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Sample records for weak lefschetz property

  1. The Weak Haagerup Property II

    DEFF Research Database (Denmark)

    Haagerup, Uffe; Knudby, Søren

    2015-01-01

    The weak Haagerup property for locally compact groups and the weak Haagerup constant were recently introduced by the second author [27]. The weak Haagerup property is weaker than both weak amenability introduced by Cowling and the first author [9] and the Haagerup property introduced by Connes [6......] and Choda [5]. In this paper, it is shown that a connected simple Lie group G has the weak Haagerup property if and only if the real rank of G is zero or one. Hence for connected simple Lie groups the weak Haagerup property coincides with weak amenability. Moreover, it turns out that for connected simple...... Lie groups the weak Haagerup constant coincides with the weak amenability constant, although this is not true for locally compact groups in general. It is also shown that the semidirect product R2 × SL(2,R) does not have the weak Haagerup property....

  2. The Lefschetz-Hopf theorem and axioms for the Lefschetz number

    Directory of Open Access Journals (Sweden)

    Brown Robert F

    2004-01-01

    Full Text Available The reduced Lefschetz number, that is, where denotes the Lefschetz number, is proved to be the unique integer-valued function on self-maps of compact polyhedra which is constant on homotopy classes such that (1 for and ; (2 if is a map of a cofiber sequence into itself, then ; (3 , where is a self-map of a wedge of circles, is the inclusion of a circle into the th summand, and is the projection onto the th summand. If is a self-map of a polyhedron and is the fixed point index of on all of , then we show that satisfies the above axioms. This gives a new proof of the normalization theorem: if is a self-map of a polyhedron, then equals the Lefschetz number of . This result is equivalent to the Lefschetz-Hopf theorem: if is a self-map of a finite simplicial complex with a finite number of fixed points, each lying in a maximal simplex, then the Lefschetz number of is the sum of the indices of all the fixed points of .

  3. Real-time Feynman path integral with Picard–Lefschetz theory and its applications to quantum tunneling

    Energy Technology Data Exchange (ETDEWEB)

    Tanizaki, Yuya, E-mail: yuya.tanizaki@riken.jp [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan); Theoretical Research Division, Nishina Center, RIKEN, Wako 351-0198 (Japan); Koike, Takayuki, E-mail: tkoike@ms.u-tokyo.ac.jp [Graduate School of Mathematical Sciences, The University of Tokyo, Tokyo 153-8914 (Japan)

    2014-12-15

    Picard–Lefschetz theory is applied to path integrals of quantum mechanics, in order to compute real-time dynamics directly. After discussing basic properties of real-time path integrals on Lefschetz thimbles, we demonstrate its computational method in a concrete way by solving three simple examples of quantum mechanics. It is applied to quantum mechanics of a double-well potential, and quantum tunneling is discussed. We identify all of the complex saddle points of the classical action, and their properties are discussed in detail. However a big theoretical difficulty turns out to appear in rewriting the original path integral into a sum of path integrals on Lefschetz thimbles. We discuss generality of that problem and mention its importance. Real-time tunneling processes are shown to be described by those complex saddle points, and thus semi-classical description of real-time quantum tunneling becomes possible on solid ground if we could solve that problem. - Highlights: • Real-time path integral is studied based on Picard–Lefschetz theory. • Lucid demonstration is given through simple examples of quantum mechanics. • This technique is applied to quantum mechanics of the double-well potential. • Difficulty for practical applications is revealed, and we discuss its generality. • Quantum tunneling is shown to be closely related to complex classical solutions.

  4. The Lefschetz-Hopf theorem and axioms for the Lefschetz number

    Directory of Open Access Journals (Sweden)

    Robert F. Brown

    2004-03-01

    Full Text Available The reduced Lefschetz number, that is, L(⋅−1 where L(⋅ denotes the Lefschetz number, is proved to be the unique integer-valued function λ on self-maps of compact polyhedra which is constant on homotopy classes such that (1 λ(fg=λ(gf for f:X→Y and g:Y→X; (2 if (f1,f2,f3 is a map of a cofiber sequence into itself, then λ(f1=λ(f1+λ(f3; (3 λ(f=−(deg(p1fe1+⋯+deg(pkfek, where f is a self-map of a wedge of k circles, er is the inclusion of a circle into the rth summand, and pr is the projection onto the rth summand. If f:X→X is a self-map of a polyhedron and I(f is the fixed point index of f on all of X, then we show that I(⋅−1 satisfies the above axioms. This gives a new proof of the normalization theorem: if f:X→X is a self-map of a polyhedron, then I(f equals the Lefschetz number L(f of f. This result is equivalent to the Lefschetz-Hopf theorem: if f:X→X is a self-map of a finite simplicial complex with a finite number of fixed points, each lying in a maximal simplex, then the Lefschetz number of f is the sum of the indices of all the fixed points of f.

  5. Lefschetz-Pontrjagin duality for differential characters

    Directory of Open Access Journals (Sweden)

    REESE HARVEY

    2001-06-01

    Full Text Available A theory of differential characters is developed for manifolds with boundary. This is done from both the Cheeger-Simons and the deRham-Federer viewpoints. The central result of the paper is the formulation and proof of a Lefschetz-Pontrjagin Duality Theorem, which asserts that the pairing given by (alpha, beta (alpha * beta [X] induces isomorphisms onto the smooth Pontrjagin duals. In particular, and are injective with dense range in the group of all continuous homomorphisms into the circle. A coboundary map is introduced which yields a long sequence for the character groups associated to the pair (X, X. The relation of the sequence to the duality mappings is analyzed.Uma teoria de caracteres diferenciais é aqui desenvolvida para variedades com bordo. Isto é feito tanto do ponto de vista de Cheeger-Simons como do deRham-Federer. O resultado central deste artigo é a formulação e a prova de um teorema da dualidade de Lefschetz-Pontrjagin, que afirma que o pareamento dado por (alfa,beta (alfa * beta [X] induz isomorfismos sobre os duais diferenciáveis de Pontrjagin. Em particular, e são injetivos com domínios densos no grupo de todos os homeomorfismos contínuos no círculo. Uma aplicação de cobordo é introduzida, a qual fornece uma sequência longa para os grupos de caracteres associados ao par ( X, X. A relação desta sequência com as aplicações de dualidade é analisada.

  6. Structure of Lefschetz thimbles in simple fermionic systems

    Energy Technology Data Exchange (ETDEWEB)

    Kanazawa, Takuya [iTHES Research Group and Quantum Hadron Physics Laboratory,RIKEN, Wako, Saitama 351-0198 (Japan); Tanizaki, Yuya [Department of Physics, The University of Tokyo,Tokyo 113-0033 (Japan); Theoretical Research Division, Nishina Center, RIKEN,Wako, Saitama 351-0198 (Japan)

    2015-03-10

    The Picard-Lefschetz theory offers a promising tool to solve the sign problem in QCD and other field theories with complex path-integral weight. In this paper the Lefschetz-thimble approach is examined in simple fermionic models which share some features with QCD. In zero-dimensional versions of the Gross-Neveu model and the Nambu-Jona-Lasinio model, we study the structure of Lefschetz thimbles and its variation across the chiral phase transition. We map out a phase diagram in the complex four-fermion coupling plane using a thimble decomposition of the path integral, and demonstrate an interesting link between anti-Stokes lines and Lee-Yang zeros. In the case of nonzero mass, it is shown that the approach to the chiral limit is singular because of intricate cancellation between competing thimbles, which implies the necessity to sum up multiple thimbles related by symmetry. We also consider a Chern-Simons theory with fermions in 0+1-dimension and show how Lefschetz thimbles solve the complex phase problem caused by a topological term. These prototypical examples would aid future application of this framework to bona fide QCD.

  7. Quantum Groups, Property (T), and Weak Mixing

    Science.gov (United States)

    Brannan, Michael; Kerr, David

    2017-11-01

    For second countable discrete quantum groups, and more generally second countable locally compact quantum groups with trivial scaling group, we show that property (T) is equivalent to every weakly mixing unitary representation not having almost invariant vectors. This is a generalization of a theorem of Bekka and Valette from the group setting and was previously established in the case of low dual by Daws, Skalski, and Viselter. Our approach uses spectral techniques and is completely different from those of Bekka-Valette and Daws-Skalski-Viselter. By a separate argument we furthermore extend the result to second countable nonunimodular locally compact quantum groups, which are shown in particular not to have property (T), generalizing a theorem of Fima from the discrete setting. We also obtain quantum group versions of characterizations of property (T) of Kerr and Pichot in terms of the Baire category theory of weak mixing representations and of Connes and Weiss in terms of the prevalence of strongly ergodic actions.

  8. Dynamic properties of superconducting weak links

    Science.gov (United States)

    Schmid, Albert; Schön, Gerd; Tinkham, Michael

    1980-06-01

    A comprehensive theoretical picture of the dynamic properties of the order parameter and the quasiparticles in superconducting short weak links is presented. Both diffusion and inelastic scattering are found to be important in relaxing nonequilibrium populations. At low voltages a dissipative current, which is considerably larger than the normal ohmic current, is found and at higher voltages the maximum supercurrent is enhanced. These effects describe quantitatively well the foot structure in the I-V characteristic observed experimentally by Octavio, Skocpol, and Tinkham.

  9. Sign problem and Monte Carlo calculations beyond Lefschetz thimbles

    Energy Technology Data Exchange (ETDEWEB)

    Alexandru, Andrei [Department of Physics, The George Washington University,Washington, DC 20052 (United States); Başar, Gökçe; Bedaque, Paulo F.; Ridgway, Gregory W.; Warrington, Neill C. [Department of Physics, University of Maryland,College Park, MD 20742 (United States)

    2016-05-10

    We point out that Monte Carlo simulations of theories with severe sign problems can be profitably performed over manifolds in complex space different from the one with fixed imaginary part of the action (“Lefschetz thimble”). We describe a family of such manifolds that interpolate between the tangent space at one critical point (where the sign problem is milder compared to the real plane but in some cases still severe) and the union of relevant thimbles (where the sign problem is mild but a multimodal distribution function complicates the Monte Carlo sampling). We exemplify this approach using a simple 0+1 dimensional fermion model previously used on sign problem studies and show that it can solve the model for some parameter values where a solution using Lefschetz thimbles was elusive.

  10. Gravitational decoupling and the Picard-Lefschetz approach

    Science.gov (United States)

    Brown, Jon; Cole, Alex; Shiu, Gary; Cottrell, William

    2018-01-01

    In this work, we consider tunneling between nonmetastable states in gravitational theories. Such processes arise in various contexts, e.g., in inflationary scenarios where the inflaton potential involves multiple fields or multiple branches. They are also relevant for bubble wall nucleation in some cosmological settings. However, we show that the transition amplitudes computed using the Euclidean method generally do not approach the corresponding field theory limit as Mp→∞ . This implies that in the Euclidean framework, there is no systematic expansion in powers of GN for such processes. Such considerations also carry over directly to no-boundary scenarios involving Hawking-Turok instantons. In this note, we illustrate this failure of decoupling in the Euclidean approach with a simple model of axion monodromy and then argue that the situation can be remedied with a Lorentzian prescription such as the Picard-Lefschetz theory. As a proof of concept, we illustrate with a simple model how tunneling transition amplitudes can be calculated using the Picard-Lefschetz approach.

  11. Integration of Cocycles and Lefschetz Number Formulae for Differential Operators

    Directory of Open Access Journals (Sweden)

    Ajay C. Ramadoss

    2011-01-01

    Full Text Available Let E be a holomorphic vector bundle on a complex manifold X such that dim_C X=n. Given any continuous, basic Hochschild 2n-cocycle ψ_{2n} of the algebra Diffn of formal holomorphic differential operators, one obtains a 2n-form f_{E,ψ_{2n}}(D from any holomorphic differential operator D on E. We apply our earlier results [J. Noncommut. Geom. 2 (2008, 405-448; J. Noncommut. Geom. 3 (2009, 27-45] to show that ∫_X f_{E,ψ_{2n}}(D gives the Lefschetz number of D upto a constant independent of X and E. In addition, we obtain a ''local'' result generalizing the above statement. When ψ_{2n} is the cocycle from [Duke Math. J. 127 (2005, 487-517], we obtain a new proof as well as a generalization of the Lefschetz number theorem of Engeli-Felder. We also obtain an analogous ''local'' result pertaining to B. Shoikhet's construction of the holomorphic noncommutative residue of a differential operator for trivial vector bundles on complex parallelizable manifolds. This enables us to give a rigorous construction of the holomorphic noncommutative residue of D defined by B. Shoikhet when E is an arbitrary vector bundle on an arbitrary compact complex manifold X. Our local result immediately yields a proof of a generalization of Conjecture 3.3 of [Geom. Funct. Anal. 11 (2001, 1096-1124].

  12. Pelczynski's property (V) and weak* basic sequences | Cilia ...

    African Journals Online (AJOL)

    In this note we study the property (V) of Pelczynski, in a Banach space X, in relation with the presence, in the dual Banach space X*, of suitable weak* basic sequences. We answer negatively to a question posed by John and we prove that, if X is a Banach space with the Property (V) of Pelczynski and the Gelfand Phillips ...

  13. Spectral Properties of AGN with Very Weak [O III] Lines

    Directory of Open Access Journals (Sweden)

    Kovacevic, J.

    2011-06-01

    Full Text Available The spectral properties of a sample of 58 Active GalacticNuclei (AGN spectra, in which emission [O~III] $lambdalambda$4959, 5007 AA lines are weak or totally absent, are analyzed. In order to investigate thephysical reason for the [O~III] emission suppression, the spectral propertiesof the weak [O~III] spectra sample are compared with the same properties of asample of 269 spectra with the strong [O~III] lines. The spectra are obtainedfrom Sloan Digital Sky Survey (SDSS Database. It is found that the objectswith the weak or absent [O~III] $lambdalambda$4959, 5007 AA linesgenerally have the high continuum luminosities (log($lambda$L$_{5100}$ $>$45, that they are very rare at smaller redshifts ($z <$ 0.3 and that theyusually have strong starburst influence. From the sample with weak or absent[O~III] lines, two boundary subgroups may be distinguished: the subgroup witha strong H$beta$ narrow component and subgroup with a very weak or negligibleH$beta$ narrow component. The physical causes for the [O~III] linessuppressing are probably different in these two subgroups: the [O~III] linesare absent in objects with strong narrow H$beta$ probably because of strongstarburst (SB activity, which produces high density of the gas, while in theobjects with the negligible narrow H$beta$, the reason for [O~III] and narrowH$beta$ suppression may be a low covering factor.

  14. Dynamic Resource Management under Weak Property Rights : A Tale of Thieves and Trespassers

    NARCIS (Netherlands)

    Rodriguez Acosta, Mauricio; Smulders, Sjak

    Using a dynamic framework with strategic interactions, we study the management of a non-renewable natural resource when property rights are generally weak. Under generally weak property rights both the resource stock and the revenues from exploiting it are imperfectly protected, due to trespassing

  15. Some Properties of Solutions to Weakly Hypoelliptic Equations

    Directory of Open Access Journals (Sweden)

    Christian Bär

    2013-01-01

    Full Text Available A linear different operator L is called weakly hypoelliptic if any local solution u of Lu=0 is smooth. We allow for systems, that is, the coefficients may be matrices, not necessarily of square size. This is a huge class of important operators which coverall elliptic, overdetermined elliptic, subelliptic, and parabolic equations. We extend several classical theorems from complex analysis to solutions of any weakly hypoelliptic equation: the Montel theorem providing convergent subsequences, the Vitali theorem ensuring convergence of a given sequence, and Riemann's first removable singularity theorem. In the case of constant coefficients, we show that Liouville's theorem holds, any bounded solution must be constant, and any Lp-solution must vanish.

  16. Weak point property and sections of Picard bundles on a ...

    Indian Academy of Sciences (India)

    Introduction. Debarre had proved that the Jacobian J0(X0) of a smooth curve X0 satisfies the diagonal property (Corollary 2.2 of [6]) i.e., there is a vector bundle of rank equal to the dimension of J0(X0) over J0(X0) × J0(X0), having a section whose zero scheme is the diagonal of J0(X0) × J0(X0). In this note, we generalize ...

  17. Intermolecular potential functions from spectroscopic properties of weakly bound complexes

    Energy Technology Data Exchange (ETDEWEB)

    Muenter, J.S.

    1992-01-01

    Goal is to consolidate the information from high resolution spectroscopy of weakly bound cluster molecules through a theoretical model of intermolecular potential energy surfaces. The ability to construct analytic intermolecular potential functions that accurately predict the interaction energy between small molecules will have a major impact in chemistry, biochemistry, and biology. This document presents the evolution and capabilities of a potential function model developed here, and then describes plans for future developments and applications. This potential energy surface (PES) model was first used on (HCCH){sub 2}, (CO{sub 2}){sub 2}, HCCH - CO{sub 2}; it had to be modified to work with HX dimers and CO{sub 2}-HX complexes. Potential functions have been calculated for 15 different molecular complexes containing 7 different monomer molecules. Current questions, logical extensions and new applications of the model are discussed. The questions are those raised by changing the repulsion and dispersion terms. A major extension of the PES model will be the inclusion of induction effects. Projects in progress include PES calculations on (HCCH){sub 3}, CO{sub 2} containing complexes, (HX){sub 2}, HX - CO{sub 2}, CO{sub 2} - CO, (CO{sub 2}){sub 3}, and (OCS){sub 2}. The first PES calculation for a nonlinear molecule will be for water and ammonia complexes. Possible long-term applications for biological molecules are discussed. Differences between computer programs used for molecular mechanics and dynamics in biological systems are discussed, as is the problem of errors. 12 figs, 74 refs. (DLC)

  18. Pressure Effect on Magnetic Properties of Weak Itinerant Electron Ferromagnet CrAlGe

    Science.gov (United States)

    Yoshinaga, Soshi; Mitsui, Yoshifuru; Umetsu, Rie Y.; Uwatoko, Yoshiya; Koyama, Keiichi

    2018-01-01

    The Pressure effect on the magnetic properties of the weak itinerant electron ferromagnet CrAlGe was investigated at pressures up to 1.0 GPa. The spontaneous magnetic moment ps and Curie temperature TC decreased with increasing applied pressure P. The pressure derivatives of ps and TC were dps/dP = -3.98 × 10-5 μB/MPa and dTC/dP = -6.58 × 10-3 K/MPa, respectively. These obtained results are discussed on the basis of Takahashi's spin fluctuation theory for weak itinerant electron ferromagnets. The characteristic parameters T0 and TA increased with pressure.

  19. Ultra-weak photon emission from biological samples: definition, mechanisms, properties, detection and applications.

    Science.gov (United States)

    Cifra, Michal; Pospíšil, Pavel

    2014-10-05

    This review attempts to summarize molecular mechanisms, spectral and intensity properties, detection techniques and applications of ultra-weak photon emission. Ultra-weak photon emission is the chemiluminescence from biological systems where electronically excited species are formed during oxidative metabolic or oxidative stress processes. It is generally accepted that photons are emitted (1) at near UVA, visible, and near IR spectral ranges from 350 to 1300nm and (2) at the intensity of photon emission in the range of several units to several hundreds (oxidative metabolic process) and several hundreds to several thousands (oxidative stress process) photons s(-1)cm(-2). Current development in detection using low-noise photomultiplier tubes and imaging using highly sensitive charge coupled device cameras allows temporal and spatial visualization of oxidative metabolic or oxidative stress processes, respectively. As the phenomenon of ultra-weak photon emission reflects oxidative metabolic or oxidative stress processes, it can be widely used as a non-invasive tool for monitoring of the physiological state of biological systems. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Synaptic organizations and dynamical properties of weakly connected neural oscillators. I. Analysis of a canonical model.

    Science.gov (United States)

    Hoppensteadt, F C; Izhikevich, E M

    1996-08-01

    We study weakly connected networks of neural oscillators near multiple Andronov-Hopf bifurcation points. We analyze relationships between synaptic organizations (anatomy) of the networks and their dynamical properties (function). Our principal assumptions are: (1) Each neural oscillator comprises two populations of neurons; excitatory and inhibitory ones; (2) activity of each population of neurons is described by a scalar (one-dimensional) variable; (3) each neural oscillator is near a nondegenerate supercritical Andronov-Hopf bifurcation point; (4) the synaptic connections between the neural oscillators are weak. All neural networks satisfying these hypotheses are governed by the same dynamical system, which we call the canonical model. Studying the canonical model shows that: (1) A neural oscillator can communicate only with those oscillators which have roughly the same natural frequency. That is, synaptic connections between a pair of oscillators having different natural frequencies are functionally insignificant. (2) Two neural oscillators having the same natural frequencies might not communicate if the connections between them are from among a class of pathological synaptic configurations. In both cases the anatomical presence of synaptic connections between neural oscillators does not necessarily guarantee that the connections are functionally significant. (3) There can be substantial phase differences (time delays) between the neural oscillators, which result from the synaptic organization of the network, not from the transmission delays. Using the canonical model we can illustrate self-ignition and autonomous quiescence (oscillator death) phenomena. That is, a network of passive elements can exhibit active properties and vice versa. We also study how Dale's principle affects dynamics of the networks, in particular, the phase differences that the network can reproduce. We present a complete classification of all possible synaptic organizations from this

  1. Page 1 y Lefschetz fixed point formula 7 Therefore to arrive at the ...

    Indian Academy of Sciences (India)

    This reduces to the definition given by O'Neill [6] for the fixed point index off on the open neighbourhood st(on(x), sd" K) of xj. 4. Weakly hyperbolic simplicial maps. We show that the class of e.d.p maps is fairly large by showing that if a simplicial map sd" K — K, n > 1 is weakly hyperbolic then it is e.d.p. We also show that a ...

  2. Titania nanotubes from weak organic acid electrolyte: Fabrication, characterization and oxide film properties

    Energy Technology Data Exchange (ETDEWEB)

    Munirathinam, Balakrishnan, E-mail: blkrish88@gmail.com; Neelakantan, Lakshman

    2015-04-01

    In this study, TiO{sub 2} nanotubes were fabricated using anodic oxidation in fluoride containing weak organic acid for different durations (0.5 h, 1 h, 2 h and 3 h). Scanning electron microscope (SEM) micrographs reveal that the morphology of titanium oxide varies with anodization time. Raman spectroscopy and X-ray diffraction (XRD) results indicate that the as-formed oxide nanotubes were amorphous in nature, yet transform into crystalline phases (anatase and rutile) upon annealing at 600 °C. Wettability measurements show that both as-formed and annealed nanotubes exhibited hydrophilic behavior. The electrochemical behavior was ascertained by DC polarization and AC electrochemical impedance spectroscopy (EIS) measurements in 0.9% NaCl solution. The results suggest that the annealed nanotubes showed higher impedance (10{sup 5}–10{sup 6} Ω cm{sup 2}) and lower passive current density (10{sup −7} A cm{sup −2}) than the as-formed nanotubes. In addition, we investigated the influence of post heat treatment on the semiconducting properties of the oxides by capacitance measurements. In vitro bioactivity test in simulated body fluid (SBF) showed that precipitation of Ca/P is easier in crystallized nanotubes than the amorphous structure. Our study uses a simple strategy to prepare nano-structured titania films and hints the feasibility of tailoring the oxide properties by thermal treatment, producing surfaces with better bioactivity. - Highlights: • TiO{sub 2} nanotubes were synthesized in a citric acid and sodium fluoride environment. • Wettability measurements show that both as-formed and annealed nanotubes exhibited hydrophilic behavior. • TiO{sub 2} nanotube layer behaves as an n-type semiconductor. • Annealed TiO{sub 2} nanotubes had a higher impedance magnitude compared to as-formed nanotubes.

  3. Properties of Weakly-decaying Bottom Baryons, Xi_b^- and Omega_b^-, at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Behari, Satyajit; Collaboration, for the CDF

    2009-10-01

    We present properties of weakly decaying bottom baryons, {Xi}{sub b}{sup -} and {Omega}{sub b}{sup -}, using 4.2 fb{sup -1} of data from p{bar p} collisions at {radical}s = 1.96 TeVf, and recorded with the Collider Detector at Fermilab. They report the observation of the {Omega}{sub b}{sup -} through the decay chain {Omega}{sub b}{sup -} {yields} J/{psi}{omega}{sup -}, where J/{psi} {yields} {mu}{sup +}{mu}{sup -}, {Omega}{sup -} {yields} {Lambda}K{sup -}, and {Lambda} {yields} p{pi}{sup -}. Significance of the observed signal is estimated to be 5.5 Gaussian standard deviations. The {Omega}{sub b}{sup -} mass and lifetime are measured to be 6054.4 {+-} 6.8(stat.) {+-} 0.9(syst.) MeV/c{sup 2} and 1.13{sub -0.40}{sup +0.53}(stat.) {+-} 0.02(syst). ps, respectively. In addition, the mass and lifetime of the {Xi}{sub b}{sup -} baryon are measured to be 5790.9 {+-} 2.6(stat.) {+-} 0.8(syst.) MeV/c{sup 2} and 1.56{sub -0.25}{sup +0.27}(stat.) {+-} 0.02(syst.) ps, respectively. Under the assumption that the {Xi}{sub b}{sup -} and {Omega}{sub b}{sup -} are produced with similar kinematic distributions as the {Lambda}{sub b}{sup 0} baryon, we measure {sigma}({Xi}{sub b}{sup -}){Beta}({Xi}{sub b}{sup -}) {yields} J/{psi}({Xi}{sup -})/{sigma}({Lambda}{sub b}{sup 0}){Beta}({Lambda}{sub b}{sup 0} {yields} J/{psi} {Lambda}) = 0.167{sub -0.025}{sup +0.037}(stat.) {+-} 0.012(syst.) and {sigma}({omega}{sub b}{sup -}){Beta}({Omega}{sub b}{sup -} J/{psi} {Omega}{sup -})/{sigma}({Lambda}{sub b}{sup 0}){Beta}({Lambda}{sub b}{sup 0}) {yields} J/{psi} {Lambda} = 0.045{sub 0.012}{sup +0.017}(stat.) {+-} 0.004(syst.) for baryons produced with transverse momentum in the range of 6-20 GeV/c.

  4. Isolating Weakly and Strongly-Absorbing Classes of Carbonaceous Aerosol: Optical Properties, Abundance and Lifecycle

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Tami C. [Univ. of Illinois, Urbana-Champaign, IL (United States); Rood, Mark J. [Univ. of Illinois, Urbana-Champaign, IL (United States); Riemer, Nicole [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2013-09-15

    absorption. Aging by NH3 produces a mild increase in the hygroscopicity of BrC, and a greater increase in cloud condensation nucleus activity. Therefore, reactions with NH3 form compounds that absorb more light than the original aerosol and act as surfactants, increasing the likelihood that these particles will participate in cloud formation. The particle-resolved model PartMC was enhanced to include additional physical processes. It was calibrated against chamber results, and we needed to account for the non-spherical structure of particle agglomerates, even for ammonium sulfate. We implemented the “volatility basis set” (VBS) framework in the model. The updated PartMC-MOSAIC model was able to simulate gas and aerosol concentrations from the CARES campaign at levels similar to observations. The PartMC model was used to evaluate plume dynamics affecting CCN activity of biomass burning aerosols early in a plume. Coagulation limits emission of CCN to about 1016 per kg of fuel. Co-emitted, semi-volatile organic compounds or emission at small particle sizes can homogenize composition before plume exit, and SVOC co-emission can be the main factor determining plume-exit CCN for hydrophobic or small particles. When externally-mixed, accumulation-mode particles are emitted in the absence of SVOCs, CCN can be overestimated by up to a factor of two. This means that measurements made on aerosol from all phases of combustion gathered into a single chamber may incorrectly estimate CCN properties. Based on the findings here, we make some recommendations for use in large-scale models: (1) inventories should represent “internally” versus “externally” mixed under certain combustion conditions; (2) consideration of non-spherical particles when coagulation is important for climate-relevant properties near sources; (3) designating organic biomass particles as weakly absorbing; (4) “inherent absorption” and hygroscopicity are not altered with aging by ozone

  5. Effect of site disorder on the magnetic properties of weak itinerant ...

    Indian Academy of Sciences (India)

    Detailed study of Ni75Al25 samples with varying degree of site disorder reveals that site disorder promotes magnetic excitations such as spin waves and local spin-density fluctuations and thereby reduces both spin-wave stiffness and Curie temperature. Irreversibility lines in the - phase diagram of the weak itinerant ...

  6. Continuous weakly cancellative triangular subnorms: I. Their web-geometric properties

    Czech Academy of Sciences Publication Activity Database

    Petrík, Milan; Sarkoci, Peter

    2018-01-01

    Roč. 332, 1 February (2018), s. 93-110 ISSN 0165-0114 R&D Projects: GA ČR GJ15-07724Y Institutional support: RVO:67985807 Keywords : associativity * conditionally cancellative * continuous triangular subnorm * contour * level set * Reidemeister closure condition * weakly cancellative * web geometry Subject RIV: BA - General Mathematics Impact factor: 2.718, year: 2016

  7. On the Construction and Properties of Weak Solutions Describing Dynamic Cavitation

    KAUST Repository

    Miroshnikov, Alexey

    2014-08-21

    We consider the problem of dynamic cavity formation in isotropic compressible nonlinear elastic media. For the equations of radial elasticity we construct self-similar weak solutions that describe a cavity emanating from a state of uniform deformation. For dimensions d=2,3 we show that cavity formation is necessarily associated with a unique precursor shock. We also study the bifurcation diagram and do a detailed analysis of the singular asymptotics associated to cavity initiation as a function of the cavity speed of the self-similar profiles. We show that for stress free cavities the critical stretching associated with dynamically cavitating solutions coincides with the critical stretching in the bifurcation diagram of equilibrium elasticity. Our analysis treats both stress-free cavities and cavities with contents.

  8. Weakly Compatible Mappings along with $CLR_{S}$ property in Fuzzy Metric Spaces

    Directory of Open Access Journals (Sweden)

    Saurabh Manro

    2013-11-01

    Full Text Available The aim of this work is to use newly introduced property, which is so called common limit in the range $(CLR_{S}$ for four self-mappings, and prove some theorems which satisfy this property. Moreover, we establish some new existence of a common fixed point theorem for generalized contractive mappings in fuzzy metric spaces by using this new property and give some examples to support our results. Ours results does not require condition of closeness of range and so our theorems generalize, unify, and extend many results in literature. Our results improve and extend the results of Cho et al. [4], Pathak et al. [20] and Imdad et. al. [10] besides several known results.

  9. Weakness in the mechanical properties of the femurs of growing female rats exposed to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Brzoska, Malgorzata M.; Moniuszko-Jakoniuk, Janina [Medical University of Bialystok, Department of Toxicology, Bialystok (Poland); Majewska, Katarzyna [University of Warmia and Mazury (Poland). Faculty of Food Science

    2005-09-01

    The study assessed the effect of cadmium (Cd) intoxication on the risk of deformities and fractures of the growing bones of female rats, in order to model human exposure to this metal. For this purpose, bone mineral density and mechanical properties of the proximal and distal ends and diaphysis of the femur were investigated in female Wistar rats exposed to 1, 5 and 50 mg Cd/l in drinking water for 3, 6, 9 and 12 months after the onset of weaning. Daily Cd doses received from drinking water during the treatment period were in the following ranges: 0.059-0.219, 0.236-1.005 and 2.247-9.649 mg/kg body weight at 1, 5 and 50 mg Cd/l, respectively. Biomechanical properties of the femoral proximal and distal ends were evaluated in a compression test, and those of the femoral diaphysis in a cutting test, with loading perpendicular to the longitudinal axis of the bone in all tests. The mineralization and mechanical properties of the bone tissue at various locations on the femur were affected by exposure to Cd in a dose- and duration-dependent manner. Exposure to 1 mg Cd/l (corresponding to low human exposure) during skeletal development weakened the fracture strength of the femoral neck and the trabecular bone at the level of the distal end of the femur and affected the elastic properties of the cortical bone at the femoral diaphysis. At higher levels of Cd exposure, adverse effects were generally observed after a shorter exposure period than for 1 mg Cd/l, and were more advanced. The cadmium-induced weakening of the biomechanical properties of bone at particular sites on the femur correlated with the decreased bone mineralization. The results indicate that even a low exposure to Cd may affect the mineralization and biomechanical properties of growing bone, thus enhancing the risk of fracture. (orig.)

  10. Weakness in the mechanical properties of the femur of growing female rats exposed to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Brzoska, Malgorzata M.; Moniuszko-Jakoniuk, Janina [Medical University of Bialystok, Department of Toxicology, Bialystok (Poland); Majewska, Katarzyna [University of Warmia and Mazury, Olsztyn (Poland). Faculty of Food Science

    2005-05-01

    This study was aimed at assessing the effect of cadmium (Cd) intoxication on the risk of deformities and fractures of the growing bone on a female rat model of human exposure to this metal. For this purpose, bone mineral density (BMD) and mechanical properties of the proximal and distal ends and diaphysis of the femur were investigated in female Wistar rats exposed to 1, 5, and 50 mg Cd L{sup -1} in drinking water for 3, 6, 9, and 12 months since weaning. Daily Cd doses received from the drinking water during the treatment period were in the ranges 0.059-0.219, 0.236-1.005, and 2.247-9.649 mg kg{sup -1} body weight at 1, 5, and 50 mg Cd L{sup -1}, respectively. Biomechanical properties of the femoral proximal and distal ends were evaluated in a compression test and those of the femoral diaphysis in a cutting test with loading perpendicular to the bone longitudinal axis in all tests. Cd dose- and exposure duration-dependently affected the mineralization and mechanical properties of the bone tissue at various locations of the femur. Exposure to 1 mg Cd L{sup -1} (corresponding to low human exposure) during skeletal development weakened the fracture strength of the femoral neck and of the trabecular bone at the level of the distal end of the femur and affected the elastic properties of the cortical bone at the femoral diaphysis. At the higher levels of Cd treatment, the adverse action generally occurred after shorter exposure than at 1 mg Cd L{sup -1} and was more seriously advanced. The Cd-induced weakening in the bone biomechanical properties at particular sites of the femur correlated with the decreased bone mineralization. The results indicate that even low exposure to Cd may affect the mineralization and biomechanical properties of growing bone, thus increasing the risk of fractures. (orig.)

  11. On the Macroeconomic Effects of Establishing Tradability in Weak Property Rights

    DEFF Research Database (Denmark)

    Eliasson, Gunnar; Wihlborg, Clas

    2003-01-01

    The New Economy is closely associated with computing & communications technology, notablythe Internet. We discuss property rights to, and trade in, the difficult-to-define intangible assetsincreasingly dominating the New Economy, and the possibility of under-investment in theseassets. For a reali......The New Economy is closely associated with computing & communications technology, notablythe Internet. We discuss property rights to, and trade in, the difficult-to-define intangible assetsincreasingly dominating the New Economy, and the possibility of under-investment in theseassets...... of the NewEconomy and the large number of possible innovative private contract arrangements make itmore important to facilitate the use and enforcement of private individualized contracts toprotect intellectual property than to rely only on standard mandatory patent and copyright law.Enabling law is one...... proposed solution. Current patent legislation in the US has led to costlylitigation processes weakening the position of small firms and individuals in patent disputes.The property rights of such firms and individuals could be strengthened with insurance orarbitration procedures.Key words: Competence bloc...

  12. Magnetic properties of weak itinerant electron ferromagnet CrAlGe

    Science.gov (United States)

    Yoshinaga, Soshi; Mitsui, Yoshifuru; Umetsu, Rie Y.; Uwatoko, Yoshiya; Koyama, Keiichi

    2017-06-01

    Magnetic properties for CrAlGe with an orthorhombic TiSi2-type structure were investigated under ambient pressure and hydrostatic pressure. CrAlGe is ferromagnetic at the temperature below Curie temperature T C of 80 K and has the spontaneous magnetic moment p s of 0.41 µ B/f.u. at 5 K and the effective moment p eff of 1.89 µ B/f.u. under ambient pressure. For the temperature T below 30 K, the decrease in p s(T) 2/p s(5K)2 was proportional to T 2. However, the decrease in p s(T) 2/p s(5K)2 was proportional to T 4/3 for 30 K high pressure of 1 GPa, T C decreased by approximately 10 K.

  13. The optical properties of a weak probe field in a graphene ensemble under Raman excitation

    Science.gov (United States)

    Raheli, Ali; Hamedi, H. R.; Sahrai, M.

    2016-06-01

    We investigate the coherent manipulation of certain optical properties in graphene under Raman excitation by using a density-matrix approach. It is shown that the absorption and dispersion, the group velocity, and the transmission coefficient of the probe field can be efficiently controlled through proper adjustment of the intensity and frequency detuning of the control field. In addition, the optical bistability (OB) behavior is explored for the proposed system. It is found that the bistable threshold intensity and related hysteresis loop of OB can be controlled by the parameters of the system. The results obtained may be used in real experiments for the development of new types of nanoelectronic devices used for the realization of all-optical switching processes.

  14. Synaptic organizations and dynamical properties of weakly connected neural oscillators. II. Learning phase information.

    Science.gov (United States)

    Hoppensteadt, F C; Izhikevich, E M

    1996-08-01

    This is the second of two articles devoted to analyzing the relationship between synaptic organizations (anatomy) and dynamical properties (function) of networks of neural oscillators near multiple supercritical Andronov-Hopf bifurcation points. Here we analyze learning processes in such networks. Regarding learning dynamics, we assume (1) learning is local (i.e. synaptic modification depends on pre- and postsynaptic neurons but not on others), (2) synapses modify slowly relative to characteristic neuron response times, (3) in the absence of either pre- or postsynaptic activity, the synapse weakens (forgets). Our major goal is to analyze all synaptic organizations of oscillatory neural networks that can memorize and retrieve phase information or time delays. We show that such network have the following attributes: (1) the rate of synaptic plasticity connected with learning is determined locally by the presynaptic neurons, (2) the excitatory neurons must be long-axon relay neurons capable of forming distant connections with other excitatory and inhibitory neurons, (3) if inhibitory neurons have long axons, then the network can learn, passively forget and actively unlearn information by adjusting synaptic plasticity rates.

  15. Nuclear structure properties and stellar weak rates for 76Se: Unblocking of the Gamow Teller strength

    Science.gov (United States)

    Nabi, Jameel-Un; Ishfaq, Mavra; Böyükata, Mahmut; Riaz, Muhammad

    2017-10-01

    At finite temperatures (≥ 107K), 76Se is abundant in the core of massive stars and electron capture on 76Se has a consequential role to play in the dynamics of core-collapse. The present work may be classified into two main categories. In the first phase we study the nuclear structure properties of 76Se using the interacting boson model-1 (IBM-1). The IBM-1 investigations include the energy levels, B (E 2) values and the prediction of the geometry. We performed the extended consistent-Q formalism (ECQF) calculation and later the triaxial formalism calculation (constructed by adding the cubic term to the ECQF). The geometry of 76Se can be envisioned within the formalism of the potential energy surface based on the classical limit of IBM-1 model. In the second phase, we reconfirm the unblocking of the Gamow-Teller (GT) strength in 76Se (a test case for nuclei having N > 40 and Z data and previous calculations. The calculated GT distribution fulfills the Ikeda sum rule. Rates for β-delayed neutrons and emission probabilities are also calculated. Our study suggests that at high stellar temperatures and low densities, the β+-decay on 76Se should not be neglected and needs to be taken into consideration along with electron capture rates for simulation of presupernova evolution of massive stars.

  16. Structural, optical and weak magnetic properties of Co and Mn codoped TiO2 nanoparticles

    Science.gov (United States)

    Kumar, Anand; Kashyap, Manish K.; Sabharwal, Namita; Kumar, Sarvesh; Kumar, Ashok; Kumar, Parmod; Asokan, K.

    2017-11-01

    The present investigation focuses on the structural properties and magnetic response of Co, Mn and Co-Mn doped TiO2 nanoparticles (within 3% dilute doping) along with their optical and electrical studies. X-ray diffraction (XRD) patterns for all these samples show the formation of tetragonal TiO2 anatase phase with no extra impurity phases. Further, Raman bands at 143 cm-1, 396 cm-1, 516 cm-1 and 639 cm-1 also confirm the anatase phase in these samples. Diamagnetic response has been observed in pure TiO2 nanoparticles. However, room temperature (RT) ferromagnetism has been observed with Co and/or Mn doping which gets enhanced further with codoping of Co ions. The observed ferromagnetism has been attributed to the formation of shallow levels with doping/codoping. The Co and/or Mn-doped TiO2 nanoparticles are referred as diluted magnetic semiconductors due to their combined semiconducting and ferromagnetic response. UV-Vis spectra show the band gap of these samples are in the range of 3.03 eV-3.24 eV and a reduction in band gap is observed after codoping. The temperature dependent electrical conductivity measurements also show an enhancement in conductivity after codoping at RT.

  17. Some fixed point theorems for weakly compatible mappings in Non-Archimedean Menger probabilistic metric spaces via common limit range property

    Directory of Open Access Journals (Sweden)

    Sunny Chauhan

    2013-11-01

    Full Text Available In this paper, we utilize the notion of common limit range property in Non-Archimedean Menger PM-spaces and prove some fixed point theorems for two pairs of weakly compatible mappings. Some illustrative examples are furnished to support our results. As an application to our main result, we present a common fixed point theorem for four finite families of self mappings. Our results improve and extend several known results existing in the literature.

  18. Investigation of mono/competitive adsorption of environmentally relevant ionized weak acids on graphite: impact of molecular properties and thermodynamics.

    Science.gov (United States)

    Moustafa, Ahmed M A; McPhedran, Kerry N; Moreira, Jesús; Gamal El-Din, Mohamed

    2014-12-16

    The thermodynamics of adsorption and competitive interactions of five weak acids on a graphite surface was assessed in alkaline solutions. Adsorption of the acids in mono- and multicompound solutions followed their Freundlich isotherms which suggest a diversity of graphite adsorption sites as confirmed by the presence of carboxylic and phenolic groups observed on graphite surfaces. Thermodynamic calculations assigned the formation of the negatively charged assisted hydrogen bond (-CAHB) between ionized solutes and adsorbent surface groups as the possible adsorption mechanism. However, the similar pKa values of current acids resulted in comparable free energies for -CAHB formation (ΔG(-CAHB)) being less than solvation free energies (ΔGSolv). Thus, additional ΔG is supplemented by increased hydrophobicity due to proton exchange of ionized acids with water (ΔΔG Hydrophobicity). Adsorption capacities and competition coefficients indicated that ΔΔG Hydrophobicity values depend on the neutral and ionized acid Kow. Competitive adsorption implies that multilayer adsorption may occur via hydrophobic bonding with the CH3 ends of the self-assembled layer which affects the acid adsorption capacities in mixtures as compared to monocompound solutions. The determination of adsorption mechanisms will assist in understanding of the fate and bioavailability of emerging and classical weak acids released into natural waters.

  19. Weak relativity

    CERN Document Server

    Selleri, Franco

    2015-01-01

    Weak Relativity is an equivalent theory to Special Relativity according to Reichenbach’s definition, where the parameter epsilon equals to 0. It formulates a Neo-Lorentzian approach by replacing the Lorentz transformations with a new set named “Inertial Transformations”, thus explaining the Sagnac effect, the twin paradox and the trip from the future to the past in an easy and elegant way. The cosmic microwave background is suggested as a possible privileged reference system. Most importantly, being a theory based on experimental proofs, rather than mutual consensus, it offers a physical description of reality independent of the human observation.

  20. Weak Intermolecular Hydrogen Bonds with Fluorine: Detection and Implications for Enzymatic/Chemical Reactions, Chemical Properties, and Ligand/Protein Fluorine NMR Screening.

    Science.gov (United States)

    Dalvit, Claudio; Vulpetti, Anna

    2016-05-23

    It is known that strong hydrogen-bonding interactions play an important role in many chemical and biological systems. However, weak or very weak hydrogen bonds, which are often difficult to detect and characterize, may also be relevant in many recognition and reaction processes. Fluorine serving as a hydrogen-bond acceptor has been the subject of many controversial discussions and there are different opinions about it. It now appears that there is compelling experimental evidence for the involvement of fluorine in weak intramolecular or intermolecular hydrogen bonds. Using established NMR methods, we have previously characterized and measured the strengths of intermolecular hydrogen-bond complexes involving the fluorine moieties CH2 F, CHF2 , and CF3 , and have compared them with the well-known hydrogen-bond complex formed between acetophenone and the strong hydrogen-bond donor p-fluorophenol. We now report evidence for the formation of hydrogen bonds involving fluorine with significantly weaker donors, namely 5-fluoroindole and water. A simple NMR method is proposed for the simultaneous measurement of the strengths of hydrogen bonds between an acceptor and a donor or water. Important implications of these results for enzymatic/chemical reactions involving fluorine, for chemical and physical properties, and for ligand/protein (19) F NMR screening are analyzed through experiments and theoretical simulations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Intermolecular potential functions from spectroscopic properties of weakly bound complexes. Third progress report, July 1, 1991--June 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Muenter, J.S.

    1992-08-01

    Goal is to consolidate the information from high resolution spectroscopy of weakly bound cluster molecules through a theoretical model of intermolecular potential energy surfaces. The ability to construct analytic intermolecular potential functions that accurately predict the interaction energy between small molecules will have a major impact in chemistry, biochemistry, and biology. This document presents the evolution and capabilities of a potential function model developed here, and then describes plans for future developments and applications. This potential energy surface (PES) model was first used on (HCCH){sub 2}, (CO{sub 2}){sub 2}, HCCH - CO{sub 2}; it had to be modified to work with HX dimers and CO{sub 2}-HX complexes. Potential functions have been calculated for 15 different molecular complexes containing 7 different monomer molecules. Current questions, logical extensions and new applications of the model are discussed. The questions are those raised by changing the repulsion and dispersion terms. A major extension of the PES model will be the inclusion of induction effects. Projects in progress include PES calculations on (HCCH){sub 3}, CO{sub 2} containing complexes, (HX){sub 2}, HX - CO{sub 2}, CO{sub 2} - CO, (CO{sub 2}){sub 3}, and (OCS){sub 2}. The first PES calculation for a nonlinear molecule will be for water and ammonia complexes. Possible long-term applications for biological molecules are discussed. Differences between computer programs used for molecular mechanics and dynamics in biological systems are discussed, as is the problem of errors. 12 figs, 74 refs. (DLC)

  2. Muscle Weakness

    Directory of Open Access Journals (Sweden)

    Ali Al Kaissi MD, MSc

    2017-01-01

    Full Text Available Marked ligamentous hyperlaxity and muscle weakness/wasting associated with awkward gait are the main deficits confused with the diagnosis of myopathy. Seven children (6 boys and 1 girl with an average age of 8 years were referred to our department because of diverse forms of skeletal abnormalities. No definitive diagnosis was made, and all underwent a series of sophisticated investigations in other institutes in favor of myopathy. We applied our methodology through the clinical and radiographic phenotypes followed by targeted genotypic confirmation. Three children (2 boys and 1 girl were compatible with the diagnosis of progressive pseudorheumatoid chondrodysplasia. The genetic mutation was correlated with the WISP 3 gene actively expressed by articular chondrocytes and located on chromosome 6. Klinefelter syndrome was the diagnosis in 2 boys. Karyotyping confirmed 47,XXY (aneuploidy of Klinefelter syndrome. And 2 boys were finally diagnosed with Morquio syndrome (MPS type IV A as both showed missense mutations in the N-acetylgalactosamine-sulfate sulfatase gene. Misdiagnosis can lead to the initiation of a long list of sophisticated investigations.

  3. Andersen Filtration and Hard Lefschetz

    OpenAIRE

    Soergel, Wolfgang

    2006-01-01

    On the space of homomorphisms from a Verma module to an indecomposable tilting module of the BGG-category O we define a natural filtration following Andersen and establish a formula expressing the dimensions of the filtration steps in terms of coefficients of Kazhdan-Lusztig polynomials.

  4. Deep learning beyond Lefschetz thimbles

    Science.gov (United States)

    Alexandru, Andrei; Bedaque, Paulo F.; Lamm, Henry; Lawrence, Scott

    2017-11-01

    The generalized thimble method to treat field theories with sign problems requires repeatedly solving the computationally expensive holomorphic flow equations. We present a machine learning technique to bypass this problem. The central idea is to obtain a few field configurations via the flow equations to train a feed-forward neural network. The trained network defines a new manifold of integration which reduces the sign problem and can be rapidly sampled. We present results for the 1 +1 dimensional Thirring model with Wilson fermions on sizable lattices. In addition to the gain in speed, the parametrization of the integration manifold we use avoids the "trapping" of Monte Carlo chains which plagues large-flow calculations, a considerable shortcoming of the previous attempts.

  5. Psychometric Properties of the Spanish Version of the Broad Autism Phenotype Questionnaire: Strengths, Weaknesses, and Future Improvements.

    Science.gov (United States)

    Godoy-Giménez, Marta; González-Rodríguez, Antonio; Cañadas, Fernando; Estévez, Angeles F; Sayans-Jiménez, Pablo

    2017-12-27

    The Broad autism phenotype (BAP) refers to a set of subclinical behavioural characteristics qualitatively similar to those presented in Autism spectrum disorders (ASDs). The BAP questionnaire (BAPQ) has been widely used to assess the BAP both in relatives of ASD people and within the general population. The current study presents the first Spanish version of the BAPQ (BAPQ-SP) and analyses its psychometric properties, including validity evidences based on the BAPQ scores relationship with other variables. Our results only support the use of the Aloof and Rigid sub-scales to assess this phenotype, whereas Pragmatic Language sub-scale seems to be the main source of misfit. This research represents a first step in the study of the BAP features in the Spanish population.

  6. Weak interactions of elementary particles

    CERN Document Server

    Okun, Lev Borisovich

    1965-01-01

    International Series of Monographs in Natural Philosophy, Volume 5: Weak Interaction of Elementary Particles focuses on the composition, properties, and reactions of elementary particles and high energies. The book first discusses elementary particles. Concerns include isotopic invariance in the Sakata model; conservation of fundamental particles; scheme of isomultiplets in the Sakata model; universal, unitary-symmetric strong interaction; and universal weak interaction. The text also focuses on spinors, amplitudes, and currents. Wave function, calculation of traces, five bilinear covariants,

  7. Weak Quantum Ergodicity

    CERN Document Server

    Kaplan, L

    1998-01-01

    We examine the consequences of classical ergodicity for the localization properties of individual quantum eigenstates in the classical limit. We note that the well known Schnirelman result is a weaker form of quantum ergodicity than the one implied by random matrix theory. This suggests the possibility of systems with non-gaussian random eigenstates which are nonetheless ergodic in the sense of Schnirelman and lead to ergodic transport in the classical limit. These we call "weakly quantum ergodic.'' Indeed for a class of "slow ergodic" classical systems, it is found that each eigenstate becomes localized to an ever decreasing fraction of the available state space, in the semiclassical limit. Nevertheless, each eigenstate in this limit covers phase space evenly on any classical scale, and long-time transport properties betwen individual quantum states remain ergodic due to the diffractive effects which dominate quantum phase space exploration.

  8. Pseudo-Weak-R0 Algebras

    Directory of Open Access Journals (Sweden)

    Yong Lin Liu

    2014-01-01

    Full Text Available A positive answer to the open problem of Iorgulescu on extending weak-R0 algebras and R0-algebras to the noncommutative forms is given. We show that pseudo-weak-R0 algebras are categorically isomorphic to pseudo-IMTL algebras and that pseudo-R0 algebras are categorically isomorphic to pseudo-NM algebras. Some properties, the noncommutative forms of the properties in weak-R0 algebras and R0-algebras, are investigated. The simplified axiom systems of pseudo-weak-R0 algebras and pseudo-R0 algebras are obtained.

  9. Anomalous physical properties of underdoped weak-ferromagnetic superconductor RuSr{sub 2}EuCu{sub 2}O{sub 8}

    Energy Technology Data Exchange (ETDEWEB)

    Chang, B.C. [Department of Physics, National Tsing Hua University, Hsinchu 300, Taiwan (China); Ku, H.C. [Department of Physics, National Tsing Hua University, Hsinchu 300, Taiwan (China)], E-mail: hcku@phys.nthu.edu.tw; Ho, J.C. [Department of Physics, Wichita State University, Wichita, KS 67260-0032 (United States)

    2008-04-01

    Similar to the optimal-doped, weak-ferromagnetic (WFM induced by canted antiferromagnetism, T{sub Curie}=131 K) and superconducting (T{sub c}=56 K) RuSr{sub 2}GdCu{sub 2}O{sub 8}, the underdoped RuSr{sub 2}EuCu{sub 2}O{sub 8} (T{sub Curie}=133 K, T{sub c}=36 K) also exhibits a spontaneous vortex state (SVS) between 16 and 36 K. The low field superconducting hysteresis loop indicates a weak and narrow Meissner state region of average lower critical field B{sub cl}{sup ave}(0)=7 G and T{sub SVS}=16 K. The vortex melting transition (T{sub melting}=21 K) below T{sub c} obtained from the broad resistivity drop and the onset of diamagnetic signal indicates a vortex liquid region due to the coexistence and interplay between superconductivity and WFM order. No visible jump in specific heat was observed near T{sub c}. This is not surprising, since the electronic specific heat is easily overshadowed by the large phonon and weak-ferromagnetic contributions. Furthermore, a broad resistivity transition due to low vortex melting temperature would also lead to a correspondingly reduced height of any specific heat jump.

  10. A classification of weakly acyclic games

    NARCIS (Netherlands)

    Apt, K.R.; Simon, S.

    2012-01-01

    Weakly acyclic games form a natural generalization of the class of games that have the finite improvement property (FIP). In such games one stipulates that from any initial joint strategy some finite improvement path exists. We classify weakly acyclic games using the concept of a scheduler recently

  11. Towards a classification of weak hand holds

    NARCIS (Netherlands)

    Kimmelman, V.; Sáfár, A.; Crasborn, O.

