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Sample records for hypernuclear non-mesonic weak

  1. 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.

  2. Two-pion-exchange in the non-mesonic weak decay of {lambda}-hypernuclei

    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)], E-mail: chumi@ecm.ub.es; Garbarino, G. [Dipartimento di Fisica Teorica, Universita di Torino and INFN, Sezione di Torino, I-10125 Turin (Italy); 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)

    2007-12-06

    The non-mesonic weak decay of {lambda}-hypernuclei is studied within a one-meson-exchange potential supplemented by a chirally motivated two-pion-exchange mechanism. The effects of final state interactions on the outgoing nucleons are also taken into account. Particular attention is payed to the asymmetry of the protons emitted by polarized hypernuclei. The one-meson-exchange model describes the non-mesonic rates and the neutron-to-proton ratio satisfactorily but predicts a too large and negative asymmetry parameter. The two-pion exchange mechanism modifies the strength and sign of some decay amplitudes. As a consequence, while the rates change moderately, the asymmetry parameter is strongly affected, acquiring values that lie well within the experimental observations.

  3. First determination of the one-proton induced Non-Mesonic Weak Decay width of p-shell Λ-Hypernuclei

    Directory of Open Access Journals (Sweden)

    M. Agnello

    2014-11-01

    Full Text Available Previous studies of proton and neutron spectra from Non-Mesonic Weak Decay of eight Λ-Hypernuclei (A=5–16 have been revisited. New values of the ratio of the two-nucleon and the one-proton induced decay widths, Γ2N/Γp, are obtained from single proton spectra, Γ2N/Γp=0.50±0.24, and from neutron and proton coincidence spectra, Γ2N/Γp=0.36±0.14stat−0.04sys+0.05sys, in full agreement with previously published ones. With these values, a method is developed to extract the one-proton induced decay width in units of the free Λ decay width, Γp/ΓΛ, without resorting to Intra Nuclear Cascade models but by exploiting only experimental data, under the assumption of a linear dependence on A of the Final State Interaction contribution. This is the first systematic determination ever done and it agrees within the errors with recent theoretical calculations.

  4. Role of the axial vector a1-meson exchange in hypernuclear nonmesonic weak decays

    Science.gov (United States)

    Itonaga, K.; Motoba, T.; Ueda, T.; Rijken, Th. A.

    2008-04-01

    In the meson-theoretical potential model for the study of the nonmesonic decay rates and asymmetries of hypernuclei, for the first time, the axial-vector a1 meson (JPC=1++,ma1=1230MeV) is introduced. The a1 meson is the chiral partner of the ρ meson and has been treated in the meson-pair exchange framework as ρπ/a1 and σπ/a1. This is analogous to the treatment of ρ and σ exchange in our model. The a1-meson exchange is found to give remarkable modifications of the parity-conserving decay potentials (1,3S→1,3S and 3S1→3D1) at short range r⩽1 fm. As a result, the calculated intrinsic asymmetry parameter αΛ for Λ5He becomes very small and positive in good agreement with the recent high-quality experimental data. The calculated small values of αΛ are well compared with the data for Λ11B and Λ12C within error bars. The inclusion of the a1 meson also improves the Γn/Γp ratios and leads to a consistent explanation for the existing nonmesonic weak decay data of the light Λ hypernuclei (A⩽12). The results calculated in the π+2π/ρ+2π/σ+ω+K+ρπ/a1+σπ/a1 exchange interaction model are presented together with the estimates without a1. Also, the derivation of the expression for the proton asymmetry is described in some detail to elucidate the calculation procedures and phase conventions.

  5. Narrow Sigma -hypernuclear states

    CERN Document Server

    Gal, A

    1980-01-01

    It is shown that the spin-isospin dependence of low-energy Sigma N to Lambda N conversion leads to substantial quenching of nuclear-matter estimates of the widths of some Sigma -hypernuclear states produced in (K/sup -/, pi ) reactions, to a level below 10 MeV. The estimated widths compare favorably with those of the Sigma -hypernuclear peaks recently observed at CERN for /sup 7/Li, /sup 9/Be, and /sup 12/C. Tentative quantum number assignments are suggested for these states. (10 refs).

  6. Hypernuclear physics at overline{P}ANDA

    Science.gov (United States)

    Achenbach, Patrick; Bleser, Sebastian; Pochodzalla, Josef; Sanchez Lorente, Alicia; Steinen, Marcel

    Hypernuclear research will be one of the main topics addressed by the overline{P} anda experiment at the planned Facility for Anti-proton and Ion Research FAIR at Darmstadt, Germany. A copious production of Ξ-hyperons at a dedicated internal target in the stored anti-proton beam is expected, which will enable the high-precision γ-spectroscopy of double strange systems for the first time. In addition to the general purpose overline{P} anda setup, the hypernuclear experiments require an active secondary target of silicon layers and absorber material as well as high purity germanium (HPGe) crystals as γ-detectors. The design of the setup and the development of these detectors is progressing: a first HPGe crystal with a new electromechanical cooling system was prepared and the properties of a silicon strip detector as a prototype to be used in the secondary target were studied. Simultaneously to the hardware projects, detailed Monte Carlo simulations were performed to predict the yield of particle stable hypernuclei. With the help of the Monte Carlo a procedure for ΛΛ-hypernuclei identification by the detection and correlation of the weak decay pions was developed.

  7. Hypernuclear Spectroscopy at JLab Hall C

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Osamu; Doi, Daisuke; Fujii, Yu; Toshiyuki, Gogami; Kanda, Hiroki; Kaneta, M; Kawama, Daisuke; Maeda, Kazushige; Maruta, Tomofumi; Matsumura, Akihiko; Nagao, Sho; Nakamura, Satoshi; Shichijo, Ayako; Tamura, Hirokazu; Taniya, Naotaka; Yamamoto, Taku; Yokota, Kosuke; Kato, S; Sato, Yoshinori; Takahashi, Toshiyuki; Noumi, Hiroyuki; Motoba, T; Hiyama, E; Albayrak, Ibrahim; Ates, Ozgur; Chen, Chunhua; Christy, Michael; Keppel, Cynthia; Kohl, Karl; Li, Ya; Liyanage, Anusha Habarakada; Tang, Liguang; Walton, T; Ye, Zhihong; Yuan, Lulin; Zhu, Lingyan; Baturin, Pavlo; Boeglin, Werner; Dhamija, Seema; Markowitz, Pete; Raue, Brian; Reinhold, Joerg; Hungerford, Ed; Ent, Rolf; Fenker, Howard; Gaskell, David; Horn, Tanja; Jones, Mark; Smith, Gregory; Vulcan, William; Wood, Stephen; Johnston, C; Simicevic, Neven; Wells, Stephen; Samantha, Chhanda; Hu, Bitao; Shen, Ji; Wang, W; Zhang, Xiaozhuo; Zhang, Yi; Feng, Jing; Fu, Y; Zhou, Jian; Zhou, S; Jiang, Yi; Lu, H; Yan, Xinhu; Ye, Yunxiu; Gan, Liping; Ahmidouch, Abdellah; Danagoulian, Samuel; Gasparian, Ashot; Elaasar, Mostafa; Wesselmann, Frank; Asaturyan, Arshak; Margaryan, Amur; Mkrtchyan, Arthur; Mkrtchyan, Hamlet; Tadevosyan, Vardan; Androic, Darko; Furic, Miroslav; Petkovic, Tomislav; Seva, Tomislav; Niculescu, Gabriel; Niculescu, Maria-Ioana; Rodriguez, Victor; Cisbani, Evaristo; Cusanno, Francesco; Garibaldi, Franco; Urciuoli, Guido; De Leo, Raffaele; Maronne, S; Achenbach, Carsten

    2010-03-01

    Since the 1st generation experiment, E89-009, which was successfully carried out as a pilot experiment of (e,e'K+) hypernuclear spectroscopy at JLab Hall C in 2000, precision hypernuclear spectroscopy by the (e,e'K+) reactions made considerable progress. It has evolved to the 2nd generation experiment, E01-011, in which a newly constructed high resolution kaon spectrometer (HKS) was installed and the “Tilt method” was adopted in order to suppress large electromagnetic background and to run with high luminosity. Preliminary high-resolution spectra of 7ΛHe and 28ΛAl together with that of 12ΛB that achieved resolution better than 500 keV(FWHM) were obtained. The third generation experiment, E05-115, has completed data taking with an experimental setup combining a new splitter magnet, high resolution electron spectrometer (HES) and the HKS used in the 2nd generation experiment. The data were accumulated with targets of 7Li, 9Be, 10B, 12C and 52Cr as well as with those of CH2 and H2O for calibration. The analysis is under way with particular emphasis of determining precision absolute hypernuclear masses. In this article, hypernuclear spectroscopy program in the wide mass range at JLab Hall C that has undergone three generation is described.

  8. HYPERNUCLEAR STRUCTURE FROM GAMMA-RAY SPECTROSCOPY.

    Energy Technology Data Exchange (ETDEWEB)

    MILLENER,D.J.

    2003-10-14

    The energies of p-shell hypernuclear {gamma} rays obtained from recent experiments using the Hyperball at BNL and KEK are used to constrain the YN interaction which enters into shell-model calculations which include both {Lambda} and {Sigma} configurations.

  9. Hypernuclear and strangeness physics program at J-PARC

    Indian Academy of Sciences (India)

    Hypernuclear and strangeness physics program at J-PARC. T NAGAE. Department of Physics, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan. E-mail: tnagae@me.com. Abstract. The inauguration ceremony of the Japan Proton Accelerator Research Com- plex (J-PARC) was held on 6 July 2009, celebrating the ...

  10. Experimental review of hypernuclear physics: recent achievements and future perspectives.

    Science.gov (United States)

    Feliciello, A; Nagae, T

    2015-09-01

    Since the shutdown of several old proton synchrotrons, which played a fundamental role in the second generation experiments in hypernuclear physics performed in Europe, USA and Japan, some new experimental setups aiming to achieve sub-MeV energy resolution have been operating for a long time. Over the last decade the hypernuclear physics community has been committed to carrying out several third generation experiments by exploiting the potential offered by new accelerators, such as a continuous electron beam machine and a ϕ-factory. Large data samples were collected on specific items thanks to dedicated facilities and experimental apparatuses. The attention was mainly focused on both high-resolution spectroscopy and the decay mode study of single Λ-hypernuclei. Nowadays this phase is over but, until recently, important and, to some extent, unexpected results were achieved. An updated review of selected experimental results is presented, as well as a survey of perspectives for future studies.

  11. Hypernuclear Physics Programs via Electroproduction in Hall C at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    L. Tang

    1998-06-01

    Hypernuclei with strangeness -1 have been intensively studied both theoretically and experimentally using hadronic probes and reactions, (K, {pi}) and ({pi}, K), for many years since the first discovery of such formation in the earlier nuclear emulsion and bubble chamber experiments. Many recent review papers exist on the status of hypernuclear physics, such as the recent one written by B.F. Gibson and Ed V. Hungerford in which one can find detailed discussion on all aspects of hypernuclear physics and more complete reference list. The unique feature of this field can be summarized, in general, into three categories: (1) Strong Interaction Involving Strangeness, (2) Weak Interaction with {Delta}S = -1, and (3) Medium Modifications. For strong interaction, it is commonly believed that a hyperon can be treated as an ''impurity'' to probe deep interior of the nuclear medium to explore fundamental issues such as the changes in size and shape due to the short range feature of YN interactions, limit of conventional nuclear model (shell or cluster) in solving for many body systems with new degree of freedom, spin dependent forces (spin-spin, spin-orbital, tensor), new symmetry and explicit QCD effect in nuclear media. Many of such issues are impossible or very difficult to be studied in the ordinary nuclear physics. The keys for success in this part of field includes good energy resolution and wide ranged spectroscopy. Until now, many important issues are still unresolved or remained to be resolved in more consistent and satisfactory fashion, such as spin dependent forces. This is due to luck of high quality experimental facilities. Recent experiments at KEK using ({pi}{sup +}, K{sup +}) reaction with a dedicated new SKS spectrometer have demonstrated the importance of improving the energy resolution. New structures were found as resolution improved only from 3 MeV to 2 MeV.

  12. Hypernuclear spectroscopy with electron beam at JLab Hall C

    Energy Technology Data Exchange (ETDEWEB)

    Yuu Fujii

    2010-12-01

    Hypernuclear spectroscopy with electron beam at JLab Hall C has been studied since 2000. The first experiment, JLab E89-009, used Short Orbit Spectrometer (SOS) as a kaon arm and a split-pole type spectrometer (ENGE) as an electron arm. E89-009 employed zero-degree tagging method, which tags scattered electrons at zero-degree and the kaon arm also covered zero-degree. This method obtains maximum yield of hypernuclei but sufferers from high rate background of electrons from bremsstrahlung and positrons from pair-creation. Nevertheless, this experiment demonstrated the possibility of the (e,e' K{sup +}) reaction for hypernuclear spectroscopy by obtaining a hypernuclear mass spectrum with an energy resolution of better than 1 MeV (FWHM) [1][2]. However, poor signal to noise ratio and poor statistics requires us to improve the experimental setup. Therefore, E01-011 experiment was proposed based on the success of the JLab E01-011 experiment. Improvements of E01-011 from E09-009 can be summarized as: 1. Employed newly constructed high resolution kaon spectrometer (HKS) as a kaon arm. 2. Employed so-called 'tilt-method' for the electron arm. With the newly constructed HKS, having 2-10-4 momentum resolution, we expect an energy resolution of 400 keV (FWHM). The 'tilt-method' means the electron arm is tilted vertically to the splitter dispersive plane to avoid background electrons from bremsstrahlung and moeller scattering. The setup allowed us to use up to a few tens beam. The experiment was performed in 2005 and final result will be shown shortly. The third experiment, JLab E05-115 experiment was proposed as a natural extension of E01-011 experiment and will be performed in 2009. Improvements of experimental setup are, 1. Employed newly constructed high resolution electron spectrometer (HES) as a electron arm, 2. Employed a new charge-separation magnet (Splitter), fully customized for hypernuclear experiment at Hall C. With the third generation

  13. Hypernuclear physics: A brief past and bright future

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, B.F.

    2000-10-01

    A primary reason for investigating the structure and reactions of baryon systems is to achieve an understanding the fundamental baryon-baryon force in the realm of non-perturbative QCD. Few-baryon systems play an essential role, because one can calculate complete solutions to test a particular baryon-baryon interaction ansatz. Hypernuclei, exotic nuclei containing one or more hyperons (Y = {Lambda}, {Sigma}, or {Xi}) are crucial to this investigation, because they permit one to probe models based upon our experience in the nonstrange sector; they lie outside of the conventional world where our models were developed. That is, we can test whether our sophisticated models of the nucleon-nucleon (NN) interaction extrapolate successfully beyond the zero strangeness region in which the parameters were determined, or whether the models merely interpolate. The presence of the strangeness degree of freedom (flavor) adds a new dimension to our evolving picture of nuclear physics. We shall see that the physics of hypernuclei is both novel and puzzling, stretching our intuition and analysis capability beyond that developed during the more than half century that we have explored conventional nuclear physics. The hypernuclear sector of hadronic physics is not just a simple extension of zero-strangeness phenomena.

  14. Direct experimental evidence of the weak $\\Lambda n p \\rightarrow n n p$ hypernucleus decay

    CERN Document Server

    Agnello, M; Bertani, M; Bhang, H C; Bonomi, G; Botta, E; Bregant, M; Bressani, T; Bufalino, S; Busso, L; Calvo, D; Camerini, P; Dalena, B; De Mori, F; D'Erasmo, G; Fabbri, F L; Feliciello, A; Filippi, A; Fiore, E M; Fontana, A; Fujioka, H; Genova, P; Gianotti, P; Grion, N; Lucherini, V; Marcello, S; Mirfakhrai, N; Moia, F; Morra, O; Nagae, T; Outa, H; Pantaleo, A; Paticchio, V; Paino, S; Rui, R; Simonetti, G; Wheadon, R; Zenoni, A

    2011-01-01

    A direct experimental evidence of the occurrence of the weak reaction $\\Lambda np\\rightarrow nnp$ in nuclei has been obtained by the FINUDA experiment. Three events have been found that can be attributed to $^{7}_{\\Lambda}$Li and $^{9}_{\\Lambda}$Be two nucleon-induced non mesonic weak decays. The kinematic analysis of such events is presented here.

  15. The Second Generation Hypernuclear Spectroscopy at JLab Hall C (E01-011 experiment)

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Akihiko [TOHOKU

    2008-11-01

    The second generation Λ hypernuclear spectroscopy by (e,e’K{sup +}) reaction has been carried out successfully at JLab in 2005. New configurations, HKS and Tilt method, significantly improved both energy resolution and statistics. Systematic error depend on tuning procedure was estimated by the blind analysis. Analysis is in the final stage. Third generation experiment (JLab E05-115) will be performed in the summer of 2009 w/ new e’ spectrometer (HES).

  16. Latest Results From the HypHI Experiments at GSI : Hypernuclear Spectroscopy with Heavy Ion Induced Reactions

    NARCIS (Netherlands)

    Saito, T. R.; Kim, E.; Nakajima, D.; Rappold, C.; Bianchin, S.; Borodina, O.; Bozkurt, V.; Kavatsyuk, M.; Ma, Y.; Maas, F.; Minami, S.; Ozel-Tashenov, B.; Yoshida, K.

