (ii) a gradient-dependent augmentation of approximation (i) using the van Leeuwen and Baerends model potential [van Leeuwen and Baerends, Phys. Rev. A 49, 2421 (1994), 10.1103/PhysRevA.49.2421], in lieu of SIC, that restores electrons' asymptotic properties intrinsically within the formalism. Ground-state results from the two schemes for both molecules show differences in the shapes of mean-field potentials and bound-level properties. The choice of an xc scheme also significantly alters the dipole single-photoionization cross sections obtained by an ab initio method that incorporates linear-response dynamical correlations. Differences in the structures and ionization responses between C60 and C240 uncover the effect of molecular size on the underlying physics. Analysis indicates that the collective plasmon resonances with the gradient-based xc option produce results noticeably closer to the experimental data available for C60.

  2. Effects of exchange-correlation potentials on the density functional description of C_60 versus C_240 photoionization

    CERN Document Server

    Choi, Jinwoo; Anstine, Dylan M; Madjet, Mohamed El-Amine; Chakraborty, Himadri S

    2016-01-01

    We study the photoionization properties of the C_60 versus C_240 molecule in a spherical jellium frame of density functional method. Two different approximations to the exchange-correlation (xc) functional are used: (i) The Gunnerson-Lundqvist parametrization [Phys. Rev. B 13, 4274 (1976)] with an explicit correction for the electron self-interaction (SIC) and (ii) a gradient-dependent augmentation of (i) by using the van Leeuwen and Baerends model potential [Phys. Rev. A 49, 2421 (1994)], in lieu of SIC, to implicitly restore electrons' asymptotic properties. Ground state results from the two schemes for both molecules show differences in the shapes of mean-field potentials and bound-level properties. The choice of a xc scheme also significantly alters the dipole single-photoionization cross sections obtained by an abinitio method that incorporates linear-response dynamical correlations. Differences in the structures and ionization responses between C_60 and C_240 uncover the effect of molecular size on the ...

  3. Effects of exchange-correlation potentials in density functional descriptions of ground-state and photoionization of fullerenes

    Science.gov (United States)

    Choi, Jinwoo; Chang, Eonho; Anstine, Dylan M.; Chakraborty, Himadri

    2016-05-01

    We study the ground state properties of C60 and C240 molecules in a spherical frame of local density approximation (LDA). Within this mean-field theory, two different approximations to the exchange-correlation (xc) functional are used: (i) The Gunnerson-Lundqvist parametrization augmented by a treatment to correct for the electron self-interaction and (ii) the van Leeuwen and Baerends (LB94) model potential that inclusively restores electron's asymptotic properties. Results show differences in the ground-state potential, level energies and electron densities between the two xc choices. We then use the ground structure to find the excited and ionized states of the systems and calculate dipole single-photoionization cross sections in a time-dependent LDA method that incorporates linear-response dynamical correlations. Comparative effects of the choices of xc on collective plasmon and single-excitation Auger resonances as well as on geometry driven cavity oscillations are found significant. The work is supported by the NSF, USA.

  4. Polynomial scaling approximations and dynamic correlation corrections to doubly occupied configuration interaction wave functions.

    Science.gov (United States)

    Van Raemdonck, Mario; Alcoba, Diego R; Poelmans, Ward; De Baerdemacker, Stijn; Torre, Alicia; Lain, Luis; Massaccesi, Gustavo E; Van Neck, Dimitri; Bultinck, Patrick

    2015-09-14

    A class of polynomial scaling methods that approximate Doubly Occupied Configuration Interaction (DOCI) wave functions and improve the description of dynamic correlation is introduced. The accuracy of the resulting wave functions is analysed by comparing energies and studying the overlap between the newly developed methods and full configuration interaction wave functions, showing that a low energy does not necessarily entail a good approximation of the exact wave function. Due to the dependence of DOCI wave functions on the single-particle basis chosen, several orbital optimisation algorithms are introduced. An energy-based algorithm using the simulated annealing method is used as a benchmark. As a computationally more affordable alternative, a seniority number minimising algorithm is developed and compared to the energy based one revealing that the seniority minimising orbital set performs well. Given a well-chosen orbital basis, it is shown that the newly developed DOCI based wave functions are especially suitable for the computationally efficient description of static correlation and to lesser extent dynamic correlation.

  5. Higher-order local and non-local correlations for 1D strongly interacting Bose gas

    Science.gov (United States)

    Nandani, EJKP; Römer, Rudolf A.; Tan, Shina; Guan, Xi-Wen

    2016-05-01

    The correlation function is an important quantity in the physics of ultracold quantum gases because it provides information about the quantum many-body wave function beyond the simple density profile. In this paper we first study the M-body local correlation functions, g M , of the one-dimensional (1D) strongly repulsive Bose gas within the Lieb-Liniger model using the analytical method proposed by Gangardt and Shlyapnikov (2003 Phys. Rev. Lett. 90 010401; 2003 New J. Phys. 5 79). In the strong repulsion regime the 1D Bose gas at low temperatures is equivalent to a gas of ideal particles obeying the non-mutual generalized exclusion statistics with a statistical parameter α =1-2/γ , i.e. the quasimomenta of N strongly interacting bosons map to the momenta of N free fermions via {k}i≈ α {k}iF with i=1,\\ldots ,N. Here γ is the dimensionless interaction strength within the Lieb-Liniger model. We rigorously prove that such a statistical parameter α solely determines the sub-leading order contribution to the M-body local correlation function of the gas at strong but finite interaction strengths. We explicitly calculate the correlation functions g M in terms of γ and α at zero, low, and intermediate temperatures. For M = 2 and 3 our results reproduce the known expressions for g 2 and g 3 with sub-leading terms (see for instance (Vadim et al 2006 Phys. Rev. A 73 051604(R); Kormos et al 2009 Phys. Rev. Lett. 103 210404; Wang et al 2013 Phys. Rev. A 87 043634). We also express the leading order of the short distance non-local correlation functions x}1)\\cdots {{{\\Psi }}}\\dagger ({x}M){{\\Psi }}({y}M)\\cdots {{\\Psi }}({y}1)> of the strongly repulsive Bose gas in terms of the wave function of M bosons at zero collision energy and zero total momentum. Here {{\\Psi }}(x) is the boson annihilation operator. These general formulas of the higher-order local and non-local correlation functions of the 1D Bose gas provide new insights into the many-body physics.

  6. Bona fide interaction-driven topological phase transition in correlated symmetry-protected topological states

    Science.gov (United States)

    He, Yuan-Yao; Wu, Han-Qing; You, Yi-Zhuang; Xu, Cenke; Meng, Zi Yang; Lu, Zhong-Yi

    2016-03-01

    It is expected that the interplay between nontrivial band topology and strong electron correlation will lead to very rich physics. Thus a controlled study of the competition between topology and correlation is of great interest. Here, employing large-scale quantum Monte Carlo simulations, we provide a concrete example of the Kane-Mele-Hubbard model on an AA-stacking bilayer honeycomb lattice with interlayer antiferromagnetic interaction. Our simulation identified several different phases: a quantum spin Hall insulator (QSH), an x y -plane antiferromagnetic Mott insulator, and an interlayer dimer-singlet insulator. Most importantly, a bona fide topological phase transition between the QSH and the dimer-singlet insulators, purely driven by the interlayer antiferromagnetic interaction, is found. At the transition, the spin and charge gap of the system close while the single-particle excitations remain gapped, which means that this transition has no mean-field analog and it can be viewed as a transition between bosonic symmetry-protected topological (SPT) states. At one special point, this transition is described by a (2 +1 )d O (4 ) nonlinear sigma model with exact S O (4 ) symmetry and a topological term at exactly Θ =π . The relevance of this work towards more general interacting SPT states is discussed.

  7. Bona fide interaction-driven topological phase transition in correlated SPT states

    Science.gov (United States)

    Meng, Zi Yang; He, Yuan-Yao; Wu, Han-Qing; You, Yi-Zhuang; Xu, Cenke; Lu, Zhong-Yi

    It is expected the interplay between non-trivial band topology and strong electron correlation will lead to very rich physics. Thus a controlled study of the competition between topology and correlation is of great interest. Here, employing large-scale quantum Monte Carlo simulations, we provide a concrete example of the Kane-Mele-Hubbard model on an AA stacking bilayer honeycomb lattice with inter-layer antiferromagnetic interaction. Our simulation identified several different phases: a quantum spin-Hall insulator (QSH), a xy-plane antiferromagnetic Mott insulator (xy-AFM) and an inter-layer dimer-singlet insulator (dimer-singlet). Most importantly, a bona fide topological phase transition between the QSH and the dimer-singlet insulators, purely driven by the inter-layer antiferromagnetic interaction is found. At the transition, the spin and charge gap of the system close while the single-particle excitations remain gapped, which means that this transition has no mean field analogue and it can be viewed as a transition between bosonic SPT states. At one special point, this transition is described by a (2+1)d O(4) nonlinear sigma model with exact SO(4) symmetry, and a topological term at theta=p. Relevance of this work towards more general interacting SPT states is discussed.

  8. Interpersonal Interactions in the Marital Pair and Mental Health: A Comparative and Correlational Study

    Directory of Open Access Journals (Sweden)

    Gleiber Couto Santos

    2015-12-01

    Full Text Available AbstractInterpersonal interactions as social processes reflect and influence individuals' mental health. The aim of the study was to verify how marital interactions relate to mental health, and to investigate evidence for the validity of the Checklist for Interpersonal Transactions II (CLOIT-II. Participants were 169 couples from the southeast of the Brazilian state of Goiás, aged between 18 and 55 years ( M = 21; SD = 5.48. They responded to a General Health Questionnaire (GHQ and the CLOIT-II. Participants with low mental health problem scores in the GHQ (asymptomatic participants tended to occupy interpersonal positions in the range between Deference/Trust and Affective warmth/Friendliness. In the group with high scores (symptomatic participants, interactions were defined by Coldness/Hostility.Mental health problems were positively correlated with mistrust, coldness and hostility and negatively correlated with positions of Affiliation. These results, in addition to supporting the validity of the CLOIT-II, indicate that the study of interpersonal relationships is relevant for the understanding of mental health.

  9. Correlation of interactions between NOS3 polymorphisms and oxygen therapy with retinopathy of prematurity susceptibility.

    Science.gov (United States)

    Yu, Chunhong; Yi, Jinglin; Yin, Xiaolong; Deng, Yan; Liao, Yujun; Li, Xiaobing

    2015-01-01

    This study was aimed to detect the correlation of nitric oxide synthase 3 (NOS3) gene polymorphisms (T-786C and G894T) and retinopathy of prematurity (ROP) susceptibility. Interaction between NOS3 gene polymorphisms and the duration of oxygen therapy was also explored in ROP babies. Genotypes of NOS3 gene polymorphisms were genotyped by MassArray method. Hardy-Weinberg equilibrium (HWE) was used to calculate the representativeness of the cases and controls. Crossover analysis was utilized to explore the gene environment interactions. Relative risk of ROP was presented by odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs). Among the subject features, oxygen therapy had obvious difference between case and control groups (PNOS3 gene polymorphisms and oxygen therapy duration. When the duration of oxygen therapy was less than 17 days, both -786CC genotype and 894GT genotype were correlated with ROP susceptibility (P=0.020, OR=0.115, 95% CI=0.014-0.960; P=0.011, OR=0.294, 95% CI=0.100-0.784). -786C allele might have a protective effect for ROP. Interactions of -786CC and 894GT genotype with oxygen therapy duration (less than 17 days) were both protection factors of ROP.

  10. Hyperon-nucleon single-particle potentials with low-momentum interactions

    CERN Document Server

    Djapo, Haris; Wambach, Jochen

    2008-01-01

    Single-particle potentials in Hartree-Fock approximation for different hyperon-nucleon (YN) channels are calculated in the framework of the effective low-momentum YN interaction V_lowk. In contrast to the nucleon-nucleon interaction, the available experimental data for the YN interaction are scarce. As a consequence no unique YN low-momentum potential V_lowk can be predicted from the various bare potentials. The resulting momentum- and density-dependent single-particle potentials for several different bare OBE models and for chiral effective field theory are compared to each other.

  11. Quantifying interhemispheric symmetry of somatosensory evoked potentials with the intraclass correlation coefficient.

    Science.gov (United States)

    van de Wassenberg, Wilma J G; van der Hoeven, Johannes H; Leenders, Klaus L; Maurits, Natasha M

    2008-06-01

    Although large intersubject variability is reported for cortical somatosensory evoked potentials (SEPs), variability between hemispheres within one subject is thought to be small. Therefore, interhemispheric comparison of SEP waveforms might be clinically useful to detect unilateral abnormalities in cortical sensory processing. We developed and evaluated a new technique to quantify interhemispheric SEP symmetry that uses a time interval including multiple SEP components, measures similarity of SEP waveforms between both hemispheres and results in high symmetry values even in the presence of small interhemispheric anatomic differences. Median nerve SEPs were recorded in 50 healthy subjects (20-70 years) using 128-channel EEG. Symmetry was quantified by the intraclass correlation coefficient and correlation coefficient between global field power of left and right median nerve SEPs. In 74% of subjects left-right intraclass correlation coefficient was higher than 0.60, implying high SEP hemispheric symmetry in terms of shape and amplitude. Left-right intraclass correlation coefficients lower than 0.60 were due to differences in amplitude, unilateral absence of peaks, or shape differences. We quantified SEP waveform interhemispheric symmetry and found it to be high in most healthy subjects. This technique may therefore be useful for detection of unilateral abnormalities in cortical sensory processing.

  12. Host-Symbiont Interactions for Potentially Managing Heteropteran Pests

    Directory of Open Access Journals (Sweden)

    Simone Souza Prado

    2012-01-01

    Full Text Available Insects in the suborder Heteroptera, the so-called true bugs, include over 40,000 species worldwide. This insect group includes many important agricultural pests and disease vectors, which often have bacterial symbionts associated with them. Some symbionts have coevolved with their hosts to the extent that host fitness is compromised with the removal or alteration of their symbiont. The first bug/microbial interactions were discovered over 50 years ago. Only recently, mainly due to advances in molecular techniques, has the nature of these associations become clearer. Some researchers have pursued the genetic modification (paratransgenesis of symbionts for disease control or pest management. With the increasing interest and understanding of the bug/symbiont associations and their ecological and physiological features, it will only be a matter of time before pest/vector control programs utilize this information and technique. This paper will focus on recent discoveries of the major symbiotic systems in Heteroptera, highlighting how the understanding of the evolutionary and biological aspects of these relationships may lead to the development of alternative techniques for efficient heteropteran pest control and suppression of diseases vectored by Heteroptera.

  13. Inverse Effectiveness and Multisensory Interactions in Visual Event-Related Potentials with Audiovisual Speech

    Science.gov (United States)

    Bushmakin, Maxim; Kim, Sunah; Wallace, Mark T.; Puce, Aina; James, Thomas W.

    2013-01-01

    In recent years, it has become evident that neural responses previously considered to be unisensory can be modulated by sensory input from other modalities. In this regard, visual neural activity elicited to viewing a face is strongly influenced by concurrent incoming auditory information, particularly speech. Here, we applied an additive-factors paradigm aimed at quantifying the impact that auditory speech has on visual event-related potentials (ERPs) elicited to visual speech. These multisensory interactions were measured across parametrically varied stimulus salience, quantified in terms of signal to noise, to provide novel insights into the neural mechanisms of audiovisual speech perception. First, we measured a monotonic increase of the amplitude of the visual P1-N1-P2 ERP complex during a spoken-word recognition task with increases in stimulus salience. ERP component amplitudes varied directly with stimulus salience for visual, audiovisual, and summed unisensory recordings. Second, we measured changes in multisensory gain across salience levels. During audiovisual speech, the P1 and P1-N1 components exhibited less multisensory gain relative to the summed unisensory components with reduced salience, while N1-P2 amplitude exhibited greater multisensory gain as salience was reduced, consistent with the principle of inverse effectiveness. The amplitude interactions were correlated with behavioral measures of multisensory gain across salience levels as measured by response times, suggesting that change in multisensory gain associated with unisensory salience modulations reflects an increased efficiency of visual speech processing. PMID:22367585

  14. The response of the polarized Fermi mixture to an artificial vector potential: The interaction strength and imbalance chemical potential effects

    Science.gov (United States)

    Ebrahimian, N.; Safiee, Z.

    2017-03-01

    We consider a polarized Fermi mixture (with normal-superfluid phase separation), subjected to artificial vector potential. We concentrate on the BCS regime with various interaction strengths and numerically obtain the polarisability of the system. We obtain the functional dependence of the polarisability of the system on frequency and the relevant physical parameters, namely the interaction strength, the mass ratio, the average and imbalance chemical potentials. Also, we find the special frequency (ωs), for which the rate of the response of system to the potential is changed and the cut-off frequency (ωcutoff), for which the response starts to become infinity. We investigate the behavior of the curves of polarisability versus proper physical parameters for ω physical parameters. Finally, the system's response can be controlled by relevant physical parameters, such as interaction strength.

  15. Accurate double many-body expansion potential energy surface of HS2A2A‧) by scaling the external correlation

    Science.gov (United States)

    Lu-Lu, Zhang; Yu-Zhi, Song; Shou-Bao, Gao; Yuan, Zhang; Qing-Tian, Meng

    2016-05-01

    A globally accurate single-sheeted double many-body expansion potential energy surface is reported for the first excited state of HS2 by fitting the accurate ab initio energies, which are calculated at the multireference configuration interaction level with the aug-cc-pVQZ basis set. By using the double many-body expansion-scaled external correlation method, such calculated ab initio energies are then slightly corrected by scaling their dynamical correlation. A grid of 2767 ab initio energies is used in the least-square fitting procedure with the total root-mean square deviation being 1.406 kcal·mol-1. The topographical features of the HS2(A2A‧) global potential energy surface are examined in detail. The attributes of the stationary points are presented and compared with the corresponding ab initio results as well as experimental and other theoretical data, showing good agreement. The resulting potential energy surface of HS2(A2A‧) can be used as a building block for constructing the global potential energy surfaces of larger S/H molecular systems and recommended for dynamic studies on the title molecular system. Project supported by the National Natural Science Foundation of China (Grant No. 11304185), the Taishan Scholar Project of Shandong Province, China, the Shandong Provincial Natural Science Foundation, China (Grant No. ZR2014AM022), the Shandong Province Higher Educational Science and Technology Program, China (Grant No. J15LJ03), the China Postdoctoral Science Foundation (Grant No. 2014M561957), and the Post-doctoral Innovation Project of Shandong Province, China (Grant No. 201402013).

  16. Severe potential drug-drug interactions in older adults with dementia and associated factors

    Directory of Open Access Journals (Sweden)

    Michele Bogetti-Salazar

    2016-01-01

    Full Text Available OBJECTIVE: To identify the main severe potential drug-drug interactions in older adults with dementia and to examine the factors associated with these interactions. METHOD: This was a cross-sectional study. The enrolled patients were selected from six geriatrics clinics of tertiary care hospitals across Mexico City. The patients had received a clinical diagnosis of dementia based on the current standards and were further divided into the following two groups: those with severe drug-drug interactions (contraindicated/severe (n=64 and those with non-severe drug-drug interactions (moderate/minor/absent (n=117. Additional socio-demographic, clinical and caregiver data were included. Potential drug-drug interactions were identified using Micromedex Drug Reax 2.0® database. RESULTS: A total of 181 patients were enrolled, including 57 men (31.5% and 124 women (68.5% with a mean age of 80.11±8.28 years. One hundred and seven (59.1% patients in our population had potential drug-drug interactions, of which 64 (59.81% were severe/contraindicated. The main severe potential drug-drug interactions were caused by the combinations citalopram/anti-platelet (11.6%, clopidogrel/omeprazole (6.1%, and clopidogrel/aspirin (5.5%. Depression, the use of a higher number of medications, dementia severity and caregiver burden were the most significant factors associated with severe potential drug-drug interactions. CONCLUSIONS: Older people with dementia experience many severe potential drug-drug interactions. Anti-depressants, antiplatelets, anti-psychotics and omeprazole were the drugs most commonly involved in these interactions. Despite their frequent use, anti-dementia drugs were not involved in severe potential drug-drug interactions. The number and type of medications taken, dementia severity and depression in patients in addition to caregiver burden should be considered to avoid possible drug interactions in this population.

  17. Exact out-of-time-ordered correlation functions for an interacting lattice fermion model

    CERN Document Server

    Tsuji, Naoto; Ueda, Masahito

    2016-01-01

    An exact solution for local equilibrium and nonequilibrium out-of-time-ordered correlation (OTOC) functions is obtained for a lattice fermion model with on-site interactions, namely the Falicov-Kimball (FK) model, in the large dimensional and thermodynamic limit. Our approach is based on the nonequilibrium dynamical mean-field theory generalized to an extended Kadanoff-Baym contour. We find that the OTOC is enhanced at intermediate coupling around the metal-insulator phase transition, implying that the system is most scrambled in that regime. In the high-temperature limit, the OTOC remains nontrivially finite, even though dynamical charge correlations probed by an ordinary response function are suppressed. We propose an experiment to measure OTOCs of fermionic lattice systems including the FK and Hubbard models in ultracold atomic systems.

  18. An explicitly correlated approach to basis set incompleteness in Full Configuration Interaction Quantum Monte Carlo

    CERN Document Server

    Booth, George H; Alavi, Ali; Tew, David P

    2012-01-01

    By performing a stochastic dynamic in a space of Slater determinants, the Full Configuration Interaction Quantum Monte Carlo (FCIQMC) method has been able to obtain energies which are essentially free from systematic error to the basis set correlation energy, within small and systematically improvable errorbars. However, the weakly exponential scaling with basis size makes converging the energy with respect to basis set costly and in larger systems, impossible. To ameliorate these basis set issues, here we use perturbation theory to couple the FCIQMC wave function to an explicitly correlated strongly orthogonal basis of geminals, following the [2]_{\\textrm{R12}} approach of Valeev {\\em et al.}. The required one- and two-particle density matrices are computed on-the-fly during the FCIQMC dynamic, using a sampling procedure which incurs relatively little additional computation expense. The F12 energy corrections are shown to converge rapidly as a function of sampling, both in imaginary time, and number of walke...

  19. Attentional focus in social anxiety disorder: potential for interactive processes.

    Science.gov (United States)

    Schultz, Luke T; Heimberg, Richard G

    2008-10-01

    The two preeminent cognitive behavioral models of social anxiety [Clark, D.M., & Wells, A., (1995). A cognitive model of social phobia. In Heimberg, R.G., Liebowitz, M., Hope, D.A., and Schneier, F.R. (Eds.), Social phobia: Diagnosis, assessment and treatment (pp. 69-93). New York: Guilford Press.; Rapee, R.M., & Heimberg, R.G., (1997). A cognitive behavioral model of anxiety in social phobia. Behaviour Research and Therapy, 35, 741-756.] suggest that attention to threat stimuli is critical in the maintenance of social fear. However, Clark and Wells assert that socially anxious persons attend almost exclusively to negative thoughts and self-imagery during social situations, whereas Rapee and Heimberg contend that socially anxious persons simultaneously attend to these internal cues and external stimuli potentially indicative of negative evaluation, such as an audience member's facial expressions. Rapee and Heimberg further suggest that attention to external and internal cues during social situations should be interdependent, such that focus on one has causal implications for the experience of the other. The current review examines the nature of the literature as it supports the assertions of each of these models of social anxiety, with particular attention to differing predictions regarding attentional focus. We conclude that socially anxious persons engage in both internal and external focus throughout the course of a social situation; however, there are a number of significant limitations to the literature. Accordingly, directions for future research are considered.

  20. On the theory of interaction potentials in ionic crystals

    Science.gov (United States)

    Acevedo, Roberto; Soto-Bubert, Andrés

    2008-11-01

    The aim of this research work is to report a more comprehensive and detailed study of both, the intermolecular and intramolecular potencial functions with reference to the various families of the elpasolite type crystals. The cohesive energy has been thought as a sum of three terms; the long range (Coulombic), the Born and the van der Waals contributions to the total energy. The Born-Mayer-Buckingham potential1 has been employed in all of these current studies and a number of convergence tests are analyzed from a formal viewpoint. Our work has been focused to the following systems: Cs2NaLnF6, Cs2NaLnCl6, Cs2NaLnBr6, Rb2NaLnF6 and Cs2KLnF6 in the Fm3m space group. A substantial amount of theoretical models have been analyzed and several computing simulations have been undertaken to estimate the reticular energies and the corresponding heat of formation for these crystals. To achieve this goal, a Born-Haber thermodynamic cycle has been introduced in our model. It is shown that the calculated energy values are reasonable and follow the expected trend along the lanthanide series in the periodic chart. We also discuss the advantages and disadvantages of the current and proposed generalized model. The most likely sources for improvement are discussed in detail. New convergence tests as well as some master equations have been introduced to study the various diagonal contributions to the total energy.

  1. Suckling behavior in Eurasian lynx (Lynx lynx L.) cubs: characteristics and correlation with competitive interactions.

    Science.gov (United States)

    Glukhova, Alla; Naidenko, Sergey

    2014-01-01

    There is substantial evidence in the literature that the offspring of many mammal species prefer a particular pair of nipples. There is also a definite "nipple order" in individual litters in which each young predominantly uses one or two particular nipples. In combination with early competitive interactions, such "constancy" can play an important role in the social development of the young. In this study, we reveal an unequal use of different pairs of mothers' nipples by 42 Eurasian lynx cubs in 16 litters and investigate the relationship of this phenomenon with the early competitive interactions of the cubs and their physical development. For the lynx cubs, the most often used pair of nipples is the middle pair. There is also definite "nipple order" in each litter. We found a negative correlation between nipples use by the offspring and their competitive activity. No influence of "nipple order" on the cubs' growth rate was detected.

  2. Reversal modes in FeCoNi nanowire arrays: Correlation between magnetostatic interactions and nanowires length

    Energy Technology Data Exchange (ETDEWEB)

    Samanifar, S. [Department of Physics, University of Kashan, Kashan, 87317-51167 (Iran, Islamic Republic of); Almasi Kashi, M., E-mail: almac@kashanu.ac.ir [Department of Physics, University of Kashan, Kashan, 87317-51167 (Iran, Islamic Republic of); Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, 87317-51167 (Iran, Islamic Republic of); Ramazani, A. [Department of Physics, University of Kashan, Kashan, 87317-51167 (Iran, Islamic Republic of); Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, 87317-51167 (Iran, Islamic Republic of); Alikhani, M. [Department of Physics, University of Kashan, Kashan, 87317-51167 (Iran, Islamic Republic of)

    2015-03-15

    FeCoNi nanowire arrays (175 nm in diameter and lengths ranging from 5 to 40 μm) were fabricated into nanopores of hard-anodized aluminum oxide templates using pulsed ac electrodeposition technique. Increasing the length had no considerable effect on the composition and crystalline characteristics of Fe{sub 47}Co{sub 38}Ni{sub 15} nanowires (NWs). By eliminating the dendrites formed at the bottom of the pores, we report a careful investigation on the effect of magnetostatic interactions on magnetic properties and the effect of nanowire length on reversal modes. Hysteresis loop measurements indicated that increasing the length decreases coercivity and squareness values. On the other hand, first-order reversal curve measurements show a linear correlation between the magnetostatic interactions and length of NWs. Comparing reversal modes of the NWs both experimentally and theoretically using angular dependence of coercivity, we find that when L≤22 μm, a vortex domain wall mode is only occurred. When L>22 μm, a non-monotonic behavior indicates a transition from the vortex to transverse domain wall propagation. As a result, a critical length was found above which the transition between the reversal modes is occurred due the enhanced interactions. The transition angle also shifts toward a lower angle as the length increases. Moreover, with increasing length from 22 to 31 μm, the single domain structure of NWs changes to a pseudo single domain state. A multidomain-like behavior is also found for the longest NWs length. - Highlights: • Fabrication of long and uniform FeCoNi NWs into hard-anodized AAO templates. • Investigation of morphology, crystalline and compositional characteristics. • Performing a careful investigation on the magnetic properties of NWs. • Obtaining a linear correlation between magnetostatic interactions and NWs length. • A critical length above which a transition between reversal modes is occurred.

  3. Correlates of directiveness in the interactions of fathers and mothers of children with developmental delays.

    Science.gov (United States)

    Girolametto, L; Tannock, R

    1994-10-01

    Twenty preschool-age children with developmental delays and language impairment participated in this study, which compared fathers' and mothers' directiveness and parental stress. Similarities between fathers and mothers were found for turntaking control, response referents, and responses to the child's participation. However, fathers differed from mothers in two of the dimensions of directiveness examined: fathers used more response control and topic control than mothers. Both parents reported similarly low levels of child-related and parenting stress, but mothers perceived more stress than fathers related to the responsibilities associated with parenting a child with a handicap. Correlations between directiveness, child characteristics, and stress revealed that fathers used greater turntaking control and topic control with children who were developmentally less mature, whereas mothers used greater topic control with children who were less involved in interaction. Both fathers' and mothers' use of response control was positively related to stress. Implications for involving fathers in parent-focused intervention include screening father-child interactions before intervention, interpreting parent-child interaction styles in terms of their role in enhancing the child's social participation, and acknowledging the role of familial factors (such as stress) on interaction styles.

  4. Investigation of hyperfine interactions in DNA nitrogenous bases using perturbed angular correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Andreia dos Santos; Carbonari, Artur Wilson; Lapolli, Andre Luis; Saxena, Rajendra Narain [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Saitovitch, Henrique, E-mail: asilva@usp.br [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    Perturbed γγ angular correlations (PAC) spectroscopy has been used to study the DNA nitrogenous bases (adenine, cytosine, guanine, thymine), using {sup 111}In→{sup 111}Cd and {sup 111m}Cd→{sup 111}Cd probe nuclei. One of the advantages of applying PAC technique to biological molecules is that the experiments can be carried out on molecules in aqueous solution [1], approaching the function of molecules under conditions that are close to in vivo conditions. The measurements were carried out for DNA nitrogenous bases molecules at 295 K and 77 K in order to investigate dynamic and static hyperfine interactions, respectively. The interpretation of the results was based on the measurements of dynamic interaction characterized by the decay constant from which valuable information on the macroscopic behavior of the molecules was obtained [2; 3]. On the other hand, PAC measurements at low temperature showed interaction frequency (ν{sub Q}), asymmetry parameter (η) and the distribution of the quadrupole frequency (δ). These parameters provide a local microscopic description of the chemical environment in the neighborhood of the probe nuclei. Results showed differences in the hyperfine interactions of probe nuclei bound to the studied biomolecules. Such differences were observed by variations in the hyperfine parameters, which depended on the type of biomolecule and the results also showed that the probe nuclei bounded at the molecules in some cases and at others did not. (author)

  5. On the theory of interaction potentials in ionic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Acevedo, Roberto [Departamento de Ciencia de los Materiales, Facultad de Ciencias Fisicas y Matematicas, Beauchef 850, Santiago (Chile); Soto-Bubert, Andres [Instituto de Ciencias Basicas, Facultad de Ingenieria, Universidad Diego Portales, Avenida Ejercito 441, Santiago (Chile)], E-mail: roberto.acevedo@umayor.cl

    2008-11-01

    The aim of this research work is to report a more comprehensive and detailed study of both, the intermolecular and intramolecular potencial functions with reference to the various families of the elpasolite type crystals. The cohesive energy has been thought as a sum of three terms; the long range (Coulombic), the Born and the van der Waals contributions to the total energy. The Born-Mayer-Buckingham potential{sup 1} has been employed in all of these current studies and a number of convergence tests are analyzed from a formal viewpoint. Our work has been focused to the following systems: Cs{sub 2}NaLnF{sub 6}, Cs{sub 2}NaLnCl{sub 6}, Cs{sub 2}NaLnBr{sub 6}, Rb{sub 2}NaLnF{sub 6} and Cs{sub 2}KLnF{sub 6} in the Fm3m space group. A substantial amount of theoretical models have been analyzed and several computing simulations have been undertaken to estimate the reticular energies and the corresponding heat of formation for these crystals. To achieve this goal, a Born-Haber thermodynamic cycle has been introduced in our model. It is shown that the calculated energy values are reasonable and follow the expected trend along the lanthanide series in the periodic chart. We also discuss the advantages and disadvantages of the current and proposed generalized model. The most likely sources for improvement are discussed in detail. New convergence tests as well as some master equations have been introduced to study the various diagonal contributions to the total energy.

  6. The effect of temperature, interaction range, and pair potential on the formation of dodecagonal quasicrystals in core-corona systems

    Science.gov (United States)

    Pattabhiraman, Harini; Dijkstra, Marjolein

    2017-03-01

    A two-dimensional dodecagonal quasicrystal was previously reported by Dotera et al (2014 Nature 506 208) in a system of particles interacting with a hard core of diameter σ and a repulsive square shoulder of diameter δ =1.40σ . In the current work, we examine the formation of this quasicrystal using bond orientational order parameters, correlation functions and tiling distributions. We find that this dodecagonal quasicrystal forms from a fluid phase. We further study the effect of the width of the repulsive shoulder by simulating the system over a range of values of δ. For the range of densities and temperatures considered, we observe the formation of the dodecagonal quasicrystal between δ =1.30σ and 1.44σ . We also study the effect of shape of the interaction potential by simulating the system using three other interaction potentials with two length scales, namely hard-core plus a linear ramp, modified exponential, or Buckingham (exp-6) potential. We observe the presence of the quasicrystal in all three systems. However, depending on the shape of the potential, the formation of the quasicrystal takes place at lower temperatures (or higher interaction strengths). Using free-energy calculations, we demonstrate that the quasicrystal is thermodynamically stable in the square-shoulder and linear-ramp system.

  7. Theory of Auger-electron and appearance-potential spectroscopy for interacting valence-band electrons

    Science.gov (United States)

    Nolting, W.; Geipel, G.; Ertl, K.

    1991-12-01

    A theory of Auger-electron spectroscopy (AES) and appearance-potential spectroscopy (APS) is presented for interacting electrons in a nondegenerate energy band, described within the framework of the Hubbard model. Both types of spectroscopy are based on the same two-particle spectral density. A diagrammatic vertex-correction method (Matsubara formalism) is used to express this function in terms of the one-particle spectral density. The latter is approximately determined for arbitrary temperature T, arbitrary coupling strength U/W (U, the intra-atomic Coulomb matrix element; W, the width of the ``free'' Bloch band), and arbitrary band occupations n (0QDOS) in relation to the Bloch density of states (BDOS), where, however, spontaneous magnetic order is excluded, irrespective of the band filling n. The AE (AP) spectra consist of only one structure a few eV wide (``bandlike'') which is strongly n dependent, but only slightly T dependent, being rather well approximated by a simple self-convolution of the occupied (unoccupied) QDOS. For strongly correlated electrons the Bloch band splits into two quasiparticle subbands. This leads for n1. For sufficiently strong correlations U/W additional satellites appear that refer to situations where the two excited quasiparticles (quasiholes) propagate as tightly bound pairs through the lattice without being scattered by other charge carriers. As soon as the satellite splits off from the bandlike part of the spectrum, it takes almost the full spectral weight, conveying the impression of an ``atomiclike'' AE (AP) line shape. The satellite has almost exactly the structure of the free BDOS. If the particle density n as well as the hole density 2-n exceed certain critical values determined by U/W and the BDOS ρ0(E), spontaneous ferromagnetism becomes possible in the strongly correlated electron band. The magnetic phase transition gives rise to a distinctive T dependence for the QDOS and hence also for the AE and AP line shapes

  8. Correlation between metastatic potential and variants from colorectal tumor cell line HT-29

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Ilka Vogel; Holger Kalthoff

    2003-01-01

    AIM: To evaluate the relationship between uPA, PAI-1,CEA, PI3K and metastatic potential in three colorectal tumor cell lines.METHODS: Metastatic model in nude rats was established by variants HT-29c and HT-29d cell lines and the metastatic potential of two tumor cell variants was compared.Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) were determined using ELISA in colorectal carcinoma WiDr, HT29 and HT-29d cell lines with different metastatic potentials.Expression of carcinoembryonic antigen (CEA) and phosphoinositide 3-kinase (PI3-Kinase) was analyzed using immunohistochemistry (IHC) in these cell lines in vitro and in vivo. CEA expression was compared using fluorescence activated cell sorter (FACS)in vitro.RESULTS: The number of HT-29d cells arrested in liver dramatically decreased within the initial 24 hours after injection. The taking rate of liver metastases in the variant HT-29d increased as compared with parental HT-29 cells (70 % versus 50 %) and a variant HT-29b cells (70 % versus 60 %), and extensive organs were synchronously involved in metastases. The uPA concentration of variant HT-29d cell line was significantly higher than that of the non-metastatic WiDr and the low metastatic HT-29 cell lines. The variant HT-29d cells produced stronger PI3-kinase expression as compared with the non-metastatic WiDr cells and the low metastatic HT-29 cellsin vivo.CONCLUSION: The selected variant HT-29d cell exhibited an enhanced metastatic potential. The level of uPA and PAI-1 is positively correlated with the metastatic capacity of tumor cells. The expression of PI3-kinase correlates with tumor development and metastasis.