    2016-01-01

    The two symmetrical manual articulators (the hands) in signed languages are a striking modalityspecific phonetic property. The weak hand can maintain the end position of an articulation while the other articulator continues to produce additional signs. This weak hand spreading (hold) has been

  12. Metal Complexes of 1,3,4-Thiadiazole-2,5-Disulfonamide are Strong Dual Carbonic Anhydrase Inhibitors, although the Ligand Possesses very Weak such Properties.

    Science.gov (United States)

    Supuran, C T

    1995-01-01

    Coordination compounds of Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) with 1,3,4-thiadiazole-2,5-disulfonamide as ligand were synthesized and characterized by IR and UV spectroscopy, conductimetry and thermogravimetry. The parent ligand is a very weak carbonic anhydrase (CA) inhibitor, although it constituted the lead for developing important classes of diuretics. The complex derivatives behave as much stronger CA inhibitors, with IC(50) values around 10(-8)M against isozyme CA II, and 10(-7) M against isozyme CAI.

  13. Metal Complexes of 1,3,4-Thiadiazole-2,5-Disulfonamide are Strong Dual Carbonic Anhydrase Inhibitors, although the Ligand Possesses very Weak such Properties

    OpenAIRE

    Claudiu T. Supuran

    1995-01-01

    Coordination compounds of Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) with 1,3,4-thiadiazole-2,5-disulfonamide as ligand were synthesized and characterized by IR and UV spectroscopy, conductimetry and thermogravimetry. The parent ligand is a very weak carbonic anhydrase (CA) inhibitor, although it constituted the lead for developing important classes of diuretics. The complex derivatives behave as much stronger CA inhibitors, with IC50 values around 10−8M against isozyme CA II, and 10−7 M agai...

  14. WEAK GORENSTEIN GLOBAL DIMENSION

    OpenAIRE

    Bennis, Driss

    2010-01-01

    In this paper, we investigate the weak Gorenstein global dimensions. We are mainly interested in studying the problem when the left and right weak Gorenstein global dimensions coincide. We first show, for GF-closed rings, that the left and right weak Gorenstein global dimensions are equal when they are finite. Then, we prove that the same equality holds for any two-sided coherent ring. We conclude the paper with some examples and a brief discussion of the scope and limits of our results.

  15. History of Weak Interactions

    Science.gov (United States)

    Lee, T. D.

    1970-07-01

    While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.

  16. Weak bond screening system

    Science.gov (United States)

    Chuang, S. Y.; Chang, F. H.; Bell, J. R.

    Consideration is given to the development of a weak bond screening system which is based on the utilization of a high power ultrasonic (HPU) technique. The instrumentation of the prototype bond strength screening system is described, and the adhesively bonded specimens used in the system developmental effort are detailed. Test results obtained from these specimens are presented in terms of bond strength and level of high power ultrasound irradiation. The following observations were made: (1) for Al/Al specimens, 2.6 sec of HPU irradiation will screen weak bond conditions due to improper preparation of bonding surfaces; (2) for composite/composite specimens, 2.0 sec of HPU irradiation will disrupt weak bonds due to under-cured conditions; (3) for Al honeycomb core with composite skin structure, 3.5 sec of HPU irradiation will disrupt weak bonds due to bad adhesive or oils contamination of bonding surfaces; and (4) for Nomex honeycomb with Al skin structure, 1.3 sec of HPU irradiation will disrupt weak bonds due to bad adhesive.

  17. Weak polyelectrolytes in Confined Geometries

    Science.gov (United States)

    Whitmer, Jonathan K.; Rathee, Vikramjit S.; Sikora, Benjamin

    Crucial to the behavior of recently designed charge-rejection and mosaic membranes are the conformations of polyelectrolyte brushes and oligomeric grafts used to control the membranes' surface charge. The use of pH-tunable weak polyelectrolytes with associative interactions enables fine tuning of material transport properties. Here, we apply constant-pH molecular dynamics along with free energy sampling algorithms to understand the subtle tug-of-war between pH, salt concentrations, and solvation forces in confined systems, and determine how each of these effects alters transport within the system. We further discuss the implications of our findings for the design of electrolyte separation membranes.

  18. Bagging Weak Predictors

    DEFF Research Database (Denmark)

    Lukas, Manuel; Hillebrand, Eric

    Relations between economic variables can often not be exploited for forecasting, suggesting that predictors are weak in the sense that estimation uncertainty is larger than bias from ignoring the relation. In this paper, we propose a novel bagging predictor designed for such weak predictor...... variables. The predictor is based on a test for finitesample predictive ability. Our predictor shrinks the OLS estimate not to zero, but towards the null of the test which equates squared bias with estimation variance. We derive the asymptotic distribution and show that the predictor can substantially lower...

  19. Gossip and Distributed Kalman Filtering: Weak Consensus Under Weak Detectability

    Science.gov (United States)

    Kar, Soummya; Moura, José M. F.

    2011-04-01

    The paper presents the gossip interactive Kalman filter (GIKF) for distributed Kalman filtering for networked systems and sensor networks, where inter-sensor communication and observations occur at the same time-scale. The communication among sensors is random; each sensor occasionally exchanges its filtering state information with a neighbor depending on the availability of the appropriate network link. We show that under a weak distributed detectability condition: 1. the GIKF error process remains stochastically bounded, irrespective of the instability properties of the random process dynamics; and 2. the network achieves \\emph{weak consensus}, i.e., the conditional estimation error covariance at a (uniformly) randomly selected sensor converges in distribution to a unique invariant measure on the space of positive semi-definite matrices (independent of the initial state.) To prove these results, we interpret the filtered states (estimates and error covariances) at each node in the GIKF as stochastic particles with local interactions. We analyze the asymptotic properties of the error process by studying as a random dynamical system the associated switched (random) Riccati equation, the switching being dictated by a non-stationary Markov chain on the network graph.

  20. Ranking Entities in Networks via Lefschetz Duality

    DEFF Research Database (Denmark)

    Aabrandt, Andreas; Hansen, Vagn Lundsgaard; Poulsen, Bjarne

    2014-01-01

    In the theory of communication it is essential that agents are able to exchange information. This fact is closely related to the study of connected spaces in topology. A communication network may be modelled as a topological space such that agents can communicate if and only if they belong...... then be ranked according to how essential their positions are in the network by considering the effect of their respective absences. Defining a ranking of a network which takes the individual position of each entity into account has the purpose of assigning different roles to the entities, e.g. agents...

  1. Anti-icing properties of a superhydrophobic surface in a salt environment: an unexpected increase in freezing delay times for weak brine droplets.

    Science.gov (United States)

    Boinovich, Ludmila B; Emelyanenko, Alexandre M; Emelyanenko, Kirill A; Maslakov, Konstantin I

    2016-01-28

    Superhydrophobic coatings on the aluminum alloy were fabricated by intensive nanosecond pulsed laser treatment and chemical surface hydrophobization, which are chemically stable in contact with 0.5 M NaCl aqueous solutions and mechanically durable against stresses arising in the repetitive freezing/thawing of brine. The statistics of the crystallization of ensembles of sessile supercooled droplets deposited on above superhydrophobic coatings indicate considerable anti-icing properties. The comparative analysis of crystallization statistics of deionized water and of brine at a temperature of -20 °C allows detecting a striking increase in freezing delay times for the latter case with freezing delay for brine droplets reaching more than 6 hours. We explain the observed phenomenon based on the structure of the double electric layer in the vicinity of the hydrophobic surface and the solution/air interface and on the concept of structure making/breaking ions.

  2. On modeling weak sinks in MODPATH

    Science.gov (United States)

    Abrams, Daniel B.; Haitjema, Henk; Kauffman, Leon J.

    2012-01-01

    Regional groundwater flow systems often contain both strong sinks and weak sinks. A strong sink extracts water from the entire aquifer depth, while a weak sink lets some water pass underneath or over the actual sink. The numerical groundwater flow model MODFLOW may allow a sink cell to act as a strong or weak sink, hence extracting all water that enters the cell or allowing some of that water to pass. A physical strong sink can be modeled by either a strong sink cell or a weak sink cell, with the latter generally occurring in low resolution models. Likewise, a physical weak sink may also be represented by either type of sink cell. The representation of weak sinks in the particle tracing code MODPATH is more equivocal than in MODFLOW. With the appropriate parameterization of MODPATH, particle traces and their associated travel times to weak sink streams can be modeled with adequate accuracy, even in single layer models. Weak sink well cells, on the other hand, require special measures as proposed in the literature to generate correct particle traces and individual travel times and hence capture zones. We found that the transit time distributions for well water generally do not require special measures provided aquifer properties are locally homogeneous and the well draws water from the entire aquifer depth, an important observation for determining the response of a well to non-point contaminant inputs.

  3. Charged weak currents

    CERN Document Server

    Turlay, René

    1979-01-01

    In this review of charged weak currents the author concentrates on inclusive high energy neutrino physics. The authors discusses the general structure of charged currents, new results on total cross- sections, the Callan-Gross relation, antiquark distributions, scaling violations and tests of QCD. A very short summary on multilepton physics is given. (44 refs).

  4. On Weak Markov's Principle

    DEFF Research Database (Denmark)

    Kohlenbach, Ulrich Wilhelm

    2002-01-01

    We show that the so-called weak Markov's principle (WMP) which states that every pseudo-positive real number is positive is underivable in E-HA + AC. Since allows one to formalize (atl eastl arge parts of) Bishop's constructive mathematics, this makes it unlikely that WMP can be proved within...

  5. A thermostable Salmonella phage endolysin, Lys68, with broad bactericidal properties against gram-negative pathogens in presence of weak acids.

    Science.gov (United States)

    Oliveira, Hugo; Thiagarajan, Viruthachalam; Walmagh, Maarten; Sillankorva, Sanna; Lavigne, Rob; Neves-Petersen, Maria Teresa; Kluskens, Leon D; Azeredo, Joana

    2014-01-01

    Resistance rates are increasing among several problematic Gram-negative pathogens, a fact that has encouraged the development of new antimicrobial agents. This paper characterizes a Salmonella phage endolysin (Lys68) and demonstrates its potential antimicrobial effectiveness when combined with organic acids towards Gram-negative pathogens. Biochemical characterization reveals that Lys68 is more active at pH 7.0, maintaining 76.7% of its activity when stored at 4°C for two months. Thermostability tests showed that Lys68 is only completely inactivated upon exposure to 100°C for 30 min, and circular dichroism analysis demonstrated the ability to refold into its original conformation upon thermal denaturation. It was shown that Lys68 is able to lyse a wide panel of Gram-negative bacteria (13 different species) in combination with the outer membrane permeabilizers EDTA, citric and malic acid. While the EDTA/Lys68 combination only inactivated Pseudomonas strains, the use of citric or malic acid broadened Lys68 antibacterial effect to other Gram-negative pathogens (lytic activity against 9 and 11 species, respectively). Particularly against Salmonella Typhimurium LT2, the combinatory effect of malic or citric acid with Lys68 led to approximately 3 to 5 log reductions in bacterial load/CFUs after 2 hours, respectively, and was also able to reduce stationary-phase cells and bacterial biofilms by approximately 1 log. The broad killing capacity of malic/citric acid-Lys68 is explained by the destabilization and major disruptions of the cell outer membrane integrity due to the acidity caused by the organic acids and a relatively high muralytic activity of Lys68 at low pH. Lys68 demonstrates good (thermo)stability properties that combined with different outer membrane permeabilizers, could become useful to combat Gram-negative pathogens in agricultural, food and medical industry.

  6. A thermostable Salmonella phage endolysin, Lys68, with broad bactericidal properties against gram-negative pathogens in presence of weak acids.

    Directory of Open Access Journals (Sweden)

    Hugo Oliveira

    Full Text Available Resistance rates are increasing among several problematic Gram-negative pathogens, a fact that has encouraged the development of new antimicrobial agents. This paper characterizes a Salmonella phage endolysin (Lys68 and demonstrates its potential antimicrobial effectiveness when combined with organic acids towards Gram-negative pathogens. Biochemical characterization reveals that Lys68 is more active at pH 7.0, maintaining 76.7% of its activity when stored at 4°C for two months. Thermostability tests showed that Lys68 is only completely inactivated upon exposure to 100°C for 30 min, and circular dichroism analysis demonstrated the ability to refold into its original conformation upon thermal denaturation. It was shown that Lys68 is able to lyse a wide panel of Gram-negative bacteria (13 different species in combination with the outer membrane permeabilizers EDTA, citric and malic acid. While the EDTA/Lys68 combination only inactivated Pseudomonas strains, the use of citric or malic acid broadened Lys68 antibacterial effect to other Gram-negative pathogens (lytic activity against 9 and 11 species, respectively. Particularly against Salmonella Typhimurium LT2, the combinatory effect of malic or citric acid with Lys68 led to approximately 3 to 5 log reductions in bacterial load/CFUs after 2 hours, respectively, and was also able to reduce stationary-phase cells and bacterial biofilms by approximately 1 log. The broad killing capacity of malic/citric acid-Lys68 is explained by the destabilization and major disruptions of the cell outer membrane integrity due to the acidity caused by the organic acids and a relatively high muralytic activity of Lys68 at low pH. Lys68 demonstrates good (thermostability properties that combined with different outer membrane permeabilizers, could become useful to combat Gram-negative pathogens in agricultural, food and medical industry.

  7. Weak lensing with GEST

    Science.gov (United States)

    Rhodes, J. D.; Bennett, D. P.; Kaiser, N.

    2001-12-01

    Weak lensing by large-scale structure (cosmic shear) provides an opportunity to directly observe the dark matter in the universe. Current ground-based and space-based surveys have demonstrated the efficacy of this technique in determining the mass distribution and thus placing constraints on cosmological parameters such as Ω m, σ 8, and the bias parameter b. Current surveys have been hampered by the comparatively low resolution of ground-based telescopes and the small field of view of HST. To make significant progress in this field, wide field space-based surveys are needed. The Galactic Exoplanet Survey Telescope (GEST) will be able to provide 500- 1000 sqare degrees with a resolution of better than 0.2 arcseconds in multiple filters. This will make it an ideal instrument for a weak lensing survey.

  8. Composite weak bosons

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, M.

    1988-04-01

    Dynamical mechanism of composite W and Z is studied in a 1/N field theory model with four-fermion interactions in which global weak SU(2) symmetry is broken explicitly by electromagnetic interaction. Issues involved in such a model are discussed in detail. Deviation from gauge coupling due to compositeness and higher order loop corrections are examined to show that this class of models are consistent not only theoretically but also experimentally.

  9. Measurement of weak radioactivity

    CERN Document Server

    Theodorsson , P

    1996-01-01

    This book is intended for scientists engaged in the measurement of weak alpha, beta, and gamma active samples; in health physics, environmental control, nuclear geophysics, tracer work, radiocarbon dating etc. It describes the underlying principles of radiation measurement and the detectors used. It also covers the sources of background, analyzes their effect on the detector and discusses economic ways to reduce the background. The most important types of low-level counting systems and the measurement of some of the more important radioisotopes are described here. In cases where more than one type can be used, the selection of the most suitable system is shown.

  10. ICU-Acquired Weakness.

    Science.gov (United States)

    Jolley, Sarah E; Bunnell, Aaron E; Hough, Catherine L

    2016-11-01

    Survivorship after critical illness is an increasingly important health-care concern as ICU use continues to increase while ICU mortality is decreasing. Survivors of critical illness experience marked disability and impairments in physical and cognitive function that persist for years after their initial ICU stay. Newfound impairment is associated with increased health-care costs and use, reductions in health-related quality of life, and prolonged unemployment. Weakness, critical illness neuropathy and/or myopathy, and muscle atrophy are common in patients who are critically ill, with up to 80% of patients admitted to the ICU developing some form of neuromuscular dysfunction. ICU-acquired weakness (ICUAW) is associated with longer durations of mechanical ventilation and hospitalization, along with greater functional impairment for survivors. Although there is increasing recognition of ICUAW as a clinical entity, significant knowledge gaps exist concerning identifying patients at high risk for its development and understanding its role in long-term outcomes after critical illness. This review addresses the epidemiologic and pathophysiologic aspects of ICUAW; highlights the diagnostic challenges associated with its diagnosis in patients who are critically ill; and proposes, to our knowledge, a novel strategy for identifying ICUAW. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  11. Quantum mechanical calculations on weakly interacting complexes

    NARCIS (Netherlands)

    Heijmen, T.G.A.

    1998-01-01

    Symmetry-adapted perturbation theory (SAPT) has been applied to compute the intermolecular potential energy surfaces and the interaction-induced electrical properties of weakly interacting complexes. Asymptotic (large R) expressions have been derived for the contributions to the collision-induced

  12. From Suitable Weak Solutions to Entropy Viscosity

    KAUST Repository

    Guermond, Jean-Luc

    2010-12-16

    This paper focuses on the notion of suitable weak solutions for the three-dimensional incompressible Navier-Stokes equations and discusses the relevance of this notion to Computational Fluid Dynamics. The purpose of the paper is twofold (i) to recall basic mathematical properties of the three-dimensional incompressible Navier-Stokes equations and to show how they might relate to LES (ii) to introduce an entropy viscosity technique based on the notion of suitable weak solution and to illustrate numerically this concept. © 2010 Springer Science+Business Media, LLC.

  13. Withering away, weakly

    NARCIS (Netherlands)

    F.A. Muller (Archibald)

    2011-01-01

    textabstractOne of the reasons provided for the shift away from an ontology for physical reality of material objects & properties towards one of physical structures & relations (Ontological Structural Realism: OntSR) is that the quantum-mechanical description of composite physical systems of similar

  14. Inversion assuming weak scattering

    DEFF Research Database (Denmark)

    Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus

    2013-01-01

    due to the complex nature of the field. A method based on linear inversion is employed to infer information about the statistical properties of the scattering field from the obtained cross-spectral matrix. A synthetic example based on an active high-frequency sonar demonstrates that the proposed...

  15. Information flow between weakly interacting lattices of coupled maps

    Energy Technology Data Exchange (ETDEWEB)

    Dobyns, York [PEAR, Princeton University, Princeton, NJ 08544-5263 (United States); Atmanspacher, Harald [Institut fuer Grenzgebiete der Psychologie und Psychohygiene, Wilhelmstr. 3a, 79098 Freiburg (Germany)]. E-mail: haa@igpp.de

    2006-05-15

    Weakly interacting lattices of coupled maps can be modeled as ordinary coupled map lattices separated from each other by boundary regions with small coupling parameters. We demonstrate that such weakly interacting lattices can nevertheless have unexpected and striking effects on each other. Under specific conditions, particular stability properties of the lattices are significantly influenced by their weak mutual interaction. This observation is tantamount to an efficacious information flow across the boundary.

  16. Kramers systems with weak spin-dependent interactions

    Energy Technology Data Exchange (ETDEWEB)

    Radwanski, R.J. [Inst. of Physics and Informatics, Pedagogical University, 30-084, Krakow (Poland)]|[Center for Solid State Physics, Sw. Filip 5, 31-150, Krakow (Poland)

    1995-02-09

    Magnetic properties of a paramagnetic Kramers f{sup 3} subsystem under charge interactions of the hexagonal symmetry have been examined in the combination with weak spin-dependent (S-D) interactions for the case of the weakly-magnetic charge-formed ground state. The Kramers systems with weak S-D interactions exhibit particular phenomena like large specific heat at low temperatures. ((orig.)).

  17. On defining soft spaces by weak soft neighborhood systems

    Directory of Open Access Journals (Sweden)

    Taha ÖZTÜRK

    2016-04-01

    Full Text Available In the present paper, we define the concepts of weak soft neighborhood space, soft w^{s}(?,?'-continuous, soft w^{s}-continuous and soft w^{s^{*}}-continuous on weak soft neighborhood spaces. Finally, we introduce their basic properties and some examples.

  18. Weak Measurement and Quantum Correlation

    Indian Academy of Sciences (India)

    Arun Kumar Pati

    The concept of the weak measurements, for the first time, was introduced by Aharonov et al.1. Quantum state is preselected in |ψi〉 and allowed to interact weakly with apparatus. Measurement strength can be tuned and for “small g(t)” it is called 'weak measurement'. With postselection in |ψf 〉, apparatus state is shifted by an ...

  19. Contextuality under weak assumptions

    Science.gov (United States)

    Simmons, Andrew W.; Wallman, Joel J.; Pashayan, Hakop; Bartlett, Stephen D.; Rudolph, Terry

    2017-03-01

    The presence of contextuality in quantum theory was first highlighted by Bell, Kochen and Specker, who discovered that for quantum systems of three or more dimensions, measurements could not be viewed as deterministically revealing pre-existing properties of the system. More precisely, no model can assign deterministic outcomes to the projectors of a quantum measurement in a way that depends only on the projector and not the context (the full set of projectors) in which it appeared, despite the fact that the Born rule probabilities associated with projectors are independent of the context. A more general, operational definition of contextuality introduced by Spekkens, which we will term ‘probabilistic contextuality’, drops the assumption of determinism and allows for operations other than measurements to be considered contextual. Even two-dimensional quantum mechanics can be shown to be contextual under this generalised notion. Probabilistic noncontextuality represents the postulate that elements of an operational theory that cannot be distinguished from each other based on the statistics of arbitrarily many repeated experiments (they give rise to the same operational probabilities) are ontologically identical. In this paper, we introduce a framework that enables us to distinguish between different noncontextuality assumptions in terms of the relationships between the ontological representations of objects in the theory given a certain relation between their operational representations. This framework can be used to motivate and define a ‘possibilistic’ analogue, encapsulating the idea that elements of an operational theory that cannot be unambiguously distinguished operationally can also not be unambiguously distinguished ontologically. We then prove that possibilistic noncontextuality is equivalent to an alternative notion of noncontextuality proposed by Hardy. Finally, we demonstrate that these weaker noncontextuality assumptions are sufficient to prove

  20. Resisting Weakness of the Will.

    Science.gov (United States)

    Levy, Neil

    2011-01-01

    I develop an account of weakness of the will that is driven by experimental evidence from cognitive and social psychology. I will argue that this account demonstrates that there is no such thing as weakness of the will: no psychological kind corresponds to it. Instead, weakness of the will ought to be understood as depletion of System II resources. Neither the explanatory purposes of psychology nor our practical purposes as agents are well-served by retaining the concept. I therefore suggest that we ought to jettison it, in favour of the vocabulary and concepts of cognitive psychology.

  1. Weak Coupling Phases future directions

    CERN Document Server

    Rosner, Jonathan L.

    2003-01-01

    Recent results obtained from B decays on the phases of weak couplings described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix are discussed, with particular emphasis on $\\alpha$ and $\\gamma = \\pi - \\beta - \\alpha$.

  2. Weakly compact operators and interpolation

    OpenAIRE

    Maligranda, Lech

    1992-01-01

    The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. In this survey, we have collected and ordered some of this (partly very new) knowledge. We have also included some comments, remarks and examples. The class of weakly compact operators is, as well as the class of compact operators, a fundamental operator ideal. They were investigated strongly in the last twenty years. I...

  3. Acute muscular weakness in children

    Directory of Open Access Journals (Sweden)

    Ricardo Pablo Javier Erazo Torricelli

    Full Text Available ABSTRACT Acute muscle weakness in children is a pediatric emergency. During the diagnostic approach, it is crucial to obtain a detailed case history, including: onset of weakness, history of associated febrile states, ingestion of toxic substances/toxins, immunizations, and family history. Neurological examination must be meticulous as well. In this review, we describe the most common diseases related to acute muscle weakness, grouped into the site of origin (from the upper motor neuron to the motor unit. Early detection of hyperCKemia may lead to a myositis diagnosis, and hypokalemia points to the diagnosis of periodic paralysis. Ophthalmoparesis, ptosis and bulbar signs are suggestive of myasthenia gravis or botulism. Distal weakness and hyporeflexia are clinical features of Guillain-Barré syndrome, the most frequent cause of acute muscle weakness. If all studies are normal, a psychogenic cause should be considered. Finding the etiology of acute muscle weakness is essential to execute treatment in a timely manner, improving the prognosis of affected children.

  4. Precision metrology using weak measurements.

    Science.gov (United States)

    Zhang, Lijian; Datta, Animesh; Walmsley, Ian A

    2015-05-29

    Weak values and measurements have been proposed as a means to achieve dramatic enhancements in metrology based on the greatly increased range of possible measurement outcomes. Unfortunately, the very large values of measurement outcomes occur with highly suppressed probabilities. This raises three vital questions in weak-measurement-based metrology. Namely, (Q1) Does postselection enhance the measurement precision? (Q2) Does weak measurement offer better precision than strong measurement? (Q3) Is it possible to beat the standard quantum limit or to achieve the Heisenberg limit with weak measurement using only classical resources? We analyze these questions for two prototypical, and generic, measurement protocols and show that while the answers to the first two questions are negative for both protocols, the answer to the last is affirmative for measurements with phase-space interactions, and negative for configuration space interactions. Our results, particularly the ability of weak measurements to perform at par with strong measurements in some cases, are instructive for the design of weak-measurement-based protocols for quantum metrology.

  5. Quantum discord with weak measurements

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Uttam, E-mail: uttamsingh@hri.res.in; Pati, Arun Kumar, E-mail: akpati@hri.res.in

    2014-04-15

    Weak measurements cause small change to quantum states, thereby opening up the possibility of new ways of manipulating and controlling quantum systems. We ask, can weak measurements reveal more quantum correlation in a composite quantum state? We prove that the weak measurement induced quantum discord, called as the “super quantum discord”, is always larger than the quantum discord captured by the strong measurement. Moreover, we prove the monotonicity of the super quantum discord as a function of the measurement strength and in the limit of strong projective measurement the super quantum discord becomes the normal quantum discord. We find that unlike the normal discord, for pure entangled states, the super quantum discord can exceed the quantum entanglement. Our results provide new insights on the nature of quantum correlation and suggest that the notion of quantum correlation is not only observer dependent but also depends on how weakly one perturbs the composite system. We illustrate the key results for pure as well as mixed entangled states. -- Highlights: •Introduced the role of weak measurements in quantifying quantum correlation. •We have introduced the notion of the super quantum discord (SQD). •For pure entangled state, we show that the SQD exceeds the entanglement entropy. •This shows that quantum correlation depends not only on observer but also on measurement strength.

  6. Warping the Weak Gravity Conjecture

    Directory of Open Access Journals (Sweden)

    Karta Kooner

    2016-08-01

    Full Text Available The Weak Gravity Conjecture, if valid, rules out simple models of Natural Inflation by restricting their axion decay constant to be sub-Planckian. We revisit stringy attempts to realise Natural Inflation, with a single open string axionic inflaton from a probe D-brane in a warped throat. We show that warped geometries can allow the requisite super-Planckian axion decay constant to be achieved, within the supergravity approximation and consistently with the Weak Gravity Conjecture. Preliminary estimates of the brane backreaction suggest that the probe approximation may be under control. However, there is a tension between large axion decay constant and high string scale, where the requisite high string scale is difficult to achieve in all attempts to realise large field inflation using perturbative string theory. We comment on the Generalized Weak Gravity Conjecture in the light of our results.

  7. Cosmology and the weak interaction

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.N. (Fermi National Accelerator Lab., Batavia, IL (USA)):(Chicago Univ., IL (USA))

    1989-12-01

    The weak interaction plays a critical role in modern Big Bang cosmology. This review will emphasize two of its most publicized cosmological connections: Big Bang nucleosynthesis and Dark Matter. The first of these is connected to the cosmological prediction of Neutrino Flavours, N{sub {nu}} {approximately} 3 which is now being confirmed at SLC and LEP. The second is interrelated to the whole problem of galaxy and structure formation in the universe. This review will demonstrate the role of the weak interaction both for dark matter candidates and for the problem of generating seeds to form structure. 87 refs., 3 figs., 5 tabs.

  8. Nonlinear waves and weak turbulence

    CERN Document Server

    Zakharov, V E

    1997-01-01

    This book is a collection of papers on dynamical and statistical theory of nonlinear wave propagation in dispersive conservative media. Emphasis is on waves on the surface of an ideal fluid and on Rossby waves in the atmosphere. Although the book deals mainly with weakly nonlinear waves, it is more than simply a description of standard perturbation techniques. The goal is to show that the theory of weakly interacting waves is naturally related to such areas of mathematics as Diophantine equations, differential geometry of waves, Poincaré normal forms, and the inverse scattering method.

  9. Classical and Weak Solutions for Two Models in Mathematical Finance

    Science.gov (United States)

    Gyulov, Tihomir B.; Valkov, Radoslav L.

    2011-12-01

    We study two mathematical models, arising in financial mathematics. These models are one-dimensional analogues of the famous Black-Scholes equation on finite interval. The main difficulty is the degeneration at the both ends of the space interval. First, classical solutions are studied. Positivity and convexity properties of the solutions are discussed. Variational formulation in weighted Sobolev spaces is introduced and existence and uniqueness of the weak solution is proved. Maximum principle for weak solution is discussed.

  10. Ultra-weak sector, Higgs boson mass, and the dilaton

    Directory of Open Access Journals (Sweden)

    Kyle Allison

    2014-11-01

    Full Text Available The Higgs boson mass may arise from a portal coupling to a singlet field σ which has a very large VEV f≫mHiggs. This requires a sector of “ultra-weak” couplings ζi, where ζi≲mHiggs2/f2. Ultra-weak couplings are technically naturally small due to a custodial shift symmetry of σ in the ζi→0 limit. The singlet field σ has properties similar to a pseudo-dilaton. We engineer explicit breaking of scale invariance in the ultra-weak sector via a Coleman–Weinberg potential, which requires hierarchies amongst the ultra-weak couplings.

  11. Submanifolds weakly associated with graphs

    Indian Academy of Sciences (India)

    Sci. (Math. Sci.) Vol. 119, No. 3, June 2009, pp. 297–318. © Printed in India. Submanifolds weakly associated with graphs. A CARRIAZO, L M FERN ´ANDEZ and A RODRÍGUEZ-HIDALGO. Department of Geometry and Topology, Faculty of Mathematics, University of Sevilla,. Apartado de Correos 1160, 41080-Sevilla, Spain.

  12. Beam splitting on weak illumination.

    Science.gov (United States)

    Snyder, A W; Buryak, A V; Mitchell, D J

    1998-01-01

    We demonstrate, in both two and three dimensions, how a self-guided beam in a non-Kerr medium is split into two beams on weak illumination. We also provide an elegant physical explanation that predicts the universal character of the observed phenomenon. Possible applications of our findings to guiding light with light are also discussed.

  13. On Weak-BCC-Algebras

    Science.gov (United States)

    Thomys, Janus; Zhang, Xiaohong

    2013-01-01

    We describe weak-BCC-algebras (also called BZ-algebras) in which the condition (x∗y)∗z = (x∗z)∗y is satisfied only in the case when elements x, y belong to the same branch. We also characterize ideals, nilradicals, and nilpotent elements of such algebras. PMID:24311983

  14. Voltage Weak DC Distribution Grids

    NARCIS (Netherlands)

    Hailu, T.G.; Mackay, L.J.; Ramirez Elizondo, L.M.; Ferreira, J.A.

    2017-01-01

    This paper describes the behavior of voltage weak DC distribution systems. These systems have relatively small system capacitance. The size of system capacitance, which stores energy, has a considerable effect on the value of fault currents, control complexity, and system reliability. A number of

  15. Competing weak localization and weak antilocalization in ultrathin topological insulators.

    Science.gov (United States)

    Lang, Murong; He, Liang; Kou, Xufeng; Upadhyaya, Pramey; Fan, Yabin; Chu, Hao; Jiang, Ying; Bardarson, Jens H; Jiang, Wanjun; Choi, Eun Sang; Wang, Yong; Yeh, Nai-Chang; Moore, Joel; Wang, Kang L

    2013-01-09

    We demonstrate evidence of a surface gap opening in topological insulator (TI) thin films of (Bi(0.57)Sb(0.43))(2)Te(3) below six quintuple layers through transport and scanning tunneling spectroscopy measurements. By effective tuning the Fermi level via gate-voltage control, we unveil a striking competition between weak localization and weak antilocalization at low magnetic fields in nonmagnetic ultrathin films, possibly owing to the change of the net Berry phase. Furthermore, when the Fermi level is swept into the surface gap of ultrathin samples, the overall unitary behaviors are revealed at higher magnetic fields, which are in contrast to the pure WAL signals obtained in thicker films. Our findings show an exotic phenomenon characterizing the gapped TI surface states and point to the future realization of quantum spin Hall effect and dissipationless TI-based applications.

  16. Optimal Weak Lensing Skewness Measurements

    OpenAIRE

    Zhang, Tong-Jie; Pen, Ue-Li; Zhang, Pengjie; Dubinski, John

    2003-01-01

    Weak lensing measurements are entering a precision era to statistically map the distribution of matter in the universe. The most common measurement has been of the variance of the projected surface density of matter, which corresponds to the induced correlation in alignments of background galaxies. This measurement of the fluctuations is insensitive to the total mass content, like using waves on the ocean to measure its depths. But when the depth is shallow as happens near a beach, waves beco...

  17. Weak neutral-current interactions

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, R.M.

    1978-08-01

    The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z/sup 0/ boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references. (JFP)

  18. [Muscle weakness in cerebral palsy].

    Science.gov (United States)

    Givon, Uri

    2009-01-01

    Over the last two decades, muscle weakness has been shown to be a major component of cerebral palsy (CP) pathology. Caused by multiple etiologies including variations in the muscle fiber type, pathologic motor unit function, co-contraction of agonists and antagonists, and muscle size and rigidity, weakness interferes with function and leads to limited function and participation. Muscle strength was found to be associated with walking ability and with functional scales. Children with CP were found to be weaker than typically developing children, and differences were found with respect to muscle groups in children with CP. Muscle weakness should be evaluated as objectively as possible to improve the quality of diagnosis and treatment. Manual muscle testing is not sufficient for evaluation, and instrumented muscle testing is validated in CP. Muscle strengthening is an important part of treatment of CP. Several methods of strengthening have been described. Muscle lengthening and other spasticity-modifying therapies have been shown to have a positive effect on muscle strength. Children who participated in muscle strengthening programs had a better quality of life and improved function.

  19. Completely continuous and weakly completely continuous abstract ...

    Indian Academy of Sciences (India)

    if the operator ρa of right multiplication by a is compact (weakly compact, respectively). An algebra A is called right completely continuous (right weakly completely continuous) if any element a ∈ A is right completely continuous (right weakly completely con- tinuous, respectively). Left completely continuous (left weakly ...

  20. Weak measurements measure probability amplitudes (and very little else)

    Energy Technology Data Exchange (ETDEWEB)

    Sokolovski, D., E-mail: dgsokol15@gmail.com [Departmento de Química-Física, Universidad del País Vasco, UPV/EHU, Leioa (Spain); IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013, Bilbao (Spain)

    2016-04-22

    Conventional quantum mechanics describes a pre- and post-selected system in terms of virtual (Feynman) paths via which the final state can be reached. In the absence of probabilities, a weak measurement (WM) determines the probability amplitudes for the paths involved. The weak values (WV) can be identified with these amplitudes, or their linear combinations. This allows us to explain the “unusual” properties of the WV, and avoid the “paradoxes” often associated with the WM. - Highlights: • Weak measurement on a pre- and post-selected system is a particular perturbative scheme. • A conventional average for the additional degree of freedom measured. • The result is proportional to the amplitudes on the virtual paths connecting two system's states. • Over-interpretation of the weak values (WV) is unwise. • “Unusual” WVs are not unusual after all.

  1. Spurious Shear in Weak Lensing with LSST

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.; Kahn, S.M.; Jernigan, J.G.; Peterson, J.R.; AlSayyad, Y.; Ahmad, Z.; Bankert, J.; Bard, D.; Connolly, A.; Gibson, R.R.; Gilmore, K.; Grace, E.; Hannel, M.; Hodge, M.A.; Jee, M.J.; Jones, L.; Krughoff, S.; Lorenz, S.; Marshall, P.J.; Marshall, S.; Meert, A.

    2012-09-19

    The complete 10-year survey from the Large Synoptic Survey Telescope (LSST) will image {approx} 20,000 square degrees of sky in six filter bands every few nights, bringing the final survey depth to r {approx} 27.5, with over 4 billion well measured galaxies. To take full advantage of this unprecedented statistical power, the systematic errors associated with weak lensing measurements need to be controlled to a level similar to the statistical errors. This work is the first attempt to quantitatively estimate the absolute level and statistical properties of the systematic errors on weak lensing shear measurements due to the most important physical effects in the LSST system via high fidelity ray-tracing simulations. We identify and isolate the different sources of algorithm-independent, additive systematic errors on shear measurements for LSST and predict their impact on the final cosmic shear measurements using conventional weak lensing analysis techniques. We find that the main source of the errors comes from an inability to adequately characterise the atmospheric point spread function (PSF) due to its high frequency spatial variation on angular scales smaller than {approx} 10{prime} in the single short exposures, which propagates into a spurious shear correlation function at the 10{sup -4}-10{sup -3} level on these scales. With the large multi-epoch dataset that will be acquired by LSST, the stochastic errors average out, bringing the final spurious shear correlation function to a level very close to the statistical errors. Our results imply that the cosmological constraints from LSST will not be severely limited by these algorithm-independent, additive systematic effects.

  2. Protecting weak measurements against systematic errors

    OpenAIRE

    Pang, Shengshi; Alonso, Jose Raul Gonzalez; Brun, Todd A.; Jordan, Andrew N.

    2016-01-01

    In this work, we consider the systematic error of quantum metrology by weak measurements under decoherence. We derive the systematic error of maximum likelihood estimation in general to the first-order approximation of a small deviation in the probability distribution, and study the robustness of standard weak measurement and postselected weak measurements against systematic errors. We show that, with a large weak value, the systematic error of a postselected weak measurement when the probe u...

  3. Conformational transitions of a weak polyampholyte

    KAUST Repository

    Nair, Arun Kumar Narayanan

    2014-10-07

    Using grand canonical Monte Carlo simulations of a flexible polyelectrolyte where the charges are in contact with a reservoir of constant chemical potential given by the solution pH, we study the behavior of weak polyelectrolytes in poor and good solvent conditions for polymer backbone. We address the titration behavior and conformational properties of a flexible diblock polyampholyte chain formed of two oppositely charged weak polyelectrolyte blocks, each containing equal number of identical monomers. The change of solution pH induces charge asymmetry in a diblock polyampholyte. For diblock polyampholyte chains in poor solvents, we demonstrate that a discontinuous transition between extended (tadpole) and collapsed (globular) conformational states is attainable by varying the solution pH. The double-minima structure in the probability distribution of the free energy provides direct evidence for the first-order like nature of this transition. At the isoelectric point electrostatically driven coil-globule transition of diblock polyampholytes in good solvents is found to consist of different regimes identified with increasing electrostatic interaction strength. At pH values above or below the isoelectric point diblock chains are found to have polyelectrolyte-like behavior due to repulsion between uncompensated charges along the chain.

  4. Weak gravity conjecture and effective field theory

    Science.gov (United States)

    Saraswat, Prashant

    2017-01-01

    The weak gravity conjecture (WGC) is a proposed constraint on theories with gauge fields and gravity, requiring the existence of light charged particles and/or imposing an upper bound on the field theory cutoff Λ . If taken as a consistency requirement for effective field theories (EFTs), it rules out possibilities for model building including some models of inflation. I demonstrate simple models which satisfy all forms of the WGC, but which through Higgsing of the original gauge fields produce low-energy EFTs with gauge forces that badly violate the WGC. These models illustrate specific loopholes in arguments that motivate the WGC from a bottom-up perspective; for example the arguments based on magnetic monopoles are evaded when the magnetic confinement that occurs in a Higgs phase is accounted for. This indicates that the WGC should not be taken as a veto on EFTs, even if it turns out to be a robust property of UV quantum gravity theories. However, if the latter is true, then parametric violation of the WGC at low energy comes at the cost of nonminimal field content in the UV. I propose that only a very weak constraint is applicable to EFTs, Λ ≲(log 1/g )-1 /2Mpl , where g is the gauge coupling, motivated by entropy bounds. Remarkably, EFTs produced by Higgsing a theory that satisfies the WGC can saturate but not violate this bound.

  5. Probing hysteretic elasticity in weakly nonlinear materials

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Paul A [Los Alamos National Laboratory; Haupert, Sylvain [UPMC UNIV PARIS; Renaud, Guillaume [UPMC UNIV PARIS; Riviere, Jacques [UPMC UNIV PARIS; Talmant, Maryline [UPMC UNIV PARIS; Laugier, Pascal [UPMC UNIV PARIS

    2010-12-07

    Our work is aimed at assessing the elastic and dissipative hysteretic nonlinear parameters' repeatability (precision) using several classes of materials with weak, intermediate and high nonlinear properties. In this contribution, we describe an optimized Nonlinear Resonant Ultrasound Spectroscopy (NRUS) measuring and data processing protocol applied to small samples. The protocol is used to eliminate the effects of environmental condition changes that take place during an experiment, and that may mask the intrinsic elastic nonlinearity. As an example, in our experiments, we identified external temperature fluctuation as a primary source of material resonance frequency and elastic modulus variation. A variation of 0.1 C produced a frequency variation of 0.01 %, which is similar to the expected nonlinear frequency shift for weakly nonlinear materials. In order to eliminate environmental effects, the variation in f{sub 0} (the elastically linear resonance frequency proportional to modulus) is fit with the appropriate function, and that function is used to correct the NRUS calculation of nonlinear parameters. With our correction procedure, we measured relative resonant frequency shifts of 10{sup -5} , which are below 10{sup -4}, often considered the limit to NRUS sensitivity under common experimental conditions. Our results show that the procedure is an alternative to the stringent control of temperature often applied. Applying the approach, we report nonlinear parameters for several materials, some with very small nonclassical nonlinearity. The approach has broad application to NRUS and other Nonlinear Elastic Wave Spectroscopy approaches.

  6. Weak and strong typicality in quantum systems.

    Science.gov (United States)

    Santos, Lea F; Polkovnikov, Anatoli; Rigol, Marcos

    2012-07-01

    We study the properties of mixed states obtained from eigenstates of many-body lattice Hamiltonians after tracing out part of the lattice. Two scenarios emerge for generic systems: (i) The diagonal entropy becomes equivalent to the thermodynamic entropy when a few sites are traced out (weak typicality); and (ii) the von Neumann (entanglement) entropy becomes equivalent to the thermodynamic entropy when a large fraction of the lattice is traced out (strong typicality). Remarkably, the results for few-body observables obtained with the reduced, diagonal, and canonical density matrices are very similar to each other, no matter which fraction of the lattice is traced out. Hence, for all physical quantities studied here, the results in the diagonal ensemble match the thermal predictions.

  7. Sex hormones and skeletal muscle weakness

    DEFF Research Database (Denmark)

    Sipilä, Sarianna; Narici, Marco; Kjaer, Michael

    2013-01-01

    Human ageing is accompanied with deterioration in endocrine functions the most notable and well characterized of which being the decrease in the production of sex hormones. Current research literature suggests that low sex hormone concentration may be among the key mechanism for sarcopenia...... and muscle weakness. Within the European large scale MYOAGE project, the role of sex hormones, estrogens and testosterone, in causing the aging-related loss of muscle mass and function was further investigated. Hormone replacement therapy (HRT) in women is shown to diminish age-associated muscle loss, loss...... properties. HRT influences gene expression in e.g. cytoskeletal and cell-matrix proteins, has a stimulating effect upon IGF-I, and a role in IL-6 and adipokine regulation. Despite low circulating steroid-hormone level, postmenopausal women have a high local concentration of steroidogenic enzymes in skeletal...

  8. Weak lensing and cosmological investigation

    CERN Document Server

    Acquaviva, V

    2005-01-01

    In the last few years the scientific community has been dealing with the challenging issue of identifying the dark energy component. We regard weak gravitational lensing as a brand new, and extremely important, tool for cosmological investigation in this field. In fact, the features imprinted on the cosmic microwave background radiation by the lensing from the intervening distribution of matter represent a pretty unbiased estimator, and can thus be used for putting constraints on different dark energy models. This is true in particular for the magnetic-type B-modes of CMB polarization, whose unlensed spectrum at large multipoles (l approximately=1000) is very small even in presence of an amount of gravitational waves as large as currently allowed by the experiments: therefore, on these scales the lensing phenomenon is the only responsible for the observed power, and this signal turns out to be a faithful tracer of the dark energy dynamics. We first recall the formal apparatus of the weak lensing in extended t...

  9. Time—periodic weak solutions

    Directory of Open Access Journals (Sweden)

    Eliana Henriques de Brito

    1990-01-01

    Full Text Available In continuing from previous papers, where we studied the existence and uniqueness of the global solution and its asymptotic behavior as time t goes to infinity, we now search for a time-periodic weak solution u(t for the equation whose weak formulation in a Hilbert space H isddt(u′,v+δ(u′,v+αb(u,v+βa(u,v+(G(u,v=(h,vwhere: ′=d/dt; (′ is the inner product in H; b(u,v, a(u,v are given forms on subspaces U⊂W, respectively, of H; δ>0, α≥0, β≥0 are constants and α+β>0; G is the Gateaux derivative of a convex functional J:V⊂H→[0,∞ for V=U, when α>0 and V=W when α=0, hence β>0; v is a test function in V; h is a given function of t with values in H.

  10. Political corruption and weak state

    Directory of Open Access Journals (Sweden)

    Stojiljković Zoran

    2013-01-01

    Full Text Available The author starts from the hypothesis that it is essential for the countries of the region to critically assess the synergy established between systemic, political corruption and a selectively weak, “devious” nature of the state. Moreover, the key dilemma is whether the expanded practice of political rent seeking supports the conclusion that the root of all corruption is in the very existence of the state - particularly in excessive, selective and deforming state interventions and benefits that create a fertile ground for corruption? The author argues that the destructive combination of weak government and rampant political corruption is based on scattered state intervention, while also rule the parties cartel in the executive branch subordinate to parliament, the judiciary and the police. Corrupt exchange takes place with the absence of strong institutional framework and the precise rules of the political and electoral games, control of public finances and effective political and anti-monopoly legislation and practice included. Exit from the current situation can be seen in the realization of effective anti­corruption strategy that integrates preventive and repressive measures and activities and lead to the establishment of principles of good governance. [Projekat Ministarstva nauke Republike Srbije, br. 179076: Politički identitet Srbije u regionalnom i globalnom kontekstu

  11. Weakly b-open functions in bitopological spaces

    Directory of Open Access Journals (Sweden)

    Diganta Jyoti Sarma

    2017-03-01

    Full Text Available Abstract: The aim of this paper is to introduce the notion of weakly b-open functions in bitopological spaces. Some properties of this functions are established and the relationships with some other types of spaces are also investigated.

  12. Theory of partial coherence for weakly periodic media

    NARCIS (Netherlands)

    Hoenders, BJ; Bertolotti, M

    2005-01-01

    The second-order theory of partial coherence for scalar and TE or TM fields is developed for weakly periodic media, and the van Cittert-Zernike theorem of classical coherence theory is generalized for such media. The coherence properties of a wave field, generated by a quasi-homogeneous source

  13. Weakly time consistent concave valuations and their dual representations

    NARCIS (Netherlands)

    Roorda, B.; Schumacher, Hans

    We derive dual characterizations of two notions of weak time consistency for concave valuations, which are convex risk measures under a positive sign convention. Combined with a suitable risk aversion property, these notions are shown to amount to three simple rules for not necessarily minimal

  14. Weakly time consistent concave valuations and their dual representations

    NARCIS (Netherlands)

    Roorda, Berend; Schumacher, Johannes M.

    2016-01-01

    We derive dual characterizations of two notions of weak time consistency for concave valuations, which are convex risk measures under a positive sign convention. Combined with a suitable risk aversion property, these notions are shown to amount to three simple rules for not necessarily minimal

  15. Quantum ion-acoustic solitary waves in weak relativistic plasma

    Indian Academy of Sciences (India)

    A linear dispersion relation is also obtained taking into account the relativistic effect. The properties of quantum ion-acoustic solitary waves, obtained from the deformed KdV equation, are studied taking into account the quantum mechanical effects in the weak relativistic limit. It is found that relativistic effects significantly ...

  16. Strong and Weak Chaos in Weakly Nonintegrable Many-Body Hamiltonian Systems

    Science.gov (United States)

    Mulansky, M.; Ahnert, K.; Pikovsky, A.; Shepelyansky, D. L.

    2011-12-01

    We study properties of chaos in generic one-dimensional nonlinear Hamiltonian lattices comprised of weakly coupled nonlinear oscillators by numerical simulations of continuous-time systems and symplectic maps. For small coupling, the measure of chaos is found to be proportional to the coupling strength and lattice length, with the typical maximal Lyapunov exponent being proportional to the square root of coupling. This strong chaos appears as a result of triplet resonances between nearby modes. In addition to strong chaos we observe a weakly chaotic component having much smaller Lyapunov exponent, the measure of which drops approximately as a square of the coupling strength down to smallest couplings we were able to reach. We argue that this weak chaos is linked to the regime of fast Arnold diffusion discussed by Chirikov and Vecheslavov. In disordered lattices of large size we find a subdiffusive spreading of initially localized wave packets over larger and larger number of modes. The relations between the exponent of this spreading and the exponent in the dependence of the fast Arnold diffusion on coupling strength are analyzed. We also trace parallels between the slow spreading of chaos and deterministic rheology.

  17. Weak transitions in lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Maturana, G.

    1984-01-01

    Some techniques to calculate the effects of the strong interactions on the matrix elements of weak processes are described. The lattice formulation of Quantum Chromodynamics is used to account for the low energy gluons, and the corresponding numerical methods are explained. The high energy contributions are included in effective lagrangians and the problem of matching the different scales related to the renormalization of the operators and wavefunctions is also discussed. The ..delta..l = 1/2 enhancement rule and the K/sup 0/-anti-K/sup 0/ are used to illustrate these techniques and the results of a numerical calculation is reported. The values obtained are very encouraging and they certainly show good qualitative agreement with the experimental values. The emphasis is on general techniques, and in particular, several improvements to this particular calculation are proposed.

  18. Strengths, weaknesses, opportunities and threats

    DEFF Research Database (Denmark)

    Bull, Joseph William; Jobstvogt, N.; Böhnke-Henrichs, A.

    2016-01-01

    The ecosystem services concept (ES) is becoming a cornerstone of contemporary sustainability thought. Challenges with this concept and its applications are well documented, but have not yet been systematically assessed alongside strengths and external factors that influence uptake. Such an assess......The ecosystem services concept (ES) is becoming a cornerstone of contemporary sustainability thought. Challenges with this concept and its applications are well documented, but have not yet been systematically assessed alongside strengths and external factors that influence uptake....... Such an assessment could form the basis for improving ES thinking, further embedding it into environmental decisions and management.The Young Ecosystem Services Specialists (YESS) completed a Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis of ES through YESS member surveys. Strengths include the approach...

  19. Fault zone fabric and fault weakness

    NARCIS (Netherlands)

    Collettini, C.; Niemeijer, A.; Viti, C.; Marone, C.

    2009-01-01

    Geological and geophysical evidence suggests that some crustal faults are weak1–6 compared to laboratory measurements of frictional strength7. Explanations for fault weakness include the presence of weak minerals4, high fluid pressures within the fault core8,9 and dynamic processes such as

  20. Weakly distributive modules. Applications to supplement submodules

    Indian Academy of Sciences (India)

    Abstract. In this paper, we define and study weakly distributive modules as a proper generalization of distributive modules. We prove that, weakly distributive supplemented modules are amply supplemented. In a weakly distributive supplemented module every submodule has a unique coclosure. This generalizes a result of ...

  1. Weak partial metric spaces and some fixed point results

    Directory of Open Access Journals (Sweden)

    Ishak Altun

    2012-10-01

    Full Text Available The concept of partial metric p on a nonempty set X was introduced by Matthews. One of the most interesting properties of a partial metric is that p(x, x may not be zero for x e X. Also, each partial metric p on a nonempty set X generates a T0 topology on X. By omitting the small self-distance axiom of partial metric, Heckmann defined the weak partial metric space. In the present paper, we give some fixed point results on weak partial metric spaces.

  2. High-redshift SDSS Quasars with Weak Emission Lines

    DEFF Research Database (Denmark)

    Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Brandt, W. N.

    2009-01-01

    We identify a sample of 74 high-redshift quasars (z > 3) with weak emission lines from the Fifth Data Release of the Sloan Digital Sky Survey and present infrared, optical, and radio observations of a subsample of four objects at z > 4. These weak emission-line quasars (WLQs) constitute a prominent...... rest-frame 0.1-5 µm spectral energy distributions that are quite similar to those of normal quasars. The variability, polarization, and radio properties of WLQs are also different from those of BL Lacs, making continuum boosting by a relativistic jet an unlikely physical interpretation. The most...

  3. Fuzzy Weak Regular, Strong and Preassociative Filters in Residuated Lattices

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2014-06-01

    Full Text Available In this paper, the notions of fuzzy weak regular, strong and preassociative filters are introduced with some properties of them investigated. In particular, under the context of Glivenko algebras, fuzzy weak regular filters and regular ones are equivalent and characterizations of Glivenko algebras are concluded by characterizations of fuzzy strong filters. At last the notion of fuzzy preassociative filters are defined, which are proved to coincide with fuzzy Boolean filters, and then some new alternative definitions of Boolean algebras are obtained by this type of filters.

  4. Weak matrix elements of kaons

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, C. (California Univ., Santa Barbara, CA (USA). Inst. for Theoretical Physics); Soni, A. (Brookhaven National Lab., Upton, NY (USA))

    1989-01-01

    We present results from the Wilson fermion part of the Grand Challenge'' weak matrix element project. A new procedure for correcting the chiral behavior of {Beta}{sub LL}{sup sd}, the K{sup 0}-{bar K}{sup 0} {Beta} parameter,'' is proposed and applied. On our largest lattice (24{sup 3} {times} 40 at {beta} = 6.0), we get {Beta}{sub LL}{sup sd} = .86 {plus minus} .11 {plus minus} .05, where the first error is statistical and the second is a measure of the systematic errors due to the procedure and to related finite-size effects. Results for the direct K{sup +} {yields} {pi}{sup +}{pi}{sup 0} amplitude are also presented. There is some evidence for higher order chiral effects which may make these results compatible both with experiment and with the {Beta}{sub LL}{sup sd} computation. The status of the direct K{sub s}{sup 0} {yields} {pi} {sup +} {pi}{sup {minus}} {Delta}I = 1/2 amplitude is then discussed. 11 refs., 6 figs., 1 tab.