    The HypHI Phase 0 experiment with Li-6 projectiles at 2 AGeV on a carbon target has been performed at GSI in order to demonstrate the feasibility of hypernuclear spectroscopy with induced reaction of heavy ion beams. Current data analyses have shown peaks in invariant mass distributions of p + pi

  17. Hypernuclear physics studies of the P̅ANDA experiment at FAIR

    Science.gov (United States)

    Sanchez Lorente, Alicia

    2015-05-01

    Hypernuclear research will be one of the main topics addressed by the PANDA experiment at the planned Facility for Antiproton and Ion Research FAIR at Darmstadt (Germany). [1, 2] Thanks to the use of stored p̅ beams, copious production of double Λ hypernuclei is expected at the PANDA experiment, which will enable high precision γ spectroscopy of such nuclei for the first time, and consequently a unique chance to explore the hyperon-hyperon interaction. In particular, ambiguities of past experiments in determining the strength of the ΛΛ interaction will be avoided thanks to the excellent energy precision of a few keV (FWHM) achieved by germanium detectors. Such a resolution capability is particularly needed to resolve the small energy spacing of the order of (10-100) keV, which is characteristic from the spin doublet in hypernuclei the so -called "hypernuclear fine structure". In comparison to previous experiments, PANDA will benefit from a novel technique to assign the various observable γ-transitions in a unique way to specific double hypernuclei by exploring various light targets. Nevertheless, the ability to carry out unique assignments requires a devoted hypernuclear detector setup. This consists of a primary nuclear target for the production of Ξ- + overline Xi pairs, a secondary active target for the hypernuclei formation and the identification of associated decay products and a germanium array detector to perform γ spectroscopy. Moreover, one of the most challenging issues of this project is the fact that all detector systems need to operate in the presence of a high magnetic field and a large hadronic background. Accordingly, the need of an innovative detector concept will require dramatic improvements to fulfil these conditions and that will likely lead to a new generation of detectors. In the present work details concerning the current status of the activities related to the detector developments for this challenging programme will be given. Among

  18. Search for $\\Sigma$ Hypernuclear States using the Strangeness Exchange Reactions $(K^{-},\\pi^{-})$ and $(K^{-},\\pi^{+})$

    CERN Multimedia

    2002-01-01

    In previous $\\Lambda$ hypernuclei experiments details of the $\\Lambda$ nucleus interaction have been deduced, the most outstanding being a very small spin orbit interaction in p$^{-}$ and sd shell $\\Lambda$ hypernuclei. This kind of information is decisive in the understanding of the baryon interaction and will contribute to distinguish between the boson exchange and the QCD motivated picture of the baryon baryon interaction. To further exploit the hyperon nucleus interaction one has to investigate hypernuclei with hyperons of different quark configuration, i.e. $\\Sigma$ hypernuclei. Since the $\\Sigma\\$ particle can, in contrast to the $\\Lambda$, decay by strong interaction in the nucleus, the existence of narrow states was not obvious. A small momentum transfer guarantees that the spectra are dominated by a few strong transitions to narrow hypernuclear states with the same spin and space quantum numbers as the target nucleus. Therefore a new kaon beamline was built with a lower momentum of 400~MeV/c and a co...

  19. Investigation of high-precision Λ hypernuclear spectroscopy via the (e,e'K+) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kawama, Daisuke [Tohoku Univ., Sendai (Japan)

    2011-01-01

    The study of Λ hypernuclear structure is very interesting in point of the understanding of the interaction between Λ and nucleon (Λ-N interaction) and its strange structure itself due to the containment of a Λ hyperon which has a strangeness as a new degree of freedom. In the several way to study the Lamda hypernuclei, the (e,e'K+) reaction spectroscopy is a powerful tool for the precise investigation of Λ hypernuclear structure. The purpose of the preset thesis is the establishment of the experimental design with the efficient data analysis method for the (e,e'K+) hypernuclear spectroscopic experiment in the wide mass region (from A=7 to A=52). It is very challenging to perform the (e,e'K+) spectroscopic experiment with such a heavy target, because of the huge electron background due to the bremsstrahlung process. In the experiment, it is required to obtain the necessary hypernuclear yield, suppressing the background event ratio. We achieved these requirements by newly constructing the high resolution electron spectrometer (HES) and splitter magnet (SPL) dedicated to the (e,e'K+) spectroscopic experiment. The HES consists of two quadrupole magnets and a dipole magnets (Q-Q-D) with a momentum resolution of dp/p = 3x10-4 at p = 0.84 GeV/c. It was used being vertically tilted by 6.5 degree so as to optimize signal to noise ratio and hypernuclear yield. The SPL is a dipole magnet. The experimental target was placed at the entrance of this magnet. The role of the SPL is to separate four kind of particles; scattered kaons, photons created by the bremsstrahlung, the post beam and scattered electrons. In addition, since the SPL is a part of the kaon and electron spectrometers. We designed the magnet shape carefully considering these points. The experiment was performed with 2.344 GeV/c electron beam from CEBAF at Jefferson Lab. The experimental setup consists of the HES, SPL and HKS (high momentum resolution kaon

  20. Hypernuclear production cross section in the reaction of 6Li + 12C at 2A GeV

    Directory of Open Access Journals (Sweden)

    C. Rappold

    2015-07-01

    Full Text Available Hypernuclear production cross sections have been deduced for the first time with induced reaction of heavy ion beam on fixed target and by means of the invariant mass method by the HypHI Collaboration exploiting the reaction of 6Li + 12C at 2A GeV or sNN=2.70 GeV. A production cross section of 3.9±1.4 μb for 3ΛH and of 3.1±1.0 μb for 4ΛH respectively in the projectile rapidity region was inferred as well as the total production cross section of the Λ hyperon was measured and found to be equal to 1.7±0.8 mb. A global fit based on a Bayesian approach was performed in order to include and propagate statistical and systematic uncertainties. Production ratios of 3ΛH/4ΛH, 3ΛH/Λ and 4ΛH/Λ were included in the inference procedure. The strangeness population factors S3 and S4 of 3ΛH and 4ΛH respectively were extracted. In addition, the multiplicities of the Λ hyperon, 3ΛH, and 4ΛH together with the rapidity and transversal momentum density distributions of the observed hypernuclei were extracted and reported.

  1. 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.

  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. Hypernuclear physics at JHF - structure

    Energy Technology Data Exchange (ETDEWEB)

    Hiyama, Emiko [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

    2002-07-01

    In order to attain the primary goal of nuclear physics, it is necessary to establish (1) an understanding of the structure of many body systems consisting of nucleons and hyperons and (2) means to use the structure information to understand the YN and YY interactions. As an example of (1), the shrinkage effect in {sub {lambda}}{sup 7}Li will be discussed. As the examples of (2) we will discuss {sub {lambda}}{sup 9}Be and {sub {lambda}}{sup 13}C related to the YN spin-orbit force, double {lambda} hypernuclei with A = 6{approx}10 related to the {lambda}{lambda} interaction and {sub {lambda}}{sup 4}He related to {lambda}N - {sigma}N coupling. (author)

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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).

  9. 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...

  10. 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.

  11. 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.

  12. 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....

  13. 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.

  14. 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.

  15. 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.

  16. 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 ...

  17. Selected problems in nuclear/high energy physics: Experimental hypernuclear physics, muon rare decay, and development of new detector system applicable to nuclear/high energy physics experiments. Final close-out report, June 1, 1994--May 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Tang, L. [Hampton Univ., VA (United States). Dept. of Physics]|[Continuous Electron Beam Accelerator Facility, Newport News, VA (United States). Physics Div.

    1998-08-01

    spectrometer systems for strangeness S = {minus}1 or {minus}2 hypernuclear programs at either hadronic facilities such as BNL and KEK (or JHF-50 the new Japanese 50 GeV proton accelerator) or electron facility (mainly CEBAF). The fission chamber has been built and tested by source in lab and it is now under beam test. The optical design of the S2S spectrometer was presented in AGS-2000 Workshop (1996) and recently in JHF98 International Conference.

  18. 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.

  19. 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 $\\gamma = \\pi - \\beta - \\alpha$.

  20. 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...

  1. 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,

  2. 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.

  3. 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.

  4. Few-body aspect of hypernuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Hiyama, E. [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    2000-01-01

    We have carried out four-body calculationals of {sub {lambda}}{sup 4}H and {sub {lambda}}{sup 4}He taking both the 3N + {lambda} and 3N + {sigma} channels explicitly with the use of realistic NN and YN interactions. The {sigma}-channel component plays an important role in binding energies of the A = 4 hypernuclei though the admixture is approximately 1%. The {lambda}N - {sigma}N coupling is found to be of central-force type in the Nijmegen model D and of tensor type in the model F. (author)

  5. Hypernuclear structure using the (. pi. ,K)

    Energy Technology Data Exchange (ETDEWEB)

    Millener, D.J.

    1990-11-01

    The result and theoretical interpretation of ({pi}{sup +},K{sup +}) experiments carried out at Brookhaven are summarized. Shell-model calculations are used to illustrate the precise spectroscopic studies of {Lambda} hypernuclei which could be carried out using the intense pion beams and good energy resolution for ({pi}{sup +},K{sup +}), ({pi}{sup +},K{sup +}{gamma}) and possibly ({pi}{sup {minus}},K{sup 0}) reactions at PILAC. 24 refs., 4 figs.

  6. Binding energies of hypernuclei and hypernuclear interactions

    Energy Technology Data Exchange (ETDEWEB)

    Bodmer, A.R. [Argonne National Lab., IL (United States)]|[Univ. of Illinois, Chicago, IL (United States). Dept. of Physics; Murali, S.; Usmani, Q.N. [Jamia Millia Islamia, New Delhi (India). Dept. of Physics

    1996-05-01

    In part 1 the effect of nuclear core dynamics on the binding energies of {Lambda} hypernuclei is discussed in the framework of variational correlated wave functions. In particular, the authors discuss a new rearrangement energy contribution and its effect on the core polarization. In part 2 they consider the interpretation of the {Lambda} single-particle energy in terms of basic {Lambda}-nuclear interactions using a local density approximation based on a Fermi hypernetted chain calculation of the A binding to nuclear matter. To account for the data strongly repulsive 3-body {Lambda}NN forces are required. Also in this framework they discuss core polarization for medium and heavier hypernuclei.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  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. 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...

  1. 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.

  2. 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.

  3. 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...

  4. 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.

  5. 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

  6. 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.

  7. 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...

  8. 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

  9. 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 ...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. 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

  17. 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...

  18. 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

  19. 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.

  20. 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

  1. 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.

  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. 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

  4. 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.

  5. About diffractive scattering of hypernuclei subLAMBDA sup 3 H and subLAMBDA sup 6 He on nuclei with allowance for the diffuseness of the nuclear edge, hypernuclear structure and multiple scattering effects

    CERN Document Server

    Evlanov, M V; Tartakovskij, V K

    2001-01-01

    The dependences of the elastic scattering differential cross sections and total cross sections for subLAMBDA sup 3 H and subLAMBDA sup 6 He hypernuclei on the magnitude of the nuclear edge diffuseness, the binding energy of the incident hypernuclei, on the finite ranges of the nuclear forces between clusters in hypernuclei, and on processes of multiple (double and triple) scattering are calculated with the use of the obtained convenient general formulae for elastic scattering amplitudes of two- and three-cluster weakly-bound nuclei on spherical nuclei for arbitrary dependence of profile functions on the impact parameter. The influence on the behavior of the cross sections during transition from two-cluster model to three-cluster one for the studied hypernuclei, is clarified as well

  6. 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.

  7. 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.

  8. 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.

  9. 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 ...

  10. 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.

  11. 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)

  12. 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.

  13. 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...

  14. 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....

  15. 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.

  16. Experiments in intermediate energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Dehnhard, D.

    2003-02-28

    Research in experimental nuclear physics was done from 1979 to 2002 primarily at intermediate energy facilities that provide pion, proton, and kaon beams. Particularly successful has been the work at the Los Alamos Meson Physics Facility (LAMPF) on unraveling the neutron and proton contributions to nuclear ground state and transition densities. This work was done on a wide variety of nuclei and with great detail on the carbon, oxygen, and helium isotopes. Some of the investigations involved the use of polarized targets which allowed the extraction of information on the spin-dependent part of the triangle-nucleon interaction. At the Indiana University Cyclotron Facility (IUCF) we studied proton-induced charge exchange reactions with results of importance to astrophysics and the nuclear few-body problem. During the first few years, the analysis of heavy-ion nucleus scattering data that had been taken prior to 1979 was completed. During the last few years we created hypernuclei by use of a kaon beam at Brookhaven National Laboratory (BNL) and an electron beam at Jefferson Laboratory (JLab). The data taken at BNL for a study of the non-mesonic weak decay of the A particle in a nucleus are still under analysis by our collaborators. The work at JLab resulted in the best resolution hypernuclear spectra measured thus far with magnetic spectrometers.

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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…

  5. 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)

  6. 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.

  7. 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.

  8. 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

  9. 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].

  10. 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

  11. 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

  12. 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.

  13. 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 ...

  14. 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...

  15. 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 ...

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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 ...

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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....

  10. 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.

  11. 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.

  12. 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 ...

  13. 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.

  14. 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).

  15. 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...

  16. 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.

  17. 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...

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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...

  3. 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

  4. 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

  5. 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.

  6. 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 ...

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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...

  14. 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.)

  15. 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.

  16. 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.

  17. Hypernuclear production from K sup - capture in liquid helium

    CERN Document Server

    Harada, T

    2000-01-01

    We examine phenomenologically the inclusive and exclusive sup 4 He(K sup - ,pi sup -) reactions from a stopped K sup - within a distorted-wave impulse approximation by using a coupled (3N-LAMBDA) + (3N-SIGMA) model with a spreading potential. We discuss these spectra from various atomic orbits of K sup - - sup 4 He atoms in order to explain the reaction mechanism quantitatively. The results show that the spectra are in excellent agreement with the available data from LAMBDA to SIGMA regions simultaneously, including the in-flight reactions; the capture probabilities per stopped K sup - for subLAMBDA sup 4 He and subSIGMA sup 4 He are 1.7% and 9.5%, respectively. It is established that there exists the subSIGMA sup 4 He unstable bound state, of which pole resides on the second Riemann sheet of the complex energy plane in the 3N-Y system.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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...

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.)).

  5. 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.

  6. 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.

  7. 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

  8. 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...

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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…

  14. 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....

  15. 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

  16. 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…

  17. 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

  18. 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.

  19. 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 ...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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 .

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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.

  18. 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 ...

  19. 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.

  20. 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).

  1. 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

  2. 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....

  3. 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...

  4. 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...

  5. 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 ...

  6. 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...

  7. 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...

  8. 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.

  9. 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...

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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 ±}〉.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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 ...

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. 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....

  19. 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.

  20. 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

  1. 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.

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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

  11. 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...

  12. 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.

  13. 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…

  14. 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 ...

  15. 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 ...

  16. 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 ...

  17. 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.

  18. 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)

  19. 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…

  20. 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.

  1. 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 ...

  2. 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

  3. 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.

  4. 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

  5. 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 ...

  6. 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.

  7. 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 ...

  8. 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.

  9. 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

  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. 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.

  5. 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

  6. 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

  7. 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

  8. 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...

  9. 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 ...

  10. 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

  11. 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.

  12. 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.

  13. [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

  14. 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.

  15. 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 ...

  16. 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.

  17. 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.

  18. 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 ...

  19. 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.

  20. 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.

  1. 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.

  2. 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 ...

  3. 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.

  4. 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 ...

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.)

  12. 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.

  13. 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.

  14. 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 .

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. [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".

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. [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.

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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...

  1. 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

  2. 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.

  3. 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...

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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 ...

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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} ...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  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. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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.

  13. Weak-lensing statistics from the Coyote Universe

    Science.gov (United States)

    Eifler, Tim

    2011-11-01

    Analysing future weak-lensing data sets from KIDS, Dark Energy Survey (DES), LSST, Euclid and WFIRST requires precise predictions for the weak-lensing measures. In this paper, we present a weak-lensing prediction code based on the Coyote Universe emulator. The Coyote Universe emulator predicts the (non-linear) power spectrum of density fluctuations (Pδ) to high accuracy for k∈[0.002; 3.4] h Mpc-1 within the redshift interval z∈[0; 1]; outside this regime, we extend Pδ using a modified HALOFIT code. This pipeline is used to calculate various second-order cosmic shear statistics, e.g., shear power spectrum, shear-shear correlation function, ring statistics and Complete Orthogonal Set of EB-mode Integrals (COSEBIs), and we examine how the upper limit in k (and z), to which Pδ is known, impacts on these statistics. For example, we find that kmax˜ 8 h Mpc-1 causes a bias in the shear power spectrum at ℓ˜ 4000 that is comparable to the statistical errors (intrinsic shape noise and cosmic variance) of a DES-like survey, whereas for LSST-like errors kmax˜ 15 h Mpc-1 is needed to limit the bias at ℓ˜ 4000. For the most recently developed second-order shear statistics, the COSEBIs, we find that nine modes can be calculated accurately knowing Pδ to kmax= 10 h Mpc-1. The COSEBIs allow for an EB-mode decomposition using a shear-shear correlation function measured over a finite range, thereby avoiding any EB-mode mixing due to finite survey size. We perform a detailed study in a five-dimensional parameter space in order to examine whether all cosmological information is captured by these nine modes with the result that already 7-8 modes are sufficient.