  9. Strong signal of dynamical long-range correlating among target fragments in relativistic and ultra-relativistic nuclear interactions

    CERN Document Server

    Ghosh, D; Bhattacharya, S; Ghosh, J; Das, R

    2003-01-01

    This paper reports an investigation on the two-particle long-range angular correlation among the target fragments produced in sup 2 sup 8 Si-AgBr interactions at 14.5 AGeV, sup 1 sup 6 O-AgBr interactions at 60 AGeV and sup 3 sup 2 S-AgBr interactions at 200 AGeV. The experimental data have been compared with Monte Carlo simulated events to extract dynamical correlation. The data exhibit two-particle long-range correlation in emission angle space at all energies. (author)

  10. Phase transition of strongly interacting matter with a chemical potential dependent Polyakov loop potential

    CERN Document Server

    Shao, Guo-yun; Di Toro, Massimo; Colonna, Maria; Gao, Xue-yan; Gao, Ning

    2016-01-01

    We construct a hadron-quark two-phase model based on the Walecka-quantum hadrodynamics and the improved Polyakov-Nambu--Jona-Lasinio model with an explicit chemical potential dependence of Polyakov-loop potential ($\\mu$PNJL model). With respect to the original PNJL model, the confined-deconfined phase transition is largely affected at low temperature and large chemical potential. Using the two-phase model, we investigate the equilibrium transition between hadronic and quark matter at finite chemical potentials and temperatures. The numerical results show that the transition boundaries from nuclear to quark matter move towards smaller chemical potential (lower density) when the $\\mu$-dependent Polyakov loop potential is taken. In particular, for charge asymmetric matter, we compute the local asymmetry of $u, d$ quarks in the hadron-quark coexisting phase, and analyse the isospin-relevant observables possibly measurable in heavy-ion collision (HIC) experiments. In general new HIC data on the location and proper...

  11. Correlation of middle latency auditory evoked potentials and cerebral blood flow changes

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Seiichiro; Sugimoto, Akiko; Ohi, Takekazu; Matsukura, Shigeru; Watanabe, Katushi [Miyazaki Medical Coll., Kiyotake (Japan); Hoshi, Hiroaki

    1997-12-01

    The purpose of this study is to find the correlation between middle latency auditory evoked potentials (MLAEP) and sound activated single photon emission computed tomography (SPECT) studies. This study was performed on six normal right-handed volunteers with a mean age of 35.2{+-}7.6 years, using the split-dose technique. First, a SPECT study was performed on subjects in blinded, awake and silent states. After bilateral ears were stimulated with a click sound, MLAEP and a second SPECT study were performed. Subtraction of the first SPECT from the second SPECT revealed a statistically significant increase of cerebral blood flow (CBF) in the bilateral superior temporal region. Bilateral Na amplitudes of MLAEP had a statistically significant and good correlation with the percentages of CBF changes in the bilateral superior temporal region. The superior temporal cerebral blood flow activation can be expressed by electrophysiological activation. Moreover, correlation during the left Na components and left frontal and occipital lobe are discussed. (author)

  12. Estimating the correlation between bursty spike trains and local field potentials.

    Science.gov (United States)

    Li, Zhaohui; Ouyang, Gaoxiang; Yao, Li; Li, Xiaoli

    2014-09-01

    To further understand rhythmic neuronal synchronization, an increasingly useful method is to determine the relationship between the spiking activity of individual neurons and the local field potentials (LFPs) of neural ensembles. Spike field coherence (SFC) is a widely used method for measuring the synchronization between spike trains and LFPs. However, due to the strong dependency of SFC on the burst index, it is not suitable for analyzing the relationship between bursty spike trains and LFPs, particularly in high frequency bands. To address this issue, we developed a method called weighted spike field correlation (WSFC), which uses the first spike in each burst multiple times to estimate the relationship. In the calculation, the number of times that the first spike is used is equal to the spike count per burst. The performance of this method was demonstrated using simulated bursty spike trains and LFPs, which comprised sinusoids with different frequencies, amplitudes, and phases. This method was also used to estimate the correlation between pyramidal cells in the hippocampus and gamma oscillations in rats performing behaviors. Analyses using simulated and real data demonstrated that the WSFC method is a promising measure for estimating the correlation between bursty spike trains and high frequency LFPs.

  13. Correlation between caloric and ocular vestibular evoked myogenic potential test results.

    Science.gov (United States)

    Huang, Chi-Hsuan; Wang, Shou-Jen; Young, Yi-Ho

    2012-02-01

    The ocular vestibular evoked myogenic potential (o-VEMP) test results correlate significantly with caloric test results for patients with acoustic neuroma (AN), but not for patients with Meniere's disease (MD), indicating that the o-VEMP test may replace the caloric test for evaluating the vestibular nerve from which the AN arises. Conversely, the caloric, o-VEMP, and cervical VEMP (c-VEMP) tests should be performed to map lesion sites in the vestibular labyrinth. This study performed caloric, o-VEMP, and c-VEMP tests on patients with central and peripheral vestibular disorders to investigate their relationships. In all, 66 patients comprising 16 with unilateral AN and 50 with unilateral definite MD were enrolled. All patients underwent caloric, o-VEMP, and c-VEMP tests. In the AN group, the caloric test identified canal paresis and caloric areflexia in 10 ears, while the o-VEMP and c-VEMP tests identified abnormal (absent or delayed) responses in 12 and 11 ears, respectively. A significant correlation existed between caloric and o-VEMP test results, but not between caloric and c-VEMP test results, or between o-VEMP and c-VEMP test results. For the MD group, abnormal caloric, o-VEMP, and c-VEMP test results were obtained for 24%, 44%, and 38% of hydropic ears, respectively. No correlation existed between any two test results.

  14. Correlation between subjective visual horizontal test and ocular vestibular-evoked myogenic potential test.

    Science.gov (United States)

    Lin, Kuei-You; Young, Yi-Ho

    2011-02-01

    The static subjective visual horizontal (SVH) test correlates with the dynamic ocular vestibular-evoked myogenic potential (oVEMP) test in healthy and pathological ears, and further confirms that both tests may, at least in part, share the same utricular reflex pathway. This study correlated the SVH test results with those of the oVEMP and cervical VEMP (cVEMP) tests to investigate their relationships. Twenty healthy subjects underwent the SVH test at a view pattern angle of 30° or 70° horizontal tilt under various background distractions to establish the optimal stimulation mode for SVH test. Thereafter, 20 patients with unilateral Meniere's disease underwent the SVH test using the optimal mode. In addition, oVEMP and cVEMP tests were performed in all subjects. The preliminary study in 20 healthy subjects at a view pattern angle of 70° under counterclockwise square background distraction revealed that the mean deviation degree of the SVH test was -0.61 ± 1.17°. Based on the criteria, abnormal percentages of SVH in 20 Meniere's patients were 40%. All healthy subjects had normal oVEMPs and cVEMPs. In contrast, eight patients (40%) showed abnormal oVEMPs and nine (45%) revealed abnormal cVEMPs. The SVH test results correlated significantly with oVEMP results, but not with cVEMP results.

  15. Potential for a biogenic influence on cloud microphysics over the ocean: a correlation study with satellite-derived data

    Directory of Open Access Journals (Sweden)

    A. Lana

    2012-09-01

    Full Text Available Aerosols have a large potential to influence climate through their effects on the microphysics and optical properties of clouds and, hence, on the Earth's radiation budget. Aerosol–cloud interactions have been intensively studied in polluted air, but the possibility that the marine biosphere plays an important role in regulating cloud brightness in the pristine oceanic atmosphere remains largely unexplored. We used 9 yr of global satellite data and ocean climatologies to derive parameterizations of the temporal variability of (a production fluxes of sulfur aerosols formed by the oxidation of the biogenic gas dimethylsulfide emitted from the sea surface; (b production fluxes of secondary organic aerosols from biogenic organic volatiles; (c emission fluxes of biogenic primary organic aerosols ejected by wind action on sea surface; and (d emission fluxes of sea salt also lifted by the wind upon bubble bursting. Series of global monthly estimates of these fluxes were correlated to series of potential cloud condensation nuclei (CCN numbers derived from satellite (MODIS. More detailed comparisons among weekly series of estimated fluxes and satellite-derived cloud droplet effective radius (re data were conducted at locations spread among polluted and clean regions of the oceanic atmosphere. The outcome of the statistical analysis was that positive correlation to CCN numbers and negative correlation to re were common at mid and high latitude for sulfur and organic secondary aerosols, indicating both might be important in seeding cloud droplet activation. Conversely, primary aerosols (organic and sea salt showed widespread positive correlations to CCN only at low latitudes. Correlations to re were more variable, non-significant or positive, suggesting that, despite contributing to large shares of the marine aerosol mass, primary aerosols are not widespread major drivers of the variability of cloud

  16. Correlation between crystallization behaviour and interfacial interactions in plasticized PLA/POSS nanocomposites

    Science.gov (United States)

    Kodal, Mehmet; Şirin, Hümeyra; Özkoç, Güralp

    2016-03-01

    In this study, the correlation between crystallization behavior and surface chemistry of polyhedral oligomeric silsesquioxanes (POSS) for plasticized poly(lactic acid) (PLA)/POSS nanocomposites was investigated. Four different kinds of POSS particles having different chemical structures were used. Poly(ethylene glycol) (PEG, 8000 g/mol) was utilized as the plasticiser. The nanocomposites were melt-compounded in an Xplore Instruments 15 cc twin screw microcompounder at 180°C barrel temperature and 100 rpm screw speed. Non-isothermal crystallization behaviour of PLA/PEG/POSS nanocomposites were evaluated from common kinetic models such as Avrami and Avrami-Ozawa and Kissinger by using the thermal data obtained from differantial scanning calorimetry (DSC). A polarized optical microscope (POM) equipped with a hot-stage was used to examine the morphology during the crystal growth. In order to investigate the interfacial interactions between POSS particles and plasticized PLA, thermodynamic work of adhesion approach was adopted using the experimentally determined surface energies. A strong correlation was obtained between interfacial chemistry and the nucleation rate in plasticized PLA/POSS nanocomposites. It was found that the polar interactions were the dominating factor which determines the nucleation activity of the POSS particles.

  17. Investigating potential correlations between jet engine noise and plume dynamics in the hypertemporal infrared domain

    Science.gov (United States)

    Cunio, Phillip M.; Weber, Reed; Knobel, Kimberly; Wager, Jason; Lopez, Gerardo

    2014-09-01

    Jet engine noise can be a hazard and environmental pollutant, affecting personnel working in close proximity to jet engines. Mitigating the effects of jet engine noise could reduce the potential for hearing loss in runway workers, but engine noise is not yet sufficiently well-characterized that it can easily be mitigated for new engine designs. That is, there exists a very complex relationship between jet engine design parameters, operating conditions, and resultant noise power levels. In this paper, we propose to evaluate the utility of high-speed imaging (also called hypertemporal imaging) in correlating the infrared signatures of jet aircraft engines with acoustic noise from the jet engines. This paper will focus on a theoretical analysis of jet engine infrared signatures, and will define potentially-detectable characteristics of such signatures in the hypertemporal domain. A systematic test campaign to determine whether such signatures actually exist and can be correlated with acoustic jet engine characteristics will be proposed. The detection of any hypertemporal signatures in association with acoustic signatures of jet engines will enable the use of a new domain in characterizing jet engine noise. This may in turn enable new methods of predicting or mitigating jet engine noise, which could lead to benefits for operators of large numbers of jet engines.

  18. Characterization and Correlation of Particle-Level Interactions to the Macroscopic Rheology of Powders, Granular Slurries, and Colloidal Suspensions

    Energy Technology Data Exchange (ETDEWEB)

    A.P. Poloski; R.C. Daniel; D.R. Rector; P.R. Bredt; E.C. Buck; Berg, J.C.; Saez, A.E.

    2006-09-29

    This project had two primary objectives. The first was to understand the physical properties and behavior of select Hanford tank sludges under conditions that might exist during retrieval, treatment, packaging, and transportation for disposal at the Waste Isolation Pilot Plant (WIPP). The second objective was to develop a fundamental understanding of these sludge suspensions by correlating the macroscopic properties with particle interactions occurring at the colloidal scale. The specific tank wastes considered herein are contained in thirteen Hanford tanks including three double-shell tanks (DSTs) (AW-103, AW-105, and SY-102) and ten single-shell tanks (SSTs) (B-201 through B-204, T-201 through T-204, T-110, and T-111). At the outset of the project, these tanks were designated as potentially containing transuranic (TRU) process wastes that would be treated and disposed of in a manner different from the majority of the tank wastes.

  19. Highly correlated configuration interaction calculations on water with large orbital bases

    Energy Technology Data Exchange (ETDEWEB)

    Almora-Díaz, César X., E-mail: xalmora@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, Apdo. Postal 20-364, México 01000, México (Mexico)

    2014-05-14

    A priori selected configuration interaction (SCI) with truncation energy error [C. F. Bunge, J. Chem. Phys. 125, 014107 (2006)] and CI by parts [C. F. Bunge and R. Carbó-Dorca, J. Chem. Phys. 125, 014108 (2006)] are used to approximate the total nonrelativistic electronic ground state energy of water at fixed experimental geometry with CI up to sextuple excitations. Correlation-consistent polarized core-valence basis sets (cc-pCVnZ) up to sextuple zeta and augmented correlation-consistent polarized core-valence basis sets (aug-cc-pCVnZ) up to quintuple zeta quality are employed. Truncation energy errors range between less than 1 μhartree, and 100 μhartree for the largest orbital set. Coupled cluster CCSD and CCSD(T) calculations are also obtained for comparison. Our best upper bound, −76.4343 hartree, obtained by SCI with up to sextuple excitations with a cc-pCV6Z basis recovers more than 98.8% of the correlation energy of the system, and it is only about 3 kcal/mol above the “experimental” value. Despite that the present energy upper bounds are far below all previous ones, comparatively large dispersion errors in the determination of the extrapolated energies to the complete basis set do not allow to determine a reliable estimation of the full CI energy with an accuracy better than 0.6 mhartree (0.4 kcal/mol)

  20. Canonical correlation analysis of synchronous neural interactions and cognitive deficits in Alzheimer's dementia

    Science.gov (United States)

    Karageorgiou, Elissaios; Lewis, Scott M.; Riley McCarten, J.; Leuthold, Arthur C.; Hemmy, Laura S.; McPherson, Susan E.; Rottunda, Susan J.; Rubins, David M.; Georgopoulos, Apostolos P.

    2012-10-01

    In previous work (Georgopoulos et al 2007 J. Neural Eng. 4 349-55) we reported on the use of magnetoencephalographic (MEG) synchronous neural interactions (SNI) as a functional biomarker in Alzheimer's dementia (AD) diagnosis. Here we report on the application of canonical correlation analysis to investigate the relations between SNI and cognitive neuropsychological (NP) domains in AD patients. First, we performed individual correlations between each SNI and each NP, which provided an initial link between SNI and specific cognitive tests. Next, we performed factor analysis on each set, followed by a canonical correlation analysis between the derived SNI and NP factors. This last analysis optimally associated the entire MEG signal with cognitive function. The results revealed that SNI as a whole were mostly associated with memory and language, and, slightly less, executive function, processing speed and visuospatial abilities, thus differentiating functions subserved by the frontoparietal and the temporal cortices. These findings provide a direct interpretation of the information carried by the SNI and set the basis for identifying specific neural disease phenotypes according to cognitive deficits.

  1. Artificial abelian gauge potentials induced by dipole-dipole interactions between Rydberg atoms

    CERN Document Server

    Cesa, A

    2013-01-01

    We analyze the influence of dipole-dipole interactions between Rydberg atoms on the generation of abelian artificial gauge potentials and fields. When two Rydberg atoms are driven by a uniform laser field, we show that the combined atom-atom and atom-field interactions give rise to new, non-uniform, artificial gauge potentials. We identify the mechanism responsible for the emergence of these gauge potentials. Analytical expressions for the latter indicate that the strongest artificial magnetic fields are reached in the regime intermediate between the dipole blockade regime and the regime in which the atoms are sufficiently far apart such that atom-light interaction dominates over atom-atom interactions. We discuss the differences and similarities of artificial gauge fields originating from resonant dipole-dipole and van der Waals interactions. We also give an estimation of experimentally attainable artificial magnetic fields resulting from this mechanism.

  2. Student Interactions with CD-ROM Storybooks: A Look at Potential Relationships between Multiple Intelligence Strengths and Levels of Interaction

    Science.gov (United States)

    Huffman, Celia A.

    2012-01-01

    This study looked at the potential relationship that may exist between students' intelligence strengths, in particular their spatial and kinesthetic strengths, and their combined cognitive and metacognitive levels of interaction with a CD-ROM storybook. The multiple intelligence strengths of a sample of students, measured via the MIDAS/My…

  3. Interaction of parasitism and nutrition in goats: effects on haematological parameters, correlations, and other statistical associations.

    Science.gov (United States)

    Blackburn, H D; Rocha, J L; Figueiredo, E P; Berne, M E; Vieira, L S; Cavalcante, A R; Rosa, J S

    1992-10-01

    Weaned wether goats (n = 144) approximately 6 months of age were placed in a 2 x 3 factorial experiment to test the effects and interaction of two levels of nutrition (growth+maintenance, NUT1; and twice growth+maintenance, NUT2) and three levels of Haemonchus contortus burden (0, 500, and 2000 larvae administered every 2 weeks; W0, W500, and W2000, respectively) on packed cell volume, red blood cell count, total serum protein and leukocytes. The statistical analysis revealed clear and proportionate differences among levels of infection for all variables. A significant (P effect was also found associated with all the variables except leukocytes. Nutrition by worm load interactions were found for packed cell volume and leukocytes. The neutrophil/lymphocyte ratio was higher in the NUT1-infected animals, leading to the nutrition by worm load interaction for leukocytes. An analysis for the different leukocyte types revealed significant (P effect for basophil count and immature white cells. Several significant correlations were observed between pairs of variables. Faecal egg output could be predicted from actual worm count in three of the four necropsy periods. The clear differences observed for blood parameters were not present in production traits, suggesting that physiological thresholds may play an important role in framing the metabolic activity of biological organisms. Total serum protein was the best indicator of these effects on production parameters.

  4. Tracking transcription factor mobility and interaction in Arabidopsis roots with fluorescence correlation spectroscopy.

    Science.gov (United States)

    Clark, Natalie M; Hinde, Elizabeth; Winter, Cara M; Fisher, Adam P; Crosti, Giuseppe; Blilou, Ikram; Gratton, Enrico; Benfey, Philip N; Sozzani, Rosangela

    2016-06-11

    To understand complex regulatory processes in multicellular organisms, it is critical to be able to quantitatively analyze protein movement and protein-protein interactions in time and space. During Arabidopsis development, the intercellular movement of SHORTROOT (SHR) and subsequent interaction with its downstream target SCARECROW (SCR) control root patterning and cell fate specification. However, quantitative information about the spatio-temporal dynamics of SHR movement and SHR-SCR interaction is currently unavailable. Here, we quantify parameters including SHR mobility, oligomeric state, and association with SCR using a combination of Fluorescent Correlation Spectroscopy (FCS) techniques. We then incorporate these parameters into a mathematical model of SHR and SCR, which shows that SHR reaches a steady state in minutes, while SCR and the SHR-SCR complex reach a steady-state between 18 and 24 hr. Our model reveals the timing of SHR and SCR dynamics and allows us to understand how protein movement and protein-protein stoichiometry contribute to development.

  5. Detection of long-range electrostatic interactions between charged molecules by means of fluorescence correlation spectroscopy

    Science.gov (United States)

    Nardecchia, Ilaria; Lechelon, Mathias; Gori, Matteo; Donato, Irene; Preto, Jordane; Floriani, Elena; Jaeger, Sebastien; Mailfert, Sebastien; Marguet, Didier; Ferrier, Pierre; Pettini, Marco

    2017-08-01

    In the present paper, an experimental feasibility study on the detection of long-range intermolecular interactions through three-dimensional molecular diffusion in solution is performed. This follows recent theoretical and numerical analyses reporting that long-range electrodynamic forces between biomolecules could be identified through deviations from Brownian diffusion. The suggested experimental technique was fluorescence correlation spectroscopy (FCS). By considering two oppositely charged molecular species in aqueous solution, namely, lysozymes and fluorescent dye molecules (Alexa488), the diffusion coefficient of the dyes has been measured for different values of the concentration of lysozyme, that is, for different average distances between the oppositely charged molecules. For our model, long-range interactions are of electrostatic origin, suggesting that their action radius can be varied by changing the ionic strength of the solution. The experimental outcomes clearly prove the detectability of long-range intermolecular interactions by means of the FCS technique. Molecular dynamics simulations provide a clear and unambiguous interpretation of the experimental results.

  6. Brain imaging investigation of the neural correlates of observing virtual social interactions.

    Science.gov (United States)

    Sung, Keen; Dolcos, Sanda; Flor-Henry, Sophie; Zhou, Crystal; Gasior, Claudia; Argo, Jennifer; Dolcos, Florin

    2011-07-06

    The ability to gauge social interactions is crucial in the assessment of others' intentions. Factors such as facial expressions and body language affect our decisions in personal and professional life alike (1). These "friend or foe" judgements are often based on first impressions, which in turn may affect our decisions to "approach or avoid". Previous studies investigating the neural correlates of social cognition tended to use static facial stimuli (2). Here, we illustrate an experimental design in which whole-body animated characters were used in conjunction with functional magnetic resonance imaging (fMRI) recordings. Fifteen participants were presented with short movie-clips of guest-host interactions in a business setting, while fMRI data were recorded; at the end of each movie, participants also provided ratings of the host behaviour. This design mimics more closely real-life situations, and hence may contribute to better understanding of the neural mechanisms of social interactions in healthy behaviour, and to gaining insight into possible causes of deficits in social behaviour in such clinical conditions as social anxiety and autism (3).

  7. Stability of stationary states of non-local equations with singular interaction potentials

    KAUST Repository

    Fellner, Klemens

    2011-04-01

    We study the large-time behaviour of a non-local evolution equation for the density of particles or individuals subject to an external and an interaction potential. In particular, we consider interaction potentials which are singular in the sense that their first derivative is discontinuous at the origin.For locally attractive singular interaction potentials we prove under a linear stability condition local non-linear stability of stationary states consisting of a finite sum of Dirac masses. For singular repulsive interaction potentials we show the stability of stationary states of uniformly bounded solutions under a convexity condition.Finally, we present numerical simulations to illustrate our results. © 2010 Elsevier Ltd.

  8. Peculiar features of the interaction potential between hydrogen and antihydrogen at intermediate separations

    Institute of Scientific and Technical Information of China (English)

    Lee Teck-Ghee; Wong Cheuk-Yin; Wang Lee-Shien

    2008-01-01

    This paper evaluates the interaction potential between a hydrogen and an antihydrogen using the second-order perturbation theory within the framework of the four-body system in a separable two-body basis. It finds that the H-H interaction potential possesses the peculiar features of a shallow local minimum located around interatomic separations of r ~ 6a.u. and a barrier rising at r<~ 5a.u.

  9. Dynamic interaction potential and the scattering cross sections of the semiclassical plasma particles

    Energy Technology Data Exchange (ETDEWEB)

    Dzhumagulova, K. N.; Shalenov, E. O.; Gabdullina, G. L. [IETP, Al Farabi Kazakh National University, 71al Farabi Street, Almaty 050040 (Kazakhstan)

    2013-04-15

    The dynamic model of the charged particles interaction in non-ideal semiclassical plasma is presented. This model takes into account the quantum mechanical diffraction effect and the dynamic screening effect. On the basis of the dynamic interaction potential, the electron scattering cross sections are investigated. Comparison with the results obtained on the basis of other models and conclusions were made.

  10. Reactive Boundary Conditions as Limits of Interaction Potentials for Brownian and Langevin Dynamics

    CERN Document Server

    Chapman, S Jonathan; Isaacson, Samuel A

    2015-01-01

    A popular approach to modeling bimolecular reactions between diffusing molecules is through the use of reactive boundary conditions. One common model is the Smoluchowski partial absorption condition, which uses a Robin boundary condition in the separation coordinate between two possible reactants. This boundary condition can be interpreted as an idealization of a reactive interaction potential model, in which a potential barrier must be surmounted before reactions can occur. In this work we show how the reactive boundary condition arises as the limit of an interaction potential encoding a steep barrier within a shrinking region in the particle separation, where molecules react instantly upon reaching the peak of the barrier. The limiting boundary condition is derived by the method of matched asymptotic expansions, and shown to depend critically on the relative rate of increase of the barrier height as the width of the potential is decreased. Limiting boundary conditions for the same interaction potential in b...

  11. Effect of interacting second- and third-order stimulus-dependent correlations on population-coding asymmetries

    Science.gov (United States)

    Montangie, Lisandro; Montani, Fernando

    2016-10-01

    Spike correlations among neurons are widely encountered in the brain. Although models accounting for pairwise interactions have proved able to capture some of the most important features of population activity at the level of the retina, the evidence shows that pairwise neuronal correlation analysis does not resolve cooperative population dynamics by itself. By means of a series expansion for short time scales of the mutual information conveyed by a population of neurons, the information transmission can be broken down into firing rate and correlational components. In a proposed extension of this framework, we investigate the information components considering both second- and higher-order correlations. We show that the existence of a mixed stimulus-dependent correlation term defines a new scenario for the interplay between pairwise and higher-than-pairwise interactions in noise and signal correlations that would lead either to redundancy or synergy in the information-theoretic sense.

  12. The N400 event-related potential as a neural correlate of language proficiency

    Directory of Open Access Journals (Sweden)

    2015-09-01

    Results: A difference wave comparing ERPs to congruent and incongruent words was calculated over the time-window associated with N400 (350 to 500 ms. The size of this difference wave was correlated with scores on the NART, sentence discrimination task, and lexical decision task. Conclusions: The relation between psychophysiological and behavioural measures of linguistic ability are important as they help to inform both theories of such behaviour, and potential efforts to find effective means for the amelioration of deficient performance. The evidence described here provides the first such investigation in an adult higher education population. The results will be used in the development of teaching strategies designed to support the acquisition of high-level language skills.

  13. Analyzing long-term correlated stochastic processes by means of recurrence networks: Potentials and pitfalls

    CERN Document Server

    Zou, Yong; Kurths, Jürgen

    2014-01-01

    Long-range correlated processes are ubiquitous, ranging from climate variables to financial time series. One paradigmatic example for such processes is fractional Brownian motion (fBm). In this work, we highlight the potentials and conceptual as well as practical limitations when applying the recently proposed recurrence network (RN) approach to fBm and related stochastic processes. In particular, we demonstrate that the results of a previous application of RN analysis to fBm (Liu \\textit{et al.,} Phys. Rev. E \\textbf{89}, 032814 (2014)) are mainly due to an inappropriate treatment disregarding the intrinsic non-stationarity of such processes. Complementarily, we analyze some RN properties of the closely related stationary fractional Gaussian noise (fGn) processes and find that the resulting network properties are well-defined and behave as one would expect from basic conceptual considerations. Our results demonstrate that RN analysis can indeed provide meaningful results for stationary stochastic processes, ...

  14. The effects of learning on event-related potential correlates of musical expectancy.

    Science.gov (United States)

    Carrión, Ricardo E; Bly, Benjamin Martin

    2008-09-01

    Musical processing studies have shown that unexpected endings in familiar musical sequences produce extended latencies of the P300 component. The present study sought to identify event-related potential (ERP) correlates of musical expectancy by entraining participants with rule-governed chord sequences and testing whether unexpected endings created similar responses. Two experiments were conducted in which participants performed grammaticality classifications without training (Experiment 1) and with training (Experiment 2). In both experiments, deviant chords differing in instrumental timbre elicited a MMN/P3a waveform complex. Violations related to learned patterns elicited an early right anterior negativity and P3b. Latency and amplitude of peak components were modulated by the physical characteristics of the chords, expectations due to prior knowledge of musical harmony, and contextually defined expectations developed through entrainment.

  15. Time-Shift Correlation Algorithm for P300 Event Related Potential Brain-Computer Interface Implementation

    Directory of Open Access Journals (Sweden)

    Ju-Chi Liu

    2016-01-01

    Full Text Available A high efficient time-shift correlation algorithm was proposed to deal with the peak time uncertainty of P300 evoked potential for a P300-based brain-computer interface (BCI. The time-shift correlation series data were collected as the input nodes of an artificial neural network (ANN, and the classification of four LED visual stimuli was selected as the output node. Two operating modes, including fast-recognition mode (FM and accuracy-recognition mode (AM, were realized. The proposed BCI system was implemented on an embedded system for commanding an adult-size humanoid robot to evaluate the performance from investigating the ground truth trajectories of the humanoid robot. When the humanoid robot walked in a spacious area, the FM was used to control the robot with a higher information transfer rate (ITR. When the robot walked in a crowded area, the AM was used for high accuracy of recognition to reduce the risk of collision. The experimental results showed that, in 100 trials, the accuracy rate of FM was 87.8% and the average ITR was 52.73 bits/min. In addition, the accuracy rate was improved to 92% for the AM, and the average ITR decreased to 31.27 bits/min. due to strict recognition constraints.

  16. General theory for calculating disorder-averaged Green's function correlators within the coherent potential approximation

    Science.gov (United States)

    Zhou, Chenyi; Guo, Hong

    2017-01-01

    We report a diagrammatic method to solve the general problem of calculating configurationally averaged Green's function correlators that appear in quantum transport theory for nanostructures containing disorder. The theory treats both equilibrium and nonequilibrium quantum statistics on an equal footing. Since random impurity scattering is a problem that cannot be solved exactly in a perturbative approach, we combine our diagrammatic method with the coherent potential approximation (CPA) so that a reliable closed-form solution can be obtained. Our theory not only ensures the internal consistency of the diagrams derived at different levels of the correlators but also satisfies a set of Ward-like identities that corroborate the conserving consistency of transport calculations within the formalism. The theory is applied to calculate the quantum transport properties such as average ac conductance and transmission moments of a disordered tight-binding model, and results are numerically verified to high precision by comparing to the exact solutions obtained from enumerating all possible disorder configurations. Our formalism can be employed to predict transport properties of a wide variety of physical systems where disorder scattering is important.

  17. Time-Shift Correlation Algorithm for P300 Event Related Potential Brain-Computer Interface Implementation.

    Science.gov (United States)

    Liu, Ju-Chi; Chou, Hung-Chyun; Chen, Chien-Hsiu; Lin, Yi-Tseng; Kuo, Chung-Hsien

    2016-01-01

    A high efficient time-shift correlation algorithm was proposed to deal with the peak time uncertainty of P300 evoked potential for a P300-based brain-computer interface (BCI). The time-shift correlation series data were collected as the input nodes of an artificial neural network (ANN), and the classification of four LED visual stimuli was selected as the output node. Two operating modes, including fast-recognition mode (FM) and accuracy-recognition mode (AM), were realized. The proposed BCI system was implemented on an embedded system for commanding an adult-size humanoid robot to evaluate the performance from investigating the ground truth trajectories of the humanoid robot. When the humanoid robot walked in a spacious area, the FM was used to control the robot with a higher information transfer rate (ITR). When the robot walked in a crowded area, the AM was used for high accuracy of recognition to reduce the risk of collision. The experimental results showed that, in 100 trials, the accuracy rate of FM was 87.8% and the average ITR was 52.73 bits/min. In addition, the accuracy rate was improved to 92% for the AM, and the average ITR decreased to 31.27 bits/min. due to strict recognition constraints.

  18. Explicit correlation treatment of the potential energy surface of CO{sub 2} dimer

    Energy Technology Data Exchange (ETDEWEB)

    Kalugina, Yulia N., E-mail: kalugina@phys.tsu.ru [Tomsk State University, 36 Lenin Ave., Tomsk 634050 (Russian Federation); Buryak, Ilya A. [Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow (Russian Federation); Chemistry Department, Lomonosov Moscow State University, Moscow (Russian Federation); Ajili, Yosra [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 Bd Descartes, 77454 Marne-La-Vallée (France); Laboratoire de Spectroscopie Atomique, Moléculaire et Applications - LSAMA Université de Tunis El Manar (Tunisia); Vigasin, Andrei A. [Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow (Russian Federation); Jaidane, Nejm Eddine [Laboratoire de Spectroscopie Atomique, Moléculaire et Applications - LSAMA Université de Tunis El Manar (Tunisia); Hochlaf, Majdi [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 Bd Descartes, 77454 Marne-La-Vallée (France)

    2014-06-21

    We present an extensive study of the four-dimensional potential energy surface (4D-PES) of the carbon dioxide dimer, (CO{sub 2}){sub 2}. This PES is developed over the set of intermolecular coordinates. The electronic computations are carried out at the explicitly correlated coupled cluster method with single, double, and perturbative triple excitations [CCSD(T)-F12] level of theory in connection with the augmented correlation-consistent aug-cc-pVTZ basis set. An analytic representation of the 4D-PES is derived. Our extensive calculations confirm that “Slipped Parallel” is the most stable form and that the T-shaped structure corresponds to a transition state. Later on, this PES is employed for the calculations of the vibrational energy levels of the dimer. Moreover, the temperature dependence of the dimer second virial coefficient and of the first spectral moment of rototranslational collision-induced absorption spectrum is derived. For both quantities, a good agreement is found between our values and the experimental data for a wide range of temperatures. This attests to the high quality of our PES. Generally, our PES and results can be used for modeling CO{sub 2} supercritical fluidity and examination of its role in planetary atmospheres. It can be also incorporated into dynamical computations of CO{sub 2} capture and sequestration. This allows deep understanding, at the microscopic level, of these processes.

  19. Expanding Interaction Potentials within Virtual Environments: Investigating the Usability of Speech and Manual Input Modes for Decoupled Interaction

    Directory of Open Access Journals (Sweden)

    Alex Stedmon

    2011-01-01

    Full Text Available Distributed technologies and ubiquitous computing now support users who may be detached or decoupled from traditional interactions. In order to investigate the potential usability of speech and manual input devices, an evaluation of speech input across different user groups and a usability assessment of independent-user and collaborative-user interactions was conducted. Whilst the primary focus was on a formative usability evaluation, the user group evaluation provided a formal basis to underpin the academic rigor of the exercise. The results illustrate that using a speech interface is important in understanding user acceptance of such technologies. From the usability assessment it was possible to translate interactions and make them compatible with innovative input devices. This approach to interaction is still at an early stage of development, and the potential or validity of this interfacing concept is still under evaluation; however, as a concept demonstrator, the results of these initial evaluations demonstrate the potential usability issues of both input devices as well as highlighting their suitability for advanced virtual applications.

  20. Path (un)predictability of two interacting cracks in polycarbonate sheets using Digital Image Correlation

    Science.gov (United States)

    Koivisto, J.; Dalbe, M.-J.; Alava, M. J.; Santucci, S.

    2016-08-01

    Crack propagation is tracked here with Digital Image Correlation analysis in the test case of two cracks propagating in opposite directions in polycarbonate, a material with high ductility and a large Fracture Process Zone (FPZ). Depending on the initial distances between the two crack tips, one may observe different complex crack paths with in particular a regime where the two cracks repel each other prior to being attracted. We show by strain field analysis how this can be understood according to the principle of local symmetry: the propagation is to the direction where the local shear - mode KII in fracture mechanics language - is zero. Thus the interactions exhibited by the cracks arise from symmetry, from the initial geometry, and from the material properties which induce the FPZ. This complexity makes any long-range prediction of the path(s) impossible.

  1. Path (un)predictability of two interacting cracks in polycarbonate sheets using Digital Image Correlation.

    Science.gov (United States)

    Koivisto, J; Dalbe, M-J; Alava, M J; Santucci, S

    2016-01-01

    Crack propagation is tracked here with Digital Image Correlation analysis in the test case of two cracks propagating in opposite directions in polycarbonate, a material with high ductility and a large Fracture Process Zone (FPZ). Depending on the initial distances between the two crack tips, one may observe different complex crack paths with in particular a regime where the two cracks repel each other prior to being attracted. We show by strain field analysis how this can be understood according to the principle of local symmetry: the propagation is to the direction where the local shear - mode KII in fracture mechanics language - is zero. Thus the interactions exhibited by the cracks arise from symmetry, from the initial geometry, and from the material properties which induce the FPZ. This complexity makes any long-range prediction of the path(s) impossible.

  2. Communication: Excited states, dynamic correlation functions and spectral properties from full configuration interaction quantum Monte Carlo.

    Science.gov (United States)

    Booth, George H; Chan, Garnet Kin-Lic

    2012-11-21

    In this communication, we propose a method for obtaining isolated excited states within the full configuration interaction quantum Monte Carlo framework. This method allows for stable sampling with respect to collapse to lower energy states and requires no uncontrolled approximations. In contrast with most previous methods to extract excited state information from quantum Monte Carlo methods, this results from a modification to the underlying propagator, and does not require explicit orthogonalization, analytic continuation, transient estimators, or restriction of the Hilbert space via a trial wavefunction. Furthermore, we show that the propagator can directly yield frequency-domain correlation functions and spectral functions such as the density of states which are difficult to obtain within a traditional quantum Monte Carlo framework. We demonstrate this approach with pilot applications to the neon atom and beryllium dimer.

  3. "My Mom Makes Me So Angry!" Adolescent Perceptions of Mother-Child Interactions as Correlates of Adolescent Emotions

    Science.gov (United States)

    Padilla-Walker, Laura M.