  5. A Universe without Weak Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Harnik, Roni; Kribs, Graham D.; Perez, Gilad

    2006-04-07

    A universe without weak interactions is constructed that undergoes big-bang nucleosynthesis, matter domination, structure formation, and star formation. The stars in this universe are able to burn for billions of years, synthesize elements up to iron, and undergo supernova explosions, dispersing heavy elements into the interstellar medium. These definitive claims are supported by a detailed analysis where this hypothetical ''Weakless Universe'' is matched to our Universe by simultaneously adjusting Standard Model and cosmological parameters. For instance, chemistry and nuclear physics are essentially unchanged. The apparent habitability of the Weakless Universe suggests that the anthropic principle does not determine the scale of electroweak breaking, or even require that it be smaller than the Planck scale, so long as technically natural parameters may be suitably adjusted. Whether the multi-parameter adjustment is realized or probable is dependent on the ultraviolet completion, such as the string landscape. Considering a similar analysis for the cosmological constant, however, we argue that no adjustments of other parameters are able to allow the cosmological constant to raise up even remotely close to the Planck scale while obtaining macroscopic structure. The fine-tuning problems associated with the electroweak breaking scale and the cosmological constant therefore appear to be qualitatively different from the perspective of obtaining a habitable universe.

  6. Protecting weak measurements against systematic errors

    Science.gov (United States)

    Pang, Shengshi; Alonso, Jose Raul Gonzalez; Brun, Todd A.; Jordan, Andrew N.

    2016-07-01

    In this work, we consider the systematic error of quantum metrology by weak measurements under decoherence. We derive the systematic error of maximum likelihood estimation in general to the first-order approximation of a small deviation in the probability distribution and study the robustness of standard weak measurement and postselected weak measurements against systematic errors. We show that, with a large weak value, the systematic error of a postselected weak measurement when the probe undergoes decoherence can be significantly lower than that of a standard weak measurement. This indicates another advantage of weak-value amplification in improving the performance of parameter estimation. We illustrate the results by an exact numerical simulation of decoherence arising from a bosonic mode and compare it to the first-order analytical result we obtain.

  7. Sign problem and Monte Carlo calculations beyond Lefschetz thimbles

    CERN Document Server

    Alexandru, Andrei; Bedaque, Paulo F; Ridgway, Gregory W; Warrington, Neill C

    2015-01-01

    We point out that Monte Carlo simulations of theories with severe sign problems can be profitably performed over manifolds in complex space different from the one with fixed imaginary part of the action. We describe a family of such manifolds that interpolate between the tangent space at one critical point, where the sign problem is milder compared to the real plane but in some cases still severe, and the union of relevant thimbles, where the sign problem is mild but a multimodal distribution function complicates the Monte Carlo sampling. We exemplify this approach using a simple 0 + 1 dimensional fermion model previously used on sign problem studies and show that it can solve the model for some parameter values where a solution using Lefshetz thimbles was elusive.

  8. Identification and classification of weak layers in the snow

    Directory of Open Access Journals (Sweden)

    E. S. Klimenko

    2013-01-01

    Full Text Available The paper considers the role of vertical snowpack structure for snow avalanche formation and describes the idea of «structural instability». It aims at enhancing the knowledge about transition mechanisms between stable and unstable states of snowpack and snow avalanches release. Structural instability implies the presence of weak layer or interface in vertical snowpack profile. Type of snow failure and avalanche characteristics are completely defined by snowpack state and properties. Thus wide variety of genetic types of snow avalanches indicates the existence of structural instability of different types. The detailed analysis of scientific publications and field observations led to the creation of a new classification of weak layers. The layers are classified basing on their cohesiveness, the causes of initial disturbance and internal and external processes which form a weak layer. The classification is a necessary part of global method which allows assessing snowpack stability using modern physical models of snow cover evolution.

  9. Competition among networks highlights the power of the weak

    Science.gov (United States)

    Iranzo, Jaime; Buldú, Javier M.; Aguirre, Jacobo

    2016-11-01

    The unpreventable connections between real networked systems have recently called for an examination of percolation, diffusion or synchronization phenomena in multilayer networks. Here we use network science and game theory to explore interactions in networks-of-networks and model these as a game for gaining importance. We propose a viewpoint where networks choose the connection strategies, in contrast with classical approaches where nodes are the active players. Specifically, we investigate how creating paths between networks leads to different Nash equilibria that determine their structural and dynamical properties. In a wide variety of cases, selecting adequate connections leads to a cooperative solution that allows weak networks to overcome the strongest opponent. Counterintuitively, each weak network can induce a global transition to such cooperative configuration regardless of the actions of the strongest network. This power of the weak reveals a critical dominance of the underdogs in the fate of networks-of-networks.

  10. Elliptic and weakly coercive systems of operators in Sobolev spaces

    Science.gov (United States)

    Limanskiĭ, D. V.; Malamud, Mark M.

    2008-12-01

    It is known that an elliptic system \\{P_j(x,D)\\}_1^N of order l is weakly coercive in \\overset{\\circ}{W}{}^l_{\\!\\infty}(\\mathbb R^n), that is, all differential monomials of order \\le l-1 on C_0^\\infty(\\mathbb R^n)-functions are subordinated to this system in the L^\\infty-norm. Conditions for the converse result are found and other properties of weakly coercive systems are investigated. An analogue of the de Leeuw-Mirkil theorem is obtained for operators with variable coefficients: it is shown that an operator P(x,D) of n\\ge 3 variables with constant principal part is weakly coercive in \\overset{\\circ}{W}{}^l_{\\!\\infty}(\\mathbb R^n) if and only if it is elliptic. A similar result is obtained for systems \\{P_j(D)\\}_1^N with constant coefficients under the condition n\\ge 2N+1 and with several restrictions on the symbols P_j(\\xi). A complete description of differential polynomials of two variables which are weakly coercive in \\overset{\\circ}{W}{}^l_{\\!\\infty}(\\mathbb R^2) is given. Wide classes of systems with constant coefficients which are weakly coercive in \\overset{\\circ}{W}{}^l_{\\!\\infty}(\\mathbb R^n), but non-elliptic are constructed. Bibliography: 32 titles.

  11. Studies on the weak interactions and CT complex formations between chloranilic acid, 2,3-dichloro-5,6-dicyano-p-benzoquinone, tetracyanoethylene and papaverine in acetonitrile and their thermodynamic properties, theoretically, spectrophotometrically aided by FTIR.

    Science.gov (United States)

    Datta, Asim Sagar; Chattaraj, Seema Bagchi; Chakrabortty, Ashutosh; Lahiri, Sujit Chandra

    2015-07-05

    Spectrophotometric, FTIR and theoretical studies of the charge-transfer complexes between mild narcotic drug papaverine and the acceptors chloranilic acid (Cl-A), 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and tetracyanoethylene (TCNE) in acetonitrile, their association constants, thermodynamic (ΔG(0), ΔH(0) and ΔS(0)) and other related properties had been described. Papaverine was found to form colored charge-transfer complexes with Cl-A, DDQ and TCNE in acetonitrile. The absorption maxima of the complexes were 518.5, 584.0 and 464.0 nm for Cl-A complex, DDQ complex, and TCNE complex respectively. The compositions of the papaverine complexes were determined to be 1:1 from Job's method of continuous variation. Solid complexes formed between papaverine and the acceptors were isolated. Comparison of the FTIR spectra of the solid complexes between papaverine and the acceptors and their constituents showed considerable shift in absorption peaks, changes in intensities of the peaks and formation of the new bands on complexation. However, no attempt has been made to purify the complexes and study the detailed spectra both theoretically and experimentally. The energies hν(CT) of the charge-transfer complexes were compared with the theoretical values of hν(CT) of the complexes obtained from HOMO and LUMO of the donor and the acceptors. The reasons for the differences in hνCT values were explained. Density function theory was used for calculation. hν(CT) (experimental) values of the transition energies of the complexes in acetonitrile differed from hν(CT) (theoretical) values. ID(V) value of papaverine was calculated. Charge-transfer complexes were assumed to be partial electrovalent compounds with organic dative ions D(+) and A(-) (in the excited state) and attempts had been made to correlate the energy changes for the formation of the complexes with the energy changes for the formation of electrovalent compounds between M(+) and X(-) ions. Copyright © 2015

  12. On the Weak Computability of Continuous Real Functions

    Directory of Open Access Journals (Sweden)

    Matthew S. Bauer

    2010-06-01

    Full Text Available In computable analysis, sequences of rational numbers which effectively converge to a real number x are used as the (rho- names of x. A real number x is computable if it has a computable name, and a real function f is computable if there is a Turing machine M which computes f in the sense that, M accepts any rho-name of x as input and outputs a rho-name of f(x for any x in the domain of f. By weakening the effectiveness requirement of the convergence and classifying the converging speeds of rational sequences, several interesting classes of real numbers of weak computability have been introduced in literature, e.g., in addition to the class of computable real numbers (EC, we have the classes of semi-computable (SC, weakly computable (WC, divergence bounded computable (DBC and computably approximable real numbers (CA. In this paper, we are interested in the weak computability of continuous real functions and try to introduce an analogous classification of weakly computable real functions. We present definitions of these functions by Turing machines as well as by sequences of rational polygons and prove these two definitions are not equivalent. Furthermore, we explore the properties of these functions, and among others, show their closure properties under arithmetic operations and composition.

  13. Quantitative analysis of the modes of growth inhibition by weak organic acids in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Ullah, A.; Orij, R.; Brul, S.; Smits, G.J.

    2012-01-01

    Weak organic acids are naturally occurring compounds that are commercially used as preservatives in the food and beverage industries. They extend the shelf life of food products by inhibiting microbial growth. There are a number of theories that explain the antifungal properties of these weak acids,

  14. Weak associativity and deformation quantization

    Energy Technology Data Exchange (ETDEWEB)

    Kupriyanov, V.G., E-mail: vladislav.kupriyanov@gmail.com [CMCC-Universidade Federal do ABC, Santo André, SP (Brazil); Tomsk State University, Tomsk (Russian Federation)

    2016-09-15

    Non-commutativity and non-associativity are quite natural in string theory. For open strings it appears due to the presence of non-vanishing background two-form in the world volume of Dirichlet brane, while in closed string theory the flux compactifications with non-vanishing three-form also lead to non-geometric backgrounds. In this paper, working in the framework of deformation quantization, we study the violation of associativity imposing the condition that the associator of three elements should vanish whenever each two of them are equal. The corresponding star products are called alternative and satisfy important for physical applications properties like the Moufang identities, alternative identities, Artin's theorem, etc. The condition of alternativity is invariant under the gauge transformations, just like it happens in the associative case. The price to pay is the restriction on the non-associative algebra which can be represented by the alternative star product, it should satisfy the Malcev identity. The example of nontrivial Malcev algebra is the algebra of imaginary octonions. For this case we construct an explicit expression of the non-associative and alternative star product. We also discuss the quantization of Malcev–Poisson algebras of general form, study its properties and provide the lower order expression for the alternative star product. To conclude we define the integration on the algebra of the alternative star products and show that the integrated associator vanishes.

  15. Weak associativity and deformation quantization

    Directory of Open Access Journals (Sweden)

    V.G. Kupriyanov

    2016-09-01

    Full Text Available Non-commutativity and non-associativity are quite natural in string theory. For open strings it appears due to the presence of non-vanishing background two-form in the world volume of Dirichlet brane, while in closed string theory the flux compactifications with non-vanishing three-form also lead to non-geometric backgrounds. In this paper, working in the framework of deformation quantization, we study the violation of associativity imposing the condition that the associator of three elements should vanish whenever each two of them are equal. The corresponding star products are called alternative and satisfy important for physical applications properties like the Moufang identities, alternative identities, Artin's theorem, etc. The condition of alternativity is invariant under the gauge transformations, just like it happens in the associative case. The price to pay is the restriction on the non-associative algebra which can be represented by the alternative star product, it should satisfy the Malcev identity. The example of nontrivial Malcev algebra is the algebra of imaginary octonions. For this case we construct an explicit expression of the non-associative and alternative star product. We also discuss the quantization of Malcev–Poisson algebras of general form, study its properties and provide the lower order expression for the alternative star product. To conclude we define the integration on the algebra of the alternative star products and show that the integrated associator vanishes.

  16. Spin effects in the weak interaction

    Energy Technology Data Exchange (ETDEWEB)

    Freedman, S.J. (Argonne National Lab., IL (USA) Chicago Univ., IL (USA). Dept. of Physics Chicago Univ., IL (USA). Enrico Fermi Inst.)

    1990-01-01

    Modern experiments investigating the beta decay of the neutron and light nuclei are still providing important constraints on the theory of the weak interaction. Beta decay experiments are yielding more precise values for allowed and induced weak coupling constants and putting constraints on possible extensions to the standard electroweak model. Here we emphasize the implications of recent experiments to pin down the strengths of the weak vector and axial vector couplings of the nucleon.

  17. Blind quantum computing with weak coherent pulses.

    Science.gov (United States)

    Dunjko, Vedran; Kashefi, Elham; Leverrier, Anthony

    2012-05-18

    The universal blind quantum computation (UBQC) protocol [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual IEEE Symposiumon Foundations of Computer Science (IEEE Computer Society, Los Alamitos, CA, USA, 2009), pp. 517-526.] allows a client to perform quantum computation on a remote server. In an ideal setting, perfect privacy is guaranteed if the client is capable of producing specific, randomly chosen single qubit states. While from a theoretical point of view, this may constitute the lowest possible quantum requirement, from a pragmatic point of view, generation of such states to be sent along long distances can never be achieved perfectly. We introduce the concept of ϵ blindness for UBQC, in analogy to the concept of ϵ security developed for other cryptographic protocols, allowing us to characterize the robustness and security properties of the protocol under possible imperfections. We also present a remote blind single qubit preparation protocol with weak coherent pulses for the client to prepare, in a delegated fashion, quantum states arbitrarily close to perfect random single qubit states. This allows us to efficiently achieve ϵ-blind UBQC for any ϵ>0, even if the channel between the client and the server is arbitrarily lossy.

  18. Blind Quantum Computing with Weak Coherent Pulses

    Science.gov (United States)

    Dunjko, Vedran; Kashefi, Elham; Leverrier, Anthony

    2012-05-01

    The universal blind quantum computation (UBQC) protocol [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual IEEE Symposiumon Foundations of Computer Science (IEEE Computer Society, Los Alamitos, CA, USA, 2009), pp. 517-526.] allows a client to perform quantum computation on a remote server. In an ideal setting, perfect privacy is guaranteed if the client is capable of producing specific, randomly chosen single qubit states. While from a theoretical point of view, this may constitute the lowest possible quantum requirement, from a pragmatic point of view, generation of such states to be sent along long distances can never be achieved perfectly. We introduce the concept of ɛ blindness for UBQC, in analogy to the concept of ɛ security developed for other cryptographic protocols, allowing us to characterize the robustness and security properties of the protocol under possible imperfections. We also present a remote blind single qubit preparation protocol with weak coherent pulses for the client to prepare, in a delegated fashion, quantum states arbitrarily close to perfect random single qubit states. This allows us to efficiently achieve ɛ-blind UBQC for any ɛ>0, even if the channel between the client and the server is arbitrarily lossy.

  19. Atomic Inference from Weak Gravitational Lensing Data

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Phil; /KIPAC, Menlo Park

    2005-12-14

    We present a novel approach to reconstructing the projected mass distribution from the sparse and noisy weak gravitational lensing shear data. The reconstructions are regularized via the knowledge gained from numerical simulations of clusters, with trial mass distributions constructed from n NFW profile ellipsoidal components. The parameters of these ''atoms'' are distributed a priori as in the simulated clusters. Sampling the mass distributions from the atom parameter probability density function allows estimates of the properties of the mass distribution to be generated, with error bars. The appropriate number of atoms is inferred from the data itself via the Bayesian evidence, and is typically found to be small, reecting the quality of the data. Ensemble average mass maps are found to be robust to the details of the noise realization, and succeed in recovering the demonstration input mass distribution (from a realistic simulated cluster) over a wide range of scales. As an application of such a reliable mapping algorithm, we comment on the residuals of the reconstruction and the implications for predicting convergence and shear at specific points on the sky.

  20. Weak isometries of the Boolean cube

    OpenAIRE

    Winter, S De; Korb, M

    2014-01-01

    Consider the metric space $\\mathcal{C}$ consisting of the $n$-dimensional Boolean cube equipped with the Hamming distance. A weak isometry of $\\mathcal{C}$ is a permutation of $\\mathcal{C}$ preserving a given subset of Hamming distances. In \\cite{Krasin} Krasin showed that in most cases preserving a single Hamming distance forces a weak isometry to be an isometry. In this article we study those weak isometries that are not automatically an isometry, providing a complete classification of weak...

  1. Probability density functions of instantaneous Stokes parameters on weak scattering

    Science.gov (United States)

    Chen, Xi; Korotkova, Olga

    2017-10-01

    The single-point probability density functions (PDF) of the instantaneous Stokes parameters of a polarized plane-wave light field scattered from a three-dimensional, statistically stationary, weak medium with Gaussian statistics and Gaussian correlation function have been studied for the first time. Apart from the scattering geometry the PDF distributions of the scattered light have been related to the illumination's polarization state and the correlation properties of the medium.

  2. Revisiting Weak Simulation for Substochastic Markov Chains

    DEFF Research Database (Denmark)

    Jansen, David N.; Song, Lei; Zhang, Lijun

    2013-01-01

    The spectrum of branching-time relations for probabilistic systems has been investigated thoroughly by Baier, Hermanns, Katoen and Wolf (2003, 2005), including weak simulation for systems involving substochastic distributions. Weak simulation was proven to be sound w.r.t. the liveness fragment...

  3. A note on Weak Stability Boundaries

    OpenAIRE

    García González, Fernando; Gómez Muntané, Gerard

    2006-01-01

    This paper is devoted to clarify the algorithmic definition of the weak stability boundary in the framework of the planar Restricted Three Body Problem. The role of the invariant hyperbolic manifolds associated to the central manifolds of the libration points L1 and L2, as boundary of the weak stability region, is shown Peer Reviewed

  4. CP Violation, Neutral Currents, and Weak Equivalence

    Science.gov (United States)

    Fitch, V. L.

    1972-03-23

    Within the past few months two excellent summaries of the state of our knowledge of the weak interactions have been presented. Correspondingly, we will not attempt a comprehensive review but instead concentrate this discussion on the status of CP violation, the question of the neutral currents, and the weak equivalence principle.

  5. Spin Seebeck effect in a weak ferromagnet

    Energy Technology Data Exchange (ETDEWEB)

    Arboleda, Juan David, E-mail: juan.arboledaj@udea.edu.co; Arnache Olmos, Oscar [Instituto de Física, Universidad de Antioquia, A.A. 1226, Medellín (Colombia); Aguirre, Myriam Haydee; Ibarra, Manuel Ricardo [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50018 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Laboratorio de Microscopías Avanzadas, Universidad de Zaragoza, E-50018 Zaragoza (Spain); Ramos, Rafael [WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Spin Quantum Rectification Project, ERATO, Japan Science and Technology Agency, Sendai 980-8577 (Japan); Anadon, Alberto [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50018 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain)

    2016-06-06

    We report the observation of room temperature spin Seebeck effect (SSE) in a weak ferromagnetic normal spinel Zinc Ferrite (ZFO). Despite the weak ferromagnetic behavior, the measurements of the SSE in ZFO show a thermoelectric voltage response comparable with the reported values for other ferromagnetic materials. Our results suggest that SSE might possibly originate from the surface magnetization of the ZFO.

  6. Intensive care unit-acquired weakness

    NARCIS (Netherlands)

    Horn, J.; Hermans, G.

    2017-01-01

    When critically ill, a severe weakness of the limbs and respiratory muscles often develops with a prolonged stay in the intensive care unit (ICU), a condition vaguely termed intensive care unit-acquired weakness (ICUAW). Many of these patients have serious nerve and muscle injury. This syndrome is

  7. Persisting weakness after withdrawal of a statin.

    Science.gov (United States)

    Mygland, Åse; Ljøstad, Unn; Krossnes, Bård Kronen

    2014-04-08

    An 81-year-old woman treated with simvastatin for several years followed by atorvastatin for about 1 year presented with fatigue, weakness and unsteady gait. The finding of elevated creatine kinase (CK) and symmetric muscle weakness around shoulders and hips led to suspicion of a toxic statin-associated myopathy. Atorvastatin was withdrawn, but her weakness persisted. Owing to persisting weakness, an autoimmune myopathy (myositis) was suspected, but initially disregarded since a muscle biopsy showed necrotic muscle fibres without inflammatory cell infiltrates and myositis-specific autoantibodies were absent. After 18 months with slowly progressive weakness and increasing CK values, awareness of new knowledge about autoimmunity as a cause of necrotic myopathy, led to a successful treatment trial with intravenous immunoglobulines, followed by steroids and metothrexate. Antibodies to the target enzyme of statins (HMGCR (3-hydroksy-3-methylglutaryl-coenzyme A reductase)) were detected in her serum, and she was diagnosed with autoimmune necrotic myositis probably triggered by atorvastatin.

  8. Interferometric Measurement of the Current-Phase Relationship of a Superfluid Weak Link

    Directory of Open Access Journals (Sweden)

    S. Eckel

    2014-09-01

    Full Text Available Weak connections between superconductors or superfluids can differ from classical links due to quantum coherence, which allows flow without resistance. Transport properties through such weak links can be described with a single function, the current-phase relationship, which serves as the quantum analog of the current-voltage relationship. Here, we present a technique for inteferometrically measuring the current-phase relationship of superfluid weak links. We interferometrically measure the phase gradient around a ring-shaped superfluid Bose-Einstein condensate containing a rotating weak link, allowing us to identify the current flowing around the ring. While our Bose-Einstein condensate weak link operates in the hydrodynamic regime, this technique can be extended to all types of weak links (including tunnel junctions in any phase-coherent quantum gas. Moreover, it can also measure the current-phase relationships of excitations. Such measurements may open new avenues of research in quantum transport.

  9. Weak gravitational shear and flexion with polar shapelets

    Science.gov (United States)

    Massey, Richard; Rowe, Barnaby; Refregier, Alexandre; Bacon, David J.; Bergé, Joel

    2007-09-01

    We derive expressions, in terms of `polar shapelets', for the image distortion operations associated with weak gravitational lensing. Shear causes galaxy shapes to become elongated, and is sensitive to the second derivative of the projected gravitational potential along their line of sight; flexion bends galaxy shapes into arcs, and is sensitive to the third derivative. Polar shapelets provide a natural representation, in which both shear and flexion transformations are compact. Through this tool, we understand progress in several weak lensing methods. We then exploit various symmetries of shapelets to construct a range of shear estimators with useful properties. Through an analogous investigation, we also explore several flexion estimators. In particular, some of the estimators can be measured simultaneously and independently for every galaxy, and will provide unique checks for systematics in future weak lensing analyses. Using simulated images from the Shear TEsting Programme, we show that we can recover input shears with no significant bias. A complete software package to parametrize astronomical images in terms of polar shapelets, and to perform a full weak lensing analysis, is available on the Internet.

  10. Weak Solution and Weakly Uniformly Bounded Solution of Impulsive Heat Equations Containing “Maximum” Temperature

    OpenAIRE

    Oyelami, Benjamin Oyediran

    2013-01-01

    In this paper, criteria for the existence of weak solutions and uniformly weak bounded solution of impulsive heat equation containing maximum temperature are investigated and results obtained. An example is given for heat flow system with impulsive temperature using maximum temperature simulator and criteria for the uniformly weak bounded of solutions of the system are obtained.

  11. Weak Solution and Weakly Uniformly Bounded Solution of Impulsive Heat Equations Containing “Maximum” Temperature

    Directory of Open Access Journals (Sweden)

    Oyelami, Benjamin Oyediran

    2013-09-01

    Full Text Available In this paper, criteria for the existence of weak solutions and uniformly weak bounded solution of impulsive heat equation containing maximum temperature are investigated and results obtained. An example is given for heat flow system with impulsive temperature using maximum temperature simulator and criteria for the uniformly weak bounded of solutions of the system are obtained.

  12. Quadriceps weakness and osteoarthritis of the knee.

    Science.gov (United States)

    Slemenda, C; Brandt, K D; Heilman, D K; Mazzuca, S; Braunstein, E M; Katz, B P; Wolinsky, F D

    1997-07-15

    The quadriceps weakness commonly associated with osteoarthritis of the knee is widely believed to result from disuse atrophy secondary to pain in the involved joint. However, quadriceps weakness may be an etiologic factor in the development of osteoarthritis. To explore the relation between lower-extremity weakness and osteoarthritis of the knee. Cross-sectional prevalence study. Population-based, with recruitment by random-digit dialing. 462 volunteers 65 years of age or older. Radiographs of the knee were graded for the presence of osteoarthritis. Knee pain and function were assessed with the Western Ontario and McMaster Universities Arthritis Index, the strength of leg flexors and extensors was assessed with isokinetic dynamometry, and lower-extremity lean tissue mass was assessed with dual-energy x-ray absorptiometry. Among participants with osteoarthritis, quadriceps weakness, but not hamstring weakness, was common. The ratio of extensor strength to body weight was approximately 20% lower in those with than in those without radiographic osteoarthritis. Notably, among women with tibiofemoral osteoarthritis, extensor weakness was present in the absence of knee pain and was seen in participants with normal lower-extremity lean mass (extensor strength, 30.1 lb-ft for those with osteoarthritis and 34.8 lb-ft for those without osteoarthritis; P osteoarthritis of the knee (odds ratio for prevalence of osteoarthritis per 10 lb-ft loss of strength, 0.8 [95% CI, 0.71 to 0.90] for radiographic osteoarthritis and 0.71 [CI, 0.51 to 0.87] for symptomatic osteoarthritis). Quadriceps weakness may be present in patients who have osteoarthritis but do not have knee pain or muscle atrophy; this suggests that the weakness may be due to muscle dysfunction. The data are consistent with the possibility that quadriceps weakness is a primary risk factor for knee pain, disability, and progression of joint damage in persons with osteoarthritis of the knee.

  13. Strong versus Weak Ties in Migration

    OpenAIRE

    Giulietti, Corrado; Wahba, Jackline; Zenou, Yves

    2014-01-01

    This paper studies the role of strong versus weak ties in the rural-to-urban migration decision in China. We first develop a network model that puts forward the different roles of weak and strong ties in helping workers to migrate to the city. We then use a unique longitudinal data that allows us to test our model by focusing on first-time migration. Strong ties are measured by the closest family contact (excluding household members) while weak ties are determined by the fraction of migrants ...

  14. Quantum correlation cost of the weak measurement

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jun; Wu, Shao-xiong; Yu, Chang-shui, E-mail: quaninformation@sina.com

    2014-12-15

    Quantum correlation cost (QCC) characterizing how much quantum correlation is used in a weak-measurement process is presented based on the trace norm. It is shown that the QCC is related to the trace-norm-based quantum discord (TQD) by only a factor that is determined by the strength of the weak measurement, so it only catches partial quantumness of a quantum system compared with the TQD. We also find that the residual quantumness can be ‘extracted’ not only by the further von Neumann measurement, but also by a sequence of infinitesimal weak measurements. As an example, we demonstrate our outcomes by the Bell-diagonal state.

  15. Understanding the Nature of X-ray Weak Quasars

    Science.gov (United States)

    Brandt, William

    We propose a program of archival X-ray and related studies designed to advance understanding of the remarkable active galactic nucleus (AGN) population of X-ray weak quasars. These exceptional objects reveal phenomena that are more generally applicable but are difficult to investigate when more subtly expressed in the overall quasar population. X-ray weak quasars furthermore challenge a central tenet of X-ray astronomy that luminous X-ray emission is a universal property of efficiently accreting supermassive black holes; this idea underlies the utility of X-ray surveys for identifying AGNs throughout the Universe. Our previous findings indicate that understanding of Xray weak quasars is now primed for rapid further advances. Our studies of X-ray weak quasars will employ data from the vast archives of forefront X-ray missions, particularly XMM-Newton and Chandra, and they will also benefit greatly from the use of NuSTAR, ROSAT, Suzaku, Swift, GALEX, and WISE data. They are largely enabled by the enormous quasar samples delivered by modern widefield sky surveys. In particular, we will identify X-ray weak quasars using the serendipitous X-ray coverage of the 380,000 relatively bright quasars spectroscopically identified by the Sloan Digital Sky Survey (SDSS) from z 0.1-5.5; these are wellmatched to the depths of typical archival X-ray observations. The number of SDSS spectroscopic quasars has more than tripled in recent years, and the sample-size improvements at redshifts of z = 2-4, important for our investigations, are even more dramatic. We will construct an unprecedented new sample of X-ray weak quasars, about 20 times larger than those used currently, to enable systematic studies of the X-ray weakness phenomenon. This work should reveal the cause of X-ray weakness for quasars with weak emission lines, allowing testing of a model that relies upon small-scale shielding of ionizing photons by a thick inner accretion disk around a black hole accreting at a high

  16. Current problems in the weak interactions

    Energy Technology Data Exchange (ETDEWEB)

    Pais, A

    1977-01-01

    Some reasons are discussed showing why the recent SU(2) x U(1) gauge theory of weak and electromagnetic interactions is not a complete theory of these interactions, Lepton theory, charm, and the CP problem are considered. 60 references. (JFP)

  17. Major strengths and weaknesses of the lod score method.

    Science.gov (United States)

    Ott, J

    2001-01-01

    Strengths and weaknesses of the lod score method for human genetic linkage analysis are discussed. The main weakness is its requirement for the specification of a detailed inheritance model for the trait. Various strengths are identified. For example, the lod score (likelihood) method has optimality properties when the trait to be studied is known to follow a Mendelian mode of inheritance. The ELOD is a useful measure for information content of the data. The lod score method can emulate various "nonparametric" methods, and this emulation is equivalent to the nonparametric methods. Finally, the possibility of building errors into the analysis will prove to be essential for the large amount of linkage and disequilibrium data expected in the near future.

  18. Renormalization Group in the uniqueness region weak Gibbsianity and convergence.

    CERN Document Server

    Bertini, L; Olivieri, E

    2004-01-01

    We analyze the block averaging transformation applied to lattice gas models with short range interaction in the uniqueness region below the critical temperature. %We discuss the %Gibbs property of the renormalized measure and the convergence of %renormalized potential under iteration of the map. We prove weak Gibbsianity of the renormalized measure and convergence of the renormalized potential in a weak sense. Since we are arbitrarily close to the coexistence region we have a diverging characteristic length of the system: the correlation length or the critical length for metastability, or both. Thus, to perturbatively treat the problem we have to use a scale--adapted expansion. Moreover, such a model below the critical temperature resembles a disordered system in presence of Griffiths' singularity. Then the cluster expansion that we use must be graded with its minimal scale length diverging when the coexistence line is approached.

  19. Structure of weakly periodic rings with potent extended commutators

    OpenAIRE

    Adil Yaqub

    2001-01-01

    A well-known theorem of Jacobson (1964, page 217) asserts that a ring R with the property that, for each x in R, there exists an integer n(x)>1 such that xn(x)=x is necessarily commutative. This theorem is generalized to the case of a weakly periodic ring R with a “sufficient” number of potent extended commutators. A ring R is called weakly periodic if every x in R can be written in the form x=a+b, where a is nilpotent and b is “potent” in the sense that bn(b)=b for some integer n(b)>1. It is...

  20. Regularity of Tor for weakly stable ideals

    Directory of Open Access Journals (Sweden)

    Katie Ansaldi

    2015-05-01

    Full Text Available It is proved that if I and J are weakly stable ideals in a polynomial ring R = k[x_1, . . ., x_n], with k a field, then the regularity of Tor^R_i (R/I, R/J has the expected upper bound. We also give a bound for the regularity of Ext^i_R (R/I, R for I a weakly stable ideal.

  1. The regularization of Old English weak verbs

    OpenAIRE

    Marta Tío Sáenz

    2015-01-01

    [EN] This article deals with the regularization of non-standard spellings of the verbal forms extracted from a corpus. It addresses the question of what the limits of regularization are when lemmatizing Old English weak verbs. The purpose of such regularization, also known as normalization, is to carry out lexicological analysis or lexicographical work. The analysis concentrates on weak verbs from the second class and draws on the lexical database of Old English Nerthus, which has incorporate...

  2. Drift waves in a weakly ionized plasma

    DEFF Research Database (Denmark)

    Popovic, M.; Melchior, H.

    1968-01-01

    A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated.......A dispersion relation for low frequency drift waves in a weakly ionized plasma has been derived, and through numerical calculations the effect of collisions between the charged and the neutral particles is estimated....

  3. Muscle weakness causes joint degeneration in rabbits.

    Science.gov (United States)

    Rehan Youssef, A; Longino, D; Seerattan, R; Leonard, T; Herzog, W

    2009-09-01

    The objective of this study was to investigate the effects of botulinum toxin type-A (BTX-A) induced quadriceps weakness on micro-structural changes in knee cartilage of New Zealand White (NZW) rabbits. Fifteen rabbits were divided randomly into an experimental and a sham control group. Each group received a unilateral single quadriceps muscle injection either with saline (sham control; n=4) or BTX-A (experimental; n=11). BTX-A injection produced significant quadriceps muscle weakness (Pmuscle mass (Pknee cartilage, assessed with the Mankin grading system, were the same for the injected and non-injected hind limbs of the experimental group animals. Sham injection had no effect on joint degeneration but all control animals showed some degenerative changes in the knee. Degenerative changes of the retro-patellar cartilage were more severe in the experimental compared to sham control group rabbits (P0.05). Quadriceps muscle weakness caused increased degeneration in the retro-patellar cartilage of NZW rabbits, providing evidence that muscle weakness might be a risk factor for the onset and progression of osteoarthritis (OA). Future work needs to delineate whether muscle weakness directly affects joint degeneration, or if changes in function and movement execution associated with muscle weakness are responsible for the increased rate of OA onset and progression observed here.

  4. SIMULATION OF SUBGRADE EMBANKMENT ON WEAK BASE

    Directory of Open Access Journals (Sweden)

    V. D. Petrenko

    2015-08-01

    Full Text Available Purpose. This article provides: the question of the sustainability of the subgrade on a weak base is considered in the paper. It is proposed to use the method of jet grouting. Investigation of the possibility of a weak base has an effect on the overall deformation of the subgrade; the identification and optimization of the parameters of subgrade based on studies using numerical simulation. Methodology. The theoretical studies of the stress-strain state of the base and subgrade embankment by modeling in the software package LIRA have been conducted to achieve this goal. Findings. After making the necessary calculations perform building fields of a subsidence, borders cramped thickness, bed’s coefficients of Pasternak and Winkler. The diagrams construction of vertical stress performs at any point of load application. Also, using the software system may perform peer review subsidence, rolls railroad tracks in natural and consolidated basis. Originality. For weak soils is the most appropriate nonlinear model of the base with the existing areas of both elastic and limit equilibrium, mixed problem of the theory of elasticity and plasticity. Practical value. By increasing the load on the weak base as a result of the second track construction, adds embankment or increasing axial load when changing the rolling stock process of sedimentation and consolidation may continue again. Therefore, one of the feasible and promising options for the design and reconstruction of embankments on weak bases is to strengthen the bases with the help of jet grouting. With the expansion of the railway infrastructure, increasing speed and weight of the rolling stock is necessary to ensure the stability of the subgrade on weak bases. LIRA software package allows you to perform all the necessary calculations for the selection of a proper way of strengthening weak bases.

  5. The First Gauge Theory of Weak Interactions and the Prediction of Weak Neutral Currents

    OpenAIRE

    Bludman, S. A.

    1992-01-01

    The three theoretical and historical components of the Standard Model are the exact chiral gauge theory of weak interactions, electroweak unification, and the Higgs mechanism for spontaneous symmetry breaking. I put into historical perspective my 1958 invention of the first gauge theory of weak interactions, predicting weak neutral currents, and show how the fundamental differences between global and gauge symmetries and between partial flavour and exact gauge symmetries, emerged in the stron...

  6. Geometric phase topology in weak measurement

    Science.gov (United States)

    Samlan, C. T.; Viswanathan, Nirmal K.

    2017-12-01

    The geometric phase visualization proposed by Bhandari (R Bhandari 1997 Phys. Rep. 281 1–64) in the ellipticity-ellipse orientation basis of the polarization ellipse of light is implemented to understand the geometric aspects of weak measurement. The weak interaction of a pre-selected state, acheived via spin-Hall effect of light (SHEL), results in a spread in the polarization ellipticity (η) or ellipse orientation (χ) depending on the resulting spatial or angular shift, respectively. The post-selection leads to the projection of the η spread in the complementary χ basis results in the appearance of a geometric phase with helical phase topology in the η ‑ χ parameter space. By representing the weak measurement on the Poincaré sphere and using Jones calculus, the complex weak value and the geometric phase topology are obtained. This deeper understanding of the weak measurement process enabled us to explore the techniques’ capabilities maximally, as demonstrated via SHEL in two examples—external reflection at glass-air interface and transmission through a tilted half-wave plate.

  7. A weak HOAS approach to the POPLmark Challenge

    Directory of Open Access Journals (Sweden)

    Alberto Ciaffaglione

    2013-03-01

    Full Text Available Capitalizing on previous encodings and formal developments about nominal calculi and type systems, we propose a weak Higher-Order Abstract Syntax formalization of the type language of pure System F<: within Coq, a proof assistant based on the Calculus of Inductive Constructions. Our encoding allows us to accomplish the proof of the transitivity property of algorithmic subtyping, which is in fact the first of the three tasks stated by the POPLmark Challenge, a set of problems that capture the most critical issues in formalizing programming language metatheory.

  8. Weak diffusion limits of dynamic conditional correlation models

    DEFF Research Database (Denmark)

    Hafner, Christian M.; Laurent, Sebastien; Violante, Francesco

    The properties of dynamic conditional correlation (DCC) models are still not entirely understood. This paper fills one of the gaps by deriving weak diffusion limits of a modified version of the classical DCC model. The limiting system of stochastic differential equations is characterized...... by a diffusion matrix of reduced rank. The degeneracy is due to perfect collinearity between the innovations of the volatility and correlation dynamics. For the special case of constant conditional correlations, a non-degenerate diffusion limit can be obtained. Alternative sets of conditions are considered...

  9. Weak KAM theory for a weakly coupled system of Hamilton–Jacobi equations

    KAUST Repository

    Figalli, Alessio

    2016-06-23

    Here, we extend the weak KAM and Aubry–Mather theories to optimal switching problems. We consider three issues: the analysis of the calculus of variations problem, the study of a generalized weak KAM theorem for solutions of weakly coupled systems of Hamilton–Jacobi equations, and the long-time behavior of time-dependent systems. We prove the existence and regularity of action minimizers, obtain necessary conditions for minimality, extend Fathi’s weak KAM theorem, and describe the asymptotic limit of the generalized Lax–Oleinik semigroup. © 2016, Springer-Verlag Berlin Heidelberg.

  10. Search for the Scalar Component of Weak Interactions

    CERN Document Server

    Zakoucky, Dalibor

    2014-01-01

    Weak interactions ar e described by the Standard Model which postulates the basic assumption about the pure " V (ector) - A (xial vector)" character of the interaction. Nevertheless, even after half a century of development of the model and experimental testing of its fundamental i ngredients, experimental data still allow the existence of other types of weak interactions - e.g. scalar interactions are ruled out only on the 7% level. Experimental project WITCH ( W eak I nteraction T rap for CH arged particles) was set up at the isoto pe separator ISOLDE at CERN trying to probe the properties of the weak interaction in order to look for their forbidden (scalar, tensor) components or at least significantly improve their current experimental limits. Experimental setup consisting of a comb ination of 2 Penning traps and retardation spectrometer allows to catch the radioactive nuclei from ISOLDE separator, traps and cools them and lets them decay in rest and then probes the energy spectrum of recoiling nuclei whic...

  11. Turbulence of Weak Gravitational Waves in the Early Universe

    Science.gov (United States)

    Galtier, Sébastien; Nazarenko, Sergey V.

    2017-12-01

    We study the statistical properties of an ensemble of weak gravitational waves interacting nonlinearly in a flat space-time. We show that the resonant three-wave interactions are absent and develop a theory for four-wave interactions in the reduced case of a 2.5 +1 diagonal metric tensor. In this limit, where only plus-polarized gravitational waves are present, we derive the interaction Hamiltonian and consider the asymptotic regime of weak gravitational wave turbulence. Both direct and inverse cascades are found for the energy and the wave action, respectively, and the corresponding wave spectra are derived. The inverse cascade is characterized by a finite-time propagation of the metric excitations—a process similar to an explosive nonequilibrium Bose-Einstein condensation, which provides an efficient mechanism to ironing out small-scale inhomogeneities. The direct cascade leads to an accumulation of the radiation energy in the system. These processes might be important for understanding the early Universe where a background of weak nonlinear gravitational waves is expected.

  12. Turbulence of Weak Gravitational Waves in the Early Universe.

    Science.gov (United States)

    Galtier, Sébastien; Nazarenko, Sergey V

    2017-12-01

    We study the statistical properties of an ensemble of weak gravitational waves interacting nonlinearly in a flat space-time. We show that the resonant three-wave interactions are absent and develop a theory for four-wave interactions in the reduced case of a 2.5+1 diagonal metric tensor. In this limit, where only plus-polarized gravitational waves are present, we derive the interaction Hamiltonian and consider the asymptotic regime of weak gravitational wave turbulence. Both direct and inverse cascades are found for the energy and the wave action, respectively, and the corresponding wave spectra are derived. The inverse cascade is characterized by a finite-time propagation of the metric excitations-a process similar to an explosive nonequilibrium Bose-Einstein condensation, which provides an efficient mechanism to ironing out small-scale inhomogeneities. The direct cascade leads to an accumulation of the radiation energy in the system. These processes might be important for understanding the early Universe where a background of weak nonlinear gravitational waves is expected.

  13. Weak layer fracture: facets and depth hoar

    Directory of Open Access Journals (Sweden)

    I. Reiweger

    2013-09-01

    Full Text Available Understanding failure initiation within weak snow layers is essential for modeling and predicting dry-snow slab avalanches. We therefore performed laboratory experiments with snow samples containing a weak layer consisting of either faceted crystals or depth hoar. During these experiments the samples were loaded with different loading rates and at various tilt angles until fracture. The strength of the samples decreased with increasing loading rate and increasing tilt angle. Additionally, we took pictures of the side of four samples with a high-speed video camera and calculated the displacement using a particle image velocimetry (PIV algorithm. The fracture process within the weak layer could thus be observed in detail. Catastrophic failure started due to a shear fracture just above the interface between the depth hoar layer and the underlying crust.

  14. Extrapolating Weak Selection in Evolutionary Games

    Science.gov (United States)

    Wu, Bin; García, Julián; Hauert, Christoph; Traulsen, Arne

    2013-01-01

    In evolutionary games, reproductive success is determined by payoffs. Weak selection means that even large differences in game outcomes translate into small fitness differences. Many results have been derived using weak selection approximations, in which perturbation analysis facilitates the derivation of analytical results. Here, we ask whether results derived under weak selection are also qualitatively valid for intermediate and strong selection. By “qualitatively valid” we mean that the ranking of strategies induced by an evolutionary process does not change when the intensity of selection increases. For two-strategy games, we show that the ranking obtained under weak selection cannot be carried over to higher selection intensity if the number of players exceeds two. For games with three (or more) strategies, previous examples for multiplayer games have shown that the ranking of strategies can change with the intensity of selection. In particular, rank changes imply that the most abundant strategy at one intensity of selection can become the least abundant for another. We show that this applies already to pairwise interactions for a broad class of evolutionary processes. Even when both weak and strong selection limits lead to consistent predictions, rank changes can occur for intermediate intensities of selection. To analyze how common such games are, we show numerically that for randomly drawn two-player games with three or more strategies, rank changes frequently occur and their likelihood increases rapidly with the number of strategies . In particular, rank changes are almost certain for , which jeopardizes the predictive power of results derived for weak selection. PMID:24339769

  15. Extrapolating weak selection in evolutionary games.

    Directory of Open Access Journals (Sweden)

    Bin Wu

    Full Text Available In evolutionary games, reproductive success is determined by payoffs. Weak selection means that even large differences in game outcomes translate into small fitness differences. Many results have been derived using weak selection approximations, in which perturbation analysis facilitates the derivation of analytical results. Here, we ask whether results derived under weak selection are also qualitatively valid for intermediate and strong selection. By "qualitatively valid" we mean that the ranking of strategies induced by an evolutionary process does not change when the intensity of selection increases. For two-strategy games, we show that the ranking obtained under weak selection cannot be carried over to higher selection intensity if the number of players exceeds two. For games with three (or more strategies, previous examples for multiplayer games have shown that the ranking of strategies can change with the intensity of selection. In particular, rank changes imply that the most abundant strategy at one intensity of selection can become the least abundant for another. We show that this applies already to pairwise interactions for a broad class of evolutionary processes. Even when both weak and strong selection limits lead to consistent predictions, rank changes can occur for intermediate intensities of selection. To analyze how common such games are, we show numerically that for randomly drawn two-player games with three or more strategies, rank changes frequently occur and their likelihood increases rapidly with the number of strategies [Formula: see text]. In particular, rank changes are almost certain for [Formula: see text], which jeopardizes the predictive power of results derived for weak selection.

  16. Weak Acid Ionization Constants and the Determination of Weak Acid-Weak Base Reaction Equilibrium Constants in the General Chemistry Laboratory

    Science.gov (United States)

    Nyasulu, Frazier; McMills, Lauren; Barlag, Rebecca

    2013-01-01

    A laboratory to determine the equilibrium constants of weak acid negative weak base reactions is described. The equilibrium constants of component reactions when multiplied together equal the numerical value of the equilibrium constant of the summative reaction. The component reactions are weak acid ionization reactions, weak base hydrolysis…

  17. A theoretical overview of hypernuclear weak decay

    Energy Technology Data Exchange (ETDEWEB)

    Chumillas, C. [Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, E-08028 Barcelona (Spain); Garbarino, G. [Dipartimento di Fisica Teorica, Universita di Torino and INFN, Sezione di Torino, I-10125 Torino (Italy)], E-mail: garbarin@to.infn.it; Parreno, A.; Ramos, A. [Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, E-08028 Barcelona (Spain)

    2008-05-15

    The physics of the weak decay of hypernuclei is briefly reviewed from a theoretical point of view. Special regard is devoted to the recent progress concerning the determination of the non-mesonic decay widths and the asymmetry parameters. Convincing evidence has been achieved for a solution of the long-standing puzzle on the ratio {gamma}{sub n}/{gamma}{sub p}. Very recently, it has been shown that the exchange of a {pi}{pi} pair in the weak mechanism plays a crucial role in explaining the discrepancies between theory and experiment on the decay asymmetries.

  18. Weak interactions at high energies. [Lectures, review

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J.

    1978-08-01

    Review lectures are presented on the phenomenological implications of the modern spontaneously broken gauge theories of the weak and electromagnetic interactions, and some observations are made about which high energy experiments probe what aspects of gauge theories. Basic quantum chromodynamics phenomenology is covered including momentum dependent effective quark distributions, the transverse momentum cutoff, search for gluons as sources of hadron jets, the status and prospects for the spectroscopy of fundamental fermions and how fermions may be used to probe aspects of the weak and electromagnetic gauge theory, studies of intermediate vector bosons, and miscellaneous possibilities suggested by gauge theories from the Higgs bosons to speculations about proton decay. 187 references. (JFP)

  19. A Continuation Method for Weakly Kannan Maps

    Directory of Open Access Journals (Sweden)

    Ariza-Ruiz David

    2010-01-01

    Full Text Available The first continuation method for contractive maps in the setting of a metric space was given by Granas. Later, Frigon extended Granas theorem to the class of weakly contractive maps, and recently Agarwal and O'Regan have given the corresponding result for a certain type of quasicontractions which includes maps of Kannan type. In this note we introduce the concept of weakly Kannan maps and give a fixed point theorem, and then a continuation method, for this class of maps.

  20. On the theory of weak turbulence for the nonlinear Schrödinger equation

    CERN Document Server

    Escobedo, M

    2015-01-01

    The authors study the Cauchy problem for a kinetic equation arising in the weak turbulence theory for the cubic nonlinear Schrödinger equation. They define suitable concepts of weak and mild solutions and prove local and global well posedness results. Several qualitative properties of the solutions, including long time asymptotics, blow up results and condensation in finite time are obtained. The authors also prove the existence of a family of solutions that exhibit pulsating behavior.

  1. Observation of the Imbert-Fedorov effect via weak value amplification

    Science.gov (United States)

    Jayaswal, G.; Mistura, G.; Merano, M.

    2014-04-01

    Weak measurements have recently allowed for the observation of the spin-Hall effect of light in reflection or transmission, which is a spin-dependent light beam shift orthogonal to the plane of incidence. We report here the observation of the Imbert-Fedorov shift via a weak value amplification scheme. The Imbert-Fedorov effect does not depend on the spin of the incident photon only, but it has richer polarization dependence. We prove that weak measurements allow for a complete experimental characterization of the polarization properties of this tiny optical effect.

  2. Studying dark matter haloes with weak lensing

    NARCIS (Netherlands)

    Velander, Malin Barbro Margareta

    2012-01-01

    Our Universe is comprised not only of normal matter but also of unknown components: dark matter and dark energy. This Thesis recounts studies of dark matter haloes, using a technique known as weak gravitational lensing, in order to learn more about the nature of these dark components. The haloes

  3. Common fixed points for weakly compatible maps

    Indian Academy of Sciences (India)

    The purpose of this paper is to prove a common fixed point theorem, from the class of compatible continuous maps to a larger class of maps having weakly compatible maps without appeal to continuity, which generalized the results of Jungck [3], Fisher [1], Kang and Kim [8], Jachymski [2], and Rhoades [9].

  4. Cultural capital: strengths, weaknesses and two advancements

    NARCIS (Netherlands)

    van de Werfhorst, H.G.

    2010-01-01

    In this paper I discuss two weaknesses in Bourdieu’s work on cultural capital, both of which are related to his integration of the multidimensional nature of social space in different domains of life: social mobility, lifestyle differentiation, and political orientation. First, there is an anomaly

  5. Reducing Weak to Strong Bisimilarity in CCP

    Directory of Open Access Journals (Sweden)

    Andrés Aristizábal

    2012-12-01

    Full Text Available Concurrent constraint programming (ccp is a well-established model for concurrency that singles out the fundamental aspects of asynchronous systems whose agents (or processes evolve by posting and querying (partial information in a global medium. Bisimilarity is a standard behavioural equivalence in concurrency theory. However, only recently a well-behaved notion of bisimilarity for ccp, and a ccp partition refinement algorithm for deciding the strong version of this equivalence have been proposed. Weak bisimiliarity is a central behavioural equivalence in process calculi and it is obtained from the strong case by taking into account only the actions that are observable in the system. Typically, the standard partition refinement can also be used for deciding weak bisimilarity simply by using Milner's reduction from weak to strong bisimilarity; a technique referred to as saturation. In this paper we demonstrate that, because of its involved labeled transitions, the above-mentioned saturation technique does not work for ccp. We give an alternative reduction from weak ccp bisimilarity to the strong one that allows us to use the ccp partition refinement algorithm for deciding this equivalence.

  6. Thermorheological effect on magnetoconvection in weak electrically ...

    Indian Academy of Sciences (India)

    Abstract. The thermorheological effect on magnetoconvection in fluids with weak elec- trical conductivity is studied numerically under 1g and μg conditions. The results with a non-linear thermorheological equation considered in the problem when compared with those of the classical approach with constant viscosity ...

  7. Solitons and Weakly Nonlinear Waves in Plasmas

    DEFF Research Database (Denmark)

    Pécseli, Hans

    1985-01-01

    Theoretical descriptions of solitons and weakly nonlinear waves propagating in plasma media are reviewed, with particular attention to the Korteweg-de Vries (KDV) equation and the Nonlinear Schrödinger equation (NLS). The modifications of these basic equations due to the effects of resonant...

  8. Fermi and the Theory of Weak Interactions

    Indian Academy of Sciences (India)

    IAS Admin

    The history of weak interactions starting with. Fermi's creation of the beta decay theory and culminating in its modern avatar in the form of the electroweak gauge theory is described. Dis- coveries of parity violation, matter{antimatter asymmetry, W and Z bosons and neutrino mass are highlighted. Introduction. Sun gives us ...

  9. Phenomenological model of the weak interaction

    OpenAIRE

    Schunck, Franz E.

    2008-01-01

    We use the informations known so far about elementary particles in order to construct a simple model. We find a reason for the gyromagnetic factor of 2 for leptons and a vivid imagination for the weak interaction. By this, we understand, why the elementary particles with lowest mass are stable and all other unstable.

  10. Fermi and the Theory of Weak Interactions

    OpenAIRE

    Rajasekaran, G.

    2014-01-01

    The history of weak interactions starting with Fermi's creation of the beta decay theory and culminating in its modern avatar in the form of the electroweak gauge theory is described. Discoveries of parity violation, matter-antimatter asymmetry, W and Z bosons and neutrino mass are highlighted.

  11. Dynamical theory of weak and electromagnetic interactions

    CERN Document Server

    Englert, F

    1974-01-01

    The gauge theory of unified weak and electromagnetic interactions is developed without the use of scalar mesons. It is shown that the Glashow Weinberg scheme is unrealistic, but that a similar such scheme is possible if one includes two pairs of leptons, identified with e-, νe and μ-, νμ.