  14. Systemic inflammatory response syndrome increases immobility-induced neuromuscular weakness.

    Science.gov (United States)

    Fink, Heidrun; Helming, Marc; Unterbuchner, Christoph; Lenz, Andrea; Neff, Frauke; Martyn, J A Jeevendra; Blobner, Manfred

    2008-03-01

    Inflammation and immobility are comorbid etiological factors inducing muscle weakness in critically ill patients. This study establishes a rat model to examine the effect of inflammation and immobilization alone and in combination on muscle contraction, histology, and acetylcholine receptor regulation. Prospective, randomized, experimental study. Animal laboratory of a university hospital. Sprague-Dawley rats. To produce systemic inflammation, rats (n = 34) received three consecutive intravenous injections of Corynebacterium parvum on days 0, 4, and 8. Control rats (n = 21) received saline. Both groups were further divided to have one hind limb either immobilized by pinning of knee and ankle joints or sham-immobilized (surgical leg). The contralateral nonsurgical leg of each animal served as control (nonsurgical leg). After 12 days, body weight and muscle mass were significantly reduced in all C. parvum animals compared with saline-injected rats. Immobilization led to local muscle atrophy. Normalized to muscle mass, tetanic contraction was reduced in the surgical leg after immobilization (7.64 +/- 1.91 N/g) and after inflammation (8.71 +/- 2.0 N/g; both p immobilization and saline injection, 11.03 +/- 2.26 N/g). Histology showed an increase in inflammatory cells in all C. parvum-injected animals. Immobilization in combination with C. parvum injection had an additive effect on inflammation. Acetylcholine receptors were increased in immobilized muscles and in all muscles of C. parvum-injected animals. The muscle weakness in critically ill patients can be replicated in our novel rat model. Inflammation and immobilization independently lead to muscle weakness.

  15. Probing Cosmology with Weak Lensing Peak Counts and Minkowski Functionals

    Science.gov (United States)

    Kratochvil, Jan Michael; Wang, S.; Lim, E. A.; Haiman, Z.; May, M.

    2010-05-01

    The new method of counting peaks in weak lensing (WL) maps, as a function of their height, to probe models of dark energy and to constrain cosmological parameters offers advantages over similar, more traditional statistics like cluster counts: Because peaks can be identified in two-dimensional WL maps directly, they can provide constraints which are free from potential selection effects and biases involved in identifying and determining the masses of galaxy clusters. Our pilot study (Kratochvil, Haiman, May 2009), where we investigated three cosmological models with different constant values of the dark energy equation of state parameter w=-0.8, w=-1, w=-1.2 and with a fixed normalization of the primordial power spectrum, revealed a parameter sensitivity of w which warrants a numerically very costly in-depth study when marginalization over other uncertain cosmological parameters is included. Towards that goal, we present recent results from a new, extensive simulation suite of ninety 5123-particle N-body simulations, run on New York Blue at BNL, allowing us to vary several cosmological parameters individually and yielding vastly improved statistics. Studies have shown that weak lensing maps likely contain as much information in the nonlinear regime as in the linear one. While being a powerful probe of the nonlinear regime, weak lensing peak counts capture by definition only a subset of the total available information in the convergence maps. In particular, we found that relatively low-amplitude peaks account for most of the parameter sensitivity detected, hinting to a more complicated structure. Therefore, we extend our work by probing the morphology of the maps with Minkowski functionals, in our quest to extract the most possible information from the nonlinear aspects of large-scale structure formation.

  16. EFFECT OF MASKED REGIONS ON WEAK-LENSING STATISTICS

    Energy Technology Data Exchange (ETDEWEB)

    Shirasaki, Masato; Yoshida, Naoki [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Hamana, Takashi, E-mail: masato.shirasaki@utap.phys.s.u-tokyo.ac.jp [National Astronomical Observatory of Japan, Tokyo 181-0015 (Japan)

    2013-09-10

    Sky masking is unavoidable in wide-field weak-lensing observations. We study how masks affect the measurement of statistics of matter distribution probed by weak gravitational lensing. We first use 1000 cosmological ray-tracing simulations to examine in detail the impact of masked regions on the weak-lensing Minkowski Functionals (MFs). We consider actual sky masks used for a Subaru Suprime-Cam imaging survey. The masks increase the variance of the convergence field and the expected values of the MFs are biased. The bias then compromises the non-Gaussian signals induced by the gravitational growth of structure. We then explore how masks affect cosmological parameter estimation. We calculate the cumulative signal-to-noise ratio (S/N) for masked maps to study the information content of lensing MFs. We show that the degradation of S/N for masked maps is mainly determined by the effective survey area. We also perform simple {chi}{sup 2} analysis to show the impact of lensing MF bias due to masked regions. Finally, we compare ray-tracing simulations with data from a Subaru 2 deg{sup 2} survey in order to address if the observed lensing MFs are consistent with those of the standard cosmology. The resulting {chi}{sup 2}/n{sub dof} = 29.6/30 for three combined MFs, obtained with the mask effects taken into account, suggests that the observational data are indeed consistent with the standard {Lambda}CDM model. We conclude that the lensing MFs are a powerful probe of cosmology only if mask effects are correctly taken into account.

  17. Isotropization and hydrodynamization in weakly coupled heavy-ion collisions

    CERN Document Server

    Kurkela, Aleksi

    2015-01-01

    We numerically solve 2+1D effective kinetic theory of weak coupling QCD under longitudinal expansion relevant for early stages of heavy-ion collisions. We find agreement with viscous hydrodynamics and classical Yang-Mills simulations in the regimes where they are applicable. By choosing initial conditions that are motivated by color-glass-condensate framework we find that for Q=2GeV and $\\alpha_s$=0.3 the system is approximately described by viscous hydrodynamics well before $\\tau \\lesssim 1.0$ fm/c.

  18. A search for weakly decaying $b$-flavored pentaquarks

    CERN Document Server

    Aaij, Roel; LHCb Collaboration; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Alfonso Albero, Alejandro; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Atzeni, Michele; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Balagura, Vladislav; Baldini, Wander; Baranov, Alexander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baryshnikov, Fedor; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Beiter, Andrew; Bel, Lennaert; Beliy, Nikita; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Beranek, Sarah; Berezhnoy, Alexander; Bernet, Roland; Berninghoff, Daniel; Bertholet, Emilie; Bertolin, Alessandro; Betancourt, Christopher; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Birnkraut, Alex; Bizzeti, Andrea; Bjørn, Mikkel; Blake, Thomas; Blanc, Frederic; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bordyuzhin, Igor; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Brodzicka, Jolanta; Brundu, Davide; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Byczynski, Wiktor; Cadeddu, Sandro; Cai, Hao; Calabrese, Roberto; Calladine, Ryan; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Cattaneo, Marco; Cavallero, Giovanni; Cenci, Riccardo; Chamont, David; Chapman, Matthew George; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu Faye; Chitic, Stefan-Gabriel; Chobanova, Veronika; Chrzaszcz, Marcin; Chubykin, Alexsei; Ciambrone, Paolo; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collins, Paula; Colombo, Tommaso; Comerma-Montells, Albert; Contu, Andrea; Coombs, George; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Da Silva, Cesar Luiz; Dall'Occo, Elena; Dalseno, Jeremy; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Del Buono, Luigi; Dembinski, Hans Peter; Demmer, Moritz; Dendek, Adam; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Nezza, Pasquale; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Douglas, Lauren; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Durante, Paolo; Durham, John Matthew; Dutta, Deepanwita; Dzhelyadin, Rustem; Dziewiecki, Michal; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fazzini, Davide; Federici, Luca; Ferguson, Dianne; Fernandez, Gerard; Fernandez Declara, Placido; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Lopes, Lino; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Funk, Wolfgang; Furfaro, Emiliano; Färber, Christian; Gabriel, Emmy; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, Vladimir; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Govorkova, Ekaterina; Grabowski, Jascha Peter; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greim, Roman; Griffith, Peter; Grillo, Lucia; Gruber, Lukas; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hamilton, Brian; Han, Xiaoxue; Hancock, Thomas Henry; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Hasse, Christoph; Hatch, Mark; He, Jibo; Hecker, Malte; Heinicke, Kevin; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hopchev, Plamen Hristov; Hu, Wenhua; Huang, Wenqian; Huard, Zachary; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hutchcroft, David; Ibis, Philipp; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kazeev, Nikita; Kecke, Matthieu; Keizer, Floris; Kelsey, Matthew; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Klimkovich, Tatsiana; Koliiev, Serhii; Kolpin, Michael; Kopecna, Renata; Koppenburg, Patrick; Kosmyntseva, Alena; Kotriakhova, Sofia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreps, Michal; Kress, Felix Johannes; Krokovny, Pavel; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Pei-Rong; Li, Tenglin; Li, Yiming; Li, Zhuoming; Liang, Xixin; Likhomanenko, Tatiana; Lindner, Rolf; Lionetto, Federica; Lisovskyi, Vitalii; Liu, Xuesong; Loh, David; Loi, Angelo; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Macko, Vladimir; Mackowiak, Patrick; Maddrell-Mander, Samuel; Maev, Oleg; Maguire, Kevin; Maisuzenko, Dmitrii; Majewski, Maciej Witold; Malde, Sneha; Malecki, Bartosz; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Marangotto, Daniele; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marinangeli, Matthieu; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurice, Emilie; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McNab, Andrew; McNulty, Ronan; Mead, James Vincent; Meadows, Brian; Meaux, Cedric; Meier, Frank; Meinert, Nis; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Millard, Edward James; Minard, Marie-Noelle; Minzoni, Luca; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Mombächer, Titus; Monroy, Igancio Alberto; Monteil, Stephane; Morandin, Mauro; Morello, Michael Joseph; Morgunova, Olga; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Thi Dung; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Nogay, Alla; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Ossowska, Anna; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palutan, Matteo; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Mitesh; Patrignani, Claudia; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Pereima, Dmitrii; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pietrzyk, Guillaume; Pikies, Malgorzata; Pinci, Davide; Pisani, Flavio; Pistone, Alessandro; Piucci, Alessio; Placinta, Vlad-Mihai; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poli Lener, Marco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Ponce, Sebastien; Popov, Alexander; Popov, Dmitry; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Prisciandaro, Jessica; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Pullen, Hannah Louise; Punzi, Giovanni; Qian, Wenbin; Qin, Jia-Jia; Quagliani, Renato; Quintana, Boris; Rachwal, Bartlomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Ratnikov, Fedor; Raven, Gerhard; Ravonel Salzgeber, Melody; Reboud, Meril; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Robbe, Patrick; Robert, Arnaud; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rogozhnikov, Alexey; Roiser, Stefan; Rollings, Alexandra Paige; Romanovskiy, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Ruiz Vidal, Joan; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarpis, Gediminas; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schreiner, HF; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepulveda, Eduardo Enrique; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Soares Lavra, Lais; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavomira; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stepanova, Margarita; Stevens, Holger; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Stramaglia, Maria Elena; Straticiuc, Mihai; Straumann, Ulrich; Sun, Jiayin; Sun, Liang; Swientek, Krzysztof; Syropoulos, Vasileios; Szumlak, Tomasz; Szymanski, Maciej Pawel; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Tourinho Jadallah Aoude, Rafael; Tournefier, Edwige; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Usachov, Andrii; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagner, Alexander; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Verlage, Tobias Anton; Vernet, Maxime; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Vieira, Daniel; Vieites Diaz, Maria; Viemann, Harald; Vilasis-Cardona, Xavier; Vitti, Marcela; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Walsh, John; Wang, Jianchun; Wang, Yilong; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Weisser, Constantin; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Winn, Michael Andreas; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wyllie, Kenneth; Xie, Yuehong; Xu, Menglin; Xu, Qingnian; Xu, Zehua; Xu, Zhirui; Yang, Zhenwei; Yang, Zishuo; Yao, Yuezhe; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhelezov, Alexey; Zheng, Yangheng; Zhu, Xianglei; Zhukov, Valery; Zonneveld, Jennifer Brigitta; Zucchelli, Stefano

    2018-02-17

    Investigations of the existence of pentaquark states containing a single $b$ (anti)quark decaying weakly into four specific final states $J/\\psi K^+\\pi^- p$, $J/\\psi K^- \\pi^- p$, $J/\\psi K^- \\pi^+ p$, and $J/\\psi \\phi (1020) p$ are reported. The data sample corresponds to an integrated luminosity of 3.0 fb$^{-1}$ in 7 and 8 TeV $pp$ collisions acquired with the LHCb detector. Signals are not observed and upper limits are set on the product of the production cross section times branching fraction with respect to that of the $\\Lambda^0_b$.

  19. 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.

  20. Inflationary Weak Anisotropic Model with General Dissipation Coefficient

    CERN Document Server

    Sharif, M

    2015-01-01

    This paper explores the dynamics of warm intermediate and logamediate inflationary models during weak dissipative regime with a general form of dissipative coefficient. We analyze these models within the framework of locally rotationally symmetric Bianchi type I universe. In both cases, we evaluate solution of inflaton, effective scalar potential, dissipative coefficient, slow-roll parameters, scalar and tensor power spectra, scalar spectral index and tensor to scalar ratio under slow-roll approximation. We constrain the model parameters using recent data and conclude that anisotropic inflationary universe model with generalized dissipation coefficient remains compatible with WMAP9, Planck and BICEP2 data.

  1. On weak decays of heavy flavors, mixing and CP violation

    Energy Technology Data Exchange (ETDEWEB)

    Bigi, I.I.

    1987-10-01

    Detailed studies of weak decays serve not only to confirm the Standard Model, but possess also a high sensitivity to New Physics: tau and top decays are discussed in this vein, with some short remarks on beauty and charm. The sensitivity to New Physics is even higher in delicate phenomena like mixing and CP violation: a fairly detailed discussion on K/sup 0/ - anti K/sup 0/, D/sup 0/ - anti D/sup 0/, and B/sup 0/ - anti B/sup 0/ mixing and on CP violation in K/sup 0/ and B decays is presented. 48 refs., 11 figs.

  2. Weak Lower Semicontinuity of Integral Functionals and Applications

    Czech Academy of Sciences Publication Activity Database

    Benešová, B.; Kružík, Martin

    2017-01-01

    Roč. 59, č. 4 (2017), s. 703-766 ISSN 0036-1445 R&D Projects: GA ČR GA14-15264S; GA ČR(CZ) GF16-34894L Grant - others:GA AV ČR(CZ) DAAD-16-14 Program:Bilaterální spolupráce Institutional support: RVO:67985556 Keywords : calculus of variations * weak lower semi-continuity Subject RIV: BA - General Mathematics Impact factor: 4.897, year: 2016 http:// library .utia.cas.cz/separaty/2017/MTR/kruzik-0481321.pdf

  3. 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...

  4. Introduction to weak interaction theories with dynamical symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Lane, K.D.; Peskin, M.E.

    1980-07-01

    A straightforward introduction to theories of the weak interactions with dynamical symmetry breaking-theories of technicolor or hypercolor is presented. The intent is to inform experimentalists, but also to goad theorists. The motivation for considering theories of this type is described. The structure that such a theory must possess, including new gauge interactions at mass scales of 1-100 TeV is then outlined. Despite their reliance on phenomena at such enormous energies, these theories contain new phenomena observable at currently accessible energies. Three such effects which are especially likely to be observed are described.

  5. Longitudinal vector form factors in weak decays of nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Šimkovic, F. [Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna (Russian Federation); Department of Nuclear Physics and Biophysics, Comenius University, Mlynská dolina F1 SK–842 48 Bratislava (Slovakia); Kovalenko, S. [Universidad Técnica Federico Santa Mariya, Centro-Cientifico-Tecnológico de Valparaiso, Casilla 110-V, Valparaiso (Chile); Krivoruchenko, M. I. [Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna (Russian Federation); Institute for Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation)

    2015-10-28

    The longitudinal form factors of the weak vector current of particles with spin J = 1/2 and isospin I = 1/2 are determined by the mass difference and the charge radii of members of the isotopic doublets. The most promising reactions to measure these form factors are the reactions with large momentum transfers involving the spin-1/2 isotopic doublets with a maximum mass splitting. Numerical estimates of longitudinal form factors are given for nucleons and eight nuclear spin-1/2 isotopic doublets.

  6. Hunting for new, weakly coupled particles with high intensities

    Energy Technology Data Exchange (ETDEWEB)

    Doebrich, Babette [CERN, 1211 Geneva 23 (Switzerland)

    2016-07-01

    A number of smaller and diverse experiments complements the high-energy explorations for new physics at the LHC. Many of these experiments are searching for new physics hiding at comparably low mass but very weak coupling. Examples of such particles are axion-like particles and dark gauge bosons, which could also explain Dark Matter. The technology to directly search for such particles are often high-intensity and precision set-ups. In my talk I give a brief overview of the motivation and search for axion-like particles and then focus on the possibility to find them in a proton-dump experiment at CERN.