    2008-01-01

    The purpose of the current study was to examine adolescents' perceptions of mother-child interactions as correlates of adolescents' positive, negative, and guilt emotions. Two hundred thirty-four adolescents (M age = 16.39, SD = 1.17) completed measures assessing parenting practices in response to typical mother-child interactions in both positive…

  4. Hybridization interactions between probesets in short oligo microarrays lead to spurious correlations

    Directory of Open Access Journals (Sweden)

    Miller Crispin J

    2006-06-01

    Full Text Available Abstract Background Microarrays measure the binding of nucleotide sequences to a set of sequence specific probes. This information is combined with annotation specifying the relationship between probes and targets and used to make inferences about transcript- and, ultimately, gene expression. In some situations, a probe is capable of hybridizing to more than one transcript, in others, multiple probes can target a single sequence. These 'multiply targeted' probes can result in non-independence between measured expression levels. Results An analysis of these relationships for Affymetrix arrays considered both the extent and influence of exact matches between probe and transcript sequences. For the popular HGU133A array, approximately half of the probesets were found to interact in this way. Both real and simulated expression datasets were used to examine how these effects influenced the expression signal. It was found not only to lead to increased signal strength for the affected probesets, but the major effect is to significantly increase their correlation, even in situations when only a single probe from a probeset was involved. By building a network of probe-probeset-transcript relationships, it is possible to identify families of interacting probesets. More than 10% of the families contain members annotated to different genes or even different Unigene clusters. Within a family, a mixture of genuine biological and artefactual correlations can occur. Conclusion Multiple targeting is not only prevalent, but also significant. The ability of probesets to hybridize to more than one gene product can lead to false positives when analysing gene expression. Comprehensive annotation describing multiple targeting is required when interpreting array data.

  5. Collisional interactions between self-interacting nonrelativistic boson stars: Effective potential analysis and numerical simulations

    Science.gov (United States)

    Cotner, Eric

    2016-09-01

    Scalar particles are a common prediction of many beyond the Standard Model theories. If they are light and cold enough, there is a possibility they may form Bose-Einstein condensates, which will then become gravitationally bound. These boson stars are solitonic solutions to the Einstein-Klein-Gordon equations but may be approximated in the nonrelativistic regime with a coupled Schrödinger-Poisson system. General properties of single soliton states are derived, including the possibility of quartic self-interactions. Binary collisions between two solitons are then studied, and the effects of different mass ratios, relative phases, self-couplings, and separation distances are characterized, leading to an easy conceptual understanding of how these parameters affect the collision outcome in terms of conservation of energy. Applications to dark matter are discussed.

  6. [Potential drug-drug interactions among elderly using antihypertensives from the Brazilian List of Essential Medicines].

    Science.gov (United States)

    Mibielli, Pablo; Rozenfeld, Suely; Matos, Guacira Corrêa de; Acurcio, Francisco de Assis

    2014-09-01

    The aim of this study was to estimate the prevalence of potential interactions between antihypertensives and other drugs. A household survey was conducted with individuals 60 years or older residing in Rio de Janeiro, Brazil. Potential moderately or very severe drug-drug interactions with antihypertensives, documented as suspected, probable or established, were identified. A total of 577 elderly were interviewed (mean age = 72 years), 45.2% of whom were using antihypertensives, of which 31.0% were subject to potential drug-drug interactions. Most of the interactions were moderately severe. Compared to the other elderly, those with potential drug-drug interactions showed more than fourfold odds of using five or more medicines and more than twofold odds of having been hospitalized in the previous year. Among the most frequent pairs of interactions, 75% cause a reduction in the hypotensive effect (65/87), which can result in low effectiveness of blood pressure control, prescribing of more drugs, and risk of other adverse events and interactions.

  7. Potential Drug-drug Interactions in Post-CCU of a Teaching Hospital.

    Science.gov (United States)

    Haji Aghajani, Mohammad; Sistanizad, Mohammad; Abbasinazari, Mohammad; Abiar Ghamsari, Mahdieh; Ayazkhoo, Ladan; Safi, Olia; Kazemi, Katayoon; Kouchek, Mehran

    2013-01-01

    Drug-drug interactions (DDIs) can lead to increased toxicity or reduction in therapeutic efficacy. This study was designed to assess the incidence of potential drug interactions (PDI) and rank their clinical value in post coronary care unit (Post-CCU) of a teaching hospital in Tehran, Iran. In this prospective study, three pharmacists with supervision of a clinical pharmacist actively gathered necessary information for detection of DDIs. Data were tabulated according to the combinations of drugs in treatment chart. Verification of potential drug interactions was carried out using the online Lexi-Interact™ 2011. A total of 203 patients (113 males and 90 females) were enrolled in the study. The mean age of patients was 61 ± 12.55 years (range = 26-93). A total of 90 drugs were prescribed to 203 patients and most prescribed drugs were atorvastatin, clopidogrel and metoprolol. Mean of drugs was 11.22 per patient. A total of 3166 potential drug interactions have been identified by Lexi- Interact™, 149 (4.71%) and 55 (1.73%) of which were categorized as D and X, respectively. The most serious interactions were clopidogrel+omeprazole and metoprolol+salbutamol. Drug interactions leading to serious adverse effects are to be cautiously watched for when multiple drugs are used simultaneously. In settings with multiple drug use attendance of a pharmacist or clinical pharmacist, taking the responsibility for monitoring drug interactions and notifying the physician about potential problems could decrease the harm in patient and increase the patient safety.

  8. Prevalence of potential drug-drug interactions in cancer patients treated with oral anticancer drugs

    NARCIS (Netherlands)

    R.W.F. van Leeuwen (Roelof); D.H.S. Brundel (D. H S); C. Neef (Cees); T. van Gelder (Teun); A.H.J. Mathijssen (Ron); D.M. Burger (David); F.G.A. Jansman (Frank)

    2013-01-01

    textabstractBackground: Potential drug-drug interactions (PDDIs) in patients with cancer are common, but have not previously been quantified for oral anticancer treatment. We assessed the prevalence and seriousness of potential PDDIs among ambulatory cancer patients on oral anticancer treatment.

  9. Prevalence of potential drug-drug interactions in cancer patients treated with oral anticancer drugs

    NARCIS (Netherlands)

    van Leeuwen, R. W. F.; Brundel, D. H. S.; Neef, C.; van Gelder, T.; Mathijssen, R. H. J.; Burger, D. M.; Jansman, F. G. A.

    2013-01-01

    Background: Potential drug-drug interactions (PDDIs) in patients with cancer are common, but have not previously been quantified for oral anticancer treatment. We assessed the prevalence and seriousness of potential PDDIs among ambulatory cancer patients on oral anticancer treatment. Methods: A

  10. Chemical Potential Dependence of the Dressed-Quark Propagator from an Effective Quark-Quark Interaction

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; PING Jia-Lun; SUN Wei-Min; CHANG Chao-Hsi; WANG Fan

    2002-01-01

    We exhibit a method for obtaining the low chemical potential dependence of the dressed quark propagatorfrom an effective quark-quark interaction model. Within this approach we explore the chemical potential dependenceof the dressed-quark propagator, which provides a means of determining the behavior of the chiral and deconfinementorder parameters. A comparison with the results of previous researches is given.

  11. Soliton-potential interaction in the Nonlinear Klein-Gordon Model

    CERN Document Server

    Saadatmand, Danial

    2011-01-01

    Interaction of solitons with external potentials in nonlinear Klein-Gordon field theory is investigated using an improved model. Presented model is constructed with a better approximation for adding the potential to the lagrangian through the metric of background space-time. The results of the model are compared with the another model and the differences are discussed.

  12. Fermi and Coulomb correlation effects upon the interacting quantum atoms energy partition

    CERN Document Server

    Ruiz, Isela; Holguín-Gallego, Fernando José; Francisco, Evelio; Pendás, Ángel Martín; Rocha-Rinza, Tomás

    2016-01-01

    The Interacting Quantum Atoms (IQA) electronic energy partition is an important method in the field of quantum chemical topology which has given important insights of different systems and processes in physical chemistry. There have been several attempts to include Electron Correlation (EC) in the IQA approach, for example, through DFT and Hartree-Fock/Coupled-Cluster (HF/CC) transition densities. This work addresses the separation of EC in Fermi and Coulomb correlation and its effect upon the IQA analysis by taking into account spin-dependent one- and two-electron matrices $D^{\\mathrm{HF/CC}}_{p\\sigma q \\sigma}$ and $d^{\\mathrm{HF/CC}}_{p\\sigma q\\sigma r\\tau s\\tau}$ wherein $\\sigma$ and $\\tau$ represent either of the $\\alpha$ and $\\beta$ spin projections. We illustrate this approach by considering BeH$_2$,BH, CN$^-$, HF, LiF, NO$^+$, LiH, H$_2$O$\\cdots$H$_2$O and C$_2$H$_2$, which comprise non-polar covalent, polar covalent, ionic and hydrogen bonded systems. The same and different spin contributions to ($i$...

  13. Quartet correlations in N = Z nuclei induced by realistic two-body interactions

    Energy Technology Data Exchange (ETDEWEB)

    Sambataro, M. [Istituto Nazionale di Fisica Nucleare - Sezione di Catania, Catania (Italy); Sandulescu, N. [National Institute of Physics and Nuclear Engineering, Bucharest-Magurele (Romania)

    2017-03-15

    Two variational quartet models previously employed in a treatment of pairing forces are extended to the case of a general two-body interaction. One model approximates the nuclear states as a condensate of identical quartets with angular momentum J = 0 and isospin T = 0 while the other let these quartets to be all different from each other. With these models we investigate the role of alpha-like quartet correlations both in the ground state and in the lowest J = 0, T = 0 excited states of even-even N = Z nuclei in the sd -shell. We show that the ground-state correlations of these nuclei can be described to a good extent in terms of a condensate of alpha-like quartets. This turns out to be especially the case for the nucleus {sup 32}S for which the overlap between this condensate and the shell model wave function is found close to one. In the same nucleus, a similar overlap is found also in the case of the first excited 0{sup +} state. No clear correspondence is observed instead between the second excited states of the quartet models and the shell model eigenstates in all the cases examined. (orig.)

  14. Correlating learning and memory improvements to long-term potentiation in patients with brain injury

    Institute of Scientific and Technical Information of China (English)

    Xingfu Peng; Qian Yu

    2008-01-01

    BACKGROUND:Brain injury patients often exhibit learning and memory functional deficits.Long-term potentiation(LTP)is a representative index for studying learning and memory cellular models; the LTP index correlates to neural plasticity. OBJECTIVE:This study was designed to investigate correlations of learning and memory functions to LTP in brain injury patients,and to summarize the research advancements in mechanisms underlying brain functional improvements after rehabilitation intervention. RETRIEVAL STRATEGY:Using the terms "brain injuries,rehabilitation,learning and memory,long-term potentiation",manuscripts that were published from 2000-2007 were retrieved from the PubMed database.At the same time,manuscripts published from 2000-2007 were also retrieved from the Database of Chinese Scientific and Technical Periodicals with the same terms in the Chinese language.A total of 64 manuscripts were obtained and primarily screened.Inclusion criteria:studies on learning and memory,as well as LTP in brain injury patients,and studies focused on the effects of rehabilitation intervention on the two indices; studies that were recently published or in high-impact journals.Exclusion criteria:repetitive studies.LITERATURE EVALUATION:The included manuscripts primarily focused on correlations between learning and memory and LTP,the effects of brain injury on learning and memory,as well as LTP,and the effects of rehabilitation intervention on learning and memory after brain injury.The included 39 manuscripts were clinical,basic experimental,or review studies. DATA SYNTHESIS:Learning and memory closely correlates to LTP.The neurobiological basis of learning and memory is central nervous system plasticity,which involves neural networks,neural circuits,and synaptic connections,in particular,synaptic plasticity.LTP is considered to be an ideal model for studying synaptic plasticity,and it is also a classic model for studying neural plasticity of learning and memory.Brain injury

  15. Neural correlates of suspiciousness and interactions with anxiety during emotional and neutral word processing.

    Science.gov (United States)

    Fisher, Joscelyn E; Miller, Gregory A; Sass, Sarah M; Silton, Rebecca Levin; Edgar, J Christopher; Stewart, Jennifer L; Zhou, Jing; Heller, Wendy

    2014-01-01

    Suspiciousness is usually classified as a symptom of psychosis, but it also occurs in depression and anxiety disorders. Though how suspiciousness overlaps with depression is not obvious, suspiciousness does seem to overlap with anxious apprehension and anxious arousal (e.g., verbal iterative processes and vigilance about environmental threat). However, suspiciousness also has unique characteristics (e.g., concern about harm from others and vigilance about social threat). Given that both anxiety and suspiciousness have been associated with abnormalities in emotion processing, it is unclear whether it is the unique characteristics of suspiciousness or the overlap with anxiety that drive abnormalities in emotion processing. Event-related brain potentials were obtained during an emotion-word Stroop task. Results indicated that suspiciousness interacts with anxious apprehension to modulate initial stimulus perception processes. Suspiciousness is associated with attention to all stimuli regardless of emotion content. In contrast, anxious arousal is associated with a later response to emotion stimuli only. These results suggest that suspiciousness and anxious apprehension share overlapping processes, but suspiciousness alone is associated with a hyperactive early vigilance response. Depression did not interact with suspiciousness to predict response to emotion stimuli. These findings suggest that it may be informative to assess suspiciousness in conjunction with anxiety in order to better understand how these symptoms interact and contribute to dysfunctional emotion processing.

  16. Neural Correlates of Suspiciousness and Interactions with Anxiety during Emotional and Neutral Word Processing

    Directory of Open Access Journals (Sweden)

    Joscelyn E Fisher

    2014-06-01

    Full Text Available Suspiciousness is usually classified as a symptom of psychosis, but it also occurs in depression and anxiety disorders. Though how suspiciousness overlaps with depression is not obvious, suspiciousness does seem to overlap with anxious apprehension and anxious arousal (e.g., verbal iterative processes and vigilance about environmental threat. However, suspiciousness also has unique characteristics (e.g., concern about harm from others and vigilance about social threat. Given that both anxiety and suspiciousness have been associated with abnormalities in emotion processing, it is unclear whether it is the unique characteristics of suspiciousness or the overlap with anxiety that drive abnormalities in emotion processing.. Event-related brain potentials were obtained during an emotion-word Stroop task. Results indicated that suspiciousness interacts with anxious apprehension to modulate initial stimulus perception processes. Suspiciousness is associated with attention to all stimuli regardless of emotion content. In contrast, anxious arousal is associated with a later response to emotion stimuli only. These results suggest that suspiciousness and anxious apprehension share overlapping processes, but suspiciousness alone is associated with a hyperactive early vigilance response. Depression did not interact with suspiciousness to predict response to emotion stimuli. These findings suggest that it may be informative to assess suspiciousness in conjunction with anxiety in order to better understand how these symptoms interact and contribute to dysfunctional emotion processing.

  17. Mental disorder recovery correlated with centralities and interactions on an online social network

    Directory of Open Access Journals (Sweden)

    Xinpei Ma

    2015-08-01

    Full Text Available Recent research has established both a theoretical basis and strong empirical evidence that effective social behavior plays a beneficial role in the maintenance of physical and psychological well-being of people. To test whether social behavior and well-being are also associated in online communities, we studied the correlations between the recovery of patients with mental disorders and their behaviors in online social media. As the source of the data related to the social behavior and progress of mental recovery, we used PatientsLikeMe (PLM, the world’s first open-participation research platform for the development of patient-centered health outcome measures. We first constructed an online social network structure based on patient-to-patient ties among 200 patients obtained from PLM. We then characterized patients’ online social activities by measuring the numbers of “posts and views” and “helpful marks” each patient obtained. The patients’ recovery data were obtained from their self-reported status information that was also available on PLM. We found that some node properties (in-degree, eigenvector centrality and PageRank and the two online social activity measures were significantly correlated with patients’ recovery. Furthermore, we re-collected the patients’ recovery data two months after the first data collection. We found significant correlations between the patients’ social behaviors and the second recovery data, which were collected two months apart. Our results indicated that social interactions in online communities such as PLM were significantly associated with the current and future recoveries of patients with mental disorders.

  18. Mental disorder recovery correlated with centralities and interactions on an online social network.

    Science.gov (United States)

    Ma, Xinpei; Sayama, Hiroki

    2015-01-01

    Recent research has established both a theoretical basis and strong empirical evidence that effective social behavior plays a beneficial role in the maintenance of physical and psychological well-being of people. To test whether social behavior and well-being are also associated in online communities, we studied the correlations between the recovery of patients with mental disorders and their behaviors in online social media. As the source of the data related to the social behavior and progress of mental recovery, we used PatientsLikeMe (PLM), the world's first open-participation research platform for the development of patient-centered health outcome measures. We first constructed an online social network structure based on patient-to-patient ties among 200 patients obtained from PLM. We then characterized patients' online social activities by measuring the numbers of "posts and views" and "helpful marks" each patient obtained. The patients' recovery data were obtained from their self-reported status information that was also available on PLM. We found that some node properties (in-degree, eigenvector centrality and PageRank) and the two online social activity measures were significantly correlated with patients' recovery. Furthermore, we re-collected the patients' recovery data two months after the first data collection. We found significant correlations between the patients' social behaviors and the second recovery data, which were collected two months apart. Our results indicated that social interactions in online communities such as PLM were significantly associated with the current and future recoveries of patients with mental disorders.

  19. Electron-phonon interaction dressed by electronic correlations near charge ordering. Possible implications for cobaltates

    Energy Technology Data Exchange (ETDEWEB)

    Foussats, A [Facultad de Ciencias Exactas, Ingenieria y Agrimensura and Instituto de Fisica Rosario (UNR-CONICET), Avenida Pellegrini 250-2000 Rosario (Argentina); Greco, A [Facultad de Ciencias Exactas, Ingenieria y Agrimensura and Instituto de Fisica Rosario (UNR-CONICET), Avenida Pellegrini 250-2000 Rosario (Argentina); Bejas, M [Facultad de Ciencias Exactas, Ingenieria y Agrimensura and Instituto de Fisica Rosario (UNR-CONICET), Avenida Pellegrini 250-2000 Rosario (Argentina); Muramatsu, A [Institut fuer Theoretische Physik III, Universitaet Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart (Germany)

    2006-12-20

    We consider possible routes to superconductivity on the basis of the t-J-V model plus phonons on the triangular lattice. We studied the stability conditions for the homogeneous Fermi liquid (HFL) phase against different broken symmetry phases. Besides the {radical}3 x{radical}3 CDW phase, triggered by the nearest-neighbour Coulomb interaction V, we have found that the HFL is unstable, at very low doping, against a bond-ordered phase due to J. We also discuss the occurrence of phase separation at low doping and V. The interplay between the electron-phonon interaction and correlations near the {radical}3 x{radical}3 CDW leads to superconductivity in the unconventional next-nearest-neighbour f-wave (NNN-f) channel with a dome shape for T{sub c} around x{approx}0.35, and with values of a few kelvin. Near the bond-ordered phase at low doping we found tendencies to superconductivity with d-wave symmetry for finite J and x<0.15. Possible implications for cobaltates are discussed.

  20. The Neural Correlates of the Body-Object Interaction Effect in Semantic Processing

    Directory of Open Access Journals (Sweden)

    Ian Scott Hargreaves

    2012-02-01

    Full Text Available The semantic richness dimension referred to as body-object interaction (BOI measures perceptions of the ease with which people can physically interact with words’ referents. Previous studies have shown facilitated lexical and semantic processing for words rated high in BOI (e.g., belt than for words rated low in BOI (e.g., sun (e.g., Siakaluk, Pexman, Sears, Wilson, Locheed, & Owen, 2008b. These BOI effects have been taken as evidence that embodied information is relevant to word recognition. However, to date there is no evidence linking BOI manipulations to differences in the utilization of perceptual or sensorimotor areas of the brain. The current study used event-related fMRI to examine the neural correlates of BOI in a semantic categorization task (SCT. Sixteen healthy adults participated. Results showed that high BOI words were associated with activation in the left inferior parietal lobule (supramarginal gyrus, BA 40, a sensory association area involved in kinesthetic memory. These results provide evidence that the BOI dimension captures sensorimotor information, and that this contributes to semantic processing.

  1. Interaction between otorhinolaryngology and orthodontics: correlation between the nasopharyngeal airway and the craniofacial complex

    Science.gov (United States)

    Stellzig-Eisenhauer, Angelika; Meyer-Marcotty, Philipp

    2011-01-01

    In terms of pathophysiology, an anatomically narrow airway is a predisposing factor for obstruction of the upper respiratory tract. The correlation between the nasopharyngeal airway and the craniofacial structures is discussed in this context. Thus a mutual interaction between the pharynx and the mandibular position was demonstrated, whereby the transverse dimension of the nasopharynx was significantly larger in patients with prognathism than in patients with retrognathism. The influence of chronic obstruction of the nasal airway on craniofacial development was also discussed. The form-and-function interaction, which ought to explain the causal relationship between nasal obstruction and craniofacial growth, appears to be of a multifactorial rather than a one-dimensional, linear nature. It is not disputed, however, that expanding the maxilla improves not only nasal volume and nasal flow, but also the subjective sensation of patients, although it is not possible to make a prognostic statement about the extent of this improvement because of the differing reactions of individuals. Orthodontic appliances for advancing the mandible can also be successfully used in the treatment of mild obstructive sleep apnea syndrome. This treatment method should be considered particularly for patients who are unwilling to undergo or cannot tolerate CPAP (continuous positive airway pressure) treatment. PMID:22073108

  2. Asymptotic behavior of correlation functions for electric potential and field fluctuations in a classical one-component plasma

    NARCIS (Netherlands)

    Suttorp, L.G.

    1992-01-01

    The correlations of the electric potential fluctuations in a classical one-component plasma are studied for large distances between the observation points. The two-point correlation function for these fluctuations is known to decay slowly for large distances, even if exponential clustering holds for

  3. Potential drug-drug interactions in intensive care units of a hospital in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique Oliveira-Paula

    2014-12-01

    Full Text Available Drug-drug interactions are important causes of adverse reactions in health units. The high consumption of medicines in intensive care units predisposes patients to potential drug-drug interactions. This study aimed at examining the frequency and the characteristics of drug-drug interactions in intensive care units of Hospital Universitario of Universidade Estadual de Londrina. We analyzed the prescriptions of patients over 18 years, admitted from January to May 2010, who remained hospitalized for at least four days. The analysis of drug-drug interactions was carried out using the Micromedex Drug-Reax® system. The interactions were classified by severity, time required for the onset of adverse effects, mechanism of action and quality of scientific evidence. Moreover, the possible adverse events were analyzed, as well as the recommended strategies of management and monitoring. Altogether, 198 different potential drug-drug interactions were identified with the occurrence of 1242 episodes. Of these, 43% were characterized by moderate interactions, 35% major, 16% minor and 6% contraindicated. The therapeutic inefficacy was the most frequent possible adverse event (18% and the main recommended strategy of management was the dose adjustment (35.6%. The most frequent interactions were: fentanyl + midazolam (8.6%, phenytoin + ranitidine (5.5% and midazolam + ranitidine (4.8%. These results demonstrate the importance of drug-drug interactions as a significant adverse event in intensive care units and thus, preventive measures are required to minimize this problem.

  4. Antiepileptic drugs: are women aware of interactions with oral contraceptives and potential teratogenicity?

    Science.gov (United States)

    Pack, Alison M; Davis, Anne R; Kritzer, Jordana; Yoon, Ava; Camus, Adela

    2009-04-01

    Women with epilepsy (WWE)'s knowledge of the interaction between antiepileptic drugs (AEDs) and oral contraceptives (OCs) and the potential teratogenicity of AEDs has received limited study. We conducted a cross-sectional questionnaire study (English or Spanish) among young WWE (18-44 years) to assess demographic characteristics, current AED use, and knowledge of AED interactions with OCs and teratogenicity. We used the Food and Drug Administration's classification system to categorize each AED's teratogenic potential. Participants (n=148) had a mean age of 32 years (SD 8); 32% spoke Spanish and described themselves as Hispanic. Among women prescribed a cytochrome p450-inducing AED, 65% were unaware of decreased OC efficacy. Forty percent of those prescribed Category D AEDs were unaware of potential teratogenic effects. WWE have limited knowledge of the potential interaction between AEDs and OCs and the teratogenic effects of AEDs. Educational efforts should highlight the reproductive health effects of AEDs in WWE.

  5. One-electron self-interaction and the asymptotics of the Kohn-Sham potential: an impaired relation

    CERN Document Server

    Schmidt, Tobias; Kronik, Leeor; Kümmel, Stephan

    2015-01-01

    One-electron self-interaction and an incorrect asymptotic behavior of the Kohn-Sham exchange-correlation potential are among the most prominent limitations of many present-day density functionals. However, a one-electron self-interaction-free energy does not necessarily lead to the correct long-range potential. This is here shown explicitly for local hybrid functionals. Furthermore, carefully studying the ratio of the von Weizs\\"acker kinetic energy density to the (positive) Kohn-Sham kinetic energy density, $\\tau_\\mathrm{W}/\\tau$, reveals that this ratio, which frequently serves as an iso-orbital indicator and is used to eliminate one-electron self-interaction effects in meta-generalized-gradient approximations and local hybrid functionals, can fail to approach its expected value in the vicinity of orbital nodal planes. This perspective article suggests that the nature and consequences of one-electron self-interaction and some of the strategies for its correction need to be reconsidered.

  6. The cortical spatiotemporal correlate of otolith stimulation: vestibular evoked potentials by body translations.

    Science.gov (United States)

    Ertl, M; Moser, M; Boegle, R; Conrad, J; Zu Eulenburg, P; Dieterich, M

    2017-02-22

    The vestibular organ senses linear and rotational acceleration of the head during active and passive motion. These signals are necessary for bipedal locomotion, navigation, the coordination of eye and head movements in 3D space. The temporal dynamics of vestibular processing in cortical structures have hardly been studied in humans, let alone with natural stimulation. The aim was to investigate the cortical vestibular network related to natural otolith stimulation using a hexapod motion platform. We conducted two experiments, 1. to estimate the sources of the vestibular evoked potentials (VestEPs) by means of distributed source localization (n=49), and 2. to reveal modulations of the VestEPs through the underlying acceleration intensity (n=24). For both experiments subjects were accelerated along the main axis (left/right, up/down, fore/aft) while the EEG was recorded. We were able to identify five VestEPs (P1, N1, P2, N2, P3) with latencies between 38 and 461 ms as well as an evoked beta-band response peaking with a latency of 68 ms in all subjects and for all acceleration directions. Source localization gave the cingulate sulcus visual (CSv) area and the opercular-insular region as the main origin of the evoked potentials. No lateralization effects due to handedness could be observed. In the second experiment, area CSv was shown to be integral in the processing of acceleration intensities as sensed by the otolith organs, hinting at its potential role in ego-motion detection. These robust VestEPs could be used to investigate the mechanisms of inter-regional interaction in the natural context of vestibular processing and multisensory integration.

  7. Potential drug-drug interactions in cardiothoracic intensive care unit of a pulmonary teaching hospital.

    Science.gov (United States)

    Farzanegan, Behrooz; Alehashem, Maryam; Bastani, Marjan; Baniasadi, Shadi

    2015-02-01

    Little is known about clinically significant drug-drug interactions (DDIs) in respiratory settings. DDIs are more likely to occur in critically ill patients due to complex pharmacotherapy regimens and organ dysfunctions. The aim of this study was to identify the pattern of potential DDIs (pDDIs) occurring in cardiothoracic intensive care unit (ICU) of a pulmonary hospital. A prospective observational study was conducted for 6 months. All pDDIs for admitted patients in cardiothoracic ICU were identified with Lexi-Interact program and assessed by a clinical pharmacologist. The interacting drugs, reliability, mechanisms, potential outcomes, and clinical management were evaluated for severe and contraindicated interactions. The study included 195 patients. Lung cancer (14.9%) was the most common diagnosis followed by tracheal stenosis (14.3%). The rate of pDDIs was 720.5/100 patients. Interactions were more commonly observed in transplant patients. 17.7% of pDDIs were considered as severe and contraindicated interactions. Metabolism (54.8%) and additive (24.2%) interactions were the most frequent mechanisms leading to pDDIs, and azole antifungals and fluoroquinolones were the main drug classes involved. The pattern of pDDIs in cardiothoracic ICU differs from other ICU settings. Specialized epidemiological knowledge of drug interactions may help clinical practitioners to reduce the risk of adverse drug events.

  8. Consistency of multi-time Dirac equations with general interaction potentials

    Science.gov (United States)

    Deckert, Dirk-André; Nickel, Lukas

    2016-07-01

    In 1932, Dirac proposed a formulation in terms of multi-time wave functions as candidate for relativistic many-particle quantum mechanics. A well-known consistency condition that is necessary for existence of solutions strongly restricts the possible interaction types between the particles. It was conjectured by Petrat and Tumulka that interactions described by multiplication operators are generally excluded by this condition, and they gave a proof of this claim for potentials without spin-coupling. Under suitable assumptions on the differentiability of possible solutions, we show that there are potentials which are admissible, give an explicit example, however, show that none of them fulfills the physically desirable Poincaré invariance. We conclude that in this sense, Dirac's multi-time formalism does not allow to model interaction by multiplication operators, and briefly point out several promising approaches to interacting models one can instead pursue.

  9. Neurophysiological correlates of response inhibition predict relapse in detoxified alcoholic patients: some preliminary evidence from event-related potentials

    Directory of Open Access Journals (Sweden)

    Petit G

    2014-06-01

    Full Text Available Géraldine Petit, Agnieszka Cimochowska, Charles Kornreich, Catherine Hanak, Paul Verbanck, Salvatore CampanellaLaboratory of Psychological Medicine and Addictology, ULB Neuroscience Institute (UNI, Université Libre de Bruxelles (ULB, Brussels, BelgiumBackground: Alcohol dependence is a chronic relapsing disease. The impairment of response inhibition and alcohol-cue reactivity are the main cognitive mechanisms that trigger relapse. Despite the interaction suggested between the two processes, they have long been investigated as two different lines of research. The present study aimed to investigate the interaction between response inhibition and alcohol-cue reactivity and their potential link with relapse.Materials and methods: Event-related potentials were recorded during a variant of a “go/no-go” task. Frequent and rare stimuli (to be inhibited were superimposed on neutral, nonalcohol-related, and alcohol-related contexts. The task was administered following a 3-week detoxification course. Relapse outcome was measured after 3 months, using self-reported abstinence. There were 27 controls (seven females and 27 patients (seven females, among whom 13 relapsed during the 3-month follow-up period. The no-go N2, no-go P3, and the “difference” wave (P3d were examined with the aim of linking neural correlates of response inhibition on alcohol-related contexts to the observed relapse rate.Results: Results showed that 1 at the behavioral level, alcohol-dependent patients made significantly more commission errors than controls (P<0.001, independently of context; 2 through the subtraction no-go P3 minus go P3, this inhibition deficit was neurophysiologically indexed in patients with greater P3d amplitudes (P=0.034; and 3 within the patient group, increased P3d amplitude enabled us to differentiate between future relapsers and nonrelapsers (P=0.026.Conclusion: Our findings suggest that recently detoxified alcoholics are characterized by poorer

  10. Thermodynamic stability of a weakly interacting Fermi gas trapped in a harmonic potential

    Institute of Scientific and Technical Information of China (English)

    Men Fu-Dian; Liu Hui; Zhu Hou-Yu

    2008-01-01

    Based on the theoretical results derived from pseudopotential method and local approximation,this paper studies the thermodynamic stability of a weakly interacting Fermi gas trapped in a harmonic potential by using analytical method of thermodynamics.The effects of the interparticle interactions as well as external potential on the thermodynamic stability of the system are discussed.It is shown that the system is stable as for the complete average,but as for local parts,the system is unstable anywhere.This instability shows that the stability conditions of mechanics cannot be satisfied anywhere,and the stability conditions of thermostatics cannot be satisfied somewhere.In addition,the interactions and external potential have direct effects on the local stability of the system.

  11. Collectivity in diffusion of colloidal particles: from effective interactions to spatially correlated noise

    Science.gov (United States)

    Majka, M.; Góra, P. F.

    2017-02-01

    The collectivity in the simultaneous diffusion of many particles, i.e. the interdependence of stochastic forces affecting different particles in the same solution, is a largely overlooked phenomenon with no well-established theory. Recently, we have proposed a novel type of thermodynamically consistent Langevin dynamics driven by spatially correlated noise (SCN) that can contribute to the understanding of this problem. This model draws a link between the theory of effective interactions in binary colloidal mixtures and the properties of SCN. In the current article, we review this model from the perspective of collective diffusion and generalize it to the case of multiple (N  >  2) particles. Since our theory of SCN-driven Langevin dynamics has certain issues that could not be resolved within this framework, in this article we also provide another approach to the problem of collectivity. We discuss the multi-particle Mori-Zwanzig model, which is fully microscopically consistent. Indeed, we show that this model supplies a lot of information, complementary to the SCN-based approach, e.g. it predicts the deterministic dynamics of the relative distance between the particles, it provides an approximation for non-equilibrium effective interactions and predicts the collective sub-diffusion of tracers in the group. These results provide the short-range, inertial limit of the earlier model and agree with its predictions under some general conditions. In this article we also review the origin of SCN and its consequences for a variety of physical systems, with emphasis on the colloids.

  12. LILRB2 interaction with HLA class I correlates with control of HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Arman A Bashirova

    2014-03-01

    Full Text Available Natural progression of HIV-1 infection depends on genetic variation in the human major histocompatibility complex (MHC class I locus, and the CD8+ T cell response is thought to be a primary mechanism of this effect. However, polymorphism within the MHC may also alter innate immune activity against human immunodeficiency virus type 1 (HIV-1 by changing interactions of human leukocyte antigen (HLA class I molecules with leukocyte immunoglobulin-like receptors (LILR, a group of immunoregulatory receptors mainly expressed on myelomonocytic cells including dendritic cells (DCs. We used previously characterized HLA allotype-specific binding capacities of LILRB1 and LILRB2 as well as data from a large cohort of HIV-1-infected individuals (N = 5126 to test whether LILR-HLA class I interactions influence viral load in HIV-1 infection. Our analyses in persons of European descent, the largest ethnic group examined, show that the effect of HLA-B alleles on HIV-1 control correlates with the binding strength between corresponding HLA-B allotypes and LILRB2 (p = 10(-2. Moreover, overall binding strength of LILRB2 to classical HLA class I allotypes, defined by the HLA-A/B/C genotypes in each patient, positively associates with viral replication in the absence of therapy in patients of both European (p = 10(-11-10(-9 and African (p = 10(-5-10(-3 descent. This effect appears to be driven by variations in LILRB2 binding affinities to HLA-B and is independent of individual class I allelic effects that are not related to the LILRB2 function. Correspondingly, in vitro experiments suggest that strong LILRB2-HLA binding negatively affects antigen-presenting properties of DCs. Thus, we propose an impact of LILRB2 on HIV-1 disease outcomes through altered regulation of DCs by LILRB2-HLA engagement.

  13. Prevalence and factors associated with potential drug interactions among elderly in a population-based study

    Directory of Open Access Journals (Sweden)

    Daniel Riani Gotardelo

    2014-04-01

    Full Text Available Objectives: The aim of this study was to determine the prevalence of potential drug interactions and the factors associated with them among elderly patients covered by the Family Health Strategy in the municipality of Timóteo, state of Minas Gerais, Brazil. Methods: Cross-sectional study, using stratified random sampling. A total of 273 household interviews were conducted in subjects aged 60 years or older, after obtaining informed consent, using a questionnaire containing questions related to identification, demography, health conditions and medication use. Drug interactions were identified and classified according to the software Micromedex®. Results: The overall prevalence of potential drug interactions was 55.6%, a total of 466 cases, of which 5.6% were mild, 81.6% moderate and 12.8% of greater severity. Therapeutic classes most frequently involved were anti-inflammatory drugs and especially drugs used in cardiovascular disease. The absence of hospitalization in the last four months was significantly associated with a lower chance of serious drug interactions and most patients who did not have any moderate drug interactions used only drugs prescribed by physicians. Conclusions: The prevalence of potential drug interactions was similar to that described in the literature, demonstrating the high frequency of this phenomenon among the elderly. The absence of prior hospitalization and drug prescription by physicians were associated with a lower frequency of interactions. The prescription of multiple drugs simultaneously to elderly patients can compromise the safety and health of this population, requiring, by caregivers, observation for the occurrence of potential drug interactions.

  14. Severe potential drug-drug interactions in older adults with dementia and associated factors

    OpenAIRE

    Michele Bogetti-Salazar; Cesar González-González; Teresa Juárez-Cedillo; Sergio Sánchez-García; Oscar Rosas-Carrasco

    2016-01-01

    OBJECTIVE: To identify the main severe potential drug-drug interactions in older adults with dementia and to examine the factors associated with these interactions. METHOD: This was a cross-sectional study. The enrolled patients were selected from six geriatrics clinics of tertiary care hospitals across Mexico City. The patients had received a clinical diagnosis of dementia based on the current standards and were further divided into the following two groups: those with severe drug-drug inte...

  15. Evoked related potentials correlates of empathy for pain from adolescence through adulthood

    Directory of Open Access Journals (Sweden)

    Nathalie eMella

    2012-11-01

    Full Text Available Affective and cognitive empathy are traditionally differentiated, the affective component being concerned with resonating with another’s emotional state, whereas the cognitive component reflects regulation of the resulting distress and understanding of another’s mental states (see Decety and Jackson, 2004 for a review. Adolescence is a critical period for the development of cognitive control processes necessary to regulate affective processes: it is only in young adulthood that these control processes achieve maturity (Steinberg, 2005. Thus, one should expect adolescents to show greater automatic empathy than young adults. The present study aimed at exploring the neural correlates of affective (automatic and cognitive empathy for pain from adolescence to young adulthood. With this aim, Event Related Potentials (ERPs were recorded in 32 participants (aged 11 to 39 in a task designed to dissociate these components. ERPs results showed an early automatic frontocentral response to pain (that was not modulated by task demand and a late parietal response to painful stimuli modulated by attention to pain cues. Adolescents exhibited earlier automatic responses to painful situations than young adults did and showed greater activity in the late cognitive component even when viewing neutral stimuli. Results are discussed in the context of the development of regulatory abilities during adolescence.