  12. The weak acid nature of precipitation

    Science.gov (United States)

    John O. Frohliger; Robert L. Kane

    1976-01-01

    Recent measurements of the pH of precipitation leave no doubt that rainfall is acidic. Evidence will be presented that precipitation is a weak acid system. The results of this research indicate the need to establish standard sampling procedures to provide uniform sampling of precipitation

  13. Neutrino propagation in a weakly magnetized medium

    Indian Academy of Sciences (India)

    of the W and Z bosons allowing us to neglect the momentum dependence in the. W and Z propagators. This is equivalent to lowest-order GF calculations and is justified for low-energy neutrinos and low temperatures and weak fields compared to the Fermi scale. Since, in this work we focus our attention on the possible astro ...

  14. Fermi and the Theory of Weak Interactions

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 1. Fermi and the Theory of Weak Interactions. G Rajasekaran. General Article Volume 19 Issue 1 January 2014 pp 18-44 ... Keywords. Fermi; beta decay; parity violation; electroweak theory; neutral current; quarks and leptons; neutrino mass.

  15. Weak organic acid stress in Bacillus subtilis

    NARCIS (Netherlands)

    ter Beek, A.S.

    2009-01-01

    Weak organic acids are commonly used food preservatives that protect food products from bacterial contamination. A variety of spore-forming bacterial species pose a serious problem to the food industry by causing extensive food spoilage or even food poisoning. Understanding the mechanisms of

  16. Information capacity in the weak-signal approximation

    CERN Document Server

    Kostal, Lubomir

    2010-01-01

    We derive an approximate expression for mutual information in a broad class of discrete-time stationary channels with continuous input, under the constraint of vanishing input amplitude or power. The approximation describes the input by its covariance matrix, while the channel properties are described by the Fisher information matrix. This separation of input and channel properties allows us to analyze the optimality conditions in a convenient way. We show that input correlations in memoryless channels do not affect channel capacity since their effect decreases fast with vanishing input amplitude or power. On the other hand, for channels with memory, properly matching the input covariances to the dependence structure of the noise may lead to almost noiseless information transfer, even for intermediate values of the noise correlations. Since many model systems described in mathematical neuroscience and biophysics operate in the high noise regime and weak-signal conditions, we believe, that the described result...

  17. In Vivo Predictive Dissolution: Comparing the Effect of Bicarbonate and Phosphate Buffer on the Dissolution of Weak Acids and Weak Bases.

    Science.gov (United States)

    Krieg, Brian J; Taghavi, Seyed Mohammad; Amidon, Gordon L; Amidon, Gregory E

    2015-09-01

    Bicarbonate is the main buffer in the small intestine and it is well known that buffer properties such as pKa can affect the dissolution rate of ionizable drugs. However, bicarbonate buffer is complicated to work with experimentally. Finding a suitable substitute for bicarbonate buffer may provide a way to perform more physiologically relevant dissolution tests. The dissolution of weak acid and weak base drugs was conducted in bicarbonate and phosphate buffer using rotating disk dissolution methodology. Experimental results were compared with the predicted results using the film model approach of (Mooney K, Mintun M, Himmelstein K, Stella V. 1981. J Pharm Sci 70(1):22-32) based on equilibrium assumptions as well as a model accounting for the slow hydration reaction, CO2 + H2 O → H2 CO3 . Assuming carbonic acid is irreversible in the dehydration direction: CO2 + H2 O ← H2 CO3 , the transport analysis can accurately predict rotating disk dissolution of weak acid and weak base drugs in bicarbonate buffer. The predictions show that matching the dissolution of weak acid and weak base drugs in phosphate and bicarbonate buffer is possible. The phosphate buffer concentration necessary to match physiologically relevant bicarbonate buffer [e.g., 10.5 mM (HCO3 (-) ), pH = 6.5] is typically in the range of 1-25 mM and is very dependent upon drug solubility and pKa . © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  18. New weak keys in simplified IDEA

    Science.gov (United States)

    Hafman, Sari Agustini; Muhafidzah, Arini

    2016-02-01

    Simplified IDEA (S-IDEA) is simplified version of International Data Encryption Algorithm (IDEA) and useful teaching tool to help students to understand IDEA. In 2012, Muryanto and Hafman have found a weak key class in the S-IDEA by used differential characteristics in one-round (0, ν, 0, ν) → (0,0, ν, ν) on the first round to produce input difference (0,0, ν, ν) on the fifth round. Because Muryanto and Hafman only use three differential characteristics in one-round, we conducted a research to find new differential characteristics in one-round and used it to produce new weak key classes of S-IDEA. To find new differential characteristics in one-round of S-IDEA, we applied a multiplication mod 216+1 on input difference and combination of active sub key Z1, Z4, Z5, Z6. New classes of weak keys are obtained by combining all of these characteristics and use them to construct two new differential characteristics in full-round of S-IDEA with or without the 4th round sub key. In this research, we found six new differential characteristics in one round and combined them to construct two new differential characteristics in full-round of S-IDEA. When two new differential characteristics in full-round of S-IDEA are used and the 4th round sub key required, we obtain 2 new classes of weak keys, 213 and 28. When two new differential characteristics in full-round of S-IDEA are used, yet the 4th round sub key is not required, the weak key class of 213 will be 221 and 28 will be 210. Membership test can not be applied to recover the key bits in those weak key classes. The recovery of those unknown key bits can only be done by using brute force attack. The simulation result indicates that the bit of the key can be recovered by the longest computation time of 0,031 ms.

  19. Model Reduction of Strong-Weak Neurons

    Directory of Open Access Journals (Sweden)

    Steven James Cox

    2014-12-01

    Full Text Available We consider neurons with large dendritic trees that are weakly excitable in the sense that back propagating action potentials are severly attenuated as they travelfrom the small, strongly excitable, spike initiation zone. In previous workwe have shown that the computational size of weakly excitable cell modelsmay be reduced by two or more orders of magnitude, and that the size of stronglyexcitable models may be reduced by at least one order of magnitude,without sacrificing thespatio-temporal nature of its inputs (in the sense we reproduce the cell's precise mapping of inputs to outputs. We combine the best of these twostrategies via a predictor--corrector decomposition scheme andachieve a drastically reduced highly accurate model of a caricature of the neuron responsible for collision detection in the locust.

  20. Model reduction of strong-weak neurons.

    Science.gov (United States)

    Du, Bosen; Sorensen, Danny; Cox, Steven J

    2014-01-01

    We consider neurons with large dendritic trees that are weakly excitable in the sense that back propagating action potentials are severly attenuated as they travel from the small, strongly excitable, spike initiation zone. In previous work we have shown that the computational size of weakly excitable cell models may be reduced by two or more orders of magnitude, and that the size of strongly excitable models may be reduced by at least one order of magnitude, without sacrificing the spatio-temporal nature of its inputs (in the sense we reproduce the cell's precise mapping of inputs to outputs). We combine the best of these two strategies via a predictor-corrector decomposition scheme and achieve a drastically reduced highly accurate model of a caricature of the neuron responsible for collision detection in the locust.

  1. Towards weakly constrained double field theory

    Directory of Open Access Journals (Sweden)

    Kanghoon Lee

    2016-08-01

    Full Text Available We show that it is possible to construct a well-defined effective field theory incorporating string winding modes without using strong constraint in double field theory. We show that X-ray (Radon transform on a torus is well-suited for describing weakly constrained double fields, and any weakly constrained fields are represented as a sum of strongly constrained fields. Using inverse X-ray transform we define a novel binary operation which is compatible with the level matching constraint. Based on this formalism, we construct a consistent gauge transform and gauge invariant action without using strong constraint. We then discuss the relation of our result to the closed string field theory. Our construction suggests that there exists an effective field theory description for massless sector of closed string field theory on a torus in an associative truncation.

  2. Weak Gravitational Lensing of Finite Beams

    Science.gov (United States)

    Fleury, Pierre; Larena, Julien; Uzan, Jean-Philippe

    2017-11-01

    The standard theory of weak gravitational lensing relies on the infinitesimal light beam approximation. In this context, images are distorted by convergence and shear, the respective sources of which unphysically depend on the resolution of the distribution of matter—the so-called Ricci-Weyl problem. In this Letter, we propose a strong-lensing-inspired formalism to describe the lensing of finite beams. We address the Ricci-Weyl problem by showing explicitly that convergence is caused by the matter enclosed by the beam, regardless of its distribution. Furthermore, shear turns out to be systematically enhanced by the finiteness of the beam. This implies, in particular, that the Kaiser-Squires relation between shear and convergence is violated, which could have profound consequences on the interpretation of weak-lensing surveys.

  3. On Uniform Weak König's Lemma

    DEFF Research Database (Denmark)

    Kohlenbach, Ulrich

    2002-01-01

    The so-called weak Konig's lemma WKL asserts the existence of an infinite path b in any infinite binary tree (given by a representing function f). Based on this principle one can formulate subsystems of higher-order arithmetic which allow to carry out very substantial parts of classical mathematics...... is of interest in the context of explicit mathematics as developed by S. Feferman. The elimination process in Kohlenbach [10] actually can be used to eliminate even this uniform weak Konig's lemma provided that PRA only has a quantifier-free rule of extensionality QF-ER instead of the full axioms (E...... as the computational strength of UWKL relative to the intuitionistic variant of PRA both with and without the Markov principle....

  4. Weak mixing angle measurements at hadron colliders

    CERN Document Server

    Di Simone, Andrea; The ATLAS collaboration

    2015-01-01

    The Talk will cover weak mixing angle measurements at hadron colliders ATLAS and CMS in particular. ATLAS has measured the forward-backward asymmetry for the neutral current Drell Yan process in a wide mass range around the Z resonance region using dielectron and dimuon final states with $\\sqrt{s}$ =7 TeV data. For the dielectron channel, the measurement includes electrons detected in the forward calorimeter which extends the covered phase space. The result is then used to extract a measurement of the effective weak mixing angle. Uncertainties from the limited knowledge on the parton distribution functions in the proton constitute a significant part of the uncertainty and a dedicated study is performed to obtain a PDF set describing W and Z data measured previously by ATLAS. Similar studies from CMS will be reported.

  5. The regularization of Old English weak verbs

    Directory of Open Access Journals (Sweden)

    Marta Tío Sáenz

    2015-07-01

    Full Text Available This article deals with the regularization of non-standard spellings of the verbal forms extracted from a corpus. It addresses the question of what the limits of regularization are when lemmatizing Old English weak verbs. The purpose of such regularization, also known as normalization, is to carry out lexicological analysis or lexicographical work. The analysis concentrates on weak verbs from the second class and draws on the lexical database of Old English Nerthus, which has incorporated the texts of the Dictionary of Old English Corpus. As regards the question of the limits of normalization, the solution adopted are, in the first place, that when it is necessary to regularize, normalization is restricted to correspondences based on dialectal and diachronic variation and, secondly, that normalization has to be unidirectional.

  6. Asymptotic theory of weakly dependent random processes

    CERN Document Server

    Rio, Emmanuel

    2017-01-01

    Presenting tools to aid understanding of asymptotic theory and weakly dependent processes, this book is devoted to inequalities and limit theorems for sequences of random variables that are strongly mixing in the sense of Rosenblatt, or absolutely regular. The first chapter introduces covariance inequalities under strong mixing or absolute regularity. These covariance inequalities are applied in Chapters 2, 3 and 4 to moment inequalities, rates of convergence in the strong law, and central limit theorems. Chapter 5 concerns coupling. In Chapter 6 new deviation inequalities and new moment inequalities for partial sums via the coupling lemmas of Chapter 5 are derived and applied to the bounded law of the iterated logarithm. Chapters 7 and 8 deal with the theory of empirical processes under weak dependence. Lastly, Chapter 9 describes links between ergodicity, return times and rates of mixing in the case of irreducible Markov chains. Each chapter ends with a set of exercises. The book is an updated and extended ...

  7. Shock Wave Dynamics in Weakly Ionized Plasmas

    Science.gov (United States)

    Johnson, Joseph A., III

    1999-01-01

    An investigation of the dynamics of shock waves in weakly ionized argon plasmas has been performed using a pressure ruptured shock tube. The velocity of the shock is observed to increase when the shock traverses the plasma. The observed increases cannot be accounted for by thermal effects alone. Possible mechanisms that could explain the anomalous behavior include a vibrational/translational relaxation in the nonequilibrium plasma, electron diffusion across the shock front resulting from high electron mobility, and the propagation of ion-acoustic waves generated at the shock front. Using a turbulence model based on reduced kinetic theory, analysis of the observed results suggest a role for turbulence in anomalous shock dynamics in weakly ionized media and plasma-induced hypersonic drag reduction.

  8. Orbits in weak and strong bars

    CERN Document Server

    Contopoulos, George

    1980-01-01

    The authors study the plane orbits in simple bar models embedded in an axisymmetric background when the bar density is about 1% (weak), 10% (intermediate) or 100% (strong bar) of the axisymmetric density. Most orbits follow the stable periodic orbits. The basic families of periodic orbits are described. In weak bars with two Inner Lindblad Resonances there is a family of stable orbits extending from the center up to the Outer Lindblad Resonance. This family contains the long period orbits near corotation. Other stable families appear between the Inner Lindblad Resonances, outside the Outer Lindblad Resonance, around corotation (short period orbits) and around the center (retrograde). Some families become unstable or disappear in strong bars. A comparison is made with cases having one or no Inner Lindblad Resonance. (12 refs).

  9. Weakly Collisional and Collisionless Astrophysical Plasmas

    DEFF Research Database (Denmark)

    Berlok, Thomas

    investigate helium mixing in the weakly collisional intracluster medium of galaxy clusters using Braginskii MHD. Secondly, we present a newly developed Vlasov-fluid code which can be used for studying fully collisionless plasmas such as the solar wind and hot accretions flows. The equations of Braginskii MHD...... are used to study weakly collisional, stratified atmospheres which offer a useful model of the intracluster medium of galaxy clusters. Using linear theory and computer simulations, we study instabilities that feed off thermal and compositional gradients. We find that these instabilities lead to vigorous...... mixing of the composition and discuss the potential consequences for X-ray observations of galaxy clusters. Collisionless plasmas can be subject to microscale velocity-space instabilities which are not well-described by Braginskii MHD. In contrast, Vlasov-fluid theory captures all the kinetic phenomena...

  10. A dynamical weak scale from inflation

    Science.gov (United States)

    You, Tevong

    2017-09-01

    Dynamical scanning of the Higgs mass by an axion-like particle during inflation may provide a cosmological component to explaining part of the hierarchy problem. We propose a novel interplay of this cosmological relaxation mechanism with inflation, whereby the backreaction of the Higgs vacuum expectation value near the weak scale causes inflation to end. As Hubble drops, the relaxion's dissipative friction increases relative to Hubble and slows it down enough to be trapped by the barriers of its periodic potential. Such a scenario raises the natural cut-off of the theory up to ~ 1010 GeV, while maintaining a minimal relaxion sector without having to introduce additional scanning scalars or new physics coincidentally close to the weak scale.

  11. Manifestations of phase-coherent transport in graphene : The Josephson effect, weak localization, and aperiodic conductance fluctuations

    NARCIS (Netherlands)

    Heersche, H.B.; Jarillo-Herrero, P.; Oostinga, J.B.; Vandersypen, L.M.K.; Morpurgoa, A.F.

    2007-01-01

    The electronic transport properties of graphene exhibit pronounced differences from those of conventional two dimensional electron systems investigated in the past. As a consequence, well established phenomena such as the integer quantum Hall effect and weak localization manifest themselves

  12. On weakly D-differentiable operators

    DEFF Research Database (Denmark)

    Christensen, Erik

    2016-01-01

    Let DD be a self-adjoint operator on a Hilbert space HH and aa a bounded operator on HH. We say that aa is weakly DD-differentiable, if for any pair of vectors ξ,ηξ,η from HH the function 〈eitDae−itDξ,η〉〈eitDae−itDξ,η〉 is differentiable. We give an elementary example of a bounded operator aa...

  13. On weak compactness in L_1 spaces

    Czech Academy of Sciences Publication Activity Database

    Fabian, Marián; Montesinos, V.; Zizler, Václav

    2009-01-01

    Roč. 39, č. 6 (2009), s. 1885-1893 ISSN 0035-7596 R&D Projects: GA AV ČR(CZ) IAA100190610; GA AV ČR IAA100190502; GA AV ČR IAA1019103 Institutional research plan: CEZ:AV0Z10190503 Keywords : weak compactness * subspace of L_1 * superreflexive space Subject RIV: BA - General Mathematics Impact factor: 0.260, year: 2009

  14. Summary of the Hadronic Weak Interaction session

    Science.gov (United States)

    Bock, G.; Bryman, D. A.; Numao, T.

    1993-07-01

    We summarize and discuss present and future experiments on decays of light mesons and muons that were presented in the Hadronic Weak Interaction working group session of the Workshop on Future Directions in Particle and Nuclear Physics at Multi-GeV Hadron Facilities. Precise measurements and rare-decay searches, which sense mass scales in the 1-1000 TeV region, are discussed in the context of the standard model and beyond.

  15. Summary of the Hadronic Weak Interaction session

    Energy Technology Data Exchange (ETDEWEB)

    Bock, G. [Fermi National Accelerator Lab., Batavia, IL (United States); Bryman, D.A.; Numao, T. [British Columbia Univ., Vancouver, BC (Canada). TRIUMF Facility

    1993-07-01

    We summarize and discuss present and future experiments on decays of light mesons and muons that were presented in the Hadronic Weak Interaction working group session of the ``Workshop on Future Directions in Particle and Nuclear Physics at Multi-GeV Hadron Facilities.`` Precise measurements and rare-decay searches, which sense mass scales in the 1--1000 TeV region, are discussed in the context of the standard model and beyond.

  16. Diffusion in a weakly random Hamiltonian flow

    OpenAIRE

    Komorowski, T.; Ryzhik, L.

    2005-01-01

    We consider the motion of a particle governed by a weakly random Hamiltonian flow. We identify temporal and spatial scales on which the particle trajectory converges to a spatial Brownian motion. The main technical issue in the proof is to obtain error estimates for the convergence of the solution of the stochastic acceleration problem to a momentum diffusion. We also apply our results to the system of random geometric acoustics equations and show that the energy density of the acoustic waves...

  17. Francium Spectroscopy for Weak Interaction Studies

    Science.gov (United States)

    Orozco, Luis

    2014-05-01

    Francium, a radioactive element, is the heaviest alkali. Its atomic and nuclear structure makes it an ideal laboratory to study the weak interaction. Laser trapping and cooling in-line with the superconducting LINAC accelerator at Stony Brook opened the precision study of its atomic structure. I will present our proposal and progress towards weak interaction measurements at TRIUMF, the National Canadian Accelerator in Vancouver. These include the commissioning run of the Francium Trapping Facility, hyperfine anomaly measurements on a chain of Fr isotopes, the nuclear anapole moment through parity non-conserving transitions in the ground state hyperfine manifold. These measurements should shed light on the nucleon-nucleon weak interaction. This work is done by the FrPNC collaboration: S. Aubin College of William and Mary, J. A. Behr TRIUMF, R. Collister U. Manitoba, E. Gomez UASLP, G. Gwinner U. Manitoba, M. R. Pearson TRIUMF, L. A. Orozco UMD, M. Tandecki TRIUMF, J. Zhang UMD Supported by NSF and DOE from the USA; TRIUMF, NRC and NSERC from Canada; and CONACYT from Mexico

  18. Mechanisms Undlerlying Quadriceps Weakness in Knee Osteoarthritis

    Science.gov (United States)

    PETTERSON, STEPHANIE C.; BARRANCE, PETER; BUCHANAN, THOMAS; BINDER-MACLEOD, STUART; SNYDER-MACKLER, LYNN

    2013-01-01

    Purpose To identify determinants of quadriceps weakness among persons with end-stage knee osteoarthritis (OA). Methods One-hundred twenty-three individuals (mean age 64.9 ± 8.5 yr) with Kellgren/Lawrence grade IV knee OA participated. Quadriceps strength (MVIC) and volitional muscle activation (CAR) were measured using a burst superimposition test. Muscle composition (lean muscle cross-sectional area (LMCSA) and fat CSA (FCSA)) were quantified using magnetic resonance imaging. Specific strength (MVIC/LMCSA) was computed. Interlimb differences were analyzed using paired-sample t-tests. Regression analysis was applied to identify determinants of MVIC. An alpha level of 0.05 was adopted. Results The OA limb was significantly weaker, had lower CAR, and had smaller LMCSA than the contralateral limb. CAR explained 17% of the variance in the contralateral limb's MVIC compared with 40% in the OA limb. LMCSA explained 41% of the variance in the contralateral limb's MVIC compared with 27% in the OA limb. Conclusion Both reduced CAR and LMCSA contribute to muscle weakness in persons with knee OA. Similar to healthy elders, the best predictor of strength in the contralateral, nondiseased limb was largely determined by LMCSA, whereas CAR was found to be the primary determinant of strength in the OA limb. Deficits in CAR may undermine the effectiveness of volitional strengthening programs in targeting quadriceps weakness in the OA population. PMID:18379202

  19. Mechanisms underlying quadriceps weakness in knee osteoarthritis.

    Science.gov (United States)

    Petterson, Stephanie C; Barrance, Peter; Buchanan, Thomas; Binder-Macleod, Stuart; Snyder-Mackler, Lynn

    2008-03-01

    To identify determinants of quadriceps weakness among persons with end-stage knee osteoarthritis (OA). One-hundred twenty-three individuals (mean age 64.9 +/- 8.5 yr) with Kellgren/Lawrence grade IV knee OA participated. Quadriceps strength (MVIC) and volitional muscle activation (CAR) were measured using a burst superimposition test. Muscle composition (lean muscle cross-sectional area (LMCSA) and fat CSA (FCSA)) were quantified using magnetic resonance imaging. Specific strength (MVIC/LMCSA) was computed. Interlimb differences were analyzed using paired-sample t-tests. Regression analysis was applied to identify determinants of MVIC. An alpha level of 0.05 was adopted. The OA limb was significantly weaker, had lower CAR, and had smaller LMCSA than the contralateral limb. CAR explained 17% of the variance in the contralateral limb's MVIC compared with 40% in the OA limb. LMCSA explained 41% of the variance in the contralateral limb's MVIC compared with 27% in the OA limb. Both reduced CAR and LMCSA contribute to muscle weakness in persons with knee OA. Similar to healthy elders, the best predictor of strength in the contralateral, nondiseased limb was largely determined by LMCSA, whereas CAR was found to be the primary determinant of strength in the OA limb. Deficits in CAR may undermine the effectiveness of volitional strengthening programs in targeting quadriceps weakness in the OA population.

  20. Systematic review: role of acid, weakly acidic and weakly alkaline reflux in gastroesophageal reflux disease

    OpenAIRE

    Boeckxstaens, Guy E; Smout, Smout J

    2010-01-01

    Abstract Background The importance of weakly acidic and weakly alkaline reflux in gastroesophageal reflux disease (GERD) is gaining recognition. Aim To quantify the proportions of reflux episodes that are acidic (pH 7) in adult patients with GERD, and to evaluate their correlation with symptoms. Methods Studies were identified by systematic PubMed and Embase searches. Data are presented as sample-size weighted ...

  1. Systematic review: role of acid, weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease

    NARCIS (Netherlands)

    Boeckxstaens, G. E.; Smout, A.

    2010-01-01

    The importance of weakly acidic and weakly alkaline reflux in gastro-oesophageal reflux disease (GERD) is gaining recognition. To quantify the proportions of reflux episodes that are acidic (pH <4), weakly acidic (pH 4-7) and weakly alkaline (pH >7) in adult patients with GERD, and to evaluate their

  2. The magnetosphere under weak solar wind forcing

    Directory of Open Access Journals (Sweden)

    C. J. Farrugia

    2007-02-01

    Full Text Available The Earth's magnetosphere was very strongly disturbed during the passage of the strong shock and the following interacting ejecta on 21–25 October 2001. These disturbances included two intense storms (Dst*≈−250 and −180 nT, respectively. The cessation of this activity at the start of 24 October ushered in a peculiar state of the magnetosphere which lasted for about 28 h and which we discuss in this paper. The interplanetary field was dominated by the sunward component [B=(4.29±0.77, −0.30±0.71, 0.49±0.45 nT]. We analyze global indicators of geomagnetic disturbances, polar cap precipitation, ground magnetometer records, and ionospheric convection as obtained from SuperDARN radars. The state of the magnetosphere is characterized by the following features: (i generally weak and patchy (in time low-latitude dayside reconnection or reconnection poleward of the cusps; (ii absence of substorms; (iii a monotonic recovery from the previous storm activity (Dst corrected for magnetopause currents decreasing from ~−65 to ~−35 nT, giving an unforced decreased of ~1.1 nT/h; (iv the probable absence of viscous-type interaction originating from the Kelvin-Helmholtz (KH instability; (v a cross-polar cap potential of just 20–30 kV; (vi a persistent, polar cap region containing (vii very weak, and sometimes absent, electron precipitation and no systematic inter-hemisphere asymmetry. Whereas we therefore infer the presence of a moderate amount of open flux, the convection is generally weak and patchy, which we ascribe to the lack of solar wind driver. This magnetospheric state approaches that predicted by Cowley and Lockwood (1992 but has never yet been observed.

  3. The magnetosphere under weak solar wind forcing

    Directory of Open Access Journals (Sweden)

    C. J. Farrugia

    2007-02-01

    Full Text Available The Earth's magnetosphere was very strongly disturbed during the passage of the strong shock and the following interacting ejecta on 21–25 October 2001. These disturbances included two intense storms (Dst*≈−250 and −180 nT, respectively. The cessation of this activity at the start of 24 October ushered in a peculiar state of the magnetosphere which lasted for about 28 h and which we discuss in this paper. The interplanetary field was dominated by the sunward component [B=(4.29±0.77, −0.30±0.71, 0.49±0.45 nT]. We analyze global indicators of geomagnetic disturbances, polar cap precipitation, ground magnetometer records, and ionospheric convection as obtained from SuperDARN radars. The state of the magnetosphere is characterized by the following features: (i generally weak and patchy (in time low-latitude dayside reconnection or reconnection poleward of the cusps; (ii absence of substorms; (iii a monotonic recovery from the previous storm activity (Dst corrected for magnetopause currents decreasing from ~−65 to ~−35 nT, giving an unforced decreased of ~1.1 nT/h; (iv the probable absence of viscous-type interaction originating from the Kelvin-Helmholtz (KH instability; (v a cross-polar cap potential of just 20–30 kV; (vi a persistent, polar cap region containing (vii very weak, and sometimes absent, electron precipitation and no systematic inter-hemisphere asymmetry. Whereas we therefore infer the presence of a moderate amount of open flux, the convection is generally weak and patchy, which we ascribe to the lack of solar wind driver. This magnetospheric state approaches that predicted by Cowley and Lockwood (1992 but has never yet been observed.

  4. Supersymmetric Higgs bosons in weak boson fusion.

    Science.gov (United States)

    Hollik, Wolfgang; Plehn, Tilman; Rauch, Michael; Rzehak, Heidi

    2009-03-06

    We compute the complete supersymmetric next-to-leading-order corrections to the production of a light Higgs boson in weak-boson fusion. The size of the electroweak corrections is of similar order as the next-to-leading-order corrections in the standard model. The supersymmetric QCD corrections turn out to be significantly smaller than expected and than their electroweak counterparts. These corrections are an important ingredient to a precision analysis of the (supersymmetric) Higgs sector at the LHC, either as a known correction factor or as a contribution to the theory error.

  5. Are the Weak Measurements Really Measurements?

    Directory of Open Access Journals (Sweden)

    Dmitri Sokolovski

    2013-05-01

    Full Text Available Weak measurements can be seen as an attempt at answering the Which way? question without destroying interference between the pathways involved. Unusual mean values obtained in such measurements represent the response of a quantum system to this forbidden question, in which the true composition of virtual pathways is hidden from the observer. Such values indicate a failure of a measurement where the uncertainty principle says it must fail, rather than provide an additional insight into physical reality. Quanta 2013; 2: 50–57.

  6. Legitimacy Building under Weak Institutional Settings

    DEFF Research Database (Denmark)

    Wejs, Anja; Harvold, Kjell; Larsen, Sanne Vammen

    2014-01-01

    Local strategies for adaptation to climate change in Denmark and Norway are discussed. In both countries, the national impetus for local adaptation is weak; it is largely left to local actors to take the initiative. The dynamics of the different approaches to climate-change adaptation at the local...... level are illuminated. Using decision-making and learning theory, we present an analytical framework to examine four cases, two in Norway and two in Denmark, which represent two different responses, i.e. anticipatory actions and obligatory actions. We find that, by bringing in knowledge and resources...

  7. Superconductor in a weak static gravitational field

    Energy Technology Data Exchange (ETDEWEB)

    Ummarino, Giovanni Alberto [Dipartimento DISAT, Politecnico di Torino, Turin (Italy); National Research Nuclear University MEPhI-Moscow Engineering Physics Institute, Moscow (Russian Federation); Gallerati, Antonio [Dipartimento DISAT, Politecnico di Torino, Turin (Italy)

    2017-08-15

    We provide the detailed calculation of a general form for Maxwell and London equations that takes into account gravitational corrections in linear approximation. We determine the possible alteration of a static gravitational field in a superconductor making use of the time-dependent Ginzburg-Landau equations, providing also an analytic solution in the weak field condition. Finally, we compare the behavior of a high-T{sub c} superconductor with a classical low-T{sub c} superconductor, analyzing the values of the parameters that can enhance the reduction of the gravitational field. (orig.)

  8. Infrared spectroscopy of weakly bound molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Lisa I-Ching

    1988-11-01

    The infrared spectra of a series of hydrated hydronium cluster ions and of protonated ethane ion are presented. A tandem mass spectrometer is ideally suited to obtaining the spectra of such weakly bound molecular ions. Traditional absorption spectroscopy is not feasible in these situations, so the techniques described in this thesis make use of some consequence of photon absorption with higher sensitivity than simply attenuation of laser power. That consequence is dissociation. By first mass selecting the parent ion under study and then mass selecting the fragment ion formed from dissociation, the near unit detection efficiency of ion counting methods has been used to full advantage.

  9. Weak η production off the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M. Rafi; Athar, M. Sajjad [Department of Physics, Aligarh Muslim University, Aligarh-202 002 (India); Alvarez-Ruso, L.; Vacas, M. J. Vicente [Departamento de Física Teórica and Instituto de Física Corpuscular, Centro Mixto Universidad de Valencia-CSIC, E-46071 Valencia (Spain)

    2015-05-15

    The weak η-meson production off the nucleon induced by (anti)neutrinos is studied at low and intermediate energies, the range of interest for several ongoing and future neutrino experiments. We consider Born diagrams and the excitation of N{sup *} (1535)S{sub 11} and N{sup *} (1650)S{sub 11} resonances. The vector part of the N-S{sub 11} transition form factors has been obtained from the MAID helicity amplitudes while the poorly known axial part is constrained with the help of the partial conservation of the axial current (PCAC) and assuming the pion-pole dominance of the pseudoscalar form factor.

  10. Didactic discussion of stochastic resonance effects and weak signals.

    Science.gov (United States)

    Adair, R K

    1996-01-01

    A simple, paradigmatic, model is used to illustrate some general properties of effects subsumed under the label "stochastic resonance." In particular, analyses of the transparent model show that 1) a small amount of noise added to a much larger signal can greatly increase the response to the signal, but 2) a weak signal added to much larger noise will not generate a substantial added response. The conclusions drawn from the model illustrate the general result that stochastic resonance effects do not provide an avenue for signals that are much smaller than noise to affect biology. A further analysis demonstrates the effects of small signals in the shifting of biologically important chemical equilibria under conditions where stochastic resonance effects are significant.

  11. Structure and weak hydrogen bonds in liquid acetaldehyde

    Directory of Open Access Journals (Sweden)

    Cordeiro Maria A. M.

    2004-01-01

    Full Text Available Monte Carlo simulations have been performed to investigate the structure and hydrogen bonds formation in liquid acetaldehyde. An all atom model for the acetaldehyde have been optimized in the present work. Theoretical values obtained for heat of vaporisation and density of the liquid are in good agreement with experimental data. Graphics of radial distribution function indicate a well structured liquid compared to other similar dipolar organic liquids. Molecular mechanics minimization in gas phase leads to a trimer of very stable structure. The geometry of this complex is in very good agreement with the rdf. The shortest site-site correlation is between oxygen and the carbonyl hydrogen, suggesting that this correlation play a important role in the liquid structure and properties. The OxxxH average distance and the C-HxxxO angle obtained are characteristic of weak hydrogen bonds.

  12. Supercurrent multiplet correlators at weak and strong coupling

    Energy Technology Data Exchange (ETDEWEB)

    Argurio, Riccardo [Physique Théorique et Mathématique Université Libre de Bruxelles, C.P. 231, 1050 Bruxelles (Belgium); International Solvay Institutes,Brussels (Belgium); Bertolini, Matteo [SISSA and INFN - Sezione di Trieste,Via Bonomea 265, I 34136 Trieste (Italy); International Centre for Theoretical Physics (ICTP),Strada Costiera 11, I 34014 Trieste (Italy); Pietro, Lorenzo Di [SISSA and INFN - Sezione di Trieste,Via Bonomea 265, I 34136 Trieste (Italy); Weizmann Institute of Science,Rehovot 76100 (Israel); Porri, Flavio [SISSA and INFN - Sezione di Trieste,Via Bonomea 265, I 34136 Trieste (Italy); Redigolo, Diego [Physique Théorique et Mathématique Université Libre de Bruxelles, C.P. 231, 1050 Bruxelles (Belgium); International Solvay Institutes,Brussels (Belgium)

    2014-04-22

    Correlators of gauge invariant operators provide useful information on the dynamics, phases and spectra of a quantum field theory. In this paper, we consider four dimensional N=1 supersymmetric theories and focus our attention on the supercurrent multiplet. We give a complete characterization of two-point functions of operators belonging to such multiplet, like the energy-momentum tensor and the supercurrent, and study the relations between them. We discuss instances of weakly coupled and strongly coupled theories, in which different symmetries, like conformal invariance and supersymmetry, may be conserved and/or spontaneously or explicitly broken. For theories at strong coupling, we exploit AdS/CFT techniques. We provide a holographic description of different properties of a strongly coupled theory, including a realization of the Goldstino mode in a simple illustrative model.

  13. Recovering information of tunneling spectrum from weakly isolated horizon

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ge-Rui; Huang, Yong-Chang [Beijing University of Technology, Institute of Theoretical Physics, Beijing (China)

    2015-02-01

    In this paper we investigate the properties of tunneling spectrum from weakly isolated horizon (WIH) - a locally defined black hole. We find that there exist correlations among Hawking radiations from a WIH, information can be carried out by such correlations, and the radiation is an entropy conservation process. Through revisiting the calculation of the tunneling spectrum from a WIH, we find that Zhang et al.'s (Ann Phys 326:350, 2011) requirement that radiated particles have the same angular momenta of a unit mass as that of the black hole is unnecessary, and the energy and angular momenta of the emitted particles are very arbitrary, restricted only by keeping the cosmic censorship hypothesis of black holes. So we resolve the information loss paradox based on the method of Zhang et al. (Phys Lett B 675:98, 2009; Ann Phys 326:350, 2011; Int J Mod Phys D 22:1341014, 2013) in a general case. (orig.)

  14. Optimal Weak-Lensing Skewness Measurements

    Science.gov (United States)

    Zhang, Tong-Jie; Pen, Ue-Li; Zhang, Pengjie; Dubinski, John

    2003-12-01

    Weak-lensing measurements are starting to provide statistical maps of the distribution of matter in the universe that are increasingly precise and complementary to cosmic microwave background maps. The most common measurement is the correlation in alignments of background galaxies, which can be used to infer the variance of the projected surface density of matter. This measurement of the fluctuations is insensitive to the total mass content and is analogous to using waves on the ocean to measure its depths. However, when the depth is shallow, as happens near a beach, waves become skewed. Similarly, a measurement of skewness in the projected matter distribution directly measures the total matter content of the universe. While skewness has already been convincingly detected, its constraint on cosmology is still weak. We address optimal analyses for the Canada-France-Hawaii Telescope Legacy Survey in the presence of noise. We show that a compensated Gaussian filter with a width of 2.5‧ optimizes the cosmological constraint, yielding ΔΩm/Ωm~10%. This is significantly better than other filters that have been considered in the literature. This can be further improved with tomography and other sophisticated analyses.

  15. Synchronizability of nonidentical weakly dissipative systems

    Science.gov (United States)

    Sendiña-Nadal, Irene; Letellier, Christophe

    2017-10-01

    Synchronization is a very generic process commonly observed in a large variety of dynamical systems which, however, has been rarely addressed in systems with low dissipation. Using the Rössler, the Lorenz 84, and the Sprott A systems as paradigmatic examples of strongly, weakly, and non-dissipative chaotic systems, respectively, we show that a parameter or frequency mismatch between two coupled such systems does not affect the synchronizability and the underlying structure of the joint attractor in the same way. By computing the Shannon entropy associated with the corresponding recurrence plots, we were able to characterize how two coupled nonidentical chaotic oscillators organize their dynamics in different dissipation regimes. While for strongly dissipative systems, the resulting dynamics exhibits a Shannon entropy value compatible with the one having an average parameter mismatch, for weak dissipation synchronization dynamics corresponds to a more complex behavior with higher values of the Shannon entropy. In comparison, conservative dynamics leads to a less rich picture, providing either similar chaotic dynamics or oversimplified periodic ones.

  16. Do weak global stresses synchronize earthquakes?

    Science.gov (United States)

    Bendick, R.; Bilham, R.

    2017-08-01

    Insofar as slip in an earthquake is related to the strain accumulated near a fault since a previous earthquake, and this process repeats many times, the earthquake cycle approximates an autonomous oscillator. Its asymmetric slow accumulation of strain and rapid release is quite unlike the harmonic motion of a pendulum and need not be time predictable, but still resembles a class of repeating systems known as integrate-and-fire oscillators, whose behavior has been shown to demonstrate a remarkable ability to synchronize to either external or self-organized forcing. Given sufficient time and even very weak physical coupling, the phases of sets of such oscillators, with similar though not necessarily identical period, approach each other. Topological and time series analyses presented here demonstrate that earthquakes worldwide show evidence of such synchronization. Though numerous studies demonstrate that the composite temporal distribution of major earthquakes in the instrumental record is indistinguishable from random, the additional consideration of event renewal interval serves to identify earthquake groupings suggestive of synchronization that are absent in synthetic catalogs. We envisage the weak forces responsible for clustering originate from lithospheric strain induced by seismicity itself, by finite strains over teleseismic distances, or by other sources of lithospheric loading such as Earth's variable rotation. For example, quasi-periodic maxima in rotational deceleration are accompanied by increased global seismicity at multidecadal intervals.

  17. Weak dispersive forces between glass and gold macroscopic surfaces in alcohols

    NARCIS (Netherlands)

    van Zwol, P. J.; Palasantzas, G.; DeHosson, J. Th. M.

    In this work we concentrate on an experimental validation of the Lifshitz theory for the van der Waals and the Casimir forces in gold-alcohol-glass systems. From this theory weak dispersive forces are predicted when the dielectric properties of the intervening medium become comparable to one of the

  18. Search for a new weakly interacting particle

    Science.gov (United States)

    Decamp, D.; Deschizeaux, B.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Alemany, R.; Crespo, J. M.; Delfino, M.; Fernandez, E.; Gaitan, V.; Garrido, Ll.; Mato, P.; Ll. M., Mir; Pacheco, A.; Catanesi, M. G.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Maggi, M.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Gao, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Lou, J.; Qiao, C.; Ruan, T.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhao, W.; Atwood, W. B.; Bird, F.; Blucher, E.; Bonvicini, G.; Bossi, F.; Brown, D.; Burnett, T. H.; Drevermann, H.; Dydak, F.; Forty, R. W.; Grab, C.; Hagelberg, R.; Haywood, S.; Hilgart, J.; Jost, B.; Kasemann, M.; Knobloch, J.; Lacourt, A.; Lançon, E.; Lehraus, I.; Lohse, T.; Marchioro, A.; Martinez, M.; Menary, S.; Minten, A.; Miotto, A.; Miguel, R.; Moser, H.-G.; Nash, J.; Palazzi, P.; Ranjard, F.; Redlinger, G.; Roth, A.; Rothberg, J.; Rotscheidt, H.; St. Denis, R.; Schlatter, D.; Takashima, M.; Talby, M.; Tejessy, W.; Wachsmuth, H.; Wasserbaech, S.; Wheeler, S.; Wiedenmann, W.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Bardadin-Otwinowska, M.; Falvard, A.; El Fellous, R.; Gay, P.; Harvey, J.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Proriol, J.; Prulhière, F.; Stimpfl, G.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nielsen, E. R.; Nilsson, B. S.; Efthymiopoulos, I.; Simopoulou, E.; Vayaki, A.; Badier, J.; Blondel, A.; Bonneaud, G.; Bourotte, J.; Braems, F.; Brient, J. C.; Fouque, G.; Gamess, A.; Guirlet, R.; Orteu, S.; Rosowsky, A.; Rougé, A.; Rumpf, M.; Tanaka, R.; Videau, H.; Candlin, D. J.; Veitch, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Mermikides, M.; Sawyer, L.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Campana, P.; Capon, G.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Nicoletti, G.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Zografou, P.; Altoon, B.; Boyle, O.; Halley, A. W.; Ten Have, I.; Hearns, J. L.; Lynch, J. G.; Morton, W. T.; Raine, C.; Scarr, J. M.; Smith, K.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geiges, R.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Belk, A. T.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Dornan, P. J.; Dugeay, S.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Patton, S. J.; Payne, D. G.; Phillips, M. J.; Sedgbeer, J. K.; Taylor, G.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Keemer, N. R.; Nuttall, M.; Patel, A.; Rowlingson, B. S.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Barczewski, T.; Bauerdick, L. A. T.; Kleinknecht, K.; Renk, B.; Roehn, S.; Sander, H.-G.; Schmelling, M.; Schmidt, H.; Steeg, F.; Albanese, J.-P.; Aubert, J.-J.; Benchouk, C.; Bernard, V.; Bonissent, A.; Courvoisier, D.; Etienne, F.; Papalexiou, S.; Payre, P.; Pietrzyk, B.; Qian, Z.; Becker, H.; Blum, W.; Cattaneo, P.; Cowan, G.; Dehning, B.; Dietl, H.; Fernandez-Bosman, M.; Hansl-Kozanecka, T.; Jahn, A.; Kozanecki, W.; Lange, E.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Pan, Y.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Stierlin, U.; Thomas, J.; Wolf, G.; Bertin, V.; Boucrot, J.; Callot, O.; Chen, X.; Cordier, A.; Davier, M.; Ganis, G.; Grivaz, J.-F.; Heusse, Ph.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Zomer, F.; Amendolia, S. R.; Bagliesi, G.; Batignani, G.; Bosisio, L.; Bottigli, U.; Bradaschia, C.; Carpinelli, M.; Ciocci, M. A.; dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Focardi, E.; Forti, F.; Giassi, A.; Giorgi, M. A.; Ligabue, F.; Lusiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Moneta, L.; Palla, F.; Sanguinetti, G.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Carter, J. M.; Green, M. G.; March, P. V.; Medcalf, T.; Quazi, I. S.; Saich, M. R.; Strong, J. A.; Thomas, R. M.; West, L. R.; Wildish, T.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Edwards, M.; Fisher, S. M.; Jones, T. J.; Norton, P. R.; Salmon, D. P.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Klopfenstein, C.; Locci, E.; Loucatos, S.; Monnier, E.; Perez, P.; Perlas, J. A.; Perrier, F.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Vallage, B.; Ashman, J. G.; Booth, C. N.; Buttar, C.; Carney, R.; Cartwright, S.; Combley, F.; Dinsdale, M.; Dogru, M.; Hatfield, F.; Martin, J.; Parker, D.; Reeves, P.; Thompson, L. F.; Brandt, S.; Burkhardt, H.; Grupen, C.; Meinhard, H.; Mirabito, L.; Neugebauer, E.; Schäfer, U.; Seywerd, H.; Apollinari, G.; Giannini, G.; Gobbo, B.; Liello, F.; Ragusa, F.; Rolandi, L.; Stiegler, U.; Bellantoni, L.; Boudreau, J. F.; Cinabro, D.; Conway, J. S.; Cowen, D. F.; Deweerd, A. J.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Jacobsen, J. E.; Jared, R. C.; Johnson, R. P.; Leclaire, B. W.; Pan, Y. B.; Pater, J. R.; Saadi, Y.; Sharma, V.; Walsh, A. M.; Wear, J. A.; Weber, F. V.; Whitney, M. H.; Sau, Lan, Wu; Zhou, Z. L.; Zobernig, G.

    1991-06-01

    A search for events of the type e+e--->l+l-X0, where X0 can be any weakly interacting particle which couples to the Z, has been performed with the ALEPH detector at LEP, by searching for acollinear lepton pairs. Such particles can be excluded up to a mass of 7.0 GeV/c2 for a value of the ratio of branching fractions, Br(Z-->X0l+l-)/Br(Z-->l+l-), greater than 2.5 × 10-3 if the X0 has third component of isospin, I3 greater than 1/2 and decays to a pair of virtual gauge bosons. When this analysis is combined with the previous results of the Higgs particle searches from ALEPH, this limit can be extended to an X0 mass of 60 GeV/c2.

  19. Simulating Error in Cluster Weak Lensing Tomography

    Science.gov (United States)

    Murphy, Kellen J.

    2012-01-01

    We present the results of an N-body simulation of the various sources of systematic error in constraining the dark energy equation of state via cluster weak lensing tomography. The use of tomographic techniques to constrain the dark energy equation of state parameter is a pivotal component of future large survey missions, however, the application of tomography to cosmic shear necessitates the exclusion of regions around galaxy clusters from analysis. We therefore test the applicability tomography to cluster-induced shear as a secondary, complementary sample through which estimates of the dark energy e.o.s. parameter can be made. Furthermore, we demonstrate the application of this technique to a test sample of 10 massive galaxy clusters imaged by the Hubble Space Telescope.

  20. Casimir apparatuses in a weak gravitational field

    DEFF Research Database (Denmark)

    Bimonte, Giuseppe; Calloni, Enrico; Esposito, Giampiero

    2009-01-01

    We review and assess a part of the recent work on Casimir apparatuses in the weak gravitational field of the Earth. For a free, real massless scalar field subject to Dirichlet or Neumann boundary conditions on the parallel plates, the resulting regularized and renormalized energy-momentum tensor...... is covariantly conserved, while the trace anomaly vanishes if the massless field is conformally coupled to gravity. Conformal coupling also ensures a finite Casimir energy and finite values of the pressure upon parallel plates. These results have been extended to an electromagnetic field subject to perfect...... conductor (hence idealized) boundary conditions on parallel plates, by various authors. The regularized and renormalized energy-momentum tensor has beene valuated up to second order in the gravity acceleration. In both the scalar and the electromagnetic case, studied to first order in the gravity...

  1. A Soberania Fraca / The Weak Sovereignty

    Directory of Open Access Journals (Sweden)

    Maíra Matthes

    2012-12-01

    Full Text Available Resumo Em Vadios: Dois Ensaios sobre a Razão, Derrida propõe que se entenda o conceito de soberania a partir de duas noções principais: incondicionalidade e indivisibilidade. O objetivo desse artigo é mostrar que o autor aborda esses dois pontos com o intuito de criar uma compreensão da soberania como uma força fraca e divisível no tempo. Palavras Chaves: Soberania, Jacques Derrida, Filosofia Francesa, Voyous, Política. Abstract In Rogues: Two Essays on Reason, Derrida argues that sovereignty is comprised of two main features: the unconditional and the indivisible. The aim of this article is to show that the author approaches these aspects in order to make a point about the concept of sovereignty. This point is precisely to think sovereignty as a weak force and as something divisible in time. Key Words: Sovereignty, Jacques Derrida, French Philosophy, Rogues, Politics.

  2. Magnified Weak Lensing Cross Correlation Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, Melville P., Clowe, Douglas I.

    2010-11-30

    This project carried out a weak lensing tomography (WLT) measurement around rich clusters of galaxies. This project used ground based photometric redshift data combined with HST archived cluster images that provide the WLT and cluster mass modeling. The technique has already produced interesting results (Guennou et al, 2010,Astronomy & Astrophysics Vol 523, page 21, and Clowe et al, 2011 to be submitted). Guennou et al have validated that the necessary accuracy can be achieved with photometric redshifts for our purposes. Clowe et al titled "The DAFT/FADA survey. II. Tomographic weak lensing signal from 10 high redshift clusters," have shown that for the **first time** via this purely geometrical technique, which does not assume a standard rod or candle, that a cosmological constant is **required** for flat cosmologies. The intent of this project is not to produce the best constraint on the value of the dark energy equation of state, w. Rather, this project is to carry out a sustained effort of weak lensing tomography that will naturally feed into the near term Dark Energy Survey (DES) and to provide invaluable mass calibration for that project. These results will greatly advance a key cosmological method which will be applied to the top-rated ground-based project in the Astro2020 decadal survey, LSST. Weak lensing tomography is one of the key science drivers behind LSST. CO-I Clowe is on the weak lensing LSST committee, and senior scientist on this project, at FNAL James Annis, plays a leading role in the DES. This project has built on successful proposals to obtain ground-based imaging for the cluster sample. By 1 Jan, it is anticipated the project will have accumulated complete 5-color photometry on 30 (or about 1/3) of the targeted cluster sample (public webpage for the survey is available at http://cencos.oamp.fr/DAFT/ and has a current summary of the observational status of various clusters). In all, the project has now been awarded the equivalent of over 60

  3. Crossover between weak antilocalization and weak localization of bulk states in ultrathin Bi₂Se₃ films.

    Science.gov (United States)

    Wang, Huichao; Liu, Haiwen; Chang, Cui-Zu; Zuo, Huakun; Zhao, Yanfei; Sun, Yi; Xia, Zhengcai; He, Ke; Ma, Xucun; Xie, X C; Xue, Qi-Kun; Wang, Jian

    2014-07-24

    We report transport studies on the 5 nm thick Bi₂Se₃ topological insulator films which are grown via molecular beam epitaxy technique. The angle-resolved photoemission spectroscopy data show that the Fermi level of the system lies in the bulk conduction band above the Dirac point, suggesting important contribution of bulk states to the transport results. In particular, the crossover from weak antilocalization to weak localization in the bulk states is observed in the parallel magnetic field measurements up to 50 Tesla. The measured magneto-resistance exhibits interesting anisotropy with respect to the orientation of parallel magnetic field B// and the current I, signifying intrinsic spin-orbit coupling in the Bi₂Se₃ films. Our work directly shows the crossover of quantum interference effect in the bulk states from weak antilocalization to weak localization. It presents an important step toward a better understanding of the existing three-dimensional topological insulators and the potential applications of nano-scale topological insulator devices.

  4. Approximation Properties for Groups and von Neumann Algebras

    DEFF Research Database (Denmark)

    Knudby, Søren

    The main topic of the thesis is approximation properties for locally compact groups with applications to operator algebras. In order to study the relationship between weak amenability and the Haagerup property, the weak Haagerup property and the weak Haagerup constant are introduced. The weak......, the weak Haagerup constants of all connected simple Lie groups are determined. In order to determine the weak Haagerup constants of the rank one simple Lie groups, knowledge about the Fourier algebras of their minimal parabolic subgroups is needed. We prove that for these minimal parabolic subgroups...

  5. Critical types of Krasnoselskii fixed point theorems in weak topologies

    African Journals Online (AJOL)

    In this note, by means of the technique of measures of weak noncompactness, we establish a generalized form of fixed point theorem for the sum of T + S in weak topology setups of a metrizable locally convex space, where S is not weakly compact, I − T allows to be noninvertible, and T is not necessarily continuous.

  6. The influence of weak impacts on certain processes of nanotechnology

    Science.gov (United States)

    Tupik, V. A.; Margolin, V. I.; Potekhin, M. S.

    2017-07-01

    The article deals with the influence of weak and super weak impacts on certain technological processes in nanotechnology related to the synthesis of nanoscale films and coatings. We also touch upon the impacts of weak diffraction fields of complex shape on the formation of fractal films and coatings.

  7. Common fixed point theorems for weakly compatible mappings in fuzzy metric spaces

    Directory of Open Access Journals (Sweden)

    Sunny Chauhan

    2013-05-01

    Full Text Available The aim of this paper is to prove a common fixed point theorem for a pair of weakly compatible mappings in fuzzy metric space by using the (CLRg property. An example is also furnished which demonstrates the validity of our main result. As an application to our main result, we present a fixed point theorem for two finite families of self mappings in fuzzy metric space by using the notion of pairwise commuting. Our results improve the results of Sedghi, Shobe and Aliouche [A common fixed point theorem for weakly compatible mappings in fuzzy metric spaces, Gen. Math. 18(3 (2010, 3-12 MR2735558].

  8. Radiography of weakly ferromagnetic metals with polarized neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael; Calzada, Elbio; Muehlbauer, Martin; Schillinger, Burkhard [FRM II, Garching (Germany); E21, Physik Department TUM, Garching (Germany); Boeni, Peter; Neubauer, Andreas; Pfleiderer, Christian [E21, Physik Department TUM, Garching (Germany)

    2009-07-01

    The depolarization of a neutron beam passing through a ferromagnet crucially depends on the magnetic properties of the sample. Combining neutron depolarisation measurements with neutron radiography allows obtaining spatially resolved information about these properties. For measuring the depolarization, we have installed a longitudinal polarized beam setup at the ANTARES beamline consisting of {sup 3}He polarizers and flat coil spin flippers. With this setup we have performed radiography with polarized neutrons in the weak itinerant ferromagnets Pd{sub 1-x}Ni{sub x} in order to determine the spatial distribution of the Curie temperatures T{sub C} in the samples. The results show that the single crystals are rather inhomogeneous showing large variations in T{sub C}. The data allows firstly to cut out small crystals with improved homogeneity for neutron scattering experiments and secondly to provide feedback for improving the growth techniques for the crystals. In the future we hope to use the potential of this method to map out magnetic domains across large volume samples.