  7. Method and apparatus for measuring weak magnetic fields

    DEFF Research Database (Denmark)

    1995-01-01

    When measuring weak magnetic fields, a container containing a medium, such as a solution containing a stable radical, is placed in a polarising magnetic field, which is essentially at right angles to the field to be measured. The polarising field is interrupted rapidly, the interruption being...... preceded by the impression of a high-frequency electromagnetic signal. The frequency of the signal corresponds to the resonance frequency of the free electron spin. The frequency and amplitude of the precessing nuclei, which are a function of the strength of the measured field, are recorded by a pick...

  8. Profound Muscle Weakness and Pain after One Dose of Actonel

    Directory of Open Access Journals (Sweden)

    Irina Badayan

    2009-01-01

    Full Text Available The World Health Organization (WHO defines osteopenia as a bone density between 1 and 2.5 standard deviation (SD below the bone density of a normal young adult Iqbal 2000. Osteoporosis is defined as 2.5 SD or more below that reference point Iqbal 2000. Bisphosphonates are a group of medications used to treat osteoporosis, Padget's disease of bone, and osteopenia. We report a woman who developed profound muscle weakness and pain after one dose of Risedronate (Actonel.

  9. Asymptotics of weakly collapsing solutions of nonlinear Schroedinger equation

    CERN Document Server

    Ovchinnikov, Yu N

    2001-01-01

    One studied possible types of asymptotic behavior of weakly collapsing solution of the 3-rd nonlinear Schroedinger equation. It is shown that within left brace A, C sub 1 right brace parameter space there are two neighboring lines along which the amplitude of oscillation terms is exponentially small as to C sub 1 parameter. The same lines locates values of left brace A, C sub 1 right brace parameters at which the energy is equal to zero. With increase of C sub 1 parameter the accuracy of numerical determination of points with zero energy drops abruptly

  10. Asymptotic behavior of a weakly forced dry friction oscillator

    Directory of Open Access Journals (Sweden)

    J. Ildefonso Diaz

    2007-05-01

    Full Text Available This note is devoted to stick-slip aspects of the motion of a dry friction damped oscillator under weak irregular forcing. Our main result complements [10, Theorem 3.(a] and is also related to [1], where a non-Lipschitz model for Coulomb friction was consider in the unforced case. We provide sufficient conditions guaranteeing that solutions stabilizing in finite time, but observe also an infinite succession of ``stick-slip'' behavior. The last section discusses an extension to certain systems of such oscillators.

  11. Quantum weak coin flipping with arbitrarily small bias

    OpenAIRE

    Mochon, Carlos

    2007-01-01

    "God does not play dice. He flips coins instead." And though for some reason He has denied us quantum bit commitment. And though for some reason he has even denied us strong coin flipping. He has, in His infinite mercy, granted us quantum weak coin flipping so that we too may flip coins. Instructions for the flipping of coins are contained herein. But be warned! Only those who have mastered Kitaev's formalism relating coin flipping and operator monotone functions may succeed. For those foolha...

  12. Weakly nonlinear electron plasma waves in collisional plasmas

    DEFF Research Database (Denmark)

    Pecseli, H. L.; Rasmussen, J. Juul; Tagare, S. G.

    1986-01-01

    The nonlinear evolution of a high frequency plasma wave in a weakly magnetized, collisional plasma is considered. In addition to the ponderomotive-force-nonlinearity the nonlinearity due to the heating of the electrons is taken into account. A set of nonlinear equations including the effect...... of a constantly maintained pump wave is derived and a general dispersion relation describing the modulation of the high frequency wave due to different low frequency responses is obtained. Particular attention is devoted to a purely growing modulation. The relative importance of the ponderomotive force...

  13. OBTAINING COTTON SEED OIL EPOXIDIZED USING AN WEAK ACID

    Directory of Open Access Journals (Sweden)

    Karina Cruz-Aldaco

    2015-12-01

    Full Text Available In this study, parameters which influence the chemical modification under mild conditions using a weak organic acid, fatty acids of unsaturated oil, cottonseed to produce epoxidized oil, which is a useful precursor in obtaining resins epoxy industrial importance, were evaluated. We studied the following reaction parameters: concentration of acetic acid, hydrogen peroxide, catalyst and solvent, as well as temperature, agitation rate and reaction time. The results showed that the agitation and temperature are the parameters which influence the modification of unsaturated fatty acids. Studied conditions allowed obtaining up to 70% relative conversion of oxygen-oxirane from cottonseed oil.

  14. Two-dimensional Bose and Fermi gases beyond weak coupling

    Science.gov (United States)

    França, Guilherme; LeClair, André; Squires, Joshua

    2017-07-01

    Using a formalism based on the two-body S-matrix we study two-dimensional Bose and Fermi gases with both attractive and repulsive interactions. Approximate analytic expressions, valid at weak coupling and beyond, are developed and applied to the Berezinskii-Kosterlitz-Thouless (BKT) transition. We successfully recover the correct logarithmic functional form of the critical chemical potential and density for the Bose gas. For fermions, the BKT critical temperature is calculated in BCS and BEC regimes through consideration of Tan’s contact.

  15. A weak blind signature scheme based on quantum cryptography

    Science.gov (United States)

    Wen, Xiaojun; Niu, Xiamu; Ji, Liping; Tian, Yuan

    2009-02-01

    In this paper, we present a weak blind signature scheme based on the correlation of EPR (Einstein-Padolsky-Rosen) pairs. Different from classical blind signature schemes and current quantum signature schemes, our quantum blind signature scheme could guarantee not only the unconditionally security but also the anonymity of the message owner. To achieve that, quantum key distribution and one-time pad are adopted in our scheme. Experimental analysis proved that our scheme have the characteristics of non-counterfeit, non-disavowal, blindness and traceability. It has a wide application to E-payment system, E-government, E-business, and etc.

  16. Quantum Butterfly Effect in Weakly Interacting Diffusive Metals

    Directory of Open Access Journals (Sweden)

    Aavishkar A. Patel

    2017-09-01

    Full Text Available 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.

  17. The Weakly Nonlinear Magnetorotational Instability in a Local Geometry

    Science.gov (United States)

    Clark, S. E.; Oishi, Jeffrey S.

    2017-05-01

    The magnetorotational instability (MRI) is a fundamental process of accretion disk physics, but its saturation mechanism remains poorly understood despite considerable theoretical and computational effort. We present a multiple-scales analysis of the non-ideal MRI in the weakly nonlinear regime—that is, when the most unstable MRI mode has a growth rate asymptotically approaching zero from above. Here, we develop our theory in a local, Cartesian channel. Our results confirm the finding by Umurhan et al. that the perturbation amplitude follows a Ginzburg-Landau equation. We further find that the Ginzburg-Landau equation will arise for the local MRI system with shear-periodic boundary conditions, when the effects of ambipolar diffusion are considered. A detailed force balance for the saturated azimuthal velocity and vertical magnetic field demonstrates that, even when diffusive effects are important, the bulk flow saturates via the combined processes of reducing the background shear and rearranging and strengthening the background vertical magnetic field. We directly simulate the Ginzburg-Landau amplitude evolution for our system, and demonstrate the pattern formation our model predicts on long scales of length- and timescales. We compare the weakly nonlinear theory results to a direct numerical simulation of the MRI in a thin-gap Taylor Couette flow.

  18. NATO Advanced Study Institute on Turbulence, Weak and Strong

    CERN Document Server

    Cardoso, O

    1994-01-01

    The present volume comprises the contributions of some of the participants of the NATO Advance Studies Institute "Turbulence, Weak and Strong", held in Cargese, in August 1994. More than 70 scientists, from seniors to young students, have joined to­ gether to discuss and review new (and not so new) ideas and developments in the study of turbulence. One of the objectives of the School was to incorporate, in the same meeting, two aspects of turbulence, which are obviously linked, and which are often treated sep­ arately: fully developed turbulence (in two and three dimensions) and weak turbulence (essentially one and two-dimensional systems). The idea of preparing a dictionary rather than ordinary proceedings started from the feeling that the terminology of turbulence includes many long, technical, poorly evocative words, which are usually not understood by people exterior to the field, and which might be worth explaining. Students who start working in the field of turbulence face a sort of curious situation:...

  19. Transition from weak to strong cascade in MHD turbulence.

    Science.gov (United States)

    Verdini, Andrea; Grappin, Roland

    2012-07-13

    The transition from weak to strong turbulence when passing from large to small scales in magnetohydrodynamic (MHD) turbulence with guide field is a cornerstone of anisotropic turbulence theory. We present the first check of this transition, using the Shell-RMHD, which combines a shell model of perpendicular nonlinear coupling and linear propagation along the guide field. This model allows us to reach Reynolds numbers around 10(6). We obtain surprisingly good agreement with the theoretical predictions, with a reduced perpendicular energy spectrum scaling as k(⊥)(-2) at large scales and as k(⊥)(-5/3) at small scales, where critical balance between nonlinear and propagation time is reached. However, even in the strong regime, a high level of excitation is found in the weak coupling region of Fourier space, which is due to the rich frequency spectrum of large eddies. A corollary is that the reduced parallel spectral slope is not a definite test of the spectral anisotropy, contrary to standard belief.

  20. Attending Weak Signals: The Prevention of Work-related Illnesses

    Directory of Open Access Journals (Sweden)

    Roy Liff

    2017-06-01

    Full Text Available This article examines the characteristics of communication among managers, human resource (HR experts, and occupational health care specialists, as they deal with such informal information as weak signals in the prevention of work-related illnesses, using a theoretical framework in which the prevention of work-related illness is analogous to theory on crisis management. This is a qualitative study in which individual and focus-group interviews were conducted in a Swedish context with occupational health care specialists, managers, and HR experts. The results suggest that organizational solutions have failed and continue to fail at controlling workers’ health problems, although the main difficulty is not in identifying the ‘right’ individually oriented weak signals. Rather, it is upper management’s reliance on formal information (e.g., statistics and surveys – because of the difficulty in supplementing it with informal information (e.g., rumors and gossip – that makes it difficult to improve traditional health and safety work

  1. Progress at the WITCH experiment towards weak interaction studies

    CERN Document Server

    Tandecki, Michaël

    A measurement of the $\\beta$–ν angular correlation in nuclear $\\beta$- decay is a good probe to search for physics beyond the Standard Model, independent of assumptions like parity, charge and time reversal violation. The WITCH (Weak Interaction Trap for Charged Particles) experiment will measure this correlation with the aim of further constraining the possible existence of scalar currents in the weak interaction or find a positive indication. The setup is located at ISOLDE/CERN and consists of a double Penning trap system combined with a retardation spectrometer to probe the energy of the recoil ions from the $\\beta$- decay. The shape of the recoil ion energy spectrum allows to determine the $\\beta$–ν angular correlation coefficient, $a$. Past experiments have allowed to measure this parameter with a precision of 0.5–1 %. The aim of the WITCH experiment is to measure $a$ with a precision of about 0.5 %.\\\\ A first step towards this goal has already been taken in 2006 with the measurement of a recoil ...

  2. Scintillation index of Gaussian waves in weak turbulent ocean

    Science.gov (United States)

    Wang, Zhiqiang; Zhang, Pengfei; Qiao, Chunhong; Lu, Lu; Fan, Chengyu; Ji, Xiaoling

    2016-12-01

    The analytical expressions of radial and the longitudinal components of scintillation index are derived in weak oceanic turbulence. The effects of off-axis distance, propagation distance, and three oceanic parameters (i.e., the ratio of temperature to salinity contribution to the refractive index spectrum w, the rate of dissipation of the mean squared temperature χT and the rate of dissipation of the turbulent kinetic energy ε) on radial component of scintillation index are examined. The influences of propagation distance and three oceanic parameters on the longitudinal component of scintillation index are investigated. It is shown that the radial component of scintillation increases as off-axis distance increases. Both radial and longitudinal components of scintillation increase as propagation distance, w and χT increase while decreases as ε increases. Besides, the longitudinal component of scintillation increases more drastically for plane wave than others, which indicates the plane wave is affected the most at the fixed turbulent strength. The longest weak turbulence distance for a plane wave is shorter than that for a Gaussian or spherical wave.

  3. Weak Lensing from Space I: Instrumentation and Survey Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, Jason; Refregier, Alexandre; Massey, Richard; Albert, Justin; Bacon, David; Bernstein, Gary; Ellis, Richard; Jain, Bhuvnesh; Kim, Alex; Lampton, Mike; McKay, Tim; Akerlof, C.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E.; Bebek, C.; Bergstrom, L.; Bercovitz, J.; Bester, M.; Bonissent, A.; Bower, C.; Carithers, W.; Commins, E.; Day, C.; Deustua, S.; DiGennaro, R.; Ealet, A.; Eriksson, M.; Fruchter, A.; Genat, J.-F.; Goldhaber, G.; Goobar, A.; Groom, D.; Harris, S.; Harvey, P.; Heetderks, H.; Holland, S.; Huterer, D.; Karcher, A.; Kolbe, W.; Kreiger, B.; Lafever, R.; Lamoureux, J.; Levi, M.; Devin, D.; Linder, E.; Loken, S.; Malina, R.; McKee, S.; Miquel, R.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi, H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Pratt, R.; Prieto, E.; Robinson, K.; Roe, N.; Sholl, M.; Schubnell, M.; Smadja, G.; Smoot, G.; Spadafora, A.; Tarle, G.; Tomasch, A.; von der Lippe, H.; Vincent, D.; Walder, J.-P.; Wang, G.

    2003-04-23

    A wide field space-based imaging telescope is necessary to fully exploit the technique of observing dark matter via weak gravitational lensing. This first paper in a three part series outlines the survey strategies and relevant instrumental parameters for such a mission. As a concrete example of hardware design, we consider the proposed Supernova/Acceleration Probe (SNAP). Using SNAP engineering models, we quantify the major contributions to this telescope's Point Spread Function (PSF). These PSF contributions are relevant to any similar wide field space telescope. We further show that the PSF of SNAP or a similar telescope will be smaller than current ground-based PSFs, and more isotropic and stable over time than the PSF of the Hubble Space Telescope. We outline survey strategies for two different regimes - a ''wide'' 300 square degree survey and a ''deep'' 15 square degree survey that will accomplish various weak lensing goals including statistical studies and dark matter mapping.

  4. Radio-weak BL Lac Objects in the Fermi Era

    Science.gov (United States)

    Massaro, F.; Marchesini, E. J.; D'Abrusco, R.; Masetti, N.; Andruchow, I.; Smith, Howard A.

    2017-01-01

    The existence of “radio-weak BL Lac objects” (RWBLs) has been an open question, and has remained unsolved since the discovery that quasars could be radio-quiet or radio-loud. Recently, several groups identified RWBL candidates, mostly found while searching for low-energy counterparts of the unidentified or unassociated gamma-ray sources listed in the Fermi catalogs. Confirming RWBLs is a challenging task since they could be confused with white dwarfs (WDs) or weak emission line quasars (WELQs) when there are not sufficient data to precisely draw their broadband spectral energy distribution, and their classification is mainly based on a featureless optical spectra. Motivated by the recent discovery that Fermi BL Lacs appear to have very peculiar mid-IR emission, we show that it is possible to distinguish between WDs, WELQs, and BL Lacs using the [3.4]-[4.6]-[12] μm color-color plot built using the WISE magnitudes when the optical spectrum is available. On the basis of this analysis, we identify WISE J064459.38+603131 and WISE J141046.00+740511.2 as the first two genuine RWBLs, both potentially associated with Fermi sources. Finally, to strengthen our identification of these objects as true RWBLs, we present multifrequency observations for these two candidates to show that their spectral behavior is indeed consistent with that of the BL Lac population.

  5. Measuring non-Hermitian operators via weak values

    Science.gov (United States)

    Pati, Arun Kumar; Singh, Uttam; Sinha, Urbasi

    2015-11-01

    In quantum theory, a physical observable is represented by a Hermitian operator as it admits real eigenvalues. This stems from the fact that any measuring apparatus that is supposed to measure a physical observable will always yield a real number. However, the reality of an eigenvalue of some operator does not mean that it is necessarily Hermitian. There are examples of non-Hermitian operators that may admit real eigenvalues under some symmetry conditions. In general, given a non-Hermitian operator, its average value in a quantum state is a complex number and there are only very limited methods available to measure it. Following standard quantum mechanics, we provide an experimentally feasible protocol to measure the expectation value of any non-Hermitian operator via weak measurements. The average of a non-Hermitian operator in a pure state is a complex multiple of the weak value of the positive-semidefinite part of the non-Hermitian operator. We also prove an uncertainty relation for any two non-Hermitian operators and show that the fidelity of a quantum state under a quantum channel can be measured using the average of the corresponding Kraus operators. The importance of our method is shown in testing the stronger uncertainty relation, verifying the Ramanujan formula, and measuring the product of noncommuting projectors.