  16. Characterization of PF4-Heparin Complexes by Photon Correlation Spectroscopy and Zeta Potential.

    Science.gov (United States)

    Bertini, Sabrina; Fareed, Jawed; Madaschi, Laura; Risi, Giulia; Torri, Giangiacomo; Naggi, Annamaria

    2017-01-01

    Heparin-induced thrombocytopenia (HIT) is associated with antibodies to complexes between heparin and platelet factor 4 (PF4), a basic protein usually found in platelet alpha granules. Heparin-induced thrombocytopenia antibodies preferentially recognize macromolecular complexes formed between positively charged PF4 and polyanionic heparins over a narrow range of molar ratios. The aim of this work was to study the complexes that human PF4 forms with heparins from various species, such as porcine, bovine, and ovine; heparins from various organs, such as mucosa and lung; and different low-molecular-weight heparins (LMWHs) at several stoichiometric ratios to evaluate their sizes and charges by photo correlation spectroscopy and zeta potential measurements. The resulting data of the PF4 complexes with unfractionated heparins (UFHs), LMWHs and their fractions, and oligosaccharide components suggest that the size of aggregates is not only a simple function of average molecular weight but also of the molecular weight distribution of the sample. Moreover, it was found that lower concentrations of the tested ovine-derived mucosal heparin are required to form the large PF4/heparin complexes as compared to mucosal porcine and bovine heparin.

  17. Correlation of IL-8 with induction, progression and metastatic potential of colorectal cancer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate the expression profile of IL-8 in inflammatory and malignant colorectal diseases to evaluate its potential role in the regulation of colorectal cancer (CRC) and the development of colorectal liver metastases (CRLM).METHODS: IL-8 expression was assessed by quantitative real-time PCR (Q-RT-PCR) and the enzyme-linked immunosorbent assay (ELISA) in resected specimens from patients with ulcerative colitis (UC, n = 6)colorectal adenomas (CRA, n = 8), different stages of colorectal cancer (n = 48) as well as synchronous and metachronous CRLM along with their corresponding primary colorectal tumors (n = 16).RESULTS: IL-8 mRNA and protein expression was significantly up-regulated in all pathological colorectal entities investigated compared with the corresponding neighboring tissues. However, in the CRC specimens IL-8 revealed a significantly more pronounced overexpression in relation to the CRA and UC tissues with an average 30-fold IL-8 protein up-regulation in the CRC specimens in comparison to the CRA tissues. Moreover, IL-8 expression revealed a close correlation with tumor grading. Most interestingly, IL-8 up-regulation was most enhanced in synchronous and metachronous CRLM, if compared with the corresponding primary CRC tissues.Herein, an up to 80-fold IL-8 overexpression in individual metachronous metastases compared to normal tumor neighbor tissues was found.CONCLUSION: Our results strongly suggest an association between IL-8 expression, induction and progression of colorectal carcinoma and the development of colorectal liver metastases.

  18. Intermolecular interaction potentials of methane-argon complex calculated using LDA approaches

    Institute of Scientific and Technical Information of China (English)

    Bai Yu-Lin; Chen Xiang-Rong; Zhou Xiao-Lin; Yang Xiang-Dong; Wang Hai-Yan

    2004-01-01

    The intermolecular interaction potential for methane-argon complex is calculated by local density approximation (LDA) approaches. The calculated potential has a minimum when the intermolecular distance of methane-argon complex is 6.75 a.u.; the corresponding depth of the potential is 0.0163eV which has good agreement with experimental data. We also have made a nonlinear fitting of our results for the Lennard-Jones (12-6) potential function and obtain that V(R) = 143794365.332/R12 - 3032.093/R6 (R in a.u. and V(R) in eV).

  19. Equation of state and interaction potential of helium under high temperatures and high densities

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the thermodynamics statistic method, the improved variational perturbation theory and the modified quantum mechanics correction model have been used to calculate the equation of state of liquid helium at pressure from 0.7 to 108 GPa. The calculation results are in good agreement with the experimental data. The EXP-6 potential (α = 13.1) can more accurately describe the interaction of helium atoms than other potentials in the scheme. Finally, a comparison is shown between our interatomic potentials and other potentials.

  20. Equation of state and interaction potential of helium under high temperatures and high densities

    Institute of Scientific and Technical Information of China (English)

    YANG JinWen; YAN YuanHong

    2009-01-01

    Based on the thermodynamics statistic method, the improved variational perturbation theory and the modified quantum mechanics correction model have been used to calculate the equation of state of liquid helium at pressure from 0.7 to 108 GPa. The calculation results are in good agreement with the experimental data. The EXP-6 potential (α=13.1) can more accurately describe the interaction of helium atoms than other potentials in the scheme. Finally, s comparison is shown between our interatomic potentials and other potentials.

  1. The dynamical behaviour of homogeneous scalar-field spacetimes with general self-interaction potentials

    CERN Document Server

    Giambó, Roberto; Magli, Giulio

    2008-01-01

    The dynamics of homogeneous Robertson--Walker cosmological models with a self-interacting scalar field source is examined here in full generality, requiring only the scalar field potential to be bounded from below and divergent when the field diverges. In this way we are able to give a unified treatment of all the already studied cases - such as positive potentials which exhibit asymptotically polynomial or exponential behaviors - together with its extension to a much wider set of physically sensible potentials. Since the set includes potentials with negative inferior bound, we are able to give, in particular, the analysis of the asymptotically anti De Sitter states for such cosmologies.

  2. Approximations to complete basis set-extrapolated, highly correlated non-covalent interaction energies

    Science.gov (United States)

    Mackie, Iain D.; DiLabio, Gino A.

    2011-10-01

    The first-principles calculation of non-covalent (particularly dispersion) interactions between molecules is a considerable challenge. In this work we studied the binding energies for ten small non-covalently bonded dimers with several combinations of correlation methods (MP2, coupled-cluster single double, coupled-cluster single double (triple) (CCSD(T))), correlation-consistent basis sets (aug-cc-pVXZ, X = D, T, Q), two-point complete basis set energy extrapolations, and counterpoise corrections. For this work, complete basis set results were estimated from averaged counterpoise and non-counterpoise-corrected CCSD(T) binding energies obtained from extrapolations with aug-cc-pVQZ and aug-cc-pVTZ basis sets. It is demonstrated that, in almost all cases, binding energies converge more rapidly to the basis set limit by averaging the counterpoise and non-counterpoise corrected values than by using either counterpoise or non-counterpoise methods alone. Examination of the effect of basis set size and electron correlation shows that the triples contribution to the CCSD(T) binding energies is fairly constant with the basis set size, with a slight underestimation with CCSD(T)/aug-cc-pVDZ compared to the value at the (estimated) complete basis set limit, and that contributions to the binding energies obtained by MP2 generally overestimate the analogous CCSD(T) contributions. Taking these factors together, we conclude that the binding energies for non-covalently bonded systems can be accurately determined using a composite method that combines CCSD(T)/aug-cc-pVDZ with energy corrections obtained using basis set extrapolated MP2 (utilizing aug-cc-pVQZ and aug-cc-pVTZ basis sets), if all of the components are obtained by averaging the counterpoise and non-counterpoise energies. With such an approach, binding energies for the set of ten dimers are predicted with a mean absolute deviation of 0.02 kcal/mol, a maximum absolute deviation of 0.05 kcal/mol, and a mean percent

  3. [Potential antimicrobial drug interactions in clinical practice: consequences of polypharmacy and multidrug resistance].

    Science.gov (United States)

    Martínez-Múgica, Cristina

    2015-12-01

    Polypharmacy is a growing problem nowadays, which can increase the risk of potential drug interactions, and result in a loss of effectiveness. This is particularly relevant to the anti-infective therapy, especially when infection is produced by resistant bacteria, because therapeutic options are limited and interactions can cause treatment failure. All antimicrobial prescriptions were retrospectively reviewed during a week in the Pharmacy Department, in order to detect potential drug-interactions and analysing their clinical significance. A total of 314 antimicrobial prescriptions from 151 patients were checked. There was at least one potential interaction detected in 40% of patients, being more frequent and severe in those infected with multidrug-resistant microorganisms. Drugs most commonly involved were quinolones, azoles, linezolid and vancomycin. Potential drug interactions with antimicrobial agents are a frequent problem that can result in a loss of effectiveness. This is why they should be detected and avoided when possible, in order to optimize antimicrobial therapy, especially in case of multidrug resistant infections.

  4. Variations in mitochondrial membrane potential correlate with malic acid production by natural isolates of Saccharomyces cerevisiae sake strains.

    Science.gov (United States)

    Oba, Takahiro; Kusumoto, Kenichi; Kichise, Yuki; Izumoto, Eiji; Nakayama, Shunichi; Tashiro, Kosuke; Kuhara, Satoru; Kitagaki, Hiroshi

    2014-08-01

    Research on the relationship between mitochondrial membrane potential and fermentation profile is being intensely pursued because of the potential for developing advanced fermentation technologies. In the present study, we isolated naturally occurring strains of yeast from sake mash that produce high levels of malic acid and demonstrate that variations in mitochondrial membrane potential correlate with malic acid production. To define the underlying biochemical mechanism, we determined the activities of enzymes required for malic acid synthesis and found that pyruvate carboxylase and malate dehydrogenase activities in strains that produce high levels of malic acid were elevated compared with the standard sake strain K901. These results inspired us to hypothesize that decreased mitochondrial membrane potential was responsible for increased malic acid synthesis, and we present data supporting this hypothesis. Thus, the mitochondrial membrane potential of high malic acid producers was lower compared with standard strains. We conclude that mitochondrial membrane potential correlates with malic acid production.

  5. Intermolecular interaction of thiosemicarbazone derivatives to solvents and a potential Aedes aegypti target

    Science.gov (United States)

    da Silva, João Bosco P.; Hallwass, Fernando; da Silva, Aluizio G.; Moreira, Diogo Rodrigo; Ramos, Mozart N.; Espíndola, José Wanderlan P.; de Oliveira, Ana Daura T.; Brondani, Dalci José; Leite, Ana Cristina L.; Merz, Kenneth M.

    2015-08-01

    DFT calculations were used to access information about structure, energy and electronic properties of series of phenyl- and phenoxymethyl-(thio)semicarbazone derivatives with demonstrated activity against the larvae of Aedes aegypti in stage L4. The way as the thiosemicarbazone derivatives can interact with solvents like DMSO and water were analyzed from the comparison between calculated and experimental 1H NMR chemical shifts. The evidences of thiosemicarbazone derivatives making H-bond interaction to solvent have provide us insights on how they can interact with a potential A. aegypti's biological target, the Sterol Carrier Protein-2.

  6. Investigating the Neural Correlates of Emotion–Cognition Interaction Using an Affective Stroop Task

    Directory of Open Access Journals (Sweden)

    Nora M. Raschle

    2017-09-01

    Full Text Available The human brain has the capacity to integrate various sources of information and continuously adapts our behavior according to situational needs in order to allow a healthy functioning. Emotion–cognition interactions are a key example for such integrative processing. However, the neuronal correlates investigating the effects of emotion on cognition remain to be explored and replication studies are needed. Previous neuroimaging studies have indicated an involvement of emotion and cognition related brain structures including parietal and prefrontal cortices and limbic brain regions. Here, we employed whole brain event-related functional magnetic resonance imaging (fMRI during an affective number Stroop task and aimed at replicating previous findings using an adaptation of an existing task design in 30 healthy young adults. The Stroop task is an indicator of cognitive control and enables the quantification of interference in relation to variations in cognitive load. By the use of emotional primes (negative/neutral prior to Stroop task performance, an emotional variation is added as well. Behavioral in-scanner data showed that negative primes delayed and disrupted cognitive processing. Trials with high cognitive demand furthermore negatively influenced cognitive control mechanisms. Neuronally, the emotional primes consistently activated emotion-related brain regions (e.g., amygdala, insula, and prefrontal brain regions while Stroop task performance lead to activations in cognition networks of the brain (prefrontal cortices, superior temporal lobe, and insula. When assessing the effect of emotion on cognition, increased cognitive demand led to decreases in neural activation in response to emotional stimuli (negative > neutral within prefrontal cortex, amygdala, and insular cortex. Overall, these results suggest that emotional primes significantly impact cognitive performance and increasing cognitive demand leads to reduced neuronal activation in

  7. Cosmological model with fermion and tachyon fields interacting via Yukawa-type potential

    Science.gov (United States)

    Ribas, Marlos O.; Devecchi, Fernando P.; Kremer, Gilberto M.

    2016-02-01

    A model for the universe with tachyonic and fermionic fields interacting through a Yukawa-type potential is investigated. It is shown that the tachyonic field answers for the initial accelerated regime and for the subsequent decelerated regime so that it behaves as an inflaton at early times and as a matter field at intermediate times, while the fermionic field has the role of a dark energy constituent, since it leads to an accelerated regime at later times. The interaction between the fields via a Yukawa-type potential controls the duration of the decelerated era, since a stronger coupling makes a shorter decelerated period.

  8. A Riccati equation based approach to isotropic scalar field cosmologies with arbitrary self-interaction potentials

    CERN Document Server

    Harko, Tiberiu; Mak, M K

    2014-01-01

    Gravitationally coupled scalar fields $\\phi $, distinguished by the choice of an effective self-interaction potential $V(\\phi )$, simulating a temporarily non-vanishing cosmological term, can generate both inflation and late time acceleration. In scalar field cosmological models the evolution of the Hubble function is determined, in terms of the interaction potential, by a Riccati type equation. In the present work we investigate scalar field cosmological models that can be obtained as solutions of the Riccati evolution equation for the Hubble function. Four exact integrability cases of the field equations are presented, representing classes of general solutions of the Riccati evolution equation, and their cosmological properties are investigated in detail.

  9. Cosmological model with fermion and tachyon fields interacting via Yukawa-type potential

    CERN Document Server

    Ribas, Marlos O; Kremer, Gilberto M

    2016-01-01

    A model for the universe with tachyonic and fermionic fields interacting through a Yukawa-type potential is investigated. It is shown that the tachyonic field answers for the initial accelerated regime and for the subsequent decelerated regime so that it behaves as an inflaton at early times and as a matter field at intermediate times, while the fermionic field has the role of a dark energy constituent, since it leads to an accelerated regime at later times. The interaction between the fields via a Yukawa-type potential controls the duration of the decelerated era, since a stronger coupling makes a shorter decelerated period.

  10. Stress response, gut microbial diversity and sexual signals correlate with social interactions.

    Science.gov (United States)

    Levin, Iris I; Zonana, David M; Fosdick, Bailey K; Song, Se Jin; Knight, Rob; Safran, Rebecca J

    2016-06-01

    Theory predicts that social interactions are dynamically linked to phenotype. Yet because social interactions are difficult to quantify, little is known about the precise details on how interactivity is linked to phenotype. Here, we deployed proximity loggers on North American barn swallows (Hirundo rustica erythrogaster) to examine intercorrelations among social interactions, morphology and features of the phenotype that are sensitive to the social context: stress-induced corticosterone (CORT) and gut microbial diversity. We analysed relationships at two spatial scales of interaction: (i) body contact and (ii) social interactions occurring between 0.1 and 5 m. Network analysis revealed that relationships between social interactions, morphology, CORT and gut microbial diversity varied depending on the sexes of the individuals interacting and the spatial scale of interaction proximity. We found evidence that body contact interactions were related to diversity of socially transmitted microbes and that looser social interactions were related to signalling traits and CORT.

  11. Uptake of munitions materiels (TNT, RDX) by crop plants and potential interactions of nitrogen nutrition

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, R.J.; Harvey, S.D.; Cataldo, D.A. [Pacific Northwest Lab., Richland, WA (United States); Mitchell, W. [USABRDL, Ft. Detrick, MD (United States)

    1995-12-31

    Munitions materiel such as trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and their combustion/decomposition products can accumulate/cycle in terrestrial environs. High soil organic matter and fertility have been previously shown to negatively correlate with both TNT or RDX uptake in plants such as grass, wheat, and bean. The present study was therefore conducted using low fertility soil to assess uptake and distribution patterns of C-radiolabelled TNT and RDX (15 and 30 {micro}g/g) within corn (Zea mays), spinach (Spinacea oleraceae), carrot (Daucus carota), and alfalfa (Medicago sativa) grown to maturity in growth chambers. Uptake by the plants at maturity (90- to 120-days) ranged from 1.8 to 2.7% of total amended {sup 14}C-TNT for carrots and corn respectively and 17 to 33% of total amended {sup 14}C-RDX for corn and carrots respectively. Distribution patterns of total radiolabel indicate that the TNT-derived label was primarily retained within the roots (60 to 85%) while the RDX-derived label was distributed to the shoots (85 to 97%). Less than 0.01 {micro}g/g dry wt. TNT was found in all analyzed shoot tissues with > 90% of the TNT-derived radiolabel in the form of polar metabolites. Concentrations of RDX in shoot tissues of corn exceeded 180 {micro}g/g dry wt. Alfalfa grown in unfertilized, fertilized (NO{sub 3}), or unfertilized-inoculated (Rhizobia) soil exhibited a 70 to 100% increase in dry wt. after 45 days in the TNT-amended (15 {micro}g/g) fertilized and unfertilized-inoculated plants versus the controls. A potential TNT/nitrogen interaction will be discussed.

  12. Interaction of antimicrobial preservatives with blow-fill-seal packs: correlating sorption with solubility parameters.

    Science.gov (United States)

    Amin, Aeshna; Dare, Manish; Sangamwar, Abhay; Bansal, Arvind Kumar

    2012-01-01

    The aim of this work was to study the interaction of four commonly used ophthalmic antimicrobial preservatives [benzyl alcohol (BA), chlorbutol (CBL), benzalkonium chloride (BKC), and chlorhexidine gluconate (CG)] with Blow-Fill-Seal (BFS) packs. Effect of packaging material [low-density polyethylene (LDPE), polypropylene (PP)], humidity (25% RH, 75% RH) and concentration (0.5, 1.0, 2.0 mM BA/CBL in LDPE) was studied. BKC and CG gave negligible loss (preservative. Loss of BA switched from Case II to anomalous behavior with increasing initial concentration. A two-stage sorption behavior was inherent at all concentrations. Loss of CBL followed anomalous behavior with biphasic kinetics of loss. It was concluded that all the four preservatives were appropriate for use in PP BFS packs. However, only BKC and CG were amenable to be used in LDPE BFS packs. Lastly, an empirical expression consisting of the "solubility parameter distance" and "molar volume" of preservatives was developed to correlate the preservative loss in LDPE with the physicochemical properties of the preservatives.

  13. Mean field propagation of infinite dimensional Wigner measures with a singular two-body interaction potential

    CERN Document Server

    Ammari, Zied

    2011-01-01

    We consider the quantum dynamics of many bosons systems in the mean field limit with a singular pair-interaction potential, including the attractive or repulsive Coulombic case in three dimensions. By using a measure transportation technique, we show that Wigner measures propagate along the nonlinear Hartree flow. Such property was previously proved only for bounded potentials in our previous works with a slightly different strategy.

  14. Evolution of a quantum system of many particles interacting via the generalized Yukawa potential

    Science.gov (United States)

    Bogoliubov, N. N.; Rasulova, M. Yu.; Avazov, U. A.

    2016-12-01

    We study the evolution of a system of N particles that have identical masses and charges and interact via the generalized Yukawa potential. The system is placed in a bounded region. The evolution of such a system is described by the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) chain of quantum kinetic equations. Using semigroup theory, we prove the existence of a unique solution of the BBGKY chain of quantum kinetic equations with the generalized Yukawa potential.

  15. A review of potential harmful interactions between anticoagulant/antiplatelet agents and Chinese herbal medicines.

    Directory of Open Access Journals (Sweden)

    Hsin-Hui Tsai

    Full Text Available BACKGROUND: The risks attributed to drug-herb interactions, even when known, are often ignored or underestimated, especially for those involving anti-clotting drugs and Chinese medicines. The aim of this study was to structurally search and evaluate the existing evidence-based data associated with potential drug interactions between anticoagulant/antiplatelet drugs and Chinese herbal medicines (CHMs and evaluate the documented mechanisms, consequences, and/or severity of interactions. METHODOLOGY AND FINDINGS: Information related to anticoagulant/antiplatelet drug-CHM interactions was retrieved from eight interaction-based textbooks, four web resources and available primary biomedical literature. The primary literature searches were conducted in English and/or Chinese from January 2000 through December 2011 using the secondary databases (e.g., PubMed, Airiti Library, China Journal full-text database. The search terms included the corresponding medical subject headings and key words. Herbs or natural products not used as a single entity CHM or in Chinese Medicinal Prescriptions were excluded from further review. The corresponding mechanisms and severity ratings of interactions were retrieved using MicroMedex®, Lexicomp® and Natural Medicines Comprehensive Database®. Finally, we found 90 single entity CHMs contributed to 306 documented drug-CHM interactions. A total of 194 (63.4% interactions were verified for its evidence describing possible mechanisms and severity. Of them, 155 interactions (79.9% were attributable to pharmacodynamic interactions, and almost all were rated as moderate to severe interactions. The major consequences of these interactions were increased bleeding risks due to the additive anticoagulant or antiplatelet effects of the CHMs, specifically danshen, dong quai, ginger, ginkgo, licorice, and turmeric. CONCLUSIONS/SIGNIFICANCE: Conventional anticoagulants and antiplatelet drugs were documented to have harmful interactions

  16. Protein-protein interactions: principles, techniques, and their potential role in new drug development.

    Science.gov (United States)

    Khan, Shagufta H; Ahmad, Faizan; Ahmad, Nihal; Flynn, Daniel C; Kumar, Raj

    2011-06-01

    A vast network of genes is inter-linked through protein-protein interactions and is critical component of almost every biological process under physiological conditions. Any disruption of the biologically essential network leads to pathological conditions resulting into related diseases. Therefore, proper understanding of biological functions warrants a comprehensive knowledge of protein-protein interactions and the molecular mechanisms that govern such processes. The importance of protein-protein interaction process is highlighted by the fact that a number of powerful techniques/methods have been developed to understand how such interactions take place under various physiological and pathological conditions. Many of the key protein-protein interactions are known to participate in disease-associated signaling pathways, and represent novel targets for therapeutic intervention. Thus, controlling protein-protein interactions offers a rich dividend for the discovery of new drug targets. Availability of various tools to study and the knowledge of human genome have put us in a unique position to understand highly complex biological network, and the mechanisms involved therein. In this review article, we have summarized protein-protein interaction networks, techniques/methods of their binding/kinetic parameters, and the role of these interactions in the development of potential tools for drug designing.

  17. Long interspersed nuclear element-1 hypomethylation and oxidative stress: correlation and bladder cancer diagnostic potential.

    Directory of Open Access Journals (Sweden)

    Maturada Patchsung

    Full Text Available Although, increased oxidative stress and hypomethylation of long interspersed nuclear element-1 (LINE-1 associate with bladder cancer (BCa development, the relationship between these alterations is unknown. We evaluated the oxidative stress and hypomethylation of the LINE-1 in 61 BCa patients and 45 normal individuals. To measure the methylation levels and to differentiate the LINE-1 loci into hypermethylated, partially methylated and hypomethylated, peripheral blood cells, urinary exfoliated cells and cancerous tissues were evaluated by combined bisulfite restriction analysis PCR. The urinary total antioxidant status (TAS and plasma protein carbonyl content were determined. The LINE-1 methylation levels and patterns, especially hypomethylated loci, in the blood and urine cells of the BCa patients were different from the levels and patterns in the healthy controls. The urinary TAS was decreased, whereas the plasma protein carbonyl content was increased in the BCa patients relative to the controls. A positive correlation between the methylation of LINE-1 in the blood-derived DNA and urinary TAS was found in both the BCa and control groups. The urinary hypomethylated LINE-1 loci and the plasma protein carbonyl content provided the best diagnostic potential for BCa prediction. Based on post-diagnostic samples, the combination test improved the diagnostic power to a sensitivity of 96% and a specificity of 96%. In conclusion, decreased LINE-1 methylation is associated with increased oxidative stress both in healthy and BCa subjects across the various tissue types, implying a dose-response association. Increases in the LINE-1 hypomethylation levels and the number of hypomethylated loci in both the blood- and urine-derived cells and increase in the oxidative stress were found in the BCa patients. The combination test of the urinary hypomethylated LINE-1 loci and the plasma protein carbonyl content may be useful for BCa screening and monitoring of

  18. Correlational study on mitochondrial DNA mutations as potential risk factors in breast cancer.

    Science.gov (United States)

    Li, Linhai; Chen, Lidan; Li, Jun; Zhang, Weiyun; Liao, Yang; Chen, Jianyun; Sun, Zhaohui

    2016-05-24

    The presented study performed an mtDNA genome-wide association analysis to screen the peripheral blood of breast cancer patients for high-risk germline mutations. Unlike previous studies, which have used breast tissue in analyzing somatic mutations, we looked for germline mutations in our study, since they are better predictors of breast cancer in high-risk groups, facilitate early, non-invasive diagnoses of breast cancer and may provide a broader spectrum of therapeutic options. The data comprised 22 samples of healthy group and 83 samples from breast cancer patients. The sequencing data showed 170 mtDNA mutations in the healthy group and 393 mtDNA mutations in the disease group. Of these, 283 mtDNA mutations (88 in the healthy group and 232 in the disease group) had never been reported in the literature. Moreover, correlation analysis indicated there was a significant difference in 32 mtDNA mutations. According to our relative risk analysis of these 32 mtDNA mutations, 27 of the total had odds ratio values (ORs) of less than 1, meaning that these mutations have a potentially protective role to play in breast cancer. The remaining 5 mtDNA mutations, RNR2-2463 indelA, COX1-6296 C>A, COX1-6298 indelT, ATP6-8860 A>G, and ND5-13327 indelA, whose ORs were 8.050, 4.464, 4.464, 5.254 and 4.853, respectively, were regarded as risk factors of increased breast cancer. The five mutations identified here may serve as novel indicators of breast cancer and may have future therapeutic applications. In addition, the use of peripheral blood samples was procedurally simple and could be applied as a non-invasive diagnostic technique.

  19. Event-related potential correlates of paranormal ideation and unusual experiences.

    Science.gov (United States)

    Sumich, Alex; Kumari, Veena; Gordon, Evian; Tunstall, Nigel; Brammer, Michael

    2008-01-01

    Separate dimensions of schizotypy have been differentially associated with electrophysiological measures of brain function, and further shown to be modified by sex/gender. We investigated event-related potential (ERP) correlates of two subdimensions of positive schizotypy, paranormal ideation (PI) and unusual experiences (UEs). Seventy-two individuals with no psychiatric diagnosis (men=36) completed self-report measures of UE and PI and performed an auditory oddball task. Average scores for N100, N200 and P300 amplitudes were calculated for left and right anterior, central and posterior electrode sites. Multiple linear regression was used to examine the relationships between the measures of schizotypy and ERPs across the entire sample, as well as separately according to sex. PI was inversely associated with P300 amplitude at left-central sites across the entire sample, and at right-anterior electrodes in women only. Right-anterior P300 and right-posterior N100 amplitudes were negatively associated with UE in women only. Across the entire sample, UE was negatively associated with left-central N100 amplitude, and positively associated with left-anterior N200 amplitude. These results provide support from electrophysiological measures for the fractionation of the positive dimension of schizotypy into subdimensions of PI and UE, and lend indirect support to dimensional or quasidimensional conceptions of psychosis. More specifically, they suggest that PI may be associated with alteration in contextual updating processes, and that UE may reflect altered sensory/early-attention (N100) mechanisms. The sex differences observed are consistent with those previously observed in individuals with schizophrenia.

  20. Auditory and visual event-related potentials and flash visual evoked potentials in Alzheimer's disease: correlations with Mini-Mental State Examination and Raven's Coloured Progressive Matrices.

    Science.gov (United States)

    Tanaka, F; Kachi, T; Yamada, T; Sobue, G

    1998-01-01

    We investigated possible correlations among neurophysiological examinations [auditory and visual event-related potentials (A-ERPs, V-ERPs), and flash visual evoked potentials (F-VEPs)] and neuropsychological tests [Mini-Mental State Examination (MMSE) and Raven's Coloured Progressive Matrices (RCPM)] in 15 subjects with probable or possible Alzheimer's disease (AD) according to the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria. The P300 latency of A-ERPs was correlated with the scores of MMSE but not with those of RCPM. The P300 latency of V-ERPs was more significantly correlated with the scores of RCPM than with those of MMSE. The P2 latency of F-VEPs was more significantly correlated with the scores of RCPM than with those of MMSE. The P2 latency of F-VEPs was not correlated with the P300 latency of A-ERPs but was correlated with the P300 latency of V-ERPs. The close relationship among V-ERPs, F-VEPs and RCPM suggests that these examinations at least partly reflect the functions of visual association areas in AD. Furthermore, discrepancy between P300 latency by A-ERPs and V-ERPs suggests that the mechanism responsible for P300 generation is not identical between these two stimulus modalities.

  1. Theoretical Studies on the Intermolecular Interactions of Potentially Primordial Base-Pair Analogues

    Energy Technology Data Exchange (ETDEWEB)

    Leszczynski, Jerzy [Computational Center for Molecular Structure and Interactions, Jackson, MS; Sponer, Judit [Academy of Sciences of the Czech Republic; Sponer, Jiri [Academy of Sciences of the Czech Republic; Sumpter, Bobby G [ORNL; Fuentes-Cabrera, Miguel A [ORNL; Vazquez-Mayagoitia, Alvaro [ORNL

    2010-01-01

    Recent experimental studies on the Watson Crick type base pairing of triazine and aminopyrimidine derivatives suggest that acid/base properties of the constituent bases might be related to the duplex stabilities measured in solution. Herein we use high-level quantum chemical calculations and molecular dynamics simulations to evaluate the base pairing and stacking interactions of seven selected base pairs, which are common in that they are stabilized by two NH O hydrogen bonds separated by one NH N hydrogen bond. We show that neither the base pairing nor the base stacking interaction energies correlate with the reported pKa data of the bases and the melting points of the duplexes. This suggests that the experimentally observed correlation between the melting point data of the duplexes and the pKa values of the constituent bases is not rooted in the intrinsic base pairing and stacking properties. The physical chemistry origin of the observed experimental correlation thus remains unexplained and requires further investigations. In addition, since our calculations are carried out with extrapolation to the complete basis set of atomic orbitals and with inclusion of higher electron correlation effects, they provide reference data for stacking and base pairing energies of non-natural bases.

  2. Host-pathogen Interaction at the Intestinal Mucosa Correlates With Zoonotic Potential of Streptococcus suis

    DEFF Research Database (Denmark)

    Ferrando, Maria Laura; de Greeff, Astrid; van Rooijen, Willemien J. M.;

    2015-01-01

    Background. Streptococcus suis has emerged as an important cause of bacterial meningitis in adults. The ingestion of undercooked pork is a risk factor for human S. suis serotype 2 (SS2) infection. Here we provide experimental evidence indicating that the gastrointestinal tract is an entry site of...

  3. PDZ Domains and Viral Infection: Versatile Potentials of HPV-PDZ Interactions in relation to Malignancy

    Directory of Open Access Journals (Sweden)

    Kazunori Nagasaka

    2013-01-01

    Full Text Available Cervical cancer is caused by high-risk human papillomaviruses (HPVs, and a unique characteristic of these is a PDZ (P̲SD-95/D̲lg/Z̲O-1-binding motif in their E6 proteins. Through this motif HPV E6 interacts with a variety of PDZ domain-containing proteins and targets them mainly for degradation. These E6-PDZ interactions exhibit extraordinarily different functions in relation to HPV-induced malignancy, depending upon various cellular contexts; for example, Dlg and Scrib show different distribution patterns from what is seen in normal epithelium, both in localization and in amount, and their loss may be a late-stage marker in malignant progression. Recent studies show that interactions with specific forms of the proteins may have oncogenic potential. In addition, it is interesting that PDZ proteins make a contribution to the stabilization of E6 and viral episomal maintenance during the course of HPV life cycle. Various posttranslational modifications also greatly affect their functions. Phosphorylation of hDlg and hScrib by certain kinases regulates several important signaling cascades, and E6-PDZ interactions themselves are regulated through PKA-dependent phosphorylation. Thus these interactions naturally have great potential for both predictive and therapeutic applications, and, with development of screening tools for identifying novel targets of their interactions, comprehensive spatiotemporal analysis is currently underway.

  4. The potential of protein-nanomaterial interaction for advanced drug delivery.

    Science.gov (United States)

    Peng, Qiang; Mu, Huiling

    2016-03-10

    Nanomaterials, like nanoparticles, micelles, nano-sheets, nanotubes and quantum dots, have great potentials in biomedical fields. However, their delivery is highly limited by the formation of protein corona upon interaction with endogenous proteins. This new identity, instead of nanomaterial itself, would be the real substance the organs and cells firstly encounter. Consequently, the behavior of nanomaterials in vivo is uncontrollable and some undesired effects may occur, like rapid clearance from blood stream; risk of capillary blockage; loss of targeting capacity; and potential toxicity. Therefore, protein-nanomaterial interaction is a great challenge for nanomaterial systems and should be inhibited. However, this interaction can also be used to functionalize nanomaterials by forming a selected protein corona. Unlike other decoration using exogenous molecules, nanomaterials functionalized by selected protein corona using endogenous proteins would have greater promise for clinical use. In this review, we aim to provide a comprehensive understanding of protein-nanomaterial interaction. Importantly, a discussion about how to use such interaction is launched and some possible applications of such interaction for advanced drug delivery are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. On the configuration of systems of interacting particle with minimum potential energy per particle

    NARCIS (Netherlands)

    Ventevogel, W.J.; Nijboer, B.R.A.

    1979-01-01

    In continuation of previous work we extend the class of two-body potentials, either repulsive or of generalized Lennard-Jones type, for which it can be proved that among all configurations of an infinite one-dimensional system of interacting particles (with fixed density in the case of repulsive int

  6. On Local Smooth Solutions for the Vlasov Equation with the Potential of Interactions {\\pm} r^{-2}

    CERN Document Server

    Zhidkov, P E

    2003-01-01

    For the initial value problem for the Vlasov equation with the potential of interactions {\\pm} r^{-2} we prove the existence and uniqueness of a local solution with values in the Schwartz space S of infinitely differentiable functions rapidly decaying at infinity.

  7. The potential of protein-nanomaterial interaction for advanced drug delivery

    DEFF Research Database (Denmark)

    Peng, Qiang; Mu, Huiling

    2016-01-01

    Nanomaterials, like nanoparticles, micelles, nano-sheets, nanotubes and quantum dots, have great potentials in biomedical fields. However, their delivery is highly limited by the formation of protein corona upon interaction with endogenous proteins. This new identity, instead of nanomaterial itself......, would be the real substance the organs and cells firstly encounter. Consequently, the behavior of nanomaterials in vivo is uncontrollable and some undesired effects may occur, like rapid clearance from blood stream; risk of capillary blockage; loss of targeting capacity; and potential toxicity....... Therefore, protein-nanomaterial interaction is a great challenge for nanomaterial systems and should be inhibited. However, this interaction can also be used to functionalize nanomaterials by forming a selected protein corona. Unlike other decoration using exogenous molecules, nanomaterials functionalized...

  8. Critical temperature of Bose-Einstein condensation for weakly interacting bose gas in a potential trap

    Institute of Scientific and Technical Information of China (English)

    YU; Xuecai; YE; Yutang; WU; Yunfeng; XIE; Kang; CHENG; Lin

    2005-01-01

    The critical temperature of Bose-Einstein condensation at minimum momentum state for weakly interacting Bose gases in a power-law potential and the deviation of the critical temperature from ideal bose gas are studied. The effect of interaction on the critical temperature is ascribed to the ratiao α/λc, where α is the scattering length for s wave and λc is de Broglie wavelength at critical temperature. As α/λc<<1/(2π)2, the interaction is negligible. The presented deviation of the critical temperature for three dimensional harmonic potential is well in agreement with recent measurement of critical temperature for 87Rb bose gas trapped in a harmonic well.

  9. Negative electron affinities from DFT: influence of asymptotic exchange-correlation potential and effective homogeneity under density scaling.

    Science.gov (United States)

    Borgoo, Alex; Tozer, David J

    2012-06-07

    The influence of the asymptotic exchange-correlation potential and density-scaling homogeneity on negative electron affinities determined using the approach of Tozer and De Proft [J. Phys. Chem. A2005, 109, 8923] is investigated. Application of an asymptotic correction to the potential improves the accuracy for several of the systems with the most negative affinities, reflecting their diffuse lowest unoccupied orbitals. For systems with modest affinities, it reduces the accuracy marginally. Enforcing a near-exact effective homogeneity through a simple shift in the potential leads to improved correlation with experimental values but significantly overestimated affinities. Optimal effective homogeneities are therefore determined, and a simple scheme is proposed for enforcing an average optimal value. Application of the scheme to a series of organic molecules maintains the excellent correlation with the experimental values while significantly reducing the absolute errors.