  9. Hunting for Intrinsically X-ray Weak Quasars: The Case of PHL 1811 Analogs

    Science.gov (United States)

    Brandt, William

    2009-09-01

    A central dogma of X-ray astronomy is that luminous X-ray emission is a universal property of efficiently accreting supermassive black holes. One interesting challenge to this idea has come from the quasar PHL 1811 which appears to be intrinsically X-ray weak and also has distinctive emission-line properties. We propose to observe a sample of eight SDSS quasars, selected to have similar UV emission-line properties to that of PHL 1811, to test if they are also X-ray weak. Our analyses of the currently available X-ray data appear to support this hypothesis but do not provide a proper test. Our results will have implications for the nature of accretion-disk coronae, emission-line formation, and AGN selection.

  10. Test of weak and strong factorization in nucleus-nucleuscollisions atseveral hundred MeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    La Tessa, Chiara; Sihver, Lembit; Zeitlin, Cary; Miller, Jack; Guetersloh, Stephen; Heilbronn, Lawrence; Mancusi, Davide; Iwata,Yoshiuki; Murakami, Takeshi

    2006-06-21

    Total and partial charge-changing cross sections have been measured for argon projectiles at 400 MeV/nucleon in carbon, aluminum, copper, tin and lead targets; cross sections for hydrogen were also obtained, using a polyethylene target. The validity of weak and strong factorization properties has been investigated for partial charge-changing cross sections; preliminary cross section values obtained for carbon, neon and silicon at 290 and 400 MeV/nucleon and iron at 400 MeV/nucleon, in carbon, aluminum, copper, tin and lead targets have been also used for testing these properties. Two different analysis methods were applied and both indicated that these properties are valid, without any significant difference between weak and strong factorization. The factorization parameters have then been calculated and analyzed in order to find some systematic behavior useful for modeling purposes.

  11. From strong to weak coupling in holographic models of thermalization

    Energy Technology Data Exchange (ETDEWEB)

    Grozdanov, Sašo; Kaplis, Nikolaos [Instituut-Lorentz for Theoretical Physics, Leiden University,Niels Bohrweg 2, Leiden 2333 CA (Netherlands); Starinets, Andrei O. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, Oxford OX1 3NP (United Kingdom)

    2016-07-29

    We investigate the analytic structure of thermal energy-momentum tensor correlators at large but finite coupling in quantum field theories with gravity duals. We compute corrections to the quasinormal spectra of black branes due to the presence of higher derivative R{sup 2} and R{sup 4} terms in the action, focusing on the dual to N=4 SYM theory and Gauss-Bonnet gravity. We observe the appearance of new poles in the complex frequency plane at finite coupling. The new poles interfere with hydrodynamic poles of the correlators leading to the breakdown of hydrodynamic description at a coupling-dependent critical value of the wave-vector. The dependence of the critical wave vector on the coupling implies that the range of validity of the hydrodynamic description increases monotonically with the coupling. The behavior of the quasinormal spectrum at large but finite coupling may be contrasted with the known properties of the hierarchy of relaxation times determined by the spectrum of a linearized kinetic operator at weak coupling. We find that the ratio of a transport coefficient such as viscosity to the relaxation time determined by the fundamental non-hydrodynamic quasinormal frequency changes rapidly in the vicinity of infinite coupling but flattens out for weaker coupling, suggesting an extrapolation from strong coupling to the kinetic theory result. We note that the behavior of the quasinormal spectrum is qualitatively different depending on whether the ratio of shear viscosity to entropy density is greater or less than the universal, infinite coupling value of ℏ/4πk{sub B}. In the former case, the density of poles increases, indicating a formation of branch cuts in the weak coupling limit, and the spectral function shows the appearance of narrow peaks. We also discuss the relation of the viscosity-entropy ratio to conjectured bounds on relaxation time in quantum systems.

  12. Aspects of electrostatics in a weak gravitational field

    Science.gov (United States)

    Padmanabhan, Hamsa; Padmanabhan, T.

    2010-05-01

    Several features of electrostatics of point charged particles in a weak, homogeneous, gravitational field are discussed using the Rindler metric to model the gravitational field. Some previously known results are obtained by simpler and more transparent procedures and are interpreted in an intuitive manner. Specifically: (a) We discuss possible definitions of the electric field in curved spacetime (and noninertial frames), argue in favour of a specific definition for the electric field and discuss its properties. (b) We show that the electrostatic potential of a charge at rest in the Rindler frame (which is known and is usually expressed as a complicated function of the coordinates) is expressible as A 0 = q/ λ where λ is the affine parameter distance along the null geodesic from the charge to the field point. (c) This relates well with the result that the electric field lines of a charge coincide with the null geodesics; that is, both light and the electric field lines ‘bend’ in the same manner in a weak gravitational field. We provide a simple proof for this result as well as for the fact that the null geodesics (and field lines) are circles in space. (d) We obtain the sum of the electrostatic forces exerted by one charge on another in the Rindler frame and discuss its interpretation. In particular, we compare the results in the Rindler frame and in the inertial frame and discuss their consistency. (e) We show how a purely electrostatic term in the Rindler frame appears as a radiation term in the inertial frame. (In part, this arises because charges at rest in a weak gravitational field possess additional weight due to their electrostatic energy. This weight is proportional to the acceleration and falls inversely with distance—which are the usual characteristics of a radiation field.) (f) We also interpret the origin of the radiation reaction term by extending our approach to include a slowly varying acceleration. Many of these results might have possible

  13. Forensic bitemark identification: weak foundations, exaggerated claims

    Science.gov (United States)

    Saks, Michael J.; Albright, Thomas; Bohan, Thomas L.; Bierer, Barbara E.; Bowers, C. Michael; Bush, Mary A.; Bush, Peter J.; Casadevall, Arturo; Cole, Simon A.; Denton, M. Bonner; Diamond, Shari Seidman; Dioso-Villa, Rachel; Epstein, Jules; Faigman, David; Faigman, Lisa; Fienberg, Stephen E.; Garrett, Brandon L.; Giannelli, Paul C.; Greely, Henry T.; Imwinkelried, Edward; Jamieson, Allan; Kafadar, Karen; Kassirer, Jerome P.; Koehler, Jonathan ‘Jay’; Korn, David; Mnookin, Jennifer; Morrison, Alan B.; Murphy, Erin; Peerwani, Nizam; Peterson, Joseph L.; Risinger, D. Michael; Sensabaugh, George F.; Spiegelman, Clifford; Stern, Hal; Thompson, William C.; Wayman, James L.; Zabell, Sandy; Zumwalt, Ross E.

    2016-01-01

    Abstract Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification—highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications—highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence. PMID:28852538

  14. Forensic bitemark identification: weak foundations, exaggerated claims.

    Science.gov (United States)

    Saks, Michael J; Albright, Thomas; Bohan, Thomas L; Bierer, Barbara E; Bowers, C Michael; Bush, Mary A; Bush, Peter J; Casadevall, Arturo; Cole, Simon A; Denton, M Bonner; Diamond, Shari Seidman; Dioso-Villa, Rachel; Epstein, Jules; Faigman, David; Faigman, Lisa; Fienberg, Stephen E; Garrett, Brandon L; Giannelli, Paul C; Greely, Henry T; Imwinkelried, Edward; Jamieson, Allan; Kafadar, Karen; Kassirer, Jerome P; Koehler, Jonathan 'Jay'; Korn, David; Mnookin, Jennifer; Morrison, Alan B; Murphy, Erin; Peerwani, Nizam; Peterson, Joseph L; Risinger, D Michael; Sensabaugh, George F; Spiegelman, Clifford; Stern, Hal; Thompson, William C; Wayman, James L; Zabell, Sandy; Zumwalt, Ross E

    2016-12-01

    Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification-highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications-highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence.

  15. Review Article: The weak interactive characteristic of resonance cells and broadband effect of metamaterials

    Directory of Open Access Journals (Sweden)

    Xiaopeng Zhao

    2014-10-01

    Full Text Available Metamaterials are artificial media designed to control electromagnetic wave propagation. Due to resonance, most present-day metamaterials inevitably suffer from narrow bandwidth, extremely limiting their practical applications. On the basis of tailored properties, a metamaterial within which each distinct unit cell resonates at its inherent frequency and has almost no coupling effect with the other ones, termed as weak interaction system, can be formulated. The total response of a weak interaction system can be treated as an overlap of the single resonance spectrum of each type of different unit cells. This intriguing feature therefore makes it possible to accomplish multiband or broadband metamaterials in a simple way. By introducing defects into metamaterials to form a weak interaction system, multiband and broadband electromagnetic metamaterials have first been experimentally demonstrated by our group. The similar concept can also be readily extended to acoustic and seismic metamaterials.

  16. Weak fault detection and health degradation monitoring using customized standard multiwavelets

    Science.gov (United States)

    Yuan, Jing; Wang, Yu; Peng, Yizhen; Wei, Chenjun

    2017-09-01

    Due to the nonobvious symptoms contaminated by a large amount of background noise, it is challenging to beforehand detect and predictively monitor the weak faults for machinery security assurance. Multiwavelets can act as adaptive non-stationary signal processing tools, potentially viable for weak fault diagnosis. However, the signal-based multiwavelets suffer from such problems as the imperfect properties missing the crucial orthogonality, the decomposition distortion impossibly reflecting the relationships between the faults and signatures, the single objective optimization and independence for fault prognostic. Thus, customized standard multiwavelets are proposed for weak fault detection and health degradation monitoring, especially the weak fault signature quantitative identification. First, the flexible standard multiwavelets are designed using the construction method derived from scalar wavelets, seizing the desired properties for accurate detection of weak faults and avoiding the distortion issue for feature quantitative identification. Second, the multi-objective optimization combined three dimensionless indicators of the normalized energy entropy, normalized singular entropy and kurtosis index is introduced to the evaluation criterions, and benefits for selecting the potential best basis functions for weak faults without the influence of the variable working condition. Third, an ensemble health indicator fused by the kurtosis index, impulse index and clearance index of the original signal along with the normalized energy entropy and normalized singular entropy by the customized standard multiwavelets is achieved using Mahalanobis distance to continuously monitor the health condition and track the performance degradation. Finally, three experimental case studies are implemented to demonstrate the feasibility and effectiveness of the proposed method. The results show that the proposed method can quantitatively identify the fault signature of a slight rub on

  17. Microinstabilities in weak density gradient tokamak systems

    Energy Technology Data Exchange (ETDEWEB)

    Tang, W.M.; Rewoldt, G.; Chen, L.

    1986-04-01

    A prominent characteristic of auxiliary-heated tokamak discharges which exhibit improved (''H-mode type'') confinement properties is that their density profiles tend to be much flatter over most of the plasma radius. Depsite this favorable trend, it is emphasized here that, even in the limit of zero density gradient, low-frequency microinstabilities can persist due to the nonzero temperature gradient.

  18. Tests of the weak equivalence principle

    Science.gov (United States)

    Speake, C. C.; Will, C. M.

    2012-09-01

    The Einstein equivalence principle is the foundation for general relativity and all metric theories of gravity. Of its three tenets—the equality of acceleration of test bodies, or weak equivalence principle; the validity of Lorentz invariance in local freely falling frames; and the position invariance of local physical laws—the weak equivalence principle has played the most important role historically, and continues to be a focus of intense theoretical and experimental investigation. From the probably apocryphal 16th century demonstrations by Galileo at Pisa's leaning tower to the sensitive torsion-balance measurements of today (both pictured on the cover of this issue), this principle, dubbed WEP, has been crucial to the development of gravitation theory. The universality of the rate of acceleration of all types of matter in a gravitational field can be taken as evidence that gravitation is fundamentally determined by the geometry, or metric, of spacetime. Newton began his magnum opus 'The Principia' with a discussion of WEP and his experiments to verify it, while Einstein took WEP for granted in his construction of general relativity, never once referring to the epochal experiments by Baron Eötvös. The classic 1964 experiment of Roll, Krotkov and Dicke ushered in the modern era of high-precision tests, and the search for a 'fifth force' during the late 1980s (instigated, ironically, by purported anomalies in Eötvös's old data) caused the enterprise to pivot from pure tests of the foundation of GR to searches for new physics beyond the standard model of the non-gravitational interactions. Today, the next generation of experimental tests of WEP are being prepared for launch or are being developed, with the goal of reaching unprecedented levels of sensitivity, in search of signatures of interactions inspired by string theory, extra dimensions and other concepts from the world of high-energy physics. At the same time observations continue using lunar laser

  19. Planckian axions and the Weak Gravity Conjecture

    Energy Technology Data Exchange (ETDEWEB)

    Bachlechner, Thomas C.; Long, Cody; McAllister, Liam [Department of Physics, Cornell University,Ithaca, NY 14853 (United States)

    2016-01-18

    Several recent works http://dx.doi.org/10.1088/1475-7516/2015/09/020, http://dx.doi.org/10.1007/JHEP08(2015)032, http://dx.doi.org/10.1007/JHEP10(2015)023 have claimed that the Weak Gravity Conjecture (WGC) excludes super-Planckian displacements of axion fields, and hence large-field axion inflation, in the absence of monodromy. We argue that in theories with N≫1 axions, super-Planckian axion diameters D are readily allowed by the WGC. We clarify the nontrivial relationship between the kinetic matrix K — unambiguously defined by its form in a Minkowski-reduced basis — and the diameter of the axion fundamental domain, emphasizing that in general the diameter is not solely determined by the eigenvalues f{sub 1}{sup 2}≤…≤f{sub N}{sup 2} of K: the orientations of the eigenvectors with respect to the identifications imposed by instantons must be incorporated. In particular, even if one were to impose the condition f{sub N}M{sub pl} does not immediately imply the existence of unsuppressed higher harmonic contributions to the potential. Finally, we argue that in effective axion-gravity theories, the zero-form version of the WGC can be satisfied by gravitational instantons that make negligible contributions to the potential.

  20. Born energy, acid-base equilibrium, structure and interactions of end-grafted weak polyelectrolyte layers

    Science.gov (United States)

    Nap, R. J.; Tagliazucchi, M.; Szleifer, I.

    2014-01-01

    This work addresses the effect of the Born self-energy contribution in the modeling of the structural and thermodynamical properties of weak polyelectrolytes confined to planar and curved surfaces. The theoretical framework is based on a theory that explicitly includes the conformations, size, shape, and charge distribution of all molecular species and considers the acid-base equilibrium of the weak polyelectrolyte. Namely, the degree of charge in the polymers is not imposed but it is a local varying property that results from the minimization of the total free energy. Inclusion of the dielectric properties of the polyelectrolyte is important as the environment of a polymer layer is very different from that in the adjacent aqueous solution. The main effect of the Born energy contribution on the molecular organization of an end-grafted weak polyacid layer is uncharging the weak acid (or basic) groups and consequently decreasing the concentration of mobile ions within the layer. The magnitude of the effect increases with polymer density and, in the case of the average degree of charge, it is qualitatively equivalent to a small shift in the equilibrium constant for the acid-base equilibrium of the weak polyelectrolyte monomers. The degree of charge is established by the competition between electrostatic interactions, the polymer conformational entropy, the excluded volume interactions, the translational entropy of the counterions and the acid-base chemical equilibrium. Consideration of the Born energy introduces an additional energetic penalty to the presence of charged groups in the polyelectrolyte layer, whose effect is mitigated by down-regulating the amount of charge, i.e., by shifting the local-acid base equilibrium towards its uncharged state. Shifting of the local acid-base equilibrium and its effect on the properties of the polyelectrolyte layer, without considering the Born energy, have been theoretically predicted previously. Account of the Born energy leads

  1. Born energy, acid-base equilibrium, structure and interactions of end-grafted weak polyelectrolyte layers.

    Science.gov (United States)

    Nap, R J; Tagliazucchi, M; Szleifer, I

    2014-01-14

    This work addresses the effect of the Born self-energy contribution in the modeling of the structural and thermodynamical properties of weak polyelectrolytes confined to planar and curved surfaces. The theoretical framework is based on a theory that explicitly includes the conformations, size, shape, and charge distribution of all molecular species and considers the acid-base equilibrium of the weak polyelectrolyte. Namely, the degree of charge in the polymers is not imposed but it is a local varying property that results from the minimization of the total free energy. Inclusion of the dielectric properties of the polyelectrolyte is important as the environment of a polymer layer is very different from that in the adjacent aqueous solution. The main effect of the Born energy contribution on the molecular organization of an end-grafted weak polyacid layer is uncharging the weak acid (or basic) groups and consequently decreasing the concentration of mobile ions within the layer. The magnitude of the effect increases with polymer density and, in the case of the average degree of charge, it is qualitatively equivalent to a small shift in the equilibrium constant for the acid-base equilibrium of the weak polyelectrolyte monomers. The degree of charge is established by the competition between electrostatic interactions, the polymer conformational entropy, the excluded volume interactions, the translational entropy of the counterions and the acid-base chemical equilibrium. Consideration of the Born energy introduces an additional energetic penalty to the presence of charged groups in the polyelectrolyte layer, whose effect is mitigated by down-regulating the amount of charge, i.e., by shifting the local-acid base equilibrium towards its uncharged state. Shifting of the local acid-base equilibrium and its effect on the properties of the polyelectrolyte layer, without considering the Born energy, have been theoretically predicted previously. Account of the Born energy leads

  2. Piezoceramic Cantilever Sensor Design for Weak-Impact Detection on Plates

    Directory of Open Access Journals (Sweden)

    Young-Sup Lee

    2012-01-01

    Full Text Available A piezoelectric cantilever type sensor for locating the precise weak-impact or touch position on a plate is presented in this paper. Since the importance of human-computer interface such as a touch panel system has been rapidly increasing recently, this study could suggest an appropriate sensor for the detection of a weak-impact point effectively and accurately for such a system. This sensor detects the out-of-plane vibration of a panel when a touch with a finger or pen is applied on it. The sensor is made with a steel beam and a single crystal PMN-PT patch is bonded on the beam, which is designed to detect the base vibration of the panel. The sensor was designed, manufactured to verify the detect ability of a weak-impact and attached on two different plates of a glass of 400 × 400 × 4 mm and a wooden MDF of 600 × 600 × 9 mm. The experiment result of the sensor was compared with that of an accelerometer which can also be used for the same purpose and shows clear weak-impact responses with a narrow-band property at its resonant frequency. It is expected that the cantilever type sensor in this study could be applied to make a simple flat plate into a touch panel when the time difference of arrivals method is used to locate the weak-impact point.

  3. Common fixed point theorems of Gregus type for weakly compatible mappings satisfying generalized contractive conditions

    Science.gov (United States)

    Aliouche, A.

    2008-05-01

    We prove a common fixed point theorem of Gregus type for four mappings satisfying a generalized contractive condition in metric spaces using the concept of weak compatibility which generalizes theorems of [I. Altun, D. Turkoglu, B.E. Rhoades, Fixed points of weakly compatible mappings satisfying a general contractive condition of integral type, Fixed Point Theory Appl. 2007 (2007), article ID 17301; A. Djoudi, L. Nisse, Gregus type fixed points for weakly compatible mappings, Bull. Belg. Math. Soc. 10 (2003) 369-378; A. Djoudi, A. Aliouche, Common fixed point theorems of Gregus type for weakly compatible mappings satisfying contractive conditions of integral type, J. Math. Anal. Appl. 329 (1) (2007) 31-45; P. Vijayaraju, B.E. Rhoades, R. Mohanraj, A fixed point theorem for a pair of maps satisfying a general contractive condition of integral type, Int. J. Math. Math. Sci. 15 (2005) 2359-2364; X. Zhang, Common fixed point theorems for some new generalized contractive type mappings, J. Math. Anal. Appl. 333 (2) (2007) 780-786]. We prove also a common fixed point theorem which generalizes Theorem 3.5 of [H.KE Pathak, M.S. Khan, T. Rakesh, A common fixed point theorem and its application to nonlinear integral equations, Comput. Math. Appl. 53 (2007) 961-971] and common fixed point theorems of Gregus type using a strict generalized contractive condition, a property (E.A) and a common property (E.A).

  4. Turing Impossibility Properties for Stack Machine Programming

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2012-01-01

    The strong, intermediate, and weak Turing impossibility properties are introduced. Some facts concerning Turing impossibility for stack machine programming are trivially adapted from previous work. Several intriguing questions are raised about the Turing impossibility properties concerning different

  5. Proximal Limb Weakness Reverting After CSF Diversion In Intracranial Hypertension

    Directory of Open Access Journals (Sweden)

    Sinha S

    2005-01-01

    Full Text Available We report about two young girls who developed progressive visual failure secondary to increased intracranial pressure and had significant proximal muscle weakness of limbs. Patients with elevated intracranial pressure (ICP may present with "false localizing signs", besides having headache, vomiting and papilledema. Radicular pain as a manifestation of raised ICP is rare and motor weakness attributable to polyradiculopathy is exceptional. Two patients with increased intracranial pressure without lateralizing signs′ had singnificant muscle weakness. Clinical evaluation and laboratory tests did not disclose any other cause for weakness. Following theco-peritoneal shunt, in both patients, there was variable recovery of vision but the proximal weakness and symptoms of elevated ICP improved rapidly. Recognition of this uncommon manifestation of raised ICP may obviate the need for unnecessary investigation and reduce morbidity due to weakness by CSF diversion procedure.

  6. Weak Lensing by Galaxy Troughs in DES Science Verification Data

    Energy Technology Data Exchange (ETDEWEB)

    Gruen, D. [Ludwig Maximilian Univ., Munich (Germany); Max Planck Inst. for Extraterrestrial Physics, Garching (Germany). et al.

    2015-09-29

    We measure the weak lensing shear around galaxy troughs, i.e. the radial alignment of background galaxies relative to underdensities in projections of the foreground galaxy field over a wide range of redshift in Science Verification data from the Dark Energy Survey. Our detection of the shear signal is highly significant (10σ–15σ for the smallest angular scales) for troughs with the redshift range z ϵ [0.2, 0.5] of the projected galaxy field and angular diameters of 10 arcmin…1°. These measurements probe the connection between the galaxy, matter density, and convergence fields. By assuming galaxies are biased tracers of the matter density with Poissonian noise, we find agreement of our measurements with predictions in a fiducial Λ cold dark matter model. Furthermore, the prediction for the lensing signal on large trough scales is virtually independent of the details of the underlying model for the connection of galaxies and matter. Our comparison of the shear around troughs with that around cylinders with large galaxy counts is consistent with a symmetry between galaxy and matter over- and underdensities. In addition, we measure the two-point angular correlation of troughs with galaxies which, in contrast to the lensing signal, is sensitive to galaxy bias on all scales. Finally, the lensing signal of troughs and their clustering with galaxies is therefore a promising probe of the statistical properties of matter underdensities and their connection to the galaxy field.

  7. Weak Gravitational Lensing by Galaxies - Implications for Dark Matter Halos

    Science.gov (United States)

    Brainerd, T. G.; Blandford, R. D.; Smail, I.

    1996-05-01

    A detection of weak, tangential distortion of the images of cosmologically distant, faint galaxies caused by gravitational lensing by foreground galaxies is reported. The imaging data consist of a 24 ksec integration in Gunn-r of a single blank field obtained with the COSMIC imaging spectrograph on the Hale 5-m telescope. The orientations of faint (23 right > = 0.011 +/- 0.006 (95% confidence bounds) is found for the faint galaxies. The variation of right > with both differential lens-source separation and the maximum radius of the annulus is investigated. From Monte Carlo simulations of galaxy-galaxy lensing that incorporate measured properties of local galaxies and modest extrapolations of the observed redshift distribution of faint galaxies, formal best-fit parameters for the dark matter halos associated with the lens galaxies are obtained. For L(*) galaxies a characteristic circular velocity of V(*) ~ 220+/- 80 km/s and outer scale radius of s(*) >= 100h(-1) kpc is found. These parameters imply a typical mass for the lens galaxies within 100 h(-1) kpc of order 1.0(+1.2}_{-0.5) x 10(12) h(-1) M_sun (90% confidence bounds), in good agreement with recent dynamical estimates of the masses of local spiral galaxies

  8. Helimagnetism and weak ferromagnetism in edge-shared chain cuprates

    Energy Technology Data Exchange (ETDEWEB)

    Drechsler, S.-L. [Leibniz-Institut fuer Festkoerper- und Werkstoffforschung IFW Dresden, Postfach 270116, D-01171 Dresden (Germany)]. E-mail: drechsler@ifw-dresden.de; Richter, J. [Institut fuer Theoretische Physik, Universitaet Magdeburg, D-39016 Magdeburg (Germany); Kuzian, R. [Institute for Problems of Materials Science, Kiev (Ukraine); Malek, J. [Institute of Physics, ASCR, Prague (Czech Republic); Tristan, N. [Leibniz-Institut fuer Festkoerper- und Werkstoffforschung IFW Dresden, Postfach 270116, D-01171 Dresden (Germany); Buechner, B. [Leibniz-Institut fuer Festkoerper- und Werkstoffforschung IFW Dresden, Postfach 270116, D-01171 Dresden (Germany); Moskvin, A.S. [Ural State University, 620083 Ekaterinburg (Russian Federation); Gippius, A.A. [Moscow State University, 119992 Moscow (Russian Federation); Vasiliev, A. [Moscow State University, 119992 Moscow (Russian Federation); Volkova, O. [Moscow State University, 119992 Moscow (Russian Federation); Prokofiev, A. [Institut fuer Festkoerperphysik, Technische Universitaet Wien, A-1040 Wien (Austria); Rakoto, H. [Laboratoire National de Champs Magnetiques Pulses, 31432 Toulouse (France); Broto, J.-M. [Laboratoire National de Champs Magnetiques Pulses, 31432 Toulouse (France); Schnelle, W. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, D-01187 Dresden (Germany); Schmitt, M. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, D-01187 Dresden (Germany); Ormeci, A. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, D-01187 Dresden (Germany); Loison, C. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, D-01187 Dresden (Germany); Rosner, H. [Max-Planck-Institut fuer Chemische Physik fester Stoffe, D-01187 Dresden (Germany)

    2007-09-15

    The present understanding of a novel growing class of chain cuprates with intriguing magnetic properties is reviewed. Among them, several undoped edge-shared CuO{sub 2} chain compounds show at low temperature a clear tendency to helicoidal magnetical ordering with acute pitch angles and sometimes also to weak ferromagnetism. Our analysis is based on the isotropic 1D frustrated J{sub 1}-J{sub 2} Heisenberg model with ferromagnetic (FM) 1st neighbor and antiferromagnetic 2nd neighbor exchange. The achieved assignment is supported by microscopic calculations of the electronic and magnetic structure. We consider Na(Li)Cu{sub 2}O{sub 2}, LiVCuO{sub 4} as the best studied helimagnets, Li{sub 2}ZrCuO{sub 4} and other systems close to a FM quantum critical point, as well as Li{sub 2}CuO{sub 2} with FM inchain ordering. The interplay of frustrated inchain couplings, anisotropy and interchain exchange is discussed.

  9. Pollux: a stable weak dipolar magnetic field but no planet?

    Science.gov (United States)

    Aurière, Michel; Konstantinova-Antova, Renada; Espagnet, Olivier; Petit, Pascal; Roudier, Thierry; Charbonnel, Corinne; Donati, Jean-François; Wade, Gregg A.

    2014-08-01

    Pollux is considered as an archetype of a giant star hosting a planet: its radial velocity (RV) presents sinusoidal variations with a period of about 590 d, which have been stable for more than 25 years. Using ESPaDOnS and Narval we have detected a weak (sub-gauss) magnetic field at the surface of Pollux and followed up its variations with Narval during 4.25 years, i.e. more than for two periods of the RV variations. The longitudinal magnetic field is found to vary with a sinusoidal behaviour with a period close to that of the RV variations and with a small shift in phase. We then performed a Zeeman Doppler imaging (ZDI) investigation from the Stokes V and Stokes I least-squares deconvolution (LSD) profiles. A rotational period is determined, which is consistent with the period of variations of the RV. The magnetic topology is found to be mainly poloidal and this component almost purely dipolar. The mean strength of the surface magnetic field is about 0.7 G. As an alternative to the scenario in which Pollux hosts a close-in exoplanet, we suggest that the magnetic dipole of Pollux can be associated with two temperature and macroturbulent velocity spots which could be sufficient to produce the RV variations. We finally investigate the scenarii of the origin of the magnetic field which could explain the observed properties of Pollux.

  10. Weak chaos and fractional dynamics in an optically driven colloidal ring

    OpenAIRE

    Roichman, Yael; Zaslavsky, George; Grier, David G.

    2006-01-01

    Three colloidal spheres driven around a ring-like optical trap known as an optical vortex have been predicted to undergo periodic collective motion due to their hydrodynamic coupling. In fact, the quenched disorder in the optically-implemented potential energy landscape drives a transition to instability evolving into microscopic weak chaos with fractional dynamics. As a result, the relation between the space-time selfsimilarity of the system's collective transport properties and its microsco...

  11. The weak π − π interaction originated resonant tunneling and fast switching in the carbon based electronic devices

    Directory of Open Access Journals (Sweden)

    Jun He

    2012-03-01

    Full Text Available By means of the nonequilibrium Green's functions and the density functional theory, we have investigated the electronic transport properties of C60 based electronic device with different intermolecular interactions. It is found that the electronic transport properties vary with the types of the interaction between two C60 molecules. A fast electrical switching behavior based on negative differential resistance has been found when two molecules are coupled by the weak π − π interaction. Compared to the solid bonding, the weak interaction is found to induce resonant tunneling, which is responsible for the fast response to the applied electric field and hence the velocity of switching.

  12. On n-weak amenability of Rees semigroup algebras

    Indian Academy of Sciences (India)

    semigroups. In this work, we shall consider this class of Banach algebras. We examine the n-weak amenability of some semigroup algebras, and give an easier example of a Banach algebra which is n-weakly amenable if n is odd. Let L1(G) be the group algebra of a locally compact group G (§3.3 of [3]). Then Johnson.

  13. Superluminal pulse reflection from a weakly absorbing dielectric slab.

    Science.gov (United States)

    Wang, Li-Gang; Zhu, Shi-Yao

    2006-07-15

    Group delay for a reflected light pulse from a weakly absorbing dielectric slab is theoretically investigated, and large negative group delay is found for weak absorption near a resonance of the slab [Re(kd)=mpi]. The group delay for both the reflected and transmitted pulses will be saturated with an increase of the absorption.

  14. Space group constraints on weak indices in topological insulators

    NARCIS (Netherlands)

    Varjas, D.; De Juan, Fernando; Lu, Yuan Ming

    Lattice translation symmetry gives rise to a large class of "weak" topological insulators (TIs), characterized by translation-protected gapless surface states and dislocation bound states. In this work we show that space group symmetries lead to constraints on the weak topological indices that

  15. Electron Capture Dissociation of Weakly Bound Polypeptide Polycationic Complexes

    DEFF Research Database (Denmark)

    Haselmann, Kim F; Jørgensen, Thomas J D; Budnik, Bogdan A

    2002-01-01

    We have previously reported that, in electron capture dissociation (ECD), rupture of strong intramolecular bonds in weakly bound supramolecular aggregates can proceed without dissociation of weak intermolecular bonds. This is now illustrated on a series of non-specific peptide-peptide dimers...

  16. Perturbated rotational motion of weakly deformable celestial bodies

    Science.gov (United States)

    Barkin, Yu. V.

    The rotation equations of weakly deformable celestial bodies (in canonical and non-canonical Andoyer variables) are developed in detail. A theory of the perturbed rotational motion of an isolated weakly deformable body has been developed. Applications to Earth's rotation theory are given.

  17. Intensive care unit-acquired weakness : Pathophysiology and diagnosis

    NARCIS (Netherlands)

    Witteveen, E.

    2017-01-01

    Many patients on the intensive care unit (ICU) develop generalized muscle weakness. This condition, called intensive care unit- acquired weakness (ICU-AW), is caused by dysfunction or damage of muscles, nerves, or both. ICU-AW is associated with increased short- and long-term morbidity and

  18. Secure Authentication from a Weak Key, Without Leaking Information

    NARCIS (Netherlands)

    N.J. Bouman (Niek); S. Fehr (Serge); K.G. Paterson (Kerry)

    2011-01-01

    htmlabstractWe study the problem of authentication based on a weak key in the information-theoretic setting. A key is weak if its min-entropy is an arbitrary small fraction of its bit length. This problem has recently received considerable attention, with different solutions optimizing different

  19. Some Viable Techniques for Assessing and Counselling Cognitive Processing Weakness

    Science.gov (United States)

    Haruna, Abubakar Sadiq

    2016-01-01

    Cognitive Processing weakness (CPW) is a psychological problem that impedes students' ability to learn effectively in a normal school setting. Such weakness may include; auditory, visual, conceptual, sequential, speed and attention processing. This paper therefore examines the basic assessment or diagnostic approaches such as Diagnosis by…

  20. Bunched soliton states in weakly coupled sine-Gordon systems

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Samuelsen, Mogens Rugholm; Lomdahl, P. S.

    1990-01-01

    The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results.......The interaction between solitons of two weakly coupled sine-Gordon systems is considered. In particular, the stability of bunched states is investigated, and perturbation results are compared with numerical results....

  1. Measuring Workload Weak Resilience Signals at a Rail Control Post

    NARCIS (Netherlands)

    Siegel, A.W.; Schraagen, J.M.C.

    2014-01-01

    OCCUPATIONAL APPLICATIONS This article describes an observational study at a rail control post to measure workload weak resilience signals. A weak resilience signal indicates a possible degradation of a system's resilience, which is defined as the ability of a complex socio-technical system to cope

  2. Covenants with Weak Swords: ISO 14001 and Facilities' Environmental Performance

    Science.gov (United States)

    Potoski, Matthew; Prakash, Aseem

    2005-01-01

    Voluntary environmental programs are codes of progressive environmental conduct that firms pledge to adopt. This paper investigates whether ISO 14001, a voluntary program with a weak sword--a weak monitoring and sanctioning mechanism--can mitigate shirking and improve participants' environmental performance. Sponsored by the International…

  3. Diaphragm weakness in pulmonary arterial hypertension: role of sarcomeric dysfunction

    NARCIS (Netherlands)

    Manders, E.; Man, F.S. de; Handoko, M.L.; Westerhof, N.; Hees, H.W.H. van; Stienen, G.J.; Vonk-Noordegraaf, A.; Ottenheijm, C.A.C.

    2012-01-01

    We previously demonstrated that diaphragm muscle weakness is present in experimental pulmonary arterial hypertension (PH). However, the nature of this diaphragm weakness is still unknown. Therefore, the aim of this study was to investigate whether changes at the sarcomeric level contribute to

  4. Measures of weak noncompactness, nonlinear Leray-Schauder ...

    African Journals Online (AJOL)

    In this paper, we establish some new nonlinear Leray-Schauder alternatives for the sum and the product of weakly sequentially continuous operators in Banach algebras satisfying certain sequential condition (P). The main condition in our results is formulated in terms of axiomatic measures of weak noncompactness.

  5. Classical simulations of heavy-ion fusion reactions and weakly ...

    Indian Academy of Sciences (India)

    This model is extended to simulate heavy-ion reactions such as 6Li + 209Bi involving the weakly-bound projectile considered as a weakly-bound cluster of deuteron and 4He nuclei, thus, simulating a 3-body system in 3S-CMD model. All the essential features of breakup reactions, such as complete fusion, incomplete fusion ...

  6. Isotropy of Angular Frequencies and Weak Chimeras with Broken Symmetry

    Science.gov (United States)

    Bick, Christian

    2017-04-01

    The notion of a weak chimeras provides a tractable definition for chimera states in networks of finitely many phase oscillators. Here, we generalize the definition of a weak chimera to a more general class of equivariant dynamical systems by characterizing solutions in terms of the isotropy of their angular frequency vector—for coupled phase oscillators the angular frequency vector is given by the average of the vector field along a trajectory. Symmetries of solutions automatically imply angular frequency synchronization. We show that the presence of such symmetries is not necessary by giving a result for the existence of weak chimeras without instantaneous or setwise symmetries for coupled phase oscillators. Moreover, we construct a coupling function that gives rise to chaotic weak chimeras without symmetry in weakly coupled populations of phase oscillators with generalized coupling.

  7. Microwave-assisted Weak Acid Hydrolysis of Proteins

    Directory of Open Access Journals (Sweden)

    Miyeong Seo

    2012-06-01

    Full Text Available Myoglobin was hydrolyzed by microwave-assisted weak acid hydrolysis with 2% formic acid at 37 oC, 50 oC, and100 oC for 1 h. The most effective hydrolysis was observed at 100 oC. Hydrolysis products were investigated using matrixassistedlaser desorption/ionization time-of-flight mass spectrometry. Most cleavages predominantly occurred at the C-termini ofaspartyl residues. For comparison, weak acid hydrolysis was also performed in boiling water for 20, 40, 60, and 120 min. A 60-min weak acid hydrolysis in boiling water yielded similar results as a 60-min microwave-assisted weak acid hydrolysis at100 oC. These results strongly suggest that microwave irradiation has no notable enhancement effect on acid hydrolysis of proteinsand that temperature is the major factor that determines the effectiveness of weak acid hydrolysis.

  8. Weakness acquired in the intensive care unit. Incidence, risk factors and their association with inspiratory weakness. Observational cohort study.

    Science.gov (United States)

    Ballve, Ladislao Pablo Diaz; Dargains, Nahuel; Inchaustegui, José García Urrutia; Bratos, Antonella; Percaz, Maria de Los Milagros; Ardariz, Cesar Bueno; Cagide, Sabrina; Balestrieri, Carolina; Gamarra, Claudio; Paz, Dario; Rotela, Eliana; Muller, Sebastian; Bustos, Fernando; Castro, Ricard Aranda; Settembrino, Esteban

    2017-12-07

    This paper sought to determine the accumulated incidence and analyze the risk factors associated with the development of weakness acquired in the intensive care unit and its relationship to inspiratory weakness. We conducted a prospective cohort study at a single center, multipurpose medical-surgical intensive care unit. We included adult patients who required mechanical ventilation ≥ 24 hours between July 2014 and January 2016. No interventions were performed. Demographic data, clinical diagnoses, the factors related to the development of intensive care unit -acquired weakness, and maximal inspiratory pressure were recorded. Of the 111 patients included, 66 developed intensive care unit -acquired weakness, with a cumulative incidence of 40.5% over 18 months. The group with intensive care unit-acquired weakness were older (55.9 ± 17.6 versus 45.8 ± 16.7), required more mechanical ventilation (7 [4 - 10] days versus 4 [2 - 7.3] days), and spent more time in the intensive care unit (15.5 [9.2 - 22.8] days versus 9 [6 - 14] days). More patients presented with delirium (68% versus 39%), hyperglycemia > 3 days (84% versus 59%), and positive balance > 3 days (73.3% versus 37%). All comparisons were significant at p 5 days as independent predictors of intensive care unit-acquired weakness. Low maximal inspiratory pressure was associated with intensive care unit-acquired weakness (p intensive care unit-acquired weakness. The intensive care unit acquired weakness is a condition with a high incidence in our environment. The development of intensive care unit-acquired weakness was associated with age, delirium, hyperglycemia, and mechanical ventilation > 5 days. The maximum inspiratory pressure value of ≥ 36cmH2O was associated with a high diagnostic value to exclude the presence of intensive care unit -acquired weakness.

  9. Modeling of crack propagation in weak snowpack layers using the discrete element method

    Science.gov (United States)

    Gaume, J.; van Herwijnen, A.; Chambon, G.; Birkeland, K. W.; Schweizer, J.

    2015-10-01

    Dry-snow slab avalanches are generally caused by a sequence of fracture processes including (1) failure initiation in a weak snow layer underlying a cohesive slab, (2) crack propagation within the weak layer and (3) tensile fracture through the slab which leads to its detachment. During the past decades, theoretical and experimental work has gradually led to a better understanding of the fracture process in snow involving the collapse of the structure in the weak layer during fracture. This now allows us to better model failure initiation and the onset of crack propagation, i.e., to estimate the critical length required for crack propagation. On the other hand, our understanding of dynamic crack propagation and fracture arrest propensity is still very limited. To shed more light on this issue, we performed numerical propagation saw test (PST) experiments applying the discrete element (DE) method and compared the numerical results with field measurements based on particle tracking. The goal is to investigate the influence of weak layer failure and the mechanical properties of the slab on crack propagation and fracture arrest propensity. Crack propagation speeds and distances before fracture arrest were derived from the DE simulations for different snowpack configurations and mechanical properties. Then, in order to compare the numerical and experimental results, the slab mechanical properties (Young's modulus and strength) which are not measured in the field were derived from density. The simulations nicely reproduced the process of crack propagation observed in field PSTs. Finally, the mechanical processes at play were analyzed in depth which led to suggestions for minimum column length in field PSTs.

  10. Ephaptic coupling rescues conduction failure in weakly coupled cardiac tissue with voltage-gated gap junctions

    Science.gov (United States)

    Weinberg, S. H.

    2017-09-01

    Electrical conduction in cardiac tissue is usually considered to be primarily facilitated by gap junctions, providing a pathway between the intracellular spaces of neighboring cells. However, recent studies have highlighted the role of coupling via extracellular electric fields, also known as ephaptic coupling, particularly in the setting of reduced gap junction expression. Further, in the setting of reduced gap junctional coupling, voltage-dependent gating of gap junctions, an oft-neglected biophysical property in computational studies, produces a positive feedback that promotes conduction failure. We hypothesized that ephaptic coupling can break the positive feedback loop and rescue conduction failure in weakly coupled cardiac tissue. In a computational tissue model incorporating voltage-gated gap junctions and ephaptic coupling, we demonstrate that ephaptic coupling can rescue conduction failure in weakly coupled tissue. Further, ephaptic coupling increased conduction velocity in weakly coupled tissue, and importantly, reduced the minimum gap junctional coupling necessary for conduction, most prominently at fast pacing rates. Finally, we find that, although neglecting gap junction voltage-gating results in negligible differences in well coupled tissue, more significant differences occur in weakly coupled tissue, greatly underestimating the minimal gap junctional coupling that can maintain conduction. Our study suggests that ephaptic coupling plays a conduction-preserving role, particularly at rapid heart rates.

  11. Nerve excitability changes related to muscle weakness in chronic progressive external ophthalmoplegia.

    Science.gov (United States)

    Gueguen, Antoine; Jardel, Claude; Polivka, Marc; Tan, S Veronica; Gray, Françoise; Vignal, Catherine; Lombès, Anne; Gout, Olivier; Bostock, Hugh

    2017-07-01

    To explore potential spreading to peripheral nerves of the mitochondrial dysfunction in chronic progressive external ophthalmoplegia (CPEO) by assessing axonal excitability. CPEO patients (n=13) with large size deletion of mitochondrial DNA and matching healthy controls (n=22) were included in a case-control study. Muscle strength was quantified using MRC sum-score and used to define two groups of patients: CPEO-weak and CPEO-normal (normal strength). Nerve excitability properties of median motor axons were assessed with the TROND protocol and changes interpreted with the aid of a model. Alterations of nerve excitability strongly correlated with scores of muscle strength. CPEO-weak displayed abnormal nerve excitability compared to CPEO-normal and healthy controls, with increased superexcitability and responses to hyperpolarizing current. Modeling indicated that the CPEO-weak recordings were best explained by an increase in the 'Barrett-Barrett' conductance across the myelin sheath. CPEO patients with skeletal weakness presented sub-clinical nerve excitability changes, which were not consistent with axonal membrane depolarization, but suggested Schwann cell involvement. This study provides new insights into the spreading of large size deletion of mitochondrial DNA to Schwann cells in CPEO patients. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  12. Spectral properties and stability of perturbed Cartesian product

    Indian Academy of Sciences (India)

    Prakash A Dabhi

    property, regularity, weak regularity as well as Ditkin's condition are stable with respect to this product. Keywords. Commutative Banach algebra; perturbed product; spectral extension property; unique uniform norm property; regularity; weak regularity; Ditkin's condition. 2010 Mathematics Subject Classification. 46J05. 1.

  13. Intensive care unit-acquired weakness in the burn population.

    Science.gov (United States)

    Cubitt, Jonathan J; Davies, Menna; Lye, George; Evans, Janine; Combellack, Tom; Dickson, William; Nguyen, Dai Q

    2016-05-01

    Intensive care unit-acquired weakness is an evolving problem in the burn population. As patients are surviving injuries that previously would have been fatal, the focus of treatment is shifting from survival to long-term outcome. The rehabilitation of burn patients can be challenging; however, a certain subgroup of patients have worse outcomes than others. These patients may suffer from intensive care unit-acquired weakness, and their treatment, physiotherapy and expectations need to be adjusted accordingly. This study investigates the condition of intensive care unit-acquired weakness in our burn centre. We conducted a retrospective analysis of all the admissions to our burn centre between 2008 and 2012 and identified 22 patients who suffered from intensive care unit-acquired weakness. These patients were significantly younger with significantly larger burns than those without intensive care unit-acquired weakness. The known risk factors for intensive care unit-acquired weakness are commonplace in the burn population. The recovery of these patients is significantly affected by their weakness. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  14. Weak-value Metrology and Shot-Noise Limited Measurements

    Science.gov (United States)

    Viza, Gerardo Ivan

    This thesis contains a subset of the research in which I have participated in during my studies at the University of Rochester. It contains three projects and one overarching theme of weak-value metrology. We start with chapter 1 where we cover the historical background leading up to quantum optics, which we use for precision metrology. We also introduce the weak-value formulation and give examples of metrological implementations for parameter estimation. Chapter 2 introduces two experiments to measure a longitudinal velocity and a transverse momentum kick. We show that weak-value based techniques are shot-noise limited because we saturate the Cramer-Rao bound for the estimator used, and efficient because we experimentally demonstrate there is virtually no loss of Fisher information of the parameter of interest from the discarded events. In Chapter 3 we present a comparison of two experiments that measure a beam deflection. One experiment is a weak-value based technique, while the other is the standard focusing technique. We set up the two experiments in the presence of simulated technical noise sources and show how the weak-value based technique out performs the standard technique in both visibility and in deviation of the transverse momentum kick. Chapter 4 contains work of the exploration of concatenated postselection for weak-value amplification. We demonstrate an optimization and conditions where postselecting on two degrees of freedom can be beneficial to enhance the weak-value amplification.

  15. Weaknesses, strengths and needs in fertility care according to patients.

    Science.gov (United States)

    van Empel, Inge W H; Nelen, Willianne L D M; Tepe, Eveline T; van Laarhoven, Esther A P; Verhaak, Christianne M; Kremer, Jan A M

    2010-01-01

    The patients' role in assessing health care quality is increasingly recognized. Measuring patients' specific experiences and needs generates concrete information for care improvement, whereas satisfaction surveys only give an overoptimistic, undifferentiating picture. Therefore, this study aimed to investigate possible weaknesses, strengths and needs in fertility care by measuring patients' specific experiences. Mixed (qualitative and quantitative) methods were used to identify weaknesses, strengths and needs in fertility care. Four focus groups with 21 infertile patients were used for documenting care aspects relevant to patients. The fully transcribed qualitative results were analysed and converted into a 124-item questionnaire, to investigate whether these aspects were regarded as weaknesses, strengths or needs in fertility care. The questionnaire was distributed to 369 eligible couples attending 13 Dutch fertility clinics. Descriptive statistics were used to determine the quantity of the weaknesses, strengths and needs. Overall, 286 women (78%) and 280 men (76%) completed the questionnaire. Patients experienced many weaknesses in fertility care, mostly regarding emotional support and continuity of care. Respect and autonomy and partner involvement were considered strengths in current care. Furthermore, women expressed their need for more doctors' continuity during their treatment, and couples strongly desired to have free access to their own medical record. The questionnaire's internal consistency and construct validity were sufficient. Infertile couples experience strengths, but also many weaknesses and needs in current fertility care. Lack of patient centredness seems to be a major cause herein. Using mixed methods is a sensitive means for identifying these weaknesses and needs.

  16. Lifting a weak Poisson bracket to the algebra of forms

    Science.gov (United States)

    Lyakhovich, S.; Peddie, M.; Sharapov, A.

    2017-06-01

    We detail the construction of a weak Poisson bracket over a submanifold Σ of a smooth manifold M with respect to a local foliation of this submanifold. Such a bracket satisfies a weak type Jacobi identity but may be viewed as a usual Poisson bracket on the space of leaves of the foliation. We then lift this weak Poisson bracket to a weak odd Poisson bracket on the odd tangent bundle ΠTM, interpreted as a weak Koszul bracket on differential forms on M. This lift is achieved by encoding the weak Poisson structure into a homotopy Poisson structure on an extended manifold, and lifting the Hamiltonian function that generates this structure. Such a construction has direct physical interpretation. For a generic gauge system, the submanifold Σ may be viewed as a stationary surface or a constraint surface, with the foliation given by the foliation of the gauge orbits. Through this interpretation, the lift of the weak Poisson structure is simply a lift of the action generating the corresponding BRST operator of the system.

  17. Prevalence of Weak D Antigen In Western Indian Population

    Directory of Open Access Journals (Sweden)

    Tanvi Sadaria

    2015-12-01

    Full Text Available Introduction: Discovery of Rh antigens in 1939 by Landsteiner and Weiner was the revolutionary stage in blood banking. Of these antigens, D, which decides Rh positivity or negativity, is the most antigenic. A problem is encountered when an individual has a weakened expression of D (Du, i.e., fewer numbers of D antigens on red cell membrane. Aims and Objectives: To know the prevalence of weak D in Indian population because incidence varies in different population. To determine the risk of alloimmunization among Rh D negative patients who receives the blood of weak D positive donors. Material and Methods: Rh grouping of 38,962 donors who came to The Department of Immunohematology and Blood Transfusion of Civil Hospital, Ahmedabad from 1st January 2013 to 30th September 2014 was done using the DIAGAST (Automated Grouping. The samples that tested negative for D antigen were further analysed for weak D (Du by indirect antiglobulin test using blend of Ig G and Ig M Anti D. This was done using Column agglutination method in ID card (gel card. Results: The total number of donors studied was 38,962. Out of these 3360(8.6% were tested Rh D negative. All Rh D negative donors were tested for weak D (Du. 22 (0.056% of total donors and 0.65% of Rh negative donors turned out to be weak D (Du positive. Conclusion: The prevalence of weak D (Du in Western Indian population is 0.056 %, So the risk of alloimmunization in our setting due to weak D (Du antigen is marginal. But, testing of weak D antigen is necessary in blood bank because weak D antigen is immunogenic and can produce alloimmunization if transfused to Rh D negative subjects.

  18. China’s Property Sector

    OpenAIRE

    Alexander Cooper; Arianna Cowling

    2015-01-01

    Property development, especially of residential property, represents a sizeable share of China’s economic activity and has made a considerable contribution to overall growth over recent history. Residential property cycles in China have been larger than cycles in commercial real estate, and may pose risks to activity and financial stability. The current weakness in the property market differs somewhat from previous downturns as there are indications that developers may be much more highly gea...

  19. Detection of weak frequency jumps for GNSS onboard clocks.

    Science.gov (United States)

    Huang, Xinming; Gong, Hang; Ou, Gang

    2014-05-01

    In this paper, a weak frequency jump detection method is developed for onboard clocks in global navigation satellite systems (GNSS). A Kalman filter is employed to facilitate the onboard real-time processing of atomic clock measurements, whose N-step prediction residuals are used to construct the weak frequency jump detector. Numerical simulations show that the method can successfully detect weak frequency jumps. The detection method proposed in this paper is helpful for autonomous integrity monitoring of GNSS satellite clocks, and can also be applied to other frequency anomalies with an appropriately modified detector.

  20. Linear optics implementation of weak values in Hardy's paradox

    Science.gov (United States)

    Ahnert, S. E.; Payne, M. C.

    2004-10-01

    We propose an experimental setup for the implementation of weak measurements in the context of the gedanken experiment known as Hardy’s paradox. As Aharonov et al. [Y. Aharonov, A. Botero, S. Popescu, B. Reznik, and J. Tollaksen, Phys. Lett. A301, 130 (2002)] showed, these weak values form a language with which the paradox can be resolved. Our analysis shows that this language is indeed consistent and experimentally testable. It also reveals exactly how a combination of weak values can give rise to an apparently paradoxical result.

  1. Properties of Bc meson

    Indian Academy of Sciences (India)

    antiquark potential of the form − c r + A r with varying from 0.5 to 2.0. The and -wave masses, pseudoscalar decay constant, weak decay partial widths in spectator model and the lifetime of c meson are computed. The properties calculated ...

  2. New Integral Inequalities with Weakly Singular Kernel for Discontinuous Functions and Their Applications to Impulsive Fractional Differential Systems

    Directory of Open Access Journals (Sweden)

    Jing Shao

    2014-01-01

    Full Text Available Some new integral inequalities with weakly singular kernel for discontinuous functions are established using the method of successive iteration and properties of Mittag-Leffler function, which can be used in the qualitative analysis of the solutions to certain impulsive fractional differential systems.

  3. Validation of the Chinese Strengths and Weaknesses of ADHD-Symptoms and Normal-Behaviors Questionnaire in Hong Kong

    Science.gov (United States)

    Lai, Kelly Y. C.; Leung, Patrick W. L.; Luk, Ernest S. L.; Wong, Ann S. Y.; Law, Lawrence S. C.; Ho, Karen K. Y.

    2013-01-01

    Objective: Unlike rating scales that focus on the severity of ADHD symptoms, the Strengths and Weaknesses of ADHD-Symptoms and Normal-Behaviors (SWAN) rating scale is phrased in neutral or positive terms for carers to compare the index child's behaviors with that of their peers. This study explores its psychometric properties when applied to…

  4. Existence of Weak Solutions for a Nonlinear Elliptic System

    Directory of Open Access Journals (Sweden)

    Gilbert RobertP

    2009-01-01

    Full Text Available We investigate the existence of weak solutions to the following Dirichlet boundary value problem, which occurs when modeling an injection molding process with a partial slip condition on the boundary. We have in ; in ; , and on .

  5. Hysteresis in superconducting short weak links and μ -SQUIDs

    Science.gov (United States)

    Hazra, Dibyendu; Pascal, Lætitia M. A.; Courtois, Hervé; Gupta, Anjan K.