  6. Development of continuous ADR system for weak gravity missions

    Energy Technology Data Exchange (ETDEWEB)

    Numazawa, T; Kamiya, K [Tsukuba Magnet Laboratory, NIMS, 3-13 Sakura, Tsukuba 305-0003 (Japan); Shirron, P [NASA/Goddard Space Flight Center, Code 552 Greenbelt, MD 20771 (United States); Mitsuda, K [JAXA/ISAS, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan)], E-mail: Numazawa.takenori@nims.go.jp

    2009-02-01

    Adiabatic Demagnetization Refrigeration (ADR) does not use working fluids contrary to conventional refrigerators that make use of the fluid density difference, which leads to superiority of the ADR under the weak gravity condition. In this study, we developed a continuous ADR system to provide constant cooling temperatures {approx}0.1 K. The system consists of four stages of magnetic materials and magnets cascaded with heat switches. The magnetic materials CPA and GdLiF{sub 4} are used for 3 stages between 0.1K and 1.4 K, and single stage between 1.4 K and 4 K, respectively. Passive heat switches are used for the stages > 0.3 K and a superconducting heat switch is used for the continuous stage at {approx}0.1 K. A G-M cycle cooler with a 100 V compressor unit is used to cool the ADR and cryostat shieldings. Total mass of flight model is less than 60 kg. Cooling tests with Transition Edge Sensor on the ground showed that the ADR provided continuous cooling temperatures between 105 mK and 120 mK and it successfully operated the TES. Airborne flight experiments confirmed the ability of the cooling system under the mili-gravity condition. The experimental results showed that the ADR could provide stable temperature under the weak gravity, however, strong vibrations coming from turbulence or takeoff affected to the stability of ADR cycle.

  7. Weakly Supervised Multilabel Clustering and its Applications in Computer Vision.

    Science.gov (United States)

    Xia, Yingjie; Nie, Liqiang; Zhang, Luming; Yang, Yi; Hong, Richang; Li, Xuelong

    2016-12-01

    Clustering is a useful statistical tool in computer vision and machine learning. It is generally accepted that introducing supervised information brings remarkable performance improvement to clustering. However, assigning accurate labels is expensive when the amount of training data is huge. Existing supervised clustering methods handle this problem by transferring the bag-level labels into the instance-level descriptors. However, the assumption that each bag has a single label limits the application scope seriously. In this paper, we propose weakly supervised multilabel clustering, which allows assigning multiple labels to a bag. Based on this, the instance-level descriptors can be clustered with the guidance of bag-level labels. The key technique is a weakly supervised random forest that infers the model parameters. Thereby, a deterministic annealing strategy is developed to optimize the nonconvex objective function. The proposed algorithm is efficient in both the training and the testing stages. We apply it to three popular computer vision tasks: 1) image clustering; 2) semantic image segmentation; and 3) multiple objects localization. Impressive performance on the state-of-the-art image data sets is achieved in our experiments.

  8. Limits On Weak Annihilation In Inclusive Charmless Semileptonic B Decays

    CERN Document Server

    Meyer, T O

    2005-01-01

    Theoretical predictions for the weak decay b → u ℓ ν are subject to the contributions of higher-order terms that must be neglected in making practical phenomenological calculations. One such term that arises at order (Λ/MB) 3 in the non-perturbative expansion describes “weak annihilation” (WA). While the contribution of this term to the total rate is expected to be small, it is predicted to have a non-trivial distribution across phase space, concentrated near the maximal value of q2. The significance of WA relative to the leading-order rate in this restricted region is thus greatly enhanced, and values for the CKM element | Vub| extracted from inclusive measurements of b → u ℓ ν made in the high q2 regime are subject to a corresponding but unknown correction from WA. In this thesis, we analyze 9.7 fb−1 of eXe−collision data collected by the CLEO detector at CESR during a running period from 1990–199...

  9. RADIO-WEAK BL LAC OBJECTS IN THE FERMI ERA

    Energy Technology Data Exchange (ETDEWEB)

    Massaro, F.; Marchesini, E. J. [Dipartimento di Fisica, Università degli Studi di Torino (UniTO), via Pietro Giuria 1, I-10125 Torino (Italy); D’Abrusco, R.; Smith, Howard A. [Smithsonian Astrophysical Observatory, 60 Garden Street, 02138 Cambridge, MA (United States); Masetti, N. [INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna, via Gobetti 101, I-40129, Bologna (Italy); Andruchow, I. [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, B1900FWA, La Plata (Argentina)

    2017-01-10

    The existence of “radio-weak BL Lac objects” (RWBLs) has been an open question, and has remained unsolved since the discovery that quasars could be radio-quiet or radio-loud. Recently, several groups identified RWBL candidates, mostly found while searching for low-energy counterparts of the unidentified or unassociated gamma-ray sources listed in the Fermi catalogs. Confirming RWBLs is a challenging task since they could be confused with white dwarfs (WDs) or weak emission line quasars (WELQs) when there are not sufficient data to precisely draw their broadband spectral energy distribution, and their classification is mainly based on a featureless optical spectra. Motivated by the recent discovery that Fermi BL Lacs appear to have very peculiar mid-IR emission, we show that it is possible to distinguish between WDs, WELQs, and BL Lacs using the [3.4]–[4.6]–[12] μ m color–color plot built using the WISE magnitudes when the optical spectrum is available. On the basis of this analysis, we identify WISE J064459.38+603131 and WISE J141046.00+740511.2 as the first two genuine RWBLs, both potentially associated with Fermi sources. Finally, to strengthen our identification of these objects as true RWBLs, we present multifrequency observations for these two candidates to show that their spectral behavior is indeed consistent with that of the BL Lac population.

  10. Pervasive Sound Sensing: A Weakly Supervised Training Approach.

    Science.gov (United States)

    Kelly, Daniel; Caulfield, Brian

    2016-01-01

    Modern smartphones present an ideal device for pervasive sensing of human behavior. Microphones have the potential to reveal key information about a person's behavior. However, they have been utilized to a significantly lesser extent than other smartphone sensors in the context of human behavior sensing. We postulate that, in order for microphones to be useful in behavior sensing applications, the analysis techniques must be flexible and allow easy modification of the types of sounds to be sensed. A simplification of the training data collection process could allow a more flexible sound classification framework. We hypothesize that detailed training, a prerequisite for the majority of sound sensing techniques, is not necessary and that a significantly less detailed and time consuming data collection process can be carried out, allowing even a nonexpert to conduct the collection, labeling, and training process. To test this hypothesis, we implement a diverse density-based multiple instance learning framework, to identify a target sound, and a bag trimming algorithm, which, using the target sound, automatically segments weakly labeled sound clips to construct an accurate training set. Experiments reveal that our hypothesis is a valid one and results show that classifiers, trained using the automatically segmented training sets, were able to accurately classify unseen sound samples with accuracies comparable to supervised classifiers, achieving an average F -measure of 0.969 and 0.87 for two weakly supervised datasets.

  11. Dark Matter Decay between Phase Transitions at the Weak Scale

    Science.gov (United States)

    Baker, Michael J.; Kopp, Joachim

    2017-08-01

    We propose a new alternative to the weakly interacting massive particle paradigm for dark matter. Rather than being determined by thermal freeze-out, the dark matter abundance in this scenario is set by dark matter decay, which is allowed for a limited amount of time just before the electroweak phase transition. More specifically, we consider fermionic singlet dark matter particles coupled weakly to a scalar mediator S3 and to auxiliary dark sector fields, charged under the standard model gauge groups. Dark matter freezes out while still relativistic, so its abundance is initially very large. As the Universe cools down, the scalar mediator develops a vacuum expectation value (VEV), which breaks the symmetry that stabilizes dark matter. This allows dark matter to mix with charged fermions and decay. During this epoch, the dark matter abundance is reduced to give the value observed today. Later, the SM Higgs field also develops a VEV, which feeds back into the S3 potential and restores the dark sector symmetry. In a concrete model we show that this "VEV flip-flop" scenario is phenomenologically successful in the most interesting regions of its parameter space. We also comment on detection prospects at the LHC and elsewhere.

  12. The Weak Lensing Masses of Filaments between Luminous Red Galaxies

    Science.gov (United States)

    Epps, Seth D.; Hudson, Michael J.

    2017-07-01

    In the standard model of non-linear structure formation, a cosmic web of dark-matter-dominated filaments connects dark matter haloes. In this paper, we stack the weak lensing signal of an ensemble of filaments between groups and clusters of galaxies. Specifically, we detect the weak lensing signal, using CFHTLenS galaxy ellipticities, from stacked filaments between Sloan Digital Sky Survey (SDSS)-III/Baryon Oscillation Spectroscopic Survey luminous red galaxies (LRGs). As a control, we compare the physical LRG pairs with projected LRG pairs that are more widely separated in redshift space. We detect the excess filament mass density in the projected pairs at the 5σ level, finding a mass of (1.6 ± 0.3) × 1013 M⊙ for a stacked filament region 7.1 h-1 Mpc long and 2.5 h-1 Mpc wide. This filament signal is compared with a model based on the three-point galaxy-galaxy-convergence correlation function, as developed in Clampitt et al., yielding reasonable agreement.

  13. Geometric Stitching Method for Double Cameras with Weak Convergence Geometry

    Science.gov (United States)

    Zhou, N.; He, H.; Bao, Y.; Yue, C.; Xing, K.; Cao, S.

    2017-05-01

    In this paper, a new geometric stitching method is proposed which utilizes digital elevation model (DEM)-aided block adjustment to solve relative orientation parameters for dual-camera with weak convergence geometry. A rational function model (RFM) with affine transformation is chosen as the relative orientation model. To deal with the weak geometry, a reference DEM is used in this method as an additional constraint in the block adjustment, which only calculates the planimetry coordinates of tie points (TPs). After that we can use the obtained affine transform coefficients to generate virtual grid, and update rational polynomial coefficients (RPCs) to complete the geometric stitching. Our proposed method was tested on GaoFen-2(GF-2) dual-camera panchromatic (PAN) images. The test results show that the proposed method can achieve an accuracy of better than 0.5 pixel in planimetry and have a seamless visual effect. For regions with small relief, when global DEM with 1 km grid, SRTM with 90 m grid and ASTER GDEM V2 with 30 m grid replaced DEM with 1m grid as elevation constraint it is almost no loss of accuracy. The test results proved the effectiveness and feasibility of the stitching method.

  14. Dark Matter Decay between Phase Transitions at the Weak Scale.

    Science.gov (United States)

    Baker, Michael J; Kopp, Joachim

    2017-08-11

    We propose a new alternative to the weakly interacting massive particle paradigm for dark matter. Rather than being determined by thermal freeze-out, the dark matter abundance in this scenario is set by dark matter decay, which is allowed for a limited amount of time just before the electroweak phase transition. More specifically, we consider fermionic singlet dark matter particles coupled weakly to a scalar mediator S_{3} and to auxiliary dark sector fields, charged under the standard model gauge groups. Dark matter freezes out while still relativistic, so its abundance is initially very large. As the Universe cools down, the scalar mediator develops a vacuum expectation value (VEV), which breaks the symmetry that stabilizes dark matter. This allows dark matter to mix with charged fermions and decay. During this epoch, the dark matter abundance is reduced to give the value observed today. Later, the SM Higgs field also develops a VEV, which feeds back into the S_{3} potential and restores the dark sector symmetry. In a concrete model we show that this "VEV flip-flop" scenario is phenomenologically successful in the most interesting regions of its parameter space. We also comment on detection prospects at the LHC and elsewhere.

  15. Ocular Motor Function in Patients with Bilateral Vestibular Weakness

    Directory of Open Access Journals (Sweden)

    Seyyed Amir Hossein Ghazizadeh Hashemi

    2016-05-01

    Full Text Available Introduction: Patients with bilateral weakness (BW have many difficulties in gaze stability that interfere with their normal function. The aim of this study was to evaluate ocular motor functions in patients with BW to better understand the problem of gaze instability in these patients.   Materials and Methods: Patients were referred from the Otolaryngology Department for Vestibular Assessment to our clinic between November 2014 and March 2015. We assessed ocular motor function (gaze, saccade, and smooth pursuit in patients over the age of 18 years with BW, as verified by a caloric test.   Results: Seventy-eight patients completed all the tests. The mean age of patients was 51.9 (±15.9 years, and 47 (60% were female. Abnormal results were found in five (6.4%, 32 (41%, and seven (9% patients with respect to gaze, smooth pursuit, and saccade, respectively. There were positive but relatively weak relationships between age and ocular motor results.   Conclusion:  Patients with BW suffer from dizziness and unsteadiness. These patients have abnormal function in ocular motor (especially smooth pursuit tests. The ocular motor dysfunction is responsible for gaze instability in static positions such as standing.

  16. 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

  17. p -wave superconductivity in weakly repulsive 2D Hubbard model with Zeeman splitting and weak Rashba spin-orbit coupling

    Science.gov (United States)

    Hugdal, Henning G.; Sudbø, Asle

    2018-01-01

    We study the superconducting order in a two-dimensional square lattice Hubbard model with weak repulsive interactions, subject to a Zeeman field and weak Rashba spin-orbit interactions. Diagonalizing the noninteracting Hamiltonian leads to two separate bands, and by deriving an effective low-energy interaction we find the mean field gap equations for the superconducting order parameter on the bands. Solving the gap equations just below the critical temperature, we find that superconductivity is caused by Kohn-Luttinger-type interaction, while the pairing symmetry of the bands is indirectly affected by the spin-orbit coupling. The dominating attractive momentum channel of the Kohn-Luttinger term depends on the filling fraction n of the system, and it is therefore possible to change the momentum dependence of the order parameter by tuning n . Moreover, n also determines which band has the highest critical temperature. Rotating the magnetic field changes the momentum dependence from states that for small momenta reduce to a chiral px±i py type state for out-of-plane fields, to a nodal p -wave-type state for purely in-plane fields.

  18. Virtually-synchronous communication based on a weak failure suspector

    Science.gov (United States)

    Schiper, Andre; Ricciardi, Aleta

    1993-01-01

    Failure detectors (or, more accurately Failure Suspectors (FS)) appear to be a fundamental service upon which to build fault-tolerant, distributed applications. This paper shows that a FS with very weak semantics (i.e., that delivers failure and recovery information in no specific order) suffices to implement virtually-synchronous communication (VSC) in an asynchronous system subject to process crash failures and network partitions. The VSC paradigm is particularly useful in asynchronous systems and greatly simplifies building fault-tolerant applications that mask failures by replicating processes. We suggest a three-component architecture to implement virtually-synchronous communication: (1) at the lowest level, the FS component; (2) on top of it, a component (2a) that defines new views; and (3) a component (2b) that reliably multicasts messages within a view. The issues covered in this paper also lead to a better understanding of the various membership service semantics proposed in recent literature.

  19. Cosmological Constraints from Galaxy Clustering and Weak Lensing

    Science.gov (United States)

    Troxel, Michael; DES Collaboration

    2018-01-01

    The Dark Energy Survey (DES) is a five-year, 5000 sq. deg. observing program using the Dark Energy Camera on the 4m Blanco telescope at CTIO. I will describe the cosmological analysis of large-scale structure in the Universe using 1321 sq. deg. of data taken in the first year of DES operations. The analysis combines unprecedented measurements of weak gravitational lensing and the clustering of galaxies over the redshift range 0.2 to 1.3 to derive the most precise such cosmological constraints to date. These DES results from the low-redshift Universe are consistent with those from the cosmic microwave background (CMB) and support the standard cosmological model, LCDM. In the coming years, DES will produce significantly tighter constraints on cosmology through similar and additional analyses using observations over more than three times the sky-area and more than twice the integrated exposure time per object as these results.

  20. Unified programs nationally? Strengths and weaknesses of the learning standards

    Directory of Open Access Journals (Sweden)

    Ignacio Polo Martínez

    2014-06-01

    Full Text Available The inclusion of measurable learning standards as an element of the curriculum has definitely opened the door to the connection between the curriculum and external assessments. Since its origin, the potential impact of that element in improving our educational system has been defended and criticized. The truth is that in our country, though all regions are based on the same Royal Decree of core curriculum, and therefore the same reference for the evaluation, curriculum that ultimately applies to students ( teaching-learning- assessment from the different regions can have significant differences . This article proposes, from the analysis of various research , training programs, the plan of action for inspection and the author's own experience in processes of curriculum specifications , assess the potential strengths and weaknesses of the learning standards.

  1. A Duffing oscillator algorithm to detect the weak chromatographic signal.

    Science.gov (United States)

    Zhang, Wei; Xiang, Bing-Ren

    2007-02-28

    Based on the Duffing equation, a Duffing oscillator algorithm (DOA) to improve the signal-to-noise ratio (SNR) was presented. By simulated and experimental data sets, it was proven that the signal-to-noise ratio (SNR) of the weak signal could be greatly enhanced by this method. Using signal enhancement by DOA, this method extends the SNR of low concentrations of methylbenzene from 2.662 to 29.90 and the method can be used for quantitative analysis of methylbenzene, which are lower than detection limit of an analytical system. The Duffing oscillator algorithm (DOA) might be a promising tool to extend instrumental linear range and to improve the accuracy of trace analysis. The research enlarged the application scope of Duffing equation to chromatographic signal processing.

  2. 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.

  3. Weak versus strong wave turbulence in the MMT model

    CERN Document Server

    Chibbaro, Sergio; Onorato, Miguel

    2016-01-01

    Within the spirit of fluid turbulence, we consider the one-dimensional Majda-McLaughlin-Tabak (MMT) model that describes the interactions of nonlinear dispersive waves. We perform a detailed numerical study of the direct energy cascade in the defocusing regime. In particular, we consider a configuration with large-scale forcing and small scale dissipation, and we introduce three non- dimensional parameters: the ratio between nonlinearity and dispersion, {\\epsilon}, and the analogues of the Reynolds number, Re, i.e. the ratio between the nonlinear and dissipative time-scales, both at large and small scales. Our numerical experiments show that (i) in the limit of small {\\epsilon} the spectral slope observed in the statistical steady regime corresponds to the one predicted by the Weak Wave Turbulence (WWT) theory. (ii) As the nonlinearity is increased, the WWT theory breaks down and deviations from its predictions are observed. (iii) It is shown that such departures from the WWT theoretical predictions are accom...