  10. Enhancing non-local correlations in the bipartite partitions of two qubit-system with non-mutual interaction

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, A.-B.A., E-mail: abdelbastm@yahoo.com [College of Sciences and Humanities, Prince Sattam Bin Abdulaziz University, Al-Aflaj (Saudi Arabia); Faculty of Science, Assiut University, Assiut (Egypt); Joshi, A., E-mail: mcbamji@gmail.com [Physics Department, Adelphi University Garden City, NY 11530 (United States); Department of Physics and Optical Engineering, RHIT, Terra Haute IN 47803 (United States); Hassan, S.S., E-mail: shoukryhassan@hotmail.com [Department of Mathematics, College of Science, University of Bahrain, P.O. Box 32038 (Bahrain)

    2016-03-15

    Several quantum-mechanical correlations, notably, quantum entanglement, measurement-induced nonlocality and Bell nonlocality are studied for a two qubit-system having no mutual interaction. Analytical expressions for the measures of these quantum-mechanical correlations of different bipartite partitions of the system are obtained, for initially two entangled qubits and the two photons are in their vacuum states. It is found that the qubits-fields interaction leads to the loss and gain of the initial quantum correlations. The lost initial quantum correlations transfer from the qubits to the cavity fields. It is found that the maximal violation of Bell’s inequality is occurring when the quantum correlations of both the logarithmic negativity and measurement-induced nonlocality reach particular values. The maximal violation of Bell’s inequality occurs only for certain bipartite partitions of the system. The frequency detuning leads to quick oscillations of the quantum correlations and inhibits their transfer from the qubits to the cavity modes. It is also found that the dynamical behavior of the quantum correlation clearly depends on the qubit distribution angle.

  11. Potential pharmacokinetic interactions between antiretrovirals and medicinal plants used as complementary and African traditional medicines.

    Science.gov (United States)

    Müller, Adrienne C; Kanfer, Isadore

    2011-11-01

    The use of traditional/complementary/alternate medicines (TCAMs) in HIV/AIDS patients who reside in Southern Africa is quite common. Those who use TCAMs in addition to antiretroviral (ARV) treatment may be at risk of experiencing clinically significant pharmacokinetic (PK) interactions, particularly between the TCAMs and the protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Mechanisms of PK interactions include alterations to the normal functioning of drug efflux transporters, such as P-gp and/or CYP isoenzymes, such a CYP3A4 that mediate the absorption and elimination of drugs in the small intestine and liver. Specific mechanisms include inhibition and activation of these proteins and induction via the pregnane X receptor (PXR). Several clinical studies and case reports involving ARV-herb PK interactions have been reported. St John's Wort, Garlic and Cat's Claw exhibited potentially significant interactions, each with a PI or NNRTI. The potential for these herbs to induce PK interactions with drugs was first identified in reports of in vitro studies. Other in vitro studies have shown that several African traditional medicinal (ATM) plants and extracts may also demonstrate PK interactions with ARVs, through effects on CYP3A4, P-gp and PXR. The most complex effects were exhibited by Hypoxis hemerocallidea, Sutherlandia frutescens, Cyphostemma hildebrandtii, Acacia nilotica, Agauria salicifolia and Elaeodendron buchananii. Despite a high incidence of HIV/AIDs in the African region, only one clinical study, between efavirenz and Hypoxis hemerocallidea has been conducted. However, several issues/concerns still remain to be addressed and thus more studies on ATMs are warranted in order for more meaningful data to be generated and the true potential for such interactions to be determined.

  12. Time evolution of initial states that extend beyond the potential interaction region in quantum decay

    Science.gov (United States)

    García-Calderón, Gastón; Villavicencio, Jorge; Hernández-Maldonado, Alberto; Romo, Roberto

    2016-08-01

    We investigate the decay of initial states that possess a tail that extends beyond the interaction potential region, for potentials of arbitrary shape that vanish exactly after a distance. This is the case for a relevant class of artificial quantum structures. We obtain that along the internal interaction region, the time evolution of the decaying wave function is formed by two terms. The first one refers to the proper decay of the internal portion of the initial state, whereas the second one, that arises from the external tail, yields a transient contribution that tunnels into the internal region, builds up to a value, and then decays. We obtain that depending on the parameters of the initial state, the nonexponential tail decaying contribution may be larger than the contribution of the proper nonexponential term. These results are illustrated by an exactly solvable model and the Heidelberg potential for decay of ultracold atoms and open the possibility to control initial states in artificial decaying systems.

  13. Many-Body Coarse-Grained Interactions using Gaussian Approximation Potentials

    CERN Document Server

    John, S T

    2016-01-01

    This thesis introduces a framework that is able to describe general many-body coarse-grained interactions. We make use of this to describe the free energy surface as a cluster expansion in terms of monomer, dimer, and trimer terms. The contributions to the free energy due to these terms are inferred from MD results of the underlying all-atom model using Gaussian Approximation Potentials, a type of machine-learning potential based on Gaussian process regression. This provides CG interactions that are much more accurate than is possible with site-based pair potentials. While slower than these, it can still be faster than all-atom simulations for solvent-free CG models of systems with a large amount of solvent, as is common in biomolecular simulations.

  14. Evaluation of screening length corrections for interaction potentials in impact-collision ion scattering spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Wataru, E-mail: take@sp.ous.ac.jp

    2013-10-15

    Since in impact-collision ion scattering spectroscopy (ICISS) data analysis the interaction potential represented by the screening length as the screening effect is not satisfactorily established up to the present, we introduce commonly the correction factor in the screening length. Previously, Yamamura, Takeuchi and Kawamura (YTK) have suggested the theory taking the shell effect of electron distributions into account for the correction factor to Firsov screening length in the Moliere potential. The application of YTK theory to the evaluation of screening length corrections for the interaction potentials in ICISS manifested that the screening length corrections calculated by the YTK theory agree almost with those determined by simulations or numerical calculations in ICISS and its variants data analyses, being superior to the evaluation of screening length corrections with the O’Connor and Biersack (OB) formula.

  15. Forward-backward multiplicity correlations in 4.5 A GeV/c 16O-emulsion interactions

    Institute of Scientific and Technical Information of China (English)

    Zhang Dong-Hai; Zhao Hui-Hua; Liu Fang; He Chun-Le; Jia Hui-Ming; Li Xue-Qin; Li Zhen-Yu; Li Jun-Sheng

    2006-01-01

    A detailed study of the mechanisms of the emissions of pions and protons in the forward and backward hemispheres in 4.5 A GeV/c oxygen-emulsion interactions has been carried out. The correlations between the multiplicities of secondary charged particles in the backward and forward hemispheres are investigated.

  16. The test-particle induced inhomogeneous direct correlation functions and extensions of Widom's theorem: impacts on the incremental chemical potentials and high-order correlation functions.

    Science.gov (United States)

    Lee, Lloyd L

    2013-10-21

    We develop the potential distributions of several test particles to obtain a hierarchy of the nonuniform singlet direct correlation functions (s-DCFs). These correlation functions are interpreted as the segmental chemical potentials or works of insertion of successive test particles in a classical fluid. The development has several interesting consequences: (i) it extends the Widom particle insertion formula to higher-order theorems, the first member gives the chemical potential as in the original theorem, the second member gives the incremental energy for dimer formation, with higher members giving the energies for forming trimers, tetramers, etc. (ii) The second and third order s-DCFs can be related to the cavity distribution functions y((2)) and y((3)) in the liquid-state theory. Thus we can express the triplet cavity function y((3)) in terms of these s-DCFs in an exact form. This enables us to calculate, as an illustration of the above theoretical developments, the numerical values of the s-DCFs via Monte Carlo (MC) simulation data on hard spheres. We use these data to critically analyze the commonly used approximations, the Kirkwood superposition (KSA) and the linear approximation (LA) for triplet correlation functions. An improved rule over KSA and LA is proposed for triplet hard spheres in the rolling-contact configurations. (iii) The s-DCFs are naturally suited for analyzing the chain-incremental Ansatz or hypothesis in the calculation of the chemical potentials of polymeric chain molecules. The first few segments of a polymer chain have been shown from extensive Monte Carlo simulations to not obey this Ansatz. By examining the insertion energies of successive segments through the s-DCFs, we are able to quantitatively decipher the decay of the segmental chemical potentials for at least the first three segments. Comparison with MC data on 4-mer and 8-mer hard-sphere fluids shows commensurate behavior with the s-DCFs. In addition, an analytical density

  17. NA61/SHINE results on fluctuations and correlations in p + p and Be + Be interactions at CERN SPS energies

    Science.gov (United States)

    Mackowiak-Pawlowska, Maja

    2016-12-01

    The aim of the NA61/SHINE strong interaction program is to explore the phase diagram of strongly interacting matter. The main physics goals are the study of the onset of deconfinement and the search for the critical point of strongly interacting matter. These goals are pursued by performing a beam momentum (13A - 158A GeV/c) and system size (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La) scan. This contribution presents results on transverse momentum and multiplicity fluctuations from the Be+Be and p+p energy scan. Also, results on two-particle correlations in pseudorapidity and azimuthal angle obtained in p+p interactions will be shown. The influence of conservation laws and resonance decays on multiplicity and chemical fluctuations of identified particles in p+p interactions will be discussed. Obtained results will be compared with data from other experiments and with model predictions.

  18. Ensuring proper short-range and asymptotic behavior of the exchange-correlation Kohn-Sham potential by modeling with a statistical average of different orbital model potentials

    Energy Technology Data Exchange (ETDEWEB)

    Gritsenko, O.V.; Schipper, P.R.T.; Baerends, E.J.

    2000-01-20

    The long-range asymptotic behavior of the exchange-correlation Kohn-Sham (KS) potential {nu}{sub xc} and its relation to the exchange-correlation energy E{sub xc} are considered using various approaches. The line integral of {nu}{sub xc}([{rho}];r) yielding the exchange-correlation part {Delta}E{sub xc} of a relative energy {Delta}E of a finite system, shows that a uniform constant shift of {nu}{sub xc} never shows up in any physically meaningful energy difference {Delta}E. {nu}{sub xv} may thus be freely chosen to tend asymptotically to zero or to some nonzero constant. Possible choices of the asymptotics of the potential are discussed with reference to the theory of open systems with a fractional number of electrons. The authors adhere to the conventional choice {nu}{sub xc}({infinity}) = 0 for the asymptotics of the potential leading to {epsilon}{sub N} = {minus}I{sub p} for the energy {epsilon}{sub N} of the highest occupied orbital. A statistical average of orbital dependent model potentials is proposed as a way to model {nu}{sub xc}. An approximate potential {nu}{sub xco}{sup SAOP} with exact {minus}1/r asymptotics is developed using the statistical average of, on the one hand, a model potential {nu}{sub xc{sigma}}{sup Ei} for the highest occupied KS orbital {psi}{sub N{sigma}} and, on the other hand, a model potential {nu}{sub xc}{sup GLB} for other occupied orbitals. It is demonstrated for the well-studied case of the Ne atom, that calculations with the new model potential can, in principle, reproduce perfectly all energy characteristics.

  19. Spectral fluctuation and correlation structure of δ(n) statistics in the spectra of interacting trapped bosons.

    Science.gov (United States)

    Roy, Kamalika; Chakrabarti, Barnali; Kota, V K B

    2013-06-01

    It is a well-known fact that the statistical behaviors of level fluctuation and level correlation in the energy-level spectra are the most efficient tool to characterize quantum chaos in nonintegrable quantum systems. The system of interacting trapped bosons is a complex system where the low-lying energy levels are highly influenced by the level repulsion. In this case, interatomic interaction is a dominating fact with strong level correlation between distant levels. Here we numerically calculate the correlation function, number variance, and Dyson-Mehta least-square deviation for the low-lying levels for a few thousand interacting trapped bosons, and our data show good analogy with the Gaussian orthogonal ensemble (GOE) results with a signature of chaos. In the next part of our study, the energy spectrum of these low-lying levels is considered as a discrete signal and the fluctuation of the excitation energy is considered as discrete time series. Then we calculate numerically the height-height correlation function for different order of momentum. In our study logarithmic correlation structure is found instead of multiscaling structure, and we observe that spectral statistics are compatible with those of GOE.

  20. Correlation dimension estimate and its potential use in analysis of gas-solid flows

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse Aistrup; Kær, Søren Knudsen

    2005-01-01

    be reproduced from the state-space trajectory (i.e., attractor) reconstructed from the time series of one single measured parameter. This method is widely used in gas-solid flows in fluidized beds. However, there exist different results in literature for correlation dimension (a key parameter to describe......-estimated correlation dimension (a spatial dimension), is highlighted and a solution is given. The technique is demonstrated by analyzing absolute pressure fluctuations from a cold fluidized bed. Comparison of estimated correlation dimensions based on the same pressure fluctuations indicates excluding dynamical...

  1. Insect antimicrobial peptides show potentiating functional interactions against Gram-negative bacteria.

    Science.gov (United States)

    Rahnamaeian, Mohammad; Cytryńska, Małgorzata; Zdybicka-Barabas, Agnieszka; Dobslaff, Kristin; Wiesner, Jochen; Twyman, Richard M; Zuchner, Thole; Sadd, Ben M; Regoes, Roland R; Schmid-Hempel, Paul; Vilcinskas, Andreas

    2015-05-01

    Antimicrobial peptides (AMPs) and proteins are important components of innate immunity against pathogens in insects. The production of AMPs is costly owing to resource-based trade-offs, and strategies maximizing the efficacy of AMPs at low concentrations are therefore likely to be advantageous. Here, we show the potentiating functional interaction of co-occurring insect AMPs (the bumblebee linear peptides hymenoptaecin and abaecin) resulting in more potent antimicrobial effects at low concentrations. Abaecin displayed no detectable activity against Escherichia coli when tested alone at concentrations of up to 200 μM, whereas hymenoptaecin affected bacterial cell growth and viability but only at concentrations greater than 2 μM. In combination, as little as 1.25 μM abaecin enhanced the bactericidal effects of hymenoptaecin. To understand these potentiating functional interactions, we investigated their mechanisms of action using atomic force microscopy and fluorescence resonance energy transfer-based quenching assays. Abaecin was found to reduce the minimal inhibitory concentration of hymenoptaecin and to interact with the bacterial chaperone DnaK (an evolutionarily conserved central organizer of the bacterial chaperone network) when the membrane was compromised by hymenoptaecin. These naturally occurring potentiating interactions suggest that combinations of AMPs could be used therapeutically against Gram-negative bacterial pathogens that have acquired resistance to common antibiotics.

  2. Frequency of potential interactions between drugs in medical prescriptions in a city in southern Brazil

    Directory of Open Access Journals (Sweden)

    Genici Weyh Bleich

    Full Text Available CONTEXT AND OBJECTIVE: Drug interactions form part of current clinical practice and they affect between 3 and 5% of polypharmacy patients. The aim of this study was to identify the frequency of potential drug-drug interactions in prescriptions for adult and elderly patients. TYPE OF STUDY AND SETTING: Cross-sectional pharmacoepidemiological survey in the Parque Verde housing project, municipality of Cascavel, Paraná, Brazil, between December 2006 and February 2007. METHODS: Stratified cluster sampling, proportional to the total number of homes in the housing project, was used. The sample consisted of 95 homes and 96 male or female patients aged 19 or over, with medical prescriptions for at least two pharmaceutical drugs. Interactions were identified using DrugDigest, Medscape and Micromedex softwares. RESULTS: Most of the patients were female (69.8%, married (59.4% and in the age group of 60 years or over (56.3%, with an income less than or equal to three minimum monthly salaries (81.3% and less than eight years of schooling (69.8%; 90.6% of the patients were living with another person. The total number of pharmaceutical drugs was 406 (average of 4.2 medications per patient. The drugs most prescribed were antihypertensives (47.5%. The frequency of drug interactions was 66.6%. Among the 154 potential drug interactions, 4.6% were classified as major, 65.6% as moderate and 20.1% as minor. CONCLUSION: The high frequency of drug prescriptions with a potential for differentiated interactions indicates a situation that has so far been little explored, albeit a reality in household surveys.

  3. Potential drug–drug interactions in Alzheimer patients with behavioral symptoms

    Directory of Open Access Journals (Sweden)

    Pasqualetti G

    2015-09-01

    Full Text Available Giuseppe Pasqualetti, Sara Tognini, Valeria Calsolaro, Antonio Polini, Fabio Monzani Geriatrics Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy Abstract: The use of multi drug regimens among the elderly population has increased tremendously over the last decade although the benefits of medications are always accompanied by potential harm, even when prescribed at recommended doses. The elderly populations are particularly at an increased risk of adverse drug reactions considering comorbidity, poly-therapy, physiological changes affecting the pharmacokinetics and pharmacodynamics of many drugs and, in some cases, poor compliance due to cognitive impairment and/or depression. In this setting, drug–drug interaction may represent a serious and even life-threatening clinical condition. Moreover, the inability to distinguish drug-induced symptoms from a definitive medical diagnosis often results in addition of yet another drug to treat the symptoms, which in turn increases drug–drug interactions. Cognitive enhancers, including acetylcholinesterase inhibitors and memantine, are the most widely prescribed agents for Alzheimer’s disease (AD patients. Behavioral and psychological symptoms of dementia, including psychotic symptoms and behavioral disorders, represent noncognitive disturbances frequently observed in AD patients. Antipsychotic drugs are at high risk of adverse events, even at modest doses, and may interfere with the progression of cognitive impairment and interact with several drugs including anti-arrhythmics and acetylcholinesterase inhibitors. Other medications often used in AD patients are represented by anxiolytic, like benzodiazepine, or antidepressant agents. These agents also might interfere with other concomitant drugs through both pharmacokinetic and pharmacodynamic mechanisms. In this review we focus on the most frequent drug–drug interactions, potentially harmful, in AD patients with

  4. Supercritical fluid of particles with a Yukawa potential: A new approximation for the direct correlation function and the Widom line

    Science.gov (United States)

    Tareyeva, E. E.; Ryzhov, V. N.

    2016-12-01

    We propose an approximation of a direct correlation function corresponding to the linearization with respect to - βϕ( r) of a generalized mean spherical approximation for a hard-core multi-Yukawa system of particles. We use the results to study the behavior of maximums of thermodynamic response functions in the supercritical region of a fluid with a two-term Yukawa potential imitating the Lennard-Jones potential.

  5. Association of COMT and COMT-DRD2 interaction with creative potential

    Directory of Open Access Journals (Sweden)

    Shun eZhang

    2014-04-01

    Full Text Available Several lines of evidence suggest that genes involved in dopamine (DA transmission may contribute to creativity. Among these genes, the catechol-O-methyltransferase gene (COMT and the dopamine D2 receptor gene (DRD2 are the most promising candidates. Our previous study has revealed evidence for the involvement of DRD2 in creative potential. The present study extended our previous study by systematically exploring the association of COMT with creative potential as well as the interaction between COMT and DRD2. Twelve single nucleotide polymorphisms (SNPs covering COMT were genotyped in 543 healthy Chinese college students whose creative potentials were assessed by divergent thinking tests. Single SNP analysis showed that rs174697 was nominally associated with verbal originality, two SNPs (rs737865 and rs5993883 were nominally associated with figural fluency, and two SNPs (rs737865 and rs4680 were nominally associated with figural originality. Haplotype analysis showed that, the TCT and CCT haplotype (rs737865-rs174675-rs5993882 were nominally associated with figural originality, and the TATGCAG and CGCGGGA haplotype (rs4646312-rs6269-rs4633-rs6267-rs4818-rs4680-rs769224 were nominally associated with figural originality and verbal flexibility, respectively. However, none of these nominal findings survived correction for multiple testing. Gene-gene interaction analysis identified one significant four-way interaction of rs174675 (COMT, rs174697 (COMT, rs1076560 (DRD2 and rs4436578 (DRD2 on verbal fluency, one significant four-way interaction of rs174675 (COMT, rs4818 (COMT, rs1076560 (DRD2 and rs4648317 (DRD2 on verbal flexibility, and one significant three-way interaction of rs5993883 (COMT, rs4648319 (DRD2 and rs4648317 (DRD2 on figural flexibility. In conclusion, the present study provides nominal evidence for the involvement of COMT in creative potential and suggests that DA related genes may act in coordination to contribute to creativity.

  6. Multiple-time correlation functions for non-Markovian interaction: Beyond the Quantum Regression Theorem

    CERN Document Server

    Alonso, D; Alonso, Daniel; Vega, In\\'es de

    2004-01-01

    Multiple time correlation functions are found in the dynamical description of different phenomena. They encode and describe the fluctuations of the dynamical variables of a system. In this paper we formulate a theory of non-Markovian multiple-time correlation functions (MTCF) for a wide class of systems. We derive the dynamical equation of the {\\it reduced propagator}, an object that evolve state vectors of the system conditioned to the dynamics of its environment, which is not necessarily at the vacuum state at the initial time. Such reduced propagator is the essential piece to obtain multiple-time correlation functions. An average over the different environmental histories of the reduced propagator permits us to obtain the evolution equations of the multiple-time correlation functions. We also study the evolution of MTCF within the weak coupling limit and it is shown that the multiple-time correlation function of some observables satisfy the Quantum Regression Theorem (QRT), whereas other correlations do no...

  7. A Study on Potential of Integrating Multimodal Interaction into Musical Conducting Education

    CERN Document Server

    Siang, Gilbert Phuah Leong; Yong, Pang Yee

    2010-01-01

    With the rapid development of computer technology, computer music has begun to appear in the laboratory. Many potential utility of computer music is gradually increasing. The purpose of this paper is attempted to analyze the possibility of integrating multimodal interaction such as vision-based hand gesture and speech interaction into musical conducting education. To achieve this purpose, this paper is focus on discuss some related research and the traditional musical conducting education. To do so, six musical conductors had been interviewed to share their musical conducting learning/ teaching experience. These interviews had been analyzed in this paper to show the syllabus and the focus of musical conducting education for beginners.

  8. A new method for detecting interactions between the senses in event-related potentials

    DEFF Research Database (Denmark)

    Gondan, Matthias; Röder, B.

    2006-01-01

    Event-related potentials (ERPs) can be used in multisensory research to determine the point in time when different senses start to interact, for example, the auditory and the visual system. For this purpose, the ERP to bimodal stimuli (AV) is often compared to the sum of the ERPs to auditory (A...... - (A + V), but common activity is eliminated because two ERPs are subtracted from two others. With this new comparison technique, the first auditory-visual interaction starts around 80 ms after stimulus onset for the present experimental setting. It is possible to apply the new comparison method...

  9. Interactions of neuropathy inducers and potentiators/promoters with soluble esterases.

    Science.gov (United States)

    Estévez, Jorge; Mangas, Iris; Sogorb, Miguel Ángel; Vilanova, Eugenio

    2013-03-25

    Organophosphorus compounds (OPs) cause neurotoxic disorders through interactions with well-known target esterases, such as acetylcholinesterase and neuropathy target esterase (NTE). However, the OPs can potentially interact with other esterases of unknown significance. Therefore, identifying, characterizing and elucidating the nature and functional significance of the OP-sensitive pool of esterases in the central and peripheral nervous systems need to be investigated. Kinetic models have been developed and applied by considering multi-enzymatic systems, inhibition, spontaneous reactivation, the chemical hydrolysis of the inhibitor and "ongoing inhibition" (inhibition during the substrate reaction time). These models have been applied to discriminate enzymatic components among the esterases in nerve tissues of adult chicken, this being the experimental model for delayed neuropathy and to identify different modes of interactions between OPs and soluble brain esterases. The covalent interaction with the substrate catalytic site has been demonstrated by time-progressive inhibition during ongoing inhibition. The interaction of sequential exposure to an esterase inhibitor has been tested in brain soluble fraction where exposure to one inhibitor at a non inhibitory concentration has been seen to modify sensitivity to further exposure to others. The effect has been suggested to be caused by interaction with sites other than the inhibition site at the substrate catalytic site. This kind of interaction among esterase inhibitors should be considered to study the potentiation/promotion phenomenon, which is observed when some esterase inhibitors enhance the severity of the OP induced neuropathy if they are dosed after a non neuropathic low dose of a neuropathy inducer. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Charged patchy particle models in explicit salt: Ion distributions, electrostatic potentials, and effective interactions

    Energy Technology Data Exchange (ETDEWEB)

    Yigit, Cemil; Dzubiella, Joachim, E-mail: joachim.dzubiella@helmholtz-berlin.de [Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, 14109 Berlin (Germany); Helmholtz Virtual Institute “Multifunctional Biomaterials for Medicine,” 14513 Teltow (Germany); Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Heyda, Jan [Department of Physical Chemistry, University of Chemistry and Technology, Prague, 166 28 Praha 6 (Czech Republic)

    2015-08-14

    We introduce a set of charged patchy particle models (CPPMs) in order to systematically study the influence of electrostatic charge patchiness and multipolarity on macromolecular interactions by means of implicit-solvent, explicit-ion Langevin dynamics simulations employing the Gromacs software. We consider well-defined zero-, one-, and two-patched spherical globules each of the same net charge and (nanometer) size which are composed of discrete atoms. The studied mono- and multipole moments of the CPPMs are comparable to those of globular proteins with similar size. We first characterize ion distributions and electrostatic potentials around a single CPPM. Although angle-resolved radial distribution functions reveal the expected local accumulation and depletion of counter- and co-ions around the patches, respectively, the orientation-averaged electrostatic potential shows only a small variation among the various CPPMs due to space charge cancellations. Furthermore, we study the orientation-averaged potential of mean force (PMF), the number of accumulated ions on the patches, as well as the CPPM orientations along the center-to-center distance of a pair of CPPMs. We compare the PMFs to the classical Derjaguin-Verwey-Landau-Overbeek theory and previously introduced orientation-averaged Debye-Hückel pair potentials including dipolar interactions. Our simulations confirm the adequacy of the theories in their respective regimes of validity, while low salt concentrations and large multipolar interactions remain a challenge for tractable theoretical descriptions.

  11. Concomitant therapy in people with epilepsy: potential drug-drug interactions and patient awareness.

    Science.gov (United States)

    Eyal, Sara; Rasaby, Sivan; Ekstein, Dana

    2014-02-01

    People with epilepsy (PWE) may use prescription and over-the-counter (OTC) drugs for the treatment of concomitant diseases. Combinations of these drugs, as well as dietary supplements, with antiepileptic drugs (AEDs) may lead to reduced control of seizures and of coexisting medical conditions and increased risk of adverse drug reactions (ADRs). The aims of this study were to obtain comprehensive lists of medications, dietary supplements, botanicals, and specific food components used by adult PWE and to evaluate the potential for interactions involving AEDs and patients' awareness of such potential interactions. We conducted a prospective, questionnaire-based study of PWE attending the Hadassah-Hebrew University Epilepsy Clinic over a period of 7months. The questionnaire interview included the listing of medications, medicinal herbs, dietary supplements, and specific food components consumed and the knowledge of potential drug-drug interactions (DDIs), and it was conducted by a pharmacist. Drug-drug interactions were analyzed via the Micromedex online database. Out of 179 patients who attended the clinic over the study period, we interviewed 73 PWE, of which 71 were included in our final analysis. The mean number of AEDs consumed per subject was 1.7 (SD: 0.8, range: 1-4). Forty (56%) subjects were also treated with other prescription and/or OTC medications, and thirty-four (48%) took dietary supplements. Drug families most prone to DDIs involving AEDs included antipsychotic agents, selective serotonin reuptake inhibitors, and statins. Two-thirds of study participants (67%) knew that DDIs may lead to ADRs, but only half (56%) were aware of the potential for reduced seizure control. Only 44% always reported treatment with AEDs to medical professionals. This study provides for the first time a comprehensive picture of prescription and OTC drugs and food supplements used by PWE. Despite a considerable potential for DDIs involving AEDs, patient awareness is limited

  12. Shape corrections to exchange-correlation potentials by gradient-regulated seamless connection of model potentials for inner and outer region

    Science.gov (United States)

    Grüning, M.; Gritsenko, O. V.; van Gisbergen, S. J. A.; Baerends, E. J.

    2001-01-01

    Shape corrections to the standard approximate Kohn-Sham exchange-correlation (xc) potentials are considered with the aim to improve the excitation energies (especially for higher excitations) calculated with time-dependent density functional perturbation theory. A scheme of gradient-regulated connection (GRAC) of inner to outer parts of a model potential is developed. Asymptotic corrections based either on the potential of Fermi and Amaldi or van Leeuwen and Baerends (LB) are seamlessly connected to the (shifted) xc potential of Becke and Perdew (BP) with the GRAC procedure, and are employed to calculate the vertical excitation energies of the prototype molecules N2, CO, CH2O, C2H4, C5NH5, C6H6, Li2, Na2, K2. The results are compared with those of the alternative interpolation scheme of Tozer and Handy as well as with the results of the potential obtained with the statistical averaging of (model) orbital potentials. Various asymptotically corrected potentials produce high quality excitation energies, which in quite a few cases approach the benchmark accuracy of 0.1 eV for the electronic spectra. Based on these results, the potential BP-GRAC-LB is proposed for molecular response calculations, which is a smooth potential and a genuine "local" density functional with an analytical representation.

  13. Medicinal plant reported with adverse reactions in Cuba: potential interactions with conventional drugs

    Directory of Open Access Journals (Sweden)

    Ioanna Martínez

    2015-04-01

    Full Text Available Context: Herbal drugs are a mixture of active compounds and the chemical complexity of each formulation increase with the possibility of interactions between them and conventional drugs. Many mechanisms are implicated in the interactions; scientific community has dedicated the attentions to enzymes as P-gp and CYP450. Aims: To investigate in the literature the principal plants with suspicions of adverse reactions in Cuba and their potential interactions with conventional drugs. Methods: PubMed was the database used as source of information until February 2014. Key words: Herb-Drug, Drug-Plant, Herbal–Drug, Interactions with scientific names of plants was used. Information was structured and analysed with EndNote X4. Analysis and integration of the information: Allium sativum L. (garlic was the plant with the high number of studies related with CYP450 and P-gp. Plants with great demand as Morinda citrifolia L. (noni, Psidium guajava L. (guayaba, Zingiber officinale Roscoe (ginger and Eucalyptus spp. (eucalyptus have a very small number of studies. The professionals of the health should keep in mind the possibility of interactions between herbal products and conventional drugs to increase the effectiveness of phytotherapy. Conclusions: It is necessary enhance reports and investigations and to put to disposition of the system of health information on the interactions of plants and to stimulate the investigation that offers information for the rational use of our medicinal plants.

  14. Natural enemy-mediated indirect interactions among prey species: potential for enhancing biocontrol services in agroecosystems.

    Science.gov (United States)

    Chailleux, Anaïs; Mohl, Emily K; Teixeira Alves, Mickaël; Messelink, Gerben J; Desneux, Nicolas

    2014-12-01

    Understanding how arthropod pests and their natural enemies interact in complex agroecosystems is essential for pest management programmes. Theory predicts that prey sharing a predator, such as a biological control agent, can indirectly reduce each other's density at equilibrium (apparent competition). From this premise, we (i) discuss the complexity of indirect interactions among pests in agroecosystems and highlight the importance of natural enemy-mediated indirect interactions other than apparent competition, (ii) outline factors that affect the nature of enemy-mediated indirect interactions in the field and (iii) identify the way to manipulate enemy-mediated interactions for biological control. We argue that there is a need to increase the link between community ecology theory and biological control to develop better agroecological methods of crop protection via conservation biological control. In conclusion, we identify (i) interventions to be chosen depending on agroecosystem characteristics and (ii) several lines of research that will improve the potential for enemy-mediated indirect interactions to be applied to biological control. © 2014 Society of Chemical Industry.

  15. Influence of bond length variation on correlated static exchange potential: A case study in e--N2 scattering

    Science.gov (United States)

    Ghose, Keya Basu; Pal, Sourav

    1994-03-01

    We discuss in this note how the correlated static exchange potential changes with bond length for N2 molecule where the earlier extensive results at equilibrium exist. We have used many-body coupled cluster technique for this study. Its relevance to e--N2 scattering is also discussed.

  16. Accuracy of geometries : influence of basis set, exchange-correlation potential, inclusion of core electrons, and relativistic corrections

    NARCIS (Netherlands)

    Swart, M; Snijders, JG

    The geometries of a set of small molecules were optimized using eight different exchange-correlation (xc) potentials in a few different basis sets of Slater-type orbitals, ranging from a minimal basis (I) to a triple-zeta valence basis plus double polarization functions (VII). This enables a

  17. Excited state potential energy surfaces and their interactions in Fe(IV)=O active sites.

    Science.gov (United States)

    Srnec, Martin; Wong, Shaun D; Solomon, Edward I

    2014-12-21

    The non-heme ferryl active sites are of significant interest for their application in biomedical and green catalysis. These sites have been shown to have an S = 1 or S = 2 ground spin state; the latter is functional in biology. Low-temperature magnetic circular dichroism (LT MCD) spectroscopy probes the nature of the excited states in these species including ligand-field (LF) states that are otherwise difficult to study by other spectroscopies. In particular, the temperature dependences of MCD features enable their unambiguous assignment and thus determination of the low-lying excited states in two prototypical S = 1 and S = 2 NHFe(IV)[double bond, length as m-dash]O complexes. Furthermore, some MCD bands exhibit vibronic structures that allow mapping of excited-state interactions and their effects on the potential energy surfaces (PESs). For the S = 2 species, there is also an unusual spectral feature in both near-infrared absorption and MCD spectra - Fano antiresonance (dip in Abs) and Fano resonance (sharp peak in MCD) that indicates the weak spin-orbit coupling of an S = 1 state with the S = 2 LF state. These experimental data are correlated with quantum-chemical calculations that are further extended to analyze the low-lying electronic states and the evolution of their multiconfigurational characters along the Fe-O PESs. These investigations show that the lowest-energy states develop oxyl Fe(III) character at distances that are relevant to the transition state (TS) for H-atom abstraction and define the frontier molecular orbitals that participate in the reactivity of S = 1 vs. S = 2 non-heme Fe(IV)[double bond, length as m-dash]O active sites. The S = 1 species has only one available channel that requires the C-H bond of a substrate to approach perpendicular to the Fe-oxo bond (the π channel). In contrast, there are three channels (one σ and two π) available for the S = 2 non-heme Fe(IV)[double bond, length as m-dash]O system allowing C-H substrate approach

  18. Epidemiology of Polypharmacy and Potential Drug-Drug Interactions Among Pediatric Patients in ICUs of U.S. Children's Hospitals.

    Science.gov (United States)

    Dai, Dingwei; Feinstein, James A; Morrison, Wynne; Zuppa, Athena F; Feudtner, Chris

    2016-05-01

    Polypharmacy is common in hospitalized children in the United States and has been identified as a major risk factor for exposure to potential drug-drug interactions. Little is known about the characteristics and prevalence of exposure of pediatric patients to polypharmacy and potential drug-drug interactions in PICUs. Retrospective cohort study using the Pediatric Health Information System database. Forty-two freestanding children's hospitals throughout the United States. A total of 54,549 patients less than 18 years old cared for in PICUs in 2011. Patients in neonatal ICUs were not included. PICU patients were on average exposed to 10 distinct drugs each hospital day and to 20 drugs cumulatively during their hospitalization. Seventy-five percent of patients were exposed to greater than or equal to one potential drug-drug interaction regardless of severity level, 6% to greater than or equal to one contraindicated potential drug-drug interaction, 69% to greater than or equal to one major potential drug-drug interaction, 57% to greater than or equal to one moderate potential drug-drug interaction, 19% to greater than or equal to one minor potential drug-drug interaction. Potential drug-drug interaction exposures were significantly associated with specific diagnoses (p risk of adverse drug events following specific potential drug-drug interaction exposures, especially the risk of adverse drug events due to multiple potential drug-drug interaction exposures, and determine the probability and magnitude of the actual harm (if any) for each specific potential drug-drug interaction, especially for multiple potential drug-drug interaction exposures.

  19. Conjugation of cholesterol to HIV-1 fusion inhibitor C34 increases peptide-membrane interactions potentiating its action.

    Directory of Open Access Journals (Sweden)

    Axel Hollmann

    Full Text Available Recently, the covalent binding of a cholesterol moiety to a classical HIV-1 fusion inhibitor peptide, C34, was shown to potentiate its antiviral activity. Our purpose was to evaluate the interaction of cholesterol-conjugated and native C34 with membrane model systems and human blood cells to understand the effects of this derivatization. Lipid vesicles and monolayers with defined compositions were used as model membranes. C34-cholesterol partitions more to fluid phase membranes that mimic biological membranes. Importantly, there is a preference of the conjugate for liquid ordered membranes, rich in cholesterol and/or sphingomyelin, as observed both from partition and surface pressure studies. In human erythrocytes and peripheral blood mononuclear cells (PBMC, C34-cholesterol significantly decreases the membrane dipole potential. In PBMC, the conjugate was 14- and 115-fold more membranotropic than T-1249 and enfuvirtide, respectively. C34 or cholesterol alone did not show significant membrane activity. The enhanced interaction of C34-cholesterol with biological membranes correlates with its higher antiviral potency. Higher partitions for lipid-raft like compositions direct the drug to the receptor-rich domains where membrane fusion is likely to occur. This intermediary membrane binding step may facilitate the drug delivery to gp41 in its pre-fusion state.

  20. Hyperon Single-Particle Potentials Calculated from SU6 Quark-Model Baryon-Baryon Interactions

    CERN Document Server

    Kohno, M; Fujita, T; Nakamoto, C; Suzuki, Y

    2000-01-01

    Using the SU6 quark-model baryon-baryon interaction recently developed by the Kyoto-Niigata group, we calculate NN, Lambda N and Sigma N G-matrices in ordinary nuclear matter. This is the first attempt to discuss the Lambda and Sigma single-particle potentials in nuclear medium, based on the realistic quark-model potential. The Lambda potential has the depth of more than 40 MeV, which is more attractive than the value expected from the experimental data of Lambda-hypernuclei. The Sigma potential turns out to be repulsive, the origin of which is traced back to the strong Pauli repulsion in the Sigma N (I=3/2) ^3S_1 state.