    2010-11-01

    Thermal hysteresis in a micron-size superconducting quantum interference device ( μ -SQUID), with weak links as Josephson junctions, is an obstacle for improving its performance for magnetometry. Following the “hot-spot” model of Skocpol [J. Appl. Phys. 45, 4054 (1974)]10.1063/1.1663912 and by incorporating the temperature dependence of the superconductor thermal conductivity under a linear approximation, we find a much better agreement with the observed temperature dependence of the retrapping current in short superconducting Nb-based weak links and μ -SQUIDs. In addition, using the temperature dependence of the critical current, we find that above a certain temperature hysteresis disappears. We analyze the current-voltage characteristics and the weak link temperature variation in both the hysteretic and nonhysteretic regimes. We also discuss the effect of the weak link geometry in order to widen the temperature range of hysteresis-free operation.

  6. Space group constraints on weak indices in topological insulators

    Science.gov (United States)

    Varjas, Dániel; de Juan, Fernando; Lu, Yuan-Ming

    2017-07-01

    Lattice translation symmetry gives rise to a large class of "weak" topological insulators (TIs), characterized by translation-protected gapless surface states and dislocation bound states. In this work we show that space group symmetries lead to constraints on the weak topological indices that define these phases. In particular, we show that screw rotation symmetry enforces the Hall conductivity in planes perpendicular to the screw axis to be quantized in multiples of the screw rank, which generally applies to interacting systems. We further show that certain 3D weak indices associated with quantum spin Hall effects (class AII) are forbidden by the Bravais lattice and by glide or even-fold screw symmetries. These results put strong constraints on weak TI candidates in the experimental and numerical search for topological materials, based on the crystal structure alone.

  7. A weakly compressible formulation for modelling liquid-gas sloshing

    CSIR Research Space (South Africa)

    Heyns, Johan A

    2012-09-01

    Full Text Available , the implementation of a weakly compressible formulation which accounts for variations in the gas density is presented. With the aim of ensuring a computational efficient implementation of the proposed formulation, an implicit iterative GMRES solver with LU...

  8. Ultrasmall polarization rotation measurements via weak value amplification

    Energy Technology Data Exchange (ETDEWEB)

    Lima Bernardo, Bertúlio de, E-mail: bertulio@fisica.ufpb.br; Azevedo, Sérgio; Rosas, Alexandre

    2014-06-13

    Highlights: • We present a class of weak measurements where the measurer is an angular variable of the system. • Photon-energy qubits are required, which seems to be the first application of this kind of light. • Both weak optical activity and reflection-induced polarization rotation can be amplified. • This protocol can amplify the optical activity signal in nanostructures and biological tissues. - Abstract: We propose a framework to analyze weak measurements based on an angular version of the von Neumann measurement scheme, where the coupling between the system and the meter causes rotation of the measuring variable. We also discuss an experimental application of this theory in which measurements of weak optical activity and reflection-induced polarization rotation could be amplified in nearly two orders of magnitude. It can shed a new light on a great variety of physical chemistry, molecular biology and nanotechnology studies.

  9. Strengths only or strengths and relative weaknesses? A preliminary study.

    Science.gov (United States)

    Rust, Teri; Diessner, Rhett; Reade, Lindsay

    2009-10-01

    Does working on developing character strengths and relative character weaknesses cause lower life satisfaction than working on developing character strengths only? The present study provides a preliminary answer. After 76 college students completed the Values in Action Inventory of Strengths (C. Peterson & M. E. P. Seligman, 2004), the authors randomly assigned them to work on 2 character strengths or on 1 character strength and 1 relative weakness. Combined, these groups showed significant gains on the Satisfaction With Life Scale (E. Diener, R. A. Emmons, R. J. Larsen, & S. Griffin, 1985), compared with a 32-student no-treatment group. However, there was no significant difference in gain scores between the 2-strengths group and the 1-character-strength-and-1-relative-character-weakness group. The authors discuss how focusing on relative character weaknesses (along with strengths) does not diminish-and may assist in increasing-life satisfaction.

  10. Managing Chemotherapy Side Effects: Fatigue (Feeling Weak and Very Tired)

    Science.gov (United States)

    ... ancer I nstitute Managing Chemotherapy Side Effects Fatigue (Feeling weak and very tired) Why do I feel ... level. Some people write down how they are feeling each day in a notebook to share with ...

  11. Graphene-Based Superconducting Weak Links in Low Magnetic Field

    Science.gov (United States)

    Mills, Scott; Kumaravadivel, Piranavan; Du, Xu

    The impact of magnetic field on Andreev reflection is studied in graphene-based superconducting weak links. We found, through studying weak links with different adhesion layers and superconducting leads (including Graphene-Ti/Au-Nb, Graphene-Ti/Pd-Nb, Graphene-V-Nb, Graphene-Ti-Nb, Graphene-Ti/Pd-NbN), that in low field (B graphene-superconductor interface. As the effective gap of the weak link approaches the intrinsic gap of the superconducting leads, a remnant of Andreev reflection can survive into the quantum Hall regime, allowing study of the interplay between the quantum Hall effect and Andreev reflection in high quality suspended graphene-superconductor weak links.

  12. Notification: FY 2018 CSB Management Challenges and Internal Control Weaknesses

    Science.gov (United States)

    December 26, 2017. The OIG is beginning work to update for fiscal year 2018 its list of proposed key management challenges and internal control weaknesses confronting the U.S. Chemical Safety and Hazard Investigation Board (CSB).

  13. Selective diaphragm muscle weakness after contractile inactivity during thoracic surgery.

    NARCIS (Netherlands)

    Welvaart, W.N.; Paul, M.A.; Stienen, G.J.; Hees, H.W.H. van; Loer, S.A.; Bouwman, R.; Niessen, H.; Man, F.S. de; Witt, C.C.; Granzier, H.; Vonk-Noordegraaf, A.; Ottenheijm, C.A.C.

    2011-01-01

    RATIONALE: Postoperative pulmonary complications are significant contributors to morbidity in patients who have undergone upper abdominal, thoracic, or cardiac surgery. The pathophysiology of these complications might involve postoperative inspiratory muscle weakness. The nature of postoperative

  14. Undecidability of Weak Bisimilarity for PA-Processes

    DEFF Research Database (Denmark)

    Srba, Jiri

    2003-01-01

    We prove that the problem whether two PA-processes are weakly bisimilar is undecidable. We combine several proof techniques to provide a reduction from Post's correspondence problem to our problem: existential quantification technique, masking technique and deadlock elimination technique....

  15. National Transportation Safety Board : weak internal control impaired financial accountability

    Science.gov (United States)

    2001-09-28

    The U. S. General Accounting Office (GAO) was asked to review the National Transportation Safety Board's (NTSB) internal controls over selected types of fiscal year expenditures. They were asked to determine whether internal control weaknesses were a...

  16. Informal Institutions and the "Weaknesses" of Human Behavior

    National Research Council Canada - National Science Library

    Goebel, Markus; Thomas, Tobias

    2005-01-01

    ... to interpersonal consistency and interpersonal conformity here. These sources of a systematic deviation from the standard model of the homo oeconomicus result in systematic weaknesses of perception and deviations of behavior...

  17. Electrostatics in Chemistry-Electrostatic Models for Weak Molecular ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 12. Electrostatics in Chemistry - Electrostatic Models for Weak Molecular Complexation. Shridhar R Gadre Pravin K Babu. Series Article Volume 4 Issue 12 December 1999 pp 11-20 ...

  18. Compressive strength of brick masonry made with weak mortars

    DEFF Research Database (Denmark)

    Pedersen, Erik Steen; Hansen, Klavs Feilberg

    2013-01-01

    (fm≈6 N/mm2) compression tests of masonry with perforated bricks show that the EC6 expression is not always safe for Danish masonry. This is probably because the tensile strength of the bricks also has an effect on the compressive strength of masonry when the mortar is stronger than weak lime mortar......The use of weak mortar has a number of advantages (e.g. prevention of expansion joints, environmental issues). However, according to EC6, the strength of masonry vanishes when the compressive strength of the mortar approaches zero. In reality the presence of even unhardened mortar kept in place...... in the joint will ensure a certain level of load-carrying capacity. This is due to the interaction between compression in the weak mortar and tension in the adjacent bricks. This paper proposes an expression for the compressive strength of masonry made with weak lime mortars (fmstrength...

  19. Stability in Real Food Webs: Weak Links in Long Loops

    National Research Council Canada - National Science Library

    Anje-Margriet Neutel; Johan A. P. Heesterbeek; Peter C. de Ruiter

    2002-01-01

    ... of these patterns, how they come about, and why they influence stability. We show that in real food webs, interaction strengths are organized in trophic loops in such a way that long loops contain relatively many weak links...

  20. Weighted interior penalty discretization of fully nonlinear and weakly dispersive free surface shallow water flows

    Science.gov (United States)

    Di Pietro, Daniele A.; Marche, Fabien

    2018-02-01

    In this paper, we further investigate the use of a fully discontinuous Finite Element discrete formulation for the study of shallow water free surface flows in the fully nonlinear and weakly dispersive flow regime. We consider a decoupling strategy in which we approximate the solutions of the classical shallow water equations supplemented with a source term globally accounting for the non-hydrostatic effects. This source term can be computed through the resolution of elliptic second-order linear sub-problems, which only involve second order partial derivatives in space. We then introduce an associated Symmetric Weighted Internal Penalty discrete bilinear form, allowing to deal with the discontinuous nature of the elliptic problem's coefficients in a stable and consistent way. Similar discrete formulations are also introduced for several recent optimized fully nonlinear and weakly dispersive models. These formulations are validated again several benchmarks involving h-convergence, p-convergence and comparisons with experimental data, showing optimal convergence properties.

  1. Shell-model description of weakly bound and unbound nuclear states

    Energy Technology Data Exchange (ETDEWEB)

    Michel, N. [University of Tennessee, Department of Physics and Astronomy, Knoxville, TN (United States); Oak Ridge National Laboratory, Physics Division, Oak Ridge, TN (United States); Joint Institute for Heavy Ion Research, Oak Ridge, TN (United States); Nazarewicz, W. [University of Tennessee, Department of Physics and Astronomy, Knoxville, TN (United States); Oak Ridge National Laboratory, Physics Division, Oak Ridge, TN (United States); Warsaw University, Institute of Theoretical Physics, Warsaw (Poland); Ploszajczak, M.; Rotureau, J. [CEA/DSM-CNRS/IN2P3, Grand Accelerateur National d' Ions Lourds (GANIL), Caen (France)

    2005-09-01

    A consistent description of weakly bound and unbound nuclei requires an accurate description of the particle continuum properties when carrying out multiconfiguration mixing. This is the domain of the Gamow Shell Model (GSM) which is the multiconfigurational shell model in the complex k-plane formulated using a complete Berggren ensemble representing bound single-particle (s.p.) states, s.p. resonances, and non-resonant complex energy continuum states. We discuss the salient features of effective interactions in weakly bound systems and show selected applications of the GSM formalism to p-shell nuclei. Finally, a development of the new non-perturbative scheme based on Density Matrix Renormalization Group methods to select the most significant continuum configurations in GSM calculations is discussed shortly. (orig.)

  2. Anomalous weak values and the violation of a multiple-measurement Leggett-Garg inequality

    Science.gov (United States)

    Avella, Alessio; Piacentini, Fabrizio; Borsarelli, Michelangelo; Barbieri, Marco; Gramegna, Marco; Lussana, Rudi; Villa, Federica; Tosi, Alberto; Degiovanni, Ivo Pietro; Genovese, Marco

    2017-11-01

    Quantum mechanics presents peculiar properties that, on the one hand, have been the subject of several theoretical and experimental studies about its very foundations and, on the other hand, provide tools for developing new technologies, the so-called quantum technologies. The nonclassicality pointed out by Leggett-Garg inequalities has represented, with Bell inequalities, one of the most investigated subjects. In this article we study the connection of Leggett-Garg inequalities with a new emerging field of quantum measurement, the weak values in the case of a series of sequential measurements on a single object. In detail, we perform an experimental study of the four-time-correlator Leggett-Garg test, by exploiting single and sequential weak measurements performed on heralded single photons.

  3. The stability of weakly collisional plasmas with thermal and composition gradients

    DEFF Research Database (Denmark)

    Pessah, M.E.; Chakraborty, S.

    2013-01-01

    temperature and composition. This allows us to discuss for the first time the dynamics of weakly collisional environments where heat conduction, momentum transport, and ion-diffusion are anisotropic with respect to the direction of the magnetic field. We show that depending on the relative signs...... the magnetic field configurations that arise as a natural consequence of the HBI, which would be MTI stable in a homogeneous medium, could be alleviated if the mean molecular weight gradient is steep enough, i.e., (¿µ)/µ > (¿T)/T. This study constitutes a first step toward understanding the interaction between...... approximation if heavy elements are able to sediment in the inner region of the galaxy cluster. Motivated by the need to obtain a more complete picture of the dynamical properties of the ICM, we analyze the stability of a weakly collisional, magnetized plane-parallel atmosphere which is stratified in both...

  4. Quantitative analysis of the modes of growth inhibition by weak organic acids in Saccharomyces cerevisiae.

    Science.gov (United States)

    Ullah, Azmat; Orij, Rick; Brul, Stanley; Smits, Gertien J

    2012-12-01

    Weak organic acids are naturally occurring compounds that are commercially used as preservatives in the food and beverage industries. They extend the shelf life of food products by inhibiting microbial growth. There are a number of theories that explain the antifungal properties of these weak acids, but the exact mechanism is still unknown. We set out to quantitatively determine the contributions of various mechanisms of antifungal activity of these weak acids, as well as the mechanisms that yeast uses to counteract their effects. We analyzed the effects of four weak organic acids differing in lipophilicity (sorbic, benzoic, propionic, and acetic acids) on growth and intracellular pH (pH(i)) in Saccharomyces cerevisiae. Although lipophilicity of the acids correlated with the rate of acidification of the cytosol, our data confirmed that not initial acidification, but rather the cell's ability to restore pH(i), was a determinant for growth inhibition. This pH(i) recovery in turn depended on the nature of the organic anion. We identified long-term acidification as the major cause of growth inhibition under acetic acid stress. Restoration of pH(i), and consequently growth rate, in the presence of this weak acid required the full activity of the plasma membrane ATPase Pma1p. Surprisingly, the proposed anion export pump Pdr12p was shown to play an important role in the ability of yeast cells to restore the pH(i) upon lipophilic (sorbic and benzoic) acid stress, probably through a charge interaction of anion and proton transport.

  5. Quantitative Analysis of the Modes of Growth Inhibition by Weak Organic Acids in Saccharomyces cerevisiae

    Science.gov (United States)

    Ullah, Azmat; Orij, Rick; Brul, Stanley

    2012-01-01

    Weak organic acids are naturally occurring compounds that are commercially used as preservatives in the food and beverage industries. They extend the shelf life of food products by inhibiting microbial growth. There are a number of theories that explain the antifungal properties of these weak acids, but the exact mechanism is still unknown. We set out to quantitatively determine the contributions of various mechanisms of antifungal activity of these weak acids, as well as the mechanisms that yeast uses to counteract their effects. We analyzed the effects of four weak organic acids differing in lipophilicity (sorbic, benzoic, propionic, and acetic acids) on growth and intracellular pH (pHi) in Saccharomyces cerevisiae. Although lipophilicity of the acids correlated with the rate of acidification of the cytosol, our data confirmed that not initial acidification, but rather the cell's ability to restore pHi, was a determinant for growth inhibition. This pHi recovery in turn depended on the nature of the organic anion. We identified long-term acidification as the major cause of growth inhibition under acetic acid stress. Restoration of pHi, and consequently growth rate, in the presence of this weak acid required the full activity of the plasma membrane ATPase Pma1p. Surprisingly, the proposed anion export pump Pdr12p was shown to play an important role in the ability of yeast cells to restore the pHi upon lipophilic (sorbic and benzoic) acid stress, probably through a charge interaction of anion and proton transport. PMID:23001666

  6. What are the weak points of LHC operation?

    CERN Document Server

    Goddard, B

    2010-01-01

    The few weeks of LHC operation in 2009 was a resounding success with extremely fast progress in the beam commissioning. Nevertheless, the period also revealed a number of possible weaknesses in various aspects of the LHC operation, including procedures, tools, discipline, equipment and organisation. The weaknesses are discussed with a view to feeding the experience back to improve the machine operation for 2010 and beyond. The distinction is made impacting efficiency, and those points which are more serious and might impact machine protection.

  7. Experimentally quantifying the advantages of weak-value-based metrology

    OpenAIRE

    Viza, Gerardo I.; Martínez-Rincón, Julián; Alves, Gabriel B.; Jordan, Andrew N.; Howell, John C.

    2014-01-01

    We experimentally investigate the relative advantages of implementing weak-value-based metrology versus standard methods. While the techniques outlined herein apply more generally, we measure small optical beam deflections both using a Sagnac interferometer with a monitored dark port (the weak-value-based technique), and by focusing the entire beam to a split detector (the standard technique). By introducing controlled external transverse detector modulations and transverse beam deflection mo...

  8. Strength and Weakness of Animal Vaccine Industry in China

    OpenAIRE

    Xie, Hong-hai; Wang, Geng-xin

    2010-01-01

    Based on the introduction of the status of animal vaccine industry in China, the strength, weakness, opportunity and threat of animal vaccine industry is analyzed by SWOT. Among them, strength is mainly reflected in the broad market, and the favorable industrial policy and development environment. Weakness is the irrational structure of product, the nonstandard production inspection, and the irregular market. Opportunity is mainly reflected in improving government’s emphasis on animal secur...

  9. Updating the theoretical analysis of the weak gravitational shielding experiment

    CERN Document Server

    Modanese, G

    1996-01-01

    The most recent data about the weak gravitational shielding produced recently through a levitating and rotating HTC superconducting disk show a very weak dependence of the shielding value ($\\sim 1 \\%$) on the height above the disk. We show that whilst this behaviour is incompatible with an intuitive vectorial picture of the shielding, it is consistently explained by our theoretical model. The expulsive force observed at the border of the shielded zone is due to energy conservation.

  10. MRT letter: recovering weak-textured surfaces using image focus.

    Science.gov (United States)

    Muhammad, Mannan Saeed; Choi, Tae-Sun

    2009-10-01

    In nature, objects have partially weak texture and their shape reconstruction using focus based passive methods like shape from focus (SFF), is difficult. This article presents a new SFF algorithm which can compute precise depth of dense as well as weak textured objects. Segmentation is applied to discard wrong depth estimate and then later interpolating them from accurate depth values of their neighbors. The performance of the proposed method is tested, using different image sequences of synthetic and real objects, with varying textures.

  11. Weak bond detection in composites using highly nonlinear solitary waves

    Science.gov (United States)

    Singhal, Taru; Kim, Eunho; Kim, Tae-Yeon; Yang, Jinkyu

    2017-05-01

    We experimentally investigate a diagnostic technique for identifying a weak bond in composites using highly nonlinear solitary waves (HNSWs). We set up a one-dimensional chain of granular crystals, consisting of spherical particles with nonlinear interactions, to generate HNSWs. These solitary wave packets are transmitted into an inspection area of composites by making a direct contact with the chain. We demonstrate that a strong type of solitary waves injected to the weak bond area can break the weak bond of laminates, thereby causing delamination. Then, to identify the creation of the delamination, we transmit a weak type of solitary waves by employing the same apparatus, and measure the solitary waves reflected from the specimens. By analyzing these reflected solitary waves, we differentiate the weak bond samples with the pristine bond ones in an efficient and fast manner. The diagnostic results based on the proposed method are compared with the strength and energy release rate at bond interfaces, which are measured via standard testing methods such as three point bending and end notched flexure tests. This study shows the potential of solitary wave-based detection of weak bonds for hot spot monitoring of composite-based structures.

  12. Chasing the peak: optimal statistics for weak shear analyses

    Science.gov (United States)

    Smit, Merijn; Kuijken, Konrad

    2018-01-01

    Context. Weak gravitational lensing analyses are fundamentally limited by the intrinsic distribution of galaxy shapes. It is well known that this distribution of galaxy ellipticity is non-Gaussian, and the traditional estimation methods, explicitly or implicitly assuming Gaussianity, are not necessarily optimal. Aims: We aim to explore alternative statistics for samples of ellipticity measurements. An optimal estimator needs to be asymptotically unbiased, efficient, and robust in retaining these properties for various possible sample distributions. We take the non-linear mapping of gravitational shear and the effect of noise into account. We then discuss how the distribution of individual galaxy shapes in the observed field of view can be modeled by fitting Fourier modes to the shear pattern directly. This allows scientific analyses using statistical information of the whole field of view, instead of locally sparse and poorly constrained estimates. Methods: We simulated samples of galaxy ellipticities, using both theoretical distributions and data for ellipticities and noise. We determined the possible bias Δe, the efficiency η and the robustness of the least absolute deviations, the biweight, and the convex hull peeling (CHP) estimators, compared to the canonical weighted mean. Using these statistics for regression, we have shown the applicability of direct Fourier mode fitting. Results: We find an improved performance of all estimators, when iteratively reducing the residuals after de-shearing the ellipticity samples by the estimated shear, which removes the asymmetry in the ellipticity distributions. We show that these estimators are then unbiased in the absence of noise, and decrease noise bias by more than 30%. Our results show that the CHP estimator distribution is skewed, but still centered around the underlying shear, and its bias least affected by noise. We find the least absolute deviations estimator to be the most efficient estimator in almost all

  13. Molecular imprinting sensor based on quantum weak measurement.

    Science.gov (United States)

    Li, Dongmei; He, Qinghua; He, Yonghong; Xin, Meiguo; Zhang, Yilong; Shen, Zhiyuan

    2017-08-15

    A new type of sensing protocol, based on a high precision metrology of quantum weak measurement, was first proposed for molecularly imprinted polymers (MIP) sensor. The feasibility, sensitivity and selectivity of weak measurement based MIP (WMMIP) sensor were experimentally demonstrated with bovine serum albumin (BSA). Weak measurement system exhibits high sensitivity to the optical phase shift corresponding to the refractive index change, which is induced by the specific capture of target protein molecules with its recognition sites. The recognition process can be finally characterized by the central wavelength shift of output spectra through weak value amplification. In our experiment, we prepared BSA@MIP with modified reversed-phase microemulsion method, and coated it on the internal surface of measuring channels assembled into the Mach-Zehnder (MZ) interferometer based optical weak measurement system. The design of this home-built optical system makes it possible to detect analyte in real time. The dynamic process of the specific adsorption and concentration response to BSA from 5×10-4 to 5×10-1μg/L was achieved with a limit of detection (LOD) of 8.01×10-12g/L. This WMMIP shows superiority in accuracy, fast response and low cost. Furthermore, real-time monitoring system can creatively promote the performance of MIP in molecular analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Weak-Values Metrological Techniques for Parameter Estimation

    Science.gov (United States)

    Martinez-Rincon, Julian Rodrigo

    Precision measurements are bounded by the Standard Quantum Limit, and preparing non-classical states is often used to circumvent such a limit. In all cases, it is common to improve the precision in a parameter estimation procedure by averaging measurements of a large ensemble of identically prepared systems. However, such a task cannot be performed indefinitely due to sources of technical noise setting an experimental bound. Weak-Value Amplification (WVA) allows one to overcome some of these issues by amplifying a signal of interest above the technical-noise floor. This built-in robustness to external sources of noise relies on a weak coupling to a meter and postselection. In this document we evaluate, theoretically and experimentally, under what circumstances the technique is superior to non-postselected standard techniques. We also present a novel protocol where a WVA-like response is induced in an optical homodyne-type detection technique. We dub this technique Almost-Balanced Weak Values (ABWV) and present three experimental measurements of different physical velocities to evaluate the practical advantages over the well-known technique of WVA. In addition, we point out the existence of a third postselected-weak-measurements technique for metrology, Inverse Weak Value (IWV), that has been ignored by the scientific community. We use this protocol to measure ultra small tilts of a mirror in a Sagnac interferometer. We report all three techniques as complementary to each other, and show their robustness for low-frequency signals.

  15. Experimentally quantifying the advantages of weak-value-based metrology

    Science.gov (United States)

    Viza, Gerardo I.; Martínez-Rincón, Julián; Alves, Gabriel B.; Jordan, Andrew N.; Howell, John C.

    2015-09-01

    We experimentally investigate the relative advantages of implementing weak-value-based metrology versus standard methods. While the techniques outlined herein apply more generally, we measure small optical beam deflections both using a Sagnac interferometer with a monitored dark port (the weak-value-based technique), and by focusing the entire beam to a split detector (the standard technique). By introducing controlled external transverse detector modulations and transverse beam deflection momentum modulations, we quantify the mitigation of these sources in the weak-value-based experiment versus the standard focusing experiment. The experiments are compared using a combination of deterministic and stochastic methods. In all cases, the weak-value technique performs the same or better than the standard technique by up to two orders of magnitude in precision for our parameters. We further measure the statistical efficiency of the weak-value-based technique. By postselecting on 1 % of the photons, we obtain 99 % of the available Fisher information of the beam deflection parameter.

  16. Weak electric fields detectability in a noisy neural network.

    Science.gov (United States)

    Zhao, Jia; Deng, Bin; Qin, Yingmei; Men, Cong; Wang, Jiang; Wei, Xile; Sun, Jianbing

    2017-02-01

    We investigate the detectability of weak electric field in a noisy neural network based on Izhikevich neuron model systematically. The neural network is composed of excitatory and inhibitory neurons with similar ratio as that in the mammalian neocortex, and the axonal conduction delays between neurons are also considered. It is found that the noise intensity can modulate the detectability of weak electric field. Stochastic resonance (SR) phenomenon induced by white noise is observed when the weak electric field is added to the network. It is interesting that SR almost disappeared when the connections between neurons are cancelled, suggesting the amplification effects of the neural coupling on the synchronization of neuronal spiking. Furthermore, the network parameters, such as the connection probability, the synaptic coupling strength, the scale of neuron population and the neuron heterogeneity, can also affect the detectability of the weak electric field. Finally, the model sensitivity is studied in detail, and results show that the neural network model has an optimal region for the detectability of weak electric field signal.

  17. Learning from Weak and Noisy Labels for Semantic Segmentation

    KAUST Repository

    Lu, Zhiwu

    2016-04-08

    A weakly supervised semantic segmentation (WSSS) method aims to learn a segmentation model from weak (image-level) as opposed to strong (pixel-level) labels. By avoiding the tedious pixel-level annotation process, it can exploit the unlimited supply of user-tagged images from media-sharing sites such as Flickr for large scale applications. However, these ‘free’ tags/labels are often noisy and few existing works address the problem of learning with both weak and noisy labels. In this work, we cast the WSSS problem into a label noise reduction problem. Specifically, after segmenting each image into a set of superpixels, the weak and potentially noisy image-level labels are propagated to the superpixel level resulting in highly noisy labels; the key to semantic segmentation is thus to identify and correct the superpixel noisy labels. To this end, a novel L1-optimisation based sparse learning model is formulated to directly and explicitly detect noisy labels. To solve the L1-optimisation problem, we further develop an efficient learning algorithm by introducing an intermediate labelling variable. Extensive experiments on three benchmark datasets show that our method yields state-of-the-art results given noise-free labels, whilst significantly outperforming the existing methods when the weak labels are also noisy.

  18. On typical properties of Hilbert space operators

    NARCIS (Netherlands)

    Eisner, T.; Mátrai, T.

    2013-01-01

    We study the typical behavior of bounded linear operators on infinite-dimensional complex separable Hilbert spaces in the norm, strong-star, strong, weak polynomial and weak topologies. In particular, we investigate typical spectral properties, the problem of unitary equivalence of typical

  19. Test masses for the G-POEM test of the weak equivalence principle

    Science.gov (United States)

    Reasenberg, Robert D.; Phillips, James D.; Popescu, Eugeniu M.

    2011-11-01

    We describe the design of the test masses that are used in the ‘ground-based principle of equivalence measurement’ test of the weak equivalence principle. The main features of the design are the incorporation of corner cubes and the use of mass removal and replacement to create pairs of test masses with different test substances. The corner cubes allow for the vertical separation of the test masses to be measured with picometer accuracy by SAO's unique tracking frequency laser gauge, while the mass removal and replacement operations are arranged so that the test masses incorporating different test substances have nominally identical gravitational properties.

  20. Lattice-Boltzmann simulation of laser interaction with weakly ionized helium plasmas.

    Science.gov (United States)

    Li, Huayu; Ki, Hyungson

    2010-07-01

    This paper presents a lattice Boltzmann method for laser interaction with weakly ionized plasmas considering electron impact ionization and three-body recombination. To simulate with physical properties of plasmas, the authors' previous work on the rescaling of variables is employed and the electromagnetic fields are calculated from the Maxwell equations by using the finite-difference time-domain method. To calculate temperature fields, energy equations are derived separately from the Boltzmann equations. In this way, we attempt to solve the full governing equations for plasma dynamics. With the developed model, the continuous-wave CO2 laser interaction with helium is simulated successfully.

  1. A linear model for amplitude modulation of Langmuir waves in weak electron-beam plasma interaction

    Directory of Open Access Journals (Sweden)

    K. Baumgärtel

    2013-01-01

    Full Text Available A simple linear approach to the phenomenon of amplitude modulation of Langmuir waves in weak beam plasma interaction is presented. During the short growth phase of the instability and within the longer period after saturation, the waves are described by their linear kinetic dispersion properties.The amplitude modulation appears as result of the beating of waves with different wavelengths and amplitudes that have grown from noise in the initial phase. The Langmuir wave fields are calculated via FFT (fast Fourier transform technique. The resulting waveforms in temporal representation are quite similar to those observed by spacecraft.

  2. Weak Second Order Explicit Stabilized Methods for Stiff Stochastic Differential Equations

    KAUST Repository

    Abdulle, Assyr

    2013-01-01

    We introduce a new family of explicit integrators for stiff Itô stochastic differential equations (SDEs) of weak order two. These numerical methods belong to the class of one-step stabilized methods with extended stability domains and do not suffer from the step size reduction faced by standard explicit methods. The family is based on the standard second order orthogonal Runge-Kutta-Chebyshev (ROCK2) methods for deterministic problems. The convergence, meansquare, and asymptotic stability properties of the methods are analyzed. Numerical experiments, including applications to nonlinear SDEs and parabolic stochastic partial differential equations are presented and confirm the theoretical results. © 2013 Society for Industrial and Applied Mathematics.

  3. Early Career: The search for weakly interacting dark matter with liquid xenon

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Carter [Univ. of Maryland, College Park, MD (United States). Dept. of Physics

    2017-02-08

    We report results from a search for weakly interacting dark matter particles obtained with the LUX experiment. LUX was located at a depth of 4850 feet at the Sanford Underground Research Facility in Lead, South Dakota from 2013 through 2016. It found no evidence for dark matter particle interactions and set new constraints on the properties of such particles for masses between 6 GeV and 100 TeV. The work reported here also characterized the performance of such experiments by developing a new calibration technique based upon a tritium beta decay source.

  4. Superfluid-Mott-insulator transition in superconducting circuits with weak anharmonicity

    Science.gov (United States)

    Zheng, Li-Li; Li, Ke-Min; Lü, Xin-You; Wu, Ying

    2017-11-01

    We investigate theoretically the ground-state property of a two-dimensional array of superconducting circuits including the on-site superconducting qubits (SQs) with weak anharmonicity. In particular, we analyze the influence of this anharmonicity on the Mott-insulator to superfluid quantum phase transition. The complete ground-state phase diagrams are presented under the mean-field approximation. Interestingly, the anharmonicity of SQs affects the Mott lobes enormously, and the single excitation Mott lobe disappears when the anharmonicity becomes zero. Our results can be used to guide the implementations of quantum simulations using the superconducting circuits, which have nice integrating and flexibility.

  5. Simple statistical channel model for weak temperature-induced turbulence in underwater wireless optical communication systems

    KAUST Repository

    Oubei, Hassan M.

    2017-06-16

    In this Letter, we use laser beam intensity fluctuation measurements to model and describe the statistical properties of weak temperature-induced turbulence in underwater wireless optical communication (UWOC) channels. UWOC channels with temperature gradients are modeled by the generalized gamma distribution (GGD) with an excellent goodness of fit to the measured data under all channel conditions. Meanwhile, thermally uniform channels are perfectly described by the simple gamma distribution which is a special case of GGD. To the best of our knowledge, this is the first model that comprehensively describes both thermally uniform and gradient-based UWOC channels.

  6. Attenuation characteristics of electromagnetic waves in a weak collisional and fully ionized dusty plasma

    Science.gov (United States)

    Dan, Li; Guo, Li-Xin; Li, Jiang-Ting; Chen, Wei; Yan, Xu; Huang, Qing-Qing

    2017-09-01

    The expression of complex dielectric permittivity for non-magnetized fully ionized dusty plasma is obtained based on the kinetic equation in the Fokker-Planck-Landau collision model and the charging equation of the statistical theory. The influences of density, average size of dust grains, and balanced charging of the charge number of dust particles on the attenuation properties of electromagnetic waves in fully ionized dusty plasma are investigated by calculating the attenuation constant. In addition, the attenuation characteristics of weakly ionized and fully ionized dusty plasmas are compared. Results enriched the physical mechanisms of microwave attenuation for fully ionized dusty plasma and provide a theoretical basis for future studies.

  7. Simple statistical channel model for weak temperature-induced turbulence in underwater wireless optical communication systems.

    Science.gov (United States)

    Oubei, Hassan Makine; Zedini, Emna; ElAfandy, Rami T; Kammoun, Abla; Abdallah, Mohamed; Ng, Tien Khee; Hamdi, Mounir; Alouini, Mohamed-Slim; Ooi, Boon S

    2017-07-01

    In this Letter, we use laser beam intensity fluctuation measurements to model and describe the statistical properties of weak temperature-induced turbulence in underwater wireless optical communication (UWOC) channels. UWOC channels with temperature gradients are modeled by the generalized gamma distribution (GGD) with an excellent goodness of fit to the measured data under all channel conditions. Meanwhile, thermally uniform channels are perfectly described by the simple gamma distribution which is a special case of GGD. To the best of our knowledge, this is the first model that comprehensively describes both thermally uniform and gradient-based UWOC channels.

  8. The origins and evolution of weak low ionization quasar absorption line systems

    Science.gov (United States)

    Narayanan, Anand

    This thesis examines the physical nature of the gaseous structures selected by weak MgII quasar absorption line systems. The classic quasar absorption systems such as damped Lyman-a absorbers (DLAs), sub-DLAs and other Lyman Limit systems are widely studied because of their established association with galaxies of a wide range of morphology and luminosity. In contrast, weak MgII absorbers represent a population(s) that does not appear to be directly associated with luminous galaxies. Nonetheless, at z ~ 1, they outnumber the strong MgII absorbers by a factor of 3:1, and also account for a large fraction (> 25%) of the high column density regime of the Ly a forest. Moreover, a significant fraction of the weak MgII gas clouds have metallicities that are 0.5-2 dex higher than the average metallicity of DLA absorbers. In spite of such unique properties, the astrophysical structures and processes associated with weak MgII systems remain unidentified. In this thesis, I present results from UV and optical spectroscopic surveys, of ~ 100 quasars, offering a full census of weak MgII absorbers over the last 10 Gyr cosmological history of the universe, corresponding to 0 z z factor of ~ 8 from z = 1 to z = 0, the estimated dN/dz , at z = 0, for a static population of absorbers is a factor of ~ 2 larger than the observed dN/dz . This suggests that the gaseous structures that produce weak MgII absorbers are evolving from z = 1 to z = 0, and are regenerated at a rate that is consistent with the observed dN/dz . Towards, high- z ( z > 1), the dN/dz evolves with the number density reaching a peak at z = 1.2, thereafter declining such that there may not be a large separate population of weak absorbers at z > 2. I hypothesize this observed trend is indicative of the weak MgII clouds, at high- z , being kinematically connected to galaxies that produce strong MgII absorption. Photoionization models have suggested the weak MgII absorbing structures are unstable over astronomical

  9. Quantum weak and modular values in enlarged Hilbert spaces

    Science.gov (United States)

    Ho, Le Bin; Imoto, Nobuyuki

    2018-01-01

    We introduce an enlarged state, which combines both pre- and postselection states at a given time t in between the pre- and postselection. Based on this form, quantum weak and modular values can be completely interpreted as expectation values of a linear combination of given operators in the enlarged Hilbert space. This formalism thus enables us to describe and measure the weak and modular values at any time dynamically. A protocol for implementing an enlarged Hamiltonian has also been proposed and applied to a simple example of a single spin under an external magnetic field. In addition, the time-dependent weak and modular values for pre- and postselection density matrices mapping onto an enlarged density matrix are also discussed.

  10. Testing the Weak Form Efficiency of Karachi Stock Exchange

    Directory of Open Access Journals (Sweden)

    Muhammad Arshad Haroon

    2012-12-01

    Full Text Available In an efficient market, share prices reflect all available information. The study of efficient market hypothesis helps to take right decisions related to investments. In this research,weak form efficiency has been tested of Karachi Stock Exchange—KSE covering the period of 2nd November 1991 to 2nd November 2011. Descriptive statistics indicated the absence of weak form efficiency while results of non-parametric tests, showed consistency as well. We employed non-parametric tests were KS Goodness-of-Fit test,run test and autocorrelation test to find out serial independency of the data. Results prove that KSE is not weak-form-efficient. This happens because KSE is an emerging market and there, it has been observed that information take time to be processed. Thus it can besaid that technical analysis may be applied to gain abnormal returns.

  11. Non-perturbative aspects in a weakly interacting Higgs sector

    CERN Document Server

    Maas, Axel

    2012-01-01

    Just like the weakly interacting QED can support non-perturbative phenomena, like atoms, so can the weak and Higgs interactions. Especially, there are strong field-theoretical arguments that only bound states can be the (quasi-)asymptotic physical degrees of freedom of this sector. After a brief review of these arguments, the 2-point, 3-point and 4-point correlation functions of the Higgs-W system are determined using lattice gauge theory. The results support a conjectured duality between elementary states and bound states for weak Higgs self-interactions. This leads to relations between the bound states and the experimentally observed particles. Interestingly, these may yield pseudo-scalar admixtures at the Higgs energy, and possibly a faint standard-model signal in the channel where a Kaluza-Klein graviton would be expected.

  12. Enhancing teleportation fidelity by means of weak measurements or reversal

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Liang, E-mail: lqiu@cumt.edu.cn [College of Sciences, China University of Mining and Technology, Xuzhou 221116 (China); Tang, Gang; Yang, Xianqing [College of Sciences, China University of Mining and Technology, Xuzhou 221116 (China); Wang, Anmin [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)

    2014-11-15

    The enhancement of teleportation fidelity by weak measurement or quantum measurement reversal is investigated. One qubit of a maximally entangled state undergoes the amplitude damping, and the subsequent application of weak measurement or quantum measurement reversal could improve the teleportation fidelity beyond the classical region. The improvement could not be attributed to the increasing of entanglement, quantum discord, classical correlation or total correlation. We declare that it should be owed to the probabilistic nature of the method. - Highlights: • The method’s probabilistic nature should be responsible for the improvement. • Quantum or classical correlation cannot explain the improvement. • The receiver cannot apply weak measurements. • The sender’s quantum measurement reversal is only useful for |Ψ{sup ±}〉.

  13. Horizontal mergers and weak and strong competition commissions

    Directory of Open Access Journals (Sweden)

    Ristić Bojan

    2014-01-01

    Full Text Available In this paper we analyse the horizontal merger of companies in an already concentrated industry. The participants in mergers are obliged to submit notification to the Competition Commission but they also have the option of rejecting the merger. At the time of the notification submission the participants do not know whether the Commission is strong or weak, and they can complain to the Court if the Commission prohibits the merger. We model the strategic interaction between Participants and Commission in a dynamic game of incomplete information and determine weak perfect Bayesian equilibria. The main finding of our paper is that Participants will base their decision to submit notification on their belief in a weak Commission decision and will almost completely ignore the possibility of a strong Commission decision. We also provide a detailed examination of one case from Serbian regulatory practice, which coincides with the results of our game theoretical model.

  14. Children's ambiguous understanding of weak and strong quantifiers

    Directory of Open Access Journals (Sweden)

    Erik-Jan Smits

    2008-02-01

    Full Text Available Despite suggestions in the literature that the semantics of many might be the key for understanding children’s non-adult-like interpretations of quantified sentences (cf. Drozd 2001, Geurts 2003, experimental data on the acquisition of weak quantifiers like many is rare. This paper investigates children’s comprehension of weak (many versus strong (many of, all quantifiers in English. In particular, by means of a truth-value judgment task, taking the semantic and syntactic characteristics of many into account, we tested whether 28 children aged between four and seven understand the ambiguous nature of many as described in the literature (Partee, 1988 and whether they transfer this ambiguity to many of and all. The results show that children have an ambiguous quantifier system for both strong and weak quantifiers. This runs counter the idea that the child always prefers a reading of many in which the arguments seem to ‘switch’ (as for adults in Many French have won the Tour de France, resulting in the interpretation Many Tour de France winners are French, as predicted by Drozd and Van Loosbroek’s (1999 Weak Quantification Hypothesis. On the basis of our experimental results on children’s understanding of both weak and strong quantifiers, we conclude that children’s non-adult interpretations of quantified sentences are due to the ambiguous nature of (weak quantifiers. This presents the language learner with the difficult, but necessary, task to distinguish between those different kinds of readings and understand their different semantic and syntactic representations in order to converge with the target language.

  15. Characterization of ocular motor deficits in congenital facial weakness: Moebius and related syndromes.

    Science.gov (United States)

    Rucker, Janet C; Webb, Bryn D; Frempong, Tamiesha; Gaspar, Harald; Naidich, Thomas P; Jabs, Ethylin Wang

    2014-04-01

    involvement. Defects in the range or dynamic properties of vertical movements in subjects with congenital facial weakness may suggest involvement of ocular motor structures in the midbrain, including oculomotor nerves or nuclei, vertical supranuclear saccadic centres, and convergence neurons. Such deficits were found even in subjects with full vertical motility range. Classification of patterns of ocular motor deficits in congenital facial weakness may assist with further delineation of anatomic localization and identification of genetic deficits underlying these disorders.

  16. Characterization of ocular motor deficits in congenital facial weakness: Moebius and related syndromes

    Science.gov (United States)

    Webb, Bryn D.; Frempong, Tamiesha; Gaspar, Harald; Naidich, Thomas P.; Jabs, Ethylin Wang

    2014-01-01

    nerve involvement. Defects in the range or dynamic properties of vertical movements in subjects with congenital facial weakness may suggest involvement of ocular motor structures in the midbrain, including oculomotor nerves or nuclei, vertical supranuclear saccadic centres, and convergence neurons. Such deficits were found even in subjects with full vertical motility range. Classification of patterns of ocular motor deficits in congenital facial weakness may assist with further delineation of anatomic localization and identification of genetic deficits underlying these disorders. PMID:24561559

  17. Weak Approximation of SDEs by Discrete-Time Processes

    Directory of Open Access Journals (Sweden)

    Henryk Zähle

    2008-01-01

    Full Text Available We consider the martingale problem related to the solution of an SDE on the line. It is shown that the solution of this martingale problem can be approximated by solutions of the corresponding time-discrete martingale problems under some conditions. This criterion is especially expedient for establishing the convergence of population processes to SDEs. We also show that the criterion yields a weak Euler scheme approximation of SDEs under fairly weak assumptions on the driving force of the approximating processes.

  18. Weak Interaction Studies by Precision Experiments in Nuclear Beta Decay

    Science.gov (United States)

    Severijns, Nathal

    The framework and formalism related to the study of symmetries and the structure of the weak interaction in nuclear -decay are presented and discussed. This is illustrated with a number of selected experiments in nuclear -decay addressing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix, the search for right-handed (V+A), scalar and tensor components in the weak interaction and the search for non-Standard Model sources of time reversal violation. Finally, an outlook is given on important progress in this field that can be expected for the near future.

  19. Weak gravitational lensing with COSMOS : galaxy selection and shape measurements.

    OpenAIRE

    Leauthaud, Alexie; Massey, Richard; Kneib, Jean-Paul; Rhodes, Jason; Johnston, David E.; Capak, Peter; Heymans, Catherine; Ellis, Richard S.; Koekemoer, Anton M.; Le Fevre, Oliver; Mellier, Yannick; Refregier, Alexandre; Robin, Annie C.; Scoville, Nick; Tasca, Lidia

    2007-01-01

    With a primary goal of conducting precision weak-lensing measurements from space, the COSMOS survey has imaged the largest contiguous area observed by Hubble Space Telescope to date, using the Advanced Camera for Surveys (ACS). This is the first paper in a series in which we describe our strategy for addressing the various technical challenges in the production of weak-lensing measurements from COSMOS data. We first construct a source catalog from 575 ACS/WFC tiles (1.64 deg^2) subsampled at ...

  20. Power control for wind turbines in weak grids: Project summary

    OpenAIRE

    Bindner, H.

    1999-01-01

    In many parts of the world and certainly in Europe large areas exist where the wind resources are good or very good and the grid is relatively weak due to a small population. In these areas the capacity of the grid can very often be a limiting factor forthe exploitation of the wind resource. There are two main problems concerned with wind power and weak grids. The first is the steady state voltage level. When the power consumption is low e.g. during the night the voltage of the grid can incre...

  1. A weak equivalence principle test on a suborbital rocket

    Energy Technology Data Exchange (ETDEWEB)

    Reasenberg, Robert D; Phillips, James D, E-mail: reasenberg@cfa.harvard.ed [Smithsonian Astrophysical Observatory, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2010-05-07

    We describe a Galilean test of the weak equivalence principle, to be conducted during the free fall portion of a sounding rocket flight. The test of a single pair of substances is aimed at a measurement uncertainty of sigma(eta) < 10{sup -16} after averaging the results of eight separate drops. The weak equivalence principle measurement is made with a set of four laser gauges that are expected to achieve 0.1 pm Hz{sup -1/2}. The discovery of a violation (eta not = 0) would have profound implications for physics, astrophysics and cosmology.

  2. A weak equivalence principle test on a suborbital rocket

    CERN Document Server

    Reasenberg, Robert D

    2010-01-01

    We describe a Galilean test of the weak equivalence principle, to be conducted during the free fall portion of a sounding rocket flight. The test of a single pair of substances is aimed at a measurement uncertainty of sigma(eta) < 10^-16 after averaging the results of eight separate drops. The weak equivalence principle measurement is made with a set of four laser gauges that are expected to achieve 0.1 pm Hz^-1/2. The discovery of a violation (eta not equal to 0) would have profound implications for physics, astrophysics, and cosmology.

  3. Weak Molecular Interactions in Clathrin-Mediated Endocytosis

    Science.gov (United States)

    Smith, Sarah M.; Baker, Michael; Halebian, Mary; Smith, Corinne J.

    2017-01-01

    Clathrin-mediated endocytosis is a process by which specific molecules are internalized from the cell periphery for delivery to early endosomes. The key stages in this step-wise process, from the starting point of cargo recognition, to the later stage of assembly of the clathrin coat, are dependent on weak interactions between a large network of proteins. This review discusses the structural and functional data that have improved our knowledge and understanding of the main weak molecular interactions implicated in clathrin-mediated endocytosis, with a particular focus on the two key proteins: AP2 and clathrin.

  4. Measurements of weak localization of graphene in inhomogeneous magnetic fields

    DEFF Research Database (Denmark)

    Lindvall, N.; Shivayogimath, Abhay; Yurgens, A.

    2015-01-01

    attribute this to the inhomogeneous field caused by vortices in the superconductor. The deviation, which depends on the carrier concentration in graphene, can be tuned by the gate voltage. In addition, collective vortex motion, known as vortex avalanches, is observed through magnetoresistance measurements......Weak localization in graphene is studied in inhomogeneous magnetic fields. To generate the inhomogeneous field, a thin film of type-II superconducting niobium is put in close proximity to graphene. A deviation from the ordinary quadratic weak localization behavior is observed at low fields. We...... of graphene....

  5. Processing on weak electric signals by the autoregressive model

    Science.gov (United States)

    Ding, Jinli; Zhao, Jiayin; Wang, Lanzhou; Li, Qiao

    2008-10-01

    A model of the autoregressive model of weak electric signals in two plants was set up for the first time. The result of the AR model to forecast 10 values of the weak electric signals is well. It will construct a standard set of the AR model coefficient of the plant electric signal and the environmental factor, and can be used as the preferences for the intelligent autocontrol system based on the adaptive characteristic of plants to achieve the energy saving on agricultural productions.

  6. On Weak and Strong 2k- bent Boolean Functions

    Science.gov (United States)

    2016-01-01

    no. 1, 34–64; translation in J. Appl. Ind. Math . 5:1 (2011), 110–129. [17] N. Tokareva, Bent Functions – Results and Applications to Cryptogra- phy...On weak and strong 2k-bent Boolean functions Pantelimon Stănică Department of Applied Mathematics Naval Postgraduate School Monterey, CA 93943-5212... functions , which we shall call (weak, strong) octa/hexadeca and in general, 2k-bent functions . We investigate relationships between these classes and

  7. Bubble, weak and strong hyperinflation: Theory and empirical evidence

    Directory of Open Access Journals (Sweden)

    Fernando de Holanda Barbosa

    2015-05-01

    Full Text Available This paper presents a theoretical framework that allows a taxonomy of hyperinflation, namely: (i bubble, (ii weak and (iii strong hyperinflation. The inflation tax revenue curve is used to characterize each type of hyperinflation and we use this curve to test them. The bubble and strong hyperinflation hypotheses are rejected using Brazilian data. The weak hyperinflation hypothesis is not rejected and the economy could have been on the ‘wrong’ side of the Laffer curve during hyperinflation. This outcome, contrary to conventional wisdom, is predicted by this hypothesis, which presents a solution to an old puzzle of the hyperinflation literature.

  8. A Weak Comparison Principle for Reaction-Diffusion Systems

    Directory of Open Access Journals (Sweden)

    José Valero

    2012-01-01

    Full Text Available We prove a weak comparison principle for a reaction-diffusion system without uniqueness of solutions. We apply the abstract results to the Lotka-Volterra system with diffusion, a generalized logistic equation, and to a model of fractional-order chemical autocatalysis with decay. Moreover, in the case of the Lotka-Volterra system a weak maximum principle is given, and a suitable estimate in the space of essentially bounded functions L∞ is proved for at least one solution of the problem.

  9. Observation of Weak Collapse in a Bose-Einstein Condensate

    Directory of Open Access Journals (Sweden)

    Christoph Eigen

    2016-12-01

    Full Text Available We study the collapse of an attractive atomic Bose-Einstein condensate prepared in the uniform potential of an optical-box trap. We characterize the critical point for collapse and the collapse dynamics, observing universal behavior in agreement with theoretical expectations. Most importantly, we observe a clear experimental signature of the counterintuitive weak collapse, namely, that making the system more unstable can result in a smaller particle loss. We experimentally determine the scaling laws that govern the weak-collapse atom loss, providing a benchmark for the general theories of nonlinear wave phenomena.

  10. Observation of Weak Collapse in a Bose-Einstein Condensate

    Science.gov (United States)

    Eigen, Christoph; Gaunt, Alexander L.; Suleymanzade, Aziza; Navon, Nir; Hadzibabic, Zoran; Smith, Robert P.

    2016-10-01

    We study the collapse of an attractive atomic Bose-Einstein condensate prepared in the uniform potential of an optical-box trap. We characterize the critical point for collapse and the collapse dynamics, observing universal behavior in agreement with theoretical expectations. Most importantly, we observe a clear experimental signature of the counterintuitive weak collapse, namely, that making the system more unstable can result in a smaller particle loss. We experimentally determine the scaling laws that govern the weak-collapse atom loss, providing a benchmark for the general theories of nonlinear wave phenomena.

  11. A weak energy stationary action principle for quantum state evolution

    Science.gov (United States)

    Parks, A. D.

    2003-06-01

    It is shown that the actual paths in Hilbert space followed by a finite set of n geq 2 quantum states evolving between initial and final end point configurations are such that an associated weak energy functional defined by Pancharatnam phases and state separation distances in projective Hilbert space determined by the generalized Fubini-Study metric is stationary for all variations of these phases, separations and time which vanish at the end points. Noether's theorem is used to identify two weak energy conservation laws which are shown to be the analogues of the momentum and energy conservation laws of Langrangian mechanics.

  12. A weak energy stationary action principle for quantum state evolution

    Energy Technology Data Exchange (ETDEWEB)

    Parks, A D [Quantum Processing Group, Systems Research and Technology Department, Naval Surface Warfare Center, Dahlgren, VA 22448 (United States)

    2003-06-27

    It is shown that the actual paths in Hilbert space followed by a finite set of n {>=} 2 quantum states evolving between initial and final end point configurations are such that an associated weak energy functional defined by Pancharatnam phases and state separation distances in projective Hilbert space determined by the generalized Fubini-Study metric is stationary for all variations of these phases, separations and time which vanish at the end points. Noether's theorem is used to identify two weak energy conservation laws which are shown to be the analogues of the momentum and energy conservation laws of Langrangian mechanics.

  13. Intensive care unit-acquired weakness: Pathophysiology and diagnosis

    OpenAIRE

    Witteveen, E

    2017-01-01

    Many patients on the intensive care unit (ICU) develop generalized muscle weakness. This condition, called intensive care unit- acquired weakness (ICU-AW), is caused by dysfunction or damage of muscles, nerves, or both. ICU-AW is associated with increased short- and long-term morbidity and mortality. The pathophysiology of ICU-AW is complex and remains to be elucidated. The first aim of this thesis was to investigate the role of inflammation in ICU-AW. We reviewed the literature and we invest...

  14. Using weak values to experimentally determine "negative probabilities" in a two-photon state with Bell correlations

    Science.gov (United States)

    Higgins, B. L.; Palsson, M. S.; Xiang, G. Y.; Wiseman, H. M.; Pryde, G. J.