  4. Weak qubit measurement with a nonlinear cavity: beyond perturbation theory.

    Science.gov (United States)

    Laflamme, C; Clerk, A A

    2012-09-21

    We analyze the use of a driven nonlinear cavity to make a weak continuous measurement of a dispersively coupled qubit. We calculate the backaction dephasing rate and measurement rate beyond leading-order perturbation theory using a phase-space approach which accounts for cavity noise squeezing. Surprisingly, we find that increasing the coupling strength beyond the regime describable by leading-order perturbation theory (i.e., linear response) allows one to come significantly closer to the quantum limit on the measurement efficiency. We interpret this behavior in terms of the non-Gaussian photon number fluctuations of the nonlinear cavity. Our results are relevant to recent experiments using superconducting microwave circuits to study quantum measurement.

  5. Weak Pseudogap Behavior in the Underdoped Cuprate Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Schmalian, J.; Pines, D. [University of Illinois at Urbana-Champaign, Loomis Laboratory of Physics, 1110 W. Green, Urbana, Illinois 61801 (United States); Pines, D.; Stojkovic, B. [Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1998-04-01

    We report on a novel solution of the nearly antiferromagnetic (AF) spin fermion model in the limit {pi}T{gt}{omega}{sub sf} , which demonstrates that the broad high energy features found in angular resolved photoemission spectroscopy measurements of the spectral density of the underdoped cuprates are determined by strong (AF) correlations and precursor effects of a spin density wave state. We show that the onset temperature, T{sup cr} , of weak pseudogap behavior is determined by the strength, {xi} , of the (AF) correlations, and obtain the generic changes in low frequency magnetic behavior seen in NMR experiments with {xi}(T{sup cr}){approx}2 , confirming the Barzykin and Pines crossover criterion. {copyright} {ital 1998} {ital The American Physical Society}

  6. Strengthening weak ties through on-line gaming

    DEFF Research Database (Denmark)

    Sudzina, Frantisek; Razmerita, Liana Virginia; Kirchner, Kathrin

    On-line gaming became widespread in the last couple of years. The aim of the research presented in the paper is to figure out to what extent does game playing helps to strengthen weak ties and what additional factors influence this process. The approach is rather exploratory – some factors...... are grounded in theory, some are new. These factors are age, gender, place of origin, number of their Facebook connections (friends in Facebook terminology), the amount of time they are on Facebook, the amount of time they keep the Facebook site open, the amount of time they play on-line games, and the reasons...... for starting to play on-line games. Regarding the latter, we chose to focus only on escapist reasons....

  7. Strengthening Institutions to Legitimise Business Continuity in Weak Institutional Environments

    DEFF Research Database (Denmark)

    Taarup Esbensen, Jacob

    institutions are either weak, by that unable to enforce its own rules, MNEs can encounter severe difficulties as they lack knowledge, especially about informal institutions, that determine ‘the rules of the game’ in the business environment. MNEs can apply two distinct generic risk management strategies...... in their dealings with local communities. One strategy is based on rules provide by the HQ, which focuses on providing guidelines in compliance with normative global institutions, while another strategy focuses on embedding the subsidiary in the local institutional environment. Both of these strategies aim...... with local community. Findings also show that local dependence on these intuitions grew stronger and community members became increasingly reliant on the benefits that came with these continuous investments. The alternative HQ driven strategy findings showed that these companies lost local legitimacy...

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

    DEFF Research Database (Denmark)

    Bindner, H.

    1999-01-01

    . 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 increase tolevels above the limits if the wind power input is high. The other main problem is voltage...... fluctuations. Because the wind is fluctuating the output from the wind turbines is also fluctuating. This together with wind turbine cut-ins can result in voltagefluctuations that are above the flicker limit. Some or all of the these problems can be avoided if a so-called power control concept is applied...... together with the wind farm. The idea behind the power control concept is to eliminate the violations of thesteady state voltage level by buffering the power from the wind turbines in periods where the voltage limits might be violated and then release it when the voltage level is lower and combine...

  9. 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.

  10. 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.

  11. Big Data and Health Economics: Strengths, Weaknesses, Opportunities and Threats.

    Science.gov (United States)

    Collins, Brendan

    2016-02-01

    'Big data' is the collective name for the increasing capacity of information systems to collect and store large volumes of data, which are often unstructured and time stamped, and to analyse these data by using regression and other statistical techniques. This is a review of the potential applications of big data and health economics, using a SWOT (strengths, weaknesses, opportunities, threats) approach. In health economics, large pseudonymized databases, such as the planned care.data programme in the UK, have the potential to increase understanding of how drugs work in the real world, taking into account adherence, co-morbidities, interactions and side effects. This 'real-world evidence' has applications in individualized medicine. More routine and larger-scale cost and outcomes data collection will make health economic analyses more disease specific and population specific but may require new skill sets. There is potential for biomonitoring and lifestyle data to inform health economic analyses and public health policy.

  12. 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.)

  13. Through casing weak electromagnetic wave signal detection and application

    Science.gov (United States)

    Li, Hui; Zhu, Xi-Fang; Cui, Cui-Mei

    2017-07-01

    Electromagnetic measurement technology is an important method for instrument parameters calibration, detection performance evaluation and complex system theory verification. In this paper, self-adaptive finite element method has been used to compute and analyze the weak electromagnetic wave signal, which is produced by changing electrode structure, transmitting frequency and antenna spacing of the through casing electromagnetic measurement tool. Numerical simulation results show that the detection depth of the tool can be influenced by the electrode structure can have the influence on, the resolution of high-resistivity and low-resistivity formation can be improved by transmitting frequency, the detection accuracy and detection depth of the through casing electromagnetic measurement tool can be influenced by the change of antenna spacing.

  14. Muon motion in pure and weakly doped aluminium

    CERN Document Server

    Niinikoski, T O; Karlsson, E; Kehr, K W; Norlin, L O; Richter, D; Welter, J M

    1981-01-01

    The authors have studied the diffusion and localization of positive muons in pure and weakly doped aluminium, in the temperature range 30 mK-100K, by measuring the damping parameter of the muon spin rotation ( mu SR) signal. In this paper they discuss some of their recent results and draw the following conclusions: i) in pure Al, positive muons are delocalized in band states (coherent motion); ii) in Al doped with 5-70 ppm Mn, the temperature, concentration and field dependences of the damping parameter suggest diffusion or capture limited trapping to octahedral interstitial sites in the aluminium lattice below 1K; iii) above 2K a two-state diffusion-trapping model explains well the peak in the damping parameter, which appears at 15-50K for the dopants Mn, Mg, Li and Ag so far studied. (11 refs).

  15. 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...

  16. Examining intergenerational violence: violent role modeling or weak parental controls?

    Science.gov (United States)

    Chapple, Constance L

    2003-04-01

    Family violence research has uncovered a positive relationship between parental violence and children's later involvement in intimate violence. In a similar vein, criminology's social control theory suggests that weak or absent parental controls are associated with a variety of delinquent acts. Little research, however, investigates the link between parental violence, parental controls, and dating violence. This article asks two research questions: How is inter-parental violence associated with parent-child attachments, monitoring, adolescent dating, attitudes toward violence, and dating violence? And second, are there independent and interactive effects of inter-parental violence, and parental controls on dating violence offending and attitudes towards violence? Dating violence offending is significantly associated with witnessed inter-parental violence, high dating frequency, and low parental monitoring. Attitudes towards violence are associated with witnessed inter-parental violence, lower parental attachment, and the interaction of witnessed inter-parental violence and parental attachment. The implications for role modeling and social control theory are discussed.

  17. Beyond strong and weak: rethinking postdictatorship civil societies.

    Science.gov (United States)

    Riley, Dylan; Fernández, Juan J

    2014-09-01

    What is the impact of dictatorships on postdictatorial civil societies? Bottom-up theories suggest that totalitarian dictatorships destroy civil society while authoritarian ones allow for its development. Top-down theories of civil society suggest that totalitarianism can create civil societies while authoritarianism is unlikely to. This article argues that both these perspectives suffer from a one-dimensional understanding of civil society that conflates strength and autonomy. Accordingly we distinguish these two dimensions and argue that totalitarian dictatorships tend to create organizationally strong but heteronomous civil societies, while authoritarian ones tend to create relatively autonomous but organizationally weak civil societies. We then test this conceptualization by closely examining the historical connection between dictatorship and civil society development in Italy (a posttotalitarian case) and Spain (a postauthoritarian one). Our article concludes by reflecting on the implications of our argument for democratic theory, civil society theory, and theories of regime variation.

  18. Theory of weakly nonlinear self-sustained detonations

    KAUST Repository

    Faria, Luiz

    2015-11-03

    We propose a theory of weakly nonlinear multidimensional self-sustained detonations based on asymptotic analysis of the reactive compressible Navier-Stokes equations. We show that these equations can be reduced to a model consisting of a forced unsteady small-disturbance transonic equation and a rate equation for the heat release. In one spatial dimension, the model simplifies to a forced Burgers equation. Through analysis, numerical calculations and comparison with the reactive Euler equations, the model is demonstrated to capture such essential dynamical characteristics of detonations as the steady-state structure, the linear stability spectrum, the period-doubling sequence of bifurcations and chaos in one-dimensional detonations and cellular structures in multidimensional detonations.

  19. Weak quasielastic electroproduction of hyperons with polarization observables

    Science.gov (United States)

    Akbar, F.; Sajjad Athar, M.; Fatima, A.; Singh, S. K.

    2017-07-01

    With the availability of high luminosity electron beams at the accelerators, there is now the possibility of studying weak quasielastic hyperon production off the proton, i.e. e^-p → ν_e Y(Y=Λ,Σ^0) , which will enable the determination of the nucleon-hyperon vector and axial-vector transition form factors at high Q^2 in the strangeness sector and provide test of the Cabibbo model, G-invariance, CVC, PCAC hypotheses and SU(3) symmetry. In this work, we have studied the total cross section, differential cross section as well as the longitudinal and perpendicular components of polarization of the final hyperons ( Λ and Σ^0 produced in these reactions) and presented numerical results for these observables and their sensitivity to the transition form factors.

  20. Weak quasielastic electroproduction of hyperons with polarization observables

    Energy Technology Data Exchange (ETDEWEB)

    Akbar, F.; Sajjad Athar, M.; Fatima, A.; Singh, S.K. [Aligarh Muslim University, Department of Physics, Aligarh (India)

    2017-07-15

    With the availability of high luminosity electron beams at the accelerators, there is now the possibility of studying weak quasielastic hyperon production off the proton, i.e. e{sup -}p → ν{sub e}Y(Y = Λ,Σ{sup 0}), which will enable the determination of the nucleon-hyperon vector and axial-vector transition form factors at high Q{sup 2} in the strangeness sector and provide test of the Cabibbo model, G-invariance, CVC, PCAC hypotheses and SU(3) symmetry. In this work, we have studied the total cross section, differential cross section as well as the longitudinal and perpendicular components of polarization of the final hyperons (Λ and Σ{sup 0} produced in these reactions) and presented numerical results for these observables and their sensitivity to the transition form factors. (orig.)

  1. Quasielastic electron-deuteron scattering in the weak binding approximation

    Energy Technology Data Exchange (ETDEWEB)

    Ethier, Jacob J. [William and Mary College, JLAB; Doshi, Nidhi P. [Carnegie Mellon University; Malace, Simona P. [JLAB; Melnitchouk, Wally [JLAB

    2014-06-01

    We perform a global analysis of all available electron-deuteron quasielastic scattering data using Q^2-dependent smearing functions that describe inclusive inelastic e-d scattering within the weak binding approximation. We study the dependence of the cross sections on the deuteron wave function and the off-shell extrapolation of the elastic electron-nucleon cross section, which show particular sensitivity at x >> 1. The excellent overall agreement with data over a large range of Q^2 and x suggest a limited need for effects beyond the impulse approximation, with the exception of the very high-x or very low-Q^2 regions, where short-distance effects in the deuteron become more relevant.

  2. Approach to equilibrium in weakly coupled nonabelian plasmas

    CERN Document Server

    Kurkela, Aleksi

    2014-01-01

    We follow the time evolution of nonabelian gauge bosons from far-from-equilibrium initial conditions to thermal equilibrium by numerically solving an effective kinetic equation that becomes accurate in the weak coupling limit. We consider initial conditions that are either highly overoccupied or underoccupied. We find that overoccupied systems thermalize through a turbulent cascade reaching equilibrium in multiples of a thermalization time $t\\approx 72./ (1-0.12\\log \\lambda)/\\lambda^2 T$, whereas underoccupied systems undergo a "bottom-up" thermalization in a time $t\\approx (34. +21. \\ln(Q/T))/ (1-0.037\\log \\lambda)(Q/T)^{1/2}/\\lambda^2 T$, where $Q$ is the characteristic momentum scale of the initial condition. We apply this result to model initial stages of heavy-ion collisions and find rapid thermalization roughly in a time $Qt \\lesssim 10$ or $t\\lesssim 1$ fm/c.

  3. Discreteness of space from GUP in a weak gravitational field

    Directory of Open Access Journals (Sweden)

    Soumen Deb

    2016-04-01

    Full Text Available Quantum gravity effects modify the Heisenberg's uncertainty principle to a generalized uncertainty principle (GUP. Earlier work showed that the GUP-induced corrections to the Schrödinger equation, when applied to a non-relativistic particle in a one-dimensional box, led to the quantization of length. Similarly, corrections to the Klein–Gordon and the Dirac equations, gave rise to length, area and volume quantizations. These results suggest a fundamental granular structure of space. In this work, it is investigated how spacetime curvature and gravity might influence this discreteness of space. In particular, by adding a weak gravitational background field to the above three quantum equations, it is shown that quantization of lengths, areas and volumes continue to hold. However, it should be noted that the nature of this new quantization is quite complex and under proper limits, it reduces to cases without gravity. These results suggest that quantum gravity effects are universal.

  4. Transient instability upon temperature quench in weakly ordered block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Shuyan [Department of Chemical Engineering, University of California, Berkeley, California 94610 (United States); Wang, Zhen-Gang [Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States)

    1999-12-15

    We report a novel transient instability upon temperature quench in weakly ordered block copolymer microphases possessing a soft direction or directions, such as the lamellar and hexagonal cylinder (HEX) phases. We show that reequilibration of the order parameter is accompanied by transient long wavelength undulation of the layers or cylinders--with an initial wavelength that depends on the depth of the temperature quench--that eventually disappears as the structure reaches its equilibrium at the new temperature. Such undulation leads to a transient transverse broadening of the scattering peaks near the Bragg positions. We argue that this instability might be responsible for the experimentally observed unusual ordering dynamics of the HEX phase of a diblock copolymer after quenching from the disordered state. (c) 1999 American Institute of Physics.

  5. Weak Business Culture as an Antecedent of Economic Crisis

    DEFF Research Database (Denmark)

    Sigurjonsson, Throstur Olaf; Vaiman, Vlad; Davídsson, Páll Ásgeir

    2011-01-01

    The authors of this article contend that traditional corruption, which was largely blamed for the current situation in the Icelandic economy, was perhaps not the most fundamental reason for the ensuing crisis. The weak business culture and a symbiosis of business and politics have actually allowed...... for the bulk of self-serving and unethical decisions made by the Icelandic business and political elite. In order to illustrate this point, 10 expert interviews have been conducted within the period of 6 months in 2009 to support in-depth research carried out by the authors. The article also discloses...... questionable business practices that have recently come to the attention of the public both in Iceland and abroad and that ultimately facilitated the downfall of the Icelandic economy. While traditional corruption has probably played its role in this downfall, the measures currently employed to determine its...

  6. Habits predict physical activity on days when intentions are weak.

    Science.gov (United States)

    Rebar, Amanda L; Elavsky, Steriani; Maher, Jaclyn P; Doerksen, Shawna E; Conroy, David E

    2014-04-01

    Physical activity is regulated by controlled processes, such as intentions, and automatic processes, such as habits. Intentions relate to physical activity more strongly for people with weak habits than for people with strong habits, but people's intentions vary day by day. Physical activity may be regulated by habits unless daily physical activity intentions are strong. University students (N = 128) self-reported their physical activity habit strength and subsequently self-reported daily physical activity intentions and wore an accelerometer for 14 days. On days when people had intentions that were weaker than typical for them, habit strength was positively related to physical activity, but on days when people had typical or stronger intentions than was typical for them, habit strength was unrelated to daily physical activity. Efforts to promote physical activity may need to account for habits and the dynamics of intentions.