  1. Scalar-fluid interacting dark energy: Cosmological dynamics beyond the exponential potential

    Science.gov (United States)

    Dutta, Jibitesh; Khyllep, Wompherdeiki; Tamanini, Nicola

    2017-01-01

    We extend the dynamical systems analysis of scalar-fluid interacting dark energy models performed in C. G. Boehmer et al., Phys. Rev. D 91, 123002 (2015), 10.1103/PhysRevD.91.123002 by considering scalar field potentials beyond the exponential type. The properties and stability of critical points are examined using a combination of linear analysis, computational methods and advanced mathematical techniques, such as center manifold theory. We show that the interesting results obtained with an exponential potential can generally be recovered also for more complicated scalar field potentials. In particular, employing power law and hyperbolic potentials as examples, we find late time accelerated attractors, transitions from dark matter to dark energy domination with specific distinguishing features, and accelerated scaling solutions capable of solving the cosmic coincidence problem.

  2. Interactions between different EEG frequency bands and their effect on alpha-fMRI correlations

    NARCIS (Netherlands)

    de Munck, J.C.; Gonçalves, S.I.; Mammoliti, R.; Heethaar, R.M.; Lopes da Silva, F.H.

    2009-01-01

    In EEG/fMRI correlation studies it is common to consider the fMRI BOLD as filtered version of the EEG alpha power. Here the question is addressed whether other EEG frequency components may affect the correlation between alpha and BOLD. This was done comparing the statistical parametric maps (SPMs)

  3. Correlation function induced by a generalized diffusion equation with the presence of a harmonic potential

    Energy Technology Data Exchange (ETDEWEB)

    Fa, Kwok Sau, E-mail: kwok@dfi.uem.br

    2015-02-15

    An integro-differential diffusion equation with linear force, based on the continuous time random walk model, is considered. The equation generalizes the ordinary and fractional diffusion equations, which includes short, intermediate and long-time memory effects described by the waiting time probability density function. Analytical expression for the correlation function is obtained and analyzed, which can be used to describe, for instance, internal motions of proteins. The result shows that the generalized diffusion equation has a broad application and it may be used to describe different kinds of systems. - Highlights: • Calculation of the correlation function. • The correlation function is connected to the survival probability. • The model can be applied to the internal dynamics of proteins.

  4. Prediction of the derivative discontinuity in density functional theory from an electrostatic description of the exchange and correlation potential

    CERN Document Server

    Andrade, Xavier

    2011-01-01

    We propose a new approach to approximate the exchange and correlation (XC) functional in density functional theory. The XC potential is considered as an electrostatic potential, generated by a fictitious XC density, which is in turn a functional of the electronic density. We apply the approach to develop a correction scheme that fixes the asymptotic behavior of any approximated XC potential for finite systems. Additionally, the correction procedure gives the value of the derivative discontinuity; therefore it can directly predict the fundamental gap as a ground-state property.

  5. Understanding consumer motivations for interacting in online food communities – potential for innovation

    DEFF Research Database (Denmark)

    Jacobsen, Lina; Sørensen, Bjarne Taulo; Tudoran, Ana Alina

    This study contributes to the understanding of online user communities as a potential source of innovation. That would require an interest from users in interacting in such communities. In order to establish interaction, users must provide as well as consume information. However, depending...... on the innovation task, one may be more important than the other. It is therefore important to understand, how companies can increase user willingness to engage in these different interaction forms. This study investigates the influence of various motivation factors and user interests on intention to provide...... or consume information in online food communities. A survey was conducted among 1009 respondents followed by analysis based on Structural Equation Modelling. Results revealed the effect of motivation factors to be stronger than basic consumer interests indicating that companies can influence the intended...

  6. Potential costs of heterospecific sexual interactions in golden orbweb spiders (Nephila spp.).

    Science.gov (United States)

    Quiñones-Lebrón, Shakira G; Kralj-Fišer, Simona; Gregorič, Matjaž; Lokovšek, Tjaša; Čandek, Klemen; Haddad, Charles R; Kuntner, Matjaž

    2016-11-15

    Though not uncommon in other animals, heterospecific mating is rarely reported in arachnids. We investigated sexual interactions among four closely related and syntopical African golden orbweb spiders, Nephila inaurata, N. fenestrata, N. komaci, and N. senegalensis. In two South African localities, female webs were often inhabited by heterospecific males that sometimes outnumbered conspecifics. Species association of males with females was random in nature. In subsequent laboratory choice experiments, N. inaurata males chose heterospecific females in 30% of trials. We also observed natural mating interactions between N. inaurata males and N. komaci females, and between N. komaci males and N. inaurata females in laboratory experiments. While heterospecific mating in the laboratory never produced offspring, conspecific mating did. We discuss potential ecological and evolutionary consequences of heterospecific mating interactions in Nephila that may be particularly costly to the rarer species.

  7. The inclusion of electron correlation in intermolecular potentials: Applications to the formamide dimer and liquid formamide

    DEFF Research Database (Denmark)

    Brdarski, S.; Åstrand, P.-O.; Karlström, G.

    2000-01-01

    are rescaled to get the correct molecular properties at the MP2 level. The potential minimum for the cyclic dimer of formamide is -17.50 kcal/mol with the MP2-scaled properties and is significantly lower than other potentials give. Two intermolecular potentials are constructed and used in subsequent molecular...... dynamics simulations: one with the regular NEMO potential and the other with the rescaled MP2 properties. A damping of the electrostatic field at short intermolecular distances is included in the present NEMO model. The average energies for liquid formamide are lower for the MP2-scaled model...

  8. Dayside and nightside contributions to the cross polar cap potential: placing an upper limit on a viscous-like interaction

    Directory of Open Access Journals (Sweden)

    S. E. Milan

    2004-11-01

    Full Text Available Observations of changes in size of the ionospheric polar cap allow the dayside and nightside reconnection rates to be quantified. From these it is straightforward to estimate the rate of antisunward transport of magnetic flux across the polar regions, quantified by the cross polar cap potential ΦPC. When correlated with upstream measurements of the north-south component of the IMF, ΦPC is found to increase for more negative Bz, as expected. However, we also find that ΦPC does not, on average, decrease to zero, even for strongly northward IMF. In the past this has been interpreted as evidence for a viscous interaction between the magnetosheath flow and the outer boundaries of the magnetosphere. In contrast, we show that this is the consequence of flows excited by tail reconnection, which is inherently uncorrelated with IMF Bz.

  9. Physical interactions between DNA and sepiolite nanofibers, and potential application for DNA transfer into mammalian cells

    Science.gov (United States)

    Castro-Smirnov, Fidel Antonio; Piétrement, Olivier; Aranda, Pilar; Bertrand, Jean-Rémi; Ayache, Jeanne; Le Cam, Eric; Ruiz-Hitzky, Eduardo; Lopez, Bernard S.

    2016-01-01

    Nanofibers of sepiolite, a natural silicate belonging to the clay minerals family, might constitute a potential promising nanocarrier for the non-viral transfer of bio-molecules. We show here that sepiolite nanofibers efficiently bind different types of DNA molecules through electrostatic interactions, hydrogen bonding, cation bridges, and van der Waals forces. Moreover, Fourier-transform infrared spectroscopy identified the external silanol groups as the main sites of interaction with the DNA. Furthermore, as a proof of concept, we show that sepiolite is able to stably transfer plasmid DNA into mammalian cells and that the efficiency can be optimized. Indeed, sonication of sepiolite 100-fold stimulated DNA transfection efficiency. These results open the way to the use of sepiolite-based biohybrids as a novel class of nanoplatform for gene transfer with potential clinical applications. PMID:27808269

  10. Multiple scattering of low energy ions in matter: Influence of energy loss and interaction potential

    Energy Technology Data Exchange (ETDEWEB)

    Mekhtiche, A. [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria); Faculté des Sciences et de la Technologie, Université Yahia Farès de Médéa (Algeria); Khalal-Kouache, K., E-mail: kkouache@yahoo.fr [Laboratoire SNIRM, Faculté de Physique, Université des Sciences et de la Technologie Houari Boumediene (USTHB), BP 32 El Alia, Bab Ezzouar, Algiers (Algeria)

    2015-07-01

    In this paper, the effect of inelastic energy loss and interaction potential on transmitted ions at low energy is studied. For this purpose, angular distributions of slow He{sup +} ions transmitted through thin Ag films are calculated using the theory of multiple scattering. Thin films (20–50 Å at 2 keV and 50–200 Å at 10 keV) are considered so that the total path length of transmitted ions can be approximated by the value of the target thickness in this calculation. The corresponding values of the relative energy loss ΔE/E are comprised between 0.04 and 0.17. We show that even if low values of the thickness are considered, the total energy loss of ions in the target should be included in the calculation. These calculated angular distributions are also influenced by the potential used to describe the interaction between the incident ion and the target atom.

  11. Interaction potential of microparticles in a plasma: role of collisions with plasma particles.

    Science.gov (United States)

    Khrapak, S A; Ivlev, A V; Morfill, G

    2001-10-01

    The interaction potential of two charged microparticles in a plasma is studied. Violation of the plasma equilibrium around the dust particles due to plasma-particle inelastic collisions results in three effects: long-range (non-Yukawa) electrostatic repulsion, attraction due to ion shadowing, and attraction or repulsion due to neutral shadowing (depending on the sign of the temperature difference between the particle surface and neutral gas). An analytical expression for the total potential is obtained and compared with previous theoretical results. The relative contribution of these effects is studied in two limiting cases-an isotropic bulk plasma and the plasma sheath region. The results obtained are compared with existing experimental results on pair particle interaction. The possibility of the so-called dust molecule formation is discussed.

  12. Essential multimeric enzymes in kinetoplastid parasites: A host of potentially druggable protein-protein interactions.

    Science.gov (United States)

    Wachsmuth, Leah M; Johnson, Meredith G; Gavenonis, Jason

    2017-06-01

    Parasitic diseases caused by kinetoplastid parasites of the genera Trypanosoma and Leishmania are an urgent public health crisis in the developing world. These closely related species possess a number of multimeric enzymes in highly conserved pathways involved in vital functions, such as redox homeostasis and nucleotide synthesis. Computational alanine scanning of these protein-protein interfaces has revealed a host of potentially ligandable sites on several established and emerging anti-parasitic drug targets. Analysis of interfaces with multiple clustered hotspots has suggested several potentially inhibitable protein-protein interactions that may have been overlooked by previous large-scale analyses focusing solely on secondary structure. These protein-protein interactions provide a promising lead for the development of new peptide and macrocycle inhibitors of these enzymes.

  13. Atoms in double-delta-kicked periodic potentials: chaos with long-range correlations

    CERN Document Server

    Jones, P H; Hur, G; Monteiro, T S

    2004-01-01

    We report an experimental and theoretical study of the dynamics of cold atoms subjected to closely-spaced pairs of pulses in an optical lattice. The experiments show the interplay between fully coherent quantum dynamics and a novel momentum-diffusion regime: for all previously-studied delta-kicked systems, chaotic classical dynamics shows diffusion with short-time (2 or 3-kick) correlations; here, chaotic diffusion combines with new types of long-ranged 'global' correlations, between all kick-pairs, which control transport through trapping regions in phase-space. Analytical formulae are presented and, with quantum localization, are used to analyse the experiments.

  14. Reconstructing interaction potentials in thin films from real-space images.

    Science.gov (United States)

    Gienger, Jonas; Severin, Nikolai; Rabe, Jürgen P; Sokolov, Igor M

    2016-04-01

    We demonstrate that an inverse Monte Carlo approach allows one to reconstruct effective interaction potentials from real-space images. The method is exemplified on monomolecular ethanol-water films imaged with scanning force microscopy, which provides the spatial distribution of the molecules. Direct Monte Carlo simulations with the reconstructed potential allow for obtaining characteristics of the system which are unavailable in the experiment, such as the heat capacity of the monomolecularly thin film, and for a prediction of the critical temperature of the demixing transition.

  15. Potential drug-drug interactions in Alzheimer patients with behavioral symptoms.

    Science.gov (United States)

    Pasqualetti, Giuseppe; Tognini, Sara; Calsolaro, Valeria; Polini, Antonio; Monzani, Fabio

    2015-01-01

    The use of multi drug regimens among the elderly population has increased tremendously over the last decade although the benefits of medications are always accompanied by potential harm, even when prescribed at recommended doses. The elderly populations are particularly at an increased risk of adverse drug reactions considering comorbidity, poly-therapy, physiological changes affecting the pharmacokinetics and pharmacodynamics of many drugs and, in some cases, poor compliance due to cognitive impairment and/or depression. In this setting, drug-drug interaction may represent a serious and even life-threatening clinical condition. Moreover, the inability to distinguish drug-induced symptoms from a definitive medical diagnosis often results in addition of yet another drug to treat the symptoms, which in turn increases drug-drug interactions. Cognitive enhancers, including acetylcholinesterase inhibitors and memantine, are the most widely prescribed agents for Alzheimer's disease (AD) patients. Behavioral and psychological symptoms of dementia, including psychotic symptoms and behavioral disorders, represent noncognitive disturbances frequently observed in AD patients. Antipsychotic drugs are at high risk of adverse events, even at modest doses, and may interfere with the progression of cognitive impairment and interact with several drugs including anti-arrhythmics and acetylcholinesterase inhibitors. Other medications often used in AD patients are represented by anxiolytic, like benzodiazepine, or antidepressant agents. These agents also might interfere with other concomitant drugs through both pharmacokinetic and pharmacodynamic mechanisms. In this review we focus on the most frequent drug-drug interactions, potentially harmful, in AD patients with behavioral symptoms considering both physiological and pathological changes in AD patients, and potential pharmacodynamic/pharmacokinetic drug interaction mechanisms.

  16. Herbal medicines in Brazil: pharmacokinetic profile and potential herb-drug interactions.

    Science.gov (United States)

    Mazzari, Andre L D A; Prieto, Jose M

    2014-01-01

    A plethora of active compounds found in herbal medicines can serve as substrate for enzymes involved in the metabolism of xenobiotics. When a medicinal plant is co-administered with a conventional drug and little or no information is known about the pharmacokinetics of the plant metabolites, there is an increased risk of potential herb-drug interactions. Moreover, genetic polymorphisms in a population may act to predispose individuals to adverse reactions. The use of herbal medicines is rapidly increasing in many countries, particularly Brazil where the vast biodiversity is a potential source of new and more affordable treatments for numerous conditions. Accordingly, the Brazilian Unified Public Health System (SUS) produced a list of 71 plant species of interest, which could be made available to the population in the near future. Physicians at SUS prescribe a number of essential drugs and should herbal medicines be added to this system the chance of herb-drug interactions further increases. A review of the effects of these medicinal plants on Phase 1 and Phase 2 metabolic mechanisms and the transporter P-glycoprotein was conducted. The results have shown that approximately half of these medicinal plants lack any pharmacokinetic data. Moreover, most of the studies carried out are in vitro. Only a few reports on herb-drug interactions with essential drugs prescribed by SUS were found, suggesting that very little attention is being given to the safety of herbal medicines. Here we have taken this information to discuss the potential interactions between herbal medicines and essential drugs prescribed to Brazilian patients whilst taking into account the most common polymorphisms present in the Brazilian population. A number of theoretical interactions are pinpointed but more pharmacokinetic studies and pharmacovigilance data are needed to ascertain their clinical significance.

  17. Relaxation of strongly coupled Coulomb systems after rapid changes of the interaction potential

    CERN Document Server

    Gericke, D O; Semkat, D; Bonitz, M; Kremp, D

    2003-01-01

    The relaxation of charged particle systems after sudden changes of the pair interaction strength is investigated. As examples, we show the results for plasmas after ionization and after a rapid change of screening. Comparisons are made between molecular dynamics simulation and a kinetic description based on the Kadanoff-Baym equations. We found the latter very sensitive to the way the scattering cross section is treated. We also predict the new equilibrium state requiring only conservation of energy. In this case, the correlation energy is computed using the hypernetted chain approximation.

  18. Isospin effects of the Skyrme potential and the momentum dependent interaction at intermediate energy heavy ion collisions

    Institute of Scientific and Technical Information of China (English)

    GUO Wen-Jun; LIU Jian-Ye

    2008-01-01

    We improve the isospin dependent quantum molecular dynamical model by including isospin effects in the Skyrme potential and the momentum dependent interaction to obtain an isospin dependent Skyrme potential and an isospin dependent momentum interaction. We investigate the isospin effects of Skyrme potential and momentum dependent interaction on the isospin fractionation ratio and the dynamical mechanism in intermediate energy heavy ion collisions. It is found that the isospin dependent Skyrme potential and the isospin dependent momentum interaction produce some important isospin effects in the isospin fractionation ratio.

  19. Realistic Two-body Interactions in Many-nucleon Systems: Correlated Motion beyond Single-particle Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Sviratcheva, K.D.; Draayer, J.P.; /Louisiana State U. /Iowa State U. /LLNL, Livermore /SLAC

    2006-06-27

    In the framework of the theory of spectral distributions we perform an overall comparison of three modern realistic interactions, CD-Bonn, CD-Bonn+3terms, and GXPF1 in a broad range of nuclei in the upper fp shell and study their ability to account for the development of isovector pairing correlations and collective rotational motion in many-particle nuclear systems. Our findings reveal a close similarity between CD-Bonn and CD-Bonn+3terms, while both interactions possess features different from the ones of GXPF1. The GXPF1 interaction is used to determine the strength parameter of a quadrupole term that augments an isovector-pairing model interaction with Sp(4) dynamical symmetry, which in turn is shown to yield a reasonable agreement with the experimental low-lying energy spectra of {sup 58}Ni and {sup 58}Cu.

  20. Effect of taurine and potential interactions with caffeine on cardiovascular function.

    Science.gov (United States)

    Schaffer, Stephen W; Shimada, Kayoko; Jong, Chian Ju; Ito, Takashi; Azuma, Junichi; Takahashi, Kyoko

    2014-05-01

    The major impetus behind the rise in energy drink popularity among adults is their ability to heighten mental alertness, improve physical performance and supply energy. However, accompanying the exponential growth in energy drink usage have been recent case reports and analyses from the National Poison Data System, raising questions regarding the safety of energy drinks. Most of the safety concerns have centered on the effect of energy drinks on cardiovascular and central nervous system function. Although the effects of caffeine excess have been widely studied, little information is available on potential interactions between the other active ingredients of energy drinks and caffeine. One of the active ingredients often mentioned as a candidate for interactions with caffeine is the beta-amino acid, taurine. Although taurine is considered a conditionally essential nutrient for humans and is thought to play a key role in several human diseases, clinical studies evaluating the effects of taurine are limited. However, based on this review regarding possible interactions between caffeine and taurine, we conclude that taurine should neutralize several untoward effects of caffeine excess. In agreement with this conclusion, the European Union's Scientific Committee on Food published a report in March 2003 summarizing its investigation into potential interactions of the ingredients in energy drinks. At the cardiovascular level, they concluded that "if there are any interactions between caffeine and taurine, taurine might reduce the cardiovascular effects of caffeine." Although these interactions remain to be further examined in humans, the physiological functions of taurine appear to be inconsistent with the adverse cardiovascular symptoms associated with excessive consumption of caffeine-taurine containing beverages.

  1. Advances in adult asthma diagnosis and treatment in 2012: potential therapeutics and gene-environment interactions.

    Science.gov (United States)

    Apter, Andrea J

    2013-01-01

    In the Journal of Allergy and Clinical Immunology in 2012, research reports related to asthma in adults clustered around mechanisms of disease, with a special focus on their potential for informing new therapies. There was also consideration of the effect of the environment on health from pollution, climate change, and epigenetic influences, underlining the importance of understanding gene-environment interactions in the pathogenesis of asthma and response to treatment.

  2. Formation of chain structures in systems of charged grains interacting via isotropic pair potentials

    Energy Technology Data Exchange (ETDEWEB)

    Vaulina, O. S.; Lisina, I. I.; Koss, K. G., E-mail: Xeniya.Koss@gmail.com [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2013-05-15

    Conditions for the formation of chain structures of charged grains confined in the gravitational field by external electric fields are studied analytically and numerically. The relationships between the parameters of the pair interaction potential, the number of grains, and the electric field gradient in the trap are found. A criterion for the violation of stable equilibrium in a quasi-one-dimensional chain of grains and the formation of a new configuration in the system is proposed.

  3. Tracking transcription factor mobility and interaction in arabidopsis roots with fluorescence correlation spectroscopy

    NARCIS (Netherlands)

    Clark, Natalie M.; Hinde, Elizabeth; Hinde, Elizabeth; Fisher, Adam P.; Crosti, Giuseppe; Blilou, Ikram; Gratton, Enrico; Benfey, Philip N.; Sozzani, Rosangela

    2016-01-01

    To understand complex regulatory processes in multicellular organisms, it is critical to be able to quantitatively analyze protein movement and protein-protein interactions in time and space. During Arabidopsis development, the intercellular movement of SHORTROOT (SHR) and subsequent interaction

  4. The potential of vertebrate microfossils for marine to non-marine correlation in the Late Jurassic

    Institute of Scientific and Technical Information of China (English)

    Detlev Thies; Alexander Mudroch; Susan Turner

    2007-01-01

    Fish (cartilaginous: elasmobranch and bony: osteichthyan actinopterygian) and reptile (crocodile) microfossils comprising scales and teeth have been examined from a series of limestone samples in the Upper Jurassic of France and Germany to gauge the possibilities of using them for correlation between fully marine and hypo- or hyper-saline (non-marine) deposits.

  5. Neural Correlates of Abstract Rule Learning: An Event-Related Potential Study

    Science.gov (United States)

    Sun, Fang; Hoshi-Shiba, Reiko; Abla, Dilshat; Okanoya, Kazuo

    2012-01-01

    Abstract rule learning is a fundamental aspect of human cognition, and is essential for language acquisition. However, despite its importance, the neural mechanisms underlying abstract rule learning are still largely unclear. In this study, we investigated the neural correlates of abstract rule learning by recording auditory event-related…

  6. Two-particle angular correlations in $e^+ e^-$ interactions compared with QCD predictions

    CERN Document Server

    Abreu, P; Adye, T; Adzic, P; Ajinenko, I; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Anassontzis, E G; Andersson, P; Andreazza, A; Andringa, S; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbiellini, Guido; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Belous, K S; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Bizouard, M A; Bloch, D; Blom, H M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Boyko, I; Bozovic, I; Bozzo, M; Branchini, P; Brenke, T; Brenner, R A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschbeck, Brigitte; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Cerruti, C; Chabaud, V; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Collins, P; Colomer, M; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Damgaard, G; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Di Diodato, A; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Dris, M; Duperrin, A; Durand, J D; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Ellert, M; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Fayot, J; Feindt, Michael; Ferrari, P; Ferrer, A; Ferrer-Ribas, E; Fichet, S; Firestone, A; Fischer, P A; Flagmeyer, U; Föth, H; Fokitis, E; Fontanelli, F; Franek, B J; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gamblin, S; Gandelman, M; García, C; García, J; Gaspar, C; Gaspar, M; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gerdyukov, L N; Ghodbane, N; Gil, I; Glege, F; Gokieli, R; Golob, B; Gonçalves, P; González-Caballero, I; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Grahl, J; Graziani, E; Green, C; Gris, P; Grzelak, K; Günther, M; Guy, J; Hahn, F; Hahn, S; Haider, S; Hallgren, A; Hamacher, K; Harris, F J; Hedberg, V; Heising, S; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, P E; Joram, C; Juillot, P; Kapusta, F; Karafasoulis, K; Katsanevas, S; Katsoufis, E C; Keränen, R; Khomenko, B A; Khovanskii, N N; Kiiskinen, A P; King, B J; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Knoblauch, D; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kreuter, C; Krstic, J; Krumshtein, Z; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lamsa, J; Lane, D W; Langefeld, P; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Leinonen, L; Leisos, A; Leitner, R; Lenzen, Georg; Lepeltier, V; Lesiak, T; Lethuillier, M; Libby, J; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; Lopes, J H; López, J M; López-Fernandez, R; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Mahon, J R; Maio, A; Malek, A; Malmgren, T G M; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Masik, J; Mazzucato, F; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Meroni, C; Meyer, W T; Myagkov, A; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Moreau, X; Morettini, P; Morton, G A; Müller, U; Münich, K; Mulders, M; Mulet-Marquis, C; Muresan, R; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Neufeld, N; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nikolaenko, V; Nikolenko, M; Nomokonov, V P; Normand, Ainsley; Nygren, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganoni, M; Paiano, S; Pain, R; Paiva, R; Palacios, J; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Pegoraro, M; Peralta, L; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rakoczy, D; Rames, J; Ratoff, P N; Read, A L; Rebecchi, P; Redaelli, N G; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Røhne, O M; Romero, A; Ronchese, P; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Ruhlmann-Kleider, V; Ruiz, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sampsonidis, D; Sannino, M; Schneider, H; Schwemling, P; Schwickerath, U; Schyns, M A E; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Sekulin, R L; Shellard, R C; Sheridan, A; Siebel, M; Silvestre, R; Simard, L C; Simonetto, F; Sissakian, A N; Skaali, T B; Smadja, G; Smirnova, O G; Smith, G R; Sopczak, André; Sosnowski, R; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stampfer, D; Stanescu, C; Stanic, S; Stapnes, Steinar; Stevenson, K; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Chikilev, O G; Tegenfeldt, F; Terranova, F; Thomas, J; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Todorova, S; Toet, D Z; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; van Apeldoorn, G W; van Dam, P; Van Eldik, J; Van Lysebetten, A; Van Vulpen, I B; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Verzi, V; Vilanova, D; Vitale, L; Vlasov, E; Vodopyanov, A S; Voulgaris, G; Vrba, V; Wahlen, H; Walck, C; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G R; Winter, M; Witek, M; Wolf, G; Yi, J; Yushchenko, O P; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zucchelli, G C; Zumerle, G

    1998-01-01

    Two--particle angular correlations in jet cones have been measured in $e^+e^-$ annihilation into hadrons at LEP energies ($\\sqrt{s}=$ 91 and 183~GeV) and are compared with QCD predictions using the LPHD hypothesis. Two different functions have been tested. While the differentially normalized correlation function shows substantial deviations from the predictions, a globally normalized correlation function agrees well. The size of $\\alpha_S^{\\rm eff}$ (and other QCD parameters) and its running with the relevant angular scale, the validity of LPHD, and problems due to non--perturbative effects are discussed critically.

  7. Spatial filtering based on canonical correlation analysis for classification of evoked or event-related potentials in EEG data.

    Science.gov (United States)

    Spüler, Martin; Walter, Armin; Rosenstiel, Wolfgang; Bogdan, Martin

    2014-11-01

    Classification of evoked or event-related potentials is an important prerequisite for many types of brain-computer interfaces (BCIs). To increase classification accuracy, spatial filters are used to improve the signal-to-noise ratio of the brain signals and thereby facilitate the detection and classification of evoked or event-related potentials. While canonical correlation analysis (CCA) has previously been used to construct spatial filters that increase classification accuracy for BCIs based on visual evoked potentials, we show in this paper, how CCA can also be used for spatial filtering of event-related potentials like P300. We also evaluate the use of CCA for spatial filtering on other data with evoked and event-related potentials and show that CCA performs consistently better than other standard spatial filtering methods.

  8. Auditory- and Vestibular-Evoked Potentials Correlate with Motor and Non-Motor Features of Parkinson’s Disease

    Science.gov (United States)

    Shalash, Ali Soliman; Hassan, Dalia Mohamed; Elrassas, Hanan Hani; Salama, Mohamed Mosaad; Méndez-Hernández, Edna; Salas-Pacheco, José M.; Arias-Carrión, Oscar

    2017-01-01

    Degeneration of several brainstem nuclei has been long related to motor and non-motor symptoms (NMSs) of Parkinson’s disease (PD). Nevertheless, due to technical issues, there are only a few studies that correlate that association. Brainstem auditory-evoked potential (BAEP) and vestibular-evoked myogenic potential (VEMP) responses represent a valuable tool for brainstem assessment. Here, we investigated the abnormalities of BAEPs, ocular VEMPs (oVEMPs), and cervical VEMPs (cVEMPs) in patients with PD and its correlation to the motor and NMSs. Fifteen patients diagnosed as idiopathic PD were evaluated by Unified Parkinson’s Disease Rating Scale and its subscores, Hoehn and Yahr scale, Schwab and England scale, and Non-Motor Symptoms Scale. PD patients underwent pure-tone, speech audiometry, tympanometry, BAEP, oVEMPs, and cVEMPs, and compared to 15 age-matched control subjects. PD subjects showed abnormal BAEP wave morphology, prolonged absolute latencies of wave V and I–V interpeak latencies. Absent responses were the marked abnormality seen in oVEMP. Prolonged latencies with reduced amplitudes were seen in cVEMP responses. Rigidity and bradykinesia were correlated to the BAEP and cVEMP responses contralateral to the clinically more affected side. Contralateral and ipsilateral cVEMPs were significantly correlated to sleep (p = 0.03 and 0.001), perception (p = 0.03), memory/cognition (p = 0.025), and urinary scores (p = 0.03). The oVEMP responses showed significant correlations to cardiovascular (p = 0.01) and sexual dysfunctions (p = 0.013). PD is associated with BAEP and VEMP abnormalities that are correlated to the motor and some non-motor clinical characteristics. These abnormalities could be considered as potential electrophysiological biomarkers for brainstem dysfunction and its associated motor and non-motor features. PMID:28289399

  9. Improving intermolecular interactions in DFTB3 using extended polarization from chemical-potential equalization

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, Anders S., E-mail: andersx@chem.wisc.edu, E-mail: cui@chem.wisc.edu; Cui, Qiang, E-mail: andersx@chem.wisc.edu, E-mail: cui@chem.wisc.edu [Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706 (United States); Elstner, Marcus [Theoretische Chemische Biologie, Universität Karlsruhe, Kaiserstr. 12, 76131 Karlsruhe (Germany)

    2015-08-28

    Semi-empirical quantum mechanical methods traditionally expand the electron density in a minimal, valence-only electron basis set. The minimal-basis approximation causes molecular polarization to be underestimated, and hence intermolecular interaction energies are also underestimated, especially for intermolecular interactions involving charged species. In this work, the third-order self-consistent charge density functional tight-binding method (DFTB3) is augmented with an auxiliary response density using the chemical-potential equalization (CPE) method and an empirical dispersion correction (D3). The parameters in the CPE and D3 models are fitted to high-level CCSD(T) reference interaction energies for a broad range of chemical species, as well as dipole moments calculated at the DFT level; the impact of including polarizabilities of molecules in the parameterization is also considered. Parameters for the elements H, C, N, O, and S are presented. The Root Mean Square Deviation (RMSD) interaction energy is improved from 6.07 kcal/mol to 1.49 kcal/mol for interactions with one charged species, whereas the RMSD is improved from 5.60 kcal/mol to 1.73 for a set of 9 salt bridges, compared to uncorrected DFTB3. For large water clusters and complexes that are dominated by dispersion interactions, the already satisfactory performance of the DFTB3-D3 model is retained; polarizabilities of neutral molecules are also notably improved. Overall, the CPE extension of DFTB3-D3 provides a more balanced description of different types of non-covalent interactions than Neglect of Diatomic Differential Overlap type of semi-empirical methods (e.g., PM6-D3H4) and PBE-D3 with modest basis sets.

  10. Phonon frequency shift and effect of correlation on the electron-phonon interaction in heavy fermion systems

    Indian Academy of Sciences (India)

    B Ojha; P Nayak; S N Behera

    2000-02-01

    The electron–phonon interaction in the periodic Anderson model (PAM) is considered. The PAM incorporates the effect of onsite Coulomb interaction () between -electrons. The influence of Coulomb correlation on the phonon response of the system is studied by evaluating the phonon spectral function for various parameters of the model. The numerical evaluation of the spectral function is carried out in the long wavelength limit at finite temperatures keeping only linear terms in . The observed behaviour is found to agree well with the general features obtained experimentally for some heavy fermion (HF) systems.

  11. One and two dimensional analysis of 3$\\pi$ correlations measured in Pb+Pb interactions

    CERN Document Server

    Bearden, I G; Boissevain, J G; Christiansen, P; Conin, L; Dodd, J; Erazmus, B; Esumi, S C; Fabjan, Christian Wolfgang; Ferenc, D; Fields, D E; Franz, A; Gaardhøje, J J; Hansen, A G; Hansen, O; Hardtke, D; van Hecke, H; Holzer, E B; Humanic, T J; Hummel, P; Jacak, B V; Jayanti, R; Kaimi, K; Kaneta, M; Kohama, T; Kopytine, M L; Leltchouk, M; Ljubicic, A; Lörstad, B; Maeda, N; Martin, L; Medvedev, A; Murray, M; Ohnishi, H; Paic, G; Pandey, S U; Piuz, François; Pluta, J; Polychronakos, V; Potekhin, M V; Poulard, G; Reichhold, D M; Sakaguchi, A; Schmidt-Sørensen, J; Simon-Gillo, J; Sondheim, W E; Sugitate, T; Sullivan, J P; Sumi, Y; Willis, W J; Wolf, K L; Xu, N; Zachary, D S

    2001-01-01

    $\\pi^{-}\\pi^{-}\\pi^{-}$ correlations from Pb+Pb collisions at 158 GeV/c per nucleon are presented as measured by the focusing spectrometer of the NA44 experiment at CERN. The three-body effect is found to be stronger for PbPb than for SPb. The two-dimensional three-particle correlation function is also measured and the longitudinal extension of the source is larger than the transverse extension.

  12. Potential interactions of central nervous system drugs used in the elderly population

    Directory of Open Access Journals (Sweden)

    Fernanda Bueno Morrone

    2009-06-01

    Full Text Available OBJECTIVE: To describe the use of CNS drugs and to identify the most frequently observed potential drug interactions in the elderly living in Southern Brazil. METHODS: A population-based, transversal and observational study was carried out during 2006-2007. Four hundred and eighty elderly individuals of both genders were randomly recruited and interviewed. A validated pharmacotherapeutic questionnaire and the Micromedex® Healthcare Series were utilized to analyze potential drug interactions. A severity rating scale employing the categories of "mild", "moderate" and "severe" was used to describe the interactions. RESULTS: A population of elderly living in Southern Brazil was interviewed and 98 reported using CNS drugs, 74.5% female and 25.5% male. Out of these patients, 32.0% reported severe or moderate pharmacological interactions related to the use of other drugs. Alprazolam and imipramine were reported to potentially interact with tobacco. Twenty potential moderate drug/ethanol interactions were found. The potential drug/caffeine interactions were classified as mild on the severity scale. CONCLUSION: Elderly being prescribed drugs that act on the CNS should be closely monitored, and furthermore, should be warned against potential drug-drug, drug-ethanol, and drug-tobacco interactions.OBJETIVO: Descrever o uso de medicamentos que atuam no sistema nervoso central (SNC e identificar as possíveis interações mais frequentes com esses medicamentos em idosos do sul do Brasil. MÉTODOS: Estudo de base populacional, transversal e observacional, realizado durante 2006-2007. Quatrocentos e oitenta idosos de ambos os sexos foram randomizados e entrevistados. Foram utilizados um questionário farmacoterapêutico validado e o programa Micromedex® Healthcare Series para analisar as potenciais interações com os medicamentos. Foi utilizada uma escala para descrever a gravidade das interações nas categorias de "leve", "moderada" e "grave". RESULTADOS

  13. Quantifying interhemispheric symmetry of somatosensory evoked potentials with the intraclass correlation coefficient

    NARCIS (Netherlands)

    van de Wassenberg, Wilma J. G.; van der Hoeven, Johannes H.; Leenders, Klaus L.; Maurits, Natasha M.

    Although large intersubject variability is reported for cortical somatosensory evoked potentials (SEPs), variability between hemispheres within one subject is thought to be small. Therefore, interhemispheric comparison of SEP waveforms might be clinically useful to detect unilateral abnormalities in

  14. Quantifying interhemispheric symmetry of somatosensory evoked potentials with the intraclass correlation coefficient

    NARCIS (Netherlands)

    van de Wassenberg, Wilma J. G.; van der Hoeven, Johannes H.; Leenders, Klaus L.; Maurits, Natasha M.

    2008-01-01

    Although large intersubject variability is reported for cortical somatosensory evoked potentials (SEPs), variability between hemispheres within one subject is thought to be small. Therefore, interhemispheric comparison of SEP waveforms might be clinically useful to detect unilateral abnormalities in

  15. Building potential patent portfolios: An integrated approach based on topic identification and correlation analysis

    National Research Council Canada - National Science Library

    Xian ZHANG Haiyun XU Shu FANG Zhengyin HU Shuying LI

    2015-01-01

    Purpose: This paper suggests a framework to identify important patents for building potential patent portfolios based on patents owned by different assignees so as to highlight the value of individual patents...

  16. X-Ray Cross-Correlation Analysis of Disordered Ensembles of Particles: Potentials and Limitations

    Directory of Open Access Journals (Sweden)

    R. P. Kurta

    2013-01-01

    Full Text Available Angular X-ray cross-correlation analysis (XCCA is an approach to study the structure of disordered systems using the results of X-ray scattering experiments. In this paper we summarize recent theoretical developments related to the Fourier analysis of the cross-correlation functions. Results of our simulations demonstrate the application of XCCA to two- and three-dimensional (2D and 3D disordered ensembles of particles. We show that the structure of a single particle can be recovered using X-ray data collected from a 2D disordered system of identical particles. We also demonstrate that valuable structural information about the local structure of 3D systems, inaccessible from a standard small-angle X-ray scattering experiment, can be resolved using XCCA.