    2015-01-01

    Bipartite quantum entangled systems can exhibit measurement correlations that violate Bell inequalities, revealing the profoundly counter-intuitive nature of the physical universe. These correlations reflect the impossibility of constructing a joint probability distribution for all values of all the different properties observed in Bell inequality tests. Physically, the impossibility of measuring such a distribution experimentally, as a set of relative frequencies, is due to the quantum back-action of projective measurements. Weakly coupling to a quantum probe, however, produces minimal back-action, and so enables a weak measurement of the projector of one observable, followed by a projective measurement of a noncommuting observable. By this technique it is possible to empirically measure weak-valued probabilities for all of the values of the observables relevant to a Bell test. The marginals of this joint distribution, which we experimentally determine, reproduces all of the observable quantum statistics including a violation of the Bell inequality, which we independently measure. This is possible because our distribution, like the weak values for projectors on which it is built, is not constrained to the interval [0 ,1 ] . It was first pointed out by Feynman that, for explaining singlet-state correlations within "a [local] hidden variable view of nature … everything works fine if we permit negative probabilities." However, there are infinitely many such theories. Our method, involving "weak-valued probabilities," singles out a unique set of probabilities, and moreover does so empirically.

  15. Weak convergence and uniform normalization in infinitary rewriting

    DEFF Research Database (Denmark)

    Simonsen, Jakob Grue

    2010-01-01

    We study infinitary term rewriting systems containing finitely many rules. For these, we show that if a weakly convergent reduction is not strongly convergent, it contains a term that reduces to itself in one step (but the step itself need not be part of the reduction). Using this result, we prov...

  16. The chiral anomaly in non-leptonic weak interactions

    CERN Document Server

    Bijnens, J; Pich, Antonio

    1992-01-01

    The interplay between the chiral anomaly and the non-leptonic weak Hamiltonian is studied. The structure of the corresponding effective Lagrangian of odd intrinsic parity is established. It is shown that the factorizable contributions (leading in $1/N_C$) to that Lagrangian can be calculated without free parameters. As a first application, the decay $K^+ \\ra \\pi^+ \\pi^0 \\gamma$ is investigated.

  17. School-Based Sexuality Education in Portugal: Strengths and Weaknesses

    Science.gov (United States)

    Rocha, Ana Cristina; Leal, Cláudia; Duarte, Cidália

    2016-01-01

    Portugal, like many other countries, faces obstacles regarding school-based sexuality education. This paper explores Portuguese schools' approaches to implementing sexuality education at a local level, and provides a critical analysis of potential strengths and weaknesses. Documents related to sexuality education in a convenience sample of 89…

  18. On the existence of weak solutions of quantum stochastic differential ...

    African Journals Online (AJOL)

    We establish further results concerning the existence, uniqueness and stability of weak solutions of quantum stochastic differential equations (QSDEs). Our results are achieved by considering a more general Lipschit condition on the coefficients than our previous considerations in [1]. We exhibit a class of Lipschitzian ...

  19. Magnetic relaxation in a three-dimensional ferromagnet with weak ...

    Indian Academy of Sciences (India)

    ... determined previously for the same sample from static critical phenomena measurements) for a nearly ordered intermetallic compound Ni3Al, which is an experimental realization of a three-dimensional (= 3) ferromagnet with weak quenched random-exchange disorder. None of the functional forms of r() predicted by ...

  20. Weak point disorder in strongly fluctuating flux-line liquids

    Indian Academy of Sciences (India)

    We consider the effect of weak uncorrelated quenched disorder (point defects) on a strongly fluctuating flux-line liquid. We use a hydrodynamic model which is based on mapping the flux-line system onto a quantum liquid of relativistic charged bosons in 2 + 1 dimensions [P Benetatos and M C Marchetti, Phys. Rev. B64 ...

  1. Early Results from the Q{sub weak} Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Androic, D; Armstrong, D S; Asaturyan, A; Averett, T; Balewski, J; Beaufait, J; Beminiwattha, R S; Benesch, J; Benmokhtar, F; Birchall, J; Carlini, R D; Cates, G D; Cornejo, J C; Covrig, S; Dalton, M M; Davis, C A; Deconinck, W; Diefenbach, J; Dowd, J F; Dunne, J A; Dutta, D; Duvall, W S; Elaasar, M; Falk, W R; Finn, J M; Forest, T; Gaskel, D; Gericke, M T.W.; Grames, J; Gray, V M; Grimm, K; Guo, F; Hoskins, J R; Johnston, K; Jones, D; Jones, M; Jones, R; Kargiantoulakis, M; King, P M; Korkmaz, E; Kowalski, S; Leacock, J; Leckey, J; Lee, A R; Lee, J H; Lee, L; MacEwan, S; Mack, D; Magee, J A; Mahurin, R; Mammei, J; Martin, J; McHugh, M J; Meekins, D; Mei, J; Michaels, R; Micherdzinska, A; Mkrtchyan, A; Mkrtchyan, H; Morgan, N; Myers, K E; Narayan, A; Ndukum, L Z; Nelyubin, V; W T H, Nuruzzaman; Oers, van; Opper, A K; Page, S A; Pan, J; Paschke, K; Phillips, S K; Pitt, M L; Poelker, M; Rajotte, J F; Ramsay, W D; Roche, J; Sawatzky, B; Seva, T; Shabestari, M H; Silwal, R; Simicevic, N; Smith, G R; Solvignon, P; Spayde, D T; Subedi, A; Subedi, R; Suleiman, R; Tadevosyan, V; Tobias, W A; Tvaskis, V; Waidyawansa, B; Wang, P; Wells, S P; Wood, S A; Yang, S; Young, R D; Zhamkochyan, S

    2014-03-01

    A subset of results from the recently completed Jefferson Lab Q{sub weak} experiment are reported. This experiment, sensitive to physics beyond the Standard Model, exploits the small parity-violating asymmetry in elastic {vector e}p scattering to provide the first determination of the protons weak charge Q{sub w}{sup p}. The experiment employed a 180 {micro}A longitudinally polarized 1.16 GeV electron beam on a 35 cm long liquid hydrogen target. Scattered electrons corresponding to Q{sup 2} of 0.025 GeV{sup 2} were detected in eight Cerenkov detectors arrayed symmetrically around the beam axis. The goals of the experiment were to provide a measure of Q{sub w}{sup p} to 4.2 percent (combined statistical and systematic error), which implies a measure of sin2(thetaw) at the level of 0.3 percent, and to help constrain the vector weak quark charges C{sub 1u} and C{sub 1d}. The experimental method is described, with particular focus on the challenges associated with the worlds highest power LH{sub 2} target. The new constraints on C{sub 1u} and C{sub 1d} provided by the subset of the experiments data analyzed to date will also be shown, together with the extracted weak charge of the neutron.

  2. Weak interactions of quarks and leptons: experimental status

    Energy Technology Data Exchange (ETDEWEB)

    Wojcicki, S.

    1984-09-01

    The present experimental status of weak interactions is discussed with emphasis on the problems and questions and on the possible lines of future investigations. Major topics include; (1) the quark mixing matrix, (2) CP violation, (3) rare decays, (4) the lepton sector, and (5) right handed currents. 118 references. (WHK)

  3. Overcoming Microsoft Excel's Weaknesses for Crop Model Building and Simulations

    Science.gov (United States)

    Sung, Christopher Teh Boon

    2011-01-01

    Using spreadsheets such as Microsoft Excel for building crop models and running simulations can be beneficial. Excel is easy to use, powerful, and versatile, and it requires the least proficiency in computer programming compared to other programming platforms. Excel, however, has several weaknesses: it does not directly support loops for iterative…

  4. Weak signal detection: A discrete window of opportunity for ...

    African Journals Online (AJOL)

    2016-01-29

    Jan 29, 2016 ... Introduction: UNAIDS' Vision 90:90:90 is a call to 'end AIDS'. Developing predictive foresight of the unpredictable changes that this journey will entail could contribute to the ambition of 'ending AIDS'. There are few opportunities for managing unpredictable changes. We introduce 'weak signal detection' as ...

  5. Theory of “Weak Value" and Quantum Mechanical Measurements

    OpenAIRE

    Shikano, Yutaka

    2012-01-01

    Comment: to be published from "Measurements in Quantum Mechanics", edited by M. R. Pahlavani (InTech, 2012) Chapter 4 page 75. Yutaka Shikano (2012). ISBN: 978-953-51-0058-4 Available from: http://www.intechopen.com/articles/show/title/theory-of-weak-value-and-quantum-mechanical-measurement

  6. Methods and models for the construction of weakly parallel tests

    NARCIS (Netherlands)

    Adema, J.J.; Adema, Jos J.

    1990-01-01

    Methods are proposed for the construction of weakly parallel tests, that is, tests with the same test information function. A mathematical programing model for constructing tests with a prespecified test information function and a heuristic for assigning items to tests such that their information

  7. Branch-point stoichiometry can generate weak links in metabolism ...

    Indian Academy of Sciences (India)

    We call these sites weak links in metabolism, as they can interfere harmfully with management of matter and energy if the network as a whole does not include ... which converts serine into glycine plus one C1 unit: this produces an absolute dependence of the glycine production flux on the utilization of C1 units for other ...

  8. One-Sided Weakness Admitted with Hypokalemic Periodic Paralysis

    Directory of Open Access Journals (Sweden)

    Fatih Yaman

    2014-04-01

    Full Text Available Hypokalemic periodic paralysis (HPP is a genetic disorder that characterized by recurrent attacks of skeletal muscle weakness with associated hypokalemia which is precipitated by hypotermia, stress, infection, carbonhydrate load, glucose infusion, metabolic alkalosis, general anesthesia, steroids and licorice root. 52-year-old male patient while working in a cold enviroment, began to complain of weakness in the arms and legs. The patient was brought to the emergency department due to the continuation of weakness complaints in the left arm and leg.The neurological examination had 5/5 strength in the upper-right and lower-right extremities, 3/5 strength in the upper-left and lower-left extremities. Serum electrolytes: Potassium: 2.7 mEq/L, 1.9 mEq/L control. There was no evidence of bleeding and infarction in Computerized Brain Tomography and Brain MR. After intravenous infusion of potassium, at the third hour the patient%u2019s neurological symptoms resolved completely, patient was mobilized. In this case we present one-sided weakness admitted to the emergency department, the diagnosis of patient with HPP. We aimed to emphasize that this diagnosis should be keeping in mind that among the causes paralysis and delayed diagnose and treatment may be mortal in HPP.

  9. Common Fixed Point of Multivalued Generalized -Weak Contractive Mappings

    Directory of Open Access Journals (Sweden)

    Moradi Sirous

    2010-01-01

    Full Text Available Fixed point and coincidence results are presented for multivalued generalized -weak contractive mappings on complete metric spaces, where is a lower semicontinuous function with and for all . Our results extend previous results by Zhang and Song (2009, as well as by Rhoades (2001, Nadler (1969, and Daffer and Kaneko (1995.

  10. Attractive critical point from weak antilocalization on fractals

    NARCIS (Netherlands)

    Sticlet, D.C.; Akhmerov, A.R.

    2016-01-01

    We report an attractive critical point occurring in the Anderson localization scaling flow of symplectic models on fractals. The scaling theory of Anderson localization predicts that in disordered symplectic two-dimensional systems weak-antilocalization effects lead to a metal-insulator

  11. The Frequency of Cohesion Weakness in Psychiatric Syndromes.

    Science.gov (United States)

    Bartolucci, Giampiero; Fine, Jonathan

    1987-01-01

    Analysis of psychiatric patients' utterances during an interview indicated that the percentage of unclear cohesive ties was significantly higher among schizophrenics than in a group of patients with mixed diagnoses (mostly affective disorders). Cohesive weakness was a more frequent characteristic of the language of schizophrenic speakers.…

  12. Patterns of Strengths and Weaknesses in Children's Knowledge about Fractions

    Science.gov (United States)

    Hecht, Steven A.; Vagi, Kevin J.

    2012-01-01

    The purpose of this study was to explore individual patterns of strengths and weaknesses in children's mathematical knowledge about common fractions. Tasks that primarily measure either conceptual or procedural aspects of mathematical knowledge were assessed with the same children in their fourth- and fifth-grade years (N = 181, 56% female and 44%…

  13. Tunneling Time and Weak Measurement in Strong Field Ionization

    Science.gov (United States)

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

    2016-06-01

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

  14. The Mathematical Strengths and Weaknesses of Children with Dyslexia

    Science.gov (United States)

    Simmons, Fiona R.; Singleton, Chris

    2009-01-01

    This paper reports the findings of two related studies that examined the mathematical strengths and weaknesses of children with dyslexia. In study one, dyslexic children were compared to children without special educational needs on tests that assessed arithmetic fact recall, place value understanding and counting speed. Study two used the same…

  15. Muscle Weakness and Speech in Oculopharyngeal Muscular Dystrophy

    Science.gov (United States)

    Neel, Amy T.; Palmer, Phyllis M.; Sprouls, Gwyneth; Morrison, Leslie

    2015-01-01

    Purpose: We documented speech and voice characteristics associated with oculopharyngeal muscular dystrophy (OPMD). Although it is a rare disease, OPMD offers the opportunity to study the impact of myopathic weakness on speech production in the absence of neurologic deficits in a relatively homogeneous group of speakers. Methods: Twelve individuals…

  16. Migrant networks and international migration: testing weak ties.

    Science.gov (United States)

    Liu, Mao-Mei

    2013-08-01

    This article examines the role of migrant social networks in international migration and extends prior research by testing the strength of tie theory, decomposing networks by sources and resources, and disentangling network effects from complementary explanations. Nearly all previous empirical research has ignored friendship ties and has largely neglected extended-family ties. Using longitudinal data from the Migration between Africa and Europe project collected in Africa (Senegal) and Europe (France, Italy, and Spain), this article tests the robustness of network theory-and in particular, the role of weak ties-on first-time migration between Senegal and Europe. Discrete-time hazard model results confirm that weak ties are important and that network influences appear to be gendered, but they do not uphold the contention in previous literature that strong ties are more important than weak ties for male and female migration. Indeed, weak ties play an especially important role in male migration. In terms of network resources, having more resources as a result of strong ties appears to dampen overall migration, while having more resources as a result of weaker ties appears to stimulate male migration. Finally, the diversity of resources has varied effects for male and female migration.

  17. Muscle weakness, afferent sensory dysfunction and exercise in knee osteoarthritis

    DEFF Research Database (Denmark)

    Roos, Ewa M.; Herzog, Walter; Block, Joel A

    2011-01-01

    Lower-extremity muscle strength and afferent sensory dysfunction, such as reduced proprioceptive acuity, are potentially modifiable putative risk factors for knee osteoarthritis (OA). Findings from current studies suggest that muscle weakness is a predictor of knee OA onset, while there is confli...

  18. Policy-based benchmarking of weak heaps and their relatives

    DEFF Research Database (Denmark)

    Bruun, Asger; Edelkamp, Stefan; Katajainen, Jyrki

    2010-01-01

    ), and a run-relaxed weak queue that of both insert and decrease to O(1). As competitors to these structures, we considered a binary heap, a Fibonacci heap, and a pairing heap. Generic programming techniques were heavily used in the code development. For benchmarking purposes we developed several component...

  19. Formation flying design and applications in weak stability boundary regions.

    Science.gov (United States)

    Folta, David

    2004-05-01

    Weak stability regions serve as superior locations for interferomertric scientific investigations. These regions are often selected to minimize environmental disturbances and maximize observation efficiency. Designs of formations in these regions are becoming ever more challenging as more complex missions are envisioned. The development of algorithms to enable the capability for formation design must be further enabled to incorporate better understanding of weak stability boundary solution space. This development will improve the efficiency and expand the capabilities of current approaches. The Goddard Space Flight Center (GSFC) is currently supporting multiple formation missions in weak stability boundary regions. This end-to-end support consists of mission operations, trajectory design, and control. It also includes both algorithm and software development. The Constellation-X, Maxim, and Stellar Imager missions are examples of the use of improved numeric methods to attain constrained formation geometries and control their dynamical evolution. This paper presents a survey of formation missions in the weak stability boundary regions and a brief description of formation design using numerical and dynamical techniques.

  20. On the dynamic buckling of a weakly damped nonlinear elastic ...

    African Journals Online (AJOL)

    In this paper we determine the dynamic buckling load of a strictly nonlinear but weakly damped elastic oscillatory model structure subjected to small perturbations The loading history is explicitly time dependent and varies slowly with time over a natural period of oscillation of the structure. A multiple timing regular ...

  1. Weak signal detection: A discrete window of opportunity for ...

    African Journals Online (AJOL)

    Introduction: UNAIDS' Vision 90:90:90 is a call to 'end AIDS'. Developing predictive foresight of the unpredictable changes that this journey will entail could contribute to the ambition of 'ending AIDS'. There are few opportunities for managing unpredictable changes. We introduce 'weak signal detection' as a potential ...

  2. Weak convergence of Jacobian determinants under asymmetric assumptions

    Directory of Open Access Journals (Sweden)

    Teresa Alberico

    2012-05-01

    Full Text Available Let $\\Om$ be a bounded open set in $\\R^2$ sufficiently smooth and $f_k=(u_k,v_k$ and $f=(u,v$ mappings belong to the Sobolev space $W^{1,2}(\\Om,\\R^2$. We prove that if the sequence of Jacobians $J_{f_k}$ converges to a measure $\\mu$ in sense of measures andif one allows different assumptions on the two components of $f_k$ and $f$, e.g.$$u_k \\rightharpoonup u \\;\\;\\mbox{weakly in} \\;\\; W^{1,2}(\\Om \\qquad \\, v_k \\rightharpoonup v \\;\\;\\mbox{weakly in} \\;\\; W^{1,q}(\\Om$$for some $q\\in(1,2$, then\\begin{equation}\\label{0}d\\mu=J_f\\,dz.\\end{equation}Moreover, we show that this result is optimal in the sense that conclusion fails for $q=1$.On the other hand, we prove that \\eqref{0} remains valid also if one considers the case $q=1$, but it is necessary to require that $u_k$ weakly converges to $u$ in a Zygmund-Sobolev space with a slightly higher degree of regularity than $W^{1,2}(\\Om$ and precisely$$ u_k \\rightharpoonup u \\;\\;\\mbox{weakly in} \\;\\; W^{1,L^2 \\log^\\alpha L}(\\Om$$for some $\\alpha >1$.    

  3. Weak managers and the plight of white-collar workers

    OpenAIRE

    Hirschhorn, Daniel

    2017-01-01

    Far too many employees are unhappy at work. Today, one of the major problems - resulting from weak, callous, dispassionate, greedy managers and leaders - is the great number of workers, including white-collar ones, who are grossly underemployed, underpaid, and maltreated by management.

  4. Oculopharyngeal muscular dystrophy with limb girdle weakness as major complaint.

    NARCIS (Netherlands)

    Sluijs, B.M. van der; Hoefsloot, L.H.; Padberg, G.W.A.M.; Maarel, S.M. van der; Engelen, B.G.M. van

    2003-01-01

    This first description of the oculopharyngeal muscular dystrophy (OPMD) phenotype in Dutch patients shows that limb girdle weakness can occur early in the course of disease and can give the first and major complaint in OPMD patients. The aim of this study was to examine clinically, histologically

  5. Microcavity polariton linewidths in the weak-disorder regime

    DEFF Research Database (Denmark)

    Borri, Paola; Langbein, Wolfgang Werner; Woggon, U.

    2000-01-01

    Polariton linewidths have been measured in a series of high-quality microcavities with different excitonic inhomogeneous broadening in the weak-disorder regime. We show experimentally that the influence of the disorder on the polariton linewidths is canceled when the polariton energies are far...

  6. The role of weak intermolecular CH… F interactions in ...

    Indian Academy of Sciences (India)

    Analysis of Cambridge Structural Database using these newly defined parameters reveals high propensity of C-H…F interactions in organic crystals. The present structural study suggests much larger role of fluorine driven intermolecular interactions that are even though weak, but possess significant ability to direct and alter ...

  7. Towards Metamathematics of Weak Arithmetics over Fuzzy Logic

    Czech Academy of Sciences Publication Activity Database

    Hájek, Petr

    2011-01-01

    Roč. 19, č. 3 (2011), s. 467-475 ISSN 1367-0751 R&D Projects: GA AV ČR IAA100300503 Institutional research plan: CEZ:AV0Z10300504 Keywords : weak arithmetics * mathematical fuzzy logic * Gödel’s theorem * essential undecidability Subject RIV: BA - General Mathematics Impact factor: 0.913, year: 2011

  8. A young man with progressive weakness, double vision and ...

    African Journals Online (AJOL)

    At this point he sought medical advice at QECH; a definitive diagnosis was not made. By August 2010 his weakness also involved both his arms, so that he was unable to raise them above his head. He noticed that he fatigued easily, especially at the end of the day, and he became breathless when doing simple tasks like.

  9. Weakly Nonlinear Waves with Slowly-Varying Speed | Chikwendu ...

    African Journals Online (AJOL)

    A previously developed method of generating uniformly valid, multiple- scale asymptotic expansions for the solution of weakly nonlinear one-dimensional wave equations is applied to problems with slowly-varying speed. The method is also shown to be applicable specifically to periodic initial data.

  10. [A woman with skin abnormalities and muscle weakness

    NARCIS (Netherlands)

    Steggink, L.C.; Hettema, M.E.; Delsing, C.E.

    2013-01-01

    A 54-year-old woman presented to the emergency department with progressive proximal muscle weakness and a symmetric skin rash. Physical examination demonstrated a heliotrope rash, Gottron lesions, mechanic's hands and symmetrical erythema of the face, neck and upper legs. The diagnosis

  11. Analytical solutions of weakly coupled map lattices using recurrence relations

    Energy Technology Data Exchange (ETDEWEB)

    Sotelo Herrera, Dolores, E-mail: dsh@dfmf.uned.e [Applied Maths, EUITI, UPM, Ronda de Valencia, 3-28012 Madrid (Spain); San Martin, Jesus [Applied Maths, EUITI, UPM, Ronda de Valencia, 3-28012 Madrid (Spain); Dep. Fisica Matematica y de Fluidos, UNED, Senda del Rey 9-28040 Madrid (Spain)

    2009-07-20

    By using asymptotic methods recurrence relations are found that rule weakly CML evolution, with both global and diffusive coupling. The solutions obtained from these relations are very general because they do not hold restrictions about boundary conditions, initial conditions and number of oscilators in the CML. Furthermore, oscillators are ruled by an arbitraty C{sup 2} function.

  12. Strengths weaknesses opportunities and threats of blended learning ...

    African Journals Online (AJOL)

    Aim: The aim of this study was to identify the strengths, weaknesses, opportunities and threats (SWOT) of BL in a premedical class. Subjects and Methods: It was a cross‑sectional study. Ninety six students in a premedical cell biology class participated in the study. SWOT analysis of students' perceptions was conducted ...

  13. Testing weak form efficiency on the capital markets in Serbia

    Directory of Open Access Journals (Sweden)

    Kršikapa-Rašajski Jovana

    2016-01-01

    Full Text Available Weak-form efficient market hypothesis assumes that participants on the financial markets are not able to achieve above-average returns based on historical prices. In order to establish the presence of a weak-form market efficiency in the Serbian market, the analysis incorporates daily data of the two most prominent indices on the Belgrade Stock Exchange, BELEX 15 and BELEX LINE, since their inception until 31 December 2014. Results obtained by the analysis and testing indicate that the capital market in Serbia can not be considered sufficiently efficient, more precisely it indicates that postulates assumed by the weak-form market efficiency are not fully met. Taking into account that the capital market in Serbia is still underdeveloped, primarily because of the small volumes, turnover and types of securities which are traded on the market, as well as the fact that it is not sufficiently regulated and transparent, lack of investors is noticeable. Consequently, analysis presented in this paper indicates a weak sustainability of the efficient market hypothesis in Serbia.

  14. Ansys Analysis of Weakly Magnetic Materials in MR Tomography

    Directory of Open Access Journals (Sweden)

    Miroslav Steinbauer

    2004-01-01

    Full Text Available The paper deals with the impact of weakly magnetic materials on magnetic field in MR tomography. The resultsobtained by finite element method modelling as well as data measured by MR tomography are introduced. Method ofmagnetic susceptibility determination using MRI is discussed.

  15. Making Weak Bonds (cooling) and Breaking Strong Bonds (heating ...

    Indian Academy of Sciences (India)

    Making Weak Bonds (cooling) and Breaking Strong Bonds (heating) with Supersonic Techniques · Acknowledgements · Outline · Slide 4 · A comparison of the two techniques · What is a hydrogen bond? Phenylacetylene and its complexes · Slide 8 · Phenylacetylene and PAH · phenylacetylene · Complexes in the interstellar ...

  16. Fast weak-lensing simulations with halo model

    Science.gov (United States)

    Giocoli, Carlo; Di Meo, Sandra; Meneghetti, Massimo; Jullo, Eric; de la Torre, Sylvain; Moscardini, Lauro; Baldi, Marco; Mazzotta, Pasquale; Metcalf, R. Benton

    2017-09-01

    Full ray-tracing maps of gravitational lensing, constructed from N-body simulations, represent a fundamental tool to interpret present and future weak-lensing data. However, the limitation of computational resources and storage capabilities severely restricts the number of realizations that can be performed in order to accurately sample both the cosmic shear models and covariance matrices. In this paper, we present a halo model formalism for weak gravitational lensing that alleviates these issues by producing weak-lensing mocks at a reduced computational cost. Our model takes as input the halo population within a desired light cone and the linear power spectrum of the underlined cosmological model. We examine the contribution given by the presence of substructures within haloes to the cosmic shear power spectrum and quantify it to the percent level. Our method allows us to reconstruct high-resolution convergence maps, for any desired source redshifts, of light cones that realistically trace the matter density distribution in the universe, account for masked area and sample selections. We compare our analysis on the same large-scale structures constructed using ray-tracing techniques and find very good agreements in both the linear and non-linear regimes up to few percent levels. The accuracy and speed of our method demonstrate the potential of our halo model for weak-lensing statistics and the possibility to generate a large sample of convergence maps for different cosmological models as needed for the analysis of large galaxy redshift surveys.

  17. G-weak contraction in ordered cone rectangular metric spaces.

    Science.gov (United States)

    Malhotra, S K; Sharma, J B; Shukla, Satish

    2013-01-01

    We prove some common fixed-point theorems for the ordered g-weak contractions in cone rectangular metric spaces without assuming the normality of cone. Our results generalize some recent results from cone metric and cone rectangular metric spaces into ordered cone rectangular metric spaces. Examples are provided which illustrate the results.

  18. g-Weak Contraction in Ordered Cone Rectangular Metric Spaces

    Directory of Open Access Journals (Sweden)

    S. K. Malhotra

    2013-01-01

    Full Text Available We prove some common fixed-point theorems for the ordered g-weak contractions in cone rectangular metric spaces without assuming the normality of cone. Our results generalize some recent results from cone metric and cone rectangular metric spaces into ordered cone rectangular metric spaces. Examples are provided which illustrate the results.

  19. A Weak Convergence to Hermite Process by Martingale Differences

    Directory of Open Access Journals (Sweden)

    Xichao Sun

    2014-01-01

    Full Text Available We consider the weak convergence to general Hermite process ZH,k of order k with index H. By applying martingale differences we construct a sequence {ZH,kn ,  n=1,2,…} of multiple Wiener-Itô stochastic integrals such that it converges in distribution to the Hermite process ZH,k.

  20. A young woman with weakness of the legs

    African Journals Online (AJOL)

    On neurological examination she had profound bilateral weakness of the lower limbs, hypertonia, hyperreflexia, a positive Babinski sign and a T6 sensory level. Tests for syphilis and HIV and screening for auto-immune conditions were negative. Magnetic resonance imaging (MRI) of the brain and spinal cord revealed ...

  1. An infinite-dimensional weak KAM theory via random variables

    KAUST Repository

    Gomes, Diogo A.

    2016-08-31

    We develop several aspects of the infinite-dimensional Weak KAM theory using a random variables\\' approach. We prove that the infinite-dimensional cell problem admits a viscosity solution that is a fixed point of the Lax-Oleinik semigroup. Furthermore, we show the existence of invariant minimizing measures and calibrated curves defined on R.

  2. Large potential steps at weakly interacting metal-insulator interfaces

    NARCIS (Netherlands)

    Bokdam, Menno; Brocks, G.; Kelly, Paul J.

    2014-01-01

    Potential steps exceeding 1 eV are regularly formed at metal|insulator interfaces, even when the interaction between the materials at the interface is weak physisorption. From first-principles calculations on metal|h−BN interfaces we show that these potential steps are only indirectly sensitive to

  3. Cardial myxoma associated with clinical weakness and thorombocytopenia: case report

    Directory of Open Access Journals (Sweden)

    Mahmoud Hosseinzadeh Maleki

    2013-02-01

    Full Text Available Atrial myxomas is the most prevalent benign heart tumor which is presented with a wide variety of symptoms. We introduce a case who suffered left atrial myxoma associated with clinical weakness and thorombocytopenia. The clinical symptoms of the patient rapidly disappeared one week after cardial myxoma resection.

  4. Hip muscle weakness in patients with symptomatic femoroacetabular impingement.

    Science.gov (United States)

    Casartelli, N C; Maffiuletti, N A; Item-Glatthorn, J F; Staehli, S; Bizzini, M; Impellizzeri, F M; Leunig, M

    2011-07-01

    Femoroacetabular impingement (FAI) is a pathomechanical process, which may cause hip pain, disability and early development of hip osteoarthritis (OA) in young and active adults. Patients with FAI experience functional disability during dynamic weight-bearing activities, which could originate from weakness of the hip muscles. The objective of this study was to compare hip muscle strength between patients with symptomatic FAI and healthy controls. It was hypothesized that patients would present overall hip muscle weakness compared to controls. A total of 22 FAI patients and 22 controls matched for gender, age, and body mass participated in the study. We evaluated isometric maximal voluntary contraction (MVC) strength of all hip muscle groups using hand-held and isokinetic dynamometry, and electromyographic (EMG) activity of the rectus femoris (RF) and tensor fasciae latae (TFL) muscles during active flexion of the hip. FAI patients had significantly lower MVC strength than controls for hip adduction (28%), flexion (26%), external rotation (18%) and abduction (11%). TFL EMG activity was significantly lower in FAI patients compared with controls (P=0.048), while RF EMG activity did not differ significantly between the two groups (P=0.056). Patients with symptomatic FAI presented muscle weakness for all hip muscle groups, except for internal rotators and extensors. Based on EMG recordings, it was demonstrated that patients with symptomatic FAI have a reduced ability to activate TFL muscle during hip flexion. These findings provide orthopedic surgeons with objective information about the amount and specificity of hip muscle weakness in patients with FAI. Future research should investigate the relationship between hip muscle weakness, functional disability and overuse injury risks, as well as the effects of hip muscle strengthening on clinical outcomes in individuals with symptomatic FAI. Copyright © 2011 Osteoarthritis Research Society International. Published by

  5. Cracking Behavior of a Concrete Arch Dam with Weak Upper Abutment

    Directory of Open Access Journals (Sweden)

    Lei Xu

    2017-01-01

    Full Text Available The cracking behavior and failure mode of a 78 m high concrete double-curvature arch dam with weak upper abutment are investigated through performing cracking analysis. The mechanical behavior of concrete is simulated using a smeared crack model, in which a combination of the compression yield surface and the crack detection surface with a damaged elasticity concept is employed to describe the failure of concrete. The arch dam with practical mechanical properties of the upper and lower abutments is firstly studied with emphasis on its cracking behavior during overloading. Then, a comprehensive sensitivity analysis is carried out to investigate the influence of the ratio of the mechanical properties of upper abutment to those of lower abutment on dam failure with prime attention placed on the failure mode. Simulation results indicate the adopted smeared crack model is well-suited to the crack analysis of concrete arch dam. It is shown that cracking is localized around the interface between upper and lower abutments, which leads to a fast crack growth in the through-thickness direction of dam and finally causes the dam failure. Furthermore, the sensitivity analysis presents three types of failure modes corresponding to different ratio value, wherein Modes II and III should be avoided since the weak upper abutment plays a predominant role in the cracking and failure of concrete arch dam.

  6. Spin-orbit coupling and weak antilocalization in the thermoelectric material β-K₂Bi₈Se₁₃.

    Science.gov (United States)

    Hu, J; Liu, J Y; Mao, Z Q

    2014-03-05

    We have studied the effect of spin-orbital coupling (SOC) on the electronic transport properties of the thermoelectric material β-K₂Bi₈Se₁₃ via magnetoresistance measurements. We found that the strong SOC in this material results in the weak antilocalization (WAL) effect, which can be described well by a three-dimensional weak localization model. The phase coherence length extracted from theoretical fitting exhibits a power-law temperature dependence, with an exponent around 2.1, indicating that the electron dephasing is governed by electron-transverse phonon interactions. As in topological insulators, the WAL effect in β-K₂Bi₈Se₁₃ can be quenched by magnetic impurities (Mn) but is robust against non-magnetic impurities (Te). Although our magnetotransport studies provide no evidence for topological surface states, our analyses suggest that SOC plays an important role in determining the thermoelectric properties of β-K₂Bi₈Se₁₃.

  7. Properties of Bc meson

    Indian Academy of Sciences (India)

    The mass spectrum of c¯b meson is investigated with an effective quark– antiquark potential of the form −αc r. + Arν with ν varying from 0.5 to 2.0. The S and. P-wave masses, pseudoscalar decay constant, weak decay partial widths in spectator model and the lifetime of Bc meson are computed. The properties calculated ...

  8. Neutrino Sources and Properties

    OpenAIRE

    Vissani, Francesco

    2014-01-01

    In this lecture, prepared for PhD students, basic considerations on neutrino interactions, properties and sites of production are overviewed. The detailed content is as follows: Sect. 1, Weak interactions and neutrinos: Fermi coupling; definition of neutrinos; global numbers. Sect. 2, A list of neutrino sources: Explanatory note and examples (solar pp- and supernova-neutrinos). Sect. 3, Neutrinos oscillations: Basic formalism (Pontecorvo); matter effect (Mikheev, Smirnov, Wolfenstein); status...

  9. Characterisation of weak magnetic field effects in an aqueous glutamic acid solution by nonlinear dielectric spectroscopy and voltammetry

    OpenAIRE

    Pazur, Alexander

    2004-01-01

    Background Previous reports indicate altered metabolism and enzyme kinetics for various organisms, as well as changes of neuronal functions and behaviour of higher animals, when they were exposed to specific combinations of weak static and alternating low frequency electromagnetic fields. Field strengths and frequencies, as well as properties of involved ions were related by a linear equation, known as the formula of ion cyclotron resonance (ICR, abbreviation mentioned first by Liboff). Under...

  10. Comparison of weak-wind characteristics across different Surface Types in stable stratification

    Science.gov (United States)

    Freundorfer, Anita; Rehberg, Ingo; Thomas, Christoph

    2017-04-01

    site) with a Leaf Area Index of LAI=9.4 m2m-2, the critical wind speed measures v_crit= (1.0±0.1) ms-1. Further analyses include developing an identification scheme to sample submeso motions using their quasi two-dimensional nature. Once separated from turbulence the properties of submeso motions and the impact of different canopy densities on those motions can be explored. We hypothesize that submeso motions are the main generating mechanism for the locally confined and intermittent turbulence in the weak-wind and stable boundary layers.

  11. The weak coupling limit as a quantum functional central limit

    Science.gov (United States)

    Accardi, L.; Frigerio, A.; Lu, Y. G.

    1990-08-01

    We show that, in the weak coupling limit, the laser model process converges weakly in the sense of the matrix elements to a quantum diffusion whose equation is explicitly obtained. We prove convergence, in the same sense, of the Heisenberg evolution of an observable of the system to the solution of a quantum Langevin equation. As a corollary of this result, via the quantum Feynman-Kac technique, one can recover previous results on the quantum master equation for reduced evolutions of open systems. When applied to some particular model (e.g. the free Boson gas) our results allow to interpret the Lamb shift as an Ito correction term and to express the pumping rates in terms of quantities related to the original Hamiltonian model.

  12. Open string T-duality in a weakly curved background

    Energy Technology Data Exchange (ETDEWEB)

    Davidovic, Ljubica [University of Belgrade, Institute of Physics, Belgrade (Serbia)

    2016-12-15

    We consider a theory of an open string moving in a weakly curved background, composed of a constant metric and a linearly coordinate dependent Kalb-Ramond field with an infinitesimal field strength. We find its T-dual using the generalized Buscher procedure developed for the closed string moving in a weakly curved background, and the fact that solving the boundary conditions, the open string theory transforms to the effective closed string theory. So, T-dualizing the effective theory along all effective directions we obtain its T-dual theory and resume the open string theory which has such an effective theory. In this way we obtain the open string theory T-dual. (orig.)

  13. Fragility analysis and weak point identification of power system

    Science.gov (United States)

    Zhao, Wenda; Su, Yongqing; Yue, Jiguang; Mu, Huihua; Liu, Xuejiao

    2017-10-01

    In order to ensure the stability of the aerospace power system in the harsh working environment and identify the weak point of the system which leads to the bad outcomes and instability of the system, the concept of power circuit fragility is raised in this paper with a thorough analysis of the stability of the aerospace power circuit. The node-index evaluation model is established based on the basic cause of the circuits stability problem. Combined with the description of the actual values of the electronic components using ternary interval number, the mathematical expression of the power supply circuits fragility is given. Taking the Superbuck aerospace power circuit as an example, this paper uses the node-index evaluation model to analyze the fragility of phase margin and overshoot, identifies the weak point of the power circuit and gives the quantization value of the phase margin and overshoot fragilities, which provides the theoretical basis for subsequent maintenance and power supply design.

  14. Weak Gravitational Lensing in Practice: Instrumentation, Systematics, and Null Tests

    Science.gov (United States)

    Bradshaw, Andrew

    2017-06-01

    Weak gravitational lensing has enormous potential for mapping the growth of large scale structure of our Universe by surveying the way distant galaxy images are slightly distorted by foreground gravitational potentials. However, in the scientific quest for sub-percent precision in cosmological measurements, a multitude of questions have been raised about particular systematic errors which could dominate the accuracy of weak lensing in the era of Stage IV experiments like the LSST. This thesis talk will discuss a few recently discovered instrumental & observational artifacts that have now been extensively measured using a novel benchtop simulation of LSST observing. In particular, systematics such as astrometric error patterns, pixelization biases, and the Brighter-Fatter effect will be discussed, as well as their estimated impact on cosmological parameters. Additionally, examples of these systematics and others will be shown using on-sky data, and the applicability of B-mode systematics null testing will be discussed.

  15. Quantum Butterfly Effect in Weakly Interacting Diffusive Metals

    Science.gov (United States)

    Patel, Aavishkar A.; Chowdhury, Debanjan; Sachdev, Subir; Swingle, Brian

    2017-07-01

    We study scrambling, an avatar of chaos, in a weakly interacting metal in the presence of random potential disorder. It is well known that charge and heat spread via diffusion in such an interacting disordered metal. In contrast, we show within perturbation theory that chaos spreads in a ballistic fashion. The squared anticommutator of the electron-field operators inherits a light-cone-like growth, arising from an interplay of a growth (Lyapunov) exponent that scales as the inelastic electron scattering rate and a diffusive piece due to the presence of disorder. In two spatial dimensions, the Lyapunov exponent is universally related at weak coupling to the sheet resistivity. We are able to define an effective temperature-dependent butterfly velocity, a speed limit for the propagation of quantum information that is much slower than microscopic velocities such as the Fermi velocity and that is qualitatively similar to that of a quantum critical system with a dynamical critical exponent z >1 .

  16. Precision Measurement of the Weak Mixing Angle in Moller Scattering

    CERN Document Server

    Anthony, P L; Arroyo, C; Bega, K; Biesiada, J; Bosted, P E; Bower, G; Cahoon, J; Carr, R; Cates, G D; Chen, J P; Chudakov, E; Cooke, M; Decowski, P; Deur, A; Emam, W; Erickson, R; Fieguth, T; Field, C; Gao, J; Gary, M; Gustafsson, K; Hicks, R S; Holmes, R; Hughes, E W; Humensky, T B; Jones, G M; Kaufman, L J; Keller, L; Kolomensky, Yu G; Kumar, K S; La Violette, P; Lhuillier, D; Lombard-Nelsen, R M; Marshall, Z; Mastromarino, P; McKeown, R D; Michaels, R; Niedziela, J; Olson, M; Paschke, K D; Peterson, G A; Pitthan, R; Relyea, D; Rock, S E; Saxton, O; Singh, J; Souder, P A; Szalata, Z M; Turner, J; Tweedie, B; Vacheret, A; Walz, D; Weber, T; Weisend, J; Woods, M; Younus, I

    2005-01-01

    We report on a precision measurement of the parity-violating asymmetry in fixed target electron-electron (Moller) scattering: A_PV = -131 +/- 14 (stat.) +/- 10 (syst.) parts per billion, leading to the determination of the weak mixing angle \\sin^2\\theta_W^eff = 0.2397 +/- 0.0010 (stat.) +/- 0.0008 (syst.), evaluated at Q^2 = 0.026 GeV^2. Combining this result with the measurements of \\sin^2\\theta_W^eff at the Z^0 pole, the running of the weak mixing angle is observed with over 6 sigma significance. The measurement sets constraints on new physics effects at the TeV scale.

  17. Francium Trapping Facility at TRIUMF for weak interaction studies

    Science.gov (United States)

    Zhang, J.; Orozco, L. A.; Collister, R.; Gwinner, G.; Tandecki, M.; Behr, J. A.; Pearson, M. R.; Gomez, E.; Aubin, S.; Frpnc Collaboration

    2014-05-01

    We present the current status of the Francium Trapping Facility at TRIUMF. After successfully commissioning the capture chamber we are now in the process of finishing the science chamber where weak interaction measurements on Fr will be performed. We require transfer of the cold atoms from the capture chamber to the science chamber where they can be re-trapped for precision spectroscopy. The modular design of the science chamber allows for microwave studies for the anapole moment measurement and optical studies for the weak charge measurements using atomic parity non-conservation. We will present our current status and the plans for the commissioning run of the science chamber. Work supported by NSERC and NRC from Canada, NSF and DOE from USA, CONACYT from Mexico.

  18. Rare weak decays of η'→K π

    Science.gov (United States)

    Gao, Dao-Neng

    2017-11-01

    Rare weak decays of η'→K π have been investigated in the framework of the U (3 ) chiral perturbation theory at the leading order. Our study shows that the branching ratio B (η'→K π ) is of the order of 10-11, which is far below the present experimental upper bound given by the BESIII Collaboration. By further analysis of η'→K+π- and η'→K0π0, the ratio of isospin amplitudes is found, |A1 /2/A3 /2|≃35 , which supports that the Δ I =1 /2 transition enhancement, namely, the Δ I =1 /2 rule, could be functional in η' weak decays.

  19. Reaction times to weak test lights. [psychophysics biological model

    Science.gov (United States)

    Wandell, B. A.; Ahumada, P.; Welsh, D.

    1984-01-01

    Maloney and Wandell (1984) describe a model of the response of a single visual channel to weak test lights. The initial channel response is a linearly filtered version of the stimulus. The filter output is randomly sampled over time. Each time a sample occurs there is some probability increasing with the magnitude of the sampled response - that a discrete detection event is generated. Maloney and Wandell derive the statistics of the detection events. In this paper a test is conducted of the hypothesis that the reaction time responses to the presence of a weak test light are initiated at the first detection event. This makes it possible to extend the application of the model to lights that are slightly above threshold, but still within the linear operating range of the visual system. A parameter-free prediction of the model proposed by Maloney and Wandell for lights detected by this statistic is tested. The data are in agreement with the prediction.

  20. Weak turbulence theory for beam-plasma interaction

    Science.gov (United States)

    Yoon, Peter H.

    2018-01-01

    The kinetic theory of weak plasma turbulence, of which Ronald C. Davidson was an important early pioneer [R. C. Davidson, Methods in Nonlinear Plasma Theory, (Academic Press, New York, 1972)], is a venerable and valid theory that may be applicable to a large number of problems in both laboratory and space plasmas. This paper applies the weak turbulence theory to the problem of gentle beam-plasma interaction and Langmuir turbulence. It is shown that the beam-plasma interaction undergoes various stages of physical processes starting from linear instability, to quasilinear saturation, to mode coupling that takes place after the quasilinear stage, followed by a state of quasi-static "turbulent equilibrium." The long term quasi-equilibrium stage is eventually perturbed by binary collisional effects in order to bring the plasma to a thermodynamic equilibrium with increased entropy.

  1. Consistently Computing the K --> π Long Distance Weak Transition

    Science.gov (United States)

    Lowe, J.; Sugimoto, M. D.

    First we extract the long-distance (LD) weak matrix element from K --> 2π, K --> 3π, KL --> 2γ, K+ --> π+e+e-, K+ --> π+μ+ μ- and KL --> μ+ μ- data and give compatible theoretical estimates. We also link this LD scale to the single-quark-line (SQL) transition scale βW and then test the latter SQL scale against the decuplet weak decay amplitude ratio /. Finally, we study LD KS --> 2γ decay. All of these experimental and theoretical values for are in good agreement. We deduce an average value from 11 experimental determinations of = (3.59 +/- 0.05) × 10-8 GeV2, while the theoretical SQL values average to (3.577 +/- 0.004) × 10-8 GeV2.

  2. [Archaeology and criminology--Strengths and weaknesses of interdisciplinary cooperation].

    Science.gov (United States)

    Bachhiesl, Christian

    2015-01-01

    Interdisciplinary cooperation of archaeology and criminology is often focussed on the scientific methods applied in both fields of knowledge. In combination with the humanistic methods traditionally used in archaeology, the finding of facts can be enormously increased and the subsequent hermeneutic deduction of human behaviour in the past can take place on a more solid basis. Thus, interdisciplinary cooperation offers direct and indirect advantages. But it can also cause epistemological problems, if the weaknesses and limits of one method are to be corrected by applying methods used in other disciplines. This may result in the application of methods unsuitable for the problem to be investigated so that, in a way, the methodological and epistemological weaknesses of two disciplines potentiate each other. An example of this effect is the quantification of qualia. These epistemological reflections are compared with the interdisciplinary approach using the concrete case of the "Eulau Crime Scene".

  3. The structure of weak shocks in quantum plasmas

    CERN Document Server

    Bychkov, Vitaly; Marklund, Mattias

    2008-01-01

    The structure of a weak shock in a quantum plasma is studied, taking into account both dissipation terms due to thermal conduction and dispersive quantum terms due to the Bohm potential. Unlike quantum systems without dissipations, even a small thermal conduction may lead to a stationary shock structure. In the limit of zero quantum effects, the monotonic Burgers solution for the weak shock is recovered. Still, even small quantum terms make the structure non-monotonic with the shock driving a train of oscillations into the initial plasma. The oscillations propagate together with the shock. The oscillations become stronger as the role of Bohm potential increases in comparison with thermal conduction. The results could be of importance for laser-plasma interactions, such as inertial confinement fusion plasmas, and in astrophysical environments, as well as in condensed matter systems.

  4. The oral thrombin inhibitor dabigatran: strengths and weaknesses.

    Science.gov (United States)

    Schulman, Sam; Majeed, Ammar

    2012-02-01

    Since the quest for a better replacement of warfarin started several decades ago and new compounds were brought forward to clinical trials, the concept of an ideal anticoagulant frequently became presented in lectures and articles. We have here reviewed strengths and weaknesses of the oral thrombin inhibitor dabigatran in terms of pharmacokinetics and clinical data. When strengths clearly exceed the weaknesses for any characteristic, the drug fits into the concept of an ideal anticoagulant in that domain. It is evident that dabigatran does not accomplish that concept for all characteristics but it reaches well above warfarin. We believe it is unlikely that any drug will fulfill all criteria for the ideal anticoagulant. Laboratory testing for dabigatran will not be discussed in any detail in this article, which is instead the focus of other articles from this issue of Seminars in Thrombosis & Hemostasis. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Strong and weak approximation of semilinear stochastic evolution equations

    CERN Document Server

    Kruse, Raphael

    2014-01-01

    In this book we analyze the error caused by numerical schemes for the approximation of semilinear stochastic evolution equations (SEEq) in a Hilbert space-valued setting. The numerical schemes considered combine Galerkin finite element methods with Euler-type temporal approximations. Starting from a precise analysis of the spatio-temporal regularity of the mild solution to the SEEq, we derive and prove optimal error estimates of the strong error of convergence in the first part of the book. The second part deals with a new approach to the so-called weak error of convergence, which measures the distance between the law of the numerical solution and the law of the exact solution. This approach is based on Bismut’s integration by parts formula and the Malliavin calculus for infinite dimensional stochastic processes. These techniques are developed and explained in a separate chapter, before the weak convergence is proven for linear SEEq.

  6. Galaxy rotation curves and the deceleration parameter in weak gravity

    Science.gov (United States)

    van Putten, Maurice H. P. M.

    2017-07-01

    We present a theory of weak gravity parametrized by a fundamental frequency ω0 = 1 - qH of the cosmological horizon, where H and q denote the Hubble and, respectively, deceleration parameter. It predicts (i) a C0 onset to weak gravity across accelerations α = adS in galaxy rotation curves, where adS = cH denotes the de Sitter acceleration with velocity of light c, and (ii) fast evolution Q(z) = dq(z)/dz of the deceleration parameter by Λ = ω02 satisfying Q0 > 2.5, Q0 = Q(0), distinct from Q0 ≲ 1 in ΛCDM. The first is identified in the high resolution data of Lelli et al. (2017), the second in the heterogeneous data on H(z) over 0 LISA Pathfinder are included.

  7. The (weak) gravitational field of a Dirac monopole

    Science.gov (United States)

    Banyas, E.; Franklin, J.

    2017-10-01

    We establish the gravitational detectability of a Dirac monopole using a weak-field limit of general relativity, which can be developed from the Newtonian gravitational potential by including energy as a source. The resulting potential matches (by construction) the weak-field limit of two different solutions to Einstein’s equations of general relativity: one associated with the magnetically monopolar spray of field lines emerging from the half-infinite solenoid that makes up the Dirac monopole, the other associated with the field-energetic source of the solenoid itself (the Dirac string). The string’s gravitational effect dominates, and we suggest that the primary strong-field contribution of the Dirac configuration is that of a half-infinite line of energy, whose GR solution is known.

  8. [Strength and weaknesses of the German digital health economy].

    Science.gov (United States)

    Leppert, Florian; Gerlach, Jan; Ostwald, Dennis A; Greiner, Wolfgang

    2017-07-26

    There are high expectations from digitalization of health care, ehealth and telemedicine. Nevertheless, the diffusion of these services falls short of expectations. This study analyses the strength and weaknesses of the German digital health economy. Thereby, we specially focus on small and medium-sized enterprises (SME). The study is based on a literature review, interviews of experts and a workshop. The digital health economy is influenced by a heterogeneous environment with both promotive and obstructive factors. One of the largest weaknesses results from a lack of business models. There is a lack of possibilities of reimbursement by the Statutory Health Insurance (SHI). In addition, private users only have a small willingness to pay for digital services. The large number of regulations makes the implementation even harder, especially for SMEs. Thus, the current environment hampers fast diffusion of digital services in the German health care market. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Engineering interlocking DNA rings with weak physical interactions

    Science.gov (United States)

    Wu, Zai-Sheng; Shen, Zhifa; Tram, Kha; Li, Yingfu

    2014-06-01

    Catenanes are intriguing molecular assemblies for engineering unique molecular devices. The resident rings of a catenane are expected to execute unhindered rotation around each other, and to do so, they must have weak physical interactions with each other. Due to sequence programmability, DNA has become a popular material for nanoscale object engineering. However, current DNA catenanes, particularly in the single-stranded (ss) form, are synthesized through the formation of a linking duplex, which makes them less ideal as mobile elements for molecular machines. Herein we adopt a random library approach to engineer ssDNA [2] catenanes (two interlocked DNA rings) without a linking duplex. Results from DNA hybridization, double-stranded catenane synthesis and rolling circle amplification experiments signify that representative catenanes have weak physical interactions and are capable of operating as independent units. Our findings lay the foundation for exploring free-functioning interlocked DNA rings for the design of elaborate nanoscale machines based on DNA.

  10. The Quasi-Static Electromagnetic Approximation for Weakly Conducting Media

    CERN Document Server

    Heubrandtner, T

    2002-01-01

    In a conducting dielectric charge and electric field decay with a time constant tau_R = \\varepsilon/\\sigma. In a weakly conducting medium, as e.g. glass or melamine-phenolic laminate in use in RPC's, this time is about 10^{-3} s; so it is long as compared to the time the charge cloud needs to move through the gap and to the time the signal needs to propagate through a dielectric to the electrode. A quasi-static theory to deal with transient phenomena in weakly conducting media has been developed in Haus and Melcher (1989), Fano, Chu and Adler (1963); it simplifies the analysis considerably since it requires only the solution of a scalar diffusion-type equations in place of the time-dependent Maxwell equations. This little known theory is applied to treat the generation of signals in simple models for chambers with such materials.

  11. Utilizing Weak Indicators to Detect Anomalous Behaviors in Networks

    Energy Technology Data Exchange (ETDEWEB)

    Egid, Adin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-01

    We consider the use of a novel weak in- dicator alongside more commonly used weak indicators to help detect anomalous behavior in a large computer network. The data of the network which we are studying in this research paper concerns remote log-in information (Virtual Private Network, or VPN sessions) from the internal network of Los Alamos National Laboratory (LANL). The novel indicator we are utilizing is some- thing which, while novel in its application to data science/cyber security research, is a concept borrowed from the business world. The Her ndahl-Hirschman Index (HHI) is a computationally trivial index which provides a useful heuristic for regulatory agencies to ascertain the relative competitiveness of a particular industry. Using this index as a lagging indicator in the monthly format we have studied could help to detect anomalous behavior by a particular or small set of users on the network.