  7. A Weak Quantum Blind Signature with Entanglement Permutation

    Science.gov (United States)

    Lou, Xiaoping; Chen, Zhigang; Guo, Ying

    2015-09-01

    Motivated by the permutation encryption algorithm, a weak quantum blind signature (QBS) scheme is proposed. It involves three participants, including the sender Alice, the signatory Bob and the trusted entity Charlie, in four phases, i.e., initializing phase, blinding phase, signing phase and verifying phase. In a small-scale quantum computation network, Alice blinds the message based on a quantum entanglement permutation encryption algorithm that embraces the chaotic position string. Bob signs the blinded message with private parameters shared beforehand while Charlie verifies the signature's validity and recovers the original message. Analysis shows that the proposed scheme achieves the secure blindness for the signer and traceability for the message owner with the aid of the authentic arbitrator who plays a crucial role when a dispute arises. In addition, the signature can neither be forged nor disavowed by the malicious attackers. It has a wide application to E-voting and E-payment system, etc.

  8. Anti-Weak Localization Measurements in the Ballistic Regime

    Science.gov (United States)

    Jayathilaka, Dilhani; Dedigama, Aruna; Murphy, Sheena; Edirisooriya, Madhavie; Goel, Niti; Mishima, Tetsuya; Santos, Michael; Mullen, Kieran

    2007-03-01

    Anti-weak localization dominates at low fields in systems in which spin-orbit coupling is strong. The experimental results are well described by theory [1] in low mobility systems in which the magnetic length (lB) is greater than the mean free path; however high mobility systems with strong spin-orbit interactions, such the InSb based two dimensional systems (2DESs) examined here, are not in this diffusive regime. A recently developed theory [2] addresses both the diffusive and ballistic regimes taking into account both the backscattered and non-backscattered contributions to the conductivity. We will discuss the agreement of the new theory to measurements of InSb 2DESs prepared with both strong Dresselhaus and Rashba effects. [1] S.V. Iordanskii, Yu B. Lyanda-Geller, and G.E. Pikus, JETP Lett. 60, 206 (1994). [2] L.E. Golub, Phys. Rev. B. 71, 235310 (2005).

  9. Corruption and internal control weaknesses. Case study Romania

    Directory of Open Access Journals (Sweden)

    Luminiţa IONESCU

    2015-03-01

    Full Text Available Corruption represents one of the major causes of poverty all over the world and European Union is fighting against it. In the last few years, the corruption phenomenon registered a high level in some European countries and became one of the most problematic factors for doing business, due to the evolution of the perceived top five global risks: interstate conflict and regional consequences, extreme weather events, failure of national governance, state collapse or crises, high structural unemployment or underemployment              (WEF-Global Risk Report 2015, p. 14. One of the modalities in combating corruption is implementing the internal control and most of the governments and organizations adopted strong control techniques. Most of the control weaknesses are related to the financial procedures and the number of controllers. Some of the controllers do not have enough financial expertise or do not understand the importance of informatics systems.

  10. Spatial acuity and prey detection in weakly electric fish.

    Directory of Open Access Journals (Sweden)

    David Babineau

    2007-03-01

    Full Text Available It is well-known that weakly electric fish can exhibit extreme temporal acuity at the behavioral level, discriminating time intervals in the submicrosecond range. However, relatively little is known about the spatial acuity of the electrosense. Here we use a recently developed model of the electric field generated by Apteronotus leptorhynchus to study spatial acuity and small signal extraction. We show that the quality of sensory information available on the lateral body surface is highest for objects close to the fish's midbody, suggesting that spatial acuity should be highest at this location. Overall, however, this information is relatively blurry and the electrosense exhibits relatively poor acuity. Despite this apparent limitation, weakly electric fish are able to extract the minute signals generated by small prey, even in the presence of large background signals. In fact, we show that the fish's poor spatial acuity may actually enhance prey detection under some conditions. This occurs because the electric image produced by a spatially dense background is relatively "blurred" or spatially uniform. Hence, the small spatially localized prey signal "pops out" when fish motion is simulated. This shows explicitly how the back-and-forth swimming, characteristic of these fish, can be used to generate motion cues that, as in other animals, assist in the extraction of sensory information when signal-to-noise ratios are low. Our study also reveals the importance of the structure of complex electrosensory backgrounds. Whereas large-object spacing is favorable for discriminating the individual elements of a scene, small spacing can increase the fish's ability to resolve a single target object against this background.

  11. Weakly nonlinear theory and sea state bias estimations

    Science.gov (United States)

    Elfouhaily, Tanos; Thompson, Donald; Vandemark, Douglas; Chapron, Bertrand

    1999-04-01

    The theory of "weakly" nonlinear (WNL) waves is commonly used in generating higher statistical moments of a random surface wave field. These moments can be used, for example, to estimate the sea state bias (SSB) in radar altimetry under a geometric optical assumption. The present investigation suggests that several previous SSB studies appear to have misapplied this WNL theory by violating its condition of validity. As a result, a pronounced inconsistency appears even for lower-order moments. This inconsistency appears as a difference between the statistical moments of the nonlinear surface generated by the application of the WNL theory and those of the linear input (or bare) spectrum. If measured spectra, which yield measured moments (such as rms elevation and slope), are chosen as an input to WNL theory, then the corresponding moments of resulting output spectra may be severely overestimated. To strictly avoid the inconsistency, WNL theory must only be applied to long gravity waves where the wave-wave interactions are weak, hence the WNL epithet. To further illustrate this problem, we present an inversion scheme that determines the proper input spectrum by forcing the low-order moments of the output spectrum to equal the measured moments. Analytical solutions are given for this inversion based on an explicit formulation of the low-order nonlinear moments and a simplified one-dimensional power law spectrum. The solutions show that the high-frequency portion (wave components shorter than about 10 m) of the input (or bare) spectrum must be significantly less energetic than that of the output spectrum. Our results emphasize the importance of the shorter-scale waves in the SSB mechanism.

  12. Congenital Myasthenic Syndromes with Predominant Limb Girdle Weakness

    Science.gov (United States)

    Evangelista, Teresinha; Hanna, Mike; Lochmüller, Hanns

    2015-01-01

    Abstract Congenital myasthenic syndromes are a heterogeneous group of genetically determined disorders characterized by impaired neuromuscular transmission. They usually present from birth to childhood and are characterised by exercise induced weakness and fatigability. Genotype-phenotype correlations are difficult. However, in some patients particular phenotypic aspects may point towards a specific genetic defect. The absence of ptosis and ophthalmoparesis in patients with limb-girdle weakness makes the diagnosis of a neuromuscular transmission defect particularly challenging (LG-CMS). This is illustrated by a well-documented case published by Walton in 1956. The diagnosis of LG-CMS is secured by demonstrating a neuromuscular transmission defect with single fibre EMG or repetitive nerve stimulation, in the absence of auto-antibodies. Ultimately, a genetic test is required to identify the underlying cause and assure counselling and optimization of treatment. LG-CMS are inherited in autosomal recessive traits, and are often associated with mutations in DOK7 and GFPT1, and less frequently with mutations in COLQ, ALG2, ALG14 and DPAGT. Genetic characterization of CMS is of the upmost importance when choosing the adequate treatment. Some of the currently used drugs can either ameliorate or aggravate the symptoms depending on the underlying genetic defect. The drug most frequently used for the treatment of CMS is pyridostigmine an acetylcholinesterase inhibitor. However, pyridostigmine is not effective or is even detrimental in DOK7- and COLQ-related LG-CMS, while beta-adrenergic agonists (ephedrine, salbutamol) show some sustained benefit. Standard clinical trials may be difficult, but standardized follow-up of patients and international collaboration may help to improve the standards of care of these conditions. PMID:26870666

  13. Predicting weak lensing statistics from halo mass reconstructions - Final Paper

    Energy Technology Data Exchange (ETDEWEB)

    Everett, Spencer [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-20

    As dark matter does not absorb or emit light, its distribution in the universe must be inferred through indirect effects such as the gravitational lensing of distant galaxies. While most sources are only weakly lensed, the systematic alignment of background galaxies around a foreground lens can constrain the mass of the lens which is largely in the form of dark matter. In this paper, I have implemented a framework to reconstruct all of the mass along lines of sight using a best-case dark matter halo model in which the halo mass is known. This framework is then used to make predictions of the weak lensing of 3,240 generated source galaxies through a 324 arcmin² field of the Millennium Simulation. The lensed source ellipticities are characterized by the ellipticity-ellipticity and galaxy-mass correlation functions and compared to the same statistic for the intrinsic and ray-traced ellipticities. In the ellipticity-ellipticity correlation function, I and that the framework systematically under predicts the shear power by an average factor of 2.2 and fails to capture correlation from dark matter structure at scales larger than 1 arcminute. The model predicted galaxy-mass correlation function is in agreement with the ray-traced statistic from scales 0.2 to 0.7 arcminutes, but systematically underpredicts shear power at scales larger than 0.7 arcminutes by an average factor of 1.2. Optimization of the framework code has reduced the mean CPU time per lensing prediction by 70% to 24 ± 5 ms. Physical and computational shortcomings of the framework are discussed, as well as potential improvements for upcoming work.

  14. 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.

  15. Yeast adaptation to weak acids prevents futile energy expenditure

    Science.gov (United States)

    Ullah, Azmat; Chandrasekaran, Gayathri; Brul, Stanley; Smits, Gertien J.

    2013-01-01

    Weak organic acids (WOAs) are widely used preservatives to prevent fungal spoilage of foods and beverages. Exposure of baker's yeast Saccharomyces cerevisiae to WOA leads to cellular acidification and anion accumulation. Pre-adaptation of cultures reduced the rate of acidification caused by weak acid exposure, most likely as a result of changes in plasma membrane or cell wall composition. In order to adapt to sublethal concentrations of the acids and grow, yeast cells activate ATP consuming membrane transporters to remove protons and anions. We explored to what extent ATP depletion contributes to growth inhibition in sorbic or acetic acid treated cells. Therefore, we analyzed the effect of the reduction of proton and anion pumping activity on intracellular pH (pHi), growth, and energy status upon exposure to the hydrophilic acetic acid (HA) and the lipophilic sorbic acid (HS). ATP concentrations were dependent on the severity of the stress. Unexpectedly, we observed a stronger reduction of ATP with growth reducing than with growth inhibitory concentrations of both acids. We deduce that the not the ATP reduction caused by proton pumping, but rather the cost of sorbate anion pumping contributes to growth inhibition. A reduction of proton pumping activity may reduce ATP consumption, but the resulting decrease of pHi affects growth more. ATP utilization was differentially regulated during moderate and severe stress conditions. We propose that the energy depletion alone is not the cause of growth inhibition during HA or HS stress. Rather, the cells appear to reduce ATP consumption in high stress conditions, likely to prevent futile cycling and maintain energy reserves for growth resumption in more favorable conditions. The mechanism for such decision making remains to be established. PMID:23781215

  16. Yeast adaptation to weak acids prevents futile energy expenditure

    Directory of Open Access Journals (Sweden)

    Azmat eUllah

    2013-06-01

    Full Text Available Weak organic acids (WOA are widely used preservatives to prevent fungal spoilage of foods and beverages. Exposure of baker’s yeast Saccharomyces cerevisiae to WOA leads to cellular acidification and anion accumulation. Pre-adaptation of cultures reduced the rate of acidification caused by weak acid exposure, most likely as a result of changes in plasma membrane or cell wall composition. In order to adapt to sublethal concentrations of the acids and grow, yeast cells activate ATP consuming membrane transporters to remove protons and anions. We explored to what extent ATP depletion contributes to growth inhibition in sorbic or acetic acid treated cells. Therefore, we analyzed the effect of the reduction of proton and anion pumping activity on intracellular pH (pHi, growth, and energy status upon exposure to the hydrophilic acetic acid (HA and the lipophilic sorbic acid (HS. ATP concentrations were dependent on the severity of the stress. Unexpectedly, we observed a stronger reduction of ATP with growth reducing than with growth inhibitory concentrations of both acids. We deduce that the not the ATP reduction caused by proton pumping, but rather the cost of sorbate anion pumping contributes to growth inhibition. A reduction of proton pumping activity may reduce ATP consumption, but the resulting decrease of intracellular pH affects growth more. ATP utilization was differentially regulated during moderate and severe stress conditions. We propose that the energy depletion alone is not the cause of growth inhibition during HA or HS stress. Rather, the cells appear to reduce ATP consumption in high stress conditions, likely to prevent futile cycling and maintain energy reserves for growth resumption in more favorable conditions. The mechanism for such decision making remains to be established.

  17. Material Accounting and Management Control Weaknesses in the Defense Agencies' FYs 1995 and 1996 Financial Information

    National Research Council Canada - National Science Library

    Gimble, Thomas

    1997-01-01

    The primary audit objective was to summarize Defense agency accounting system weaknesses and related management control program weaknesses identified during audits of defense agencies' FYs 1995 and 1996 financial data...

  18. Diaphragm muscle fiber weakness and ubiquitin-proteasome activation in critically ill patients

    NARCIS (Netherlands)

    Hooijman, P.E.; Beishuizen, A.; Witt, C.C.; Waard, M.C. de; Girbes, A.R.; Spoelstra-de Man, A.M.; Niessen, H.W.; Manders, E.; Hees, H.W.H. van; Brom, C.E. van den; Silderhuis, V.; Lawlor, M.W.; Labeit, S.; Stienen, G.J.; Hartemink, K.J.; Paul, M.A.; Heunks, L.M.A.; Ottenheijm, C.A.

    2015-01-01

    RATIONALE: The clinical significance of diaphragm weakness in critically ill patients is evident: it prolongs ventilator dependency, and increases morbidity and duration of hospital stay. To date, the nature of diaphragm weakness and its underlying pathophysiologic mechanisms are poorly understood.

  19. A Generalization of Weak WT2-Class of Differential Forms and Its Applications

    Directory of Open Access Journals (Sweden)

    Gao Hongya

    2016-05-01

    Full Text Available A generalized class of weak ${\\cal WT}_2$-class of differential forms is defined, a weak reverse H\\"older inequality is obtained for this class, and some applications to the regularity theory of weakly $(K_1, K_2$-quasiregular mappings, very weak solutions of nonhomogeneous $\\cal A$-harmonic equations, and generalized solutions of Beltrami system with three characteristic matrices are given.

  20. Detection of Weak D (Du) Phenotype among Rh-D Negative Males ...

    African Journals Online (AJOL)

    Weak Rh D phenotypes are very frequent in Africans. They are capable of causing alloimmunization in Rh D-negative individuals. Some weak Ds may elude routine typing using direct agglutination techniques. This study aimed at determining the prevalence of weak D phenotype among Rhnegatives, using indirect ...

  1. Diaphragm single-fiber weakness and loss of myosin in congestive heart failure rats

    NARCIS (Netherlands)

    Hees, H.W.H. van; Heijden, H.F.M. van der; Ottenheijm, C.A.C.; Heunks, L.M.A.; Pigmans, C.J.; Verheugt, F.W.A.; Brouwer, R.M.H.J.; Dekhuijzen, P.N.R.

    2007-01-01

    Diaphragm weakness commonly occurs in patients with congestive heart failure (CHF) and is an independent predictor of mortality. However, the pathophysiology of diaphragm weakness is poorly understood. We hypothesized that CHF induces diaphragm weakness at the single-fiber level by decreasing myosin

  2. Strong and weak hydrogen bonds in drug–DNA complexes: A ...

    Indian Academy of Sciences (India)

    A statistical analysis of strong and weak hydrogen bonds in the minor groove of DNA was carried out for a set of 70 drug–DNA complexes. The terms `strong' and `weak' pertain to the inherent strengths and weakness of the donor and acceptor fragments rather than to any energy considerations. The dataset was extracted ...

  3. How crosscutting weak ties are established : The case of Muslims in Europe

    NARCIS (Netherlands)

    Damstra, A.; Tillie, J.