  17. Analysis of regression-correlation relationships between indicators of university potential and macroeconomic indicators of Ukrainian regions

    Directory of Open Access Journals (Sweden)

    Zhuravka Andrey V.

    2017-03-01

    Full Text Available The purpose of the article is to study the competitive university potential of the regions and its relationship with the macroeconomic indicators of the regions of Ukraine. An analysis of regression-correlation relationships between four macroeconomic indicators and two indicators of the university potential of the regions of Ukraine is made. As a result of the research, the best correlation was obtained between the number of universities and the indicator Ij, calculated on the basis of aggregating the webometric ratings of universities for each region. It is shown that both indicators of the regional university potential correlate well with all four macroeconomic indicators. At the same time, analysis of the essence of regional development shows that with the growth of cities and the social and economic power of the regions, the university potential of the regions also grows, and not vice versa. Prospects for further research in this area are the inclusion of a larger number of scientific, innovation and macroeconomic indicators.

  18. Bronchial reacutization and gastroesophageal reflux: is there a potential clinical correlation?

    Science.gov (United States)

    Mauroner, Luisa; Paiano, Simona; Assante, Luca Rosario; Bertolaccini, Luca; Ruffo, Giacomo; Mainardi, Paride; Bocus, Paolo; Geccherle, Andrea; Albanese, Sergio Ivan; Ciaffoni, Stefano

    2016-01-01

    Background Pepsin plays a role in gastroesophageal reflux (GER). Aims of this study were to verify if pepsin could be the cause of frequent bronchial exacerbations and to check if the persistence of chronic respiratory symptoms were correlated with pre-existing respiratory diseases. Methods From January to May 2016, 42 patients underwent a diagnostic bronchoscopy. All patients had a history of at least one bronchial exacerbation during the previous year. Bronchial lavage fluid specimens were obtained. A semiquantitative assessment of pepsin in the samples was carried out based on the intensity of the test sample. Results Pepsin was present in 37 patients (88%), but in patients with bronchial asthma and chronic obstructive pulmonary disease (COPD), the finding of pepsin in the bronchoalveolar fluid was 100%. There was a strong positive statistical correlation between pepsin detection and radiological signs of GER (ρ=0.662), and between pepsin detection and diagnosis (ρ=0.682). No correlation was found between the bacteriology and the presence of pepsin in the airways (ρ=0.006). Conclusions The presence of pepsin in the airways shows the occurrence of reflux. The persistence of respiratory symptoms by at least 2 months suggest an endoscopic bronchial examination. This straightforward test confirms the cause possible irritation of the airways and may prevent further diagnostic tests, such as an EGD or pH monitoring esophageal. PMID:27668224

  19. Study of Potential Drug-Drug Interactions in Prescriptions of University- Based Pharmacies

    Directory of Open Access Journals (Sweden)

    Sarah Mousavi

    2015-10-01

    Full Text Available Background: Drug-Drug Interactions (DDIs are adverse reactions caused by a combination of drugs; they are often predictable and therefore avoidable or manageable. The objective of this study was to evaluate the nature, type and prevalence of potential DDIs in prescriptions dispensed in university-based community pharmacies in Tehran, Iran.Methods: From July 2012 to February 2014, sample of 1260 prescriptions were collected from community and outpatient hospital pharmacies affiliated to Tehran University of Medical Sciences (TUMS, Iran. The prescriptions were assessed using the reference text “drug interaction facts”. The identified DDIs were categorized according to their level of significance into three classes (minor, moderate, major.Results: At least one drug-drug interaction was present in 339 (26.9% of prescriptions and a total of 751 cases of interactions were found in prescriptions. Major DDIs represented 7.3% of all DDIs detected, whereas moderate DDIs were 75% of all DDIs. The mean number of drugs per prescriptions was 3.2, with a median of 4 (range, 2-10.There was a positive association between number of prescribed drugs and occurrence of DDIs (OR: 2.14, 95% CI: 1.9-2.4. The prescriptions of medical specialist had greater risk of occurrence of moderate severity DDIs than general practitioners (OR: 1.52, 95%CI: 1.08-2.15.Conclusion: Despite the prescriptions were collected from university-based pharmacies, but the overall prevalence of potential DDIs were high among patients. Physicians should be aware of potentially harmful DDIs. Meanwhile Pharmacists can contribute to the detection and prevention of drug-related injuries. Appropriate education, collaborating drug selection and pharmaceutical care are strongly recommended for physicians and pharmacists.

  20. Whitebark pine facilitation at treeline: potential interactions for disruption by an invasive pathogen.

    Science.gov (United States)

    Tomback, Diana F; Blakeslee, Sarah C; Wagner, Aaron C; Wunder, Michael B; Resler, Lynn M; Pyatt, Jill C; Diaz, Soledad

    2016-08-01

    In stressful environments, facilitation often aids plant establishment, but invasive plant pathogens may potentially disrupt these interactions. In many treeline communities in the northern Rocky Mountains of the U.S. and Canada, Pinus albicaulis, a stress-tolerant pine, initiates tree islands at higher frequencies than other conifers - that is, leads to leeward tree establishment more frequently. The facilitation provided by a solitary (isolated) P. albicaulis leading to tree island initiation may be important for different life-history stages for leeward conifers, but it is not known which life-history stages are influenced and protection provided. However, P. albicaulis mortality from the non-native pathogen Cronartium ribicola potentially disrupts these facilitative interactions, reducing tree island initiation. In two Rocky Mountain eastern slope study areas, we experimentally examined fundamental plant-plant interactions which might facilitate tree island formation: the protection offered by P. albicaulis to leeward seed and seedling life-history stages, and to leeward krummholz conifers. In the latter case, we simulated mortality from C. ribicola for windward P. albicaulis to determine whether loss of P. albicaulis from C. ribicola impacts leeward conifers. Relative to other common solitary conifers at treeline, solitary P. albicaulis had higher abundance. More seeds germinated in leeward rock microsites than in conifer or exposed microsites, but the odds of cotyledon seedling survival during the growing season were highest in P. albicaulis microsites. Planted seedling survival was low among all microsites examined. Simulating death of windward P. albicaulis by C. ribicola reduced shoot growth of leeward trees. Loss of P. albicaulis to exotic disease may limit facilitation interactions and conifer community development at treeline and potentially impede upward movement as climate warms.

  1. Mapping of the interaction sites of galanthamine: a quantitative analysis through pairwise potentials and quantum chemistry

    Science.gov (United States)

    Galland, Nicolas; Kone, Soleymane; Le Questel, Jean-Yves

    2012-10-01

    A quantitative analysis of the interaction sites of the anti-Alzheimer drug galanthamine with molecular probes (water and benzene molecules) representative of its surroundings in the binding site of acetylcholinesterase (AChE) has been realized through pairwise potentials calculations and quantum chemistry. This strategy allows a full and accurate exploration of the galanthamine potential energy surface of interaction. Significantly different results are obtained according to the distances of approaches between the various molecular fragments and the conformation of the galanthamine N-methyl substituent. The geometry of the most relevant complexes has then been fully optimized through MPWB1K/6-31 + G(d,p) calculations, final energies being recomputed at the LMP2/aug-cc-pVTZ(-f) level of theory. Unexpectedly, galanthamine is found to interact mainly from its hydrogen-bond donor groups. Among those, CH groups in the vicinity of the ammonium group are prominent. The trends obtained provide rationales to the predilection of the equatorial orientation of the galanthamine N-methyl substituent for binding to AChE. The analysis of the interaction energies pointed out the independence between the various interaction sites and the rigid character of galanthamine. The comparison between the cluster calculations and the crystallographic observations in galanthamine-AChE co-crystals allows the validation of the theoretical methodology. In particular, the positions of several water molecules appearing as strongly conserved in galanthamine-AChE co-crystals are predicted by the calculations. Moreover, the experimental position and orientation of lateral chains of functionally important aminoacid residues are in close agreement with the ones predicted theoretically. Our study provides relevant information for a rational drug design of galanthamine based AChE inhibitors.

  2. Mapping of the interaction sites of galanthamine: a quantitative analysis through pairwise potentials and quantum chemistry.

    Science.gov (United States)

    Galland, Nicolas; Kone, Soleymane; Le Questel, Jean-Yves

    2012-10-01

    A quantitative analysis of the interaction sites of the anti-Alzheimer drug galanthamine with molecular probes (water and benzene molecules) representative of its surroundings in the binding site of acetylcholinesterase (AChE) has been realized through pairwise potentials calculations and quantum chemistry. This strategy allows a full and accurate exploration of the galanthamine potential energy surface of interaction. Significantly different results are obtained according to the distances of approaches between the various molecular fragments and the conformation of the galanthamine N-methyl substituent. The geometry of the most relevant complexes has then been fully optimized through MPWB1K/6-31 + G(d,p) calculations, final energies being recomputed at the LMP2/aug-cc-pVTZ(-f) level of theory. Unexpectedly, galanthamine is found to interact mainly from its hydrogen-bond donor groups. Among those, CH groups in the vicinity of the ammonium group are prominent. The trends obtained provide rationales to the predilection of the equatorial orientation of the galanthamine N-methyl substituent for binding to AChE. The analysis of the interaction energies pointed out the independence between the various interaction sites and the rigid character of galanthamine. The comparison between the cluster calculations and the crystallographic observations in galanthamine-AChE co-crystals allows the validation of the theoretical methodology. In particular, the positions of several water molecules appearing as strongly conserved in galanthamine-AChE co-crystals are predicted by the calculations. Moreover, the experimental position and orientation of lateral chains of functionally important aminoacid residues are in close agreement with the ones predicted theoretically. Our study provides relevant information for a rational drug design of galanthamine based AChE inhibitors.

  3. The Mann-Kendall test: the need to consider the interaction between serial correlation and trend - doi: 10.4025/actasciagron.v35i4.16006

    Directory of Open Access Journals (Sweden)

    Gabriel Constantino Blain

    2013-05-01

    Full Text Available Pre-whitening approaches have been widely used to remove the influence of serial correlations on the Mann-Kendall trend test (MK_prew. However, previous studies indicate that this procedure may lead to a false reduction of the significance of a trend. An alternative approach (MK_interact has been proposed to improve the assessment of the significance of a trend in auto-correlated data. Therefore, the present study compared the performance of the MK_prew and MK_interact for detecting trends in auto-correlated series. Sets of Monte Carlo experiments were carried out to evaluate the occurrence of type I and II errors obtained from both approaches. The analyses were also based on 10-day values of the difference between precipitation and potential evapotranspiration (P-EP obtained from the location of Campinas, State of São Paulo, Brazil. The results found in this study allow us to conclude that the MK_interac outperformed the MK_prew in correctly identifying the significance of trends and that, concerning agricultural interests, the decreasing trend described by the MK_interac during the beginning of the crop growing seasons may reveal an unfavorable temporal distribution of the P-EP values.

  4. Dirac equation for the Hulthén potential within the Yukawa-type tensor interaction

    Institute of Scientific and Technical Information of China (English)

    Oktay Aydo(g)du; Elham Maghsoodi; Hassan Hassanabadi

    2013-01-01

    Using the Nikiforov-Uvarov (NU) method,pseudospin and spin symmetric solutions of the Dirac equation for the scalar and vector Hulthén potentials with the Yukawa-type tensor potential are obtained for an arbitrary spin-orbit coupling quantum number κ.We deduce the energy eigenvalue equations and corresponding upper-and lower-spinor wave functions in both the pseudospin and spin symmetry cases.Numerical results of the energy eigenvalue equations and the upper-and lower-spinor wave functions are presented to show the effects of the external potential and particle mass parameters as well as pseudospin and spin symmetric constants on the bound-state energies and wave functions in the absence and presence of the tensor interaction.

  5. Unexplored regions in QFT: delocalization of quantum matter through interactions with zero mass potentials

    CERN Document Server

    Schroer, Bert

    2010-01-01

    Massive quantum matter of prescribed spin permits infinitely many possibilities of covariantization in terms of spinorial (undotted/dotted) pointlike fields, whereas massless finite helicity representations lead to large gap in this spinorial spectrum which quantum field theorists usually try to fill by inventing an indefinite metric vectorpotential (Gupta-Bleuler, BRST) outside the quantum theoretic realm. Only after completing the computation the expecration of the gauge invariant observables are obtained. The full range of covariant possiblities (without indefinite metric) is restored if one allows localization along semiinfinite strings in addition to pointlike localization. These stringlike potentials fluctuate in the direction of the string (points in a lower de Sitter space) and absorb part of the short distance singularity: there always exists a potential with the smallest short distance dimension allowed by unitarity: sdd=1. In case the interaction with the potential remains linear (QED), there is a ...

  6. Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p + p interactions at the CERN Super Proton Synchrotron

    Science.gov (United States)

    Aduszkiewicz, A.; Ali, Y.; Andronov, E.; Antićić, T.; Antoniou, N.; Baatar, B.; Bay, F.; Blondel, A.; Bogomilov, M.; Brandin, A.; Bravar, A.; Brzychczyk, J.; Bunyatov, S. A.; Busygina, O.; Christakoglou, P.; Ćirković, M.; Czopowicz, T.; Damyanova, A.; Davis, N.; Dembinski, H.; Deveaux, M.; Diakonos, F.; Luise, S. Di; Dominik, W.; Dumarchez, J.; Engel, R.; Ereditato, A.; Feofilov, G. A.; Fodor, Z.; Garibov, A.; Gaździcki, M.; Golubeva, M.; Grebieszkow, K.; Grzeszczuk, A.; Guber, F.; Haesler, A.; Hasegawa, T.; Hervé, A. E.; Hierholzer, M.; Hylen, J.; Igolkin, S.; Ivashkin, A.; Johnson, S. R.; Kadija, K.; Kapoyannis, A.; Kaptur, E.; Kiełbowicz, M.; Kisiel, J.; Knezević, N.; Kobayashi, T.; Kolesnikov, V. I.; Kolev, D.; Kondratiev, V. P.; Korzenev, A.; Kovalenko, V.; Kowalik, K.; Kowalski, S.; Koziel, M.; Krasnoperov, A.; Kuich, M.; Kurepin, A.; Larsen, D.; László, A.; Lewicki, M.; Lundberg, B.; Lyubushkin, V. V.; Maćkowiak-Pawłowska, M.; Maksiak, B.; Malakhov, A. I.; Manić, D.; Marchionni, A.; Marcinek, A.; Marino, A. D.; Marton, K.; Mathes, H.-J.; Matulewicz, T.; Matveev, V.; Melkumov, G. L.; Merzlaya, A.; Messerly, B.; Mills, G. B.; Morozov, S.; Mrówczyński, S.; Nagai, Y.; Nakadaira, T.; Naskręt, M.; Nirkko, M.; Nishikawa, K.; Ozvenchuk, V.; Panagiotou, A. D.; Paolone, V.; Pavin, M.; Petukhov, O.; Pistillo, C.; Płaneta, R.; Popov, B. A.; Posiadała, M.; Puławski, S.; Puzović, J.; Rameika, R.; Rauch, W.; Ravonel, M.; Redij, A.; Renfordt, R.; Richter-Wąs, E.; Robert, A.; Röhrich, D.; Rondio, E.; Roth, M.; Rubbia, A.; Rumberger, B. T.; Rustamov, A.; Rybczynski, M.; Rybicki, A.; Sadovsky, A.; Sakashita, K.; Sarnecki, R.; Schmidt, K.; Sekiguchi, T.; Selyuzhenkov, I.; Seryakov, A.; Seyboth, P.; Sgalaberna, D.; Shibata, M.; Słodkowski, M.; Staszel, P.; Stefanek, G.; Stepaniak, J.; Ströbele, H.; Šuša, T.; Szuba, M.; Tada, M.; Taranenko, A.; Tefelska, A.; Tefelski, D.; Tereshchenko, V.; Tsenov, R.; Turko, L.; Ulrich, R.; Unger, M.; Vassiliou, M.; Veberič, D.; Vechernin, V. V.; Vesztergombi, G.; Vinogradov, L.; Walewski, M.; Wickremasinghe, A.; Wilczek, A.; Włodarczyk, Z.; Wojtaszek-Szwarc, A.; Wyszyński, O.; Zambelli, L.; Zimmerman, E. D.; Zwaska, R.

    2017-02-01

    Results on two-particle Δ η Δ φ correlations in inelastic p + p interactions at 20, 31, 40, 80, and 158 GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the Epos and UrQMD models.

  7. Intermolecular Interaction Potentials of CH4-Ne Complex Calculated with Local Density Approximation Methods

    Institute of Scientific and Technical Information of China (English)

    BAI Yu-Lin; CHENG Xiao-Hong; CHEN Xiang-Rong; YANG Xiang-Dong; ZHU Jun

    2004-01-01

    @@ The intermolecular interactions potentials for two configurations of CH4-Ne complex are calculated with local density approximation methods in the frame of density functional theory. It is found that the calculated potentials have two minima when the distance between the carbon atom of CH4 and the Ne atom takes R = 5.80 a.u.and 6.20a. u. for both the two configurations. For the edge configuration, the corresponding depth of the potential is 0.0669536 eV and 0.0671416 eV. For the face configuration, the corresponding depth of the potential is 0.0737956 eV and 0.0645506 eV. The global minimum occurs at R = 5.80 a.u. for the face configuration with a depth of the potential 0.0737956 eV. The depths of our calculation are in better agreement with the experimental data than the quantum chemical calculation approach, while the position of minimum potential for our calculation is underestimated.

  8. Microorganisms in potential host rocks for geological disposal of nuclear waste and their interactions with radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Cherkouk, A.; Liebe, M.; Luetke, L.; Moll, H.; Stumpf, T. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology

    2015-07-01

    The long-term safety of nuclear waste in a deep geological repository is an important issue in our society. Microorganisms indigenous to potential host rocks are able to influence the oxidation state, speciation and therefore the mobility of radionuclides as well as gas generation or canister corrosion. Therefore, for the safety assessment of such a repository it is necessary to know which microorganisms are present in the potential host rocks (e.g. clay, salt) and if these microorganisms can influence the performance of a repository. Microbial diversity in potential host rocks for geological disposal of nuclear waste was analyzed by culture-independent molecular biological methods (e.g. 16S rRNA gene retrieval) as well as enrichment and isolation of indigenous microbes. Among other isolates, a Paenibacillus strain, as a representative of Firmicutes, was recovered in R2A media under anaerobic conditions from Opalinus clay from the Mont Terri in Switzerland. Accumulation experiments and potentiometric titrations showed a strong interaction of Paenibacillus sp. cells with U(VI) within a broad pH range (3-7). Additionally, the interactions of the halophilic archaeal strain Halobacterium noricense DSM 15987, a salt rock representative reference strain, with U(VI) at high ionic strength was investigated. After 48 h the cells were still alive at uranium concentrations up to 60 μM, which demonstrates that Halobacterium noricense can tolerate uranium concentrations up to this level. The formed uranium sorption species were examined with time-resolved laser-induced fluorescence spectroscopy (TRLFS). The results about the microbial communities present in potential host rocks for nuclear waste repositories and their interactions with radionuclides contribute to the safety assessment of a prospective nuclear waste repository.

  9. Correlation of inhibitory effects of polymers on indomethacin precipitation in solution and amorphous solid crystallization based on molecular interaction.

    Science.gov (United States)

    Chauhan, Harsh; Kuldipkumar, Anuj; Barder, Timothy; Medek, Ales; Gu, Chong-Hui; Atef, Eman

    2014-02-01

    To correlate the polymer's degree of precipitation inhibition of indomethacin in solution to the amorphous stabilization in solid state. Precipitation of indomethacin (IMC) in presence of polymers was continuously monitored by a UV spectrophotometer. Precipitates were characterized by PXRD, IR and SEM. Solid dispersions with different polymer to drug ratios were prepared using solvent evaporation. Crystallization of the solid dispersion was monitored using PXRD. Modulated differential scanning calorimetry (MDSC), IR, Raman and solid state NMR were used to explore the possible interactions between IMC and polymers. PVP K90, HPMC and Eudragit E100 showed precipitation inhibitory effects in solution whereas Eudragit L100, Eudragit S100 and PEG 8000 showed no effect on IMC precipitation. The rank order of precipitation inhibitory effect on IMC was found to be PVP K90 > Eudragit E100 > HPMC. In the solid state, polymers showing precipitation inhibitory effect also exhibited amorphous stabilization of IMC with the same rank order of effectiveness. IR, Raman and solid state NMR studies showed that rank order of crystallization inhibition correlates with strength of molecular interaction between IMC and polymers. Correlation is observed in the polymers ability to inhibit precipitation in solution and amorphous stabilization in the solid state for IMC and can be explained by the strength of drug polymer interactions.

  10. Isolating the non-polar contributions to the intermolecular potential for water-alkane interactions.

    Science.gov (United States)

    Ballal, Deepti; Venkataraman, Pradeep; Fouad, Wael A; Cox, Kenneth R; Chapman, Walter G

    2014-08-14

    Intermolecular potential models for water and alkanes describe pure component properties fairly well, but fail to reproduce properties of water-alkane mixtures. Understanding interactions between water and non-polar molecules like alkanes is important not only for the hydrocarbon industry but has implications to biological processes as well. Although non-polar solutes in water have been widely studied, much less work has focused on water in non-polar solvents. In this study we calculate the solubility of water in different alkanes (methane to dodecane) at ambient conditions where the water content in alkanes is very low so that the non-polar water-alkane interactions determine solubility. Only the alkane-rich phase is simulated since the fugacity of water in the water rich phase is calculated from an accurate equation of state. Using the SPC/E model for water and TraPPE model for alkanes along with Lorentz-Berthelot mixing rules for the cross parameters produces a water solubility that is an order of magnitude lower than the experimental value. It is found that an effective water Lennard-Jones energy ε(W)/k = 220 K is required to match the experimental water solubility in TraPPE alkanes. This number is much higher than used in most simulation water models (SPC/E-ε(W)/k = 78.2 K). It is surprising that the interaction energy obtained here is also higher than the water-alkane interaction energy predicted by studies on solubility of alkanes in water. The reason for this high water-alkane interaction energy is not completely understood. Some factors that might contribute to the large interaction energy, such as polarizability of alkanes, octupole moment of methane, and clustering of water at low concentrations in alkanes, are examined. It is found that, though important, these factors do not completely explain the anomalously strong attraction between alkanes and water observed experimentally.

  11. A method for computing the inter-residue interaction potentials for reduced amino acid alphabet

    Indian Academy of Sciences (India)

    Abhinav Luthra; Anupam Nath Jha; G K Ananthasuresh; Saraswathi Vishveswara

    2007-08-01

    Inter-residue potentials are extensively used in the design and evaluation of protein structures. However, dealing with all (20×20) interactions becomes computationally difficult in extensive investigations. Hence, it is desirable to reduce the alphabet of 20 amino acids to a smaller number. Currently, several methods of reducing the residue types exist; however a critical assessment of these methods is not available. Towards this goal, here we review and evaluate different methods by comparing with the complete (20×20) matrix of Miyazawa-Jernigan potential, including a method of grouping adopted by us, based on multi dimensional scaling (MDS). The second goal of this paper is the computation of inter-residue interaction energies for the reduced amino acid alphabet, which has not been explicitly addressed in the literature until now. By using a least squares technique, we present a systematic method of obtaining the interaction energy values for any type of grouping scheme that reduces the amino acid alphabet. This can be valuable in designing the protein structures.

  12. The hyperon-nucleon interaction potential in the bound-state soliton model: the {lambda} N case

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, G.L.; Herscovitz, V.E. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Schat, C.L. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Scoccola, N.N. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Dept. de Fisica

    1999-05-01

    We develop the formalism the study the hyperon-nucleon interaction potential within the bound state approach to the SU (3) Skyrme model. The general framework is illustratedby applying it to the diagonal {lambda} N potential. The central, spin-spin and tensor components of this interaction are obtained and compared with those derived using alternative schemes. (author)

  13. Assessment of potential drug–drug interactions and its associated factors in the hospitalized cardiac patients

    Directory of Open Access Journals (Sweden)

    Ghulam Murtaza

    2016-03-01

    Full Text Available Drug–drug interactions (DDIs may result in the alteration of therapeutic response. Sometimes they may increase the untoward effects of many drugs. Hospitalized cardiac patients need more attention regarding drug–drug interactions due to complexity of their disease and therapeutic regimen. This research was performed to find out types, prevalence and association between various predictors of potential drug–drug interactions (pDDIs in the Department of Cardiology and to report common interactions. This study was performed in the hospitalized cardiac patients at Ayub Teaching Hospital, Abbottabad, Pakistan. Patient charts of 2342 patients were assessed for pDDIs using Micromedex® Drug Information. Logistic regression was applied to find predictors of pDDIs. The main outcome measure in the study was the association of the potential drug–drug interactions with various factors such as age, gender, polypharmacy, and hospital stay of the patients. We identified 53 interacting-combinations that were present in total 5109 pDDIs with median number of 02 pDDIs per patient. Overall, 91.6% patients had at least one pDDI; 86.3% were having at least one major pDDI, and 84.5% patients had at least one moderate pDDI. Among 5109 identified pDDIs, most were of moderate (55% or major severity (45%; established (24.2%, theoretical (18.8% or probable (57% type of scientific evidence. Top 10 common pDDIs included 3 major and 7 moderate interactions. Results obtained by multivariate logistic regression revealed a significant association of the occurrence of pDDIs in patient with age of 60 years or more (p < 0.001, hospital stay of 7 days or longer (p < 0.001 and taking 7 or more drugs (p < 0.001. We found a high prevalence for pDDIs in the Department of Cardiology, most of which were of moderate severity. Older patients, patients with longer hospital stay and with elevated number of prescribed drugs were at higher risk of pDDIs.

  14. Assessment of potential drug-drug interactions and its associated factors in the hospitalized cardiac patients.

    Science.gov (United States)

    Murtaza, Ghulam; Khan, Muhammad Yasir Ghani; Azhar, Saira; Khan, Shujaat Ali; Khan, Tahir M

    2016-03-01

    Drug-drug interactions (DDIs) may result in the alteration of therapeutic response. Sometimes they may increase the untoward effects of many drugs. Hospitalized cardiac patients need more attention regarding drug-drug interactions due to complexity of their disease and therapeutic regimen. This research was performed to find out types, prevalence and association between various predictors of potential drug-drug interactions (pDDIs) in the Department of Cardiology and to report common interactions. This study was performed in the hospitalized cardiac patients at Ayub Teaching Hospital, Abbottabad, Pakistan. Patient charts of 2342 patients were assessed for pDDIs using Micromedex® Drug Information. Logistic regression was applied to find predictors of pDDIs. The main outcome measure in the study was the association of the potential drug-drug interactions with various factors such as age, gender, polypharmacy, and hospital stay of the patients. We identified 53 interacting-combinations that were present in total 5109 pDDIs with median number of 02 pDDIs per patient. Overall, 91.6% patients had at least one pDDI; 86.3% were having at least one major pDDI, and 84.5% patients had at least one moderate pDDI. Among 5109 identified pDDIs, most were of moderate (55%) or major severity (45%); established (24.2%), theoretical (18.8%) or probable (57%) type of scientific evidence. Top 10 common pDDIs included 3 major and 7 moderate interactions. Results obtained by multivariate logistic regression revealed a significant association of the occurrence of pDDIs in patient with age of 60 years or more (p < 0.001), hospital stay of 7 days or longer (p < 0.001) and taking 7 or more drugs (p < 0.001). We found a high prevalence for pDDIs in the Department of Cardiology, most of which were of moderate severity. Older patients, patients with longer hospital stay and with elevated number of prescribed drugs were at higher risk of pDDIs.

  15. Accuracy of simple folding model in the calculation of the direct part of real − interaction potential

    Indian Academy of Sciences (India)

    Keshab C Panda; Binod C Sahu; Jhasaketan Bhoi

    2014-05-01

    The direct part of real − interaction potential is calculated in the simple folding model using density-dependent Brink–Boeker effective interaction. The simple folding potentials calculated from the short- and finite-range components of this effective interaction are compared with their corresponding double folding results obtained from the oscillator model wave function to establish the relative accuracy of the model. It is found that the direct part of real – interaction potential calculated in the simple folding model is reliable.

  16. Correlation function induced by a generalized diffusion equation with the presence of a harmonic potential

    Science.gov (United States)

    Fa, Kwok Sau

    2015-02-01

    An integro-differential diffusion equation with linear force, based on the continuous time random walk model, is considered. The equation generalizes the ordinary and fractional diffusion equations, which includes short, intermediate and long-time memory effects described by the waiting time probability density function. Analytical expression for the correlation function is obtained and analyzed, which can be used to describe, for instance, internal motions of proteins. The result shows that the generalized diffusion equation has a broad application and it may be used to describe different kinds of systems.

  17. Entangling spin-spin interactions of ions in individually controlled potential wells

    Science.gov (United States)

    Wilson, Andrew; Colombe, Yves; Brown, Kenton; Knill, Emanuel; Leibfried, Dietrich; Wineland, David

    2014-03-01

    Physical systems that cannot be modeled with classical computers appear in many different branches of science, including condensed-matter physics, statistical mechanics, high-energy physics, atomic physics and quantum chemistry. Despite impressive progress on the control and manipulation of various quantum systems, implementation of scalable devices for quantum simulation remains a formidable challenge. As one approach to scalability in simulation, here we demonstrate an elementary building-block of a configurable quantum simulator based on atomic ions. Two ions are trapped in separate potential wells that can individually be tailored to emulate a number of different spin-spin couplings mediated by the ions' Coulomb interaction together with classical laser and microwave fields. We demonstrate deterministic tuning of this interaction by independent control of the local wells and emulate a particular spin-spin interaction to entangle the internal states of the two ions with 0.81(2) fidelity. Extension of the building-block demonstrated here to a 2D-network, which ion-trap micro-fabrication processes enable, may provide a new quantum simulator architecture with broad flexibility in designing and scaling the arrangement of ions and their mutual interactions. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), ONR, and the NIST Quantum Information Program.

  18. Clinical relevancy and risks of potential drug–drug interactions in intensive therapy

    Science.gov (United States)

    Rodrigues, Aline Teotonio; Stahlschmidt, Rebeca; Granja, Silvia; Falcão, Antonio Luis Eiras; Moriel, Patricia; Mazzola, Priscila Gava

    2014-01-01

    Purpose Evaluate the potential Drug–Drug Interactions (pDDI) found in prescription orders of adult Intensive Care Unit (ICU) of a Brazilian public health system hospital; quantify and qualify the pDDI regarding their severity and risks to the critical patient, using the database from Micromedex®. Methods Prospective study (January–December of 2011) collecting and evaluating 369 prescription orders (convenient sampling), one per patient. Results During the study 1844 pDDIs were identified and distributed in 405 pairs (medication A × medication B combination). There was an average of 5.00 ± 5.06 pDDIs per prescription order, the most prevalent being moderate and important interactions, present in 74% and 67% of prescription orders, respectively. In total, there were 9 contraindicated, 129 important and 204 moderate pDDIs. Among them 52 had as management recommendation to “avoid concomitant use” or “suspension of medication”, while 306 had as recommendation “continuous and adequate monitoring”. Conclusion The high number of pDDIs found in the study combined with the evaluation of the clinical relevancy of the most frequent pDDIs in the ICU shows that moderate and important interactions are highly incident. As the majority of them demand monitoring and adequate management, being aware of these interactions is major information for the safe and individualized risk management. PMID:27134536

  19. Language learning, recasts, and interaction involving AAC: background and potential for intervention.

    Science.gov (United States)

    Clarke, Michael T; Soto, Gloria; Nelson, Keith

    2017-03-01

    For children with typical development, language is learned through everyday discursive interaction. Adults mediate child participation in such interactions through the deployment of a range of co-constructive strategies, including repeating, questioning, prompting, expanding, and reformulating the child's utterances. Adult reformulations of child utterances, also known as recasts, have also been shown to relate to the acquisition of linguistic structures in children with language and learning disabilities and children and adults learning a foreign language. In this paper we discuss the theoretical basis and empirical evidence for the use of different types of recasts as a major language learning catalyst, and what may account for their facilitative effects. We consider the occurrence of different types of recasts in AAC-mediated interactions and their potential for language facilitation, within the typical operational and linguistic constraints of such interactions. We also consider the benefit of explicit and corrective forms of recasts for language facilitation in conversations with children who rely on AAC. We conclude by outlining future research directions.

  20. Encoding social interactions: the neural correlates of true and false memories.

    Science.gov (United States)

    Straube, Benjamin; Green, Antonia; Chatterjee, Anjan; Kircher, Tilo

    2011-02-01

    In social situations, we encounter information transferred in firsthand (egocentric) and secondhand (allocentric) communication contexts. However, the mechanism by which an individual distinguishes whether a past interaction occurred in an egocentric versus allocentric situation is poorly understood. This study examined the neural bases for encoding memories of social interactions through experimentally manipulating the communication context. During fMRI data acquisition, participants watched video clips of an actor speaking and gesturing directly toward them (egocentric context) or toward an unseen third person (allocentric context). After scanning, a recognition task gauged participants' ability to recognize the sentences they had just seen and to recall the context in which the sentences had been spoken. We found no differences between the recognition of sentences spoken in egocentric and allocentric contexts. However, when asked about the communication context ("Had the actor directly spoken to you?"), participants tended to believe falsely that the actor had directly spoken to them during allocentric conditions. Greater activity in the hippocampus was related to correct context memory, whereas the ventral ACC was activated for subsequent inaccurate context memory. For the interaction between encoding context and context memory, we observed increased activation for egocentric remembered items in the bilateral and medial frontal cortex, the BG, and the left parietal and temporal lobe. Our data indicate that memories of social interactions are biased to be remembered egocentrically. Self-referential encoding processes reflected in increased frontal activation and decreased hippocampal activation might be the basis of correct item but false context memory of social interactions.

  1. A correlation-based approach for determining the threshold value of singular value decomposition filtering for potential field data denoising

    Science.gov (United States)

    Wang, Jun; Meng, Xiaohong; Guo, Lianghui; Chen, Zhaoxi; Li, Fang

    2014-10-01

    We present a correlation coefficient analysis (CCA) method for obtaining threshold when using singular value decomposition (SVD) filtering method to reduce noise in potential field data. Before computation of correlation coefficients, SVD is performed on the gridded potential field data with the purpose of obtaining singular values of the data. A sliding window is utilized to truncate the acquired singular values, which allows us to obtain different singular value sequences. The lower limit of the sliding window is generally set to zero and the upper limit of the sliding window is the threshold. Then, we calculate and plot the correlation coefficients associated with the initial sequence and the newly obtained sequences, choosing the inflection point of the plotted correlation coefficients as the threshold. The CCA method offers a quantitative way to determine a threshold, which can be easily implemented by a computer program. We illustrate the method using synthetic datasets and field data from a metallic deposit area in the middle-lower reaches of the Yangtze River in China. The results show that the proposed method is effective and is able to provide an optimal threshold.

  2. Correlation between histological grading and ploidy status in potentially malignant disorders of the oral mucosa: A flow cytometric analysis

    Directory of Open Access Journals (Sweden)

    T Vijayavel

    2013-01-01

    Full Text Available Background: Histopathological grading of oral dysplastic lesions is the method of choice for evaluating malignant and potentially malignant disorders. Owing to inter- and intra-observer variability, determination of the DNA ploidy status of lesions may serve as an adjunct in the prediction of malignant transformation. Aim: To correlate histopathological grading and ploidy status in potentially malignant and malignant disorders of the oral mucosa. Settings and Design: A pilot study was done with 30 patients (10 patients with oral potentially malignant disorders predominantly leukoplakia, 10 patients with oral malignant lesions and 10 patients with normal mucosa. Materials and Methods: Incisional biopsy was done after isolating the biopsy site with 1% Toluidine blue staining. Two sections of the tissue were removed and sent for histopathological and Flow-cytometric analysis respectively. Histopathological diagnosis was obtained and compared with Flow-cytometric results which were graded as diploid and aneuploid. Further, the S - phase fraction, DNA index were also calculated to evaluate the severity of malignant transformation or malignancy. Statistical Analysis: The results were analyzed using Pearson Chi-Square Test. Results: There exists a significant correlation between histopathology and ploidy status in both potentially malignant and malignant group. (P = 0.002. Conclusion: The data from this study has shown that DNA Ploidy analysis can be used as a valuable tool in assessing the carcinomatous progression of potentially malignant and malignant lesions.

  3. Similar Neural Correlates for Language and Sequential Learning: Evidence from Event-Related Brain Potentials

    Science.gov (United States)

    Christiansen, Morten H.; Conway, Christopher M.; Onnis, Luca

    2012-01-01

    We used event-related potentials (ERPs) to investigate the time course and distribution of brain activity while adults performed (1) a sequential learning task involving complex structured sequences and (2) a language processing task. The same positive ERP deflection, the P600 effect, typically linked to difficult or ungrammatical syntactic…

  4. Analytical Determination of the Confinement Potential and Coupling Constant of Spin--Orbit Interactions of Electrons in Nanostructures

    CERN Document Server

    Dineykhan, M; Zhaugasheva, S A; Al Farabi Kazakh State National University. Almaty

    2005-01-01

    Multilayer nanocrystalline structure is represented by the electrostatic field inducted by total image charge, and the confinement potential for electrons is determined. Assuming that at a given distance the confinement potential is equal to the Coulomb repulsion and an interaction between electrons becomes spin-orbit, the constant of the spin-orbit interaction of electrons in nanostructures is determined. The dependence of the constant of the spin-orbit interaction on environment parameters and the distance between electrons is studied.