  12. Weak ergodicity breaking, irreproducibility, and ageing in anomalous diffusion processes

    Energy Technology Data Exchange (ETDEWEB)

    Metzler, Ralf [Institute for Physics and Astronomy, University of Potsdam, D-14476 Potsdam-Golm, Germany and Department of Physics, Tampere University of Technology, FI-33101 Tampere (Finland)

    2014-01-14

    Single particle traces are standardly evaluated in terms of time averages of the second moment of the position time series r(t). For ergodic processes, one can interpret such results in terms of the known theories for the corresponding ensemble averaged quantities. In anomalous diffusion processes, that are widely observed in nature over many orders of magnitude, the equivalence between (long) time and ensemble averages may be broken (weak ergodicity breaking), and these time averages may no longer be interpreted in terms of ensemble theories. Here we detail some recent results on weakly non-ergodic systems with respect to the time averaged mean squared displacement, the inherent irreproducibility of individual measurements, and methods to determine the exact underlying stochastic process. We also address the phenomenon of ageing, the dependence of physical observables on the time span between initial preparation of the system and the start of the measurement.

  13. A weakly constrained $W'$ at the early LHC

    CERN Document Server

    Grojean, Christophe; Torre, Riccardo

    2011-01-01

    We study, within an effective approach, the phenomenology of a charged W' vector which transforms as an isosinglet under the Standard Model gauge group. We discuss bounds from present data, finding that these are quite weak for suitable choices of the right-handed quark mixing matrix. Then we study the resonant production at the early LHC of such a weakly constrained W'. We start discussing the reach in the dijet final state, which is one of the channels where the first W' signal would most likely appear, and then we analyse prospects for the more challenging discovery of W' decays into W{\\gamma} and WZ. We show in particular that the former can be used to gain insight on the possibly composite nature of the resonance.

  14. Can quantum probes satisfy the weak equivalence principle?

    Energy Technology Data Exchange (ETDEWEB)

    Seveso, Luigi, E-mail: luigi.seveso@unimi.it [Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I-20133 Milano (Italy); Paris, Matteo G.A. [Quantum Technology Lab, Dipartimento di Fisica, Università degli Studi di Milano, I-20133 Milano (Italy); INFN, Sezione di Milano, I-20133 Milano (Italy)

    2017-05-15

    We address the question whether quantum probes in a gravitational field can be considered as test particles obeying the weak equivalence principle (WEP). A formulation of the WEP is proposed which applies also in the quantum regime, while maintaining the physical content of its classical counterpart. Such formulation requires the introduction of a gravitational field not to modify the Fisher information about the mass of a freely-falling probe, extractable through measurements of its position. We discover that, while in a uniform field quantum probes satisfy our formulation of the WEP exactly, gravity gradients can encode nontrivial information about the particle’s mass in its wavefunction, leading to violations of the WEP. - Highlights: • Can quantum probes under gravity be approximated as test-bodies? • A formulation of the weak equivalence principle for quantum probes is proposed. • Quantum probes are found to violate it as a matter of principle.

  15. Weak, Quiet Magnetic Fields Seen in the Venus Atmosphere.

    Science.gov (United States)

    Zhang, T L; Baumjohann, W; Russell, C T; Luhmann, J G; Xiao, S D

    2016-03-24

    The existence of a strong internal magnetic field allows probing of the interior through both long term changes of and short period fluctuations in that magnetic field. Venus, while Earth's twin in many ways, lacks such a strong intrinsic magnetic field, but perhaps short period fluctuations can still be used to probe the electrical conductivity of the interior. Toward the end of the Venus Express mission, an aerobraking campaign took the spacecraft below the ionosphere into the very weakly electrically conducting atmosphere. As the spacecraft descended from 150 to 140 km altitude, the magnetic field became weaker on average and less noisy. Below 140 km, the median field strength became steady but the short period fluctuations continued to weaken. The weakness of the fluctuations indicates they might not be useful for electromagnetic sounding of the atmosphere from a high altitude platform such as a plane or balloon, but possibly could be attempted on a lander.

  16. Weak and strong coupling equilibration in nonabelian gauge theories

    CERN Document Server

    Keegan, Liam; Romatschke, Paul; van der Schee, Wilke; Zhu, Yan

    2016-01-01

    We present a direct comparison studying equilibration through kinetic theory at weak coupling and through holography at strong coupling in the same set-up. The set-up starts with a homogeneous thermal state, which then smoothly transitions through an out-of-equilibrium phase to an expanding system undergoing boost-invariant flow. This first apples-to-apples comparison of equilibration provides a benchmark for similar equilibration processes in heavy-ion collisions, where the equilibration mechanism is still under debate. We find that results at weak and strong coupling can be smoothly connected by simple, empirical power-laws for the viscosity, equilibration time and entropy production of the system.

  17. On weak solvability of boundary value problems for elliptic systems

    OpenAIRE

    Ponce, Felipe; Lebedev, Leonid,; Rendón, Leonardo,

    2013-01-01

    This paper concerns with existence and uniqueness of a weak solution for elliptic systems of partial differential equations with mixed boundary conditions. The proof is based on establishing the coerciveness of bilinear forms, related with the system of equations, which depend on first-order derivatives of vector functions in Rn. The condition of coerciveness relates to Korn's type inequalities. The result is illustrated by an example of boundary value problems for a class of elliptic equatio...

  18. Weak estrogenic transcriptional activities of Bisphenol A and Bisphenol S

    OpenAIRE

    GRIGNARD ELISE; Bremer, Susanne; LAPENNA SILVIA

    2011-01-01

    In 2011, the European Commission has restricted the use of Bisphenol A in plastic infant feeding bottles. In a response to this restriction, Bisphenol S is now often used as a component of plastic substitutes for the production of babybottles. One of the major concerns leading to the restriction of Bisphenol A was its weak estrogenic activity. By using two highly standardised transactivation assays, we could demonstrate that the estrogenic activity of Bisphenol A and Bisphenol S i...

  19. Hyperglycemia-induced diaphragm weakness is mediated by oxidative stress

    Science.gov (United States)

    2014-01-01

    Introduction A major consequence of ICU-acquired weakness (ICUAW) is diaphragm weakness, which prolongs the duration of mechanical ventilation. Hyperglycemia (HG) is a risk factor for ICUAW. However, the mechanisms underlying HG-induced respiratory muscle weakness are not known. Excessive reactive oxygen species (ROS) injure multiple tissues during HG, but only one study suggests that excessive ROS generation may be linked to HG-induced diaphragm weakness. We hypothesized that HG-induced diaphragm dysfunction is mediated by excessive superoxide generation and that administration of a specific superoxide scavenger, polyethylene glycol superoxide dismutase (PEG-SOD), would ameliorate these effects. Methods HG was induced in rats using streptozotocin (60 mg/kg intravenously) and the following groups assessed at two weeks: controls, HG, HG + PEG-SOD (2,000U/kg/d intraperitoneally for seven days), and HG + denatured (dn)PEG-SOD (2000U/kg/d intraperitoneally for seven days). PEG-SOD and dnPEG-SOD were administered on day 8, we measured diaphragm specific force generation in muscle strips, force-pCa relationships in single permeabilized fibers, contractile protein content and indices of oxidative stress. Results HG reduced diaphragm specific force generation, altered single fiber force-pCa relationships, depleted troponin T, and increased oxidative stress. PEG-SOD prevented HG-induced reductions in diaphragm specific force generation (for example 80 Hz force was 26.4 ± 0.9, 15.4 ± 0.9, 24.0 ± 1.5 and 14.9 ± 0.9 N/cm2 for control, HG, HG + PEG-SOD, and HG + dnPEG-SOD groups, respectively, P hyperglycemia-induced diaphragm dysfunction. This new mechanistic information could explain how HG alters diaphragm function during critical illness. PMID:24886999

  20. The future of Jungian analysis: strengths, weaknesses, opportunities, threats ('SWOT').

    Science.gov (United States)

    Samuels, Andrew

    2017-11-01

    Using a methodology derived from management and organizational studies, the author reviews the future of Jungian analysis. The methodology is termed SWOT - strengths, weaknesses, opportunities, threats. A selected list in each of these categories is presented. The author is transparent in allowing for the fact that the paper not only derives from a public lecture on the topic, but also retains the immediacy and the contrarian and opinionated style of such a lecture. © 2017, The Society of Analytical Psychology.

  1. Superconductivity from weak repulsion in hexagonal lattice systems

    OpenAIRE

    Nandkishore, Rahul; Thomale, Ronny; Chubukov, Andrey V.

    2014-01-01

    We analyze the pairing instabilities for fermions on hexagonal lattices (both honeycomb and triangular ones) in a wide range of fermionic densities. We argue that for a generic doping in this range, superconductivity at weak coupling is of Kohn-Luttinger type, and, due to the presence of electronic interactions beyond on-site repulsion, is a threshold phenomenon, with superconductivity emerging only if the attraction generated by the Kohn-Luttinger mechanism exceeds the bare repulsion in some...

  2. Entanglement and area laws in weakly correlated gaussian states

    OpenAIRE

    Matera, Juan Mauricio; Rossignoli, Raúl Dante; Canosa, Norma B.

    2012-01-01

    We examine the evaluation of entanglement measures in weakly correlated gaussian states. It is shown that they can be expressed in terms of the singular values of a particular block of the generalized contraction matrix. This result enables to obtain in a simple way asymptotic expressions and related area laws for the entanglement entropy of bipartitions in pure states, as well as for the logarithmic negativity associated with bipartitions and also pairs of arbitrary subsystems. As illustrati...

  3. Pulsed photothermal phase-shift spectroscopy for weak absorption measurement.

    Science.gov (United States)

    Li, B; Deng, Y; Cheng, J

    1996-04-01

    A novel photothermal phase-shift spectroscopy configuration based on the retro-reflected beam interference has been developed and its operational principle is described. The weak absorption measurement ability of this technique is experimentally proven with a water/ethanol solution of standard Pyronine G dye and the limit of detection is found to be 1.8 x 10(-6) absorbance. Potential applications of the technique are discussed.

  4. Invariant scrambled sets, uniform rigidity and weak mixing

    OpenAIRE

    Foryś, Magdalena; Huang, Wen; Li, Jian; Oprocha, Piotr

    2014-01-01

    We show that for a non-trivial transitive dynamical system, it has a dense Mycielski invariant strongly scrambled set if and only if it has a fixed point, and it has a dense Mycielski invariant $\\delta$-scrambled set for some $\\delta>0$ if and only if it has a fixed point and not uniformly rigid. We also provide two methods for the construction of completely scrambled systems which are weakly mixing, proximal and uniformly rigid.

  5. Weakly nonlinear electrophoresis of a highly charged colloidal particle

    Science.gov (United States)

    Schnitzer, Ory; Zeyde, Roman; Yavneh, Irad; Yariv, Ehud

    2013-05-01

    At large zeta potentials, surface conduction becomes appreciable in thin-double-layer electrokinetic transport. In the linear weak-field regime, where this effect is quantified by the Dukhin number, it is manifested in non-Smoluchowski electrophoretic mobilities. In this paper we go beyond linear response, employing the recently derived macroscale model of Schnitzer and Yariv ["Macroscale description of electrokinetic flows at large zeta potentials: Nonlinear surface conduction," Phys. Rev. E 86, 021503 (2012), 10.1103/PhysRevE.86.021503] as the infrastructure for a weakly nonlinear analysis of spherical-particle electrophoresis. A straightforward perturbation in the field strength is frustrated by the failure to satisfy the far-field conditions, representing a non-uniformity of the weak-field approximation at large distances away from the particle, where salt advection becomes comparable to diffusion. This is remedied using inner-outer asymptotic expansions in the spirit of Acrivos and Taylor ["Heat and mass transfer from single spheres in Stokes flow," Phys. Fluids 5, 387 (1962), 10.1063/1.1706630], with the inner region representing the particle neighborhood and the outer region corresponding to distances scaling inversely with the field magnitude. This singular scheme furnishes an asymptotic correction to the electrophoretic velocity, proportional to the applied field cubed, which embodies a host of nonlinear mechanisms unfamiliar from linear electrokinetic theories. These include the effect of induced zeta-potential inhomogeneity, animated by concentration polarization, on electro-osmosis and diffuso-osmosis; bulk advection of salt; nonuniform bulk conductivity; Coulomb body forces acting on bulk volumetric charge; and the nonzero electrostatic force exerted upon the otherwise screened particle-layer system. A numerical solution of the macroscale model validates our weakly nonlinear analysis.

  6. Cosmic Divergence, Weak Cosmic Convergence, and Fixed Points at Infinity

    OpenAIRE

    Ryu, Ernest K.

    2017-01-01

    To characterize the asymptotic behavior of fixed-point iterations of non-expansive operators with no fixed points, Bauschke et al. [Fixed Point Theory Appl. (2016)] recently studied cosmic convergence and conjectured that cosmic convergence always holds. This paper presents a cosmically divergent counter example, which disproves this conjecture. This paper also demonstrates, with a counter example, that cosmic convergence can be weak in infinite dimensions. Finally, this paper shows positive ...

  7. Manifest Weakness Of Some Consumers In State Of Insolvency

    OpenAIRE

    Montiel Fuentes, Carlos Mario

    2014-01-01

    The Consumer Insolvency Statute, enclosed in the new General Code of Procedure, did not consider the people who are in a state of manifest weakness and who, by their condition cannot normally meet their obligations. This statute was precisely the opportunity to protect these parties through a legal protection mechanism, parties who enjoy constitutional special protection, but, since the opportunity was not taken, these parties need to turn to the “acción de tutela” to seek protection of their...

  8. Early occurrence of inspiratory muscle weakness in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Guillaume Baille

    Full Text Available In Parkinson's disease (PD, respiratory insufficiency (including functional and muscle disorders can impact dysarthria and swallowing. Most studies of this topic have been performed retrospectively in populations of patients with advanced PD. The objective of the present study was to characterize lung function (under off-drug conditions in early-stage PD patients at baseline and then again two years later.Forty-one early-stage PD patients (mean ± SD age: 61.7 ± 7.7; mean ± SD disease duration: 1.9 ± 1.7 years were prospectively enrolled and compared with 36 age-matched healthy controls. Neurological evaluations and pulmonary function testing were performed in the off-drug condition at the inclusion visit and then two years later.Pulmonary function testing did not reveal any restrictive or obstructive disorders; at baseline, inspiratory muscle weakness was the only abnormality observed in the PD group (in 53.7% of the patients, vs. 25% in controls; p = 0.0105. The PD patients had a lower mean maximal inspiratory mouth pressure than controls and a lower sniff nasal inspiratory pressure. Two years after the initiation of chronic treatment with antiparkinsonian medications, the maximal inspiratory mouth pressure and the sniff nasal inspiratory pressure tended to be higher. Lastly, overall motor outcomes were not significantly worse in patients with inspiratory muscle weakness than in patients without inspiratory muscle weakness.Inspiratory muscle weakness seems to be common in patients with early-stage PD, and was seen to be stable over a two-year period. Additional long-term follow-up studies are required to specify the impact of this new feature of PD.

  9. Semilocal Convergence Analysis for Inexact Newton Method under Weak Condition

    Directory of Open Access Journals (Sweden)

    Xiubin Xu

    2012-01-01

    Full Text Available Under the hypothesis that the first derivative satisfies some kind of weak Lipschitz conditions, a new semilocal convergence theorem for inexact Newton method is presented. Unified convergence criteria ensuring the convergence of inexact Newton method are also established. Applications to some special cases such as the Kantorovich type conditions and γ-Conditions are provided and some well-known convergence theorems for Newton's method are obtained as corollaries.

  10. Stable sound wave generation in weakly ionized air medium

    OpenAIRE

    Chizhov, Maxim; Eingorn, Maxim; Kulinskii, Vladimir

    2013-01-01

    We consider the generation of sound waves in the air medium between electrodes at the voltages near electrical breakdown in the presence of the time dependent constituent of the electric field. Within the standard multicomponent hydrodynamic model of the weakly ionized gas it is shown that the generation of sound is possible due to instantaneous character of the ionization equilibrium. The influence of the electronegative ions on the sound intensity is also discussed.

  11. Optical properties of NaYF sub 4 weakly doped with Eu sup 3+

    Energy Technology Data Exchange (ETDEWEB)

    Zakaria, D.; Mahiou, R.; Zambon, D.; Fournier, M.T. (Clermont-Ferrand-2 Univ., 63 - Aubiere (France))

    1991-01-01

    Optical studies of NaYF{sub 4} powder samples doped with Eu{sup 3+} have been performed. By excitation with a nitrogen laser (unusually used for Eu{sup 3+}), emission spectra and decay characteristics of fluorescences produced by two intense satellites, one in the yellow and the other in the orange-red wavelength ranges, have been obtained. These lines can be associated with Eu{sup 3+}-O{sup 2-} or Eu{sup 3+}-Eu{sup 3+} coupled ions.

  12. Microscopic theory of weak pseudogap behavior in the underdoped cuprate superconductors: General theory and quasiparticle properties

    Energy Technology Data Exchange (ETDEWEB)

    Schmalian, J. [University of Illinois at Urbana-Champaign, Loomis Laboratory of Physics, 1110 West Green Street, Urbana, Illinois 61801 (United States); Pines, D. [University of Illinois at Urbana-Champaign, Loomis Laboratory of Physics, 1110 West Green Street, Urbana, Illinois 61801 (United States)]|[Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Stojkovic, B. [Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1999-07-01

    We use a solution of the spin fermion model which is valid in the quasistatic limit {pi}T{gt}{omega}{sub sf}, found in the intermediate (pseudoscaling) regime of the magnetic phase diagram of cuprate superconductors, to obtain results for the temperature and doping dependence of the single particle spectral density, the electron-spin fluctuation vertex function, and the low frequency dynamical spin susceptibility. The resulting strong anisotropy of the spectral density and the vertex function lead to the qualitatively different behavior of {ital hot} [around {bold k}=({pi},0)] and {ital cold} [around {bold k}=({pi}/2,{pi}/2)] quasiparticles seen in ARPES experiments. We find that the broad high energy features found in ARPES measurements of the spectral density of the underdoped cuprate superconductors are determined by strong antiferromagnetic (AF) correlations and incoherent precursor effects of an SDW state, with reduced renormalized effective coupling constant. Due to this transfer of spectral weight to higher energies, the low frequency spectral weight of {ital hot} states is strongly reduced but couples very strongly to the spin excitations of the system. For realistic values of the antiferromagnetic correlation length, their Fermi surface changes its general shape only slightly but the strong scattering of hot states makes the Fermi surface crossing invisible above a pseudogap temperature T{sub {asterisk}}. The electron spin-fluctuation vertex function, i.e., the effective interaction of low energy quasiparticles and spin degrees of freedom, is found to be strongly anisotropic and enhanced for hot quasiparticles; the corresponding charge-fluctuation vertex is considerably diminished. We thus demonstrate that, once established, strong AF correlations act to reduce substantially the effective electron-phonon coupling constant in cuprate superconductors. {copyright} {ital 1999} {ital The American Physical Society}

  13. Effect of site disorder on the magnetic properties of weak itinerant ...

    Indian Academy of Sciences (India)

    [1] S N Kaul, J. Phys.: Condens. Matter 11, 7597 (1999) and references cited therein. S N Kaul and A Semwal, Phys. Lett. A254, 101 (1998). [2] F R de Boer, C J Schinkel, J Biesterbos and S Proost, J. Appl. Phys. 40, 1049 (1969). [3] C G Robbins and H Claus, in Magnetism and magnetic materials edited by C D Graham and.

  14. Weak temperature dependence of ageing of structural properties in atomistic model glassformers

    Science.gov (United States)

    Jenkinson, Thomas; Crowther, Peter; Turci, Francesco; Royall, C. Patrick

    2017-08-01

    Ageing phenomena are investigated from a structural perspective in two binary Lennard-Jones glassformers, the Kob-Andersen and Wahnström mixtures. In both, the geometric motif assumed by the glassformer upon supercooling, the locally favoured structure (LFS), has been established. The Kob-Andersen mixture forms bicapped square antiprisms; the Wahnström model forms icosahedra. Upon ageing, we find that the structural relaxation time has a time-dependence consistent with a power law. However, the LFS population and potential energy increase and decrease, respectively, in a logarithmic fashion. Remarkably, over the time scales investigated, which correspond to a factor of 104 change in relaxation times, the rate at which these quantities age appears almost independent of temperature. Only at temperatures far below the Vogel-Fulcher-Tamman temperature do the ageing dynamics slow.

  15. Quantum Weak Values and Logic: An Uneasy Couple

    Science.gov (United States)

    Svensson, Bengt E. Y.

    2017-03-01

    Quantum mechanical weak values of projection operators have been used to answer which-way questions, e. g. to trace which arms in a multiple Mach-Zehnder setup a particle may have traversed from a given initial to a prescribed final state. I show that this procedure might lead to logical inconsistencies in the sense that different methods used to answer composite questions, like "Has the particle traversed the way X or the way Y?", may result in different answers depending on which methods are used to find the answer. I illustrate the problem by considering some examples: the "quantum pigeonhole" framework of Aharonov et al., the three-box problem, and Hardy's paradox. To prepare the ground for my main conclusion on the incompatibility in certain cases of weak values and logic, I study the corresponding situation for strong/projective measurements. In this case, no logical inconsistencies occur provided one is always careful in specifying exactly to which ensemble or sample space one refers. My results cast doubts on the utility of quantum weak values in treating cases like the examples mentioned.

  16. Weak nanoscale chaos and anomalous relaxation in DNA

    Science.gov (United States)

    Mazur, Alexey K.

    2017-06-01

    Anomalous nonexponential relaxation in hydrated biomolecules is commonly attributed to the complexity of the free-energy landscapes, similarly to polymers and glasses. It was found recently that the hydrogen-bond breathing of terminal DNA base pairs exhibits a slow power-law relaxation attributable to weak Hamiltonian chaos, with parameters similar to experimental data. Here, the relationship is studied between this motion and spectroscopic signals measured in DNA with a small molecular photoprobe inserted into the base-pair stack. To this end, the earlier computational approach in combination with an analytical theory is applied to the experimental DNA fragment. It is found that the intensity of breathing dynamics is strongly increased in the internal base pairs that flank the photoprobe, with anomalous relaxation quantitatively close to that in terminal base pairs. A physical mechanism is proposed to explain the coupling between the relaxation of base-pair breathing and the experimental response signal. It is concluded that the algebraic relaxation observed experimentally is very likely a manifestation of weakly chaotic dynamics of hydrogen-bond breathing in the base pairs stacked to the photoprobe and that the weak nanoscale chaos can represent an ubiquitous hidden source of nonexponential relaxation in ultrafast spectroscopy.

  17. Weak ionization of the global ionosphere in solar cycle 24

    Directory of Open Access Journals (Sweden)

    Y. Q. Hao

    2014-07-01

    Full Text Available Following prolonged and extremely quiet solar activity from 2008 to 2009, the 24th solar cycle started slowly. It has been almost 5 years since then. The measurement of ionospheric critical frequency (foF2 shows the fact that solar activity has been significantly lower in the first half of cycle 24, compared to the average levels of cycles 19 to 23; the data of global average total electron content (TEC confirm that the global ionosphere around the cycle 24 peak is much more weakly ionized, in contrast to cycle 23. The weak ionization has been more notable since the year 2012, when both the ionosphere and solar activity were expected to be approaching their maximum level. The undersupply of solar extreme ultraviolet (EUV irradiance somewhat continues after the 2008–2009 minimum, and is considered to be the main cause of the weak ionization. It further implies that the thermosphere and ionosphere in the first solar cycle of this millennium would probably differ from what we have learned from the previous cycles of the space age.

  18. Search for anomalous weak dipole moments of the $\\tau$ lepton

    CERN Document Server

    Heister, A; Barate, R; De Bonis, I; Décamp, D; Goy, C; Lees, J P; Merle, E; Minard, M N; Pietrzyk, B; Bravo, S; Casado, M P; Chmeissani, M; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Martínez, M; Pacheco, A; Ruiz, H; Colaleo, A; Creanza, D; De Palma, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Azzurri, P; Buchmüller, O L; Cattaneo, M; Cerutti, F; Clerbaux, B; Drevermann, H; Forty, R W; Frank, M; Gianotti, F; Hansen, J B; Harvey, J; Hutchcroft, D E; Janot, P; Jost, B; Kado, M; Mato, P; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Schneider, O; Sguazzoni, G; Tejessy, W; Teubert, F; Valassi, Andrea; Videau, I; Ward, J; Badaud, F; Falvard, A; Gay, P; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Kyriakis, A; Markou, C; Simopoulou, Errietta; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Rougé, A; Rumpf, M; Swynghedauw, M; Verderi, M; Videau, H L; Ciulli, V; Focardi, E; Parrini, G; Antonelli, A; Antonelli, M; Bencivenni, G; Bossi, F; Capon, G; Chiarella, V; Laurelli, P; Mannocchi, G; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Lynch, J G; Negus, P; O'Shea, V; Raine, C; Thompson, A S; Wasserbaech, S R; Cavanaugh, R J; Geweniger, C; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Stenzel, H; Tittel, K; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, P J; Girone, M; Marinelli, N; Sedgbeer, J K; Thompson, J C; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Pearson, M R; Robertson, N A; Jakobs, K; Kleinknecht, K; Renk, B; Sander, H G; Wachsmuth, H W; Zeitnitz, C; Bonissent, A; Coyle, P; Leroy, O; Payre, P; Rousseau, D; Talby, M; Ragusa, F; David, A; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Männer, W; Moser, H G; Settles, Ronald; Wolf, G; Boucrot, J; Callot, O; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Lefrançois, J; Veillet, J J; Yuan, C; Bagliesi, G; Boccali, T; Foà, L; Giammanco, A; Giassi, A; Ligabue, F; Messineo, A; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Tenchini, Roberto; Venturi, A; Verdini, P G; Blair, G A; Cowan, G; Green, M G; Medcalf, T; Misiejuk, A; Strong, J A; Teixeira-Dias, P; Clifft, R W; Edgecock, T R; Norton, P R; Tomalin, I R; Bloch-Devaux, B; Colas, P; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Schuller, J P; Vallage, B; Konstantinidis, N P; Litke, A M; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Lehto, M H; Thompson, L F; Böhrer, A; Brandt, S; Grupen, Claus; Ngac, A; Prange, G; Giannini, G; Rothberg, J E; Armstrong, S R; Berkelman, K; Cranmer, K; Ferguson, D P S; Gao, Y; Gonzáles, S; Hayes, O J; Hu, H; Jin, S; Kile, J; McNamara, P A; Nielsen, J; Pan, Y B; Von Wimmersperg-Töller, J H; Wiedenmann, W; Wu, J; Wu Sau Lan; Wu, X; Zobernig, G; Dissertori, G

    2003-01-01

    The anomalous weak dipole moments of the $\\tau$ lepton are measured in a data sample collected by ALEPH from 1990 to 1995 corresponding to an integrated luminosity of 155~pb$^{-1}$. Tau leptons produced in the reaction $e^+ e^- \\rightarrow \\tau^+ \\tau^-$ at energies close to the ${\\rm Z}$ mass are studied using their semileptonic decays to $\\pi$, $\\rho$, $a_1 \\rightarrow \\pi 2\\pi^0$ or $a_1 \\rightarrow 3 \\pi$. The real and imaginary components of both the anomalous weak magnetic dipole moment and the CP-violating anomalous weak electric dipole moment, $ {\\rm Re}\\,\\mu_{\\tau}$, ${\\rm Im}\\,\\mu_{\\tau}$, ${\\rm Re}\\,d_{\\tau}$ and ${\\rm Im}\\,d_{\\tau}$, are measured simultaneously by means of a likelihood fit built from the full differential cross section. No evidence of new physics is found. The following bounds are obtained (95\\% CL): $|{\\rm Re}\\, \\mu_{\\tau} | < 1.14 \\times 10^{-3}$, $|{\\rm Im}\\, \\mu_{\\tau} | < 2.65 \\times 10^{-3}$, $|{\\rm Re}\\, d_{\\tau} | < 0.91 \\times 10^{-3}$, and $|{\\rm Im}\\, d_{\\tau} ...

  19. When Amplification with Weak Values Fails to Suppress Technical Noise

    Directory of Open Access Journals (Sweden)

    George C. Knee

    2014-03-01

    Full Text Available The application of postselection to a weak quantum measurement leads to the phenomenon of weak values. Expressed in units of the measurement strength, the displacement of a quantum coherent measuring device is ordinarily bounded by the eigenspectrum of the measured observable. Postselection can enable an interference effect that moves the average displacement far outside this range, bringing practical benefits in certain situations. Employing the Fisher-information metric, we argue that the amplified displacement offers no fundamental metrological advantage, due to the necessarily reduced probability of success. Our understanding of metrological advantage is the possibility of a lower uncertainty in the estimate of an unknown parameter with a large number of trials. We analyze a situation in which the detector is pixelated with a finite resolution and in which the detector is afflicted by random displacements: imperfections that degrade the fundamental limits of parameter estimation. Surprisingly, weak-value amplification is no more robust to them than a technique making no use of the amplification effect brought about by a final, postselected measurement.

  20. Distinguishing Motor Weakness From Impaired Spatial Awareness: A Helping Hand!

    Directory of Open Access Journals (Sweden)

    Suneil A Raju

    2017-05-01

    Full Text Available Our patient, aged 73 years, had background peripheral neuropathy of unknown cause, stable for several years, which caused some difficulty in walking on uneven ground. He attended for a teaching session but now staggered in, a new development. He had apparent weakness of his right arm, but there was difficulty in distinguishing motor weakness from impaired spatial awareness suggestive of parietal lobe dysfunction. With the patient seated, eyes closed, and left arm outstretched, S.A.R. lifted the patient’s right arm and asked him to indicate when both were level. This confirmed motor weakness. Urgent computed tomographic scan confirmed left subdural haematoma and its urgent evacuation rapidly resolved the patient’s symptoms. Intrigued by our patient’s case, we explored further and learnt that in rehabilitation medicine, the awareness of limb position is commonly viewed in terms of joint position sense. We present recent literature evidence indicating that the underlying mechanisms are more subtle.

  1. Limits Of Quantum Information In Weak Interaction Processes Of Hyperons.

    Science.gov (United States)

    Hiesmayr, B C

    2015-07-06

    We analyze the achievable limits of the quantum information processing of the weak interaction revealed by hyperons with spin. We find that the weak decay process corresponds to an interferometric device with a fixed visibility and fixed phase difference for each hyperon. Nature chooses rather low visibilities expressing a preference to parity conserving or violating processes (except for the decay Σ(+)→ pπ(0)). The decay process can be considered as an open quantum channel that carries the information of the hyperon spin to the angular distribution of the momentum of the daughter particles. We find a simple geometrical information theoretic interpretation of this process: two quantization axes are chosen spontaneously with probabilities where α is proportional to the visibility times the real part of the phase shift. Differently stated, the weak interaction process corresponds to spin measurements with an imperfect Stern-Gerlach apparatus. Equipped with this information theoretic insight we show how entanglement can be measured in these systems and why Bell's nonlocality (in contradiction to common misconception in literature) cannot be revealed in hyperon decays. Last but not least we study under which circumstances contextuality can be revealed.

  2. Human action recognition based on estimated weak poses

    Science.gov (United States)

    Gong, Wenjuan; Gonzàlez, Jordi; Roca, Francesc Xavier

    2012-12-01

    We present a novel method for human action recognition (HAR) based on estimated poses from image sequences. We use 3D human pose data as additional information and propose a compact human pose representation, called a weak pose, in a low-dimensional space while still keeping the most discriminative information for a given pose. With predicted poses from image features, we map the problem from image feature space to pose space, where a Bag of Poses (BOP) model is learned for the final goal of HAR. The BOP model is a modified version of the classical bag of words pipeline by building the vocabulary based on the most representative weak poses for a given action. Compared with the standard k-means clustering, our vocabulary selection criteria is proven to be more efficient and robust against the inherent challenges of action recognition. Moreover, since for action recognition the ordering of the poses is discriminative, the BOP model incorporates temporal information: in essence, groups of consecutive poses are considered together when computing the vocabulary and assignment. We tested our method on two well-known datasets: HumanEva and IXMAS, to demonstrate that weak poses aid to improve action recognition accuracies. The proposed method is scene-independent and is comparable with the state-of-art method.

  3. Weakly supervised semantic segmentation using fore-background priors

    Science.gov (United States)

    Han, Zheng; Xiao, Zhitao; Yu, Mingjun

    2017-07-01

    Weakly-supervised semantic segmentation is a challenge in the field of computer vision. Most previous works utilize the labels of the whole training set and thereby need the construction of a relationship graph about image labels, thus result in expensive computation. In this study, we tackle this problem from a different perspective. We proposed a novel semantic segmentation algorithm based on background priors, which avoids the construction of a huge graph in whole training dataset. Specifically, a random forest classifier is obtained using weakly supervised training data .Then semantic texton forest (STF) feature is extracted from image superpixels. Finally, a CRF based optimization algorithm is proposed. The unary potential of CRF derived from the outputting probability of random forest classifier and the robust saliency map as background prior. Experiments on the MSRC21 dataset show that the new algorithm outperforms some previous influential weakly-supervised segmentation algorithms. Furthermore, the use of efficient decision forests classifier and parallel computing of saliency map significantly accelerates the implementation.

  4. Strengths and Weaknesses of Synthetic Mammography in Screening.

    Science.gov (United States)

    Ratanaprasatporn, Linda; Chikarmane, Sona A; Giess, Catherine S

    2017-01-01

    Synthetic mammography (SM) consists of two-dimensional images reconstructed from digital breast tomosynthesis (DBT) data. Unlike standard full-field digital mammography (FFDM), SM does not require additional radiation exposure. SM is being introduced in breast imaging centers because early clinical data demonstrate that synthetic images are comparable to FFDM in cancer detection, positive predictive values, and recall rates. SM has completely replaced FFDM in some practices. Thus, an understanding of SM and its strengths and weaknesses compared with those of FFDM is essential. The artifacts of SM include blurring subcutaneous tissue, loss of resolution in the axilla on mediolateral oblique views, pseudocalcifications, and decreased resolution near foreign bodies (eg, biopsy markers). SM's strengths include a reduced radiation dose, shorter acquisition time compared with a combined FFDM/DBT screening examination (with potentially less motion artifact), and increased conspicuity of calcifications, spiculated margins, and architectural distortion. The weaknesses of SM include the potential for false positives due to pseudocalcifications and the difficulty in assessing for motion artifact. This article reviews SM and its role in screening and presents clinical cases to highlight SM's strengths, weaknesses, and artifacts. © RSNA, 2017.

  5. A weakly-compressible Cartesian grid approach for hydrodynamic flows

    Science.gov (United States)

    Bigay, P.; Oger, G.; Guilcher, P.-M.; Le Touzé, D.

    2017-11-01

    The present article aims at proposing an original strategy to solve hydrodynamic flows. In introduction, the motivations for this strategy are developed. It aims at modeling viscous and turbulent flows including complex moving geometries, while avoiding meshing constraints. The proposed approach relies on a weakly-compressible formulation of the Navier-Stokes equations. Unlike most hydrodynamic CFD (Computational Fluid Dynamics) solvers usually based on implicit incompressible formulations, a fully-explicit temporal scheme is used. A purely Cartesian grid is adopted for numerical accuracy and algorithmic simplicity purposes. This characteristic allows an easy use of Adaptive Mesh Refinement (AMR) methods embedded within a massively parallel framework. Geometries are automatically immersed within the Cartesian grid with an AMR compatible treatment. The method proposed uses an Immersed Boundary Method (IBM) adapted to the weakly-compressible formalism and imposed smoothly through a regularization function, which stands as another originality of this work. All these features have been implemented within an in-house solver based on this WCCH (Weakly-Compressible Cartesian Hydrodynamic) method which meets the above requirements whilst allowing the use of high-order (> 3) spatial schemes rarely used in existing hydrodynamic solvers. The details of this WCCH method are presented and validated in this article.

  6. What is the magnetic Weak Gravity Conjecture for axions

    Energy Technology Data Exchange (ETDEWEB)

    Hebecker, Arthur; Henkenjohann, Philipp [Institute for Theoretical Physics, University of Heidelberg (Germany); Witkowski, Lukas T. [APC, Universite Paris 7, CNRS/IN2P3, CEA/IRFU, Obs. de Paris, Sorbonne Paris Cite, Paris (France)

    2017-03-15

    The electric Weak Gravity Conjecture demands that axions with large decay constant f couple to light instantons. The resulting large instantonic corrections pose problems for natural inflation. We explore an alternative argument based on the magnetic Weak Gravity Conjecture for axions, which we try to make more precise. Roughly speaking, it demands that the minimally charged string coupled to the dual 2-form-field exists in the effective theory. Most naively, such large-f strings curve space too much to exist as static solutions, thus ruling out large-f axions. More conservatively, one might allow non-static string solutions to play the role of the required charged objects. In this case, topological inflation would save the superplanckian axion. Furthermore, a large-f axion may appear in the low-energy effective theory based on two subplanckian axions in the UV. The resulting effective string is a composite object built from several elementary strings and domain walls. It may or may not satisfy the magnetic Weak Gravity Conjecture depending on how strictly the latter is interpreted and on the cosmological dynamics of this composite object, which remain to be fully understood. Finally, we recall that large-field brane inflation is naively possible in the codimension-one case. We show how string-theoretic back-reaction closes this apparent loophole of large-f (non-periodic) pseudo-axions. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Weak nuclear interactions in neon-21 and neon-18

    Energy Technology Data Exchange (ETDEWEB)

    Von Lintig, Richard David [Univ. of Washington, Seattle, WA (United States)

    1981-01-01

    The results of two experiments involving weak meson exchange among nucleons are reviewed. Measurements are described of the circular polarization of 2.789 MeV gamma rays associated with the 2.789/2.796 MeV parity mixed doublet in 21Ne. Also reported are measurements of the 0+ - 0- beta decay from 18Ne to the 1.081 MeV 0- state of 18F, itself part of a spin-zero doublet of considerable interest for parity mixing. The significance of the results to the theory of weak non-leptonic interactions is examined. An argument is repeated that more careful interpretation of the results in terms of the fundamental weak interaction is needed. The circular polarization of the 2.789 MeV radiation from 21Ne is (20 +- 26) x 10-4, a small result in view of the enhancement of this effect due to narrow doublet separation and the forbidden character of the transition. Simultaneous measurements of the circular polarization of 2.439 MeV radiation, which should not exhibit the parity violating effect even if the 1/2- (2.789 MeV) state contains a significant parity impurity, indicate an absence of bias in the measurements. The relative probability of the 0+ - 0- (1.081 MeV) decay from 18Ne is (2.26 ± .37) x 10-4. The two-body (or meson exchange) contribution to this transition is the isospin analog of parity mixing between the 1042-keV (Jπ;T = 0+;1) and 1081-keV (Jπ;T = 0-;0) states of 18F. The theoretical relation which has been shown to exist between these two weak interaction phenomena is recounted, so that the importance of the beta-decay measurement to non-leptonic weak interaction physics can be appreciated.

  8. The Born-Oppenheimer molecular simulations of infrared spectra of crystalline poly-(R)-3-hydroxybutyrate with analysis of weak Csbnd H⋯Odbnd C hydrogen bonds

    Science.gov (United States)

    Brela, Mateusz Z.; Boczar, Marek; Wójcik, Marek J.; Sato, Harumi; Nakajima, Takahito; Ozaki, Yukihiro

    2017-06-01

    In this letter we present results of study of weak Csbnd H⋯Odbnd C hydrogen bonds of crystalline poly-(R)-3-hydroxybutyrate (PHB) by using Born-Oppenheimer molecular dynamics. The polymeric structure and IR spectra of PHB result from the presence of the weak hydrogen bonds. We applied the post-molecular dynamics analysis to consider a Cdbnd O motion as indirectly involved in the hydrogen bonds. Quantization of the nuclear motion of the oxygens was done to perform detailed analysis of the strength and properties of the Cdbnd O bands involved in the weak hydrogen bonds. We have also shown the dynamic character of the weak hydrogen bond interactions.

  9. Wigner's quantum phase-space current in weakly-anharmonic weakly-excited two-state systems

    Science.gov (United States)

    Kakofengitis, Dimitris; Steuernagel, Ole

    2017-09-01

    There are no phase-space trajectories for anharmonic quantum systems, but Wigner's phase-space representation of quantum mechanics features Wigner current J . This current reveals fine details of quantum dynamics —finer than is ordinarily thought accessible according to quantum folklore invoking Heisenberg's uncertainty principle. Here, we focus on the simplest, most intuitive, and analytically accessible aspects of J. We investigate features of J for bound states of time-reversible, weakly-anharmonic one-dimensional quantum-mechanical systems which are weakly-excited. We establish that weakly-anharmonic potentials can be grouped into three distinct classes: hard, soft, and odd potentials. We stress connections between each other and the harmonic case. We show that their Wigner current fieldline patterns can be characterised by J's discrete stagnation points, how these arise and how a quantum system's dynamics is constrained by the stagnation points' topological charge conservation. We additionally show that quantum dynamics in phase space, in the case of vanishing Planck constant ℏ or vanishing anharmonicity, does not pointwise converge to classical dynamics.

  10. Weak Hard X-Ray Emission from Broad Absorption Line Quasars: Evidence for Intrinsic X-Ray Weakness

    DEFF Research Database (Denmark)

    Luo, B.; Brandt, W. N.; Alexander, D. M.

    2014-01-01

    We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z = 0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z 330 times weaker than...... expected for typical quasars. Our results from a pilot NuSTAR study of two low-redshift BAL quasars, a Chandra stacking analysis of a sample of high-redshift BAL quasars, and a NuSTAR spectral analysis of the local BAL quasar Mrk 231 have already suggested the existence of intrinsically X-ray weak BAL...... quasars, i.e., quasars not emitting X-rays at the level expected from their optical/UV emission. The aim of the current program is to extend the search for such extraordinary objects. Three of the six new targets are weakly detected by NuSTAR with ≲ 45 counts in the 3-24 keV band, and the other three...

  11. Magnetic properties of hematite nanoparticles

    DEFF Research Database (Denmark)

    Bødker, Franz; Hansen, Mikkel Fougt; Bender Koch, Christian

    2000-01-01

    The magnetic properties of hematite (alpha-Fe2O3) particles with sizes of about 16 nm have been studied by use of Mossbauer spectroscopy, magnetization measurements, and neutron diffraction. The nanoparticles are weakly ferromagnetic at temperatures at least down to 5 K with a spontaneous magneti...

  12. The Cucker-Smale Equation: Singular Communication Weight, Measure-Valued Solutions and Weak-Atomic Uniqueness

    Science.gov (United States)

    Mucha, Piotr B.; Peszek, Jan

    2017-08-01

    The Cucker-Smale flocking model belongs to a wide class of kinetic models that describe a collective motion of interacting particles that exhibit some specific tendency, e.g. to aggregate, flock or disperse. This paper examines the kinetic Cucker-Smale equation with a singular communication weight. Given a compactly supported measure as an initial datum we construct a global in time weak measure-valued solution in the space {C_{weak}(0,∞;M)} . The solution is defined as a mean-field limit of the empirical distributions of particles, the dynamics of which is governed by the Cucker-Smale particle system. The studied communication weight is {ψ(s)=|s|^{-α}} with {α \\in (0, 1/2)} . This range of singularity admits the sticking of characteristics/trajectories. The second result concerns the weak-atomic uniqueness property stating that a weak solution initiated by a finite sum of atoms, i.e. Dirac deltas in the form {m_i δ_{x_i} ⊗ δ_{v_i}} , preserves its atomic structure. Hence these coincide with unique solutions to the system of ODEs associated with the Cucker-Smale particle system.

  13. The Cucker-Smale Equation: Singular Communication Weight, Measure-Valued Solutions and Weak-Atomic Uniqueness

    Science.gov (United States)

    Mucha, Piotr B.; Peszek, Jan

    2018-01-01

    The Cucker-Smale flocking model belongs to a wide class of kinetic models that describe a collective motion of interacting particles that exhibit some specific tendency, e.g. to aggregate, flock or disperse. This paper examines the kinetic Cucker-Smale equation with a singular communication weight. Given a compactly supported measure as an initial datum we construct a global in time weak measure-valued solution in the space {C_{weak}(0,∞M)}. The solution is defined as a mean-field limit of the empirical distributions of particles, the dynamics of which is governed by the Cucker-Smale particle system. The studied communication weight is {ψ(s)=|s|^{-α}} with {α \\in (0,1/2)}. This range of singularity admits the sticking of characteristics/trajectories. The second result concerns the weak-atomic uniqueness property stating that a weak solution initiated by a finite sum of atoms, i.e. Dirac deltas in the form {m_i δ_{x_i} ⊗ δ_{v_i}}, preserves its atomic structure. Hence these coincide with unique solutions to the system of ODEs associated with the Cucker-Smale particle system.

  14. Development of the symmetrical laser shock test for weak bond inspection.

    Science.gov (United States)

    Sagnard, Maxime; Berthe, Laurent; Ecault, Romain; Touchard, Fabienne; Boustie, Michel

    2017-06-01

    This paper presents the LAser Shock Adhesion Test (LASAT) using symmetrical laser shocks. The study is part of ComBoNDT European project that develops new Non-Destructive Tests (NDT) to assess adherence properties of bonded composite structures. This NDT technique relies on the creation of a plasma on both side of the sample using two lasers. The plasma expands and generates shockwaves inside the material. When combined, the shockwaves create a local tensile strength. Properly set, this stress can be used to test interfaces adherence. Numerous experiments have shown that this adaptive technique can discriminate a good bond from a weak one, without damaging the composite structure. Weak bonds are usually created by contaminated surfaces (residues of release agent, finger prints, ...) and were artificially recreated for ComBoNDT test samples. Numerical simulations are being developed as well, to improve the comprehension of the physical phenomenon. And ultimately, using these numerical results, one should be able to find the correct laser parameters (intensity, laser spot diameter) to generate the right tensile strength at the desired location. This project has received funding from the European Union's Horizon 2020 research and innovation program under Grant agreement N 63649.

  15. 'Trophic whales' as biotic buffers: weak interactions stabilize ecosystems against nutrient enrichment.

    Science.gov (United States)

    Schwarzmüller, Florian; Eisenhauer, Nico; Brose, Ulrich

    2015-05-01

    Human activities may compromise biodiversity if external stressors such as nutrient enrichment endanger overall network stability by inducing unstable dynamics. However, some ecosystems maintain relatively high diversity levels despite experiencing continuing disturbances. This indicates that some intrinsic properties prevent unstable dynamics and resulting extinctions. Identifying these 'ecosystem buffers' is crucial for our understanding of the stability of ecosystems and an important tool for environmental and conservation biologists. In this vein, weak interactions have been suggested as stabilizing elements of complex systems, but their relevance has rarely been tested experimentally. Here, using network and allometric theory, we present a novel concept for a priori identification of species that buffer against externally induced instability of increased population oscillations via weak interactions. We tested our model in a microcosm experiment using a soil food-web motif. Our results show that large-bodied species feeding at the food web's base, so called 'trophic whales', can buffer ecosystems against unstable dynamics induced by nutrient enrichment. Similar to the functionality of chemical or mechanical buffers, they serve as 'biotic buffers' that take up stressor effects and thus protect fragile systems from instability. We discuss trophic whales as common functional building blocks across ecosystems. Considering increasing stressor effects under anthropogenic global change, conservation of these network-intrinsic biotic buffers may help maintain the stability and diversity of natural ecosystems. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

  16. The meaning of “anomalous weak values” in quantum and classical theories

    Energy Technology Data Exchange (ETDEWEB)

    Sokolovski, D., E-mail: dgsokol15@gmail.com [Departamento de Química-Física, Universidad del País Vasco, UPV/EHU, Leioa (Spain); IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013, Bilbao (Spain)

    2015-06-19

    The readings of a highly inaccurate “weak” quantum meter, employed to determine the value of a dichotomous variable S without destroying the interference between the alternatives, may take arbitrary values. We show that the expected values of its readings may take any real value, depending on the choice of the states in which the system is pre- and post-selected. Some of these values must fall outside the range of eigenvalues of S, in which case they may be expressed as “anomalous” averages obtained with negative probability weights, constructed from available probability amplitudes. This behaviour is a natural consequence of the Uncertainty Principle. The phenomenon of “anomalous weak values” has no non-trivial analogue in classical statistics. - Highlights: • Average reading of a weak meter can take any value, depending on the transition. • No information about intrinsic properties of the measured system, e.g., the size of a spin. • This is a direct consequence of the Uncertainty Principle, which forbids distinguishing between interfering alternatives. • Some of the average have to lie outside the spectrum of the measured operator, i.e., be “anomalous”. • There can be no anomalous averages in a purely classical theory.

  17. Acutolysin C, a weak hemorrhagic toxin from the venom of Agkistrodon acutus with leucoagglutination activity

    Directory of Open Access Journals (Sweden)

    CB Wei

    2011-01-01

    Full Text Available The properties and agglutination activity of acutolysin C, a hemorrhagic metalloproteinase obtained from Agkistrodon acutus venom, were studied herein. Acutolysin C is a basic glycoprotein consisting of a single polypeptide chain with a molecular weight of 23.1 kDa and pI 8.7, containing one Zn2+ and one Ca²+ per molecule. It possesses caseinolytic, weak lethal (LD50 = 7.6 mg/kg and weak hemorrhagic (MHD = 12.0 μg activities, but does not present fibrinolytic, fibrinogenolytic, arginine esterase and phospholipase A2 actions. In addition, it revealed agglutination activity on some animal lymphocytes, including five species of mammals, six of birds, three of reptiles and one of amphibians, but had no effect on lymphocytes from two species of reptiles, one amphibian and nine species of fish. It had no effects on the erythrocytes and platelets of all 26 animal species tested. Both leucoagglutination and caseinolytic activities were inhibited by EDTA; while cysteine, 2-mercaptoethanol, 1,4-dithiothreitol, glutathione, serum against acutolysin C and serum against homologous snake venom as well as glucose, sucrose, mannose, lactose and galactose had no effects on inhibition. The lowest concentration of acutolysin C that induced mouse lymphocyte agglutination was 2.5 μg/mL. Acutolysin C is an interesting substance since it is the first member of the hemorrhagin family to be shown to have leucoagglutination activity.

  18. Arotinolol is a weak partial agonist on beta 3-adrenergic receptors in brown adipocytes.

    Science.gov (United States)

    Zhao, J; Golozoubova, V; Cannon, B; Nedergaard, J

    2001-07-01

    Arotinolol, a clinically used alpha/beta-adrenergic blocker, has been demonstrated to be an anti-obesity agent. The anti-obesity effect of arotinolol was suggested to be the result of direct activation of thermogenesis in brown-fat cells. We tested the ability of arotinolol to stimulate thermogenesis (oxygen consumption) in isolated brown-fat cells and in intact animals. Arotinolol stimulated thermogenesis in brown-fat cells isolated from mouse and hamster. A relatively low sensitivity to the beta-adrenergic antagonist propranolol (pK(B) approximately 6) indicated that arotinolol interacted with the beta3-adrenergic receptor. On the beta3-receptor, arotinolol was a very weak (EC50 approximately 20 microM) and only partial (approximately 50%) agonist, but arotinolol also demonstrated the properties of being a beta3-receptor antagonist with a pK(B) of 5.7. In intact animals, only the antagonistic action of arotinolol could be observed. Because arotinolol is only a very weak and partial agonist on the beta3-receptors, direct stimulation of thermogenesis in brown adipose tissue is unlikely to be sufficient to cause significant weight loss. It may be necessary to invoke additional pathways to explain the anti-obesity effects of chronic treatment with arotinolol.

  19. Nuclear Spiral Shocks and Induced Gas Inflows in Weak Oval Potentials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Woong-Tae [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Elmegreen, Bruce G., E-mail: wkim@astro.snu.ac.kr, E-mail: bge@us.ibm.com [IBM T. J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598 (United States)

    2017-05-20

    Nuclear spirals are ubiquitous in galaxy centers. They exist not only in strong barred galaxies but also in galaxies without noticeable bars. We use high-resolution hydrodynamic simulations to study the properties of nuclear gas spirals driven by weak bar-like and oval potentials. The amplitude of the spirals increases toward the center by a geometric effect, readily developing into shocks at small radii even for very weak potentials. The shape of the spirals and shocks depends rather sensitively on the background shear. When shear is low, the nuclear spirals are loosely wound and the shocks are almost straight, resulting in large mass inflows toward the center. When shear is high, on the other hand, the spirals are tightly wound and the shocks are oblique, forming a circumnuclear disk through which gas flows inward at a relatively lower rate. The induced mass inflow rates are enough to power black hole accretion in various types of Seyfert galaxies as well as to drive supersonic turbulence at small radii.

  20. Weak measurements, quantum-state collapse, and the Born rule

    Science.gov (United States)

    Patel, Apoorva; Kumar, Parveen

    2017-08-01

    Projective measurement is used as a fundamental axiom in quantum mechanics, even though it is discontinuous and cannot predict which measured operator eigenstate will be observed in which experimental run. The probabilistic Born rule gives it an ensemble interpretation, predicting proportions of various outcomes over many experimental runs. Understanding gradual weak measurements requires replacing this scenario with a dynamical evolution equation for the collapse of the quantum state in individual experimental runs. We revisit the quantum trajectory framework that models quantum measurement as a continuous nonlinear stochastic process. We describe the ensemble of quantum trajectories as noise fluctuations on top of geodesics that attract the quantum state towards the measured operator eigenstates. In this effective theory framework for the ensemble of quantum trajectories, the measurement interaction can be specific to each system-apparatus pair, a context necessary for understanding weak measurements. Also in this framework, the constraint to reproduce projective measurement as per the Born rule in the appropriate limit requires that the magnitudes of the noise and the attraction are precisely related, in a manner reminiscent of the fluctuation-dissipation relation. This relation implies that both the noise and the attraction have a common origin in the underlying measurement interaction between the system and the apparatus. We analyze the quantum trajectory ensemble for the scenarios of quantum diffusion and binary quantum jump, and show that the ensemble distribution is completely determined in terms of a single evolution parameter. This trajectory ensemble distribution can be tested in weak measurement experiments. We also comment on how the required noise may arise in the measuring apparatus.