    2016-01-01

    Building on the work of Granovetter [1973. “The Strength of Weak Ties.” American Journal of Sociology 78 (6): 1360–1380.], weak ties are assumed to play a vital role in processes of integration. In this paper, the focus lies on weak ties that cut across ethnic boundaries, connecting Muslim

  4. Light weakly interacting particles. Constraints and connection to dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Andreas, Sarah

    2013-07-15

    The so far unknown particle nature of dark matter is a main motivation for extending the Standard Model of particle physics. A recently promoted approach to solving this puzzle is the concept of hidden sectors. Since the interactions of such sectors with the visible sector are very weak, so are the current experimental bounds. Hidden sectors might even contain sub-GeV scale particles that have so far escaped detection. In this thesis, we study the phenomenology of Weakly Interacting Slim Particles (WISPs) as well as their connection to dark matter in different Standard Model extensions. In the Next-to-Minimal Supersymmetric Standard Model (NMSSM), a light CPodd Higgs, arising from spontaneous breaking of approximate symmetries, represents an example of a WISP. Light gauge bosons of an extra U(1) symmetry in a hidden sector are other well motivated candidates for WISPs and called hidden photons. Such light hidden photons appear naturally in supersymmetry or string theory and might resolve the observed deviation in the muon anomalous magnetic moment from predictions. Moreover, scenarios in which hidden sector dark matter interacts via a light hidden photon with the visible sector exhibit appealing features in view of recent astrophysical anomalies. We study how the coupling of the CP-odd Higgs A{sup 0} to fermions can be constrained by current measurements for the case where the A{sup 0} is lighter than two muons. Analysing measurements of different rare and radiative meson decays, the muon anomalous magnetic moment as well as results from beam dump and reactor experiments, we severely constrain the CP-odd Higgs to be heavier than 210 MeV or to couple to fermions four orders of magnitude weaker than the Standard Model Higgs. These results apply more generally to the coupling of an axion-like particle to matter. Hidden photons can be constrained by experiments since they couple to charged Standard Model particles via kinetic mixing with the ordinary photon. We derive

  5. Measurement of the Weak Mixing Angle in Moller Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Klejda, B.

    2005-01-28

    The weak mixing parameter, sin{sup 2} {theta}{sub w}, is one of the fundamental parameters of the Standard Model. Its tree-level value has been measured with high precision at energies near the Z{sup 0} pole; however, due to radiative corrections at the one-loop level, the value of sin{sup 2} {theta}{sub w} is expected to change with the interaction energy. As a result, a measurement of sin{sup 2} {theta}{sub w} at low energy (Q{sup 2} << m{sub Z}, where Q{sup 2} is the momentum transfer and m{sub Z} is the Z boson mass), provides a test of the Standard Model at the one-loop level, and a probe for new physics beyond the Standard Model. One way of obtaining sin{sup 2} {theta}{sub w} at low energy is from measuring the left-right, parity-violating asymmetry in electron-electron (Moeller) scattering: A{sub PV} = {sigma}{sub R}-{sigma}{sub L}/{sigma}{sub R}+{sigma}{sub L}, where {sigma}{sub R} and {sigma}{sub L} are the cross sections for right- and left-handed incident electrons, respectively. The parity violating asymmetry is proportional to the pseudo-scalar weak neutral current coupling in Moeller scattering, g{sub ee}. At tree level g{sub ee} = (1/4 -sin{sup 2} {theta}{sub w}). A precision measurement of the parity-violating asymmetry in Moeller scattering was performed by Experiment E158 at the Stanford Linear Accelerator Center (SLAC). During the experiment, {approx}50 GeV longitudinally polarized electrons scattered off unpolarized atomic electrons in a liquid hydrogen target, corresponding to an average momentum transfer Q{sup 2} {approx} 0.03 (GeV/c){sup 2}. The tree-level prediction for A{sub PV} at such energy is {approx}300 ppb. However one-loop radiative corrections reduce its value by {approx}40%. This document reports the E158 results from the 2002 data collection period. The parity-violating asymmetry was found to be A{sub PV} = -160 {+-} 21 (stat.) {+-} 17 (syst.) ppb, which represents the first observation of a parity-violating asymmetry in Moeller

  6. Weak preservation of local neutral substitution rates across mammalian genomes

    Directory of Open Access Journals (Sweden)

    Karro John E

    2009-05-01

    Full Text Available Abstract Background The rate at which neutral (non-functional bases undergo substitution is highly dependent on their location within a genome. However, it is not clear how fast these location-dependent rates change, or to what extent the substitution rate patterns are conserved between lineages. To address this question, which is critical not only for understanding the substitution process but also for evaluating phylogenetic footprinting algorithms, we examine ancestral repeats: a predominantly neutral dataset with a significantly higher genomic density than other datasets commonly used to study substitution rate variation. Using this repeat data, we measure the extent to which orthologous ancestral repeat sequences exhibit similar substitution patterns in separate mammalian lineages, allowing us to ascertain how well local substitution rates have been preserved across species. Results We calculated substitution rates for each ancestral repeat in each of three independent mammalian lineages (primate – from human/macaque alignments, rodent – from mouse/rat alignments, and laurasiatheria – from dog/cow alignments. We then measured the correlation of local substitution rates among these lineages. Overall we found the correlations between lineages to be statistically significant, but too weak to have much predictive power (r2 5%. These correlations were found to be primarily driven by regional effects at the scale of several hundred kb or larger. A few repeat classes (e.g. 7SK, Charlie8, and MER121 also exhibited stronger conservation of rate patterns, likely due to the effect of repeat-specific purifying selection. These classes should be excluded when estimating local neutral substitution rates. Conclusion Although local neutral substitution rates have some correlations among mammalian species, these correlations have little predictive power on the scale of individual repeats. This indicates that local substitution rates have changed

  7. Weak matrix elements on the lattice - Circa 1995

    Energy Technology Data Exchange (ETDEWEB)

    Soni, A.

    1995-10-03

    Status of weak matrix elements is reviewed. In particular, e{prime}/e, B {yields} K*{gamma}, B{sub B} and B{sub B}, are discussed and the overall situation with respect to the lattice effort and some of its phenomenological implications are summarised. For e{prime}/e the need for the relevant matrix elements is stressed in view of the forthcoming improved experiments. For some of the operators, (e.g. O{sub 6}), even bound on their matrix elements would be very helpful. On B {yields} K{degrees}{gamma}, a constant behavior of T{sub 2} appears disfavored although dependence of T{sub 2} could, of course, be milder than a simple pole. Improved data is badly needed to settle this important issue firmly, especially in view of its ramification for extractions of V{sub td} from B {yields} {rho}{gamma}. On B{sub {kappa}}, the preliminary result from JLQCD appears to contradict Sharpe et al. JLQCD data seems to fit very well to linear {alpha} dependence and leads to an appreciably lower value of B{sub {kappa}}. Four studies of B{sub {kappa}} in the {open_quotes}full{close_quotes} (n{sub f} = 2) theory indicate very little quenching effects on B{sub {kappa}}; the full theory value seems to be just a little less than the quenched result. Based on expectations from HQET, analysis of B-parameter (B{sub h}{ell}) for the heavy-light mesons via B{sub h}{ell}) = constant + constants{prime}/m{sub h}{ell} is suggested. A summary of an illustrative sample of hadron matrix elements is given and constraints on CKM parameters (e.g. V{sub td}/V{sub ts}, on the unitarity triangle and on x{sub s}/x{sub d}, emerging from the lattice calculations along with experimental results are briefly discussed. In quite a few cases, for the first time, some indication of quenching errors on weak matrix elements are now becoming available.

  8. Topic Detection Based on Weak Tie Analysis: A Case Study of LIS Research

    Directory of Open Access Journals (Sweden)

    Ling Wei

    2016-11-01

    Full Text Available Purpose: Based on the weak tie theory, this paper proposes a series of connection indicators of weak tie subnets and weak tie nodes to detect research topics, recognize their connections, and understand their evolution. Design/methodology/approach: First, keywords are extracted from article titles and preprocessed. Second, high-frequency keywords are selected to generate weak tie co-occurrence networks. By removing the internal lines of clustered sub-topic networks, we focus on the analysis of weak tie subnets' composition and functions and the weak tie nodes' roles. Findings: The research topics' clusters and themes changed yearly; the subnets clustered with technique-related and methodology-related topics have been the core, important subnets for years; while close subnets are highly independent, research topics are generally concentrated and most topics are application-related; the roles and functions of nodes and weak ties are diversified. Research limitations: The parameter values are somewhat inconsistent; the weak tie subnets and nodes are classified based on empirical observations, and the conclusions are not verified or compared to other methods. Practical implications: The research is valuable for detecting important research topics as well as their roles, interrelations, and evolution trends. Originality/value: To contribute to the strength of weak tie theory, the research translates weak and strong ties concepts to co-occurrence strength, and analyzes weak ties' functions. Also, the research proposes a quantitative method to classify and measure the topics' clusters and nodes.

  9. 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.

  10. Search for a tensor component in the weak interaction Hamiltonian

    CERN Document Server

    Soti, Gergely

    The search for physics beyond the standard model can, besides in high-energy experiments such as the ones at the LHC accelerator, also be carried out at lower energies. Measurements of correlation coefficients in neutron and nuclear b decay constitute a reliable and model-independent method for such efforts. The topic of this thesis is the precision measurement of the beta asymmetry parameter A. It was measured in the decay of 67Cu, which proceeds via a pure Gamow-Teller b transition, thus its A parameter is sensitive to possible tensor type currents in the weak interaction. The experiment was performed at the NICOLE setup in ISOLDE (CERN), using the technique of low temperature nuclear orientation. The b particles were observed with custom made planar high purity germanium detectors operating at around 10 K. The beta asymmetry of 68Cu was measured on-line for normalization purposes. Geant4 simulations were used to gain control over systematic effects such as electron scattering on the particle detectors. As...

  11. Weak and strong confinements in prismatic and cylindrical nanostructures.

    Science.gov (United States)

    Vorobiev, Yuri V; Mera, Bruno; Vieira, Vítor R; Horley, Paul P; González-Hernández, Jesús

    2012-07-05

    Cylindrical nanostructures, namely, nanowires and pores, with rectangular and circular cross section are examined using mirror boundary conditions to solve the Schrödinger equation, within the effective mass approximation. The boundary conditions are stated as magnitude equivalence of electron's Ψ function in an arbitrary point inside a three-dimensional quantum well and image point formed by mirror reflection in the walls defining the nanostructure. Thus, two types of boundary conditions - even and odd ones - can be applied, when Ψ functions in a point, and its image, are equated with the same and the opposite signs, correspondingly. In the former case, the Ψ function is non-zero at the boundary, which is the case of a weak confinement. In the latter case, the Ψ function vanishes at the boundary, corresponding to strong quantum confinement. The analytical expressions for energy spectra of electron confined within a nanostructure obtained in the paper show a reasonable agreement with the experimental data without using any fitting parameters.

  12. Weakly nonlinear incompressible Rayleigh-Taylor instability in spherical geometry

    Science.gov (United States)

    Zhang, J.; Wang, L. F.; Ye, W. H.; Wu, J. F.; Guo, H. Y.; Zhang, W. Y.; He, X. T.

    2017-06-01

    In this research, a weakly nonlinear (WN) model for the incompressible Rayleigh-Taylor instability in cylindrical geometry [Wang et al., Phys. Plasmas 20, 042708 (2013)] is generalized to spherical geometry. The evolution of the interface with an initial small-amplitude single-mode perturbation in the form of Legendre mode (Pn) is analysed with the third-order WN solutions. The transition of the small-amplitude perturbed spherical interface to the bubble-and-spike structure can be observed by our model. For single-mode perturbation Pn, besides the generation of P 2 n and P 3 n , which are similar to the second and third harmonics in planar and cylindrical geometries, many other modes in the range of P0- P 3 n are generated by mode-coupling effects up to the third order. With the same initial amplitude, the bubbles at the pole grow faster than those at the equator in the WN regime. Furthermore, it is found that the behavior of the bubbles at the pole is similar to that of three-dimensional axisymmetric bubbles, while the behavior of the bubbles at the equator is similar to that of two-dimensional bubbles.

  13. Weakly nonlinear analysis of short-wave elliptical instability

    Science.gov (United States)

    Rodrigues, Savio B.; De Luca, Jayme

    2009-01-01

    Two-dimensional inviscid flows with elliptical streamlines have linearly unstable three-dimensional modes close to the center of the ellipse. The linear instability equilibrates in the presence of enough viscosity, yielding a continuous set of neutrally stable plane waves known as Craik-Criminale waves (CCWs). For initial disturbance in a discrete superposition of plane waves our weakly nonlinear analysis yields a cubic ordinary differential equation for the slow-time evolution of the neutrally stable plane-wave amplitudes. In the subcritical region we find that all solutions eventually vanish, while in the supercritical region the amplitudes either saturate or have exponential growth; the existence of a finite-time blowup at cubic order being unlikely. The saturation to a steady state is possible only for special initial conditions, and for generic initial conditions the amplitudes saturate to a chaotic state. In contrast, a single CCW with exponential growth is still unstable, but it loses stability to cycles of growth and decay among the plane waves.

  14. The Effect of Weak Collisions on the Plasma Wave Echo

    Science.gov (United States)

    Black, Carrie; Germaschewski, Kai; Ng, C. S.; Bhattacharjee, Amitava

    2008-11-01

    It has been shown recently that weak collisions, which are a singular perturbation on the collisionless Vlasov equation, have a profound effect on the underlying spectrum for linear plasma waves by eliminating the Case-Van Kampen continuous spectrum and replacing it with a complete class of discrete eigenmodes [C.S. Ng, A. Bhattacharjee, F. Skiff, Phys. Rev. Lett. 83, 1974 (1999); 92, 065002 (2004).]. This discovery has important consequences for the regime of validity of C. H. Su and C. Oberman's classical theory [Phys. Rev. Lett. 20, 427 (1968)] on the collisional decay of plasma wave echoes. Using a fully nonlinear one-dimensional Vlasov-Poisson system solver including the Lenard-Bernstein collision operator, we have studied the effects of collisions on the echoes. We have identified the Su-Oberman regime on intermediate time scales. The long-time asymptotics of the system and its relation to the complete set of discrete eigenmodes found by Ng, Bhattacharjee and Skiff will be discussed.

  15. Inclusive breakup of three-fragment weakly bound nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, B.V.; Frederico, T. [Instituto Tecnológico de Aeronáutica, DCTA, 12.228-900 São José dos Campos, SP (Brazil); Hussein, M.S., E-mail: hussein@if.usp.br [Instituto Tecnológico de Aeronáutica, DCTA, 12.228-900 São José dos Campos, SP (Brazil); Instituto de Estudos Avançados, Universidade de São Paulo, C.P. 72012, 05508-970 São Paulo, SP (Brazil); Instituto de Física, Universidade de São Paulo, C.P. 66318, 05314-970 São Paulo, SP (Brazil)

    2017-04-10

    The inclusive breakup of three-fragment projectiles is discussed within a four-body spectator model. Both the elastic breakup and the non-elastic breakup are obtained in a unified framework. Originally developed in the 80's for two-fragment projectiles such as the deuteron, in this paper the theory is successfully generalized to three-fragment projectiles. The expression obtained for the inclusive cross section allows the extraction of the incomplete fusion cross section, and accordingly generalizes the surrogate method to cases such as (t, p) and (t, n) reactions. It is found that two-fragment correlations inside the projectile affect in a conspicuous way the elastic breakup cross section. The inclusive non-elastic breakup cross section is calculated and is found to contain the contribution of a three-body absorption term that is also strongly influenced by the two-fragment correlations. This latter cross section contains the so-called incomplete fusion where more than one compound nuclei are formed. Our theory describes both stable weakly bound three-fragment projectiles and unstable ones such as the Borromean nuclei.

  16. 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

  17. Wormholes, emergent gauge fields, and the weak gravity conjecture

    Energy Technology Data Exchange (ETDEWEB)

    Harlow, Daniel [Center for the Fundamental Laws of Nature, Physics Department, Harvard University,Cambridge MA, 02138 (United States)

    2016-01-20

    This paper revisits the question of reconstructing bulk gauge fields as boundary operators in AdS/CFT. In the presence of the wormhole dual to the thermofield double state of two CFTs, the existence of bulk gauge fields is in some tension with the microscopic tensor factorization of the Hilbert space. I explain how this tension can be resolved by splitting the gauge field into charged constituents, and I argue that this leads to a new argument for the “principle of completeness”, which states that the charge lattice of a gauge theory coupled to gravity must be fully populated. I also claim that it leads to a new motivation for (and a clarification of) the “weak gravity conjecture”, which I interpret as a strengthening of this principle. This setup gives a simple example of a situation where describing low-energy bulk physics in CFT language requires knowledge of high-energy bulk physics. This contradicts to some extent the notion of “effective conformal field theory”, but in fact is an expected feature of the resolution of the black hole information problem. An analogous factorization issue exists also for the gravitational field, and I comment on several of its implications for reconstructing black hole interiors and the emergence of spacetime more generally.

  18. Intensive Care Unit-Acquired Weakness: Implications for Case Management.

    Science.gov (United States)

    Harvey, Nina R; Stanton, Marietta P

    The purpose of this case study is to provide a specific example of the disease trajectory for one patient's experience with intensive care unit-acquired weakness (ICUAW). This case study provides those in case management with an overview of some of the common signs and symptoms of ICUAW, as well as the possible prognosis and recovery from ICUAW. The events in this case study take place in the acute care setting including the intensive care unit of a mid-sized health center, a general medical-surgical (med-surg) unit, and a long-term acute care facility. ICUAW affects the clinical, functional, and financial outcomes of patients. If the patient survives, their quality of life and the quality of life of their family members could be severely impacted. Case management practice has a significant role in coordinating care for those diagnosed with ICUAW. Case managers can use knowledge about ICUAW to improve the patient's transition throughout the hospital stay, improve discharge recommendations, and improve the patient's short-term and long-term outcomes. This may reduce unnecessary utilization of health care resources.

  19. Salivary IgA is a weak stress marker.

    Science.gov (United States)

    Mouton, C; Fillion, L; Tawadros, E; Tessier, R

    1989-01-01

    Several studies support the hypothesis that psychological stress may negatively affect immunocompetence. The present study sought to determine whether a relationship can be established between a measure of psychological state of stress and level of immunoglobulin of the A class (IgA) in saliva. To this end, 44 dentistry students were tested on four occasions; two occasions were stress inductive (examination situation), and two occasions were free of any academic stressor. At each session, the participants were asked to fill out the stress rating instrument, and unstimulated whole saliva samples were obtained. Salivary IgA was measured by a microplate Enzyme Linked Immunosorbent Assay (ELISA). A significant difference in the level of salivary IgA was observed only for the most polarized contrast, ie, between final exam and end of summer vacation (p less than .01). A weak negative correlation between the level of salivary IgA and the stress rating was observed (r = -0.25) only at the final exam. Our results suggest that assaying immunoglobulin A in saliva to measure stress may not be as useful in psychophysiological research as expected.

  20. 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.