  5. [Interactive effects between plant allelochemicals, plant allelopathic potential and soil nutrients].

    Science.gov (United States)

    Xiao, Huilin; Peng, Shaolin; Zheng, Yuji; Mo, Jiangming; Luo, Wei; Zeng, Xiaoduo; He, Xiaoxia

    2006-09-01

    Plant allelopathy relates to many ecological factors. The deficit of soil nutrients can influence the production of plant allelochemicals, and thus, influence plant allelopathic potential, while plant allelochemicals can influence the form and level of soil nutrients by the ways of complexation, adsorption, acid dissolution, competition, inhibition, and others. In this paper, the interactive effects between plant allelochemicals, plant allelopathic potential and soil nutrients were summarized, and further research aspects in this field were prospected. It was suggested that following aspects should be strengthened: (1) the integration of plant allelopathy and soil-plant nutrition research to more precisely and deeply interpret the relationships between plant allelochemicals, plant allelopathic potential and soil nutrients, (2) the integration of plant allelopathy and ecosystem nutrient cycling research to simulate the plant nutrients disturbance in nature and make the allelopathy research results more true and more reliable, and (3) the allelopathy research with soils containing excessive nutrients or polluted to provide new ideas and scientific basis in revealing the mechanisms of plants interaction and biomass variation in agricultural and forestry production, and in ecological protection.

  6. Interaction of capsaicinoids with cell membrane models does not correlate with pungency of peppers

    Science.gov (United States)

    Geraldo, Vananélia P. N.; Ziglio, Analine C.; Gonçalves, Débora; Oliveira, Osvaldo N.

    2017-04-01

    Mixed monolayers were prepared using phospholipids in order to mimic cell membranes and fractions of capsaicinoids (extracted from Malagueta, Caps-M, and Bhut Jolokia, Caps-B, peppers). According to their surface-pressure isotherms and polarization-modulated infrared reflection absorption spectra (PM-IRRAS), weak molecular-level interactions were observed between Caps and phospholipids. Both Caps-M and Caps-B penetrated into the alkyl tail region of the monolayer, interacted with the phosphate group of the phospholipids and affected hydration of their Cdbnd O groups. Since the physiological activity of Caps is not governed solely by interaction with cell membranes, it should require participation of a neuronal membrane receptor, e.g. vanilloid receptor (TRPV1).

  7. Applying Monte Carlo configuration interaction to transition metal dimers: exploring the balance between static and dynamic correlation

    CERN Document Server

    Coe, J P; Paterson, M J

    2014-01-01

    We calculate potential curves for transition metal dimers using Monte Carlo configuration interaction (MCCI). These results, and their associated spectroscopic values, are compared with experimental and computational studies. The multireference nature of the MCCI wavefunction is quantified and we estimate the important orbitals. We initially consider the ground state of the chromium dimer. Next we calculate potential curves for Sc$_{2}$ where we contrast the lowest triplet and quintet states. We look at the molybdenum dimer where we compare non-relativistic results with the partial inclusion of relativistic effects via effective core potentials, and report results for scandium nickel.

  8. Radiative bound-state-formation cross-sections for dark matter interacting via a Yukawa potential

    CERN Document Server

    Petraki, Kalliopi; de Vries, Jordy

    2016-01-01

    We calculate the cross-sections for the radiative formation of bound states by dark matter whose interactions are described in the non-relativistic regime by a Yukawa potential. These cross-sections are important for cosmological and phenomenological studies of dark matter with long-range interactions, residing in a hidden sector, as well as for TeV-scale WIMP dark matter. We provide the leading-order contributions to the cross-sections for the dominant capture processes occurring via emission of a vector or a scalar boson. We offer a detailed inspection of their features, including their velocity dependence within and outside the Coulomb regime, and their resonance structure. For pairs of annihilating particles, we compare bound-state formation with annihilation.

  9. Experimenting with ecosystem interaction networks in search of threshold potentials in real-world marine ecosystems.

    Science.gov (United States)

    Thrush, Simon F; Hewitt, Judi E; Parkes, Samantha; Lohrer, Andrew M; Pilditch, Conrad; Woodin, Sarah A; Wethey, David S; Chiantore, Mariachiara; Asnaghi, Valentina; De Juan, Silvia; Kraan, Casper; Rodil, Ivan; Savage, Candida; Van Colen, Carl

    2014-06-01

    Thresholds profoundly affect our understanding and management of ecosystem dynamics, but we have yet to develop practical techniques to assess the risk that thresholds will be crossed. Combining ecological knowledge of critical system interdependencies with a large-scale experiment, we tested for breaks in the ecosystem interaction network to identify threshold potential in real-world ecosystem dynamics. Our experiment with the bivalves Macomona liliana and Austrovenus stutchburyi on marine sandflats in New Zealand demonstrated that reductions in incident sunlight changed the interaction network between sediment biogeochemical fluxes, productivity, and macrofauna. By demonstrating loss of positive feedbacks and changes in the architecture of the network, we provide mechanistic evidence that stressors lead to break points in dynamics, which theory predicts predispose a system to a critical transition.

  10. Mechanisms of radiation interaction with DNA: Potential implications for radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, W.K.; Fry, R.J.M.

    1987-01-01

    An overview of presentations and discussions which took place at the US Department of Energy/Commission of European Communities (DOE/CEC) workshop on ''Mechanisms of Radiation Interaction with DNA: Potential Implications for Radiation Protection,'' held at San Diego, California, January 21-22, 1987, is provided. The Department has traditionally supported fundamental research on interactions of ionizing radiation with different biological systems and at all levels of biological organization. The aim of this workshop was to review the base of knowledge in the area of mechanisms of radiation action at the DNA level, and to explore ways in which this information can be applied to the development of scientifically sound concepts and procedures for use in the field of radiation protection.

  11. Arsenic: A Review of the Element's Toxicity, Plant Interactions, and Potential Methods of Remediation.

    Science.gov (United States)

    Hettick, Bryan E; Cañas-Carrell, Jaclyn E; French, Amanda D; Klein, David M

    2015-08-19

    Arsenic is a naturally occurring element with a long history of toxicity. Sites of contamination are found worldwide as a result of both natural processes and anthropogenic activities. The broad scope of arsenic toxicity to humans and its unique interaction with the environment have led to extensive research into its physicochemical properties and toxic behavior in biological systems. The purpose of this review is to compile the results of recent studies concerning the metalloid and consider the chemical and physical properties of arsenic in the broad context of human toxicity and phytoremediation. Areas of focus include arsenic's mechanisms of human toxicity, interaction with plant systems, potential methods of remediation, and protocols for the determination of metals in experimentation. This assessment of the literature indicates that controlling contamination of water sources and plants through effective remediation and management is essential to successfully addressing the problems of arsenic toxicity and contamination.

  12. Antinucleon-nucleus interaction near threshold from the Paris $\\bar NN$ potential

    CERN Document Server

    Friedman, E; Loiseau, B; Wycech, S

    2015-01-01

    A general algorithm for handling the energy dependence of hadron-nucleon amplitudes in the nuclear medium, consistently with their density dependence, has been recently applied to antikaons, eta mesons and pions interacting with nuclei. Here we apply this approach to antiprotons below threshold, analyzing experimental results for antiprotonic atoms across the periodic table. It is also applied to antiproton and antineutron interaction with nuclei up to 400~MeV/c, comparing with elastic scattering and annihilation cross sections. The underlying $\\bar pN$ scattering amplitudes are derived from the Paris $\\bar NN$ potential, including modifications in the medium. Emphasis is placed on the role of the $P$-wave amplitudes with respect to the repulsive $S$-wave amplitudes.

  13. Research on the potential use of interactive materials on astronomy education

    Science.gov (United States)

    Voelzke, Marcos Rincon; Macedo, Josue

    2016-07-01

    This study presents results of a survey conducted at the Federal Institution of Education, Science and Technology in the North of Minas Gerais (IFNMG), and aimed to investigate the potentialities of the use of interactive materials in the teaching of astronomy. An advanced training course with involved learning activities about basic concepts of astronomy was offered to thirty-two Licenciate students in Physics, Mathematics and Biological Sciences, using the mixed methodology, combined with the three pedagogical moments. Among other aspects, the viability of the use of resources was noticed, involving digital technologies and interactive materials on teaching of astronomy, which may contribute to the broadening of methodological options for future teachers and meet their training needs.

  14. Antinucleon-nucleus interaction near threshold from the Paris N bar N potential

    Science.gov (United States)

    Friedman, E.; Gal, A.; Loiseau, B.; Wycech, S.

    2015-11-01

    A general algorithm for handling the energy dependence of hadron-nucleon amplitudes in the nuclear medium, consistently with their density dependence, has been recently applied to antikaons, eta mesons and pions interacting with nuclei. Here we apply this approach to antiprotons below threshold, analyzing experimental results for antiprotonic atoms across the periodic table. It is also applied to antiproton and antineutron interactions with nuclei up to 400 MeV/c, comparing with elastic scattering and annihilation cross sections. The underlying p bar N scattering amplitudes are derived from the Paris N bar N potential, including in-medium modifications. Emphasis is placed on the role of the P-wave amplitudes with respect to the repulsive S-wave amplitudes.

  15. Television Violence and Aggression: A Genotype-Environment Correlation and Interaction Theory.

    Science.gov (United States)

    Lynn, Richard; And Others

    1989-01-01

    Examined relationships among aggression, viewing and enjoyment of television violence, and personality traits of extraversion, neuroticism, and psychoticism in sibling pairs (N=386) ages 11 to 16. Found no support for theory of causal effect on amount of viewing television violence on aggression. Found no within family correlations between amount…

  16. Dynamic Panel Data Models Featuring Endogenous Interaction and Spatially Correlated Errors

    NARCIS (Netherlands)

    Jacobs, J.P.A.M.; Ligthart, J.E.; Vrijburg, H.

    2009-01-01

    We extend the three-step generalized methods of moments (GMM) approach of Kapoor, Kelejian, and Prucha (2007), which corrects for spatially correlated errors in static panel data models, by introducing a spatial lag and a one-period lag of the dependent variable as additional explanatory variables.

  17. Television Violence and Aggression: A Genotype-Environment Correlation and Interaction Theory.

    Science.gov (United States)

    Lynn, Richard; And Others

    1989-01-01

    Examined relationships among aggression, viewing and enjoyment of television violence, and personality traits of extraversion, neuroticism, and psychoticism in sibling pairs (N=386) ages 11 to 16. Found no support for theory of causal effect on amount of viewing television violence on aggression. Found no within family correlations between amount…

  18. Effects of adiabatic, relativistic, and quantum electrodynamics interactions on the pair potential and thermophysical properties of helium.

    Science.gov (United States)

    Cencek, Wojciech; Przybytek, Michał; Komasa, Jacek; Mehl, James B; Jeziorski, Bogumił; Szalewicz, Krzysztof

    2012-06-14

    The adiabatic, relativistic, and quantum electrodynamics (QED) contributions to the pair potential of helium were computed, fitted separately, and applied, together with the nonrelativistic Born-Oppenheimer (BO) potential, in calculations of thermophysical properties of helium and of the properties of the helium dimer. An analysis of the convergence patterns of the calculations with increasing basis set sizes allowed us to estimate the uncertainties of the total interaction energy to be below 50 ppm for interatomic separations R smaller than 4 bohrs and for the distance R = 5.6 bohrs. For other separations, the relative uncertainties are up to an order of magnitude larger (and obviously still larger near R = 4.8 bohrs where the potential crosses zero) and are dominated by the uncertainties of the nonrelativistic BO component. These estimates also include the contributions from the neglected relativistic and QED terms proportional to the fourth and higher powers of the fine-structure constant α. To obtain such high accuracy, it was necessary to employ explicitly correlated Gaussian expansions containing up to 2400 terms for smaller R (all R in the case of a QED component) and optimized orbital bases up to the cardinal number X = 7 for larger R. Near-exact asymptotic constants were used to describe the large-R behavior of all components. The fitted potential, exhibiting the minimum of -10.996 ± 0.004 K at R = 5.608 0 ± 0.000 1 bohr, was used to determine properties of the very weakly bound (4)He(2) dimer and thermophysical properties of gaseous helium. It is shown that the Casimir-Polder retardation effect, increasing the dimer size by about 2 Å relative to the nonrelativistic BO value, is almost completely accounted for by the inclusion of the Breit-interaction and the Araki-Sucher contributions to the potential, of the order α(2) and α(3), respectively. The remaining retardation effect, of the order of α(4) and higher, is practically negligible for the bound

  19. Solid phase stability of a double-minimum interaction potential system

    Energy Technology Data Exchange (ETDEWEB)

    Suematsu, Ayumi; Yoshimori, Akira, E-mail: a.yoshimori@cmt.phys.kyushu-u.ac.jp; Saiki, Masafumi; Matsui, Jun [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan); Odagaki, Takashi [School of Science and Engineering, Tokyo Denki University, Hatoyama, Saitama 350-0394 (Japan)

    2014-06-28

    We study phase stability of a system with double-minimum interaction potential in a wide range of parameters by a thermodynamic perturbation theory. The present double-minimum potential is the Lennard-Jones-Gauss potential, which has a Gaussian pocket as well as a standard Lennard-Jones minimum. As a function of the depth and position of the Gaussian pocket in the potential, we determine the coexistence pressure of crystals (fcc and bcc). We show that the fcc crystallizes even at zero pressure when the position of the Gaussian pocket is coincident with the first or third nearest neighbor site of the fcc crystal. The bcc crystal is more stable than the fcc crystal when the position of the Gaussian pocket is coincident with the second nearest neighbor sites of the bcc crystal. The stable crystal structure is determined by the position of the Gaussian pocket. These results show that we can control the stability of the solid phase by tuning the potential function.

  20. Baryon interactions in lattice QCD: the direct method vs. the HAL QCD potential method

    CERN Document Server

    Iritani, Takumi

    2016-01-01

    We make a detailed comparison between the direct method and the HAL QCD potential method for the baryon-baryon interactions, taking the $\\Xi\\Xi$ system at $m_\\pi= 0.51$ GeV in 2+1 flavor QCD and using both smeared and wall quark sources. The energy shift $\\Delta E_\\mathrm{eff}(t)$ in the direct method shows the strong dependence on the choice of quark source operators, which means that the results with either (or both) source are false. The time-dependent HAL QCD method, on the other hand, gives the quark source independent $\\Xi\\Xi$ potential, thanks to the derivative expansion of the potential, which absorbs the source dependence to the next leading order correction. The HAL QCD potential predicts the absence of the bound state in the $\\Xi\\Xi$($^1$S$_0$) channel at $m_\\pi= 0.51$ GeV, which is also confirmed by the volume dependence of finite volume energy from the potential. We also demonstrate that the origin of the fake plateau in the effective energy shift $\\Delta E_\\mathrm{eff}(t)$ at $t \\sim 1$ fm can b...

  1. Matter-Wave Solitons in Two-Component Bose-Einstein Condensates with Tunable Interactions and Time Varying Potential

    Institute of Scientific and Technical Information of China (English)

    宣恒农; 左苗

    2011-01-01

    We present three families of exact matter-wave soliton solutions for an effective one-dimension two- component Bose-Einstein condensates (BECs) with tunable interactions, harmonic potential and gain or loss term. We investigate the dynamics of bright-bright solitons, bright-dark solitons and dark-dark solitons for the time-dependent expulsive harmonic trap potential, periodically modulated harmonic trap potential, and kinklike modulated harmonic trap potential. Through the Feshbach resonance, these dynamics can be realized in experiments by suitable control of time-dependent trap parameters, atomic interactions, and interaction with thermal cloud.

  2. The Potential of Magnetostratigraphy for a Global Correlation of the Germanic Triassic - Case Study Buntsandstein

    Science.gov (United States)

    Szurlies, M.

    2004-12-01

    The Buntsandstein represents the lower group of the tripartite classic Germanic Triassic supergroup. In its type area of Central Germany, the thickness of the Buntsandstein is about 1000 m. The predominantly clastic sediments were deposited during latest Permian to earliest Middle Triassic times in mainly fluvio-lacustrine environments of a large intracratonic basin. Traditionally, the Buntsandstein is subdivided by lithological criteria, showing a distinct cyclicity, pragmatically subdivided in 5 to 25 m thick small-scale fining-upward cycles. Above all, these cycles are correlation cycles, that are obvious in wireline logs, cores and outcrops. With wireline logs (e.g., gamma-ray logs) they can be correlated over almost the entire epicontinental Central European Basin. The thickness of these fining-upward cycles corresponds to that of genetic cycles, which are considered to reflect climatic fluctuation of alternating drier and wetter periods due to solar-induced 100 ka eccentricity cycles. On the basis of this robust high-resolution lithostratigraphic framework a very precise positioning and verification of paleomagnetic results has been realized. In Central Germany eighteen sections (twelve outcrops, six wells) were collected at 1-2 m intervals, yielding a total of nearly 2100 oriented standard samples. From about 81 % of them a characteristic remanence was obtained, being carried by magnetite in the gray lithologies and by hematite in the red-brown lithologies, respectively. The inter-section correlation of all investigated profiles allows the creation of a well-defined composite magnetic polarity record for Central Germany, being in good agreement with polarity scales from the Boreal and Tethyan realms. The magnetozones of the Buntsandstein last 0.1-0.9 Ma, with an average duration of approx 0.3 Ma. According to magnetostratigraphic and biostratigraphic data, the position of the Hindeodus parvus calibrated Permian-Triassic boundary is located within the so

  3. Predicting potential responses to future climate in an alpine ungulate: interspecific interactions exceed climate effects.

    Science.gov (United States)

    Mason, Tom H E; Stephens, Philip A; Apollonio, Marco; Willis, Stephen G

    2014-12-01

    The altitudinal shifts of many montane populations are lagging behind climate change. Understanding habitual, daily behavioural rhythms, and their climatic and environmental influences, could shed light on the constraints on long-term upslope range-shifts. In addition, behavioural rhythms can be affected by interspecific interactions, which can ameliorate or exacerbate climate-driven effects on ecology. Here, we investigate the relative influences of ambient temperature and an interaction with domestic sheep (Ovis aries) on the altitude use and activity budgets of a mountain ungulate, the Alpine chamois (Rupicapra rupicapra). Chamois moved upslope when it was hotter but this effect was modest compared to that of the presence of sheep, to which they reacted by moving 89-103 m upslope, into an entirely novel altitudinal range. Across the European Alps, a range-shift of this magnitude corresponds to a 46% decrease in the availability of suitable foraging habitat. This highlights the importance of understanding how factors such as competition and disturbance shape a given species' realised niche when predicting potential future responses to change. Furthermore, it exposes the potential for manipulations of species interactions to ameliorate the impacts of climate change, in this case by the careful management of livestock. Such manipulations could be particularly appropriate for species where competition or disturbance already strongly restricts their available niche. Our results also reveal the potential role of behavioural flexibility in responses to climate change. Chamois reduced their activity when it was warmer, which could explain their modest altitudinal migrations. Considering this behavioural flexibility, our model predicts a small 15-30 m upslope shift by 2100 in response to climate change, less than 4% of the altitudinal shift that would be predicted using a traditional species distribution model-type approach (SDM), which assumes that species' behaviour

  4. Rapidity dependence of multiplicity fluctuations and correlations in high-energy nucleus–nucleus interactions

    Indian Academy of Sciences (India)

    Dipak Ghosh; Argha Deb; Swarnapratim Bhattacharyya; Utpal Datta

    2011-08-01

    The multiplicity fluctuations of the produced pions were studied using scaled variance method in 16O–AgBr interactions at 2.1 AGeV, 24Mg–AgBr interactions at 4.5 AGeV, 12C–AgBr interactions at 4.5 AGeV, 16O–AgBr interactions at 60 AGeV and 32S–AgBr interactions at 200 AGeV at two different binning conditions. In the first binning condition, the rapidity interval was varied in steps of one centring about the central rapidity until it reached 14. In the second case, the rapidity interval was increased in steps of 1.6 up to 14.4. Multiplicity distributions and their scaled variances were presented as a function of the dependence on the rapidity width for both the binning conditions. Multiplicity fluctuations were found to increase with the increase of rapidity interval and later found to saturate at larger rapidity window for all the interactions and in both the binning conditions. Multiplicity fluctuations were found to increase with the energy of the projectile beam. The values of the scaled variances were found to be greater than one in all the cases in both the binning conditions indicating the presence of correlation during the multiparticle production process in high-energy nucleus–nucleus interactions. Experimental results were compared with the results obtained from the Monte Carlo simulated events for all the interactions. The Monte Carlo simulated data showed very small values of scaled variance suggesting very small fluctuations for the simulated events. Experimental results obtained from 16O–AgBr interactions at 60 AGeV and 32S–AgBr interactions at 200 AGeV were compared with the events generated by Lund Monte Carlo code (FRITIOF model). FRITIOF model failed to explain the multiplicity fluctuations of pions emitted from 16O–AgBr interactions at 60 AGeV for both the binning conditions. However, the experimental data agreed well with the FRITIOF model for 32S–AgBr interactions at 200 AGeV.

  5. Evoked potential correlates of selective attention with multi-channel auditory inputs

    Science.gov (United States)

    Schwent, V. L.; Hillyard, S. A.

    1975-01-01

    Ten subjects were presented with random, rapid sequences of four auditory tones which were separated in pitch and apparent spatial position. The N1 component of the auditory vertex evoked potential (EP) measured relative to a baseline was observed to increase with attention. It was concluded that the N1 enhancement reflects a finely tuned selective attention to one stimulus channel among several concurrent, competing channels. This EP enhancement probably increases with increased information load on the subject.

  6. Scalar-field cosmological and collapse models with general self-interaction potentials

    Energy Technology Data Exchange (ETDEWEB)

    Giambo, Roberto; Giannoni, Fabio [Dipartimento di Matematica e Informatica, Universita di Camerino (Italy); Magli, Giulio, E-mail: roberto.giambo@unicam.i, E-mail: fabio.giannoni@unicam.i, E-mail: magli@mate.polimi.i [Dipartimento di Matematica, Politecnico di Milano (Italy)

    2009-10-01

    We present the results of the investigation of a wide class of self-interacting, self-gravitating homogeneous scalar fields models, characterized by quite general conditions on the scalar field potential, and including both asymptotically polynomial and exponential behaviors. We show that the generic evolution is always divergent in a finite time, and this result is used to construct cosmological models as well as radiating collapsing star models of the Vaidya type - for the latter it turns out that black holes are generically formed.

  7. A case of a potential drug interaction between clobazam and etravirine-based antiretroviral therapy.

    Science.gov (United States)

    Naccarato, Mark; Yoong, Deborah; Kovacs, Colin; Gough, Kevin

    2012-01-01

    The cytochrome P450 isoforms primarily involved in clobazam metabolism are CYP3A4 and 2C19. Drugs that modulate these enzymes would then be expected to alter the exposure of clobazam and its major metabolites. Etravirine, a second-generation non-nucleoside reverse transcriptase inhibitor has been shown to induce CYP3A4, while inhibiting CYP2C9 and CYP2C19. We report a case in which a potential drug interaction between clobazam and etravirine may have led to increased concentrations of clobazam and its pharmacologically active metabolite, N-desmethylclobazam, causing neurotoxic symptoms.

  8. Cross-Modal Interactions in the Experience of Musical Performances: Physiological Correlates

    Science.gov (United States)

    Chapados, Catherine; Levitin, Daniel J.

    2008-01-01

    This experiment was conducted to investigate cross-modal interactions in the emotional experience of music listeners. Previous research showed that visual information present in a musical performance is rich in expressive content, and moderates the subjective emotional experience of a participant listening and/or observing musical stimuli [Vines,…

  9. Spatially-Correlated Mass Spectrometric Analysis of Microbe-Mineral Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Jill R. Scott; Beizhan Yan; Daphne L. Stoner

    2006-11-01

    A new methodology for examining the interactions of microbes with heterogeneous minerals is presented. Imaging laser-desorption Fourier transform mass spectrometry was used to examine the colonization patterns of Burkholderia vietnamiensis (Burkholderia cepacia) G4 on a heterogeneous basalt sample. Depth-profile imaging found that the bacterium preferentially colonized the plagioclase mineral phases within the basalt.

  10. Cross-Modal Interactions in the Experience of Musical Performances: Physiological Correlates

    Science.gov (United States)

    Chapados, Catherine; Levitin, Daniel J.

    2008-01-01

    This experiment was conducted to investigate cross-modal interactions in the emotional experience of music listeners. Previous research showed that visual information present in a musical performance is rich in expressive content, and moderates the subjective emotional experience of a participant listening and/or observing musical stimuli [Vines,…

  11. Neural Correlates of Appetitive-Aversive Interactions in Pavlovian Fear Conditioning

    Science.gov (United States)

    Nasser, Helen M.; McNally, Gavan P.

    2013-01-01

    We used Pavlovian counterconditioning in rats to identify the neural mechanisms for appetitive-aversive motivational interactions. In Stage I, rats were trained on conditioned stimulus (CS)-food (unconditioned stimulus [US]) pairings. In Stage II, this appetitive CS was transformed into a fear CS via pairings with footshock. The development of…

  12. Interaction-powered supernovae: rise-time versus peak-luminosity correlation and the shock-breakout velocity

    Energy Technology Data Exchange (ETDEWEB)

    Ofek, Eran O.; Arcavi, Iair; Tal, David; Gal-Yam, Avishay; Ben-Ami, Sagi; De Cia, Annalisa; Yaron, Ofer [Benoziyo Center for Astrophysics, Weizmann Institute of Science, 76100 Rehovot (Israel); Sullivan, Mark [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Kulkarni, Shrinivas R.; Cao, Yi [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Nugent, Peter E. [Computational Cosmology Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Bersier, David [Astrophysics Research Institute, Liverpool John Moores University, Liverpool L3 5RF (United Kingdom); Cenko, S. Bradley [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Filippenko, Alexei V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Fransson, Claes [Department of Astronomy, The Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Kasliwal, Mansi M. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara St, Pasadena, CA 91101 (United States); Laher, Russ; Surace, Jason [Spitzer Science Center, MS 314-6, California Institute of Technology, Pasadena, CA 91125 (United States); Quimby, Robert [Kavli IPMU (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8583 (Japan)

    2014-06-20

    Interaction of supernova (SN) ejecta with the optically thick circumstellar medium (CSM) of a progenitor star can result in a bright, long-lived shock-breakout event. Candidates for such SNe include Type IIn and superluminous SNe. If some of these SNe are powered by interaction, then there should be a specific relation between their peak luminosity, bolometric light-curve rise time, and shock-breakout velocity. Given that the shock velocity during shock breakout is not measured, we expect a correlation, with a significant spread, between the rise time and the peak luminosity of these SNe. Here, we present a sample of 15 SNe IIn for which we have good constraints on their rise time and peak luminosity from observations obtained using the Palomar Transient Factory. We report on a possible correlation between the R-band rise time and peak luminosity of these SNe, with a false-alarm probability of 3%. Assuming that these SNe are powered by interaction, combining these observables and theory allows us to deduce lower limits on the shock-breakout velocity. The lower limits on the shock velocity we find are consistent with what is expected for SNe (i.e., ∼10{sup 4} km s{sup –1}). This supports the suggestion that the early-time light curves of SNe IIn are caused by shock breakout in a dense CSM. We note that such a correlation can arise from other physical mechanisms. Performing such a test on other classes of SNe (e.g., superluminous SNe) can be used to rule out the interaction model for a class of events.

  13. APOE modulates the correlation between triglycerides, cholesterol, and CHD through pleiotropy, and gene-by-gene interactions.

    Science.gov (United States)

    Maxwell, Taylor J; Ballantyne, Christie M; Cheverud, James M; Guild, Cameron S; Ndumele, Chiadi E; Boerwinkle, Eric

    2013-12-01

    Relationship loci (rQTL) exist when the correlation between multiple traits varies by genotype. rQTL often occur due to gene-by-gene (G × G) or gene-by-environmental interactions, making them a powerful tool for detecting G × G. Here we present an empirical analysis of apolipoprotein E (APOE) with respect to lipid traits and incident CHD leading to the discovery of loci that interact with APOE to affect these traits. We found that the relationship between total cholesterol (TC) and triglycerides (ln TG) varies by APOE isoform genotype in African-American (AA) and European-American (EA) populations. The e2 allele is associated with strong correlation between ln TG and TC while the e4 allele leads to little or no correlation. This led to a priori hypotheses that APOE genotypes affect the relationship of TC and/or ln TG with incident CHD. We found that APOE*TC was significant (P = 0.016) for AA but not EA while APOE*ln TG was significant for EA (P = 0.027) but not AA. In both cases, e2e2 and e2e3 had strong relationships between TC and ln TG with CHD while e2e4 and e4e4 results in little or no relationship between TC and ln TG with CHD. Using ARIC GWAS data, scans for loci that significantly interact with APOE produced four loci for African Americans (one CHD, one TC, and two HDL). These interactions contribute to the rQTL pattern. rQTL are a powerful tool to identify loci that modify the relationship between risk factors and disease and substantially increase statistical power for detecting G × G.

  14. Isotropization in Bianchi type-I cosmological model with fermions and bosons interacting via Yukawa potential

    Science.gov (United States)

    Ribas, M. O.; Samojeden, L. L.; Devecchi, F. P.; Kremer, G. M.

    2015-10-01

    In this work we investigate a model for the early Universe in a Bianchi type-I metric, where the sources of the gravitational field are a fermionic and a bosonic field, interacting through a Yukawa potential, following the standard model of elementary particles. It is shown that the fermionic field has a negative pressure, while the boson has a small positive pressure. The fermionic field is the responsible for an accelerated regime at early times, but since the total pressure tends to zero for large times, a transition to a decelerated regime occurs. Here the Yukawa potential answers for the duration of the accelerated regime, since by decreasing the value of its coupling constant the transition accelerated-decelerated occurs in later times. The isotropization which occurs for late times is due to the presence of the fermionic field as one of the sources of the gravitational field.

  15. Isotropization in Bianchi type-I cosmological model with fermions and bosons interacting via Yukawa potential

    CERN Document Server

    Ribas, M O; Devecchi, F P; Kremer, G M

    2015-01-01

    In this work we investigate a model for the early Universe in a Bianchi type-I metric, where the sources of the gravitational field are a fermionic and a bosonic field, interacting through a Yukawa potential, following the standard model of elementary particles. It is shown that the fermionic field has a negative pressure, while the boson has a small positive pressure. The fermionic field is the responsible for an accelerated regime at early times, but since the total pressure tends to zero for large times, a transition to a decelerated regime occurs. Here the Yukawa potential answers for the duration of the accelerated regime, since by decreasing the value of its coupling constant the transition accelerated-decelerated occurs in later times. The isotropization which occurs for late times is due to the presence of the fermionic field as one of the sources of the gravitational field.

  16. Interactions of zearalenone with native and chemically modified cyclodextrins and their potential utilization.

    Science.gov (United States)

    Poór, Miklós; Kunsági-Máté, Sándor; Sali, Nikolett; Kőszegi, Tamás; Szente, Lajos; Peles-Lemli, Beáta

    2015-10-01

    Zearalenone (ZEA) is a widespread xenoestrogenic mycotoxin produced by several Fusarium species. ZEA can cause reproductive disorders in farm animals and hyperoestrogenic syndromes in humans; therefore, development of more sensitive analytical methods (to quantify the mycotoxin) as well as strategies for prevention of its toxic impacts is highly important. In this study, the interactions of ZEA with native and chemically modified cyclodextrins (CDs) were investigated using fluorescence spectroscopy. Furthermore, in vitro experiments on liver cells were also performed to test the potential effect of CDs on toxin uptake. Our results demonstrate that ZEA forms stable complexes with CDs (logK values are approximately 3.7-4.7) resulting in the considerable elevation of its fluorescence signal. In addition, some of the CDs show ability to inhibit the cellular uptake of ZEA, suggesting their potential suitability to develop new CD-based preventive/detoxification strategies against ZEA in the future. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. The interaction of anticipatory anxiety and emotional picture processing: an event-related brain potential study.

    Science.gov (United States)

    Bublatzky, Florian; Flaisch, Tobias; Stockburger, Jessica; Schmälzle, Ralf; Schupp, Harald T

    2010-07-01

    The present study examined the interaction of anticipatory anxiety and selective emotion processing. Toward this end, a rapid stream of pleasant, neutral, and unpleasant pictures was presented in alternating blocks of threat-of-shock or safety, which were signaled by colored picture frames. The main finding is that pleasant pictures elicited a sustained negative difference potential over occipital regions during threat as compared to safety periods. In contrast, unpleasant and neutral picture processing did not vary as a function of threat-of-shock. Furthermore, in both the safety and threat-of-shock conditions, emotional pictures elicited an enlarged early posterior negativity and late positive potential. These data show that the activation of the fear/anxiety network exerts valence-specific effects on affective picture processing. Pleasant stimuli mismatching the current state of anticipatory anxiety apparently draw more attentional resources.

  18. The role of internal waves in larval fish interactions with potential predators and prey

    Science.gov (United States)

    Greer, Adam T.; Cowen, Robert K.; Guigand, Cedric M.; Hare, Jonathan A.; Tang, Dorothy

    2014-09-01

    Tidally driven internal wave packets in coastal environments have the potential to influence patchiness of larval fishes, prey, and gelatinous predators. We used the In Situ Ichthyoplankton Imaging System (ISIIS) to synoptically sample larval fishes, copepods, and planktonic predators (ctenophores, hydromedusae, chaetognaths, and polychaetes) across these predictable features in the summer near Stellwagen Bank, Massachusetts, USA. Full water column profiles and fixed depth transects (∼10 m depth) were used to quantify vertical and horizontal components of the fish and invertebrate distributions during stable and vertically mixed conditions associated with tidally generated internal waves. Larval fishes, consisting mostly of Urophycis spp., Merluccius bilinearis, and Labridae, were concentrated near the surface, with larger sizes generally occupying greater depths. During stable water column conditions, copepods formed a near surface thin layer several meters above the chlorophyll-a maximum that was absent when internal waves were propagating. In contrast, ctenophores and other predators were much more abundant at depth, but concentrations near 10 m increased immediately after the internal hydraulic jump mixed the water column. During the propagation of internal waves, the fine-scale abundance of larval fishes was more correlated with the abundance of gelatinous predators and less correlated with copepods compared to the stable conditions. Vertical oscillations caused by the internal hydraulic jump can disperse patches of zooplankton and force surface dwelling larval fishes into deeper water where probability of predator contact is increased, creating conditions potentially less favorable for larval fish growth and survival on short time scales.

  19. A C-code for the double folding interaction potential of two spherical nuclei

    Science.gov (United States)

    Gontchar, I. I.; Chushnyakova, M. V.

    2010-01-01

    We present a C-code designed to obtain the nucleus-nucleus potential by using the double folding model (DFM) and in particular to find the Coulomb barrier. The program calculates the nucleus-nucleus potential as a function of the distance between the centers of mass of colliding nuclei. The most important output parameters are the Coulomb barrier energy and the radius. Since many researchers use a Woods-Saxon profile for the nuclear term of the potential we provide an option in our code for fitting the DFM potential by such a profile. Program summaryProgram title: DFMSPH Catalogue identifier: AEFH_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFH_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 5929 No. of bytes in distributed program, including test data, etc.: 115 740 Distribution format: tar.gz Programming language: C Computer: PC Operating system: Windows XP (with the GCC-compiler version 2) RAM: Below 10 Mbyte Classification: 17.9 Nature of problem: The code calculates in a semimicroscopic way the bare interaction potential between two colliding spherical nuclei as a function of the center of mass distance. The height and the position of the Coulomb barrier are found. The calculated potential is approximated by a conventional Woods-Saxon profile near the barrier. Dependence of the barrier parameters upon the characteristics of the effective NN forces (like, e.g. the range of the exchange part of the nuclear term) can be investigated. Solution method: The nucleus-nucleus potential is calculated using the double folding model with the Coulomb and the effective M3Y NN interactions. For the direct parts of the Coulomb and the nuclear terms, the Fourier transform method is used. In order to calculate the exchange parts the density matrix expansion method

  20. Interaction of landscape varibles on the potential geographical distribution of parrots in the Yucatan Peninsula, Mexico

    Directory of Open Access Journals (Sweden)

    Plasencia–Vázquez, A. H.

    2014-12-01

    Full Text Available The loss, degradation, and fragmentation of forested areas are endangering parrot populations. In this study, we determined the influence of fragmentation in relation to vegetation cover, land use, and spatial configuration of fragments on the potential geographical distribution patterns of parrots in the Yucatan Peninsula, Mexico. We used the potential geographical distribution for eight parrot species, considering the recently published maps obtained with the maximum entropy algorithm, and we incorporated the probability distribution for each species. We calculated 71 metrics/variables that evaluate forest fragmentation, spatial configuration of fragments, the ratio occupied by vegetation, and the land use in 100 plots of approximately 29 km², randomly distributed within the presence and absence areas predicted for each species. We also considered the relationship between environmental variables and the distribution probability of species. We used a partial least squares regression to explore patterns between the variables used and the potential distribution models. None of the environmental variables analyzed alone determined the presence/absence or the probability distribution of parrots in the Peninsula. We found that for the eight species, either due to the presence/absence or the probability distribution, the most important explanatory variables were the interaction among three variables, particularly the interactions among the total forest area, the total edge, and the tropical semi–evergreen medium– height forest. Habitat fragmentation influenced the potential geographical distribution of these species in terms of the characteristics of other environmental factors that are expressed together with the geographical division, such as the different vegetation cover ratio and land uses in deforested areas.